Direct access transcatheter mitral annuloplasty with a sutureless and adjustable device: preclinical experience†

OBJECTIVES The aim of the study was to evaluate the technical feasibility and performance of a transcatheter mitral annuloplasty system. METHODS Adult swines (n=15) underwent left thoracotomy through the 4th-5th intercostal space. A transcatheter device (CardioBand, Valtech-Cardio Ltd) was introduced through an 18F sheath through the left atrium and attached to the annulus between the posterior and anterior commissures using echocardiographic and fluoroscopic guidance, on the beating heart. The sutureless device was implanted using a steerable delivery system to deploy sequential fixation elements. Following implantation, the device length was adjusted on the beating heart to reduce the intercommissural and septolateral dimension, under echocardiographic guidance. Finally, the flexible adjustment tool was withdrawn from the working sheath and the atrial purse-string closed. All but five animals were sacrificed acutely by intent, while the others were sacrificed at 90 days. RESULTS All animals survived the acute implant. One animal died at the third post-operative day due to bleeding. The annuloplasty system was successfully implanted in all animals. A mean of 12±3 fixation elements were deployed. The band length was reduced up to 20% after implantation in each animal. At necropsy, the location of the implant was within a few millimetres of the annulus (3.5±4mm). In three animals, fixation elements were implanted inadvertently in the leaflets, but no coronary lesions were observed. All animals survived the acute implant. One animal died on the third post-operative day due to bleeding. In the four long-term survivors, the implanted annuloplasty device showed satisfactory healing and no ring dehiscence. CONCLUSIONS Transcatheter minimally invasive, beating-heart implantation of an adjustable annuloplasty band is feasible in the animal model. This approach may be an alternative to open surgical procedures in high-risk patient

Beating-heart implantation of adjustable length mitral valve chordae: acute and chronic experience in an animal model

Objective: This study aimed to determine the acute and chronic performance of a new system designed to conduct beating-heart implantation and off-pump adjustment of neochordal length. Methods: In 14 adult sheep (group A) selected to undergo beating-heart cardiopulmonary bypass, the left atrium was opened through a left thoracotomy. Two or more primary chordae in the A2 region were severed to produce a model of a flail leaflet. A chordal adjustment mechanism (V-Chordal, Valtech Cardio Ltd., Or-Yehuda, Israel) was affixed to the head of the papillary muscle. The system includes two adjustable neochordae. The distal end of the neochordae was sutured to the flail segment without estimating the appropriate length. The neochordal length was adjusted off-pump under real-time echo-guidance. The adjustment tool was removed and the atriotomy was closed with a purse-string suture. Control animals (group B, n=4) were implanted with the conventional neochordae. Animals in both groups were sacrificed 3 months after the procedure. Results: In both groups, prior to repair, mitral regurgitation (MR) was severe in all animals. In group A, following adjustment of neochordae, MR was absent in all animals, with the exception of two animals that had residual 2+ MR irresponsive to neochordae adjustments. In group B, MR was 2+ in two of the four animals following repair. At 3 months, mitral competence was stable in all animals. At necropsy, normal healing of the papillary head and leaflet was observed in both the groups. Conclusions: The V-Chordal system simplifies the process of neochordal implantation and precise off-pump adjustment of the neochordal length to correct MR occurring due to a flail leaflet. This technology may improve the technical feasibility for adoption of chordal repair during open or minimally invasive surgical procedure

Real-time three-dimensional echocardiographic assessment of mitral valve: Is it really superior to 2D transesophageal echocardiography?

Aim of our study was to investigate the feasibility of use and possible additional value of real-time 3D transesophageal echocardiography (RT-3D-TEE) compared to conventional 2D-TEE in patients undergoing elective mitral valve repair. After ethical committee approval, patients were included in this prospective study. After induction of anesthesia, a comprehensive 2D-TEE examination was performed, followed with RT-3D-TEE. The intraoperative surgical finding was used as the gold standard for segmental analysis. Only such segments which were surgically corrected either by resection or insertion of artificial chords were judged pathologic. A total of 50 patients were included in this study; usable data were available from 42 of these patients . Based on the Carpentier classification, the pathology found was type I in 2 (5%) patients, type II in 39 (93%) patients and type IIIb in 1 (2%) patient. We found that 3D imaging of complex mitral disease involving multiple segments, when compared to 2D-TEE did not show any statistically significant difference.RT-3D-TEE did not show any major advantage when compared to conventional 2D-TEE for assessing mitral valve pathology, although further study in a larger population is required to establish the validity of this study

Innovations in minimally invasive mitral valve pair

Mitral valve (MV) insufficiency is the second most common heart valve disease represented in cardiac surgery. The gold standard therapy is surgical repair of the valve. Today, most centers prefer a minimally invasive approach through a right-sided mini-thoracotomy. Despite the small access, there is still the need to use cardiopulmonary bypass (CPB), and the operation has to be performed on the arrested heart. New devices have been developed to optimize the results of surgical repair by implementing mechanisms for post-implantation adjustment on the beating heart or the avoidance of CPB. Early attempts with adjustable mitral annuloplasty rings go back to the early 1990s. Only a few devices are available on the market. Recently, a mitral valve adjustable annuloplasty ring was CE-marked and is under further clinical investigation. In addition, a sutureless annuloplasty band to be implanted on the beating heart is under preclinical and initial clinical investigation for transatrial and transfemoral transcatheter implantation. Furthermore, new neochord systems are being developed, which allow for functional length adjustment on the beating heart after implantation. Some devices were developed for percutaneous MV repair implanted into the coronary sinus to reshape the posterior MV annulus. Other percutaneous devices are directly fixed to the posterior annulus to alter its shape. Several disadvantages have been observed preventing a broad clinical use of some of these devices. There is a continuous effort to develop innovative techniques to optimize MV repair and to decrease invasiveness