Indications and Outcomes of the Nasoseptal Flap for Pituitary Surgery

Educational Objectives: Since the introduction of the nasoseptal flap (NSF), it has served as the workhorse of reconstruction of complex skull base defects following endoscopic endonasal surgery. Advantages of this vascularized tissue include ease of harvest, lengthy pedicle, reliable blood supply and versatility of use. It has been shown to be superior to free and synthetic grafts with respect to high flow cerebrospinal fluid (CSF) leaks and clival involvement. However, the indications for its use following routine pituitary surgery are not well defined. We review the indications and outcomes of the NSF for reconstruction following endoscopic pituitary surgery.

Methods: A retrospective review of all patients who underwent an endoscopic trans-sphenoidal procedure for removal of a pituitary adenoma at a tertiary referral center from 2013 to 2017 was performed.

Results: Overall, 44/346 or 12.7% of patients required a nasoseptal flap. Preoperative factors were assessed and a NSF was significantly more likely to be utilized in patients less than fifty years old (p < 0.05). More than half (57%) of NSF were employed during primary surgery. The remainder occurred either after a prior resection by another physician (20%), a second operation during the study period (16%) or a postoperative leak requiring surgical repair (7%).

Of the patients who underwent NSF repair, 89% (39/44) had an intraoperative CSF leak. These leaks were more commonly low flow (79%) compared with high flow (21%). For those with a low flow leak, they were identified as a complicated leak to repair secondary to a challenging location or multiple defect sites. The overall postoperative leak rate for our series was 1.7%. In those who had a NSF the postoperative leak rate was 6.8% (3/44), with all three patients having a high flow intraoperative CSF leak during revision surgery. With regard to complications, patients with a NSF were significantly more likely to develop a sellar hemorrhage, sinusitis and prolonged crusting (p < 0.05) as compared with the remaining cohort.

Conclusion: The NSF is not required for the vast majority of cases following pituitary surgery (only 12.7% in this series). The overall postoperative CSF leak for our 346 patients was low at a rate of 1.7%, with 87.3% of patients having a reconstruction that did not include a NSF. While the NSF has many advantages regarding closure for complex defects, it is also associated with increased morbidity such as septal perforation, saddle nose deformity, crusting, sinusitis and duration of surgery. We recommend the judicious use of the NSF following pituitary surgery and to consider it for high flow intraoperative CSF leaks and complicated low flow leaks that are not well closed with a primary dural repair.