351 Anterior Ethmoid Artery Septal Flap for Endoscopic Reconstruction of Frontal Sinus CSF Leak

Introduction Anterior skull base cerebrospinal fluid (CSF) leaks are managed successfully with endonasal surgery. Endoscopic closure of CSF leaks from posterior table of the frontal sinus remains challenging. Vascularized Hadad-Bassagasteguy flap (HBF) reconstruction of the skull base has increased CSF closure rates but does not extend to frontal sinus. We describe our technique using septal flap pedicled by anterior ethmoid artery (AEA) for repairing frontal defects. Method Retrospective review of cases of frontal CSF leak repair using the AEA flap reconstruction. Flap design: an anterior vertical septal mucosa incision at posterior border of the frontal sinusotomy is made and extended to nasal floor. Posterior vertical incision is made 1 cm posterior to the projection of the axilla of the middle turbinate on the septum and extended to nasal floor. A horizontal incision along the nasal floor joins the two incisions. The flap is raised and rotated into the frontal sinus over the posterior table reconstructed defect. Results Three patients identified. Two males, one female, aged 11, 33 and 56. Patient histories included recurrent bacterial meningitis following head trauma, recurrent sinusitis and fronto-ethmoidal osteoma, with intraoperative CSF leak and CSF rhinorrhea due to meningoencephalocele. The three posterior wall defects were successfully repaired endoscopically with multilayer reconstruction and the AEA septal flap. Conclusions The anterior ethmoid artery septal flap can be successfully utilised for frontal CSF leak repair. Flap is conveniently located for frontal sinus defects. When the septum is intact it provides an excellent final layer as part of multilayer reconstruction.