Abstract
Background
Although transthoracic echocardiography (TTE) is easy and more widely available with excellent acquisitions in children, there is limited evidence regarding its use in guiding transcatheter closure of ASD.
Objectives
We aimed to evaluate the safety, feasibility, and outcome of transcatheter closure of ASD in children guided by TTE in combination with fluoroscopy.
Methods
All children aged 4–15 years who were considered for and underwent transcatheter ASD closure of ASD Secundum type under TTE and fluoroscopy guidance at the National Heart Centre in Kathmandu, Nepal, from August 2018 through May 2021, were retrospectively reviewed.
Results
Of the 94 children, transcatheter closure was attempted in only 89 patients, and implantation of the device was successful in all of them (100 %). The procedure was done under total intravenous anesthesia in 79.8 % of children and local anesthesia in the rest. The ASD size varied between 7 and 32 (15.2 ± 5.8) mm. ASDs were closed using the device size ranged between 10 and 38(19.2 ± 1) mm. The mean of device/patient weight and device/ASD size ratio were 82 ± 0.33 and 1.28 ± 0.25, respectively. Similarly, mean duration of the procedure and fluoroscopy was 31.2 ± 8.6 and 6.5 ± 2.8 min, respectively. Five children (5.6 %) had tiny residual shunt, which closed spontaneously, as documented by TTE within 6 months after the procedure. A new onset atrial tachycardia was detected in one child during follow up. Otherwise, we observed no major early postprocedural or late complications during follow up period of 18.4 ± 8.5 months.
Conclusion
TTE is a safe and feasible guiding tool in children with adequate acoustic windows for the deployment of the ASD device under fluoroscopy.
Highlights
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The success rate of TTE guided ASD device closure in children with adequate TTE acoustic is 100 %.
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The postprocedural complication rates after TTE guided ASD device closure is comparable with TEE guided ASD device closure.
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Thus, it is a more attractive option for children in resource limited settings as it is safe and cost- effective procedure.
1
Introduction
In the general population, the incidence of congenital heart disease (CHD) is 8–9 per 1000 live births [ ]. The most frequent type of atrial septal defect (ASD) is the ostium secundum type. It accounts for approximately 7 % of all cases of CHD [ ]. Although surgical closure of ASD is known to be associated with very low morbidity and mortality, transcatheter closure of ASD has been accepted as the standard treatment with excellent outcomes [ ].
TEE is considered the imaging technique of choice while performing percutaneous ASD device closure due to its higher resolution images [ ]. However, it requires insertion of a transesophageal probe and general anesthesia with endotracheal intubation, which potentially increases the incidence of post procedural complications and costs. Moreover, availability of TEE might be limited in resource limited settings. On the contrary, transthoracic echocardiography (TTE) is easy and more widely available with excellent acquisitions in children, especially from subcostal views [ ].
There is limited evidence in the literature regarding the appropriateness of TTE to guide transcatheter closure of ASD in children [ , ]. Thus, the aim of this study was to evaluate the safety, feasibility, and outcome of transcatheter closure of ASD in children guided by TTE in combination with fluoroscopy at Shahid Gangalal National Heart Centre, a tertiary cardiac center in Nepal. The results of this study may be useful in the adoption of similar protocols at other resource limited centers.
2
Materials and methods
2.1
Study population and data collection
The study population included all patients aged 4- 15 years who underwent transcatheter ASD closure at the Shahid Gangalal National Heart Centre (SGNHC) in Kathmandu, Nepal, from August 2018 through May 2021.
The data were reviewed and collected from in-hospital documentation of the SGNHC medical records. The documents reviewed included echocardiography reports, catheterization reports, progress notes, and discharge summaries. Collected information included demographic data, defect properties (number, size, presence or absence of sufficient rims of atrial tissue), size and type of device used, procedural success, type of anesthesia, procedural duration, fluoroscopy duration, and complications at the time of intervention or during the follow-up period. Potential complications included device embolization, pericardial effusion, atrioventricular valve regurgitation, deaths, cardiac erosions, thrombus formation or thromboembolisms, stroke, conduction abnormality, infective endocarditis, or significant vascular complications. The study was approved by the SGNHC Institutional Review Board.
2.2
Devices
The two devices used at our center were the Amplatzer™ septal occluder (ASO, Abbott structural heart, Illinois, USA) and the MemoPart™ ASD occluder (Lepu Medical, Beijing, China).
2.3
Procedure
The diagnosis ASD was made by transthoracic echocardiography using EPIQ CVx 6.0 (Philips Ultrasound Machine) equipped with S5–1 and S8–3. However, if the weight of the patient was ≥28 kg and inadequate acoustic windows, preprocedural conscious TEE using EPIQ CVx 6.0 (Philips Ultrasound Machine) equipped with X7-2t transducer was done for better assessment of the defect, including number, size, and rims. We do not have pediatric TEE and intracardiac echocardiography (ICE). The acquisition of multiple ASDs and relation to surrounding structure could not be assured with 2-D echocardiography. Thus we performed real-time 3-D echocardiography using EPIQ CVx 6.0 (Philips Ultrasound Machine) equipped with X5–1 to improve acquisition in selected children. The ASD rim was characterized as small, sufficient, and floppy rims. The rim was defined as adequate if measured ≥5 mm and as small when measured <5 mm in at least one direction for interventional device closure. Similarly, rim was defined as floppy when it was small and moved back and forth within blood flow during the cardiac cycle. Exclusion criteria for device closure were age <4 years, large ASD (device size and body weight ratio > 2), absent inferior/posterior rims, maligned ASD, significant mitral valve prolapse with mitral regurgitation, or the presence of any concomitant requiring surgical intervention. Similarly, device closure performed under TEE guidance was excluded from enrollment in this study. Before the procedure, all children underwent physical examination, ECG, chest X-ray, and complete blood examination. Informed written consent was obtained from their parents.
The procedures were performed under total intravenous or local anesthesia for cooperative children in the presence of the anesthesia team. After obtaining femoral venous access, heparin was administered at a dose of 100 units/Kg. They were given prophylactic antibiotics (Cefazolin) prior to the procedure and continued every 8 h for an additional three doses. The selection of device size was decided upon intraprocedural TTE measurement of ASD size. The probe was carefully swept in multiple views to image the largest ASD size that was taken as the reference defect size for selecting the optimal size of device. The balloon sizing of ASD is not routinely done in our center. The ASD device size is chosen to be 2–4 mm larger than the measured defect size. Device implantation was performed using either conventional approach, which involved opening the left atrial (LA) disc from the delivery sheath into LA, then the whole system was gradually pulled until the LA disc touched the atrial septum, followed by slow withdrawing of the delivery sheath to open the right atrial disc in right atrium or the non-conventional approach where the LA disc was opened in the pulmonary vein or LA roof. Non-conventional approach was adopted when the conventional approach was failed. Device deployment was done in anterior posterior (AP) view under fluoroscopy. The position and stability of device were checked in left anterior oblique (LAO) 30 0 and cranial 30 0 under fluoroscopy. Furthermore, the position and stability of the device, the presence of residual leak, and interference with neighboring structures were evaluated using TTE prior to its release. Device stability was tested by the so called “Minnesota wiggling maneuver.” [ ] After confirmation, the device was released from the carrier system. The sheaths were removed, and hemostasis was achieved by manual compression.
Procedure duration was defined as the time from insertion of femoral sheath to removal of sheath at end of procedure.
Before discharge, all children were assessed clinically by chest x-ray, TTE, and ECG. The device position, residual leakage, and its interference to neighboring structures were evaluated. The heart rhythm/rate and the presence of any ECG changes from the baseline were documented. Children were discharged on Aspirin and added clopidogrel if device size>30 mm was used. They were instructed about infective endocarditis prophylaxis regimen for the first 6 months. Children were followed up regularly by TTE and ECG at 1 month, 6 months, 12 months, and yearly after discharge from our center.
2.4
Statistical analysis
The statistical analysis was conducted using SPSS 20.0 software. Continuous data were presented as the means <SPAN role=presentation tabIndex=0 id=MathJax-Element-1-Frame class=MathJax style="POSITION: relative" data-mathml='±’>±±
±
standard deviation. Discrete data were presented as absolute numbers and percentages of the total.
3
Results
3.1
Demographic data
At the time of implantation, the mean age of the children was 9.3 ± 3.4 years, with 23.6 % being under 6 years of age. Their mean body weight and height were 24.4 ± 10.6 kg and 126.3 ± 17.5 cm, respectively. The female gender was slightly more predominant in our study population (57.3 %) ( Table 1 ).
