Abstract 13611: Analysing Microvascular Alterations During Minimal Extracoporal Circulation and Conventional Cardiopulmonary Bypass in Coronary Bypass Surgery Using Orthogonal Polarization Spectral Imaging: A Prospective, Randomized Study
Objectives: In order to minimize cardiopulmonary bypass related side effects, minimal extracorporeal circulation systems have been developed and introduced successfully in the clinical routine, offering possible clinical benefits due to reduced priming volume and no blood-air interface. Yet, the effects of minimal extracorporeal circulation (MECC) systems on the intraoperative microvascular perfusion in comparison to conventional cardiopulmonary bypass (CCPB) have not been studied conclusively so far.
Methods: Orthogonal polarization spectral (OPS) imaging enables for non-invasive visualization of the microvascular blood flow in humans. The current study aimed to analyze alterations in microvascular perfusion at four pre-defined time-points (T1-T4) during on-pump CABG by measuring changes in functional capillary density (FCD), blood flow velocity and vessel diameter. Fourty patients scheduled for elective CABG were randomized for being operated either utilizing a MECC system or a CCPB.
Results: There was no difference in the baseline level (T1) of the FCD between the two groups. After start of the extracorporeal circulation and aortic crossclamping (T2) both groups showed significant drop of the FCD. At T3, in the late phase of the CPB, the FCD in the MECC group was still impaired but not significantly below the baseline value, whereas the CECC group was still significantly depressed. After termination of the CPB (T4) the FCD recovered in both groups to baseline values. Measurements of red blood cell velocity in post-capillary venules revealed no significant intraoperative changes in microvascular blood flow velocity during on-pump CABG. Yet, blood flow velocity tended to be higher in the MECC group.
Conclusions: In general, data obtained by OPS imaging indicate, that no severe intraoperative microvascular alterations occur during on-pump CABG surgery. However, since analysis of changes in functional capillary density (FCD) - representing a key marker of nutritive tissue perfusion - indicates a faster recovery of the FCD in the MECC group, MECC might be advantageous in preserving microvascular perfusion. Preserved microvascular perfusion could at least partly explain the peri-operative advantages reported for the MECC system.
- © 2011 by American Heart Association, Inc.