I. Background
China is one of the countries with a high incidence of congenital heart disease (congenital heart disease) in the world, with about 150,000-170,000 congenital heart disease patients born each year and about 100,000 patients requiring surgical treatment. Since the successful ligation of patent ductus arteriosus by Gross et al. in 1938, surgical treatment of congenital heart disease has made great progress, enabling the majority of patients to be treated in a timely manner. However, surgery requires open-heart, or (and) extracorporeal cardiopulmonary diversion, surgical complications, and cosmetic problems associated with surgical scarring. These prompted attempts to replace surgical procedures by inserting various catheters and devices from the peripheral vasculature into the cardiovascular cavity to be treated through a non-open route, which developed into interventional catheterization.
In precardiac disease, there is a wide range of pathologies, different types of pathology, age and severity of the disease, and different hemodynamics, through postoperative follow-up and comparative studies with surgical procedures. Although transcatheter interventions have the advantages of better aesthetics, less trauma, avoidance of extracorporeal circulation and shorter hospitalization days, they may still be accompanied by serious complications, such as thromboembolism, vascular injury, and even cardiac perforation, and there is a deep understanding of the problems as well as the limitations. In recent years, minimally invasive cardiac surgery (MICS) has developed rapidly, and now minimally invasive parachute occlusion with small thoracic incisions is widely used in the treatment of pediatric congenital heart disease (CHD). In this paper, we briefly introduce the common atrial septal defect surgical interventions as follows.
II. Historical review of interventional treatment for pediatric congenital heart disease
Transcatheter interventions for precardiac disease began in the mid-20th century, with Rashkind and Miller first proposing the use of balloon catheters to perform atrial septal stoma for palliative treatment of transposition of the great arteries in 1966; Porstmann first carried out interventions for patent ductus arteriosus (PDA) in 1971; King and Mills first tried transcatheter delivery of double umbrella patch closers in 1974, and then performed the first trial in five patients with atrial septal defect. In 1976, Rashkind invented the umbrella closure device and successfully treated atrial septal defects (ASDs) with sealing; in 1982, Kan first reported the treatment of pulmonary artery braid stenosis with balloon dilation, followed by Lababidi’s successful aortic braid balloon dilation in 1984; in 1988 Lock et al. first applied the Rashkind double-sided umbrella to close VSD, and in 1989 Lock et al. designed a double-umbrella occluder called the Clamshell occluder to close ASD, but a high residual shunt rate was found in clinical trials. 1990 Sideris applied the button-type double-disc closure system device to close ASD, but due to In 1990, Sideris applied a button double-disc closure system device to close ASDs, but it was not widely used because of the complexity of operation and high residual shunt rate.
In 1992, Combier et al. first reported the success of PDA plugging with spring ring, which was then promoted at home and abroad; Amplatzer developed a new generation of plugging device with nickel-titanium alloy braid in 1997 and used it in clinical practice. The “waist” of the device matches the diameter of the ASD, which makes the plugger less likely to shift. The disc-like structure on both sides can assist in plugging the marginal part of the ASD and further reduce the incidence of residual shunt after restoring the memory shape. The use of this type of blocker is easy to operate and the delivery sheath is thin, which makes it suitable for ASD blocking in pediatric patients, thus significantly improving the safety and success rate of the interventional treatment for precardiac disease. In addition, the localization of interventional devices for precardiac disease has played a positive role in promoting the interventional treatment of precardiac disease in China.
In 1997, Amin et al. first introduced the technique of transventricular blocking of ventricular septal defects based on animal studies of myocardial and membranous ventricular septal defects, and successfully operated on an infant with a myocardial ventricular septal defect under non-extracorporeal circulation. In 2002, Yu Shiqiang et al. were the first to report a large number of cases of atrial septal defect occlusion with a small transthoracic incision and umbrella piece under non-extracorporeal circulation. In 2007, Diab et al. reported the use of the Amplatzer umbrella to seal the atrial septal defect via the right atrium. In the same year, Li Hongxin also reported the experience of 100 cases of intraoperative closure of atrial septal defects with the parachute device via a small right anterior thoracic incision.
Small thoracic incision for non-extracorporeal circulation atrial septal defect (ASD) occlusion
Atrial septal defect is one of the common congenital heart diseases, and its incidence accounts for about 6-10% of congenital heart diseases. There are primary orifice type and secondary orifice type, 84% of which are secondary orifice type ASD, and those who can be cured by interventional means are secondary orifice type ASD.
1. Indications for surgical occlusion of ASD:
(1) age >1 year, weight >8Kg; (2) ASD diameter 5mm-34mm; (3) defect edge to coronary sinus, upper and lower vena cava and pulmonary vein opening distance >5mm, to atrioventricular braid distance >7mm; (4) septal diameter is greater than the diameter of the selected blocker left atrial lateral disc; (5) not combined with other cardiac malformations that must be surgically operated. With the maturation of surgical occlusion techniques, the age of surgery can be relaxed to infants less than 1 year old. Diab reported that the age of infants with transatrial occlusion of atrial septal defects ranged from 2.2 to 3.4 months, with an average of 2.9 ± 0.6 months. The following conditions are contraindicated for ASD intervention: (1) primary orifice ASD and venous sinus ASD; (2) combined endocarditis and hemorrhagic disease; (3) thrombosis at the placement of the blocker and thrombosis at the catheter insertion route; (4) severe pulmonary hypertension leading to right-to-left shunt; (5) other serious myocardial disease or heart braid disease.
2. Surgical methods.
2.1 TEE guidance: The procedure is performed under intravenous complex anesthesia with tracheal intubation. The patient is placed in a supine position with the right chest elevated 30 degrees, and the esophageal ultrasound probe is placed. The two-chamber section of the atria, the apical four chambers and the short-axis section of the great vessels are observed on transesophageal echocardiography (or subxiphoid chest wall ultrasound), and the size of the long diameter and transverse diameter of the defect and the distance from the superior vena cava, inferior vena cava, left atrial apex and mitral annulus are measured.
2.2 Umbrella piece type selection: The double-disc umbrella piece blocker is the same as the blocker used in the transcatheter route in internal medicine. If the shape of the ASD is round or round-like; choose the maximum ASD diameter plus 4 mm, if the ASD is oval, choose the longest ASD diameter plus ≥ 4 mm; if it is a double-hole ASD, choose the model of the umbrella piece as the sum of the maximum ASD diameter and the distance between the two holes plus 4 or 6 mm.
2.3 Placement of the blocker: routine disinfection and towel laying, small incision of 2-2.5 cm next to the sternum in the fourth intercostal space of the right anterior chest, layer by layer through the intercostal space into the chest, “H”-shaped incision of the pericardium, and suspension on both sides. The right atrium was double loaded with heparinized 1mg/kg, and the blocker was soaked with heparinized saline for 1min. The transmission wire was threaded into the sheath and rotated to connect the central threaded inner port of the blocker, while 2-0 Prolene thread was sewn in the center of the right atrial lateral umbrella of the blocker to make a lead through the sheath to lead out, and the blocker was placed into the sheath. The right atrial incision was made and the sheath was inserted. Under the guidance of ultrasound esophageal probe, the sheath was inserted into the left atrium through the atrial defect and the blocker was pushed forward to open the blocking umbrella on the left atrial side, pulling back the umbrella to cover the left atrial side of the septal defect, and retracting the outer sheath to open the blocking umbrella on the right atrial side to close the septal defect. The position of the blocker was normal without dislodgement in the pull-back boost test. The left-to-right shunt disappeared, and the mitral and tricuspid orifices and the right pulmonary vein opening in the upper and lower vena cava were unaffected by the ultrasound color examination. The blocker was released by rotating the detached transmission wire, and the lead was cut and withdrawn after the echocardiography confirmed the normal position of the blocker. The right atrial ruffle was tied without bleeding. No neutralization of heparin, sutured intercostal, intraoperative chest venting, routine chest closure, no need to place closed chest drainage tube.
3.The advantages of surgical non-extracorporeal circulation atrial septal defect sealing.
(1) Wide surgical indications, especially for younger infants and children, it is not necessary to place a tube through the femoral artery to transmit the blocker;
(2) High safety, the operation is operated by a surgeon who is familiar with the anatomy of the heart, and the operation is performed in the operating room, and the repair can be done directly by extracorporeal circulation in case of accidents, while medical interventions are usually performed in the DSA catheterization room and operated by an internist, and if there are serious complications such as blocker dislodgement, heart rupture, or pericardial tamponade, the patient needs to be sent to the operating room, which takes a long time and is unsafe for emergency treatment.
(3) Avoid extracorporeal circulation, no need to split the sternum and place drainage tube after surgery;
(4) Small incision on the chest and inconspicuous scars;
(5) The atrial septal defect can be blocked under the guidance of esophageal ultrasound or subxiphoid four-chamber view, which can clearly show the whole process of blocking without X-ray guidance, avoiding long time X-ray radiation and intake of contrast agent, and the operation can be monitored by esophageal ultrasound in real time, and the effect of blocker on mitral valve, aortic valve, superior vena cava and inferior vena cava can be detected immediately.
(6) The blocking process is intuitive and safe, and the path of pushing the sheath to release the blocker is short and the sheath is perpendicular to the atrial septal defect, so the position is accurate and fast, while the catheter intervention requires a turn to reach the atrial septal defect after inserting the delivery device from the inferior vena cava, which can easily stimulate the right atrium and cause arrhythmia;
(7) The incidence of blocker dislodgement is low. The blocker is hard and produces a greater retraction force, which can be more closely stuck to the edge of the atrial septal defect, and the blocker is tested for dislodgement by pushing and pulling vertically back and forth.
(8) The operation time is short, the postoperative recovery is faster than conventional open chest, the postoperative time off the ventilator is short, and the hospital stay is reduced accordingly.
(9) The overall cost of the operation is comparable to that of extracorporeal repair, and cheaper than that of medical interventional blocking.
Complications are mainly intraoperative detachment of the umbrella piece, small amount of pleural effusion, intraoperative transient arrhythmia, etc. Intraoperative detachment of the umbrella piece can be removed and the atrial septal defect repaired under extracorporeal circulation. A small amount of pleural effusion can be thoracentesis or self-absorption.