Defining benchmarks for robotic-assisted low anterior rectum resection in low-morbid patients: a multicenter analysis

PURPOSE: To define the best possible outcomes for robotic-assisted low anterior rectum resection (RLAR) using total mesorectal excision (TME) in low-morbid patients, performed by expert robotic surgeons in German robotic centers. The benchmark values were derived from these results.

METHODS: The data was retrospectively collected from five German expert centers. After patient exclusion (prior surgery, extended surgery, no prior anastomosis, hand-sewn anastomosis), the benchmark cohort was defined (n = 226). The median with interquartile range was first calculated for the individual centers. The 75th percentile of the median results was defined as the benchmark cutoff and represents the "perfect" achievable outcome. This applied to all benchmark values apart from lymph node yield, where the cutoff was defined as the 25th percentile (more lymph nodes are better).

RESULTS: The benchmark values for conversion and intraoperative complication rates were ≤ 4.0% and ≤ 1.4%, respectively. For postoperative complications, the benchmark was ≤ 28% for "any" and ≤ 18.0% for major complications. The R0 and complete TME rate benchmarks were both 100%, with a lymph node yield of > 18. The benchmark for rate of anastomotic insufficiency was < 12.5% and 90-day mortality was 0%. Readmission rates should not exceed 4%.

CONCLUSION: This outcome analysis of patients with low comorbidity undergoing RLAR may serve as a reference to evaluate surgical performance in robotic rectum resection.