RESUMEN
A retropective study was perfomed to asses risk factors in patients with esophageal echalasia undergoing pneumatic dilatation. Of 140 patients who underwent 159 dilatations, 7 sustained esophageal perforation (4.4 percent). They were matched with a group of 52 non perforated, dilated achalasia patients. History of prior pneumatic dilatation and small esophageal diameter were found to be risk factors by chi square and ANOVA. Conclusions: 1) Pneumatic dilatation for esophageal achalasia is a procedure with 4.4 percent risk of perforation and 0.6 percent mortality rate. 2) The risk of developping an esophageal perforation is increased by previous pneumatic dilatation and small esophageal diameter. Another risk factor such as a possible anatomical weakness of the esophageal wall (and the likelihood of it being evaluated by ultrasonography) at the site of perforation is suggested.