[Surgical treatment of complete atrioventricular canals, regular and irregular forms, in 75 patients].

The cases of 75 consecutive patients operated for complete atrioventricular canal between 1/1/1978 and 1/1/1985 at Marie-Lannelongue Hospital were reviewed. The age ranged from 1.5 months to 16 years. Forty-nine per cent of patients were operated in the first year of life in the period 1982-1984. Seventy-eight per cent of patients were operated before one year of age. Certain anatomical characteristics enable regular and irregular forms of the condition to be distinguished. Regular forms are characterised by the association of a defect of the inter atrio-ventricular septum, of a common atrioventricular orifice and of ventricles of equal volume without other associated malformations. Irregular forms include the parachute mitral valve, the double mitral orifice, deficient mitral valvular tissue, ventricular hypoplasia, subaortic stenosis, abnormal right ventricular muscular bands, associated cardiac malformations and pulmonary obstructive vascular disease. Surgery comprises repair of the ventricular septal defect and the ostium primum with two separate patches, respecting the anterior and posterior valves and partial or complete closure of the cleft valve. The hospital mortality rate was 33 p. cent. It was 16 p. cent in regular forms and 58 p. cent in irregular forms (p less than 0.01). The hospital mortality of patients operated before 1 year of age with the regular form of the malformation was 22 p. cent. Six children were reoperated secondarily with 2 deaths. Four pacemakers were implanted for complete atrioventricular block. The secondary mortality was 10 p. cent. Thirty-nine patients were followed up for an average of 28 months (range 3 months to 5.5 years).(ABSTRACT TRUNCATED AT 250 WORDS)