Percutaneous Ultrasound-Guided Kidney Transplant Biopsy Outcomes: From the Nephrologist to the Radiologist Standpoint

Abstract

Key Points Ultrasound-guided kidney transplant biopsy is considered safe, with similar complications rates regardless of the performing team. Besides well-known risk factors for complications, we found that sex and race are also predictors. The performance of kidney transplant biopsy remains an integral part of nephrology training. Background Kidney transplant biopsies are the gold standard for evaluating allograft dysfunction. These biopsies are performed by nephrologists and radiologists under real-time ultrasound guidance. A few studies have examined the outcomes of ultrasound-guided kidney transplant biopsy in transplant recipients; however, none have compared these outcomes between both specialties. Methods We retrospectively analyzed a cohort of 678 biopsies performed in a single center during a 44-month study period. Biopsies were stratified into two groups based upon the specialist performing the procedure: interventional radiology (IR; N=447) and transplant nephrology (TN; N=231). Results There were 55 (8%) complications related to biopsies in the entire cohort: 37 (8.2%) in the IR group and 18 (7.7%) in the TN group, without statistical difference between the groups (P=0.94). Blood pressure control and prior use of anticoagulation were significant predictors of complicated biopsies (P=0.004 and 0.02, respectively). Being a woman and prior use of anticoagulation were significant predictors of transfusion of blood products (P=0.01 and 0.01, respectively). Being a woman and blood pressure control were significant predictors of overall perinephric hematoma (P=0.01 and 0.01, respectively), and Black race was a significant predictor of perinephric hematoma without worsening of renal function (P=0.005). The specialist team performing the procedure was not a statistically significant predictor of biopsy complications, transfusion of blood products, or perinephric hematoma with comparable sample yield. Conclusions Percutaneous ultrasound-guided kidney transplant biopsy performed by transplant nephrologists have similar complication rates when compared with interventional radiologists in an academic center.