Fifty-two months' mean follow up of decellularized SynerGraft™- treated pulmonary valve allografts

Background and aim of the study: It has been reported previously that the use of a decellularized pulmonary allograft (SynerGraft; CryoLife Inc.) for right ventricular outflow tract reconstruction in adults is associated with reduced immunization. The implantation appeared to be safe, but was not associated with any detectable clinical or echocardiographic advantage. The study aim was to follow further the outcome of SynerGraft patients. Methods: Twenty-three adult patients (19 males, four females) each received a SynerGraft-allograft during a Ross procedure. A further 49 patients (37 males, 12 females) who underwent a Ross procedure using a conventional pulmonary allograft during the same period served as controls. Follow up examinations using transthoracic echocardiography in standard views was performed on a regular basis. The latest follow up was performed after a mean of 52 months. Results: Directly after implantation, there were no echocardiographic differences between the two groups, but with time the pressure gradients increased significantly (p <0.001) in both groups. At the latest follow up, pressure gradients were slightly higher across the SynerGraft-allograft valves than across conventional allografts (P_max 18.2 ± 9.0 versus 14.0 ± 6.9 mmHg, respectively; p = 0.049). On regression analysis (considering pre- and intraoperative variables), 'SynerGraft-allograff was the only variable predicting the increase in pressure gradient from its postoperative value to that at follow up. However, no clinical differences were observed between the groups. Conclusion: The present results relate to the longest follow up on decellularized pulmonary SynerGraft-allografts conducted to date. No reoperations were required after a mean follow up of 52 months, and the echocardiographic results were stable after the first postoperative year. Based on these data, the use of pulmonary SynerGraft-allograft valves in adults appears not to provide any advantage over conventional allografts, although further follow up is warranted before any final judgment is made regarding this new technology.