Renal Artery Aneurysm Clinical Presentation

Updated: Oct 23, 2019
  • Author: Lindsay Gates, MD; Chief Editor: Vincent Lopez Rowe, MD  more...
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Presentation

History and Physical Examination

Asymptomatic

Most renal artery aneurysms (RAAs) are asymptomatic and are found incidentally during investigation of other intra-abdominal pathologies with diagnostic imaging studies such as computed tomography (CT), duplex ultrasonography (US), angiography, magnetic resonance imaging (MRI), or magnetic resonance angiography (MRA). In a small series by Dzsinich et al, only 34% (11 of 32) patients who underwent surgery were symptomatic. [8]

In asymptomatic patients, complications from RAA are relatively infrequent. In one study, 62 asymptomatic patients who had solitary saccular aneurysms with a mean size of 1.5 cm (range, 0.3-4.0 cm) were followed over a mean period of 5.7 years (median, 8 years). No ruptures, need for operations, or new symptoms developed. Eight patients (12%) did expire, but all of these deaths were unrelated to the aneurysm. [11]

In another series, 34 RAAs were managed nonoperatively and followed with serial arteriograms. Over a mean interval of 35 months, no changes were found in 28 (82.4%) RAAs, and slight changes were found in the other six (17.6%). Again, no ruptures were found during follow-up. [35]

Morita et al published an additional study with similar results. They followed 30 patients for a median follow up of 69 months with conservative management only. At the end of the study, only two patients showed growth in their aneurysm, and only two other patients required an increase in blood pressure medications. [36]

Symptomatic

Hypertension is the most common symptom found in RAA, with reported incidence as high as 90%. Often, renal artery stenosis is associated with a poststenotic fusiform aneurysm. In this case, the hypertension can be attributed to the renal artery stenosis and activation of the renin-angiotensin system, with increased angiotensin II levels resulting in fluid retention and vasoconstriction. [23]

Hypertension in RAA without a renal artery stenosis is not as well understood. Possible causes of hypertension in these cases may be related to renal ischemia secondary to thromboembolization distal to the aneurysm; in cases of large aneurysms, anatomic kinking of the renal artery has been reported. [37] Saccular and intrarenal aneurysms are less likely to be associated with hypertension.

In case series, 8-25% of patients presented with abdominal pain. [8, 11, 13] Patients with RAAs caused by dissection may present with flank pain, though most of those with spontaneous dissections are asymptomatic. New or worsening pain may also be indicative of a rapidly expanding aneurysm or impending rupture.

Hematuria may be another manifestation of dissecting RAA. Intraparenchymal aneurysms, which rupture into the collecting system, may also manifest as hematuria.

Collecting system obstruction is a rare presentation but has been documented in patients with larger aneurysms.

Renal infarction may be visualized on CT and is the result of embolization from the aneurysm sac.

Fewer than 3% of patients with RAAs experience a rupture. [6] Patients with RAA rupture typically have signs and symptoms of an abdominal catastrophe and may be in frank shock. [10]