Repair of posterior mitral valve prolapse with a novel leaflet plication clip in an animal model.

OBJECTIVE: Recently, there has been increased interest in minimally invasive mitral valve prolapse repair techniques; however, these techniques have limitations. A new technique was developed for treating mitral valve prolapse that uses a novel leaflet plication clip to selectively plicate the prolapsed leaflet segment. The clip's efficacy was tested in an animal model. METHODS: Yorkshire pigs (n = 7) were placed on cardiopulmonary bypass (CPB), and mitral valve prolapse was created by cutting chordae supporting the P2 segment of the posterior leaflet. Animals were weaned off CPB and mitral regurgitation (MR) was assessed echocardiographically. CPB was reinitiated and the plication clip was applied under direct vision to the P2 segment to eliminate the prolapse. The animals survived for 2 hours. Epicardial echocardiography was obtained before and after prolapse creation and 2 hours after clip placement to quantify MR grade and vena contracta area. Posterior leaflet mobility and coaptation height were analyzed before and after clip placement. RESULTS: There were no cases of clip embolization. Median MR grade increased from trivial (0-1.5) to moderate-severe after MR creation (2.5-4+) (P < .05), and decreased to mild after clip placement (0-3+) (P < .05). Vena contracta area tended to increase after cutting the chordae and decrease after clip placement: 0.08 ± 0.10 cm(2) versus 0.21 ± 0.15 cm(2) versus 0.16 ± 0.16 cm(2) (P = .21). The plication clip did not impair leaflet mobility. Coaptation height was restored to baseline: 0.51 ± 0.07 cm versus 0.44 ± 0.18 cm (P = 1.0). CONCLUSIONS: The leaflet plication clip can treat mitral valve prolapse in an animal model, restoring coaptation height without affecting leaflet mobility. This approach is a simple technique that may improve the effectiveness of beating-heart and minimally invasive valve surgery.

Chronic hypobaric hypoxia, patent arterial duct and a new interventional technique to close it.

BACKGROUND: Interventional closure of patent arterial duct has become an accepted alternative to surgical closure. Clinical trial with "Nit-Occlud® PDA-R". METHODS AND RESULTS: To assess the safety and efficacy of the device, we performed a prospective clinical study between June, 2009 and December, 2010 in La Paz, Bolivia. In all, 29 - 22 female patients and 7 male patients - out of 59 patients were selected on the basis of inclusion criteria. The procedures were performed under sedation at an age and weight of 5.7 years and 22.7 kilograms, respectively, with 4-6 French arterial sheaths and 5-7 French venous sheaths. The minimal diameter of the duct was 3.5 millimetres. The procedure, fluoroscopy, and hospitalisation times were 96.4 minutes (55 to 145), 13.1 minutes (3 to 25.2), and 24 hours, respectively. The "Nit-Occlud® PDA-R" was successfully deployed in all patients. Immediate, 24-hour, 1-, 3-, and 6-month closure rates were 65.5%, 79.3%, 96.5%, and 100%, respectively. The systolic pulmonary pressure diminished from 37 millimetres of mercury (21 to 57) before the intervention to 31 millimetres of mercury (21 to 45) after the intervention. No early or late embolisation, haemolysis, left pulmonary artery, or descending aorta obstruction occurred. CONCLUSIONS: We conclude that the "Nit-Occlud® PDA-R" device is safe and effective in closing patent arterial duct up to a diameter of 8 millimetres.

Beating-heart patch closure of muscular ventricular septal defects under real-time three-dimensional echocardiographic guidance: a preclinical study.

OBJECTIVES: Safe and effective device closure of ventricular septal defects remains a challenge. We have developed a transcardiac approach to close ventricular septal defects using a patch delivery and fixation system that can be secured under real-time three-dimensional echocardiographic guidance. METHODS: In Yorkshire pigs (n = 8) a coring device was introduced into the left ventricle through a purse-string suture placed on the left ventricular apex, and a muscular ventricular septal defect was created. The patch deployment device containing a 20-mm polyester patch was advanced toward the ventricular septal defect through another purse-string suture on the left ventricular apex, and the patch was deployed under real-time three-dimensional echocardiographic guidance. The anchor delivery device was then introduced into the left ventricle through the first purse-string suture. Nitinol anchors to attach the patch around the ventricular septal defect were deployed under real-time three-dimensional echocardiographic guidance. After patch attachment, residual shunts were sought by means of two-dimensional and three-dimensional color Doppler echocardiography. The heart was then excised, and the septum with the patch was inspected. RESULTS: A ventricular septal defect was created in the midventricular (n = 4), anterior (n = 2), and apical (n = 2) septum. The mean size was 9.8 mm (8.2-12.0 mm), as determined by means of two-dimensional color Doppler scanning. The ventricular septal defects were completely closed in 7 animals. In one a 2.4-mm residual shunt was identified. No anatomic structures were compromised. CONCLUSIONS: Beating-heart perventricular muscular ventricular septal defect closure without cardiopulmonary bypass can be successfully achieved by using a catheter-based patch delivery and fixation system under real-time three-dimensional echocardiographic guidance. This approach might be a better alternative to cardiac surgery or transcatheter device closure.

Three-dimensional echo and videocardioscopy-guided atrial septal defect closure.

BACKGROUND: Current real-time three-dimensional echocardiography systems (RT3DE) can provide sufficient visualization to permit atrial septal defect (ASD) closure. However, detailed visualization of small objects inside the heart is still suboptimal because of limited resolution, which is a limitation for clinical application. We evaluate the complementary use of videocardioscopy in image-guided ASD closure. METHODS: In a pig model (n = 5), a 4-mm to 8-mm ASD was created with RT3DE guidance. Defect closure was accomplished with a catheter-based patch-delivery system fixed around the defect with mini-anchors under combined RT3DE and videocardioscopy guidance. The endoscope was inserted into the heart through a custom built port designed to allow visualization in the presence of blood. RESULTS: All ASDs were successfully closed. The combination of RT3DE and videocardioscopy allowed detailed visualization of intracardiac structures, instruments, patch, and mini-anchors. CONCLUSIONS: Beating-heart ASD closure can be achieved with combined RT3DE and videocardioscopy imaging. Use of videocardioscopy provides high-resolution imaging and likely improves safety of the image-guided procedure.