Prevention of esophageal strictures after endoscopic submucosal dissection

Balloon dilatation followed by triamcinolone acetonide injection for colostomy stenosis: A case report

INTRODUCTION

Stenosis is a serious complication associated with stomas. The initial treatment for stoma stenosis is mainly the finger-bougie technique or balloon dilatation, and recurrence requires stomal reconstruction. However, the use of local triamcinolone injections for treating stoma stenosis has not been reported. Herein, we reported a case of repeated stoma stenosis in a high-risk patient in whom balloon dilatation combined with local triamcinolone injection effectively avoided stomal reconstruction.

PRESENTATION OF CASE

A woman in her 70s was admitted to our hospital with the chief complaint of a positive fecal occult blood test and was diagnosed with Ra advanced rectal cancer. Owing to the presence of multiple comorbidities, a laparoscopic Hartmann procedure with D3 dissection was performed. The operative time was 165 min and the intraoperative blood loss was 5 mL. On postoperative day 2, the colostomy stump became discolored, and stoma necrosis was diagnosed, which was successfully treated conservatively, with no findings of stoma falling or peritonitis. Six months after surgery, late stoma stenosis causing colonic obstruction was diagnosed, and the finger-bougie technique and balloon dilatation were ineffective. To avoid reoperation under general anesthesia, balloon dilatation using a CRE™ PRO GI Wireguided (Boston Scientific) at 19 mm for 3 min combined with a 40 mg injection of local triamcinolone into the stoma orifice scar was successfully performed.

DISCUSSION

No restenosis was observed after treatment.

CONCLUSION

Balloon dilatation combined with local triamcinolone injections may be effective for recurrent stoma stenosis in patients with high-risk comorbidities after rectal cancer surgery.

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.

Association of local steroid injection as a risk factor for electrocoagulation syndrome after esophageal endoscopic submucosal dissection

BACKGROUND

Postendoscopic submucosal dissection electrocoagulation syndrome (PEECS) is commonly observed after performing endoscopic submucosal dissection (ESD) for esophageal neoplasia. However, data on the incidence and risk factors for PEECS in the esophagus are lacking due to an unclear definition of PEECS and varied clinical settings. Therefore, we aimed to determine the risk factors for PEECS in patients undergoing ESD for esophageal neoplasia.

METHODS

We retrospectively reviewed data of relevant clinical and endoscopy-specific parameters from 202 consecutive patients with esophageal neoplasias (139 carcinomas and 63 dysplasias) who underwent ESD under general anesthesia. Esophageal PEECS was defined by satisfying at least two of the following criteria: fever ≥ 37.8 °C, leukocytosis ≥ 10,800/mm3, and localized chest pain ≥ 5/10 points as assessed on a numeric rating scale within 24 h after ESD. Significant factors associated with PEECS were determined by regression analysis.

RESULTS

PEECS was recorded in 98 of 202 (48.5%) patients. Patients with PEECS exhibited a larger tumor size (25.0 vs. 17.0 mm, P = 0.002), longer procedure (40.0 vs. 29.5 min, P = 0.021) and hemostasis times (5.0 vs. 3.5 min, P = 0.004), required greater submucosal injection volume (60.0 mL vs. 50.0 mL, P = 0.030), and had a lower rate of local steroid injection (4.1% vs. 12.5%, P = 0.029) than those without PEECS. Multivariate regression analysis revealed tumor size ≥ 17 mm (P = 0.047), procedure time ≥ 33 min (P = 0.027), and hemostasis time ≥ 5 min (P = 0.007) as risk factors for PEECS. In addition, local steroid injection was a significant negatively associated factor (P = 0.001).

CONCLUSIONS

Patients with a large tumor, prolonged procedure and hemostasis times are at a high risk of PEECS occurrence. Further, local steroid injection is a negatively associated factor.

Strategies for Preventing Esophageal Stenosis After Endoscopic Submucosal Dissection and Progress in Stem Cell-Based Therapies

Endoscopic submucosal dissection (ESD) has been widely used in the early neoplasia of the esophagus. However, postoperative esophageal stenosis is a big problem, particularly when a large circumferential proportion of esophageal mucosa is resected. Currently, there are several methods available to prevent esophageal stenosis after ESD, including steroid administration, esophageal stent implantation, and endoscopic balloon dilation (EBD). However, the therapeutic effects of these are not yet satisfactory. Stem cell-based therapies has shown promising potential in reconstructing tissue structure and restoring tissue function. In this study, we discussed the current strategies for preventing esophageal stenosis after ESD and perspectives of stem cell-based therapies for the prevention of esophageal stenosis.

Paclitaxel-coated balloon catheter for benign esophageal stenosis in a rabbit model

Most patients with benign esophageal stenosis require multiple or even continuous balloon dilation treatments to achieve symptom relief. In this study, eighteen rabbits were used to establish an esophageal benign stenosis model and were divided into a control group (n = 6), a balloon group (n = 6) and a PTX-coated balloon group (n = 6) to evaluate the feasibility and effectiveness of paclitaxel (PTX)-coated balloons for the rabbit esophageal benign stenosis model. The weight and esophageal diameter were recorded every 2 weeks until 8 weeks post-surgery. Hematoxylin-eosin staining, Masson's trichrome staining and immunohistochemical staining were performed for pathological analysis. Four weeks post-operation, there was a significant difference in weight between the control group and the balloon group (p = 0.01) and between the control group and the PTX balloon group (p = 0.01). There was a significant difference in the esophageal diameter between the balloon group and the PTX balloon group at 8 weeks post-operation (p = 0.02). Four weeks post-operation, the degree of inflammatory cell infiltration in the PTX balloon group was significantly lower than that in the control group (p = 0.002) and balloon group (p = 0.001). The degree of collagen deposition in the PTX balloon group was significantly lower than that in the control group (p = 0.002) and balloon group (p = 0.03). Eight weeks post-operation, the percentage of cells positive for TGF-β (p < 0.001), the degree of inflammatory cell infiltration (p = 0.02) and the degree of collagen deposition (p = 0.02) in the PTX balloon group were significantly lower than those in the balloon group. Therefore, PTX-coated balloons may alleviate the local inflammatory response and collagen deposition when used during dilation treatment of benign esophageal stenosis.

Allogeneic transplantation of epidermal cell sheets followed by endoscopic submucosal dissection to prevent severe esophageal stricture in a porcine model

Introduction

Endoscopic submucosal dissection (ESD) is a minimally invasive treatment for early esophageal cancer. However, large mucosal defects after esophageal ESD result in refractory strictures. In the present study, we histologically evaluated the endoscopic transplantation of allogeneic epidermal cell sheets (ECSs) as a feasible therapy for preventing esophageal stricture after circumferential ESD in a porcine model.

Methods

Epidermal cells were isolated from the skin tissue of allogeneic pigs and cultured on temperature-responsive cell culture inserts for 2 weeks. Transplantable ECSs were harvested by reducing the temperature and endoscopically transplanting the sheets to ulcer sites immediately after esophageal ESD. The engraftment of transplanted ECSs was then evaluated in two pigs at 7 days after transplantation. Next, ten pigs were divided into two groups to evaluate the endoscopic transplantation of allogeneic ECSs for the prevention of esophageal strictures after ESD. Allogeneic ECSs were transplanted immediately after esophageal ESD in the transplantation group (n = 5), whereas the control group (n = 5) did not undergo transplantation.

Results

Most of the transplanted allogeneic ECSs were successfully engrafted at the ulcer sites in the early phase. Fluorescence in situ hybridization analysis revealed that several allogeneic cells were present in the transplanted area at 7 days after ESD. At 14 days after ESD, significant differences in body weight loss, dysphagia scores, and mucosal strictures were observed between the control and transplantation groups. Transplanting allogeneic ECSs after esophageal ESD promotes mucosal healing and angiogenesis and prevents excessive inflammation and granulation tissue formation.

Conclusions

Endoscopic and histological analyses revealed that allogeneic ECSs promoted artificial ulcer healing after ESD, preventing esophageal strictures after ESD.

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Large mucosal defects of the esophagus cause severe strictures.

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Allogeneic epidermal cell sheets promote esophageal mucosal healing.

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Allogeneic epidermal cell sheets induce angiogenesis in esophageal ulcers.

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Allogeneic epidermal cell sheets prevent excessive inflammation in esophageal ulcers.

Poly(lactic acid)-hyperbranched polyglycerol nanoparticles enhance bioadhesive treatment of esophageal disease and reduce systemic drug exposure

The effective treatment of esophageal disease represents a significant unmet clinical need, as existing treatments often lead to unnecessary systemic drug exposure and suboptimal concentrations at the disease site. Here, surface-modified bioadhesive poly(lactic acid)-hyperbranched polyglycerol nanoparticles (BNPs), with an average 100-200 nm diameter, were developed for local and sustained esophageal drug delivery. BNPs showed significantly higher adhesion and permeation into ex vivo human and rat esophageal tissue than non-adhesive nanoparticles (NNPs) and had longer residence times within the rat esophagus in vivo. Incubation with human esophagus (Het-1A) cells confirmed BNPs' biocompatibility at clinically relevant concentrations. In a rat model of achalasia, nifedipine-loaded BNPs significantly enhanced esophageal drug exposure, increased therapeutic efficacy, and reduced systemic drug exposure compared to NNPs and free drug. The safety of BNPs was demonstrated by an absence of intestinal, hepatic, and splenic toxicity following administration. This study is the first to demonstrate the efficacy of BNPs for esophageal drug delivery and highlight their potential for improving the lives of patients suffering with esophageal conditions.

Transplantation of acellularized dermis matrix (ADM) plus fully covered metal stent to prevent stricture after circumferential endoscopic submucosal dissection of early esophageal cancer (with video)

Backgroud and study aims

Esophageal stricture is a serious adverse event occurring after circular endoscopic submucosal dissection (ESD) involving the whole esophagus. However, there is still a lack of effectively preventive methods. The main purpose of this study is to evaluate the efficacy of application of acellularized dermis matrix (ADM) for the prevention of post-ESD esophageal stricture. The main objective of this study was to evaluate the use of decellularized dermal matrix (ADM) in the prevention of post-esophageal ESD strictures.

Patients and methods

A pilot, single-center, prospective study was conducted. The study enrolled seven patients who had high-risks with extended resection of developing post-ESD esophageal stricture. After undergoing ESD, we attached different size of ADM patches to the mucosal defects using titanium clips then fixed with a metal mesh stent. The stent covered with metal mesh was removed at the median time of 27 days after the endoscopic procedure. Follow-up and repeated outpatient endoscopic screening were performed at appropriate scheduled times.

Results

The average longitudinal diameter of the resected specimens was 58.3 mm (range 38–90 mm). There were three patients developing strictures postoperatively at a mean time of 87 days (range 42–140). The median number of postoperative endoscopic balloon dilatation (EBD) in patients with stenosis was 2 (range 2–9). There were no deaths during a median follow-up period of 6 moths (range 1–12).

Conclusions

This study was performed to assess the efficacy and safe method of relieving the severity of esophageal stricture after ESD through transplantation of ADM.

Stent placement to prevent strictures after esophageal endoscopic submucosal dissection: a systematic review and meta-analysis

Endoscopic submucosal dissection (ESD) is an important method for the treatment of early esophageal cancer. However, post-procedure stenosis is one of the most common long-term complications. This meta-analysis aimed to investigate whether stent placement is effective in the stenosis prevention, and which type of stent would be more effective. A systematic and electronic search of clinical trials and observational studies conducted before March 2020 on the efficacy of stent placement in preventing esophageal stricture after ESD was performed. Search terms included "ESD," "esophageal stenosis," "esophageal stricture," and "stents." We conducted a bias risk assessment of the eligible reports and a meta-analysis of the data using Revman 5.3 software. We included two randomized controlled trials (RCTs) and a prospective cohort study involving 163 patients with esophageal mucosal defects encompassing at least three-quarters of the esophagus circumference after ESD. The meta-analysis results showed that post-ESD stenosis rates (RR, 0.37; 95% CI, 0.22-0.64; P = 0.0003) and the number of endoscopic balloon dilations (EBDs) (MD, -1.74; 95% CI, -2.46 to -1.01; P < 0.00001) were reduced in the pooled analysis of three studies, indicating that stent placement was effective for stenosis prevention, especially a polyglycolic acid (PGA) sheet combined with stent placement can prevent stenosis (RR, 0.41; 95% CI, 0.23-0.74; P = 0.003) and reduce the number of EBDs (MD, -1.65; 95% CI, -2.40 to -0.90; P < 0.0001) significantly. Stent placement can reduce the rate of esophageal stenosis after ESD, especially when stents are covered with PGA sheets. However, more high-quality, low-bias RCTs with a sufficient sample size are needed to demonstrate its effectiveness.

Allogeneic epithelial cell sheet transplantation for preventing esophageal stricture after circumferential ESD in a porcine model: preliminary results

OBJECTIVES

Circumferential endoscopic submucosal dissection (ESD) for large lesions induces severe stricture, requiring subsequent treatment. We aimed to evaluate the efficacy of allogeneic epithelial cell sheet transplantation in preventing esophageal stricture after circumferential ESD in a porcine model.

MATERIALS AND METHODS

A total of 15 conventional pigs underwent a 4 cm long circumferential ESD in the mid-esophagus. Out of these animals, 11 were immediately subjected to allogeneic oral mucosal cell sheet transplantation at the resection site, whereas four pigs underwent circumferential ESD only. We performed upper endoscopy 1 and 2 weeks after ESD and assessed the degree of esophageal stricture and histologic characteristics.

RESULTS

Dysphagia scores and weight change ratios recorded 1 and 2 weeks after ESD did not differ between the two groups. The stricture rate 2 weeks after ESD was 100% in the control group and 90.9% in the cell sheet group (p = 1.000). The median mucosal constriction rates of the control and cell sheet groups were 73.5% (range 63.0-80.0%) and 53.8% (37.5-73.3%, p = .018), respectively. With regard to microscopic measurements, the length of re-epithelialization was greater in the cell sheet group than in the control group (2,495 µm vs. 369 µm, p = .008). Median fibrosis thickness and degree of muscle damage were not significantly different between groups.

CONCLUSIONS

Although allogeneic epithelial cell sheet transplantation showed greater re-epithelialization and less mucosal constriction of post-ESD ulcers, it was not sufficiently effective in preventing post-ESD stricture.

Transplantation of autologous oral mucosal epithelial cell sheets inhibits the development of acquired external auditory canal atresia in a rabbit model

Acquired external auditory canal atresia is characterized by fibrous tissue formation in the ear canal, hearing loss and chronic otorrhea. Although the disease can be treated surgically, the recurrence rate is high. This study explored whether autologous oral mucosal epithelial cell sheets could be used as a novel therapy for ear canal atresia. We succeeded in generating a rabbit model of acquired external auditory canal atresia by dissecting the skin of the ear canal. Endoscopic and histological findings in this model indicated that atresia developed over a 4-week period and was not inhibited by the placement of polyglycolic acid sheets immediately after skin dissection. By contrast, transplantation of autologous oral mucosal epithelial cell sheets, which had been fabricated by culture on temperature-responsive inserts without a feeder layer, prevented the development of atresia during the 4-week period after skin dissection. Transplantation of autologous epithelial cell sheets after surgical treatment of acquired external auditory canal atresia could be a promising new method to reduce the risk of disease recurrence. STATEMENT OF SIGNIFICANCE: Acquired external auditory canal atresia is characterized by fibrous tissue formation in the ear canal, which leads to hearing loss and chronic otorrhea. Although surgical treatments are available, the recurrence rate is high. In this study, we successfully generated a rabbit model of acquired external auditory canal atresia by dissecting the skin of the ear canal. Furthermore, we utilized this new animal model to investigate whether the transplantation of autologous oral mucosal epithelial cell sheets could be used as a novel therapy for ear canal atresia. Our results raise the possibility that the transplantation of autologous epithelial cell sheets after surgical treatment of ear canal atresia could be a promising new method to reduce the risk of disease recurrence.

Comparison of general anesthesia and conscious sedation in procedure-related complications during esophageal endoscopic submucosal dissection

BACKGROUND

Endoscopic submucosal dissection (ESD) has a favorable outcome, compared to esophagectomy, for early esophageal neoplasia. Recent studies used general anesthesia for esophageal ESD to minimize complications due to insufficient sedation and patient movement. We aimed to evaluate the safety of general anesthesia in comparison with conscious sedation provided by anesthesiologists for esophageal ESD.

METHODS

We retrospectively reviewed the electronic medical records of 158 patients who underwent esophageal ESD under general anesthesia or conscious sedation provided by anesthesiologists. We evaluated the incidence of procedure-related complications, including perforation, post-ESD bleeding, cardiopulmonary adverse events (arrhythmia, hypotension, and hypoxemia), procedure failure, stricture, and new lung consolidation after ESD. Cases of frank perforation, post-ESD bleeding requiring a vigorous diagnostic approach, and cardiopulmonary adverse events were regarded as acute complications of ESD.

RESULTS

Acute complications occurred only in the conscious sedation group (8/83 [9.6%] vs. 0/75 [0.0%]; p value = 0.007). The numbers of patients with frank perforation, post-ESD bleeding, and cardiopulmonary adverse events were four, one, and three, respectively. Moreover, new lung consolidation after ESD developed only in the conscious sedation group (7/83 [8.4%] vs. 0/75 [0.0%]; p value = 0.014). ESD failed in four patients in the conscious sedation group. The incidences of stricture that required stent insertion and hospital stay after ESD were comparable between the two groups.

CONCLUSION

General anesthesia is associated with a lower incidence of acute procedure-related complications in esophageal ESD compared to conscious sedation provided by anesthesiologists. Therefore, we recommend general anesthesia as a safer option for esophageal ESD.

Safety and histologic outcomes of endoscopic submucosal dissection with a novel articulating knife for esophageal neoplasia

BACKGROUND AND AIMS

Treatment of large esophageal neoplasia is gradually evolving from piecemeal to en bloc resections. Endoscopic submucosal dissection (ESD) is known to achieve more complete resections than piecemeal EMR for large lesions, yet it remains underused in the West because of technical and safety concerns with traditional electrosurgical knives. We aimed to evaluate a novel endoscopic articulating knife used with ESD (ESD-AR) to determine its safety and efficacy for large esophageal neoplasms in comparison with EMR.

METHODS

We retrospectively studied clinically indicated cases of ESD-AR and EMR for esophageal lesions that were 15 mm or greater. All EMR cases had at least 3 simultaneous EMRs to adequately compare resection area. Rates of perforation, GI bleeding, technical performance, and pre- and postendoscopic resection diagnoses were evaluated.

RESULTS

Seventy-two ESD-AR and 72 widespread EMR cases were evaluated for Barrett's esophagus (56%), adenocarcinoma (36%), squamous nodularity (2%), and squamous cell carcinoma (6%). There were no statistical differences in age, sex, Barrett's esophagus length, and lesion or resection size between the 2 groups. No perforations occurred. Two adverse events were recorded with ESD-AR and none with EMR (3% vs 0%, P = .50); these were associated with anticoagulation use (P = .04) and greater resection area (P = .02). There were more upgraded diagnoses post-ESD versus EMR (27% vs 12%, P = .05).

CONCLUSIONS

ESD-AR by an experienced endoscopist has a comparable safety profile with widespread EMR for large esophageal neoplasia and may have advantages for diagnostic staging.

Fabrication of tissue-engineered cell sheets by automated cell culture equipment

Most cells for regenerative medicine are currently cultured manually. In order to promote the widespread use of regenerative medicine, it will be necessary to develop automated culture techniques so that cells can be produced in greater quantities at lower cost and with more stable quality. In the field of regenerative medicine technology, cell sheet therapy is an effective tissue engineering technique whereby cells can be grafted by attaching them to a target site. We have developed automated cell culture equipment to promote the use of this cell sheet regenerative treatment. This equipment features a fully closed culture vessel and circuit system that avoids contamination with bacteria and the like from the external environment, and it was designed to allow 10 cell sheets to be simultaneously cultured in parallel. We used this equipment to fabricate 50 sheets of human oral mucosal epithelial cells in five automated culture tests in this trial. By analyzing these sheets, we confirmed that 49 of the 50 sheets satisfied the quality standards of clinical research. To compare the characteristics of automatically fabricated cell sheets with those of manually fabricated cell sheets, we performed histological analyses using immunostaining and transmission electron microscopy. The results confirmed that cell sheets fabricated with the automated cell culture are differentiated in the same way as cultures fabricated manually.

Novel detachable stents for the treatment of benign esophageal strictures

The radial force of esophageal stents may not completely change during extraction and therefore, the procedure of stent removal may cause tissue damage. The present study reports the manufacture of 2 novel detachable stents, which were designed to reduce tissue damage through their capacity to be taken or fall apart prior to removal and evaluated the supporting properties of these stents and the extent of local mucosal injury during their removal. The stents were manufactured by braiding, heat-setting, coating and connecting. The properties of the stents were evaluated by determining the following parameters: Expansion point, softening point, stent flexibility, radial compression ratio and radial force. A total of 18 rabbits with induced esophageal stricture were randomly assigned to 3 groups as follows: Detachable stent (DS) group, biodegradable stent (BS) group and control group. The stricture rate, complications, survival, degradation and stent removal were observed over 8 weeks. The stents of the DS and BS groups provided a similar supporting effect. The stricture rate, incidence of complications and survival were also similar between the 2 groups, while significant differences were noted between the DS and control groups and between the BS and control groups. In the BS group, the stents were degraded and moved to the stomach within 7 weeks (2 in 6 weeks and 3 in 7 weeks). The debris was extracted using biopsy forceps. In the DS group, all stents were easy to remove and 2 cases exhibited minor hemorrhage. In conclusion, the 2 types of novel detachable stent provided an equally efficient supporting effect in vitro and in vivo and may reduce the incidence of secondary injury during stent removal.

Development and validation of a model to determine risk of refractory benign esophageal strictures

BACKGROUND

Current research has identified several risk factors for refractory benign esophageal strictures (RBES), but research is scarce on the prediction of RBES in benign esophageal strictures patients. Meanwhile, the long-term outcomes of RBES remain unclear. The aim of this study was to develop and validate a model to determine the progression of RBES in patients with benign esophageal strictures. And we also explored the long-term outcomes and safety in patients with RBES.

AIM

To develop and validate a model to determine the progression of RBES in patients with benign esophageal strictures, based on the demographic data and endoscopic findings.

METHODS

A total of 507 benign esophageal stricture patients treated by dilation alone or in combination with stenting were retrospectively enrolled between January 2009 and February 2018. The primary outcome was to establish a risk-scoring model predicting RBES in benign esophageal strictures. The secondary outcome was to explore the clinical effectiveness and adverse events in patients with RBES.

RESULTS

In the study, age, etiology, and number and length of strictures were the independent risk factors for the refractory performance of benign esophageal strictures. According to risk factors of benign esophageal strictures, a risk-scoring model for predicting RBES in benign esophageal strictures was established: The risk score ranged from 0 to 8 points, and the risk scores were divided into low risk (0-2 points), intermediate risk (3-5 points), and high risk (6-8 points). The proportions of RBES in the corresponding risk categories were 1.0%, 12.2%, and 76.0%, respectively. Among 507 patients, 57 had RBES (39 males; median age, 60 years). The success rate of dilation treatment (51.2%, 21/41) was higher than that of stent placement (37.5%, 6/16).

CONCLUSION

In this study, 11.3% (57/507) patients had RBES at our hospital. The risk-scoring model predicting RBES in benign esophageal strictures could predict the long-term outcome of patients with strictures ahead.

The role of endoscopic dilation and stents in refractory benign esophageal strictures: a retrospective analysis

Background

The outcomes of patients with refractory benign esophageal strictures (RBES) are unclear, and the clinical efficacy of dilation versus stent placement is lacking. Our objective was to explore the role of endoscopic dilation and stents placement in the management of RBES.

Methods

RBES patients treated with dilation and stents in our hospital between January 2009 and December 2017 were included in this study. The primary outcomes were to assess clinical effectiveness and adverse events. The secondary outcome was to identify factors that predicted the dysphagia-free period.

Results

Among 75 RBES patients (54 male; median age 59 years), 39 (52%), 20 (26.7%), 3 (4%), 10 (13.3%), and 3 (4%), were postsurgical, post-ESD, achalasia of cardia, caustic and mixed etiology, respectively. The median number of endoscopic therapy was 5 times (range 3, 21). Endoscopic therapy was successful in 46 patients (61.3%). Patients treated with dilation showed a higher success rate (70.9%, 39/55) than that treated with stents (35%, 7/20). Fifteen patients died during follow-up. Nineteen patients had adverse events after endoscopic therapy. In total, the mean dysphagia-free period was 3.4 months (95% CI, 2.5–4.3). The patients treated with dilation demonstrated a dysphagia-free period of 3.7 months (95% CI, 2.7–5), while patients treated with stents displayed a dysphagia-free period of 2.3 months (95% CI, 1.5–3). The dysphagia-free period had a linear growth trend over time, with an increase of 12 days per endoscopic therapy.

Conclusion

The dysphagia-free period increased by 12 days per endoscopic therapy, so the endoscopic therapy tended to be effective in patients with RBES by increasing the dysphagia-free period. However, compared to dilation therapy, stent therapy was not effective in increasing the dysphasia-free period and reducing the times and frequency of dilation. In addition, univariate and multivariate analyses also indicated that etiology may predict the endoscopic therapy outcome.

Trial registration

This study was retrospectively registered and approved by the Ethics Committee of West China Hospital of Sichuan University (IRB number: ChiCTR1800016321).

Efficacy and safety of steroid in the prevention of esophageal stricture after endoscopic submucosal dissection: A network meta-analysis

BACKGROUND AND AIM

Even though endoscopic submucosal dissection is an important endoscopic resection technique for gastrointestinal neoplasms, there are chances that postoperative esophageal stricture might take place as a side effect. Steroid applications were reported to be effective for the prevention of stricture formation. Therefore, this study aims to evaluate the efficacy and safety of different steroid applications.

METHODS

Eligible studies published on PubMed, the Cochrane Library, Embase, Web of Science, and Chinese Biomedical Literature Database before August 2018 were reviewed. The preventions were divided as placebo/no treatment, long-term oral steroid (LOS), median-term oral steroid, short-term oral steroid, single-dose steroid injection, multiple-dose steroid injection, topical superficial steroid, steroid injection combined with oral steroid, and preemptive endoscopic balloon dilatation. The primary outcomes were postoperative esophageal stricture rate and endoscopic balloon dilatation sessions required. Complications were also analyzed.

RESULTS

A total of 19 studies were included. The network meta-results illustrated that compared with the placebo, all kinds of steroid interventions were associated with lower rates of postoperative esophageal stenosis and less number of endoscopic balloon dilatation sessions. Moreover, combined therapy was no better than single regimen therapy. No significant differences between various steroid applications in the incidence of complications were spotted during this study. Based on the results of the network and clustered ranking, LOS might be the superior prevention for postoperative stricture with satisfying efficacy.

CONCLUSION

The present study showed that LOS appears to be the optimal prevention method for postoperative stricture formation.

Prevention of esophageal stricture after endoscopic resection

Stricture formation after esophageal endoscopic resection has a negative impact on patients' quality of life because it causes dysphagia and requires multiple endoscopic dilations. Various methods by which to prevent stricture have recently been developed and reported. Among these methods, local steroid injection is the most commonly used and is currently considered the standard method for noncircumferential resection. However, local steroid injection has a limited effect on circumferential resection. Thus, oral steroid administration is used for such cases because it may have a stronger effect than local injection. Steroid treatment, both by local injection and oral administration, is effective and low-cost; however, it may cause fragility of the esophageal wall, resulting in adverse events such as perforation during balloon dilatation. Many innovative approaches have been developed, such as tissue-shielding methods with polyglycolic acid, tissue engineering approaches with autologous oral mucosal epithelial cell sheet transplantation, and stent insertion. These methods may be promising, but they are limited by a scarcity of data. Further investigations are needed to confirm the efficacy of these methods.

Cyclodextrin Polymer Preserves Sirolimus Activity and Local Persistence for Antifibrotic Delivery over the Time Course of Wound Healing

Fibrosis and dysphagic stricture of the esophagus is a major unaddressed problem often accompanying endoscopic removal of esophageal cancers and precancerous lesions. While weekly injections of antiproliferative agents show potential for improved healing, repeated injections are unlikely clinically and may alternatively be replaced by creating an esophageal drug delivery system. Affinity-based polymers have previously shown success for continuous delivery of small molecules for weeks to months. Herein, we explored the potential of an affinity-based microparticle to provide long-term release of an antiproliferative drug, sirolimus. In molecular docking simulations and surface plasmon resonance experiments, sirolimus was found to have suitable affinity for beta-cyclodextrin, while dextran, as a low affinity control, was validated. Polymerized beta-cyclodextrin microparticles exhibited 30 consecutive days of delivery of sirolimus during in vitro release studies. In total, the polymerized beta-cyclodextrin microparticles released 36.9 mg of sirolimus per milligram of polymer after one month of incubation in vitro. Taking daily drug release aliquots and applying them to PT-K75 porcine mucosal fibroblasts, we observed that cyclodextrin microparticle delivery preserved bioactivity of sirolimus inhibiting proliferation by 27-67% and migration of fibroblasts by 28-100% of buffer treated controls in vitro. Testing for esophageal injection site losses, no significant loss was incurred under simulated saliva flow for 10 min, and 16.7% of fluorescently labeled polymerized cyclodextrin microparticle signal was retained at 28 days after submucosal injection in esophageal tissue ex vivo versus only 4% of the initial amount remaining for free dye molecules injected alone. By combining affinity-based drug delivery for continuous long-term release with a microparticle platform that is injectable yet remains localized in tissue interstitium, this combination platform demonstrates promise for preventing esophageal fibrosis and stricture.

White coat status is a predictive marker for post-esophageal endoscopic submucosal dissection stricture: a retrospective study

BACKGROUND

Steroid therapy is primarily used to prevent esophageal stricture after endoscopic submucosal dissection (ESD). However, esophageal stricture can still occur after preventive therapy, and the effect of preventive steroid therapy cannot be predicted before stricture formation. This study aimed to clarify the risk factors for esophageal stricture after preventive steroid therapy.

METHODS

This was a retrospective study conducted at three institutions. From January 2011 to February 2018, 28 large-sized SENs in 26 patients who had a mucosal defect that involved more than three-quarters of the esophageal circumference were enrolled. We classified white coats on artificial ulcers after esophageal ESD into three groups (thin, moderately thick, thick) based on endoscopic images obtained on postoperative day 7.

RESULTS

The white coat status on the artificial ulcer after ESD was a significant risk factor for post-ESD stricture (p < 0.05). The stricture rates in patients with thin, moderately thick and thick white coats were 10.0, 36.4 and 85.7%, respectively. When thin and moderately thick white coats were combined, the stricture rate was 23.8%. The rate of stricture in lesions with thick white coats was significantly higher than that in patients with thin white coats or thin to moderately thick white coats (p < 0.05). The multivariate analysis revealed that the white coat status was an independent factor related to esophageal stricture (odds ratio 13.70, 95% confidence interval 1.22-154.0; p = 0.034).

CONCLUSIONS

The thickness of the white coat is a useful marker for predicting the risk of post-ESD stricture and the effectiveness of preventive steroid therapy.

Early esophageal squamous cell carcinoma management through endoscopic submucosal dissection

The incidence of esophageal cancer is steadily increasing worldwide. Outcome is poor, given that the majority of cases are diagnosed at advanced disease stages. However, when detected at early stages, esophageal tumors can be curatively treated through less invasive methods, resulting in a 5-year survival rate above 90%. Therefore, it is essential to identify the high-risk population and recommend those patients undergo screening using high-resolution endoscopy, adding the resources of chromoendoscopy with Lugol's solution (or digital chromoendoscopy) and magnification. Such systematized examination makes it possible to recognize early-stage esophageal neoplasia and propose endoscopic submucosal dissection as treatment. In that procedure, the tumor is resected en bloc, resulting in lower morbidity and mortality, compared with previous standard treatment, including early-stage esophagectomy. The present article is a review of the latest advances in the management of superficial esophageal tumors through endoscopic submucosal dissection.

Oral epithelial cell sheets engraftment for esophageal strictures after endoscopic submucosal dissection of squamous cell carcinoma and airplane transportation

Endoscopic submucosal dissection (ESD) permits en bloc removal of superficial oesophageal squamous cell carcinoma (ESCC). However, post-procedure stricture is common after ESD for widespread tumours, and multiple endoscopic balloon dilation (EBD) procedures are required. We aimed to evaluate the safety and effectiveness of endoscopic transplantation of tissue-engineered autologous oral mucosal epithelial cell sheets that had been transported by air over a distance of 1200 km in controlling postprocedural oesophageal stricture. Ten patients who underwent complete circular or semicircular ESD for ESCC were transplanted with cell sheets. The safety of the entire process including cell sheet preparation, transport, ESD and cell sheet transplantation was assessed. The incidence of oesophageal stricture, number of EBD sessions, and time until epithelialization were investigated. Each ESD was successfully performed, with subsequent cell sheet engrafting carried out safely. Following cell sheet transplantation, the luminal stenosis rate was 40%, while the median number of EBD sessions was 0. The median post-ESD ulcer healing period was rather short at 36 days. There were no significant complications at any stage of the process. Cell sheet transplantation and preparation at distant sites and transportation by air could be a safe and promising regenerative medicine technology.

Regenerative medicine for the esophagus

Advances in tissue engineering techniques have made it possible to use human cells as biological material. This has enabled pharmacological studies to be conducted to investigate drug effects and toxicity, to clarify the mechanisms underlying diseases, and to elucidate how they compensate for impaired organ function. Many researchers have tried to construct artificial organs using these techniques, but none has succeeded in growing a whole organ. Unlike other digestive organs with complicated functions, such as the processing and absorption of nutrients, the esophagus has the relatively simple function of transporting content, which can be replicated easily by a substitute. In regenerative medicine, various combinations of materials have been applied, including scaffolding, cell sources, and bioreactors. Exciting results of tissue engineering techniques for the esophagus have been reported. In animal models, replacing full-thickness and full-circumferential defects remains challenging because of stenosis and leakage after implantation. Although many reports have manipulated various scaffolds, most have emphasized the importance of both epithelial and mesenchymal cells for the prevention of stenosis. However, the results of repair of partial full-thickness defects and mucosal defects have been promising. Two successful approaches for the replacement of mucosal defects in a clinical setting have been reported, although in contrast to the many animal models, there are few pilot studies in humans. We review the recent results and evaluate the future of regenerative medicine for the esophagus.

Cell sheet engineering using the stromal vascular fraction of adipose tissue as a vascularization strategy

Current vascularization strategies for Tissue Engineering constructs, in particular cell sheet-based, are limited by time-consuming and expensive endothelial cell isolation and/or by the complexity of using extrinsic growth factors. Herein, we propose an alternative strategy using angiogenic cell sheets (CS) obtained from the stromal vascular fraction (SVF) of adipose tissue that can be incorporated into more complex constructs. Cells from the SVF were cultured in normoxic and hypoxic conditions for up to 8days in the absence of extrinsic growth factors. Immunocytochemistry against CD31 and CD146 revealed spontaneous organization in capillary-like structures, more complex after hypoxic conditioning. Inhibition of HIF-1α pathway hindered capillary-like structure formation in SVF cells cultured in hypoxia, suggesting a role of HIF-1α. Moreover, hypoxic SVF cells showed a trend for increased secretion of angiogenic factors, which was reflected in increased network formation by endothelial cells cultured on matrigel using that conditioned medium. In vivo implantation of SVF CS in a mouse hind limb ischemia model revealed that hypoxia-conditioned CS led to improved restoration of blood flow. Both in vitro and in vivo data suggest that SVF CS can be used as simple and cost-efficient tools to promote functional vascularization of TE constructs.

STATEMENT OF SIGNIFICANCE

Neovascularization after implantation is a major obstacle for producing clinically viable cell sheet-based tissue engineered constructs. Strategies using endothelial cells and extrinsic angiogenic growth factors are expensive and time consuming and may raise concerns of tumorigenicity. In this manuscript, we describe a simplified approach using angiogenic cell sheets fabricated from the stromal vascular fraction of adipose tissue. The strong angiogenic behavior of these cell sheets, achieved without the use of external growth factors, was further stimulated by low oxygen culture. When implanted in an in vivo model of hind limb ischemia, the angiogenic cell sheets contributed to blood flux recovery. These cell sheets can therefore be used as a straightforward tool to increase the neovascularization of cell sheet-based thick constructs.

Endoscopic treatment of benign esophageal strictures: a literature review

Benign esophageal strictures arise from various etiologies and are frequently encountered. Although endoscopic dilation is still the first-line therapy, recurrent strictures do occur in approximately 10% of the cases and remains a challenge to gastroenterologists. Areas covered: A literature search was performed using PubMed and Google Scholar databases for original and review articles on endoscopic treatment of benign esophageal strictures. This review outlines the main available treatment options and its controversies in the management of refractory benign esophageal strictures. Expert commentary: Adding local steroid injections to dilation can be effective for peptic stenosis and strictures after endoscopic submucosal dissection, but remains uncertain for anastomotic strictures. Intralesional injections of mitomycin-C could be useful in corrosive strictures. Incisional therapy can be a reliable alternative in Schatzki rings and in anastomotic strictures, in experienced hands. By contrast, long-term outcome with endoprosthetic treatment is disappointing, and stent placement should be carefully considered and individualized.

Transplantation of epidermal cell sheets by endoscopic balloon dilatation to avoid esophageal re-strictures: initial experience in a porcine model

Background and study aims: Epidermal cell sheet (ECS) transplantation immediately after aggressive endoscopic submucosal dissection (ESD) has been shown to be safe and effective in the prevention of esophageal strictures. This study evaluated the feasibility of ECS transplantation after endoscopic balloon dilation (EBD) in a porcine model. Methods: Six pigs underwent circumferential esophageal ESD under general anesthesia. Two weeks later, two pigs underwent EBD and transplantation of an autologous ECS, two underwent EBD alone, and two underwent endoscopic observation only (control). Results: The two pigs in the transplantation group underwent six ECS transplants after EBD with five of the six (83 %) being successful, as shown by engraftment of transplanted ECSs after 7 days. No adverse events were observed. Stricture rates were lower in the two transplanted pigs (55 % and 60 %) than in the control (92.2 % and 87.7 %) and EBD-treated (71.7 % and 78.2 %) pigs. Infiltration of inflammatory cells was significantly lower in the transplanted pigs than in the control and EBD-treated pigs. Conclusion: Preliminary results indicate the stability of the ECS transplantation procedure and the engraftment of transplanted ECS in the tears after EBD. This proof-of-concept study suggests that covering tears with ECSs after EBD may avoid re-strictures.

Steroid pulse therapy prevents restenosis following balloon dilatation for esophageal stricture

PURPOSE

This study aimed to evaluate the effectiveness of intravenous steroid pulse therapy following balloon dilatation for esophageal stenosis and stricture in children.

METHODS

The study enrolled six children, including three with congenital esophageal stenosis and three with anastomotic strictures after surgery for esophageal atresia, all of whom were treated by balloon dilatation combined with high-dose intravenous methylprednisolone pulse therapy. Methylprednisolone was injected intravenously at a dose of 20 mg/kg/day for 2 days, starting from the day of dilatation, followed by 10 mg/kg/day for 2 days, for a total of 4 days.

RESULTS

Esophageal stricture recurred in all three patients with congenital esophageal stenosis despite repeated balloon dilatation without methylprednisolone. However, the symptoms of dysphagia improved and did not recur after systemic steroid pulse therapy following balloon dilatation. Symptoms also resolved in all three patients with anastomotic strictures following balloon dilatation with systemic steroid pulse therapy. All six patients remained asymptomatic after 6-21 months follow-up, with no complications.

CONCLUSION

Intravenous methylprednisolone pulse therapy following balloon dilatation is safe and effective for the treatment of esophageal stenosis and strictures in children.

Topical hemostatic powder promotes reepithelialization and reduces scar formation after extensive esophageal mucosal resection

The development of techniques for endoscopic resection has provided new strategies for radical conservative treatment of superficial esophageal neoplasms, even those that are circumferential, such as Barrett's neoplasia. However, it is necessary to prevent the formation of scar tissue that can be responsible for esophageal strictures following circumferential resection. Preliminary data have suggested the possible efficacy of a hemostatic powder in the promotion of wound healing. The study aims to assess the effectiveness of Hemospray (Cook Medical) in a swine model of post-endoscopic esophageal stricture. Our prospective controlled study included 21 pigs. A 6-cm circumferential submucosal dissection of the esophagus (CESD) was performed in each pig. Group 1 (n = 11) only underwent CESD and Group 2 (n = 10) had repeated Hemospray applications after CESD. Clinical, endoscopic, and radiological monitoring were performed, blood levels of four inflammatory or pro-fibrotic cytokines were assessed, and histological analysis was performed. Median esophageal diameter was greater in the group treated with Hemospray (2 mm [1-3] vs. 3 mm [2-4], P = 0.01), and the rate of symptomatic esophageal stricture was 100% and 60% in Groups 1 and 2, respectively (P = 0.09). The thicknesses of esophageal fibrosis and inflammatory cell infiltrate were significantly lower in Group 2 than in Group 1 (P = 0.002 and 0.0003, respectively). The length of the neoepithelium was greater in Group 2 than in Group 1 (P = 0.0004). Transforming growth factor-β levels were significantly lower in Group 2 than in Group 1 (P = 0.01). The application of Hemospray after esophageal CESD reduces scar tissue formation and promotes reepithelialization, and therefore is a promising therapeutic approach in the prevention of post-endoscopic esophageal stricture.

Prevention of Esophageal Stricture After Endoscopic Submucosal Dissection: A Systematic Review

BACKGROUND

Endoscopic submucosal dissection (ESD) is rapidly becoming a favored method for removing early esophageal cancer, but the residual defects can be complicated with strictures that require repeated endoscopic balloon dilatation. Measures for preventing the post-ESD strictures have been sought. We conducted a systematic review of recent studies to evaluate these methods.

METHODS

We searched MEDLINE, Cochrane Central Register of Controlled Trials, Embase, and Google Scholar until November 30, 2014. Included studies were prospective and retrospective one- and two-arm studies. All studies had to include at least on preventive method for post-ESD stricture. Thirteen studies were included in the review.

RESULTS

Among the studies that used corticosteroids to prevent post-ESD stricture, we found that (1) injection of triamcinolone acetonide into the esophageal lesion resulted in a substantial reduction in the rate of stricture, and (2) the use of oral prednisolone was associated with a significantly reduced rate of dilatation sessions and stricture. Studies of other preventative measures included more recently developed scaffold-based and cell-based tissue-engineering approaches which seem very promising but require additional rigorously controlled studies to test their effectiveness.

CONCLUSIONS

Until a safer and more effective method is developed, our review supports the use of corticosteroids, either through injection or oral route, together with endoscopic dilatation in prevention of post-ESD strictures.

Prevention of Esophageal Strictures After Endoscopic Submucosal Dissection: A Promising Therapy Using Carboxymethyl Cellulose Sheets

BACKGROUND

Esophageal stricture is one of the serious adverse events following endoscopic submucosal dissection (ESD). However, optimum preventive techniques are still lacking.

AIMS

Our primary objective was to evaluate the incidence of post-ESD esophageal stricture with the application of carboxymethyl cellulose (CMC) sheets. Secondary objectives were to determine the number of sessions of endoscopic balloon dilatation (EBD) required to resolve post-ESD strictures and the incidence rate of peri-operative adverse events.

METHODS

This was a pilot, single-center, prospective study. Seven patients who had high risks of developing post-ESD esophageal stricture were enrolled into our study. CMC sheets were applied to the mucosal defects immediately after the completion of ESD. Patients were monitored and reviewed after ESD to detect any adverse events.

RESULTS

The incidence rate of post-operative stricture was 57 % (4/7 patients). Among patients who required EBD, the number of sessions performed was 2.8 ± 2.2. No serious post-operative adverse events were reported.

CONCLUSION

The use of CMC sheets appears to be a safe and effective prophylactic treatment for esophageal stricture following extensive ESD.

Systematic review: the prevention of oesophageal stricture after endoscopic resection

BACKGROUND

Extensive endoscopic resections for the treatment of early oesophageal neoplasia can result in fibro-inflammatory strictures that require repeated interventions, which significantly alter the patients' quality of life.

AIMS

To review current evidence about the prevention of oesophageal strictures following endoscopic resections.

METHODS

Systematic search of PubMed and Embase from inception to March 2015 using appropriate keywords. All original publications in English were included, and articles on the treatment of oesophageal stricture were excluded.

RESULTS

Of the 461 hits, 62 studies were included in the analysis. Among the wound-protective strategies, polyglycolic acid sheets showed the most convincing evidence with a 37.5% stricture rate and excellent safety. Regenerative medicine, using cell sheets of autologous keratinocytes, resulted in a 25% stricture rate, although with cost and availability concerns. Among anti-proliferative treatment modalities, steroid treatment, either endoscopically injected triamcinolone in the resection wound or orally administered prednisolone, proved effective with an overall stricture rate of 13.5%, with safety concerns regarding late oesophageal perforations and infectious morbidity. Among mechanical treatment options, poorly effective and high-risk preventive balloon dilation tend to be replaced by prophylactic covered stent, with 18-28% stricture rates.

CONCLUSIONS

Although oral or locally injected steroids are promising options, no currently available technique is sufficiently efficient and devoid of significant safety concerns to recommend its routine use for the prevention of strictures after extensive endoscopic resection. Improving our knowledge in the mechanisms of oesophageal wound healing will guide the development of novel methods for stricture prevention.

Useful strategies to prevent severe stricture after endoscopic submucosal dissection for superficial esophageal neoplasm

The minimal invasiveness of endoscopic submucosal dissection (ESD) prompted us to apply this technique to large-size early esophageal squamous cell carcinoma and Barrett’s adenocarcinoma, despite the limitations in the study population and surveillance duration. A post-ESD ulceration of greater than three-fourths of esophageal circumference was advocated as an important risk factor for refractory strictures that require several sessions of dilation therapy. Most of the preoperative conditions are asymptomatic, but dilatation treatment for dysphagia associated with the stricture has potential risks of severe complications and a worsening of quality of life. Possible mechanisms of dysphasia were demonstrated based on dysmotility and pathological abnormalities at the site: (1) delayed mucosal healing; (2) severe inflammation and disorganized fibrosis with abundant extracellular matrices in the submucosa; and (3) atrophy in the muscularis proper. However, reports on the administration of anti-scarring agents, preventive dilation therapies, and regenerative medicine demonstrated limited success in stricture prevention, and there were discrepancies in the study designs and protocols of these reports. The development and consequent long-term assessments of new prophylactic technologies on the promotion of wound healing and control of the inflammatory/tumor microenvironment will require collaboration among various research fields because of the limited accuracy of preoperative staging and high-risk of local recurrence.

Advances in prevention and treatment of esophageal stenosis after endoscopic submucosal dissection

Endoscopic submucosal dissection (ESD) is one of endoscopic minimally invasive techniques, referring to submucosal dissection of lesions greater than 2 cm using a variety of electric scalpels. At present ESD has become the most common choice of treatment for early esophageal cancer and precancerous lesions. With the wide application and development of esophageal ESD technology, post-ESD esophageal stenosis, as a major complication of esophageal ESD, has affected endoscopic treatment for the larger scope of early esophageal cancer and precancerous lesions and has plagued digestive endoscopy experts. For this complication, there have been no universally accepted treatment guidelines in the world. Scholars of different countries are taking efforts to develop different treatment or prevention strategies, looking forward to finding a better solution to the treatment or prevention of this complication. In this paper, we focus on the recent progress in the prevention and treatment of post-ESD esophageal stenosis.