4:03 PM Abstract No. 206 The risk factors for major bleeding following ultrasound-guided native renal biopsy: what is the “core” of the problem? A case-control study

Abstract

To identify risk factors for major bleeding following ultrasound (US)-guided random renal biopsy by microscopic analysis and comparison of the cores obtained in patients with and without bleeding. A retrospective review identified 17 of 179 patients (9.50%) with major bleeding complications (per criteria determined by the Society of Interventional Radiology guidelines) post-US-guided native renal biopsy between July 2014 and June 2019. Case-control matching was accomplished by propensity score based on sex, age, body mass index (BMI), blood pressure (BP), international normalized ratio (INR), platelet (PLT), blood urea nitrogen (BUN), and creatinine (Cr) concentration, estimated glomerular filtration rate (eGFR), needle size, and core number. The cores obtained in the bleed and non-bleed patients were analyzed for total length, medullary length, cortical thickness, and number of arcuate/interlobular vessels by the pathologist. 26 controls were matched to 17 cases (with and without major hemorrhage, respectively). Conditional logistic regression was used to explore the statistical significance between core characteristics obtained from random renal biopsies and the probability of a major bleed. Analysis revealed that arcuate artery (AA) quantity per specimen exhibits a significant association with a major bleed (P = 0.0006). When 0, 1, or ≥ 2 AA were identified, the frequency of major bleeding was 13.04%, 66.67%, and 75.00%, respectively. The odds of major bleed are 6 times higher with 1 AA (95% CI, 1.28 – 32.30) and 15 times higher with ≥ 2 AAs (95% CI, 1.41 – 169.57). Despite lacking statistical significance, correlations between medullary length (P = 0.228), medulla-cortex (MC) (P = 0.089), medulla-total (MT) (P = 0.108), and cortex-total (CT) (P = 0.112) length ratios to major bleeding may require a larger population study. A strong and incremental correlation between major renal hemorrhage following native renal biopsy and the number of arcuate arteries per core specimen exists. Identification of arcuate arteries by the pathologist while assessing sample adequacy in the US suite can help predict major hemorrhage in patients undergoing random renal biopsies.