Introduction
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.
Case report
A 62-year-old woman visited the emergency with abdominal pain and vomiting that had started a day earlier. The patient was on medication for hypertension and diabetes. The initial blood pressure was 120/80 mmHg with a heart rate of 104 beats/min. In the physical examination, a pulsating mass was palpated in the middle abdomen. Hemoglobin dropped from 11 to 6.8 g/dL. An abdominal computed tomography (CT) scan revealed a 6 × 5 cm ruptured aneurysm with active bleeding, and hematoma was spreading widely through the periand pararenal spaces into the right retroperitoneum (Fig. 1). We diagnosed ruptured right renal artery aneurysm. We started emergency transfusion, and performed an emergency operation. The patient underwent a right nephrectomy approached by lumbotomy (Fig. 2). Surgery was completed after bleeding control and hematoma evacuation in the retroperitoneal space. The pathological report revealed an atherosclerosis of the renal artery and renal infarction (Fig. 3). After the surgery, the patient maintained normal renal function, and she was asymptomatic.
Fig. 1.
Abdominal computed tomography CT scan shows a 6 × 5 cm right ruptured renal artery aneurysm with active bleeding. Hematoma is extended into the pelvic extraperitoneal space along the right periand pararenal space (arrow).
Fig. 2.
The operative piece of nephrectomy.
Fig. 3.
Ischemic renal cortical infarction.
Discussion
Renal artery aneurysms are localized dilations of the renal artery and/or branches. It was the first disease process of the renal artery to be identified and has historically been considered a rare phenomenon until the widespread use of angiography.1 There are 4 basic structural types: saccular, fusiform, dissecting, and arteriovenous/microaneurysms.2 Aneurysms have some risk factors such as atherosclerosis, fibromuscular dysplasia, trauma, or iatrogenic damages. Spontaneous rupture of the aneurysm is uncommon. The risk factors for the rupture of aneurysm include size>2cm, hypertension, and pregnancy.3 Renal artery aneurysm incidence is very low and is usually asymptomatic. It is commonly discovered randomly through conducting surveys for hypertension. Although microscopic hematuria is observed in 10–40% of cases, the kidney functions normally. Abdominal or back pain are the clinical symptoms of ruptured renal aneurysm. When patients do present with symptoms, they usually present with flank pain and hematuria that can range from mild microscopic hematuria to gross hemorrhage leading to hemodynamic instability.1 In most reported cases of ruptured renal aneurysm, nephrectomy was inevitable but mortality was dependent on early diagnosis and a skilled surgeon. Aneurysm rupture begins with an initial pain and it follows the symptoms of hemorrhagic shock after the progress of rupture to retroperitoneal space.1 Imaging is required to confirm the diagnosis of a RAA. In one series, only 66% of excretory urograms were diagnostic or suggestive of the presence of a renovascular lesion, whereas angiography was 100% diagnostic. Although angiography is the gold standard, perhaps the best non invasive test to evaluate location, size, structure, and relation to nearby organs is CT/MRA.4 Indications for renal artery aneurysms treatment include hemorrhage, uncontrolled hypertension, pain, progressive enlargement, presence of an arteriovenous fistula, size >2–2.5 cm, or >1 cm in a female of childbearing age. Currently, endovascular surgery is the intervention of choice in elective or emergent circumstances.5 Endovascular repair of renal artery aneurysms has been associated with a decreased length of hospital stay, lower morbidity rates (including a lower incidence of nephrectomy), and lower mortality rates compared to open repair.5 At the same time, aneurysm-related outcomes are near equivalent to surgical interventions. Renal artery aneurysms that are not amenable to endovascular therapy may undergo nephrectomy, partial nephrectomy, renal artery grafting, aneurysmectomy, autotransplantation, and/or renal artery ligation.5
Conclusion
Although rare, the diagnosis of renal artery aneurysms is being made more frequently with more patients undergoing abdominal aortography and abdominal imaging for unrelated causes. It is imperative for the practicing urologist and clinician to be aware of life-threatening causes of gross hematuria, appropriate evaluation and imaging of suspected renal artery aneurysms, endovascular management, operative indications, and techniques.
Conflicts of interest
The authors declare that there are no conflicts of interest regarding the publication of this article.
References
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