Long-term transesophageal echocardiography after patent foramen ovale closure by BioSTAR and Amplatzer patent foramen ovale occluders

Relationship between patent foramen ovale anatomical features and residual shunt after patent foramen ovale closure

Transcatheter closure of patent foramen ovale (PFO) is an effective strategy for preventing recurrence of paradoxical embolism. However, PFO closure is often associated with residual shunt, which is a risk of recurrent stroke. This study aimed to evaluate the relationship between the anatomical features of PFO and residual shunt. The degree of residual shunt and its relationship with the anatomical features of PFO were evaluated in 106 patients who underwent PFO closure at our institution between March 2011 and January 2022 and in whom contrast transthoracic echocardiography was performed 1 year later. The mean PFO tunnel length was 9.3 ± 3.6 mm and the mean PFO height was 3.2 ± 2.2 mm. Atrial septal aneurysm (ASA) was found in 37 patients. After PFO closure, residual shunt was observed in 28 patients (grade 1, n = 8; grade 2, n = 16; grade 3, n = 3; grade 4, n = 1). Univariate logistic analysis identified ASA to be associated with residual shunt (odds ratio 2.78, 95% confidence interval 1.14 to 6.79; p = 0.024). There was no association of residual shunt with the size of the PFO, the length of PFO tunnel, or the size of the device used for closure. Two of four patients with a large residual shunt of grade 3 or grade 4 were found to have device size mismatch. Residual shunt after PFO closure was observed in a quarter of patients and was related to the presence of ASA. A few patients had a large residual shunt due to the device size mismatch.

Progress of biodegradable polymer application in cardiac occluders

Cardiac septal defect is the most prevalent congenital heart disease and is typically treated with open-heart surgery under cardiopulmonary bypass. Since the 1990s, with the advancement of interventional techniques and minimally invasive transthoracic closure techniques, cardiac occluder implantation represented by the Amplazter products has been the preferred treatment option. Currently, most occlusion devices used in clinical settings are primarily composed of Nitinol as the skeleton. Nevertheless, long-term follow-up studies have revealed various complications related to metal skeletons, including hemolysis, thrombus, metal allergy, cardiac erosion, and even severe atrioventricular block. Thus, occlusion devices made of biodegradable materials have become the focus of research. Over the past two decades, several bioabsorbable cardiac occluders for ventricular septal defect and atrial septal defect have been designed and trialed on animals or humans. This review summarizes the research progress of bioabsorbable cardiac occluders, the advantages and disadvantages of different biodegradable polymers used to fabricate occluders, and discusses future research directions concerning the structures and materials of bioabsorbable cardiac occluders.

Patent Foramen Ovale-associated Stroke and COVID-19 Vaccination

Background: COVID-19 infection has been associated with paradoxical thromboembolism through a patent foramen ovale (PFO) and ischaemic stroke. Such events have not been reported after COVID-19 vaccination. The aim of the present study was to investigate PFO-associated stroke during the mass COVID-19 vaccination in Slovenia. Methods: This prospective study, conducted between 26 December 2020 and 31 March 2022, enrolled consecutive patients (≥18 years) with PFO-associated stroke referred for a percutaneous closure to a single interventional facility in Slovenia. Results: A total of 953,546 people aged between 18 and 70 years received at least one dose of a COVID-19 vaccine approved by the European Medicines Agency. Of the 28 patients presenting with PFO-associated stroke, 12 patients (42.9%) were vaccinated prior to the event, of whom nine were women and three were men, aged between 21 and 70 years. Stroke occurred within 35 days after vaccination in six patients (50%). Clinical presentation included motor dysphasia, paresis, vertigo, ataxia, paraesthesia, headache, diplopia and hemianopia. At hospital discharge, 11 patients (91.6%) had at least one residual ischaemic lesion. Conclusion: A temporal coincidence of COVID-19 vaccination and PFO-associated stroke has been described. A potential cause–effect relationship may only be hypothesised.

Recent advances in catheter devices for patent foramen ovale closure

INTRODUCTION

Over the last 5 years, the armamentarium of the interventional cardiologist dealing with percutaneous closure of patent foramen ovale (PFO) has been enriched by some novel devices and further improvements of existing ones that have or promise to increase the safety and effective closure rate of PFO patients.

AREAS COVERED

This review presents and discusses recent advancements in device design and composition from both technical and clinical perspectives.

EXPERT OPINION

Device technology is continuously evolving. The recent modification of delivery system, device hooking, and composition, as well as the advent of new bioabsorbable materials, is promising to make percutaneous PFO closure devices safer. The search for more effectiveness with possibly less metal behind is still ongoing.

Favorable mid-term performance of fully biodegradable implantable device for ventricular septal defect closure

Objectives

To assess the mid-term safety and efficacy of transthoracic perimembranous ventricular septal defect (Pm-VSD) closure using a new biodegradable device. Implantation entailed right subaxillary minithoracotomy under transesophageal echocardiography guidance.

Methods

Between October 2019 and January 2020, 13 patients (males, 5; mean age, 3.6 ± 2.5 years) with Pm-VSDs underwent transthoracic device closures at Zhengzhou University Central China Fuwai Hospital as described previously. Delivery pathways were established by manipulating a hollow probe from right atrium through tricuspid valve to right ventricle and then through VSDs to left ventricle, whereupon installation took place.

Results

All occluder implantations were successfully executed. Mean defect size was 4.1 ± 1.0 mm, and mean device waist size was 5.2 ± 1.1 mm. One patient (7.7%) with 1.5-mm residual shunt showed complete closure at discharge. There was 1 instance of postoperative incomplete right bundle branch block, which converted to complete right bundle branch block at month 1. During patient follow-up (mean, 24.6 ± 0.8 months), no device dislocations, new residual shunts, new valvular regurgitation, or detectable atrioventricular block ensued.

Conclusions

Closure of Pm-VSDs using a novel, fully biodegradable occluder in the manner described has proven safe and effective at mid-term follow-up. Long-term safety and efficacy of this device must be further corroborated in a large patient cohort going forward.

A Prospective, Single-Center, Phase I Clinical Trial to Evaluate the Value of Transesophageal Echocardiography in the Closure of Patent Foramen Ovale With a Novel Biodegradable Occluder

Objective

Traditional metal alloy occluders for the closure of patent foramen ovale (PFO) may be associated with some potential complications, and may restrict the trans-septal access to the left atrium for future treatment of left-sided heart disease. Increasing attention has been paid to novel biodegradable occluders (NBOs) to achieve PFO closure. We aimed to evaluate the role of transesophageal echocardiography (TEE) in the diagnostic and anatomical evaluation of PFO, as well as in the Post-procedural assessment after transcatheter closure with a NBO.

Methods

We conducted a prospective, single-center clinical study of 44 patients who were diagnosed with PFO by contrast transthoracic echocardiography (c-TTE) and TEE from June 2019 to June 2020. All patients underwent PFO occlusion with NBO under TTE guidance. Follow-up was performed at 2 days and 3 months after the procedure with TTE, and at 6 months and 1 year after the procedure with c-TTE, TTE, and TEE.

Results

Interventional treatment was successfully performed in all patients. The left and right sides of the occluder device disc were significantly reduced at 3, 6, and 12 months compared to 2 days after the procedure (all P < 0.01), and decreased gradually. The thickness was significantly reduced at 12 months compared to the first three time points (all P < 0.01). Thrombus was found on the surface of the occluder device in three patients (6.4%) at 3 and 6 months after occlusion. At 6 months after procedure, there were 3 (6.8%) cases of extensive residual right-to-left shunt (RLS), 2 (4.5%) cases of moderate shunt, and 7 (15.9%) cases of small shunts. One year after procedure, 2 (4.5%) cases had a extensive residual shunt, 6 (13.6%) cases of small shunts were confirmed to originate from pulmonary veins by TEE, and the PFO-RLS occlusion rate reached 95.5%.

Conclusion

This study demonstrates the feasibility, safety, and effectiveness of NBO for the closure of PFO in humans, with a high rate of complete shunt closure. Accurate TEE assessment of the PFO anatomy before closure with NBO is important to ensure that the procedure remains safe and effective. Furthermore, TEE plays a crucial role in the Post-procedure follow-up.