Interscalene Versus Costoclavicular Blocks for Shoulder Surgery

The costoclavicular block was first described by Karmakar et al. in 2015. It is a type of brachial plexus block that targets the three cords located lateral to the axillary artery within the costoclavicular space. The costoclavicular space is defined as the area between the middle third of the clavicle and the anterior thoracic wall. Within this space, the cords of the brachial plexus are situated lateral to the axillary artery, positioned between the pectoralis major, subclavius, and serratus anterior muscles. In contrast to the traditional infraclavicular approach, the cords in the costoclavicular block are located more superficially and are more consistently clustered lateral to the axillary artery, which may facilitate visualization and needle targeting. After the needle is placed between the three cords under ultrasound guidance, the local anesthetic (20 mL of 0.25% bupivacaine) is injected.

Originally described by Etienne in 1925, the technique was later refined into its modern clinical form by Alon Winnie in 1970. The interscalene approach, primarily preferred for shoulder surgeries, aims to target the upper roots of the brachial plexus (C5-C7). In interscalene block, a needle is placed under ultrasound guidance around the upper and middle trunks of the brachial plexus, which pass through the space between the anterior and middle scalene muscles, and the local anesthetic (20 mL of 0.25% bupivacaine) is injected while its spread is observed.

In interscalene block, using an ultrasound probe placed on the neck, the course of the brachial plexus trunks between the anterior and middle scalene muscles is visualized. Then, after the needle is inserted under ultrasound guidance between the anterior and middle scalene muscles, 20 mL of 0.25% bupivacaine is injected as the local anesthetic.