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

by John R. Craig, MD, Matthew Kim, MD, Daniel B. Spielman, MD, Jonathan Overdevest, MD, Tamer Ghanem, MD, and David A. Gudis, MD •

The superior flap incision began at the sphenoid ostium, then was carried along the septum about 1 cm below the cribriform plate, and anteriorly to the septal mucocutaneous junction, then connected to the lateral incision along the pyriform aperture. Note that the superior and inferior posterior choanal rim incisions were carried far laterally to the region of the sphenopalatine foramen to improve pedicle mobility. The flap was elevated in submucoperichondrial/osteal planes, then tucked into the nasopharynx until the reconstruction.

Next, to facilitate flap advancement into the maxillary sinus, a modified endoscopic Denker’s approach was performed by removing the inferior turbinate and medial maxillary sinus wall, preserving the bone at the pyriform aperture, and transecting the nasolacrimal duct. The NSF was then rotated into the maxillary sinus to cover the entire sinus floor (Figure 1). This was then carried out on the patient.

Figure 1. Endoscopic view of the cadaver dissection showing a left nasoseptal flap (NSF) having been rotated over the palatine bone and posterior wall of the maxillary sinus (PW-MS) to cover the maxillary sinus floor completely to the anterior wall of the maxillary sinus (AW-MS). In this cadaver, the pterygopalatine fossa (PPF) contents were exposed, but this was not part of the NSF technique.

Surgical Case

Intraoperatively, the NSF was harvested and the modified endoscopic Denker’s approach was performed as in the cadaver dissection, the maxillary sinus walls were prepared for NSF inset. The previous free flap appeared viable and occupied the anterior third of the sinus floor, but had pulled away posteriorly, angling inferiorly away from the anterior maxillary sinus wall as it fistulized into the neck.

To optimize wound healing potential, a maximal amount of contact was desired between the NSF, maxillary sinus walls, and free flap. A suction monopolar Bovie was used to cauterize and incise mucosa around the sinus floor defect. Angled curettes and grasping forceps were then used to remove 5–10 mm of mucosa from the anterior, lateral, and posterior maxillary sinus walls around the perimeter of the sinus floor defect.

When the NSF was first rotated into the maxillary sinus through the medial maxillectomy opening, it barely covered the posterior third of the floor defect and appeared to be at high risk for failure. Pedicle rotation was inhibited by portions of the palatine bone and posterior maxillary sinus wall, as well as the inferior and middle turbinate stumps.