Analysis of right radial artery for transradial catheterization by quantitative angiography--anatomical consideration of optimal radial puncture point.

Objectives: To determine the optimal radial puncture point, we analyzed the anatomy and luminal diameter of the right radial artery (RA) by quantitative angiography.

Background: Difficulty of radial puncture has impeded the establishment of the transradial approach as the standard procedure for cardiac catheterization.

Methods: Antegrade angiography was performed from the right brachial artery in 135 patients who underwent coronary angiography. Presence and location of a bifurcation in the area of the RA puncture were analyzed. Furthermore, inner luminal diameter of the RA was quantitatively measured. We used the line between the styloid process and the ulnar styloid process (R-U line) as an anatomical reference point.

Results: Radial arterial bifurcation with a superficial palmar branch was angiographically observed in 66 patients (48.9%). The inner luminal diameter was significantly larger at the proximal point to the point of bifurcation. The bifurcation level was located at a median of -3.33 mm (interquartile range: -5.60 to 4.69 mm) below the R-U line. Radial puncture at 10 mm proximal to the R-U line could avoid bifurcation in 91.9% of all cases. Mean radial, ulnar and brachial arterial inner diameters were 2.94 +/- 0.52 mm, 2.51 +/- 0.49 mm and 4.53 +/- 0.62 mm. The RA size within 10-60 mm above the R-U line was nearly invariable throughout the range. CONCLUSION The radial puncture level should be proximal to the radial bifurcation because of its lumen size. The ideal puncture point was found to be at least 10 mm proximal to the R-U line.