Risk factors for bleeding after liver biopsy

Abstract

Objective: Determine factors that increase the risk of bleeding after liver biopsy.

Methods: Retrospective review of radiology and clinical databases from Jan 2008 to Jun 2014 revealed 847 patients with liver biopsy. Of these, 154 (group I) had targeted biopsy of focal lesion and 142 (group 2) had random core biopsy for diffuse liver disease. The rest of the patients were excluded due to insufficient post-biopsy data. Data including pre-biopsy laboratory results, history of transfusion, and biopsy complications were recorded in the study cohort. After review of initial results, a "Risk Score" for bleeding was created using platelet count, INR, estimated glomerular filtration rate (eGFR), and suspicion of malignancy. Zero point was given for normal laboratory results or absence of malignancy. One point was given for mildly abnormal laboratory values or presence of malignancy. Severe biochemical abnormalities, e.g., INR > 2.0, eGFR < 30 mL/min, or platelet count ≤ 50 × 10(9)/L were given two points each. The "Risk Score" was made of adding individual points.

Results: Of 847 patients queried by retrospective database search, 296 had adequate records for the period of 2 weeks prior to biopsy to 4 weeks after biopsy. The remaining patients had liver biopsy as outpatients and probably did not have bleeding complications but no electronic records were found to confirm this. 25 (8.4%) of 296 patients had post-biopsy bleeding, with incidences of 11.7% and 4.9% in groups 1 and 2 (p = 0.04). On logistic regression analysis, the only significant predictor of bleeding was the "Risk Score" (p = 0.01, odds ratio 4.6). There was substantial overlap in INR, and platelet count in bleeders vs. non-bleeders. Pre-biopsy fresh frozen plasma or platelet concentrate infusions did not reduce the risk of bleeding.

Conclusion: INR and platelet count are not an independent risk factors for post-biopsy bleeding. A "Risk Score" made up of individual risk factors was a better predictor of bleeding.

Keywords: Estimated GFR; Hemorrhage; INR; Liver biopsy; Platelet count.