Portal Vein Thrombosis After Venous Reconstruction During Pancreatectomy: Timing and Risks

Background: Numerous studies have shown that portal vein resection during pancreatectomy can help achieve complete tumor clearance and long term-survival. While the safety of vascular resection during pancreatectomy is well documented, the risk of superior mesenteric vein/portal vein (SMV/PV) thrombosis after reconstruction remains unclear. This study aimed to describe the incidence and risk factors of SMV/PV thrombosis after vein reconstruction during pancreatectomy. Methods: All patients who underwent portal vein resection (PVR) during pancreatectomy (2007–2019) were identified from a single institution prospective clinical database. Demographic and clinical data, operative and pathological findings, and postoperative outcomes were analyzed. Results: Pancreatectomy with PVR was performed in 220 patients (mean age 65.1 years, male/female ratio 0.96). Thrombosis occurred in 36 (16.4%) patients after a median of 15.5 days [IQR 38.5, 1–786 days]. SMV/PV patency rates were 92.7% and 88.7% at 1 and 3 months, respectively. The rate of SMV/PV thrombosis varied according to SMV/PV reconstruction technique: 12.8% after venorrhaphy, 13.2% end-to-end anastomosis, 22.6% autologous vein, and 83.3% synthetic graft interposition (p < 0.0001). SMV/PV thrombosis was associated with increased 90-day mortality (16.7% vs 4.9%, p = 0.02) and overall 30-day complication rate (69.4% vs 42.9%, p = 0.006). Pancreatectomy type, neoadjuvant chemoradiation, pathologic tumor venous invasion, resection margin status, and manner of perioperative anticoagulation did not influence the incidence of PV thrombosis. SMV/PV thrombosis was associated with a nearly 5-times increased risk of postoperative sepsis after pancreatectomy. Conclusion: Portal vein thrombosis developed in 16% of patients who underwent pancreatectomy with PVR at a median of 15 days. PVR with synthetic interposition graft carries the highest risk for thrombosis.