Segmented biodegradable esophageal stents in a porcine model: preclinical evaluation of degradation, complications and tissue reactions

: Objective: To evaluate the feasibility of two types of segmented biodegradable esophageal stents in treatment of refractory benign esophagus strictures. Methods: Uncovered biodegradable segmented stent and fully-covered biodegradable segmented stent were implanted into the porcine esophagus (6 for each). Data on biodegradation, complications, and tissue reactions were compared between two groups. Results: All animals kept good general conditions; no death, decreased food intake, weight loss and malnutrition were observed. No perforation, ulcer, hemorrhage, stent migration and severe complications occurred. Stents degradation commenced at week 3. Stents structure breakage and complete stents absorption occurred at week 7-8 and week 9-10 in uncovered stents. While in fully-covered stents, stents structure breakage and complete stents absorption occurred at week 8-9 and week 10-11. Hyperplasia was prominent at week 1-3 and ameliorated at week 6 after stent implantation. A longer degradation period was present in fully-covered stents than in uncovered stents, while fully-covered stents induced tissue reactions at early stage were mild. Conclusions: The application of biodegradable esophageal stents with a segmented trunk in refractory benign esophagus strictures worth further investigation. The fully-covered stent has longer degradation period, which may be more suitable for clinical use.