Pectoralis Major Flap with Sternum

Abstract

Sir:FigureThe vast majority of segmental bony defects of the mandible are treated with free vascularized bone flaps. There are certain patients, however, who are poor candidates for free tissue transfer but still require vascularized bone. These include patients who have no recipient vessels or donor sites, or are too ill for a lengthy procedure. The following case is one such patient. The patient was a 73-year-old man with a history of a T1N2bM0 squamous cell carcinoma of the tongue. Previous treatment included surgical excision and bilateral neck dissections in 2003, followed by irradiation (total, 160 Gy) to the oral cavity and neck. He subsequently developed osteoradionecrosis, treated with serial sequestrectomies, followed by recurrences in 2008 and 2009, requiring excision. He presented to our institution with another recurrence in 2011 and was scheduled for a composite resection of the body of the mandible and floor of the mouth. On examination, his neck was as solid as wood from the mandibular angle to the clavicle. On computed tomography, he had bilateral severe atherosclerosis of the carotids and no remaining branches of the external carotids. He had bilateral congenital club feet, for which he underwent nine operative procedures and was ambulatory only with orthoses. Finally, he had severe chronic obstructive pulmonary disease and hepatitis C and was an active smoker and alcoholic. Clearly, this patient was a poor candidate for free tissue transfer; however, his tumor was causing severe pain and ulceration and was growing rapidly. To achieve intraoral skin coverage, vascularized bony reconstruction, and neck coverage, we opted for a pedicled pectoralis major muscle flap with skin and a vascularized split sternum. The pectoralis major with a vascularized sternum was described by Green et al. in 19811 and further refined by Robertson2,3 but has been lost to history in the era of free tissue transfer. The technique involves a skin island oriented vertically over the lateral aspect of the lower third of the sternum (Fig. 1). The medial incision is made, and the anterior table of the ipsilateral lower third of the sternum is osteotomized with the oscillating saw. A curved osteotome separates the anterior and posterior tables. The skin incision is continued along the costal margin to create a rotation flap to close the donor site. The pectoralis muscle is elevated in the submuscular plane until the lateral border of the sternum is encountered. The sternocostochondral junction is separated with sharp Mayo scissors (Fig. 2). The remainder of the myo-osseocutaneous flap is elevated in standard fashion.4 The native mandible was burred down to create a step-cut in which the sternum was press-fit. Osteosynthesis was achieved with 8-mm nonlocking screws (Fig. 3). The patient had an uneventful hospital course and was discharged to home on postoperative day 6. After 2 weeks, the patient developed an orocutaneous fistula; however, on surgical débridement, the bone remained well vascularized by the muscle.Fig. 1: The skin island is centered over the ipsilateral border and the inferior half of the sternum. The bony sternal segment is marked over the ipsilateral half and the inferior third of the sternum, not including the xiphoid. The incision is designed to continue inferolaterally, creating a fasciocutaneous rotation flap to close the donor defect.Fig. 2: The medial incision is made first, and the anterior table of the ipsilateral lower third of the sternum is osteotomized with the oscillating saw. A curved osteotome separates the anterior and posterior tables. The skin incision is continued along the costal margin to create the rotation flap. The pectoralis muscle is elevated in the submuscular plane until the lateral border of the sternum is encountered. The sternocostochondral junction is separated with sharp Mayo scissors.Fig. 3: The native mandible was burred down to create a step-cut in which the sternum was press-fit. Osteosynthesis was achieved with 8-mm nonlocking screws. Different orientations of the bone and skin island are possible, depending on whether intraoral or extraoral skin is required.Free vascularized bone flaps are standard treatment for segmental mandibular defects. Occasionally, however, for reasons of donor-site, recipient-site, or patient disease, free tissue transfer is inadvisable. In these cases, pectoralis major flap with vascularized sternum represents one of the few remaining options for this subset of patients. Jesse Creed Selber, M.D., M.P.H. Shadi Ghali, M.D. University of Texas M. D. Anderson Cancer Center, Houston, Texas DISCLOSURE The authors have no financial interest to declare in relation to the content of this article.