O1010: Outcome of Homograft Replacement for Right Ventricular Outflow Tract Obstruction in Children

Background: Homograft replacement or implantation for right ventricular outflow tract is an essential component of contemporary congenital heart surgery. It is however inevitable to encounter progressive valve dysfunction over time, as the longevity of homografts is limited by complications such as calcification and stenosis. In this retrospective study, we analysed the long-term outcomes of homograft replacement or implantation in a single institution.

Methods: The medical records of children aged less than 18 year-old who had undergone homograft replacement or implantation over 16 years were retrospectively reviewed. The following data was collected: diagnosis, age at surgery, donor and recipient demographics, ABO and Rhesus compatibility, graft properties, duration of cardiopulmonary bypass and cross-clamp, surgical details, date of reintervention or death. Outcomes were represented by survival and freedom from re-intervention.

Results: There were a total of 83 patients, and 39 (47%) were female. The median age at time of operation was 6 years (range 0.25-25 years) and body weight was 19.3kg (range 3.17-88.3kg). 41 pulmonary (49.4%) and 42 aortic (50.6%) homografts were implanted. The most common indications for surgery were Tetralogy of Fallot (n=39, 47%) and Tetralogy of Fallot plus Pulmonary Atresia (n=31, 37.3%). There were 8 deaths during the immediate postoperative period, and 4 deaths after 90 days without further re-intervention. The 5-year, 10-year, and 15-year freedom from re-intervention were 81.9%, 75.9% and 69.9% respectively.

In univariate analysis, longer freedom from re-intervention was demonstrated in beating-heart donors compared to cadaveric donors (p=0.003). A shorter ischemic time is also favored (p=0.006) for longer survival of the grafts. Homografts with a larger annulus (p=0.005) and implanted in female patients (p=0.017) had better outcomes. In a backward multivariate linear regression model, the “annulus size” (p=0.044), “type of donor” (p=0.046), and “recipient gender” (p=0.04) were remaining predictors found to be independently associated with longer freedom. No factors appeared to have affected the survival of recipients.

Conclusion: Longer freedom from re-intervention is observed in the use of homografts harvested from beating-heart donors, shorter ischemic time intra-operatively, and larger-sized conduits. Further studies from a larger series and with a longer follow-up period are required to validate these findings.