310 T.W. Kwon, K.-B. Sung, G.-E. Kim Fig. 1. Transfemoral aortogram shows one renal artery from the abdominal aorta for the upper (right) kidney, and two renal arteries from the aneurysm and 1 renal artery from the left common iliac artery for the lower kidney (crossover left). (white arrows: renal arter- ies). DISCUSSION Developmental abnormalities of the kidney are technical- ly challenging to the vascular surgeon at the time of aortic reconstruction, especially during abdominal aortic aneurysm (AAA) surgery due to the presence of aberrant, accessory, or multiple renal arteries, and the risk of unexpected injury to the collecting system (1-4). Crossed renal ectopia is the sec- ond most common renal fusion anomaly following the horse- shoe kidney with an incidence in the general population of 1 in 1000, and crossover of the left kidney to the right side is the most common form of this variation (1, 2). Crossed renal ectopia has been further classified depend- ing on the shape assumed by the fused renal masses, but all types are managed similarly during aortic reconstruction (1). Once the diagnosis of renal ectopia or fusion is made, preoper- ative imaging to identify the vascular and collecting system anatomies is necessary for planning of the optimal strategy for reconstruction of the aorta and renal arteries (1-3). The renal arteries may arise from the aneurysm itself requiring reimplantation or bypass grafting. Renal blood supply must be preserved because all renal and accessory renal arteries are end arteries without communication. The sacrifice of any blood supply to the kidney is disastrous, especially if the other kidney is absent or has impairment of renal function (4). Crossed ectopia is always associated with abnormally locat- ed ureters, and the involved ureter or ureters cross the mid- line at the level of the distal aorta or bifurcation and enter the bladder on the side of embryonic origins (2). Rapid reper- fusion of the renal artery is the most critical factor to avoid postoperative renal failure (5). The renal arteries must be iden- Fig. 2. Postoperative MR angiogram shows patent renal arteries. During operation, we dissected the lower 2 renal arteries (1 from the aneurysm itself, 1 from the left common iliac artery) and anas- tomosed the lowest renal artery (from the left common iliac artery) to middle renal artery (from the aneurysm itself) in a side-to-end fashion before aneurysm resection. (white arrows: renal arteries). tified before the aortic clamping, and either be reimplanted or bypassed within the allowable ischemic time. Otherwise implementation of some protective measures such as cooling of the kidney or temporary shunting is necessary to avoid renal ischemic injury (5). Our method of joining two renal arter- ies after mobilization before the aortic cross clamping could shorten the renal ischemic time. In conclusion, preoperative imaging to define the arterial and collecting system anatomies and planning of the operation accordingly is essential during AAA repair in a patient with combined renal developmen- tal abnormalities. REFERENCES 1. Water HJ, Gaspar MR. Abdominal aortic and multiple iliac aneurysms associated with crossed-fused ectopia of the kidney: A case report and review. J Vasc Surg 1988; 8: 172-6. 2. Crawford ES, Coselli JS, Safi HJ, Martin TD, Pool JL. The impact of renal fusion and ectopia on aortic surgery. J Vasc Surg 1988; 8: 375- 83. 3. O’Hara PJ, Hakaim AG, Hertzer NR, Krajewski LP, Cox GS, Beven EG. Surgical management of aortic aneurysm and coexistent horse- shoe kidney: Review of a 31-year experience. J Vasc Surg 1993; 17: 940-7. 4. Graves FT. The arterial anatomy of the congenitally abnormal kidney. Br J Surg 1969; 56: 533-41. 5. Allen BT, Anderson CB, Rubin BG, Flye M, Baumann DS, Sicard GA. Preservation of renal function in juxtarenal and suprarenal abdomi- nal aortic aneurysm repair. J Vasc Surg 1993; 17: 948-58.