Risk factors for late pulmonary homograft stenosis after the Ross procedure

Background. We reviewed our experience with the Ross procedure to identify the prevalence and predictors of late pulmonary homograft stenosis. Methods. between June 1992 and December 1997, 109 consecutive patients (age 34.5 +/- 8.6 years) underwent the Ross procedure, with reconstruction of t he right ventricular outflow tract with a cryopreserved pulmonary homograft (22 to 30 mm diameter). There was one early and one late death. Echocardio graphic follow-up was available in 105 of 108 patients (97%), with a follow -up of 39 +/- 20 months. Homograft donor and preservation measurements and patient variables were subjected to multivariable analyses to identify inde pendent predictors of late homograft performance. Results. The major physiopathologic finding was homograft stenosis. Peak sy stolic gradients across the homograft were 20 mm Hg or more in 30 of 105 pa tients (28.5%) and 40 mm Hg or more in 4 of 105 patients (3.8%). One patien t required two re-replacements of her homograft for severe stenosis. Modera te or severe homograft insufficiency was noted in 10 of 105 patients (9.5%) . The independent predictors of late pulmonary homograft stenosis were youn ger donor age (p = 0.03), shorter duration of cryopreservation (p = 0.01), and smaller homograft size (p = 0.06). Beating heart donor status, short ho mograft ischemic time, and other factors that have been shown to be associa ted with increased graft viability were associated with graft stenosis but did not reach statistical significance. However, mean gradients across the homograft were significantly related (p 0.002) to the number of these risk factors in each patient. Conclusions. Stenosis of the pulmonary homograft can be a significant probl em following the Ross procedure, and was predicted by younger donor age and shorter duration of cryopreservation. These factors may be related to incr eased cellular viability, which might actually predispose to late homograft stenosis in a subgroup of patients. (Ann Thorac Surg 2000;70:1953-7) (C) 2 000 by The Society of Thoracic Surgeons.