Repair of the left AV valve in atrioventricular septal defect in adults

This study examined the septal cleft and septal commissure of the left atrioventricular (AV) valve, which are two different anatomical structures.

We presented 36 cases of adult partial atrioventricular septal defect. A distinction was made between patients based on the anatomy of the anterior leaflet of the left AV valve. The left AV valve appeared to be normal or to have minimal radial openings from the free edge of the anterior leaflet of the left AV valve in 10 patients (28%). There was a septal commissure structure in 8 (22%), and a septal cleft structure in 18 (50%) patients. In the commissure type anatomy, leaflet coaptation was usually adequate and no or mild degree of left AV regurgitation existed preoperatively. Cleft type structure usually was associated with some degree of left AV regurgitation. Attempts were made to close the septal clefts and leave the septal commissures unsutured during the repair of the partial AV septal defects.

We have not found any increase of left AV regurgitation in patients with commissures during the follow-up period. Closure of the cleft successfully eliminated regurgitation. Long-term results for septal cleft and septal commissure after repair of partial AV septal defect were excellent with survival of 100% and freedom from reoperation of 100% at mean 6.5 years.

Septal cleft and septal commissure should be considered two different structures. Repairing procedures for left AV valve abnormalities associated with partial AV septal defect should only be done in patients who have cleft type of leaflet structure.