[Measurement of radial artery diameter by optical coherence tomography via distal radial access].

<b>Objective:</b> To measure the radial artery (RA) diameter and explore its related factors by using optical coherence tomography (OCT). <b>Methods:</b> This was a cross-sectional study conducted in Cardiac Care Unit of Beijing Luhe Hospital, Capital Medical University. Patients who underwent first-ever right forearm access and OCT guided coronary intervention via right distal RA, and measurement of the whole portion of RA diameter with OCT in our center between January 2021 to December 2021 were enrolled. Following the coronary intervention, OCT was used to assess the entire RA. The RA diameter was measured from the RA ostium to 2 cm above the radial styloid process, with a 1 mm interval. Multiple linear regression analysis was performed to determine the factors related the RA diameter. <b>Results:</b> The study enrolled 124 patients with an age of (61.6±12.6) years, of whom 98 (79%) were male. The total length of the RA was (19.5±1.8) cm, for males (20.2±1.3) cm and females (17.2±1.2) cm. The average RA diameter was (3.13±0.50) mm, and the RA diameter at 2 to 5 cm above the radial styloid process was (2.98±0.53) mm. The average RA diameter was significantly larger for male patients than for female patients ((3.21±0.50) mm vs. (2.84±0.37) mm, <i>P</i><0.001). Multiple linear regression analysis indicated that gender was significantly associated with RA diameter (<i>P</i>=0.019). <b>Conclusions:</b> The average RA diameter measured by OCT is (3.13±0.50) mm, (2.98±0.53) mm at 2 to 5 cm above the radial styloid process. Gender is identified as a factor related to the RA diameter.