(From Lammers RL. Methods of wound closure. In Roberts JR, Hedges JR [eds]. Clinical Procedures in Emergency Medicine, 5th ed. Elsevier, Philadelphia, 2010.)

Needle drivers should fit the physician’s hand; the ring finger fits in the lower circle of the handle, and the thumb may fit in the top circle of the handle with the index finger extended along the shaft to stabilize the needle driver. Load the needle by locking the needle driver about three-quarters the way up the shank of the needle, with the needle held perpendicular to the needle driver. Sharps are kept in the same area of the sterile field to develop a system for reducing needle stick injuries.

Suture

Three basic types of suture exist: natural absorbable, synthetic absorbable, and nonabsorbable. Sutures are sized according to the 1937 U.S. Pharmacopeia classification system. Smaller suture has a higher number of zeroes (2-0 is 00 and 4-0 is 0000). The physician should use the smallest size that provides adequate tensile strength initially to close the wound and not to fail during the healing process. The clinician should use deep sutures to reduce surface tension if the wound is deep and there is high skin surface tension. Ideally, skin sutures gently approximate the skin edges with minimal tension.

Absorbable types of suture include plain gut, chromic gut, and synthetic sutures made of polyglycolic acid, polylactic acid, polydioxanone, and caprolactone. Plain gut suture used externally has a tensile strength lasting 5 to 7 days, whereas chromic gut used internally has a tensile strength lasting 10 to 14 days. The synthetic absorbable types of suture vary in length of tensile strength and rate of absorption. Nonabsorbable suture is made of nylon, special silk, polypropylene, or polyester. These sutures are made in different colors and are inert. Most have long-lasting tensile strength. Non-absorbable sutures are used externally but can be used internally for prolonged tissue reinforcement. Nonabsorbable sutures cause less immune response and therefore less scarring. Frequently, they are used superficially when cosmetic outcome is critical.

Traditionally, it was advised that absorbable suture be used only if it is placed below the skin’s surface because of its porous structure and a possible wick for bacteria on the skin surface. However, this recommendation is not evidence based. A meta-analysis of two randomized, controlled trials (RCTs, Jadad scores 3) comparing absorbable versus nonabsorbable sutures in the management of traumatic lacerations and surgical wounds showed no changes in infection rates, scar appearance, patient satisfaction, or dehiscence. In children, the benefit is not requiring suture removal (Al-Abdullah et al., 2007).

Plain gut sutures last intact for 5 to 7 days and may be used to close small mucosal lacerations or excisions. Plain gut sutures do not survive long enough for use on deep tissue reapproximation. Use 5.0 to 6.0 nylon suture on the face, and remove in 3 to 5 days. If the wound is elsewhere on the trunk, extremities, or other areas with tension, use 3.0 to 4.0 nylon sutures and remove in 10 to 14 days.

Needles

Suture needles are classified by the geometry of their points. Taper needles have a round body that tapers smoothly to a point. Cutting needles are triangular with a sharp cutting edge on the inside curve of the needle; reverse cutting needles have the cutting edge on the outside of the curve. A taper-cut needle is round but ends in a short, triangular cutting point. Some needles are attached permanently to suture and others, called “pop offs” separate from the suture with a sharp pull. With a wide range of needle types, the physician should be familiar with supplies and examine the outside of the package closely before opening. Reverse cutting needles are stronger than conventional cutting needles; both minimize trauma to the skin and so are appropriate for most skin closure.

Anesthesia

(From Frank BL. Principles of pain management. In Auerbach PS. Wilderness Medicine, 5th ed, Mosby-Elsevier, Philadelphia, 2007.)

Complications with Local Anesthesia

Recognizing the various side effects and reactions to local anesthesia is critical to prevent serious complications. The most common complication with the use of local infiltrative anesthesia is a vasovagal episode. The patient may look pale, begin to sweat, and then feel faint or even fall unconscious. Although accompanied by one or two tonic-clonic beats in some cases, this is not considered a seizure. Lying the patient down in reverse Trendelenburg positioning with both legs elevated can increase blood return to the heart and improve vagally depressed cardiac output. Atropine can reverse vagal bradycardia but is rarely needed. Recovery occurs spontaneously within minutes, but the queasiness may persist for 30 to 60 minutes.

Inadvertent instillation of an anesthetic into a blood vessel may cause seizures, jitteriness, or palpitations and may be avoided by always aspirating before infiltrating the local anesthetic. If a flash of blood is obtained on aspiration, pull the needle back partially, aspirate again, and instill only if no blood return occurs. Other reactions to local anesthesia are discomfort, bruising, and edema of the injection site. True anaphylaxis to lidocaine is estimated to occur in less than 1% of injections (Haugen and Brown, 2007). Administer diphenhydramine (Benadryl), 25 to 50 mg orally, intravenously, or intramuscularly in adults and 1 mg/kg in children, and epinephrine 1:1000 subcutaneously every 5 minutes as needed. The adult dose of epinephrine 1:1000 is 0.3 to 0.5 mL/kg and the pediatric dose 0.01 mL/kg at the same intervals. Emergency response personnel should be notified, and prolonged observation may be warranted.

Sedation

Some patients may require minimal to mild conscious sedation during a procedure in the outpatient clinic setting. Use of a low-dose benzodiazepine, such as 1 to 2 mg of lorazepam or 0.5 to 1 mg of alprazolam, may be appropriate for light conscious sedation. Sedation may also be accomplished with a dose of an oral opioid, such as hydrocodone or oxycodone. These patients should not operate a car or heavy machinery, and another person should provide their transportation. Use of an opioid in combination with a benzodiazepine may cause significant respiratory depression. This mixture is usually considered moderate to heavy sedation and requires additional constant monitoring of cardiac and oxygenation status, which may not be available in some ambulatory clinical practices.

Wound Irrigation

Wound healing is affected by infection, tension, perfusion, and alignment. Cleaning a wound with tap water or isotonic saline removes debris and bacteria mechanically from the wound and reduces infection rates. One study found no clinically important differences in infection rates between wounds irrigated with tap water or a normal saline solution (Valente et al., 2003).

Many studies recommend 7 psi (lb/in²) or greater for adequate irrigation of dirty wounds and 0.5 psi for clean wounds. Irrigation of the wound with a 35-mL syringe and a 19-gauge needle produces 7 psi, whereas using a bulb syringe only produces 0.5 psi, which is inadequate to flush and decontaminate a dirty wound. The potential for lateral subcutaneous dissemination with use of high-pressure irrigation can make a clean wound more susceptible to infection, so it should be reserved for contaminated wounds where benefits are greater than the risk of dissemination. The low-pressure bulb syringe is used for clean lacerations. The pressure is more important in dislodging adherent bacterial and small particles than the amount of solution used. Splash protection should be used by all health care personnel (Edlich et al., 2010).

There is debate on using povidone-iodine (Betadine) to cleanse dirty wounds. In general, avoid Betadine surgical scrubs within the laceration because it can be toxic to tissue. If used, dilute Betadine 1:10 with water. Chlorhexidine and hydrogen peroxide may also be toxic to tissue inside a laceration and should be used with care. Poloxamer-188 solutions are safe to use within wounds and are even used on ophthalmologic skin surgeries to cleanse the conjunctiva and by dentists to cleanse oral mucosa.

KEY TREATMENT

Studies recommend 7 psi or greater for adequate irrigation of dirty wounds (Edlich et al., 2010) (SOR: A).

Debridement

A dirty, uneven wound may benefit from direct sharp debridement back to clean viable tissue. Obtaining clean, even skin edges may improve healing, facilitate repair, and reduce scarring. If road grit is present, it must be removed to avoid infection and tattooing and may also need to be scrubbed. Generally, unless high-pressure irrigation is not removing grit, scrubbing is avoided because it may disrupt clotting along the skin edges. High-velocity trauma, soiled deep wounds, and fecal contamination represent wounds best cleaned in the operating room and allowed to heal open by secondary intention, as primary closure is contraindicated (Edlich et al., 2010).

Good anesthesia is critical to appropriate irrigation and debridement. If significant debridement is planned, the physician should document neurologic function in the injured area and distally before infiltration of the anesthetic.

Principles of Healing

Wound healing begins immediately after the initial trauma or cut. Traditional descriptions of wound healing use three distinct but overlapping phases (inflammatory, proliferative, remodeling), whereas others use four phases to better describe the healing process. Surgical technique and smoking are modifiable risk factors for poor wound healing. Other factors affecting wound healing include anemia, diabetes, malnutrition, HIV infection, and cancer.

Trauma to surrounding tissue by the injury and surgical techniques (e.g., too much tension on sutures) may affect healing. Adequate oxygenation and blood flow are critical to good healing. Medications that affect healing include steroids, NSAIDs, and immunosuppressive medications.

Stages of Healing

Exudative or Inflammatory Phase

Immediately after a laceration, fibrin deposits with an influx of platelets, forming a visible clot. The platelets secrete various wound-healing growth factors that activate macrophages and fibroblasts. These growth factors and more then 30 cytokines cause an influx of cellular structures. This phase occurs from 0 to 72 hours (Fig. 28-3).

Figure 28-3 Cutaneous wound 3 days after injury. The cells and growth factors necessary to facilitate cell migration into the wound are shown. FGF, Fibroblast growth factor; IGF, insulin-like growth factor; KGF, keratinocyte growth factor; PDGF, platelet-derived growth factor; TGF, transforming growth factor; VEGF, vascular endothelial growth factor.

(From Singer AJ, Clark RAF: Mechanisms of disease: cutaneous wound healing. N Engl J Med 1999;341:738; and Ethridge RT, Leong M, Phillips LG. Wound healing. In Townsend CM, Beauchamp RD, Evers BM, Mattox KL [eds]. Sabiston Textbook of Surgery, 18th ed. Saunders-Elsevier, Philadelphia, 2008.)

Resorptive Phase

After 24 to 72 hours, the degradation products of fibrin lead to activation of chemotaxis in the resorptive phase. Leukocytes and macrophages migrate into the wound, causing inflammation. The cellular components then begin autolysis and remove injured tissue by a fermentative process. This process creates an effective phagocytosis, a sterilizing defense, and an activation of the immune system.

Proliferative Phase

Between 72 hours and day 7, fibroblasts migrate into the wound, and vascular proliferation occurs. Granulation tissue formation marks the proliferative phase. Epidermal cells begin to grow at the edges of the wound. A delicate balance of cytokine systems leads to new capillary formation to feed and oxygenate the budding granulation tissue. Extracellular matrices form and act as struts to support the new tissue. The primary clots are broken down by naturally developing fibrinolytic compounds (Fig. 28-4).

Figure 28-4 Cutaneous wound 5 days after injury. Blood vessels are seen sprouting into the fibrin clot as epidermal cells resurface the wound. Some of the proteinases involved in cell movement at this point are shown. MMP-1, 2, 3, and 13, matrix metalloproteinases 1, 2, 3, and 13 (collagenase 1, gelatinase A, stromelysin 1, and collagenase 3, respectively); t-PA, tissue plasminogen activator; u-PA, urokinase-type plasminogen activator.

(Modified from Singer AJ, Clark RAF. Mechanisms of disease: cutaneous wound healing. N Engl J Med 1999;341:738; and Ethridge RT, Leong M, Phillips LG. Wound healing. In Townsend CM, Beauchamp RD, Evers BM, Mattox KL [eds]. Sabiston Textbook of Surgery, 18th ed. Saunders-Elsevier, Philadelphia, 2008.)

Regenerative or Remodeling Phase

The remodeling stage is a continuation of the proliferative phase, with ongoing maturation of collagen. The thickening collagen leads to an increased resistance to shearing and tearing forces. The regenerative phase is characterized by epithelialization and scar formation. This last phase may take up to 1 year. Collagen type III is converted into the mature type I collagen (Fig. 28-5). The extracellular matrix and cells within the wound are regulated by cytokines and integrins (transmembrane cell receptors) (Fig. 28-6).

Figure 28-5 Interaction of cellular and humoral factors in wound healing. Note the key role of the macrophage. bFGF, Basic fibroblast growth factor; EGF, epidermal growth factor; GAGs, glycosaminoglycans; H₂O₂, hydrogen peroxide; IFN-γ, interferon gamma; IGF, insulin-like growth factor; IL, interleukin; KGF, keratinocyte growth factor; O₂⁻, superoxide; PDGF, platelet-derived growth factor; PGE₂, prostaglandin E₂; TGF, transforming growth factor; TNF, tumor necrosis factor; VEGF, vascular endothelial growth factor.

(Modified from Witte MB, Barbul A. General principles of wound healing. Surg Clin North Am 1997;77:513; and Ethridge RT, Leong M, Phillips LG. Wound Healing. In Townsend CM, Beauchamp RD, Evers BM, Mattox KL [eds]. Sabiston Textbook of Surgery, 18th ed. Saunders-Elsevier, Philadelphia, 2008.)

Figure 28-6 Rate of wound healing. Based on the rate of maximum collagen strength, limitation of strenuous activity after 6 weeks of wound healing is not indicated.

(From Lawrence WT, Bevin AG, Sheldon GF. Acute wound care. In Emergency Care. Chicago, Scientific American, American College of Surgeons, 1998; and Chavez MC, Maker VK. Office surgery. In Rakel RE. Textbook of Family Medicine, 7th ed. Saunders-Elsevier, Philadelphia, 2007.)

Keloids

Keloids are fibrous elevated scars that extend outside wound margins. Keloids are unlikely to regress, are likely to recur if excised, and are most likely to occur in patients with darker skin (relative risk [RR] 15-20). Keloids are frequently located over the midline chest, cheeks, and earlobes, and peak incidence is age 10 to 20 years. Wounds that heal by secondary intention and burn wounds are high risks for developing keloids. Keloids may be painful as well as cosmetically unacceptable (Juckett and Hartman-Adams, 2009) (Fig. 28-7).

Figure 28-7 Skin keloid.

(From Habif TP. Clinical Dermatology, 5th ed. Elsevier, Philadelphia, 2010.)

Hypertrophic Scars

Hypertrophic scars are limited to the wound edges and tend to regress over the first year. The treatment of both keloid and hypertrophic scars is similar, except hypertrophic scars have better outcomes. Genetic expression of various cytokines and inflammatory pathways may affect the myofibrocytes in granulation tissue to continue producing scar; the exact causes are being investigated. Pressure dressings and colloidal silicone placed on scars after suture removal or on burn scars may reduce the incidence of both keloids and hypertrophic scars, whereas onion-skin extract (Mederma) alone is not effective (Karagoz et al., 2009).

Hypertrophic scar fibroblasts exhibit resistance to a specific form of apoptosis, or cell death, elicited by contraction of collagen matrix gels. This phenomenon depends on excess activity of cell surface tissue transglutaminases (Linge et al., 2005).

Juckett and Hartman-Adams, 2009.

KEY TREATMENT

Cryotherapy is useful for smaller lesions such as acne and keloids (SOR: B).

Pressure dressings in burns help prevent hypertrophic scars (SOR: B).

Intralesional corticosteroid injections are first-line primary care therapies for keloids; surgery is a second-line option (SOR: B).

Wound Dressings

Covering the wound with an occlusive dressing prevents drying and allows the wound to be moist, promoting healing with collagen synthesis and angiogenesis (Field, 1994). Using a topical antibiotic reduces infection only in wound laceration repairs (Dire et al., 1995), not in elective hospital or office surgical procedures (Smack et al., 1996). Studies show no dressing preference for burn wound care (American Burn Association, 2001), although it should be based on wound origin, depth, size, location, exudate, and degree of contamination (Singer et al., 2008a). Wounds closed with tissue adhesives provide their own protection and require no additional dressing. Review warning signs of infection with the patient, and advise on standard postoperative wound care and timing of suture removal.

Nonhealing Wounds

Patients underlying healing status may be affected by nutritional status and underlying medical conditions such diabetes, cancer, and anemia. Healing may be slowed by smoking as well as age. Surgical repairs with too much tension on skin closure increase the chance of dehiscence and nonhealing. In the United States, chronic wounds affect 6.5 million patients. More than $25 billion is spent annually on treatment of chronic wounds, and the burden is rapidly growing because of increasing health care costs, an aging population, and a sharp rise in the incidence of diabetes and obesity worldwide (Sen et al., 2009).

Principles of Skin Closure

Closure techniques should minimize skin trauma, result in good skin-edge approximation without undue tension, and result in a cosmetically pleasing appearance (Fig. 28-8). The best cosmetic results can be achieved by using the finest suture possible, depending on skin thickness and tension. Generally a 3-0 (000) or 4-0 (0000) suture is appropriate on the trunk, 4-0 or 5-0 on the extremities and scalp, and 5-0 or 6-0 on the face. Forceps with teeth and skin hooks should be used to reduce crush injury to wound edges. Use the least amount of sutures to close the skin with good approximation and without deep, open space. Sutures on the face should be removed about day 3 to day 5, wounds not under tension on day 7 to 10, and wounds under tension, on the hands, or over joints on day 10 to 14. If you remove a suture and the wound opens up, cease removing the other sutures and place a sterile strip while asking the patient to return in 2 days.

Figure 28-8 Wound repair: skin closure. A, Too few stitches used. Note gaping between sutures. B, Too many stitches used. C, Correct number of stitches used for a wound under an average amount of tension.

(From Lammers RL. Methods of wound closure. In Roberts JR, Hedges JR [eds]. Clinical Procedures in Emergency Medicine, 5th ed. Elsevier, Philadelphia, 2010.)

Sutures are an option along with staples, tissue adhesives, and use of hair to tie edges together on some scalp wounds. Avoid staples in the scalp if computed tomography (CT) or magnetic resonance imaging (MRI) is planned. Expedient cleaning, debridement, and closure with the least trauma to the wound and patient should be the goal.

Skin Tension Orientation

Surgeons searching for an ideal guide for elective incisions have developed 36 named guidelines. Karl Langer (1819–1887) studied and drew skin lines of cleavage after noting that round punctures in cadaveric skin produced ellipses. The topographic orientation of these lines coincides with the dominant axis of mechanical tension in the skin. Langer lines were developed by studying skin tension in cadavers with rigor mortis and therefore may not be representative of a living human’s skin tension lines. Kraissl noted tension lines in living tissue and developed lines oriented perpendicular to the contraction of the underlying muscles. Later, Borges described relaxed skin tension lines (RSTLs), which follow furrows formed when the skin is relaxed and are produced by pinching the skin. These are only guidelines, however, and many factors contribute to the camouflaging of scars, including wrinkles and contour lines. RSTLs are formed by the natural tension on the skin from underlying soft tissue and rigid bony or cartilaginous substructure.

Superior results in scar revision arise from making incisions parallel or nearly parallel to RSTLs. The Borges RSTLs and Kraissl lines may be the best guides for elective incisions of the face and body and are often mislabeled “Langer lines.” Cosmetic appearance is best if RSTLs are used on the face. The face can be divided into parallel variations of the four main facial lines: the facial median, nasolabial, facial marginal, and palpebral lines. When doing punch biopsies, stretch the skin 90 degrees perpendicular to follow the RSTLs so that the resulting ellipse-shaped wound and closure are parallel. This also improves cosmesis (Fig. 28-9).

Figure 28-9 A, Facial relaxed skin tension lines (RSTLs). B, RSTLs of the entire body.

(From Trott A. Wounds and Lacerations: Emergency Care and Closure, 2nd ed. St Louis, Mosby, 1997; and Burns JL, Blackwell SJ. Plastic surgery. In Townsend CM, Beauchamp RD, Evers BM, Mattox KL [eds]. Sabiston Textbook of Surgery, 18th ed. Saunders-Elsevier, Philadelphia, 2008.)

Skin Tension on Closure

Ideally, any wound, excision, or repair should be designed so that the skin edges approximate under minimal tension. If not, and it is a clean laceration or elective excision, the surgeon may undermine tissue and trim to make edges approximate. Debridement or excision of the edges of dirty wounds may improve alignment and allow closure. Placement of tension-relieving sutures or deep sutures should always be considered to facilitate direct closure of noninfected wounds under tension. If a suture is less than ideal, it is best to remove and replace it.

Tips and beveled lacerations are challenges because too much tension on the narrowest edges may contribute to necrosis or wound breakdown. Ideally, the skin sutures are used to approximate slightly everted edges and not to pull primary deep tissue under high tension. If the wound or excision has a clean approximation under minimal tension, a single-layer repair is preferred. If not, consider deep interrupted sutures to close the potential space (Fig. 28-10). The goal is also to avoid deep pockets where hematomas, infection, or abscesses could develop. (See Tuggy Video: Inverted Subcuticular Stitches.)

Figure 28-10 Inverted subcutaneous stitches.

(From Lammers RL. Methods of Wound Closure. In Roberts JR, Hedges JR [eds]. Clinical Procedures in Emergency Medicine, 5th ed. Elsevier, Philadelphia, 2010.)