Comparing microvascular alterations during minimal extracorporeal circulation and conventional cardiopulmonary bypass in coronary artery bypass graft surgery: a prospective, randomized study.
OBJECTIVE
Minimal extracorporeal circulation (MECC) has been introduced in coronary artery bypass graft (CABG) surgery, offering clinical benefits owing to reduced hemodilution and no blood-air interface. Yet, the effects of MECC on the intraoperative microvascular perfusion in comparison with conventional extracorporeal circulation (CECC) have not been studied so far.


METHODS
The current study aimed to analyze alterations in microvascular perfusion at 4 predefined time points (T1-T4) during on-pump CABG using orthogonal polarization spectral imaging. Forty patients were randomized for being operated on with either MECC or CECC. Changes in functional capillary density (FCD), blood flow velocity, and vessel diameter were analyzed by a blinded investigator.


RESULTS
After start of extracorporeal circulation (ECC) and aortic crossclamping (T2), both groups showed a significant drop of FCD, with a significantly higher FCD in the MECC group (206.8 ± 33.6 cm/cm² in CECC group versus 217.8 ± 35.3 cm/cm² in MECC group; P = .034). In the late phase of the ECC (T3), FCD in the MECC group was already recovered, whereas FCD in the CECC group was still significantly depressed (223.1 ± 35.6 cm/cm² in MECC group; P = .100 vs T1; 211.1 ± 36.9 cm/cm² in CECC group; P = .017 vs T1). After termination of ECC (T4), FCD recovered in both groups to baseline. Blood flow velocity tended to be higher in the MECC group, with a significant intergroup difference after aortic crossclamping (T2).


CONCLUSIONS
Orthogonal polarization spectral imaging data reveal an impairment of microvascular perfusion during on-pump CABG. Changes in FCD indicate a faster recovery of the microvascular perfusion in MECC during the reperfusion period. Beneficial recovery of microvascular organ perfusion could partly explain the perioperative advantages reported for MECC.
Department of Cardiac Surgery, University of Rostock, Rostock, Germany. peter.donndorf@med.uni-rostock.de
Peter
P
Donndorf
Franziska
F
Kühn
Brigitte
B
Vollmar
Jan
J
Rösner
Andreas
A
Liebold
Philipp
P
Gierer
Gustav
G
Steinhoff
Alexander
A
Kaminski
D000368:Aged; D015415:Biomarkers / Q000097:blood; D001783:Blood Flow Velocity; D002315:Cardiopulmonary Bypass / Q000009:adverse effects; D001026:Coronary Artery Bypass / Q000009:adverse effects; D005112:Extracorporeal Circulation / Q000009:adverse effects / Q000379:methods*; D005260:Female; D005858:Germany; D006400:Hematocrit; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D008833:Microcirculation; D008859:Microscopy, Polarization; D018715:Microscopy, Video; D008875:Middle Aged; D009060:Mouth Floor / Q000098:blood supply*; D055420:Perfusion Imaging / Q000379:methods; D011446:Prospective Studies; D020127:Recovery of Function; D012039:Regional Blood Flow; D013997:Time Factors; D016896:Treatment Outcome
D015415:Biomarkers; D019344:Lactic Acid