Abstract 10430: Radial First! Ulnar Next? Forearm Arterial Anatomy Study

Abstract

Introduction: In patients with small Right Radial Artery ( RRA ), access site failure may result in a radial to femoral crossover. Methods: The arterial anatomy of the distal forearm was studied using ultrasound in 167 hospitalized patients. The radial and ulnar artery dimensions were imaged in triplicates. The average cross-sectional area (CSA) and average diameter (AD) were measured using open-source ImageJ software. Variations in distal forearm arterial anatomy (branches) were documented. Results: The mean CSA and AD for the largest of the bilateral radial and ulnar arteries - Largest Forearm Artery ( LFA ), were 5.4 ± 2.5 mm 2 (1.1 → 13.3 mm 2 ) and 2.6 ± 0.6 mm (1.2 → 4.1 mm) respectively. The mean CSA and AD for RRA were 4.8 ± 2.5 mm 2 (0.7 → 13.3 mm 2 ) and 2.4 ± 0.6 mm (0.9 → 4.1 mm). In 46% of patients, RRA was not the LFA. The ulnar artery was larger than the radial artery in 25% of patients in the right wrist and 29% in the left wrist. The left radial was larger than the right radial in 31% and the left ulnar was larger than the right ulnar in 42%. In 58% of patients, RRA was < 2.5 mm (outer diameter of common radial access sheaths). In 24% of patients, RRA was <2 mm. In patients with RRA < 2.5 mm, 17% had another artery >2.5 mm and 6% had another artery > 3 mm. Men had 53% larger CSA compared to women. Smoking, intravenous drug use, diabetes, hyperlipidemia, peripheral vascular disease, chronic kidney disease (CKD), and hemodialysis predicted smaller-sized forearm arteries. CKD patients had 33% smaller CSA compared to patients without CKD. In 23 patients (14%), one or more of the forearm arteries had branches in the distal forearm. In 12 patients (7%), branches were seen in RRA. Conclusions: Right Radial Artery was not the largest forearm artery in almost half the patients. Right Radial Artery was smaller in size than common radial access sheaths in more than half of the patients. Of these patients, 17% had a different forearm artery > 2.5 mm that could be accessed instead of Femoral Artery. Female sex and CKD predicted smaller forearm artery sizes increasing the risk of radial access failure. Ultrasound use is advisable to identify the best forearm artery for access and avoid accessing smaller accessory branches that were seen in 7% of right radial and 14% of one or more forearm arteries.