Abstract: Objective To establish a stable and feasible rabbit model of cardiopulmonary bypass (CPB) in acute cerebral
embolism phase for studying the effects of CPB on brain tissues and the timing of surgical intervention of acute cerebral
embolism. Methods Fifty-four rabbits were randomized into group A (n=18) to receive CPB without middle cerebral artery
occlusion (MCAO) and group B to undergo CPB at 24 h (group B1, n=18) or 1 week (group B2, n=18) after MCAO. Through a
supraorbital margin approach, electrocoagulation was carried out to occlude the main stem of the left MCA under direct vision
to establish MCAO. Magnetic resonance imaging (MRI) was performed at both 24 h and 1 week after MCAO, and the severity
of cerebral embolization was evaluated. CPB was established by cannulation of the ascending aorta and the right atrium
through a median sternotomy incision. MRI was performed at 2 h after CPB to observe the brain tissues. Results MCAO was
successfully established in groups B1 and B2, and all the rabbits survived after MCAO. In both groups A and B, MRI
examination detected no cerebral hemorrhage or new embolism 2 h after CPB. Conclusions We have established a stable and
feasible CPB model in rabbits with acute cerebral embolism to allow study of the mechanisms of CPB-related organ damage
and its interventions.