nitinol and Mitral-Valve-Insufficiency

Mitral regurgitation is the most commonly occurring valvular heart disease in developed countries. Transcatheter mitral valve replacement (TMVR) has emerged as a novel potential therapy for patients with severe mitral valve disease who are unsuitable candidates for conventional surgery or transcatheter edge-to-edge mitral repair. TMVR with the Tendyne prosthesis has shown potential at short-term follow-up to be an effective and safe treatment alternative for high-risk patients with severe mitral valve disease.

Topics: Aged; Aged, 80 and over; Alloys; Cardiac Catheterization; Clinical Trials as Topic; Echocardiography, Transesophageal; Feasibility Studies; Heart Valve Diseases; Heart Valve Prosthesis Implantation; Humans; Mitral Valve; Mitral Valve Insufficiency; Multimodal Imaging; Non-Randomized Controlled Trials as Topic; Prospective Studies; Prosthesis Design; Quality of Life; Severity of Illness Index; Treatment Outcome; Ventricular Outflow Obstruction

Transcatheter mitral valve replacement with the Intrepid device is intended for patients who need mitral valve replacement and who are at an increased risk for conventional surgery. The early published results of the early feasibility trial are reviewed as well as device design and the implant procedure. The Apollo trial is reviewed: a randomized trial of the Intrepid device versus conventional surgery including a single arm study for inoperable patients. The mitral valve structure, pathophysiology, and postimplant physiology pose unique hurdles for any transcatheter implant.

Topics: Aged; Aged, 80 and over; Alloys; Cardiac Catheterization; Echocardiography, Transesophageal; Feasibility Studies; Female; Fluoroscopy; Heart Valve Prosthesis Implantation; Humans; Male; Mitral Valve; Mitral Valve Insufficiency; Prosthesis Design; Randomized Controlled Trials as Topic; Tomography, X-Ray Computed; Treatment Outcome

Topics: Alloys; Cardiac Catheterization; Heart Failure, Systolic; Heart Valve Prosthesis; Heart Valve Prosthesis Implantation; Humans; Mitral Valve; Mitral Valve Insufficiency; Patient Selection; Prosthesis Design; Risk Factors; Treatment Outcome

Topics: Alloys; Bioprosthesis; Cardiac Catheterization; Heart Valve Prosthesis; Heart Valve Prosthesis Implantation; Humans; Mitral Valve; Mitral Valve Insufficiency; Patient Selection; Prosthesis Design; Radiography, Interventional; Risk Factors; Treatment Outcome

Topics: Alloys; Bioprosthesis; Cardiac Catheterization; Heart Valve Prosthesis; Heart Valve Prosthesis Implantation; Humans; Mitral Valve; Mitral Valve Insufficiency; Patient Selection; Prosthesis Design; Risk Factors; Treatment Outcome

Topics: Alloys; Bioprosthesis; Cardiac Catheterization; Echocardiography, Three-Dimensional; Echocardiography, Transesophageal; Heart Valve Prosthesis; Heart Valve Prosthesis Implantation; Humans; Mitral Valve; Mitral Valve Insufficiency; Multidetector Computed Tomography; Patient Selection; Polyethylene Terephthalates; Prosthesis Design; Risk Factors; Treatment Outcome

Topics: Alloys; Animals; Cardiac Catheterization; Cattle; Heart Valve Prosthesis; Heart Valve Prosthesis Implantation; Humans; Mitral Valve; Mitral Valve Insufficiency; Prosthesis Design; Research; Surgical Instruments; Treatment Outcome

The MiCardia DYANA annuloplasty system (MiCardia Corp, Irvine, Calif) is a nitinol-based dynamic complete ring that allows modification of the septal-lateral diameter under transesophageal echocardiography guidance in the loaded beating heart after mitral valve repair. Shape alteration is induced by radiofrequency via detachable activation wires. This multicenter study reports the first human experience with this device.. Patients (n = 35, 67 ± 8 years) with degenerative (n = 29), functional/ischemic (n = 5), or rheumatic (n = 1) mitral regurgitation underwent mitral valve repair using the new device. We analyzed the occurrence of death, endocarditis, ring dehiscence, systolic anterior motion, thromboembolism, pulmonary edema, heart block, ventricular arrhythmia, hemolysis, or myocardial infarction at 30 days (primary end point) and 6 months (secondary end point) postprocedure.. All patients exhibited mitral regurgitation of 2 or less early postoperatively and at 6 months follow-up. In 29 patients, the initial mitral valve repair result was satisfactory and no ring activation was required. In 6 patients, the nitinol-based ring was deformed intraoperatively postrepair with further improvement of mitral regurgitation in all cases (preactivation: 0.9 ± 0.2, postactivation: 0.2 ± 0.3; P = .001). One death (2.9%, multisystem organ failure, non-device related), 2 ventricular arrhythmias (5.7%), and 1 heart block (2.9%) occurred, all in the first 30 days after surgery. No additional major adverse clinical events occurred later than 1 month postprocedure (total observed major adverse clinical event rate 11.5%).. The implantation of the new dynamic annuloplasty ring allows for safe mitral valve repair. The option of postrepair modification of the septal-lateral diameter by radiofrequency may further optimize repair results.

Topics: Aged; Alloys; Female; Germany; Heart Valve Prosthesis; Heart Valve Prosthesis Implantation; Humans; Male; Michigan; Middle Aged; Mitral Valve Annuloplasty; Mitral Valve Insufficiency; Postoperative Complications; Prospective Studies; Prosthesis Design; Time Factors; Treatment Outcome

Functional mitral regurgitation in heart failure limits survival in a severity-graded fashion. Even mild mitral regurgitation doubles mortality risk. We report the use of a non-stented coronary sinus device to reduce mitral annulus dimension in order to re-establish mitral valve competence. The device (PTMA, Viacor, Inc., Wilmington, MA, USA) consists of a multi-lumen PTFE (Teflon) PTMA catheter in which Nitinol (nickel-titanium alloy) treatment rods are advanced. For individual use up to three rods of different length and stiffness can be used. Therefore dimension reduction can be performed in an incremental fashion. Fluoroscopy and 3 D echocardiography are performed throughout the procedure to visiualize the positioning and confirm maximum treatment effect. The case describes the use and the effect of PTMA treatment. Safety and efficacy of the PTMA device will be investigated in the upcoming PTOLEMY 2 trial.

Topics: Aged; Aged, 80 and over; Alloys; Cardiac Catheterization; Coronary Sinus; Echocardiography, Three-Dimensional; Female; Fluoroscopy; Follow-Up Studies; Heart Failure; Heart Valve Prosthesis; Heart Valve Prosthesis Implantation; Humans; Male; Middle Aged; Mitral Valve Insufficiency; Prosthesis Design; Treatment Outcome

Tissue reaction to transcatheter mitral valve replacement in the mitral annulus remains to be elucidated.. Trileaflet porcine pericardial valves were sewn onto self-expanding d-shaped nitinol stents, which were delivered transapically and in an off-pump fashion into the mitral position of 10 pigs. After at least 4 weeks of follow-up, gross pathological assessment and histological examination were performed. The specimens were stained with Movat's pentachrome, Elastica-van-Gieson and von Kossa staining. The leucocytes, B cells, T cells or macrophages were detected by specific immunohistochemical staining.. Proper stent positioning in the mitral annulus was achieved in 9/10 animals. Nine of 10 animals survived the desired observation period. In all but one, the mitral valve stent was well integrated into the left atrium and perpendicularly embedded into the annulus by 85 ± 24%. One animal had minor fractures in the nitinol struts and another animal showed tearing of 1 of 4 tethers. Histological examination demonstrated no major tissue reaction with the nitninol struts but well-preserved overall structures around the mitral annulus in 8/9 cases.. This is the first report demonstrating good in-growth of transcatheter-delivered anatomically shaped mitral valve stents after at least 4 weeks of follow-up. Histological examination demonstrated progressive healing and neointimalization.

Topics: Alloys; Animals; Cardiac Catheterization; Heart Valve Prosthesis; Heart Valve Prosthesis Implantation; Mitral Valve; Mitral Valve Insufficiency; Prosthesis Design; Stents; Swine

In this study, results of a functional in vitro study of 2 newly developed valved stents for transcatheter mitral valve implantation are presented.. Two novel stent designs, an oval-shaped and a D-shaped stent with a strut fixation system were developed. The fixation force of the novel stents were tested in vitro in porcine hearts with a tensile test set-up. In further experiments, the stents were equipped with a circular valved stent, and the valve performances were investigated in a pulsatile heart valve tester.. Sufficient mean stent fixation forces in the range of 24.2 ± 0.9 N to 28.6 ± 1.9 N were measured for the different stent models. The novel valved stents showed good performance in an in vitro pulsatile heart valve tester. A sufficient opening area and low opening pressures were measured for all tested mitral valved stents. Compared with an established reference valve, the D-shaped stent and the oval-shaped valved stent showed a lower systolic transvalvular pressure gradient, which indicates slightly greater extent of valvular leakage of the closed valved stents. However, the mitral nitinol valved stents demonstrated adequate durability.. This study indicates a sufficient annular fixation force of the tested transcatheter mitral valve implantation valved stent prototypes. Therefore, these mitral valved stents demonstrate a new type of mitral valved stent design.

Topics: Alloys; Animals; Cardiac Catheterization; Disease Models, Animal; Echocardiography; Heart Valve Prosthesis Implantation; Mitral Valve; Mitral Valve Insufficiency; Prosthesis Design; Self Expandable Metallic Stents; Swine

The present study investigates outcomes one month after implanting pigs with a novel mitral valved stent.. A novel nitinol stent custom designed for this study included a bovine pericardial valve. Six pigs received a valved stent into the mitral position by means of the transapical implantation technique. Afterwards, haemodynamic stability and valve function were assessed, immediately after implantation (n = 6), 4 weeks (n = 4) and 8 weeks (n = 1) thereafter using transoesophageal echocardiography (TEE), ventriculography and cardiac computed tomography (CT). Four of 6 surviving pigs were sacrificed at 4 weeks after implantation and one at 8 weeks thereafter.. Optimal deployment and positioning were obtained in all but one animal. This animal died of unrecognized imperfect valved stent positioning after 4 days. The average mean gradient across the new valves and the left ventricular outflow tract (LVOT) were small. Mild regurgitation developed after valved stent deployment in one of six animals just after 1 h, and in none thereafter. All animals exhibited normal haemodynamics after mitral valved stent implantation, and stability was maintained throughout the monitoring period. Migration, embolization and paravalvular leakage were not evident in the remaining animals after 4 and 8 weeks. Gross evaluation revealed that 50-70% of the atrial element was covered by tissue growth at 4 weeks/8 weeks.. This study demonstrates adequate deployment and anchorage of a unique, repositionable mitral valved stent. A good valve function was revealed in animals observed for 4 weeks and in one pig after 8 weeks.

Topics: Alloys; Animals; Echocardiography, Transesophageal; Heart Valve Prosthesis; Heart Valve Prosthesis Implantation; Hemodynamics; Minimally Invasive Surgical Procedures; Mitral Valve; Mitral Valve Insufficiency; Prosthesis Design; Stents; Sus scrofa; Tomography, X-Ray Computed

Transcatheter replacement or repair of mitral valve regurgitation has proved demanding. We aimed for a new approach to anchor a biologic heart valve in the mitral position by inserting a valve-carrying hollow body into the left atrium. This approach was investigated in both a simulation and an animal model.. After creating a mold representing the porcine left atrium from the pulmonary veins as far as the mitral valve, a nitinol skeleton was sutured onto interlaced yarns of polyvinylidene fluoride fitting the mold. The resulting device was equipped with a commercially available stentless valve (25 mm) and investigated in a simulator regarding basic functionality. Furthermore, the device was implanted in 8 female pigs through incision of the left atrium during extracorporeal circulation. Before implantation, artificial regurgitation was created by means of excision from the posterior mitral leaflet. Hemodynamic, echocardiographic, and radiologic examinations followed. For a postmortem examination, the entire heart and the lungs were excised.. We could demonstrate the functionality of the heart valve in a complex, collapsible, and self-expanding hollow body. The device adapted to the surrounding structures, leading to an exclusion of the left atrium. Sufficient treatment of mitral regurgitation was monitored hemodynamically and by means of echocardiographic analysis, although overall visualization remained difficult. Therefore in 4 animals computed tomographic scans were performed. Autopsy revealed proper positioning without major trauma to the surrounding structures.. Anchoring an additional heart valve in the atrioventricular position does not necessarily need to be performed in the heart valve structure itself. Placement of an additional valve in the mitral position is feasible through this approach.

Topics: Alloys; Animals; Cardiac Catheterization; Disease Models, Animal; Echocardiography, Transesophageal; Feasibility Studies; Female; Heart Valve Prosthesis; Heart Valve Prosthesis Implantation; Hemodynamics; Materials Testing; Mitral Valve; Mitral Valve Insufficiency; Models, Anatomic; Polyvinyls; Prosthesis Design; Swine; Tomography, X-Ray Computed

A totally endoscopic method of placing multiple premeasured artificial chordae with the assistance of the da Vinci surgical system (Intuitive Surgical Inc, Sunnyvale, Calif) and V60 U-clip devices (Medtronic Inc, Minneapolis, Minn) was evaluated.. Totally endoscopic placement of multiple artificial chordae with robotic assistance and nitinol clips was performed in 30 patients. After subvalvular exposure with a robotically controlled Atrial Retractor (Intuitive Surgical Inc), artificial chordae constructed of 4-0 polytetrafluoroethylene (Gore-Tex; WL Gore & Associates Inc, Flagstaff, Ariz) were secured to the prolapsing leaflet edge with V60 U-clips. Transesophageal echocardiography to assess successful repair was performed.. Repairs of the anterior leaflet, the posterior leaflet, and combinations of both were performed. Crossclamp and cardiopulmonary bypass times were in the range of 78.63 +/- 17.03 minutes and 118.17 +/- 22.55 minutes, respectively. Transesophageal echocardiography showed grade 0 to less than grade 1 mitral regurgitation postoperatively. All patients had an uneventful recovery phase and were discharged within 5 days.. Endoscopic placement of premeasured artificial neochordae is greatly facilitated by applying robotic assistance and using nitinol clips for chordae fixation. The endoscopic robotic technique provides excellent functional and clinical outcomes.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Bioprosthesis; Chordae Tendineae; Cohort Studies; Echocardiography, Transesophageal; Endoscopy; Female; Follow-Up Studies; Heart Valve Prosthesis Implantation; Humans; Male; Middle Aged; Mitral Valve; Mitral Valve Insufficiency; Mitral Valve Prolapse; Robotics; Surgical Instruments; Suture Techniques; Treatment Outcome

Topics: Aged; Alloys; Balloon Occlusion; Female; Heart Septal Defects, Atrial; Humans; Mitral Valve Insufficiency; Platelet Aggregation Inhibitors; Postoperative Complications; Surgical Mesh; Treatment Outcome; Wound Healing