EXPERIMENTAL AUGMENTATION OF PORTAL BLOOD FLOW

Management of portal hypertension and its consequences

Increased pressure in the protal venous system results from impedance to blood flow at any point along it's course from the splanchnic circulation through the liver to the right heart. Typical manifestations of sustained increases in portal venous pressure commonly may include accumulation of abdominal fluid and development of acquired portosystemic shunts. Pathophysiology of altered portal vascular dynamics, diagnostic approach for animals suspected of having an intra-abdominal source of portal hypertension and treatment options are discussed.

Arterialization of liver transplants in rats: I. Application of the tissue perfusion monitor in hemodynamic studies

This study demonstrates the use of the tissue perfusion monitor in the investigation of arterialization (using an arteriovenous fistula) of the heterotopic partial liver transplant. An index of peak perfusion rate was introduced as a reliable and accurate measure of the index of delivery rate of blood to the liver. Results revealed a significant (P less than .01) difference between arterialized and nonarterialized liver grafts when compared with their respective recipient host livers. Arterialization of grafted livers raised the index of peak perfusion rate to levels that were comparable to host livers. Arterialization also had a significant effect (P less than .01) on the host liver, whose values dropped by 74.26% when compared with the normal liver. Surprisingly, host values of the nonarterialized group fell by 61.54%. At this point, explanations for this phenomenon are speculatory. An extensive review of the literature exposes the variability in the observations of the role and usefulness of arterialization in hepatocellular function.

Esophageal varices produced in dogs

In attempts to produce esophageal varices in dogs, we designed a procedure based on the concept of hyperdynamic flow. The first stage operation involved the achievement of an arteriovenous shunt between the left renal artery and the proximal splenic vein, in concert with the distal splenic venous-left renal venous shunt. About one month after the initial operation, sixteen of the twenty-eight dogs had tolerated the manipulations. Both shunts proved to be functioning well in six of sixteen survivors, in which an ameroid constrictor was placed around the splenic vein just proximal to the confluence of the left gastric vein. Again one month later, in five of these six, esophageal varices were evidenced, both endoscopically and histologically. Arterialization of left gastric vein concomitant with the distal splenorenal shunt, gave rise to a hyperdynamic state in the upper stomach and resulting in reproducible esophageal varices.

Portal hypertension due to hepatic artery-portal vein arteriovenous fistula--a case report

A case of portal hypertension secondary to traumatic hepatoportal arteriovenous fistula with portal fibrosis was successfully treated by ligation of the afferent hepatic arteries which decreased significantly portal pressure and corrected the abnormal blood inflow to the portal vein via A-V fistula resulting in a recovery of the disturbed liver function. Collateral blood supply from the left hepatic artery into the right hepatic lobe was found to be quite satisfactory after the ligation of the hepatic artery. Hemodynamic data and clinical findings of the present case suggest that the mechanism responsible for the portal hypertension is the inflow block resulting from the interruption of portal venous flow by the inflow of arterial blood via A-V fistula and the subsequent increased blood pressure in portal vein radicals.

Liver in Felty's syndrome

Liver function and histology, together with the haematological changes, were investigated in 12 patients with Felty's syndrome. Six of them were anaemic. The red cell mass was either normal or increased, and the anaemia was due to a considerable increase in the plasma volume. Two patients had increased haemolysis associated with red cell sequestration by the enlarged spleens.In eight patients liver function tests were abnormal, while in five the liver histology showed lymphocytic infiltration of the sinusoids and portal tracts together with portal tract fibrosis. One of these was later found to have a macronodular cirrhosis. In another there were apparent nodules without a true cirrhosis, and this appearance was also seen in two other patients with Felty's syndrome in whom histology was available. An increased blood flow through the spleen was found in the two patients examined.