Intraoperative frozen section analysis of the portal or superior mesenteric vein transection margin in pancreatectomy with venous resection for pancreatic cancer.

[BACKGROUND] Portomesenteric vein (PMV) resection is performed for pancreatic ductal adenocarcinoma with venous invasion. However, positive transection margins may lead to local recurrence. This study aimed to evaluate whether routine intraoperative frozen section analysis (FSA) reduces positive PMV transection margins.

[METHODS] This retrospective study reviewed patients who underwent pancreatectomy with PMV resection at Kobe University Hospital from 2010 to 2020. Routine FSA of the PMV transection margin was introduced in 2017. Clinicopathological factors and the incidence of positive PMV transection margins were compared between patients who underwent FSA (PMV frozen [+]) and those who did not (PMV frozen [-]). Cox regression was used to assess the prognostic effect of margin status.

[RESULTS] A total of 115 patients were included (57 in the PMV frozen [+] group and 58 in the PMV frozen [-] group). The rate of positive PMV transection margins was significantly lower in the PMV frozen (+) group than in the PMV frozen (-) group (1.8% vs 17.2%, respectively; P =.003). Multivariate logistic regression analysis demonstrated that intraoperative FSA of the PMV transection margin was an independent factor associated with a reduced risk of positive PMV transection margins on final pathological diagnosis (odds ratio, 13.7 [95% CI, 1.61-116.7]; P =.017). However, the positive PMV transection margin was not associated with overall survival (hazard ratio, 0.96 [95% CI, 0.31-2.50; P =.937).

[CONCLUSION] Routine FSA of the PMV transection margin markedly reduces positive PMV transection margins after pancreatectomy. However, the prognostic effect of a positive PMV transection margin remains unclear. Larger prospective studies are needed to determine its prognostic relevance.