Atrioventricular septal defects: effect of bridging leaflet division on early valve function.

Background: Bridging leaflet division may facilitate repair of atrioventricular septal defects (AVSD). However, the consequences of bridging leaflet division on early valve function and mortality are not well defined.

Methods: Records of children undergoing AVSD repair between January 1995 and January 2002 were reviewed. Multivariable analysis defined risk factors for moderate or greater atrioventricular valve regurgitation (AVVR) and death/reoperation within 1 year of repair.

Results: A total of 209 children (median age 5 months, median weight 5 kg) had defects whose repair included the possibility of bridging leaflet division. Bridging leaflets divided were both (n = 119, 58%), one (n = 30, 15%), or none (n = 55, 27%). Freedom from AVVR (moderate or greater) is 84%, 80%, and 78% at 1, 6, and 12 months. Risk factors include technical factors: number of bridging leaflets divided, longer cross-clamp time, and right-sided annuloplasty. Other risk factors include preoperative AVVR (moderate or greater), double-orifice or parachute left AV valve, and younger age. Freedom from death/reoperation for AVVR is 96%, 92%, and 90% at 1, 6, and 12 months. Risk factors are preoperative AVVR (moderate or greater) and parachute left AV valve. Findings at reoperation (n = 15, 7.2%) were cleft dehiscence or tear along cleft closure (n = 10), dehiscence of divided leaflet from septation patch (n = 1), or other (n = 4). Operative mortality (n = 6, 2.9%) included failed reoperations for AVVR (n = 4), dehiscence of divided leaflet from septation patch (n = 1), and sepsis (n = 1).

Conclusions: Division of bridging leaflets is a risk factor for AVVR (moderate or greater) during the first year after repair. Preservation of bridging leaflet integrity may improve valve competency, decrease the need for future reoperation, and eliminate some causes of operative mortality.