Temporary self-expanding cardia stents for the treatment of achalasia: an experimental study in dogs.

摘要

BACKGROUND: To assess the performance, efficiency and optimal removal time of a newly designed temporary retrievable cardia covered stent (TRC-CS) for the treatment of achalasia in a dog model. METHODS: Eighty-four achalasia-like dog models were randomly divided into seven groups of 12, a control group (CG; no stent insertion), a standard stent control group (NSCG, standard esophageal stent) and five treatment groups (TG, TRC-CS). Stents were retrieved at 4 days after insertion in the NSCG and at 4 days(4 d-TG), 2 weeks(2 w-TG), 1 month(1 m-TG), 3 months(3 m-TG), and 6 months(6 m-TG) in the TGs. Lower esophageal sphincter pressure (LESP) and a timed barium esophagram were assessed before stent insertion, after stent retrieval, and at 1-week, 1-, 3- and 6-month follow-up. Three dogs in NSCG and 4 d-TG were sacrificed for histological examination at each follow-up to investigate the inflammatory reaction after stent insertion. KEY RESULTS: Stent insertion/removal and the follow-up procedures were well tolerated. At 6-month follow-up, the 2 w-TG and 1 m-TG demonstrated an acceptable stent migration (n = 2 in both TGs vs n = 4 in NSCG, n = 4 in 3 m-TG, and n = 6 in 6 m-TG), improved LESP compared to after benzyl-dimethyltetradecylammonium chloride (BAC) injection (P < 0.05), and improved timed barium height (P = 0.0144 and 0.0409). Mouse -proliferating cell nuclear antigen (PCNA) and alpha-smooth muscle actin staining revealed no inflammatory reaction difference between the NSCG and 4 d-TG at each follow-up. CONCLUSIONS & INFERENCES: The TRC-CS was effective in the treatment of achalasia in a dog model. LESP measurements, timed barium esophagram studies suggest an optimal stent retrieval time of between 2 w approximately 1 m.