Identification of impaired oesophageal bolus transit and clearance by secondary peristalsis in patients with non-obstructive dysphagia

Impaired secondary peristalsis has been shown in non-obstructive dysphagia (NOD). The relationship between such changes and alterations in bolus transport has not been studied. The aim of this study was to evaluate the integrity and characteristics of oesophageal bolus transit by secondary peristalsis in NOD patients with multichannel intraluminal impedance (MII). Eleven healthy volunteers and 10 consecutive patients underwent combined MII recording and manometry. Secondary peristalsis was stimulated by mid-oesophageal injections of saline. Values for bolus presence time at each of the recording sites and bolus transit time were calculated. Bolus transit was considered to be complete when impedance defined complete bolus clearance at all recording sites. Secondary peristaltic responses were triggered significantly less frequently in patients with NOD than in controls (P < 0.001). The proportion of secondary peristalsis demonstrating complete bolus transit was lower in NOD patients than in controls (P < 0.001). Oesophageal bolus transit time by secondary peristalsis was longer in NOD patients than in controls (P = 0.005), as was bolus presence time at each of the recording sites (P < 0.05). When compared with controls, NOD patients demonstrated a higher proportion of incomplete bolus transit in response to normal secondary peristalsis (P < 0.001). Abnormal bolus transit occurred more often associated with ineffective and synchronous responses than normal responses in both groups studied (P < 0.001). Multichannel intraluminal impedance identifies functional defects of oesophageal bolus clearance by secondary peristalsis in NOD patients and such defects are characterized by a longer oesophageal dwell and a prolonged clearance time.