Endoscopic Pituitary Surgery - A Retrospective Review to Determine the Risk Factors for CSF Leak and Vascular Complications

Introduction: Endoscopic transsphenoidal pituitary surgery has become the mainstay of pituitary surgery and evidence suggests that it results in better surgical outcomes in terms of removal of tumor burden.

Aim: To present the surgical results of a single neurosurgeon operating in a Skull Base Unit over ten years of endoscopic pituitary surgery and determine risk factors for CSF leak and vascular complications.

Methods: A retrospective review of the charts, operative notes, histopathology and radiology of all patients who underwent pituitary surgery for presumed pituitary adenoma by surgeons within our unit over a ten-year period 2006–2016. This comprised a single neurosurgeon and 3 otolaryngologists. 207 patients were eligible for inclusion in this study. Tumors were divided according to histological subtype. Our practice is to replace sphenoid mucosa and then utilize a septal mucosal flap based on the inferior septal vessels as a pedicle. This is then reinforced with DuraSeal. If this is not possible, DuraGen and fascial graft is used.

Results: 96 (46.3%) tumors were classified as non-functioning, 35 (16.4%) as growth-hormone producing, 40 (19.3%)as adrenocorticotrophin producing, 15 (7.2%) prolactin-producing, 3 (1.4%) thyroid stimulating hormone producing, 8 (3.8%) luteinizing hormone/follicle stimulating hormone producing, 5 (2.4%) Rathke’s cleft cysts and 6 (2.8%) other (metastases and inflammatory tissue). Cerebrospinal fluid leak rate was 6.76% and 50% of these required operative repair (the remainder settled with lumbar drainage). 7 (50%) of these leaks were in patients having surgery for recurrent tumors. Diabetes insipidus was seen transiently in 49 patients (23%) and was permanent in 10 (4.8%) patients. There were no cases of major vessel hemorrhage.

Conclusion: Recurrent tumors requiring a second operation, cavernous sinus invasion and macroadenoma all pose an independent and increased risk of post-operative CSF leak. No major vascular complications occurred in this series.