Safety and utility of kidney biopsy in patients with estimated glomerular filtration rate < 30 ml/min/1.73 m2.

Kidney biopsy (KBx) is the gold standard for evaluation of kidney disease, but is associated with a higher risk of complications in patients with reduced glomerular filtration rate (GFR). We studied the safety and utility of KBx in patients with eGFR <30 ml/min/1.73 m2 . METHODS Consecutive adult patients with eGFR <30 ml/min/1.73 m2 , who were planned for a KBx and consented to participate were prospectively enrolled. Patients with solitary/transplant kidney or acute kidney injury were excluded. Haemoglobin was checked on the day of KBx and repeated 18-24 h later along with a screening ultrasound. Post-KBx complications were noted and their risk-factors analysed. The utility of the KBx was graded as effecting significant, some, or no change to subsequent management. RESULTS Of the 126 patients included, 75% were male, 27.7% were diabetic, and the median eGFR was 13.5 ml/min/1.73m2 . Major complications occurred in 5.6%. Peri-renal haematomas were detected in 37.3%, and haematomas ≥2 cm were significantly more frequent in those with eGFR <15 ml/min/1.73 m2 (29.2% vs. 13%, p = .032). Dialysis was a risk factor, while pre KBx blood transfusion, diabetes and higher serum albumin were protective against any complication. KBx was more likely to make a significant difference in management in those with eGFR 15-29 ml/min/1.73m2 (44.1% vs. 11.1%, p < .001). Increasing age, lower serum creatinine and albumin were independently associated with KBx utility. CONCLUSION KBx is relatively safe in severe kidney disease but its risk to benefit balance needs to be carefully considered when eGFR is <15 ml/min/1.73m2 . This article is protected by copyright. All rights reserved.