Clinical results of freehand subcoronary aortic valve and root replacement with cryopreserved homografts (allografts)

The homograft valve as a biologic valve substitute has gone through three major developmental phases, namely, 1) chemical sterilization (6,7,11), irradiation and freeze drying, 2) antibiotic sterilization (13, 16) and 3) cryopreservation (19, 23) since its introduction into clinical surgery in 1962 (2, 20). Antibiotic sterilization and cryopreservation methods have improved the allograft tissue quality and therefore the long-term durability. This was confirmed at the international Homograft meeting held in Berlin in 1987 and by others (13, 17, 18, 22, 24). The turning point in the era of allograft surgery in the 1990s has been a controversy about a particular implantation technique to achieve a longer-term allograft valve durability (3, 5, 12–14, 17, 18, 22). The clinical results and durability of cryopreserved aortic homografts in the aortic position might not depend on the quality of the tissue alone, but on other factors such as specific implantation technique in a specific patient group and in a specific aortic root if one assumes an immunological factor as a common hazard for the AVR and ARR techniques. The purpose of this report therefore is to review our 9-year experience with the freehand subcoronary aortic valve implantation and root replacement techniques with cryopreserved homograft valves.