Haemodynamic changes after portal vein ligation and mesocaval interposition "H" grafting in the dog
Höckerstedt, K.; Nieminen, J.; Scheinin, T.M.; Wahl, H.
Annales Chirurgiae et Gynaecologiae 70(3): 133-138
1981
ISSN/ISBN: 0355-9521 PMID: 7325581 Document Number: 170124
The hemodynamic effects of portal ligation combined with mesocaval H grafting were evaluated experimentally. Acute portal hypertension was induced in 20 mongrel dogs by ligation of the portal vein; in 15 of these a mesocaval shunt was constructed using an autogenous venous segment and the rest served as controls and were left without shunting. All animals with portal occlusion only died within 80 min, while 9 dogs in the H graft group survived. The 1 mo. patency rate was 78%. Slight portal hypertension was observed only in the early post-shunt period, 1 mo. later the pressure was normal. By this time the flow through the shunt was significantly reduced and numerous but small portosystemic collaterals were visualized radiographically. Varices formation was not observed. The 133Xe washout of the liver and liver pO2 were normal in the early post-shunt period. These findings were in marked contrast to those in the control group where both variables showed rapid deterioration. The pre-shunt spleen flow was of prognostic significance; poor flow was associated with bad prognosis. After 1 mo., the liver flow was decreased while the spleen flow was increased, perhaps indicating increased spleno collateral flow. Portal ligation combined with mesocaval H grafting seemed to induce slight and temporary portal hypertension in this model. This appeared to be caused by the relatively narrow lumen of the shunt. Normotension was soon established by the rapid opening of portosystemic collaterals.