EFFECTS OF PORTACAVAL SHUNTING ON HYPERDYNAMIC CIRCULATION IN BILE DUCT-LIGATED CIRRHOTIC RATS

Background/Aims: Liver cirrhosis and portal hypertension are associate d with hyperdynamic circulation. Portacaval shunts are widely used to prevent recurrent hemorrhage, but the hemodynamic effects caused by th ese procedures have not been well characterized in cirrhosis. We there fore compared the hemodynamic effects of both end-to-side and side-to- side portacaval shunts in normal and cirrhotic rats. Methods: Sprague- Dawley rats were divided into six groups according to the operations t hey underwent. End-to-side or side-to-side portacaval shunts were perf ormed in both rats with cirrhosis induced by bile duct ligation and sh am-operated rats. Systemic and regional blood flows were measured by t he radioactive microsphere method. Results: Portal pressures in the sh unted rats decreased significantly. Cardiac index in cirrhotic rats (5 57+/-27 ml . min(-1). kg(-1)) was significantly higher than controls ( 455+/-21 ml . min(-1). kg(-1)), but the two types of shunts did not fu rther increase cardiac index in either the cirrhotic or the sham-opera ted rats. After shunting, hepatic arterial flows approximately doubled . Portal tributary blood flows in the end-to-side shunted sham (108+/- 13 ml . min(-1). kg(-1)) and cirrhotic (139+/-19 ml . min(-1). kg(-1) groups were significantly higher than their respective controls (62+/- 8 and 76+/-5 ml . min(-1). kg(-1)). Portosystemic shunting indices wer e >99% in both the end-to-side and side-to-side shunted groups in cirr hotic and sham-operated rats. Conclusions: The hyperdynamic circulatio n in cirrhotic rats was not augmented by portacaval shunting operation s (either end-to-side or side-to-side), despite essentially total port osystemic blood diversion. Compensatory increase in the hepatic arteri al blood flow to the liver remained intact even in cirrhotic rats. A s elective redistribution of cardiac output to the mesenteric vascular b ed was observed after the shunting procedure. However, there were no s ignificant differences in hemodynamics between the end-to-side and sid e-to-side shunted groups.