Abstract
This letter presents a critical analysis of the study by Zhao et al, which proposed a therapeutic strategy for difficult common bile duct stones focusing on the "ice-breaking sign" as a pivotal radiological feature. Based on magnetic resonance cholangiopancreatography with three-dimensional reconstruction, the diagnostic criteria for this sign were established by identifying an abrupt narrowing at the distal bile duct caused by impacted stones, analogous to the morphology of an ice-breaking vessel. Specifically, the proximal bile duct (hepatic hilar side) exhibited significant dilatation upstream of the stenosis, while the distal segment (duodenal papillary side) presented with stricture or occlusion. This study was the first to introduce the radiological marker termed the "ice-breaking sign", providing a novel dimension for the evaluation of refractory common bile duct stones. However, notable limitations were also present in this study. The interpretation of the ice-breaking sign depended largely on subjective assessments by physicians, even though a multidisciplinary consensus approach was employed. Objective quantification criteria, such as specific thresholds for the degree of stenosis, were not established. Furthermore, being a single-center study, it might have influenced the reproducibility of findings across different centers. Future studies should explore the pathophysiological mechanisms of the "ice-breaking sign" in greater depth, increase the sample size, and conduct multicenter research to validate its clinical universality and guiding significance for treatment strategies.