Abstract
Splenomegaly in Banti's syndrome was found to be accompanied by a growth of the trunk of splenic artery. The blood flow Q of an artery is expressed as a function of the arterial radius r in the form of Q=qrn, q and n being constants. Accordingly, increased blood flow of the Banti spleen was presumed on the anatomical basis. This implies at the same time remarkably decreased resistance to blood flow, because the effective pressure difference between the splenic artery and vein is reduced on account of elevated portal pressure. However, the geometrical configuration of the splenic arterial tree from the trunk to its terminal arterioles was identical in both normal and Banti spleens. The blood pressure level at terminal arterioles in the Banti spleen was regarded as practically the same as in the normal spleen. Consequently, the mechanism of lowered resistance was sought in the structural transformation of the splenic cord. Histological examination demonstrated the presence of direct arteriolosinal shunts, which could be interpreted as one of the anatomical expressions of lowered peripheral resistance in the Banti spleen. No arterial growth was confirmed in splenomegaly not associated with portal hypertension.
