A novel infraclavicular brachial plexus block: the lateral and sagittal technique, developed by magnetic resonance imaging studies

Abstract

A new infraclavicular brachial plexus block method has the patient supine with an adducted arm. The target is any of the three cords behind the pectoralis minor muscle. The point of needle insertion is the intersection between the clavicle and the coracoid process. The needle is advanced 0 degrees -30 degrees posterior, always strictly in the sagittal plane next to the coracoid process while abutting the antero-inferior edge of the clavicle. We tested the new method using magnetic resonance imaging (MRI) in 20 adult volunteers, without inserting a needle. Combining 2 simulated needle directions by 15 degrees posterior and 0 degrees in the images of the volunteers, at least one cord in 19 of 20 volunteers was contacted. This occurred within a needle depth of 6.5 cm. In the sagittal plane of the method the shortest depth to the pleura among all volunteers was 7.5 cm. The MRI study indicates that the new infraclavicular technique may be efficient in reaching a cord of the brachial plexus, often not demanding more than two needle directions. The risk of pneumothorax should be minimal because the needle is inserted no deeper than 6.5 cm. However, this needs to be confirmed by a clinical study.

Implications: A new infraclavicular brachial plexus block method was investigated using magnetic resonance imaging without inserting needles in the volunteers. The study suggests two needle directions for performance of the block and that the risk of lung injury should be minimal. Expectations need to be confirmed by a clinical study.