Nasoseptal Flap for Skull Base Reconstruction using Cone Beam Computed Tomography: A Cadaveric Study

Objective: We hypothesized that cone beam computed tomography (CBCT) is suitable for measuring nasoseptal flap (NSF) dimensions. Therefore, CBCT derived 3D NSF dimensions were compared with anatomical dissections. In addition, the NSF reach was evaluated. Study Design. Anatomical study (n = 10). Methods: Using CBCT, 3D NSF reconstructions were made. The NSF length and surface were calculated and compared with anatomical dissections. The NSF reach was evaluated by positioning the NSF to the skull base from the planum sphenoidale and from the sella toward the frontal sinus. Results: The correlations between 3D NSFs and anatomical dissections were strong positive (r > 0.70). The surface of the 3D NSF was 19.8 cm² (16.6-22.3) and the length on the left and right side of the septum was 78.3 mm (73.2-89.5) and 77.7 mm (72.2-88.4), respectively. The surface of the anatomical dissected NSF was 18.7 cm² (16.1-24.6), the length on the left and right side of the septum was 77.6 mm (73.0-83.0) and 78.7 mm (71.6-81.5), respectively. Covering of the ventral skull base was possible by positioning the NSF anterior of the sphenoid sinus. If the NSF was positioned to the skull base from the sella toward the frontal sinus, the NSF reached partially into the anterior ethmoidal sinuses. Conclusion: CBCT is a valuable technique for calculating NSF dimensions. This study encourages preoperative planning of a customized NSF, thereby sparing septal mucosa which can benefit postoperative morbidity.