Mechanotechnical faults and particular issues of anastomotic complications following robot-assisted anterior resection in 968 rectal cancer patients

Background As most risk factors for anastomotic complications (AC) in rectal cancer patients appear to be noncorrectable, it is needed to find the correctable causes. Additionally, the outcomes of indocyanine-green fluorescence imaging (IFI) and robot-stapled anastomosis have yet been undetermined. Methods This study retrospectively analyzed 968 consecutive patients with rectal cancer, who underwent curative robot-assisted anterior resections between 2010 and 2018. IFI parameters and stapling features in the surgical records were reviewed, and reconfirmed. Results AC occurred in 54 patients (5.6%), 34 (3.5%) with anastomotic leakage (AL) and 24 (2.5%) with anastomotic stenosis (AS). Mechanotechnical faults including defective stapling configurations, including angles lesser than or equal to 150 degrees and outer deviation (more than half from the center of the circle) of linear staples, between the two linear staples were independently associated with AL (P < .001 each). IFI significantly reduced AL rate (2.5% vs 5.3%, P = .029) and AS rate (2% vs 18.8%, P = .006), respectively. Robot linear stapling enabled to maintain the obtuse angle during consecutive staplings and reduced console time. AL and AS were independent risk factors for disease-free survival (P = .02) and local recurrence (P = .03), respectively. Conclusions AC were associated with some correctable causes, namely, mechanotechnical errors and lack of use of IFI.