Resection of abdominal aortic aneurysm in the presence of horseshoe kidney.

We report four cases of abdominal aortic aneurysm associated with horseshoe kidney. These cases illustrate the factors that determine the ease of resection in this situation: whether the isthmus of the kidney is parenchymatous or thin and fibrous; the presence or absence of anomalous renal arteries; and the origin of the arterial supply of the renal isthmus. Although the technical challenges involved in aneurysm resection in the presence of horseshoe kidney are significant, these cases illustrate that standard resection and replacement of the aneurysm with a prosthetic graft usually should be possible.