Echoendoscopic evaluation of botulinum toxin intrasphincteric injections in Chagas' disease achalasia

Botulinum toxin (BT) has recently been indicated as an alternative treatment of idiopathic achalasia with a success rate of 60-70%. One-third of BT-treated cases either fail to respond or fail to sustain the response beyond 6 months. An explanation for BT therapeutic failure would be that the lower esophageal sphincter muscular layer (LES) may be missed as injection is delivered 'blindly'. We aimed to evaluate the percentage of exact endoscopically 'blind' LES punctures using echoendoscopy after the injection of BT for the treatment of Chagas' achalasia (CA). Five patients with CA (mean age 53 years) were randomized to receive 1.2 ml of BT or the same amount of saline injected endoscopically. Echoendoscopy was performed immediately after puncture. Patients were evaluated by the clinical score of dysphagia, radiological examination, upper endoscopy and esophageal manometry and followed up for 6 months. All puncture sites were identified: 17 out of 20 (85%) in the muscle layer and 3 out of 20 (15%) in the submucosa. The three patients in the treatment group showed clinical improvement (average clinical score fell from 14 to 2 after 7 days, and remained at 4 after 6 months of follow-up). The mean pressure of the LES dropped by 29%. Neither patient in the placebo group showed clinical improvement, and the mean pressure of the LES increased by 35%. Endoscopic 'blind' injection of BT into the LES through endoscopy for the management of achalasia is a safe and reproducible technique and has a high percentage of exactness.