Implications of portal vein/superior mesenteric vein involvement in pancreatic cancer: A comprehensive correlation from preoperative radiological assessment to resection, pathology, and long-term outcomes. A retrospective cohort study.

Background: The incidence of portal vein/superior mesenteric vein (PV/SMV) resection during pancreatoduodenectomy is increasing in clinical practice. This study investigated the clinical significance of preoperative PV/SMV assessment and intraoperative resection and their correlation with pathological results and long-term survival outcomes.

Methods: We analyzed 443 patients undergoing pancreatoduodenectomy at a tertiary center from 2012 to 2017 based on PV/SMV resection. Subgroup analyses were performed based on preoperative PV/SMV involvement, resection, and margin status.

Results: Total of 441 patients were analyzed; 175 had PV/SMV involvement on preoperative radiological assessments and 128 underwent PV/SMV resection. True pathological invasion was observed in 78 patients (60.9%), with 34.3% showing no invasion and negative margins. The positive predictive value for preoperative PV/SMV involvement was 61.7%, with a false-negative value of 28.9%. Overall survival of patients who underwent PV/SMV resection was worse than those who did not (2-year survival rate, 38.1% vs 54.9%, P < 0.001). Patients without PV/SMV resection with an rR1/R1 margin showed no decrease in survival compared to those with PV/SMV resection and R0 margins (54.9% vs 40.3%, P = 0.029). Prognostic factors included hypertension, PV/SMV resection, PV/SMV R2 margin, T stage, N stage, cell differentiation, adjuvant treatment, and recurrence.

Conclusions: PV/SMV resection could ensure R0 resection but may lead to unnecessary resection. Careful consideration is essential in determining the need for PV/SMV resection. Poor survival in such patients highlights the need for tailored treatments, including neoadjuvant therapy, for those who are expected to undergo PV/SMV resections.