Effects of end-to-side portacaval shunt and distal splenorenal shunt on systemic and pulmonary haemodynamics in patients with cirrhosis

Background: Patients with cirrhosis exhibit splanchnic, peripheral and pulm onary vasodilation, which are thought to play a role in increasing portal p ressure, promoting sodium retention and determining arterial hypoxaemia. Th e present study investigated whether these abnormalities are influenced by portal hypertension or by portal systemic shunting. Methods: Sixty-one patients with cirrhosis who had haemodynamic measurement s before and after end-to-side portacaval shunt (n=30) or distal splenorena l shunt (n=31) were evaluated. Results: End-to-side portacaval shunts were more effective than distal sple norenal shunts in decompressing the portal system (portocaval pressure grad ient 3.2+/-2.5 vs splenocaval gradient 6.5+/-3.2 mmHg, P<0.0001), because o f a greater shunt blood flow (33+/-12 vs 21+/-12 mL/min per kg, P<0.005). A zygos blood flow and hepatic blood flow decreased significantly after both surgical shunts. However, end-to-side portacaval shunts caused a greater de crease in peripheral resistance than distal splenorenal shunts (-23+/-18 vs -11+/-27%, P<0.05). Mean arterial pressure and pulmonary vascular resistan ce were significantly reduced after an end-to-side portacaval shunt (-7+/-1 0%, P<0.001 and -14+/-33%, P<0.004, respectively), but not after splenorena l shunt. Conclusions: These results show that end-to-side portacaval shunts, despite normalizing portal pressure, worsen the peripheral and pulmonary vasodilat ation. The splenorenal shunt that maintained a higher portal pressure, caus ed less peripheral vasodilatation and did not enhance pulmonary vasodilatat ion. These findings suggest that portal systemic shunting is more important than increased portal pressure in determining peripheral vasodilatation in cirrhosis. (C) 1999 Blackwell Science Asia Pry Ltd.