Abstract
BACKGROUND AND PURPOSE: Anterior scalene block is a helpful diagnostic test for NTOS and a good predictor of surgical outcome. The purpose of this study was to describe the technique, success rate, and complications associated with CT-guided anesthetic and botulinum toxin injection of the ASM/MSM in patients with NTOS symptoms.
MATERIALS AND METHODS: One hundred six participants (mean age, 41.5 ± 10 years; 80 women) were identified via a retrospective review of medical records for CT-guided scalene blocks. The procedure was evaluated regarding the technical success, defined as satisfactory detection of the ASM/MSM; intramuscular needle placement; intramuscular injection of contrast; appropriate delivery of medication; and frequency of unintended BP block or other complications. We also determined the outcome of patients who underwent surgery following the block.
RESULTS: Study participants underwent 146 scalene injections, 83 blocks, and 63 chemodenervations, which were included in this investigation. In all cases, detection of the ASM/MSM and intramuscular needle placement was satisfactory. Postprocedural complications included 5 (3.4%) temporary BP blocks, 1 patient with (0.7%) Horner sign, 7 (4.8%) needle-induced pain reports, 1 (0.7%) case of dysphagia, and 2 (1.4%) instances of muscle weakness. There were no major complications reported. The rate of good outcome following surgery was the same in patients with positive versus negative blocks, 30/43 (70%) versus 5/7 (71%), respectively.
CONCLUSIONS: CT guidance is a useful adjunct in performing accurate ASM/MSM blocks with a low rate of minor complications.
Abbreviations
- ASM
- anterior scalene muscle
- BP
- brachial plexus
- CR
- cervical rib
- EMG
- electromyography
- EMR
- electronic medical record
- IJV
- internal jugular vein
- MSM
- middle scalene muscle
- NTOS
- neurogenic thoracic outlet syndrome
- TOS
- thoracic outlet syndrome
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