Reactivity of the Internal Thoracic Artery Graft to Drugs in Coronary Artery Bypass Grafting / 日本心臓血管外科学会雑誌

ABSTRACT

The internal thoracic artery is a useful conduit for coronary artery bypass grafting (CABG). Recently we have developed a method for increasing blood flow by directly injecting a phosphodiesterase III (PDE III) inhibitor into the left internal thoracic artery (LITA) to inflate the artery and prevent its contraction. In the present study we compared the reactivity of the LITA to three drugs PDE III inhibitor, papaverine hydrochloride and isosorbide dinitrate (ISDN). Forty-two patients with a mean age of 66.8±11.5 years old who were undergoing primary CABG were enrolled in this study and were randomly separated into one of three groups based on the vasodilating drug administered. Each drug was used in 14 cases. Graft free flow (GFF) and systemic blood pressure were measured before and one minute after drug administration to calculate blood vessel resistance (<i>R</i>). All the drugs significantly increased GFF, and reduced both <i>R</i> and blood pressure. A comparison of the change rate of blood pressure did not differ significantly among the three drug groups. The PDE III inhibitor significantly increased change rates of both GFF and <i>R</i>, compared with the other drugs. These results indicate that PDE III inhibitor is most effective for increasing the blood flow of LITA grafts for CABG.