EUS Shear Wave Measurement for Early Chronic Pancreatitis: A Retrospective Diagnostic Accuracy Study Using the 2019 JPS Criteria

<b>Background/Objectives:</b> Diagnosis of early chronic pancreatitis (eCP) is important to prevent progression to established CP. Endoscopic ultrasonography (EUS) plays an important role in diagnosis; however, it is still difficult and has drawbacks in its inability to assess progression. EUS shear wave measurement (EUS-SWM) has been established to be a precise method for evaluating stiffness and the degree of fibrosis. This study aimed to evaluate the utility of EUS-SWM in eCP findings. <b>Method:</b> This study was retrospective, single center, and identified the 2019 Japan Pancreas Society (JPS) eCP criteria as the reference standard. We evaluated 38 patients who underwent EUS-SWM between April and November 2022. Patients were classified into positive EUS findings based on the JPS criteria for less than 2 (non-eCP finding group) and 2 or more (eCP finding group). The EUS-SWM value was compared between these groups and the relationship was analyzed with EUS findings. <b>Result:</b> Eleven of thirty-eight patients had eCP findings. The EUS-SWM value is significantly higher in the eCP finding group (2.39 ± 0.54 vs. 1.84 ± 0.46, <i>p</i> = 0.0065), and the EUS-SWM value is positively correlated with the number of positive EUS findings (r = 0.62, <i>p</i> < 0.001). The area under the receiver operating characteristic curve for EUS-SWM to distinguish the eCP finding group was 0.78 (0.62-0.95). The cut-off value of 1.87 showed sensitivity and specificity of 90.9% and 63.0%, respectively. <b>Conclusions:</b> EUS-SWM values correlate with EUS findings in eCP and may serve as an objective biomarker for disease progression.