Surgical Knot Tying Manual Needles and Suture Materials Knots table of contents I. Individualized Self-Instruction 1 II. Introduction 2 III. Scientific Basis for Selection of Sutures 4 1. Nonabsorbable Suture 5 2. Absorbable Suture 12 IV. Components of a Knotted Suture Loop using either a Granny Knot Type or a Square Knot Type 22 V. Mechanical Performance 28 1. Knot Slippage 30 2. Knot Breakage 31 3. Suture Cutting Tissue 32 4. Mechanical Trauma 33 VI. Tying Techniques 34 1. Instrument Tie 37 2. Hand Tie 39 VII. Essential Elements 42 VIII. Two-Hand Techniques 44 1. Square Knot (1=1) 44 2. Surgeons Knot Square (2=1) 52 3. Slip Knot (S=S) 62 IX. One-Hand Technique 1. Square (1=1) 70 X. Instrument-Tie Technique 1. Square Knot (1=1) 78 XI. Selection of Suture and Needle Products 86 XII. References 87 --------------------------------------- 5 I. individualized self instruction The root origin of the word education is educare or to anglicize it, edu-care. The meaning of education, therefore, is to care for, to nourish, to cause to grow. This being their ultimate responsibility, teachers of surgery should be the most responsive component of the instruction system. Numerous other pressing clinical and administrative commitments, however, often limit interactions with the medical students, nurses, nurse practitioners physician assistants, surgical residents and surgeons. Consequently, learning difficulties may not be identified. This manual was designed to be a self-instructional teaching aid for the medical student, resident, and surgeon providing an individualized environment of learning. For convenience, each page of this manual has wide margins to accommodate personal thoughts and further clarification. This manual is bound in a ring binder so that it lies flat, a prerequisite for any knot tying manual. The reader should take as little or as much time as needed to digest the information and to develop the illustrated psychomotor skills. At the end of this instruction, you should feel considerably more comfortable in understanding the science of tying surgical knots. More importantly it is our hope that this manual will inspire, motivate, and encourage creativity and self-direction in your study of the biology of wound repair and infection. This Knot Tying Manual is available online at www.covidien.com/syneture. 1 --------------------------------------- 6 II. introduction 1 Through the ages, the tying of knots has played an important role in the life of man. Most of the ancient civilized nations, as well as savage tribes, were accomplished rope makers. Because rope could have served few useful purposes unless it could be attached to objects by knots, mans conception of the rope and the knot must have occurred concomitantly. Knotted ropes played many important roles in the ancient world, being used in building bridges and in rigging ships. Because rope and knots have been two of mans most useful tools since the dawn of history, it is not surprising that they also have symbolic and even magical connotations. It was the custom of Roman brides to wear a girdle tied with a square (reef) knot, which their husbands untied on their marriage night, as an omen of prolific offspring. Moreover, it was believed that wounds healed more rapidly when the bandages which bound them were tied with a square (reef) knot. This mythology of knots may have contributed to some surgeons perception of surgical knots more as an art form, than as a science. For those artisans, the use of methods and materials for suturing is usually a matter of habit, guesswork, or 2 tradition. This approach to suturing has contributed to a growing concern that the knot construction employed by many surgeons is not optimal and that they  --------------------------------------- 7 3. Individualized Self Instruction use faulty technique in tying knots, which is the weakest link in a tied surgical suture. When the recommended configuration of a knot, ascertained by mechanical performance tests was compared to those used by board-certified general surgeons, only 25% of the surgeons 3 correctly used the appropriate knot construction. Of the 25 gynecologists, mostly department heads, who were polled about their knot tying technique, most were convinced they they made square knots, even though their knot tying technique resulted in slipknots that became untied.4 When a knotted suture fails to perform its functions, the consequences may be disastrous. Massive bleeding may occur when the suture loop surrounding a vessel becomes untied or breaks. Wound dehiscence or incisional hernia may follow knot disruption. As with any master surgeon, he/she must understand the tools of his/her profession. The linkage between a surgeon and surgical equipment is a closed kinematic chain in which the surgeons power is converted into finely coordinated movements that result in wound closure with the least possible scar and without infection. The ultimate goal of this linkage the perfection of the surgical discipline. This manual has been written for medical students, nurses, nurse practitioners physician assistants, surgical residents and surgeons who view themselves as scientists cultivating and practicing the science of surgery. 3 --------------------------------------- 8 III. scientific basis for the selection of surgical sutures There are several different suture materials and needles that provide an accurate and secure approximation of the wound edges. Ideally, the choice of the suture material should be based on the biological interaction of the materials employed, the tissue configuration, and the biomechanical properties of the wound. The tissue should be held in apposition until the tensile strength of the wound is sufficient to withstand stress. A common theme of the many reportable investigations is that all biomaterials placed within the tissue damage the host defenses and invite infection. Because surgical needles have a proven role in spreading deadly blood borne viral infection, the surgeon must select surgical 5 gloves that reduce the risk of accidental injuries during surgery. Important considerations in wound closure are the type of suture, the tying technique, and the configuration of the suture loops. Selection of a surgical suture material is based on its biologic interaction with the wound and its mechanical performance in vivo and in vitro. Measurements of the in vivo degradation of sutures separate them into two general classes.6 Sutures that undergo rapid degradation in tissues, losing their tensile strength within 60 days, are considered absorbable sutures. Those that maintain their tensile strength for longer than  --------------------------------------- 9 60 days are nonabsorbable sutures. This terminology is somewhat misleading because even some nonabsorbable sutures (i.e., silk, cotton and nylon) lose some tensile 7 strength during this 60-day interval. Postlethwait measured the tensile strength of implanted nonabsorbable sutures during a period of two years. Silk lost approximately 50% of its tensile strength in one year and had no strength at the end of two years. Cotton lost 50% of its strength in six months, but still had 30-40% of its original strength at the end of two years. Nylon lost approximately 25% of its original strength throughout the two-year observation period. 1. Nonabsorbable surgical sutures The nonabsorbable sutures of Covidien (formerly Tyco Healthcare, Norwalk, CT) can be classified according to their origin. Nonabsorbable sutures made from natural fibers are silk sutures. Sofsilk silk sutures are nonabsorbable, sterile, non-mutagenic surgical sutures composed of natural proteinaceous silk fibers called fibroin. This protein is derived from the domesticated silkworm species Bombyx mori of the family bombycidae. The silk fibers are treated to remove the naturally-occurring sericin gum and braided sutures are available coated uniformly with a special wax mixture  --------------------------------------- 10 III. scientific basis for the selection of surgical sutures (cont’d) or silicone to reduce capillarity and to increase surface lubricity which enhances handling characteristics, ease of passage through tissue, and knot run-down properties. Sofsilk sutures are available colored black with Logwood extract. Metallic Steel sutures are derived from monofilament stainless steel. Modern chemistry has developed a variety of synthetic fibers from polyamides (nylon), polyesters (Dacron), polyolefins (polyethylene, polypropylene), polytetrafluoroethylene, to polybutester. Polypropylene is a linear hydrocarbon polymer that consists of a strand of polypropylene, a synthetic linear polyolefin. All polypropylenes begin with a base resin and then go through the following steps: extrusion, drawing, relaxation, and annealing. Each step in the process will influence the ultimate biomechanical performance of the suture. Biomechanical studies demonstrate that the manufacturing process (i.e., annealing, relaxation) can dramatically influence the surface characteristics without altering its strength. Changes in the surface characteristics can facilitate knot construction of the suture. Polypropylene sutures (Surgipro) that have a low coefficient of friction will facilitate knot rundown and suture passage through the tissue. A new polypropylene suture  --------------------------------------- 11 (Surgipro II) has been developed that has increased resistance to fraying during knot rundown. Polypropylene sutures are extremely inert in tissue and have been found to retain tensile strength in tissues for a period as long as two years. Polypropylene sutures are widely used in plastic, cardiovascular, general, and orthopedic surgery. They exhibit a lower drag coefficient in tissue than nylon sutures, making them ideal for use in continuous dermal and percutaneous suture closure. Monosof and Dermalon are monofilament sutures composed of the long-chain polyamide polymers Nylon 6 and Nylon 6.6. They have a high tensile strength and low tissue reactivity. The pliability characteristics of these sutures permit good handling. Because nylon sutures are more pliable and easier to handle than polypropylene sutures, they are favored for the construction of interrupted percutaneous suture closures. However, polypropylene sutures encounter lower drag forces in tissue than nylon sutures, accounting for their frequent use in continuous dermal and percutaneous suture closure. Nylon sutures are also available in a braided construction. Only nylon sutures are available both as monofilament and multifilament sutures (Surgilon). These braided nylon sutures are relatively inert  --------------------------------------- 12 III. scientific basis for the selection of surgical sutures (cont’d) in tissue and possess the same handling and knot construction characteristics as the natural fiber, silk sutures (Sofsilk). Polyester sutures (Surgidac, TiCron) are comprised of fibers of polyethylene terephthalate, a synthetic linear polyester derived from the reaction of a glycol and a dibasic acid. Polyester sutures were the first synthetic braided suture material shown to last indefinitely in tissues. Their acceptance in surgery was initially limited because the suture had a high coefficient of friction that interfered with passage through tissue and with the construction of a knot. When the sutures were coated with a lubricant, polyester sutures gained wide acceptance in surgery. This coating markedly reduced the sutures coefficient of friction, thereby facilitating knot construction and passage through tissue. The TiCron polyester sutures are coated with silicone, while the surface lubricant for Surgidac is polybutylene adipate. Because some surgeons prefer to tie sutures with a high coefficient of friction, the Surgidac sutures are also available without a surface coating. The polybutester suture (Novafil) is a block copolymer that contains butylene terephthalate (84%) and polytetramethylene ether glycol terephthalate (16%).  --------------------------------------- 13 Polybutester suture has unique performance characteristics that may be advantageous for wound closure.8 This monofilament synthetic nonabsorbable suture exhibits distinct differences in elongation compared with other sutures. With the polybutester suture, low forces yield significantly greater elongation than that of the other sutures. In addition, its elasticity is superior to that of other sutures, allowing the suture to 9 return to its original length once the load is removed. In a study by Trimbos et al. they compared the cosmetic outcome of lower midline laparotomy scars using either nylon or polybutester suture for skin closure. A randomized clinical trial compared polybutester skin suture with that of nylon for lower midline laparotomy wounds in 50 women undergoing gynecologic surgery. Scar hypertrophy, scar width, scar color, the presence of cross-hatching marks, and a total score was assessed in all patients at 18 months following surgery and compared by nonparametric statistical tests. The wounds closed with polybutester suture were significantly less hypertrophic than those closed with nylon. Regardless of the suture material used, the lower part of the laparo-tomy scar showed an inferior cosmetic result compared with the upper part underneath the umbilicus for scar hypertrophy, scar width, and the total scar score. The surgeons concluded that polybutester skin suture diminished the risk of  --------------------------------------- 14 III. scientific basis for the selection of surgical sutures (cont’d) hypertrophic scar formation because of its special properties allowing it to adapt to changing tensions in the wound. Increased closure tension of the skin in the midline region above the pubic bone may be caused by a relative immobility of 10 the skin. In 1997, Pinheiro et al. compared the performance of polybutester sutures to that of nylon sutures in 70 male and female rats in which they examined the clinical response of the skin in abdominal wall muscle to the use of these sutures. Under general anesthesia, standard wounds were created in the dorsum and abdomen of the animals and subjected to suture closure with either polybutester or nylon. The animals were sacrificed immediately, 12, 24, and 72 hours and at four, five and seven days to evaluate the impact of the sutures on the wounds. They found that polybutester produced some advantages such as strength, lack of package memory, elasticity, and flexibility which made suturing quicker and easier. They concluded that Novafil suture can be used safely on skin and mucosal wounds because it is less irritating to tissues than nylon. The clinical performance of polybutester suture has been enhanced by coating its 11 surface with a unique absorbable polymer (Vascufil). The coating is a poly- tribolate polymer that is composed of three compounds: gylcolide, e-caprolactone, 10 --------------------------------------- 15 and poloxamer 188. Coating the polybutester suture markedly reduces its drag forces in musculoaponeurotic, colonic, and vascular tissue. Knot security with the Vascufil suture was achieved with only one more throw than with comparably sized, uncoated polybutester sutures. On the basis of the results of our investigations, coating the polybutester suture represents another major advance in surgical suture performance. 2. Absorbable surgical sutures The absorbable sutures of Covidien are made from either collagen or synthetic polymers. The collagen sutures are derived from the serosal layer of bovine small intestine (gut). This collagenous tissue is treated with an aldehyde solution, which cross-links and strengthens the suture and makes it more resistant to enzymatic degradation. Suture materials treated in this way are called plain gut (Plain Gut). If the suture is additionally treated with chromium trioxide, it becomes chromic gut (Chromic Gut), which is more highly cross-linked than plain gut and more resistant to absorption. When this treatment of collagen sutures is limited, the result is a special form of chromic gut (Mild Gut) that is more susceptible to tissue absorption. The plain gut and chromic gut sutures are composed of several plies that have been twisted 11 --------------------------------------- 16 III. scientific basis for the selection of surgical sutures (cont’d) slightly, machine ground, and polished, yielding a relatively smooth surface that 12 is monofilament-like in appearance. Salthouse and colleagues demonstrated that the mechanism by which gut reabsorbs is the result of sequential attacks by lysosomal enzymes. In most locations, this degradation is started by acid phosphatase, with leucine aminopeptidase playing a more important role later in the absorption period. Collagenase is also thought to contribute to the enzymatic degradation of these collagen sutures. Natural fiber absorbable sutures have several distinct disadvantages. First, these natural fiber absorbable sutures have a tendency to fray during knot construction. Second, there is considerably more variability in their retention of tensile strength than is found with the synthetic absorbable sutures. A search for a synthetic substitute for collagen sutures began in the 1960s. Soon procedures were perfected for the synthesis of high molecular weight polyglycolic acid, which 13 led to the development of the polyglycolic acid sutures (Dexon II, Dexon S). These sutures are produced from the homopolymer, polyglycolic acid. Because of the inherent rigidity of this homopolymer, monofilament sutures produced from polyglycolic acid sutures are too stiff for surgical use. This homopolymer 1 --------------------------------------- 17 can be used as a monofilament suture only in the finest size. Consequently, this high molecular weight homo-polymer is extruded into thin filaments and braided.13 The thin filaments of Dexon II are coated with Polycaprolate, a copolymer of glycolide and epsilon-caprolactone, to reduce the coefficient of friction encountered in knot construction. Dexon S is an uncoated braided suture. The polyglycolic acid sutures (Dexon II, Dexon S) degrade in an aqueous environment through hydrolysis of the ester linkage. Copolymers of glycolide and lactide were then synthesized to produce a Lactomer copolymer that is used to produce a new braided absorbable suture (Polysorb). The glycolide and lactide behaved differently when exposed to tissue hydrolysis. Glycolide 13 provides for high initial tensile strength, but hydrolyses rapidly in tissue. Lactide has a slower and controlled rate of hydrolysis, or tensile strength loss, and provides 13 for prolonged tensile strength in tissue. The Lactomer copolymer consists of glycolide and lactide in a 9:1 ratio. The handling characteristics of the Polysorb sutures were found to be superior to 14 those of the Polyglactin 910 suture. Using comparable knot construction and 13 --------------------------------------- 18 III. scientific basis for the selection of surgical sutures (cont’d) suture sizes, the knot breaking strength for Polysorb sutures was significantly greater than that encountered by Polyglactin 910 sutures. In addition, the mean maximum knot rundown force encountered with the Polysorb sutures was significantly lower than that noted with the Polyglactin 910 sutures, facilitating knot construction. The surfaces of the Polysorb sutures have been coated to decrease their 14 coefficient of friction. The new Polysorb suture is coated with an absorbable mixture of caprolactone/glycolide copolymer and calcium steraroyl lactylate. At 14 days post-implantation, nearly 80% of the USP (United States Pharmacopoeia) tensile strength of these braided sutures remains. Approximately 30% of their USP tensile strength is retained at 21 days. Absorption is essentially complete between days 56 and 70. We recently studied the determinants of suture extrusion following subcuticular 15 closure by synthetic braided absorbable sutures in dermal skin wounds. Miniature swine were used to develop a model for studying suture extrusion. Standard, full-thickness skin incisions were made on each leg and the abdomen. 1 --------------------------------------- 19 The wounds were closed with size 4/0 Polysorb or Coated Vicryl (Ethicon, Inc., Somerville, NJ) sutures. Each incision was closed with five interrupted, subcuticular, vertical loops secured with a surgeons knot. The loops were secured with 3-throw knots in one pig, 4-throw knots in the second pig, and 5-throw knots in the third pig. The swine model reproduced the human clinical experience and suture extrusion, wound dehiscence, stitch abscess, and granuloma formation were all observed. The cumulative incidence of suture extrusion over 5 weeks ranged from 10 to 33%. Coated Vicryl sutures had a higher mean cumulative incidence of suture extrusion than that of Polysorb sutures (31% vs. 19%). With Polysorb sutures, the 5-throw surgeons knots had a higher cumulative incidence of suture extrusion than the 3-throw or 4- throw surgeons knot square, 30% vs. 17% and 10%, respectively. This swine model offers an opportunity to study the parameters that influence suture extrusion. Because the volume of suture material in the wound is obviously a critical determinant of suture extrusion, it is imperative that the surgeon construct a knot that fails by breakage, rather than by slippage with the least number of throws. Because both braided absorbable suture materials are constructed with a secure surgical knot that fails only by breakage rather than slippage with a 3-throw surgeons knot square (2 =1 = 1), the 1 --------------------------------------- 20 III. scientific basis for the selection of surgical sutures (cont’d) construction of additional throws with these sutures does not enhance the suture holding capacity, but plays a key factor in precipitating suture extrusion. Finally, it is important to emphasize that the surgeon must always construct symmetrical surgical knots for dermal subcuticular skin closure in which the constructed knot is always positioned perpendicular to the linear wound incision. Asymmetrical knot construction for dermal wound closure becomes an obvious invitation for suture extrusion. A monofilament absorbable suture (Maxon) has been developed using 16 trimethylene carbonate. Glycolide trimethylene carbonate is a linear copolymer made by reacting trimethylene carbonate and glycolide with diethylene glycol as an initiator and stannous chloride dihydrate as the catalyst. The strength of the monofilament synthetic absorbable suture, glycolide trimethylene carbonate (Maxon), is maintained in vivo much longer than that of the braided synthetic absorbable suture. This monofilament suture retained approximately 50% of its breaking strength after implantation for 28 days, and still retained 25% of its original strength at 42 days. In contrast, braided absorbable sutures retained only 1% to 5% of their strength at 28 days. Absorption of the trimethylene carbonate 1 --------------------------------------- 21 suture is minimal until about the 60th day post-implantation and essentially complete within six months. Another innovation in the development of monofilament synthetic absorbable sutures has been the production of Glycomer 631, a terpolymer composed of glycolide (60%), trimethylene carbonate (26%), and dioxanone (14%) (Biosyn). The Biosyn 17 suture has many distinct advantages over the braided synthetic absorbable sutures. First, this monofilament suture is significantly stronger than the braided synthetic absorbable suture over four weeks of implantation. It maintains approximately 75% of its USP tensile strength at two weeks and 40% at three weeks post- implant. Absorption is complete between 90 to 110 days. Due to its construction, Monofilament suture potentiates less bacterial infection than does the braided suture. The handling characteristic of this monofilament suture is superior to the braided suture because it encounters lower drag forces in the tissue than does the braided suture. The latest innovation in the development of monofilament absorbable sutures has been the rapidly absorbing Caprosyn suture. Caprosyn monofilament synthetic 1 --------------------------------------- 22 III. scientific basis for the selection of surgical sutures (cont’d) absorbable sutures are prepared from Polyglytone 6211 synthetic polyester which is composed of glycolide, caprolactone, trimethylene carbonate, and lactide. Implantation studies in animals indicate that Caprosyn suture retains a minimum of 50-60% USP knot strength at five days post implantation, and a minimum of 20-30% of knot strength at 10 days post implantation. All of its tensile strength is essentially lost by 21 days post implantation. We recently have compared the biomechanical performance of Caprosyn 18 suture to that of Chromic Gut suture. The biomechanical performance studies included quantitative measurements of wound security, strength loss, mass loss, potentiation of infection, tissue drag, knot security, knot rundown, as well as suture stiffness. Both Caprosyn and Chromic Gut sutures provided comparable resistance to wound disruption. Prior to implantation, suture loops of Caprosyn had a significantly greater mean breaking strength than suture loops of Chromic Gut. Three weeks after implantation of these absorbable suture loops, the sutures had no appreciable strength. The rate of loss of suture mass of these two sutures was similar. As expected, Chromic Gut sutures potentiated significantly more infection than did the Caprosyn sutures. 1 --------------------------------------- 23 The handling properties of the Caprosyn sutures were far superior to those of the Chromic Gut sutures. The smooth surface of the Caprosyn sutures encountered lower drag forces than did the Chromic Gut sutures. Furthermore, it was much easier to reposition the Caprosyn knotted sutures than the knotted Chromic Gut sutures. In the case of Chromic Gut sutures, it was not possible to reposition a two-throw granny knot. These biomechanical performance studies demonstrated the superior performance of synthetic Caprosyn sutures compared to Chromic Gut sutures and provide compelling evidence of why Caprosyn sutures are an excellent alternative to Chromic Gut sutures. The direct correlation of molecular weight and breaking strength of the synthetic absorbable sutures with both in vivo and in vitro incubation implies a similar mechanism of degradation. Because in vitro incubation provides only a buffered aqueous environment, the chemical degradation of these sutures appears to be by non-enzymatic hydrolysis of the ester bonds. Hydrolysis would be expected to proceed until small, soluble products are formed, then dissolved, and removed from the implant site. In contrast, the gut or collagen suture, being a proteinaceous substance, is degraded primarily by the action of proteolytic enzymes. 1 --------------------------------------- 24 III. scientific basis for the selection of surgical sutures (cont’d) A distinction must be made between the rate of absorption and the rate of tensile strength loss of the suture material. The terms rate of absorption and rate of tensile strength loss are not interchangeable. Although the rate of absorption is of some importance with regard to late suture complications, such as sinus tracts and granulomas, the rate of tensile strength loss is of much greater importance to the surgeon considering the primary function of the suture, maintaining tissue approximation during healing. When considering an absorbable sutures tensile strength in vivo, we recommend that the manufacturer provide specific measurements of its holding capacity, rather than the percentage retained of its initial tensile strength. The United States Pharmacopoeia (USP) has set tensile strength standards for synthetic absorbable suture material. If the manufacturers were to use these standards to describe maintenance of tensile strength, the surgeon would have a valid clinical perspective to judge suture performance. Some manufacturers persist in reporting maintenance of the tensile strength of their suture in tissue by referring only to the percentage retained of its initial tensile strength, making comparisons between 0 --------------------------------------- 25 sutures difficult. The need to use USP standards in reporting is particularly important when there are marked differences in the initial tensile strengths of the synthetic sutures. For example, the initial tensile strength of Biosyn is 43% stronger than that of polydioxanone. At two weeks, the Biosyn suture is approximately 30% stronger. 1 --------------------------------------- 26 IV. components of a knotted suture loop using either a granny knot type or a square knot type The mode of operation of a suture is the creation of a loop 19 of fixed perimeter secured in the geometry by a knot. A tied suture has three components (Figure 1). First, the loop created by the knot maintains the approximation of the divided wound edges. Second, the knot is composed of a number of throws snugged against each other. A throw is a wrapping or weaving of two strands. Finally, the ears act as insurance that the loop will not become untied because of knot slippage. The doctors side of the knot is defined as the side of the knot with ears, or the side to which tension is applied during tying. The patients side is the portion of the knot adjacent to the loop. Figure 1. The components of a tied suture.  --------------------------------------- 27 Each throw within a knot can either be a single or double throw. A single throw is formed by wrapping the two strands around each other so that the angle of the wrap equals 360. In a double throw, the free end of a strand is passed twice, instead of once, around the other strand; the angle of this double-wrap throw is 720. The tying of one or more additional throws completes the knot. The configuration of the knot can be classified into two general types by the relationship between the knot ears and the loop (Figure 2). When the right ear and the loop of the two throws exit on the same side of the knot or parallel to each other, the type of knot is judged to be square (reef). The knot is considered a granny type if the right ear and the loop exit or cross different sides of the knot. When the knot is constructed by an initial double-wrap throw followed by a single throw, it is called a surgeons (friction) knot. The configuration of a reversed surgeons knot is a single throw followed by a double-wrap throw. A knot consisting of two double-wrap throws is appropriately called a double-double. Figure 2. The configuration of surgical knots. 3 --------------------------------------- 28 IV. components of a knotted suture loop (cont’d) When forming the first throw of either a square or granny knot, the surgeon is merely wrapping one suture end (360) around the other, with the suture ends exiting in opposite directions. The surgeon will apply equal and opposing tension to the suture ends in the same planes. The direction of the applied tensions will be determined by the orientation of the suture loop in relation to that of the surgeons hands. When the surgeons hands lie on each side and parallel to the suture loop, the surgeon will apply tensions in a direction parallel to his/her forearms. (Figure 3). Figure 3. During knot construction, the surgeons hands should be on each side and parallel to the suture loop  --------------------------------------- 29 Tension will be applied to the farther suture end in a direction away from the surgeon. Conversely, and equal opposing force will be applied to the closer suture end in a direction toward the surgeon. After constructing the second throw of these knots, the direction of the suture ends must be reversed, with an accompanying reversal of the position of the surgeons hand. As the surgeons hands move toward or away from his body, the movements of his right and left hands are in separate and distinct areas that do not cross, permitting continuous visualization of knot construction. With each additional throw, the surgeon must reverse the position of his/her hands. Orientation of the suture loop in a plane that is perpendicular to that of the surgeons forearms considerably complicates knot construction (Figure 4). In this circumstance, reversal of the position of the hands occurs in the same area, with crossing and overlapping Figure 4. The surgeons hands frequently of the surgeons hands, temporarily obscuring overlap (arrows) when the orientation of the hands is perpendicular to that of the visualization of knot construction. This circumstance may be encountered when constructing knots in a suture loop. deep body cavity, which considerably limits changes in hand positions. This relatively cumbersome hand position may interfere with the application of uniform opposing tensions to the suture ends, an invitation to the conversion of a square knot construction to a slip knot.  --------------------------------------- 30 IV. components of a knotted suture loop (cont’d) The granny knot and square knot can become a slip knot by making minor changes in the knot tying technique (Figure 5). Surgeons who do not reverse the position of their hands after forming each throw will construct slip knots. Furthermore, the application of greater tension to one ear than the other encourages construction of slip knots, a practice commonly encountered in tying 20 deep-seated ligatures. Figure 5. When the tension (arrow) is reapplied in equal and opposing directions, the slip knot can be converted into a square knot.  --------------------------------------- 31 When the tension is reapplied in equal and opposing directions, the slip knots can usually be converted into either the square or granny knots. A simple code has been 21 devised to describe a knots configuration (Figure 2). The number of wraps for each throw is indicated by the appropriate Arabic number. The relationship between each throw being either crossed or parallel is signified by the symbols X or =, respectively. In accordance with this code, the square knot is designated 1=1, and the granny knot 1x1. The presence of a slip knot construction is indicated by the letter S. This method of describing knots facilitates their identification and reproduction. It is, for example, perfectly obvious what is meant by 2x2x2, without giving the knot a name, and all surgical knots can be defined unequivocally in this international language. Sutures remain the most common method of approximating the divided edges of skin. Skin closure can be achieved by either percutaneous suture closure, dermal suture closure, or a combination of both techniques. Dermal or percutaneous suture closures are accomplished by either interrupted suture or a continuous suture closure technique. When utilizing a continuous suture, the first suture loop is constructed by using the single strand of the fixed suture end attached to the needle and a single strand of the free suture end. However, the knot of the last suture loop at the end of the continuous suture is constructed by a suture loop containing two strands and the single strand of the fixed suture end attached to the needle.  --------------------------------------- 32 IV. components of a knotted suture loop (cont’d) The first knot in a percutaneous and dermal suture closure usually has a square knot construction. A tied square knot suture has three components (Figure 6). The loop created by the knot maintains the apposition of tissue. The knot is composed of a number of throws secured against each other. The ears are the cut ends of the suture, which add security to the knot by preventing Figure 6. Construction of a square knot with two single strands. untying during slippage. At the end of a percutaneous and dermal closure, te knot must be constructed as a square knot with a single strand and a suture loop. A square knot of an interrupted suture loop is formed by two single throws in which the right ear and loop come out in a position that is directly opposite to that of the left ear and loop. The configuration of a knot using a looped suture end and a fixed suture end attached to a needle is markedly different from the interrupted knotted suture loop in which knot construction is Figure 7. Construction of a square knot with accomplished by two separate strands of sutures. The interrupted suture has a knot constructed by two single strands. In contrast, a single strand and suture loop. knots constructed with a suture loop have two suture strands that  --------------------------------------- 33 are intertwined with the single strand of the fixed suture end. When knot construction is complete, the interrupted percutaneous suture has two cut suture ends. Knots constructed by a double-strand suture loop and a single strand of the fixed suture end has three separate knot ears (Figure 7). The square knot is formed when the right ear and the loop of a two-throw knot exit on the same side of the knot and are parallel to each other. During wound closure, knot construction involves two steps. The first secures precise approximation of the wound edges by advancing either a one-throw or a two-throw knot to the wound surface. The second step is the construction of additional throws until knot security is attained and slippage is prevented.22 Our biomechanical performance studies demonstrate that secure knot configuration of the interrupted suture loop created at the beginning of the wound is quite different from secure knot configuration of the knot constructed at the end of the wound. These differences in secure knot configurations are related to the types of suture strands used in knot construction. The first knot in a continuous suture is constructed by two single strands, and the second knot is created by a single strand and a suture loop. Knot construction with a suture loop predisposes the knot to suture slippage and requires additional throws for knot security. When constructing the first interrupted suture loop with either absorbable or nonabsorbable monofilament sutures, knot security is achieved with square knot construction by using three or four throws. The last suture loop and single strand involves at least five or six throws for knot security. If the trauma surgeon fails to construct secure knots at the beginning or the end of the laceration, knot slippage will occur, resulting in wound dehiscence.  --------------------------------------- 34 V. mechanical performance The mechanical performance of a suture is an important consideration in the selection of a surgical suture and can be measured by reproducible, 23 biomechanical parameters. The sutures stiffness reflects its resistance to bending. Its coefficient of friction is a measure of the resistive forces encountered by contact of the surfaces of the suture material during knot construction. Strength is a key performance parameter that indicates the sutures resistance to breakage. The knot breakage load for a secure knot that fails by breakage is a reliable measure of strength. During these tests, forces are applied to the divided ends of the suture loop, the patients side of the knot. As the suture is subjected to stress, it will elongate. The load elongation properties of a suture have important clinical implications. Ideally, the suture should elongate under low loads to accommodate for the developing wound edema, but return to its original length after resolution of the edema. Although it should exhibit an immediate stretch under low loads, it should not elongate any further while continuously maintaining the load, exhibiting a resistance to creep. These biomechanical parameters play important roles in the clinical 24 performance of the suture. Surgeons consider the handling characteristics of the suture to be one of the most important parameters in their selection of sutures. Surgeons evaluate the handling characteristics of sutures by constructing knots using manual and instrument-tie techniques. The surgeon prefers a suture which permits two-throw knots to be easily advanced to the wound edges, providing a preview of the ultimate 30 --------------------------------------- 35 apposition of the wound edges. The force required to advance the knot is called knot rundown force. Once meticulous approximation of the wound edges is achieved, the surgeon prefers to add one more throw to the two-throw knot so that it does not fail by slippage. The magnitude of the knot rundown force is influenced considerably by the configuration of two-throw knots. 24 Knot rundown of the surgeons knot square (2=1) generates sufficient forces to break the knot. In contrast, knot rundown of square (1=1), granny (1x1) and slip (S=S, SxS) knots occurs by slippage. For comparable sutures, the mean knot rundown force for square knots is the greatest, followed by that for the granny (1x1) knots, and then the slip (S=S, SxS) knots. Failure of the knotted suture loop may be the result of either knot slippage or breakage, suture cutting through tissues, and mechanical crushing of the suture by surgical instruments. Initially, the knotted suture fails by slippage, which results in untying of the knot. All knots slip to some degree regardless of the type of suture material. When slippage is encountered, the cut ends (ears) of the knot must provide the additional material to compensate for the enlarged suture loop. When the amount of knot slippage exceeds the length of the cut ears, the throws of the knot become untied. In general, surgeons recommend that the length of the knot ears be 3mm to accommodate for any knot slippage. 3 Dermal sutures are, however, an exception to this rule. Because the ears of dermal suture knots may protrude through the divided skin edges, surgeons prefer to cut their dermal suture ears as they exit from the knot. It must be emphasized that knot security is achieved in a knot with earswith one more throw than in a comparable knot whose ear length is 3mm. 31 --------------------------------------- 36 Knot slippage is counteracted by the frictional forces of the knots. The knot slippage degree to which a knot slips can be influenced by a variety of factors including the coefficient of friction of the suture material, suture diameter, moisture, knot type and final geometry. Knots of the granny type (crossed) usually exhibit more slippage than do knots with a square-type (parallel) construction. With each additional throw, incrementally greater forces are required for knot untying. After a specified number of throws, failure will occur by knot breakage, after which the knot breakage force will not be enhanced by the addition of more throws. Consequently, these additional throws offer no mechanical advantage and represent more foreign bodies in the wound that damage host defenses and resistance to infection. The human element in knot tying has considerable influence on the 19 magnitude of knot slippage. The amount of tension exerted by the surgeon on the ears of the knot significantly alters the degree of slippage. The careless surgeon who applies minimal tension (10% of knot break strength) to the ears of the knot constructs knots that fail by slippage. Knot slippage can be minimized by applying more tensions (80% of knot break strength) to the ears of the knot. Another serious error often made by the inexperienced surgeon is not to change the position of his/her hands appropriately during construction of square and/or granny type knots. The resulting knot, a sliding or slip knot, will become untied regardless of the suture material. The risk of forming a slip knot is greatest when tying one- 20-23 hand knots and/or with deep seated ligatures. 3 --------------------------------------- 37 When enough force is applied to the tied suture to result in breakage, the site of knot breakage disruption of the suture is almost always the knot. The force necessary to break a knotted suture is lower than that required to break an untied suture made 19 of the same material. The forces exerted on a tied suture are converted into shear forces, by the knot configuration that break the knot. The percentage loss of tensile strength, as a result of tying a secure knot, is least with mono-filament and multifilament steel.25 This relationship between the tensile strength of unknotted and knotted suture which is designated knot efficiency, is described in the following equation: Knot efficiency (%) = tensile strength of a knotted suture tensile strength of unknotted suture Regardless of the type of suture material, the efficiency of the knot is enhanced with an increasing number of throws, although only up to a certain limit. The type of knot configuration that results in a secure knot that fails by breaking varies considerably with different suture material. The magnitude of force necessary to produce knot breakage is influenced by the configuration of the knotted suture loop, type of suture material, and the diameter of the 3 suture. The tissue in which the suture is implanted also has considerable influence on the knot strength of suture. In the case of absorbable sutures, a progressive decline in knot breaking strength is noted after tissue implantation. In addition, the magnitude of knot breakage force is significantly influenced by 23 the rate of application of forces to the ears of the knot. When a constant force is applied slowly to the knot ears, the knot breakage force is significantly greater than that for knots in which the same constant force is applied rapidly to the ears. The latter knot loading rate is often referred to as the jerk at the end of the knot, especially when the knotted suture breaks. 33 --------------------------------------- 38 Suture failure also may occur if the knotted suture loop cuts through the suture cutting tissue. The type of tissue has considerable influence on the magnitude of tissue26 force required to tear the suture through the tissue. Howes and Harvey reported that the forces required to tear gut sutures through canine fascia was the greatest followed by muscle, peritoneum and then fat. 27 Using cadaver specimens 6 to 93 days after death, Tera and Aberg measured the magnitude of forces required for suture to tear through excised musculoaponeurotic layers of laparotomy incisions. The rationale for this study was that the forces required to tear sutures through a musculoaponeurotic layer would provide a basis for the choice of a suture whose strength is at least as strong as the forces required to tear the suture through the tissue. When the suture was passed lateral to the transition between the linea alba and the rectus sheath, the force required to tear the suture through the tissue was greater than that for any other musculoaponeurotic layer tested; the paramedian incision required the lowest forces to pull sutures through its sheaths. When they recorded the forces needed for sutures to tear through structures involved in the repair of inguinal hernia, the structures making up the conjoined tendon and Coopers ligament were the strongest and exhibited twice the resistance to suture tearing than those of the other structures. As expected, the force required for sutures to tear through tissue changes 28 during healing. Aberg reported that the forces needed for sutures to tear through the aponeurotic muscle layer reduced significantly during the first week of healing. When the wound edges were approximated by suture tied tightly around this aponeurotic muscle layer, the reduction in force needed for the suture to pull through this tissue persisted for two weeks. 3 --------------------------------------- 39 Mechanical trauma to the suture by surgical instruments can also result in mechanical trauma suture failure. Nichols et al29 cautioned surgeons about the handling of sutures by surgical instruments. They indicated that either the application of clamps and forceps to the suture or rough handling of sutures could damage 30 and weaken them. Stamp et al incriminated the teeth in the needle holder jaws as important causal factors of sutural damage. Compression of sutures between the needle holder jaws with teeth produced morphologic changes in sutures that resulted in a marked reduction in the suture breaking strength. Similarly, the sharp edges of needle holder jaws without teeth can even crush 31 the suture and, thereby, decrease its strength. Finally application of large compressive loads by pinching polypropylene sutures with DeBakey forceps 32 decreases the strength of the suture. 3 --------------------------------------- 40 VI. tying techniques The surgeon may use an individual ligature (free tie) or a suture that is attached to a needle or ligature reel. The length of a free tie or suture attached to a needle is usually 18 inches. The longest strands of suture material are available on a reel or spool. When the suture is attached to a needle or reel, there is a free end and a fixed end; the fixed end is attached to either the needle or reel. The first throw of a knot is accomplished by wrapping the free end either once or twice (surgeons) around the fixed end. During practice, clamp one end of the suture with an instrument that serves to represent either the needle or the reel, which is the fixed end of the suture. Formation of each throw of a knot is accomplished in three steps. The first step is the formation of a suture loop. In the second step, the free suture end is passed through the suture loop to create a throw. The final step is to advance the throw to the wound surface. For the first throw of a square, granny, and surgeons knot square, for each additional throw the direction in which tension is applied to the suture ends is reversed. The surgeon should construct a knot by carefully snugging each throw tightly against another. The rate of applying tension to each throw should be relatively slow. For either the square knot or surgeons knot square, the direction in which the free suture end is passed through the loop will be reversed for each additional throw. If the free suture end is passed down through the first suture loop, it must be passed up through the next suture loop. Reversal of the direction of passage of the free suture end through the loops does not alter either the knots mechanical performance or its configuration. It simply reverses the presentation of the knot (Figure 8). For granny knots, the direction in which the free suture end is passed 3through the loop is the same for each additional throw. --------------------------------------- 41 Figure 8. Square knot (1=1) (A) is formed by first passing the free suture end up through the suture loop to create the first throw. The second throw is formed by passing the free suture end down through the suture loop. Square knot (1=1) (B) is formed by passing the free suture end down through the suture loop to create the first throw. The second throw is formed by passing the free suture end up through the suture loop. During surgery, knot construction involves two distinct steps. The purpose of the first step is to secure precise approximation of the wound edges by advancing either a one-throw or a two-throw knot to the wound surface. Once the throw or throws contact the wound, the surgeon will have a preview of the ultimate apposition of the wound edges. Ideally, the knotted suture loop should reapproximate the divided wound edges without strangulating the tissue encircled by the suture loop. If there is some separation of the wound edges, the one- throw or two-throw knot can be advanced to reduce the size of the suture loop and thereby bring the wound edges closer together. When the surgeon forms a double-wrap throw, the first throw of the surgeons knot square (2=1) can maintain apposition of the wound edged by locking or temporarily securing it in place by reversing the direction of pull on its ears. The locked double throw is not 3 --------------------------------------- 42 VI. tying techniques (cont’d) a reliable means of maintaining wound apposition because any tension applied to the ears from the patients side of the knot will unlock the knot. The addition of the second throw to the surgeons knot square (2=1) will provide additional resistance to wound disruption, but this knot will not advance by slippage, limiting the surgeons 24 ability to secure meticulous coaptation of the wound edges. In contrast, two-throw square (1=1) or granny (1x1) knots can be advanced to the wound surface to secure precise wound edge apposition. These two-throw square (1=1) or granny (1x1) knots can be easily converted into their respective slip knots by applying tension to only one ear in a direction that is perpendicular to that of the tissue surface. Square (S=S) or granny (SxS) slip knots require lower knot rundown force for knot advancement than either the square (1=1) or granny (1x1) knots, but will never reach knot security even with 5 throws. 9 The risk of tying slip knots can be obviated by applying tensions to both ears in horizontal planes parallel to the tissue surface. The second step in knot construction is the addition of a sufficient number of throws to the knot so that it does not fail by slippage. The magnitude of knot breakage force is always greater than that for knot slippage force of a comparable suture, ensuring optimal protection against wound dehiscence. The magnitude of knot breakage force is significantly influenced by the rate of application of forces to the knot. When constant force is applied slowly to the knot ears, the knot breakage force is significantly greater than that for knots in which the same constant force is applied rapidly to the ears. 3 --------------------------------------- 43 instrument tie Knot construction can be accomplished by either an instrument or hand tie. An instrument tie occurs by the formation of suture loop over an instrument, usually a needle holder. The right hand holds the needle holder, while the left hand loops the fixed suture end around the instrument. The position of the instrument in relation to the suture ends during knot construction will determine the type of knot. When the instrument is placed above the fixed suture end during the first and second throws, a square-type knot will develop. In contrast, a granny-type knot will first result when the instrument is placed above the fixed suture end for the first throw and then below the fixed suture end for the second throw. By repeating this positioning, the instrument tie is a reliable and easy method to produce multiple throw granny knots (1x1x1), a circumstance not encountered in hand ties. Granny knots with more than two throws cannot be constructed by either the one-hand or two-hand technique, without releasing hold of both suture ends. Instrument tying is accomplished primarily by the surgeons left hand, which holds the fixed suture end. Initially the length of the fixed suture end held by the left hand is long (17 in.), making it difficult to form knots without injuring the attending assistant. This assault can be avoided by shortening the length of the fixed suture end held by the left hand. Preferably, the fixed suture end should be coiled into loops, which are held between the tips of the thumb and index finger. 3 --------------------------------------- 44 instrument tie (cont’d) This maneuver is accomplished by first grasping the fixed suture end with the small and ring fingers, while it is being pinched between the tips of the index finger and thumb. By pronating the wrist, a loop forms around the grasped fingers, and the top of the loop must again be grasped between the tips of the thumb and index fingers. The small and ring fingers are then withdrawn from the loop before coiling more suture. The rasped suture can be easily lengthened by releasing the coils held between the tips of the thumb and index finger. When tying knots with an instrument, it is difficult to apply continuous tension to the suture ends. Consequently, widening of the suture loop due to slippage is frequently encountered in wounds subjected to strong tension. This technique, however, is ideally suited for closing a wound which is subjected to weak tensions. In this circumstance, instrument ties can be accomplished more rapidly and accurately than hand ties, while conserving considerably more suture. By using this technique, the parsimonious surgeon can complete 10 interrupted suture loops from one suture measuring 18 inches in length. This feat would be impossible if the knots had been tied by hand. The value of instrument ties has become readily apparent in special situations in which hand ties are impractical or impossible. In microsurgical procedures, an instrument tie provides the most reliable and easiest method of knot construction. When employing suture in the recesses of the body (e.g. mouth, vagina, etc.) or during endoscopic surgery, instruments can also form knots in sites to which the hand could never gain access. 0 --------------------------------------- 45 Hand tying of knots can be accomplished by either the two-hand or one-hand technique. Each technique has distinct advantages as well as drawbacks. The two-hand hand tie technique of knot tying is easier to learn than the one hand. An additional advantage of the two-hand tie is that the surgeon can apply continuous tension to the suture ends until a secure knot is formed. With the one-hand method, it is often difficult to maintain tension on the suture ends during the formation of the knot and slippage of the first or second throws will be encountered, especially by the inexperienced surgeon. When the surgeon attempts to shorten the resultant enlarged loop by advancing the knot, breakage of the suture may occur, requiring passage of another suture through the once punctured tissue. The student of surgery should master first the construction of square type knots because knot security can usually be achieved with fewer throws than the granny-type knots.21 The additional foreign bodies required to form a secure granny knot, predisposes the wound to the development of infection. The hand-tying techniques illustrated in this manual are those used by right-handed individuals. Using the two-hand technique, he/she constructs the knot predominantly with his/her left hand, which forms a suture loop through which the free suture end is passed. The left hand continually holds the suture end until knot construction is complete. In contrast, the right hand merely holds, lets go, and regrasps the free suture end. If the surgeon inadvertently manipulates the fixed suture end with his/her right hand, he/she will be passing either the needle or reel through the formed loop. The latter case is an invitation to needle puncture. Many right-handed surgeons prefer to manipulate the free end of the suture with their left and during two-hand ties. In such cases, the right hand performs the major manipula-tion of the suture during formation of the loop. An advantage of this 1 --------------------------------------- 46 technique is that a surgeon who ties his/her own knots by hand tie the two-hand technique during wound closure can hold the (cont’d) needle holder in his/her right hand during knot construction. If one desired to learn to tie knots using the left hand to manipulate the free end of the suture, study the illustrations in a mirror. Using the one-hand tie, one hand forms the suture loop while manipulating the free suture end. The other hand merely holds the mother suture end taut. Most surgeons prefer to manipulate the free suture end with their left hand, allowing them to hold the needle holder in their right hand while they construct knots with their left hand. There are several important recommendations for selecting a knot tying technique. First, position the hands on each side of and parallel to the suture loop. Second, grasp the appropriate suture ends and form the suture loop, without exchanging suture ends between the hands. While exchanging suture ends between the hands forms a triangular-shaped suture loop, it is an unnecessary step that wastes valuable time. Third pass the free suture end, rather than the fixed suture end, through the suture loop. Finally, reverse the position of the hands after Figure 9. Standard format for illustrating the knot tying technique.  --------------------------------------- 47 each additional throw. Most of the knot tying techniques in this manual comply with these recommendations. However, it is important to point out that the fixed end of the suture is being passed through the suture loops in the two-hand ties. Consequently, the surgeon must detach the needle from the fixed suture end before a two-hand tie. A standard format for illustrating surgical knot tying techniques has been used throughout the manual (Figure 9). A horizontal incision is pictured in the top of each illustration. Because the wound edges are subjected to static tensions, there is retraction of the wound edges, with exposure of the underlying tissue. The surgeon is standing facing the wound from the bottom of each illustration. Because the surgeon usually passes the needle swaged to a suture toward himself (herself), the fixed end (black) of the suture with its attached needle enters the farther side of the mid-portion of the wound and exits from the side of the wound closer to the surgeon. The free end of the suture is white to facilitate illustration of the knot tying technique. The suture end (white) farther from the surgeon is grasped between the tips of the distal phalanges of the left thumb and index finger (tip-to-tip pinch). The tips of the distal phalanges of the thumb and index finger of the right hand grasp the suture end (black) exiting from the wound edge closer to the surgeon. The grasped fingers apply constant tension to the suture ends. The security of this tip-to-tip pinch can be enhanced by grasping the suture ends between the tips of the long fingers, ring fingers, small fingers, and the palm of each hand (grip activity). The tying of square, slip, and surgeons knots using manual and instrument-tying techniques are illustrated in Sections VIII-X. The technique of tying slip knots has been included in the manual because it is an excellent method to approximate temporarily the edges of wounds subjected to strong tensions In fact, a slip knot has greater holding power 22 than either a single-wrap or double-wrap throw. Once there is meticulous approximation of wound edges, the slip knot can be converted to a square knot, after which a sufficient number of throws are added to the knot to ensure knot security. 3 --------------------------------------- 48 VII. essential elements DODON’T 1. Pass the surgical needle swaged to a 1. Pass the surgical needle swaged to a suture through the wound edges in a suture through the wound edge in a direction toward you.direction away from you. . Construct a two-throw square knot that . Construct a secure knot that cannot be can be advanced to the wound edge, advanced to the wound edges. providing a preview of the ultimate 3. Apply frictional forces (sawing) apposition of the wound edges.between the suture “ears” during knot 3. Approximate the edges of the divided construction that damage the suture and tissue without strangulating the tissue reduce its strength. encircled by the suture loop. . Add further throws to a knot that has . Once meticulous apposition of the the required number of throws for wound edges is achieved, construct a knot security. knot that has has sufficient number of . Position your hands perpendicular to throws that allow it to fail by breakage the suture loop. rather than by slippage. . Position your hands on each side and parallel to the suture loop.  --------------------------------------- 49 DODON’T . Apply opposing forces to the knot . Exert unequal levels of tension to the ears that are equal in magnitude suture ends that convert the knot into and in a plane parallel to that of the a slip knot. wound surface. . Maintain the same position of your . After each throw, reverse the position of hands after each additional throw. your hands that apply tension to the . Apply a constant force rapidly to the suture ends. ears of each throw of the knot. . Apply constant force slowly to the . Use the one-hand tie technique to ears of each throw of the knot. maintain continuous tension of the . Use the two-hand tie technique to suture ends. maintain continuous tension on suture 10. During an instrument tie, position the ends. needle holder perpendicular to the 10. During an instrument tie, position the wound. needle holder parallel to the wound. 11. Position the needle holder above the 11. Position the needle holder above the fixed suture end to form the first fixed suture end to form the first and throw, and then below the fixed suture second suture throws of a square end to form the second throw of the (1=1) knot.square knot (1=1). 1. Clamp only the free end of the suture 1. Clamp the suture loop with an instru- ment because it will crush the suture, during the instrument tie. reducing its strength.30-3  --------------------------------------- 50 VIII. two-hand tie techniques — square knot (1=1) formation of the first throw Step 1. Hold Suture Ends The suture end exiting from the side of the wound farther from the surgeon is grasped between the tips of the distal phalanges of the left thumb and index finger (tip-to-tip pinch), while the tips of the distal phalanges of the right thumb and index finger grasp the suture end exiting from the closer side of the wound. The grasped fingers apply constant tension to the suture ends. The security of this tip-to-tip pinch of the suture ends can be enhanced by grasping the suture ends between the tips of the long fingers, ring fingers, small fingers and the palm of each hand (grip activity).  --------------------------------------- 51 Step 3. VIII. t wo-hand tie techniques — square knot (1=1) Pass Thumb formation of the first throwUp Through the Suture Loop The tip of the left thumb advances up through the suture loop, replacing the tip of the left index finger. Step 2. Step 4. Form the First Suture LoopPass Free The first loop is formed by the tip of the Suture End left index finger that passes its suture end Over the Suture Loop over the other suture end held by the right hand. As the tip of the left index finger The free suture end, passes its suture end over the suture end held by the right hand, held by the right hand, the left thumb is passed over (arrow) passes under (arrow) the suture end held the suture loop. by the right hand.  --------------------------------------- 52 VIII. two-hand tie techniques — square knot (1=1) formation of the first throw (cont’d) Step 5. Pass Free Suture End Down Through the Suture Loop to Form Single-Wrap Throw After the suture end is grasped between the tips of the left thumb and index finger, the pinched suture end is passed downward through the suture loop. The right hand releases its free suture end so that it can be passed down through the suture loop. The free suture end is regrasped between the tips of the right thumb and index finger to withdraw (arrow) it through the suture loop to form a single-wrap throw.  --------------------------------------- 53 Step 6. Advance First Single-Wrap Throw to Wound Surface With the suture ends grasped in the palms of the surgeons hands, the tips of the index fingers and thumbs position the suture ends in a direction (arrows) perpendicular to that of the wound. The surgeon applies constant tension to the suture ends, which advances the first single-wrap throw of the square knot to the surface of the wound. Advancement of the first throw is complete when the divided skin edges of the mid-portion of the wound are approximated.  --------------------------------------- 54 VIII. two-hand tie techniques — square knot (1=1) formation of the second throw Step 7. Begin Formation of the Second Suture Loop The dorsum of the tip of the left thumb is passed under its suture end in order to direct it beneath (arrow) the other suture end that is held by the right hand. During formation of the second throw, constant tension is applied to the suture ends to maintain wound approximation. 0 --------------------------------------- 55 Step 9. Pass Index Finger Down Through the Suture Loop After the tip of the left index finger contacts the tip of the left thumb (tip- to-tip pinch), both are advanced down (arrow) through the suture loop so that only the tip of the left index finger remains in the loop. Step 8. Step 10. Form the Second Suture LoopPass Free Suture End The left thumb advances its suture end beneath Under the Suture Loop the other suture end to form a suture loop. The free suture end held The tip of the left index finger passes down by the right hand is (arrow) to touch the left thumb.passed under the suture loop to be positioned (arrow) between the tips of the left index finger and thumb. 1 --------------------------------------- 56 VIII. two-hand tie techniques — square knot (1=1) formation of the second throw (cont’d) Step 11. Pass Free Suture End Up Through the Suture Loop to Form Second, Single-Wrap Throw The free suture end grasped between the tips of the left thumb and index finger is advanced upward through the suture loop. The right hand releases its free suture end to allow its passage through the suture loop, after which it regrasps the free suture end to withdraw (arrow) through the suture loop.  --------------------------------------- 57 Step 12. Advance Square Knot (1=1) to Wound Surface The second throw is advanced and set against the first throw by applying tension in a direction (arrows) perpendicular to that of the wound. Advancement of the second throw is complete when the second throw contacts the first throw to form a square (1=1) knot. Ideally, the surgeon should be able to advance the two-throw, square knot to allow meticulous approximation of the wound edges. Once exact approximation of the wound edges is accomplished, the surgeon will construct a knot with a sufficient number of throws and 3mm cut ears so that knot security is determined by knot breakage, rather than by 3 slippage. 3 --------------------------------------- 58 VIII. two-hand tie techniques — surgeon’s knot square (=1) formation of the first, double-wrap throw Step 1. Hold Suture Ends The suture end exiting from the side of the wound farther from the surgeon is grasped between the tips of the distal phalanges of the left thumb and index finger (tip-to-tip pinch), while the tips of the distal phalanges of the right thumb and index finger grasp the suture end exiting from the closer side of the wound. The grasped fingers apply constant tension to the suture ends. The security of this tip-to-tip pinch of the suture ends can be enhanced by grasping the suture ends between the tips of the long fingers, ring fingers, small fingers and the palm of each hand (grip activity).  --------------------------------------- 59 Step 3. 1. IntroductionPass Thumb Up Through the Suture Loop The tip of the left thumb advances up through the suture loop, replacing the tip of the left index finger. Step 2. Step 4. Form the First Suture LoopPass Free The first suture loop is formed by the tip of the Suture End left index finger that passes its suture end over the Over the other suture end held by the right hand. As the Suture Loop tip of the left index finger passes its suture end The free suture end, over the suture end held by the right hand, the left held by the right hand, thumb passes under (arrow) the suture end held is passed over (arrow) by the right hand.the suture loop.  --------------------------------------- 60 VIII. two-hand tie techniques — surgeon’s knot square (=1) formation of the first, double-wrap throw (cont’d) Step 5. Pass Free Suture End Down Through the Suture Loop to Form Single-Wrap Throw After the free suture end is grasped between the tips of the left thumb and index finger, the pinched suture end is passed downward through the suture loop. The right hand releases its free suture end so that it can be passed through the loop. The tips of the right thumb and index finger regrasp the free suture end to withdraw (arrow) it through the suture loop to form a single-wrap throw.  --------------------------------------- 61 Step 7. Pass Left Thumb Up Into the Suture Loop The left thumb passes up (arrow) through the suture loop, replacing the left index finger in preparation for the formation of the double-wrap first throw. Step 6. Step 8. Maintain Suture Loop with Left Index FingerPass Free Suture End The rectangular configuration of the suture Over the Suture Loop loop is maintained by keeping the tip of The free suture end the index finger (arrow) in the suture loop.held by the right hand is passed over (arrow) the suture loop and grasped between the tips of the left thumb and index finger.  --------------------------------------- 62 VIII. two-hand tie techniques — surgeon’s knot square (=1) formation of the first, double-wrap throw (cont’d) Step 9. Pass Free Suture End Down Through the Suture Loop to Form Double-Wrap, First Throw The free suture end grasped between the tips of the left thumb and index finger is passed down (arrow) through the suture loop. The right hand releases its suture end so that it can be withdrawn through the suture loop. As the free suture end passes through the loop, it is regrasped by the right hand to withdraw it through the suture loop.  --------------------------------------- 63 Step 10. Advance Double-Wrap, First Throw to Wound Surface With the suture ends grasped in the palms of the surgeons hands, the tips of the index fingers and thumbs position the suture ends in a direction (arrows) perpendicular to that of the wound. The surgeon applies constant tension to the suture ends, which advances the double-wrap, first throw of the surgeons knot square to the surface of the wound. Advancement of the first throw is complete when the divided edges of the mid-portion of the wound are approximated.  --------------------------------------- 64 VIII. two-hand tie techniques — surgeon’s knot square (=1) formation of the second throw Step 11. Begin Formation of the Second Suture Loop The dorsum of the tip of the left thumb is passed under (arrow) its suture end in order to direct it beneath the other suture end that is held by the right hand. During formation of the second throw, constant tension is applied to the suture ends to maintain wound approximation. 0 --------------------------------------- 65 Step 13. Pass Index Finger Down Through Suture Loop After the tip of the left index finger contacts the tip of the left thumb (tip- to-tip pinch), both are advanced down (arrow) through the suture loop so that only the tip of the left index finger remains in the suture loop. Step 12. Step 14. Form the Second Suture LoopPass Free Suture End The left thumb advances its suture end Under the Suture Loop beneath the other suture end to form The free suture end held a suture loop. The tip of the left index by the right hand is passed finger passes down (arrow) to touch under the suture loop to the left thumb.be positioned (arrow) between the tips of the left index finger and thumb. 1 --------------------------------------- 66 VIII. two-hand tie techniques — surgeon’s knot square (=1) formation of the second throw (cont’d) Step 15. Pass Free Suture End Up Through the Suture Loop To Form Single-Wrap Throw The free suture end grasped between the tips of the left thumb and index finger is advanced upward though the suture loop. The right hand releases its free suture end to allow its passage through the suture loop, after which it regrasps the free suture end to withdraw (arrow) it through the suture loop.  --------------------------------------- 67 Step 16. Advance Surgeons Knot Square (2=1) to Wound Surface The single-wrap throw is advanced and set against the first double-wrap throw by applying tension in a direction (arrows) perpendicular to that of the wound. Advancement of the second throw is complete when the second throw contacts the first throw to form a surgeons knot square (2=1). The direction of the tension applied to the suture ends of the first throw is opposite to that exerted on the suture ends of the second throw. Once exact approximation of the wound edges is accomplished, the surgeon will construct a knot with a sufficient number of throws and 3mm cut ears so that knot security is determined by knot 3 breakage, rather than by slippage. 3 --------------------------------------- 68 VIII. two-hand tie techniques — slip knot (S=S) formation of the first throw Step 1. Hold Suture Ends The suture end exiting from the side of the wound farther from the surgeon is grasped between the tips of the distal phalanges of the left thumb and index finger (tip- to-tip pinch), while the tips of the distal phalanges of the right thumb and index finger grasp the suture end exiting from the closer side of the wound. The grasped fingers apply constant tension to the suture ends. The security of this tip-to-tip pinch of the suture ends can be enhanced by grasping the suture ends between the tips of the long fingers, ring fingers, small fingers and the palm of each hand (grip activity).  --------------------------------------- 69 Step 3. Pass Thumb Up Through the Suture Loop The tip of the left thumb advances up through the suture loop, replacing the tip of the left index finger. Step 2. Step 4. Form the First Suture LoopPass Free Suture End Over The first suture loop is formed by the tip of the Suture Loop the left index finger that passes its suture end over The free suture end, held the other suture end held by the right by the right hand, is passed hand. As the tip of the left index finger passes over (arrow) the suture its suture end over the suture end held by loop. the right hand, the left thumb passes under (arrow) the suture end held by the right hand.  --------------------------------------- 70 VIII. two-hand tie techniques — slip knot (S=S) formation of the first throw (cont’d) Step 5. Pass Free Suture End Down Through the Suture Loop After the suture end is grasped between the tips of the left thumb and index finger, the pinched suture end is passed downward through the suture loop. The right hand releases its free suture end so that it can be passed down through the suture loop. The free suture end is regrasped between the tips of the right thumb and index finger to withdraw (arrow) it through the suture loop.  --------------------------------------- 71 Step 6. Step 7. Apply Tension to the Straight, Taut Suture EndAdvance First Throw The first throw of the slip knot is completed to Wound by first applying tension (arrow) to the suture The tip of the right index finger slides (arrow) held by the left hand causing the suture end the loop along the straight, taut suture end held to be straight and taut. The suture end held by the left hand until the loop contacts the wound. by the right hand forms a loop around the Advancement of the first throw is complete when straight, taut suture held by the left hand.the divided skin edges of the mid-portion of the wound are approximated.  --------------------------------------- 72 VIII. two-hand tie techniques — slip knot (S=S) formation of the second throw Step 8. Begin Formation of Second Suture Loop The dorsum of the tip of the left thumb is passed under its suture end in order to direct it beneath (arrow) the other suture end that is held by the right hand. During formation of the second throw, constant tension is applied to the suture ends to maintain wound approximation.  --------------------------------------- 73 Step 10. Pass Index Finger Down Through the Suture Loop After the tip of the left index finger contacts the tip of the left thumb (tip- to-tip pinch), both are advanced down (arrow) through the suture loop so that only the tip of the left index finger remains in the suture loop. Step 9. Step 11. Form the Second Suture LoopPass Free Suture End Under the The left thumb advances its suture end beneath Suture Loop the other suture end to form a suture loop. The tip of the left index finger passes down The free suture end held (arrow) to touch the left thumb.by the right hand is passed under the suture loop to be positioned (arrow) between the tips of the left index finger and thumb.  --------------------------------------- 74 VIII. two-hand tie techniques — slip knot (S=S) formation of the second throw (cont’d) Step 12. Pass Free Suture End Up Through the Suture Loop The free suture end grasped between the tips of the left thumb and index finger is advanced upward through the suture loop. The right hand releases its free suture end to allows its passage through the suture loop, after which it regrasps the free suture end to withdraw (arrow) it through the suture loop. 0 --------------------------------------- 75 Step 13. Step 14. Apply Tension to the Straight, Taut Suture End Advance Slip Knot (S=S) to Wound Surface to Form Second ThrowThe tip of the right index finger slides (arrow) The tension applied (arrow) to the suture end this second throw against the first throw, held by the left hand causes this suture end completing the slip knot (S=S), while the left to become straight and taut. The suture end hand maintains tension (arrow) on its suture held by the right hand forms a second loop end. The slip knot will become a square knot around the straight, taut suture end held by by applying tension to the suture end held the left hand.by the right hand. (Insert) The square knot can be converted to a slip knot by applying tension primarily to one suture end. 1 --------------------------------------- 76 IX. one-hand tie technique — square knot (1=1) formation of the first throw Step 1. Hold Suture Ends The suture end exiting from the side of the wound farther from the surgeon is grasped between the tips of the distal phalanges of the left thumb and index finger (tip-to-tip pinch), while the tips of the distal phalanges of the right thumb and index finger grasp the suture end exiting from the closer side of the wound. The grasped fingers apply constant tension to the suture ends. The security of this tip-to-tip pinch of the suture ends can be enhanced by grasping the suture ends between the tips of the long fingers, ring fingers, small fingers and the palm of each hand (grip activity).  --------------------------------------- 77 Step 2. Step 3. Form the First Suture LoopPass Index Finger Down into The first throw of the square knot is initiated by The Suture Loop the tip of the left index finger that passes its free As the index finger passes into the suture loop, suture end over the fixed suture end held between flexion of the tip of the left index finger the tips of the right index finger and thumb. continues until the dorsal surface of its distal The tip of the left index finger begins to flex phalanx contacts the free suture end held by the around (arrow) the fixed suture end held by the left hand. After the free suture end rests on the right hand. Note that the left hand forms the dorsal surface of the tip of the left index finger, suture loop and passes the free suture end through extension of the finger will begin withdrawal the suture loop. Consequently, knot construction (arrow) of the free suture end up through the can be safely accomplished without detaching suture loop. the needle from the fixed suture end. 3 --------------------------------------- 78 IX. one-hand tie technique — square knot (1=1) formation of the first throw (cont’d) Step 4. Begin Withdrawal of Free Suture End Up Through the Suture Loop Extension of the distal phalanx of the left index finger brings the suture end held by the left hand upward (arrow) through the loop.  --------------------------------------- 79 Step 5. Step 6. Pass Free Suture End Up Through Advance First Single-Wrap Throw the Suture Loopto Wound Surface For the left index finger to bring the entire suture With the suture ends grasped in the palms of the end up (arrow) through the loop, the left hand surgeons hands, the tips of the thumbs and index must release its grip of the suture. During this fingers position the suture ends in a direction (arrows) interval, tension cannot be maintained continually perpendicular to that of the wound. The surgeon on the first throw, allowing the first-throw suture applies constant tension to the suture ends, which loop to widen, with subsequent partial separation advances the first, single-wrap throw of the square of the wound edges.knot to the surface of the wound. Advancement of the first throw is complete when the divided skin edges of the mid-portion of the wound are approximated.  --------------------------------------- 80 IX. one-hand tie technique — square knot (1=1) formation of the second throw Step 7. Begin Formation of the Second Suture Loop While grasping the suture end exiting from the farther side of the wound between the tips of the left thumb and index finger, the surgeon supinates the left wrist so that the free suture end is positioned over the tips of the long, ring and small fingers.  --------------------------------------- 81 Step 8. Step 9. Form the Second Suture LoopFlex Long Finger Toward the With continued supination of the wrist, the Free Suture End tips of the left long and ring fingers advance Continued flexion (arrow) of the distal phalanx their free suture end under the suture end of the left long finger allows the tip of the finger held by the right hand to form a suture loop.to pass beneath the free suture end held between the tips of the left thumb and index finger.  --------------------------------------- 82 IX. one-hand tie technique — square knot (1=1) formation of the second throw (cont’d) Step 10. Begin Withdrawal of the Free Suture End Down Through the Suture Loop Once the dorsum of the distal phalanx of the left long finger is beneath the free suture end held between the tips of the left thumb and index finger, extension of the distal phalanx of the long finger begins to withdraw (arrow) the suture end down through the loop. For the left long finger to withdraw the entire free suture end down through the loop, the left thumb and index finger must release their grip of the suture. During this interval, tension cannot be maintained continually on the first throw, allowing the first-throw, suture loop to widen with subse- quent partial separation of the wound edges.  --------------------------------------- 83 Step 11. Step 12. Complete Withdrawal of the Free Suture End Down Advance Square Knot (1=1) to Wound Surface Through the Suture Loop to Form Second, The second throw is advanced and set against the first throw by Single-Wrap Throw applying tension in a direction (arrows) perpendicular to that During withdrawal (arrow) of the free suture end through of the wound. Advancement of the second throw is complete the loop, it is held loosely between the tips of the left long when the second throw contacts the first throw to form a square and ring fingers. This loose grasp (key pinch) between the (1=1) knot. Ideally, the surgeon should be able to advance the ulnar side of the distal phalanx of the left long finger and two-throw, square knot to allow meticulous approximation of the the radial side of the distal phalanx of the left ring finger wound edges. Once exact approximation of the wound edges is does not allow constant tension to be maintained on this accomplished, the surgeon will construct a knot with a sufficient suture end. For the left long and ring fingers to withdraw number of throws and 3mm cut ears so that knot security is (arrow) the entire suture end through the loop, the tips of determined by knot breakage, rather than by slippage.3 the left thumb and index finger must release the suture.  --------------------------------------- 84 X. instrument-tie technique — square knot (1=1) formation of the first throw (cont’d) Step 1. Position the Needle Holder The instrument tie is performed with a needle holder held in the surgeons right hand. The left hand holds the fixed suture end between the tips of the thumb and index finger. The needle holder is positioned perpendicular to and above the fixed suture end. By keeping the length of the free suture end relatively short (<2 cm), it is easy to form (arrow) suture loops as well as to save suture material. Because the needle holder passes the free suture end through the suture loop, knot construction can be safely accomplished without detaching the needle from the fixed suture end. 0 --------------------------------------- 85 Step 2. Form the First Suture Loop The fixed suture end held by the left hand is wrapped over and around the needle holder jaws to form the first suture loop. (If the suture is wrapped twice around the needle holder jaws, the first, double-wrap throw of the surgeons knot square will be formed. A double-wrap, first throw displays a greater resistance to slippage than a single- wrap throw, accounting for its frequent use in instrument ties in wounds subjected to strong, static skin tensions). 1 --------------------------------------- 86 X. instrument-tie technique — square knot (1=1) formation of the first throw (cont’d) Step 3. Clamp Free Suture End And Withdraw it Through the Suture Loop to Form the First, Single-Wrap Throw The tips of the needle holder jaws grasp the suture end and withdraw (arrow) it through the first suture loop. The resulting first throw will have a figure 8 shape.  --------------------------------------- 87 Step 4. Advance the First Single-Wrap Throw to Wound Surface The figure 8 shape throw will be converted into a rectangular-shaped throw by reversing the direction of the hand movement. The left hand moves away from the surgeon, while the needle holder held in the right hand advances toward the surgeon. This single- wrap throw is advanced to the wound surface by applying tension in a direction (arrows) that is perpendicular to that of the wound. Once the first throw of the square knot contacts the skin, the edges of the mid-portion of the wound are approximated. 3 --------------------------------------- 88 X. instrument-tie technique — square knot (1=1) formation of the second throw Step 5. Position the Needle Holder The needle holder releases the free suture end. The right hand holding the needle holder moves away from the surgeon to be positioned perpendicular to and above the fixed suture end. A second throw will be formed by the left hand as it wraps the fixed suture end over and around (arrow) the needle holder jaws. If the surgeon were to place the needle holder beneath the fixed suture end, the ultimate knot construction would be a granny knot (1x1).  --------------------------------------- 89 Step 6. Form the Second Suture Loop The fixed suture end held by the left hand is wrapped over and around the needle holder to form the second suture loop. With the suture wrapped around the needle holder jaws, the needle holder is moved to grasp the free suture end, after which it is withdrawn through the suture loop.  --------------------------------------- 90 X. instrument-tie technique — square knot (1=1) formation of the second throw (cont’d) Step 7. Clamp Suture End and Withdraw it Through the Suture Loop to Form the Second, Single-Wrap Throw The tips of the needle holder jaws grasp the free suture end and withdraw (arrow) it through the second suture loop. By withdrawing the free suture end through the loop, a rectangular-shaped second throw is formed. The surgeon will apply tension to the suture ends in a direction perpendicular to that of the wound.  --------------------------------------- 91 Step 8. Advance Square Knot (1=1) to Wound Surface The second throw is advanced and set against the first throw by applying tension to the suture ends in a direction (arrows) perpendicular to that of the wound. Advancement of the second throw is complete when the second throw contacts the first throw and forms a square knot. Ideally, the surgeon should be able to advance the two-throw, square knot (1=1) to allow meticulous approximation of the wound edges. Once exact approximation of the wound edges is accomplished, the surgeon will construct a knot using this instrument technique, with a sufficient number of throws and 3mm cut ears so that knot security is determined by knot 3 breakage, rather than by slippage.  --------------------------------------- 92 XI. selection of suture and needle products On the basis of the largest multicentric evaluation of suture and needle products reported, suture and needle products made by Covidien (formerly Tyco Healthcare Group LP, Norwalk, CT) received an extremely high acceptability 33 rating by the surgeons. In this multicentric evaluation of suture and needle products conducted by Consorta, Inc. (Rolling Meadows, IL), 42 shareholder hospitals enrolled 1913 surgeons to participate in this nonexperimental observational study of the clinical performance of 25,545 suture and needle products. Performance characteristics of the suture and needle products produced by Covidien were judged by clinically acceptable and nonacceptable ratings. Of these suture and needle products, the surgeons found that 98.1% had clinical acceptable ratings for the 25,545 suture and needle products evaluated. While the study coordinated by Consortia Inc. provides important guidelines for judging the clinical acceptability of suture and needle products in a hospital setting, this rigorous suture and needle performance evaluation confirms the high level of performance of the suture and needle products made by Covidien.  --------------------------------------- 1 BASIC KNOTS ............................................................................................................................................. 2 KNOT SECURITY .......................................................................................................................................... 3 GENERAL PRINCIPLES OF KNOT TYING........................................................................................................ 5 SQUARE KNOT........................................................................................................................................... 7 SQUARE KNOT PICTURES............................................................................................................................. 7 TWO HAND TECHNIQUE............................................................................................................................... 8 Square Knot Two-Hand Technique Page 1 of 3....................................................................................8 Square Knot Two-Hand Technique Page 2 of 3..................................................................................10 Square Knot Two-Hand Technique Page 3 of 3..................................................................................11 ONE-HANDED TECHNIQUE ........................................................................................................................ 12 Square Knot One-Hand Technique Page 1 of 2..................................................................................12 SURGEON’S OR FRICTION KNOT....................................................................................................... 14 SURGEON'S OR FRICTION KNOT PAGE 1 OF 3 ............................................................................................ 14 SURGEON'S OR FRICTION KNOT PAGE 2 OF 3 ............................................................................................ 16 SURGEON'S OR FRICTION KNOT PAGE 3 OF 3 ............................................................................................ 17 DEEP TIE.................................................................................................................................................... 19 DEEP TIE PAGE 1 OF 2 ...............................................................................................................................19 DEEP TIE PAGE 2 OF 2 ...............................................................................................................................21 LIGATION AROUND HEMOSTATIC CLAMP.................................................................................... 22 LIGATION AROUND MEMOSTATIC CLAMP -MORE COMMON OF TWO METHODS....................................... 22 LIGATION AROUND HEMOSTATIC CLAMP -ALTERNATE TECHNIQUE......................................................... 24 INSTRUMENT TIE ................................................................................................................................... 26 INSTRUMENT TIE PAGE 1 OF 2 ................................................................................................................... 26 INSTRUMENT TIE PAGE 2 OF 2 ................................................................................................................... 28 GRANNY KNOT ........................................................................................................................................ 29 SUTURE MATERIALS............................................................................................................................. 30 PRINCIPLES OF SUTURE SELECTION .............................................................................................. 32 PRINCIPLES OF SUTURE SELECTION .............................................................................................. 32 ABSORBABLE SUTURES........................................................................................................................ 34 ABSORBABLE SUTURES PAGE 1................................................................................................................. 34 ABSORBABLE SUTURES PAGE 2................................................................................................................. 36 NONABSORBABLE SUTURES............................................................................................................... 40 NONABSORBABLE SUTURES PAGE 1 .......................................................................................................... 40 NONABSORBABLE SUTURES PAGE 2 .......................................................................................................... 42 TRADEMARKS.......................................................................................................................................... 45 SURGICAL NEEDLES.............................................................................................................................. 46 PRACTICE BOARD .................................................................................................................................. 48 SELECTED TERMS.................................................................................................................................. 49 --------------------------------------- 2 Basic Knots The knots demonstrated on the following pages are those most frequently used, and are applicable to all types of operative procedures. The camera was placed behind the demonstrator so that each step of the knot is shown as seen by the operator. For clarity, one-half of the strand is purple and the other white. The purple working strand is initially held in the right hand. The left-handed person may choose to study the photographs in a mirror. 1. Simple knot: incomplete basic unit 2. Square knot: completed knot 3. Surgeon's or Friction knot: completed tension knot --------------------------------------- 3 Knot Security The knots demonstrated on the following pages are those most frequently used, and are applicable to all types of operative procedures. The camera was placed behind the demonstrator so that each step of the knot is shown as seen by the operator. For clarity, one-half of the strand is purple and the other white. The purple working strand is initially held in the right hand. The left-handed person may choose to study the photographs in a mirror. 1. Simple knot: incomplete basic unit 2. Square knot: completed knot 3. Surgeon's or Friction knot: completed tension knot Knot Security The construction of ETHICON* sutures has been carefully designed to produce the optimum combination of strength, uniformity, and hand for each material. The term hand is the most subtle of all suture quality aspects. It relates to the feel of the suture in the surgeon's hands, the smoothness with which it passes through tissue and ties down, the way in which knots can be set and snugged down, and most of all, to the firmness or body of the suture. Extensibility relates to the way in which the suture will stretch slightly during knot tying and then recover. The stretching characteristics provide the signal that alerts the surgeon to the precise moment when the suture knot is snug. Multifilament sutures are generally easier to handle and to tie than monofilament sutures, however, all the synthetic materials require a specific knotting technique. With multifilament sutures, the nature of the material and the braided or twisted construction provide a high coefficient of friction and the knots remain as they are laid down. In monofilament sutures, on the other hand, the coefficient of friction is relatively low, resulting in a greater tendency for the knot to loosen after it has been tied. In addition, monofilament synthetic polymeric materials possess the property of memory. Memory is the tendency not to lie flat, but to return to a given shape set by the material's extrusion process or the suture's packaging. The RELAY* suture delivery system delivers sutures with minimal package memory due to its unique package design. --------------------------------------- 4 Suture knots must be properly placed to be secure. Speed in tying knots may result in less than perfect placement of the strands. In addition to variables inherent in the suture materials, considerable variation can be found between knots tied by different surgeons and even between knots tied by the same individual on different occasions. --------------------------------------- 5 General Principles of Knot Tying Certain general principles govern the tying of all knots and apply to all suture materials. 1. The completed knot must be firm, and so tied that slipping is virtually impossible. The simplest knot for the material is the most desirable. 2. The knot must be as small as possible to prevent an excessive amount of tissue reaction when absorbable sutures are used, or to minimize foreign body reaction to nonabsorbable sutures. Ends should be cut as short as possible. 3. In tying any knot, friction between strands ("sawing") must be avoided as this can weaken the integrity of the suture. 4. Care should be taken to avoid damage to the suture material when handling. Avoid the crushing or crimping application of surgical instruments, such as needleholders and forceps, to the strand except when grasping the free end of the suture during an instrument tie. 5. Excessive tension applied by the surgeon will cause breaking of the suture and may cut tissue. Practice in avoiding excessive tension leads to successful use of finer gauge materials. 6. Sutures used for approximation should not be tied too tightly, because this may contribute to tissue strangulation. 7. After the first loop is tied, it is necessary to maintain traction on one end of the strand to avoid loosening of the throw if being tied under any tension. 8. Final tension on final throw should be as nearly horizontal as possible. 9. The surgeon should not hesitate to change stance or position in relation to the patient in order to place a knot securely and flat. 10. Extra ties do not add to the strength of a properly tied knot. They only contribute to its bulk. With some synthetic materials, knot security requires the standard surgical technique of flat and square ties with additional throws if indicated by surgical circumstance and the experience of the surgeon. An important part of good suturing technique is correct method in knot tying. A seesaw motion, or the sawing of one strand down over another until the knot is formed, may materially weaken sutures to the point that they may break when the second throw is made or, even worse, in the postoperative period when the suture is further weakened by increased tension or motion. --------------------------------------- 6 If the two ends of the suture are pulled in opposite directions with uniform rate and tension, the knot may be tied more securely. This point is well-illustrated in the knot tying techniques shown in the next section of this manual. --------------------------------------- 7 Square Knot Square Knot Pictures Two-Hand Technique One-Hand Technique --------------------------------------- 8 Two Hand Technique Square Knot Two-Hand Technique Page 1 of 3 The two-hand square knot is braided synthetic the easiest and most reliable absorbable suture, for tying most suture materials. MONOCRYL* It may be used to tie surgical (poliglecaprone 25) suture, gut, virgin silk, surgical cotton, Coated VICRYL* and surgical stainless steel. (polyglactin 910) suture, Standard technique of flat Coated VICRYL and square ties with RAPIDE* (polyglactin additional throws if 910) suture, PDS* II indicated by the surgical (polydioxanone) suture, circumstance and the ETHILON* nylon suture, experience of the ETHIBOND* EXCEL operator should be used polyester suture, PERMA- to tie PANACRYL* HAND* silk suture, PRONOVA* poly (hexafluoropropylene- VDF) suture, and PROLENE* polypropylene suture. 1 White strand placed over Purple strand held in right 2 extended index finger of hand brought between left hand acting as left thumb and index bridge, and held in palm finger. of left hand. Purple strand held in right hand. --------------------------------------- 9 3 4 Left hand turned Purple strand crossed inward by pronation, over white and held and thumb swung between thumb and under white strand to index finger of left form the first loop. hand. --------------------------------------- 10 Square Knot Two-Hand Technique Page 2 of 3 5 6 Right hand releases Purple strand purple strand. Then released by left hand left hand supinated, and grasped by right. with thumb and index Horizontal tension is finger still grasping applied with left hand purple strand, to toward and right bring purple strand hand away from through the white operator. This loop. Regrasp purple completes first half strand with right hitch. hand. 7 8 Left index finger Purple strand released from white brought toward the strand and left hand operator with the again supinated to right hand and loop white strand placed between left over left thumb. thumb and index Purple strand held in finger. Purple strand right hand is angled crosses over white slightly to the left. strand. --------------------------------------- 11 Square Knot Two-Hand Technique Page 3 of 3 9 10 By further supinating Left hand rotated left hand, white inward by pronation strand slides onto left with thumb carrying index finger to form purple strand through a loop as purple loop of white strand. strand is grasped Purple strand is between left index grasped between finger and thumb. right thumb and index finger. 11 12 Horizontal tension The final tension on applied with left hand the final throw away from and right should be as nearly hand toward the horizontal as operator. This possible. completes the second half hitch. --------------------------------------- 12 One-Handed Technique Square Knot One-Hand Technique Page 1 of 2 surgeon be holding a reel of Wherever possible, the square suture material in the right hand knot is tied using the two-hand and placing a series of ligatures. technique. On some occasions In either case, it cannot be too it will be necessary to use one strongly emphasized that the hand, either the left or the directions the hands travel must right, to tie a square knot. be reversed proceeding from one These illustrations employ the throw to the next to ensure that left-handed technique. the knot formed lands flat and square. Half hitches result if this The sequence of throws precaution is not taken. illustrated is most commonly used for tying single suture strands. The sequence may be reversed should the 1 2 White strand held Purple strand brought between thumb and over white strand on left index finger of left hand index finger by moving with loop over extended right hand away from index finger. Purple operator. strand held between thumb and index finger of right hand. --------------------------------------- 13 3 With purple strand The first half hitch is completed by supported in right hand, advancing tension in the horizontal plane the distal phalanx of with the left hand drawn toward and right left index finger passes hand away from the operator. under the white strand to place it over tip of left index finger. Then the white strand is pulled through loop in preparation for applying tension. --------------------------------------- 14 Surgeon’s or Friction Knot Surgeon's or Friction Knot Page 1 of 3 The surgeon's or friction knot PRONOVA* poly is recommended for tying (hexafluoropropylene- PANACRYL* braided VDF) suture, and synthetic absorbable suture, Coated VICRYL* (polyglactin PROLENE* 910) suture, ETHIBOND* polypropylene suture. EXCEL polyester suture, The surgeon's knot also may be ETHILON* nylon suture, performed using a one-hand MERSILENE* polyester technique in a manner analogous fiber suture, to that illustrated for the square NUROLON* nylon knot one-hand technique. suture, 1 2 White strand placed over Purple strand crossed extended index finger of over white strand by left hand and held in moving right hand away palm of left hand. Purple from operator at an strand held between angle to the left. Thumb thumb and index finger and index finger of left of right hand. hand pinched to form loop in the white strand over index finger. --------------------------------------- 15 3 Left hand turned Left hand rotated by supination extending inward by pronation, left index finger to pass purple strand and loop of white through loop. Regrasp purple strand with strand slipped onto left right hand. thumb. Purple strand grasped between thumb and index finger of left hand. Release right hand. --------------------------------------- 16 Surgeon's or Friction Knot Page 2 of 3 5 6 The loop is slid onto Purple strand drawn the thumb of the left left with right hand hand by pronating the and again grasped pinched thumb and between thumb and index finger of left index finger of left hand beneath the hand. loop. 7 8 Left hand rotated by Horizontal tension is supination extending applied with left hand left index finger to toward and right again pass purple hand away from the strand through operator. This double forming a double loop must be placed loop. in precise position for the final knot. --------------------------------------- 17 Surgeon's or Friction Knot Page 3 of 3 9 10 With thumb Purple strand swung under released. Left white strand, hand supinates to purple strand is regrasp purple grasped between strand with index thumb and index finger beneath the finger of left hand loop of the white and held over strand. white strand with right hand. 11 Purple strand Hands continue to apply rotated beneath the horizontal tension with left hand white strand by away from and right hand toward supinating pinched the operator. Final tension on final thumb and index throw should be as nearly finger of left hand horizontal as possible. to draw purple strand through the loop. Right hand regrasps purple strand to complete --------------------------------------- 18 the second throw square. --------------------------------------- 19 Deep Tie Deep Tie Page 1 of 2 Tying deep in a body However the operator must cavity can be difficult. avoid upward tension The square knot must be which may tear or avulse firmly snugged down as the tissue. in all situations. 1 2 Strand looped Purple strand held in around hook in right hand brought plastic cup on between left thumb Practice Board with and index finger. Left index finger of right hand turned inward hand which holds by pronation, and purple strand in palm thumb swung under of hand. White white strand to form strand held in left the first loop. hand. --------------------------------------- 20 3 4 By placing index Horizontal tension finger of left hand applied by pushing on white strand, down on white advance the loop strand with left into the cavity. index finger while maintaining counter-tension with index finger of right hand on purple strand. --------------------------------------- 21 Deep Tie Page 2 of 2 5 6 Purple strand Purple strand looped over and looped around under white white strand to strand with right form second loop. hand. This throw is advanced into the depths of the cavity. 7 Horizontal tension applied by pushing down on purple strand with right index finger while maintaining counter- tension on white strand with left index finger. Final tension should be as nearly horizontal as possible. --------------------------------------- 22 Ligation Around Hemostatic Clamp Ligation Around Memostatic Clamp -More Common of Two Methods Frequently it is necessary to ligate a blood vessel or tissue grasped in a hemostatic clamp to achieve hemostasis in the operative field. 1 2 When sufficient Left hand grasps free tissue has been end of the strand and cleared away to gently advances it permit easy passage behind clamp until of the suture ligature, both ends are of the white strand held equal length. in the right hand is passed behind the clamp. 3 As the first throw 4 To prepare for of the knot is placing the knot completed the thhit --------------------------------------- 23 square, the white assistant removes strand is the clamp. This transferred to the maneuver permits right hand and the any tissue that purple strand to may have been the left hand, thus bunched in the crossing the white clamp to be strand over the securely crushed purple. by the first throw. The second throw of the square knot is then completed with either a two- hand or one-hand technique as previously illustrated. --------------------------------------- 24 Ligation Around Hemostatic Clamp -Alternate Technique Some surgeons prefer this technique because the operator never loses contact with the suture ligature as in the preceding technique. 1 2 Center of the strand Purple strand swung placed in front of the behind clamp and tip of hemostatic grasped with index clamp with purple finger of left hand. strand held in right Purple strand will be hand and white strand transferred to left in left hand. hand and released by right. 3 4 Purple strand First throw is crossed under completed in white strand with usual manner. left index finger Tension is placed and regraspedon both strands --------------------------------------- 25 with right hand. below the tip of the clamp as the first throw of the knot is tied. The assistant then removes the clamp. The square knot is completed with either a two- hand or one-hand technique as previously illustrated. --------------------------------------- 26 Instrument Tie Instrument Tie Page 1 of 2 The instrument tie is absorbable suture or any useful when one or both monofilament suture, as ends of the suture repeated bending may material are short. For cause these sutures to best results, exercise break. caution when using a needleholder with PANACRYL* braided synthetic 1 2 Short purple strand lies Needleholder in right freely. Long white end hand grasps short of strand held between purple end of strand. thumb and index finger of left hand. Loop formed by placing needleholder on side of strand away from the operator. --------------------------------------- 27 3 4 First half hitch White strand is completed by drawn toward pulling operator with left needleholder hand and looped toward operator around with right hand and needleholder held drawing white in right hand. Loop strand away from is formed by operator. placing Needleholder is needleholder on released from side of strand purple strand. toward the operator. --------------------------------------- 28 Instrument Tie Page 2 of 2 5 6 With end of the Square knot strand grasped by completed by the needleholder, horizontal tension purple strand is applied with left drawn through loop hand holding white in the white strand strand toward away from the operator and operator. purple strand in needleholder away from operator. Final tension should be as nearly horizontal as possible. --------------------------------------- 29 Granny Knot A granny knot is not only to warn against its recommended. However, use. It has the tendency to it may be inadvertently slip when subjected to tied by incorrectly increasing pressure. crossing the strands of a square knot. It is shown --------------------------------------- 30 Suture Materials The requirement for wound support varies in different tissues from a few days for muscle, subcutaneous tissue, and skin; weeks or months for fascia and tendon; to long-term stability, as for a vascular prosthesis. The surgeon must be aware of these differences in the healing rates of various tissues and organs. In addition, factors present in the individual patient, such as infection, debility, respiratory problems, obesity, etc., can influence the postoperative course and the rate of healing. Suture selection should be based on the knowledge of the physical and biologic characteristics of the material in relationship to the healing process. The surgeon wants to ensure that a suture will retain its strength until the tissue regains enough strength to keep the wound edges together on its own. In some tissue that might never regain preoperative strength, the surgeon will want suture material that retains strength for a long time. If a suture is going to be placed in tissue that heals rapidly, the surgeon may prefer to select a suture that will lose its tensile strength at about the same rate as the tissue gains strength and that will be absorbed by the tissue so that no foreign material remains in the wound once the tissue has healed. With all sutures, acceptable surgical practice must be followed with respect to drainage and closure of infected wounds. The amount of tissue reaction caused by the suture encourages or retards the healing process. When all these factors are taken into account, the surgeon has several choices of suture materials available. Selection can then be made on the basis of familiarity with the material, its ease of handling, and other subjective preferences. Sutures can conveniently be divided into two broad groups: absorbable and nonabsorbable. Regardless of its composition, suture material is a foreign body to the human tissues in which it is implanted and to a greater or lesser degree will elicit a foreign body reaction. Two major mechanisms of absorption result in the degradation of absorbable sutures. Sutures of biological origin such as surgical gut are gradually digested by tissue enzymes. Sutures manufactured from synthetic polymers are principally broken down by hydrolysis in tissue fluids. Nonabsorbable sutures made from a variety of nonbio-degradable materials are ultimately encapsulated or walled off by the body?s fibroblasts. Nonabsorbable sutures ordinarily remain where they --------------------------------------- 31 are buried within the tissues. When used for skin closure, they must be removed postoperatively. A further subdivision of suture materials is useful: monofilament and multifilament. A monofilament suture is made of a single strand. It resists harboring microorganisms, and it ties down smoothly. A multifilament suture consists of several filaments twisted or braided together. This gives good handling and tying qualities. However, variability in knot strength among multifilament sutures might arise from the technical aspects of the braiding or twisting process. The sizes and tensile strengths for all suture materials are standardized by U.S.P. regulations. Size denotes the diameter of the material. Stated numerically, the more zeroes (0's) in the number, the smaller the size of the strand. As the number of 0's decreases, the size of the strand increases. The 0's are designated as 5-0, for example, meaning 00000 which is smaller than a size 4- 0. The smaller the size, the less tensile strength the strand will have. Tensile strength of a suture is the measured pounds of tension that the strand will withstand before it breaks when knotted. (Refer to Absorbable Sutures & Nonabsorbable Sutures section) --------------------------------------- 32 Principles of Suture Selection The surgeon has a choice of suture materials from which to select for use in body tissues. Adequate strength of the suture material will prevent suture breakage. Secure knots will prevent knot slippage. But the surgeon must understand the nature of the suture material, the biologic forces in the healing wound, and the interaction of the suture and the tissues. The following principles should guide the surgeon in suture selection. 1. When a wound has reached maximal strength, sutures are no longer needed. Therefore: a. Tissues that ordinarily heal slowly such as skin, fascia, and tendons should usually be closed with nonabsorbable sutures. An absorbable suture with extended (up to 6 months) wound support may also be used. b. Tissues that heal rapidly such as stomach,colon, and bladder may be closed with absorbable sutures. 2. Foreign bodies in potentially contaminated tissues may convert contamination to infection. Therefore: a. Avoid multifilament sutures which may convert a contaminated wound into an infected one. b. Use monofilament or absorbable sutures in potentially contaminated tissues. 3. Where cosmetic results are important, close and prolonged apposition of wounds and avoidance of irritants will produce the best result. Therefore: a. Use the smallest inert monofilament suture materials such as nylon or polypropylene. b. Avoid skin sutures and close subcuticularly, whenever possible. c. Under certain circumstances, to secure close apposition of skin edges, a topical skin adhesive or skin closure tape may be used. 4. Foreign bodies in the presence of fluids containing high concentrations of crystalloids may act as a nidus for precipitation and stone formation. Therefore: a. In the urinary and biliary tract, use rapidly absorbed --------------------------------------- 33 sutures. 5. Regarding suture size: a. Use the finest size, commensurate with the natural strength of the tissue. b. If the postoperative course of the patient may produce sudden strains on the suture line, reinforce it with retention sutures. Remove them as soon as the patient?s condition is stabilized. Metric Measures and U.S.P Suture Diameter Equivalents 11-10-9-8-7-6-5-4-3-2- U.S.P. Size 0 1 2 3 4 5 6 0 0 0 0 0 0 0 0 0 0 Natural - 0.2 0.3 0.5 0.7 1.0 1.5 2.0 3.0 3.5 4.0 5.0 6.0 7.0 8.0 - - Collagen Synthetic - 0.2 0.3 0.4 0.5 0.7 1.0 1.5 2.0 3.0 3.5 4.0 5.0 6.0 6.0 7.0 - Absorbables Nonabsorbable 0.1 0.2 0.3 0.4 0.5 0.7 1.0 1.5 2.0 3.0 3.5 4.0 5.0 6.0 6.0 7.0 8.0 Materials --------------------------------------- 34 Absorbable Sutures Absorbable Sutures Page 1 The United States Pharmacopeia (U.S.P.) defines an absorbable surgical suture as a "sterile strand prepared from collagen derived from healthy mammals or a synthetic polymer. It is capable of being absorbed by living mammalian tissue, but may be treated to modify its resistance to absorption. It may be impregnated or coated with a suitable antimicrobial agent. It may be colored by a color additive approved by the Federal Food and Drug Administration (F.D.A.)." The United States Pharmacopeia, Twentieth Revision, Official from July 1, 1980. Absorbable Suture Materials Most Commonly Used TENSILE COLOR OF STRENGTH ABSORPTION SUTURE TYPES RAW MATERIAL MATERIALRETENTION RATE in vivo Surgical Gut Plain Collagen derived from Individual Absorbed by Yellowish- Suture healthy beef and patient proteolytic tan sheep. characteristics enzymatic Blue Dyed can affect rate digestive of tensile process. strength loss. Surgical Gut Chromic Collagen derived from Individual Absorbed by Brown Suture healthy beef and patient proteolytic Blue Dyed sheep. characteristics enzymatic can digestive affect rate of process. tensile strength loss. Coated Copolymer of lactide Approximately Essentially Braided Violet VICRYL and glycolide coated 75% remains complete (polyglactin Monofilament Undyed with polyglactin 370 at two weeks. between 56-70 910) Suture (Natural) and calcium stearate. Approximately days. 50% remains Absorbed by at three weeks. hydrolysis. Coated Braided Undyed Copolymer of lactide Approximately Essentially --------------------------------------- 35 VICRYL (Natural) and glycolide coated 50% remains complete by 42 RAPIDE with polyglactin 370 at 5 days. All days. Absorbed (polyglactin and calcium stearate. tensile by hydrolysis. 910) strength is lost Suture at approximately 14 days. MONOCRYL Monofilament Copolymer of Approximately Complete at Undyed (poliglecaprone glycolide and epsilon-50-60% 91-119 days. (Natural) 25) Suture caprolactone. (violet: 60-Absorbed by Violet 70%) remains hydrolysis. at one week. Approximately 20-30% (violet: 30- 40%) remains at two weeks. Lost within three weeks (violet: four weeks). PDS II Monofilament Polyester polymer. Approximately Minimal until Violet (polydioxanone) 70% remains about 90th day. Suture Blue at two weeks. Essentially Approximately complete Clear 50% remains within six at four weeks. months. Approximately Absorbed by 25% remains slow at six weeks. hydrolysis. PANACRYL Braided Copolymer of lactide Approximately Undyed Essentially Braided and glycolide coated 80% remains (White) complete Synthetic with at 3 months. between 18 and Absorbable caprolactone/glycolide.Approximately 30 months. Suture 60% remains Absorbed by at 6 months. slow Approximately hydrolysis. 20% remains at 12 months. Trademarks of ETHICON, INC. are capitalized. --------------------------------------- 36 Absorbable Sutures Page 2 The United States Pharmacopeia (U.S.P.) defines an absorbable surgical suture as a "sterile strand prepared from collagen derived from healthy mammals or a synthetic polymer. It is capable of being absorbed by living mammalian tissue, but may be treated to modify its resistance to absorption. It may be impregnated or coated with a suitable antimicrobial agent. It may be colored by a color additive approved by the Federal Food and Drug Administration (F.D.A.)." The United States Pharmacopeia, Twentieth Revision, Official from July 1, 1980. COLOR FREQUENT HOW SUTURE CONTRAINDICATIONS CODE OF USES SUPPLIED PACKETS Moderate Being absorbable, should Yellow General soft 7-0 thru 3 reaction not be used where tissue with and extended approximation approximation without of tissues under stress is and/or needles, required. Should not be ligation, and on used in patients with including use LIGAPAK known sensitivities or in ophthalmic dispensing allergies to collagen or procedures. reels chromium. Not for use in cardiovascular 0 thru 1 with and CONTROL neurological RELEASE tissues. needles Moderate Being absorbable, should General soft 7-0 thru 3 Beige reaction not be used where tissue with and extended approximation approximation without of tissues under stress is and/or needles, required. Should not be ligation, and on used in patients with including use LIGAPAK known sensitivities or in ophthalmic dispensing allergies to collagen or procedures. reels chromium. Not 0 thru 1 for use in --------------------------------------- 37 cardiovascular with and CONTROL neurological RELEASE tissues. needles Minimal acute Being absorbable, should General soft 8-0 thru 3 Violet inflammatory not be used where tissue with and reaction extended approximation approximation without of tissue is required. and/or needles, ligation, and on including use LIGAPAK in ophthalmic dispensing procedures. reels Not for use in 4-0 thru 2 cardiovascular with and CONTROL neurological RELEASE tissues. needles 8-0 with attached beads for ophthalmic use Minimal to Should not be used where Superficial .5-0 thru 1 Violet and moderate extended approximation soft tissue with Red acute of tissue under stress is approximation needles. inflammatory required or where wound of skin and reaction support beyond 7 days is mucosa only. required.Superficial soft Not for use in tissue approximation of ligation, skin and mucosa only. ophthalmic, Not for use in ligation, cardiovascular ophthalmic, or neurological cardiovascular or procedures. neurological procedures. 5-0 thru 1 with needles. Minimal Being absorbable, should General soft 6-0 thru 2 Coral acute not be used where tissue with and inflammatory extended approximation approximation without of tissue under and/or needles stress is required. Undyed ligation. Not not indicated for use in for use in 3-0 thru 1 fascia. cardiovascular with CONTROL --------------------------------------- 38 or neurological CONTROL tissues, RELEASE microsurgery, needles. or ophthalmic surgery. Slight Being absorbable, should All types of 9-0 thru 2 Silver reaction not be used where prolonged approximation soft tissue with approximation, needles of tissues under stress is including required. Should not be pediatric 4-0 thru 1 used with prosthetic with devices, such as heart cardiovascular CONTROL and valves or synthetic grafts.ophthalmic RELEASE needles procedures. Not for use in 9-0 thru 7- adult cardiovascular 0 with needles tissue, microsurgery, 7-0 thru 1 and neural with tissue. needles Minimal Being absorbable, should General soft 2-0 through Purple acute not be used where tissue 2 with inflammatory extended approximation approximation needles reaction of tissue and/or beyond six months is ligation, and 2-0 through required. 1 with orthopaedic CONTROL uses including tendon and RELEASE ligament needles repairs and reattachment to bone. Particularly useful where extended wound support (up to 6 months) is desirable. Not for use in ophthalmic, cardiovascular, --------------------------------------- 39 or neurological tissue. --------------------------------------- 40 Nonabsorbable Sutures Nonabsorbable Sutures Page 1 By U.S.P. definition, "nonabsorbable sutures are strands of material that are suitably resistant to the action of living mammalian tissue. A suture may be composed of a single or multiple filaments of metal or organic fibers rendered into a strand by spinning, twisting, or braiding. Each strand is substantially uniform in diameter throughout its length within U.S.P. limitations for each size. The material may be uncolored, naturally colored, or dyed with an F.D.A. approved dyestuff. It may be coated or uncoated; treated or untreated for capillarity." Nonabsorbable Suture Materials Most Commonly Used TENSILE COLOR OF STRENGTH ABSORPTION SUTURE TYPES RAW MATERIAL MATERIALRETENTION RATE in vivo PERMA-HAND Silk Braided Organic protein Violet Progressive Gradual Suture called fibroin. degradation encapsulation White of fiber may by fibrous result in connective gradual loss tissue. of tensile strength over time. Surgical Stainless Monofilament Silver 316L stainless steel. Indefinite. Nonabsorbable. Steel Suture metallic Multifilament ETHILON Nylon Monofilament Violet Long-chain aliphatic Progressive Gradual Suture polymers hydrolysis encapsulation Green Nylon 6 or Nylon 6,6.may result in by fibrous gradual loss connective Undyed of tensile tissue. (Clear) strength over time. --------------------------------------- 41 NUROLON Nylon Braided Violet Long-chain aliphatic Progressive Gradual Suture polymers hydrolysis encapsulation Green Nylon 6 or Nylon 6,6.may result in by fibrous gradual loss connective Undyed of tensile tissue. (Clear) strength over time. MERSILENE Braided Green Poly (ethylene No Gradual Polyester Fiber Suture terephthalate). significant encapsulation Monofilament Undyed change by fibrous (White) known to connective occur in vivo. tissue. ETHIBOND EXCEL Braided Green Poly (ethylene No Gradual Polyester Fiber Suture terephthalate) coated significant encapsulation Undyed with polybutilate. change by fibrous (White) knownto connective occur in vivo. tissue. PROLENE Monofilament Clear Isotactic crystalline Not subject to Nonabsorbable. Polypropylene Suture stereoisomer of degradation Blue polypropylene. or weakening by action of tissue enzymes. PRONOVA* Poly Monofilament Blue Polymer blend of Not subject to Nonabsorbable. (hexafluoropropylene-poly (vinylidene degradation VDF) Suture fluoride) and poly or weakening (vinylidene fluoride-by action of co- tissue hexafluoropropylene).enzymes. Trademarks of ETHICON, INC. are capitalized --------------------------------------- 42 Nonabsorbable Sutures Page 2 By U.S.P. definition, "nonabsorbable sutures are strands of material that are suitably resistant to the action of living mammalian tissue. A suture may be composed of a single or multiple filaments of metal or organic fibers rendered into a strand by spinning, twisting, or braiding. Each strand is substantially uniform in diameter throughout its length within U.S.P. limitations for each size. The material may be uncolored, naturally colored, or dyed with an F.D.A. approved dyestuff. It may be coated or uncoated; treated or untreated for capillarity." COLOR TISSUE FREQUENT HOW CONTRAINDICATIONSCODE OF REACTION USES SUPPLIED PACKETS Acute Should not be used in Light Blue General soft 9-0 thru 5 inflammatory patients with known tissue with and reaction sensitivities or allergies to approximation without silk and/or needles, and ligation, on LIGAPAK including dispensing cardiovascular, reels opthalmic and neaurological 4-0 thru 1 procedures. with CONTROL RELEASE needles Minimal Should not be used in Abdominal 10-0 thru 7 Yellow- acute patients with known wound with and Ochre inflammatory without sensitivities or allergies to closure, hernia reaction needles 316L stainless steel, or repair, sternal constituent metals such as closure and chromium and nickel. orthopaedic procedures including cerclage and tendon repair. --------------------------------------- 43 Minimal Should not be used where General soft 11-0 thru 2 Mint acute with and inflammatory permanent retention of tissue without Green reaction tensile strength is approximation needles required. and/or ligation, including use in cardiovascular, ophthalmic and neurological procedures. Minimal Should not be used where General soft 6-0 thru 1 Mint acute permanent retention of tissue with and Green inflammatory tensile strength is approximation without reaction required. and/or needles ligation, 4-0 thru 1 including use with in CONTROL cardiovascular, RELEASE ophthalmic and needles neurological procedures. Minimal None known. General soft 6-0 thru 5 Turquoise acute tissue with and inflammatory approximation without reaction and/or needles ligation, including use 10-0 and 11-0 in for opthalmic cardiovascular, (green monofilament) ophthalmic and 0 with neurological CONTROL procedures. RELEASE needles Minimal None known. General soft 7-0 thru 5 Orange acute tissue with and inflammatory approximation without reaction and/or needles ligation, 4-0 thru 1 including use --------------------------------------- 44 including use with in CONTROL cardiovascular, RELEASE ophthalmic needles and neurological various sizes procedures. attached to TFE polymer pledgets Minimal None known. General soft 6-0 thru 2 Deep Blue acute tissue (clear) with inflammatory reaction approximation and without and/or needles ligation, 10-0 thru 8-0 including use and 6-0 thru 2 in cardiovascular, (blue) with ophthalmic and without and needles neurological procedures. 0 thru 2 wuth CONTROL RELEASE needles various sizes attached to TFE polymer pledgets Minimal None known. General soft 6-0 through 5-Royal acute tissue 0 with Blue inflammatory approximation TAPERCUT* reaction and/or surgical ligation, needle including use in 8-0 through 5- cardiovascular, 0 with taper point needle. ophthalmic and neurological procedures. --------------------------------------- 45 Trademarks The following are trademarks of ETHICON, INC.: ATRALOC surgical needle Coated VICRYL (polyglactin 910) suture Coated VICRYL RAPIDE (polyglactin 910) suture CONTROL RELEASE needle/needle suture CS ULTIMA ophthalmic needle ETHALLOY needle alloy ETHIBOND EXCEL polyester suture capitalized ETHICON sutures or products ETHILON nylon suture LIGAPAK dispensing reel MERSILENE polyester fiber suture MICRO-POINT surgical needle MONOCRYL (poliglecaprone 25) suture NUROLON nylon suture PANACRYL braided synthetic absorbable suture P PRIME needle PC PRIME needle PS PRIME needle PDS II (polydioxanone) suture PERMA-HAND silk suture PROLENE polypropylene suture PRONOVA poly (hexafluoropropylene-VDF) suture RELAY suture delivery system SABRELOC spatula needle TAPERCUT surgical needle VICRYL (polyglactin 910) suture VISI-BLACK surgical needle --------------------------------------- 46 Surgical Needles Necessary for the placement of sutures in tissue, surgical needles must be designed to carry suture material through tissue with minimal trauma. They must be sharp enough to penetrate tissue with minimal resistance. They should be rigid enough to resist bending, yet flexible enough to bend before breaking. They must be sterile and corrosion-resistant to prevent introduction of microorganisms or foreign bodies into the wound. To meet these requirements, the best surgical needles are made of high quality stainless steel, a noncorrosive material. Surgical needles made of carbon steel may corrode, leaving pits that can harbor microorganisms. All ETHICON* stainless steel needles are heat-treated to give them the maximum possible strength and ductility to perform satisfactorily in the body tissues for which they are designed. ETHALLOY* needle alloy, a noncorrosive material, was developed for unsurpassed strength and ductility in precision needles used in cardiovascular, ophthalmic, plastic, and microsurgical procedures. Ductility is the ability of the needle to bend to a given angle under a given amount of pressure, called load, without breaking. If too great a force is applied to a needle it may break, but a ductile needle will bend before breaking. If a surgeon feels a needle bending, this is a signal that excessive force is being applied. The strength of a needle is determined in the laboratory by bending the needle 900; the required force is a measurement of the strength of the needle. If a needle is weak, it will bend too easily and can compromise the surgeon?s control and damage surrounding tissue during the procedure. Regardless of ultimate intended use, all surgical needles have three basic components: the attachment end, the body, and the point. The majority of sutures used today have appropriate needles attached by the manufacturer. Swaged sutures join the needle and suture together as a continuous unit that is convenient to use and minimizes tissue trauma. ATRALOC* surgical needles, which are permanently swaged to the suture strand, are supplied in a variety of sizes, shapes, and strengths. Some incorporate the CONTROL RELEASE* needle suture principle which facilitates fast separation of the needle from the suture when desired by the surgeon. Even though the suture is securely fastened to the needle, a slight, straight tug on the needleholder will release it. This feature allows rapid placement of many sutures, as in interrupted suture techniques. --------------------------------------- 47 The body, or shaft, of a needle is the portion which is grasped by the needleholder during the surgical procedure. The body should be as close as possible to the diameter of the suture material. The curvature of the body may be straight, half-curved, curved, or compound curved. The cross-sectional configuration of the body may be round, oval, side-flattened rectangular, triangular, or trapezoidal. The oval, side-flattened rectangular, and triangular shapes may be fabricated with longitudinal ribs on the inside or outside surfaces. This feature provides greater stability of the needle in the needleholder. The point extends from the extreme tip of the needle to the maximum cross-section of the body. The basic needle points are cutting, tapered, or blunt. Each needle point is designed and produced to the required degree of sharpness to smoothly penetrate the types of tissue to be sutured. Surgical needles vary in size and wire gauge. The diameter is the gauge or thickness of the needle wire. This varies from 30 microns (.001 inch) to 56 mil (.045 inch, 1.4 mm). Very small needles of fine gauge wire are needed for micro-surgery. Large, heavy gauge needles are used to penetrate the sternum and to place retention sutures in the abdominal wall. A broad spectrum of sizes are available between these two extremes. Of the many types available, the specific needle selected for use is determined by the type of tissue to be sutured, the location and accessibility, size of the suture material, and the surgeon's preference. --------------------------------------- 48 Practice Board Practice Board* The KNOT TYING MANUAL and practice board are available from ETHICON, INC., without charge for all learners of suturing and knot tying techniques. *Contributing Designer-Bashir Zikria, MD, FACS --------------------------------------- 49 Selected Terms Measures how quickly a suture is absorbed, or broken down by the body. Refers only to the Absorption Rate presence or absence of suture material and not to the amount of strength remaining in the suture. Measures tensile strength (see below) retained Breaking by a suture in vivo over time. For example, a Strength suture with an initial tensile strength of 20 lbs. Retention (BSR) and 50% of its BSR at 1 week has 10 lbs. of tensile strength in vivo at 1 week. The characteristic of suture stretch during knot tying and recovery thereafter. Familiarity with a Extensibility suture's extensibility will help the surgeon know when the suture knot is snug. Refers to a suture's tendency to retain kinks or Memory bends (set by the material's extrusion process or packaging) instead of lying flat. Describes a suture made of a single strand or Monofilament filament. Describes a suture made of several braided or Multifilament twisted strands or filaments. The measured pounds of tension that a knotted Tensile Strength suture strand can withstand before breaking. An organization that promotes the public health by establishing and disseminating officially United States recognized standards of quality and Pharmacopeia authoritative information for the use of (U.S.P.) medicines and other health care technologies by health professionals, patients, and consumers. http://www.bumc.bu.edu/generalsurgery/technical-training/basic-knot-tying-suturing/ med.brown.edu/surgery/download/current/KnotTyingManual.pdf www.bumc.bu.edu/generalsurgery/.../basic-knot-tying-suturing/ www.cs.jhu.edu/~rajesh/images/8/83/Knot-tying.pdf