Renal Biopsy in Acute Renal Failure: Its Indications and Usefulness

Acute tubular necrosis (ATN) is the most common form of ARF. Less often, ARF results from arterial, glomerular, or interstitial lesions. These forms of ARF may regress, but may also lead to chronic renal failure (CRF). Progression to CRF may sometimes be prevented by appropriate therapeutic measures, especially if they are undertaken early, for often the lesions only become irreversible later in the course of the illness. These treatments are potentially expensive and hazardous. Thus, they must rely on precise and early identification of the anatomical lesions, their mechanism, and their cause. The situation may be highly complex since the same etiology can produce different forms of ARF, each of which requires its own treatment. In order to guide the therapy and in the absence of the usual contraindications (which are often temporary), early renal biopsy should be considered in ARF whenever the diagnosis of ATN appears doubtful and/or the etiology equivocal.