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.

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.

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.

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.

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.

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.

Repeated steroid injection and polyglycolic acid shielding for prevention of refractory esophageal stricture.

BACKGROUND: Postoperative stricture and refractory stricture are severe adverse events which occur after expansive esophageal endoscopic submucosal dissection (ESD). The aim of this study was to assess the efficacy of steroid injection, polyglycolic acid (PGA) shielding, and of additional steroid injection thereafter for the prevention of refractory esophageal stricture. METHODS: This is a retrospective cohort study of 816 consecutive cases of esophageal ESD performed between 2002 and 2021 at the University of Tokyo Hospital. After 2013, all patients with a diagnosis of superficial esophageal carcinoma covering over 1/2 the esophageal circumference underwent preventive treatment immediately after ESD with either "PGA shielding", "steroid injection", or "steroid injection + PGA shielding". Additional steroid injection was performed for high-risk patients after 2019. RESULTS: The risk of refractory stricture was especially high in the cervical esophagus (OR 24.77, p = 0.002) and after total circumferential resection (OR 894.04, p < 0.001). "Steroid injection + PGA shielding" was the only method significantly effective in preventing stricture occurrence (OR 0.36; 95% CI 0.15-0.83, p = 0.012). This method also decreased the risk of refractory stricture (OR 0.38; 95% CI 0.10-1.28, p = 0.096), but additional steroid injection was the only significantly effective method for prevention of refractory stricture (OR 0.42; 95% CI 0.14-0.98, p = 0.029). CONCLUSION: Combining steroid injection and PGA shielding is effective for preventing post-ESD stricture and refractory stricture. Additional steroid injection is a viable option for patients at high-risk for refractory stricture.

Mixed-methods feasibility study to inform a randomised controlled trial of proton pump inhibitors to reduce strictures following neonatal surgery for oesophageal atresia.

OBJECTIVES: This mixed-methods feasibility study aimed to explore parents' and medical practitioners' views on the acceptability and design of a clinical trial to determine whether routine prophylactic proton pump inhibitors (PPI) reduce the incidence of anastomotic stricture in infants with oesophageal atresia (OA). DESIGN: Semi-structured interviews with UK parents of an infant with OA and an online survey, telephone interviews and focus groups with clinicians. Data were analysed using reflexive thematic analysis and descriptive statistics. PARTICIPANTS AND SETTING: We interviewed 18 parents of infants with OA. Fifty-one clinicians (49 surgeons, 2 neonatologists) from 20/25 (80%) units involved in OA repair completed an online survey and 10 took part in 1 of 2 focus groups. Interviews were conducted with two clinicians whose survey responses indicated they had concerns about the trial. OUTCOME MEASURES: Parents and clinicians ranked the same top four outcomes ('Severity of anastomotic stricture', 'Incidence of anastomotic stricture', 'Need for treatment of reflux' and 'Presence of symptoms of reflux') as important to measure for the proposed trial. RESULTS: All parents and most clinicians found the use, dose and duration of omeprazole as the intervention medication, and the placebo control, as acceptable. Parents stated they would hypothetically consent to their child's participation in the trial. Concerns of a few parents and clinicians about infants suffering with symptomatic reflux, and the impact of this for study retention, appeared to be alleviated through the symptomatic reflux treatment pathway. Hesitant clinician views appeared to change through discussion of parental support for the study and by highlighting existing research that questions current practice of PPI treatment. CONCLUSIONS: Our findings indicate that parents and most clinicians view the proposed Treating Oesophageal Atresia with prophylactic proton pump inhibitors to prevent STricture (TOAST) trial to be feasible and acceptable so long as infants can be given PPI if clinicians deem it clinically necessary. This insight into parent and clinician views and concerns will inform pilot phase trial monitoring, staff training and the development of the trial protocol.

Prophylactic use of steroids for a mucosal defect with a circumference of less than three-fourths prevents both symptomatic and asymptomatic stricture after esophageal endoscopic submucosal dissection.

BACKGROUND: Subclinical stricture after esophageal endoscopic submucosal dissection (ESD) makes the detection and re-ESD of metachronous lesions difficult. This study aimed to investigate the effectiveness of prophylactic steroid use after esophageal ESD for mucosal defects with a circumference less than 75% for the prevention of symptomatic and asymptomatic stricture. METHODS: In 80 retrospectively enrolled patients, we collected paired endoscopic images of a mucosal defects immediately after resection and a scar thereafter. After calculating circumference by image analysis software, all patients were classified into three groups in reference to mucosal defect circumference (MDC; ≤ 50%, 50-75%, ≥ 75%). Frequency of steroid use and symptomatic stricture were compared, and in < 75% MDC patients, a degree of asymptomatic stricture with or without steroid was compared by calculating a scar contraction rate (SCR). RESULTS: In the ≤ 50% (43 patients), 50-75% (27 patients) and ≥ 75% (10 patients) MDC groups, steroids were used in 12%, 59% and 100%, respectively, and symptomatic stricture occurred in 0%, 7% and 40%, respectively. In < 75% MDC patients, SCR in the steroid cohort was significantly lower than that in the nonsteroid cohort (42% vs. 65%, p = 0.002). No steroid-related adverse events occurred. CONCLUSION: Steroid use even for mucosal defects with < 75% circumference appears effective for the reduction of the risk on both symptomatic and asymptomatic stricture after esophageal ESD.

Effectiveness of sucralfate in preventing esophageal stricture in children after ingestion of caustic agents.

Ingestion of caustic agents by children is a serious health issue that can affect the patient for the rest of his life. The role of sucralfate in preventing stricture caused by caustic agents is controversial, and limited studies have been conducted in this field. We aimed to investigate the effect of sucralfate on preventing esophageal stricture in children. Sixty children with mean age of 36.69 ± 20.50 months and grade II B esophageal burns due to ingestion of caustic agents were enrolled in the study. In the intervention group, in addition to the usual treatment, sucralfate was administered orally at a dose of 80 mg/kg every 2 h for 3 days. For the control group, only the usual treatment was prescribed. Stricture development was compared between groups based on endoscopic and radiologic findings. Of the 60 patients enrolled in the study, 53 were examined. The incidence of esophageal stricture in the intervention group was significantly lower than in the control group (37% versus 67%, P-value = 0.042). In addition, the odds of esophageal stricture after sucralfate intervention was significantly reduced after adjustment for potential confounders (OR = 0.198, P-value = 0.031).  Conclusions: The results of this study showed that sucralfate may reduce the development of esophageal stricture in children when used to manage IIB esophageal burns due to ingestion of caustic agents. What is Known: • Ingestion of caustic agents by children is a serious health issue that can affect the patient for the rest of his life. • The role of sucralfate in preventing stricture caused by caustic agents is controversial and limited studies have been conducted in this field. What is New: • It seems that sucralfate significantly reduces the incidence of esophageal stricture following the ingestion of caustic agents in children compared to the control group. • We believe that the prognosis may be improved and the risk of stricture formation may be reduced with high doses of sucralfate therapy in grade IIB esophageal injury.

Successful prevention of stenosis after circumferential endoscopic resection of esophageal cancer.

Circumferential resection of a >5-cm longitudinal mucosal defect following esophageal endoscopic submucosal dissection (ESD) is a risk factor for refractory stenosis. Circumferential ESD was performed in 3 patients with 64, 69, and 70 mm longitudinal mucosal defects. A local steroid injection was used to treat the postoperative ulcer, followed by an oral steroid. In all three cases, the ulcer healed without the need for endoscopic dilation. A combination of local injection and oral steroids effectively prevented esophageal stenosis in patients with high-risk stenosis after ESD.

Complete Circumferential Endoscopic Submucosal Dissection for Esophageal Cancer Leaving an Island of Normal Mucosa.

Esophageal stricture caused by complete circumferential endoscopic submucosal dissection (ESD) of extensive esophageal squamous cell carcinoma (ESCC) is a major concern and can result in a low quality of life. Normal mucosa may remain within a complete circumferential lesion of ESCC in some cases. We herein report a case of ESCC in which a complete circumferential lesion was treated with ESD while leaving an island of normal mucosa within it. This case demonstrates that preserving areas of normal mucosa within lesions during complete circumferential ESD is not technically difficult and may be an effective measure for preventing esophageal stricture.