Geometric analysis of the anterior mitral leaflet and mitral valve orifice in cadaveric hearts.
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BACKGROUND: To establish the criteria for selecting a mitral annuloplasty ring of the correct size, the dimensions of the mitral valve orifice were analyzed in cadaveric hearts. MATERIALS AND RESULTS: From December 2000 to July 2006, the mitral valve diameter [DM (Obs)] and Z-values [DM (Z); standardized value based on Rowlatt's criteria], the angles of the trigones (theta Tg) and commissures (theta Com) and the intertrigonal distance [L (T)] were measured in 82 fresh cadaveric hearts from cases with variable causes of death (mean age 64.8+/-15.7 years; body surface area [BSA] 1.51+/-0.21 m2). DM (Obs), DM (Z) and L (T) were 2.8+/-0.5 cm, 1.16+/-0.98, and 1.8+/-0.2 cm, respectively. Theta Tg and theta Com averaged 76+/-13 and 121+/-11 degrees, respectively. There was a significant inverse linear relationship between DM (Z) and theta Tg [theta Tg =-10x DM (Z) +88] and a significant logarithmic correlation between L (T) and BSA [L (T) =0.54xLn (BSA) +1.55]. The anterior annular length and L (T) remained unchanged. CONCLUSION: In non-dilated cadaveric hearts, the trigones were located at one-quarter of the mitral annulus, so the appropriate length of the posterior annuloplasty band should be adjusted to L (T) x3.33. (+info)
Mitral valve replacement with chordae tendineae preservation, traction and fixation in end-stage dilated cardiomyopathy.
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OBJECTIVE: This study aimed at evaluating results of mitral valve replacement using a new technique of complete chordae tendineae adjustment for left ventricular remodeling. METHODS: Twenty end-stage idiopathic dilated cardiomyopathy patients with severe functional mitral valve regurgitation underwent mitral valve replacement. Seventeen (85%) were in functional class IV. Both anterior and posterior leaflets of the mitral valve were divided to obtain 4 pillars of chordae tendineae. These were displaced with traction toward the left atrium and anchored between the mitral annulus and a valvular prosthesis. To evaluate the left ventricular remodeling, Doppler echocardiography was performed. For statistical analysis, variance analysis and the Friedman's test were employed. RESULTS: Two (10%) early deaths occurred. Kaplan-Meyer showed survival at one year post-operative was 85%, 2 years it was 44%, at 3 years 44%, at 4 years 44% and at 5 years it was 44%. In the 48- and 54-month follow-ups, the McNemar test showed improvement in the functional class (p<0.001). In the third month of follow-up, variance analysis showed improvement in the ejection fraction (p=0.008) and reductions of the end diastolic diameter (p=0.038), end systolic diameter (p=0.008), end systolic volume (p=0.029) and end diastolic volume (p=0.009). No statistical differences were noted in the systolic volume. Comparing pre-operative and third- and six-month follow-ups, the Friedman test showed no statistical differences for all studied variables. Variance analyses between pre, three-month and final evaluations showed no significant differences. CONCLUSION: This technique of mitral valve replacement improved the left ventricle ejection fraction and decreased the end diastolic and systolic diameters and the end systolic diastolic volumes up to the third month of follow-up. From then on the variables stabilized. (+info)
Echocardiographic evaluation of patients submitted to replacement of ruptured chordae tendineae.
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OBJECTIVE: The objective of this study was to evaluate, using echocardiography, the functioning of the mitral valve apparatus in patients submitted to standardized bovine pericardium chordae implantation to substitute ruptured chordae tendineae or elongated chordae with a significant degree of thinning. METHOD: Standardized bovine pericardium chordae were implanted in 23 patients with mitral valve insufficiency due to ruptured or elongated chordae with significant thinning. The ages of the patients varied from 23 to 84 years old (mean 62 years old). The most common cause was fibroelastic degeneration affecting 20 (87.0%) patients. The standardized bovine pericardium chordae were manufactured in sets connected at both ends by two polyester-reinforced rods thereby forming a single block. The bovine pericardium chordae measure 2 mm wide with 3 mm between the chordae. The sets of bovine pericardium chordae are produced in lengths varying from 20 to 35 mm. In 17 (73.9%) patients bovine pericardium chordae were implanted in the posterior cusp and in 6 (26.1%) in the anterior cusp. All the patients were evaluated in the postoperative period by echocardiography after a mean follow-up of six months. RESULTS: The echocardiography in the postoperative period demonstrated an absence of reflux in 11 (47.8%) patients, slight reflux in 8 (34.8%) and slight to moderate reflux in 3 (13.0%). The opening and mobility of the mitral valve was normal in the 22 surviving patients. CONCLUSION: The echocardiography demonstrated good functioning of the mitral valve apparatus in patients submitted to the implantation of standardized bovine pericardium chordae to substitute ruptured chordae tendineae or elongated chordae with a significant degree of thinning. (+info)
Mitral valve replacement with the preservation of the entire valve apparatus.
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OBJECTIVE: The papillary muscles and the chordae tendineae of both mitral leaflets contribute to the preservation of the left ventricular function. Most surgeons, however, routinely excise the anterior mitral leaflet. METHODS: In a group of nine patients, six of them underwent mitral valve replacement alone and three underwent both aortic and mitral valve replacements, all the mitral apparatus was preserved. All of these patients had mechanical valves using CarboMedics cardiac prosthesis (CarboMedics, Inc. Austin, Texas). RESULTS: There was no mortality. Postoperative echocardiographic assessment revealed maintained left ventricular function with no interference with the prosthetic leaflet mobility and no left ventricular outflow tract gradient. CONCLUSION: We believe that in most patients with long-standing mitral valve regurgitation, thinned out papillary muscles and elongated chordae tendineae that are not amenable to repair, valve replacement with the preservation of the entire native valve is possible and should be encouraged. This is especially valuable for those with depressed left ventricular function, who might otherwise suffer from left ventricular dysfunction in the long-term if the entire mitral valve apparatus were to be excised. (+info)
Ultrastructural quantification of collagen fibrils in chordae tendineae of the sheep and rabbit.
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Collagen fibril diameters and the volume occupied by collagen were quantified at the ultrastructural level in the chordae tendineae of the rabbit and the sheep. Collagen fibril diameter distribution was unimodal and significant differences were found between values on the left and right sides, those on the left being greater than those on the right. The differences are discussed in terms of mechanical loading and compared with results obtained from other tendinous structures subjected to continuous loading. (+info)
Total chordal augmentation in a child with Marfan syndrome and severe mitral insufficiency.
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Mitral valve repair has become an established treatment in adults, but there is limited experience with the procedure in children, in whom the avoidance of a valve prosthesis is particularly advantageous. Repair of the mitral valve in children who have Marfan syndrome is especially difficult due to the presence of generalized connective tissue disorder, which may lead to future elongation and rupture of chordae tendineae that were unaffected at the time of mitral valve repair. We performed a total augmentation of all segments of the mitral valve, using artificial chordae tendineae. Herein, we describe the procedure and the positive outcome in a 10-year-old girl. (+info)
Incidental finding of a papillary fibroelastoma of the mitral valve chordae.
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