Both the scalp and forehead overlie bone with little cushioning fat and have thick skin (Figure 42-1). The one difference is that the scalp has abundant hair follicles and sebaceous glands. Three branches of the external carotid artery (occipital, superficial temporal, and posterior auricular arteries) and two branches from the internal carotid artery (supraorbital and supratrochlear arteries) provide a rich blood supply to the scalp and forehead. The fibrous dermal tissue limits vessel retraction after injury, so significant hemorrhage can result from an arterial laceration. The potential space between the pericranium (periosteum covering the external surface of the skull bones) and the galea aponeurosis that allows for easy movement of the scalp over the cranium also enables hematoma and infection to collect in this subaponeurotic space and spread to involve the entire forehead and scalp. This high degree of mobility sometimes leads to a scalping injury, in which a large segment of the scalp is torn off in one piece.
For some patients with scalp and forehead lacerations, the wound may be only a minor part of the overall injury. Perform a focused assessment looking for intracranial injury before definitive wound care. Control scalp hemorrhage by applying direct pressure or clamping the involved vessel(s) at the wound edges (e.g., using Raney clips; see chapter 40) until the assessment is completed.16
Inspect scalp lacerations, and gently palpate with a gloved finger to determine depth and to identify galeal laceration or depressed skull fracture. Evaluate palpable depressions with a CT scan. Orientation of forehead lacerations has important cosmetic implications. In general, forehead wounds that fall parallel to the lines of skin tension have better cosmetic results than wounds that are perpendicular. The horizontal lines seen on the forehead when the brow is raised are perpendicular to the frontalis muscle underneath (Figure 42-2).
Skin tension lines. Skin tension lines are perpendicular to underlying muscles.
Children may need sedation for wound repair (see chapter 113, "Pain Management and Procedural Sedation in Infants and Children"). Anesthesia can be provided by topical, local, or regional infiltration. Topical agents alone, such as lidocaine-epinephrine-tetracaine, provide adequate anesthesia in about half of patients and reduce the pain of local anesthetic injection.17,18,19,20 Local anesthetics containing epinephrine are often used in highly vascular wounds to help control hemorrhage from small vessels.
Irrigate (see chapter 40, "Wound Preparation") to reduce contamination and lessen the risk of wound infection. Appropriate pressure for irrigation can be accomplished with a 30-mL syringe and 18-gauge IV catheter or commercially available irrigation device. However, in resource-poor situations, because the face and scalp are highly vascular, clean-appearing wounds have been repaired using adhesive strips, without prior cleansing and irrigation.21
Repair of Scalp Lacerations
Do not shave hair before wound closure, because shaving increases the risk of infection.22 To visualize the injured area, brush the hair aside or matt it down with an ointment, such as bacitracin zinc or petrolatum.23 If visualization is still difficult, trim the adjacent scalp hair with scissors.
Suture accessible lacerations of the galea24 to prevent formation of a subgaleal hematoma (Table 42-2).25
TABLE 42-2Suturing Guidelines for the Face and Scalp ||Download (.pdf) TABLE 42-2 Suturing Guidelines for the Face and Scalp
|Area ||Suture ||Size ||Anesthetic ||Removal |
|Galea ||Absorbable ||4-0 ||Local ||Not removed |
|Skin ||Staples ||Standard ||Local ||14 d |
| ||Nonabsorbable monofilament ||4-0 ||Local ||14 d |
| ||Rapidly absorbing ||4-0 ||Local ||Not removed |
|Frontalis muscle ||Absorbable ||4-0 ||Local or supraorbital nerve block ||Not removed |
|Skin ||Nonabsorbable monofilament ||5-0 or 6-0 ||Local or supraorbital nerve block ||5 d |
| ||Tissue adhesive ||May need deep layer ||— ||Not removed |
|Cheek and face |
|Muscle fascia ||Absorbable ||4-0 ||Local or infraorbital nerve block ||Not removed |
|Skin ||Nonabsorbable monofilament ||6-0 ||Local or infraorbital nerve block ||5 d |
| ||Rapidly absorbing ||6-0 ||Local or infraorbital nerve block ||Not removed |
| ||Tissue adhesive ||May need facial layer closure ||— ||Not removed |
|Skin ||Nonabsorbable monofilament ||6-0 or 7-0 ||Supra- or infraorbital nerve block ||3 d |
|Mucosa ||Rapidly absorbing ||4-0 ||Intranasal ||Not removed |
|Cartilage ||Nonabsorbable (if necessary) ||5-0 ||Intranasal ||Not removed |
|Skin ||Nonabsorbable monofilament ||6-0 ||Local or intranasal ||3–5 d |
|Skin ||Nonabsorbable monofilament ||6-0 ||Auricular block ||5 d |
|Cartilage ||Nonabsorbable monofilament ||5-0 ||Auricular block ||Not removed |
|Mucosa ||Rapidly absorbing ||5-0 ||Local, infraorbital, mandibular, or mental nerve block ||Not removed |
|Muscle fascia ||Absorbable ||4-0 or 5-0 ||Local, infraorbital, submandibular, or mental nerve block ||Not removed |
|Skin ||Nonabsorbable monofilament ||6-0 ||Local, infraorbital, or mental nerve block ||3–5 d |
Close scalp skin with surgical staples or simple interrupted percutaneous sutures using nonabsorbable monofilament or rapidly absorbable material.26,27,28,29 Leave suture tails long, and use sutures of a color different than the hair for easy suture removal.
Hair braiding is a technique combining hair apposition and tissue adhesive.30,31,32 In this technique, bring together four to five strands of hair from opposite sides of the wound, twist the strands once, and secure them with a drop of tissue adhesive. This technique requires the wound edges to approximate with little tension, so subcutaneous sutures are sometimes necessary before hair apposition is used to close the skin.
Consider a pressure dressing over a deep scalp laceration for the first 24 hours after repair, to prevent wound hematoma formation.
Repair of Forehead Lacerations
Forehead lacerations are categorized as either superficial, meaning the frontalis muscle is not injured, or deep, meaning the frontalis muscle is involved. For superficial lacerations, close the skin with 6-0 nonabsorbable interrupted suture, rapidly absorbable suture, or tissue adhesive.24,33,34 For deep lacerations, close the muscle layer to avoid noticeable defects, especially when the facial muscles of expression are involved. Close the muscle layer with buried 5-0 absorbable suture. Close the epidermal layer with 6-0 nonabsorbable sutures in a simple, interrupted fashion; with skin closure strips; or with tissue adhesive (Table 42-3).35 Strips or adhesives are especially attractive if the patient is at risk for keloids or hypertrophic scars. Use key stitches to align skin tension lines and the hairline (Figure 42-3).
TABLE 42-3Indications for Tissue Adhesives on the Face ||Download (.pdf) TABLE 42-3 Indications for Tissue Adhesives on the Face
Not a hair-covered area
Epidermal closure only (no mucosa)
Key stitches in the forehead to align natural skin tension lines and cosmetically important landmarks.
Repair of Eyebrow Lacerations
Do not clip or shave eyebrows because their delicate contour and form are valuable landmarks for wound edge reapproximation. Debridement of loose or nonviable skin in the eyebrow region should be minimal and, if necessary, done so that the remaining hairs preserve as much as possible of the original length, width, and curve of the eyebrow. Use care to align the hair margins. Use sutures that are a different color from the hair and leave long tails to facilitate removal.