The effect of photodynamic therapy (PDT) on oesophageal motility and acid clearance in patients with Barrett’s oesophagus

Esophageal Function Abnormalities in Patients With Barrett's Esophagus

Various esophageal functional abnormalities have been described in patients with Barrett's esophagus (BE). A significantly higher esophageal acid exposure especially in the supine position has been documented in BE, as compared with the other gastroesophageal reflux disease phenotypes. In addition, weakly acidic reflux and duodenogastroesophageal reflux are more common in BE patients. The presence of Barrett's mucosa reduces esophageal mucosal impedance, occasionally to a level that prevents detection of reflux episodes. Reduced amplitude contractions and lower esophageal sphincter basal pressure are more common in BE patients as compared with the other gastroesophageal reflux disease groups. Ineffective esophageal motility is the most commonly defined motor disorder in BE. Reduced chemoreceptor and mechanoreceptor sensitivity to acid and balloon distention, respectively, have been suggested to explain lack or significantly less reports of reflux-related symptoms by BE patients.

The effect of argon plasma coagulation ablation on esophageal motility and chemoreceptor sensitivity in Barrett's esophagus patients

Patients with Barrett's esophagus usually demonstrate impaired esophageal motility, which affects acid clearance, together with reduced chemo-receptor sensitivity and symptom severity. Ablative endoscopic techniques are now used to eliminate Barrett's cells. The hypothesis for this study was that ablation with argon plasma coagulation (APC) may affect esophageal sensitivity and motility in patients with Barrett's esophagus, and the aim of this study was to assess differences in these parameters before and after APC treatment. Twenty patients with Barrett's esophagus were investigated before and after APC therapy. After standard pull through manometry, water bolus aliquots were given to assess primary peristalsis and rapid water and air bolus injections to assess secondary peristalsis. Sensitivity studies were carried out using weak solutions of either hydrochloric acid or sodium hydroxide, together with saline washouts. Onset time for typical symptoms (t), sensory intensity rating (I), and a sensory score (SS) = (t) x (I)/100 was observed. There were no significant differences in the lower esophageal sphincter pressures (13.6 mm Hg versus 12.6 mm Hg, P= 0.8) and successful test swallows (3 mm Hg versus 5 mm Hg, P= 0.5) before and after treatment, but there was a trend for secondary peristalsis to improve (air bolus 0 versus 2, P= 0.05, water bolus 0 versus 1, P= 0.07). Sensitivity studies showed a smaller sensitivity intensity rating to both acid (61 versus 31, P= 0.02) and alkaline (91 versus 64, P= 0.03) after treatment. In conclusion, we have shown no substantive changes in esophageal motility after ablation of Barrett's esophagus cells, but have demonstrated reduced sensitivity to reflux type solutions.