Magnetic Resonance Imaging Confirms Vascularity of Nasoseptal Flaps in the Late Postoperative Period

Background: The vascularized nasoseptal flap (NSF) has become a technique often utilized in reconstruction after endoscopic intradural skull base surgery. Reconstruction with this robust flap has expanded the nature of skull base surgery while decreasing postoperative complication rates. Prior studies have suggested that the NSF may not have consistent contrast uptake on MRI. This raised the question of the vascularity of the actual flap. The aims in this study were to compare vascularity visualized on gadolinium-enhanced magnetic resonance imaging between the immediate postoperative and late postoperative periods and to correlate these findings with complication rates in patients with NSF reconstructions.

Methods: Retrospective cohort study of patients with NSF reconstructions over a 2-year period. Inclusion criteria involved all patients with early and late postoperative gadolinium-enhanced MRI. These postoperative MRIs were evaluated for enhancement of NSF with contrast and graded by full vascularity (full contrast uptake), congested vascularity (contrast uptake noted but less than native turbinate mucosa), or not vascular (no contrast uptake). Matched comparisons between early and late MRIs were performed.

Results: Thirty-one patients, 15 males and 16 females ages 10-79, were identified who had immediate postoperative (less than 6 weeks) and late postoperative (greater than 8 weeks) MRI scans to evaluate flap vascularity. MRIs had contrast uptake in 100% of the cohort in the early and late postoperative periods. Two patients (6.4%) were found to have NSF with evidence of congestion on early postoperative MRI scans. One patient was found to have a flap that initially demonstrated congestion but later demonstrated full vascularization on late MRI. Two patients required re-exploration for CSF leak, and both of these patients had fully vascularized flaps on MRI at both time points. No flap deaths were noted in clinical endoscopic follow-up.

Conclusion: Nasoseptal flaps consistently provide an excellent tool for reconstruction of the skull base, and this data suggest a 100% rate of vascularity in the postoperative period. The vascularity of this robust flap can consistently be assessed on MRI scans and is found to be similar both on perioperative and late scans. Patients with notable congestion on MRI scans are rare and do not demonstrate a higher complication rate. None of the patients in the cohort demonstrated absent vascularity; therefore, we were unable assess complication rates in this population.