Atrial septal defect (ASD) is a relatively common type of congenital heart disease (CHD), and its incidence accounts for about 10% of pediatric CHD; secondary foramen ovale ASD is the most common type. Transcatheter interventions for secondary orifice ASD have become increasingly sophisticated, and with the improvement of interventional techniques for congenital heart disease, many special types of ASD (e.g., giant ASD, short stump ASD, multiforaminal ASD, ASD with atrial septal tumors, and ASD combined with other cardiac malformations) have been treated by interventional methods. In this paper, we summarize our experience with transcatheter interventions for the treatment of specific types of pediatric atrial septal defects in our department from November 1998 to December 2009. Data and methods From November 1998 to December 2009, 390 cases of secondary foramen ASD were treated with the double-disc umbrella ASD blocker, of which 88 cases were special types of ASD, namely 24 cases of multiple ASD (with 2 cases of atrial septal tumor) and 64 cases of short stump ASD. Among them, 39 cases were male and 49 cases were female (male:female 1:1.25); age ranged from 3 to 18 years old, mean (7.3±4.4) years old; body mass ranged from 10 to 70 kg, mean (26.5±14.4) kg. Diagnostic criteria 1. Multiple ASD: It refers to the coexistence of 2 or more secondary orifice type ASDs at the same time. 2.Short residual margin ASD: The guidelines for interventional treatment of precardiac disease stipulate that the indications for interventional treatment of ASD are: ASD diameter 5 to 36 mm, distance from the edge of ASD to the coronary sinus, upper and lower vena cava and pulmonary veins ≥ 5 mm, and distance to the atrioventricular valve ≥ 7 mm. Short residual edge ASD. Preoperative ECG was normal in 46 cases, complete and incomplete right bundle branch block in 36 cases, right ventricular hypertrophy in 4 cases, I0 AV block in 1 case, and frequent ventricular anterior contraction in 1 case. Cardiac image C/T 0.38-0.65 mean (0.51±0.05). All cases in this group were examined by transthoracic echocardiography, one case by intraoperative esophageal ultrasound, one case by intracardiac ultrasound, and four cases by balloon measurement. The upper and lower, anterior and posterior diameters of the ASD and the anatomical relationship between the ASD and the surrounding tissues were measured by transthoracic ultrasound in multiple views to determine the number of ASDs and the distance between each defect. Intraoperative transcatheter measurement of main pulmonary artery pressure (systolic/diastolic) (22.7±8.6)/(15.6±5.2) mmHg (1 mmHg=0.133 kpa), mean pressure (17.2±5.9) mmHg; Qp/Qs (2.5±1.4):1, whole lung resistance 194.8 dyn.s.cm-5. All children underwent detailed preoperative All children underwent a detailed preoperative interview, with full explanation of the interventional procedure, surgical risks and complications, and the family signed informed consent before the procedure was scheduled. The procedure was performed under local or basic anesthesia, or general anesthesia if intraoperative esophageal ultrasound was used. The right femoral vein was punctured for right heart catheterization, pulmonary artery pressure was measured, and pulmonary-to-body flow ratio and pulmonary circulation resistance were calculated. Heparin 100 U/kg was pushed intravenously, and a 0.035-inch diameter wire 260 cm long was sent through interatrial traffic to the left upper pulmonary vein. The blocker was selected according to the diameter, number and location of ASDs measured by transthoracic ultrasound with reference to the general blocker >; 1 to 2 mm in diameter measured by thoracic ultrasound, or 4 to 5 mm larger if there was no interatrial septal margin between it and the aortic root. Choose one blocker to close multiple defects. If 2 blockers are needed, place the smaller blocker first and then the larger one. After ultrasound and fluoroscopy confirmed that the blocker was properly positioned, the left-to-right shunt of the ASD disappeared, the mitral, tricuspid and aortic valve motion was normal, and the coronary sinus and pulmonary vein flow were normal, the blocker was released, the sheath was withdrawn, and pressure bandages were applied. Postoperatively, heparin was anticoagulated twice at 0.5 mg/time, oral aspirin was given for 6 months, pediatric dose 3-5 mg/(kg.d), antibiotics were routinely given to prevent infection for 3 d. Echocardiogram and ECG were reviewed within 3 d after surgery, 1, 3 and 6 months. Results 1. Multiple ASD: 24 cases of multiple ASD, including 17 cases with 2 defects, 4 cases with 3 defects, 3 cases with sieve-like holes, and 2 cases with combined atrial septal bulging tumors. 24 cases were successfully blocked, 23 cases were successfully closed with one blocker, the average diameter of ASD was (15.3±5.3) mm, the diameter of the selected blocker was (16.8±4.9) mm, and 1 case (the distance between the 2 defective holes The distance between the 2 defect holes was 10 mm) was blocked with 2 blockers of 14 mm and 10 mm, respectively. The immediate effect of surgery was 91.7% complete blockage rate of multiple ASDs; (22/24), except for a small amount of left-to-right shunt in 2 patients, the atrial level shunt disappeared completely in the rest; during the follow-up period of 6 months to 4 years, the residual shunt disappeared in 1 case at 6 months, and a trace residual shunt still existed in 1 case, but the size of the heart chamber returned to normal without other complications. 2. Short residual ASD: In 64 children, 60 cases (92.3%;) had defective aortic margins less than 5(3.0 soil 1.0) mm in diameter, of which 56 cases (87.5%;) had only defective aortic margins less than 3 mm in diameter alone, 3 cases had combined inferior vena cava margins less than 3 mm, 1 case had combined superior vena cava margins less than 4(3.0 soil 0.7) mm in diameter; 4 cases had only defective superior vena cava margins less than 5 mm in diameter alone. The maximum diameter of the preoperative defect ranged from 6 to 26 mm, with a mean of (12.7±5.2) mm. The size of the applied occluders ranged from 12 to 32 mm, with a mean of (17±5) mm. 61 cases were occluded with a single umbrella, and 3 cases failed (children with insufficient aortic and inferior vena cava margins), with a success rate of 95.3%; (61/64); 5 cases were placed twice successfully, and the rest were placed once. The immediate results of the procedure were 98.4% complete occlusion rate; (60/61), and 1 case (1.6%;) had a small residual shunt. One case (1.6%;) in the group with short residual margins on echocardiographic review 3 d after surgery had a slight to small amount of residual shunt, and on review at 6 months, the residual shunt had not disappeared. Discussion Since the introduction of Amplatzer ASD blocker in 1997, it has been widely used in clinical practice because of its easy operation, good safety and wide application. With the improvement of interventional techniques for precardiac disease, many special types of ASD (such as giant ASD, short stump ASD, porous ASD, ASD with atrial septal tumor and ASD combined with other cardiac malformations) can also be treated by interventional methods. In this group of cases, mainly pediatric cases were selected for analysis. For the interventional treatment of multiple ASDs, it has been reported in foreign literature that there are generally several defects and several blockers are applied to close them. However, combining with some domestic experiences, we have learned that there are some disadvantages in placing blockers according to the number of defects in children with multiple ASDs: 1. The septal tissue is very thin, and placing multiple blockers can easily cause overloading of the septum, making it angularly deformed and affecting the atrial function and conduction tissue; 2. The economic burden caused by multiple blockers is too high. According to our preliminary clinical experience, intraoperative echocardiography is used to clarify the diagnosis, determine the number and diameter of ASDs and the spacing of each defect; try to choose one blocker to close multiple defects. When establishing a track through the interatrial septum, the larger ASD should be selected for passage. The compression of the blocker waist on the surrounding interatrial septum, together with the coverage of the blocker umbrella, can make both large and small ASDs free of shunts; even if a small amount of residual shunts still exist immediately after surgery, most of them can disappear in the course of follow-up. ASD, two or more ASD blockers should be placed separately. Our experience is that for multiple ASDs with a spacing of ≥8-10 mm, it is more appropriate to choose 2 blockers to close the ASDs separately, and ultrasound monitoring and guidance are required to place the smaller blocker first and the larger blocker later. More than 2 blockers are not suitable for pediatric atrial septal defects. The vast majority of short stump ASDs are characterized by a lack of or insufficient stumps at the anterior margin of the defect. Our experience in this group of children is that if the atrial apex margin is absent in the four-chamber cardiac view and the aortic side stump is also absent in the short-axis view of the aorta, surgical repair is often required. The success of occlusion of the anterior aortic margin alone without a stump or with a short stump is high. In the three cases of failed occlusion, there were short and soft posterior inferior margins, and in two cases, the occluder slipped to the right atrium and then retracted. The reasons considered were soft septal tissue in children, short and soft posterior inferior margins, and poor support for the occluder, as well as the weight of the large occluder itself, leading to the failed occlusion. The subxiphoid section of the two atrial hearts and inferior vena cava can show the distance of the ASD margin from the inferior vena cava, determine the upper and lower ASD diameters, and show the whole picture of the ASD, which is helpful for indications and blocker selection. In children with short and soft margins, the left atrial disc always slides from the ASD margin to the right atrium or rides over the septum during routine operation, making it difficult to place the blocker. In addition, the left atrium is usually small when the ASD is large, which makes it difficult to open the left atrial disc completely, so the pulmonary vein release method can be tried at this time. The left atrial disc is gently extended in the left superior pulmonary vein but before it is fully opened, the right atrial disc is rapidly opened in the right atrium, and at the same time the left atrial disc is automatically rebounded and rapidly formed in the left atrium due to gravity and pulling action, and the double discs are simultaneously clamped in the housing interval and the ASD is successfully blocked. The left atrial disc should not remain in the pulmonary vein for too long, and it is best to control the time when the right atrial disc is opened in the right atrium, and the left atrial disc is automatically rebounded by gravity or can be slid down and the right atrial disc is opened from the left and right side almost simultaneously by gentle shaking. In the fluoroscopic position, observe whether the blocker is formed satisfactorily and make a blocker shake test to observe whether the position is appropriate and firm before releasing the umbrella. The pulmonary vein method of releasing the ASD umbrella is not a routine operation and requires a physician with certain experience and skills to attempt it. From the results of domestic follow-up, compared with the group with adequate margins of ASD, patients in the group with inadequate ASD margins had a large preoperative defect of maximum diameter and a lower rate of complete occlusion immediately after surgery, but the effect of occlusion was exactly the same at 3d and 6-month review. In conclusion, the technical requirements for interventional treatment of pediatric special types of ASD are high, and its interventional treatment is safe and feasible under the premise of strictly grasping the indications.