Surgical Knot Tying Manual Third Edition
Surgical Knot Tying Manual Third Edition Richard F. Edlich, M.D., Ph.D. Distinguished Professor of Plastic Surgery, Biomedical Engineering and Emergency Medicine Founder of DeCamp Burn and Wound Healing Center University of Virginia Health System Director of Trauma Prevention, Education and Research Trauma Specialists, LLP, Legacy Emanuel Hospital Portland, Oregon William B. Long III, M.D.
forward If this manual heightens only perceptibly students, nurses, nurse practitioners, physician assistants, surgical residents and surgeon’s interest in the biology of wound closure and infection, the long years occupied in my search for improved methods of wound management would more than fulfill my expectations. However, another important purpose of this manual is to honor my colleagues, who collaborated in our clinical and experimental research investigations.
table of contents I. Individualized Self-Instruction 1 II. Introduction 2 III. Scientific Basis for Selection of Sutures 1. Nonabsorbable Suture 2. Absorbable Suture 4 5 12 IV. Components of a Knotted Suture Loop using either a Granny Knot Type or a Square Knot Type 22 V. Mechanical Performance 1. Knot Slippage 2. Knot Breakage 3. Suture Cutting Tissue 4. Mechanical Trauma 28 30 31 32 33 VI. Tying Techniques 1. Instrument Tie 2. Hand Tie 34 37 39 VII. Essential Elements 42 VIII.
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.
II. introduction Through the ages, the tying of knots has played an important role in the life of man.1 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, man’s 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.
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 correctly used the appropriate knot construction.
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.
60 days are nonabsorbable sutures. This terminology is somewhat misleading because even some nonabsorbable sutures (i.e., silk, cotton and nylon) lose some tensile strength during this 60-day interval. Postlethwait7 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.
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.
(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.
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.
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 return to its original length once the load is removed. In a study by Trimbos et al.
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 the skin. In 1997, Pinheiro et al.
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.
III. scientific basis for the selection of surgical sutures (cont’d) slightly, machine ground, and polished, yielding a relatively smooth surface that is monofilament-like in appearance. Salthouse and colleagues12 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.
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.
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 coefficient of friction.
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 surgeon’s 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.
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.
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™ suture has many distinct advantages over the braided synthetic absorbable sutures.
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.
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.
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.
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.
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 of fixed perimeter secured in the geometry by a knot.19 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.
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.
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 surgeon’s hands.
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 surgeon’s hand.
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 deep-seated ligatures.20 Figure 5.
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 devised to describe a knot’s configuration (Figure 2).21 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.
IV. components of a knotted suture loop (cont’d) Figure 6. Construction of a square knot with two single strands. Figure 7. Construction of a square knot with a single strand and suture loop. 28 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.
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.
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, biomechanical parameters.23 The suture’s 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 suture’s resistance to breakage.
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 surgeon’s knot square (2=1) generates sufficient forces to break the knot.
knot slippage Knot slippage is counteracted by the frictional forces of the knots. The 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.
When enough force is applied to the tied suture to result in breakage, the site of 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 of the same material.19 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.
suture cutting tissue Suture failure also may occur if the knotted suture loop cuts through the tissue. The type of tissue has considerable influence on the magnitude of force required to tear the suture through the tissue. Howes and Harvey26 reported that the forces required to tear gut sutures through canine fascia was the greatest followed by muscle, peritoneum and then fat.
Mechanical trauma to the suture by surgical instruments can also result in 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 and weaken them. Stamp et al30 incriminated the teeth in the needle holder jaws as important causal factors of sutural damage.
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.
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.
VI. tying techniques (cont’d) a reliable means of maintaining wound apposition because any tension applied to the “ears” from the patient’s side of the knot will unlock the knot. The addition of the second throw to the surgeon’s knot square (2=1) will provide additional resistance to wound disruption, but this knot will not advance by slippage, limiting the surgeon’s ability to secure meticulous coaptation of the wound edges.
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.
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.
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 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.
hand tie (cont’d) technique is that a surgeon who ties his/her own knots by the two-hand technique during wound closure can hold the 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.
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).
VII. essential elements DO DON’T 1. Pass the surgical needle swaged to a suture through the wound edges in a direction toward you. 1. Pass the surgical needle swaged to a suture through the wound edge in a direction away from you. 2. Construct a two-throw square knot that can be advanced to the wound edge, providing a preview of the ultimate apposition of the wound edges. 2. Construct a secure knot that cannot be advanced to the wound edges. 3.
DO DON’T 6. Apply opposing forces to the knot “ears” that are equal in magnitude and in a plane parallel to that of the wound surface. 6. Exert unequal levels of tension to the suture ends that convert the knot into a slip knot. 7. After each throw, reverse the position of your hands that apply tension to the suture ends. 8. Apply constant force slowly to the “ears” of each throw of the knot. 9. Use the two-hand tie technique to maintain continuous tension on suture ends. 10.
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.
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. Form the First Suture Loop The first loop is formed by the tip of the left index finger that passes its suture end over the other suture end held by the right hand. As the tip of the left index finger passes its suture end over the suture end held by the right hand, the left thumb passes under (arrow) the suture end held by the right hand. Step 4.
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.
Step 6. Advance First Single-Wrap Throw to Wound Surface With the suture ends grasped in the palms of the surgeon’s 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.
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.
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 (tipto-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. Form the Second Suture Loop The left thumb advances its suture end beneath the other suture end to form a suture loop. The tip of the left index finger passes down (arrow) to touch the left thumb. Step 10.
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.
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.
VIII. two-hand tie techniques — surgeon’s knot square (2=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.
1. Introduction 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. Form the First Suture Loop The first suture loop is formed by the tip of the left index finger that passes its suture end over the other suture end held by the right hand.
VIII. two-hand tie techniques — surgeon’s knot square (2=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.
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. Maintain Suture Loop with Left Index Finger The rectangular configuration of the suture loop is maintained by keeping the tip of the index finger (arrow) in the suture loop. Step 8.
VIII. two-hand tie techniques — surgeon’s knot square (2=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.
Step 10. Advance Double-Wrap, First Throw to Wound Surface With the suture ends grasped in the palms of the surgeon’s 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 surgeon’s knot square to the surface of the wound.
VIII. two-hand tie techniques — surgeon’s knot square (2=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.
Step 13. Pass Index Finger Down Through Suture Loop After the tip of the left index finger contacts the tip of the left thumb (tipto-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. Form the Second Suture Loop The left thumb advances its suture end beneath the other suture end to form a suture loop. The tip of the left index finger passes down (arrow) to touch the left thumb. Step 14.
VIII. two-hand tie techniques — surgeon’s knot square (2=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.
Step 16. Advance Surgeon’s 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 surgeon’s 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.
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 (tipto-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.
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. Form the First Suture Loop The first suture loop is formed by the tip of the left index finger that passes its suture end over the other suture end held by the right hand. As the tip of the left index finger passes its suture end over the suture end held by the right hand, the left thumb passes under (arrow) the suture end held by the right hand.
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.
Step 6. Apply Tension to the Straight, Taut Suture End The first throw of the slip knot is completed by first applying tension (arrow) to the suture held by the left hand causing the suture end to be straight and taut. The suture end held by the right hand forms a loop around the straight, taut suture held by the left hand. Step 7.
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.
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 (tipto-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. Form the Second Suture Loop The left thumb advances its suture end beneath the other suture end to form a suture loop. The tip of the left index finger passes down (arrow) to touch the left thumb. Step 11.
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.
Step 13. Apply Tension to the Straight, Taut Suture End to Form Second Throw The tension applied (arrow) to the suture end held by the left hand causes this suture end to become straight and taut. The suture end held by the right hand forms a second loop around the straight, taut suture end held by the left hand. Step 14.
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.
Step 2. Form the First Suture Loop The first throw of the square knot is initiated by the tip of the left index finger that passes its free suture end over the fixed suture end held between the tips of the right index finger and thumb. The tip of the left index finger begins to flex around (arrow) the fixed suture end held by the right hand. Note that the left hand forms the suture loop and passes the free suture end through the suture loop.
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.
Step 5. Pass Free Suture End Up Through the Suture Loop Step 6. Advance First Single-Wrap Throw to Wound Surface For the left index finger to bring the entire suture end up (arrow) through the loop, the left hand must release its 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 subsequent partial separation of the wound edges.
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.
Step 8. Form the Second Suture Loop With continued supination of the wrist, the tips of the left long and ring fingers advance their free suture end under the suture end held by the right hand to form a suture loop. Step 9. Flex Long Finger Toward the Free Suture End Continued flexion (arrow) of the distal phalanx of the left long finger allows the tip of the finger to pass beneath the free suture end held between the tips of the left thumb and index finger.
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 78 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.
Step 11. Complete Withdrawal of the Free Suture End Down Through the Suture Loop to Form Second, Single-Wrap Throw During withdrawal (arrow) of the free suture end through the loop, it is held loosely between the tips of the left long and ring fingers. This loose grasp (key pinch) between the ulnar side of the distal phalanx of the left long finger and the radial side of the distal phalanx of the left ring finger does not allow constant tension to be maintained on this suture end.
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 surgeon’s 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.
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 surgeon’s knot square will be formed. A double-wrap, first throw displays a greater resistance to slippage than a singlewrap throw, accounting for its frequent use in instrument ties in wounds subjected to strong, static skin tensions).
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.
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 singlewrap throw is advanced to the wound surface by applying tension in a direction (arrows) that is perpendicular to that of the wound.
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.
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.
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.
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.
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 rating by the surgeons.33 In this multicentric evaluation of suture and needle products conducted by Consorta, Inc.
XII. full text scientific articles available at www.covidien.com/syneture A complete copy of this study can be found at www.covidien.com/syneture. A. Rodeheaver GT, Shimer AL, Boyd LM, Drake DB, Edlich RF. An innovative absorbable coating for the polybutester suture. J Long Term Eff Med Implants 2001;11(1-2):41-54. B. Szarmach RR, Livingston J, Rodeheaver GT, Thacker JG, Edlich RF. An innovative surgical suture and needle evaluation and selection program. J Long Term Eff Med Implants 2002;12(4):211-229.
XIII. references 1. Graumont R, Hensel J: Encyclopedia of knots and fancy rope work. Cornell Maritime Press, N.Y., 1943, pp 3-10. 2. Haxton H: The influence of suture materials and methods on the healing of abdominal wounds. Br J Surg 1965;52:372-375. 3. Thacker JG, Rodeheaver G, Kurtz L, Edgerton MT, Edlich RF. Mechanical Performance of sutures in surgery Am J Surg 1977;133:713-715. 4. Trimbos JB. Security of various knots commonly used in surgical practice. Obstet Gynecol 1984;64:274-280. 5.
10. Pinheiro AL, de Castro JF, Thiers FA, Cavalcanti ET, Rego TI, de Quevedo AS, Lins AJ, Aca CR. Using Novafil: would it make suturing easier? Braz Dent J 1997;8(1):21-25. 11. Rodeheaver GT, Shimer AL, Boyd LM, Drake DB, Edlich RF. An innovative absorbable coating for the polybutester suture. J Long Term Effects Med Implants 2001;11 (1 & 2):41-54. 12. Salthouse TN, Williams JA, Willigan DA. Relationship of cellular enzyme activity to catgut and collagen suture absorption.
XIII. references (cont’d) 18. Pineros-Fernandez A, Drake DB, Rodeheaver PA, Moody DL, Edlich RF Rodeheaver GT. CAPROSYN™, another major advance in synthetic monofilament absorbable suture. J Long Term Eff Med Implants 2005;14(5):359-368. 19. Thacker JG, Rodeheaver GT, Moore JW, Kauzlarich JJ, Kurtz L, Edgerton MT, Edlich RF: Mechanical performance of surgical sutures. Am J Surg 1975;130:374-380. 20. Taylor FW: Surgical knots. Ann Surg 1938;107:458-468. 21. Tera H, Åberg C.
26. Howes EL, Harvey SC. The strength of the healing wound in relation to the holding strength of the catgut suture. N Engl J Med 1929; 200:1285-1290. 27. Tera H, Åberg C. Tissue strength of the healing wound in relation to the holding strength of the catgut suture. N Engl J Med 1929;200:1285-1290. 28. Åberg C. Change in strength of aponeurotic tissue enclosed in the suture during the initial healing period. An Experimental investigation in rabbits. Acta Chir Scand 1976;142:429-432. 29.
Acknowledgements: We would like to acknowledge the gifted talents of Graphic Designer, Michael Lobasz, as well as the extremely talented pre-medical student, Amy Cochran, the creative research assistant, Dayna Woode and the dynamic Nursing Student, Jill Amanda Greene for all their innovative work in getting this book completed. This manual was illustrated by: Craig A. Luce, MS.
COVIDIEN and COVIDIEN with Logo and ™ marked brands are trademarks of Covidien AG or its affiliate. © 2008 Covidien AG or its affiliate. All rights reserved. 22316 SS 5M 3.08 CBK00020i 150 Glover Avenue Norwalk, CT 06856 1-800-722-8772 www.covidien.
