Surgical repair for degenerative and rheumatic mitral valve disease. Operative and mid-term results.

BACKGROUND

Non randomized studies suggest that mitral valve repair for rheumatic disease is technically more difficult than repair for degenerative disease, and that operative and late results are worse. New surgical techniques have been developed in our and other institutes during the last 5 years, and this moved us to review the experience with these two pathologies and to compare the operative and mid-term

METHODS

From March 1996 to September 1997, 66 patients underwent primary mitral valve repair for treatment of degenerative or rheumatic disease. Fifty-two patients (79%) were in the former group (group A) and 14 in the latter (group B). Surgery was performed by 2 experienced cardiac surgeons. A new technique to calculate the exact artificial chordae length was introduced. In 2 cases, tricuspid autografts were transposed to mitral position and reinforced with artificial chordae. Patients were followed both clinically and echocardiographically. The follow-up data were collected in a 1-month period (May 2000). The average clinical follow-up was 3.1+/-0.9 years (range 1.7 to 4.2 years) while the average echocardiographic follow-up was 2.7+/-0.7 years (range 9 months to 4 years). All values were expressed by means of the average and standard deviation. chi(2) and Student's "t"-test were used to analyze the significance between variables. The Kaplan-Meyer method was used for actuarial statistics.

RESULTS

There were no operative deaths in either group. In group A, 1 patient underwent a second surgical repair 1 week later, successfully. In group B no patients underwent reoperation within 30 days or during the initial hospitalization. At follow-up of group A there were the following events: deaths from cancer (n=2), endocarditis (n=1), aortic dissection (n=1). At follow-up of group B there were mitral valve replacement (1 year after first operation, n=1), Ross procedure (n=1), ischemic heart failure (n=1). Among the remaining 62 patients followed, 32 were in NYHA class I, 15 in class II, 3 in class III, and none in class IV, in group A. In group B, 7 patients were in class I, 4 in class II, 1 in class III and none in class IV (p=ns). In group A mitral regurgitation was absent in 23 patients, mild in 21, moderate in 6, while in group B it was absent in 4, mild in 6, and moderate in 2 (p=ns). In both groups there were no cases of severe insufficiency. The mean gradient was 1.1+/-1.7 mmHg in group A (median=0), and 2.4+/-3.1 mmHg in group B (median=0), (p=ns). No case of systolic anterior movement was seen at mid-term. The event free-survival rate was 92.8% in group A and 92.3% in B.

CONCLUSIONS

Perfecting and innovation of surgical techniques make possible nowadays to reach good and equivalent operative and mid-term results in both pathologies.