A review of the advantages of the anterolateral thigh flap in head and neck reconstruction

Transcription

1 The British Association of Plastic Surgeons (2004) 57, A review of the advantages of the anterolateral thigh flap in head and neck reconstruction Jagdeep S. Chana, Fu-chan Wei* Department of Plastic and Reconstructive Surgery, Chang Gung Memorial Hospital, 199 Tung Hwa North Road, Taipei 10591, Taiwan, ROC and Mt Vernon Hospital, Northwood, Middlesex HA6 2RN, UK Received 3 July 2003; accepted 27 May 2004 The anterolateral thigh flap was originally described by Song in 1984 as a septocutaneous flap based on the descending branch of the lateral circumflex artery. 1 It was later determined that in the majority of cases the flap was supplied only by musculocutaneous perforators and septocutaneous supply only occurred in a small percentage of case. 2 5 In the past, the variable anatomy and the necessity for intramuscular dissection of perforators has given this flap the reputation of requiring a relatively difficult dissection. In recent years, advances in perforator flaps have provided familiarity of the technique required for safe dissection and in turn this has popularised the use of this flap for a wide variety of indications. Koshima et al. 6,7 and Kimata et al. 8 first described the use of this flap for the reconstruction of head and neck defects. Further reports have outlined the utility of this flap in head and neck reconstruction since it may be adapted to cover most defects of the face, neck or intraoral regions. 5,9 12 The flap may be thinned for pure intraoral defects. It also has good pliability and may be folded for the reconstruction of both the inner and outer lining of through and through defects. The vascular pattern also allows the use of a more versatile design with double skin paddles based on multiple perforators. In addition, the flap may be used in combination with vastus lateralis muscle as *Corresponding author. address: fcw2007@adm.cgmh.org.tw a myocutaneous flap or combined with adjacent flaps according to the chimaeric flap principle to reconstruct large or complex 3-dimensional defects. It is the aim of this article to describe the advantages of the use of this flap for reconstruction of a wide variety of head and neck defects. Flap anatomy The anterolateral thigh flap is supplied by the descending branch of the lateral circumflex femoral artery, which is the largest branch of the profunda femoris system. The pedicle lies in the groove between the rectus femoris and vastus lateralis muscles along with the motor nerve to the vastus lateralis. The anterior branch of the lateral cutaneous nerve of the thigh can be included to create a sensory flap. The pedicle length ranges between 8 and 16 cm with a vessel diameter larger than 2 mm. The pedicle supplies perforating branches to the surrounding rectus femoris and vastus lateralis muscles and septocutaneous vessels to the anterolateral thigh skin. Some of the perforators to the vastus lateralis muscle pierce the deep fascia and terminate in the anterolateral thigh skin after giving off numerous side branches to the muscle. These musculocutaneous perforators are dissected for harvest of a cutaneous or fasciocutancous flap. S /$ - see front matter Q 2004 The British Association of Plastic Surgeons. Published by Elsevier Ltd. All rights reserved. doi: /j.bjps

2 604 J.S. Chana, F.-c. Wei Flap dissection With the patient in a supine position, a line is drawn between the anterior superior iliac spine to the superolateral border of the patella. This line represents the muscular septum between the rectus femoris and the vastus lateralis muscles. The cutaneous vessels are mapped by portable handheld pencil Doppler probe centred over the midpoint of this line. 3,5,13 The majority of skin perforators are located within a circle of 3 cm radius centred at this midpoint (Fig. 1). Xu et al. located at least one perforator in the inferolateral quadrant of this circle in 80% of cases. 2 The flap is centred over the location of these vessels, and its long axis is designed parallel to that of the thigh. Dissection begins at the medial border of the flap, which should be located over the rectus femoris muscle. An incision is made through the deep fascia and the flap is raised laterally for a short distance until the intermuscular septum between the rectus femoris and vastus lateralis is reached. At this stage, the descending branch of the lateral femoral circumflex artery is identified in the groove between the rectus femoris and vastus lateralis, and a septocutaneous vessel may be identified which facilitates further dissection. However, in the largest series to date septocutaneous vessels were encountered in only 12.9% of cases. 5 Therefore, in the majority of cases flap harvest requires a careful dissection of a suitable intramuscular perforator. The musculocutaneous perforator gives off many small branches to the vastus lateralis muscle from the lateral and posterior sides of the vessel, but fewer from the anterior side. The course of the perforator can, therefore, easily be traced by incising the muscle over the perforator, and ligating the branches to the muscle from the lateral and posterior sides (Fig. 2). The perforator is traced back to the main descending branch of the lateral circumflex femoral artery, which is divided according to pedicle length requirements. In the majority of cases, the flap is harvested as a fasciocutaneous flap. When a thin pliable flap is required for intraoral defects a cutaneous flap may be raised using a suprafascial dissection. Once a suitable skin perforator is identified the flap is raised suprafascially and a small cuff of fascia is maintained around the perforator (Fig. 3(A) and (B)). The cutaneous flap can be further thinned to 5 mm but excessive thinning should be avoided to prevent marginal necrosis. Indications for thin anterolateral thigh flaps include reconstruction for hemitongue, buccal mucosa, palate and pharyngeal wall. When soft tissue bulk is required for the reconstruction the flap may be raised as a musculocutaneous flap. If a septocutaneous vessel is found, the skin and muscle components can be raised on different branches of the same vascular pedicle as a bipaddled composite flap. In the majority of cases, an intramuscular dissection of the perforator is not required. However, it is prudent to determine the course of the perforator to the source vessel by deroofing the muscle fibres over the chosen perforator. The perforator may have a variable and tortuous intramuscular course; this manoeuvre avoids inadvertent injury to the perforator during incision of the muscle, and also establishes that the perforator supplies the skin paddle of the musculocutaneous flap. Determining the course of the perforator to the source vessel is important since in 10% of cases the perforator may arise from the transverse branch of the lateral circumflex artery, and enters the muscle superiorly with a vertical course and is liable to damage during muscle incision at the upper border of the flap. 9 Figure 1 flap. Surface markings of the anterolateral thigh Figure 2 Perforator being dissected back to descending branch of the circumflex femoral vessels.

3 A review of the advantages of the anterolateral thigh flap in head and neck reconstruction 605 Advantages in head and neck reconstruction The anterolateral thigh flap can be harvested as thin as the radial forearm flap, with the advantage of reduced donor site morbidity. In most situations, the donor site can be closed directly when the width of the flap is 7 8 cm or less. It can, therefore, replace most intraoral reconstructions where previously the radial forearm flap has been the preferred option. This flap also allows a two team approach with flap harvest allowed to proceed simultaneously with the head and neck resection, and therefore has advantages over scapular, parascapular and latissimus dorsi flaps. The anterolateral thigh flap can be harvested with a skin paddle as large as that of abdominal perforator flaps and provides a longer pedicle length. It also avoids the issue of abdominal donor site complications when myocutaneous flaps are required. The anterolateral thigh flap, therefore, provides all the advantages of other commonly used flaps in head and neck reconstruction. Reconstruction of buccal defects Figure 3 A thin suprafascial anterolateral thigh flap. (A) Note the perforator emerging from the fascia and preserved sensory nerve. (B) Elevated cutaneous flap with a small fascia cuff around the perforator. Large defects of the head and neck are challenging to reconstruct since there may be a 3-dimensional requirement of both volume and multiple surfaces of oral lining and external skin. In these situations, the chimaeric anterolateral thigh flap is particularly versatile. Since the lateral circumflex femoral artery gives off lateral, medial and descending branches, multiple components can be harvested based on the main pedicle. There are many combinations of chimaeric anterolateral thigh flaps, the majority of which are combined with the rectus femoris muscle, tensor fasciae latae, anteromedial thigh skin and vastus lateralis muscle. 14,15 Double skin paddle flaps may also be used with each paddle based on separate perforators. 16 Musculocutaneous flaps may also be raised with muscle and skin paddles based on separate perforators. This versatility facilitates insetting of the flap to complex 3-dimensional defects. Buccal defects requiring reconstruction of oral lining alone are relatively straightforward for which thin anterolateral thigh flaps may be used. Larger defects may involve external cheek skin resulting in through and through defects. In this situation, a folded anterolateral thigh flap can be used with the intervening folded portion being deepithelialised. These defects have a significant volume deficit, which often results in a long-term sunken appearance of the cheek. In our experience, this can be improved by incorporating muscle with the anterolateral thigh skin to provide extra bulk, which augments the cheek and improves cosmesis (Fig. 4). If two suitable perforators are present the skin paddle can be split as a chimaeric flap which allows for a more elegant reconstruction. 16 If the oral commisure is involved in the defect the fascia lata can be split and sutured into the upper and lower obicularis oris muscle as a static sling. 16 Anterolateral thigh flap in extensive composite defects of the mandible More extensive composite defects involving segmental resection of the mandible often result in extensive soft tissue loss of the cheek. The skin islands of the osteoseptocutaneous flap may be

4 606 J.S. Chana, F.-c. Wei Figure 4 ALT flap for tongue reconstruction and submental augmentation after hemiglossectomy and radical neck dissection. (A) Inset of flap for tongue reconstruction and neck augmentation. (B) Appearance of reconstructed tongue two years postoperation. (C) and (D) Face and neck appearance 2 years postoperation. adequate for coverage of both inner and outer lining but inadequate to replace soft tissue loss. Soft tissue reconstruction in these situations has at least as great a significance for the functional result as does the bony reconstruction. 17,18 The dead space left by extirpation of the masseter muscles, buccal fat and the parotid gland must be obliterated to prevent fluid accumulation and secondary infection and to prevent further soft-tissue contraction. A two flap procedure in these situations provides adequate volume to prevent these complications and also avoids a sunken appearance of the cheek which may occur after radiotherapy. 18 In our previous experience, a free osteoseptocutaneous fibula flap may be used for mandibular reconstruction and inner lining together with a free radial forearm flap or rectus abdominis flap for the cheek. 19 The radial forearm flap is usually too thin to cover the fibula and reconstruction plate and has an inferior donor site when compared to an

5 A review of the advantages of the anterolateral thigh flap in head and neck reconstruction 607 anterolateral thigh flap. The rectus abdominis flap may be too bulky and has disadvantages with regard to the abdominal donor site. The anterolateral thigh flap is more suitable in these situations. 16,18 It has a large cutaneous area 10 and the volume is easily adjustable by incorporating part of the vastus lateralis muscle 18 (Fig. 5). Tongue reconstruction The anterolateral thigh flap has largely replaced the radial forearm flap in reconstruction of tongue defects in our centres. 5 This flap is pliable, adapts well to 3-dimensional defects in the oral cavity, 12 and the donor site is superior to that of the radial forearm flap since primary closure is achieved. Hemitongue defects are reconstructed using a thin sensate anterolateral thigh flap incorporating the lateral cutaneous nerve of the thigh (Fig. 5). Partial tongue defects involving more of the floor of the mouth can be reconstructed with a larger flap part of which may be de-epithelialised and used to fill the dead space and augment the defect in the submandibular region. Total glossectomy defects require significant bulk to restore height and volume to the reconstructed tongue and a myocutaneous flap is therefore required. The muscle component can also be used to fill dead space in the neck from an associated neck dissection. The anterolateral thigh flap can provide as much volume as a rectus abdominis myocutaneous flap which previously has been the most commonly used flap for total glossectomy reconstruction and has the added advantage of avoiding abdominal wall complications. Midfacial reconstruction These defects are complex because they generally involve more than one midfacial component and often require skin cover, mucosal lining and bony support. Although various free flaps have been used for midface reconstruction the commonly used flaps include the radial forearm flap for small defects and the rectus abdominis or latissimus dorsi myocutaneous flaps for larger defects combined with bone grafts for orbital support if indicated. 20,21 Small defects involving palate alone or midfacial skin alone may be reconstructed with a cutaneous or fasciocutaneous anterolateral thigh flap. Larger defects following maxillectomy require muscle to obliterate the dead space and a myocutaneous anterolateral thigh flap provides Figure 5 Extensive composite mandibular defect reconstruction with a fibula osteoseptocutaneous flap for intraoral lining and the mandible defect and an anterolateraled thigh flap for external face defect (A) Extensive composite left mandibular defect. (B) After double flap reconstruction. (C) Appearance one and half year after surgery. sufficient volume. An important consideration in midface reconstruction using free tissue transfer is the use of recipient vessels. The pedicle has to be long enough to reach donor vessels in the neck. The anterolateral thigh flap is ideal under these

6 608 J.S. Chana, F.-c. Wei circumstances since a cm pedicle is easily provided. Flaps harvested according to volume requirement from this single donor site can, therefore, replace the radial forearm, rectus abdominis or latissimus dorsi flaps which have been commonly used for midface reconstruction. Scalp reconstruction The anterolateral thigh flap provides an extremely large surface area of skin 10 and lends itself to resurfacing extensive defects of the scalp with bone exposure. 22 An excellent contour of the scalp is achieved without excessive bulkiness that can result from the use of other flaps with wide skin territory such as the rectus abdominis and latissimus dorsi flaps. Donor site morbidity One of the primary advantages of the anterolateral thigh flap is the reduced donor site morbidity. Few other donor sites in the body offer such an ample amount of sensate skin and muscle for the reconstruction of through and through tumour defects in the head and neck. To preserve maximal quadriceps function, a careful dissection and preservation of the nerve to the vastus lateralis should be performed. Kimata et al. observed that weakness of the limb were related to the degree of muscle dissection and if a skin graft had been used. 23 The use of a V Y perforator based local advancement flap has been described to avoid the use of a skin graft. Other authors have not found the donor site to be problematic. Even when the vastus lateralis is transferred as a free muscle flap Wolff and Grundman found that there was no motor dysfunction in their series confirmed by clinical comparison of the load capacity of both legs. 13 In a further recent report Kuo et al. have shown objectively, using a kinetic communicator machine, that patients who underwent a myocutaneous anterolateral thigh flap showed minimal weakness of the donor thigh at long term follow-up. 24 The most important aspect of the anterolateral thigh flap in reconstruction of head and neck defects lies in its versatility in design and composition and low donor site morbidity. While a very thin pliable innervated flap may be harvested for intraoral reconstruction in one patient, the whole vastus lateralis may be incorporated in the flap to reconstruct a massive perioral defect in another patient. Thus, the anterolateral thigh flap may be used to reconstruct most soft tissue defects in the head and neck region including intraoral, tongue, buccal, midface and scalp. With the diversity that this flap provides the anterolateral thigh flap can cover most of the indications of two commonly used soft tissue free flaps in head and neck reconstruction, namely the radial forearm flap and the rectus abdominis flap. As Ao et al. 4 have indicated the morbidity resulting from these two donor sites should not be overlooked when a versatile alternative such as the anterolateral thigh flap is available. References 1. Song YG, Chen GZ, Song YL. The free thigh flap: a new free flap concept based on the septocutaneous artery. Br J Plast Surg 1984;37(2): Xu DC, Zhong SZ, Kong JM, et al. Applied anatomy of the anterolateral femoral flap. Plast Reconstr Surg 1988;82(2): Kimata Y, Uchiyama K, Ebihara S, et al. Anatomic variations and technical problems of the anterolateral thigh flap: a report of 74 cases. Plast Reconstr Surg 1998;102(5): Ao M, Uno K, Maeta M, et al. De-epithelialised anterior (anterolateral and anteromedial) thigh flaps for dead space filling and contour correction in head and neck reconstruction. Br J Plast Surg 1999;52(4): Wei FC, Jain V, Celik N, et al. Have we found an ideal softtissue flap? An experience with 672 anterolateral thigh flaps. Plast Reconstr Surg 2002;109(7): discussion Koshima I, Hosoda S, Inagawa K, et al. Free combined anterolateral thigh flap and vascularized fibula for wide, through-and-through oromandibular defects. J Reconstr Microsurg 1998;14(8): Koshima I. Free anterolateral thigh flap for reconstruction of head and neck defects following cancer ablation. Plast Reconstr Surg 2000;105(7): Kimata Y, Uchiyama K, Ebihara S, et al. Versatility of the free anterolateral thigh flap for reconstruction of head and neck defects. Arch Otolaryngol Head Neck Surg 1997;123(12): Demirkan F, Chen HC, Wei FC, et al. The versatile anterolateral thigh flap: a musculocutaneous flap in disguise in head and neck reconstruction. Br J Plast Surg 2000;53(1): Shieh SJ, Chiu HY, Yu JC, et al. Free anterolateral thigh flap for reconstruction of head and neck defects following cancer ablation. Plast Reconstr Surg 2000;105(7): discussion Nakayama B, Hyodo I, Hasegawa Y, et al. Role of the anterolateral thigh flap in head and neck reconstruction: advantages of moderate skin and subcutaneous thickness. J Reconstr Microsurg 2002;18(3): Cipriani R, Contedini F, Caliceti U, Cavina C. Threedimensional reconstruction of the oral cavity using the free anterolateral thigh flap. Plast Reconstr Surg 2002;109: Wolff KD, Grundmann A. The free vastus lateralis flap: an anatomic study with case reports. Plast Reconstr Surg 1992; 89(3): discussion

7 A review of the advantages of the anterolateral thigh flap in head and neck reconstruction Koshima I, Fukuda H, Soeda S. Free combined anterolateral thigh flap and vascularized iliac bone graft with double vascular pedicle. J Reconstr Microsurg 1989;5: Koshima I, Hosoda M, Moriguchi T, et al. A combined anterolateral thigh flap, anteromedial thigh flap, and vascularized iliac bone graft for a full-thickness defect of the mental region. Ann Plast Surg 1993;31(2): Huang WC, Chen HC, Jain V, et al. Reconstruction of through-and-through cheek defects involving the oral commissure, using chimeric flaps from the thigh lateral femoral circumflex system. Plast Reconstr Surg 2002;109(2): discussion Urken ML, Weinberg H, Vickery C, et al. Oromandibular reconstruction using microvascular composite free flaps. Report of 71 casts and a new classification scheme for bony, soft-tissue, and neurologic-defects. Arch Otolaryngol Head Neck Surg 1991;117(7): Wei FC, Celik N, Chen HC, et al. Combined anterolateral thigh flap and vascularized fibula osteoseptocutancous flap in reconstruction of extensive composite mandibular defects. Plast Reconstr Surg 2002;109(1): Wei FC, Demirkan F, Chen HC, Chen IH. Double free flaps in reconstruction of extensive composite mandibular defects in head and neck cancer. Plast Reconstr Surg 1999;103(1): Cordeiro PG, Santamaria E. A classification system and algorithm for reconstruction of maxillectomy and midfacial defects. Plast Reconstr Surg 2000;105(7): discussion Cordeiro PG, Disa JJ. Challenges in midface reconstruction. Semin Surg Oncol 2000;19(3): Lutz BS. Aesthetic and functional advantages of the anterolateral thigh flap in reconstruction of tumor-related scalp defects. Microsurgery 2002;22(6): Kimata Y, Uchiyama K, Ebihara S, et al. Anterolateral thigh flap donor-site complications and morbidity. Plast Reconstr Surg 2000;106(3): Kuo YR, Jeng SF, Kuo MH, et al. Free anterolateral thigh flap for extremity reconstruction: clinical experience and functional assessment of donor site. Plast Reconstr Surg 2001; 107(7):