DETERMINATION OF FUNCTIONAL PORTAL-SYSTEMIC SHUNTING IN PATIENTS SUBMITTED TO HEPATIC ANGIOGRAPHY

Angiographic visualization of the hepatic vascular bed by selective an giography can be profitably complemented with the evaluation of functi onal portal-systemic shunting by D-sorbitol bioavailability. Seventeen patients requiring diagnostic arterial catheterization were studied: most of them had biopsy-proven liver cirrhosis. Patients were studied at rest and after overnight fasting on two subsequent days, in which a sterile pyrogen-free solution (1.5%) of D-sorbitol was administered b y direct infusion (15 mg/min for 20 min) into the superior mesenteric artery and an antecubital vein, respectively. The fractional bioavaila bility (Fma) of D-sorbitol was calculated as the ratio between the net cumulative urinary outputs obtained after infusion through the cathet er into the superior mesenteric artery and the systemic vein, respecti vely. A good correlation was found between the estimated fractional po rtal-systemic shunting, which in the present study ranged between 1.4% and 96.7%, and a suitable index scoring the clinical evidence of coll ateral circulation. Since the hepatic removal of D-sorbitol is not aff ected by sinusoidal capillarization and its hepatic extraction ratio i s quite high and only slightly modified by reduction in the number or functional activity of hepatocytes, the measured Fma can be assumed as a parameter reflecting the entity of portal-systemic shunting. The te st is safe and inexpensive, and appears potentially useful in several situations in which portal-systemic shunting is pathophysiologically r elevant.