B0536 - EUS-Guided Shear Wave Elastography Appears to Be More Accurate Than Transient Elastography in Predicting Liver Fibrosis Staging in Patients With Obesity

Thomas Wang, MD¹, Picahmol Jirapinyo, MD, MPH¹, Kanwal Bains, MBBS², Kimberly F. Schuster, BA³, Marvin Ryou, MD^4
1Brigham and Women's Hospital, Boston, MA; ²Brigham and Women’s Hospital, Boston, MA; ³Tufts University School of Medicine, Boston, MA; ⁴Brigham & Women's Hospital, Boston, MA

Introduction: Transient elastography (TE) is a non-invasive clinical tool used to assess liver stiffness measurement (LSM) and can be correlated to liver fibrosis staging. Obesity can make elastography challenging to perform due to increased abdominal wall thickness, with high failure rates for TE. Fibroscan XL probes have lower failure rates, though it is unclear if readings are reliable or correlate well with liver biopsies. EUS guided shear wave elastography (EUS-SWE) can potentially circumvent this limitation, as liver parenchyma via EUS can be visualized under a thin subcentimeter gastric or duodenal wall, which does not change appreciably with body habitus. We aim to determine whether TE or EUS-SWE correlate better with liver biopsy fibrosis staging for patients with obesity.

Methods: A retrospective chart review was performed for patients with obesity at a single tertiary hospital from Dec 2021 to May 2022. Patients with obesity (BMI≥30) with LSM concerning for advanced fibrosis (F3 or F4) were referred for EUS-SWE and EUS guided liver biopsy, both of which performed in the left liver lobe. LSM (reported in kPa) were correlated with fibrosis staging on liver biopsy and were considered accurate if they fell within cutoff ranges: kPa ≤7 = F0-1, kPa 7-8 = F2, kPa 8-12 = F3, and kPa >12 = F4. No established cutoffs exist for EUS-SWE, so stiffness values were compared to that for TE on which were closer to TE cutoff ranges.

Results: 12 consecutive patients with obesity underwent TE, EUS-SWE, and EUS guided liver biopsy. The mean age was 55.3 [range 18-69], 9 (75%) were females, and mean BMI was 44.9 [range 30.2-67.8]. LSM ranged from 9.1 to 41.9 kPa. Only 2 (17%) patients’ TE results correlated accurately with liver fibrosis staging on biopsy; see Table 1. Assuming similar fibrosis staging cutoff ranges for TE, EUS-SWE accurately downgraded 8 (67%) patients and demonstrated no change for 4 (33%) patients. EUS-SWE was closer to biopsy LSM cutoffs for 9 (75%) patients, while TE was more accurate in only 1 (8%) patient.

Discussion: In this small cohort of patients with obesity with possible advanced fibrosis, TE appeared to overdiagnose fibrosis stage, while EUS-SWE appeared to downgrade LSM appropriately for patients who were overdiagnosed. Larger cohort studies are ongoing to allow proper interpretation of EUS-SWE stiffness values and compare its utility and accuracy to TE.



Disclosures:


Thomas Wang, MD¹, Picahmol Jirapinyo, MD, MPH¹, Kanwal Bains, MBBS², Kimberly F. Schuster, BA³, Marvin Ryou, MD⁴. B0536 - EUS-Guided Shear Wave Elastography Appears to Be More Accurate Than Transient Elastography in Predicting Liver Fibrosis Staging in Patients With Obesity, ACG 2022 Annual Scientific Meeting Abstracts. Charlotte, NC: American College of Gastroenterology.