Endoscopic Ultrasound Guided Liver Biopsy Is Effective and Safe in Patients After Liver Transplant

Introduction: Endoscopic ultrasound guided liver biopsy (EUS-LB) is effective and safe for liver parenchymal sampling, however no data are available in post-orthotropic liver transplantation (OLT) patients. In this series we aimed to examine efficacy and safety of EUS-LB in post-OLT patients. Methods: All patients who had a history of OLT and who underwent EUS-LB at a single tertiary academic medical center were identified. The majority were performed by 1 advanced endoscopist using a 19G fork-tipped biopsy needle and multiple actuations per pass, mostly left lobe only. The pathology was re- reviewed by 1 hepatopathologist for total specimen length (TSL), number of complete portal triads (CPTs, specimen fragmentation), and final pathologic diagnosis. Sample adequacy was assessed using guidelines from the American Association for the Study of Liver Diseases (AASLD) which included TSL ≥ 30mm and CPTs ≥ 11 (Table 1). Results: 31 specimens were identified and included. The median number of passes was 2 (range 1-5). The median TSL was 36.6mm (range 10.6mm-74.6mm) and median CPTs were 17 (range 1-63). When the 1-pass specimens were excluded, median TSL was 39.8mm and median CPTs were 19. Of the specimens analyzed, 26 (83.8%) met the AASLD recommended metric for TSL and 22 (70.9%) met the AASLD recommended metric for number of CPTs. All but 1 (97%) of the specimens were fragmented; 28 (90.3%) yielded a pathologic diagnosis with the most common diagnoses being indeterminate for acute cellular rejection, acute cellular rejection, and chronic rejection. The 3 specimens that did not yield a pathologic diagnosis were those with the least TSL (≤15mm) and least number of CPTs (≤5). TSL and number of CPTs was closely correlated (R2=0.81). One serious adverse event (3.2%) (intra-luminal gastrointestinal bleeding) occurred. Conclusion: EUS-LB appears effective and safe in post-OLT patients. Most specimens were deemed adequate by AASLD criteria and led to a pathologic diagnosis. Our series suggests that at least 2 passes are necessary to optimize specimen adequacy when using the multi-actuation technique. The key factor in obtaining adequate tissue for diagnostic interpretation is TSL. Specimen fragmentation may be caused by the multi-actuation technique and/or the use of a “dry” slow-pull as opposed to wet suction. Table 1. - Specimen Characteristics Specimen Number of passes TSL (mm) CPTs Pathologic diagnosis 1 2 37.1 30 ACR 2 1 29.2 15 ICR 3 2 16.6 5 ACR 4 2 40.3 8 CR 5 3 61.2 34 ACR 6 2 39.1 21 ICR 7 2 51.3 43 ACR 8 3 10.6 3 ND 9 2 29.7 8 ACR 10 2 17 11 ICR 11 2 28.4 15 ACR/CR 12 2 46.7 20 ACR/CR 13 5 69.2 23 OTH 14 2 38.2 20 ICR 15 2 45 34 ICR 16 1 32.1 22 ACR 17 3 36.6 14 ICR 18 1 12.3 5 ND 19 2 20.9 8 ICR 20 2 28.3 9 ICR 21 1 13.9 1 ND 22 2 39 22 ICR 23 2 60.5 63 ACR 24 2 35.9 31 ACR/CR 25 2 50 15 ICR 26 2 59.2 17 ICR 27 2 74.6 23 ICR 28 2 25.2 6 CR 29 2 25.5 12 CR 30 2 30.1 19 ICR 31 2 58 47 ACR Average 2 37.5 19.5 Median 2 36.6 17 ACR=Acute Cellular Rejection, ICR=Indeterminate for Cellular Rejection, CR=Chronic Rejection, ND=Non-diagnostic, OTH=Other.