Introduction of modified cervical cardiac transplant model in mice

The murine cervical heterotopic heart transplant model was initially designed to test the immune response to third-party allografts, modified by cuff techniques. While cuff techniques simplify the execution of this procedure, cutting of the carotid artery and the external jugular vein alters the blood supply to central nervous system and makes it difficult to achieve long-term graft survival. In the present study, we describe modified techniques that preserve the continuity and function of blood vessels and improve transplant integrity.

The modified techniques in this study comprise the following aspects: (1) Preservation of the sternal head of the right sternocleidomastoid muscle, (2) use of the donor's intrathoracic inferior vena cava for anastomosis and (3) preservation of the function of the recipient's carotid artery and external jugular vein and thus, continuity of blood flow to the central nervous system.

Stable, long-term, disease-free allograft survival has been achieved with syngeneic transplants (> 200 days), whereas allografts from fully major histocompatibility complex-mismatched donors were acutely rejected in a time similar to the traditional abdominal heterotopic heart transplant model (8.2 ± 1.3 vs 8.4 ± 1.4 days; P = .73 in the Mantel Cox test, and P = .61 in the Gehan-Breslow-Wilcoxon test). Similar alloresponses could be induced in these 2 models.

It is possible and feasible to achieve long-term graft survival in the mouse cervical heart transplant model using the modified procedures described in the present study.