landmarks for a needle puncture (right oblique view). Note needle insertion in the “V” of the junction of the anterior border of the trapezius and the posterior border of the levator scapulae muscles.
The cervical paravertebral approach to the brachial plexus is a brachial plexus root or trunk block with the same indications as for the continuous interscalene block. Following interscalene block, patients frequently complain of an uncomfortable “dead feeling” of the arm, which is caused by a dense sensory, motor, and proprioceptive block following a conventional continuous interscalene block. The desire to provide a sensory block with more motor sparing, enabling participation of patients in physical therapy (especially patients with a “frozen shoulder”), was primary in designing the continuous postoperative cervical paravertebral block.
In the plane of the paravertebral space, the roots of the posterior sensory and anterior motor fibers are joined to become the individual nerve roots. This may explain why more electrical current is often required to elicit a motor response when performing a cervical paravertebral block compared with the anterior interscalene approach. This block was originally described by Kappis in the 1920s and modified by Pippa in 1990. As originally described, the block was painful, probably owing to penetration of the paraspinal extensor muscles of the neck. It was infrequently used until recently, when a modification was described that avoids penetrating the extensor cervical muscles. This technique minimizes the pain associated with the approach to the brachial plexus by inserting the needle in the “V” between the levator scapulae and trapezius muscles at the level of the sixth cervical vertebra
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