Orthotopic aortic transplantation in mice: A new model of allograft arteriosclerosis

Background: Graft arteriosclerosis is a major cause of death after allotran splantation of organs such as the heart or the kidney. Aortic allotransplan tation in mice is a useful experimental model to study the mechanisms of th is pathology. However, the conventional heterotopic aortic model is limited by a high morbidity and is technically difficult to perform. We developed a new simple method for aortic transplantation in mice. Methods: The infrarenal aorta from the donor mouse was anastomosed to the r ecipient's aorta at the same position using a sleeve technique. Orthotopic aortic transplantation was performed in 45 mice, 5 isografts and 40 allogra fts. No immunosuppression was given, and the mice were killed at day 15 or 30. The graft was examined macroscopically, and several histologic sections were made. Results: The overall survival rate was 78%. The incidence of thrombosis was low (4 cases) compared with previously published series. Histology of aort as revealed typical aspects of rejection in the allografts with a chronic p icture at day 30. No significant lesion was observed in isografts. Conclusions: We have developed a model of orthotopic aortic transplantation in mice. This new model is easy to carry out and has a low incidence of th rombosis, probably because there is no size discrepancy between donor and r ecipient aortic segment.