Safety and efficacy of OAGB/MGB during the learning curve: setting a benchmark in a bariatric center of excellence.

Very little has been published on the learning curve (LC) of the One Anastomosis /Mini Gastric Bypass (OAGB/MGB). Aim of this study was to compare perioperative outcomes of OABG/MGBs performed during the LC of an experienced laparoscopic surgeon to global benchmark cut-offs. First 200 patients undergoing OAGB/MGB at our university hospital from 2010 to 2016 were retrospectively included in this study. LC of the surgeon was divided in two groups of 100 consecutive patients each and perioperative outcomes were compared to abovementioned global benchmarks for LSG and RYGB. A cumulative sum (CUSUM) analysis was performed for operative time and hospital stay. Uneventful postoperative recovery was recorded in 95% of patients. All benchmark values for RYGB were met in group 2. Comparison with cut-offs for LSG showed longer hospital stay and operative time in both groups but postoperative rate of complications resulted lower even for Group 1. CUSUM graph of the operative time runs randomly above the predetermined limit till the 40th cases but reaches the plateau after the 115th operation. CUSUM curve of the hospital stay reaches the plateau after the 57th case. OAGB/MGB confirms to be a feasible procedure, which can be safely and effectively performed during the learning curve. However, at least 100 hundred cases are required to reduce operative time and hospital stay.