胶原含量变化在食管支架术后再狭窄形成中的意义

Study on the changes of collagen content in the esophageal tissue after stenting

目的研究食管支架术后再狭窄组织中胶原纤维含量的变化及其意义。方法选择16只成年健康实验犬,均分为4组。采用“自体阔筋膜移植固定法”植入“Z”型食管支架,分别于术后1、2、4、8周处死动物,取出置架部位的食管组织,进行大体形态、光学显微镜、电子显微镜观察;经特殊染色,计算胶原纤维的体积密度,同时采用放免方法检测组织中Ⅰ、Ⅲ型胶原的含量;氨基酸成分分析法检测组织中羟脯氨酸及氨基酸总量。结果术后1、2周,食管组织炎性反应明显,局部有广泛肉芽组织形成及部分纤维化,某些部位组织开始向管腔内生长;组织中成纤维细胞处于旺盛的增殖及分泌状态,羟脯氨酸及氨基酸总量较正常明显升高。术后4、8周,管腔明显狭窄,局部出现大量的纤维结缔组织,炎性细胞显著减少。术后4周内组织中胶原纤维的染色强度呈上升趋势,4周后胶原含量则趋向于稳定,与再狭窄的病理过程基本一致。I型胶原羧基端肽(PICP)、Ⅲ型胶原氨基端肽(PⅢNP)的检测结果变化与胶原染色基本一致。术后4周组织的氨基酸含量较术后2周升高显著,术后8周与4周的氨基酸水平基本一致。结论再狭窄主要表现为纤维化,术后4、8周随着炎性反应的减弱,纤维化过程渐趋稳定。组织中胶原纤维尤其是Ⅰ、Ⅲ型胶原的含量在支架术后4周内呈上升趋势,4周后逐渐稳定。

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.