Pulsatile versus non-pulsatile flow during cardiopulmonary bypass and its impact on microcirculation

Objective. To compare pulsatile versus non-pulsatile flow during cardiopulmonary bypass (CPB) and its impact on microcirculation. Material and methods. We randomized 42 cardiac surgery patients into 2 groups depending on blood flow during CPB: group 1 (n=21) — pulsatile flow, group 2 (n=21) — non-pulsatile flow. To assess microcirculation disturbances, we estimated the following laboratory parameters: syndecan-1, ADAMTS-13, heparan sulfate and von Willebrand factor (vWF). Measurements were carried out after induction to anesthesia (baseline), at the end of CPB and 6 hours later. Results. In the 2nd group, syndecan-1 increased at the end of CPB and 6 hours later compared to baseline values. In the 1st group, heparan sulfate decreased during CPB with subsequent tendency to increase 6 hours later. In both groups, there was a tendency towards lower ADAMTS-13 at the end of CPB followed by significant increase 6 hours later. In the 1st group, vWF decreased at the end of CPB and increased 6 hours later. In the 2nd group, vWF concentration did not change throughout CPB. However, vWF increased in 6 hours after CPB. There was significant between-group difference in serum vWF at the end of CPB. Conclusion. Syndecan-1 and heparan sulfate indicate a less shedding of endothelial glycocalyx after pulsatile CPB. vWF dynamics demonstrates higher endothelial shear stress under pulsatile blood flow. ADAMTS-13 dynamics does not allow to draw any conclusion about the advantages of any type of CPB.