Arterial balloon catheter: a new atraumatic device for dilating arterial grafts.
BACKGROUND
Harvesting of the internal mammary artery (IMA) for use in myocardial revascularization may result in spasm, which can impair early graft flow. Hydrostatic and mechanical dilatation can exert an intraluminal shear force, causing denudation of the IMA endothelium. A new long balloon dilatation technique (LB) has been developed to mechanically increase IMA diameter and flow without exerting any shear force on the endothelium.


METHODS
Vascular rings of porcine IMA were divided into four groups: no manipulation (control), metal dilators (MD), short balloon (SB), or LB intraluminal dilation. In situ flows after dilation and percentage of intact endothelium after silver nitrate staining were determined. Endothelium-dependent contractions with arachidonic acid, relaxations with acetylcholine, endothelium-independent contractions with norepinephrine, and relaxation with sodium nitroprusside were recorded in organ chamber experiments.


RESULTS
Increases in IMA flows were similar in all dilated groups. Endothelium-independent contractions and relaxations of IMA smooth muscle were unaffected by any type of mechanical dilation. However, endothelium-dependent contractions and relaxations were significantly impaired after MD and SB but preserved after LB dilation compared with control. Silver nitrate staining showed a greater preservation of the endothelial coverage after LB dilation.


CONCLUSIONS
IMA dilatation with the novel arterial LB catheter increases IMA flow and preserves endothelial cell integrity, making it an effective and atraumatic method to relieve IMA spasm before use for coronary artery bypass grafting.
Jeanmart
H
H
Research Center and Department of Surgery, Montreal Heart Institute, Quebec, Canada.
Perrault
L P
LP
Desjardins
N
N
Chavanon
O
O
Carrier
M
M
Fonger
J D
JD
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D016718:Arachidonic Acid / Q000494:pharmacology; D001783:Blood Flow Velocity; D002404:Catheterization / Q000295:instrumentation*; D001026:Coronary Artery Bypass / Q000295:instrumentation*; D004106:Dilatation / Q000295:instrumentation / Q000379:methods; D004730:Endothelium, Vascular / Q000473:pathology / Q000502:physiology; D006083:Graft Occlusion, Vascular / Q000628:therapy; D066298:In Vitro Techniques; D008323:Mammary Arteries / Q000187:drug effects / Q000473:pathology / Q000502:physiology / Q000637:transplantation*; D009599:Nitroprusside / Q000494:pharmacology; D013552:Swine; D014661:Vasoconstriction / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology
D014665:Vasodilator Agents; D009599:Nitroprusside; D016718:Arachidonic Acid; D000109:Acetylcholine