An unusual lethal complication of preservation of chordae tendineae in mitral valve replacement

In two patients, several chordae tendineae of the mural leaflet were preserved during mitral valve replacement. Hemorrhagic necrosis and spontaneous rupture of the preserved posterior papillary muscle led to disc entrapment and the death of both patients.     

Replacement of ruptured chordae tendineae of the mitral valve with autologous pericardial chordae.

Severe mitral regurgitation owing to rupture of chordae tendineae has been repaired in 10 patients by construction of new chordae from autologous pericardium. The site of rupture was the posterior leaflet in eight patients, the anterior leaflet in one patient, and both leaflets in one patient. Cardiac catheterization demonstrated severe mitral regurgitation (average 49%) and a left atrial V wave of 45 mm. Hg. The reconstruction was carried out with pericardium rolled into a chorda with one end attached to the appropriate papillary muscle and the other attached to the flail edge of the mitral valve leaflet being repaired. One patient died on the seventh postoperative day from pneumonia. The remaining nine patients are alive and well (Functional Class I) from 6 months to 9 1/2 years (average 3 years) following the operation. None requires anticoagulants.     

Correction of discrete subaortic stenosis with abnormal chordae tendineae

The case of a 52-year-old woman with subvalvular aortic stenosis and aortic regurgitation is presented. Mitral regurgitation was associated, due to insertion of two abnormal chordae tendineae at the apex of the anterior papillary muscle and at the free border of the subvalvular membranous annulus. This abnormality displaced the anterior papillary muscle, thus applying a traction at the mitral leaflet. The patient was operated on through a valve-sparing approach, in which the discrete subaortic stenosis was removed through aortotomy and the ectopic chordae were excised. Suture mitral annuloplasty completed the procedure. Aortic and mitral insufficiency almost disappeared at follow-up. From the examination of this case and from a review of pertinent literature it emerges that in event of similar complex congenital abnormalities without intrinsic valve disease, a conservative approach should be chosen so that valve replacement can be avoided.     

The use of a high-power laser on swine mitral valve chordae tendineae

Worldwide, rheumatic fever remains a significant cause of mitral valve insufficiency. It is responsible for approximately 90 % of early childhood valvular surgeries in Brazil. Elongated or flail chordae are frequently responsible and require surgical correction. The purpose of this study was to analyze and compare the histological tissues of the mitral valve chordae and the mechanical resistance generated by the chordae, both with and without the application of a high-power laser. Twenty normal porcine mitral valve chordae were measured and divided randomly into the following two groups: control group (not subjected to a high-power laser) and laser group (subjected to photonic irradiation). Laser surgery was performed under controlled conditions, using following parameters: λ?=?980-nm wavelength, power?=?3 W, and energy?=?60 J. A mechanical test machine was used in combination with a subsequent histological study to measure chordae tensile properties. A histological analysis demonstrated a typical collagen bundle arrangement in the control group; however, under a particular reached temperature range (48), the collagen bundles assumed different arrangements in the laser group. Significant reductions in the chordae tendineae lengths and changes in their resistance in the laser group were observed, as these chordae exhibited less rigid fibers. The chordae tendineae of normal porcine valves subjected to a high-power laser exhibited its length reduction and less stiffness compared to the control group. A histological analysis of the laser treatment specimens demonstrated differences in collagen bundle spatial organization, following slight changes into tissue temperature.     

Rupture of chordae tendineae associated myxoma of the left atrium

Mitral insufficiency is unusual in patients with left atrial myxoma. A patient with myxoma of the left atrium presented with acute pulmonary edema due to ruptured chordae tendineae. Both lesions were unequivocally demonstrated by echocardiography, permitting emergency surgical correction to be undertaken without recourse to angiographic studies. Despite the rarity of acute mitral regurgitation due to rupture of chordae tendineae in association with left atrial myxoma, with only one such case previously reported, an etiologic relationship between the two disorders can be postulated. The association between the two thus should not be unexpected.     

Mitral valve repair by replacement of chordae tendineae with polytetrafluoroethylene sutures

Expanded polytetrafluoroethylene sutures have been used for replacement of diseased chordae tendineae during reconstructive procedures on the mitral valve in 43 patients. There were 28 men and 15 women whose mean age was 55 years, range 21 to 76. Three fourths of the patients were in New York Heart Association class III or IV. Replacement of primary chordae tendineae of the anterior leaflet was performed with 4-0 or 5-0 polytetrafluoroethylene sutures. A double-armed suture was passed twice through the fibrous portion of the papillary muscle head and tied down. Each arm of the suture was brought up to the free margin of the leaflet and passed through the area where the native chorda was attached. After the lengths of the two arms were adjusted, the ends were tied together on the ventricular side of the leaflet. Thirty patients had degenerative disease of the mitral valve; the incompetence was due to prolapse of the anterior leaflet in 14 patients and prolapse of the anterior and posterior leaflets in 16. Eleven patients had rheumatic mitral valve disease: four had stenosis, three had regurgitation, and four had mixed lesions. Two patients had ischemic mitral regurgitation caused by rupture of a papillary muscle head. There were no operative deaths. Patients have been followed up from 5 to 61 months, mean 13. Doppler echocardiographic studies were performed at regular intervals after the operation and revealed normal mitral valve function in most patients There were two failures that necessitated mitral valve replacement: one because of acute mitral regurgitation and the other because of hemolysis. There have been two late deaths, neither one valve related. Replacement of chordae tendineae with polytetrafluoroethylene sutures is simple and allows for reconstruction of the mitral valve in many patients who would otherwise require mitral valve replacement. Because our patients have been followed up for a limited time, the long-term results of this procedure remain unknown.     

Mitral valve replacement with preservation of chordae tendineae and papillary muscles

An operative technique for mitral valve replacement (MVR) with preservation of the chordae tendineae to the anterior leaflet as well as the posterior leaflet is reported. This technique consists of the division of the anterior leaflet into anterior and posterior segments, the shifting and reattachment of the divided segments to the mitral ring of the respective commissural areas, and the use of a low-profile bileaflet prosthetic valve. A comparison of left ventricular function data between patients having operation with this technique and those having operation with the conventional method of MVR revealed significantly better improvement in cardiac index (p less than 0.06), left ventricular end-systolic volume index (p less than 0.05), and left ventricular ejection fraction (p less than 0.10) in the former group. Left ventricular wall motion improved in the anterolateral (p less than 0.01) and apical areas (p less than 0.02) in patients operated on with our technique. Maintenance of continuity between the mitral annulus and papillary muscles is expected to have a beneficial effect on postoperative left ventricular performance in spite of increased afterload.