”Residual shunts” are commonly seen in patients “after septal/atrial septal defect repair,” “after arterial catheterization,” or “after other complex precordial disease containing The residual shunt is common in patients with “ventricular septal/atrial septal defect repair,” “arterial catheter ligation,” or “other complex precordial disease with ventricular defect and repair. According to the literature, the incidence of re-leakage of the patched “hole” is about 5%. The main reasons are as follows: 1, multiple ventricular defects are often combined with several defects, sometimes it is difficult to completely expose the defect during surgery, only part of the defect is sutured during surgery, there are still some residual. 2, suture avulsion occurs more frequently in the repair of large ventricular defects. In order to prevent the normal tissues around the defect, especially the conduction system of the heart, the sutures can only be placed in the superficial layer of the defect during repair. 3. Incomplete repair mostly occurs in small ventricular defects, especially in patients with pseudoventricular wall tumor formation, where the opening appears to be small but the base is large, and residual shunts often occur after surgery if only the opening is sutured closed. (Pseudoventricular wall tumor means that the opening of ventricular defect is larger, and with the continuous impact of blood flow, the fibrous tissue at the edge of the defect proliferates and forms a tumor-like protrusion, and the opening looks smaller but actually has a larger base.) 4.Infection occurs in children with congenital heart disease after surgery, such as bacterial endocarditis, and once infection occurs around the patch after surgery, the sutures often tear off at the suture, causing partial residual shunt. 5. The residual shunt after arterial catheterization is due to the fragility of the catheter tissue, which may lead to a small amount of residual in the center of the lumen due to excessive force during the ligation. Or the lumen may reopen after ligation. The clinical manifestations of residual shunts after ventricular septal surgery include an increased heart rate and a change in the nature of the murmur. The presence of a residual shunt is diagnosed by cardiac ultrasound or cardiac catheterization. A small number of residual shunts (3 mm) usually do not require surgical management and will close spontaneously in more than 50% of patients after six months. A small percentage of patients fail to close on their own and are generally not treated if they are not enlarged. Residual defects with larger shunts or increasing residual shunts often require reoperative treatment.