ObjectiveTo evaluate the effect of transecting the body of pancreas via inferior mesenteric vein (IMV) pathway during pancreaticoduodenectomy (PD) with venous resection. MethodsAccording to the inclusion and exclusion criteria, from February 1, 2016 to January 1, 2021, the patients who underwent PD with portal vein / superior mesenteric vein (PV/SMV) resection for resectable pancreatic adenocarcinoma were gathered. According to whether the traditional approach could be adopted to create a tunnel in front of the PV/SMV axis, the patients were allocated to the standard procedure group (S-group) or a modified procedure group (M-group). In the M-group, the patients who transected the pancreatic body via IMV pathway were allocated to the IMV-subgroup, while the patients who transected the pancreatic body via the left side of PV or in the middle of the pancreas were allocated to the central subgroup (C-subgroup). The clinicopathologic characteristics and survival (overall survival) were compared between the M-group and S-group, as well as between the IMV-subgroup and C-subgroup. The survival curve was drawn using Kaplan-Meier method for survival analysis, and the risk factors affecting overall survival by Cox proportional hazards regression model. ResultsA total of 142 patients were gathered, including 77 in the S-group, 65 in the M-group, 29 in the IMV-subgroup and 36 in the C-subgroup. The results of clinicopathologic data of patients among the different groups showed that the M-group had a more intraoperative bleeding (P＜0.001), longer postoperative hospital stay (P=0.021), and a proportion of vascular invasion (P=0.017), as well as the IMV-subgroup only had a higher proportion of vascular invasion (P=0.030) as compared with the S-group; At the same time, compared with the C-subgroup, the IMV-subgroup had a less intraoperative bleeding volume (P＜0.001) and a higher proportion of R0 resection (P=0.031). There were no statistically differences in other clinicopathologic data among the groups (P＞0.05). The analysis of survival curve by Kaplan-Meier method showed that the median overall survival (OS) of IMV-subgroup, C-subgroup, and S-group was 21, 17, and 22 months, respectively. The OS of IMV-subgroup was better than that of the C-subgroup (χ2=4.676, P=0.031), which had no statistical difference between the IMV-subgroup and S-group ( χ2=0.007, P=0.934). The multivariate analysis results showed that the patients with postoperative adjuvant chemotherapy [RR=0.519, 95%CI (0.324, 0.833), P=0.007] and with R0 margin [RR=0.434, 95%CI (0.218, 0.865), P=0.018] were the protective factors affecting the OS, while low tumor differentiation [RR=2.433, 95%CI (1.587, 3.730), P<0.001], PV/SMV pathological invasion [RR=2.788, 95%CI (1.543, 5.039), P=0.001], and tumor infiltration into PV/SMV intima [RR=1.838, 95%CI (1.062, 3.181), P=0.030] were the risk factors affecting the OS. ConclusionsThe results of this study suggest that, transecting the body of pancreas via IMV pathway can improve the rate of R0 resection, improve OS, and do not increase postoperative morbidity and mortality. It may provide a better selection for transecting the body of pancreas when the anterior PV/SMV and posterior surface of the neck of the pancreas are invaded by tumors or has inflammatory adhesion.