Perimembranous ventricular septal defects (pmvsds) are

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1 Transcatheter Closure of Congenital Perimembranous Ventricular Septal Defect in Children Using Symmetric Occluders: An 8-Year Multiinstitutional Experience Lei Wang, MD, PhD,* Sancheng Cao, MD, Jun Li, MD,* Lifang Yang, MD,* Yin Liu, MD, Jun Ren, MD, PhD, Qiaomei Ma, MD, Haijian Xing, MD, Dan Li, MD, Danqiu Tian, MD, Yi Wan, MD, PhD, Shiqiang Yu, MD, PhD, Tao Chen, MD, Xiuling Yang, MD, and Jian Yang, MD, PhD Department of Cardiology, Xi an Children Hospital, Departments of Ultrasound Diagnosis and Anesthesiology, Xijing Hospital, Department of Health Statistics, and Xijing Cardiovascular Hospital, Fourth Military Medical University, Xi an, People s Republic of China, Department of Cardiology, Affiliated Hospital of Qinghai Medical University, Xi Ning, People s Republic of China; and College of Health Sciences, University of Wyoming, Laramie, Wyoming Background. Perimembranous ventricular septal defects (pmvsds) are one of the most common forms of congenital cardiac malformation in children. Results of transcatheter pmvsd closure remain debatable, prompting the need for further evaluation with regard to the safety and efficacy of this procedure. The aim of the study was to analyze the safety, efficacy, and long-term follow-up data associated with transcatheter closure of pmvsds in children using symmetric occluders. Methods. From December 2002 to October 2011, 525 children with pmvsds between 2 and 12 years of age underwent transcatheter closure at three major heart centers in northwest China with symmetric pmvsd occluders. All patients were followed up until October 2011 with electrocardiogram and transthoracic echocardiography. Adverse events were recorded and evaluated. Results. There were 252 male and 273 female patients with an average weight of 21.5 kg. The mean age at the time of transcatheter closure was 5.6 years, and the average ratio of pulmonic to systemic blood flow was 2.5. Transcatheter intervention was successfully performed in 502 patients (95.6%). The median device size implanted was 6.5 mm (range, 4 to 18 mm). During a median 45-month follow-up period, no mortality occurred. A total of three major adverse events (0.6%) were reported; two were valve-related. Meanwhile, 104 minor adverse events were detected during the entire follow-up period. All individuals experiencing major adverse events were younger than 3 years of age. The incidence of major adverse events in patients younger than 3 years old was significantly higher than that of patients older than 3 years old (3.75% versus 0.00%; Fisher s exact test p 0.004). Conclusions. Data from the current study suggest that transcatheter pmvsd closure using symmetric occluders displayed an excellent success rate and long-term follow-up results. The transcatheter approach provides a less-invasive alternative to open surgery and displays some promise in the treatment of pmvsds in certain patient populations. (Ann Thorac Surg 2012;94:592 8) 2012 by The Society of Thoracic Surgeons Perimembranous ventricular septal defects (pmvsds) are one of the most common forms of congenital cardiac malformations in children, accounting for up to 40% of all cardiac anomalies [1 4]. During the past decade, transcatheter techniques for closure of pmvsds using the Amplatzer pm- VSD occluder (AGA Medical, Golden Valley, MN) have been developed [5, 6]. Unfortunately, at the present time this technique is not well implemented worldwide because of an unacceptably high rate of postprocedural and late-onset heart block [7, 8]. Based on the design of the Amplatzer pmvsd Accepted for publication March 26, *These authors are equal contributors. Address correspondence to Dr J Yang, Xijing Cardiovascular Hospital, 15 Chang Le West Rd, Xincheng District, Xi an , People s Republic of China; yangjian1212@hotmail.com. device, modified double-disk symmetric devices were introduced in China in 2003, aiming to decrease the high rate of heart block and improve clinical outcomes [9]. However, reports of the indication of transcatheter pmvsd closure using symmetric occluders and its long-term follow-up results in children were rare [10]. In our series, we report on the experience of transcatheter closure of congenital pmvsds in children with a multicenter regional cohort study, discussing the long-term safety and efficacy of the symmetric occluders. Patients and Methods Patients From December 2002 to October 2011, 2,546 children between 2 and 12 years of age with congenital pmvsds were enrolled in three major medical centers in north by The Society of Thoracic Surgeons /$36.00 Published by Elsevier Inc doi: /j.athoracsur

2 Ann Thorac Surg WANG ET AL 2012;94:592 8 TRANSCATHETER VSD CLOSURE IN CHILDREN 593 Table 1. Baseline Characteristics Variable Result (median with range) Patients (n) 525 Sex (F/M) (n/%) 273 (52.0%)/252 (48.0%) Age (y) 5.6 (2 12) Weight (kg) 21.5 ( ) Indications Symptoms (frequent respiratory 136 (25.9%) infections, edema, NYHA functional class II or greater) Hemodynamic changes 385 (73.3%) (cardiomegaly on chest radiograph, left atrial or left ventricular enlargement verified by echocardiography) Previous SBE 4 (0.8%) Echocardiography Subaortic rim (mm) 3.2 ( ) Subtricuspid rim (mm) 5.3 ( ) VSD size (mm) 4.4 ( ) Heart function (NYHA grade) I 477 (90.9%) II 45 (8.6%) III 3 (0.5%) IV 0 LVEDD (mean SD, Z score) LVEDD left ventricular end-diastolic dimension; NYHA New York Heart Association; SBE subacute bacterial endocarditis; SD standard deviation; VSD ventricular septal defect. west China (Xi an Children Hospital and Xijing Hospital, Xi an, and Affiliated Hospital of Qinghai Medical University, Xi Ning). All patients underwent routine examination including chest radiograph, standard 12-lead electrocardiogram, and transthoracic echocardiography (TTE). Transthoracic echocardiography was used for patient selection of transcatheter pmvsd closure. After TTE screening, 525 children were included in this study based on the inclusion and exclusion criteria. There were 252 male patients and 273 female patients with an average weight of 21.5 kg. The average ratio of pulmonic to systemic blood flow was 2.5 (range, 1.7 to 6.8). Demographic and diagnostic data are summarized in Table 1. The median hospital stay was 3.4 days (range, 1 to 18 days). Echocardiographic Assessment The echocardiography inclusion criteria were (1) a congenital pmvsd with the defect located at the 9 to 11 o clock positions of an analog clock in the short-axis parasternal view with left-to-right shunt; (2) a pmvsd diameter of greater than 2 mm and less than 10 mm; (3) a distance of greater than 1 mm from the pmvsd to the aortic valve; (4) mild aortic valve prolapse and no pathologic aortic regurgitation; (5) no active infective endocarditis; and (6) no main tricuspid chordae tendineae located around the rim of the pmvsd. The distance between the pmvsd and aortic valve as well as the presence of abnormal tricuspid main chordae tendineae was examined in each patient before intervention (Fig 1). After TTE screening, 525 patients were selected for the attempted transcatheter closure using symmetric occluders and were enrolled in the study (Fig 2). Before intervention, an informed written consent was obtained from the patients parents. The ethics committee of each hospital approved the study, and it was registered with ClinicalTrials.gov (number NCT ) and carried out in accordance with the Declaration of Helsinki (1996) and all relevant Chinese laws. Device The Shanghai pmvsd occluder (LEPU Medical Technology Co, Ltd, Beijing, China) was used in the study. The device was made of inch nitinol wire mesh and fabric inside, and the diameter of both disks was 4 mm larger than that of the waist. The thickness of the waist of the Shanghai pmvsd occluder was 3 mm (Fig 3). The symmetric occluder was approved in 2003 by the State Food and Drug Administration, P.R. China, and it received the Conformité Européenne mark in 2008 [9, 11]. Device Implantation The catheterization procedure was performed under basal anesthesia without tracheal intubation for all patients. Heparin (100 IU/kg) and antibiotics were admin- Fig 1. Routine transthoracic echocardiography screening. (A) Presence of abnormal tricuspid main chordae tendineae (red arrow). (B) Distance between the perimembranous ventricular septal defect (VSD) and aortic valve was measured in each patient. (AO aorta; IVS interventricular septum; LA left atrium; LV left ventricle; RV right ventricle.)

3 594 WANG ET AL Ann Thorac Surg TRANSCATHETER VSD CLOSURE IN CHILDREN 2012;94:592 8 Fig 2. Cohort flow diagram of the study. (TTE transthoracic echocardiography.) istered intravenously during the procedure. Through femoral artery cannulation, angiography in the left ventricle at a 55-degree to 20-degree left anterior oblique to-cranial projection was used to profile the pmvsd, and the diameter was measured at the largest diastolic phase (Fig 4A). The pmvsd was then entered through the left ventricle using a right Judkins catheter or a 5F partly cut pigtail catheter. Once the wire passed through the pm- VSD and entered into the pulmonary artery or inferior or superior vena cava, a gooseneck snare through a femoral vein approach was used to capture the wire and establish the arteriovenous circuit. A long sheath (6F to 12F) was advanced to the left ventricle through the arteriovenous circuit (Fig 5A). Caution was taken to avoid interfering with the tricuspid chordae tendineae. By maneuvering the Judkins or partly cut pigtail catheter and wires, the long sheath was positioned beneath the aortic valve. An occluder was selected based on the measurement of pmvsd size by angiography and TTE, and the size of the occluder was usually 1 to 4 mm larger than the pmvsd size. Through the long sheath, a selected occluder was deployed under fluoroscopic control and echocardiographic guidance (Fig 5B). Transthoracic echocardiography was used during the entire procedure to monitor the Fig 3. Shanghai perimembranous ventricular septal defect occluder in (A) lateral and (B) front views.

4 Ann Thorac Surg WANG ET AL 2012;94:592 8 TRANSCATHETER VSD CLOSURE IN CHILDREN 595 Fig 4. Procedure of transcatheter perimembranous ventricular septal defect closure. (A) Diameter of the perimembranous ventricular septal defect was measured at the largest diastolic phase (red arrow). (B) Ascending aortic angiography was performed again to verify complete occlusion, new-onset aortic valve regurgitation, and residual shunts. (C) Simultaneous atrial septal defect occlusion. position of the sheath, the shape and position of the occluder, and the presence of residual shunts. After full deployment of the occluder, a left ventriculogram and ascending aortic angiography were performed again to verify complete occlusion, as well as the absence of residual shunts and new-onset aortic valve regurgitation (Fig 4B). Then the device was released, and the patient was transferred to the general wards with continuous electrocardiogram monitoring for 24 hours. In some cases, atrial septal defect, patent foramen ovale, or patent ductus arteriosus was occluded simultaneously (Fig 4C). Patients were routinely discharged on the fourth day after intervention, and aspirin (5 mg/kg daily) was administered for 6 months [11]. Follow-Up and Outcome Assessment Follow-up included clinical examination, electrocardiogram, and TTE. Adverse events were recorded and divided into major and minor adverse events. Major adverse events included but were not limited to death, cerebrovascular accident, complete atrioventricular block (cavb) requiring pacemaker implantation, thromboembolism, and new-onset valvular regurgitation requiring surgical repair. Minor adverse events included but were not limited to groin hematoma, blood loss requiring transfusion, hemolysis requiring medication, fever, rash, new or increased valvular regurgitation less than two grades, and cardiac arrhythmia requiring medication. Patients were requested to come back to the hospital or to have the follow-up examination performed at a local hospital. Electrocardiogram and TTE examinations were performed at 1, 3, 6, and 12 months after the procedure and annually thereafter. Data Analysis All continuous variables were expressed as mean standard deviation or median with range as appropriate, and discrete variables are presented as frequencies or percentages. Statistical analysis was performed using SPSS 16.0 for Windows (SPSS, Inc, Chicago, IL). Analysis of categorical variables was performed with the 2 test and Fisher s exact test. Linear regression analysis was used to analyze the relationship between variables. A probability value of less than 0.05 was considered as statistically significant. Fig 5. Transthoracic echocardiography monitoring during transcatheter intervention. (A) The sheath entered into the left ventricle (LV) through the perimembranous ventricular septal defect. (B) The occluder was partially deployed. (LA left atrium; RA right atrium; RV right ventricle.)

5 596 WANG ET AL Ann Thorac Surg TRANSCATHETER VSD CLOSURE IN CHILDREN 2012;94:592 8 Table 2. Procedural Data and Devices Used Variable Result (median with range) Fluoroscopic time (min) 15.6 (5 195) Procedure time (min) 46.3 (20 253) Catheterization VSD size in ventriculography (mm) 4.6 ( ) PA systolic pressure (mm Hg) 25.6 (18 55) PA mean pressure (mm Hg) 17.4 (15 44) PA diastolic pressure (mm Hg) 14.3 (8 32) Q p/q s 2.5 ( ) Defect shape, as determined by ventriculography (n/%) Tubular 122 (23.2%) Window-like 15 (2.9%) Aneurysmal 48 (9.2%) Infundibular 340 (64.7%) Mean size of the device used (mm) 6.5 (4 18) Combined procedures (n) ASD closure 5 PFO closure 6 PDA closure 7 Median hospital stay (d) 3.4 (2 18) ASD atrial septal defect; PA pulmonary artery; PDA patent ductus arteriosus; PFO patent foramen ovale; Q p/q s pulmonary to systemic flow ratio; VSD ventricular septal defect. All authors had full access to and took full responsibility for the integrity of the data. Results Patients and Device Implantation Among all 525 patients in whom transcatheter pmvsd closure was attempted, 502 patients (95.6%) were successfully treated by transcatheter intervention, and 502 Shanghai pmvsd occluders were implanted. Twentythree patients failed transcatheter intervention owing to the impossibility of passing through the defect (n 8), impingement of the aortic valve (n 12), or tricuspid valve regurgitation (n 3). The most frequently used device size was 6 mm (n 114), and the proportion of the 6-, 7-, and 8-mm devices (n 278) was 55.4% of all devices. Combined procedures included 5 atrial septal defect closures, 6 patent foramen ovale closures, and 7 patent ductus arteriosus closures (Table 2). Echocardiographic Assessment According to echocardiography, the mean measured pm- VSD size was 4.4 mm (range, 1.8 to 18.3 mm), and there was a good correlation between occluder size (y) and pmvsd size (x), which was measured by echocardiography to be y 0.982x (R ). Based on the ventriculography, pmvsd was classified as tubular (n 122), windowlike (n 15), aneurysmal (n 48), and infundibular (n 340) types. The mean measured pm- VSD size by ventriculography was 4.6 mm (range, 1.9 to 21.6 mm), and the relationship between occluder size (y) and pmvsd size (x) as measured by ventriculography was y 0.966x (R ). We also calculated the relationship between pmvsd sizes measured by ventriculography (y) and echocardiography (x), which generated a consistent linear relationship expressed by y 0.994x (R ). Follow-Up Evaluation All patients were followed until October Eight-six patients were followed for longer than 5 years, 137 for longer than 3 years, 162 for longer than 1 year, and 71 for less than 1 year; 46 patients were lost to follow-up (Fig 2). During a median 45 months (range, 1 to 96 months) of follow-up, there was no death. A total of three major adverse events (0.6%) were noted. One 3-year-old boy experienced a new-onset mild-to-moderate tricuspid valvular regurgitation and received a surgical repair 12 months after the intervention. Another 3-year-old girl experienced a gradual increase of aortic valvular regurgitation (from 0.6 cm 2 to6cm 2 ) and received surgical removal and polyethylene terephthalate fiber (Dacron) patch repair 8 months after intervention. Complete atrioventricular block was observed in a 2.5-year-old girl 7 days after placement of a 7-mm symmetric occluder device, and the girl received a permanent pacemaker implantation 1 month after intervention. One hundred four minor adverse events were detected during the follow-up period, including 55 different types of cardiac arrhythmia, 1 immediate device embolization, 5 mild aortic valvular regurgitation, 3 cases of new-onset stable mild-to-moderate tricuspid valvular regurgitation, 4 mild residual shunts in the rim of the occluder, 21 postintervention fevers, and 12 groin hematomas (Table 3). No Table 3. Adverse Events Events Number Major adverse events 3 cavb that required pacemaker implantation 1 New-onset valvular regurgitation that 2 required surgical repair Minor adverse events 104 Device embolization with transcatheter 1 removal Junctional rhythm 28 cavb recovered after medication 1 LBBB 6 RBBB 21 Mild aortic valvular regurgitation 5 New-onset stable tricuspid valvular 3 regurgitation Transient headache 2 Mild residual shunt 4 Hematoma of the groin 12 Others (eg, fever 38.5 C, rash, loss of 21 peripheral pulse) cavb complete atrioventricular block; LBBB left bundle-branch block; RBBB right bundle-branch block.

6 Ann Thorac Surg WANG ET AL 2012;94:592 8 TRANSCATHETER VSD CLOSURE IN CHILDREN 597 hemolysis was observed, and no blood transfusion was needed in the study. The incidence of major adverse events in patients younger than 3 years old was significantly higher than that of patients older than 3 years old (3.75% versus 0.00%; Fisher s exact test p 0.004). However, no statistical difference was found for the incidence of minor adverse events between patients younger and older than 3 years old (25.76% versus 26.28%; Fisher s exact test p 0.540). During the follow-up, TTE examination showed an intact ventricular septum without interseptal shunt. Immediate closure through the occluder, as evidenced by the absence of a left-to-right shunt in color Doppler flow mapping, was seen in 288 (54.9%) patients, and most residual shunts diminished 3 days later. The device position was parallel to the ventricular septum in 486 patients, and the occluder overlapped the ventricular septum without residual shunt in 16 patients. Decreased left ventricle size and pulmonary pressure as well as improved symptoms were observed in most of patients. Comment Since Hijazi and colleagues [12] first reported transcatheter pmvsd closure using the Amplatzer pmvsd occluder in 2002, this asymmetric device has been widely used to treat congenital pmvsds with proven advantages compared with the Clamshell, Cardioseal, and other occlusion devices. Since then, transcatheter pmvsd closure was performed at an increasing rate worldwide [8, 13 15]. However, results from recent studies showed that the risk of cavb and other major complications remained an unavoidable issue for the Amplatzer pmvsd occluder, and the device was not approved by the US Food and Drug Administration for clinical practice [7, 8]. Meanwhile, other devices were designed and developed for pmvsd, among which the Shanghai symmetric pmvsd occluder was introduced early with encouraging results [9]. However, long-term follow-up of symmetric occluders has not been reported in a large patient population. In addition, the crucial tactics and strategy needed to perform a successful pmvsd intervention were not sufficiently described. Effectiveness of Transcatheter Symmetric Device Closure of Perimembranous Ventricular Septal Defects In our present study, 525 of 2,546 congenital pmvsd patients were chosen for transcatheter closure using symmetric occluders, with a median follow-up of 45 months. We considered the effectiveness of the treatment using the following aspects: procedural success, complications, hospital stay, and time to return to normal activity. Our study demonstrated that, based on strict inclusion and exclusion criteria, transcatheter pmvsd closure using a symmetric occluder is capable of achieving an excellent immediate outcome and favorable follow-up results. Most pmvsds (95.6%) were effectively closed, as evidenced by a stable device position and significantly decreased interventricular flow by echocardiography at all postimplantation times. During the follow-up period, adverse events were rare and did not outweigh the benefits. Adverse Events Cardiac arrhythmia has been commonly reported in transcatheter pmvsd closure using the asymmetric Amplatzer device, with a risk of cavb varying from 3.5% to 8.6% [16 18]. In our hands, we only reported a single case of permanent cavb in a 2.5-year-old girl during our early practice. Most other cardiac arrhythmias seen in this study were mild lesions and were recoverable. In our opinion, by selecting appropriate patients, using proper maneuvering, and avoiding oversized devices, cavb is no longer an obstacle to transcatheter pmvsd closure using symmetric devices. In our study, two other major adverse events were valve-related. Statistical analysis exhibited a strong correlation between occurrence of valvular regurgitation and age. In clinical practice, tricuspid valvular regurgitation is usually not readily determined during the transcatheter process and has often been neglected by cardiologists. However, the function of the tricuspid valve is very important for children and should be preserved during the procedure. Improper placement of the occluder, migration, and rupture of chordae tendineae are all risk factors of postoperative tricuspid valvular regurgitation [19]. In our late series, abnormal tricuspid chordae tendineae origination from the pmvsd was routinely screened by TTE before intervention, and this was an important exclusion criterion. Technical and Device Considerations The inclusion and exclusion criteria for transcatheter pm- VSD closure using symmetric pmvsd occluders are crucial to the overall success of the intervention and should be strictly adhered to [11]. Transthoracic echocardiography screening is the first step to successful transcatheter pm- VSD closure. In our study, severe aortic valve prolapse, large pmvsd size (usually 10 mm), moderate-to-severe pulmonary hypertension, abnormal tricuspid chordae tendineae origination, and small infants with low body weight were referred to open surgery or medication and were excluded. Meanwhile, TTE has an advantage in monitoring the whole procedure of transcatheter pmvsd closure. The position of the sheath, the shape of the occluder, and the presence of aortic or tricuspid valvular regurgitation can all be clearly manifested by TTE during transcatheter intervention. We only used transesophageal echocardiography in monitoring the first 20 patients and replaced it with TTE in the remaining patients. Our study indicated that TTE combined with angiography can guide transcatheter pmvsd closure and reduce the entire procedural time. Meanwhile, a large surgical series presented a larger mean and median size of the pmvsd and a lower mean and median age of the patients being treated [3]. According to us, more pmvsd patients were referred to surgery (only 20% of patients underwent successful transcatheter intervention) [3]. We believe only patients meeting our inclusion and exclusion criteria are suitable candidates for transcatheter intervention. Transcatheter closure is a less-invasive approach and represents the future direction of treatment. For pmvsd patients with a suitable anatomy, a future

7 598 WANG ET AL Ann Thorac Surg TRANSCATHETER VSD CLOSURE IN CHILDREN 2012;94:592 8 possible transcatheter intervention should be considered and recommended to avoid the risk and side effects of open surgery. Device selection is another important factor for the success of transcatheter pmvsd closure using symmetric pmvsd occluders. Based on the measurements using TTE and angiography, the formula y 0.982x was used to select an appropriate occluder. In our study, most pmvsds could be successfully closed with the symmetric device with a 4.4% failure rate. Meanwhile, the residual shunt rate was also very low with no patients displaying clinical symptoms. Limitations A number of limitations are possible for this long-term study. First and perhaps most importantly, our inclusion and exclusion criteria were vigorous, and only pmvsd patients with a suitable anatomy and meeting the criteria were included for the attempted intervention. Second, the outcome of the Shanghai symmetric device was not assessed in comparison with other devices of the same nature. Third, this is a small-scale study involving only three medical centers, and approximately 9% of patients were lost to follow-up and 4 patients still had mild shunt. A large-scale study is needed to provide a more representative comparison. Future prospective randomized studies should be performed to further evaluate the safety and effectiveness of transcatheter pmvsd closure using symmetric occluders. Conclusions Based on strict inclusion and exclusion criteria, transcatheter pmvsd closure using symmetric occluders is associated with excellent success rates and low mortality or morbidity. The transcatheter approach provides a less-invasive alternative avenue for open heart surgery and may become the treatment of choice for selected children with pmvsd. This work was supported by the National Natural Science Foundation of China (grants , ). References 1. Ho SY, McCarthy KP, Rigby ML. Morphology of perimembranous ventricular septal defects: implications for transcatheter device closure. J Interv Cardiol 2004;17: Penny DJ, Vick GW 3rd. Ventricular septal defect. Lancet 2011;377: Minette MS, Sahn DJ. Ventricular septal defects. Circulation 2006;114: Hoffman JIE, Kaplan S. The incidence of congenital heart disease. J Am Coll Cardiol 2002;39: Bass JL, Kalra GS, Arora R, et al. Initial human experience with the Amplatzer perimembranous ventricular septal occluder device. Catheter Cardiovasc Interv 2003;58: Thanopoulos BD, Rigby ML, Karanasios E, et al. Transcatheter closure of perimembranous ventricular septal defects in infants and children using the Amplatzer perimembranous ventricular septal defect occluder. Am J Cardiol 2007;99: Sullivan ID. Transcatheter closure of perimembranous ventricular septal defect: is the risk of heart block too high a price? Heart 2007;93: Fu YC, Bass J, Amin Z, et al. Transcatheter closure of perimembranous ventricular septal defects using the new Amplatzer membranous VSD occluder: results of the U.S. phase I trial. J Am Coll Cardiol 2006;47: Qin Y, Chen J, Zhao X, et al. Transcatheter closure of perimembranous ventricular septal defect using a modified double-disk occluder. Am J Cardiol 2008;101: Yang R, Sheng Y, Cao K, et al. Transcatheter closure of perimembranous ventricular septal defect in children: safety and efficiency with symmetric and asymmetric occluders. Catheter Cardiovasc Interv 2011;77: Yang J, Yang L, Wan Y, et al. Transcatheter device closure of perimembranous ventricular septal defects: mid-term outcomes. Eur Heart J 2010;31: Hijazi ZM, Hakim F, Haweleh AA, et al. Catheter closure of perimembranous ventricular septal defects using the new Amplatzer membranous VSD occluder: initial clinical experience. Catheter Cardiovasc Interv 2002;56: Lock JE, Block PC, McKay RG, Baim DS, Keane JF. Transcatheter closure of ventricular septal defects. Circulation 1988;78: Knauth AL, Lock JE, Perry SB, et al. Transcatheter device closure of congenital and postoperative residual ventricular septal defects. Circulation 2004;110: Gu MB, Bai Y, Zhao XX, Zheng X, Li WP, Qin YW. Transcatheter closure of postoperative residual perimembranous ventricular septal defects. Ann Thorac Surg 2009;88: Tucker EM, Pyles LA, Bass JL, Moller JH. Permanent pacemaker for atrioventricular conduction block after operative repair of perimembranous ventricular septal defect. J Am Coll Cardiol 2007;50: Butera G, Carminati M, Chessa M, et al. Transcatheter closure of perimembranous ventricular septal defects: early and long-term results. J Am Coll Cardiol 2007;50: Carminati M, Butera G, Chessa M, Drago M, Negura D, Piazza L. Transcatheter closure of congenital ventricular septal defect with Amplatzer septal occluders. Am J Cardiol 2005;96(12A):52L Carminati M, Butera G, Chessa M, et al. Transcatheter closure of congenital ventricular septal defects: results of the European Registry. Eur Heart J 2007;28: