Clinical performance of decellularized cryopreserved valved allografts compared with standard allografts in the right ventricular outflow tract

Background: Although decellularized cryopreserved valved allografts (DCAs) have reduced immunogenicity, proof of clinical superiority over standard cryopreserved allografts (SCAs) is lacking. To assess functional results and durability, we studied a group of patients with DCAs implanted between 2000 and 2005 and compared them with a similar group with SCAs.

Methods: From July 2000 until January 2005, 47 patients underwent insertion of a DCA between the right ventricle and pulmonary arteries. The DCA patients were compared with 47 age-matched and diagnosis-matched controls receiving SCAs. All patients received pulmonary allografts and were matched for valve position (orthotopic versus heterotopic). We analyzed each group for survival, reoperation, reintervention (surgical or catheter-based), stenosis, and regurgitation.

Results: There were no differences between groups with respect to weight, age, valve size, or survival. Actuarial freedom from reintervention at 8 years was 79% for DCAs as compared with 63% for SCAs (p = 0.31, log-rank). Echocardiogram in the DCA group (median 66 months) showed a slightly lower median peak gradient of 16 mm Hg (range, 0 to 82 mm Hg) as compared with 22 mm Hg (range, 0 to 63) in the SCA group (median 61 months, p = 0.051, Wilcoxon). However, when conduits 18 mm or less in diameter were compared, DCA patients had a median peak gradient of 10 mm Hg (range, 0 to 43) compared with 25 mm Hg in SCAs (range, 0 to 55 mm Hg, p = 0.03). There were no differences in the degree of allograft insufficiency in either group.

Conclusions: Decellularized cryopreserved valved allografts have a nonsignificant trend toward lower peak valve gradient and reintervention in comparison with SCAs. Small valve sizes (18 mm or less) show a slight but significant improvement in peak gradient, but no advantage in valve insufficiency. These findings and a significantly higher cost (>$3,000) make further direct comparisons necessary before widespread use of DCAs can be justified.