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

BACKGROUND: Barrett's oesophagus is the major risk factor for oesophageal adenocarcinoma. It is proposed that long-term re-epithelialisation, which has been achieved following ablation using 5-aminolaevulinic acid (5-ALA) photodynamic therapy (PDT) may reduce the risk of malignant change. However, it is not known whether PDT modifies oesophageal motility. AIM: To assess oesophageal pH and motility before and after PDT ablation in treated and untreated areas of the oesophagus. METHODS: Twelve patients (10 male) with Barrett's oesophagus, median segment length 4 cm, were treated with PDT ablation. Twenty-four hours pH assessment and oesophageal manometry were performed before and 4-6 weeks after ablation. PDT was carried out using 635 nm red light, 4-6h after administration of 30 mg/kg 5-ALA. Proximal (untreated) and distal (treated) oesophageal resting pressure, wave amplitude, percentage peristalsis and percentage study time oesophageal pH<4, were assessed. Proton pump inhibitors (PPI) were administered throughout the study. RESULTS: There were no significant differences in oesophageal motility in treated or untreated areas of the oesophagus after PDT compared to pre-treatment values. Patients who continued to experience oesophageal acid exposure required more treatments to achieve complete Barrett's ablation. CONCLUSIONS: Oesophageal motility following ALA-PDT suggests a trend toward enhanced wave propagation however continued oesophageal acid exposure may affect PDT efficacy.