Assessment of esophageal motor function using combined multichannel intraluminal impedance and manometry in patients with achalasia

SummaryBackgroundAchalasia is characterized by esophageal aperistalsis and a failure of lower esophageal sphincter (LES) relaxation. Combined multichannel intraluminal impedance and manometry (MII-EM) allows the simultaneous recording of esophageal peristalsis and bolus transport patterns. The aim of this study was to evaluate the feasibility of MII-EM for the assessment of esophageal motility and to characterize patterns of esophageal bolus transport in patients with achalasia with or without Heller myotomy.Materials and methodsA total of nine patients (2 men and 7 women, age range 25–46 years) were enrolled in this study. Two of the patients had previously undergone Heller myotomy. All patients underwent combined MII-EM with a nine-channel esophageal function testing catheter containing four impedance measuring segments and five solid-state pressure transducers. Each patient received 10 liquid and 10 viscous swallows in a sitting position. All tracings were recorded and analyzed for esophageal contractions and bolus transit.ResultsNone of the patients with achalasia, whether they had undergone a Heller myotomy or not, had manometrically normal esophageal peristalsis during saline or viscous swallowing. They had a normal LES resting pressure, incomplete LES relaxation, and lower distal esophageal contraction. The LES relaxation percentages in the patients who had undergone Heller myotomy (97% and 51%) were higher than those of the untreated patients (mean 47%). All patients demonstrated a low baseline impedance level in the distal esophagus. Air trapping in the proximal esophagus was also detected in nearly all of the patients. None of the patients in either group had complete bolus transit with either saline or viscous swallows.ConclusionPatients with achalasia are characterized by poor esophageal contraction and absent esophageal bolus clearance and such abnormalities are still noticeable after Heller myotomy. Although combined MII-EM can provide additional information regarding esophageal bolus transit, a low baseline impedance level and air trapping in the proximal esophagus may limit its utility in the diagnosis of esophageal dysmotility in patients with achalasia.