CONSERVATIVE MITRAL-VALVE SURGERY IN THE TREATMENT OF MITRAL REGURGITATION DUE TO INFECTIVE ENDOCARDITIS

In order to analyse the results of conservative mitral valve surgery i n the treatment of mitral regurgitation due to infective endocarditis, the authors reviewed the cases of 48 patients operated between 1974 a nd April 1993 (36 operations having been performed after 1989, a perio d during which only 3 patients underwent mitral valve replacement for the same indication). Thirty-four patients were operated after sterili sation of the infective endocarditis, and 14 patients were treated dur ing the active phase. There were 32 men and 16 women with an average a ge of 45 +/- 13 years. In two thirds of the cases, the causative organ ism was a streptococcus. Half of the patients were operated during the acute stage because of their poor haemodynamic status, 5 because of r esidual bacterial vegetations after one or more embolic events and two because of the infection itself. On the other hand, patients were ope rated after the infective phase because of severe mitral regurgitation , responsible for severe symptoms (NYHA Class III) in 16 cases. From t he anatomical point of view, the peroperative finding of 14 patients o perated in the acute phase included dilatation of the annulus (N = 9), ruptured chordae (N = 9), perforation (N = 8) or vegetations (N = 8) ; in the patients operated later, the incidence of perforation and veg etations was much lower (20 %) whereas dilatation of the annulus was a lmost constant (91 %). Using Carpentier's technique, conservative surg ery associated the implantation of a prosthetic ring (N = 40), valvula r resection (N = 33), ablation of vegetations (N = 12), closure of a p erforation by a pericardial patch (N = 7) or transposition of chordae (N = 5). There were no operative deaths in this series. Two patients w ere lost to follow-up and the others followed for an average of 3 +/- 3 years. There were 2 late deaths during follow-up (one haemorrhage wi th oral anticoagulant therapy and one extra-cardiac death) ; the 5 yea r actuarial survival rate was 92 +/- 6 %. No recurrence of infectious endocarditis was observed. Three patients were reoperated : two had st enotic complications and one had significant residual regurgitation. I n actuarial terms, 83 % of patients were pauci- symptomatic and free o f reoperation at 5 years. During the last follow-up, mitral regurgitat ion assessed by Doppler echocardiography was absent in 23 patients, mi ld in 18 patients and moderate in 4 patients. In conclusion, conservat ive mitral valve surgery for infective endocarditis gives satisfactory results in terms of survival and symptomatic improvement with a very low operative risk. With antibiotic therapy, it provides a cure of mit ral lesions even when carried out in the acute phase of endocarditis. Finally it seems feasible in the majority of cases, providing the surg ical teams has the necessary experience.