Mitral leaflet anatomy revisited

ObjectiveThe aims of this work were to employ functional imaging capabilities of the Visible Heart laboratory and endoscopic visualization of mitral valves in perfusion-fixed specimens to better characterize variability in mitral valve leaflet anatomy and to provide a method to classify mitral leaflets that varies from the current nomenclature.MethodsWe gathered functional endoscopic video footage (11 isolated reanimated human hearts) and static endoscopic anatomical images (38 perfusion-fixed specimens) of mitral leaflets. Commissure and cleft locations were charted using Carpentier's accepted description.ResultsAll hearts had 2 commissures separating anterior and posterior leaflets. “Standard” clefts separating P1/P2 were found in 66% of hearts (n = 25), and standard clefts separating P2/P3 were present in 71% of hearts (n = 27). “Deviant” clefts occurred in each region of the anterior leaflet (A1, A2, A3), and their relative occurrences were 5%, 8%, and 13% (n = 2, 3, 5), respectively. Deviant clefts were found in posterior leaflets: 13.2% in P1 (n = 5), 32% in P2 (n = 12), and 21% in P3 (n = 8).ConclusionsHumans elicit complex and highly variable mitral valve anatomy. We suggest a complementary, yet simple nomenclature to address variation in mitral valve anatomy by describing clefts as either standard or deviant and locating regions in which they occur (A1 to A3 or P1 to P3)

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 Finally, the flexible adjustment tool was withdrawn from the working sheath and the atrial purse-string closed.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

validation of a decision making strategy for systolic anterior motion following mitral valve repair

Low cardiac output syndrome and hypotension are dreadful consequences of systolic anterior motion (SAM) after a mitral valve (MV) repair. The management of SAM in the operating room remains controversial. We validate a recently suggested two-step management method and classification of this complication. This was a teaching hospital-based observational study. We validated a novel two-step conservative management method, consisting in intravascular volume expansion and discontinuation of inotropic drugs (step 1), and increasing the afterload by ascending aorta manual compression while administering esmolol e.v. (step 2). We also validate a novel classification of SAM: easy-to-revert (responding to step 1), difficult-to-revert (responding to step 2), or persistent. Fifty patients had an easy-to-revert while 26 had a difficult-to-revert SAM; 4 patients had a persistent condition (promptly diagnosed through our decisional algorithm) and underwent an immediate second pump run to repeat the mitral repair surgery. We confirmed that SAM after a repair of a degenerative MV is common and validated a simple two-step conservative management method that allows to clearly identify those few patients who require immediate surgical revision

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

Genetic background of mitral valve prolapse

Mitral valve prolapse (MVP) has a prevalence of 2-3% among the population. It involves a heterogeneous group of patients with different expressions and according to the phenotype can be further divided into fibroelastic deficiency, which is mainly considered as a degeneration due to aging, and myxomatous disease, frequently associated with familiar clusters. Thus, MVP can be present in syndromic, when part of a well-defined syndrome, and non-syndromic forms. The latter occurs more often. To the second belong both familiar and isolated or sporadic forms. On one hand, among familial forms, although X-linked transmission related t