Abdominal aortic aneurysm associated with crossed renal ectopia without fusion: Case report and literature review

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1 Abdominal aortic aneurysm associated with crossed renal ectopia without fusion: Case report and literature review Hiromi Yano, MD, a Naoki Konagai, MD, a Mitsunori Maeda, MD, a Mikihiko Itoh, MD, a Atsushi Kuwabara, MD, a Tatsuhiko Kudou, MD, a and Shin Ishimaru, MD, b Tokyo, Japan Genitourinary anomalies can present a formidable challenge to the vascular surgeon at abdominal aortic reconstruction. We saw a case of crossed renal ectopia without fusion, a rare anomaly, associated with abdominal aortic aneurysm. Because of risk for injury to the kidney during surgery, preoperative evaluation of this anomaly must include computed tomography, angiography, and intravenous pyelography. Preoperative placement of a ureteral catheter may prevent injury to the anomalous ureter. Renal failure of the ectopic kidney during aortic reconstruction can be a serious problem. We used in situ hypothermic perfusion with cold (4 C) Ringer solution for renal protection, and reimplanted the aberrant renal artery. The postoperative course was good, without major complications. The procedure for renal preservation must be selected on the basis of anatomic findings. We review the literature and present the first case of crossed renal ectopia. (J Vasc Surg 2003;37: ) Crossed renal ectopia is an uncommon genitourinary anomaly, detected in 1 of 7000 autopsies. 1 The ectopic kidney crosses the midline and lies contralateral to its normal position, 2 and may be fused to the normal kidney. The ureter of the ectopic kidney crosses the midline to enter the bladder at its normal position. The blood supply to the kidneys is from the aorta or the iliac arteries, and the number of renal arteries varies. 3,4 Such aberrations may provide a significant challenge to the vascular surgeon if aortic reconstruction is required. The English literature includes only been a few reports of abdominal aneurysm repair complicated by crossed fused ectopic kidney, 5-10 and no reports of this operation without fusion. We report successful aneurysm reconstruction in a patient with crossed ectopic kidney without fusion. computed tomography (CT) the presence of an 8 cm infrarenal AAA was confirmed, and the ectopic kidney attached to the right lower aspect of the aneurysm was seen (Fig 2). Intravenous pyelography (IVP) revealed a normal right kidney and ureter, but the ureter of the ectopic kidney could not be clearly identified. Renal CASE REPORT A 63-year-old man was found to have an abdominal aortic aneurysm (AAA) at physical examination during admission to another hospital for treatment of gastric ulcer. He was referred to our center for surgical intervention. Transbrachial aortography revealed a 7.5 cm infrarenal AAA involving the left common iliac artery. The right kidney was located normally and was supplied by a single renal artery. The left kidney was malrotated and was situated on the right side of the pelvis, with its blood supply arising from the AAA (Fig 1). The dimensions of the right kidney were mm, and the left kidney was mm. At From the Department of Cardiovascular Surgery, a Hachiouji Medical Center, and the Second Department of Surgery, b Tokyo Medical University ( yanoyumi-2378@nifty.com). Competition of interest: none. Reprint requests: Hiromi Yano, Department of Cardiovascular Surgery, Hachiouji Medical Center, Tokyo Medical University, 1163 Tate-machi, Hachiouji-city, Tokyo , Japan. Copyright 2003 by The Society for Vascular Surgery and The American Association for Vascular Surgery /2003/$ doi: /mva Fig 1. Transbrachial aortogram demonstrates a huge infrarenal abdominal aortic aneurym involving the left common iliac artery and the left crossed ectopic kidney, which is malrotated and located on the right side of the pelvis. Feeding artery of the ectopic kidney originates from the aneurysm.

2 JOURNAL OF VASCULAR SURGERY Volume 37, Number 5 Yano et al 1099 Fig 2. CT scans reveal an abdominal aortic aneurysm, 8 cm in diameter (A), and the contrast-enhanced crossed ectopic kidney (B). scintigraphy with technetium 99m mercapto-acetyl-triglycine indicated excellent function of the right kidney, with excretion of 193 ml/min (normal, ml/min), and dysfunction of the crossed ectopic kidney (37 ml/min). Creatinine concentration was 1.4 mg/dl. Because we could not localize the abnormal ureter, there was a risk for intraoperative injury. To prevent this complication, an 8F ureteral stent (Urosoft; Medicon ANGIO- MED, Wachhausstra e, Germany) was placed preoperatively as a marker of the abnormal ureter. This showed that the ureter originated from the crossed ectopic kidney, crossed the midline, and entered the bladder at its normal anatomic location. A schema of the expected anatomy is shown in Fig 3. Elective aneurysmectomy was performed through a midline transperitoneal approach. The large infrarenal AAA involved the left common iliac artery, and the crossed ectopic left kidney was recognized in the right side of the pelvis, as expected. The single artery feeding the crossed ectopic kidney arose from the anterior portion of the AAA, below the level of the inferior mesenteric artery, but the veins of this kidney could not be detected. The feeding artery was firmly adherent to the aneurysmal wall and was difficult to dissect free because of the time involved and risk for bleeding and vascular injury. First we exposed the proximal neck of the AAA and the bilateral iliac arteries, taking care not to injure the anomalous kidney or ureter. Forced diuresis with mannitol and furosemide was performed before cross-clamping the aorta. After systemic heparinization (50 U/kg IV), the aorta was crossclamped below the level of the right renal artery. The iliac arteries were also clamped. The aneurysm was opened carefully to avert injury to the aberrant renal artery. We confirmed the orifice of the aberrant artery, which was stenotic, from inside the aneurysmal sac,

3 1100 Yano et al JOURNAL OF VASCULAR SURGERY May 2003 and infused 250 ml of cold (4 C) Ringer solution containing heparin (2000 U/L) into the orifice every 20 minutes to preserve the ectopic kidney. Retrograde bleeding from several lumbar arteries was controlled with transfixing sutures. A 16 8 mm gelatin-coated knitted Dacron bifurcated prosthesis was anastomosed end-to-end to the aorta below the right renal artery. The proximal part of the aberrant renal artery was dissected from the aneurysmal wall and reimplanted into the body of the prosthesis. The limbs of the graft were anastomosed to the common iliac arteries. The inferior mesenteric artery stump pressure systemic pressure ratio was more than 0.6, so the artery was ligated. Duration of ischemia of the ectopic kidney was 50 minutes. The postoperative course was complicated by prolonged ileus due to intestinal adhesions, but conservative therapy with an ileus tube was effective. Postoperative aortograpms clearly visualized the ectopic kidney and anomalous venous return (Fig 4), and renal scintigrams demonstrated improved function (76 ml/min). The postoperative creatinine concentration was 1.3 mg/dl. The improvement might have resulted from correction of a stenotic lesion by surgical reimplantation of the aberrant renal artery. No additional surgical intervention was necessary, and the patient was discharged. Fig 3. Schema of expected anatomy. Ureter originates from ectopic kidney, crosses the midline, and enters the bladder at its normal anatomic location. DISCUSSION Genitourinary anomalies can present a formidable challenge to the vascular surgeon dealing with an AAA. The most common anomaly associated with AAA is horseshoe kidney Crossed renal ectopia is a rare congenital condition in which a ureter in the normal bladder position crosses the midline to an ectopic kidney lying on the opposite side of the body. The ectopic kidney is most often malrotated and situated below the normal kidney. This anomaly can be classified into four types 2 : type A, crossed ectopia with fusion; type B, crossed ectopia without fusion; type C, solitary crossed ectopia; and type D, bilaterally crossed ectopia (Fig 5). Our patient had type B. Type A is seen most frequently, and the other three types much less commonly. 2 In this anomaly, the kidneys, including the nonectopic kidney, have an anomalous blood supply. 3,4 Renal arteries, as well as iliac arteries, originate from the aorta. 3,4 Venous drainage may also be abnormal, but because venous structures are not involved in aortic surgery, there have been no reports regarding this. 7 The anomaly is more common in male patients, and usually involves the left kidney. 2,4 Causes may include faulty development of the ureteric buds, vascular obstruction to the ascent of the kidneys, and environmental factors. 2 Extensive review of the literature revealed only six cases in which crossed renal ectopia was associated with AAA During abdominal aortic reconstruction the anomalous kidneys, ureters, and arteries may be at significant risk for injury, so it is essential that preoperative evaluation include CT, angiography, and IVP. Ultrasonography has also been recommended. 5,7,9 Retrograde pyelography may provide further information about the path of ureters. Because arteries not identified at preoperative arteriography are occasionally found at surgery, 12 too much confidence should not be placed on preoperative evaluation. Accordingly, careful search for anomalies should be undertaken during surgery. To minimize the risk for complications, we placed a ureteral catheter for intraoperative identification, as recommended by Bigley et al. 5 In patients with other renal abnormalities, preoperative placement of a ureteral catheter may also be a good strategy to ensure a successful outcome. 7 Renal failure after aortic reconstruction can be serious in patients with crossed renal ectopia. A variety of renal preservation techniques have been used during aortic reconstruction, 13 each with advantages and disadvantages. Conventional repair with administration of furosemide and mannitol before cross-clamping and in situ hypothermic perfusion with cold (4 C) Ringer solution may offer excellent short-term protection 14 and can be performed at any hospital. Ipsilateral axillofemoral bypass grafting, 15 the double proximal clamping technique, 16 temporary bypass grafting (Gott shunt), and pump oxygenation 17 can be used alternatively. Choice of procedure will depend on anatomic considerations, and an adequate procedure must be selected for each patient on the basis of detailed preoperative examination. We used in situ hypothermic perfusion, which is the preferable method at our center, along with furosemide and mannitol before cross-clamping. In previous reports 5-10 this technique was the most frequently used (3 of 6 patients [50%]) (Table). The prognosis will be

4 JOURNAL OF VASCULAR SURGERY Volume 37, Number 5 Yano et al 1101 Fig 4. Postoperative aortograms show contrast-enhanced ectopic kidney (A) and anomalous venous return (B; arrow). Fig 5. A-D, Four types of crossed renal ectopia. (Reprinted from McDonald JH, McClellan DS, Am J Surg 1957;93: , with permission from Excerpta Medica, Inc.) Abdominal aortic aneurysm repair in patients with crossed renal ectopia Author Patient Age (y) Sex Type Preoperative ureteral marker Number of renal arteries Method of renal preservation Renal ischemia time (min) Complications Bigley et al 5 55 Male A Two (above AAA) None Waters and Gaspar 6 64 Male A Two (CIA, above AAA) Cold Ringer solution 45 Ileus Crawford et al 7 NA A Three (AAA) NA NA NA Lepantalo et al 8 69 Male A Two (above AAA) None Virgilio et al 9 NA A Four (AAA, above AAA, CIA) Cold salt solution NA NA Mizuno et al Male A Three (AAA, CIA) Cold Ringer solution 45 Small renal infarction AAA, Abdominal aortic aneurysm; CIA, common iliac artery; NA, data not available.

5 1102 Yano et al JOURNAL OF VASCULAR SURGERY May 2003 good if the ureter and the blood supply to the ectopic kidney can be preserved. Endovascular stent grafting is another alternative method for AAA repair if the proximal landing zone in large enough. Previous reports include no cases in which stent grafting was used. In summary, it is mandatory that the anatomy be carefully evaluated to minimize complications in patients with AAA associated with an ectopic kidney. CT, angiography, and IVP are helpful for defining the anomalies. Preoperative placement of a ureteral catheter can enable identification of the anomalous ureter. Renal failure associated with vascular reconstruction can be serious in patients with crossed renal ectopia. The method for renal preservation must be selected on the basis of anatomic variations in each patient. REFERENCES 1. Kretschmer HL. Unilateral fused kidney. Surg Gynecol Obstet 1925; 40: McDonald JH, McClellan DS. Crossed renal ectopia. Am J Surg 1957; 93: Rubinstein ZJ, Hertz M, Shahin N, Deutsch V. Crossed renal ectopia: Angiographic findings in six cases. Am J Roentgenol 1976;126: Hertz M, Rubinstein ZJ, Shahin N, Melzer M. Crossed renal ectopia: Clinical and radiological findings in 22 cases. Clin Radiol 1977;28: Bigley HA, Barreca JP, Chenault OW. Crossed renal ectopia and abdominal aortic aneurysm. Urology 1977;10: Waters HJ, Gaspar MR. Abdominal aortic and multiple iliac aneurysms associated with crossed-fused ectopia of kidney: A case report and review. J Vasc Surg 1988;8: 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: Lepantalo M, Siponen J, Tierala E. Crossed fused ectopy of the right kidney complicating the repair of abdominal aortic aneurysm. J Cardiovasc Surg 1989;30: Virgilio C, Gloviczki P, Cherry KJ, Stanson AW, Bower TC, Hallett JW, et al. Renal artery anomalies in patients with horseshoe or ectopic kidneys: The challenge of aortic reconstruction. Cardiovasc Surg 1995; 3: Mizuno T, Toyama M, Tabuchi N, Kuriu K, Kato M. A case report of abdominal aortic aneurysm associated with crossed-fused ectopia of the kidney. Jpn J Cardiovasc Surg 2001;30: O Hara PJ, Hakaim AG, Hertzer NR, Krajewski LP, Cox GS, Beven EG. Surgical management of aortic aneurysm and coexistent horseshoe kidney: Review of a 31-year experience. J Vasc Surg 1993;17: Virgilio C, Gloviczki P. Aortic reconstruction in patients with horseshoe or ectopic kidneys. Semin Vasc Surg 1996;9: Hollis HW, Rutherford RB, Crawford GJ, Cleland BP, Marx WH, Clark JR. Abdominal aortic aneurysm repair in patients with pelvic kidney: Technical considerations and literature review. J Vasc Surg 1989;9: Pegg DE. Organ preservation. Surg Clin North Am 1986;66: Giulini SM, Maffeis R, Cangiotti L, Bonardelli S, Bertoloni G, Caratozzolo E. Temporary axillo-femoral bypass graft for renal transplant protection during aortic aneurysm repair. J Cardiovasc Surg 1996;37: Lacombe M. Abdominal aortic aneurysmectomy in renal transplant patients. Ann Surg 1986;203: Wolf W, Ayisi K, Ismail M, Kalmar P, Pokar H, Trautwein S. Abdominal aortic aneurysm repair after renal transplantation with extracorporeal bypass. Thorac Cardiovasc Surg 1991;39: Submitted Mar 5, 2002; accepted Oct 22, Authors requested to declare conditions of research funding When sponsors are directly involved in research studies of drugs and devices, the editors will ask authors to clarify the conditions under which the research project was supported by commercial firms, private foundations, or government. Specifically, in the methods section, the authors should describe the roles of the study sponsor(s) and the investigator(s) in (1) study design, (2) conduct of the study, (3) data collection, (4) data analysis, (5) data interpretation, (6) writing of the report, and (7) the decision regarding where and when to submit the report for publication. If the supporting source had no significant involvement in these aspects of the study, the authors should so state.