Principles of planning local plastic operations on the maxillofacial area. Methods and techniques of local plastic surgery.
Acquired defects and deformities of the lips, cheeks, nose, chin, fill defects and eliminate strain local tissues, including graft on leg.
Flap Principles
Over the past 50 years the development and application of several different flaps has led to reliable reconstruction of facial defects. Most defects can be reconstructed immediately, leading to better restoration of form and function with early rehabilitation. 1 Reconstructing facial defects can be both challenging and rewarding. Missing tissue most often results from either trauma or oncologic surgery. Commonly there is a wide range of options for repairing a given defect, including healing by secondary intention, primary closure, placement of a skin graft, or mobilization of local or regional tissue. Compared to skin grafts, local flaps often produce superior functional and esthetic results.2–6 A great advantage of local tissue transfer is that the tissue closely resembles the missing skin in color and texture. These flaps can be rotated, advanced, or transposed into a tissue defect. Regional tissue can also be recruited to repair facial defects. When deciding which option to use, there should be a progression from simple to complex treatments. Consideration should be given to primary closure or the use of skin grafts first, followed by local, then regional, and finally distant pedicled or microsurgical free tissue transfer. Flaps require additional incisions and tissue movement, which increase the risks of postoperative bleeding, hematoma, pain, and infection. Confirmation of tumor free margins should be done prior to flap reconstruction if a malignant lesion has been excised.7 Some defects are amenable to closure with a single flap, but others require a combination of flaps for optimal results.8 An advantage of using multiple flaps is that they can be harvested from separate esthetic units. This decreases the size of the secondary defect and may allow placement of scars between esthetic units, thus improving scar camouflage leading to better cosmesis. Often, separated repair of individual facial subunits with separate flaps provides a better cosmetic result than if a single flap is used to reconstruct the entire defect. Flaps differ from grafts in that they maintain their blood supply as they are moved. Abundant dermal and subdermal plexus allow for predictable elevation of random cutaneous flaps. A cutaneous flap may also have its arterial supply based on a dominant artery in the subcutaneous layer. Muscular perforating arteries are important contributors to the cutaneous vascular bed. The most important variable for flap viability is not the length-to-width ratio but, rather, the perfusion pressure and vascularity at the pedicle base.9 Because local flaps provide their own blood supply, they are particularly useful in patients with compromised recipient sites such as those that have been irradiated. As local flaps heal, regaining of blood flow and cutaneous sensibility increases. The rate of blood flow and two-point discrimination on the surface of local flaps is statistically no different when compared with the corresponding area of the unoperated side.10 The recovery of sensory nerve function in facial flaps is dependent on the intimacy of contact between the flap and the recipient bed and on the viability of the type of restoration. Relaxed skin tension lines (RSTLs) result from vectors within the skin that reflect the intrinsic tension of the skin at rest. They are due to the microarchitecture of the skin and represent the directional pull on wounds. The RSTLs are generally parallel to the facial rhytids. Lines of minimal tension (rhytids) result from repeated bending of the skin from muscular contraction. A permanent crease results from the adhesions between the dermis and deeper tissues. These natural skin creases run perpendicular to the direction of muscle pull and can guide incision orientation for optimal scar camouflage and cosmesis. The face is composed of esthetic subunits. 11,12 The areas where these subunits meet are referred to as anatomic borders. The esthetic subunit principle is based on the fact that our eyes see objects as a series of block images that are spatially organized. Scars that are located at the junction of two adjacent anatomic subunits are inconspicuous because one expects to see a delineation between these areas.
Flap Nomenclature
There are many methods described for classifying cutaneous flaps: by the arrangement of their blood supply, their configuration, location, tissue content, and method of transferring the flap. Blood Supply Cutaneous flaps consist of skin and subcutaneous tissue and can be characterized by their predominant arterial supply. These include random pattern, axial pattern, and pedicle flaps (Figure 38-1). Random flaps are supplied by the dermal and subdermal plexus alone and are the most common type of flap used for reconstructing facial defects. Axial pattern flaps are supplied by more dominant superficial vessels that are oriented longitudinally along the flap axis. Pedicle flaps are supplied by large named arteries that supply the skin paddle through muscular perforating vessels. Free tissue transfer refers to flaps that are harvested from a remote region and have the vascular connection reestablished at the recipient site.
Location Another means of classification is by the region from which the tissue is mobilized. This includes local, regional, and distant flaps. Local flaps imply use of tissue adjacent to the defect, whereas regional flaps refer to those flaps recruited from different areas of the same part of the body. Distant flaps are harvested from different parts of the body.
Configuration Flaps are often referred to by their geometric configuration. Examples of these flaps include bilobed, rhombic, and Z-plasty. Tissue Content The layers of tissue contained within the flap can also be used to classify a flap. Cutaneous flap refers to those flaps that contain the skin only. When other layers are incorporated into the flap they are classified accordingly. Examples include myocutaneous and fasciocutanous flaps.
Method of Transfer The most common method of classifying flaps is based on the method of transfer. Advancement flaps are mobilized along a linear axis toward the defect (Figure 38-2). Rotation flaps pivot around a point at the base of the flap (Figure 38-3). Although most flaps are moved by a combination of rotation and advancement into the defect, the major mechanism of tissue transfer is used to classify a given flap. Transposition flap refers to one that is mobilized toward an adjacent defect over an incomplete bridge of skin. Examples of transposition flaps include rhombic flaps and bilobed flaps (Figure 38-4). Interposition flaps differ from transposition flaps in that the incomplete bridge of adjacent skin is also elevated and mobilized. An example of an interposition flap is a Z-plasty. Interpolated flaps are those flaps that are mobilized either over or beneath a complete bridge of intact skin via a pedicle. These flaps often require a secondary surgery for pedicle division. Microvascular free tissue transfer from a different part of the body relies on reanastomosis of the vascular pedicle.
Designing the Flap There are many options for reconstructing facial defects. Often the optimal method is not readily apparent. A stepwise approach can be helpful in selecting and designing a flap. The characteristics of the defect and adjacent tissue must be analyzed. These include color, elasticity, and texture of the missing tissue. The defect size, depth, and location are evaluated as well as the availability and characteristics of adjacent or regional tissue. It is important to determine the mobility of adjacent structures and to identify those anatomic landmarks that must not be distorted. The orientation of the RSTLs and esthetic units should by analyzed closely. Potential flap designs should be drawn on the skin surface being careful to avoid those designs that obliterate or distort anatomic landmarks. The final location of the resultant scar should be anti-cipated by previsualizing suture lines and choosing flaps that place the lines iormal creases. The secondary defect that is created as the tissue is transferred into the primary defect must be able to be closed easily. When designing a flap, it is important to avoid secondary deformities that distort important facial landmarks or affect function. Avoid obliterating critical anatomic lines that are essential for normal function and appearance. Proper surgical technique involves gentle handling of the tissue by grasping the skin margins with skin hooks or fine-toothed tissue forceps. Avoid traumatizing the vascular supply by twisting or kinking the base of the flap. Deep pexing sutures minimize tension on the flap and eliminate dead space. Excessive tension on the flap may decrease blood flow and cause flap necrosis. Meticulous hemostasis should be achieved prior to final suturing so that a hematoma does not develop beneath the flap. It is important to adequately mobilize and extend the flap, which should be of adequate size to remain in place without tension to minimize the chance of dehiscence, scarring, or ectropion.
Types of Flaps
Local Flaps
Advancement Flaps
Advancement flaps have a linear configuration and are advanced into the defect along a single vector. These flaps can be single or double. Advancement flaps are often chosen when the surrounding skin exhibits good tissue laxity and the resulting incision lines can be hidden iatural creases.Advancement flaps limit wound tension to a single vector with minimal perpendicular tension. They are often helpful in reconstructing defects involving the forehead, helical rim, lips, and cheek. In these areas advancement flaps capitalize on the natural forehead furrows without causing vertical distortion of the hairline superiorly or the eyebrow inferiorly (Figure 38-5). Advancement flaps are created by parallel incisions approximately the width of the defect. Standing cutaneous deformities (“dog ears”) are usually created and are managed with excision. A Z-plasty incision or Burow’s triangle may be performed at the base of the flap, reducing the standing cutaneous deformities. A variation of the advancement flap is the V-Y flap. A triangular island of tissue adjacent to the defect is isolated and attached only to the subcutaneous tissue. It relies on a subcutaneous pedicle for blood supply. As it is advanced into the defect, the secondary defect is closed primarily in a simple V-Y manner. These flaps are especially amenable for cheek defects along the alar facial groove and are generally avoided where there are superficial nerves because of the depth of the incisions. Intraoral uses of advancement flaps include covering oroantral fistulas and alveolar clefts. A disadvantage of buccal advancement flaps is the decrease in vestibular sulcus depth (Figure 38-6).
Rotation Flaps Rotation flaps have a curvilinear configuration. Defects reconstructed with rotation flaps should be somewhat triangular or modified by removing normal tissue to create a triangular defect. These flaps have a large base and are usually random in their vascularity but may be axial. One or more rotation flaps are often used to reconstruct scalp defects. Because of the relative inelasticity of the scalp tissue, these flaps must be large relative to the size of the defect. Scoring of the galea is helpful in gaining additional rotation and advancement (Figure 38-7). The axial frontonasal flap is a modified simple rotation flap with a back cut.13–16 It is useful for closing nasal defects (Figure 38-8). The flap is based on a vascular pedicle at the level of the medial canthus. This pedicle consists of a branch of the angular artery and the supraorbital artery. Rotated palatal flaps are helpful for closing large oroantral fistulas.8,17 Fistulas < 5 mm in diameter usually close
spontaneously.18,19 Local flaps or grafts can be used to close larger fistulas. Twolayer closures are less prone to developing recurrence of oroantral fistulas. Approximately 75% of the palatal soft tissue can be rotated to cover adjacent defects.
Transposition Flaps
These flaps are rotated and advanced over adjacent skin to close a defect. Examples of transposition flaps include rhombic flaps and bilobed flaps. These flaps are advantageous in areas where it is desired to transfer the tension away from closure of the primary defect and into the repair of the secondary defect. Transposition flaps have a straight linear axis and are usually designed so that one border of the flap is also a border of the defect. An advantage of this type of flap is that it can be developed at variable distances. Areas where these flaps are often used include the nasal tip and ala, the inferior eyelid, and the lips. The rhombic flap is a precise geometric flap that is useful for many defects of the face.20,21 The traditional rhombic (“Limberg”) flap is designed with 60 and 120° angles and equal-length sides. The angle of the leading edge of the rhombic flap is approximately 120° but may vary. The flap is begun by extending an incision along the short axis of the defect that is equal to the length of one side of the rhombic defect. Another incision is then made at 60° to the first and of equal length (Figure 38-9). Disadvantages of the rhombic flap are the significant tension at the closure point as well as the amount of discarded tissue to transform a circular defect into a rhombus. The bilobed flap is a transposition flap with two circular skin paddles (see Figure 38-4).22,23 Esser is credited with the design of the bilobed flap in 1918. It
is useful for skin repairing of lateral nose and nasal tip defects up to 1.5 cm. The bilobed flap has a random pattern blood supply. The flap is primarily rotated around a pivot point and the paddles are transposed over an incomplete bridge of skin. The second lobe allows the transfer of tension further from the primary defect closure. The bilobed design rotates around an arc that is usually 90 to 100°. In the bilobed flap the first lobe closes the defect and the second closes the first lobe defect. The flap is designed with a pivot point approximately a radius of the defect away from the wound margin. The first lobe is usually the same size as the defect, and the second lobe is slightly smaller with a triangular apex to allow for primary closure. The axis of the second flap is roughly 90 to 100° from the primary defect and undermined widely to distribute the tension. An advantage of the bilobed flap is that one can construct a flap at some distance from the defect with an axis that is independent of the linear axis of the defect. A disadvantage of this flap is that it leaves a circular scar that does not blend with the existing skin creases. During healing the flap may become elevated (“pin cushioning”) because of the narrow pedicle that is prone to congestion, scar tissue that impedes lymphatic drainage, and curvilinear scars that tend to bunch the flap up as they shorten.
Interpolation Flaps
Interpolation flaps contain a pedicle that must pass over or under intact intervening tissue. A disadvantage of these types of flaps is that for those passing over bridging skin, the pedicle must be detached during a second surgical procedure. Occasionally it is possible to perform a single-stage procedure by deepithelializing the pedicle and passing it under the intervening skin. Advantages of interpolation flaps include their excellent vascularity, and also their skin color and texture match. The forehead flap (median and paramedian) is a commonly used interpolation flap and remains the workhorse flap for large nasal defects.24–27 It is a robust and dependable flap. The forehead flap is primarily based on the supratrochlear vessel, is relatively narrow, and uses a skin paddle from the forehead region. The flap is supplied by a rich anastomosis between the supratrochlear and angular arteries. Because of the marked vascularity, it is possible to incorporate cartilage or tissue grafts for nasal reconstruction. The forehead flap has abundant tissue available, allowing resurfacing of the entire nasal unit with a single flap and provides a good texture and color match to the native nose. The technique for elevating the forehead flap is straightforward. The flap can be designed directly in the midline or in a paramidline location. A template of the defect is used to outline the flap. Elevation of the flap proceeds in either a subgaleal or subcutaneous plane. The pedicle is always elevated in such a way as to incorporate the frontalis muscle. The width of the pedicle is usually 1.0 to 1.5 cm, which allows for easy rotation of the pedicle. Prior to inset the skin paddle is selectively thinned to match the native skin thickness. The pedicle is divided approximately 3 weeks later, with the base of the pedicle inset into the glabellar area to reestablish brow symmetry. The incision, and resulting scar, is perpendicular to the RSTLs but tends to heal well (Figure 38-10). The nasolabial flap (melolabial) is useful for reconstructing defects involving the oral cavity and those involving the lower third of the nose (Figure 38-11).28–31 It can be used as an interpolation flap with either a single or staged technique. The flap is supplied by the angular artery, intraorbital artery, and infratrochlear artery and can be based either superiorly or inferiorly. The area of recruitment for nasal reconstruction is in closer proximity to the primary defect than is the forehead flap. A disadvantage of the nasolabial flap is that there is a limited amount of tissue available, and asymmetry can occur along the
nasolabial flap folds.When the pedicle is divided, the defect can be closed primarily by placing the scar in the nasal facial junction and the nasolabial flap fold. The lip-switch flap (Abbe) can be taken from either lip, but it is most commonly switched from the lower to the upper lip.32–34 This flap can be used to reconstruct as much as one-third of the upper lip. The lower lip can supply a flap of one-quarter of its length, and the Abbe flap offers immediate replacement of total lip anatomy (Figure 38-12). The labial artery supplies the flap and should be maintained with a small cuff of subcutaneous tissue and muscle surrounding the vascular pedicle. The pedicle is divided after approximately 2 to 3 weeks. Tongue flaps are excellent flaps for intraoral reconstruction. They use adjacent tissue, have an excellent blood supply, and are associated with minimal morbidity. The tongue has excellent axial and collateral circulation, with the lingual artery providing the main blood supply. Up to onehalf of the tongue can be rotated for tissue coverage without compromising speech, mastication, or deglutition.35 A variety of flap designs have been described including anterior- and posterior-based tongue flaps (Figure 38-13). Some indications include repair of oral defects and fistula closure. These flaps are helpful for providing
closure of large oroantral fistulas.
Regional Flaps
For large facial defects, local flaps may not provide sufficient tissue to adequately restore the missing tissue. In these cases consideration should be given to using a regional flap.36,37 Regional flaps are defined as those that are located near a defect but are not in the immediate proximity. They are frequently harvested from the neck, chest, or axilla and can provide coverage of large surface areas on the face. Selection of a specific regional flap depends on the size and location of the defect and also on the intrinsic properties of the flap. Advantages of regional flaps include the large amount of soft tissue and skin available. Disadvantages of these types of flaps include poor color and texture match, excessive bulkiness of the flap, and donor site morbidity
Pectoralis Major Myocutaneous Flap
The pectoralis major myocutaneous flap remains a workhorse of reconstructive surgery.38–40 The flap was introduced by Ariyan41 and has provided a reliable method of soft tissue reconstruction of bone and soft tissue defects of the mandible and maxilla. The pectoralis major myocutaneous flap can be rotated around a pivot point 180° and is supplied by two separate blood supplies (Figure 38-14). The thoracoacromial artery arises from the second portion of the axillary artery and forms four branches as it penetrates the fascia. The pectoral branch is the major artery that supplies the pectoralis major myocutaneous flap. The position of the vascular pedicle can be approximated by drawing a line from the shoulder point to the xiphoid. The pectoral branch descends at a right angle from the middle of the clavicle until it meets this line. Branches of the internal mammary artery supply the medial portion of the muscle and skin over the sternum. The flap provides good coverage for the carotid artery when combined with a neck dissection. Deltopectoral Flap
The introduction of the deltopectoral flap by Bakamjian and colleagues represented a significant improvement for reconstructing large ablative resections for head and neck cancer. 42–44 Currently it is used as an alternative to the pectoralis major myocutaneous flap for soft tissue reconstruction of the mandible and maxilla. This flap is composed of fascia, subcutaneous tissue, and skin but does not contain muscle (Figure 38-15). Perforators from the internal mammary artery provide vascular supply to the flap. The secondary defect is covered with a skin graft.
Temporalis Flap
The temporalis flap was introduced by Golovine in 1898 and remains useful for covering intraoral defects (Figure 38-16).45–48 The outer portion of the muscle is invested by the deep temporal fascia. This fascia is supplied by the middle temporal vessel, which originates just below the zygomatic arch. The temporalis muscle is supplied by both the anterior and posterior deep temporal arteries, which arise from the second portion of the internal maxillary artery. This dual blood supply allows for splitting of the muscle into anterior and posterior flaps. When elevating the muscle, it is important to remain on the deep temporal fascia beneath the superficial temporal fascia to avoid damage to the frontal branch of the facial nerve. Elevation of the inferior portion of the flap is performed in a subperiosteal plane to avoid damage to the deep temporal arteries, which lie on the undersurface of the muscle. An osteotomy of the zygomatic arch is often helpful to facilitate placement of the muscle into the mouth. The arch can be put back into place and
secured with
plates and screws. A disadvantage of the temporalis flap is the minimal cosmetic deformity of hollowing in the temporal region; this can be corrected with autogenous or alloplastic materials and can be minimized by using either an anterior or a posterior flap.
Sternocleidomastoid Flap
First described by Jinau in 1909 for facial reanimation, the sternocleidomastoid flap was repopularized by Owens.49–55 The muscle is invested by the deep cervical fascia and is supplied by three arteries. The dominant vessel is the occipital artery, which enters the muscle below the mastoid tip and supplies the superior portion of the muscle. The superior thyroid artery supplies the middle portion, and the thyrocervical trunk supplies the inferior third of the muscle. The muscle is elevated over the deep cervical fascia superior to the carotid sheath. It is recommended to maintain two of the three vessels when elevating the flap to enhance the viability of the flap. The spinal accessory nerve enters the deep portion of the muscle approximately at the carotid bifurcation and should be preserved to prevent denervation atrophy of the muscle (Figure 38- 17). Advantages of the sternocleidomastoid flap include its close proximity to the defect and minimal donor site defect (Figures 38-18 and 38-19).
Trapezius Myocutaneous Flap
The trapezius myocutaneous flap is supplied by three arteries, allowing several flaps to be used. The main vessel supplying the trapezius muscle is the transverse cervical artery, which is a branch of the thyrocervical trunk. The upper portion of the muscle is supplied by the occipital artery. The trapezius myocutaneous flap is a ready source of skin of uniform thickness without excessive muscle bulk.56 The main disadvantage is the limited rotation and the short pedicle.
Latissimus Dorsi Myocutaneous Flap
Quillen and colleagues first described the use of the latissimus dorsi myocutaneous flap for head and neck reconstruction in 1978.57,58 The flap is not commonly used for head and neck reconstruction unless other flaps are unavailable or there are very large defects requiring coverage. The muscle is supplied by the thoracodorsal artery, which is the dominant vessel, and also by four to six perforators from the posterior intercostals and lumbar vessels. The main advantage of the latissimus dorsi flap is the large amount of skin provided. The main disadvantages are the need to reposition the patient during the operation and morbidity from the donor site. Complications Postoperative complications can be minimized with careful preoperative planning of flap design and by early recognition of problems.59 A medical history can be used to identify patients with risk factors involving small vessels. These risk factors include smoking, diabetes, hypertension, previous radiation, and preexisting scars.60,61 Complications may be reversible or irreversible. Early recognition and treatment can minimize complications and prevent them from becoming irreversible. Two main unwanted outcomes are flap failure and unacceptable cosmetic results. Flap survival depends on early recognition of flap compromise. Ischemia is defined as an inadequacy of perfusion in providing tissue needs. Signs of arterial ischemia include a pale and cool flap that does not blanch with pressure and typically does not bleed with a pinprick. Flaps are somewhat ischemic initially because the original tissue perfusion has been compromised by flap elevation. Most tissue can survive on 10% of its average blood flow.59 Whether the flap will undergo necrosis depends on patient-related and surgery-related factors that influence the risk of necrosis in facial flaps. Smoking is associated with an increased risk of flap failure. The deleterious effects of smoking on flap survival include hypoxemia and vasoconstriction. Patients should be advised to quit smoking during the perioperative period. Common causes of bleeding in facial reconstruction with local flaps include inadequate hemostasis and drug-induced coagulopathy. Hematoma formation should be identified and decompressed within 24 hours.62 Decompression can be accomplished with aspiration using a 22- gauge needle or by taking out one or two sutures and applying gentle compression on the flap. Hematoma formation may diminish tissue perfusion and can lead to ischemia or necrosis by inducing vasospasm, stretching the subdermal plexus, or separating the flap from its recipient bed. Patients should be questioned carefully about the use of medications that affect coagulation such as acetylsalicylic acid, nonsteroidal antiinflammatory drugs, and vitamin E. If possible, these medications should be avoided for 2 weeks prior to and 1 week after surgery. Congestion is the most common vascular problem associated with facial flaps. Signs of a congested flap include warmth, edema, and a purple color that blanches with pressure then immediately refills. A pinprick will cause release of dark venous blood.Venous congestion can lead to arterial compromise and flap necrosis. Management of congested flaps may include temporarily releasing sutures to allow decompression at the flap edges or possible impingement involving the flap pedicle. Tight bandages around the flap pedicle should be removed. Medicinal leeches (Hirudo medicinalis) may be useful in decompressing congested flaps.63,64 Saliva from the leech contains an anticoagulant and a vasodilator that facilitate continued oozing from the site even up to 6 hours after they detach. Hyperbaric oxygen (HBO) has been shown to be beneficial in improving the vascularity of marginal tissues.65 Prophylactic HBO therapy in cutaneous flap surgery in the irradiated tissue bed may be particularly helpful to combat the hypoxia and hypocellularity. HBO is beneficial in treating both venous congestion and arterial ischemia by creating a local
arterial vasoconstriction through the rise in arterial oxygen content, which reduces the amount of inflow. The tissue oxygen levels continue to rise owing to the improved diffusion even though there is vasoconstriction and a reduction in vascular perfusion. The flap can maintain viability while continued neovascularization occurs. Other options include the use of heparin and dipyridamole to help increase the survival of an ischemic flap.66 Infection can complicate flap healing. 67 The postoperative infection rate for clean wounds in facial surgery is as low as 2.8%, with higher rates in facial reconstruction with local flaps.68 Tissue oxygenation is an important factor in prevention of wound infection and is closely related to blood supply. Infections involving local flaps may result in flap failure or poor cosmetic outcome secondary to wound dehiscence and scarring.
Conclusion
A variety of facial flaps are available to the reconstructive surgeon for repairing facial defects. The goal of flap surgery is to restore form, function, and esthetics. There are many advantages to using local and regional flaps, which can lead to optimal esthetic results.
Types of Injuries
Abrasions
Shear forces that remove a superficial layer of skin cause abrasions. The wound should be gently cleansed with a mild soap solution and irrigated with normal saline. These superficial injuries usually heal with local wound care. It is important to determine whether foreign bodies have been embedded in the wound. Failure to remove all foreign material can lead to permanent “tattooing” of the soft tissue. After the wound is cleansed the abrasion is covered with a thin layer of topical antibiotic ointment to minimize desiccation and secondary crusting of the wound. Reepithelialization without significant scarring is complete in 7 to 10 days if the epidermal pegs have not been completely removed. If the laceration significantly extends into the reticular dermal layer, significant scarring is likely.
Contusions
Contusions are caused by blunt trauma that causes edema and hematoma formation in the subcutaneous tissues. The associated soft tissue swelling and ecchymosis can be extensive. Small hematomas usually resolve without treatment; hypopigmentation or hyperpigmentation of the involved tissue can occur, but is rarely permanent. Large hematomas should be drained to prevent permanent pigmentary changes and secondary subcutaneous atrophy.
Lacerations
Lacerations are caused by sharp injuries to the soft tissue (Figure 19-6). Lacerations can have sharp, contused, ragged, or stellate margins. The depth of penetration should be carefully explored in the acute setting. Closure is performed using a layered technique. If the margins are beveled or ragged they should be conservatively excised to provide perpendicular skin edges to prevent excessive scar formation. Rarely is there an indication for changing the direction of the wound margins by Zplasty at the time of primary wound repair. Flap-like lacerations occur when a component of the soft tissue has been elevated secondary to trauma. Eliminating dead space by layered closure and pressure dressings is especially important in these “trapdoor” injuries.
Avulsive Injures
Avulsive injures are characterized by the loss of segments of soft tissue. Undermining the adjacent tissue, followed by primary closure, can close small areas.When primary closure is not possible, other options are considered. These include local flaps or allowing the wound to heal by secondary intention followed by delayed soft tissue techniques. If a significant amount of soft tissue is missing, then a skin graft, local flaps, or free-tissue transfer may be necessary (Figure 19-7).
Animal and Human Bites Dog bites are most common in children and the midface is frequently involved.26,27 Canines can generate 200 to 450 psi when biting, and examination for fractures should be performed.28 Management of bite injuries involves liberal amounts of irrigation and meticulous primary closure.29 Wound irrigation and debridement are important in reducing infection. Animal and human bites are most often polymicrobial, containing aerobic and anaerobic organisms. Dog bites are often open and lend themselves to vigorous irrigation and debridement. Cats have a large quantity of bacteria in their mouth, with the most frequent and important pathogen being Pasteurella multocida.30 Cat bites are associated with a twofold higher risk of infection than the more common dog bite wounds. Because their bites usually cause puncture wounds, they are difficult to clean. Having the patient follow up 24 to 48 hours after the initiation of therapy allows the surgeon to monitor the wound for any signs of infection. Antibiotic prophylaxis for animal bites continues to be debated with few good prospective studies available.26,31 Amoxicillinclavulanate is the current drug of choice for bite wounds. Antibiotic prophylaxis should be directed at Pasteurella multocida for infections presenting within 24 hours of injury. For wounds that present after 24 hours of injury, Streptococcus and Staphylococcus species are more common, and antibiotic prophylaxis with a penicillinase-resistant antibiotic should be chosen.32 Immediate closure of bite injuries is safe, even with old injuries.33 There is approximately a 6% rate of infection when bite wounds are sutured primarily in lacerations where there are cosmetic concerns.34 Extensive animal bite wounds involving the face should be treated according to the criteria of esthetic reconstructive surgery. Rabies prophylaxis should be given for bite wounds that occurred from an unprovoked domestic dog or cat that exhibits bizarre behavior or from an attack by a wild animal such as a raccoon, skunk, bat, fox, or coyote.
Scalp and Forehead
Scalp wounds can occasionally cause a large amount of blood loss due to the rich vascular supply in this region and the inelasticity of the scalp preventing contraction and closure of the vessels. The layers of the scalp (SCALP) include the skin, subcutaneous tissue, aponeurosis layer, loose subepicranial space, and pericranial layer. In patients sustaining scalp injuries it is important to evaluate for associated intracranial injuries. Careful inspection should be performed to look for evidence of skull fractures. Because the scalp has an excellent blood supply in the subcutaneous tissues as well as the pericranial layers, avulsed tissue, skin grafts, and various flaps have a high rate of survival. Hollander and colleagues found no significant difference in rate of infection in scalp lacerations that were irrigated compared to those that were not.37 In avulsive defects in which the pericranium is intact and primary closure is not possible, a split-thickness skin graft can be used. A secondary reconstructive procedure involving various rotational and advancement flaps or tissue expansion can be undertaken after healing of the defect.38 If the cranial bone is exposed with large avulsive defects, then various flap procedures are indicated primarily. Reconstruction of the eyebrow is difficult secondarily, and efforts to repair lacerations primarily without distortion are important. Eyebrows should never be shaved, as regrowth of the hair is unpredictable. Closure of lacerations should attempt to salvage as much tissue as possible. Care should be taken to avoid damage to the remaining hair follicles. Scars can be removed 6 to 12 months later with incisions made parallel to the hair follicles to avoid injury.
Eyelid and Nasolacrimal Apparatus
A thorough ophthalmologic examination is important to assess for injuries to the globe and to evaluate and document visual acuity. Closure of lacerations involving the eyelids is done in a layered fashion (Figure 19-9). Care should be taken to precisely reapproximate the eyelid margins and the tarsus (Figure 19-10). The conjunctiva and tarsus are closed with resorbable sutures with the knot buried to avoid irritating the cornea. The orbicular muscle is then closed followed by closure of the skin. Injuries involving the upper eyelid may include detachment of the levator aponeurosis and Muller’s muscle from the tarsal plate. The muscles should be identified and reattached to the tarsal plate in order to prevent ptosis and restore levator function. The lacrimal gland produces tears, which flow across the cornea and drain into canaliculi via the puncta of the upper and lower eyelid margins (Figure 19-11). From the canaliculi the tears enter the nasolacrimal duct and drain into the inferior meatus of the nose. Any lacerations that involve the medial third of the eyelid should be carefully inspected for damage to the canaliculus.39 Repair is accomplished by introducing a lacrimal duct probe into the puncta and into the wound (Figure 19-12). The ends of the lacerated duct are identified and approximated over a polymeric silicone tube (Crawford tube). The tube is left in place for 8 to 12 weeks. If only one canaliculus is intact and functioning, the patient most likely will have adequate drainage.40 If the patient exhibits chronic epiphora postoperatively, then a dacryocystorhinostomy is indicated. Avulsive injuries to the eyelids are treated with skin grafts and/or local flaps. Defects of up to 25% of the eyelid length can be closed primarily. Skin grafts harvested from the opposite eyelid provide excellent texture and color match.
Nose
The nose occupies a prominent position on the face and is often injured. Injuries of the internal nose should be evaluated using a nasal speculum. The septum should be evaluated for the presence of a hematoma, which appears as a bluish elevation of the mucosa. Hematomas involving the nasal septum should be evacuated with a small incision or needle aspiration. Nasal packing or polymeric silicone nasal splints can be placed to prevent recurrence of the hematomas and are removed in 7 to 10 days. A running 4-0 chromic gut mattress suture placed in and through the septum can prevent recurrence. Untreated hematomas can lead to infection and necrosis of the cartilage, which may cause collapse of the septum and a resultant “saddle nose.” There is an excellent blood supply to the nose. Lacerations of the external nose should be closed with 6-0 nonabsorbable sutures. Key sutures should be placed to reapproximate anatomic landmarks to ensure proper orientation, especially around the nasal rim. Bone, cartilage, and/or skin grafts may be required to reconstruct avulsive defects of the nose. Skin grafts harvested from the periauricular regions provide excellent color and texture match.41 Local flaps may be required to restore missing tissue (Figure 19-13).
Ear
Injuries involving the external ear should alert one to the possibility of other injuries. An otoscopic examination of the external auditory canal and tympanic membrane combined with a hearing assessment should be performed prior to treatment. Injuries to the auricle include ecchymosis, abrasion, laceration, hematoma, and partial or total avulsion. Hematomas involving the ear usually occur when the ear sustains a glancing blow. These should be drained with a needle or incision. An incision is often preferable to simple aspiration because there is less of a chance of reaccumulation of the hematoma.42 Evacuation of the hematoma prevents fibrosis and development of a “cauliflower ear” deformity. A bolster dressing should be placed to prevent recurrence of the hematoma. A stent can also be fabricated from polysiloxane impression material and kept in place for 7 days.43 The ear has a very good vascular supply and can maintain tissue on a small pedicle. Injuries involving the cartilage often do not require sutures. If sutures are required a minimal amount are used to avoid devitalizing the region of cartilage (Figure 19-14). Avulsive injuries of the ear can involve a portion of the ear or the entire ear (Figure 19-15). If the avulsed segment is 1 cm or less, it can be reattached and allowed to revascularize.
Lip
The lip anatomy involves a transition of mucosal tissue to skin. Scars that affect the orbicularis oris may result in functional difficulties. Nerve blocks are helpful in wounds involving the lip to prevent distortion caused from injecting directly into the wound. A single suture should be placed initially to reapproximate the vermilion border exactly. Deep tissues are closed in layers, followed by closure of the mucosa with 4-0 chromic and skin closure with 6-0 nylon suture. Avulsive defects of the lips require special attention. Up to one-fourth of the lip can be closed primarily with acceptable functional and esthetic results. Injuries that involve a greater amount of tissue loss can be reconstructed with a variety of flaps such as Abbe-Estlander or Karapandzic (Figure 19-18).
Postoperative Wound Care
Careful postoperative care and follow-up are important to optimize results. Wounds should be monitored closely to determine whether early intervention is indicated to minimize scar contracture or hypertrophic scarring. Local flaps and grafts may be indicated secondarily. Local injection of steroids provides an adjunct in the management of specific types of injuries. Facial scars continue to mature over a period of 12 to 18 months. A recent study found no difference in outcome of surgical scars treated with pulsed carbon dioxide laser when compared with dermabrasion.51 Keeping a wound clean and scab free allows for more rapid reepithelialization.52 Epithelial cells survive and migrate better in a moist environment. Antibiotic ointment can enhance this migration. It is not epithelialization that provides strength to the wound but rather the collagen fibers supporting the surface. Rebuilding of fibers takes time, and suturing a wound splints the skin together until new connective tissue is built. Cleaning daily with dilute hydrogen peroxide and dressing with antibiotic ointment is standard. Patients should avoid sun exposure for the first 6 months after the injury to prevent hyperpigmentation of the areas.
Summary
Soft tissue injuries involving the face can be devastating to the patient. Primary repair of these wounds is almost always advantageous over delayed secondary procedures. The primary goals of treatment are to restore patients to their preoperative state of function and to achieve an esthetic result.
Bilozetskyi Ivan
