RÉSUMÉ
Botulinum toxin (BoTox) is a potent inhibitor of the release of acetylcholine from terminal nerves and has been used succesfully in spastic disorders of skeletal muscle. Its used for the treatment of disorders of gastrointestinal smooth muscle has recently been explored. In this study we evaluated the efficacy of transendoscopic injection of BoTox in 13 symptomatic patients with achalasia G II (Siewert classification) without previous treatment of an angoing randomized-controlled trial. Patients were blindy randomized to administrate: a) 8OU of BoTox were injected in four quadrants (1 ml in each quadrant-20 U/ml) (n=8) normal saline solution as placebo injected in the same way (n=5). Patientes who did not respond were retreated in an open design with the same schedule of BoTox. BoTox or placebe were injected directly into the lower esophageal sphincter (LES), located by manometric and endoscopic procedures, via sclerotherapy injector. Response to treatment was assessed by changes in symptoms score, weight, LES pressure, barium esophagograms and endoscopy. All determinations were repeated at basal and after 7-30-60 and 90 days of treatment. Post treatment response was considered positive if at one month, 3 of 4 parameters were improved. No evidence of response to BoTox were assessed in 3 patients. At 90 days, 10 patients remain well and data are as follows: (X + SD) symptoms score: (Pre: 3.23 + 0.44) (Post: 1.31 + 0.95); LES pressure (mmHg) (Pre: 53,15 + 66.31 + 7.49); per cent reduction of esophageal diameter 55 per cent (p< 0.0001) (pair T-test). Relaxation of LES did not change after treatment. There were no side effects related to BoTox injection. Conclusions: Endoscopic intrasphincteric BoTox injection is safe, simple and effective in the short term treatment for achalasia. Further studies are necessary for evaluation of long term effects.