Portal vein thrombosis after right hepatectomy: impact of portal vein resection and morphological changes of the portal vein

Background: Right hepatectomy occasionally requires portal vein resection (PVR) and causes postoperative portal vein thrombosis (PVT). Methods: A total of 247 patients who underwent right hepatectomy were evaluated using a threedimensional analyzer to identify the morphologic changes in the portal vein (PV). The patients' characteristics were compared between the PVR group (n = 73) and non-PVR group (n = 174), and risk factors for PVT were investigated. The PVR group were subdivided into the wedge resection (WR) group (n = 38) and segmental resection (SR) group (n= 35). Results: Postoperative PVT occurred in 20 patients (8.1%). Multivariate analyses in all patients revealed that postoperative left PV diameter/main PV diameter (L/M ratio) <0.56 (odds ratio [OR] 4.00, p = 0.009) and PVR (OR 3.31, p = 0.031) were significant risk factors for PVT. In 73 patients who underwent PVR, PVT occurred in 14 (19%) and WR (OR 11.5, p = 0.005) and L/M ratio <0.56 (OR 5.51, p = 0.016) were significant risk factors for PVT. Conclusion: PVR was one of the significant risk factors for PVT after right hepatectomy. SR rather than WR may be recommended for preventing PVT.