British Journal of Radiology (2007) 80, e262-e264
© 2007 British Institute of Radiology
doi: 10.1259/bjr/36343011
Rupture of renal artery aneurysm into the renal pelvis, clinically mimicking renal colic: diagnosis with multidetector CT
V De Wilde, MD
1
K Devue, MD
2
F Vandenbroucke, MD
1
C Breucq, MD
1
M De Maeseneer, MD
3 and
J De Mey, MD
1
Departments of 1 Medical Imaging and 2 Emergency, Vrije Universiteit Brussel, Belgium and 3 Department of Radiology, University of Michigan Health System, Ann Arbor, USA
Correspondence: Dr Vally De Wilde, Laarbeeklaan 101, Jette, 1090 Belgium. E-mail: vallydewilde{at}hotmail.com
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Abstract
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We report on a 60-year-old man, seen at the emergency department because of severe left flank pain. Clinical diagnosis was that of renal colic. Overnight he became haemodynamically unstable and haematuria became massive, so multidetector CT (MDCT) was performed. MDCT with reconstructions can represent complex imaging findings in a more straightforward way compared with transverse images. Rupture of a renal artery aneurysm into the left pelvis was seen on coronal reconstructed CT images. Nephrectomy was performed. Rupture of a renal artery aneurysm into the pelvis is unusual and death is likely if diagnosis and treatment are delayed. The initial clinical presentation may be very similar to renal colic. MDCT allows timely and correct diagnosis of this unusual condition.
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Introduction
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Renal artery aneurysms were once thought to be rare. With the advent of angiography and vascular CT imaging, it became clear that they are not so uncommon. However, symptoms related to the aneurysm are uncommon, which makes the clinical diagnosis of renal artery aneurysm extremely difficult. The present article reports a case of a renal artery aneurysm with rupture into the renal pelvis which, to our knowledge, has not been previously reported.
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Case report
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A 60-year-old man presented to the emergency department with nausea and severe left flank pain of sudden onset. Previous medical history included urolithiasis and hepatitis C. Abnormal findings on clinical examination included temperature of 38°C and blood pressure of 150/90 mmHg. Results of urinalysis revealed haematuria (++++) and leukocytosis (++++). Renal function was within normal limits. Initial abdominal radiography was interpreted as normal by the emergency doctor (Figure 1
). No attention was drawn to the calcifications seen left of L2 vertebra. Ultrasound of the abdomen showed urolithiasis, hydronephrosis and massive fluid collections adjacent to the kidney. Fine topographic relationships were obscured by the collections. The parenchyma of the left kidney showed areas of higher echogenicity interspersed with areas of lower echogenicity, imaging findings suggestive of pyelonephritis. Considering the history of this patient, and the clinical and ultrasound findings, he was initially treated for pyelonephritis and renal colic. A CT was to be performed, but was then delayed as major traumas arrived in the emergency unit. The patient was haemodynamically stable. It was then decided to admit the patient, commence antibiotics and analgesics, and to schedule a CT for the next day. During the night, the patient developed massive haematuria and hypovolaemic shock. Multidetector CT (MDCT) was immediately performed (Figures 2–4). The patient was imaged on a Siemens Somatom Volume Zoom (Siemens, Erlangen, Germany) with the following parameters: 120 kVp, 120 mAs, pitch 1, slice collimation 4x1 mm, reconstructed slice width 1.5 mm. CT images in the arterial phase demonstrated a rounded aneurysm of the left renal artery (diameter: 5 cm) with marginal calcification (Figures 2–4). The renal pelvis and left ureter contained contrast medium. CT findings were consistent with a rupture of the aneurysm into the left renal pelvis and ureter. Delayed images showed a wedge-shaped area in the kidney, compatible with renal infarction. The patient was haemodynamically unstable and nephrectomy was performed. At operation, the aneurysm was located immediately adjacent to the pelvis. The patient remained in a critical condition for several days, but ultimately recovery was complete and follow-up was unremarkable.
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Figure 1. Abdominal radiography. This image was initially interpreted as non-specific by the emergency room physician. Retrospectively, marginal calcifications can be seen to the left of the L2 vertebra (arrows), corresponding to aneurysmal rim calcification. The pattern of distended small bowel loops (B) can be explained as a sign of retroperitoneal irritation.
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Figure 2. Transverse CT image. High-density contrast medium is seen in the aorta in prevertebral location and in the renal artery aneurysm (P). Marginal calcifications (long arrows) are also noted in the wall of the aneurysm. Important perirenal collections (double arrows) are seen.
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Figure 3. Transverse CT image shows perirenal and pararenal collection(short arrows) with streaky aspect corresponding to haemorrhage. Also note contrast in the ureter (long white arrow) and wedge-shaped renal infarction (I) in the kidney. Renal cyst (C ) is also seen.
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Figure 4. Coronal reconstructed CT image. Renal artery(black arrow) is seen to originate from atheromatous aorta. Aneurysm with marginal calcification is located adjacent to renal pelvis and immediately fills with contrast medium (A). The pelvis (long white arrow) and ureter (small white arrows) also immediately fill with contrast medium. A lateral displacement of the collecting system secondary to the pressure of the aneurysm can be seen.
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Discussion
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Aneurysms of the renal artery are uncommon, occurring in about 0.09% of individuals. They comprise 22% of visceral aneurysms [1–3]. Predisposing factors for renal artery aneurysm include arteriosclerosis, fibromuscular dysplasia, congenital malformations of the kidney, renal angiomyolipoma, pregnancy and trauma. Four types of renal artery aneurysm have been described: saccular, fusiform dilatation, aneurysmal dissection and intrarenal microaneurysms [3]. Lumsden reported a prevalence of renal artery aneurysm of 39% in patients with hypertension who had been unresponsive to medical treatment [2]. Clinical findings of renal artery aneurysm are non-specific and include microscopic haematuria, hypertension and flank pain. Rupture of the aneurysm leads to acute flank pain and shock. Rupture is, however, uncommon [5]. The risk of rupture increases during pregnancy and in patients with polyarteritis nodosa. Some authors consider marginal calcification to protect against rupture, although this is debated by other authors [6].
Indications for surgery include hypertension with renal failure, hypertension with a solitary kidney, pain, haematuria, enlarging aneurysm and the diameter of the aneurysm being larger than 2 cm. Also, young females with a renal artery aneurysm should be considered for surgery.
Plain film findings include marginal calcifications of the aneurysm and distended bowel loops as a sign of retroperitoneal irritation. Ultrasound may demonstrate distended pelvis and perirenal collections in cases of rupture. Ultrasound findings may be non-specific and similar to what is seen in renal infection, obstruction and urinoma. When non-specific findings are seen with ultrasound, CT must be performed as soon as possible to make an accurate diagnosis.
With the use of MDCT, the renal vasculature can be demonstrated and abnormalities are easier to depict. MDCT now offers unique capabilities for diagnosis and follow-up of renal artery aneurysm [7]. MDCT also gives a good overview of anatomical topographical relationships. Coronal reconstructed CT images exquisitely demonstrate the presence and rupture of the aneurysm in the pelvis and ureter.
In summary, we report on an 60-year-old man presenting with clinical symptoms suggestive of renal colic. MDCT demonstrated rupture of a renal aneurysm into the left renal pelvis. Timely and accurate diagnosis by MDCT allowed immediate surgery as a life-saving measure in this patient.
Received for publication February 8, 2006.
Revision received July 24, 2006.
Accepted for publication August 24, 2006.
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References
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- Martin RS 3rd, Meacham PW, Ditesheim JA, Mulherin JL Jr, Edwards WH. Renal artery aneurysm: selective treatment for renovascular hypertension and prevention of rupture. J Vasc Surg 1998;9:26–34.[CrossRef]
- Hupp T, Allenberg JR, Post K, Roeren T, Meier M, Clorius JH. Renal artery aneurysm: surgical indications and results. Eur J Vasc Surg 1992;6:477–86.[CrossRef][Medline]
- Ortenberg J, Novick AC, Straffon RA, Stewart BH. Surgical treatment of renal artery aneurysms. Br J Urol 1983;55:341–6.[Medline]
- Lumsden AB, Salem TA and Walton KG. Renal artery aneurysm: a report of 28 cases. Cardiovasc Surg 1996;4:185–9.[CrossRef][Medline]
- Cheng C, Jenkins IL, Ramsay JWA and Hendry WF. Spontaneous rupture of renal artery aneurysm. J R Soc Med 1990;83:464–5.[Medline]
- Henke PK, Cardneau JD, Welling H 3rd, Upchurch GR Jr, Wakefield TW, Jacobs LA, et al. Renal artery aneurysm: a 35-year clinical experience with 252 aneurysms in 168 patients. Ann Surg 2001;234:454–63.[CrossRef][Medline]
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Abstract
Introduction
