Cholesterol crystal embolism: A recognizable cause of renal disease

Cholesterol crystal embolism, sometimes separately designated atheroembolis m, is an increasing and still underdiagnosed cause of renal dysfunction ant emortem in elderly patients. Renal cholesterol crystal embolization, also k nown as atheroembolic renal disease, is caused by showers of cholesterol cr ystals from an atherosclerotic aorta that occlude small renal arteries. Alt hough cholesterol crystal embolization can occur spontaneously, it is incre asingly recognized as an iatrogenic complication from an invasive vascular procedure, such as manipulation of the aorta during angiography or vascular surgery, and after anticoagulant and fibrinolytic therapy. Cholesterol cry stal embolism may give rise to different degrees of renal impairment. Some patients show only a moderate loss of renal function; in others, severe ren al failure requiring dialysis ensues. An acute scenario with abrupt and sud den onset of renal failure may be observed. More frequently, a progressive loss of renal function occurs over weeks. A third clinical form of renal at heroemboli has been described, presenting as chronic, stable, and asymptoma tic renal insufficiency. The renal outcome may be variable; some patients d eteriorate or remain on dialysis, some improve, and some remain with chroni c renal impairment. In addition to the kidneys, atheroembolization may invo lve the skin, gastrointestinal system, and central nervous system. Renal at heroembolic disease is a difficult and controversial diagnosis for the prot ean extrarenal manifestations of the disease. In the past, the diagnosis wa s often made postmortem. However, in the last decade, awareness of atheroem bolic renal disease has improved, enabling us to make a correct premortem d iagnosis in a number of patients. Correct diagnosis requires the clinician to be alert to the possibility. The typical patient is a white man aged old er than 60 years with a baseline history of hypertension, smoking, and arte rial disease. The presence of a classic triad characterized by a precipitat ing event, acute or subacute renal failure, and peripheral cholesterol crys tal embolization strongly suggests the diagnosis. The confirmatory diagnosi s can be made by means of biopsy of the target organs, including kidneys, s kin, and the gastrointestinal system. Thus, Cinderella and her shoe now can be well matched during life. Patients with renal atheroemboli have a disma l outlook. A specific treatment is lacking. However, it is an important dia gnosis to make because it may save the patient from inappropriate treatment . Finally, recent data suggest that an aggressive therapeutic approach with patient-tailored supportive measures may be associated with a favorable cl inical outcome. (C) 2000 by the National Kidney Foundation, Inc.