ESOPHAGEAL AND LOWER ESOPHAGEAL SPHINCTER RESPONSE TO BALLOON DISTENSION IN PATIENTS WITH ACHALASIA

Achalasia is characterized by absent or incomplete lower esophageal sp hincter (LES) relaxation and aperistalsis in the smooth muscle esophag eal body in response to swallowing. The esophageal and LES response to distention has not previously been studied. I aimed to characterize t he responses to esophageal balloon distention in achalasia patients in comparison to controls. Sixteen consecutive achalasia patients and 11 healthy volunteers underwent standard esophageal manometry followed b y graded midesophageal balloon distention during which LES (as measure d by the Dent sleeve) and esophageal body pressures were monitored. Su bject perception of distention was also recorded using a standardized scoring system. The LES relaxation response to esophageal balloon dist ention was markedly impaired in achalasia patients, irrespective of wh ether the patient had radiological evidence of a dilated or nondilated esophagus. However, phasic contractions proximal to the distending ba lloon were preserved. The esophageal body responses below the balloon were inconsistent in both groups, and not significantly different from one another. Pain-sensation scores were significantly lower in achala sia patients at the highest distending volumes, but this difference wa s attributable to the subgroup of patients with a dilated esophagus, D istention-induced LES relaxation is markedly impaired in achalasia pat ients in keeping with loss of intrinsic inhibitory innervation, Preser vation of the proximal excitation suggests that extrinsic vagal reflex es are intact.