Ultrasound-Guided Brachial Plexus Block by Costoclavicular Space Approach: A Narrative Review.

In recent years, ultrasound-guided costoclavicular brachial plexus block (CCB) has gained attention as a novel approach for brachial plexus nerve block. Human anatomy studies have identified the costoclavicular space as the area between the midpoint of the clavicle and the first rib. This space accommodates the brachial plexus, axillary arteries, and veins. Its superficial and fixed position makes it a promising option for infraclavicular brachial plexus blockage, providing a safe and reliable analgesic effect. CCB combines the benefits of real-time ultrasound visualization of the nerve block needle, avoidance of peripheral blood vessels, and targeted delivery of local anesthetics to the nerve. Consequently, it significantly reduces the associated complications of other classical approaches such as interscalene brachial plexus block (ISB), supraclavicular brachial plexus block (SCB), lateral sagittal infraclavicular brachial plexus block (LS-ICB), and axillary brachial plexus block. These complications include phrenic paralysis, incomplete brachial plexus block, and pneumothorax. This narrative review examines the literature on brachial plexus block in the costoclavicular space, discussing the anatomical position, the procedure, clinical indications, choice of local anesthetic concentration and volume, and continuous nerve block of CCB. The aim is to provide a basis for future clinical practice and enhanced safety.

Study on Residual Stress in Disc-Milling Grooving of Blisks.

The disc-milling method is expected to increase the grooving efficiency of blisks. However, there are few studies about the residual stress on a blisk during disc-milling grooving. In this study, a single-factor experiment and an orthogonal experiment of blisk disc-milling and grooving were designed to obtain the residual stress. Surface subsurface residual stress were also studied. The results showed that the surface of the milling groove bore compressive stress. Residual stress decreased with increasing spindle speed and increased with increasing feed speed and spindle rotation angle. Moreover, residual stress was most sensitive to spindle rotation angle and least sensitive to feed speed. A higher residual stress produced on the machined surface led to a deeper layer of residual stress.