Treatment of renal artery aneurysms.

Renal artery aneurysms (RAAs) represent a rare disease and are most commonly discovered as an incidental imaging finding. RAA may be associated with hypertension and are usually asymptomatic at presentation but may result in rupture, hematuria, or renal infarction. The natural history of RAA is poorly understood. Although there is general consensus that RAA that are symptomatic or identified in women at risk for pregnancy should be repaired, diameter criteria for repair of asymptomatic RAA are controversial and emerging evidence suggests that rupture incidence is low for those <2.5 cm in diameter. Options for repair of RAA have expanded over the preceding decades with expansion of both open surgical and endovascular treatments.

Revascularization for atherosclerotic renal artery stenosis: the treatment of choice?

Atherosclerotic renal artery stenosis (ARAS) is an important cause of renal dysfunction and secondary hypertension, and is associated with adverse cardiovascular events and increased mortality. The natural history of ARAS is characterized by anatomic disease progression and/or renal dysfunction in only a minority of patients. Medical therapy for ARAS is directed primarily toward blood pressure control and cardiovascular risk factor reduction. Renal artery revascularization is an additional treatment option for ARAS associated with ischemic nephropathy or severe, poorly controlled hypertension despite aggressive medical therapy. Unfortunately, the benefits associated with revascularization versus medical therapy alone remain unproven. Renal artery revascularization may be accomplished through open surgical revascularization or angioplasty and stenting. Although surgical renal revascularization is associated with more durable results and relatively lower risk for postoperative renal function decline, the increased risk of death or major complications associated with this management approach limit its use in patients with significant comorbidities. Renal artery angioplasty and stenting is being utilized with increasing frequency but is of uncertain benefit and is associated with rates of post-intervention renal function improvement and deterioration that are approximately equal. Renal function outcomes associated with angioplasty and stenting may be improved through a selective treatment approach and utilization of distal embolic protection. Renal artery revascularization represents the only treatment alternative for patients unresponsive to medical management, and is therefore the ''treatment of choice'' in this select group. Results of ongoing randomized trials are eagerly anticipated and may provide useful guidance for future management of ARAS.

Is embolic protection during renal artery intervention really necessary?

Atherosclerotic renovascular disease is an increasingly recognized cause of both renal function impairment and hypertension, and its presence is associated with increased cardiovascular mortality and dialysis dependence. Although surgical renal revascularization is associated with the most favorable reported renal function outcomes, the significant perioperative mortality and complication rates have resulted in a shift to renal artery percutaneous transluminal angioplasty and stenting (RA-PTAS) as the most frequently performed method of revascularization. Renal function outcomes following RA-PTAS are less favorable, with patients experiencing functional improvement and deterioration with approximately equal frequency in reported series. Distal atheroembolization is thought to occur during RA-PTAS and has been suggested as a potential cause of the disparate renal function outcomes. Distal embolic protection devices primarily used and evaluated in the coronary and cerebrovascular circulations have also been successfully employed during RA-PTAS. Initial clinical results following RA-PTAS with distal embolic protection have been promising, with high rates of technical success, renal function outcomes that approximate those reported with open surgical revascularization, and maintenance of relatively low death and complication rates. Further investigation with controlled comparison groups is warranted before routine use of distal embolic protection can be uniformly endorsed.