To investigate the abnormal esophageal motility in achalasia and sliding hiatal hernia patients using combined multichannel intraluminal impedance and esophageal manometry(MII-EM).

Consecutive 10 patients with sliding hiatal hernia and 6 patients with achalasia diagnosed by endoscopy or esophageal dynamic radio-graphy were enrolled, and also 10 healthy volunteers in Beijing Tongren Hospital, Capital Medical University. All objects underwent MII-EM examination. Differences were compared between the detection indexes of either patient group and the control.

Both the patient groups showed a significantly lower Complete Bolus Transit Rate compared to the control. The achalasia group had significantly higher LES residual pressure, more esophageal simultaneous contractions and retrograde contractions , lower LES percent relaxation and proximal-mid esophageal constriction amplitude (P<0.05) compared to the control. No significant differences were found in LES pressure, LES length, and any functional indexes of upper esophageal sphincter (UES) between the achalasia group and the control. The sliding hiatal hernia group had a significantly lower LES pressure, longer UES relaxation duration, and lower proximal esophageal constriction amplitude (P<0.05). No mid- distal esophageal functional abnormities were found in sliding hiatal hernia group.

MII-EM can help evaluate the esophageal dysfunction in achalasia and sliding hiatal hernia patients, and may help with diagnosis.