Free Flap Reconstruction of Endoscopic Skull Base Defects

Objective 1) Propose a novel technique using free tissue transfer to reconstruct large endoscopic skull base surgery defects. 2) Demonstrate the anatomic feasibility of this technique. Method Two cadaver heads and forearms were obtained with permission from the university body donation program. Anterior skull base defects were created from planum sphenoidale to the frontal recess. Radial forearm free flaps were then harvested using standard techniques, taking care to preserve maximum length of the pedicle vessels. Results To inset the flap, a maxillary antrostomy was performed. An incision was made in the gingivolabial sulcus of the upper lip and extended laterally and inferiorly. Subperiosteal dissection was performed, and an anterior maxillotomy created. Dissection was then performed through the incision over the mandible. A cervical incision was then made. A subcutaneous tunnel was created. The pedicle was tunnelled through the cervical incision, through the maxillotomy and maxillary antrostomy, and then inset by draping the skin paddle over the skull base defect. This provided ample coverage of the defect and the pedicle length comfortably spanned the course of dissection. Conclusion As expanded endonasal approaches develop, so too must skull base reconstruction techniques. Vascularized tissue is ideal, especially in patients with extensive prior surgery and radiation. A vascularized free flap is a feasible option for reconstruction of large anterior skull base defects.