A model of gradual onset brain death for transplant-associated studies in rats.

Abstract

The relatively few studies that have examined the systemic events after brain death have primarily involved large animals. For more precise definition of the physiology of this central catastrophe and its influence on peripheral organs, we have established a reproduceable model of gradual onset brain death in rats. The central injury is induced by graded inflation of a Fogarty catheter placed intracranially under EEG and blood pressure monitoring. The rats were mechanically ventilated for 6 hr before removal of their kidneys. Complications and mortality are discussed. The majority (83%) of the 100 experimental animals could be used as organ donors. After a transient period of autonomic storm, the mean arterial blood pressure remained consistently between 80-100 mmHg, not appreciably different from controls. Despite normotension, the transplanted kidneys from brain dead donors showed a significantly longer interval to regain uniform cortical color and turgor than kidneys from control animals. We describe a controlled model of gradual onset brain death in the rat in which normotension can be sustained for several hours before the kidneys are removed for transplantation. Despite stable donor blood pressure, ischemia of peripheral organs may explain in part the increased incidence of delayed graft function of cadaver kidneys compared with those from living donors. This model is suitable for transplant-related studies involving organs from donors with irreversible central injury.