Endoscopic Endonasal Reconstruction of High-Flow Cerebrospinal Fluid Leak with Fascia Lata “Button” Graft and Nasoseptal Flap: Surgical Technique and Case Series

Background The endoscopic endonasal approach (EEA) has become increasingly used for resection of skull base tumors in the sellar and suprasellar regions. Opening the cisterns above the sellar diaphragm with or without opening of the third ventricle creates a high-flow intraoperative leak and a robust reconstruction is of paramount importance to avoid postoperative CSF leak. The nasoseptal flap is routinely used for reconstruction of the skull base in this area; however, there are numerous additional exogenous and endogenous grafts that are being used in conjunction with the nasoseptal flap for reconstruction as well as the use of lumbar drains. The “button” graft has been previously described and consists of two rectangular pieces of fascia lata sutured together in the center. One piece is placed inlay and it is 1 to 2 mm larger than the dural defect. The outer piece is positioned onlay and it is 5 to 8 mm larger than the defect.

Objectives To present the surgical technique and results of reconstruction utilized in our institution for pathologies with an intraoperative high-flow leak without the perioperative use of lumbar drains. Important characteristics of the patients, which could affect reconstruction such as body mass index (BMI) are studied.

Methods A retrospective chart review of 24 patients who underwent expanded endoscopic cranial base surgery to the supradiaphragmatic space with opening of the suprasellar cisterns from 2013 to 2017 at Albany Medical Center was conducted. Demographic data, BMI, data related to their pathology, and complications were reviewed. All patients had reconstruction of the defect with a “button” fascia lata inlay-onlay graft, nasoseptal flap and fibrin glue. Lumbar drains were not used.

Results All patients studied had high-flow intraoperative CSF leak due to opening of the suprasellar cisterns. Patient BMIs ranged from 23 to 49 kg/m² (median = 30 kg/m²), with 12 patients meeting criteria for obesity (BMI > 30 kg/m²) and 11 patients overweight (25 kg/m²< BMI < 29.9 kg/m²). The diagnoses were the following: seven craniopharyngiomas, nine pituitary tumors with large suprasellar extension, four tuberculum meningiomas, one arachnoid cyst, one suprasellar Rathke's cleft cyst, one cavernous sinus hemangioma with suprasellar extension and into the optic canal, and one spontaneous high-flow CSF leak with tuberculum defect. Eight patients had intraoperative opening of the lamina terminalis and communication with the third ventricle. There were no postoperative CSF leaks. No patients developed meningitis postoperatively. One patient after meningioma resection had to be reoperated due to development of an intra-axial brain abscess in an area of previous pial invasion of the tumor. There was no evidence of CSF leak in the postoperative period or at the time of the second operation, which was performed endonasally. Two patients developed diabetes insipidus postoperatively.

Conclusion These data suggest that nasoseptal flap in conjunction with the “button” fascial lata graft is a safe and robust technique for reconstruction in cases of a high-flow intraoperative CSF leaks with no need of perioperative lumbar drain, even in obese patients.