Given the abundance of arteries in the neck, a significant risk of puncturing arteries exists when performing a brachial plexus block. Therefore, it is important to confirm the presence of arteries when performing a brachial plexus block via the interscalene approach. This study aimed to investigate the frequency and variations of arteries in the interscalene region in healthy Japanese adults using ultrasonography.

This is an observational study at a university hospital. We analyzed videos of the brachial plexus recorded in another study using an ultrasound device and then investigated the frequency of the presence of arteries and the location of arteries in the interscalene region.

Among 68 cases, 48 (70.6%) had one or more arteries in the interscalene region (63 arteries in total). The artery frequency on the ventral side of the 5th cervical nerve (C5), between C5 and the 6th cervical nerve (C6), between C6 and the 7th cervical nerve (C7), between C7 and the 8th cervical nerve (C8), and on the dorsal side of C8 was 19.1%, 1.5%, 35.3%, 29.4%, and 7.4%, respectively. The artery frequencies between C6 and C7 and between C7 and C8 were higher than those between C5 and C6 and on the dorsal side of C8.

Interscalene observations using ultrasound devices revealed a high artery frequency, with numerous topographic variations.