[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.

SUBJECTS 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 (deltaD) was assessed; RA tone and nitric oxide (NO) concentrations were estimated during surgery; RA EDVD was re-estimated in 12 lercanidipine-treated patients with deltaD < 8%.

RESULTS

The patients were primarily divided into 2 groups: 1) deltaD > or = 8% (RA spasm intra- and postoperatively); 2) EDVD deltaD < 8% (RA spasm). Significant differences between Groups 1 and 2 were intraoperatively recorded in vascular wall tone (U = 1.0; Z = -2.3; p = 0.02) and NO concentrations (p = 0.0); a relationship was found between these parameters. After lercanidipine treatment, the degree of deltaD = 4.36 +/- 1.89% increased to 11.32 +/- 2.22% (p = 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. deltaD < 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.