MFGE8 in exosomes derived from mesenchymal stem cells prevents esophageal stricture after endoscopic submucosal dissection in pigs.

BACKGROUND: Endoscopic submucosal dissection (ESD) is the current standard treatment for early-stage esophageal neoplasms. However, the postoperative esophageal stricture after extensive mucosal dissection remains a severe challenge with limited effective treatments available. In this study, we introduced a chitosan/gelatin (ChGel) sponge encapsulating the adipose mesenchymal stem cells (ADMSCs)-derived exosomes (ChGelMSC-Exo) for the prevention of esophageal stenosis after ESD in a porcine model. RESULTS: Pigs were randomly assigned into (1) ChGelMSC-Exo treatment group, (2) ChGelPBS group, and (3) the controls. Exosome treatments were applied immediately on the day after ESD as well as on day 7. Exosome components crucial for wound healing were investigated by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and small RNA sequencing. ChGelMSC-Exo treatment significantly reduced mucosal contraction on day 21, with less fiber accumulation and inflammatory infiltration, and enhanced angiogenesis when compared with the control and ChGelPBS groups. The anti-fibrotic effects following MSC-Exo treatment were further found to be associated with the anti-inflammatory M2 polarization of the resident macrophages, especially within the M2b subset characterized by the reduced TGFß1 secretion, which sufficiently inhibited inflammation and prevented the activation of myofibroblast with less collagen production at the early stage after ESD. Moreover, the abundant expression of exosomal MFGE8 was identified to be involved in the transition of the M2b-macrophage subset through the activation of MFGE8/STAT3/Arg1 axis. CONCLUSIONS: Our study demonstrates that exosomal MFGE8 significantly promotes the polarization of the M2b-macrophage subset, consequently reducing collagen deposition. These findings suggest a promising potential for MSC-Exo therapy in preventing the development of esophageal stricture after near-circumferential ESD.

Administration of oral prednisolone to prevent esophageal stricture after balloon-type radiofrequency ablation for ultralong-segment esophageal neoplasia.

BACKGROUND AND AIMS: Endoscopic radiofrequency ablation (RFA) has shown good efficacy and safety in eradicating flat-type early esophageal squamous cell neoplasia (ESCN). However, post-RFA stricture is still a major concern, especially when treating ultralong-segment ESCNs. The aim of this study was to investigate the efficacy and safety of oral prednisolone to prevent post-RFA stricture. METHODS: We prospectively enrolled 48 patients treated with balloon-type RFA who had Lugol-unstained or mosaic-like flat-type ESCNs with an expected treatment area of >10 cm. Oral prednisolone was started at a dose of 30 mg/day on the third day after RFA and continued for 4 weeks. The results were compared with an historical control group of 25 patients who received RFA without oral steroids. The primary endpoint was the frequency of post-RFA stricture. Secondary endpoints were the number of balloon dilation sessions and adverse event rate. RESULTS: No significant differences were found in the worst pathology grade at baseline and length of unstained lesions between the 2 groups. The complete response rates after 1 session of RFA were 73% and 72%, respectively. Compared with the control group, the oral prednisolone group had a significantly lower stricture rate (4% [2/48 patients] vs 44% [11/25 patients]; P < .0001) and a lower number of balloon dilation sessions (median, 0 [range, 0-4] vs 6 [range, 0-10]). Two cases of asymptomatic candida esophagitis occurred in the study group, but no severe adverse effects. CONCLUSIONS: Oral prednisolone may offer a useful and safe preventive option for post-RFA stricture in ultralong ESCNs. (Clinical trial registration number: NCT05768282.).

The use of a self-assembling peptide gel for stricture prevention in the esophagus after endoscopic submucosal dissection: a U.S. multicenter prospective study (with video).

BACKGROUND AND AIMS: Postoperative stricture is a serious common adverse event after extensive endoscopic submucosal dissection (ESD) in the esophagus. Self-assembling peptide (SAP) gel has been shown to promote tissue healing and re-epithelialization. The aim of this study was to evaluate the effect of the SAP gel for esophageal stricture prevention after ESD. METHODS: This was a multicenter prospective study of patients who underwent esophageal ESD followed by SAP gel application between March 2022 and December 2023. Patients were included if the ESD mucosal defect involved ≥50% of the circumference of the esophagus. High-risk cases were defined as mucosal defects ≥75% of the circumference. Stricture was defined as the inability to pass an endoscope ≥8.9 mm in diameter or a narrow-caliber lumen in a patient with symptoms. RESULTS: A total of 43 patients (median age, 71 years; 81.4% male) underwent ESD (median resected specimen size, 50 mm) during the study period. SAP gel (median, 3 mL) was successfully applied in all cases (median time, 4 minutes). In aggregate, stricture occurred in 20.9% (9 of 43) of the cases. Stricture developed in 30.8% of the high-risk cases: 80% (4 of 5) after circumferential ESD and 19% (4 of 21) in those with defects ≥75% but <100% of the circumference. All cases of stricture resolved with endoscopic treatment. Three cases (6.9%) of postoperative bleeding occurred and were adequately managed endoscopically. CONCLUSIONS: We show that SAP gel application was easy, quick, and associated with a relatively low stricture rate comparable to other prophylactic methods. Additional comparative studies are needed to corroborate these preliminary findings.

Progress in the treatment and prevention of esophageal stenosis after endoscopic submucosal dissection.

The primary treatment for early esophageal cancer and precancerous lesions is endoscopic submucosal dissection (ESD). However, this approach leads to a high incidence of postoperative esophageal stenosis, which can significantly impact a patient's quality of life. While various methods are available to prevent post-ESD esophageal stenosis, their effectiveness varies. Therefore, this study aims to provide an overview of the currently employed methods for preventing post-ESD esophageal stenosis in clinical practice in view of assisting clinical practitioners.

The Effect of Laparoscopic Gastric Ischemic Preconditioning Prior to Esophagectomy on Anastomotic Stricture Rate and Comparison with Esophagectomy-Alone Controls.

BACKGROUND: Benign anastomotic stricture is a recognized complication following esophagectomy. Laparoscopic gastric ischemic preconditioning (LGIP) prior to esophagectomy has been associated with decreased anastomotic leak rates; however, its effect on stricture and the need for subsequent endoscopic intervention is not well studied. METHODS: This was a case-control study at an academic medical center using consecutive patients undergoing oncologic esophagectomies (July 2012-July 2022). Our institution initiated an LGIP protocol on 1 January 2021. The primary outcome was the occurrence of stricture within 1 year of esophagectomy, while secondary outcomes were stricture severity and frequency of interventions within the 6 months following stricture. Bivariable comparisons were performed using Chi-square, Fisher's exact, or Mann-Whitney U tests. Multivariable regression controlling for confounders was performed to generate risk-adjust odds ratios and to identify the independent effect of LGIP. RESULTS: Of 253 esophagectomies, 42 (16.6%) underwent LGIP prior to esophagectomy. There were 45 (17.7%) anastomotic strictures requiring endoscopic intervention, including three patients who underwent LGIP and 42 who did not. Median time to stricture was 144 days. Those who underwent LGIP were significantly less likely to develop anastomotic stricture (7.1% vs. 19.9%; p = 0.048). After controlling for confounders, this difference was no longer significant (odds ratio 0.46, 95% confidence interval 0.14-1.82; p = 0.29). Of those who developed stricture, there was a trend toward less severe strictures and decreased need for endoscopic dilation in the LGIP group (all p < 0.20). CONCLUSION: LGIP may reduce the rate and severity of symptomatic anastomotic stricture following esophagectomy. A multi-institutional trial evaluating the effect of LGIP on stricture and other anastomotic complications is warranted.

TGF-ß1 inhibitor P144 protects against benign restenosis after esophageal stenting through TGF-ß1/Smads signaling pathway inhibition.

BACKGROUND AND STUDY AIMS: Esophageal restenosis is a serious complication after esophageal stent placement, which influences the clinical prognosis of stent implantation and the patient's quality of life. TGF-ß1/Smads signaling pathway plays an important role in the development of the eosinophilic esophagitis and scar repair after skin trauma. However, the role of TGF-ß1/Smads in the development of esophageal restenosis after esophageal stent placement remains unknown. Our study aimed to investigate whether TGF-ß1/Smads plays an important role in the development of esophageal restenosis after esophageal stent, and whether the exogenous TGF-ß1 inhibitor supplement could ameliorate the esophageal restenosis after esophageal stent. MATERIAL AND METHODS: We established the model of esophageal restenosis after esophageal stenting in rats, and determined the expression levels of TGF-ß1/Smads signaling pathway and the relevant markers of fibroblast activation by immunochemistry (IHC), Western Blot and real time qPCR. Those all the indicators were also determined in esophageal fibroblast when exposed to rhTGF-ß1 with or without TGF-ß1 inhibitor P144. RESULTS: The serum level of IL-1ß and TNFα were significantly increased in stent implantation group compared to blank control group, and obviously ameliorated when treated with P144. The TGF-ß1/Smads signaling pathway and the relevant markers of fibroblast activation were significantly increased in stent implantation group compared to blank control group, and obviously ameliorated when treated with P144. Those all the indicators were significantly increased when exposed to rhTGF-ß1, and obviously decreased when treated with P144. CONCLUSIONS: TGF-ß1 Inhibitor P144 could protect against benign restenosis after esophageal stenting by down-regulating the expression levels of relevant markers of fibroblast activation through TGF-ß1/Smads signaling pathway inhibition, and may be used as a novel therapy for benign restenosis after esophageal stenting.

Research on triamcinolone-loaded thermosensitive chitosan hydrogels for preventing esophageal stricture induced by endoscopic submucosal dissection.

Early-stage esophageal cancer is primarily treated by endoscopic submucosal dissection (ESD). However, extensive mucosal dissection creates a significant risk of postoperative esophageal stricture. Clinically, postoperative stricture can be prevented by glucocorticoids; however, there are drawbacks to both systemic and local administration of glucocorticoids, and improving drug administration methods is crucial. In this study, we developed a chitosan-based thermosensitive hydrogel for triamcinolone (TA) delivery. Our results indicated that the hydrogel remains liquid at low temperatures and can be injected into the esophageal wound site through an endoscopic biopsy channel. Upon reaching body temperature, the hydrogel undergoes spontaneous gelation and firmly adheres to the wound surface. The liquid phase enables convenient and precise delivery, while the gel phase achieves remarkable adhesion, tensile strength, and resistance to degradation. Moreover, the hydrogel exhibited an extended release duration of >10 days when loaded with a 10 mg dose. In vitro studies revealed that the hydrogel suppresses the proliferation and fibrogenesis of human scar fibroblasts (HKF). In a rat skin dermal defect model, the hydrogel attenuated keloid formation during the healing process. Consequently, the chitosan-based thermosensitive hydrogel developed in this study for triamcinolone delivery may be an effective tool for preventing post-ESD esophageal stricture.

Predictive factors for esophageal stenosis in patients receiving prophylactic steroid therapy after endoscopic submucosal dissection for esophageal squamous cell carcinoma.

BACKGROUND: Methods to prevent esophageal stenosis (ES) after endoscopic submucosal dissection (ESD) for superficial esophageal squamous cell carcinoma (ESCC) have received increasing attention. Although steroid administration is a prophylactic treatment, the risk factors for ES during prophylactic steroid therapy remain unknown. Therefore, this study aimed to retrospectively evaluate the risk factors for refractory ES in patients administered prophylactic steroids after ESD for ESCC. METHODS: Among 795 patients with ESCC (854 lesions), 180 patients (211 lesions) administered local triamcinolone acetonide (TrA) and/or oral prednisolone were recruited for this study. We compared the total number of endoscopic balloon dilatation (EBD) procedures performed for post-ESD ES and clinical findings (tumor size, ESD history or chemoradiation therapy [CRT], entire circumferential resection, muscle layer damage, supplemental oral prednisolone administration, EBD with TrA injection, and additional CRT) between patients with refractory and non-refractory ES. EBD was continued until dysphagia resolved. We categorized cases requiring ≥ 8 EBD procedures as refractory postoperative stenosis and divided the lesions into two groups. RESULTS: Multivariate logistic regression analysis revealed that factors such as ESD history, CRT history, tumor size, and entire circumferential resection were independently associated with the development of refractory ES. The withdrawal rates of EBD at 3 years were 96.1% (52/53) and 58.5% (39/59) in the non-refractory and refractory groups, respectively. CONCLUSIONS: Our data suggest that entire circumferential resection and CRT history are risk factors for refractory post-ESD ES in ESCC, even with prophylactic steroid administration.

The occurrence and development mechanisms of esophageal stricture: state of the art review.

BACKGROUND: Esophageal strictures significantly impair patient quality of life and present a therapeutic challenge, particularly due to the high recurrence post-ESD/EMR. Current treatments manage symptoms rather than addressing the disease's etiology. This review concentrates on the mechanisms of esophageal stricture formation and recurrence, seeking to highlight areas for potential therapeutic intervention. METHODS: A literature search was conducted through PUBMED using search terms: esophageal stricture, mucosal resection, submucosal dissection. Relevant articles were identified through manual review with reference lists reviewed for additional articles. RESULTS: Preclinical studies and data from animal studies suggest that the mechanisms that may lead to esophageal stricture include overdifferentiation of fibroblasts, inflammatory response that is not healed in time, impaired epithelial barrier function, and multimethod factors leading to it. Dysfunction of the epithelial barrier may be the initiating mechanism for esophageal stricture. Achieving perfect in-epithelialization by tissue-engineered fabrication of cell patches has been shown to be effective in the treatment and prevention of esophageal strictures. CONCLUSION: The development of esophageal stricture involves three stages: structural damage to the esophageal epithelial barrier (EEB), chronic inflammation, and severe fibrosis, in which dysfunction or damage to the EEB is the initiating mechanism leading to esophageal stricture. Re-epithelialization is essential for the treatment and prevention of esophageal stricture. This information will help clinicians or scientists to develop effective techniques to treat esophageal stricture in the future.

Prevention of Esophageal Stricture after Endoscopic Submucosal Dissection with an Autologous Esophageal Epithelial Cell Suspension: An Animal Study.

BACKGROUND: Severe esophageal stricture decreases patient's quality of life after circumferential endoscopic submucosal dissection (ESD). We aimed to evaluate the efficacy of autologous esophageal epithelial cell suspensions in preventing esophageal stricture after circumferential ESD. METHODS: Twelve male mini-pigs underwent circumferential ESD and were randomized into four groups: G1 (control), G2 (esophageal stent), G3 (autologous esophageal epithelial cell suspension), and G4 (autologous esophageal epithelial cell suspension combined with esophageal stent). Post-ESD status was observed in each group, and endoscopy was performed weekly. Esophageal stents were removed 3 weeks after ESD. The esophageal stricture rates and histologic characteristics were assessed 4 weeks after ESD. RESULTS: G1 showed the greatest weight loss (p < 0.05). Dysphagia scores were not significantly different among the groups. The esophageal mucosal stricture rates were 77.7 ± 2.9%, 74.2 ± 1.9%, 69.2 ± 3.8% and 65.9 ± 1.9% in G1-4, respectively; with the highest in G1 (G1 vs. G3, p = 0.005; G1 vs. G4, p = 0.001). The regenerated epithelium lengths were 4.408 ± 1.980 mm, 8.319 ± 0.857 mm, 11.801 ± 2.455 mm and 12.353 ± 1.111 mm in G1-4, respectively. The lowest degree of re-epithelialization was observed in G1, followed by G2, with the highest degrees in G3 and G4 (G1 vs. G3, p = 0.001; G1 vs. G4, p = 0.000). The maximum wound fibrosis thicknesses were 2.546 ± 0.389 mm, 2.136 ± 0.231 mm, 1.126 ± 0.211 mm and 1.131 ± 0.438 mm in G1-4, respectively, with higher degrees in G1 and G2 than in G3 and G4 (G1 vs. G3, p = 0.001; G1 vs. G4, p = 0.001). CONCLUSIONS: Autologous esophageal epithelial cell suspensions can promote re-epithelialization and reduce fibrosis, thus decreasing esophageal stricture severity after ESD.

Prevention of esophageal stricture after endoscopic submucosal dissection of squamous cell carcinoma using a 20-French nasogastric tube combined with oral steroid administration.

BACKGROUND: Esophageal stricture is a major complication after esophageal endoscopic submucosal dissection (ESD) and when the mucosal defect exceeds 3/4 of the circumference. Various preventive methods have been reported to prevent stenosis. However, in the case of circumferential ESD, there is no way to prevent luminal stenosis effectively. This retrospective study aimed to evaluate the efficacy of 20-French nasogastric tubes (NGT) combined with oral steroids for the prevention of esophageal stricture after endoscopic submucosal dissection. METHODS: Between January 2012 and December 2021, we enrolled 57 patients with post-ESD mucosal defects exceeding 3/4 of the esophageal circumference. Of them, the initial seven patients received oral steroid therapy and the subsequent 50 patients received 20-French NGT placements combined with oral steroid therapy. We retrospectively evaluated the rates of strictures and refractory strictures and explored risk factors for strictures with 20-French NGT. RESULTS: The overall esophageal stricture rate was 42.1% (24/57). In the noncircumferential group, the esophageal stricture rate in patients with only oral steroid to prevent esophageal stricture was 85.7% (6/7), while the esophageal stricture rate was only 4.3% (1/23) in those with 20-French NGT placements and oral steroid. All 27 patients with whole-circumferential resection received 20-French NGT placements. The stricture rate was 63.0% (17/27), and the refractory stricture rate was 17.6% (3/27). CONCLUSION: Using a 20-French NGT placement combined with oral steroid administration is an easy and safe alternative to prevent esophageal stricture after ESD, especially for patients with noncircumferential mucosal defects. Further studies are needed to develop an effective stricture prevention method for post-ESD whole-circumferential mucosal defects of the esophagus.

Prevention of esophageal stenosis via in situ cross-linkable alginate/gelatin powder in a new submucosal exfoliation model in rats.

Endoscopic submucosal dissection (ESD) for the treatment of esophageal mucosal lesions often leads to postoperative stenosis, causing difficulty in swallowing, known as dysphagia. In this study, we developed an in situ cross-linkable powder composed of alginate, gelatin, transglutaminase (TG), and calcium chloride ions (Ca2+), which can be administered through a 1.5 m-long and 3.2 mm-diameter endoscopic instrument channel. The powdered mixture of alginate and gelatin quickly formed a hydrogel by absorbing body fluids and was cross-linked by TG and Ca2+, which adhered ex vivo to porcine submucosal layers for over 2 weeks. In addition, we developed a new submucosal exfoliation model in rats that induced severe stenosis, similar to the ESD-induced stenosis models in clinical practice. When administered to the new rat model, the powder system effectively reduced the severity of esophageal stenosis based on body weight change monitoring, anatomical findings, and histological analysis. The body weight of the rats was maintained at the initial weight on postoperative day 14 (POD14), and epithelialization on POD7 and 14 improved to almost 100%. Additionally, collagen accumulation and the number of α-SMA-positive cells decreased due to powder administration. Therefore, these findings indicate that the in situ cross-linkable powder can prevent esophageal stenosis after ESD.

Infigratinib, a Selective Fibroblast Growth Factor Receptor Inhibitor, Suppresses Stent-Induced Tissue Hyperplasia in a Rat Esophageal Model.

PURPOSE: Stent-induced tissue hyperplasia remains a challenge for the application of self-expanding metal stents in the management of esophageal stricture. This study aimed to evaluate the efficacy of infigratinib, which is a selective fibroblast growth factor receptor inhibitor, in the prevention of stent-induced tissue hyperplasia in a rat esophageal model. METHODS: Twenty-four male Sprague-Dawley rats underwent esophageal stent placement and were randomized to receive 1 ml of vehicle, 5 mg/kg infigratinib in 1 ml of vehicle, or 10 mg/kg infigratinib in 1 ml of vehicle via naso-gastric tube once daily for 28 days. Follow-up fluoroscopy was performed on postoperative day 28, and the stented esophageal tissues were harvested for histological and immunofluorescence examinations. RESULTS: All rats survived until euthanasia on postoperative day 28 without procedure-related adverse events. The incidence of stent migration was 12.5%, 12.5% and 25% in the control group, the 5 mg/kg infigratinib group and, the 10 mg/kg infigratinib group, respectively. The percentage of granulation tissue area, the submucosal fibrosis thickness, the number of epithelial layers, the degree of inflammatory cell infiltration, the degree of collagen deposition, the number of fibroblast growth factor receptor 1 (FGFR1)-expressing myofibroblasts, and the number of proliferating myofibroblasts were all significantly lower in both infigratinib groups than in the control group (P < 0.05) but were not significantly different between the two infigratinib groups (P > 0.05). CONCLUSIONS: Infigratinib significantly suppresses stent-induced tissue hyperplasia by inhibiting FGFR1-mediated myofibroblast proliferation and profibrotic activities in a rat esophageal model.

Prophylactic Acid-suppression Medication to Prevent Anastomotic Strictures After Oesophageal Atresia Surgery: A Systematic Review and Meta-analysis.

BACKGROUND: Anastomotic stricture is a common postoperative complication of oesophageal atresia ± tracheoesophageal fistula (OA/TOF) repair. Acid gastro-oesophageal reflux disease (GORD) is considered to be a factor in stricture formation and acid suppression medication is recommended post-operatively in consensus guidance. We aimed to investigate whether patients who were treated prophylactically with acid suppression medication had a reduced incidence of strictures compared to those who did not receive it. METHODS: A systematic review of studies was performed, searching multiple databases without language or date restrictions. Multiple reviewers independently assessed study eligibility and literature quality. The primary outcome was anastomotic stricture formation, with secondary outcomes of GORD, anastomotic leak, and oesophagitis. Meta-analysis was performed using a random effects model, and the results were expressed as an odds ratio (OR) with 95% confidence intervals (CI). RESULTS: No randomised studies on the topic were identified. Twelve observational studies were included in the analysis with ten reporting the primary outcome. The quality assessment showed a high risk of bias in several papers, predominantly due to non-objective methods of assessment of oesophageal stricture and the non-prospective, non-randomised nature of the studies. Overall, 1395 patients were evaluated, of which 753 received acid suppression medication. Meta-analysis revealed a trend towards increased odds of anastomotic strictures in infants receiving prophylactic medication, but this was not statistically significant (OR 1.33; 95% CI 0.92, 1.92). No significant differences were found in secondary outcomes. CONCLUSIONS: This meta-analysis found no evidence of a statistically significant link between the prophylactic prescribing of acid suppression medication and the risk of developing anastomotic stricture after OA repair. The literature in this area is limited to observational studies and a randomised controlled trial is recommended to explore this question. LEVEL OF EVIDENCE: Level III.

A novel tetra-PEG based hydrogel for prevention of esophageal stricture after ESD in a porcine model.

Endoscopic submucosal dissection (ESD) is an accepted treatment for early esophageal cancer and precancerous lesions, but resection of a large mucosal area often leads to postoperative esophageal stricture. Biomaterials provide a new option for the treatment of post-ESD ulcers. In this study, we developed a well-defined ammonolysis-based tetra-armed poly (ethylene glycol) (Tetra-PEG) hydrogel and investigated its efficacy and related mechanisms for preventing esophageal ESD-induced stricture in a porcine model. In terms of material properties, Tetra-PEG hydrogel present great biocompatibility，great capability to retain moisture, strong tissue adhesion and high mechanical strength. Then, six domestic female pigs were randomly divided into PEG (n = 3) and control groups (n = 3). A 3/4 of the esophageal circumference ESD was performed in all pigs. In PEG group, Tetra-PEG hydrogel was easily delivered via endoscopy and adhered to the ulcer bed tightly. Compared to control group, Tetra-PEG hydrogel accelerated esophageal ulcer healing at an early stage with enhanced epithelium regeneration, milder inflammation and lesser fibrosis by regulating TGF-ß/Smad2 signaling. Taken together, our findings reveal Tetra-PEG hydrogel is a promising and attractive candidate for preventing the formation of fibrotic stricture in the process of esophageal ESD-induced ulcer repair.