Study on the changes of collagen content in the esophageal tissue after stenting / 中华消化内镜杂志

ABSTRACT

Objective To study the changes of collagen content in the esophageal tissue after stenting. Methods To select healthy adult dogs as experimental subjects.Esophageal stent was installed by the method of “autogenous fascia lata femoris transplantation and fixation",the dogs were killed at the end of 1,2,4 and 8 weeks,and the esophageal tissues with stent were taken out and studied by gross observation,light microscopy and electromicroscopy. The bulk density and distribution of collagen fiber were studied by special staining and computer technology.The content of P I CP and PⅢNP in restenosis tissue were measured by radio immunoassay(RIA).The contents of hydroxyproline and total amino acid(AA) in restenosis tissue were measured by amino acid analyser. Results At week 1 and 2 the inflammatory reaction occurred evidently in stenting esophagus with granulation and fibrosis,in some sites the esophageal tissue began to proliferate towards the lumen where the fibroblasts were in the state of active proliferation and secretion .The contents of hydroxyproline and total amino acid were significantly higher in the esophageal tissue within 1 and 2 weeks of stenting than those in normal esophagus.At week 4 and 8 esophageal lumen narrowed conspicuously,with a lot of fibrotic tissue and a little of inflammatory cells.The staining density of collagen elevated gradually within 4 weeks,there after the content of collagen was stabilized.The change of P I CP and PⅢNP accorded with that of collagen staining.The content of AA at week 4 increased significantly compared with that at week 2,its level was similar to that between 4 and 8 weeks. Conclusions Re-stenosis mainly expressed as fibrosis. At week 4,8 the fibrosis stabilized gradually with the lessening of inflammatory reaction. The content of collagen in re-stenosis tissue elevated within 4 weeks,and stablilized after week 4,it was in accordance with the pathological changes of re-stenosis.