Single-Center Experience in Resection of Pituitary Adenomas with High-Grade Cavernous Sinus Invasion

Background The extent of cavernous sinus invasion in pituitary adenomas is inversely correlated with extent of resection due to risk to neurovascular structures. With a greater extent of resection, there is a higher rate of resolution of presenting symptoms and a lower chance of requiring adjuvant radiotherapy or repeat resection in the future. This series presents a high-volume center’s experience in resection of pituitary adenomas with cavernous sinus invasion.

Methods From July 2008 to December 2015, data were collected retrospectively from 40 patients with Knosp grade 3 or 4 pituitary adenomas graded on preoperative MRI. The primary outcome assessed was extent of resection. Secondary outcomes of resolution of presenting symptoms, postoperative cerebrospinal fluid leak rate, and hypopituitarism were also collected. Average follow-up time was 24 months.

Results Of the 40 patients, 17 underwent endoscopic, endonasal resection, while the remaining underwent microscopic, sublabial approach. Ten patients presented with secretory adenomas. Overall, gross total resection (GTR) was obtained in 12 out of 40 (30%). GTR in Knosp grade 3 was 10 out of 22 (45.5%), and Knosp grade 4 was 2 out of 18 (11.1%). Average extent of resection was 81.5% (grade 3: 88.1% and grade 4: 74.3%). Complete resolution of symptoms was obtained in 16 patients (40%) (6 in grade 3 and 10 in grade 4) and partial in 22 patients. The cerebrospinal fluid leak rate was 10%, with the preponderance from Knosp grade 4 with three patients. Postoperative hypopituitarism was seen in 13 patients. Only one patient required repeat resection or postoperative radiotherapy.

Conclusion The goal of pituitary adenoma resection is to maximize resection to improve preoperative symptoms, reduce the risk of recurrence while minimizing complications. In this series, 81.5% extent of resection was obtained with 95% of patients with improvement in presenting symptoms. One patient required further intervention at 2 years follow-up. This series demonstrates an acceptable rate of complications in resection of lesions with high-grade cavernous sinus invasion with a significantly low rate of further intervention.