Minimizing Postoperative CSF Leaks: An Algorithm for Sellar Reconstruction following Transsphenoidal Pituitary Surgery

Introduction: One of the common and troublesome complications of endoscopic pituitary surgery is postoperative cerebrospinal fluid (CSF) leak. Options for repair of the skull base include synthetic materials, autografts such as fat or fascia, and pedicled flaps. The vascularized nasoseptal flap has been popularized as the preferred option for most surgeons for complex defects. Our group typically reconstructs with a nasoseptal flap for tumor larger than 1.5 cm in size and performs a rescue flap intervention for smaller defects. Our primary objective was to retrospectively evaluate the rate of postoperative CSF leak with our reconstructive approach. Our secondary objective was to identify factors predictive of postoperative CSF leak.

Methods: A retrospective review was conducted of all transnasal endoscopic pituitary cases performed at a single institution over a 6-year period. Patient demographic, diagnostic, and postoperative management details were collected from the electronic health record and confirmed using pathology reports. Details of intraoperative CSF leak and skull base reconstructive techniques were obtained from the operative report. Categorical data were compared using Pearson’s chi square test.

Results: A total of 167 cases were identified, 19 of which were revision procedures. Median age was 53 years (range: 18–82) and the male to female ratio was 1:1.6. Repair techniques ranged from a simple closure using absorbable products to complex multilayer repair with a combination of underlay and overlay grafts and a vascularized flap. Seventy-four patients (44.3%) had CSF leaks detected intraoperatively, 15 of which were of high volume (11.1%). Intraoperative leak was associated with patients undergoing revision procedures (p = 0.02). It was not associated with age, gender, or tumor histopathology (including secreting tumors). Most patients underwent reconstruction with a vascularized pedicled nasoseptal flap (62.7% of low-volume and 100% of high-volume leaks), combined with allograft underlay. Of those who did not, the majority had an underlay with either synthetic material or fat graft.

Three patients (1.8%) had postoperative CSF leaks. Two of the three had large tumors (4.4 and 4.7 cm), one resolved with lumbar drain insertion and one required return to the operating room. The final patient had an ACTH-secreting microadenoma and required surgical repair. None of these patients had high-volume leaks, and all had undergone nasoseptal flap reconstruction. Due to the low number of postoperative CSF leaks, it was not possible to draw any conclusions regarding predictive factors. There was no significant difference between the incidence of leaks in patients who had nasoseptal flaps compared with those who did not (p = 0.30).

Conclusion: Our data demonstrate there is a low rate of postoperative CSF leaks in endoscopic pituitary surgery. Our reconstruction approach consists of a nasoseptal flap for tumors larger than 1.5 cm and a rescue flap for those with smaller tumors that require intervention. For those with a small defect and low-flow CSF leak, we favor allograft underlay with sealant. Determining optimal reconstructive techniques remains a challenge and is impacted by individual surgeon preferences. A more comprehensive evaluation of larger patient numbers should be undertaken, including quality of life and patient-reported outcome parameters.