Endoscopic transsphenoidal pituitary surgery: a single surgeon experience and the learning curve

Abstract

Endoscopic transsphenoidal surgery for pituitary adenomas has been introduced as an alternative to transsphenoidal microsurgery. This is the first Australian study to evaluate a single surgeon's experience by comparing our results with other series and attempting to identify a learning curve. Retrospective analysis was carried out on 79 consecutively treated patients by fully endoscopic transsphenoidal surgery by a single neurosurgeon over a period spanning from July 1998 to September 2010 at St George Public and Private hospitals. The mean age at time of surgery was 56.7 years (SD ± 16.3, range 26–85) and the mean follow-up period was 38.2 months (SD ± 33, range 1–136). Gross total resection (GTR) was noted in 63% of patients, endocrinological cure was achieved in 53% and visual field improvements were noted in 86% of patients. Intra-operative CSF leaks occurred in 19% of procedures, while the rates of post-operative CSF rhinorrhea was 3% and post-operative diabetes insipidus was 13%. There was one post-operative death (1%). Compared to microsurgery, intra-operative CSF leaks and meningitis seem less frequent with an endoscopic approach. With increasing experience, we found a non-statistically significant trend towards higher rates of GTR, and improved visual fields. Endocrinological cure rates were clearly better with experience (p < 0.01). There may be a learning curve that can be overcome in 30–40 cases. Endoscopic transsphenoidal surgery provides similar tumour and patient outcomes when compared to transsphenoidal microsurgery. In this single surgeon's experience, there was a trend to indicate improved performance with more case experience.