Repair Strategies in Hammock and Parachute Mitral Valves in Infants and Children

Objective: We report our experience with valve-preserving techniques and the long-term outcome in parachute and hammock valves in infants and children.

Methods: From 1992 to 2012, 12 infants and children, median age 9 months, underwent mitral valve (MV) repair in our institution. Six (50%) belong to age group <1 year. Eight (median age 6 months) have parachute valves. Seven had grade IV mitral insufficiency (MI) and 5 had grade III MI. All had moderate mitral stenosis.

Results: Intraoperative findings included dysplastic and shortened chordae, absence of papillary muscles with fused and thickened commissures in children with hammock valves with two having annular dilatation. Those with parachute valves have fused and shortened chordae with single papillary muscles. MV repair was performed using annuloplasty, commissurotomy and papillary muscle splitting, applied according to the presenting morphology. Postoperative echocardiography showed absence to grade I MI, except for a one-month old infant whose MI was progressive and underwent MV replacement using a 14mm biological prosthesis but died a week postoperatively. Another 4 month-old infant underwent repeat MV reconstruction a month after the initial repair, but severe MI persisted, hence underwent replacement 2 weeks later and survived. During the 19-year follow-up, 5 patients with hammock valves and one with parachute valve underwent repeat MV reconstruction. A 7-month old infant died of unknown cause 5 years later. Freedom from reoperation was 50% and survival rate was 83.4%. Age less than 1 year proved to be a high risk factor for reoperation and mortality (p = 0.00).

Conclusion: In children with parachute and hammock valves, surgical repair offered a satisfactory long-term functional outcome. Repeat MV repair may be necessary during the course of follow-up. Infants have a greater risk for reoperation and mortality.