Endoscopic Pituitary Tumor Surgery: The Learning Curve

Introduction: Endoscopic endonasal pituitary surgery is increasing utilized and is being passed on to the next generation of neurosurgeons. This approach can be technically challenging due to lack of 3 dimensional visualization, increased operative working distance and novel/different instrumentation. We present our experience with the exclusive endoscopic endonasal approach over the past 10 years.

Methods: We performed a retrospective review of patients who underwent an endoscopic endonasal pituitary tumor resection between 2003–2012 by a single neurosurgeon/ ENT surgeon team (PT, LZ). We assessed the extent of resection based on comparison of pre and post-operative imaging for each case. We reviewed complications including post-operative hypopituitarism, diabetes insipidus and CSF leaks. We then compared these outcome parameters in the first half of patients operated on (group A) with the second half of patients (group B).

Results: A total of 240 patients with adequate follow up were included in the study. Average patient age in both groups was 51 years. F:M ratio in both groups was 1.15:1. In Group A 55.8% had a GTR and 44.2% had a STR. In Group B, 59.2% had a GTR and 40.8% had a STR. The rate of new post-operative pituitary dysfunction was 18.3% in Group A and 15% in group B. The rate of diabetes insipidus was 12.5% in group A and 3.3% in group B (p < 0.01). The rate of post-operative CSF leaks was 3.3% in Group A and 2.5% in group B.

Conclusion: The 2 dimensional view, increased working distance and novel instrumentation can result in a steep learning curve for endoscopic pituitary surgery. Increased experience should result in improved patient outcomes, particularly a decreased rate of diabetes insipidus.