A possible explanation for the frequent concomitance of arterial hypertension and multiple renal arteries.

In more than 20% of subjects, at least one kidney is found to be supplied by more than one artery arising from the aorta. This aberrant renovascular anatomy has been reported in the literature to occur in up to 80% of patients who suffer from essential hypertension. Predominant numbers of the so-called 'accessory' vessels are longer and narrower than the segmental arteries arising in the main renal artery. As a result (in accordance with Poiseuille's law of fluid flow), the renal segments supplied by these 'accessory' vessels may have lower levels of blood pressure than the remainder of the parenchyma, thereby increasing the renin secretion. This hypothesis could be significant in terms of finding a causal treatment for a disorder induced by such a mechanism. We first review the literature in which the frequency of these vascular anomalies in normotensive and hypertensive patients is described, and then advance a hypothesis explaining the frequent incidence of essential hypertension in these subjects, as well as the ramifications of this phenomenon.