Pirfenidone suppressing esophageal stent-related restenosis after stent placement: an animal experimental study / 中华放射学杂志

ABSTRACT

Objective:To investigate the preventive efficacy of pirfenidone in esophageal stent-related restenosis and the related underlying mechanisms.Methods:Twenty-four rats underwent esophageal stent placement were included in this study. The rats were randomly assigned to three groups, with 8 rats in each group. The three groups were set to receive placebo, 150 mg/kg pirfenidone and 300 mg/kg pirfenidone daily by oral administration for 28 days, respectively. Twenty-eight days after stent placement, the stented esophagi were harvested for histological examinations. The number of epithelial layers, the thickness of submucosal fibrosis, the percentage of granulation tissue area, the degree of inflammatory cell infiltration, the degree of collagen deposition, and the α-SMA staining scores were evaluated. One-way ANOVA was performed for the statistical comparison of the number of epithelial layers, the degree of inflammatory cell infiltration, the degree of collagen deposition and the α-SMA staining scores among these three groups. The Kruskal-Wallis H test was used for comparison of the thickness of submucosal fibrosis and the percentage of granulation tissue area among the three groups. Results:Gross pathological findings showed that both pirfenidone groups had significantly less luminal fibrotic tissue formation and restenosis than placebo group. The percentage of granulation tissue areas in placebo group, 150 mg/kg and 300 mg/kg pirfenidone groups were 57.23%±25.68%, 21.80%±6.65% and 12.18%±6.37%, respectively. Both pirfenidone groups showed significantly less granulation tissue areas than placebo group ( P<0.01). The degree of inflammatory cell infiltration, the degree of collagen deposition and the α-SMA staining scores were 3.28±0.55, 3.38±0.63 and 2.75±0.38 in placebo group, 2.30±0.46, 2.36±0.58 and 2.00±0.42 in 150 mg/kg pirfenidone group, and 1.86±0.38, 1.91±0.41 and 1.57±0.28 in 300 mg/kg pirfenidone group, respectively. Both pirfenidone groups showed significantly less inflammatory cell infiltration, collagen deposition and α-SMA staining scores than placebo group ( P<0.01). Conclusion:Pirfenidone can suppress esophageal stent-related restenosis in rats by significantly inhibiting inflammation, myofibroblast activation and proliferation, and fibrotic tissue formation.