nitinol and Heart-Septal-Defects--Ventricular

Although the use of bioabsorbable occluder is expected to reduce the risk of metal occluder-related complications, it has not been approved due to incomplete degradation and new complications. Novel fully bioabsorbable occluders were designed to overcome such limitations. The aim of this study was to investigate the efficacy and safety of a fully biodegradable occluder in patients with ventricular septal defects. 125 patients with perimembranous ventricular septal defect (VSD) larger than 3 mm were screened from April 2019 to January 2020 in seven centers. 108 patients were enrolled and randomized into the bioabsorbable occluder group (n = 54 patients) and nitinol occluder group (n = 54). A non-inferiority design was utilized and all patients underwent transcatheter device occlusion. Outcomes were analyzed with a 24-month follow-up. All patients were successfully implanted and completed the trial. No residual shunt >2 mm was observed during follow-up. Transthoracic echocardiography showed a hyperechoic area corresponding to the bioabsorbable occluder which decreased primarily during the first year after implantation and disappeared within 24 months. Postprocedural arrhythmia was the only occluder-related complication with an incidence of 5.56% and 14.81% for the bioabsorbable and nitinol groups, respectively (P = 0.112). The incidence of sustained conduction block was lower in the bioabsorbable occluder group (0/54 vs. 6/54, P = 0.036) at 24-month follow-up. In conclusion, the novel fully bioabsorbable occluder can be successfully and safely implanted under echocardiography guidance and reduce the incidence of sustained postprocedural arrythmia. The efficacy and safety of this fully biodegradable occluder are non-inferior to that of a traditional nitinol one.

Topics: Absorbable Implants; Arrhythmias, Cardiac; Cardiac Catheterization; Echocardiography; Heart Septal Defects, Ventricular; Humans

Topics: Alloys; Cardiac Catheterization; Child, Preschool; Heart Septal Defects, Ventricular; Humans; Prosthesis Design; Radiography, Interventional; Septal Occluder Device; Treatment Outcome

Transcatheter closure has become the method of choice for treatment of many heart defects. Recently, Lifetech Scientific introduced the Cera occluder (CO), a self-expandable nitinol wire-mesh device covered with ceramic coating. We present our preliminary experience in transcatheter closure of atrial septal defect (ASD), patent foramen ovale (PFO), patent ductus arteriosus (PDA), and post-infarction ventricular septal defect (PIVSD) with the CO.. The study population consisted of 25 patients (17 female) ages 1.1-82 years (median age, 34.0 years) with either ASD (n = 7), PFO (n = 11), PDA (n = 6), or PIVSD (n = 1). All patients were treated percutaneously with appropriate CO devices, without any preliminary patient selection. The implantation technique applied in these procedures was the same as previously described for Amplatzer occluders.. All procedures were performed successfully. Complete shunt closure was achieved in all but 1 patient with PIVSD. No complications were observed during procedures or during follow-up of 0.5-4 months.. Our preliminary experience in the clinical application of COs for transcatheter closure of ASD, PFO, PDA, and PIVSD has confirmed their utility, feasibility, and safety, at least in the short-term follow-up.

Topics: Adult; Alloys; Cardiac Catheterization; Echocardiography, Transesophageal; Female; Heart Defects, Congenital; Heart Septal Defects, Ventricular; Humans; Male; Prosthesis Design; Prosthesis Implantation; Prosthesis Retention; Retrospective Studies; Septal Occluder Device; Treatment Outcome

This study evaluated feasibility and safety of implanting the polyester-coated nitinol ventricular septal defect occluder (pcVSDO) in the canine model.. VSD models were successfully established by transseptal ventricular septal puncture via the right jugular vein in 15 out of 18 canines. Two types of VSDOs were implanted, either with pcVSDOs (n = 8) as the new type occluder group or with the commercial ventricular septal defect occluders (VSDOs, n = 7, Shanghai Sharp Memory Alloy Co. Ltd.) as the control group. Sheath size was 10 French (10 Fr) in two groups. Then the general state of the canines was observed after implantation. ECG and TTE were performed, respectively, at 7, 30, 90 days of follow-up. The canines were sacrificed at these time points for pathological and scanning electron microscopy examination. The devices were successfully implanted in all 15 canines and were retrievable and repositionable. There was no thrombus formation on the device or occurrence of complete heart block. The pcVSDO surface implanted at day 7 was already covered with neotissue by gross examination, and it completed endothelialization at day 30, while the commercial VSDO was covered with the neotissue in 30th day and the complete endothelialization in 90th day.. The study shows that pcVSDO is feasible and safe to close canine VSD model and has good biocompatibility and shorter time of endothelialization.

Topics: Alloys; Animals; Catheters; Coated Materials, Biocompatible; Disease Models, Animal; Dogs; Heart Septal Defects, Ventricular; Humans; Polyesters; Septal Occluder Device

To evaluate the feasibility and efficacy of a new nanoplatinum-coated nitinol device for transcatheter ventricular septal defect (VSD) closure in a swine model.. In spite of its good closure results, the previous version of Amplatzer perimembranous VSD device had a relatively high incidence of complete heart block as compared to surgical closure. This new VSD device is made from meshed nitinol wires, nanoplatinum-coated and filled with polypropylene sheaths to enhance thrombogenicity. With special design, the device has minimal expanding pressure on the nearby tissue. This may reduce the possibility of atrioventricular block after implantation.. VSD was created in 12 pigs via retrograde aortic approach, by ventricular septal puncture with Brokenbrough needle and ventricular septal balloon dilation, under echocardiographic and fluoroscopic guidance. After imaging study, the device was deployed for VSD closure.. The device was successfully deployed to close the created VSD in all 12 animals. Angiographic and echocardiographic studies demonstrated complete closure of the VSD in 11 animals. One animal had residual VSD leakage. Three animals had unstable hemodynamics and died within 12 hours after the procedure. The remaining 9 animals survived in normal condition. The autopsy findings demonstrated complete endothelialization at 8 weeks after implantation.. Transcatheter VSD closure with the new nanoplatinum-coated nitinol device is feasible and efficacious. The good occlusion results and complete endothelialization after implantation in the swine model potentiates human application.

Topics: Alloys; Animals; Cardiac Catheterization; Coated Materials, Biocompatible; Disease Models, Animal; Echocardiography; Heart Septal Defects, Ventricular; Nanostructures; Platinum; Prostheses and Implants; Prosthesis Design; Septal Occluder Device; Swine; Treatment Outcome

This study assessed the feasibility and efficacy of implanting a new nitinol device for closure of perimembranous ventricular septal defects in a swine model.. Perimembranous ventricular septal defect occurs in 80% of patients requiring treatment for congenital heart disease.. The Amplatzer perimembranous ventricular septal occluder device (pmVSO2 device, AGA Medical Company, Plymouth MN) is a new transcatheter Nitinol device containing polyester fabric designed to close the perimembranous ventricular septal defect (VSD). The device has 75% reduction in radial force, 45% reduction in clamping force, and increased stability as compared to the previous version. The device was implanted in six swine with naturally occurring perimembranous VSD with immediate, 1, 7, ∼30, and ∼90 day followup by echocardiography, angiography, and final pathological examination.. The device was successfully implanted in all animals and was retrievable and repositionable. There was complete occlusion of the VSD in five of six cases without embolization. There was no thrombus formation on the device or occurrence of complete heart block. A single instance of a tiny residual shunt was attributed to capture of tricuspid valve apparatus.. The success of this animal study confirms safety and feasibility of the Amplatzer pmVSO2 device. Human trials are planned.

Topics: Alloys; Animals; Cardiac Catheterization; Coronary Angiography; Echocardiography, Doppler, Color; Feasibility Studies; Heart Septal Defects, Ventricular; Materials Testing; Prosthesis Design; Septal Occluder Device; Swine; Swine, Miniature; Time Factors

The Amplatzer ventricular septal defect (VSD) occluder has a fixed stainless steel pin bottom protruding out of the surface at the center of the discs on both sides. Theoretically, this protruding bottom may interfere with epithelialization or, in some cases, cause thrombosis.. To evaluate a new type of pan-nitinol VSD occluder without the protruding stainless steel pin bottom on both sides in a canine VSD model designed to ensure safety, effectiveness, and feasibility.. VSDs were successfully created by transseptal ventricular septal puncture with a Brockenbrough needle and dilation with an 8-mm-diameter balloon via the right jugular vein in 9 out of 12 canines. The new type VSD occluder was successfully implanted in 8 of the 9 modeled canines. No procedure- or device-related complication was observed. Transthoracic echocardiography and MRI 2 months after device implantations showed that there was no device dislocation or heart valve dysfunction in 6 of the 8 tested canines. In addition, gross and pathological examinations 3-6 months after implantation showed no corrosion of the devices or serious inflammatory reactions in the modeled animals. Complete endothelialization was seen over the surface of the discs.. The new pan-nitinol VSD device can be successfully implanted in a canine VSD model via a transcatheter approach featuring high success rate, low risk of procedure-related complications, and sound biocompatibility. The result suggests that this new VSD occluder could be used safely in future clinical trials for further test.

Topics: Alloys; Angioplasty, Balloon, Coronary; Animals; China; Disease Models, Animal; Dogs; Electrocardiography; Euthanasia, Animal; Heart Septal Defects, Ventricular; Prosthesis Implantation; Treatment Outcome

In the last decade percutaneous transcatheter techniques and devices for closure of intracardiac defects have considerably improved. Transcatheter ASD closure has become a routine procedure in many centers. It is technically feasible in about 80% of the patients with a secundum type defect. The success rate today is higher than 99% and the rate of any complication below 0.5%. The advantages compared to surgery are the avoidance of a thoracotomy, postoperative pain and morbidity. The length of hospital stay is much shorter and most often general anesthesia is not necessary. Patent foramen ovale has been recognized as a potential cause of paradoxical embolism and embolic stroke particularly in younger patients. Transcatheter closure has recently gained popularity since several studies demonstrated a reduced rate of recurrent strokes after device closure. The occlusion is technically relatively simple and can be performed with ASD closure devices or with devices modified according to the anatomy of the foramen ovale. Catheter closure has certain advantages compared with life-long anticoagulation. For some patients this is the only therapeutic option. Nevertheless, there is still a need for randomized studies. Catheter closure of ventricular septal defects is possible today in selected patients. There are devices available specifically designed for muscular defects, for perimembraneous defects and subaortic ventricular septal defects.

Topics: Adolescent; Adult; Age Factors; Aged; Aged, 80 and over; Alloys; Animals; Child; Clinical Trials as Topic; Dogs; Echocardiography, Transesophageal; Female; Follow-Up Studies; Heart Septal Defects, Atrial; Heart Septal Defects, Ventricular; Humans; Intraoperative Complications; Middle Aged; Multicenter Studies as Topic; Patient Selection; Polytetrafluoroethylene; Prostheses and Implants; Time Factors

Transcatheter closure of a membranous ventricular septal defect (MVSD) is much more difficult than closure of other intracardiac defects because of the proximity to the aortic and tricuspid valves and their relatively large size in small children. In this report, transcatheter closure of naturally occurring membranous VSDs was attempted in 12 Yucatan minipigs. The prosthesis is constructed from fine Nitinol wires in the shape of two buttons and a connecting waist filled with polyester fiber. Two kinds of prosthesis were used in this study: concentric and eccentric left-sided retention disks. A 6 or 7 Fr delivery sheath was advanced across the membranous VSD over a wire from femoral vein. The prosthesis was inserted through the sheath by pushing the delivery cable to deploy a button into left ventricle and the second button was then deployed into right ventricle by withdrawing the sheath. Successful implantation of the device was achieved in all animals except one. Complete closure rate was 58.3% immediately after placement, 100% at 1 week, 90.9% at 1 month and 3 months, and 100% at 6 months. An associated aneurysm of the membranous septum increased significantly in size in two of three animals using the concentric device, and in none of the animals using the eccentric device. A trace to mild aortic regurgitation was present in two of the three animals using the concentric device, and only in one of the eight animals using the eccentric device. Five animals developed a trace to mild tricuspid regurgitation. Pathologic examination showed all devices to be covered by smooth neoendothelium at 3 months. This report presents the first experimental study where closure of membranous ventricular septal defects in a swine model was attempted by specially constructed devices. Procedural success and occlusion rates are very encouraging but overall results cannot equal surgery. Further experimentation is needed with devices that are redesigned according to the experience gained from this study.

Topics: Alloys; Angiography; Animals; Biocompatible Materials; Cardiac Catheterization; Disease Models, Animal; Heart Septal Defects, Ventricular; Prosthesis Design; Prosthesis Implantation; Stents; Swine, Miniature

Repair of muscular ventricular septal defects (MVSDs) has always been challenging to the surgeon. Long-term morbidity and mortality are significantly increased if the defects are closed via left ventriculotomy or if they are associated with other complex congenital anomalies. The purpose of this study was to close MVSDs with the Amplatz ventricular septal defect device. This device is constructed from 0.004-in nitinol wire mesh filled with polyester fibers. It is retrievable, repositionable, self-centering, and of low profile.. MVSDs were created with the help of a sharp punch in 10 dogs. The location of the defects was anterior muscular (n=3), midmuscular (n=3), apical (n=3), and inlet muscular (n=1). The diameter of the defects ranged from 6 to 14 mm. All defects were closed in the catheterization laboratory. The device was placed with the help of transesophageal echocardiography and fluoroscopy. A 7F sheath was used to deploy the device from the right ventricular side in 8 and the left ventricular side in 2 dogs. Placement was successful in all animals. The complete closure rate was 30% (3/10) immediately after placement and 100% at 1-week follow-up. Pathological examination of the heart revealed complete endothelialization of the device in dogs killed after 3 months.. The Amplatz ventricular septal defect device appears highly efficacious in closing MVSDs. The advantages include a small delivery sheath, complete retrievability before release, and the fact that it is self-centering and self-expanding, thereby making it an attractive option in smaller children.

Topics: Alloys; Animals; Cardiac Surgical Procedures; Coronary Angiography; Disease Models, Animal; Dogs; Echocardiography, Transesophageal; Endocardium; Fluoroscopy; Follow-Up Studies; Heart Septal Defects, Ventricular; Heart Ventricles; Time Factors