Keith E. Blackwell
INTRODUCTION
Multiple factors need to be considered when selecting a technique for reconstruction of defects of the scalp. As it is a hair-bearing region, aesthetic considerations favor reconstruction using local hair-bearing tissues whenever possible. The frontal, parietal, and occipital scalp offer considerable soft tissue laxity that facilitates repair by means of primary closure and local flaps when compared to defects arising at the vertex of the scalp, where there is less soft tissue laxity. At the vertex, wide subgaleal undermining, galeal relaxing incisions, and tissue creep allow for primary closure of defects as wide as 5 cm. Local rotation, advancement, and transposition flaps are useful for reconstruction of larger defects. Defects of up to 50 cm2 at the vertex of the scalp can be reconstructed using bilateral laterally based advancement flaps combined with a posteriorly based rotational flap.
If a scalp defect has intact periosteum, the wound can be left open to heal by secondary intention or a skin graft can be used on the periosteum, and the rigid nature of the underlying calvarium helps to prevent distortion of the wound by scar contraction. Biologic dressings such as Integra and wound vacuums can be applied in cases in which the periosteum is absent to promote formation of granulation tissue and thereby facilitate healing by second intention or skin grafting. These methods, however, will result in compromised aesthetic results due to alopecia, cavity of the wound, and unpredictable pigmentation of the healed wound.
Wound repair by primary closure and local flaps may be impossible or ill-advised in cases when prior therapies using surgery and radiation therapy make local tissues unreliable for reconstruction of defects that otherwise might be repaired using local tissues. Unfortunately, this is a common situation, with one prior large series of scalp reconstructions reporting that 65% of patients had undergone prior scalp surgery and 44% of patients had undergone prior radiation therapy. Among patients undergoing microvascular flap reconstruction of the scalp, Van Driel et al. reported prior scalp reconstructive surgery in 80% of patients and prior scalp radiation in 50% of patients.
Associated defects of the calvarium and dura need to be carefully considered when thinking through options for reconstruction of scalp defects. Attempting to repair a wound under tension using local tissues over an alloplastic cranioplasty or in a patient with a dural repair carries a high risk of wound dehiscence that can result in cranioplasty extrusion and/or cerebrospinal fluid leak. In cases where local tissues cannot reliably be used for reconstruction of defects of the temporal and occipital scalp, the inferior island trapezius flap has proven to be a reliable method of reconstruction. However, when the defect involves the parietal or frontal scalp, free tissue transfer is often needed when local tissues prove to be inadequate, as the arc of rotation provided by regional flaps is insufficient to reach defects that extend to the vertex of the scalp or to the forehead.
While radial forearm flaps, rectus abdominis flaps, anterolateral thigh flaps, and omental flaps are also useful for scalp reconstruction, many series have reported that latissimus dorsi flaps are the most commonly used free flaps for reconstruction of scalp defects (Table 38.1). The latissimus dorsi free flap offers many desirable attributes for scalp reconstruction, including a large volume of soft tissue that can be combined with other subscapular system flap components for reconstruction of very large or complex defects, a long vascular pedicle that usually can reach recipient vessels without using vein grafts, and limited long-term flap donor site morbidity.
TABLE 38.1 Use of Latissimus Dorsi Flaps and Incidence of Complete Free Flap Necrosis in Series of Scalp Reconstructions that Relied Predominantly on Latissimus Dorsi Free Flaps
General Concepts
The latissimus dorsi flap can be used as a myofascial flap or as a myocutaneous flap for reconstruction of scalp defects (Fig. 38.1). It is critically important to consider the nature of the scalp defect when planning the design of a latissimus dorsi flap for scalp reconstruction, as the nature of the defects of the scalp skin, calvarium, and dura all have a significant impact on flap design. For soft tissue defects of the scalp where there is not a fullthickness defect of the calvarium, a myofascial flap combined with a skin graft often results in the best possible aesthetic reconstruction (Fig. 38.2). As they are harvested from a sun-protected donor site, myocutaneous latissimus dorsi flap often are pale in color, so they result in a poor color match for native scalp skin, especially when used in the common situation of patients with scalp skin cancers, who invariably have significant chronic actinic damage to their scalp skin. In addition, the flank skin is very thick, and the skin paddle of a latissimus dorsi myocutaneous flap is often too bulky to restore an appropriate scalp contour. This often results in a pincushioned appearing scalp reconstruction (Fig. 38.3). As a broad, thin muscle that will undergo postoperative denervation atrophy when inset over the rigid infrastructure of an intact calvarium, latissimus dorsi myofascial flaps often produce superior aesthetic results with regard to the thickness and contour of the resulting scalp reconstruction, and the color match of a skin-grafted myofascial flap is often superior to that achieved using a latissimus dorsi myocutaneous flap.
FIGURE 38.1 A. Latissimus dorsi myofascial flap. B. Latissimus dorsi myocutaneous flap.
FIGURE 38.2 Two-year postoperative appearance of scalp reconstruction using latissimus dorsi myofascial flap with meshed split-thickness skin graft.
FIGURE 38.3 Five-year postoperative appearance of scalp reconstruction using latissimus dorsi myocutaneous flap with duraplasty and titanium mesh cranioplasty.
In situations where there is a scalp skin defect occurring in conjunction with a full-thickness defect of the calvarium, a latissimus dorsi myocutaneous flap may be the best option. In this situation, the increased thickness of the flap helps to camouflage contour defects of the skull in patients who have small calvarial defects. Many patients with larger defects of the calvarium will undergo cranioplasty reconstruction using nonvascularized bone grafts or alloplastic materials. In this situation, scalp reconstruction using a myofascial flap is ill-advised, as there will be a risk of cranioplasty extrusion after a myofascial flap becomes very thin due to postoperative denervation atrophy. The risk of cranioplasty extrusion may be reduced in patients with thick myocutaneous flap reconstructions, although the aesthetics of the resulting reconstruction are usually compromised.
Myocutaneous flaps may be preferred for reconstruction of scalp defects that occur in conjunction with defects of the dura. This is the case because it is difficult to achieve a watertight closure of the scalp skin defect when using a myofascial latissimus dorsi flap that is resurfaced with a skin graft, thereby increasing the risk of a postoperative cerebrospinal fluid leak that can lead to meningitis. In this situation, the use of a myocutaneous latissimus dorsi flap may lessen the risk of cerebrospinal fluid leak by allowing for a watertight scalp wound closure, thereby increasing the safety of the reconstruction at the expense of the aesthetic results.
Multiple other flap components that are perfused by the subscapular vascular pedicle are available for transfer with the latissimus dorsi muscle in patients with large or complex defects of the scalp. When the soft tissue defect of the scalp is larger than what can reliably be resurfaced using a latissimus dorsi flap, additional soft tissue components can be incorporated, including the serratus anterior muscle that is perfused by the serratus anterior branch of the thoracodorsal artery, and the parascapular and scapular fasciocutaneous flaps that are perfused by the circumflex scapular artery. Using these additional soft tissue components, even near-total defects of the scalp can be reconstructed using a single subscapular system “megaflap” (Fig. 38.4). Osseous reconstruction of the calvarium can be accomplished using vascularized ribs, which are perfused either by the serratus anterior branch of the thoracodorsal artery or by the perforating branches from the intercostal blood vessels. In addition, a vascularized graft of the lateral border of the scapula and scapular tip can be transferred based upon the circumflex scapular vessels or the angular branch of the thoracodorsal vessels. Vascularized thoracolumbar or serratus anterior fascia can be used for reconstruction of associated defects of the dura.
FIGURE 38.4 A. Defect of the left cheek, forehead, and subtotal resection of scalp sparing only the right temporal scalp after excision of angiosarcoma. B. A latissimus dorsi myofascial—serratus anterior myofascial—parascapular fasciocutaneous flap allows for single-flap reconstruction of this large defect. C. The latissimus dorsi myofascial—serratus anterior myofascial flap components are used to resurface temporal, parietal, and occipital calvarium. D. The parascapular fasciocutaneous flap component is used to resurface the cheek and forehead defect. E. The myofascial flaps have been covered with a meshed split-thickness skin graft.
Identification of the borders of the latissimus dorsi muscle is usually a straightforward endeavor using visible and palpable landmarks. The latissimus dorsi muscle is a broad thin muscle that covers most of the lower back from the inferior tip of the scapula to the iliac crest (Fig. 38.5). The anterior border of the latissimus dorsi muscle is an important landmark that is usually identified early during the flap harvest procedure and is a key landmark with regard to identifying the flap’s vascular pedicle. The anterior border of the latissimus dorsi muscle can be palpated in thin patients by asking patients to press their hands against their hips. The location of the anterior border of the latissimus dorsi muscle can also be estimated drawing a line from the humerus in an inferior direction toward the ipsilateral iliac crest at approximately the midaxillary line.
FIGURE 38.5 The latissimus dorsi muscle. The latissimus dorsi muscle is a broad thin muscle that covers most of the lower back from the inferior tip of the scapula to the iliac crest.
HISTORY
With regard to the patient’s history, because free tissue transfer provides the advantage of transferring well-vascularized tissue to a recipient site, the condition of the recipient site is important. Any history of prior radiation may impede healing. This should be elicited in the history to prepare the patient for the potential for wound healing problems. A history of prior surgery or trauma to the donor site(s) may eliminate the use of this flap.
PHYSICAL EXAMINATION
The physical examination should include an examination of the recipient site and the donor site. In many cases, the patient will have sustained the scalp defect as a result of excision of skin cancer. It is important to assess both sites for skin cancers that may have been missed or incompletely excised. The condition of the recipient site should also be evaluated to anticipate the potential for wound healing complications. The donor site must be examined to rule out previous trauma or surgery in this tissue.
INDICATIONS
Latissimus dorsi free flaps are indicated for reconstruction of scalp defects that cannot reliably be reconstructed using local tissues, skin grafts, or regional flaps. As previously discussed, this indication varies according to the size of the defect in different regions of the scalp as determined by laxity of the scalp tissue, the location of the defect with regard to the utility of regional flaps as determined by their arc of rotation, prior therapies that affect the reliability of local and regional flaps, and the nature of associated defects of the calvarium and dura.
CONTRAINDICATIONS
Prior surgeries that might have adversely affected the integrity of the thoracodorsal vascular pedicle need to be recognized. In this regard, the most common prior surgeries to consider include prior axillary lymph node dissection and prior thoracotomy. In these patients, preoperative flap angiography or an alternative flap donor site should be considered. In addition, use of a large skin paddle can produce a restrictive pulmonary defect caused by tight primary closure of the flank skin after latissimus dorsi flap harvest, so large myocutaneous flaps should be used with caution in patients with limited pulmonary reserve. In this situation, the flap donor site can be repaired with a skin graft, but skin graft healing is notoriously slow due to a shearing effect on the skin graft caused by respiratory motion of the flap donor site.
PREOPERATIVE PLANNING
The magnitude of the defect and nature of associated defects of the calvarium and dura need to be considered in planning to use a myofascial or myocutaneous latissimus dorsi flap and when considering the need to incorporate other osseous and soft tissue components that are perfused by branches of the subscapular blood vessels.
Patient positioning should be planned to allow for simultaneous two-team surgery at the flap donor site and in the head and neck whenever possible. Subscapular system flaps that incorporate the latissimus dorsi muscle and overlying flank skin, the serratus anterior muscle, the parascapular fasciocutaneous flap, and vascularized ribs can be harvested with the patient in a supine position, with slight elevation of the ipsilateral shoulder, or with the patient in a full decubitus position, thereby allowing simultaneous two-team surgery in all cases that require scalp reconstruction (Fig. 38.6). Flaps that include the lateral border of the scapula bone or the scapular fasciocutaneous skin paddle usually require intraoperative positioning in a full lateral decubitus position, with the patient’s position supported by a beanbag. This patient positioning may still allow simultaneous two-team surgery in patients with pathologies of the posterior or lateral scalp.
FIGURE 38.6 It is a common misconception that lateral decubitus positioning is necessary to harvest free flaps based upon the subscapular vascular pedicle. Flaps that are perfused by the thoracodorsal vessels including the latissimus dorsi and serratus anterior muscles are easily harvested with patients positioned in a supine position.
SURGICAL TECHNIQUE
Instruct the anesthesiologist and nurses not to place arterial or intravenous lines in the upper extremity on the side of the flap donor site, as this upper extremity will be prepped and draped into the field so that the arm position can be adjusted during flap harvest. Place a beanbag on the operating room table even if it is anticipated that flap harvest will be done in the supine position. This will allow for lateral decubitus repositioning if necessary. If flap harvest is done in the supine position, place an armrest on the operating room table on the side of the flap donor site. This supports the arm and shoulder position to prevent a traction injury to the brachial plexus.
While endoscopic flap harvest has been described, myofascial latissimus dorsi flaps are more often harvested using an open technique. A longitudinal incision that is placed along the anterior border of the latissimus dorsi muscle is made, and the anterior border of the latissimus dorsi muscle is exposed. The anterior border of the latissimus dorsi muscle is elevated off the underlying serratus anterior muscle and rolled posteriorly. The thoracodorsal vascular pedicle is identified on the deep surface of the latissimus dorsi muscle, about 4 cm posterior to the anterior border of the latissimus dorsi muscle. The vascular pedicle enters into the hilum of the latissimus dorsi muscle at a distance of about 12 cm inferior to the insertion of the latissimus dorsi muscle into the humerus. The vascular pedicle is then traced superiorly through the axilla up to the takeoff of the subscapular vessels from the axillary vessels. During this dissection, branches of the vascular pedicle including the serratus anterior branch, the angular branch, branches to teres major muscle, and the circumflex scapular vessels are encountered. These side branches of the vascular pedicle are ligated unless they are supplying additional osseous or soft tissue flap components that are to be incorporated into the flap for reconstruction of large or complex defects. Flap harvest is then completed by elevating the superficial surface of the latissimus dorsi muscle from the overlying flank skin and then detaching the insertions of the latissimus dorsi muscle from the ilium inferiorly, from the vertebrae posteriorly, and from the humerus superiorly.
When a myocutaneous flap is needed, an oval flap skin paddle is often designed overlying the anterior border of the latissimus dorsi muscle. The width of the flap skin paddle is determined by the width of the scalp skin defect and also by pinching the flank skin to determine how much flank skin can be removed while allowing for primary closure of the flank donor site wound. The amount of flank skin that can be removed while allowing for primary closure of the resulting flank skin defect usually varies from 8 to 10 cm in width. In cases where a myocutaneous flap is needed but the width of scalp defect exceeds 8 to 10 cm, a wider flap skin paddle can be harvested, but skin graft reconstruction of the flank donor site with possible delayed healing for the flap donor site should be anticipated. The length of the flap skin paddle is determined by the length of the scalp skin defect and the distance of the scalp defect from the recipient vessels that will perfuse the free flap. Skin paddles that are centered only over the middle and inferior thirds of the latissimus dorsi muscle are prone to experience distal marginal skin paddle necrosis, so in all cases, the skin paddle should be designed to incorporate skin that is overlying the superior third of the latissimus dorsi muscle, where cutaneous perforators to the skin paddle are plentiful. In cases where the defect cross the vertex of the scalp and the flap recipient vessels are located in the neck, the most proximal portion of the flap skin paddle is either deepithelialized or incorporated into a preauricular or postauricular incision to enhance perfusion to the most distal aspect of the skin paddle.
The scalp defect should be widely undermined in a subgaleal plane before latissimus dorsi flap insetting, and the peripheral edges of the latissimus dorsi muscle should be tacked to the galea or pericranium at least a few centimeters away from the skin edges of the scalp defect. A second layer of flap insetting is then done from the edges of the scalp skin defect to the superficial myofascial component or to the skin paddle of the flap so that the scalp skin overlaps the myofascial component that has been inset to the periosteum or galea (Fig. 38.7). This two-layer overlapping flap insetting reduces the risk of a wound dehiscence that might result in calvarial or cranioplasty exposure, and the risk of cerebrospinal fluid leak is reduced in cases where there is an associated defect of the dura.
FIGURE 38.7 A two-layer, overlapping “vest-over-pants” flap insetting reduces the risk of scalp wound dehiscence that can lead to exposed cranium, exposed cranioplasty, or cerebrospinal fluid leak.
Superficial temporal blood vessels can be used to perfuse the flap if they are of suitable caliber to match the vascular pedicle of the flap. In many patients, the superficial temporal artery at the level of the root of the zygomatic arch is of suitable caliber to match the caliber of the subscapular or thoracodorsal artery, but the caliber and quality of the superficial temporal vein is more variable and will usually determine whether the superficial temporal vessels can be used as recipient vessels. When the superficial temporal vessels prove to be unsuitable, then recipient vessels in the upper neck are used to perfuse the flap, and the flap’s vascular pedicle is passed through a preauricular or postauricular subcutaneous tunnel, or the vascular pedicle can be brought through the cheek wound if a parotidectomy has been done in conjunction with removal of regional lymph nodes. In most cases, the vascular pedicle of the flap is long enough to reach recipient blood vessels in the upper neck without the need to extend the length of the vascular pedicle using vein grafts.
POSTOPERATIVE MANAGEMENT
Flaps should be monitored for postoperative vascular compromise. My preference is to monitor flaps using transcutaneous Doppler stethoscope assessment of the flap’s arterial inflow, with the Doppler checks being done by the nursing staff on an hourly basis that is equal to the postoperative day number. In addition, myocutaneous flaps are monitored by observation of the color and turgor of the flap’s skin paddle. I have observed an incidence of free flap failure of less than 1% with this postoperative flap monitoring protocol.
Skin-grafted myofascial flaps are covered with a Xeroform dressing that is stapled to the wound edges at the conclusion of surgery. This dressing is moisturized with Bacitracin ointment on a twice a day basis to prevent it from drying. The Xeroform dressing that is placed at the time of surgery is removed 5 to 7 days after surgery, and daily Xeroform dressing changes are then instituted until the skin-grafted muscle as fully epithelialized. A regimen of daily scalp wound care for 4 to 8 weeks after surgery is often needed in patients who have myofascial flaps resurfaced with split-thickness skin grafts (Fig. 38.8).
FIGURE 38.8 Two-week postoperative appearance of a scalp reconstruction using a latissimus dorsi myofascial flap with a meshed split-thickness skin graft. Full epithelialization of the meshed skin graft frequently takes 4 to 8 weeks.
In cases where there is no defect of the dura, the scalp wound is drained with a subgaleal 10-mm flat Jackson-Pratt drain that is positioned so that it does not compress the flap’s vascular pedicle. When a dural defect is present, the scalp wound is not drained in order to lessen the risk of cerebrospinal fluid leak.
Prolonged high-output drainage from the flank donor site is common, and indwelling flank closed suction drains are sometimes needed for a long as 3 weeks after surgery to prevent seroma formation at the flank donor site. As length of hospitalization in patients who have uncomplicated recoveries after surgery is frequently 5 to 7 days, hospital discharge with an indwelling flank drain is necessary in some patients. Lipa and Butler proposed application of an aerosolized fibrin sealant to the flap donor site to reduce the risk of prolong flank wound drainage.
Myocutaneous latissimus dorsi free flaps often result in a bulky-appearing reconstruction that may benefit from a revision procedure to improve the contour of the flap. However, care must be taken to try to preserve the integrity of the flap’s vascular pedicle during secondary revision surgeries, as neovascularization of the flap may be very slow and incomplete with large volume flaps, especially when there is a history of radiation therapy. I have treated a patient who suffered near-total necrosis of a latissimus dorsi myocutaneous flap that was used for scalp reconstruction when flap debulking done 9 months after free flap transfer resulted in injury to the flap’s vascular pedicle.
Reconstructed hair-bearing regions of the scalp will suffer from alopecia after latissimus dorsi flap reconstruction. Small to moderate areas of alopecia in patients who have not had radiation can be successfully managed by tissue expansion of adjacent hair-bearing scalp or by follicular unit hair transplantation. However, many patients who undergo resection of advanced skin cancers of the scalp that require free flap reconstruction also undergo wide-field scalp radiation therapy, which makes them poor candidates to undergo tissue expansion, and there is frequently little hair-bearing scalp tissue left to serve as a follicular unit transplant donor site after the completion of surgery and radiation therapy. In these patients, camouflaging the defect with a wig or hat is often the best option for management of the resulting alopecia.
COMPLICATIONS
Free Flap Failure
Like any microvascular free tissue transfer, complete free flap necrosis can occur, usually during the early postoperative period and usually secondary to thrombosis of the flap’s vascular pedicle.
Scalp Wound Dehiscence
Scalp wound dehiscence is a serious complication that can result in exposure of the calvarium, cranioplasty exposure, and/or cerebrospinal fluid leak. Small dehiscences can often be managed using local wound care, but large or complicated dehiscences may need more complex revision surgery, including a second free flap in some cases.
Flap Donor Site Morbidity
The shoulder and upper extremity position needs to be supported during latissimus dorsi flap harvest in order to avoid a traction injury to the brachial plexus. The long-term donor site morbidity after harvest of a latissimus dorsi flap is often quite acceptable. Litung and Peck reported that shoulder disability after latissimus dorsi flap harvest diminishes with time, and most patients regain a normal shoulder range of motion and report no occupational limitations or interference with sporting activities. However, Russell et al. reported frequent change in occupation, household activities, and sporting activities after latissimus dorsi flap harvest.
RESULTS
The risk of complete flap necrosis in series of microvascular flap reconstruction of the scalp that relied predominantly on latissimus dorsi flaps ranges from 0% to 6% (Table 38.1). Recipient blood vessel selection reported in some of these series is summarized in Table 38.2. The incidence of vein grafts that were needed to lengthen the vascular pedicle varied from 3% to 7%. Van Driel et al. reported a significantly increased incidence of scalp wound healing complications including partial and total flap necrosis in patients who needed vein grafts.
TABLE 38.2 Recipient Vessels Used to Perfuse Free Flaps in Series of Scalp Reconstructions that Relied Predominantly on Latissimus Dorsi Free Flaps
O’Connell reported five cases of scalp wound dehiscence among 68 free flap scalp reconstructions. Four healed by secondary intention, but one patient with a major dehiscence required a second free flap. Afifi et al. reported scalp wound dehiscence in 5 of 13 cases of microvascular flap reconstruction of the scalp in patients who underwent free flap reconstruction of the scalp in conjunction with cranioplasty. Those authors concluded that primary cranioplasty using acrylic implants should be avoided in patients who have contaminated surgical wounds. Lipa and Butler advocated a two-layer overlapping “vest-over-pants” flap insetting to reduce the risk of scalp wound dehiscence.
O’Connell reported that myofascial latissimus dorsi flaps used in conjunction with skin grafts were the most useful method for free flap reconstruction of scalp defects, being used in 86% of cases. Oh et al. reported increased patient satisfaction with regard to durability and well-fitting wigs in patients who underwent scalp reconstruction with skin-grafted myofascial latissimus dorsi free flaps. Van Driel reported improved color match, contour, overall aesthetic result in patients with skin-grafted muscle flaps versus fasciocutaneous flaps, although this difference in outcome did not reach statistical significance.
PEARLS
• Latissimus dorsi flaps are the most common type of free flap used for microvascular flap reconstruction of scalp defects.
• Myofascial latissimus dorsi flaps that are resurfaced with a skin graft provide the optimal aesthetic result of reconstruction.
• Myocutaneous latissimus dorsi flaps may be indicated in cases of alloplastic cranioplasty reconstruction to reduce the risk of cranioplasty extrusion.
• Myocutaneous latissimus dorsi flaps may be indicated in cases where there is a defect of the dura to lessen the risk of cerebrospinal fluid leak.
• Latissimus dorsi flaps can be combined with other soft tissue and osseous flaps that are also perfused by the subscapular vascular pedicle to allow for single-flap reconstruction of very large or complex defects of the scalp.
• The long thoracodorsal vascular pedicle usually reaches superficial temporal or cervical recipient blood vessels without the need to perform a vein graft.
• Latissimus dorsi flaps are very reliable for reconstruction of scalp wounds, and long-term donor site morbidity is frequently acceptable.
• When harvesting a large volume latissimus dorsi flap, leave the humeral insertion of the latissimus dorsi muscle attached to the humerus until the flap is ready to be moved up to the scalp defect.
• In patients in whom a skin graft is needed in conjunction with a myofascial flap, it is my preference to design a myocutaneous flap with an elliptical skin paddle that has a width of approximately 7 cm overlying the anterior border of the latissimus dorsi muscle. A dermatome is used to harvest a split-thickness skin graft from the flap skin paddle at the beginning of the flap harvest, and the resulting deepithelialized flap skin paddle is subsequently excised and discarded. The resulting 7-cm-wide flank donor site wound is closed primarily in a tension-free closure, and skin graft donor site morbidity is thereby avoided since the skin graft donor site is excised and discarded. Skin grafts are expanded using a 3:1 skin graft mesher to cover large scalp skin defects. Nonmeshed skin grafts are often used for reconstruction of smaller defects to avoid a fish net stocking appearance of the healed skin graft, and additional split-thickness skin grafts are harvested from the thigh as needed (Fig. 38.9).
• At the beginning of the flap insetting, the latissimus dorsi muscle tendon that was detached from the humerus should be tacked down to deep fascia in the cheek or upper neck in a position where the geometry of the flap’s vascular pedicle relative to the recipient vessels is suitable for microvascular anastomosis. This will prevent the vascular pedicle from retracting superiorly and becoming too short for anastomosis during flap insetting.
FIGURE 38.9 Nine-month postoperative appearance of a scalp reconstruction using a latissimus dorsi myofascial flap combined with a meshed split-thickness skin graft. The meshed split-thickness skin graft has a fish net stocking appearance, so nonmeshed skin grafts should be used in patients who do not plan on wearing a wig or a hat.
PITFALLS
• Large-volume latissimus dorsi flaps that are commonly used to reconstruct large scalp defects are very heavy. The weight of the flap can cause a traction or avulsion injury to the flap’s vascular pedicle after the flap harvest dissection is completed but before the flap is transferred to the scalp defect.
• Myofascial latissimus dorsi flap often require large skin grafts for restoration of an epithelial surface. This can create additional donor site morbidity at the skin graft harvest site.
• During flap insetting into the scalp wound, there is a tendency for the latissimus dorsi muscle to contract and become foreshortened, which pulls the flap’s vascular pedicle superiorly and can adversely affect vessel geometry for microvascular anastomosis.
INSTRUMENTS TO HAVE AVAILABLE
• Standard head and neck surgical set
• A rib tray including Doyen periosteal dissectors
• Reciprocating and oscillating saws
• Monopolar and bipolar electrocauteries
• Hemoclips
• Dermatome
• Utrasonic shears (Harmonic Focus, Ethicon Endo-Surgery, Cincinnati, OH)
SUGGESTED READING
Cho BC, Lee JH, Ramasastry SS, et al. Free latissimus dorsi muscle transfer using an endoscopic technique. Ann Plast Surg 1997;38:586–593.
Frodel JL Jr, Ahlstrom K. Reconstruction of complex scalp defects: the “Banana Peel” revisited. Arch Facial Plast Surg 2004;6:54–60.
Hierner R, Van Loon J, Goffin J. Free latissimus dorsi flap transfer for subtotal scalp and cranium defect reconstruction: report of 7 cases. Microsurgery 2007;27:425–428.
Blackwell KE, Rawnsley JR. Aesthetic considerations in scalp reconstruction. Facial Plast Surg 2008;24:11–21.
Afifi A, Djohan RS, Hammert W, et al. Lessons learned reconstructing complex scalp defects using free flaps and a cranioplasty in one stage. J Craniofac Surg 2010;21(4):1205–1209.