Complexity and heterogeneity of vascular anatomy in gastric cancer surgery: a multicenter retrospective cohort study.

Safe and effective gastric cancer surgery requires detailed knowledge of vascular anatomy, but vascular complexity and heterogeneity relevant to gastrectomy have not been comprehensively quantified. This study aimed to determine whether this anatomy can be categorized into a limited set of patterns or whether its heterogeneity requires patient-level characterization. This retrospective multicenter study included patients at five tertiary institutions who underwent standardized preoperative abdominopelvic computed tomography angiography between April 2021 and October 2023. Patient-specific three-dimensional reconstructions were reviewed using a surgical navigation system to characterize 23 gastrectomy-related vessels by number, origin, drainage, or position. Combined arterial and venous structures were encoded as a 92-digit sequence to identify unique configurations. Interindividual heterogeneity was quantified using diversity indices. Among 310 patients, only 4 of 23 gastrectomy-related vessels exhibited a single anatomical pattern: celiac artery, anterior superior pancreaticoduodenal artery, left gastroepiploic artery, and left gastroepiploic vein. The remaining vessels showed variable patterns in number, origin, drainage, or position. Combined arterial and venous assessment identified 292 unique vascular configurations; 277 were each observed in a single patient (277 patients, 89.4%), 12 were shared by 2 patients (24 patients, 7.7%), and 3 were shared by 3 patients (9 patients, 2.9%). Diversity indices indicated marked interindividual heterogeneity (Shannon, 5.651; Simpson, 0.996), with the Simpson index corresponding to a 99.6% probability that two randomly selected patients had different vascular configurations. Gastrectomy-related vascular anatomy showed substantial complexity and heterogeneity, suggesting that reliance on a limited set of patterns may be insufficient. These findings provide an anatomical framework for patient-specific vascular mapping and a basis for future validation in image-guided surgery.