Prospective study of the complications associated with percutaneous renal biopsy of native kidneys: experience in a centre

Background: Percutaneous renal biopsy (PRB) is a key invasive technique in the study of kidney disease and it is associated with considerable morbidity. Retrospective studies have shown minor complications in 10%-20% and major complications in 1.2%-6.6% of cases. However; this aspect has not been studied prospectively. Objective: The aim of our study was to prospectively assess complications related to PRB in the native kidney. Methods: From January 2009 to May 2013, we prospectively analysed PRB performed by nephrologists in native kidneys under ultrasound guidance. We analysed clinical and laboratory variables. We defined minor complications as the decrease in haemoglobin (Hb) of more than 1g/dL and major complications as the need for a transfusion or invasive technique. Results: 241 PRB were performed over this period. The mean patient age was 49 years ( 17), the majority (56%) were male and 58.1% had high blood pressure. In 51% of cases, we carried out 2 punctures. There were minor complications in 46 patients (19.1%) and major complications in 9 patients (3.7%). In the univariate analysis, pre-PRB Hb was 10.3g/dL (+/- 1.3) in patients with major complications and 12.3g/dL (+/- 2.2) in the remaining patients (p=.003); in the multivariate analysis: OR 0.51, 95% CI (0.2-0.9), p<.05. Conclusions: PRB is a procedure that is not without risk, since minor complications occurred in 19.1% and major complications in 3.7% of cases. Pre-PRB Hb is an independent risk factor for the development of major complications.