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.