High-flow gas insufflation to facilitate MIDCABG: effects on coronary endothelium.
BACKGROUND
During less invasive coronary bypass operations on the beating heart, as well as conventional operations using continuous warm cardioplegia, a precise anastomosis is facilitated by a bloodless field. To maintain a clear field, many surgeons use high-flow gas insufflation. However, the potentially damaging effects of gas insufflation on coronary endothelium have not been elucidated.


METHODS
Seven pigs underwent median sternotomy. Between two coronary occluders, an arteriotomy in the mid left anterior descending coronary artery (LAD) was performed. In the experimental group (n = 5), the operative field was kept clear by exposing the arteriotomy to a catheter-directed stream of carbon dioxide at 15 L/min. In the control group (n = 2), the arteriotomy was left open to room air. After 20 minutes, the segments of LAD exposed to carbon dioxide or room air, and the unexposed proximal LAD and right coronary artery, were processed, sectioned, and stained together. A murine anti-human tie-2 monoclonal antibody was used to identify endothelium.


RESULTS
All unexposed LAD and right coronary artery segments and all LAD segments exposed only to room air demonstrated normal, contiguous staining of endothelium with the murine anti-human tie-2 monoclonal antibody. In contrast, all LAD segments exposed to high-flow carbon dioxide gas insufflation demonstrated near-complete loss of endothelium.


CONCLUSIONS
These data demonstrate that high-flow carbon dioxide gas insufflation denudes the coronary artery of its endothelium. This exposes blood elements to the subendothelium and promotes clotting, and endothelial loss may promote smooth muscle cell migration and proliferation. These events set the stage for early and late graft failure.
Burfeind
W R
WR
Department of Surgery, Duke University Medical Center, Durham, North Carolina 27710, USA.
Duhaylongsod
F G
FG
Annex
B H
BH
Samuelson
D
D
D000818:Animals; D000911:Antibodies, Monoclonal; D002245:Carbon Dioxide / Q000008:administration & dosage / Q000009:adverse effects*; D001026:Coronary Artery Bypass / Q000379:methods*; D003331:Coronary Vessels / Q000293:injuries*; D004730:Endothelium, Vascular / Q000293:injuries*; D006801:Humans; D007327:Insufflation / Q000009:adverse effects*; D007430:Intraoperative Care; D008297:Male; D051379:Mice; D019060:Minimally Invasive Surgical Procedures; D013552:Swine
D000911:Antibodies, Monoclonal; D002245:Carbon Dioxide