The learning curve of robotic hysterectomy

To evaluate the learning curve of robotic hysterectomy using objective, patient-centered outcomes and analytic methods proposed in the literature.

All cases of robotic hysterectomy performed at Mayo Clinic, Rochester, Minnesota, from January 1, 2007, through December 31, 2009, were collected. Experience was analyzed in 6-month periods. Operative time, complications, and length of stay longer than 1 day were compared between periods for significant change. For learning curve analysis, standard and risk-adjusted cumulative summation charting was used for the two most experienced robotic surgeons (A and B). Outcomes of interest were intraoperative complications and intraoperative or postoperative complications within 6 weeks. Proficiency was defined as the point at which each surgeon's curve crossed H0 based on complication rates of abdominal hysterectomy. Cumulative summation parameters were p0=5.7% and p1=11.4% for outcome 1 and p0=36.0% and p1=50% for outcome 2.

In 325 cases, operative time decreased significantly from 3.5 to 2.7 hours during the 3-year period. The proportion of patients with length of stay longer than 1 day decreased significantly from 49.2% to 14.7%. Complications did not decrease significantly. The average number of procedures to cross H0 was 91 for outcome 1 and 44 for outcome 2. Observed cumulative summation curves of surgeons A and B differed from the average number of attempts calculated from p0 and p1.

Operative time and length of stay decrease with 36 months of experience with robotic hysterectomy, whereas complications may not. Cumulative summation analysis provides an objective, individualized tool to evaluate surgical proficiency and suggests this occurs after performing approximately 91 procedures.

III.