Improvement of a Model of Brain Death for Transplant-Associated Studies in Rats

The most common method of inducing brain death in rats is inflating an intracranially placed balloon of a Fogarty catheter inserted through a burr hole. However, because of the poor controllability of balloon position, the standardization and stability of the model are compromised. This study examined an improved technique in which the balloon is placed and fixed through double holes.

Forty adult male Sprague-Dawley (SD) rats were randomly and equally assigned into the single-hole (SH) group and the double-hole (DH) group. In each rat in the DH group, 2 holes were made, at the left frontal bone and parietal bone. A Fogarty catheter was inserted outside of the dura mater through the frontal hole, and its tip was guided out through the parietal hole using an arc-shaped needle. The SH group served as a control. In both groups, normal saline was injected into the balloon at 40 μL/minute until breathing stopped. Mechanical ventilation was instituted immediately and provided for another 6 hours after the determination of brain death.

Typical blood pressure patterns were observed in both groups during the brain death induction period, whereas the fluctuation seemed relatively mild in the DH group. Stable brain death with normotension for 6 hours was induced successfully in 18 rats (90%) in the DH group and in 9 rats (45%) in the SH group (P = .002). The mean arterial pressure at 3 hours and thereafter was significantly higher in the DH group compared to the SH group (P < .05).

Our results demonstrate that the DH method is a simple and effective technique to make the brain death model more stable and standardized, possibly due to precise control of the direction of the cannulation and the position of the balloon.