Office-based Electromyography-guided Botulinum Toxin Injection to the Cricopharyngeus Muscle: Optimal Patient Selection and Technique

Objectives: This retrospective study was carried out to investigate the effectiveness and safety of office-based electromyography-guided injection of botulinum toxin in the cricopharyngeus muscle of patients who did not show upper esophageal sphincter passage in a swallowing study in spite of maximal swallowing rehabilitation. Methods: Thirty-six patients who showed no or limited ability to oral feed after maximum swallowing rehabilitation were enrolled. Video fluoroscopic swallowing study, flexible endoscopic evaluation of swallowing, disability rating scale, penetration aspiration score, and National Institutes of Health swallowing safety scale were used in the evaluation of dysphagia. Results: Success was defined as nondependence on gastrostomy for patients who previously were dependent on gastrostomy and improvement in disability rating scale score after botulinum toxin injections. The total success rate was 63.9%. The complication rate was very low, with only 1 patient showing temporary unilateral vocal fold paralysis. Botulinum toxin injection was more effective in patients with cranial nerve IX or X palsy than in those without it (P =.006). Conclusions: This procedure can be a simple, safe, and effective tool in patients with cricopharyngeal dysfunction after swallowing rehabilitation, especially for cranial nerve IX or X palsy.