Until recently, pneumatic dilatation and intrasphincteric injection of botulinum toxin (Botox) have been used as initial treatments for achalasia, with myotomy reserved for patients with residual dysphagia. It is unknown, however, whether these nonsurgical treatments affect the performance of a subsequent myotomy. We compared the results of laparoscopic Heller myotomy and Dor fundoplication in 44 patients with achalasia who had been treated with medications (group A, 16 patients), pneumatic dilatation (group B, 18 patients), or botulinum toxin (group C, 10 patients). The last group was further subdivided according to whether there was (C2, 4 patients) or was not (C1, 6 patients) a response to the treatment. Results for groups A, B, C1, and C2, respectively, were: anatomic planes identified at surgery (% of patients)--100%, 89%, 100%, and 25%; esophageal perforation (% of patients)--0%, 5%, 0%, and 50%; hospital stay (hrs)--26+/-8, 38+/-25, 26+/-11, and 72+/-65; and excellent/good results (% of patients)--87%, 95%, 100%, and 50%. These results show that: (1) previous pneumatic dilatation did not affect the results of myotomy; (2) in patients who did not respond to botulinum toxin, the myotomy was technically straightforward and the outcome was excellent; (3) in patients who responded to botulinum toxin, the LES muscle had become fibrotic (perforation occurred more often in this setting, and dysphagia was less predictably improved); and (4) myotomy relieved dysphagia in 91% of patients who had not been treated with botulinum toxin. These data support a strategy of reserving botulinum toxin for patients who are not candidates for pneumatic dilatation or laparoscopic Heller myotomy.