title: The contracting and relaxing responses of human internal mammary artery grafts harvested by two different methods.
abstract: Perioperative spasm of internal mammary artery is a common experience in coronary artery bypass grafting. Many techniques were described of harvesting the internal mammary artery to prevent vasospasm. We investigated the comparison of the contracting and relaxing responses of human internal mammary artery grafts harvested by two different methods. Patients were divided into two groups depending on the harvesting technique. In the first and second groups arteries were harvested by classical and carbon dioxide insufflation techniques, respectively. In both groups, endothelial function of arteries was assessed by precontracting the rings with phenylephrine (10(-5)M) and dilatating them by cumulative acetylcholine (10(-8) to 10(-5)M) concentrations. Cumulative concentration-response curves for phenylephrine (10(-8) to 10(-4)M), noradrenaline (10(-9) to 10(-4)M), and 5-hydroxytryptamine (10(-9) to 10(-4)M) were obtained in all groups. Endothelial integrity of arteries were histopathologically evaluated. In both groups, acetylcholine caused concentration-dependent relaxations in rings precontracted with phenylephrine (10(-5)M). In arteries harvested by carbon dioxide insufflation technique, acetylcholine caused significantly higher relaxations compared to the rings obtained by classical technique (p<0.05). In all rings of study groups, phenylephrine, noradrenaline and 5-hydroxytryptamine caused concentration-dependent contractions. There was not any significant difference in concentration-dependent responses of these contracting pharmacological agents between the groups. Histopathological evaluation revealed no major arterial damage in both groups. Carbon dioxide insufflation technique does seem not only to protect the integrity of the endothelium and the whole vessel, but also prevent the possible vasospasm of the internal mammary artery segments.
authors.affiliation: Karadeniz Technical University, School of Medicine, Department of Cardiovascular Surgery, TR-61187 Trabzon, Turkey. ismailkoramaz@yahoo.com
authors.forename: Ismail
authors.initials: I
authors.lastname: Koramaz
authors.forename: Mehmet
authors.initials: M
authors.lastname: Ozkan
authors.forename: Murat
authors.initials: M
authors.lastname: Kesim
authors.forename: Kibar Yasar
authors.initials: KY
authors.lastname: Güven
authors.forename: Mine
authors.initials: M
authors.lastname: Kadioglu
authors.forename: Cunay
authors.initials: C
authors.lastname: Ulku
authors.forename: Umit
authors.initials: U
authors.lastname: Cobanoglu
authors.forename: Ersin
authors.initials: E
authors.lastname: Yaris
authors.forename: Nuri Ihsan
authors.initials: NI
authors.lastname: Kalyoncu
authors.forename: Fahri
authors.initials: F
authors.lastname: Ozcan
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D001026:Coronary Artery Bypass / Q000379:methods; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008323:Mammary Arteries / Q000187:drug effects / Q000502:physiology / Q000637:transplantation*; D012701:Serotonin / Q000494:pharmacology; D018709:Statistics, Nonparametric; D016378:Tissue Transplantation / Q000379:methods*; D019737:Transplants; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology*; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology*
chemical_list: D012701:Serotonin; D000109:Acetylcholine