Percutaneous renal biopsy in children: survey of pediatric nephrologists in Japan.

Between 1996 and 1997, 2,045 percutaneous renal biopsies were performed on native kidneys in 2,013 patients in pediatric nephrology units in Japan. Of these, 50.8% were performed by automated needle biopsy gun under ultrasound guidance, and the standard biopsy needle, Tru-cut needle or Vim-Silverman needle, under fluoroscopic guidance was used in 12.4% and 12.3% of the biopsies, respectively. Adequate renal tissue for histological diagnosis was obtained in 98.7% of cases, and the success rates for the techniques were not significantly different. The overall complication rate was 5.8%; gross hematuria occurred in 2.7% and large perirenal hematoma in 0.9% of cases. These complication rates were higher when a standard needle under fluoroscopic guidance was used compared with an automated needle under ultrasound guidance. We conclude that pediatric nephrologists in Japan perform percutaneous renal biopsies safely, partly due to technical improvements, such as the automated needle or ultrasound guidance.