Effect of the Distance Between the Radial Artery Puncture Site and the Styloid Process on Radial Artery Spasm in Transradial Coronary Interventions: A Randomized Study.

BACKGROUND

Radial artery spasm (RAS) remains a clinically relevant limitation of the transradial approach (TRA).

AIMS: This study aimed to evaluate the influence of the distance between the radial artery puncture site and the radial styloid process on RAS and access-site complications.

METHODS

This prospective, single-center, randomized, single-blind trial enrolled 380 patients undergoing diagnostic coronary angiography or percutaneous coronary intervention via TRA. Using fluoroscopic identification of the radial styloid process as a fixed anatomical reference, patients were randomized 1:1 to Near-Styloid (0-20 mm) or Far-Styloid (21-40 mm) puncture. The primary endpoint was clinical RAS. Secondary endpoints included puncture efficiency, pain scores, crossover, and access-site complications, including radial artery occlusion (RAO) and hematoma.

RESULTS

Clinical RAS occurred in 14.7% of the Near-Styloid group and 17.9% of the Far-Styloid group (p = 0.488). First-attempt puncture success was significantly higher with Near-Styloid access (74.2% vs. 58.4%, p = 0.002), with shorter puncture time (median 20 vs. 30 s, p < 0.001) and fewer puncture attempts (p = 0.003). Procedural characteristics and fluoroscopy parameters were similar between groups. Persistent forearm pain (3.2% vs. 8.4%, p = 0.048), RAO (1.6% vs. 6.8%, p = 0.019), and access-site hematoma (1.1% vs. 5.8%, p = 0.020) were less frequent in the Near-Styloid group.

CONCLUSIONS

No statistically significant difference in clinical RAS was detected between puncture sites located closer to or farther from the radial styloid process. Near-Styloid access was associated with improved puncture efficiency and lower rates of RAO and access-site hematoma. As these findings were derived from secondary endpoint analyses, they should be considered exploratory and warrant confirmation in future multicenter studies.

TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT07060820.