S2298 Adequacy of Endoscopic Ultrasound-Guided Liver Biopsy Specimens: Experience from a New Endohepatology Program

Introduction: Histologic assessment of liver parenchyma is essential for the diagnosis of many liver diseases. Endoscopic ultrasound guided liver biopsy (EUS-LB) is an emerging method which can provide adequate tissue for diagnosis, provide portal pressure measurements, and can be performed at time of endoscopy for any other indication. Here we aim to compare the quality of specimens from EUS-LB with transjugular liver biopsy (TJ-LB) and percutaneous liver biopsy (PC-LB) specimens in the first year of an academic endohepatology program. Methods: Retrospective review of pathology slides from patients who had EUS-LB (n = 18), TJ-LB (n = 12), and PC-LB (n = 18) at a single center from 2023-2024 were compared a single pathologist. All EUS-LB were performed by one advanced endoscopist trained by an expert endohepatologist at an external institution. TJ and PC-LB were performed by multiple interventional radiologists. The primary outcome was the percentage of patients with adequate samples obtained, defined as >11 portal tracts. Secondary outcomes included number of complete portal tracts, total specimen length, longest fragment length, number of complete portal tracts, percentage of patients with histologic diagnosis, and tissue fragmentation. Results: The EUS, TJ, and PC liver biopsies yielded a histologic diagnosis in 100% patients. 100% of EUS-LB were adequate tissue samples which was not significantly different from TJ-LB where 91.7% adequate tissue samples were obtained, but was significantly higher than PC-LB (p 0.03) group where 77.8% of the tissue samples were adequate. Mean total specimen length of EUS-LB was 4.7 cm which is significantly longer than TJ-LB samples with a mean length of 3.1 cm (P < 0.01) and PC-LB samples with a mean length of 1.8 cm (P < 0.01). EUS-LB yielded significantly higher number of complete portal tracts (mean 45.9) compared to TJ-LB (mean 23.3, P < 0.01) and PC-LB (mean 17.2, P < 0.01). In terms of fragmentation 88.9% of EUS-LB were fragmented which is similar to 83.3% of TJ-LB (P 0.66) and significantly more than 5.6% of PC-LB (P < 0.01). Conclusion: From this single center retrospective review we can conclude that EUS-LB is able to provide adequate tissue samples for evaluation and diagnosis. In comparison with TJ-LB and PC-LB, EUS-LB has a significantly greater number of complete portal tracts, longer total specimen length, and longer fragment lengths. EUS-LB did have significantly more fragmentation compared to PC-LB but similar fragmentation compared to TJ-LB.