Nasoseptal Flap Reconstruction of High Flow Intraoperative Cerebral Spinal Fluid Leaks during Endoscopic Skull Base Surgery

Abstract

Over the past 10 years, significant anatomic, technical, and instrumentation advances have facilitated the exposure and resection of intradural lesions via a fully endoscopic expanded endonasal approach (EEA). The vascularized nasoseptal flap (based on the posterior nasoseptal artery) has become our primary endoscopic reconstructive technique. The goals of this study are to prospectively evaluate the nasoseptal flap and high-risk cerebral spinal fluid (CSF) leak variables. Prospective evaluation was performed of EEA patients with intraoperative high-flow leaks (either a cistern or ventricle open to nasal cavity during tumor dissection) who underwent nasoseptal flap reconstruction. Seventy consecutive nasoseptal flaps for high-flow intraoperative leaks were evaluated prospectively by the primary author. Twelve risk factors were then graded at the time of the operations and correlated to CSF leak outcomes. The overall postoperative CSF leak rate was 5.7% (4/70). All four postoperative leaks were successfully managed with endoscopic repair and CSF diversion. A multivariate analysis of all 12 risk factors is detailed. Pediatric patients, large dural defects, and radiation therapy were noted to be factors in reconstructive failure. One flap death occurred in a patient with prior surgery and proton therapy, this leak was managed with a temporoparietal flap and endonasal repair. The nasoseptal flap is an excellent anterior skull base reconstructive technique. Patients with high-flow intraoperative CSF leaks had a 94% successful reconstruction rate. Patients with skull base proton radiation therapy are at higher risk for flap failure and preparation for nonradiated tissue reconstruction should be discussed with the patient.