Reconstruction of an extensive scalp defect using the split latissimus dorsi flap in combination with the serratus anterior musculo-osseous flap

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1 British Journal of Plastic Surgery (1998), 51, The British Association of Plastic Surgeons BRITISH JOURNAL OF PLASTIC SURGERY Reconstruction of an extensive scalp defect using the split latissimus dorsi flap in combination with the serratus anterior musculo-osseous flap Y. Tanaka*, K. Miki*, S. Tajima*, J. Akamatsu*, Y. Tsukazaki * and T. Inomoto* Department of Plastic and Reconstructive Surgery, Osaka Medical College, Osaka, Japan and ~Division of Neurosurgery, Shingu City Hospital, Wakayama, Japan S UMMAR Y. A combination of split latissimus dorsi musculocutaneous flap with the serratus anterior musculoosseous flap was used to cover a very large defect of the scalp. This technique offers a new alternative for singlestage reconstruction of extensive scalp defects. Extensive scalp defects, which include the cranial bone and underlying dura resulting from tumour ablation, present reconstructive challenges. A latissimus dorsi muscle flap with a split-thickness skin graft provides adequate coverage for large areas and has been used as the first choice for repair of large scalp defects? -6 However, when a defect is truly extensive, as in the present case, it is impossible to cover it with a single flap. We report a successful reconstruction of an extensive full-thickness cranial defect using a technique of splitting the latissimus dorsi musculocutaneous flap in combination with the serratus anterior musculoosseous flap. Case report A 56-year-old woman was referred with a massive malignant endothelioma of the scalp that had been hidden by her long frontal hair for approximately 10 years. Examination revealed extensive foul-smelling ulcerating lesions which encompassed the entire posterior scalp and extended to the posterior neck (Fig. 1A). Cerebral pulsation was noted beneath the crust in the centre of the lesion and the cervical lymph nodes were palpable bilaterally. Head MRI showed involvement of the occipital bone and dura (Fig. 1B). MR sinography demonstrated complete occlusion of the posterior third of the superior sagittal sinus. However, 67Ga-scintigram and 99mTc-bone scintigram of the whole body revealed no apparent metastasis of the turnout. She was therefore offered the option of surgical removal to stop a process that would certainly cause her ultimate demise. En bloc resection of the involved scalp skin, including the underlying left trapezius and sternocleidomastoid muscles, occipital bone and dura was performed (Fig. 2). A small area of the brain was noted to be involved within the right parieto-occipital cortex, and this was excised together with the involved sagittal sinus. Reconstruction of the sagittal sinus was not performed because there had been no preoperative clinical symptom suggesting impairment of the cerebral venous drainage. The dural defect (8 cmx 6 cm) was reconstructed with a fascia latae graft. Then, the latissimus dorsi musculocutaneous flap and the lower half of the serratus anterior muscle flap including the 6th and 7th ribs (12 cm in length each) were raised based on the common thoracodorsal vessels (Fig. 3A). The ribs were fixed with wires across the occipital bone defect (10 cm x 8 cm) and the serratus muscle covered the central portion of the defect. The latissimus dorsi musculocutaneous flap was split into medial and lateral units and was placed over the exposed skull surrounding the serratus muscle flap (Fig. 3B, C). The thoraeodorsal artery and vein were anastomosed to the occipital artery and the external jugular vein, respectively. The latissimus dorsi and serratus anterior muscle flaps were covered with meshed skin grafts, while a skin paddle over the latissimus dorsi muscle was used for postoperative monitoring (Fig. 3D, E). The postoperative course was uneventful, and the palpable cervical lymph nodes spontaneously regressed, suggesting that the reactive lymph node swelling was probably secondary to wound infection. The margins of the specimen were clear of tumour on permanent histologic sections and, therefore, radical neck dissections were not performed. Postoperative CT-scans at 11 months showed the transferred ribs had obtained the same density as normal skull without any evidence of resorption (Fig. 4A). The patient has remained well and is clinically free of disease at 1-year follow-up (Fig. 4B). Discussion Microsurgical flee flap transfers are indicated when defects of the scalp are too extensive to be reconstructed by local flaps? -11 Among these free flaps, the latissimus dorsi muscle with split-thickness skin graft provides coverage of the largest area and has been used by many plastic surgeons as the first choice for reconstruction of extensive scalp defects? -6 However, even this flap is inadequate for truly extensive defects as in the present case. In 1984, Batchelor et al H reported a case of total scalp reconstruction using a multiple territory free tissue transfer. Although the survival area of the skin flap was not confirmed because of the perioperative death of the patient, a multiple territory free tissue transfer is an alternative to be considered. Scalp defects after tumour treatment are usually circular and markedly convex. Therefore, as described by Pennington et al, 4 draping of a skin flap to fit the defect produces significant dog ears which require a larger skin flap than the real defect. Skin flaps are also usually too thick for the ideal resurfacing the scalp. 250

2 Reconstruction of an extensive scalp defect 251 Fig. 1 Fig. 2 Figure 1--(A) Preoperative view, massive malignant endothelioma of the scalp. (B) Preoperative MRI demonstrating involvement of the scalp, skull, dura and brain (arrow). Figure 2~Excision specimen. (A) Skin surface. (B) Deep surface showing extent of bone involvement.

3 252 British Journal of Plastic Surgery skull Fig. 3 Figure 3 (A-C)--Intraoperative view. (A) Defect of scalp and cranial bone. The dura repaired with a fascia latae graft. (B) The split latissimus dorsi muscle, and the serratus anterior musculo-osseous flap placed over the bone defect. (C) Schematic illustration of the reconstruction.

4 Reconstruction of an extensive scalp defect 253 Lateral i ~ splliatbtissimus ~I~ Fig. 3 Figure 3 (D, E)--Immediately after surgery (D) and its schematic illustration (E). Fig. 4 Figure 4~(A) Postoperative CT-scan. The transferred rib (arrow) showing the same density as the cranial bone. (B) Eight-month postoperative view.

5 254 British Journal of Plastic Surgery Furthermore, a larger skin flap inevitably requires a skin graft to its donor site, which would prevent the simultaneous harvest of both the muscle and ribs. For these reasons, skin flaps are not generally suitable for reconstruction of extensive scalp defects. In 1981, Tobin et al m~ reported an anatomical study and the clinical versatility of the split latissimus dorsi muscle or musculocutaneous flap. Many split latissimus dorsi free flaps have since been reported? 4,1~ In the present case, the split latissimus dorsi flap was used in combination with the serratus anterior musculoosseous flap to resurface the entire posterior defect of the scalp. This procedure has not been reported previously and has the advantages that it provides (1) suitable coverage of an extensive convex defect of the scalp, (2) simultaneous calvarial bony reconstruction with vascularised ribs and (3) a reliable long vascular pedicle for microvascular transfer. The bony reconstruction of cranial bone defects remains controversial? s Free vascularised bone grafts are rarely used because free bone grafts are usually successful. However, the occipital region is a weight bearing area of the head; a reliable bony reconstruction is therefore mandatory to reduce the risk of postoperative complications especially when postoperative irradiation therapy is anticipated. In the present case, the ribs were well vascularised on flap elevation and have not undergone resorption as visualised on postoperative CT scan. The bony reconstruction has been well tolerated in her daily life and the contour was also well maintained at 1-year follow-up. Although the transferred muscle showed postoperative atrophy and the patient had no sensory recovery in the reconstructed area, no ulceration developed. The fact that the serratus and the intercostal muscle had firmly attached to the bony segments may have contributed to the restoration of both bony structure and contour by preventing friction between the transferred muscle and bone. Acknowledgements We would like to thank Professor W. A. Morrison, Bernard O'Brien Institute of Microsurgery, for his advice in preparing this manuscript. References 1. Jones NF, Hardesty RA, Swartz WM, Ramasastry SS, Heckler FR, Newton ED. Extensive and complex defects of the scalp, middle third of the face, and palate: the role of microsurgical reconstruction. Plast Reconstr Surg 1988; 82: Jones TR, Jones NF. Advances in reconstruction of the upper aerodigestive tract and cranial base with free tissue transfer. Clin Plast Surg 1992; 19: 819-3i. 3. Oishi SN, Luce EA. The difficult scalp and skull wound. Clin Plast Surg 1995; 22: Pennington DG, Stern HS, Lee KK. Free-flap reconstruction of large defects of the scalp and calvarium. Plast Reconstr Surg 1989; 83: Robson MC, Zachary LS, Schmidt DR, Faibisoff B, Hekmatpanah J. Reconstruction of large cranial defects in the presence of heavy radiation damage and infection utilizing tissue transferred by microvascular anastomoses. Plast Reconstr Surg 1989; 83: Earley M J, Green MF, Milling MAR A critical appraisal of the use of free flaps in primary reconstruction of combined scalp and calvarial cancer defects. Br J Plast Surg 1990; 43: Hirase Y, Kojima T, Kinoshita Y, Bang HH, Sakaguchi T, Kijima M. Composite reconstruction for chest wall and scalp using multiple ribs-latissimus dorsi osteomyocutaneous flaps as pedicled and free flaps. Plast Reconstr Surg 1991; 87: 555-6t. 8. Shen Z. Reconstruction of refractory defect of scalp and skull using microsurgical free flap transfer. Microsurgery 1994; 15: 633-8, 9. Chicarilli ZN, Ariyan S, Cuono CB. Single-stage repair of complex scalp and cranial defects with the free radial forearm flap. Plast Reconstr Surg 1986; 77: Koshima I, Fukuda H, Yamamoto H, Moriguchi T, Soeda S, Ohta S. Free anterolateral thigh flaps for reconstruction of head and neck defects. Plast Reconstr Surg 1993; 92: Batchelor AG, Sully L. A multiple territory free tissue transfer for reconstruction of a large scalp defect. Br J Plast Surg 1984; 37: Tobin GR, Schusterman M, Peterson GH, Nichols G, Bland KI. The intramuscular neurovascular anatomy of the latissimus dorsi muscle: the basis for splitting the flap. Plast Reconstr Surg 1981; 67: Tobin GR, Moberg AW, DuBou RH, Weiner LJ, Bland KI. The split latissimus dorsi myocutaneous flap. Ann Plast Surg 1981; 7: Elliott LF, Raffel B, Wade J. Segmental latissimus dorsi free flap. Clinical applications. Ann Plast Surg 1989; 23: Chiang YC, Wei FC. Simultaneous coverage of two separate defects with two free hemiflaps harvested from one latissimus dorsi muscle. Plast Reconstr Surg 1995; 95: The Authors Yoshio Tanaka MD, Associate Professor Sadao Tajima MD, Professor Jun Akamatsu MD Department of Plastic and Reconstructive Surgery, Osaka Medical College, 2-7 Daigakucho, Tukatsuki City, Osaka 569, Japan. Kazuhito Miki MD, Head of Neurosurgery Yuji Tsukazaki MD Takaaki Inomoto MD Division of Neurosurgery, Shingu City Hospital, Wakayama, Japan. Correspondence to Yoshio Tanaka. Paper received 29 January Accepted 23 January 1998, after revision.