6Ponce J, Garrigues V, Pertejo V, et al. Individual prediction of response to pneumatic dilation in patients with achalasia. Dig Dis Sci,1996;1(11):2135
7Borotto E, Gaudic M, Danel B, et al. Risk factors of esophageal perforation during pneumatic dilation for achalasia. Gut, 1996; 9 (1):9
8E Kardt VF, Kanzler G, westermeier T. complication and theirmpact after peumatic dilation for achalasia: prospective long - term fol- low - up study. Gastrointest Endosc, 1997 ;45: 349~ 353
9Pasricha PJ, Rai R, Ravich WJ , et al. Botulinm toxin for achalasia :long - term outcome and predictors of response. Gastroenterology, 1996; 110:1410~1415