Skin laceration repair with sutures

INTRODUCTION — 

Laceration repair with sutures will be discussed here. Information concerning wound preparation and irrigation, topical and infiltrative anesthesia, and laceration closure with tissue adhesive or staples is discussed separately:

●(See "Minor wound evaluation and preparation for closure".)

●(See "Clinical use of topical anesthetics in children" and "Subcutaneous infiltration of local anesthetics".)

●(See "Minor wound repair with tissue adhesives (cyanoacrylates)" and "Closure of minor skin wounds with staples".)

PRINCIPLES OF WOUND HEALING — 

The relevant tissue layers for wound healing with a skin laceration repair are the epidermis, dermis, and subcutaneous layer:

●The epidermis and dermis are tightly adhered and clinically indistinguishable; together, they constitute the skin (figure 1). Dermal approximation provides the strength and alignment of skin closure.

●The subcutaneous layer is mainly comprised of adipose tissue. Nerve fibers, blood vessels, and hair follicles are located here (figure 2). This layer provides little strength to the repair; sutures should be avoided since they do not relieve tension and may increase infection rates [1].

The healing process of skin occurs in several stages, which are discussed in detail separately (figure 3) (see "Basic principles of wound healing"):

●Hemostasis – Hemostasis and clot formation occur within minutes of superficial skin injury in healthy patients. The fibrin matrix stabilizes the wound and serves as an initial scaffold for wound healing.

●Inflammation – Inflammation promotes vascular permeability, local vasodilation, and cellular migration and, in the absence of infection or other causes of impaired wound healing, is complete by three days. Polymorphonucleocytes engulf and enzymatically digest bacteria, foreign material, and necrotic tissue.

●Proliferation – Epithelial cells arise from basal cells in the epithelium and bridge clean wounds within one to two days after suturing, providing a barrier that is waterproof. However, this superficial layer is thin and easily disrupted.

●Remodeling – Fibroblasts derived from mesenchymal cells proliferate near the wound site approximately 24 hours after injury. Building upon the fibrin matrix, they produce essential elements for wound contraction and scar formation, including collagen.

Collagen formation is necessary to restore tensile strength to the wound. The process begins within 48 hours of the injury and peaks in the first 1 to 4 weeks. Collagen production and remodeling continue for 6 to 12 months.

WOUND EVALUATION — 

Important elements of wound evaluation include the following, and are discussed separately (see "Minor wound evaluation and preparation for closure", section on 'Evaluation'):

●Mechanism of injury

●Wound age

●Degree of contamination

●Presence of a foreign body

●Wound size and depth

●Presence of neurovascular compromise

●Injury to adjacent structures (eg, ligaments, tendons, muscles, bone, or joints)

●Need for tetanus prophylaxis (table 1)

●Potential for impaired wound healing (see "Minor wound evaluation and preparation for closure", section on 'Risks for poor outcome')

Indications for primary closure — Sutures are appropriate to use for primary closure of skin lacerations when the wound extends through the dermis and is likely to cause excess scarring if the wound edges are not properly opposed. Sutures are preferred when the wound requires careful approximation (eg, lacerations that cross skin tension [Langer] lines (figure 4) or that span important structures such as the eyebrow or vermilion border).

The appropriateness of primary closure with sutures is also determined by the age of the wound, wound location, and patient factors that impact the risk of wound infection:

●Clean, uninfected lacerations on any part of the body may be closed primarily for up to 12 to 18 hours following the injury without a significant increase in the risk of wound infection. Lacerations on the trunk and proximal extremity and lack of risk factors (eg, diabetes, steroid use, contamination) favor better outcomes even with later closure. (See "Minor wound evaluation and preparation for closure", section on 'Type of closure'.)

●Facial wounds may be closed primarily up to 24 hours following the injury in all patients because of lower risk of infection and poor wound healing. In selected patients (no signs of infection, otherwise healthy patient, and easily approximated wound), closure of facial wounds may occur up to 48 to 72 hours after injury. (See "Assessment and management of facial lacerations", section on 'Indications for primary closure'.)

Some lacerations that meet criteria for closure with sutures may also be amenable to closure with staples, skin adhesives, or wound closure tapes (table 2). Closure of lacerations with other techniques is discussed separately:

●(See "Closure of minor skin wounds with staples".)

●(See "Minor wound repair with tissue adhesives (cyanoacrylates)".)

●(See "Assessment and management of facial lacerations", section on 'Adhesive tapes'.)

Contraindications — Contraindications to primary closure in the ambulatory setting include (see "Minor wound evaluation and preparation for closure", section on 'Type of closure'):

●Lacerations for which suturing will significantly increase the risk of wound infection:

•Lacerations through infected skin

•Deep puncture wounds

•Lacerations that have been grossly contaminated with foreign debris that cannot be completely removed by irrigation and debridement at the bedside

●Superficial wounds that would be expected to heal without significant scarring, such as lacerations or abrasions that only involve the epidermis. Suturing in these wounds will potentially cause increased scar formation and risk for infection.

Relative contraindications to primary closure of skin lacerations in the ambulatory setting include:

●Dog and cat bites (exception facial and other potentially cosmetic wounds). (See "Animal bites (dogs, cats, and other mammals): Evaluation and management", section on 'Wound management'.)

●Most human bites (exception facial and other potentially cosmetic wounds). (See "Human bites: Evaluation and management", section on 'Wound closure'.)

●Wounds, other than facial wounds, that are older than 24 hours in patients with risk factors for infection or poor wound healing (eg, immunocompromise, peripheral arterial disease, or diabetes mellitus), especially when presentation from the time of injury is delayed (eg, >18 hours old) or the wound site is more prone to infection (eg, hands or feet). (See "Basic principles of wound healing".)

●Lacerations with significant tissue loss in which suturing will cause too much tension across the suture line. In this instance, surgical consultation for consideration of grafting or use of a flap versus healing by secondary intention with later scar revision may be a better approach.

Lacerations not closed primarily may be left for delayed primary closure (within 3 to 5 days) or healing by secondary intention. (See "Minor wound evaluation and preparation for closure", section on 'Type of closure'.)

Indications for surgical consultation — Consultation with a plastic surgeon or other surgical specialist is warranted for the following wounds:

●Large or complex laceration that will require prolonged repair or use of grafts or flaps (eg, significant tissue loss)

●Severe contamination that cannot be properly managed at the bedside under local anesthesia with or without procedural sedation

●Neurovascular compromise

●Fracture, amputation, or joint penetration (eg, laceration through the knee joint capsule) associated with the laceration

●Anatomic sites requiring specialized repair to ensure optimal cosmetic outcomes:

•The nasal cartilage, ala, or columella (see "Assessment and management of facial lacerations")

•Eyelid or orbital lacerations that involve the eyelid margin or tarsal plate, have protruding subcutaneous fat, or involve the tear duct or lacrimal gland (figure 5) (see "Eyelid lacerations")

•Selected auricle (ear) lacerations (see "Assessment and management of auricle (ear) lacerations", section on 'Indications for subspecialty consultation or referral')

Depending upon the clinician's experience, strong concern about cosmetic outcome by either the patient or family may also be a reason for referring a laceration to a surgeon for closure. However, for experienced clinicians, the outcome of clean skin lacerations in low-risk patients (eg, healthy children) is similar regardless of who performs the primary closure.

ANESTHESIA AND ANALGESIA

Topical, local, or regional anesthesia — Anesthesia (either topical, local infiltration, or a regional block) is necessary in all patients undergoing suturing, including individuals receiving procedural sedation. For most patients, infiltration of a local anesthetic is effective for pain control during laceration repair. The choice of agent depends on several factors, including the duration of the procedure, need for hemostasis, patient sensitivity to catecholamines, and patient allergy to local anesthetics (table 3). Subcutaneous infiltration of local anesthetics, including methods to decrease the pain of injection and techniques for direct infiltration, is discussed separately. (See "Subcutaneous infiltration of local anesthetics".)

For children with uncomplicated facial or scalp lacerations, we suggest initial anesthesia with topical lidocaine-epinephrine-tetracaine (LET) rather than infiltrative anesthesia. (See "Clinical use of topical anesthetics in children", section on 'Agents for laceration repair'.)

Regional anesthesia provides full local anesthesia without distorting tissues adjacent to the wound. This approach permits better approximation for complex lacerations on the face, ear, and lip. In addition, full local anesthesia is difficult to achieve by direct infiltration in some body regions (eg, fingers, toes, tongue, sole of foot). Regional anesthesia in these sites permits greater patient comfort.

Specific nerve blocks by site are listed below and discussed in detail separately:

●Face (see "Assessment and management of facial lacerations", section on 'Facial nerve blocks'):

•Mental nerve block (figure 6)

•Supraorbital or supratrochlear nerve block (figure 7)

•Infraorbital nerve block (figure 8)

●Lip – Mental (figure 6) or infraorbital nerve block (figure 8)

●Auricle (ear) – Auricular field block (figure 9)

●Tongue – Inferior alveolar nerve block (figure 10)

●Fingers and toes – Digital nerve block (picture 1 and picture 2A-B) (see "Digital nerve block")

●Sole of foot – Tibial nerve block (see "Lower extremity nerve blocks: Techniques", section on 'Ankle block')

Nonpharmacologic interventions — In children and anxious older patients, use of nonpharmacologic interventions help alleviate anxiety and may prevent the need for procedural sedation. Child life specialists are experts in applying these techniques when performing laceration repair in children. (See "Procedural sedation in children: Selection of medications", section on 'Nonpharmacologic interventions'.)

Role of procedural sedation — Selected patients may need procedural sedation for suturing a laceration, such as children with complex wounds or when anesthetics and nonpharmacologic interventions are not sufficient. These patients should also receive local or regional anesthesia.

Commonly used agents in children (table 4) are discussed in detail separately. (See "Procedural sedation in children: Selection of medications", section on 'Minimally painful procedures'.)

Procedural sedation in adults is discussed separately. (See "Procedural sedation in adults in the emergency department: General considerations, preparation, monitoring, and mitigating complications" and "Procedural sedation in adults in the emergency department: Medication selection, dosing, and discharge criteria".)

EQUIPMENT — 

Equipment used for skin laceration repair with sutures includes the following [2-4]:

●Personal protective equipment:

•Sterile surgical gloves (clean surgical gloves if sterile not available)

•Surgical mask

•Goggles or face shield

●Anesthesia:

•Local anesthetic for infiltration (table 3) with syringe (1, 3, 5, 6, or 10 mL), needle for drawing up, and narrow-gauge needle (25-, 27-, or 30-gauge) for infiltration (see "Subcutaneous infiltration of local anesthetics")

•Facial and scalp wounds (children): Topical anesthetic (eg, lidocaine-epinephrine-tetracaine [LET] in aqueous or methylcellulose gel) (see "Clinical use of topical anesthetics in children", section on 'Laceration repair')

●Irrigation:

•Irrigation solution (irrigation volume determined by wound location, size, and degree of contamination) (see "Minor wound evaluation and preparation for closure", section on 'Irrigation solution')

•Large syringe (eg, 60 mL) with irrigation attachment with a splash shield, 19-gauge needle, intravenous catheter, or prepackaged pressurized saline wound wash product (see "Minor wound evaluation and preparation for closure", section on 'Irrigation pressure')

●Suture tray (emergency departments typically have trays that contain these items):

•Sterile field drapes

•Needle holder

•Atraumatic tissue forceps

•Scissors (for cutting suture and wound modification [eg, iris scissors])

•Hemostats (if ligating bleeding vessels)

•Sterile cotton swab or surgical probe

•Sterile gauze

●Suture (see 'Suture selection' below)

●Number 10 or 15 blade scalpel and handle if sharp debridement or wound modification is needed

The use of clean rather than sterile gloves does not increase the risk of wound infection and is an acceptable practice for uncomplicated skin lacerations undergoing suturing in the ambulatory setting. A meta-analysis (6 trials, 6182 patients with lacerations and incisions) found no difference in infection rates between sterile and non-sterile gloves (3.3 versus 2.8 percent, relative risk [RR] 1.17, 95% CI 0.89-1.55) [5].

SUTURE SELECTION

Material — Suture material and size selection depends on the wound location, wound characteristics, patient factors, and layer for closure (skin, dermal, and/or mucous membrane) (table 5A and table 5B) [2,3]. For all skin lacerations, the optimal suture minimizes the risk of excess inflammation or infection and maintains its tensile strength during the initial stages of healing (figure 3). The rate of healing varies by body site and individual patient factors such as age and comorbidities that may slow healing (eg, diabetes mellitus or use of corticosteroids or other immunosuppressive medications).

Specific suture selection for facial, scalp, lip, and oral lacerations (table 6) are discussed in detail separately. (See "Assessment and management of facial lacerations", section on 'Suture selection' and "Assessment and management of scalp lacerations", section on 'Simple interrupted sutures' and "Assessment and management of lip lacerations", section on 'Equipment' and "Assessment and management of intra-oral lacerations", section on 'Suture selection'.)

Absorbable versus nonabsorbable — The type of suture material (absorbable versus nonabsorbable) is primarily determined by the skin layer being closed and the disadvantages of suture removal (eg, another minor procedure in a young child, repeat visit). The skin layer can be closed with absorbable or nonabsorbable sutures, while dermal closures require absorbable sutures.

●Absorbable – An absorbable suture is made from either natural mammalian collagen or synthetic polymers, breaks down in the body, and thus does not require removal [4,6]. Different types of absorbable suture degrade at different rates. Absorbable suture forms a secure knot after three ties (throws). Some absorbable sutures (eg, polyglactin 910 [Vicryl] and poliglecaprone 25 [Monocryl]) handle well during suturing, while others can break easily (eg, fast-absorbing gut) or are more difficult to handle (eg, polyglycolic acid [Dexon sutures], polydioxanone [PDS], or polyglyconate [Maxon]).

●Nonabsorbable – Nonabsorbable sutures are made from synthetic materials such as nylon, polybutester, polypropylene, or natural silk and require removal after placement. The major disadvantage of nonabsorbable sutures compared with absorbable sutures is the need for the patient to return for suture removal. Because a synthetic nonabsorbable suture tends to maintain its shape (memory) and not adhere to itself as tightly during knot tying when compared with absorbable suture or natural silk, these sutures require up to five ties (throws) to make a secure knot [4,6]. When compared with absorbable sutures, synthetic nonabsorbable sutures have better handling and will stretch to handle wound swelling. They also come in a variety of colors to make them easier to see during suturing and suture removal.

Skin versus dermal closure — The layer undergoing closure, and for percutaneous sutures, the site-specific timing for wound healing, further determines the suture material.

●Percutaneous closure – Options for percutaneous closure include nonabsorbable synthetic sutures, fast-absorbing gut, polyglactin 910 (Vicryl Rapide), and chromic gut:

•Synthetic nonabsorbable suture – Monofilament nonabsorbable sutures (eg, nylon, polypropylene, and polybutester) theoretically promote the least inflammation relative to braided or absorbable sutures and are easy to handle [4]. All three sutures have elasticity, which permits stretching if wound swelling should occur, followed by return to their prior length once swelling resolves. Polypropylene has the greatest elasticity.

•Fast-absorbing gut – Fast-absorbing gut is heat treated to accelerate tensile strength loss and absorption, which typically occur by six days [7]. It is frequently used for closure of small, low-tension wounds on the face, particularly if suture removal will be difficult (eg, young, uncooperative child or when return for suture removal is not assured) [6]. If fast-absorbing gut is used for wounds with higher tension, placement of dermal sutures with a synthetic absorbable suture (eg, polyglactin 910 [Vicryl] or Monocryl) may decrease wound tension and provide support once the fast-absorbing gut has dissolved.

Fast-absorbing gut is tan and can be difficult to see during suturing. Furthermore, it easily breaks during tying, especially when it becomes dried out [6]. Sterile application of a petroleum coating (eg, antibiotic ointment such as bacitracin [Polysporin]) is used by some clinicians to improve handling and decrease brittleness. Based on one small randomized trial in 14 patients, coating the suture does not appear to impair its absorption [8]. However, in this study, absorption varied significantly among individuals. Thus, patients should be advised to return for suture removal at five days if the fast-absorbing gut sutures are still present. (See 'Follow-up visits' below.)

•Polyglactin 910 (Vicryl Rapide) – Polyglactin 910 (Vicryl Rapide) is a synthetic absorbable suture for approximation of the skin and mucosa. Almost all of its tensile strength is lost by 10 to 14 days, and the suture begins to "fall off" in 7 to 10 days as the wound heals [6]. Thus, it may be appropriate for skin closure in sites where persistence of suture for one week or longer is appropriate (eg, scalp, trunk, extremities, palm, or sole) and when suture removal would be difficult (eg, lacerations located under casts). A trial comparing closure of 200 facial lacerations with Vicryl Rapide and nylon found no differences in cosmetic outcome nor patient satisfaction [9].

•Chromic gut – Similar to Vicryl Rapide, chromic gut retains tensile strength for 10 to 14 days and may be used for repair of fingertip and nailbed lacerations, under a cast or splint, or when follow-up is not assured on scalp lacerations.

Evidence suggests that cosmetic outcomes or frequency of wound complications after repair of traumatic skin lacerations or surgical wounds are similar when lacerations are percutaneously closed with either nonabsorbable or absorbable sutures [10-13]. As an example, in a meta-analysis of 19 trials (1748 patients) comparing the efficacy of nonabsorbable sutures with absorbable sutures for skin closure of surgical and traumatic lacerations, absorbable and nonabsorbable sutures had equivalent cosmetic outcomes and no significant difference for wound infection or wound dehiscence, although follow-up was insufficient in several studies [10]. However, evidence from large trials of suture closure of traumatic skin lacerations is lacking. Thus, the clinician should choose suture material for a specific patient based upon other factors such as need and ease of removal, clinician preference based on handling characteristics, and whether follow-up for suture removal can be assured.

●Dermal closure – Dermal closure requires the use of absorbable suture that retains tensile strength until the collagen formation stage of wound healing is well established (figure 3). Polyglactin 910 (Vicryl) and poliglecaprone 25 (Monocryl) are most commonly used for this purpose:

•Polyglactin 910 (Vicryl) – This is a lubricated, braided synthetic material with excellent handling and smooth tie-down properties [6]. It retains significant tensile strength for three to four weeks. Complete absorption occurs in 60 to 90 days. It has decreased tissue reactivity compared with catgut as well as improved tensile strength and knot strength.

•Monocryl – This is a monofilament suture that has superior pliability for easier handling and tying of knots. Its monofilament quality gives it a theoretical advantage over braided sutures for contaminated wounds requiring deep sutures [6]. This suture is often used by plastic surgeons for facial lacerations closed with subcuticular running sutures. All of its tensile strength is lost by 21 days postimplantation.

Other absorbable sutures such as polyglycolic acid (Dexon), polydioxanone (PDS), or polyglyconate (Maxon) are acceptable alternatives for dermal closure but may be more difficult to handle during suturing and have potential for promoting more inflammation during healing.

Chromic gut and fast-absorbing gut should not be used for dermal sutures because of their rapid absorption and inadequate wound support.

●Oral or tongue lacerations – Because of the difficulty of suture removal, intraoral and tongue lacerations should be closed using absorbable suture. Chromic gut or Vicryl Rapide retain tensile strength for 10 to 14 days in the mouth but are more rapidly absorbed in the oral cavity than other absorbable sutures, making them good choices for this environment. Fast-absorbing gut is broken down too rapidly by enzymes in the saliva to provide adequate time for wound healing and should not be used. Repair of tongue and intraoral lacerations are discussed in detail separately. (See "Evaluation and repair of tongue lacerations" and "Assessment and management of intra-oral lacerations".)

Size — Suture size and tensile strength are commonly measured by the United States Pharmacopeia (USP) system. Tensile strength is defined as the amount of weight required to break a suture divided by its cross-sectional area. In the USP system, the number of zeros inversely correlates with size: the higher the number of zeros, the smaller the size and the lower the strength. For example, a 3-0 suture has a diameter that is approximately two to four times larger than a 6-0 suture (table 5B).

In general, larger suture size is associated with greater inflammation and scarring [2,4,6]. Thus, a smaller suture (eg, USP 5-0 or 6-0) is used for repairs that require close approximation and/or are in regions of cosmetic importance (eg, face, ear, or nailbed) [14]. A larger suture (eg, USP 3-0 or 4-0) is used for:

●Dermal closure of wide gaping wounds

●Intraoral or tongue lacerations

●Percutaneous closure of lacerations for which significant tension across the wound is anticipated (wounds near joints or wide gaping wounds in noncosmetic regions) or where cosmetic outcome is of less importance (eg, scalp)

Needle — For most traumatic skin lacerations, the clinician should choose a suture needle with the following characteristics [2-4]:

●Reverse cutting

●Three-eighths curvature

●Labelled for use on the skin (eg, FS, CE, P, PS, PC, or PRE)

The basic components of a suturing needle are (figure 11):

●The eye (or swage) is the end of the needle attached to the suture. All sutures used for traumatic skin laceration repair are swaged (ie, the needle and suture are connected as a continuous unit).

●The body of the needle is the portion that is grasped by the needle holder during the procedure. The body determines the shape of the needle and is curved for cutaneous suturing. The curvature may be one-fourth, three-eighths, one-half, or five-eighths circle. For traumatic skin lacerations, the most commonly used curvature is the three-eighths circle, requiring only minimal pronation of the wrist for large and superficial wounds. The one-half and five-eighths circles were devised for suturing in confined spaces, such as the oral cavity.

●The point of the needle extends from the extreme tip to the maximum cross-section of the body.

Needle points for use on the skin are triangular and include (figure 12):

●Reverse cutting – Cutting edge is located on the outer (convex) curvature of the needle and perpendicular to two other opposing cutting edges. This type of needle is preferred for most skin closures.

●Conventional cutting – Cutting edge is located on the inside (concave) curvature of the needle and perpendicular to two other opposing cutting edges. This needle type may be prone to cutout of tissue because the inside cutting edge cuts toward the edges of the incision or wound. Thus, conventional cutting needles should be avoided for closure of skin lacerations.

Needles are further divided by manufacturer designations, which do not necessarily follow a specific convention. Common designations include [15]:

●Standard skin needles such as FS (for skin) or CE (cutting edge) series are suitable for closure of scalp, trunk, and extremity lacerations.

●Plastic needles are smaller and more sharply honed for use during closures requiring precise approximation (eg, facial lacerations) and are indicated by acronyms such as P (plastic), PS (plastic skin), PC (precision cosmetic), or PRE (plastic reconstruction).

SUTURING TECHNIQUES — 

Methods to ensure adequate hemostasis, debridement, and irrigation prior to laceration repair are discussed in detail separately. (See "Minor wound evaluation and preparation for closure", section on 'Preparation for closure'.)

Choice of technique — The clinician needs to decide whether to place sutures only in the skin or in several layers (dermal or multilayer) and whether to tie each suture (interrupted) or place a continuous suture (running).

Skin versus dermal/multilayer — The simple interrupted suture is the most common method used to close most small, uncomplicated, traumatic skin lacerations [2,15,16]. (See 'Interrupted percutaneous closure' below.)

Dermal (multilayer) closure is typically used for clean wounds with the following characteristics (see 'Dermal closure' below):

●Deep – closing the cutaneous layer alone will leave significant dead space, with the potential for hematoma or abscess formation

●Wide (gaping) – approximation of the dermis permits less tension at the skin level, which improves cosmetic outcome

Wounds under tension (eg, wounds with tissue loss or requiring extensive debridement) may benefit from vertical or horizontal mattress sutures, especially if dermal sutures are not used to relieve tension or the edges tend to invert. (See 'Mattress sutures' below.)

A triangular wound with a flap can be closed with a corner stitch, which combines elements of a horizontal mattress suture with a dermal closure. (See 'Corner stitch' below.)

Interrupted versus running — Most wounds should be closed with an interrupted suture because the whole wound does not dehisce if one suture breaks and the edges can be more accurately approximated and everted. (See 'Interrupted percutaneous closure' below.)

A continuous (running) skin suture is a more rapid closure and may spread out tension across the whole wound edge. It is generally reserved for wounds that are long, straight, at low risk of infection, have easily aligned edges, and are not on cosmetically important regions. It can also be used combined with a dermal closure (including on cosmetically important areas). (See 'Running skin suture' below.)

A straight laceration on the face may be closed with an intracuticular running suture by an experienced clinician. (See 'Subcuticular running suture' below.)

Technique description

Interrupted percutaneous closure — This common technique involves closing the skin layer with sutures that are individually tied (figure 13). For proper healing, the edges of the wound must be everted by each suture. Wound eversion is accomplished using the following technique (figure 14 and figure 15):

●The needle should penetrate the skin surface at a 90° angle.

●The suture loop should be at least as wide or wider at the base than at the skin surface.

●The width and depth of the suture loop should be the same on both sides of the wound.

●The width and depth of the suture loop should be similar to the thickness of the dermis and will therefore differ from wound to wound, according to the anatomic location.

●The suture is then tied using a surgeon's knot (nonabsorbable suture) or a square knot (absorbable suture) (figure 16). (See 'Instrument knot tying' below.)

The number of ties (throws) is determined by suture type: three to four ties for an absorbable suture or four to five ties for a synthetic nonabsorbable suture.

●Once tied, the knot is positioned to one side or the other of the wound so that the knot does not interfere with wound healing at the margin.

To ensure proper apposition of the wound without excess tissue on one side (also called a "dog ear"), the clinician places the first suture at the midline of the wound (figure 13). The next two sutures go on each side of the first suture, midway between the center suture and the wound corners [16]. Additional bisecting sutures are placed until the wound is properly aligned.

The number of sutures needed to close a wound varies depending upon the length, shape, and location of the laceration. In general, sutures are placed just far enough from each other so that no gap appears in the wound edges. This can be approximated by placing the sutures apart from each other at roughly the same distance as they are from the wound edge.

Dermal closure — The dermal or buried suture approximates the dermis just below the dermal-epidermal junction. The cosmetic result is improved by minimizing skin tension. To limit the amount of suture material placed below the skin (ie, reduce inflammation and risk of wound infection) and to further approximate the edges, simple interrupted sutures or a running suture are placed following the dermal sutures. If the edges are very well approximated with the dermal closure, the skin can be closed with a tissue adhesive instead of sutures.

Absorbable suture material must be used for dermal or buried sutures. The knot should be buried away from the skin surface of the wound so that it will not interfere with epidermal healing. This knot orientation is accomplished by inverting the suture loop using the following technique (figure 17):

●The needle should be inserted in the dermis and directed toward the skin surface, exiting near the dermal-epidermal junction on the same side.

●The needle should then be inserted on the opposite side of the wound near the dermal-epidermal junction, directly across from the point of exit.

●The suture loop should be completed in the dermis, directly opposite the origin of the loop, and the knot tied.

●Before tying the knot, pulling the two ends longitudinally along the course of the wound helps to bring the two sides of the wound together more effectively compared with pulling the ends perpendicular to the wound margin [16].

●The suture is then tied using a square knot (figure 16) with no more than three ties (throws). (See 'Instrument knot tying' below.)

Dermal sutures do not increase the risk of infection in clean, uncontaminated lacerations [17]. However, animal studies suggest that dermal sutures should be avoided in highly contaminated wounds [18]. Thus, reduced dead space and tension across the wound should be achieved with the fewest number of sutures possible.

Instrument knot tying — After the suture is placed, it is tied using the needle holder as follows (figure 18):

●Pull the suture through the wound and leave a tail approximately 1 inch (2.5 cm) long at the initial entry site.

●Drop the suture needle on the sterile field and close the empty needle holder.

●Place the closed needle driver along the axis of the wound between the two ends of the suture. (Repeat for each throw, described below.)

●For the first tie (throw), in the nondominant hand, grasp the suture on the side of the wound where the needle emerged, approximately halfway between the needle and the wound site, and wrap it twice (surgeon's knot) or once around the needle holder (square knot) being held in the dominant hand.

●Open the needle holder and grasp the tail end of the suture.

●Pull the tail end through the two loops and across the wound, while moving the nondominant hand in the opposite direction across the wound. This action forms a surgeon's knot (two wraps) or a one-half knot (one wrap) (figure 16).

●For percutaneous closure, pull the surgeon's knot flat to the skin, with enough tension to gently evert the skin edges without strangulating the tissue, and then release the tail.

●Wrap the suture around the needle holder once in the opposite direction of the first two loops and pull the one-half knot so that it lies flat on the surgeon's knot.

●Repeat the one-half knot tie to place the suggested number of throws as determined by suture type and layer of closure (table 5A).

●Cut the suture ends at the appropriate length, as follows:

•Percutaneous knot – approximately the distance between sutures to prevent the ends from entangling

•Dermal knot – close to the last knot to minimize the amount of suture in the wound

●For percutaneous closure, the completed knot is positioned to one side or the other of the wound so that the knot does not interfere with wound healing at the margin.

Corner stitch — The corner of a flap can be approximated with a corner stitch, which is a half-buried horizontal mattress suture [3,4]:

●The needle is introduced through the skin in the portion of the wound that does not include the flap (figure 19).

●In the dermal (or buried) portion of the suture, the needle is passed through the corner of the flap horizontally through the deep dermis.

●The suture is completed by bringing the needle out through the skin on the opposite side of the non-flap portion. The knot is tied on the non-flap portion of the wound.

Mattress sutures — Mattress sutures provide additional eversion to wounds under tension:

●Vertical mattress suture – The vertical mattress suture is recommended for wounds under tension and for those with edges that tend to invert (fall or fold into the wound) [19,20]. It acts as a deep and superficial closure all in one suture. Vertical mattress sutures are well suited for body regions with thin or lax skin or reduced subcutaneous tissue (eg, the shin) that do not provide adequate subcutaneous tissue for dermal closure [4].

We prefer the shorthand vertical mattress technique (figure 20) [3]:

•The needle is initially inserted at the epidermal/dermal (near-near) edges as if performing a simple interrupted suture. This near-near portion of the suture loop everts the edges of the wound.

•The needle is then rotated 180° in the needle holder, and the direction of the suture loop is reversed (backhanded). The needle entrance is at a distance from the wound edge, crossing through the dermal tissue and exiting through the skin on the opposite side at an equal distance from the wound edge. This is the far-far portion. This suture approximates the dermal structures.

•The knot is then tied in standard fashion. (See 'Instrument knot tying' above.)

Alternatively, in the traditional vertical mattress technique, the deeper bites are performed first, followed by the smaller wound edge bites. In one trial that compared repair time and wound healing for patients randomized to receive either the traditional or the shorthand technique, wounds were repaired in one-half of the time using the shorthand technique [21]. There was no difference between the two groups with respect to wound healing.

●Horizontal mattress suture – A horizontal mattress suture also achieves wound eversion in areas of high skin tension [19,20]. In addition, horizontal mattress sutures distribute tension along the length of the laceration.

The needle is introduced into the skin in the usual manner and brought out on the opposite side of the wound (figure 21). A second bite is taken along the opposite side, approximately 0.5 cm from the first exit site, and is brought back to the original starting side, also 0.5 cm from the initial entry point.

Both vertical and horizontal mattress sutures can cause excess tension at the wound margin, which can lead to skin ischemia with wound breakdown [4]. To decrease the chance of this complication, clinicians may alternate mattress sutures with simple interrupted sutures or only use a mattress suture at the point of maximal tension.

Running skin suture — A running suture provides a rapid means of percutaneous closure for long, straight wounds with edges that align easily (figure 22):

●The closure is started with the standard technique of a percutaneous simple interrupted suture, but the suture is not cut after the initial knot is tied.

●The needle is then used to make repeated bites, starting at the original knot, by making each new bite through the skin at an angle of 45° to the wound orientation.

●The cross stays on the surface of the skin will be at an angle of 90° to the wound.

●The final bite is made at an angle of 90° to the wound direction to bring the suture out next to the previous bite. The final bite is left in a loose loop, which acts as a free end for tying the knot.

A disadvantage to this technique is that if the suture breaks, then wound dehiscence may occur. Furthermore, good wound eversion is more difficult to achieve with running sutures, which may increase the risk of scarring [3,4]. For these reasons, this technique is avoided on the face or other cosmetically important regions unless a dermal closure was first performed.

Subcuticular running suture — The subcuticular running suture is often used by plastic surgeons and other experienced clinicians to close straight lacerations on the face. An absorbable suture, such as Monocryl or Vicryl, is used. The suture is anchored at one end of the laceration, and then a plane is chosen in the dermis or just deep to the dermis in the superficial subcutaneous fascia (figure 23). Mirror-image bites are taken horizontally in this plane for the full length of the laceration. The final bite leaves a trailing loop of suture so a final knot can be tied. The wound is then reinforced with adhesive tape [3].

Specific wound sites — The evaluation and management of traumatic lacerations at specific locations listed below are discussed in detail separately:

●Lip – (see "Assessment and management of lip lacerations")

●Tongue and intraoral mucosa – (see "Evaluation and repair of tongue lacerations" and "Assessment and management of intra-oral lacerations")

●Eyebrow – (see "Assessment and management of facial lacerations", section on 'Eyebrow')

●Eyelids – (see "Eyelid lacerations")

●Cheek (zygoma) – (see "Assessment and management of facial lacerations", section on 'Cheek')

●Ear – (see "Assessment and management of auricle (ear) lacerations")

●Scalp – (see "Assessment and management of scalp lacerations")

AFTERCARE

Topical antibiotics and wound dressing — For traumatic lacerations closed with sutures, we recommend application of a topical antibiotic ointment [22,23]. We prefer an ointment that does not contain neomycin sulfate (such as topical bacitracin zinc ointment) because many people have a neomycin sensitivity [24]. In patients who have used neomycin previously without issues, a reasonable alternative is a combination ointment containing neomycin sulfate, bacitracin zinc, and polymyxin B sulfate. For patients with a known sensitivity to neomycin or prior dermatitis from an antibiotic ointment, a reasonable alternative is a petrolatum ointment without topical antibiotics.

To enhance healing, we also suggest that lacerations repaired with sutures be initially covered with an open or semiocclusive dressing, as determined by the amount of anticipated drainage:

●Wounds with potential drainage or closed with nonabsorbable sutures – Sterile gauze dressing or adhesive bandage (open dressing).

●Wounds without drainage or closed with absorbable sutures (fast-absorbing gut or Vicryl Rapide) – Either an open or semiocclusive dressing such as a polymer film (eg, Tegaderm, Cutifilm, BlisterFilm, or Bioclusive) can keep the sutures dry. Polymer films may permit the patient to shower more easily without getting the wound wet and permit examination of the wound for signs of infection without removing the dressing.

The dressing should be left in place for at least 24 hours, after which time, wounds can be left open to air. An antibiotic or petrolatum ointment can be applied to the wound as well, with instructions to apply the ointment two times per day at home until suture removal.

The use of a topical antibiotic ointment is supported by a trial of 426 adults undergoing traumatic laceration repair with sutures in which a topical ointment containing only bacitracin zinc or a combination ointment containing neomycin sulfate, bacitracin zinc, and polymyxin B sulfate, as compared with a petroleum ointment control, reduced the rates of wound infection (5.5, 4.5, and 17.6 percent, respectively) [22]. In another trial of 177 children with minor wounds, most of which were grazes, abrasions, and cuts, patients treated with a gel containing cetrimide, bacitracin, and polymyxin B, as compared with placebo, had lower rates of infection (1.6 versus 12.5 percent), although the rate of infection in the control group was higher than expected [25].

Topical antibiotics have not been shown to prevent infection or hasten healing after minor skin surgery (eg, punch biopsy or skin excision); petrolatum ointment is suggested instead to avoid potential contact dermatitis. (See "Skin biopsy techniques", section on 'Wound dressing'.)

Occlusion of the wound helps to maintain a moist environment, which enhances wound healing. Small crossover trials evaluating surgical wounds also indicate that occlusion of the wound increases the speed of re-epithelialization, although complete healing appears to occur at approximately the same time when compared with uncovered wounds [26,27]. (See "Principles of acute wound management", section on 'Wound dressings'.)

Washing and bathing — For patients with lacerations closed with a nonabsorbable (eg, nylon, polypropylene) suture, we advise gentle cleaning using mild soap and water or one-half-strength peroxide 24 hours after closure to prevent crusting over the suture knots. Furthermore, these patients may be allowed to shower or wash the wound with soap and water without risking increased rates of infection.

Lacerations closed with percutaneous absorbable sutures may also be gently cleaned 24 to 48 hours after placement, although some experts advise keeping the suture dry until it is mostly absorbed (typically five days for fast-absorbing gut or 7 to 10 days for Vicryl Rapide).

Prolonged soaking of sutures, including swimming in chlorinated water, should be avoided because of the theoretical risk of premature loss of suture tensile strength with wound dehiscence. Patients with sutures should also not swim in natural bodies of water because of a potential increased risk of infection.

Evidence is limited and provides only indirect guidance in the timing of bathing after suture placement. As examples, in a trial of 857 patients who underwent minor skin excisions that were repaired with a nonabsorbable suture and were dressed with dry gauze, those who washed the wound site within 12 hours after suture placement and left the wound open had similar infection rates compared with those who kept their wounds dry and covered for at least 48 hours (8.4 versus 8.9 percent, respectively) [28,29]. Patients were advised to avoid the use of antiseptic solutions or antibacterial soap on the wound site and were not given topical antibiotics, which likely explains the relatively high rates of infection in these clean surgical wounds. An observational study of 100 patients who underwent primary excision of a skin or soft-tissue lesion or local flap closure and began washing their wounds twice daily within 24 hours of surgery found no wounds that developed infection or dehiscence [30].

Tetanus prophylaxis — Tetanus prophylaxis should be provided for all wounds as needed (table 1). (See "Diphtheria, tetanus, and pertussis immunization in children 6 weeks through 6 years of age" and "Diphtheria, tetanus, and pertussis immunization in children 7 through 18 years of age", section on 'Wound management' and "Tetanus-diphtheria toxoid vaccination in adults", section on 'Immunization for patients with injuries'.)

Tetanus prophylaxis during pregnancy depends upon the immunization history and is discussed in detail separately. (See "Immunizations during pregnancy", section on 'Tetanus, diphtheria, and pertussis vaccination'.)

Role of prophylactic antibiotics — For healthy patients with uncomplicated traumatic skin lacerations, routine use of prophylactic systemic antibiotics is not necessary. All patients should receive instructions advising that they return for evaluation if they develop signs of wound infection (eg, pain, redness, swelling, drainage of pus, or fever).

Proper wound preparation is the essential measure for preventing wound infection after suturing simple lacerations. (See "Minor wound evaluation and preparation for closure".)

Evidence suggests that the use of prophylactic antibiotics does not reduce wound infections in healthy patients with clean traumatic skin lacerations. In a meta-analysis of seven trials (1701 total patients with a total of 110 wound infections), prophylactic antibiotics in healthy patients with wounds other than bite wounds did not decrease the infection rate (odds ratio 1.2, 95% CI 0.8-1.7; mean infection rate among controls 6 percent) [31].

The use of prophylactic antibiotics for selected wounds with higher baseline risks of infection are discussed in detail separately:

●Animal and human bites (see "Animal bites (dogs, cats, and other mammals): Evaluation and management" and "Human bites: Evaluation and management")

●Intraoral lacerations (see "Assessment and management of intra-oral lacerations", section on 'Prophylactic antibiotics')

●Nailbed injuries (see "Evaluation and management of fingertip injuries", section on 'Wound care and patient instructions')

●Patients with excessive wound contamination (eg, soil or water contamination) (see "Soft tissue infections following water exposure")

Suture removal — The timing of nonabsorbable suture removal varies with the anatomic site, according to the expected rate of healing [2,3]:

●Face – 5 days

●Eyelids – 5 days (3 days for low-tension wounds and up to 7 days for high-tension wounds)

●Neck – 5 to 7 days

●Scalp – 7 days

●Trunk and upper extremities – 7 to 10 days

●Lower extremities – 8 to 10 days

●Digits, palm, and sole – 10 to 14 days

Follow-up visits — Most clean wounds do not need to be seen by a clinician until suture removal (if nonabsorbable sutures were placed) or if absorbable sutures have not dissolved as expected.

Wounds at higher risk for infection (eg, repaired lacerations due to animal or human bites or in patients with risk factors for infection [eg, diabetes mellitus, immunocompromised host, or contaminated wound]) warrant evaluation at a follow-up visit in 48 to 72 hours.

PEDIATRIC CONSIDERATIONS

Anxious caregiver — A caregiver is an important advocate for their child, and their concerns need to be addressed with patience and understanding. It is inevitable that the clinician will encounter some caregivers who demand a plastic surgeon for simple laceration repairs or procedural sedation for a laceration that easily could be managed with patient distraction, topical and/or injectable anesthetics, and an assistant to help hold the child still. The best approach is to listen first and to suggest reasonable alternatives later.

In some instances, there is no choice but to consult a surgeon. At other times, caregivers will listen to the explanation that for a simple, clean laceration, the cosmetic outcome will be acceptable whether repaired by a surgeon or another clinician. At times, it is also an issue of plastic surgeon availability.

In cases where a caregiver demands procedural sedation for a simple laceration, they must understand that sedation has risks that are unnecessary if a reasonable and safe alternative exists. The use of distraction methods and the use of topical anesthetics should also be explained to the caregiver. Child life specialists, if available, can provide invaluable assistance in this scenario, along with an assistant to hold the child still. The child life specialist can adequately distract many patients by reading books with the patient, playing a video, or providing visual imagery. (See "Procedural sedation in children: Selection of medications", section on 'Nonpharmacologic interventions'.)

Uncooperative child — The anxious and uncooperative patient is a challenge that, at times, can be managed with an assistant to hold the child still and to use similar methods of distraction and imagery, but, at other times, leaves no choice but to perform procedural sedation to repair the laceration. We have found that simple lacerations in toddlers and other anxious children can be successfully managed with topical anesthesia (eg, lidocaine-epinephrine-tetracaine [LET]), intranasal midazolam (table 4), and a child life specialist or caregiver to soothe and distract with age-appropriate videos or games. Sedation choices vary depending upon age, mechanism of injury, and time required for repair and are discussed in detail separately. (See "Procedural sedation in children: Approach" and "Procedural sedation in children: Selection of medications", section on 'Minimally painful procedures'.)

SOCIETY GUIDELINE LINKS — 

Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Minor wound management".)

INFORMATION FOR PATIENTS — 

UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5^th to 6^th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10^th to 12^th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)

●Basics topic (see "Patient education: Stitches and staples (The Basics)").

SUMMARY AND RECOMMENDATIONS

●Wound evaluation – The management of minor skin lacerations begins with the assessment and preparation of the wound, including tetanus prophylaxis, if needed (table 1). (See "Minor wound evaluation and preparation for closure".)

●Indications for primary closure – Sutures are appropriate when the depth of the wound will lead to excessive scarring if the wound edges are not properly apposed. Concern about wound infection is the main reason not to close a wound primarily (see 'Indications for primary closure' above):

•Clean, uninfected lacerations on any part of the body in healthy patients may be closed primarily for up to 18 hours following the injury without a significant increase in the risk of wound infection.

•Because of the lower risk of infection or poor wound healing, facial wounds may be closed primarily up to 24 hours following the injury in all patients. In selected patients (no signs of infection, otherwise healthy patient, and easily approximated wound), closure of facial wounds may occur up to 48 to 72 hours after injury.

●Contraindications – Contraindications to primary closure in the ambulatory setting include (see 'Contraindications' above):

•Lacerations through infected skin

•Deep puncture wounds

•Lacerations that have been grossly contaminated with foreign debris that cannot be completely removed by irrigation and debridement at the bedside

•Superficial wounds that would be expected to heal without significant scarring, such as lacerations or abrasions that only involve the epidermis

•Relative contraindications include certain human, dog, and cat bites, wounds that are older than 24 hours, and lacerations with significant tissue loss

●Specialty consultation – Consultation with a plastic surgeon or other surgical specialist is warranted for (see 'Indications for surgical consultation' above):

•A large or complex laceration that will require prolonged repair or use of grafts or flaps (eg, significant tissue loss)

•Severe contamination that cannot be properly managed at the bedside under local anesthesia

•Neurovascular compromise

•Fracture, amputation, or joint penetration (eg, laceration through the knee joint capsule) associated with the laceration

•Specialized repair necessary to ensure optimal cosmetic outcomes, such as:

-Lacerations involving the nasal cartilage, ala, or columella (see "Assessment and management of facial lacerations")

-Eyelid or orbital lacerations that involve the eyelid margin or tarsal plate, have protruding subcutaneous fat, or involve the tear duct or lacrimal gland (figure 5) (see "Eyelid lacerations")

-Selected auricle (ear) lacerations (see "Assessment and management of auricle (ear) lacerations", section on 'Indications for subspecialty consultation or referral')

●Anesthesia – For most patients, infiltration of a local anesthetic is effective for pain control during laceration repair (table 3). We use topical lidocaine-epinephrine-tetracaine (LET) for pain control in children with uncomplicated facial or scalp lacerations. (See 'Anesthesia and analgesia' above and "Clinical use of topical anesthetics in children", section on 'Agents for laceration repair'.)

●Wound preparation – Wound irrigation, foreign body removal, and necrotic tissue debridement are the main preventive measures against tissue infection. Suggested solutions and proper performance of these measures are discussed in detail separately. (See "Minor wound evaluation and preparation for closure", section on 'Preparation for closure'.)

●Equipment and suture selection – Equipment used for skin laceration repair (including general guidance for suture material, needle, and size by wound location and for closure of skin, dermal, and intraoral lacerations) is provided in the tables (table 5A-B). (See 'Equipment' above and 'Suture selection' above.)

●Choice of suturing technique – The simple interrupted suture provides adequate closure for most uncomplicated skin lacerations (figure 14 and figure 15). (See 'Interrupted percutaneous closure' above.)

For deep or wide lacerations, the clinician should first perform dermal closure (figure 17). (See 'Dermal closure' above.)

Wounds that may benefit from other closure techniques include:

•Triangular wound with a flap - half-buried mattress (figure 19) (see 'Corner stitch' above)

•Wounds under tension - vertical (figure 20) or horizontal mattress (figure 21) (see 'Mattress sutures' above)

•Long, straight wounds - running suture (figure 22) (see 'Running skin suture' above)

●Aftercare – For patients undergoing repair of traumatic skin lacerations with sutures, we suggest application of a topical antibiotic ointment (Grade 1B). Topical antibiotic ointment may reduce wound infection. We prefer an ointment that does not contain neomycin sulfate (such as topical bacitracin zinc ointment) because many people have a neomycin sensitivity. Petrolatum ointment is a reasonable alternative in patients with a known sensitivity to antibiotic ointment. (See 'Topical antibiotics and wound dressing' above.)

We initially cover with an open (eg, sterile gauze or adhesive bandage) or semiocclusive (eg, polymer film) dressing. Maintaining a moist environment enhances wound healing. The dressing should be left in place for at least 24 hours, after which wounds can be left open to air. (See 'Topical antibiotics and wound dressing' above.)

For patients with lacerations closed with nonabsorbable sutures, we advise gentle cleaning using mild soap and water or one-half-strength peroxide 24 hours after closure to prevent crusting over the suture knots; patients may be allowed to shower or wash the wound with soap and water without risking increased rates of infection. Lacerations closed with percutaneous absorbable sutures may also be gently cleaned 24 to 48 hours after placement, although some experts advise keeping the sutures dry until they are mostly absorbed (typically five days for fast-absorbing gut or 7 to 10 days for Vicryl Rapide). (See 'Washing and bathing' above.)

For healthy patients with uncomplicated traumatic skin lacerations, prophylactic systemic antibiotics are not necessary (see 'Role of prophylactic antibiotics' above). The use of prophylactic antibiotics for selected wounds with higher baseline risks of infection is discussed in detail separately:

•Animal and human bites (see "Animal bites (dogs, cats, and other mammals): Evaluation and management" and "Human bites: Evaluation and management")

•Intraoral lacerations (see "Assessment and management of intra-oral lacerations", section on 'Prophylactic antibiotics')

•Nailbed injuries (see "Evaluation and management of fingertip injuries", section on 'Wound care and patient instructions')

•Patients with excessive wound contamination (eg, soil or water contamination) (see "Soft tissue infections following water exposure")

●Suture removal – The timing of nonabsorbable suture removal varies with the anatomic site, according to the expected rate of healing (see 'Suture removal' above):

•Eyelids – 5 days (3 days for low-tension wounds and up to 7 days for high-tension wounds)

•Face – 5 days

•Neck – 5 to 7 days

•Scalp – 7 days

•Trunk and upper extremities – 7 to 10 days

•Lower extremities – 8 to 10 days

•Digits, palm, and sole – 10 to 14 days