A RAT MODEL FOR THE EVALUATION OF SMALL-CALIBER VASCULAR GRAFTS

This article describes the development of a new experimental model usi ng rats for the evaluation of small-caliber vascular grafts. By modify ing heterotopic heart transplantation, two 1.5- to 2.0-cm long vascula r prostheses were interposed between a syngeneic donor heart and the r ecipient abdominal vessels in the form of vascular bridges. Once blood flow through the vascular grafts was reestablished, the donor heart r esumed normal beating. The status of the vascular grafts could be easi ly monitored by palpation. Occlusion of the grafts stopped donor heart beating without affecting survival of the animals. Once the surgical method was mastered, the postoperative mortality was approximately 10% , and the total procedure took less than 2 hours. Although microvascul ar surgical technique and equipment are required, this model has sever al advantages, including easy detection of thrombotic occlusion of the grafts, the use of small animals of defined genetic background, the a bsence of effect of graft occlusion on the recipient's life, and possi ble repeated operation on the same animal.