Return of esophageal function after treatment for achalasia as determined by impedance-manometry.

BACKGROUND: Treatment for achalasia is aimed at the lower esophageal sphincter (LES), although little is known about the effect, if any, of these treatments on esophageal body function (peristalsis and clearance). We sought to measure the effect of various treatments using combined manometry (peristalsis) with Multichannel Intraluminal Impedance (MII) (esophageal clearance).
METHODS: We enrolled 56 patients with Achalasia referred to the University of Washington Swallowing Center between January 2003 and January 2006. Each was grouped according to prior treatment: 38 were untreated (untreated achalasia), 10 had undergone botox injection or balloon dilation (endoscopic treatment), and 16 a laparoscopic Heller myotomy. The preoperative studies for 8 of the myotomy patients were included in the untreated achalasia group. Each patient completed a dysphagia severity questionnaire (scale 0-10). Peristalsis was analyzed by manometry and esophageal clearance of liquid and viscous material by MII.
RESULTS: Mean dysphagia severity scores were significantly better in patients after Heller Myotomy than in either of the other groups (2.0 vs. 5.3 in the endoscopic group and 6.5 in untreated achalasia, p < 0.05). Peristaltic contractions were observed in 63% of patients in the Heller myotomy group, compared with 40% in the endoscopic group and 8% in untreated achalasia (p < 0.05 for both treatment groups vs. untreated achalasia). Liquid clearance rates were significantly better in both treatment groups: 28% in Heller myotomy and 16% in endoscopic treatment compared to only 5% in untreated achalasia (p < 0.05). Similarly, viscous clearance rates were 19% in Heller myotomy and 11% in endoscopic treatment, vs. 2% in untreated achalasia (p < 0.05). In the subset of patients who underwent manometry/MII both pre- and postoperatively, peristalsis was observed more frequently postoperatively than in preop studies (63% of patients exhibiting peristalsis vs. 12%), as was complete clearance of liquid (35% of swallows vs. 14%) and viscous boluses (22% of swallows vs. 14%). These differences were not significant, however. In the patients who had a myotomy the return of peristalsis correlates with effective esophageal clearance (liquid bolus: r = 0.46, p = 0.09 and viscous bolus: r = 0.63, p < 0.05). There is no correlation between peristalsis and bolus clearance in the endoscopic treatment group.
CONCLUSIONS: With treatment Achalasia patients exhibit some restoration in peristalsis as well as improved bolus clearance. After Heller Myotomy, the return of peristalsis correlates with esophageal clearance, which may partly explain its superior relief of dysphagia.