Risk factors, dynamics, and cutoff values for homograft stenosis after the Ross procedure

Background. The purpose of this study was to find homograft-related factors that might be associated with the development of stenosis after the Ross procedure, as well as to identify the natural dynamics of stenosis and find echographic cutoff values after one year of follow-up that might predict such an outcome. Methods. We followed up 71 patients (mean age, 24.27 +/- 16.57 years) who had such a procedure prospectively by transthoracic echocardiography, between 1993 and 2002. Follow-up was 55.26 +/- 29.63 months and was 90.14% complete. Homografts were harvested from heartbeating donors or cardiac transplant recipients. Allograft stenosis was analyzed and risk factors were identified by univariate, multivariate, and survival analysis methods. Stenosis was defined as a mean gradient greater than or equal to 20 mm Hg. Results. There were two reoperations and 21 homografts were stenotic at the last follow-up, ten of which were already so at one year after the procedure. Cox regression analysis revealed a transhomograft gradient greater than 9 mm Hg at 1 year after the procedure (hazard ratio [HR] = 10.04) and homograft size (HR = 0.75) as independent predictors for stenosis. Stenosis-free survival was 85.94 +/- 4.35%, 75.51 +/- 5.55%, and 68.56 +/- 6.34 after 1, 3, and 5 years, respectively. A cutoff value of 9 mm Hg at 1 year of follow-up could predict different stenosis-free survival rates. Conclusions. Homograft size is the most important homograft-related factor for stenosis. Most of the increase in transhomograft gradient occurs in the first 24 months. A gradient of 9 mm Hg or more after 1 year predicts the late occurrence of stenosis. (c) 2005 by The Society of Thoracic Surgeons.