The clinical spectrum of renal cholesterol embolization.

Renal cholesterol embolization can occur spontaneously or as a complication of aortic surgery or major vessel angiography in patients with diffuse atherosclerosis. The demonstration of characteristic cholesterol crystals in tissue biopsy specimens is a pathognomonic finding. However, renal cholesterol embolism may be clinically diagnosed when renal failure develops after known inciting factors or together with systemic manifestations of atheromatous embolization such as lower extremity livedo reticularis, focal digital ischemia or retinal embolism. Previous investigators have emphasized the progressive nature of renal insufficiency due to cholesterol embolism, its poor prognostic significance and almost uniformly fatal outcome. In this report, we describe five additional patients with renal cholesterol embolization. In three of them only moderate renal insufficiency developed, and kidney function subsequently improved in all. In two patients the condition progressed to end-stage renal disease; one died with chronic renal failure whereas the other patient required four months of hemodialysis before kidney function eventually improved. Thus, cholesterol embolization may produce a spectrum of renal functional impairment. In some patients there is only a moderate loss of renal function with subsequent improvement; in others renal failure ensues. In this latter group, eventual return of kidney function can occur even after a prolonged period of renal insufficiency.