Transitioning From Blind to Real-Time Ultrasound-Guided Kidney Biopsy in Children: Diagnostic Yield and Bleeding Outcomes in a Vietnamese Tertiary Referral Hospital, a Retrospective Cohort Study.

Abstract

Background: Kidney biopsy is the gold standard for diagnosing renal parenchymal diseases, guiding treatment and assessing prognosis. Real-time ultrasound-guided biopsy is widely regarded as the preferred technique. However, the implementation may be affected by equipment availability, trained personnel and workflow constraints in resource-limited settings worldwide.

Objective: This study compared the safety and effectiveness of real-time ultrasound-guided and blind kidney biopsy techniques in a paediatric tertiary referral hospital in Vietnam and examined the practical implications of transitioning to real-time ultrasound guidance.

Methods: A retrospective cohort study was conducted at the Nephro-Endocrinology Department, City Children's Hospital, Ho Chi Minh City, Vietnam, from May 2018 to April 2025. All native kidney biopsies performed during the study period were included. A standardised questionnaire was used to extract data from medical records, including demographics, biopsy techniques, glomerular yield, samples containing ≥ 10 and ≥ 25 glomeruli, and inadequate yield and complications, including macroscopic haematuria and major complications.

Results: Among 221 participants (median age: 11 [IQR 7-13] years), 173 underwent real-time ultrasound-guided biopsy and 48 used the blind technique. The ultrasound-guided group had a significantly higher median glomerular count (p = 0.01) and greater proportion of samples with ≥ 10 (p < 0.001) and ≥ 25 glomeruli (p = 0.04). There were no significant differences in inadequate sample rates (p = 0.06), macroscopic haematuria (p = 0.63) or major complications (p = 0.60). Lower eGFR was independently associated with post-biopsy bleeding events, mainly macroscopic haematuria (AOR = 0.809 per 10 mL/min/1.73 m² increase, 95% CI 0.671-0.975, p = 0.03).

Conclusion: In this Vietnamese paediatric tertiary referral setting, real-time ultrasound-guided biopsy provided superior tissue adequacy compared with the blind technique, without a detectable increase in macroscopic haematuria or major complications. Lower estimated glomerular filtration rate was associated with post-biopsy bleeding events in this cohort, mostly macroscopic haematuria rather than major bleeding.