Angioscopic Evaluation of Atrial Septal Defect Closure Device Neo‐Endothelialization

Abstract

Background Current guidelines recommend at least 6 months of antithrombotic therapy and antibiotic prophylaxis after septal‐occluding device deployment in transcatheter closure of atrial septal defect. It has been estimated that it takes ≈6 months for complete neo‐endothelialization; however, neo‐endothelialization has not previously been assessed in vivo in humans. Methods and Results The neointimal coverage of septal occluder devices was evaluated 6 months after implantation in 15 patients by angioscopy from the right atrium. Each occluder surface was divided into 9 areas; the levels of endothelialization in each area were semiquantitatively assessed by 4‐point grades. Device neo‐endothelialization was sufficient in two thirds of patients, but insufficient in one third. In the comparison between patients with sufficiently endothelialized devices of average grade score ≥2 (good endothelialization group, n=10) and those with poorly endothelialized devices of average grade score <2 (poor endothelialization group, n=5), those in the poor endothelialization group had larger devices deployed (27.0 mm [25.0–31.5 mm] versus 17.0 mm [15.6–22.5 mm], respectively) and progressive right heart dilatation. The endothelialization was poorer around the central areas. Moreover, the prevalence of thrombus formation on the devices was higher in the poorly endothelialized areas than in the sufficiently endothelialized areas (Grade 0, 94.1%; Grade 1, 63.2%; Grade 2, 0%; Grade 3, 1.6%). Conclusions Neo‐endothelialization on the closure devices varied 6 months after implantation. Notably, poor endothelialization and thrombus attachment were observed around the central areas and on the larger devices.

Assessment of Device Neoendothelialization With Cardiac Computed Tomography Angiography After Transcatheter Closure of Atrial Septal Defect

“…A recently published study based on angioscopy evaluation of ASD devices also supported the possibilities of delayed incomplete NE. 41 Although it is challenging to describe the more reliable mechanism, our assessment via CCTA could aid in understanding the natural course of devices with noninvasive and objective modalities.…”

“… 44 , 45 Several reports showed a significant association between bulky shape with greater device thickness and incomplete device NE. 39 , 41 Although we suggested the cutoff of 21 mm as a predictor for incomplete NE, it is too early to use this value itself to make clinical decisions. Due to the selection bias and other contributing factors, this cutoff value would not necessarily present relevant clinical implications, and this was rather represented to demonstrate the increased risk of incomplete NE in larger devices.…”

An unusual site of ablation for a ventricular tachycardia

“…Endothelialization of occluder devices used for atrial septal defects (ASD) typically occurs within 6 months to 2 years 4 . This experience is likely extrapolated to VSD septal occluder devices as well.…”

Late bacterial endocarditis after percutaneous atrial septal defect closure

“…They evaluated neo-endothelialisation on the surface of discs with angioscopy 6 months after device implantation. 10 They described that the neo-endothelialisation of the devices varied among the study patients and that the patients treated with a large device might show poor endothelialisation. Moreover, the endothelialisation of the central areas was insufficient.…”

“…They considered that incomplete endothelialisation was related to the device size, right ventricular systolic pressure, and enlargement of the right ventricle volume overload. 10 The period until complete endothelialisation in humans may differ substantially among individuals. The current guidelines are primarily focused on appropriate antibiotic prophylaxis for infective endocarditis.…”