Effect of propranolol on portosystemic collateral circulation estimated by per-rectal portal scintigraphy with technetium-99m pertechnetate.

Background/aims: Propranolol is widely used in the prevention of variceal bleeding. However, in certain patients with cirrhosis, the portal hypotensive effect of propranolol cannot be obtained. An explanation for portal unresponsiveness to propranolol could be an increase in portocollateral vascular resistance mediated by this drug.

Methods: In 33 patients with cirrhosis the effect of chronic administration of propranolol on portocollateral blood flow from the inferior mesenteric vein was examined by means of per-rectal portal Tc-99m pertechnetate scintigraphy.

Results: Propranolol significantly reduced the shunt index by 15.3 +/- 4.2%. This reduction was observed only in patients with cirrhosis classified as Child-Pugh A and B groups, but not group C. Differences between groups in portosystemic shunt index changes after propranolol were significant (F = 3.4, p < 0.05).

Conclusions: The data presented suggest that propranolol changes the distribution of blood between the portal and systemic circulation, which is probably due to the increase in vascular resistance of portocollateral vessels. The magnitude of the vascular response to propranolol depends on the severity of liver disease.