Evaluation of biodegradable paclitaxel-eluting nanofibre-covered metal stents for the treatment of benign cardia stricture in an experimental model

Abstract

Abstract Background Benign strictures at the cardia are troublesome for patients and often require repeated endoscopic treatments. Paclitaxel can reduce fibrosis. This study evaluated a biodegradable paclitaxel-eluting nanofibre-covered metal stent for the treatment of benign cardia stricture in vitro and in vivo. Methods Drug release was investigated in vitro at pH 7·4 and 4·0. Eighty dogs were divided randomly into four groups (each n = 20): controls (no stent), bare stent (retained for 1 week), and two drug-eluting stent (DES) groups with retention for either 1 week (DES-1w) or 4 weeks (DES-4w). Lower oesophageal sphincter pressure (LOSP) and 5-min barium height (5-mBH) were assessed before, immediately after stent deployment, at 1 week, and 1, 3 and 6 months later. Five dogs in each group were killed for histological examination at each follow-up point. Results Stent migration rates were similar (0 bare stent versus 2 DES; P = 0·548). The percentage and amount of paclitaxel released in vitro was higher at pH 4·0 than at pH 7·4. After 6 months, LOSP and 5-mBH were both improved in the DES-1w (P = 0·004 and P = 0·049) and DES-4w (both P < 0·001) groups compared with the bare-stent group, with better relief when the stent was retained for 4 weeks (P = 0·004 and P = 0·007). The DES was associated with a reduced peak inflammatory reaction and less scar formation compared with bare stents, especially when inserted for 4 weeks. Conclusion The DES was more effective for the treatment of benign cardia stricture than bare stents in a canine model. Retention of the DES for 4 weeks led to a better clinical and pathological outcome than 1 week.