Intrasphincteric botulinum toxin for the treatment of achalasia

Achalasia is a disorder of swallowing in which the lower esophageal sphincter fails to relax. We report the use of botulinum toxin, a paralytic agent, for the treatment of this condition.

In a double-blind trial, 21 patients with achalasia received either 80 units of botulinum toxin or placebo, injected endoscopically into the lower esophageal sphincter. One week later, the response to treatment was assessed on the basis of changes in the symptom scores (measured on a scale from 0 to 9), pharyngoesophagograms, and results of esophageal manometric and scintigraphic studies. Patients who received placebo initially were subsequently treated with botulinum toxin. After six months, esophageal scintigraphy was repeated.

One week after treatment, the mean decrease in the symptom score was 5.4 points for the patients treated with botulinum toxin and 0.5 point for the placebo group (P = 0.001). The mean decrease in the pressure of the lower esophageal sphincter was 33 percent in the treatment group, as compared with a mean increase of 12 percent in the placebo group (P = 0.02), and the mean increase in the width of the opening of the lower esophageal sphincter was 204 percent in the treatment group, as compared with a mean decrease of 14 percent in the placebo group (P = 0.02). Nineteen of the 21 patients treated with botulinum toxin had symptomatic improvement initially; after six months 14 patients were still in remission. This improvement was accompanied by a decrease in esophageal retention that was sustained at six months (46 percent, as compared with a pretreatment value of 77 percent; P = 0.04). There were no serious adverse effects.

Injection of botulinum toxin into the lower esophageal sphincter is an effective, safe, and simple method of treatment for achalasia, with results that are sustained for several months.