Device selection
Final operation plan of PmVSD was chosen according to the TEE results of the patient after anesthesia in the operating room (Fig. 3A). The size, location, morphology, and surrounding tissue of PmVSD were comprehensively evaluated. For PmVSD with AMS, the diameter, number and direction of the defect in the AMS and the distance between the defects were seriously analyzed. Simultaneously, the left ventricular side diameter of AMS was carefully measured. A proper concentric occluder device size was chosen according to the diameter of the VSD by TEE measure. Usually, the waist sizes of devices were 0.5-1.5 mm larger than the VSD maximum diameters. For the patients who had multistream (more than or equal to 2) PmVSDs in the AMS, the occluder was selected according to the specific circumstances such as the multistream maximum distance and the left ventricular side diameter of AMS.