Lu Guoliang, Ma Lunchao, Yang Chao, Zhang Yingyuan, Xie Shaobo, Department of Cardiac Surgery, The First Hospital of Guangzhou Medical University, Guangzhou 510120, China Abstract: To summarize the clinical application experience of transthoracic minimally invasive ventricular septal defect (VSD) occlusion surgery. METHODS: From August 2013 to October 2014, 142 patients with VSD, 72 males and 70 females, aged 2 months to 33 years, average (4.4±5.3) years; weight 4.5 to 69 kg, average (16.4±12.3) kg; VSD diameter 2 to 12 mm, average (5.1±1.9) mm; among them, 85 cases were perimembranous, 40 cases were perimembranous tumors, 8 cases were subdermal, 7 cases were intramembranous, and 2 cases were myelomeningocele. Results: 136 cases (95.8%) were successfully occluded, 106 cases (77.9%) with symmetric occluder, 28 cases (20.6%) with eccentric occluder, and 2 cases (1.5%) with myocardial VSD with arterial catheter occluder. Four cases were operated at the same time, including one arterial catheter block, one atrial septal defect block, and two pulmonary valve balloon dilatation. six cases (4.2%) were converted to conventional extracorporeal circulation. one case (0.7%) developed third-degree atrioventricular block after surgery, and one case had a new postoperative right ventricular outflow tract with accelerated blood flow. CONCLUSION: The recent treatment results of transthoracic minimally invasive blocking VSD surgery were satisfactory. There is a lack of long-term follow-up data, and further follow-up observations are needed. Keywords: ventricular septal defect; minimally invasive transthoracic; closure; non-external circulation The clinical analysis of 142 cases of minimally invasive transthoracic device closure of ventricular septal defect LU Guoliang, MA Lunchao, YANG Chao, ZHANG Yingyuan, XIE Shaobo. Department of Cardiac Surgery, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, China University, Guangzhou 510120, China [Abstract] Objective To summarize the minimally invasive transthoracic ventricular septal defect (VSD) occlusion operation experience in the clinical setting. To summarize the minimally invasive transthoracic ventricular septal defect (VSD) occlusion operation experience in the clinical application. Methods From August 2013 to October 2014, 142 patients with VSD underwent transthoracic device closure in The First Affiliated Hospital From August 2013 to October 2014, 142 patients with VSD underwent transthoracic device closure in The First Affiliated Hospital of Guangzhou Medical University.Of these patients, 72 were male, 70were female; the age of these patients ranged from 2 months to 33 years. Of these patients, 72 were male, 70were female; the age of these patients range from 2 months to 33 years, average (4.4 + 5.3)years; the weight of 4.5 ~ 69 kg, average (16.4 + 12.3) kg; the diameter of VSD from 2 to 12 mm, average (5.1 + 1.5) years; the weight of 4.5 ~ 69 kg, average (16.4 + 12.3) kg; the diameter of VSD from 2 to 12 mm, average (5.1 + 1.5) years. average (5.1 + 1.9) mm. Perimembranous VSD in 85 cases, Aneurysm of membranous VSD in 40 cases, Subarterial VSD in 8 cases, intracristal VSD in 7 cases, muscular VSD in 2 cases. Results Successful implantation of the device was achieved in 136 patients (95.8%). In 106 cases (77.9%) with symmetrical occluder, 28 cases (20.6%) with eccentric occluder,, 2 cases (1.5%) of muscular artery VSD duct occluder 4 cases of surgery, including 1 case of arterial catheter occlusion, 1 case of atrial septal defect closure, 2 cases of pulmonary valvuloplasty.6 cases (4.2%) converted to traditional surgery with CPB.In 1 case (0.7%) appeared in three degree atrioventricular block, 1 new case of In 1 case (0.7%) appeared in three degree atrioventricular block, 1 new case of right ventricular outflow tract flow speed up after operation (6000px/s).Follow up was available in 102 cases (75%) for 3 to 12 months, 16 cases (15.7%) Conclusion The short-term therapeutic effect of minimally invasive transthoracic device closure of VSD is definitely, the long -term follow-up remains to be The short-term therapeutic effect of minimally invasive transthoracic device closure of VSD is definitely, the long-term follow-up remains to be studied.[Keywords: transthoracic minimally invasive ventricular septal defect closure, non-external circulation Key words] ventricular septal defect; transthoracic; minimally invasive; non- Cardiopulmonary bypass ventricular septal defect (VSD) is a common congenital heart disease, and transthoracic minimally invasive VSD occlusion has the advantages of safety, effectiveness, minimal trauma, low transfusion rate and short hospital stay, which has been carried out in several cardiac centers in China in recent years [1-3]. From August 2013 to October 2014, the cardiac surgery department of the First Hospital of Guangzhou Medical University used transthoracic minimally invasive blocking surgery for 142 cases of VSD, with good recent results, which are summarized as follows.1 Data and methods 1.1 General data 142 cases in this group, including 72 males and 70 females, aged from February to 33 years old, average (4.4±5.3) years old; weight 4.5 to 69 The physical examination revealed systolic murmurs between the third and fourth ribs at the left edge of the sternum. 2-12 mm VSD diameter, average (5.1±1.9) mm; 85 cases were perimembranous, 40 cases were perimembranous tumors, 8 cases were substernal, 7 cases were intracrural, and 2 cases were myocardial. The patients were operated in the supine position under general anesthesia with tracheal intubation, and a transesophageal echocardiography (TEE) probe (GE vivid) was placed. A 2-3 cm incision was made at the 2nd or 3rd intercostal space on the left edge of the sternum, heparin 1 mg/kg was applied intravenously, the coronary vessels were avoided on the right ventricular surface, the ventricular puncture site was determined and the purse was sewn under TEE surveillance, the 20F puncture needle was inserted into the right ventricle through the purse, the guidewire was passed through the VSD into the left ventricle or ascending aorta under TEE guidance, and the delivery sheath was placed along the guidewire. According to the type of VSD and the distance between the VSD and the aortic annulus, the appropriate blocker was selected (PDA blocker was selected for the myocardium, eccentric umbrella was selected for the distance between the VSD and the aortic annulus ≤2 mm, and equilateral umbrella was selected for the rest), and the safety wire was left in place during the operation. The blocker was delivered under TEE monitoring to observe whether there was residual shunt and whether there was any effect on each valve, and the blocker was released after pushing test. The pericardium was partially sutured, a single-lumen central venous catheter drain was placed according to the situation, and the chest was routinely closed. Postoperatively, antibiotics were routinely applied for 3 d to prevent infection, and enteral aspirin 3-5 mg/kg was administered orally for 3-6 months. Cardiac ultrasound was reviewed before discharge and 3 to 12 months after discharge.2 Results Among 142 cases, 136 cases were successfully blocked, of which 106 cases (77.9%) used symmetric blockers, 28 cases (20.6%) used eccentric blockers, and 2 cases (1.5%) chose arterial catheter blockers for muscular ventricular septal defects. Four cases were operated at the same time, including one case of arterial catheter occlusion, one case of atrial septal defect occlusion, and two cases of pulmonary valve balloon dilatation. The operating time was 30 to 255 min, mean (72.8±34.1) min, intraoperative bleeding was 5 to 200 ml, mean (43.0±44.1) ml, and perioperative transfusion was performed in 13 cases (9.6%). 65 patients (47.8%) were extubated in the anesthesia resuscitation room and returned to the general ward, and 71 patients (52.8%) were ventilator-assisted in the monitoring room for 0 to 21 h, mean (2.2±3.2) h. The postoperative hospital stay ranged from 3 to 12 d, mean (5.1±1.9) d. Six cases (4.2%) were converted to conventional extracorporeal circulation surgery. In one case, although the blocker was successfully placed, bleeding from the posterior wall of the left ventricle was found during chest closure, but the location of the bleeding was difficult to reveal; in one case, there were multiple openings for a membranous tumor VSD, and there was still a significant residual shunt after placement of the blocker. 4 cases (3 with perimembranous VSD and 1 with a membranous tumor VSD) had recurrent cardiac murmurs after surgery (3 within 24 h and 1 at 72 h postoperatively), and bedside cardiac One case (0.7%) had complete postoperative atrioventricular block in a 2-month-old child with an 8 mm defect and moderate pulmonary hypertension, in which a 10-gauge eccentric blocker was placed, and sinus rhythm was restored after 24 hours of temporary pacemaker and hormonal therapy. Of the 136 patients with successful postoperative interventional occlusion, 102 (75%) returned for follow-up, with a follow-up time of 3 to 12 months. 16 (15.6%) had residual shunts, including 7 perimembranous VSDs, 7 perimembranous tumor VSDs, 1 myocardial VSD, and 1 intracrural VSD, with a shunt bundle width of 1.3 to 4.7 mm, with a mean (2.3 ± 0.8) mm, and a shunt bundle blood flow 3 Discussion There are two main previous treatments for ventricular septal defect (VSD): surgical repair under cardiac arrest with extracorporeal circulation (CPB) and medical catheter interventional occlusion treatment [4,5]. Surgical procedures have the potential risk of complications from extracorporeal circulation [6] and are more invasive, with large surgical wounds that can affect the aesthetics and may cause sternal deformities; medical catheter interventions require the patient and physician to be exposed to X-rays, which can potentially cause radiological damage, especially in immature children [7]; and are limited by the diameter of the femoral artery, making infants and children weighing less than 15 kg unsuitable for this treatment. The VSD periphery is closely related to the aortic valve, tricuspid valve, mitral valve and conduction system, and there is a risk of postoperative valve dysfunction and complete AV block [8,9]. In our group, there was one case of complete AV block after surgery, and the presence of compression of the conduction system by a large blocker was considered. In the occurrence of atrioventricular block, most scholars believe that it is related to the damage of the blocker delivery system or the local tissue inflammatory edema triggered by the blocker. In contrast, short-term postoperative application of steroid preparations may avoid the occurrence of AV block or shorten its duration [10]. Late blocker dislodgement has been reported, and its causes are mostly related to hemodynamic correction after blocking and reversal of myocardial tissue hypertrophy after volume load reduction, causing relative enlargement of VSD [11]. It has also been suggested that inappropriate blocker positioning and poor post-release blocker umbrella apposition can cause inadequate postoperative blocker endothelialization and also lead to late blocker dislodgement [12]. However, early blocker displacement, dislodgement and residual shunts have been reported relatively rarely. In our group, four patients showed more obvious residual shunts in early postoperative period, and the exploration under CPB showed two cases of well positioned blockers and two cases of blockers placed across the VSD. We analyzed the reasons: (1) None of the actual VSDs were orthocircular, but similar to oval, and oversized blockers would compress the direction of the minimum diameter of the VSD [13], which may lead to AV block. Smaller blockers are chosen to avoid triggering AV block. (2) Due to ventricular septal thickening, there may be insufficient blocker waist height despite good intraoperative placement of the blocker. Postoperatively, the patient’s heart rate is accelerated due to irritability, crying or wound pain, which may trigger the blocker to shift or even dislodge. (3) Membranous tumor VSD may be accompanied by multiple openings on the right ventricular surface, and the exit directions are not consistent and the distances between the exits are not equal. Although the intraoperative TEE shows good position of the blocker and no residual shunt due to the selection of a large hole and a thin waist and large side blocker, the blocker may be displaced and cause residual shunt due to the thin wall of the membranous tumor and the large mobility of the blocker. (4) For multiple VSDs in the myocardium, the appropriate size and number of blockers should be selected according to the size of the defect, the volume of the cardiac cavity and the adjacent surrounding tissues, but it is not recommended to place more than two [14], so there are cases of incomplete blocking of VSDs. In conclusion, transthoracic minimally invasive VSD occlusion is a safe, effective, and simple treatment, but it is important to prevent blindly expanding the indications and to carefully select the occluders and enhancement techniques, especially for “borderline” patients. Minimally invasive transthoracic VSD occlusion has good application prospects, but long-term clinical follow-up data are still lacking, and further follow-up is needed to observe the long-term effects.