Portal and systemic effects of selective infusion of vasopressin into the superior mesenteric artery in cirrhotic patients.

Selective infusion of vasopressin (0.2 U per min) was performed in 8 cirrhotic patients with portal hypertension who underwent umbilicoportal catheterization. There was a significantly decreased (9.6%) of the free portal venous pressure from 27.0 plus or minus 1.4 mm Hg to 24.4 plus or minus 1.4 mm Hg. In all patients, the portal PO2 significantly decreased with a mean fall of 18.8%. However, in all patients, significant systemic effects were noted: an increase in arterial blood pressure and a decrease in the arterial PO2. In 3 patients, a marked fall of the cardiac output (greater than 2.0 liters per min) was recorded during the selective infusion of vasopressin. It is concluded that if selective infusion of vasopressin into the superior mesenteric artery is efficacious in the control of bleeding varices, the therapeutic effect cannot be totally explained by the lowering of the portal venous pressure in cirrhotic patients with portal hypertension. The risk of vascular thrombosis, the decreased portal PO2, and the systemic effects have to be considered when this approach is used in cirrhotic patients with ruptured esophageal and/or gastric varices.