Valvotomy in calcific mitral stenosis

Restenosis of the mitral valve

It is suggested that restenosis is inevitable after mitral valvotomy and that only the time taken for it to occur is variable. The major factor affecting the lapse of time between operations is the extent of the original valvotomy. Calification of the valve is less important, and coincident mitral incompetence and the age of the patient have almost no influence on the time taken for restenosis to develop. A study has been made of 281 second closed valvotomies and 53 third ones. The operative mortality for second closed valvotomy was 6.7% and for third closed valvotomy 4%. Late emboli were rare. The average follow-up period after second valvotomies was 12.8 years: the condition of 29% of these patients was still satisfactory; 21% had had third valvotomies. At 5 years the condition of 53% was satisfactory. The average length of follow-up after third valvotomy was 6.4 years: the condition of 47% of patients was still satisfactory and the results were similar to those after second valvotomy. It is concluded that closed valvotomy remains the operation of choice when restenosis has occurred.

Second closed mitral valvotomy for recurrent mitral stenosis

Sixty-seven patients undergoing a second closed mitral valvotomy between 1957 and 1974 have been reviewed. Since 1951, 510 patients have had a primary closed valvotomy in the same unit. The incidence of restenosis severe enough to warrant further surgery is higher after a finger fracture procedure (40%) than after a Tubbs dilator valvotomy (9.2%). There is an operative mortality of 10.4%, and a further late mortality of 23.8% after a second closed valvotomy. Of the surviving patients, 70.5% have had a good or excellent result. The group with poor results is characterised by the presence of a calcified fixed valve, making valvotomy difficult and incomplete. In the presence of a non-calcified valve, a second valvotomy still has a place when surgery for restenosis is required.

Mitral commisurotomy versus replacement. Preoperative evaluation by echocardiography

Echocardiographic studies of the mitral valve were performed in 57 patients with pure or predominant mitral stenosis who subsequently underwent surgery (30 commissurotomy, 27 valve replacement). Mitral valve calcification was graded heavy (thick, conglomerate echoes), light (multiple, discrete linear echoes) or none (thin, single or duplicate signals). Valve mobility, measured as the excursion from the systolic closed position to the fully opened position in diastole, was classified as normal (20 mm or over), restricted (16-19 mm) or poor (15 mm or less). Absence of mitral valve caclification was the most useful echocardiographic indicator for commissurotomy (18 of )9 cases. The most reliable criteria for valve replacement were heavy valve calcification (11 of 11 cases) and poor cusp mobility (11 of 11 cases). The poor mobility group included 3 patients with heavily calcified valves. Thus 37 of 57 cases (65%) could be reliably categorized regarding the type of surgery performed using these three parameters. The remaining echocardiographic parameters (normal mobility, restricted mobility and light calcification) were less valuable in the assignment of the operative category. Echocardiographic assessment of mitral valve calcification and mobility appears to be of value in planning the surgical approach in patients with pure or predominant mitral stenosis.

Conservative approach to the treatment of mixed mitral valve disease

Belcher, J. R. (1973). Thorax, 28, 608-612. Conservative approach to the treatment of mixed mitral valve disease. One hundred patients with mixed mitral valve disease have been treated with the `stand-by' bypass principle. In 59 the valve was replaced; in 41 a closed transventricular valvotomy was done. The results in the two groups have been compared.

The operative mortality for valvotomy was 7%; for valve replacement 20%. Late death occurred in 14% after valvotomy; in 25% after replacement. `Good' results were achieved in 49% after valvotomy; in 41% after replacement. Among the survivors 61% had `good' results after valvotomy as against 75% after replacement. Late emboli occurred in one patient after valvotomy; in 11 after replacement. Methods for improved selection of patients for simple valvotomy are discussed.