The Buccal Flap Pad Vascularized Rotational Flap for Reconstruction of Ventral Skull Base Defects

Introduction/Objectives: Resecting skull base neoplastic disease via an expanded endonasal approach (EEA) can result in large sinonasal–intradural communications. The use of vascularized rotational flaps to reconstruct these defects has proven an effective technique in preventing postoperative complications such as cerebrospinal fluid (CSF) leaks and, when adjuvant radiotherapy is performed, skull base osteoradionecrosis. The nasoseptal flap has become the workhorse for closure of skull base defects. However, with the large variety of skull base pathology and subsequent defects many situations exist when an alternate flap is necessary. The buccal fat pad (BFP) is a vascularized graft previously described in open zygomaticotemporal skull base resections as rotated on its lateral attachment. However, the procurement technique and vascular supply have not been examined for use with EEA. This study was undertaken to characterize the harvest, blood supply, and application of the BFP in a cadaveric setting.

Methods: Step I: The BFP vascular anatomy was characterized in a fixed, latex-injected cadaveric model. Step II: A total of 10 BFP flaps were endoscopically harvested in five cadavers. An endoscopic medial maxillectomy combined with an anterior maxillectomy and transseptal approach was performed. The BFP was elevated truncating its anterior and lateral, inferior and superior attachments. On the basis of a posteromedial hinge point, the BFP was rotated into the nasal cavity to cover the defects along the rostral-caudal axis from the frontal sinus to the craniovertebral junction. The ability of the BFP to reconstruct defects at seven separate anatomic locations along ventral skull base was evaluated.

Results: In fresh specimens, the length of the BFP was measured up to 10 cm long. The BFP had adequate fat to reach and cover defects on the greater sphenoid wing, inferior and superior clivus, sella, planum, and bilateral ethmoid sinuses in all the 10 cadaveric specimens. Furthermore, in some cases, it capably covered two sites along the ventral skull base concurrently. Grossly, its perfusion via the internal maxillary artery was left intact following rotation.

Conclusion: We present the first anatomic description of the endonasal endoscopically harvested BFP-pedicled rotational flap. The BFP flap is based on the internal maxillary artery capable of reconstructing defects of the ventral skull base defects and should be considered as a potential alternate flap after EEA in selected cases.