Abstract Introduction:LAmbre device was rarely reported to get dislocated during the procedure and it can be deliberately recaptured, completely retrieved and re-deployed.A LAmbre device trapped in the mitral valve is infrequent and which can hardly be recaptured by percutaneous retrieval. Methods：We reported a planted LAmbre device(Lifetech Scientific Corp.) that was dislocated during the procedure of Left Atrial Appendage Occlusion.The patient’s hemodynamic parameters suddenly changed while we withdrew the delivery sheath.The fluoroscopy and TEE showed that the device was detached from the landing zone and closed to the mitral valve. Result:We attempted percutaneous retrieval but failed and the device was subsequently recapatured by a cardiovascular surgery. Conclusion:We should make sure the occluder in the optimal position and operate prudently to avoid device migration or detachment.If the device locates in the mitral valve or LV and causes hemodynamic changes,a surgery should be performed as quickly as possible to retrieve the implant.