Research on the relationship between functional changes of fibroblasts in local esophageal tissues and re-stenosis after stenting / 中华消化杂志

ABSTRACT

Objective Re stenosis is the common complication of stenting. This study was designed to investigate the functional changes of fibroblast in local re stenosis esophageal tissue after stenting and its relation to re stenosis. Methods Sixteen healthy adult dogs were divided into four groups. Esophageal stent was placed by means of “autogenous broad fascia transplantation and fixation”. At the end of 1,2,4 and 8 weeks,the dogs were killed, and the esophageal tissue with stent were taken out and analyzed by gross observation, light microscopy and electron microscopy. The expression of proliferation cell nuclear antigen (PCNA) and alpha smooth muscle actin (? SMA) in esophageal tissue at 1,2,4 and 8 weeks after stenting were studied by immunohistochemistry. The contents of hydroxyproline and gross amino acid(AA) in re stenosis tissue were measured by amino acid analysis. Results At week 1 and 2 the inflammatory reaction occurred evidently in stented esophagus, with granulation and fibrosis; in some places esophageal tissues began to proliferate towards the lumen. At week 1 some fibroblasts began to express PCNA and ? SMA, and at week 2 the expression augmented significantly. The content of hydroxyproline and AA was significantly higher in the esophageal tissues at 1 and 2 weeks after stenting than that in normal esophagus. At week 4 and 8 esophageal lumen became narrow conspicuously, with a lot of fibrotic tissue and few inflammatory cells. Only a few fibroblasts displayed the expression of PCNA instead of the expression of ? SMA at week 4. There was no expression of PCNA and ? SMA at week 8. The content of AA at week 4 increased significantly compared with that at week 2, and the level was similar between 4 and 8. Electron microscopy revealed that the fibroblasts were in the state of vigorous proliferation and secretion in esophageal tissue at week 2, and a lot of fibrotic tissue formed at week 8. Conclusions Re stenosis mainly expressed as granulation and fibrosis. At week 4 and 8 the fibrosis becomes stable gradually with the lessening of inflammatory reaction. Within 4 weeks of stenting fibroblast retains active proliferation and secretion, but after week 4 the function of fibroblasts gradually lessen or even lose.