The Posterior Septal Nasal Floor Mucosal Flap for Cranial Base Reconstruction

Abstract

Objective: While pedicled intranasal flaps, such as the nasoseptal flap (NSF), successfully reduce postoperative CSF leaks following endoscopic endonasal approaches (EEA) to the skull base, morbidity remains prevalent. This study describes the first cadaveric description and radiographic analysis of the posterior septal nasal floor mucosal flap (PSNF) designed to reduce pedicled nasal flap morbidity. A case series is also detailed.Study Design: Cadaveric dissection, radiographic analysis, and case series. Methods: Seven cadaver specimens underwent harvest of the PSNF. PSNF flap dimensions were measured on the thirty deidentified sinus computed tomography (CT) scans. A retrospective case series was performed on the first set of patients who received the PSNF for reconstruction of a sellar base defect. Information concerning complications, symptoms, and the appearance of the flap was recorded from records of the patient's postoperative inpatient stay, 1-week postop visit, and 1-month postop visit.Results: Cadaver dissection of the PSNF flap demonstrated good arc rotation along its pedicle with ability to cover both sellar and planum defects. Cadaveric flap measurements and CT-derived measurements estimated a mean surface area of 16.7 and 18.3 cm 2 , respectively. 15 patients underwent reconstruction of a sellar or planum defect using the PSNF technique. Only one CSF leak was encountered postoperatively. Minimal crusting of the flap and donor site was seen 1 month postoperatively. Conclusion:The PSNF flap provides a sizeable pedicled region for reconstruction comparable to other pedicled nasal flaps. Our case series demonstrated good postoperative outcomes without reduced donor site morbidity.

Takedown and Reuse of a Posterior Septal Nasal Floor Mucosal Flap for Skull Base Reconstruction in a Revision Surgery for a Recurrent Pituitary Tumor

“…Although the width and length of a PS-NF are similar to those of an NSF, the total area of a PS-NF is slightly smaller; therefore, use of a PS-NF should be limited to coverage of skull base defects <3 cm in diameter if high-flow CSF leakage is encountered during surgery [ 7 ]. In our patient, high-flow CSF leakage was encountered and the skull base defect was <3 cm in diameter.…”

“…In addition, other reconstructive materials should be used if the flap is too small or flap blood flow is deemed insufficient. Flap hemodynamics can be evaluated using intraoperative indocyanine green angiography [ 7 ], which we are considering using in the future. Interestingly, contrast enhancement of the flap was more pronounced in the second flap.…”