Effect of angiotensin II on arteriovenous shunting assessed by hepatic arterial perfusion scintigraphy.

Angiotensin II (AT II) has been reported to improve drug delivery in intraarterial chemotherapy for hepatic tumors. We studied the effect of this agent on arteriovenous (AV) shunting in the liver. Eleven patients with hepatic tumors and an indwelling catheter in the hepatic artery underwent hepatic arterial perfusion scintigraphy with and without AT II infusion. At baseline, following the administration of technetium-99m macroaggregated albumin (Tc-99m MAA) through the catheter, static images of the upper abdomen and whole-body anterior and posterior images were obtained. Two to 14 days later, AT II was infused via the catheter one minute prior to Tc-99m MAA injection, and imaging was performed in the same way as the baseline study. Visual interpretation of the static images showed improvement of drug delivery to the hepatic tumors in eight of 11 patients and no changes in the remaining patients. The percent injected dose in the lungs assessed quantitatively using the whole-body images increased in all patients, suggesting enhancement of AV shunt flow. It was concluded that intraarterial infusion of AT II increases AV shunting in the liver with better targeting to hepatic tumors.