3|DISCUSSION
Many complications such as deice embolization, erosion, bleeding, arrhythmias, infection, air embolism and thromboembolism have been reported in previous studies [2,3], embolization has the highest incidence rate among all complications.The major time of embolization is reported in the first 24h, and the most common sites are the main or branched pulmonary artery and atrioventricular valve, rarely migrate to the left side.However, several weeks or months after deployment, because of endothelialization, device is firmly fixed in the tissue, there is little chance for device to migrate. On the other hand, once these devices of endothelial happen to migrate, retrieving the embolization percutaneously is hard and dangerous. Surgical retrieval could be selected and done with less risks and better results when failing or hard to retrieve percutaneously. Techniques such as direct retrieval and using two forceps to fold the device have been reported [4]. In this case, we performed a safe procedure to retrieve the migrated device by deploying from a sheath (Figure 3), which could minimize valve and conduction system complications.