Diagnostic Performance of 2D Shear Wave (2D-SWE) for Liver Fibrosis in Adults Undergoing Bariatric Surgery

Background: Among the most recent methods to diagnose liver fibrosis is 2D shear wave elastography (2D-SWE). However, the evidence in the Latin population is limited, and there is no consensus on the cutoff points for each stage of fibrosis. Aim: To evaluate the diagnostic performance of 2D-SWE for liver fibrosis in adults with obesity who underwent bariatric surgery (BS). Methods: We conducted a cross-sectional study on patients with obesity who underwent BS between 2020 and 2021. Liver stiffness measurement was reported as the mean of valid measurements in kilopascals made with the 2D-SWE. The outcome was biopsy-proven liver fibrosis. ROC curves were constructed for significant fibrosis (F≥2) and advanced fibrosis (F≥3), with their respective area under the curve (AUC). To obtain the best cutoff point for each scenario, we used the Youden index. The 95% confidence intervals (95% CI) for each cutoff point were estimated by bootstrap with 1000 replications. Results: We analyzed data from 227 patients. The mean age was 37.8 ± 11.1 years and 65.2% were women. Overall, the AUC for significant and advanced fibrosis was 0.54 (95% CI: 0.47–0.62) and 0.73 (95% CI: 0.60–0.87), respectively. For advanced fibrosis, higher AUCs were found among women (AUC: 0.82; 95% CI: 0.59–1.00) and among patients with morbid obesity (AUC: 0.78; 95% CI: 0.61–0.99). Conclusion: The 2D-SWE appears to be a valuable tool for screening advanced liver fibrosis in candidates for BS, mainly in the female population and in adults with morbid obesity. Graphical Abstract: [Figure not available: see fulltext.]