Cardiac allografts: a 24-year South African experience

Abstract

The history of using homologous cardiac valves dates back more than 30 years. Through the years emphasis was placed on the optimization of graft retrieval, preservation techniques and clinical application. A cardiac homograft valve bank was established at the Department of Cardiothoracic Surgery, University of the Free State, Bloemfontein in 1982. A retrospective analysis was performed on all allograft data since 1984. Since the first valve was successfully procured and transplanted in 1984, 2,540 aortic and pulmonary homografts were harvested from 1,792 donors, of which 1,545 [989 (64%) aortic and 556 (36%) pulmonary] were released for clinical use. Valves were discarded for various reasons, the main reasons being Human Immunodeficiency Virus (32.4%), Hepatitis B (9.6%) and venereal diseases (8.9%). The mean donor age was 26.98 years with a male predominance of 1,368 males versus 424 females. The average ischemic time was 33 h mainly due to medico-legal autopsies exceeding the desired 24 h time limit. The valves were disinfected in an antibiotic cocktail of Mefoxin, Piperacillin, Amikacin and Amphotericin B prior to cryopreservation. The surgical procedures utilizing the majority of homografts were aortic valve replacements (42.9%), aortic root replacements (19.3%) and right ventricular-pulmonary artery conduits (33.3%). The bank also supplied 23 other centers with homografts (402 aortic and 301 pulmonary). The Bloemfontein bank has established itself over the years as a viable and functional cardiac homograft bank. However, with increasing activity in the procurement arena and widened applications in the operating room the role of the homograft seems assured but availability still remains a major concern.