Acute renal artery occlusion: the role of collateral circulation.

It is not known if no when the probability of success is sufficient to warrant emergency revascularization of acute renal artery occlusion. This probability depends on the ability of collateral circulation to maintain viability. The role of collateral circulation in maintaining renal viability during six and 48 hours of renal artery occlusion has been studied in mongrel dogs. Collateral circulation is sufficient to maintain renal viability beyond the three hours of warm complete ischemia known to cause infarction. It is not sufficient to prevent progressive loss of renal function. Hypertension frequently results. Emergency revascularization of acute bilateral renal artery occlusion, therefore, is indicated. It is not indicated for unilateral occlusion with adequate contralateral function because of the high probability of resulting hypertension.