A Comparison of a Fully Covered and an Uncovered Segmented Biodegradable Esophageal Stent in a Porcine Model: Preclinical Evaluation of Degradation, Complications, and Tissue Reactions

Aims. This study was to compare the degradation, complications, and tissue reactions of two segmented biodegradable esophageal stents in a porcine model. Methods. Uncovered biodegradable segmented stents and fully covered biodegradable segmented stents (FCBDS) were transplanted into the porcine esophagus lumen. Data on biodegradation, complications, and tissue reactions were collected and compared. Results. All animals kept good general conditions. No severe complications and stents migration occurred. Stents degradation commenced at week 3. Compared with uncovered stents, stents structure breakage and complete stents absorption in FCBDS were postponed for 1-2 weeks. Hyperplasia was prominent at early stage and ameliorated at late stage after stents insertion. Tissue reactions in FCBDS were milder than those in uncovered stents in the early stage. A longer degradation period was present in FCBDS than in uncovered stents, while FCBDS induced tissue reaction at late stage was mild. Conclusions. Biodegradable esophageal stents with a segmented trunk may be further evaluated in refractory benign esophagus strictures. This FCBDS may be advantageous compared with uncovered stents for a longer degradation period.