Case 16.3

Abstract

43-year-old man with hypertension resistant to medical therapy Focal dilatation of the right renal artery at its bifurcation is seen on VR images from 3D CE MRA (Figure 16.3.1). Renal artery aneurysm Renal artery aneurysms are relatively infrequent, but nevertheless they are the second most common visceral artery aneurysm after splenic artery aneurysms. The estimated incidence on autopsy studies is approximately 0.01%, while an incidence of 0.3% to 1% has been reported for patients undergoing renal angiography. Renal artery aneurysms are most often detected in middle age and are more common in women. Patients are typically asymptomatic. The aneurysms are associated with hypertension in as many as 73% of cases, but it is not always clear whether the aneurysm is the result or the cause of hypertension. Certainly poststenotic dilatation can result from severe renal artery stenosis, and distal embolization from renal artery aneurysms could result in parenchymal loss and activation of the renin-angiotensin cascade. Renal artery aneurysms have several potential causes, but the 2 most common are atherosclerosis and FMD. Both tend to occur most frequently in the main renal artery, at its bifurcation, or in the proximal branches. Aneurysms due to arteritis, such as polyarteritis nodosa, Wegener granulomatosis, and necrotizing angiitis, as well as most posttraumatic aneurysms and pseudoaneurysms, occur within intrarenal arteries. Additional causes include EDS, neurofibromatosis, infection (mycotic), and iatrogenic causes. FMD is discussed more completely in ...