Renal malperfusion: spontaneous renal artery dissection and with aortic dissection.

Renal malperfusion associated with renal artery dissection can present as either an isolated disease process or in the setting of branch vessel stenosis complicating aortic dissection. Isolated renal artery dissection is a rare disorder, the clinical presentation of which often presents both diagnostic and therapeutic challenges. The true incidence and natural history of this phenomenon also remain unclear. Multiple approaches to management have been described. Medical therapy typically consists of anticoagulation and blood pressure management and is reserved for cases with well-controlled symptoms and blood pressure and preserved, stable renal function. Historically, surgical reconstruction with in situ or more complex ex vivo reconstruction has been described for the treatment of uncontrolled hypertension with preservation of renal perfusion. Nephrectomy, either partial or total, for control of hypertension, is reserved for cases where parenchymal injury necessitates this radical intervention. Recently, endovascular stenting of the renal artery has shown excellent and durable results and is now considered to be the first-line intervention for renal artery dissection. Renal malperfusion associated with complicated aortic dissection is a different entity and one that is consistently an independent predictor of poor prognosis. The pathogenesis of malperfusion can be dynamic, static, or a combination. In addition, renal hypoperfusion may occur with or without extension of the intimal flap into the renal artery itself. Traditional open surgical interventions to treat aortic dissection with malperfusion have a very high perioperative mortality rate. Endovascular fenestration and stenting of both the thoracic aortic and it's branch vessels have significantly improved clinical outcomes in complicated aortic dissections relative to open surgical fenestration. Although a significant body of long-term data has yet to be accumulated, endovascular stent grafting has the added advantage over fenestration that it may affect aortic remodeling and prevent the very morbid complication of aneurysmal degeneration.