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). 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. 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.