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 in the treatment of mitral regurgitation due to infective endocarditis, the authors reviewed the cases of 48 patients operated between 1974 and April 1993 (36 operations having been performed after 1989, a period during which only 3 patients underwent mitral valve replacement for the same indication). Thirty-four patients were operated after sterilisation of the infective endocarditis, and 14 patients were treated during the active phase. There were 32 men and 16 women with an average age of 45 +/- 13 years. In two thirds of the cases, the causative organism was a streptococcus. Half of the patients were operated during the acute stage because of their poor haemodynamic status, 5 because of residual bacterial vegetations after one or more embolic events and two because of the infection itself. On the other hand, patients were operated after the infective phase because of severe mitral regurgitation, responsible for severe symptoms (NYHA Class III) in 16 cases. From the anatomical point of view, the peroperative finding of 14 patients operated 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 vegetations was much lower (20 %) whereas dilatation of the annulus was almost constant (91 %). Using Carpentier's technique, conservative surgery associated the implantation of a prosthetic ring (N = 40), valvular resection (N = 33), ablation of vegetations (N = 12), closure of a perforation by a pericardial patch (N = 7) or transposition of chordae (N = 5). There were no operative deaths in this series. Two patients were 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 with oral anticoagulant therapy and one extra-cardiac death) ; the 5 year actuarial survival rate was 92 +/- 6 %. No recurrence of infectious endocarditis was observed. Three patients were reoperated : two had stenotic complications and one had significant residual regurgitation. In actuarial terms, 83 % of patients were pauci- symptomatic and free of reoperation at 5 years. During the last follow-up, mitral regurgitation assessed by Doppler echocardiography was absent in 23 patients, mild in 18 patients and moderate in 4 patients. In conclusion, conservative 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 mitral lesions even when carried out in the acute phase of endocarditis. Finally it seems feasible in the majority of cases, providing the surgical teams has the necessary experience.