(1208) Analysis of Pituitary Adenoma Volume Versus Diameter to Predict CSF Leak

Introduction: Pituitary adenomas are classified as macroadenomas or microadenomas based on whether the largest cross-sectional dimension is greater than 1cm. Cerebrospinal fluid (CSF) leak is a complication after endonasal resection of these masses; multiple studies have shown that a larger tumor size is an independent risk factor for developing both intraoperative and postoperative CSF leaks. This study aims to assess whether adenoma volume is a better predictor of intraoperative and postoperative CSF leak than is its largest dimension.

Methods: A retrospective chart review was performed for patients who underwent endoscopic endonasal resection of pituitary adenomas at the Mayo Clinic and Albany Medical Center. The following data were collected: demographic data, tumor dimensions, intraoperative CSF leak and flow, postoperative CSF leak, and other complications. Statistical analysis was performed using a robust Poisson distribution, adjusted based on graft source, age, sex, BMI, and tumor size.

Results: Charts of 439 patients were reviewed. Largest tumor dimension was found to be significantly predictive of intraoperative leak (p = 0.001), while computed tumor volume was not a significant predictor (p = 0.128). Neither tumor dimension nor computed tumor volume was found to be a significant predictor of CSF leak flow rate (p = 0.308 for largest diameter and p = 0.329 for volume) or postoperative CSF leak (p = 0.577 for largest diameter and p = 0.830 for volume).

Conclusions: The greatest measured diameter of a pituitary adenoma is a statistically significant predictor of intraoperative CSF leak compared to its measured volume. Neither volume nor largest diameter was a significant predictor of intraoperative leak flow rate or postoperative CSF leak.