Growth potential of aortic autografts and allografts: effects of cryopreservation and immunosuppression in an experimental model.
OBJECTIVE
An animal model has been used to evaluate the potential of growth of vascular autografts and allografts, and the effects of cryopreservation, rejection and immunosuppression on this growth.


METHODS
In 35 animals (seven groups of five female NZW rabbits; age 5-6 weeks; weight 1.1 kg), a graft interposition was performed at the level of the infrarenal aorta. Different groups included fresh autografts, fresh and cryopreserved consanguineous allografts (donor: litter sister), fresh and cryopreserved immunosuppressed (IS) consanguineous allografts (receiving cyclosporin 10 mg/kg per day) and fresh and cryopreserved allografts. Animals were allowed to grow normally and were sacrificed at the mean weight of 2.89 kg. We studied the growth of the native aorta and of the graft and calculated the growth ratio (growth of the graft/growth of native vessel). Grafts and adjacent aorta were histologically studied.


RESULTS
Growth of the graft was normal (mean ratio 1.08; S.D. = 0.21) for autografts, and for fresh and cryopreserved IS consanguineous grafts. Growth was absent (mean ratio 0.12; S.D. = 0.15) for fresh and cryopreserved allografts (P = 0.0001). In consanguineous grafts without IS, growth was absent or normal, presumably according to genetic compatibility, but never intermediate. Histological study showed normal optic microscopic aspects when growth was normal and, when growth was absent, aspects compatible with rejection including mainly intimal hyperplasia and medial thinning.


CONCLUSIONS
(1) Normal growth of arterial autografts was confirmed; (2) cryopreservation did not prevent potential growth of an arterial graft; and (3) in an allogenic situation, without IS, an aortic graft, fresh or cryopreserved, never showed any growth potential.
Kreitmann
B
B
Cardiac Surgery, La Timone Children's Hospital, Marseille, France.
Riberi
A
A
Zeranska
M
M
Novakovitch
G
G
Metras
D
D
D000818:Animals; D001012:Aorta, Abdominal / Q000254:growth & development* / Q000637:transplantation*; D015925:Cryopreservation; D016572:Cyclosporine / Q000627:therapeutic use; D005260:Female; D006084:Graft Rejection / Q000503:physiopathology / Q000517:prevention & control; D006648:Histocompatibility; D007165:Immunosuppression Therapy; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D011817:Rabbits; D014182:Transplantation, Autologous; D014184:Transplantation, Homologous
D007166:Immunosuppressive Agents; D016572:Cyclosporine