Background

Current pulsatile pumps for cardiopulmonary bypass (CPB) are far from satisfactory because of the poor pulsatility. This study was undertaken to examine the efficiency of a novel pulsatile catheter pump on pulsatility and its effect on abdominal organ perfusion during CPB.

Methods

Twelve pigs weighing 89±11 kg were randomly divided into a pulsatile group (n=6) and a non-pulsatile group (n=6). All animals had a CPB for 120 min, aorta clamped for 60 min, temperature down to 32°C, and a perfusion flow of 60 ml/kg/min. In the pulsatile group, a 21 Fr intra-aortic pulsatile catheter, which was connected to a 40 mL membrane pump, was placed in the descending aorta and activated by a balloon pump driver during the first 90 minutes of CPB until aortic declamping. Hemodynamics, organ blood flow, body metabolism, and blood trauma were studied during experiments.

Results

Compared with the non-pulsatile group during CPB, the pulsatile group had a higher systolic blood pressure (P&0.01), higher mean arterial pressure (P&0.05), and higher blood flow to the superior mesenteric artery (P&0.05). The hemodynamic energy, indicated by the energy equivalent pressure (EEP) was higher in the gastrointestinal tract and kidney in the pulsatile group (P&0.01, P&0.01). Abdominal organ perfusion status, as indicated by SvO₂ in the inferior vena cava, was higher in the pulsatile group (P&0.05) 30 min after cessation of CPB. Hemolysis indicated by release of free hemoglobin during CPB was similar in the two groups.

Conclusion

Applying the pulsatile catheter pump in the descending aorta is effective in supplying the pulsatile flow to the abdominal organs and results in improved abdominal organ perfusion during the ischemic phase of CPB.