The Orbitofrontal Expansion for Extending Nasoseptal Flap Reach in the Frontal Sinus

Abstract

Skull base defects involving the superior and lateral posterior table of the frontal sinus are challenging to reconstruct due to limited surgical access and restricted reach of available reconstructive options. External approaches are often required, increasing morbidity and prolonging recovery. We describe the orbito-frontal recess expansion (OFRE), a minimally invasive endoscopic technique designed to enhance the superior and lateral reach of the pedicled vascularized nasoseptal flap (NSF) for reconstruction in this region.

A cadaveric feasibility study was performed using 10 specimens to evaluate the impact of OFRE on NSF reach. Flap reach was measured in centimeters along cranio-caudal (CC) and lateral axes from the frontoethmoidal transition zone (FTZ) to the frontal sinus apex and lateral wall at the anterior–posterior table junction. NSFs were harvested using a standard technique, then remeasured following OFRE, with each specimen serving as its own control. Data were analyzed using a Wilcoxon signed-rank test.

Mean CC and lateral frontal sinus dimensions were 2.16 ± 0.41 and 2.23 ± 0.46 cm, respectively. Average NSF length was 7.60 ± 0.58 cm. OFRE significantly increased flap reach in both axes, with gains of 0.89 ± 0.64 cm in the CC axis (p = 0.0017) and 0.58 ± 0.49 cm in the lateral axis (p = 0.0051).

OFRE enhances superior and lateral coverage of the posterior frontal sinus table using a standard NSF. This technique expands endoscopic reconstructive options and may reduce the need for external approaches, offering a less invasive option for this challenging anatomical region.