Safety of kidney biopsy in pediatric transplantation - A report of the controlled clinical trials in pediatric transplantation trial of induction therapy study group

Background, Historically, young children undergoing renal transplantation have lower allograft survival than adults, and potential causes of this are being addressed by the North American Pediatric Renal Transplant Cooperative Study through the National Institutes of Health-sponsored study Cooperative Clinical Trials in Pediatric Transplantation. Included in this study is evaluation of surveillance renal biopsies (SB) and clinically indicated biopsies (CB). Few data exist in children to identify the risk involved with renal transplant biopsies. Methods. Questionnaires were mailed to 21 participating centers asking for descriptions of adverse events associated with kidney biopsies, with choices limited to none, gross hematuria, perinephric hematoma, and other. Further clinical details were obtained from review of medical records of all patients with reported adverse events. Data were collected from 19 centers on 126 patients. Results. Eighty-six patients had undergone 212 biopsies (75 SB and 137 CB). Nine biopsy-related adverse events were reported (4.2%): three SE (4.0%) and six CB (4.4%). Gross hematuria was reported in six patients (2.8%): two SE (2.7%) and four CB (2.9%). A perinephric hematoma was reported in one patient. Two patients with intraperitoneal kidneys developed significant bleeding after biopsy and required transfusions and surgical exploration. No patient lost kidney function or required nephrectomy after biopsy. No difference was noted in adverse events between SE at day 5 or 12 versus CB. Conclusion. Evaluation of transplanted kidney tissue may provide important information for the care of the transplantation patient. This analysis suggests that transplanted kidney biopsies can be performed with minimal risks in pediatric patients.