OBJECTIVETo investigate the effects of peroral endoscopic myotomy(POEM) on esophageal dynamics in patients with esophageal achalasia.

METHODSFrom September 2011 to November 2011, 20 cases with esophageal achalasia received POEM at the Endoscopic Center in the Zhongshan Hospital of Fudan University. Pre-operation esophageal dynamics of all the patients were evaluated by high resolution manometry(HRM) system and 3 days after operation the test was repeated. Lower esophagus sphincter resting pressure(LESP), 4-second integrated relaxation pressure(4sIRP), lower esophagus sphincter relax rate(LESRR), lower esophagus sphincter length(LESL), and esophageal manometry were analyzed.

RESULTSAfter POEM, LESP decreased from(29.1±17.0) mm Hg to(14.6±4.9) mm Hg, and decrease rate was 49.8%(P<0.01). However, the decreases in LESRR and LESL were not statistically significant(P>0.05). Esophageal peristaltic contraction was absent in all the 20 patients preoperatively. After POEM, changes in the esophageal contraction were seen in 7 patients, and peristalsis was noticed but was below normal level. There were no significant changes in peristalsis in the remaining 13 patients.

CONCLUSIONPOEM can significantly reduce LESP and 4sIRP in patients with achalasia, but can not affect the contraction of the esophagus.