We describe herein our method of performing centrifugal pump-assisted venous bypass between the superior mesenteric vein and the umbilical vein, developed with the aim of preventing congestion of the small intestine and promoting strong and constant hepatic blood flow during portal vein resection. By using this bypass method, portal vein resection and reconstruction was able to be carried out with ease and safety in six patients undergoing surgery for a pancreatic mass or cancer. No coagulation abnormalities, thrombocytopenia, leukocytopenia, severe liver dysfunction, or portal vein thrombosis developed in any of the patients postoperatively. Thus, we highly recommend this simple and reliable method of bypass when portal vein resection is being performed.