Cryopreserved homografts in the pulmonary position: determinants of durability

The cryopreserved homograft has emerged as the pulmonary conduit of choice for the repair of many congenital heart defects. It is also used for pulmonary valve replacement in the Ross procedure. Because of a wide range of patient ages and diagnoses, the risk of homograft failure may vary.

We reviewed 185 consecutive pulmonary position implants performed between September 1985 and January 1999. We examined three age groups: patients less than 1 year of age (n = 53), patients 1 to 10 years of age (n = 46), and patients more than 10 years of age (n = 86).

Five-year Kaplan-Meier homograft survival was 25%, 61%, and 81% for the groups, respectively (p < 0.02). Smaller homograft size, younger patient age, and truncus arteriosus were risk factors for homograft failure in univariate analysis (p < 0.05). Smaller homograft size was the only predictor for homograft failure in multivariate analysis (p < 0.001). Twenty of 99 implants in patients less than 10 years old underwent transcatheter intervention. The 3-year Kaplan-Meier implant survival of this group (79%) was not different from those who did not undergo intervention (77%, p = 0.84). Survival of aortic and pulmonary homografts in patients less than 10 years of age was not different (p = 0.35). Ross procedure implants appear to have optimal survival (94%) at 5 years. Non-Ross implants in patients more than 10 years of age have 76% 5-year Kaplan-Meier survival, which is not different from Ross patients (p = 0.33).

Small homografts have limited durability. Aortic homografts perform as well as pulmonary homografts in young patients. Once patients receive an "adult-size" homograft, at approximately 10 years of age, risk for implant failure approximates that of patients undergoing the Ross procedure. Transcatheter interventions, when indicated, may prolong homograft life.