Costoclavicular Brachial Plexus Block for Upper Limb Procedures: A Narrative Review of Efficacy and Safety.

Regional anesthesia techniques for upper limb surgery continue to evolve to improve block reliability while minimizing approach-specific complications. This narrative review evaluates the efficacy and safety of the costoclavicular brachial plexus block, a modified infraclavicular approach that targets the clustered cords of the brachial plexus lateral to the axillary artery. The objective is to synthesize current evidence on clinical performance, analgesic outcomes, and complications in upper limb procedures. A structured literature review of studies published between 2015 and 2025 was conducted using major medical databases, including randomized trials, observational studies, systematic reviews, and relevant anatomical investigations. The evidence demonstrates that the costoclavicular block provides reliable surgical anesthesia and postoperative analgesia for distal and intermediate upper limb procedures, with high success rates and predictable onset under ultrasound guidance. Continuous catheter techniques further extend its analgesic utility. A consistent and clinically significant finding is the lower incidence of hemidiaphragmatic paralysis compared with interscalene and supraclavicular blocks, supporting its use in patients with limited respiratory reserve. Complication rates, including vascular puncture and neurological injury, are low and comparable to other infraclavicular techniques. Although the block alone may not provide complete anesthesia for extensive shoulder surgery, it offers a safe, efficient, and diaphragm-sparing alternative for a wide range of upper limb procedures. This review supports the costoclavicular approach as an important component of contemporary, anatomy-based regional anesthesia practice.