Histological changes in the human esophagus following triamcinolone injection to prevent esophageal stricture after endoscopic submucosal dissection

Local triamcinolone injection and selective add-on oral steroids to prevent esophageal post-endoscopic submucosal dissection stricture: a retrospective analysis in a Western center

BACKGROUND

Extensive esophageal endoscopic submucosal dissections (ESDs) without preventive measures carry a high risk of stricture. Oral steroids and local injection of triamcinolone acetonide have proven to be effective in Asia for the prevention of esophageal stricture. This study aimed to assess the efficacy of a systematic steroid administration protocol for stricture prevention in a Western center.

METHODS

A retrospective review was conducted of all esophageal ESDs performed at H.U.B. Erasme Hospital, Brussels between 2016 and 2022. Injection of triamcinolone was performed for mucosal defects between 50% and 89% of the circumference. We added oral corticosteroids for patients with resections of ≥90% of the circumference. The primary outcome was the incidence of symptomatic stenosis at 3 months. Secondary outcomes included the cumulative stricture rate assessed by endoscopy within 6 months of ESD. Potential risk factors of stricture were evaluated with univariate and multivariate analysis.

RESULTS

111 patients underwent 130 esophageal ESDs, with 59 patients receiving triamcinolone acetonide local injection and eight receiving local and oral corticosteroids. The primary outcome demonstrated a stricture incidence of 8.4%. The cumulative stricture rate assessed by endoscopy within 6 months of ESD was 10.4%. A mucosal defect of ≥60 mm in length was associated with a 15-fold increased risk of stricture, with circumferential extent also identified as being an independent prognostic factor for stricture.

CONCLUSIONS

Our protocol led to a low stricture rate, even after extensive resection. As a single session treatment without systemic side effects, triamcinolone injection could provide benefits as a preventive method after large esophageal resections.

Benign esophageal stricture model construction and mechanism exploration

Esophageal stricture is a debilitating condition that negatively impacts patients' quality of life after undergoing endoscopic mucosal resection (EMR). Despite its significance, this disease remains underexplored due to the lack of a stable animal model. Under direct visualization with choledochoscopy, we retrogradely damaged the esophageal mucosal layer through the gastrostomy to create a rat model of esophageal stricture. The development of histological defects in the mucosal layer was assessed over a 2-week period after model induction. Then the models were evaluated using X-ray barium radiography, Hematoxylin-Eosin, Masson's trichrome, Sirius red, and Victoria blue staining, multiphoton microscopic imaging. Additionally, the molecular mechanisms of esophageal stricture were explored by conducting RNA transcriptome sequencing, PCR, immunohistochemistry, and immunofluorescence staining. We successfully established fifteen rat models of esophageal stricture by injuring the mucosal layer. In the model group, the mucosal defect initially occurs and subsequently repaired. The epithelium was absent and was plastically remodeled by collagen during the acute inflammatory phase (Day 1), proliferation phase (Day 7), anaphase of proliferation (Day 10), and plastic remodeling phase (Day 14). We observed increased expression of COL1A1, acta2, FGF, IL-1, and TGF-β1 pathway in the model group. We established a highly repeatable rat model of esophageal stricture, and our results suggest that the mucosal defect of the esophagus is a critical factor in esophageal stricture development, rather than damage to the muscularis layer. We identified Atp4b, cyp1a2, and gstk1 as potential targets for treating esophageal stricture, while the TGF-β pathway was found to play an important role in its development.

Advances in the application of regenerative medicine in prevention of post-endoscopic submucosal dissection for esophageal stenosis

Endoscopic submucosal dissection (ESD) is a curative treatment for superficial esophageal cancer with distinct advantages. However, esophageal stenosis after ESD remains a tough problem, especially after large circumferential proportion of esophageal mucosa is removed, which limits the wide use of ESD, especially in circumferential lesions. In this scenario, preventive procedures are highly recommended against post-ESD esophageal stenosis. However, the efficacy and safety of traditional prophylactic methods (steroids, metal and biodegradable stents, balloon dilation, radial incision, etc.) are not satisfactory and novel strategies need to be developed. Regenerative medicine has been showing enormous potential in the reconstruction of organs including the esophagus. In this review, we aimed to describe the current status of regenerative medicine in prevention of post-ESD esophageal stenosis. Cell injection, cell sheet transplantation, and extracellular matrix implantation have been proved effective. However, numerous obstacles still exist and further studies are necessary.