A New Pedicled Internal Mammary Osteomyocutaneous Chimeric Flap (PIMOC) for Salvage Head and Neck Reconstruction: Anatomic Study and Clinical Application.

Well-vascularized composite tissue offers improved outcomes for complex head and neck reconstruction. Patients with vessel-depleted necks and failed reconstructions require alternative reconstructive options. We describe a pedicled internal mammary artery osteomyocutaneous chimeric flap (PIMOC) for salvage head and neck reconstruction. Bilateral dissections of 35 fresh cadavers were performed to study individual tissue components and vascular pedicles to develop the PIMOC technique. The flap was then utilized in a series of patients with vessel-depleted neck anatomy. The PIMOC was dissected bilaterally in all cadavers and there were no statistical differences in vascular pedicle caliber or length with regards to laterality or gender. Five patients subsequently underwent this procedure. The flaps included a vertical rectus abdominis myocutaneous component and a 6th or 7th rib with adjacent muscle and skin to restore bone defects, internal lining, and external coverage. All donor sites were closed primarily. There were no flap losses and all patients gained improvements in facial contour, speech and swallow. Although technically complex, the PIMOC is reproducible and provides a safe and reliable option for salvage head and neck reconstruction. The harvest of the 6th or 7th rib and rectus abdominis muscle renders an acceptable donor site.