HPB P49 Vein wall invasion is a more reliable predictor of oncological outcomes than vein related surgical margins after pancreaticoduodenectomy for early stages of pancreatic ductal adenocarcinoma

Abstract Background Pancreaticoduodenectomy (PD) with vein resection is the only potentially curative option for patients with pancreatic ductal adenocarcinoma (PDAC) with venous involvement. The aim of our study was to assess the oncological prognostic significance of the different variables of venous involvement in patients undergoing PD for resectable and borderline resectable with venous only involvement (BR-V) PDAC. Methods Retrospective analysis of prospectively maintained PD database from 2011–2020 was performed. Standard descriptive statistical analysis; statistical comparisons with the use of the appropriate test; survival analysis with the Kaplan-Meier method and log rank test for overall survival (OS), disease-free survival (DFS) and local recurrence (LR); risk analysis for separate surgicalmargins with univariable and multivariable Cox proportional hazard model were used. Results One hundred and five of 372 patients (28%) required vein resection and vein wall involvement was identified in 37% of those. More vein resections were performed in female patients and as expected for BR-V disease. OS, DFS and LR were significantly longer after R0 resection, irrespective of the need for a venous resection. Following analysis of separate surgical margins, the vein groove and the vein transection margins (the latter only applicable in patients that had a venous resection) were not identified as predictors of oncological outcomes. On the contrary, vein wall invasion was an independent predictor of OS (HR:1.947, CI: 1.228–3.089, p=0.005), DFS (HR: 2.169, CI: 1.306–3.602, p=0.003) and LR (HR: 2.365, CI: 1.089–5.133, p=0.030) after PD with venous resection. Conclusions Vein wall tumour invasion may be a more reliable predictor of oncological outcomes compared to traditionally reported parameters. Future studies should focus on possible pre-operative investigations that could identify these cases and management pathways that could yield survival benefit, such as the use of neoadjuvant treatments.