Cameron Battersby

Acute occlusion of the portal vein in the calf

Complete occlusion of the portal vein for 2 hours has been studied, in the calf, in an attempt to produce survival with appropriate resuscitation. Systemic blood pressure fell immediately on occlusion and the portal blood became markedly acidotic with a rise in packed cell volume and plasma potassium. Circulating blood volume decreased by 50 per cent despite major transfusion. When the occlusion was released, blood pressure returned to normal levels for several hours. However a hemorrhagic enteropathy developed in the small intestine. Large quantities of serosanguineous fluid collected in the intestinal wall and lumen and in the peritoneal cavity. Marked hemo-concentration developed and the animal did not respond to further resuscitation. All animals grew E. coli on portal blood culture after occlusion. It is concluded that sequestration of fluid in the portal circulation is the main cause of death following portal occlusion, but that a rise in plasma potassium, coliform bacteremia, and progressive acid-base disturbances may well be contributory factors.