AIM:To elucidate the mechanism of restenosis followingballoon dilation of benign esophageal stenosis.METHODS:A total of 49 rats with esophageal stenosis wereinduced in 70 rats using 5 ml of 50 % sodium hydroxidesolution and the double-balloon method,and an esophagealrestenosis (RS) model was developed by esophageal stenosisusing dilation of a percutaneous transluminal coronaryangioplasty (PTCA) balloon catheter.These 49 rats weredivided into two groups:rats with benign esophageal stricturecaused by chemical burn only (control group,n=21) andrats with their esophageal stricture treated with ballooncatheter dilation (experimental group,n=28).Imaginganalysis and immunohistochemistry were used for bothquantitative and qualitative analyses of esophageal stenosisand RS formation in the rats,respectively.RESULTS:Cross-sectional areas and perimeters of theesophageal mucosa layer,muscle layer,and the entireesophageal layers increased significantly in the experimentalgroup compared with the control group.Proliferating cellnuclear antigen (PCNA) was expressed on the 5th day afterdilation,and was still present at 1 month.Fibronectin (FN)was expressed on the 1st day after dilation,and was stillpresent at 1 month.CONCLUSION:Expression of PCNA and FN plays animportant role in RS after balloon dilation of benignesophageal stenosis. AIM: To elucidate the mechanism of restenosis following balloon dilation of benign esophageal stenosis. METHODS: A total of 49 rats with esophageal stenosis were induced in 70 rats using 5 ml of 50% sodium hydroxidesolution and the double-balloon method, and an esophageal restenosis (RS) model was developed by esophageal stenosis using dilation of a percutaneous transluminal coronary angioplasty (PTCA) balloon catheter. These 49 rats weredivided into two groups: rats with benign esophageal stricturecaused by chemical burn only (control group, n = 21) andrats with their esophageal stricture treated with Balloon Catheter Dilation (experimental group, n = 28). Imaging analysis and immunohistochemistry were used for both quantitative and qualitative analyzes of esophageal stenosis and RS formation in the rats, respectively .RESULTS: Cross-sectional areas and perimeters of the esophageal mucosa layer, muscle layer, and the entireesophageal layers increased significantly in the experimental group compared with the cont rol group. Proliferating cell nuclear antigen (PCNA) was expressed on the 5th day afterdilation, and was still present at 1 month. Fibronectin (FN) was expressed on the 1st day after dilation, and was still present at at 1 month. and FN plays animportant role in RS after balloon dilation of benignesophageal stenosis.