Aneurysm of a polar renal artery

A patient with a saccular aneurysm arising from the left superior polar renal artery is presented together with a review of two further reports from the literature. The importance of selective arteriography and the interpretation of the "naked calyx" sign in the diagnosis of supernumerary renal arteries has been emphasized. We feel that this is the only report of an aneurysm of a polar artery successfully treated by excision and end-to-end arterial anastomosis.