Clinical course of photodynamic therapy induced esophageal strictures

Introduction: Photodynamic therapy has been applied to the treatment of Barrett's esophagus but has been found to produce strictures in up to half of the treated patients. Aim: To determine the clinical course of esophageal strictures produced by photodynamic therapy of Barrett's esophagus. Methods: Patients who are ineligible for surgery with high grade dysplasia or superficial cancer have been offered photodynamic therapy as part of a prospective clinical trial. All patients have been treated by first administering intravenous hematoporphyrin derivative (HpD) at a dose of 4 mg/kg followed in 48 hours by endoscopy and photoradiation at a dose of 200 J/cm fiber using a 2.5 cm cylindrical diffusing fiber. Patients are re-endoscoped again in a day at which time any residual untreated areas are again photo radiated. Patients are sequentially endoscoped at 3 month intervals. If dysplagia develops, patients are endoscoped immediately. If strictures were found, dilatation would be performed to attempt to achieve a diameter of 18 mm. If strictures re-appeared after two consecutive dilatations to large diameters, steroid injection (80 mg triamcinalone) was performed directly into the stricture. Further dilatations were performed as clinically necessary. Results: A total of 36 patients, 31 male, have been treated under this protocol. Of these patients, 9 (25%) males with a mean age 69±4 years had dysphagia and developed esophageal strictures after photodynamic therapy. All strictures developed within 2 months of treatment and had a mean diameter of 9±1 mm (range 7-12 mm). The strictures were treated with balloon dilators in 7 (78%) of the cases and Savoray dilators in the remainder. The mean diameters achieved after dilatation was 17±1 mm. A mean of 8±2 dilatations were required to treat these patients with eventual resolution of the strictures in 7 (78%) after 7±1 month. This is significantly more than the 1±1 dilatations required for benign strictures previously reported (p<0.05). One patient has required self dilatation on a weekly basis with a 45 Fr Maloney dilator. One patient has been unable to be dilated adequately because of severe pulmonary disease. Conclusions: PDT induced strictures appear to be more difficult to treat in terms of the number of dilatations required and the duration of time prior to resolution of stricture than reflux strictures. Patients need to be informed about the aggressive therapy needed to resolve these strictures.