Collateral ablation improves portal perfusion after partial portacaval shunt.

ABSTRACT

Small-diameter portacaval H-grafts (partial shunts) effectively abolish bleeding from esophageal varices. Goals are 1) to prevent variceal hemorrhage by subtotal portal decompression, and 2) to minimize postshunt encephalopathy by maintaining substantial residual pressure and prograde flow in the portal vein. To reduce spontaneous shunting of portal blood away from the liver, we advocate ablation of collateral vessels after partial shunts. Others have performed partial shunts without collateral ablation. We postulated that ablation of collateral vessels would augment portal perfusion pressure and preserve prograde portal flow after partial shunts. In 15 patients undergoing 8 or 10 mm portacaval H-grafts, portal pressure was measured intraoperatively before and after ligation of principal venous collaterals. In another 13 patients, collateral embolization was performed during postoperative portography. The degree of portal perfusion was scored. Pressure measurements demonstrated a mean rise in portal pressure of 2.8 cm saline after ligation (P = 0.025). Angiographic perfusion scores after embolization improved by a mean of 0.57 points on a 4 point scale (P = 0.032). We conclude that intraoperative collateral ligation augments residual portal pressures and that postoperative collateral embolization improves portal flow patterns. Since both observed effects have been associated with decreased postshunt encephalopathy rates, ablation of collateral vessels must be an integral component of the partial portacaval shunt.