Chapter 93. Basic Wound Closure Techniques

Wound management is crucial to the practice of Emergency Medicine. Emergency Physicians routinely care for wounds ranging from simple lacerations to complex injuries in the trauma patient.1–6 Wound repair is always secondary to the evaluation and stabilization of any life-threatening and limb-threatening emergencies. However, patients are often legitimately concerned about the outcome of wounds and lacerations. There are several basic suture principles that will help to provide optimal wound healing and ensure a more than acceptable cosmetic result. The previous chapter outlines the essential principles of wound management. This chapter describes the basic methods used to close wounds.

The choice of suture materials is important in wound closure. Sutures are made of a wide variety of materials, both natural and synthetic. Natural substances include gut (sheep and beef), cotton, and silk. Natural substance sutures cause more tissue reactions and scarring, which limits their use. Cotton sutures are not discussed, as they are no longer used in clinical practice. Synthetic sutures can be made of nylon, polyethylene (Dacron), polyglactin (Vicryl), polypropylene (Surgilene, Prolene), polyglycolic acid (Dexon), poliglecaprone (Monocryl), polydiaxanone (PDS), polyglyconate (Maxon), and metal.6 Metal sutures are used in the Operating Room and not in the Emergency Department as they are difficult to handle, prone to breakage, and indicated in only a few situations. Synthetic sutures tend to have a problem with “memory.” That is, they tend to retain the shape of their packaging. This can make it difficult to manipulate the suture during wound closure.

Sutures are constructed as monofilaments or polyfilaments. Polyfilament fibers consist of multiple filaments braided together to form one suture. They are easier to handle than monofilament sutures, as they tend to be more pliable. Polyfilament sutures have better knot security and therefore reduce the incidence of knot slippage. However, they can be associated with a higher incidence of infection than monofilament sutures. They allow bacteria to migrate (or wick) between the strands of the suture located at the skin surface and into the wound.

Select the smallest diameter suture that can adequately hold the tissue edges together in order to reduce tissue damage and scarring. The largest suture material available is size #5. The suture sizes decrease to zero (#4, #3, #2, #1, #0) and then are followed by #00 (2-0), #000 (3-0), and #0000 (4-0), in decreasing size. The smallest suture commonly used in the Emergency Department is 6-0 for facial lacerations, nail bed lacerations, as well as lacerations in cosmetically sensitive areas. The tensile strength of sutures is related to their size. The tensile strength of suture increases as the size increases. For example, 4-0 is stronger than 5-0.

The other main category of suture classification is absorbable versus nonabsorbable. In the past, absorbable sutures were primarily used to close the subcutaneous layers of a wound. More recently, absorbable sutures have also been used for skin closure. Nonabsorbable sutures are primarily used for skin closure.

Absorbable Suture Materials

Absorbable sutures are degraded by the body and do not require removal. They usually do not maintain their tensile strength for longer than 60 days. Body enzymes dissolve the absorbable sutures with the aid of an inflammatory reaction. The rate of absorption of the sutures varies based upon the tissue where it is placed, the composition of the suture, and the size of the suture. Absorbable sutures placed in mucous membranes absorb faster than those placed in muscle tissue or fascia. Smaller sizes of suture dissolve faster than larger sizes.

There are several types of absorbable sutures, both natural and synthetic (Table 93-1). The most commonly used absorbable sutures in the Emergency Department are plain gut, chromic gut, polyglycolic acid (Dexon), polyglactin (Vicryl), and Vicryl Rapide. Plain gut and chromic gut are both natural forms of absorbable sutures. They are made from the intestines of sheep and cattle. Gut is a tissue irritant and can cause a substantial tissue reaction while it is being absorbed and degraded by the body. Chromic gut is plain gut that has been soaked in chromic acid salts. This process helps to extend the half-life of the suture and allows it to maintain its tensile strength longer than plain gut. Chromic gut may retain its tensile strength for 2 to 3 weeks, while plain gut retains its tensile strength for 1 to 2 weeks. Both types of gut are packaged wet in order to keep them from drying out and becoming too stiff.

Synthetic absorbable sutures, such as Dexon and Vicryl, are typically used more often than natural absorbable sutures in the Emergency Department. They are degraded by the body more slowly than natural fibers and can therefore help maintain the strength of the wound longer. Vicryl and Dexon maintain their tensile strength at 80 days and 120 days, respectively. They cause less reaction in the tissues as they break down when compared to natural absorbable sutures.

Recently, absorbable sutures have gained some popularity for use in skin closure.7–10 Absorbable sutures have been shown to yield equal results in their rate of dehiscence, rate of infection, and cosmesis when compared to nonabsorbable sutures.7 Absorbable sutures have the added benefit for the patient of not having to return to have their sutures removed. Vicryl Rapide is a newer form of Vicryl that is especially suited for this purpose. This type of suture is rapidly absorbed. They begin to fall off in 7 to 10 days as the wound heals. This can be especially useful for children in whom suture removal can be difficult, under casts, or if a patient will not be able to follow up due to travel.

Nonabsorbable Suture Materials

Nonabsorbable sutures are not degraded by the body and must be removed. They maintain their tensile strength for longer than 60 days. They are composed of monofilament or polyfilament strands of organic, synthetic, or metal fibers (Table 93-2). Nonabsorbable sutures generally have greater tensile strength and lower tissue reactivity than absorbable sutures. They are used in a variety of applications including skin closure. Nonabsorbable sutures can be used within a body cavity and subcutaneously, where they will eventually become encapsulated in connective tissue.

Nonabsorbable sutures can be classified as organic, synthetic, and wire. Organic sutures include those made of cotton or silk. Cotton is the oldest of the nonabsorbable sutures. It is not discussed here as cotton sutures are no longer used in general medical practice. Silk is a polyfilament suture that has limited use in the practice of Emergency Medicine. There are several advantages to silk suture material. Its pliability makes it very easy to handle. It holds knots better than other types of suture. However, as with all natural and/or polyfilament sutures, it has a greater tendency to cause wound infections. The polyfilament braids can provide a place for bacteria to lodge. Silk suture may actually protect the bacteria from attack by the body's defenses if the wound becomes infected. The primary use of silk sutures is for the repair of lip, oral cavity, and tongue lacerations.

Synthetic nonabsorbable sutures are available in monofilament and polyfilament forms. Commonly used synthetic sutures include nylon, polypropylene, polybutester, and Dacron. Nylon, polypropylene, and polybutester are monofilament synthetic sutures. Dacron is a polyfilament synthetic suture. The synthetic nonabsorbable sutures have several advantages over the natural nonabsorbable sutures. They are less reactive in tissues, generally stronger than the natural sutures, and retain their tensile strength over many years.

Nylon (Ethilon, Dermalon) is the most common nonabsorbable suture used in the Emergency Department. It is a monofilament suture, it is inert, and it does not tend to harbor bacteria. It is primarily used for skin closure. Nylon has good tensile strength and minimal tissue reactivity. However, nylon is difficult to handle and difficult to tie. It requires more knots to achieve good knot security than other types of suture. This is primarily due to the tendency of the suture to return to its packaged shape. This tendency is also known as “memory.” Because the knot can unravel or slip, it is important to place at least four or five knots when using nylon suture.

Polypropylene and polybutester are less commonly used synthetic nonabsorbable sutures. Polypropylene (Prolene) is stronger but more difficult to work with than nylon because it has greater memory. Polybutester (Novafil) is a newer suture in this category. It is stronger than the other monofilaments and does not have significant memory. Therefore, it is easier to work with than the other monofilament synthetic sutures.

• Needle drivers, 4.5 and 6.0 in.
• Skin hooks
• Scalpel blades (#10, #11, and #15)
• Scalpel handles
• Iris scissors, straight 4 in. and curved 4 in.
• Suture scissors, 6 in.
• Forceps, toothed Adson
• Metzenbaum scissors, curved 6 in.
• Hemostats, straight 6 in., and curved mosquitoes
• Suture material
• Skin closure tapes
• Benzoin solution, swabs, or spray
• Gum mastic (e.g., Mastisol)
• Tissue adhesive
• Tissue adhesive forceps
• Skin stapler
• Staple remover
• Gauze, 4 × 4 squares

Much of the above equipment can be purchased in single-use, sterile, and disposable suture kits from several commercial manufacturers (Figure 93-1A). These kits tend to be expensive and occasionally have a limited amount of equipment. Many hospitals package and sterilize their own wound repair kits (Figure 93-1B). This decreases the cost, as the equipment can be repeatedly sterilized and reused. It also allows the kits to contain a wide variety of instruments for multiple situations (e.g., minor laceration, large laceration, and plastics closure).

Needle drivers come in a variety of sizes. A 4.5 in. needle driver can be used comfortably with most types of needles. A 6 in. needle driver may be required if large needles are used to close a wound. Hold the needle driver with the fingertips to provide greater flexibility. The fingers can also be placed through the finger holes, but this is not as efficient when closing a wound. Grasp the needle one-third of the way from the swag (distal) end with the tip of the needle driver.

The skin must be grasped and manipulated during wound repair to allow for proper suture placement. Forceps are most commonly used to grasp and manipulate the skin. Smooth (nontoothed) forceps should never be used to grasp skin. They require the application of a large amount of force to grasp the tissue. This can crush tissue very easily. An Adson forceps is the forceps of choice. It has fine teeth that grasp tissue securely with minimal force.

A skin hook is a sharp, pointed instrument that is inserted into the wound edge and grasps the tissue from the undersurface. It produces a small puncture wound in the subcutaneous tissues and does not penetrate the skin surface. Skin hooks are preferable to forceps, as they do not crush tissues. A skin hook is awkward to use at first. With proper instruction and experience, the Emergency Physician will most certainly prefer a skin hook to forceps.

Several types of scissors are required for proper wound closure. Iris scissors have sharp, delicate tips for making precise cuts in tissue. They should not be used to cut suture material, as this rapidly dulls and nicks the blades. Suture scissors have one blunt tip and one pointed tip. Both blades of the suture scissors are sharp. Suture scissors are used to cut adhesive tape, gauze, rubber drains, and suture material. Metzenbaum scissors should be used to debride heavy tissue, bluntly dissect tissue, and undermine tissue.

Hemostats are used to clamp small vessels that are bleeding, to explore a wound, and to grasp fascia. Hemostats are available in a variety of sizes and styles. A straight 6 in. hemostat is used for most purposes during wound repair. A curved 5 in. mosquito hemostat can be used for small wounds or delicate tissues. Do not use a hemostat to grasp or drive the suture needle. The suture needle can bend, rotate, and break as it enters tissue if driven by a hemostat.

Three different scalpel blades should be available when a wound is being repaired. A #11 blade is used to make stab incisions. It is often used for the incision and drainage of abscesses, cricothyroidotomies, and the removal of small or tight sutures. A #10 blade is used to make straight cuts in the skin and debride wound edges. It is rarely used in laceration repair. A #15 blade is small and curved to allow precise incisions. It is used for excising foreign bodies and wound debridement.

Proper wound closure requires an understanding of certain basic principles. The needle should enter and exit the skin at a 90° angle and perpendicular to the wound edges. By doing so, when the suture loop is closed, the wound edges will be everted. Sutures should be placed as close to the wound edge as possible (2 to 3 mm) in order to avoid excessive tension on the wound. More force will be required to close the wound if the sutures are placed too far from the wound edge. Edema develops in a wound in the first 48 hours after closure. Sutures placed too far from the wound edge can result in large scars when the edema subsides.

The layers of the wound should be matched evenly and each layer should be closed separately. If a wound involves the deeper layers of skin, fascia should be matched to fascia, dermis should be matched to dermis, and epidermis should be matched to epidermis. The proper matching of layers avoids an uneven closure, helps to prevent an unnecessarily large scar, and eliminates dead space.

The epidermal edges of the wound must be everted to allow for proper healing. Scars contract with time. They will flatten and heal with a better cosmetic result if the wound edge is everted and slightly elevated. The wound edges will contract into a “pit” below the plane of the skin, will be more noticeable, and the final result will be less appealing cosmetically if the wound edges are not everted.

Handle the tissues gently and do not squeeze or twist them too tightly with the instruments. This helps to avoid strangulation, which can result in tissue necrosis. The sutures should be placed carefully and with the proper amount of tension to help promote healing. Sutures should be snug. Attempts should be made to avoid excessive tension on the wound edges in order to prevent wound dehiscence. The use of the smallest suture size necessary to approximate the wound edges will reduce tissue damage and minimize scarring. Table 93-3 lists the appropriate suture types and sizes for each body region.

If there will be a temporary delay in the closure of a laceration because of other injuries that may be life-threatening or of greater importance, cover the wound with a saline-soaked gauze in order to keep the tissues from drying.

Principle of Halving

Large wounds gape open and are difficult to approximate. Closure of the deeper layers will often bring the skin edges into apposition. If not, the principle of halving may be used to approximate the wound (Figure 93-2). Identify the midpoint of the laceration. Place the first suture at the midpoint (Figure 93-2A). This stitch is known as the central suture. The next sutures are placed in halves on each side of the central suture (Figures 93-2B & C). Continue the process by placing sutures halfway between previous sutures until the wound is approximated. This results in even closure of the wound edge. This principle can be used for closure of both the deep layers and the skin.

Two-Handed Square Knot

This is the easiest and most reliable method of tying most suture materials. It involves the classic “right-over-left and left-over-right” tie (Figure 93-3). The incorrect “right-over-left and right-over-left” is a granny knot, which will slip if it is tied in this manner. This square knot is quick and simple to perform. However, it does take significant practice to master this technique.

Place a suture through the skin on both sides of the laceration (Figure 93-3A). Pull the suture through the wound until half is on each side of the laceration. Grasp the right half of the suture with the right thumb and index finger (Figure 93-3A). Grasp the left half of the suture with the left third through fifth fingers and the suture draped over the thumb (Figure 93-3A). Cross the right hand toward the left hand (Figure 93-3B). Continue to move the right hand until the suture is between the left thumb and index finger (Figure 93-3C). Close the left thumb and index finger to entrap the right half of the suture in the pads of the fingers (Figure 93-3D). Pull the right hand down and to the left so that the two halves of the suture form an X over the left thumb (Figure 93-3E). Flex the left wrist to slide the X off the left thumb and onto the left index finger (Figure 93-3F). Lift the left thumb backward and upward so that the X overlies the tip of the left index finger (Figure 93-3G). Reapply the left thumb over the left index finger to entrap the X (Figure 93-3H). Extend the left wrist to push the left thumb and the X through the loop (Figure 93-3I). Release the suture held with the right hand (Figure 93-3J). Regrasp the suture with the right hand after it passes through the loop (Figure 93-3K). Pull the suture completely through the loop with the right hand. Simultaneously move the left hand toward the left and move the right hand toward the right (Figure 93-3L). Cross the hands so that the left hand goes toward the right side and the right hand goes toward the left side (Figure 93-3M). Continue to pull both sides of the suture until the knot lies flat and the skin edges are apposed (Figure 93-3M). The first half of the knot is now complete.

Make the second half of the knot to complete the square knot. Raise both hands upward and uncross them until an X is formed over the left index finger (Figure 93-3N). Close the left thumb and index finger to entrap the suture being held with the right hand (Figure 93-3O). Extend the left wrist to push the left thumb through the loop (Figure 93-3P). Lift the left index finger upward (Figure 93-3Q). Move the right hand away from you until the suture it holds drapes over the left thumb (Figure 93-3R). Reapply the left index finger onto the thumb to entrap the suture held with the right hand (Figure 93-3S). Release the suture held with the right hand (Figure 93-3T). Flex the left wrist to push the left index finger and suture through the loop (Figure 93-3U). Regrasp the free suture with the right hand after it passes through the loop (Figure 93-3V). Move the right hand upward and to the right to complete the second half of the knot overlying the left index finger (Figure 93-3W). Simultaneously move the left hand toward the left and move the right hand toward the right (Figure 93-3X). Continue to pull both halves of the suture until both halves of the knot come into contact (Figure 93-3Y). Pull both halves of the suture to secure the knot. The square knot is now complete. Continue the process to add additional knots onto the suture. Cut off excess suture on both sides of the knots.

Surgeon's Knot

The physician may choose to use a surgeon's knot instead of a square knot (Figure 93-4). The square knot has one loop in the first throw and one loop in the second throw (Figure 93-4A). The surgeon's knot has two loops in the first throw and one loop in the second throw (Figure 93-4B). The only difference between these two knots is the two loops in the first throw. The second throw and subsequent knots are exactly the same for both knots. The advantage of the surgeon's knot is that the two loops are more secure and stay in place while the second throw is being tied. The choice to use either knot is dependent on the experience and the training of the physician.

Instrument Tie

The instrument tie is the most efficient method to complete a simple interrupted suture (Figure 93-5). It is the tie that is most commonly used in the Emergency Department. An instrument tie is often quicker, requires less dexterity, and is easier to perform than the two-handed method. It may be used with the square knot or the surgeon's knot.

Place a suture through the skin on both sides of the laceration (Figure 93-5A). Carefully grasp the needle in its midportion and pull it through the laceration (Figure 93-5B). Continue to pull the needle until approximately 1 to 2 cm of suture on the tail end remains outside the laceration (Figure 93-5C). A large amount of suture will be wasted if the tail is left too long, as it will be later cut off and discarded. On first learning the instrument tie, it may be best to leave a tail of 3 to 4 cm until one is proficient with this technique.

Place the needle driver over the laceration but not touching it (Figure 93-5C). Loosely loop the needle end of the suture over (Figure 93-5D) and around (Figure 93-5E) the needle driver. Loosely loop the needle end of the suture over and around the needle driver a second time (Figures 93-5F & G). This will eventually result in the first half of a surgeon's knot. Looping the suture once around the needle driver will result in a simple square knot. Move the tip of the needle driver toward the tail of the suture without letting the loops fall off the needle driver (Figure 93-5H). Grasp the tail of the suture with the needle driver (Figure 93-5I). Pull the tail of the suture through the loop (Figure 93-5J). Pull the tail completely through the loops (Figure 93-5K). Simultaneously move the left hand toward the right and the right hand/needle driver toward the left (Figure 93-5L). Continue to pull both sides of the suture until the hands are opposite each other, the knot lies flat, and the skin edges are apposed (Figure 93-5M). The first half of the knot is now complete.

Make the second half of the knot. Continue to hold the needle and release the tail of the suture from the needle driver (Figure 93-5N). Place the needle driver over the laceration but not touching it (Figure 93-5N). Loosely loop the needle end of the suture over (Figure 93-5O) and around (Figure 93-5P) the needle driver. Move the tip of the needle driver toward the tail of the suture without letting the loop fall off the needle driver (Figure 93-5Q). Grasp the tail of the suture with the needle driver (Figure 93-5R). Pull the tail of the suture completely through the loop (Figure 93-5S). Simultaneously move the left hand toward the left and the right hand/needle driver toward the right (Figure 93-5T). Continue to pull both sides of the suture until both halves of the knot come into contact. Pull both sides of the suture to secure the knot. The knot is now complete. Continue this process three or four more times, each in alternative directions, to place additional knots. Cut off the excess suture on both sides of the knots.

Simple Interrupted Stitch

The simple interrupted stitch is the most commonly used suture technique and is useful in many situations (Figure 93-6). One major advantage is that each stitch is placed independent of the others. Therefore tension on each stitch can be adjusted separately. Additionally, the entire repair is not compromised if one suture should happen to come out. The other sutures will remain in place to help assure proper wound healing. The needle must enter and exit the skin at a 90° angle to help evert the wound edges. Take equal volumes of skin from each side of the area being sutured. Drive the needle equidistantly into and out of the wound edges and incorporate the base of the wound.

Insert the needle at a 90° angle to the skin (Figure 93-6A). Drive the needle through the tissue until the tip exits the skin (Figure 93-6B). Grasp the needle behind the tip and pull it through the wound (Figure 93-6C). The suture should enter and exit the skin equidistant from the wound edges (Figure 93-6D). If it does not, pull the suture out and repeat the stitch so that it is equidistant from the wound edges. Make a loop in the suture with the two-handed tie or the instrument tie. Pull the suture to appose the wound edges and cinch down the knot (Figure 93-6E). The tissue at the base of the wound will come into apposition before the tissue at the skin surface and thus evert the wound edge. Complete the knot to one side of the laceration (Figure 93-6F). Just prior to cinching the second throw onto the first, pull the ends so that the knot is not directly over the wound and the edges of the wound remain in apposition. Apply additional sutures equidistant from each other until the wound is closed (Figure 93-6G).

Open-Loop Simple Interrupted Stitch

The open-loop simple interrupted stitch is a variation of the simple interrupted stitch (Figure 93-7). The same basic technique is used except that the knot is tied differently. The tie involves laying down the first knot with an instrument tie. However, the second knot placed on the suture is not pulled all the way down. Pull the second knot only until it is just above the first knot (Figure 93-7A). In other words, the second knot is loosely tied, leaving a loop between the first and second knots. Place a third knot as a single knot square to the second knot (Figure 93-7B). Cinch the third knot tightly to the second knot. This “locks” the third knot onto the second knot.

This knot is indicated when there is the possibility of edema forming at the suture site. If edema forms, the first knot will have room to open as it slides toward the second knot. This stitch avoids excessive tension on the wound and prevents the suture from cutting into the skin. This stitch facilitates suture removal when numerous small stitches are placed next to a wound edge. Cutting the open loop unravels the knot and allows for easy removal of the suture. This stitch should not be used in areas where the skin is thin or if there is little subcutaneous tissue (e.g., dorsal hand and foot). In these areas, the wound edges often become unopposed while the knot is being secured.

Interlocking Slip Knot

This technique can be used in patients who will be traveling, camping, or otherwise away from their primary source of medical care (Figure 93-8). The patient can easily remove the sutures without having to find an unfamiliar or foreign healthcare provider for routine suture removal. The interlocking slip knot can be removed by hand without the use of a scissors or a scalpel. This can be useful for suture removal in pediatric patients, who may find it hard to sit still for suture removal.

Place a suture through the skin on both sides of the laceration (Figure 93-8A). Loop the tail end of the suture around the tip of the needle driver (Figure 93-8A). Grasp the needle end of the suture with the needle driver (Figure 93-8B). Pull the needle end of the suture through the loop while simultaneously pulling on the tail end of the suture with a second needle driver (Figure 93-8C). Continue to pull both suture halves in opposite directions until a knot is formed against the skin and the wound edges are apposed (Figure 93-8D). Release the needle driver holding the now formed loop. Insert the needle driver through the loop and grasp the tail end of the suture (Figure 93-8E). Grasp the needle end of the suture with the second needle driver (Figure 93-8E). Pull the needle drivers in opposite directions to lock and secure the knot (Figure 93-8F). The knot is now complete (Figure 93-8G). To remove the stitch, pull the free end of the suture to unlock the knot. Continue to pull the suture until it is free from the skin. This stitch can easily become loose or open before the wound is healed. Thus, it is recommended to cover the wound and sutures with skin closure tape (e.g., Steri-Strips).

Continuous over‐and‐over Stitch (Simple Running Stitch)

Continuous (simple running) sutures minimize the time required for laceration repair. Stitches can be placed very quickly, since each individual stitch does not have to be tied. This stitch provides strength and applies equal tension on all sutures in the repair. This stitch can be used to achieve hemostasis. The wound must be long and straight. Simple running stitches can effectively be used in partial-thickness lacerations and wounds under minimal tension.

However, there are several disadvantages to this stitch. It can be associated with significant epithelialization of the suture track. This is especially true if the suture is not removed early and remains for a prolonged period of time. Inclusion cysts may form within a few weeks after removal of the sutures. Simple running stitches should not be used on any wound under tension. If one suture breaks, the entire wound may open. This stitch should not be used when closing a wound where there is a risk of subsequent hematoma formation. Hematoma formation would require the removal of all of the sutures in order to drain the hematoma. Although this suture is not commonly used in the Emergency Department, it can be very helpful for closing bleeding scalp wounds, as the injury will be covered with hair and cosmesis is a secondary concern.

Place the initial stitch as a simple interrupted stitch (Figure 93-9A). Do not cut the suture after the knots are securely tied. Place a second stitch 3 to 5 mm from the first stitch as if placing another simple interrupted stitch (Figures 93-9B & C). Place a third stitch 3 to 5 mm from the second stitch (Figures 93-9D & E). Continue to place additional stitches until the end of the laceration is reached. Use care to ensure that the sutures are all lined up with each other and equidistant from the laceration. Do not pull the last throw taut against the skin (Figure 93-9F). The loop will act as the tail end of the suture for knot tying. Loop the needle end of the suture twice around the tip of the needle driver (Figure 93-9G). Grasp the last throw with the tips of the needle driver (Figure 93-9G). Pull the last throw through the loops until the knot is against the skin (Figure 93-9H). Perform three to five more instrument ties to secure the knot. Cut off the excess suture (Figure 93-9I).

Continuous Single-Locked Stitch (Running-Locked Closure)

This stitch may promote less epithelialization of the suture track than the continuous over-and-over stitch. It maintains the advantages of a continuous suture. This variation of the simple running closure locks each stitch after it is placed (Figure 93-10). It provides a secure apposition of the wound edges while each subsequent stitch is placed. The main disadvantage of this stitch is the time it takes compared to a continuous over-and-over stitch.

Place the initial stitch as a simple interrupted stitch (Figure 93-10A). Do not cut the suture after the knots are securely tied. Loop the tail end of the suture over the nondominant fifth finger (Figure 93-10B). Apply slight tension on the tail end of the suture while placing the second stitch (Figures 93-10C & D). As the needle exits the skin, move the nondominant hand to bring the suture loop down and over the needle (Figure 93-10E). Grasp the front of the needle with the needle driver. Simultaneously pull the needle and suture through the laceration while releasing the loop from the fifth finger (Figure 93-10F). Repeat this procedure until the laceration is closed (Figure 93-10G). Do not pull the last throw taut against the skin. The loop will act as the tail end of the suture for knot tying. Loop the needle end of the suture twice around the tip of the needle driver (Figure 93-10H). Grasp the last throw with the tips of the needle driver. Pull the last throw through the loops until the knot is against the skin (Figure 93-10I). Perform three to five more instrument ties to secure the knot. Cut off the excess suture (Figure 93-10J).

Vertical Mattress Stitch

The vertical mattress stitch is a double stitch that provides for excellent wound eversion (Figure 93-11). It optimizes wound closure of lacerations under tension. This stitch is useful in areas where the skin is very lax, such as the elbow and the dorsum of the hand. This stitch provides for both superficial as well as deep closure of lacerations. This stitch is contraindicated in lacerations involving the volar aspect of the hands and feet or the face, as it requires the blind placement of a deep suture. The main disadvantage of the vertical mattress closure is the time it takes to place it.

Place the first throw much like a simple interrupted stitch with a few noted differences. The needle should enter and exit the skin 1.0 to 1.5 cm from the wound edge. The needle should traverse the base of the wound and grasp a large amount of tissue (Figures 93-11A & B). Reverse the needle. The second throw should enter and exit the skin approximately 2 to 3 mm from the wound edge (Figures 93-11C & D). The first and second throws must be directly over each other and parallel. Tie the suture to approximate the wound edges (Figure 93-11E). The first throw will close the wound base and relieve the tension at the skin surface. The second throw approximates and everts the skin edges.

The newer version of the classic vertical mattress is referred to as the “shorthand” vertical mattress stitch (Figure 93-12). It provides wound eversion in half the time as the traditional method. Place the first throw close to the lacerated wound edge to approximate the skin edges (Figures 93-12A & B). Grasp and pull the suture to elevate the wound edges (Figure 93-12C). This allows the needle to more easily take a large bite of tissue on the second throw. Place the second throw 1.0 to 1.5 cm from the wound edge (Figures 93-12C & D). Release the suture. Tie the suture to approximate the wound edges and evert the skin surface (Figure 93-12E). The final product looks exactly the same as the traditional vertical mattress suture (Figure 93-12F).

Locked Vertical Mattress Stitch

The locked vertical mattress stitch is useful in areas that are widely separated and where deep sutures must be avoided (Figure 93-13). This stitch helps to reduce the amount of tension needed to close a wound. It helps to avoid the pain and scarring that can result if too much tension is applied to a laceration. It does not put an excessive amount of tension on the deep throw, as does the vertical mattress stitch.

This is a modification of the vertical mattress stitch (Figures 93-11 & 93-12). Place the first two throws as if placing a vertical mattress stitch (Figure 93-13A). Leave the suture lax with a loop above the wound surface. Pass the needle end of the suture through the open loop (Figure 93-13B). This step will form the locked portion of the stitch. Pull the needle end of the suture taut to appose the wound edges (Figure 93-13C). Tie and secure the suture in the standard manner.

Horizontal Mattress Stitch

The horizontal mattress stitch is placed along the axis of the wound and helps to eliminate tension on the wound (Figure 93-14). It is a good closure technique for wounds with relatively poor circulation to the wound edges because, theoretically, no suture is placed through the wound edges. This helps to avoid tension on the wound edges from the suture and subsequent local necrosis. This stitch is placed more rapidly than the vertical mattress stitch. It requires fewer stitches to close a wound with horizontal rather than vertical mattress stitches. The throws are side by side rather than on top of each other, as with the vertical mattress, and each stitch closes more tissue. This closure may be used on the volar surfaces of the hands and fingers, as these delicate skin areas may swell and be cut by simple interrupted sutures. The main disadvantage of the horizontal mattress stitch is that it takes more experience to properly place this stitch to achieve wound eversion than with the vertical mattress stitch.

Place the first throw much like a simple interrupted stitch with a few noted differences. The needle should enter and exit the skin 0.5 to 1.0 cm from the wound edge. The needle should traverse the base of the wound (Figures 93-14A & B). Reverse the needle and make a second throw 0.5 cm from the first (Figure 93-14C). The needle must enter and exit the skin and the wound edges so that the first and second throws are parallel to each other (Figures 93-14C & D). Pull the free ends of the suture taut to appose and evert the wound edges (Figures 93-14E & F). Tie and secure the suture in the standard manner.

Half-Buried Horizontal Mattress Stitch

This is the stitch of choice to close complex wounds with multiple flaps in a single-layer closure. This stitch is ideal to close stellate, Y-shaped, V-shaped, and T-shaped lacerations. The half-buried horizontal mattress stitch allows a tissue flap to be reapproximated without tension on the edges of the flap. The vascular supply to a flap is derived from its base. The flaps sometimes have a limited or poor vascular supply. This stitch may be used to approximate a flap-like laceration in which the corner has limited vascularity and/or viability.

The key to this stitch is that the needle and suture pass through the dermis of the flap and not the epidermis (Figure 93-15). Begin by placing the first stitch percutaneously through the skin adjacent to the tip of the flap (Figure 93-15A). Advance the needle through the dermal layer of the flap, the dermal layer of the skin adjacent to the tip of the flap, and out the skin adjacent to the tip of the flap opposite to where the stitch began (Figure 93-15A). The needle must traverse the dermis of the flap and adjacent tissue at the same level of the dermis to properly approximate the wound edges. Gently pull on the free ends of the suture to approximate the flap against the adjacent skin edges. Tie and secure the suture in the usual manner. Secure the edges of the flap with half-buried horizontal mattress stitches (Figure 93-15A), simple interrupted stitches, vertical mattress stitches, or horizontal mattress stitches.

Stellate lacerations are often seen in the Emergency Department. They occur due to bursting of the skin from crush injuries. These lacerations are often encountered on the extremities, forehead, and scalp. Begin by inserting the needle through the skin of the largest flap. Advance the needle so that its tip exits the dermis. Continue to advance the needle through the dermis of each flap. The half-buried horizontal mattress stitch should encompass the tips of all the flaps (Figure 93-15B). The remainder of the procedure is as described above.

Continuous (Running) Horizontal Mattress Stitch

The running horizontal mattress stitch is indicated in areas of the body where there is loose skin that tends to overlap or invert, such as the skin of the upper eyelids or the dorsum of the hand. This stitch can also be used as the surface closure in a multiple-layer closure if there is a tendency for wound inversion. Like the traditional horizontal mattress stitch, it provides good apposition and can be placed rapidly. The running horizontal mattress stitch is contraindicated in wounds under tension if the goal of wound closure is optimal cosmesis.

This stitch begins with a simple interrupted stitch at one end of a laceration (Figure 93-16). The needle is then run along the length of the wound while placing horizontal mattress stitches. The difference between this and the standard horizontal mattress stitch is that the suture is not tied and cut after each individual stitch. Rather, the stitch is continued (running) the length of the laceration. At the end of the laceration, the stitch is tied and secured in the same way as the simple running stitch (Figure 93-9).

Continuous Subcuticular Stitch

This closure is ideal for lacerations of the face and neck. It provides excellent cosmesis, leaves no suture marks on the skin, and causes minimal scarring. It requires more time and skill to place than other types of stitches. It may be performed for the temporary pull-out (Figure 93-17) or permanent placement (Figure 93-18) of subcutaneous sutures. Polypropylene or nylon sutures must be used for this stitch. Polypropylene is preferred as it is stiffer, stronger, and easier to remove than nylon.

The use of this stitch is limited to lacerations that are clean, straight, have sharp edges, and are less than 6 cm in length. It may be extremely difficult to remove the suture material for the pull-out technique if the laceration is greater than 6 cm in length. The laceration can be longer if the permanent placement of absorbable sutures is being used. The dermis and subcutaneous tissue must be apposed before proceeding with this stitch. If necessary, apply buried absorbable sutures to appose the dermis before applying this stitch. The superficial wound surface must be tension-free, as this stitch is for cosmesis and not strength. The wound may require undermining to release the tension from the wound edges. Refer to Chapter 92 for details regarding wound undermining.

The pull-out technique allows the subcuticular stitch to be removed after the laceration heals (Figure 93-17). The subcuticular suture should enter the intact skin 3 to 4 mm from one end of the laceration and burrow through the dermal-epidermal junction to emerge through the skin at the other end of the laceration (Figure 93-17A). The suture will continuously pass through the subcuticular layer on alternate sides of the laceration. The point of entry of each stitch should be directly across from or slightly behind the exit point of the previous stitch. It is very important to keep the needle at the same level of depth throughout the wound. The tension on the suture should be adjusted to ensure that there is no puckering of the skin. Tape the free suture at both ends of the laceration to the skin (Figure 93-17B). Place wound tape (e.g., Steri-strips) across the laceration to help maintain the apposition of the epidermis. This stitch is easily removed. Remove the wound tape and slowly pull one end of the suture with a needle driver.

As an alternative, the continuous stitch may be placed using absorbable suture material to provide longer-lasting strength to the wound (Figure 93-18). Suture material of choice includes Dexon, PDS, or Vicryl. The same indications, preparation, and stitch are used as with the pull-out technique. The only difference is in the starting and ending stitch. Place the first stitch into the dermis, just inside the laceration edge, as a buried knot (Figures 93-18A to C). Place the continuous suture until the opposite end of the laceration is reached (Figure 93-18D). The final throw should be left lax with a trailing loop of suture (Figure 93-18E). The loop should be used as the “tail end” to perform an instrument tie (Figure 93-18F). Tie three or four knots in the suture. Lift the free ends of the suture and cut them just above the knot. Apply wound tape across the laceration to help maintain the apposition of the wound.

Buried (Subcutaneous) Knot Stitch

This stitch helps to decrease potential dead space underneath a laceration and gives tensile support for up to 4 to 6 weeks, while the wound is still weak. The loop is constructed so that the knot lies at the bottom of the wound base (Figure 93-19). This helps to keep the skin surface smooth and flat. The buried knot stitch is most useful in closing subcutaneous tissue just under the skin surface.

This stitch requires practice to master. Insert the needle into one side of the base of the wound (Figure 93-19A). Drive the needle from deep to superficial and exiting at the dermal-epidermal junction (Figure 93-19A). Insert the needle through the dermal-epidermal junction on the opposite side of the wound and drive it through the base of the wound (Figure 93-19B). The suture should exit the base of the wound across from and level with the entrance site of the first throw. Pull both free ends of the suture up and out through the laceration (Figure 93-19C). Tie a knot in the suture (Figure 93-19D). Pull both free ends of the suture to lower the knot to the base of the wound and appose the tissue (Figure 93-19E). Tie two additional knots to secure the suture. Cut off any excess suture.

Reinforcing (Retention) Sutures for Wounds under Tension

Reinforcing or retention sutures are particularly useful for wounds in which the edges are widely separated or where the skin is too atrophic to approximate without the suture cutting through the skin. The reinforcing sutures help to decrease the tension on the wound by providing more support for the wound edges. Reinforcing sutures can be placed using sterile buttons or rubber tubing (Figure 93-20). Heavy sizes of nonabsorbable suture materials are used for reinforcing sutures. This is not for strength but to avoid the finer suture from cutting through the tissue.

Ideally, a double-swaged (needle) suture should be used to place suture from the inside of the wound toward the outside skin to avoid pulling potentially contaminated epithelial cells through the wound. The stitch is placed like the horizontal mattress stitch and sterile buttons or rubber tubing is used to achieve approximation to a point where the wound edges can be closed without significant tension (Figures 93-20A & B). Do not attempt to appose the wound edges when using retention sutures. Appose the remaining skin edges with simple interrupted, vertical mattress, or horizontal mattress stitches. The reinforcing sutures should remain in place after the skin sutures are removed. The reinforcing sutures should be removed after the wound has healed and gained significant tensile strength.

Remove sutures as soon as possible to avoid the possibility of infection and prevent the formation of suture marks. However, if they are removed too early, wound dehiscence may occur. Simple interrupted sutures should be cut at the end away from the knot and then pulled out (Figure 93-21A). This helps to prevent the outer contaminated portion of the suture from passing back through the wound. In order to remove a running simple or running-locked stitch, grasp the knot at the end of the closure and cut each loop (Figures 93-21B & C). Pull out each individual suture piece. Vertical and horizontal mattress sutures can be removed in much the same way as the simple interrupted stitch (Figures 93-21D & E).

Tissue adhesives (skin glues) are best used to close low-tension, small, straight-edged, and superficial wounds (Figure 93-22). They should not be used for lacerations that are bleeding, lacerations over joints, or lacerations under tension. There must be adequate hemostasis and the tissue must be as dry as possible. The major advantage to the use of tissue adhesives is speed. Wounds can be repaired quickly and without anesthesia. Other contraindications to this type of closure are angled or beveled wounds. Petroleum-based ointments or similar products will dissolve the tissue adhesive and should be avoided on this type of closure. Refer to Chapter 94 for a more complete discussion of tissue adhesives.

Tissue adhesives come in a variety of forms and applicator tips (Figure 93-22A). Approximate the wound edges with forceps. Commercially available, disposable, single-patient-use tissue forceps can be used (Bionix Development Corp., Toledo, OH). These are specifically designed to approximate the wound edges prior to using cyanoacrylates (Figure 93-22B). Apply the adhesive in two or three layers along the wound edge (Figure 93-22C). The adhesive may also be applied in spots over the laceration (Figure 93-22D) or across the laceration, like wound tape (Figure 93-22E). Droplets or lines should be placed 0.5 cm from each other. Support the wound for 30 to 60 seconds while the adhesive dries.

Skin closure tapes (e.g., Steri-Strips) are used to close very low tension wounds that are tidy and small. They can be used as the primary closure technique for superficial wounds (Figure 93-23) or they can provide reinforcement after sutures have been placed (Figure 93-24). Skin tapes are easy to use and can be placed relatively quickly. They do not leave suture marks and have no skin reactivity.

Skin closure tapes should not be used in wounds where the edges are widely separated or on parts of the body where there is movement or moisture. This technique does not work well on irregularly shaped wounds or wounds where there will be a propensity for swelling of the wound edges. Care should be taken in using these tapes in a child. If they are not secured properly, the child may remove them prematurely.

After the initial cleansing of the skin, clean the skin surface with acetone or alcohol to remove any surface oils. Allow the skin to dry. Apply benzoin solution, or gum mastic (e.g., Mastisol), to the skin on both sides of the wound (Figure 93-23A). Allow 60 to 90 seconds for the liquid benzoin to dry and become tacky. Cut the skin closure tapes to the proper length (Figure 93-23B). Gently tear the end-tab off the back of the card to prevent the strips from deforming (Figure 93-23C). Remove a strip from the card (Figure 93-23D). Firmly secure the tape to one side of the wound (Figure 93-23E). Use the nondominant hand to appose the wound edges as the tape is brought over and secured to the skin on the opposite wound edge (Figure 93-23F). Place additional tapes at 2 to 3 mm intervals until the wound edges are apposed (Figures 93-23G & H). Place pieces of tape across the tape edges to prevent premature removal and skin blistering from the tape ends (Figure 93-23I).

Skin closure tapes may be placed over a sutured laceration (Figure 93-24). The tapes will provide additional support to the wound edge and help to prevent dehiscence. This technique is especially useful in areas of cosmetic concern, such as the face.

The skin closure tapes should remain in place for at least as long as the sutures. They must be kept dry to prevent them from coming off prematurely and the wound from dehiscing. The wound should be observed daily for signs of infection.

Skin closure tapes may be placed across a wound when sutures or staples are removed. The tapes will maintain the apposition of the epidermis as the wound matures. Apply benzoin solution to the skin before removing the sutures or staples. Remove several sutures or staples and apply the skin closure tapes. Continue this process until all the sutures or staples have been removed and the wound is covered with skin closure tapes. Alternatively, remove all of the sutures or staples and then apply the skin closure tapes.

Suturing lacerations in a thin-skinned individual is often difficult. The skin frequently tears as the wound is approximated and the suture is tied. The use of skin closure tapes can facilitate wound closure, strengthening the skin edges, and allow for a more secure wound closure. Clean, prep, and anesthetize the skin. Apply benzoin solution to the skin adjacent to and on both sides of the laceration. Allow the benzoin to sit and become tacky. Apply skin closure tapes over the benzoin on both sides of the laceration. Suture the laceration, ensuring that the needle enters the skin on one side of the laceration and exits the skin on the other side of the laceration through the skin closure tapes on each side. Remove the skin closure tapes at the time of suture removal.

Two advanced skin closure tape-based systems are the ClozeX (Clozex Medical LLC, Wellesly, MA) and the 3M Steri-Strip S Surgical Skin Closure (3M Healthcare, St. Paul, MN). These are nonlatex, disposable, single patient use, transparent, adhesive-based wound closure devices for the primary closure of lacerations and wounds not under tension. They align the wound edges and provide good cosmetic results. They come in a variety of sizes, ranging from 10 to 100 mm.

Stapling is a rapid closure technique that is useful for superficial scalp lacerations and linear lacerations of the trunk and extremities. Staples should not be used on the face, neck, hands, or feet. These areas have little subcutaneous tissue and the staples can damage underlying structures. Staples should also be avoided in any area of the body that will be exposed to computed tomography (CT) or magnetic resonance imaging (MRI). The staples are made of an inert material, which helps to decrease tissue reactivity. Staples should not be used for wounds that are crush wounds, infected, irregular, macerated, over bony prominences, or under tension.

The skin stapler is a simple device (Figure 93-25). It is a single patient use, sterile, disposable unit that is preloaded with staples. It is grasped and held with one hand. When the handle is squeezed, a staple is inserted into the tissue. The stapler automatically loads the next staple after one staple is discharged. Skin staplers typically have 10 or 35 preloaded staples.

Prepare the wound for stapling. Place deep sutures to close the subcutaneous tissue and, if the wound is gaping, bring the wound edges into apposition. Approximate the skin edges with the dominant hand (Figure 93-26A). Evert the wound edges with a forceps held in the nondominant hand (Figure 93-26A). Grasp the stapler with the dominant hand. Gently place the skin stapler over the laceration (Figure 93-26B). Start at one end of the laceration and work toward the opposite end. Do not indent the skin with the stapler, as this will cause the staples to be placed too deep. Align the arrow on the front of the stapler over the laceration (Figure 93-26C). Squeeze the handle of the stapler. A plunger will advance a staple into the wound margins (Figure 93-26D). An anvil will bend the staple into a square or rectangular shape to secure the staple (Figure 93-26E). Continue to evert the wound edges and apply staples every 3 to 5 mm until the wound is approximated and without any gaps (Figure 93-26F). A small space will be visible between the skin surface and the staple if it is properly positioned. If the staple is against the skin, it has been placed too deep. Remove the staple and replace it.

There are a few complications associated with staple use. Their removal can be uncomfortable or difficult. Minor bleeding can occur from the holes after the staples are removed. Staples placed on the face, feet, hands, and neck can damage superficial subcutaneous structures (e.g., blood vessels, muscles, nerves, and tendons). Improper wound eversion can result in wound dehiscence upon staple removal, larger scars, and poor wound healing. Staples can cause larger and more prominent skin marks and subsequent scarring when compared to sutures.

Staple Removal

Staples should remain in place for approximately 5 to 10 days, the same amount of time as sutures. They can remain longer if placed over a joint or in cases of slow wound healing. The staple remover is a disposable, sterile, single-patient-use device (Figure 93-27A). It is made of metal or plastic with metal tips. The lower jaw of the stapler has two upwardly angled metal prongs (Figures 93-27B & 93-28). The upper jaw of the stapler is a flat piece of metal. Insert the prongs of the lower jaw of the staple remover between the staple and the skin (Figure 93-28A). Close the handles of the staple remover. This will cause the upper jaw to compress the center of the staple and the arms of the staple to withdraw from the skin (Figure 93-28B). Lift the staple remover and staple off of the skin. Discard the staple and continue the process until all the staples have been removed. A patient who plans to follow-up in a clinic or office should be given a staple remover to take with them, as many clinics and offices do not routinely stock these devices.

Scalp wounds can be closed using hair-tying, also known as the hair apposition technique (HAT).11–15 This technique is relatively painless, does not usually require anesthesia, results in a shorter procedure time, eliminates the need for staple or suture removal, is cost-effective, and the wound outcome is similar or superior to sutures.11,12,15 This technique should not be used on wounds under tension, wounds with ongoing hemorrhage, wounds that are grossly contaminated, or if the hair is <3 cm in length.

Clean, prep, anesthetize, and dry the laceration and surrounding skin. Start at one end of the laceration and grasp 5 to 15 hairs on each side of the laceration. Twist the hair strands on each side of the laceration to form a single “rope.” Tie the two “ropes” of hair together to close the wound and appose the edges. Use a hemostat and an instrument tie to make the process simpler and easier. Continue this process until the entire laceration is closed with hair ties. As the laceration heals, the hair know will grow away from the wound edges. The hair knot can be cut off by a family member, friend, or primary care provider in 2 to 4 weeks.

An alternative HAT uses tissue adhesive instead of making a hair knot (Figure 94-5).15 Clean, prep, anesthetize, and dry the laceration and surrounding skin. Start at one end of the laceration and grasp 5 to 15 hairs on each side of the laceration. Twist the hair strands on each side of the laceration to form a single “rope.” Twist the two “ropes” of hair together to close the wound and appose the edges. Apply tissue adhesive to the twisted hair and apposed skin segment of the laceration. Allow 30 seconds for the tissue adhesive to dry. Apply a second layer of tissue adhesive and allow it to dry. Continue this process until the entire laceration is closed. This method does not require the later cutting away of the hair knot. Unfortunately, this technique may not produce as much hemostasis or wound eversion as tying a hair knot.15

V-Loc Absorbable Wound Closure Device

The V-Loc (Covidien, Norwalk, CT) is an absorbable, disposable, single use, unidirectional barbed wound closure device. The proximal end is the suture needle attached to an absorbable barbed suture. The distal end is a fixed loop of the suture material. This self-anchoring loop and barb combination eliminates knot tying when closing wounds. It is placed similar to a running subcuticular stitch. The barbs are circumferentially distributed on the suture strand and spread tension evenly across the wound. This device is mostly used for postoperative skin wounds but may become more popular in the Emergency Department.

Insorb Subcuticular Skin Stapler

The Insorb subcuticular skin stapler (Incisive Surgical, Plymouth, MN) combines absorbable sutures and a device similar to a skin stapler (Figure 93-29). This is a sterile, single patient use device that deploys up to 20 absorbable subcutaneous staples (Figure 93-29A). The subcutaneous staples are horse shoe-shaped (Figure 93-29B). The device allows wound eversion with no external sutures or metal staples that require later removal (Figures 93-29C & D). The final cosmetic results are similar to sutures or skin staples. The company also sells a reusable three-arm proprietary forceps to make wound approximation easier for one person.

There are multiple techniques available for closing wounds. The principles and techniques discussed will help to provide the most appropriate closure for the various types of wounds that are seen in the Emergency Department. Care should be taken to provide the best closure possible to provide good cosmesis and avoid complications.