EFFECT OF PROPRANOLOL ON PORTOSYSTEMIC COLLATERAL CIRCULATION ESTIMATED BY PER-RECTAL PORTAL SCINTIGRAPHY WITH TC-99M PERTECHNETATE

Background/Aims: Propranolol is widely used in the prevention of varic eal bleeding. However, in certain patients with cirrhosis, the portal hypotensive effect of propranolol cannot be obtained. An explanation f or portal unresponsiveness to propranolol could be an increase in port ocollateral vascular resistance mediated by this drug. Methods: In 33 patients with cirrhosis the effect of chronic administration of propra nolol on portocollateral blood flow from the inferior mesenteric vein was examined by means of per-rectal portal Tc-99m per-technetate scint igraphy. Results: Propranolol significantly reduced the shunt index by 15.3 +/- 4.2%, This reduction was observed only in patients with cirr hosis classified as Child-Pugh A and B groups, but not group C. Differ ences between groups in portosystemic shunt index changes after propra nolol were significant (F = 3.4, p < 0.05). Conclusions: The data pres ented suggest that propranolol changes the distribution of blood betwe en the portal and systemic circulation, which is probably due to the i ncrease in vascular resistance of portocollateral vessels. The magnitu de of the vascular response to propranolol depends on the severity of liver disease.