A rat model of cardiopulmonary bypass with excellent survival

Elucidating the underlying mechanisms and developing protective strategies for the pathophysiological consequences of cardiopulmonary bypass (CPB) have been hampered due to the absence of a satisfactory long-term recovery animal model. The objective of this study was to establish a survival experimental model of CPB in rats to meet the requirement of these studies.

Male SD rats (450-550 g) were randomly divided into CPB (n = 10) group and Sham group (n = 10). All rats were anaesthetized and mechanically ventilated. The femoral artery and vein were cannulated for continuous blood pressure recordings and fluid replacement, respectively. The CPB circuit comprised a venous reservoir, a membrane oxygenator, and a roller pump. Blood was drained from the right atrium via a jugular vein catheter and returned to the right carotid artery. Priming consisted of 8 ml of homologous blood and 8 ml of colloid. CPB was conducted for 60 min at a flow rate of 100-150 ml/kg/min in the CPB group. Haemodynamic investigations, blood gas analysis, and survival studies were performed subsequently.

Our data show that the rat model principally simulated the clinical setting of CPB in terms of its construction, configuration, performance, material surface area, and priming volume to blood volume ratio. All CPB rats survived and the 2-week follow-up period remained uneventful.

The rat model of CPB was easy to establish and was associated with excellent survival. This model should facilitate the investigation of the pathophysiological processes concerning CPB-related multiple organ dysfunction and possible protective interventions.