[Atheroembolism renal disease: diagnosis and etiologic factors]

Abstract

Atheromatous renal disease is the major cause of renal insufficiency in the elderly, and cholesterol embolism is a manifestation of this disease. Cholesterol embolism occurs in patients suffering from diffuse erosive atherosclerosis, usually after triggering causes, such as aortic surgery, arterial invasive procedures (angiography, left heart catheterization and coronary angioplasty) and anticoagulant or thrombolytic therapy. It is characterized by occlusion of small arteries with cholesterol emboli deriving from eroded atheromatous plaques of the aorta or large feeder arteries. The proximity of the kidneys to the abdominal aorta and the large renal blood supply make the kidney a frequent target organ for cholesterol atheroembolism. The exact incidence of atheroembolic renal disease (AERD) is not known. The reported incidence AERD varied in the literature because of the differences in study design and the different criteria used for making the diagnosis. Retrospective data derived from autopsy or biopsy studies may exaggerate the frequency by including many subclinical cases. Clinical observations that are based on a short duration of follow-up after an invasive vascular procedure and the infrequency of the confirmatory renal biopsies can lead to an underestimation of the true incidence of AERD. The initial signs and symptoms in patients diagnosed with cholesterol embolism were blue toes syndrome, livedo reticularis, gangrene, leg, toe or foot pain, abdominal pain and flank or back pain, gross haematuria, accelerated hypertension and renal failure. Cholesterol embolism may also be associated with fever, increased erythrocyte sedimentation rate and eosinophilia. Thus, in the cases of spontaneous cholesterol embolism, differential diagnosis includes, polyarteritis nodosa, allergic vasculitis and subacute bacterial endocarditis. Skin and renal biopsy specimens are the best sample for histologic diagnosis. There is, at present, no pharmacological treatments shown to be effective in altering the course of the disease. Management is limited to supportive therapy and avoidance of anticoagulation; aortic procedures should be postponed.