Abstract
The costoclavicular block is a proximal approach for blocking the brachial plexus in the infraclavicular fossa. Whether the costoclavicular block offers advantages over lateral paracoracoid approaches has been debated. However, diaphragm-sparing anesthesia for shoulder surgery has recently reignited interest in the costoclavicular space. In this review, we examine the costoclavicular block as an alternative to the interscalene block for shoulder surgery, focusing on minimizing involvement of the phrenic nerve. We conducted a systematic search of MEDLINE, EMBASE, and Google Scholar databases using the search terms "costoclavicular block" and "shoulder surgery," to identify relevant studies published up to April 2025. Only randomized trials meeting rigorous inclusion criteria, i.e., those that were prospectively registered, used blinded assessment, and provided sample size justification, were included. The findings of these studies suggested that local anesthetic deposition in the costoclavicular space can reliably anesthetize the brachial plexus cords, achieving a high rate of suprascapular nerve blockade, while sparing the diaphragm. The effectiveness of the anesthesia and analgesia provided by this block depends on use of the appropriate local anesthetic volume and concentration. Further research is needed to validate these findings. Nevertheless, the evidence to date indicates that the costoclavicular block is a promising alternative for patients at risk of respiratory insufficiency secondary to hemidiaphragmatic paralysis.