Learning curve in robotic rectal cancer surgery: A national two-centre study.

Introduction: Colon and rectal surgery was amongst the earliest specialities to adopt robotic surgery, with Weber and Hashizume reporting the first operations for benign and malignant colorectal disease, respectively, in 2002. Although robotic-assisted surgery benefits from technical advantages that shorten the learning curve, it nonetheless presents a steep and extended learning curve.

Patients and methods: A prospective study was performed by a surgical team formed from two different departments in Bulgaria, using the da Vinci Si HD robotic system. The patients were divided into two groups: group I - the first 28 patients without indocyanine green (ICG) use and group II - the next 17 patients with ICG fluorescence imaging to assess bowel perfusion. Correlations between patient characteristics, operation duration, conversions, hospitalisation duration, complications, bleeding, reoperation, type of operation and ICG usage were assessed using multivariate analysis. This research aims to evaluate our learning curve, oncological safety and technical proficiency using the cumulative summation (CUSUM) method. To determine the CUSUM scores for each procedure index, the average console and docking time were taken into account. Subsequently, CUSUM plots were generated for the initial 45 cases.

Results: Forty-five patients were included: 32 men (71.1%) and 13 women (28.9%). The procedures performed included 37 anterior resections (82.2%) and 8 (17.8%) abdominoperineal excisions. The operative time was shorter in group II for both the docking and console times. The docking time in group I was 10 min (range, 4-30 min) compared with 9 min (ranging 5-20 min) in group II ( P = 0.691). The console time was 166 min in group I (ranging 45-300 min) and 147 min in group II (ranging 60-235 min) ( P = 0.020).

Conclusion: A significant reduction in console time was observed after the 28 th case. Anastomotic leaks were not observed in the ICG group. Despite our small patient cohort, we believe our institution contributes to the literature by describing our experience and the learning curve associated with robotic rectal resections.