The surgical learning curve for salvage robot-assisted radical prostatectomy: a prospective single-surgeon study.

BACKGROUND To report the overall results and the learning curve (LC) in salvage robot-assisted radical prostatectomy (sRARP) patients, in terms of morbidity, oncological and functional outcomes in a single surgeon tertiary-referral center. METHODS One hundred and twenty patients underwent sRARP by a single surgeon (V.P.) from 2008 to 2018. To assess the trends in the learning experience they were sub-divided in 4 groups of 30 consecutive patients based on date of surgery. The Kaplan- Meier method and regression models were used to identify survival estimations and predictors of potency, continence and biochemical failure (BCF) at 12 months. RESULTS As the learning experience for sRALP increased operative time (OT) was significantly shorter (from 139,5 to 121 min) and the amount of nerve-sparing (NS) undertaken increased (from 46 to 80%). While complications rate remained stable, estimated blood loss (EBL) and radiographic anastomotic leaks (RAL) decreased through the groups (from 124 to 69 ml and 40% to 16,7%, respectively). BCF and continence rates at 12 months after sRARP were similar among groups (23-36% and 36,7-50%, respectively) and chance of potency rates tended to increase (from 3,3% to 16-23%) but was not statistically significant. In a multivariate analysis, predictors for BCF were PSM and GS 8-10. Non-radiation primary treatment was the unique predictor of continence at 12 months after sRARP. CONCLUSIONS Our data may suggest a decreasing trend in terms of OT and EBL through the sRARP learning curve. While morbidity remained stable through the time, radiographic anastomotic leaks trended towards a decline. A higher degree of NS was observed through the groups and there was a slight correlation trend between surgical expertise and potency recovery. PSM and GS 8-10 were predictors of BCF and non-radiation primary treatment predicted a better continence after sRARP.