2025 Poster Presentations
P259: TECHNIQUE TO ADD SUPERIOR AND LATERAL REACH OF THE NASOSEPTAL FLAP FOR FRONTAL SINUS POSTERIOR TABLE SKULL BASE DEFECTS: THE ORBITO-FRONTAL RECESS EXPANSION.
Axel Renteria, MD, MS1; Maxime Fieux, MD, PhD1; Lirit Levi, MD1; Cecilia Rosso, MD2; Lya Mont'Alverne, MD3; Zechariah Franks, MD, MPH1; Michael Chang, MD1; Jayakar Nayak, MD, PhD1; Peter Hwang, MD1; Juan-Carlos Fernandez-Miranda, MD1; Zara Patel, MD1; 1Stanford University; 2University of Milan, Milan, Italy; 3Hospital de Clínicas da Unicamp, Sao Paolo, Brazil
Introduction: Skull base defects in the superior and lateral aspects of the posterior table of the frontal sinuses are challenging to reconstruct because of access and reach of reconstructive options. Often, external approaches are needed to reconstruct such defects, potentially increasing the morbidity and healing time of the procedure. We present a technique that increases superior and lateral reach for the pedicled vascularized nasoseptal flap to the posterior table by selectively removing bone to expand the orbito-frontal recess.
Methods: In this cadaveric study, 10 specimens were used to investigate the feasibility of increasing the superior and lateral reach of a nasoseptal flap to reconstruct a posterior table defect of the frontal sinuses. Reach of the flap within the frontal sinus was measured in centimeters in a cranio-caudal (CC) axis from the inflection point between the posterior table and ethmoid skull base to the point directly superiorly where the anterior and posterior table met, and the latero-lateral (LL) axis from the lateral most inflection point of the meeting of the posterior table and the ethmoid skull base to the side wall of the sinus. The nasoseptal flaps were harvested via standard approach, and their lengths were measured, along with their reach, along the frontal sinus posterior table. After orbito-frontal recess expansion, the reach of the flap was again measured to assess for any change.
Results: On average, the mean CC and LL lengths of the frontal sinuses were of 2.16 ± 0.41 cm and 2.230 ± 0.46 cm respectively. Average nasoseptal flap length was measured at 7.60 ± 0.58 cm. The average nasoseptal flap reach increase after orbito-frontal recess expansion was statistically significant in the CC axis with an increase of 0.89 ± 0.64 cm (p=0.017). The average nasoseptal flap reach increase after orbito-frontal recess expansion was statistically significant in the LL axis with an increase of 0.58 ± 0.50 cm (p=0.005).
Conclusion: The study demonstrates that a technique for selectively removing bone to expand the orbito-frontal recess region allows for improved coverage both superiorly and laterally along the posterior table of the frontal sinus with a standard nasoseptal flap. This novel technique increases the field of coverage and case selection for this common reconstructive option, adding to our reconstructive armamentarium for this challenging region, while potentially decreasing procedure morbidity.