Achalasia is an idiopathic neuromuscular disorder of the esophagus which is associated with absence of esophageal peristalsis and incomplete relaxation of a normal or raised lower esophageal sphincter (LES). Dysphagia is the most commonly associated symptom. Conventional therapeutic approaches are directed to reducing LES pressure and include orally-administered smooth muscle relaxants, forceful sphincter dilation with balloon dilators, and open or laparoscopic-assisted myotomy of the LES. Pharmacologic therapies have a low success rate. Forceful dilation has a perforation complication rate of 2% to 5%, and myotomies may precipitate significant gastroesophageal reflux, a complication minimized when a partial fundal wrap is employed simultaneously. In recent years, botulinum toxin, utilized widely as a striated muscle relaxant in managing blepharospasm, anal sphincter spasm, and muscle spasm complicating CVAs, and in smoothening facial wrinkles, has been extended to the management of achalasia on the basis that it impairs smooth muscle responsiveness to acetylcholine. Eighty units of Botox (botulinum toxin) are injected directly into the endoscopically (endoscopic ultrasound techniques may facilitate localization) located LES region (20 units into each of 4 quadrants). Symptom relief lasting 6 months on average is experienced in more than 65% of treated patients, and the complication rate is negligible. This therapeutic option is reserved for patients too ill to undergo any surgical procedure and is most effective when the lower esophageal region is hypertonic.
ASJC Scopus subject areas
- Pharmacology (medical)