Renal Ischemia

Acute renal ischemia occurs because of a transient sudden drop of total or regional blood flow to the kidney. Acutely diminished renal perfusion results in acute kidney injury. Impaired blood flow to both kidneys or to a solitary functional kidney can occur due to generalized hypoperfusion in case of hypovolemia or decreased cardiac output in acute cardiac decompensation, leading to acute renal failure. Acute unilateral renal artery occlusion is usually noted as a result of trauma or embolism leading to acute renal ischemia. Patients usually present with acute onset of loin pain, vomiting, and hematuria. The precise role of revascularization and the optimal timing of intervention in patients with acute renal occlusion are not clearly defined. The goals of revascularization include the preservation of renal function and the amelioration of renovascular hypertension. Salvage of viable parenchyma requires revascularization before ischemia has progressed to infarction. The relief of renovascular hypertension is a secondary goal in acute ischemic kidney and may be accomplished by either revascularization or nephrectomy. The choice between these two alternatives requires an assessment of the quantity of the remaining functional renal tissue. Endovascular treatment options such as balloon angioplasty and stenting are today established methods for the management of acute renal ischemia. In this chapter the indications, techniques, and outcomes of endovascular revascularization for acute renal ischemia are discussed.