Program maturation across 364 robotic colorectal procedures: postoperative recovery, operative efficiency, and major morbidity

Robotic colorectal learning-curve studies commonly define proficiency using operative time or cumulative-sum thresholds, which may not capture maturation of a heterogeneous program. In this retrospective longitudinal cohort, we analyzed 364 consecutive robotic colorectal procedures from a single-surgeon, single-center program using prior global robotic colorectal experience as a continuous exposure. Principal clinical outcomes were postoperative length of stay (LOS) and major morbidity (Clavien-Dindo grade III or higher); operative duration was the principal process/efficiency outcome. Multivariable log-linear models adjusted for procedure family, robotic platform, associated procedures, age, and American Society of Anesthesiologists (ASA) class; major morbidity was analyzed with Firth penalized logistic regression. Each doubling of (1 + prior experience) was associated with 5.1% shorter LOS (95% CI 2.2%-7.9% shorter; p < 0.001) and 5.3% shorter operative duration (95% CI 3.3%-7.4% shorter; p < 0.001). Restricted cubic spline analysis showed no evidence of LOS non-linearity (p = 0.621) but significant non-linearity for operative duration (p < 0.001). Major morbidity occurred in 15/364 procedures (4.1%); the adjusted Firth odds ratio was 1.48 per experience doubling (95% profile-likelihood CI 0.84-3.64; p = 0.208). Because cumulative experience and calendar time were essentially collinear, estimates represent longitudinal program maturation rather than an isolated causal surgeon-experience effect. Greater cumulative experience was associated with shorter LOS and operative duration, but the LOS association should be interpreted as a program-level signal that may also reflect evolving perioperative care; major morbidity remained uncommon but imprecisely estimated longitudinally.