Intra-operative transoesophageal echocardiography after mitral repair--specific conditions and pitfalls

Mitral Valvuloplasty with Carpentier's Techniques

From January 1992 to January 1997, 586 patients with mitral incompetence were treated by Carpentier's techniques in the Heart Institute of Ho Chi Minh City, Vietnam. Ages ranged from 6 to 60 years (mean, 26.4 ± 9.9 years) and 124 patients were younger than 15 years of age. Mitral valve incompetence was classified into three types according to leaflet pliability: type I, normal leaflet motion, 7 cases (1.2%); type II, leaflet prolapse, 185 cases (31.6%); type III, restricted leaflet motion, 394 cases (67.2%). Associated tricuspid valvular disease was present in 337 cases (57.5%). Mitral valve prosthetic ring annuloplasty was used in 532 cases (90.8%). The operative mortality rate was 1.9% (11/586). According to the New York Heart Association functional classification, 3.9% (23/586) of the patients were in class I, 52% (305/586) were in class II, 42.3% (248/586) were in class III, and 1.7% (10/586) were in class IV. Mitral valve disease was due to rheumatic fever in 96.7% of the patients. Follow-up data were available in 572 patients from 1 year to 5 years (mean, 38 months). The late mortality rate was 0.7% (4/572). Morbidity comprised endocarditis in 2 patients, one patient had a cerebral hemorrhage, and 16 patients underwent reoperation for recurrent mitral incompetence (incorrect operative indication). There were 2 incidents of thromboembolism. Patient selection was based on valvular disease rather than age, physical condition, or cause of valvular disease. The low mortality and complication rates in this series confirm that mitral valve reconstruction by Carpentier's techniques was appropriate for the patients with mitral incompetence, particularly for children.

Homograft replacement of the mitral valve. Graft selection, technique of implantation, and results in forty-three patients

Because of experience gained in reconstructive mitral valve surgery, we have reevaluated the implantation of cryopreserved homografts in the mitral position. Forty-three patients, aged 11 to 69 years (mean 34 years), underwent mitral valve replacement with cryopreserved mitral homografts. The indications for the procedure were acute endocarditis (n = 14), rheumatic stenosis (n = 26), systemic lupus endocarditis (n = 2), and marasmic endocarditis (n = 1). All homografts were obtained from hearts explanted in the course of transplantation and were cryopreserved at -160 degrees C in 10% dimethyl sulfoxide solution without antibiotics. Appropriate sizing was based on morphologic study of the homografts and preoperative echocardiographic assessment of the recipient valve. In 82 homografts analyzed, the height of the anterior leaflet was 25 +/- 3 mm and the distance from the anulus to the apex of the anterior papillary muscle was 21 +/- 3 mm. The morphologic features of the papillary muscles were classified according to four types of increasing complexity. Nine valves with complex (type IV) papillary muscle abnormalities were discarded. Echocardiographic measurements of the valve were matched with those of the homograft identification cards and a slightly larger homograft was selected (measurements + 3 mm). Partial homograft replacement was done in case of a localized lesion (abscess or calcification) (n = 21). Total homograft replacement was undertaken in the presence of diffuse lesions (n = 22). Two hospital deaths occurred as a result of poor cardiac output. One patient required reoperation on the tenth postoperative day after a dehiscence on the valvular suture line. After a mean follow-up of 14 months, there has been one late death caused by a bronchial neoplasm and one reoperation for residual stenosis (partial replacement). The remaining patients were in either New York Heart Association class I (n = 25) or II (n = 13). Thirty-three patients were in sinus rhythm. Follow-up echocardiography has revealed no mitral regurgitation (n = 20), minimal mitral regurgitation (n = 13), and mild mitral regurgitation (n = 5). Surface valve area has been calculated at 2.5 +/- 0.4 cm2 in partial homograft reconstruction and 2.7 +/- 0.3 cm2 in total homograft replacement, with a transvalvular gradient of 3 +/- 4 mm Hg.

CONCLUSION

In a selected group of patients, the use of mitral homografts significantly extended the present limitations of reparative surgery of the mitral valve.