The currently clinically used precordial interventional occluders are woven with high quality Nitinol alloy wire, which has good shape memory and biocompatibility, and should be delivered in a sheath to ensure precise placement and enable flexible positioning and retrieval. The middle is fitted with ePTFE flow-blocking membrane, which has a very small pore size and can directly block the blood flow, with good biocompatibility, immediate blockage, good results and low incidence of long-term residuals. The epithelial cells can completely cover the blocker 3 months after its placement to achieve a permanent cure. The current study found that this material is biocompatible and has no adverse reaction with human body. Li Fuhai, Department of Pediatric Internal Medicine, Qilu Hospital, Shandong University