Consistence of the radial artery as a conduit used in aortocoronary bypass surgery, a possibility of preventing shunt spasm

AIM: To develop a new procedure to evaluate the functional consistence of the radial artery (RA) as a conduit used in aortocoronary bypass surgery (ACBS), to verify the prognostic value of the changed diameter of RA, and to prevent its spasm. /MATERIAL AND METHODS: The study enrolled 34 patients aged 59.4±8.6 years with coronary artery stenoses, who underwent ACBS using a RA conduit. While preparing them for surgery, endothelium-dependent vasodilation (EDVD) of RA, i.e. the magnitude of a change in its diameter (ΔD) was assessed; RA tone and nitric oxide (NO) concentrations were estimated during surgery; RA EDVD was re-estimated in 12 lercanidipine-treated patients with ΔD <8% /RESULTS: The patients were primarily divided into 2 groups: 1) ΔD ≥8% (RA spasm intra- and postoperatively); 2) EDVD ΔD <8% (RA spasm). Significant differences between Groups 1 and 2 were intraoperatively recorded in vascular wall tone (U=1.0; Z = -2.3; р=0.02) and NO concentrations (p=0.0); a relationship was found between these parameters. After lercanidipine treatment, the degree of ΔD=4.36±1.89% increased to 11.32±2.22% (р=0.0) and RA tone dropped from -1.68 to -3.9 mm in Group 2a with the baseline decreased vasodilating activity of RA /CONCLUSION: Ultrasound assessment of the vasodilating activity of RA provides adequate evidence about its arterial wall tone during surgery. ΔD <8% is prognostically unfavorable and serves as a contraindication to the use of RA as a conduit during ACBS. The administration of lercanidipine allows effective correction of the dilatory capacities of an arterial conduit.

aortocoronary bypass surgery, radial artery, lercanidipine