Impact of an Occluder on Cardiovascular Structures After Transcatheter Closure of an Atrial Septal Defect: Computed Tomography and Echocardiography

Chia-Hung Su ； Yu Hsuan Chang ； Jou Hsuan Huang ； Ming-Tai Lin ； Shyh-Jye Chen ； Jou-Kou Wang

《Journal of Radiological Science》 46卷 (2021/03) Pp. 93-100

https://doi.org/10.6698/JRS.202103_46.0018

摘要

PURPOSE. Our purpose in this study was to demonstrate the usefulness of computed tomography (CT) to assess the impact of occluders on cardiovascular structures in patients after transcatheter closure of secundum atrial septal defects (ASDs). MATERIALS AND METHODS. Cardiac CT was performed on 131 patients who had undergone transcatheter ASD closure at one institution over a 6-year period. The interval between ASD closure and CT study ranged from 3 to 13 months. Transverse sections, multiplanar reformatted images, and three-dimensional reconstructed images were retrospectively reviewed to disclose the effects of these implanted occluders on the systemic/pulmonary veins and the intracardiac structures. Echocardiography was used to follow the effects shown on CT, and the interval ranged from 4.1 months to 8.5 years. Descriptive statistics were used for data analysis. RESULTS. No major complications requiring intervention were noted. The presence of significant structural impingement by the occluder was noted in CT on the aortic locus (12.2%), on the tricuspid annulus (2.3%), on the tricuspid valve (1.5%), on the dorsal wall of the right atrium (0.8%), on the mitral annulus (9.2%), on the mitral valve (2.3%), and on the dorsal wall of the left atrium (2.3%). Echocardiography showed mild and moderate regurgitation of the tricuspid, mitral, pulmonary, and aortic valves in 40.5%, 22.9%, 12.2%, and 0.8% of patients, respectively. The sensitivity, specificity, and accuracy of mitral impingement on CT in predicting the occurrence of significant mitral regurgitation in echocardiography were 83.3%, 83.2%, and 83.2%, respectively. The sensitivity, specificity, and accuracy of tricuspid impingement on CT in predicting the occurrence of significant tricuspid regurgitation in echocardiography were 100.0%, 60.9%, and 61.8%, respectively. Significant ostial impingement by the occluder appeared in the right lower pulmonary vein (11.5%), in the right upper pulmonary vein (9.2%), in the right middle pulmonary vein (7.6%), in the inferior vena cava (3.8%), in the superior vena cava (2.3%), and in none of the coronary sinuses. Follow-up echocardiographic studies of all patients showed that none had significantly accelerated flow from pulmonary or systemic veins into the atria. Four patients (3.1%) had arrhythmia after occluder implantation, and all had prominent structural impingement on the CT images. Mild residual shunt appeared in 9.2% of patients. CONCLUSION. Cardiac CT imaging can be useful for assessing the relationship between the occluder and intracardiac structures in ASD patients following transcatheter closure. Pulmonary or systemic venous orifice impingement by the occluder observed in CT imaging had no effect on inflow pattern. Mitral or tricuspid impingement may predict their regurgitation. Arrhythmia after occluder implantation occurred in the case of severe device impingement on the central part of the fibrous skeleton of the heart. Thus, this study suggests that the deployment of the ASD occluder is safer over the long term in more dorsal positions.

關鍵字

atrial septal defect ； transcatheter closure ； occluder device ； computed tomography ； echocardiography