Facilitation of radial artery cannulation by periradial subcutaneous administration of nitroglycerin

To determine whether subcutaneous administration of nitroglycerin mixed with local anesthetic agent results in effective vasodilation of the radial artery, and whether this technique improves access time and decreases complications.

This prospective study consisted of two consecutive investigations. In the first (n = 30), only local anesthetic agent (prilocaine 2%) was injected into one arm, and local anesthetic agent plus 500 microg nitroglycerin was injected into the other arm. Radial artery diameters before and after injections were measured by ultrasonography. In the second, 33 patients received local anesthetic agent (prilocaine 2%) plus 500 microg nitroglycerin (group A) and 30 received only local anesthetic agent (group B) to determine whether the addition of nitroglycerin would improve radial artery access time, duration of angiography, perception of arterial pulse (ie, pulse score), number of punctures before successful cannulation, and complication rates.

In the first investigation, radial artery diameter increased significantly in the nitroglycerin-treated arm (2.3 mm +/- 0.4 vs 2.9 mm +/- 0.5; P = .05). In the second, there were no significant differences between groups with respect to age, sex, duration of angiography, and number of punctures before cannulation. However, the pulse score increased and radial artery access time improved significantly after addition of nitroglycerin (79% vs 10% [P < .001] and 75 sec +/- 47 vs 132 sec +/- 100 [P = .005], respectively). Radial artery spasm and thrombosis were less frequently observed in group A, albeit to an insignificant extent (P = .39 and P = .49, respectively).

Subcutaneous administration of nitroglycerin significantly increased radial artery diameter, which can lead to facilitation of catheterization of the radial artery for arteriography and interventions.