Ensuring hemostasis prior to wound closure is important to minimize risk of postoperative hematoma and complications with wound healing. However, although the visible deeper tissue vessels will require meticulous hemostasis with either bipolar or monopolar forceps, the skin edge dermal bleeding does not usually require this. Instead, dermal bleeding usually stops once the dermal edges are reapproximated. Excessive cautery to the dermal edge can lead to unnecessary tissue damage and subsequent wound healing problems. Where bleeding from the wound edges persists such as in anticoagulated patients, or specific body sites such as the scalp, use of hemostatic sutures can be helpful. These include horizontal mattress sutures which serve to evert the wound edges more effectively, or running sutures which more effectively seal the entire wound edge. However, care must be taken when using such suture techniques not to strangulate the tissues and cause necrosis.
managed? When soft tissues are inflamed, they tend to be more fragile and less resilient to manipulation and even careful tissue handling. Prolonged or intense inflammation can cause injury to viable tissues, resulting in failure for the wound to progress in terms of healing.1 Furthermore, independent of etiology, local edema impedes cell signaling and cell migration, thereby disrupting normal immunological processes essential to wound healing. It is generally accepted that meticulous tissue handling is vital, especially in such circumstances, and that where tissue is inflamed, direct wound closure should be avoided or postponed.
When suturing wounds, there is a fine balance to be achieved between the provision of adequate support for the healing wound, and avoiding an excess of sutures which may cause vascular compromise or scarring to the wound edges. In addition, the duration of support must be sufficient to facilitate wound healing. For this reason, a safe guide is to adequately offset tension with enough sutures and avoid either overtightening them or placing too many of them such that vascular compromise at the wound edge occurs. There are no set numbers of sutures required to close a given wound length although there may be rules of thumb. In most delicate areas such as the face, placement of sutures 5–10 mm apart is usually satisfactory. They may be placed slightly further apart in the trunk and limbs. Placing them closer will only serve to restrict wound edge blood supply. If there remains obvious gapping, then additional sutures may be selectively placed to address this. When considering timing for suture removal, wound strength needs to be considered. For example, at 1 week it is estimated that the newly healing wound will only have 3% of its previous strength and should therefore be supported further with sutures. The exception to this rule is where deeper sutures have also been placed and this can facilitate early removal of the superficial external sutures. Unwisely placed sutures can cause local tissue damage and ischemia. Avoiding excessive compression at the wound edge is especially critical when reapproximating a “tip” or “corner” of a skin flap or where there is pre-existing vascular compromise. Sutures should not be overtightened as this can further compromise wound edge vascularity.
The timing of suture removal following surgery will be dependent on a number of factors including wound type (size, location, chronicity, vascularity, wound tension) and general patient factors (systemic disease, age, nutrition, recent infection, and smoking history). Furthermore, it will depend on sutures used, for example, whether deeper dermal sutures have been placed or not. However, it is generally accepted that sutures may be removed at fairly consistent times post wound closure with predictable results. Sutures are normally removed earlier from areas where vascularity is highest and where cosmesis is most critical such as the central face. For this reason, sutures can be removed from the periorbital, cheek, lip, and chin areas early, e.g., 4–7 days post surgery. Ideally, there will be deeper absorbable sutures supporting the wound beyond this timeframe unless the skin is particularly thin like the upper eyelid, where a single layer closure is safe and effective. Sutures in the scalp can also be removed fairly early and 7–10 days is typical for this body site, although again deeper support may still be required. Sutures are left longer in other areas such as the trunk and limbs (2–3 weeks typically). The downside to leaving them longer is that suture marks are left on the skin. For this reason, many plastic surgeons have a preference for using buried sutures, such as a running subcuticular, on the trunk and limbs (Table 17.1). Table 17.1 Timing for Suture Removal Location Timing Scalp 1–2 weeks Face 4–7 days Trunk 2 weeks Extremities 2 weeks
Following wound closure, there ensues a process of scar maturation and remodeling as collagen fibers realign and progressively change in ratio of type III to type I subtypes. By 3 months the wound should have reached a fairly steady state in terms of new collagen formation and turnover, but may still undergo further maturation until 1 year. Peak tensile strength is normally reached at approximately 90 days (80% preinjury strength) and ultimately determined by the quality and quantity of collagen. It never reaches 100% of the preinjury of presurgery status.
All bite injuries should be thoroughly debrided as early as possible due to the fact that animals and humans carry a high volume of bacteria within the mouth so bite injuries have a high chance of developing wound infection. Although in some carefully debrided human and dog bite wounds loose approximation of the wound edges is an acceptable practice, this is not appropriate in cat bites which tend to be small, but deeply penetrating injuries that have a high risk of associated infection. For this reason, they warrant aggressive early intervention with formal debridement, copious irrigation, and should then be left open to heal by secondary intent. Cat bites can be quite resistant to treatment and daily review with wound irrigation and continued antibiotics are the mainstay of treatment. Due to the small wound size (as feline teeth are small), it would be extremely unusual to require skin grafting. Human and dog bites should also be debrided and irrigated early after presentation to the ER, and antibiotics commenced immediately. Bites affecting the face which are well vascularized (and also cosmetically sensitive) should generally be closed directly, if possible, at the time of initial debridement. Many surgeons prefer leaving bite injuries elsewhere on the body, such as the trunk and limbs, open with at most some loose tacking sutures or none at all to minimize the risk of infection.
Delayed primary closure is where a wound, which may be subacute or chronic, is converted to an acute wound by sharp debridement back to healthy viable tissues. Following this delayed debridement, the wound can be treated as an acute wound and closed directly, providing there is sufficient tissue laxity to do so. This approach may be indicated in wounds which are edematous at presentation, or those which have been contaminated or recently infected. For example, during limb fasciotomies in a trauma setting, the wounds can be left open for a few days until soft tissue swelling has reduced, then closed directly. Sometimes in the situation where a leg has a medial and lateral wound, the medial wound can be closed by delayed primary closure, but the lateral wound will still require a split skin graft. This will depend on many factors related to both the wounds themselves and the patient. Other wounds that may be treated well with delayed primary closure are those where infection has been present, but is no longer active. This can be undertaken providing there is sufficient soft tissue laxity and the tissues are sufficiently pliable. Otherwise allowing to heal by secondary intention or skin grafting may be required. The final outcome following delayed primary healing is comparable to primary closure of a wound and is generally a preferable approach to flap or graft closure in terms of long-term function and cosmesis. Negative pressure dressings are useful to temporize larger wounds after their initial debridement until definitive wound closure is performed. Therefore, they sometimes have a role in the process of delayed primary closure, for example, in open tibial fractures where primary closure is delayed to allow soft tissues to recover from the initial injury and swelling to reduce. The benefit of the negative pressure dressing in this setting is that it maintains a closed wound environment in the interim between first debridement and final closure.
Healing by secondary intention is where a wound is allowed to heal on its own by contraction, granulation, and epithelialization. It does not involve sutures or skin grafts. This modality can be very useful in some cases where there is insufficient tissue laxity for direct closure or where there has been tissue damage and/or infection where it is not ideal to seal the wound early. It is therefore used for closure of primary surgical wounds as well as wounds in the emergency setting. In some situations, healing by secondary intent will give a good cosmetic outcome and one which is superior to skin grafting. For example, small wounds on the scalp tend to do well with healing by secondary intent as do some on the lower limb after removal of small skin cancers. The classic example of good healing by secondary intent is the donor site of a paramedian forehead flap when used for nasal reconstruction. The main reason this is preferable to a graft in the longer term is that the use of a graft leaves a depression where the graft is inset. In contrast, during the process of secondary intent, the healing wound fills with granulation tissue such that there is usually no contour defect once healing is complete. The other obvious benefit for allowing healing by secondary intent is that it avoids a donor graft site. However, not all cases are well suited to healing by secondary intention because it results in contraction of the wound edges and can lead to quite significant distortion of tissues. This can be quite marked in areas such as the lower eyelid where an ectropion can develop, or around the nose where distortion of the alar and nostrils can occur. It is important to explain to patients before surgery that the process will be quite drawn out and their wound is likely to take at least 6–8 weeks to fully heal depending on site and size.
When surgically managing a wound following trauma, it is important to ensure removal of all potentially nonviable/damaged tissue as well as foreign material. Therefore, the surgeon should sharply debride grossly nonviable tissue and ragged skin edges prior to reapproximation of the wound edges. For facial wounds and cosmetically sensitive areas, one should err on the side of leaving marginal appearing tissue behind. This is because the scalp and face have a rich vascular supply and the skin and soft tissues tend to tolerate insult better than within other anatomic regions. Furthermore, there tends to be less excess tissue (except in the elderly patient) and also the tissue can be quite specialized (e.g., lips, nose and eyelids); so it should be preserved, if at all possible. This is particularly important when taking infants and children to operating theater even for animal bite injuries.
outcome? Ensuring thorough wound irrigation is key to the proper management of traumatic soft tissue wounds prior to definitive wound closure. The most important element of this process is the technique used by the operating surgeon, rather than choice of irrigation fluid. This means that sufficient irrigation volume needs to be used with adequate pressure to facilitate satisfactory removal of foreign bodies and gross contamination. Of course, irrigation alone is not a substitute for surgical debridement in the presence of necrotic tissue or biofilm. The two processes go together. The fluid options for irrigation include sterile water, normal saline, hydrogen peroxide, chlorhexidine and iodine-based products. However, there is little evidence to support the use of one lavage fluid over another. By tradition, surgeons tend to use normal saline as the lavage fluid of choice, although sterile water or iodine-based substances are also each regularly used for wound irrigation. In terms of skin preparation, both iodine- and chlorhexidine-based skin preparations are effective, although there is conflicting evidence on which is superior. What is known definitively is that alcohol-based skin preparations are superior to those that are not alcohol based. For this reason, many units will use this as their first-line skin preparation agent in open fracture management.1,2 (Note that care should be taken when using hydrogen peroxide or chlorhexidine close to the eyes as these can potentially cause ocular damage.) The use of loupe magnification is standard practice for plastic surgeons and this helps the surgeon to identify small foreign body particles and accurately assess the viability of wound margins. However, this alone is not the most important factor in irrigation or debridement. For small wounds, using a blunt tipped needle on a syringe is sometimes favored for irrigation to increase driving pressure of the irrigate, but again, this alone is not the key factor in optimizing the outcome. Indeed, it should not be assumed that higher pressures will necessarily improve wound irrigation as one study has shown. In this multicenter randomized control trial, a low pressure lavage was effective in reducing infection, wound healing problems, and nonunion in open fracture wounds.3
process? Debridement is a term used to describe the removal of all nonviable tissue and foreign material from a wound to return it to a healthy wound bed that should be suitable for wound closure. Surgical debridement is performed either in operating theater or in the ward using a range of different surgical instruments. These include a scalpel, scissors, curette, rongeur, or hydrosurgical device, such as a Versajet. The aim is to achieve the following end points: • Healthy skin edges with bleeding, dense dermis • Viable, soft, yellow subcutaneous fat • Solid tendon substance • Red bleeding muscle • Hard, healthy bone with pinpoint bleeding, or “paprika sign” Debridement should ideally be performed with no tourniquet (if working on a limb) and with sharp, progressive, tissue removal so that continued assessment of viability is possible. If viability of the tissue is in question, either more should be resected or reconstruction should be delayed to allow time for demarcation of nonviable tissue. For this reason, monopolar is not recommended for debridement as this will mask dermal and wound edge bleeding, thereby making accurate assessment of tissue viability more difficult. Furthermore, the electrocautery can further damage wound edges secondary to thermal injury. Instead, sharp debridement should be performed and once done, electrocautery can be used to control bleeding as required. It should also be remembered that debridement does not only need to be surgical, but can be chemical or mechanical and in some cases these approaches are favored.
When closing skin wounds, it is important to ensure that the wound edges are everted. This serves to increase the amount of dermal contact, i.e., surface area for skin healing. Eversion can be achieved by both buried and epidermal sutures, whether simple or mattress techniques are used. This is achieved by passing the needle in such a way that more dermal tissue is captured at the depths than at the surface. Eversion of the skin edges will, however, result in a poorer early cosmetic result as it leaves a ridged appearance often described as a “pasty” or “Cornish pasty” look where pastry is squeezed into a ridge. This is only a temporary finding and will settle with time. It is important therefore to advise patients of this prior to and following surgery that it is intended and will settle. This can help reduce their anxiety about early wound appearances. This ridge should ultimately lead to less dehiscence, less scar widening, and better cosmesis. An important consideration when closing skin wounds is to minimize strangulation of tissues and thus disrupting local blood supply. Eversion, per se, does not cause strangulation of tissues but certain techniques such as mattress sutures can increase strangulation as can poor or excessive suture placement. Creating wound eversion will not affect the tissue handling providing it is done carefully with respect to the tissues. In cases where it is desirable to deepen the final scar appearance as may be the case in some nasolabial fold closures, the use of an inverting suture would be preferable, but everting would not help in this situation.
There are a number of advantages and disadvantages to both monofilament and braided sutures, so it is important that surgeons have a good understanding of these in order to select the most appropriate suture material for a given situation. In general, braided or multifilament sutures have good handling characteristics, with good pliability, low memory, and secure knot strength. Therefore, in the situation described they would be ideal where loosening of knots would be detrimental to overall outcome. In contrast, monofilament sutures are more likely to have slippage of knots due to their smooth surface. That does not mean that monofilament sutures will be unsuitable for permanent repairs, although in theory, the knots will be less secure. For example, monofilament sutures remain popular in flexor tendon repair, but in this situation a high number of throws are passed on the knot to minimize slippage post surgery. The disadvantages of braided sutures include a higher coefficient of friction and hence increased drag and tissue damage with each pass of the thread, and a theoretical increase in risk of infection due to their higher surface area, capillarity, and inflammatory potential. For this reason, they would be best avoided in the context of a dog bite wound closure to the limb. Usually, there is no significant difference in terms of wound closure speed with a monofilament versus a multifilament suture. This probably is affected only by surgeon’s preference and experience. If more rapid wound closure is required or where more even tension distribution is required, a barbed suture may be advantageous as it can potentially achieve both.
When placing sutures, it is important to consider postoperative wound management and general aftercare. Often surgeons may place sutures without giving much thought to their subsequent removal. Therefore, when placing sutures in long hair of the scalp, it is wise to select a color that will be easily visible for both the surgeon placing them and the individual removing them down the line. In addition, it is helpful to leave the sutures longer than usual to facilitate this. Therefore, a colored suture such as blue polypropylene is well suited to this scenario. Although silk is easily visible, it is not a good choice for skin closure due to its reactivity.
When closing skin wounds, it is normally recommended to do so with a two-layer approach involving a series of sutures placed in the dermis with deep buried knots (sometimes called deep dermal) followed by either a subcutaneous continuous suture (which can be either absorbable or nonabsorbable), or an external suture (which again can be either absorbable or nonabsorbable). This helps to distribute tension across the wound and allows for nonabsorbable sutures to be removed early and thereby reduce the risk of suture track marks. Although Monocryl and Vicryl have similar qualities and are often used in similar settings, there is some evidence that deep absorbable sutures with Monocryl demonstrate less extrusion than polyglactin 910 (Vicryl). Sutures placed in the deep fascia, tendons, or cartilage are preferentially made with nonabsorbable suture material. In the setting of a rectus plication, it is best to use either long-acting resorbable or permanent suture, as use of a rapidly absorbable suture will not provide the desired long-term outcome in terms of soft tissue support. In contrast, buried skin sutures and superficial fascial sutures should be of an absorbable type. Although the use of silk sutures for securing drains to the skin is a widely practiced technique among surgeons in all disciplines (because of its high friction coefficient and grip on materials), it increases the local inflammatory response and the surface can harbor more bacteria. With proper technique, monofilament suture material (Nylon, polypropylene, etc.) will reliably secure drains, so consideration of these for drain fixation should be given. When insetting the umbilicus using a monofilament permanent or braided nonpermanent sutures, the knots should be tightened to be snug, but not loose nor overly tight as it is important to allow for postoperative soft tissue swelling without compromising wound edge vascularity. Furthermore, it may be beneficial to use a half-buried mattress in this setting as this will enable the knots to be buried on the inside of the umbilicus and therefore any scarring from the suture will be less visible post surgery.1
A purse string suture is used to reduce the size of a circular defect that cannot be closed directly. It involves using a continuous subcuticular suture around the edge of the defect and tightening it to reduce the overall internal wound length. Such an approach is useful to allow healing by secondary intention or reduce the size of skin graft required. A three-point suture is indicated for use as a corner suture in many situations. One example is when closing a Wise pattern breast reduction. The lower medial and lateral skin flap corners are sutured to one another and then sutured to the inframammary fold as a single suture. This is usually performed as a buried dermal suture. A figure-of-eight suture is typically indicated for closure of fascia, muscle, or tendon, rather than skin. There is less chance of cutting through the tissues with such a suture compared with a standard interrupted suture of similar equivalent material. It is also effective at obtaining hemostasis, for example, where bleeding is through a muscle and the precise bleeding point is not easily identified. Progressive tension sutures are useful when closing large subcutaneous skin flaps such as an abdominoplasty as they distribute tension to multiple points and help obliterate dead space. The horizontal mattress suture is used to close the skin where significant eversion is required, such as when closing the palm after fasciectomy. The running horizontal mattress distributes the coaptive tension of the suture along a greater length of the wound and is indicated where the wound edges are friable.
Externally placed skin staples have a number of potential advantages for wound closure. First, they are rapid to use and can therefore help reduce operating times compared with suture placement, particularly in long wounds such as abdominoplasty or brachioplasty. They are also useful as they evert the wound edges well and therefore should result in good healing due to dermal apposition and are also hemostatic, so are well suited for use in the scalp. In addition, they have a high tensile strength and low reactivity with low rates of infection. The downside to using skin clips is that their removal in clinic following surgery is time consuming and patients can find them uncomfortable or painful to remove. This is often the case where wounds are slightly inflamed or swollen or where the staples are not fully opened before attempted removal. In contrast, buried subcuticular continuous sutures such as Monocryl for the same closure would have taken longer time in the OR, but will avoid the need for any removal in clinic, saving time and completely avoiding patient discomfort. Furthermore, if staples are left for too long, they will leave permanent markings on the skin as do skin sutures (i.e., railroad track). This is in part because of their shape and the fact that there is no give in the metal staple to allow for expansion secondary to swelling. Skin staples have an excellent place in plastic surgery for “tailor tacking” temporary wound closure in procedures such as breast reduction, reconstruction, and mastopexy as they provide a rapid means of closure for the operating surgeon to trial close wounds intraoperatively. Otherwise they are probably best reserved for use in the scalp for definitive wound closure.1–4