Bleeding complications after percutaneous liver biopsy: Do subcapsular lesions pose a higher risk?

OBJECTIVE. The purpose of this study is to determine the incidence of moderate and severe bleeding complications after subcapsular liver mass biopsy and compare it with the incidences of such complications after nonsubcapsular liver mass biopsy and after random biopsy. MATERIALS AND METHODS. This retrospective review of ultrasound-guided liver biopsies was performed between January 2006 and February 2015. Biopsy type, needle size, the number of needle passes, and mass size and depth were recorded. A mass was categorized as subcapsular if it abutted the capsule and if the needle entered the mass directly without first traversing normal liver. Patients were observed postprocedurally, and the electronic medical record and findings from imaging performed within 1 month of the procedure were reviewed to assess for bleeding. Bleeding complications were categorized by size (with mild bleeding denoted by perihepatic blood ≤ 2 cm thick; moderate bleeding denoted by perihepatic blood > 2 cm thick, observation of blood elsewhere in the upper abdomen, or a combination of both findings; and severe bleeding denoted by blood extending into the lower abdomen, pelvis, or both). Bleeding rates were compared between groups using the Fisher exact test. RESULTS. Of a total of 1876 biopsies, 347 (18.5%) involved subcapsular masses, 760 (40.5%) involved nonsubcapsular masses, and 769 (41.0%) were random biopsies. There were no significant differences in biopsy type (p = 1.00), needle size (p = 0.12), or the number of needle passes (p = 0.10) when subcapsular and nonsubcapsular masses were compared. Thirteen moderate or severe bleeding complications (0.69%) occurred overall. The bleeding rate after subcapsular mass biopsy (3/347; 0.86%) was not statistically different from that noted after nonsubcapsular mass biopsy (5/760; 0.66%) (p = 0.71) or after random biopsy (5/769; 0.65%) (p = 0.71). CONCLUSION. Moderate and severe bleeding complications are rare after subcapsular liver mass biopsy, and their incidence is not significantly higher than that noted after nonsubcapsular mass biopsy or random biopsy. Biopsy of subcapsular lesions should no longer be considered contraindicated.