[Intermdeiate forms of atrioventricular defects. Reflections apropos of 50 consecutively operated cases].

Fifty cases of intermediate forms of atrioventricular defect were treated surgically. The operation was performed in the traditional manner in all cases. One post-operative death and three cases of severe mitral incompetence leading to reoperation were observed. The authors emphasise that it is essential to look for and excise the chordae and abnormal fibrous bands, that it is generally unnecessary to touch the tricuspid valve and that there is a danger of obstructing the aortic canal if the correction of the asymmetry of some mitral clefts is attempted. Analysis of the results leads them to tend to respect the cleft mitral valve when the regurgitation is minimal and to suture it all along its length when the regurgitation is severe. Mitral annuloplasty may be a useful complementary procedure and a left atrial approach may be proposed with this in mind in certain cases. Conduction defects remain a serious problem in this type of surgery; not so much complete heart block, which is exceptional, but trifascicular block, often present preoperatively, whose prognostic is, to say the least, uncertain.