2023 May 30. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan–.
Renal infarction is a rare ischemic event or insult caused by the complete or partial occlusion of the main renal artery or its segmental branches, which may ultimately lead to the ischemic necrosis of renal tissue. It most commonly occurs due to an embolus originating from the heart or an in-situ thrombosis. Patients may have a history of atrial fibrillation, where cardiac thrombi can dislodge and eventually infarct the renal artery or one of its branches. Interventional procedures like angiography can result in embolic renal infarctions by causing an injury to the endothelium or dislodging an atherosclerotic plaque.
Other etiological promotors of renal infarction are coagulation disorders, vasculitis, connective tissue diseases, valvular endocarditis (native or prosthetic valve), atherosclerosis of the aorta or renal artery, aortic aneurysms, smoking, and trauma.
Renal infarction patients typically present with abdominal or flank pain, nausea, vomiting, or fever. Gross or microscopic hematuria is often present. With the advent of contrast-enhanced computed tomography (CT) scans and other imaging modalities, more incidental cases of renal infarction are being detected in patients presenting with non-specific symptoms.
Often an underreported diagnosis, renal infarction patients can present late, or the diagnosis can be missed. An overlooked diagnosis can result in irreversible loss of renal function, as renal reperfusion therapy is ineffective in a substantially delayed presentation. In a study by Korzets et al., the time from admission to diagnosis ranged from 24 hours to 6 days. Lessman et al. reported that only 4 out of 17 cases they studied were diagnosed correctly at initial presentation.
The diagnosis of renal infarction should be considered in patients who develop sudden abdominal or flank pain with reduced renal function, hematuria, elevated LDH, or proteinuria and who do not have urolithiasis or any other diagnosable explanation for their symptoms. The chances increase if the patient has cardiac disease, especially atrial fibrillation, or is older. Since many of these patients will receive an initial non-contrast abdominal CT scan, progressing immediately to a contrast-enhanced study if the original CT scan is negative is quite reasonable and facilitates arriving at the correct diagnosis much more rapidly. This is essential for initiating revascularization therapy promptly, which optimizes renal functional recovery.