BACKGROUND: Despite high-level evidence that variations of surgical technique in laparoscopic Roux-en-Y gastric bypass (LRYGB) are correlated with postoperative outcomes and might be linked to intraoperative adverse events (iAEs), there are a paucity of studies analyzing iAEs in depth. The impact of surgical technique on the temporal occurrence of iAEs regarding phases and steps of LRYGB has not been studied so far. The objective of this study was to analyze the impact of variance in surgical technique on temporal occurrence, frequency, and type of iAEs in a multicentric dataset of LRYGB videos. METHODS: MultiBypass140, a video dataset containing 70 LRYGB surgeries each from Strasbourg University Hospital (StrasBypass70) and Bern University Hospital (BernBypass70) was annotated with surgical phases, iAE type, and grade. The cumulative severity of iAEs per procedure was measured using the SEVERE score and correlated with procedure duration. RESULTS: Surgical technique significantly differed between StrasBypass70 and BernBypass70 (omentum division: 94% vs. 36%, p <
0.01
closure of mesenteric defects: 100% vs. 21%, p <
0.01). In MultiBypass140, a total of 797 iAEs were analyzed. The most iAE-prone phases were gastric pouch creation, gastrojejunal, and jejunojejunal anastomosis creation containing 77% (616/797) of all iAEs. StrasBypass70 showed significantly more iAEs in the omentum division (23 vs. 5, p <
0.01), Petersen space closure (13 vs. 1, p <
0.01), and mesenteric defect closure phases (34 vs. 1, p <
0.01) compared to BernBypass70. In both centers, SEVERE score was correlated with procedure duration. In BernBypass70, insufficient closure of anastomosis was significantly more frequent in patients with postoperative complications (0.2 ± 0.6 vs. 0.0 ± 0.1, p <
0.01). CONCLUSION: Variations of the LRYGB technique between centers influence the temporal occurrence and frequency of iAEs. The frequency and severity of iAEs are correlated with procedure duration.