Interaction between the Splenic and Hepatic Arteries in Portal Hypertension

Abstract

Experimental production of an arterio-venous fistula between the splenic artery and vein of the dog causes increased splenic arterial flow, and reduction of hepatic arterial flow . In the majority of clinical cases of splenomegaly of periportal fibrosis (Banti's syndrome) , selective celiac angiography reveals narrowing of the hepatic artery proper , and there is a significant negative correlation between the radii of splenic and hepatic arteries on the x-ray films. The results suggest reduced hepatic arterial flow in such cases. Two different mechanisms are taken into consideration for the expla nation of this circulatory condition:There may be some hemodynamical inter action between the portal system and the hepatic artery, or increased blood flow of the splenic artery, or increased blood flow of the splenic artery may reduce the hepatic share of celiac arterial flow. No arteriographical narrowing of the hepatic artery proper was demonstrated in splenomegalic cirrhosis even if high portal inflow is expected through the massive splenomegaly.A comparison of the radius of the hepatic artery proper and the percentage of intrahepatic shunted flow supports the view that the effective portal flow is unchanged in those cases. splenic artery; hepatic artery; portal flow Dilatation of the splenic artery in splenomegalic disorders is especially pronounced in cases of portal hypertension. In previous reports of ours (Yamauchi 1968;Yamauchi et al. 1970) a remarkable increase in the radii of the splenic arteries in periportal fibrosis accompanied by increased blood flow and concomitant narrowing of the proper hepatic artery was arteriographically or histometrically demonstrated.The purpose of this paper is to examine possible interaction between the splenic and hepatic arterial systems in the clinical and experimental portal hypertension. MATERIALS AND METHODS Clinical investigationsMeasurement of splenic blood flow: Splenic blood flow was measured at laparotomy by means of the dye dilution technique (Koyama 1967) or a square wave electromagnetic flowmeter (Nihonkoden MF-5) in 14 cases of periportal fibrosis, 6 cases of splenomegalic Received for publication,

72-Hour perfusion of the isolated spleen at normothermia

“…Using our technique the flow remained at a high level of about 5 ml/min/g splenic weight for 72 hrs. This is several times the normal splenic blood flow: Ueda et al 1.18 ml/g/min [15], Vaupel et al 1.1 ml/g/min [16], ¥amauchi et al 0.7 ml/g/min [18]. Such a high flow is essential when one tries to perfuse organs at normothermia with a hemoglobin-free solution.…”