Effect of portasystemic shunt operations on hepatic portal perfusion.

We recently developed a radiocolloid technique for quantifying the fraction of superior mesenteric venous blood that bypasses liver sinusoids through extra- and intrahepatic collateral vessels. In the present investigation we applied this method, which is performed in conjunction with visceral angiography, to the assessment of patients with portal hypertension before and after surgical construction of portasystemic shunts. The mean corrected shunt index was 0.89 in 27 preoperative patients, and 48 percent of the patients had no evidence of sinusoidal perfusion by superior mesenteric venous blood (shunt index greater than 0.95). Sinusoidal perfusion was absent in five patients with residual hepatic portal flow by angiography, indicating that they had a high degree of intrahepatic shunting. Hepatic portal perfusion was preserved in 80 percent of patients after distal splenorenal shunt, and the corrected shunt index was significantly smaller after this procedure than after portacaval and interposition shunts. . Three patients with no sinusoidal perfusion by superior mesenteric blood preoperatively had restoration of portal flow after distal splenorenal shunt. Five patients undergoing portacaval and interposition shunts had no evidence of portal sinusoidal perfusion by the radiocolloid technique either before or after the operative procedure.