Validation of Shear Wave Elastography as a Non Invasive Procedure to Detect and Grade Oesophageal Varices in Chronic Liver Disease: A Cross-sectional Study

Introduction: Chronic Liver Disease (CLD) is characterised by progressive liver dysfunction. The most serious consequence of CLD is portal hypertension, which can lead to ascites, Gastroesophageal Varices (GEV) and hepatic encephalopathy. Of these, the development of GEV is a major complication. Given the high mortality associated with variceal bleeding, screening for GEV is recommended for all patients with diagnosed CLD. Shear Wave Elastography (SWE) is a novel imaging modality that can measure Liver Stiffness (LS) and Splenic Stiffness (SS) in real time. Most studies have assessed Transient Elastography (TE) and Acoustic Radiation Force Impulse (ARFI); however, only a few have evaluated SWE. Moreover, appropriate cut-off values to categorise the severity of varices are not available for liver. Aim: To evaluate SWE as a non invasive method to detect and grade Oesophageal Varices (EV) in CLD. Materials and Methods: A cross-sectional study was conducted in the Department of Gastroenterology at Believers Church Medical College Hospital, Thiruvalla, Kerala, India, from April 2023 to March 2024. All individuals aged 18 years or older, of any gender, with diagnosed CLD of any aetiology who consented to participate were eligible. The diagnosis of CLD was based on clinical, biochemical and radiological features. The study evaluated the role of SWE in conjunction with endoscopy in CLD and assessed variables such as age, Body Mass Index (BMI), aetiology and the grading of EV. The study estimated SWE’s ability to demonstrate associations between LS and SS with the presence and severity of EV. Sensitivity, specificity, Positive Predictive Value (PPV) and Negative Predictive Value (NPV) were calculated for validation of SWE. To assess SWE, Receiver Operating Characteristics (ROC) curves were plotted and optimal cut-off values were estimated using Youden’s index. Results: Of 96 patients evaluated, 76% were male, with a mean age of 45±13.42 years. Alcoholic cirrhosis emerged as the most prevalent aetiology, accounting for 54 (56.25%) cases. EV was detected in 59 patients (61.46%). The area under the ROC curve (AUC) values were 0.855 for Liver Stiffness, measurement (LSM) and 0.938 for Splenic Stiffness Measurement (SSM). LSM had a specificity of 97.03%, while SSM had a sensitivity of 91.5% and a specificity of 91.9%, indicating that SWE offers robust diagnostic capability for detecting and grading EV. Conclusion: The study underscores the clinical significance of SWE as a non invasive tool for assessing and grading EV in CLD.