Relaxing Sphenoidal Slit Incision: A Simple Technique to Extend the Anterior and Posterior Reach of Pedicled Nasoseptal Flaps during Endoscopic Skull Base Reconstruction of Transcribriform Defects

Abstract

Objective: Endoscopic endonasal skull base surgery via the transcribriform corridor has become an accepted approach for lesions of the cribriform plate such as olfactory groove meningiomas and esthesioneuroblastomas. Nevertheless, reconstruction of the large anterior skull base (ASB) defects after endoscopic endonasal transcribriform approaches remain a technical challenge despite the advent of the vascularized pedicled nasoseptal flap (PNSF). These defects often extend from orbit to orbit in the coronal plane and from the posterior table of the frontal sinus to the planum sphenoidale in the sagittal plane. In some cases, the PNSF may be under tension and not have enough anterior reach to cover the posterior table of the frontal sinus. In addition, tension across the sphenoidal portion of the PNSF prevents the flap from covering the posterior extent of transcribriform defects. We describe a relaxing slit incision that is made in the sphenoidal portion of the PNSF that extends the anterior reach as well as the posterior reach of the PNSF to maximize tensionless flap coverage of transcribriform ASB defects. We also present illustrative cases demonstrating the operative technique and nuances.