ASD is a common CHD [12]. In their careers, Chinese cardiovascular surgeons start from ASD surgery and progress to more complex surgeries for CHD, valve surgery, and lastly, coronary surgery; our hospital is no exception. So far, the cardiac surgery department of the Cardiovascular Center in our hospital offers several treatment methods for ASD. We undertook closed surgical device closure and transcatheter closure under echocardiography in recent years. These different methods have their own advantages and disadvantages. Doctors who are experienced in ASDR surgery can easily understand the surgical indications of different operation methods from anatomical points. We analyzed the three operative methods of ASD in our hospital for the past 6 years. Although our data are slightly inconsistent with previous published reports, this is the actual trajectory of our doctors’ learning and the overall development of ASD treatment in our department.
Traditional treatments include open heart surgery and interventional closure. The ASDR surgical technique under CPB is very developed. The curative effect is accurate under direct vision, and the success rate is high. Almost all types of ASD can be treated in this precedure with low mortality. However, the disadvantages include long-term hospitalization, patient trauma, need for significant blood products, long-term antibiotic dependency, need for CPB, high costs, and possible adherence of the pericardium to the surface of the heart that may lead to complex future secondary surgeries. In addition, owing to the distinct and obvious scarring, patient is not willingly to accept this procedure. Eight patients in this paper experienced failed closed surgical device or transcatheter occlusion, two of whom underwent unsuccessful percutaneous closure at other hospital. These eight cases comprised huge ASDs, multiple ASDs, or unsuitable edge for occlusion.
ASD interventional occlusion has the advantage of minimal trauma and quick recovery after surgery, but X-ray cause damage to the human body. Furthermore, intraoperative use of contrast agents carries the risk of allergies and kidney failure. The TEE-guided closed surgical device occlusion circumvents the need for long incisions and CPB, but incisions are still required. Some Chinese scholars have proposed the following indications for the procedure in Chinese journals, namely when: (1) without other complicated intracardiac malformations; (2) for secundum ASDs; (3) the diameter of the septal defect is ≤40 mm; and (4) each edge of the septal defect is ≥4 mm. Several patients in this study were infant or low-weight children, and therefore unsuited for transcatheter occlusion. The closed surgical device closure also achieved satisfactory results. In addition, patients with large ASDs, especially those who had unsuccessful transcatheter occlusion, may also be suitable candidates for closed surgical device closure. We had the same successful cases in this study. Chen et al. [13] reported the reliable efficacy of the use of large occluder in mid-term follow-up. Therefore, apart from the usual indications, this procedure may be also suitable for infant, low-weight children who need treatment but are not suitable for transcatheter closure and patients with large ASDs whose margins are suitable for closure. Zhu et al. [14] reported that closed surgical device closure is more suitable for patients with ASDs who are older or have pulmonary arterial hypertension.
At present, the two more common ASD occlusion methods are slightly different with each other. The sheath travel path of transcatheter closure is much longer than that of closed surgical device closure. The angle between the delivery sheath and the atrial septum is different (transcatheter non-perpendicular vs. closed surgical device vertical), which determines whether the occluder umbrella disc and ASD are parallel or not (the transcatheter is not parallel, whereas the closed surgical device is). Therefore, it is easier to control, adjust the position, and release a closed surgical device closure, thereby improving the accuracy and safety of the operation. For large ASDs that cannot undergo transcatheter closure, closed surgical device closure may be attempted.
Mazic et al. [15] reported TEE-guided transcatheter ASD occlusion. This technique avoids the use of X-rays, but requires tracheal cannulation to avoid aspiration and affect breathing. Moreover, an esophageal probe is needed for insertion, which increases patient suffering and increases costs. Ultrasound-guided transcatheter occlusion is still in its infancy in our hospital, so the patients in this study were operated upon under general anesthesia and tracheal intubation. Both TTE and TEE were combined for transcatheter occlusion. Xu et al. [16] reported that TEE can replace X-rays with transcatheter occlusion, and the clinical effect is the same. Based on proficient TEE guidance, the development of TTE guidance is inevitable. In the case of unsatisfactory transthoracic imaging in adults, local anesthesia can be converted to general anesthesia for TEE-guided ASD occlusion. Pan et al. [11] compared TTE and TEE methods and found that TTE has the advantages of shorter operative time, shorter ventilator assist time, lower propofol usage, fewer esophageal complications, and fewer costs. In the transcatheter occlusion group, three cases were converted into other surgical methods, and they had special anatomical features: two cases of residual shunt after multiple ASD occlusion, wherein ASDR was conducted after retrieving the occluder; two case of large ASD was successfully converted to closed surgical device closure.
Many articles have reported that the successful closure of ASD in infants is safe and effective [17,18,19]. In this study, many patients under the age of 1 year old or weighing less than 10 kg were included in the closed surgical device closure group, and treatment effects were satisfied. Transcatheter closure studies suggest that a child’s ASD diameter/weight ratio of less than 1.2 can be safely and effectively occluded [20, 21]. Chinese experts believe that ultrasound-guided transcatheter closure of ASD diameter ≤ 20 mm is the safest and most effective [22]. Erdem et al. [23] selected transcatheter closure under general anesthesia TEE for unsatisfactory transthoracic acoustic window, aneurysmal septal defect, and/or multiple defects.
The age of patients in the open repair group was diffused, mainly because most of the patients had unsuitable anatomy for occlusion. Patients who underwent closed surgical device closure were relatively younger. Moreover, most of these patients relied on financial aid and lived in remote areas. Because waiting for the appropriate age and weight for transcatheter ASD occlusion was inconvenient, so most of them underwent closed surgical device closure, which is also a feature of this group. If solely from a medical point of view, we agree that patients with appropriate conditions should choose transcatheter closure as much as possible. If a large ASD in infancy caused repeated respiratory infections and limited growth and development, and if the ASD is too large or in a unique location unsuitable for transcatheter occlusion, closed surgical device closure can be considered. Infants and young children with appropriate structure and ASD size can also undergo transcatheter closure after careful evaluation [17, 18]. After the failure of transcatheter closure, closed surgical device occlusion can also be tried. There were two successful cases in our study.
This study has its limitations. First, we relied on our own clinical experience and advanced experience from domestic and foreign counterparts to determine the surgical plan; thus, it is not a randomized controlled study. Second, the choice of surgical methods for some patients was determined by the wishes of the patients or their parents. While there were certain attempts at transcatheter closure and a reluctance to try closure directly with CPB-ASDR, these approaches were unlikely to be randomized control groups. In this case, it is necessary to observe the clinical effect to determine which type of surgery is suitable for the chosen patients. Third, mid-term and long-term follow-up results are lacking. We aim to continue the follow-up of this group of patients from a multi-angle observation to compare whether the mid-term and long-term efficacy is different. Cardiovascular Center in our hospital has both surgeon and cardiologist, and cardiologist presently also performs percutaneous ASD closure under X-rays. This part of the patients is not included in this paper.
We believe that echocardiography is very important in decision-making. It is necessary to accurately measure the diameter of the ASD and determine the peripheral residual size of the defect, whether to have multiple atrial defects, and whether the residual edge can fix the occluder, thereby determining ASDR or occlusion. These parameters should be considered with age and body weight together to determine whether closed surgical device or transcatheter closure is suitable for the patient. Closed surgical device closure indications are extensive, with no X-ray radiation and ease of operation and mastering. Based on the proficiency of this surgical procedure, doctors can attempt ultrasound-guided transcatheter closure. In case of strict interventional ASD occlusion indications, ultrasound-guided transcatheter ASD closure is the preferred method, followed by closed surgical device closure which can replace ASDR to some extent. Despite successful experiences, it is worthwhile to discuss whether a patient is suitable for tclosed surgical device closure after failure of interventional closure under X-ray or transcatheter closure under echocardiography. Patient-specific analysis and decision-making are critical for successful outcome.