How to: Nasoseptal Flap to Repair Large Maxillary Sinus Floor Defects

INTRODUCTION

An oroantral fistula (OAF) is an epithelialized tract from the maxillary sinus to the oral cavity. OAFs occur most commonly after maxillary molar extraction, but may also occur following tumor resection or osteoradionecrosis. For OAFs after dental extraction, multiple studies have demonstrated OAF closure success rates of 90% or greater with transoral approaches such as buccal mucosal or fat pad advancement flaps (Eur J Oral Implantol. 2014;7:347–357). However, when OAF closures fail, salvage transoral reconstructive options may be limited.

In recent years, lateral nasal wall (Laryngoscope. 2022;132:2259–2261), greater palatine artery (Laryngoscope. 2022 [published online ahead of print]), and nasoseptal flaps (NSFs) (J Oral Maxillofac Surg. 2016;74(704):e701–e706) have been used to close OAFs after dental extractions. Noel et al. published the only report of a successful NSF reconstruction of a 2 x 1.5 cm2 OAF after dental extraction and previous chemoradiation (J Oral Maxillofac Surg. 2016;74(704):e701–e706). Based on literature to date, if buccal or palatal mucosa or buccal fat is available for OAF repair, high success rates should be expected, and transnasal options should be unnecessary. However, should transoral options be limited or unavailable, recent reports have demonstrated success in closing OAFs with different intranasal mucosal flaps.

This article describes using an NSF to close a large maxillary sinus floor defect if transoral options are limited or unavailable to the otolaryngologist, with emphasis on technical nuances to assist surgeons in performing this technique.

METHOD

A 74-year-old male suffered from a recurrent deep neck space abscess after infrastructural maxillectomy and adjuvant radiation therapy for a buccal and alveolar ridge squamous cell carcinoma. His radial forearm free flap skin paddle that had been used previously to reconstruct the sinus floor dehisced, causing a fistula between the sinus and neck.

Due to a lack of transoral reconstructive options, a transnasal repair was planned. He had an intact nasal septum and nasal floor, and given the size of the sinus floor defect and previously radiated tissue bed, a large vascularized nasoseptal flap was felt to offer the highest likelihood of success.

Cadaver Dissection

To prepare for the case, a cadaveric dissection was performed to simulate the transnasal closure of a complete maxillary sinus floor defect. An NSF was first harvested by making an incision along the choanal rim and vomer, and across the nasal floor along the soft/hard palate junction to the lateral wall of the inferior meatus. The incision was then carried anteriorly to the pyriform aperture, staying inferior to the nasolacrimal duct orifice.