Microfibrillar Collagen Tract Embolization in Percutaneous Liver Biopsy: A Single-Center Experience

To evaluate the incidence of bleeding-related adverse events associated with microfibrillar collagen tract embolization (MCTE) during percutaneous non-targeted liver biopsy in adult patients.

In this retrospective observational cohort study, consecutive percutaneous non-targeted native or transplant liver biopsy procedures were reviewed at a tertiary academic center between August 2022 and July 2025. 695 records met inclusion criteria including: random (non-targeted) liver biopsy, and routine MCTE following sampling with a full core coaxial 17/18-gauge biopsy system. Targeted biopsies performed for specific hepatic lesions were excluded. Indication for biopsies included evaluation of diffuse parenchymal liver disease or transplant allograft assessment. Contraindications included INR or platelet values (≤1.8, ≥50,000, respectfully), use of antiplatelet or anticoagulants that were outside of Society of Interventional Radiology (SIR) guidelines, or ascites. Demographic, clinical, laboratory, and procedural variables, including number of biopsy passes, were collected. The primary endpoint of the study was major bleeding adverse events requiring transfusion, embolization, surgery, or hemodynamic instability (SIR AE Class 2-5). Secondary endpoints included minor bleeding adverse events (hematoma or hemoglobin decline requiring observation only; SIR AE Class 1), emergency department (ED) visits within two weeks, CT-confirmed hematoma, and 30-day readmission. Data are reported as proportions with 95% confidence intervals (CIs) calculated using the exact binomial (Clopper-Pearson) method; continuous variables as mean ± SD.

Among 695 non-targeted biopsies, major bleeding occurred in 1 case (0.14%, 95% CI 0.00-0.80%) requiring endovascular and operative intervention, and minor bleeding in 1 case (0.14%, 95% CI .00-0.80%) . The mean number of biopsy passes was 2.41 ± 0.58. Seventeen patients (2.4%, 95% CI 1.43-3.89%) were readmitted within 30 days; no readmissions were attributed to biopsy-related adverse event.

Routine MCTE in percutaneous ultrasound-guided non-targeted native and transplant liver biopsy was associated with extremely low rates of major and minor bleeding adverse events. Bleeding rates appear below published benchmarks in non-tract embolized procedures, supporting MCTE as a safe and effective adjunct to liver biopsy protocols.