Accuracy of non-invasive liver stiffness measurement and steatosis quantification in patients with severe and morbid obesity

Magdalena Eilenberg; Petra Munda; Judith Stift; Felix B Langer; Gerhard Prager; Michael Trauner; Katharina Staufer

doi:10.21037/hbsn-20-787

Accuracy of non-invasive liver stiffness measurement and steatosis quantification in patients with severe and morbid obesity

Hepatobiliary Surg Nutr. 2021 Oct;10(5):610-622. doi: 10.21037/hbsn-20-787.

Authors

Magdalena Eilenberg^{1

2}, Petra Munda³, Judith Stift⁴, Felix B Langer¹, Gerhard Prager¹, Michael Trauner³, Katharina Staufer^{2

3

5}

Affiliations

¹ Division of General Surgery, Department of Surgery, Medical University of Vienna, Vienna, Austria.
² Department of Visceral Surgery and Medicine, Inselspital, University Hospital Bern, Bern, Switzerland.
³ Division of Gastroenterology & Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria.
⁴ Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria.
⁵ Division of Transplantation, Department of Surgery, Medical University of Vienna, Vienna, Austria.

Abstract

Background: Vibration controlled transient elastography (VCTE) and controlled attenuation parameter (CAP™) have shown reliable performance predicting fibrosis and steatosis in normal- to overweight patients but have not been validated in severe to morbid obesity. This study aimed at determining the accuracy of VCTE, CAP™ and the composite score FibroScan-AST (FAST) in patients with a body mass index (BMI) of ≥35 kg/m².

Methods: Patients scheduled for bariatric-metabolic surgery underwent preoperative VCTE/CAP™ measurement, and intraoperative liver biopsy. The feasibility and accuracy of VCTE, CAP™ and the composite score FAST were retrospectively analysed to evaluate fibrosis, steatosis and active fibrotic non-alcoholic steatohepatitis [NASH + non-alcoholic fatty liver disease (NAFLD) activity score ≥4 + fibrosis grade ≥2] using per protocol (PP) and intent to diagnose (ITD) calculation.

Results: In total, 170 patients (median BMI 44.4 kg/m²) were included in the study. Liver biopsy showed NASH, simple steatosis, and normal livers in 60.6% (n=103), 28.8% (n=49), and 10.6% (n=18), respectively. VCTE and CAP™ delivered reliable results in 90.6% (n=154/170) and 90.5% (n=134/148). The AUC (PP) of VCTE, CAP™, and FAST were 0.687 (≥F2), 0.786 (≥F3), 0.703 (≥S2), 0.738 (S3), and 0.780 (active fibrotic NASH). The AUC increased to 0.742 (≥F2), 0.842 (≥F3), 0.712 (≥S2), 0.780 (S3), and 0.836 (active fibrotic NASH) in patients below the median BMI of 44.4 kg/m².

Conclusions: VCTE, CAP™ and FAST show acceptable accuracy for the detection of fibrosis, steatosis and NASH in a real-life cohort of patients with obesity. Accuracy improves in patients with a BMI <44.4 kg/m².

Keywords: FibroScan-AST score (FAST score); Transient elastography; controlled attenuation parameter (CAP™); non-alcoholic fatty liver disease (NAFLD); obesity.