Aberrant renal arteries.

A case is reported of a patient with aberrant right renal artery arising at the level of the eleventh thoracic segment associated with renal artery aneurysm and systemic hypertension. Knowledge of the existence of aberrant renal arteries is important because they may be inadvertently damaged during renal surgery and their presence must be considered in evaluating a donor kidney for possible renal transplantation. Variations in the origin and course of the renal arterial blood supply occur frequently and are of special interest to the urologist. Aberrant renal arteries may produce a variety of urologic diseases and their presence must be suspected particularly in patients with systemic hypertension or proximal ureteral obstruction. There are various types of renal arterial aberrancies. The right and left renal arteries normally arise from the aorta within several millimeters of each other, the right originating somewhat higher. In 25 per cent of patients, significant disparity in the levels of origin may occur, in some cases as much as two vertebral segments apart. In addition, the arteries may arise from a partially dorsal or ventral aortic site rather than directly lateral. Prehilar branching of the renal arteries is common and is usually bilaterally symmetrical. When present, the prehilar branching may occur at any point from the main renal artery, and the branch is more often superiorly than inferiorly, directed.l Frequently, one or both kidneys are supplied by multiple renal arteries having aortic origin. Multiple arteries were seen in 28 per cent of 11,000 autopsies, and the arteries were found to arise anywhere between the eleventh thoracic and fourth lumbar vertebrae.2 Another autopsy study showed the presence of aberrant renal arteries in 49 per cent of normotensive and 80 *Present address: Chief, Urology Service, Davis-Monthan Air Force Base, Arizona, 85707 per cent of hypertensive patients.3 Angiographic series have shown multiple renal arteries in from 20.5 to 24 per cent of studied patients.4,5 Segmental renal arteries arising directly from the iliac, superior mesenteric, and internal spermatic arteries have been described. This study is based on a patient in whom an aberrant right renal artery arising at the level of the eleventh thoracic segment was associated with renal artery aneurysm and systemic hypertension.