# Effectiveness and Safety of Image-Guided Renal Biopsies: Insights from 5,235 Procedures in the German Society for Interventional Radiology and Minimally Invasive Therapy (DeGIR) Registry

## TL;DR

This study shows that image-guided kidney biopsies are highly effective and safe, with ultrasound guidance being linked to fewer complications.

## Contribution

The study provides the largest multicenter registry analysis of image-guided renal biopsies, highlighting safety and diagnostic yield.

## Key findings

- Technical success rate was 98.38% and diagnostic yield was 94.92% across 5,235 procedures.
- Ultrasound-guided biopsies had lower complication rates compared to CT-guided procedures.

## Abstract

This study evaluates the technical success, diagnostic yield, and complication rates of image-guided percutaneous renal biopsies based on multicenter registry data from the German Society for Interventional Radiology and Minimally Invasive Therapy.

This retrospective analysis included 5,235 renal biopsies at 176 centers in Germany, Austria, and Switzerland between 2018 and 2024. Technical success was defined as image-guided confirmed needle placement within the target lesion. Diagnostic yield is defined as proportion of procedures providing adequate samples for clinical diagnosis.

CT was used for image guidance in 78.53% followed by ultrasound in 12.32%. Technical success was 98.38% and diagnostic yield 94.92%. Technical success was high in both inpatients (98.33%) and outpatients (99.26%; OR = 0.44, 95%CI 0.11–1,80; p = 0.241). The overall complication rate was 5.04%, with major complications in 0.74%. Complications were more frequent with pathological platelet counts and INR values, but none of these coagulation parameters remained independently associated in multivariable analysis. CT-guided biopsies showed higher complication rates than ultrasound-guided procedures, and this association remained after adjustment (adjusted OR 8.57, 95%CI 3.40–21.58; p < 0.001). No fatal complications occurred within 24 h; however, three delayed deaths were documented among hospitalized patients.

Percutaneous image-guided renal biopsies are effective and safe, with low complication rates and high diagnostic yield. Ultrasound guidance remained independently associated with a lower complication risk, likely reflecting selection bias.