Operative Learning Curve After Transition to Endoscopic Transsphenoidal Pituitary Surgery.

Background: No clear consensus yet defines the endpoints for operative learning curves in the transition to minimally invasive endoscopic techniques. This retrospective review of our first 202 patients who underwent endoscopic pituitary resection examines the statistical learning curve related to operative times-a measure of our surgical team's efficiency and complication rate, a reflection of surgical skill and maturity.

Methods: Retrospective chart review included patient demographic data, tumor type, operative time, complications, and follow-up. During the 5-year study period, surgeries were performed by an otolaryngology-neurosurgery team. Statistical analysis by Pearson's correlation delineated a learning curve for operative time and complications.

Results: Our learning curve showed comparable plateaus: 120 cases (48% males, 52% females) for operative time (mean, 134 minutes; range, 62-307 minutes) and 100 cases for incidence of cerebrospinal fluid (CSF) leak. The risk of CSF leak declined significantly with the surgeon's increasing experience. Complication rates were as follows: temporary nasal obstruction, 9.9%; CSF leak, 8.4%; postoperative epistaxis, 7%; sinusitis, 4.5%; septal osteomyelitis, 2.4%; postoperative sellar hematoma, 1.5%; anosmia, 0.5%; and septal perforation, 0.5%. The overall CSF leak rate included 5.5% intraoperative and 2.9% postoperative; most cases resolved with a lumbar drain. Four patients (2%) underwent postoperative surgical repair and lumbar drainage.

Conclusion: Our learning curve-defined endpoints for 2 measures, operative time and complication rates, support improved outcomes for reduced CSF leaks, the most common complication, with increasing operative experience. We will continue to examine the implications related to safety, efficacy, and the need for subspecialization in this minimally invasive surgery.