Indications for renal biopsy in chronic kidney disease.

There are many clinical situations in which physicians may be uncertain whether to refer a patient to a nephrologist for renal biopsy. Biopsy is often necessary in unexplained acute renal failure (ARF) and in nephrotic syndrome (Table 1). This article addresses the more difficult question of when renal biopsy may be indicated in suspected chronic renal disease. Renal biopsy should be performed only when the risks of the procedure are justified by a reasonable expectation that the results will have a useful impact on management. A recent comprehensive review1 of published series gave the risks for the following procedures: • renal biopsy: 0.06% • surgery or embolisation to control bleeding: 0.3% • major complications: 1.5%, and • all complications: 7.4%. A period of observation of at least eight hours following biopsy to allow detection of bleeding complications is considered ideal.2 Possible indications for biopsy are listed in Table 2 and relative contraindications in Table 3. A biopsy is occasionally justified solely for prognostic reasons: for instance, if premiums for life insurance, prospects for employment (eg in the armed services) or for emigration might be affected. Also occasionally, the risks of renal biopsy will be considered justified simply to reassure the patient or to provide a specific diagnosis or, as with suspected thin basement membrane nephropathy (TBMN), to provide a diagnosis to spare another family member (eg a child with haematuria) a renal biopsy. In previous studies of the role of renal biopsy in influencing clinical decisions, changes in management commonly resulted from the biopsy diagnosis in patients with ARF and nephrotic syndrome, less commonly in those with Charles RV Tomson BM BCh DM FRCP, Consultant Nephrologist, Richard Bright Renal Unit, Southmead Hospital, Bristol