P1.115. Efficacy of Local Injection of Prednisolone for the Prevention of Esophageal Stricture After ESD

Topic Esophageal Cancer: Non-Surgical Treatment of Esophageal Cancer Background For prevention of post-ESD esophageal stricture, we have routinely performed local triamcinolone injection for high-risk lesions. During a period when triamcinolone was unavailable, prednisolone was used as an alternative. We investigated whether prednisolone demonstrates equivalent preventive efficacy to triamcinolone in preventing post-ESD stricture. Methods This retrospective observational study was conducted at a single tertiary cancer center. Between October 2024 and September 2025, 250 esophageal lesions underwent ESD at our institution. Non-circumferential lesions measuring ≥ 2.5 cm that received local steroid injection (either triamcinolone or prednisolone) were included. Until May 2025, triamcinolone was used; thereafter, prednisolone replaced triamcinolone due to unavailability. Our indications for local steroid injection were mucosal defects involving ≥3/4 of the circumference or lesions judged by the operator to be at high risk of stricture, such as those with pre-existing stenosis. Both agents were used following institutional approval for off-label use. Cases requiring oral steroids were excluded. Finally, 33 lesions in 31 patients were analyzed, including the triamcinolone group (n=25) and the prednisolone group (n=8). Stricture was defined as the inability to pass a standard endoscope during any follow-up endoscopy, and stricture rates were compared between groups. Results In the prednisolone and triamcinolone groups, lesion locations (Ce/Ut/Mt/Lt/Jz) were 3/2/2/1/0, and 1/4/12/7/1, respectively. Mean lesion diameter (mm) was 41.2 (SD 9.5) and 33.6 (SD 9.3), respectively. Circumferential extent of the mucosal defects (≤1/2, 1/2–3/4, >3/4) was 1/5/2 and 10/8/7, respectively. Overall stricture rate was significantly higher in the prednisolone group than in the triamcinolone group (50.0% [4/8] vs. 8.0% [2/25], p=0.016). In subgroup analysis, for mucosal defects involving 1/2–3/4 of the circumference, stricture rates were 60% (3/5) and 12.5% (1/8), respectively, and for ≥3/4 circumferential defects, 50% (1/2) and 14.3% (1/7), respectively. Conclusion Local prednisolone injection showed a significantly higher stricture rate than triamcinolone injection, suggesting insufficient preventive efficacy against post-ESD esophageal stricture. Despite the small sample size, the magnitude of difference raises concerns about using prednisolone as an alternative to triamcinolone. Caution is warranted when substituting prednisolone for triamcinolone in preventing post-ESD stricture, and further investigation with larger cohort is needed.