[Renal biopsy: procedures, contraindications, complications].

Renal biopsy plays a central role in the investigational approach of the nephrologist. The technique has significantly improved over the past two decades as a result of the introduction of ultrasonography and automated-gun biopsy devices. Percutaneous renal biopsy has become a relatively safe procedure with life-threatening complications occurring in less than 0.1% of biopsies in recent reports. However, percutaneous kidney biopsy is not without risk. Overt complications occurring in up to 13% of the cases, and 6 to 7% of complications were considered major, needing for an intervention such as transfusion of blood product or invasive procedure (radiographic or surgical). Major complications were apparent in more than 90% of patients by 24 hours. In situations in which the potential benefit of obtaining renal histology outweighs the risks of the procedure, transjugular kidney biopsy or surgical biopsy offers an attractive alternative. At present, we have no definite predictive indicators of postbiopsy bleeding complication, with the exception of age, gender, advanced renal insufficiency and the baseline partial thromboplastin time. Bleeding time is not significantly predictive and has been reported to have substantial limitations as a screening test. The use of the PFA-100 may replace the bleeding time and is now considered as a more valuable screening test for prebiopsy identification and management of patients with impaired haemostasis. Four groups of patients benefit from the findings of renal biopsy: those with a nephrotic syndrome, those with a renal disease in a context of systemic disorder, those with acute renal failure and those with a renal transplant. Some patients with non-nephrotic proteinuria, hematuria and chronic renal failure may also benefit from the procedure.