In the presence of extrahepatic block of the portal vein, secondary hypersplenism, prior biliary surgery, and/or cavernomatous changes of the portal vein, a shunt between the splenic vein and left renal vein may be the procedure of choice, provided the splenic vein is patent and of adequate size. If it is necessary or desirable to remove the spleen, a conventional splenorenal anastomosis (Figure C) may be performed. The distal splenorenal shunt (Warren shunt, Figure D) retains the spleen and, while selectively decompressing the esophageal varices, allows maintenance of portal pressure and perfusion of the liver, thus providing protection against hepatic encephalopathy. This shunt is particularly indicated in the presence of normal liver function, high volume of portal flow to the liver, minimal hepatocellular disease, marked splenomegaly, or idiopathic portal hypertension. The procedure consists of dividing the splenic vein at its junction with the superior mesenteric vein, ligating the proximal portion of the vein, and anastomosing the distal portion to the left renal vein. As an alternative to dividing the splenic vein, an interposition graft may be anastomosed between the splenic vein and the left renal vein, with ligation of the splenic vein proximal to the graft as well as ligation of the coronary and right gastroepiploic veins.
See Plates 175 and 176 for details of the Warren splenorenal shunting procedures.