Real-World Evidence of Porto-Mesenteric Vein Resections with Pancreatectomy and the Development of Predictive Clinical Nomograms for Postoperative Outcomes-An Analysis of 389 Cases: The "Porto-Mesenteric Vein Resection-Indian MulticentrE" (PRIME) Study.

Background: With better surgery and chemotherapeutic agents, borderline resectable or locally advanced pancreatobiliary tumours are being treated with curative intent. This study presents real-world evidence of porto-mesenteric vein resections (PVR) with pancreatectomy and generates predictive nomograms for postoperative mortality (POM) and major complications (MC).

Methods: A retrospective multicentre study, including 11 high-volume centres, evaluated patients undergoing PVR. Factors affecting 90-day POM and MC (Clavien-Dindo grades ≥ 3a) were assessed, and predictive nomograms were generated. Overall survival (OS) and disease-free survival (DFS) were estimated for patients with pancreatic ductal adenocarcinoma (PDAC). Cox regression analysis was performed to ascertain factors affecting OS and DFS.

Results: Among 389 patients, POM was 6.4%, and MCs were 32.6%. Charlson comorbidity index > 4, preoperative biliary drainage, preoperative radiotherapy (PRT), segmental PVR, and additional organ resection (AOR) were predictive of POM. The independent predictors of MCs were American Society of Anesthesiologists status 3/4, PRT, and AOR. The generated model had an area under the curve (AUC) of 0.757, cutoff > 1.79 to predict POM, and AUC of 0.669, cutoff > 0.678 for MCs. In the 263 patients with PDAC, the median OS was 25.01 months (95% confidence interval [CI] 21.9-28.11), and DFS was 16.72 months (95% CI 14.56-18.89). Perineural invasion, segmental PVR, and margin positivity predicted worse survival, while completing multi-modality treatment was protective.

Conclusions: The POM and MCs of PVR with pancreatectomy were at par with the world standards. The generated predictive nomograms for POM and MC revealed a good predictive potential. In patients with PDAC, completion of multimodality treatment offers better long-term survival.