Late embolectomy has led to improvement in renal function in selected patients, indicating that ischemic atrophy can still be reversed. Clinically important atheroemboli most often result from manipulation of the aorta or other large arteries during arteriography, angioplasty, or surgery, including organ transplantation. Examination of renal tissue by light microscopy is often pathognomonic of atheroembolism. The biconcave slits represent cholesterol crystals that have been dissolved during paraffin fixation. With time, a foreign-body reaction often develops, causing intimal proliferation and further narrowing of the vascular lumen.
Similar emboli are commonly present in other organs.
It is important to emphasize that the localization of atheroemboli within the kidney is focal. Consequently, because of a sampling error, a percutaneous renal biopsy may miss the characteristic arterial lesions, even in patients who have documented atheroemboli in other organs or in the kidney at postmortem examination. The severe, erosive vascular disease that leads to atheroemboli is most commonly observed in patients older than 50 years. Thus, most patients have no symptoms referable to the kidneys. The history and physical examination may reveal signs and symptoms characteristic of extrarenal atheroemboli.