Establishment and observation of animal model with benign proliferative stenosis after esophageal stent implantation / 中华消化内镜杂志

ABSTRACT

Objective To establish and observe the canine model with esophageal stent implantation for further study of the benign stenosis caused by proliferation.Methods According to orthogonal design,different combinations of two stents and six polytetrafluoroethylene (PTFE) patches were confirmed.Stent was designed as cylinder with mushroom shape on both ends.Beagle dogs (weight 10-12 kg) were adopted and cervical segment of esophagus were dissected.After PTFE patch was encircled around the esophagus,stent was delivered under fluoroscopy.The main body of the stent was located in accordance with the patch.Eating condition and position of the stent were followed on week 1,2,4,6 and 8.Gross specimen was harvested at the end point,and the degree of tissue hyperplasia was evaluated.Each animal model was given a mark according to the eating condition and tissue hyperplasia.Results Eight combinations of stent and patch were provided with orthogonal design.Three models failed for the following reasonsunable to eat in one dog,stent disgorged out in another,and the third died from esophageal necrosis between stent and patch.Four models had obvious tissue hyperplasia on the segment of stent,and weight loss or stent dislocation were observed in each model.One model developed appropriate tissue hyperplasia with normal diet,and stent dislocation was not found during the follow-up.Significant difference was confirmed among 8 models (F =14.7000,P =0.031).Conclusion Animal model with appropriate tissue hyperplasia could be established with following elementsbeagle dogs weight from 10 kg to 12 kg; stent 50 mm in length,20 mm in diameter,with top mushroom 10 mm in length,30 mm in diameter,and end mushroom 10 mm in length,25 mm in diameter; PTFE patch 60 mm in length,15 mm in width.