Botulinum neurotoxin for pharyngeal constrictor muscle spasm in tracheoesophageal voice restoration

The purpose of the study was to evaluate the effectiveness of Botulinum neurotoxin (Botox) for elimination of pharyngeal constrictor muscle spasm in tracheoesophageal voice restoration.

A retrospective review was made of 62 patients between 1991 and 2002 who had Botox as the initial treatment for pharyngeal constrictor muscle spasm.

One hundred units of Botox properly diluted in 3 mL saline was instilled unilaterally under electromyographic guidance after fluoroscopic identification and marking of the contracted pharyngeal constrictor muscles. The patients were divided into three groups based on their response to the first Botox injection: group I, complete relaxation of the pharyngeal constrictors resulting in fluent voice, intratracheal phonation pressure of 20 to 40 cm H2O, and the ability to say 15 to 20 uninterrupted syllables; group II, hypertonic or incomplete relaxation of the pharyngeal constrictors resulting in intratracheal phonation pressure of 45 to 70 cm H2O and the ability to say 7 or 8 syllables; and group III, failure to produce relaxation of the pharyngeal constrictors.

After the first injection of Botox, 49 (79%) patients were in group I or II (41 in group I and 8 in group II) and group III consisted of 13 patients. Thirty-four patients (55%) had group I (28) or II (6) responses for greater than 6 months. A second Botox injection enabled 6 of the 13 failures to move into group I. In all, 8 pharyngeal constrictor muscle myotomies (13%) were ultimately required in the 62 patients. The group I speaker for the longest period has enjoyed 11 years of fluency and successful daily use of a tracheostoma valve after two Botox injections.

Botox relaxation of the pharyngeal constrictor muscles has proven to be effective, has replaced secondary pharyngeal myotomy for the initial treatment of pharyngeal muscle spasm, and is the only treatment in patients who are not candidates for elective surgery. Radiographic assessment, electromyographically monitored injection, and the number of Botox units appear to be important to successful outcomes.