Effects of intracoronary shunts on coronary endothelial coating in the human beating heart.
BACKGROUND
Local occlusion of coronary arteries during beating heart revascularization leads to injury of the arterial wall especially disturbing the integrity of the endothelium. The aim of this study was to elucidate the effects of intracoronary shunts versus local occlusion with elastic silicone loops on the beating heart in human coronary arteries by scanning electron microscopy.


METHODS
Coronary arteries of patients with dilated cardiomyopathy (n = 4) or ischemic heart disease (n = 8) undergoing heart transplantation were locally occluded either with a silicone loop or with a shunt inserted after arteriotomy. Unmanipulated segments of the coronary arteries served as controls. Integrity of the endothelial lining was observed with scanning electron microscopy.


RESULTS
Scanning electron microscopy revealed a statistically significant higher injury after shunting compared with controls (p < 0.001) and vessel loop occlusion (p < 0.001). There was no difference between both patient groups according to control specimens or after manipulation.


CONCLUSIONS
From this investigation we conclude that insertion of intracoronary shunts during beating heart surgery leads to severe endothelial denudation in human coronary arteries. Therefore, at present we recommend using intracoronary shunts selectively in cases in which critical ischemia or technical difficulties as a result of anatomic conditions are expected during anastomosis and avoiding routine shunt insertion into coronary arteries during beating heart revascularization.
Department of Cardiac Surgery, Institute of Anatomy Histology and Embryology, Leopold-Franzens-University, Innsbruck, Austria. herbert.hangler@uibk.ac.at
Herbert B
HB
Hangler
Kristian
K
Pfaller
Elfriede
E
Ruttmann
Daniel
D
Hoefer
Thomas
T
Schachner
Guenther
G
Laufer
Herwig
H
Antretter
D003331:Coronary Vessels / Q000502:physiology / Q000601:surgery* / Q000648:ultrastructure*; D004730:Endothelium, Vascular / Q000648:ultrastructure*; D006801:Humans; D066298:In Vitro Techniques; D008855:Microscopy, Electron, Scanning; D012828:Silicones
D012828:Silicones