Balancing Safety and Value: Bleeding Risk and Detection Timing in Native and Transplant Renal Parenchymal Biopsies

Purpose: Monitored recovery time following renal biopsies varies widely across institutions and by biopsy type, despite evidence that transplant biopsies incur lower bleeding risks than native kidney biopsies. To inform timely and safe post-procedure discharge, this study evaluated the rate and timeframe of 30-day bleeding complications at a tertiary center with a fixed 23-hour post-biopsy admission policy.

Methods/Materials: A radiology information search was conducted to identify all image-guided renal biopsies performed between 01/01/2021 and 04/01/2025. Data were collected on biopsy target (native vs. transplant), patient demographics, procedural parameters, and intra- and post-procedure findings indicative of bleeding. Clinically significant bleeding was defined by a moderate or large perinephric hematoma on post-procedure CT and/or a procedural or surgical intervention to treat bleeding.

Results: Among 1,121 image-guided renal biopsies, clinically significant bleeding was nearly three times more likely in native than transplant kidneys (5.7% [29/508] vs. 2.0% [12/613], p=0.0011). Post-procedure CT was performed within 30 days in 115 patients (60 native, 55 transplant), demonstrating a significant hematoma in 41 patients (29 native, 12 transplant). Interventions for bleeding were required in 21/508 (4.1%) native and 5/613 (0.82%) transplant biopsies. Detection of bleeding was temporally distributed, with 16/41 events (39.0%) detected within 2 hours, 3 between 2-6 hours, 11 between 6-24 hours, and 11 (26.8%) >24 hours post-procedure. Among the 26 patients (21 native, 5 transplant) requiring intervention, bleeding was detected within 2 hours for 12 patients (all native kidneys), between 2-6 hours in 2 patients (all native), between 6-24 hours in 4 patients (2 native, 2 transplant), and >24 hours later in 8 patients (5 native, 3 transplant).

Conclusions: Bleeding detection after kidney biopsy is temporally heterogeneous: 11/41 (26.8%) of hematomas were detected and 8/26 (30.8%) cases requiring intervention were identified more than 24 hours post-procedure. Clear instructions on bleeding signs and a structured post-discharge plan may provide greater value than prolonged inpatient monitoring.