Approaches for stricture prevention after esophageal endoscopic resection

Self-expandable metallic stents may be more efficient than balloon dilatation alone for esophageal stricture after circumferential endoscopic submucosal dissection: a retrospective cohort study in China

INTRODUCTION

Self-expandable metallic stents (SEMSs) can be used to treat esophageal stricture after circumferential endoscopic submucosal dissection (ESD), but its efficacy and placement timing remain to be determined. In this study, the treatment time and number of dilatations were compared between the SEMS placement group and the balloon dilatation (BD) group to clarify the efficacy and placement time of SEMSs in the treatment of esophageal stricture after circumferential esophageal ESD.

METHODS

This was a retrospective cohort study. Patients with esophageal stricture after circumferential ESD between January 2015 and January 2020 were included. Data on the patients' demographic characteristics, esophageal lesion-related factors, esophageal stricture occurrence, and measures taken to treat the stricture were collected. The primary outcome was the treatment time, and the secondary outcome was the number of dilatations.

RESULTS

The total number of dilatations was 30 in the SEMS group and 106 in the BD group. The average number of dilatations in the SEMS group (1.76 ± 1.64) was significantly lower than that in the BD group (4.42 ± 5.32) (P = 0.016). Among the patients who underwent SEMS placement first had a shorter treatment time (average 119 days) than those who underwent BD first (average 245 days) (P = 0.041), and the average number of dilatations inpatients who underwent SEMS placement first (0.71 ± 1.07) was significantly lower than that in the patients who underwent BD first (2.5 ± 1.54).

CONCLUSION

SEMSs were more efficient in the treatment of esophageal stricture in a cohort of patients after circumferential esophageal ESD.

A Novel Rat Model to Simulate the Benign Esophageal Stricture Induced by Endoscopic Submucosal Dissection

Objective

This study aimed to establish a rat model that simulates benign esophageal strictures induced by endoscopic submucosal dissection (ESD).

Materials and Methods

Sixteen male Sprague-Dawley rats were randomly divided into mucosal resection (n = 8) and sham-operated groups (n = 8). The rats in the mucosal resection group underwent a 5-mm three-fourths mucosal resection by way of a 3-mm incision in the distal esophagus under direct visualization via laparotomy. Rats in the sham-operated group underwent a 3-mm incision of the muscularis propria layer in the distal esophagus via laparotomy without mucosal resection. Dysphagia score, weight gain, mucosal constriction rate, and histology were evaluated 2 weeks after surgery.

Results

Technical success was achieved in all the animals. One rat in the mucosal resection group died of infection, and no other complications were observed. Weight gain (P < 0.001) and luminal diameter derived from the esophagograms (P < 0.001) were significantly lower in the mucosal resection group than those in the sham-operated group. Dysphagia score (P < 0.001) and mucosal constriction rate (P < 0.001) were significantly higher in the mucosal resection group than those in the sham-operated group. The inflammation grade (P = 0.002), damage to the muscularis propria (P < 0.001), number of nascent microvessels (P = 0.006), and degree of α-SMA positive deposition (P = 0.006) were significantly higher in the mucosal resection group.

Conclusion

A rat model of benign esophageal stricture induced by ESD was successfully and safely established by mucosal resection.

Acute esophageal stricture after bone marrow transplant

Esophageal stricture after bone marrow transplantation (BMT) is exceptionally rare, with only a few cases reported in the literature. We present an interesting case of a 58-year-old male with refractory multiple myeloma who developed dysphagia five days following his second bone marrow transplantation. He was found to have a severe esophageal stricture. The patient was treated with multiple esophageal dilations and triamcinolone injections in the following weeks to months, resulting in an improvement in symptoms. Although the exact underlying mechanism remains unknown, high-dose chemotherapy conditioning with melphalan prior to BMT likely contributed to the stricture. Our case highlights the importance of heightened post-bone marrow transplantation management for rare complications, such as an esophageal stricture.

Prospects of polyglycolic acid sheets for the treatment of esophageal stricture after esophageal endoscopic submucosal dissection

Esophageal cancer is the seventh most common type of cancer and the sixth leading cause of cancer -related mortality worldwide. Endoscopic submucosal dissection (ESD) is widely used for the resection of early esophageal cancer. However, post-ESD esophageal stricture is a common long-term complication, which requires attention. Patients with post-ESD esophageal stricture often experience dysphagia and require multiple dilatations, which greatly affects their quality of life and increases healthcare costs. Therefore, to manage post-ESD esophageal stricture, researchers are actively exploring various strategies, such as pharmaceutical interventions, endoscopic balloon dilation, and esophageal stenting. Although steroids-based therapy has achieved some success, steroids can lead to complications such as osteoporosis and infection. Meanwhile, endoscopic balloon dilatation is effective in the short term, but is prone to recurrence and perforation. Additionally, esophageal stenting can alleviate the stricture, but is associated with discomfort during stenting and the complication of easy displacement also present challenges. Tissue engineering has evolved rapidly in recent years, and hydrogel materials have good biodegradability and biocompatibility. A novel type of polyglycolic acid (PGA) sheets has been found to be effective in preventing esophageal stricture after ESD, with the advantages of a simple operation and low complication rate. PGA membranes act as a biophysical barrier to cover the wound as well as facilitate the delivery of medications to promote wound repair and healing. However, there is still a lack of multicenter, large-sample randomized controlled clinical studies focused on the treatment of post-ESD esophageal strictures with PGA membrane, which will be a promising direction for future advancements in this field.

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.

Predictors of stricture after non-circumferential endoscopic submucosal dissection of the esophagus and single-dose triamcinolone injection immediately after the procedure

BACKGROUND AND AIMS

Local triamcinolone (TA) injection is widely used to prevent stricture formation after endoscopic submucosal dissection (ESD). However, stricture develops in up to 45% of patients despite this prophylactic measure. We therefore conducted a single-center prospective study to identify predictors of stricture after esophageal ESD and local TA injection.

METHODS

Patients who underwent esophageal ESD and local TA injection and who were comprehensively assessed for lesion- and ESD-related factors were included in the study. Multivariate analyses were conducted to identify the predictors of stricture.

RESULTS

A total of 203 patients were included in the analysis. Multivariate analysis identified residual mucosal width ≤5 mm (odds ratio [OR], 29.0; P < .0001) or 6 to 10 mm (OR, 3.7; P = .04), history of chemoradiotherapy (OR, 5.1; P = .045), and tumor in the cervical or upper thoracic esophagus (OR, 3.8; P = .018) as independent predictors of stricture. Based on the ORs of the predictors, patients were stratified into 2 groups according to stricture risk: patients in the high-risk group (residual mucosal width ≤5 mm or 6-10 mm with another predictor) had a stricture rate of 52.5% (31 of 59 cases), and patients in the low-risk group (residual mucosal width ≥11 mm or 6-10 mm without other predictors) had a stricture rate of 6.3% (9 of 144 cases).

CONCLUSIONS

We identified predictors of stricture after ESD and local TA injection. Local TA injection prevented stricture formation after ESD in low-risk patients but was not sufficient to prevent stricture in high-risk patients. Additional interventions should thus be considered in high-risk patients. (University Hospital Medical Network Clinical Trials Registry number: UMIN 000028894.).

Benign esophageal stricture model construction and mechanism exploration

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

Self-help inflatable balloon versus autologous skin-grafting surgery for preventing esophageal stricture after complete circular endoscopic submucosal dissection: a propensity score matching analysis

BACKGROUND

The self-help inflatable balloon (SHIB) and autologous skin-grafting surgery (ASGS) were used to prevent stricture after esophageal complete circular endoscopic submucosal dissection (cESD) with promising clinical results. We aim to evaluate which method is more suitable for patients who underwent esophageal cESD.

METHODS

From October 2017 to July 2021, patients whose mucosal defect length were between 30 and 100 mm after esophageal cESD were retrospectively reviewed from two prospective studies. They were enrolled once SHIB or ASGS was used as preventive methods to prevent stricture. Propensity score matching (PSM) was used to balance the baseline characteristics between the two groups. Comparisons were made between the two groups, including operation time, the longitudinal length of ulceration, fasting time, hospitalization days, and the incidence of stricture.

RESULTS

A total of 41 patients who met the inclusion criteria were enrolled in the study. The numbers of patients in SHIB group and ASGS group were 25 and 16, respectively. Fifteen patients in each group were selected after performing PSM. The basic baseline characteristics were comparable between the two groups. The stricture rates were 20% (3/15) in SHIB group and 40% (6/15) in ASGS group, while the difference was not statistically significant (p = 0.427). The SHIB group showed significantly shorter operation time, shorter hospitalization days, lower cost, and longer removing balloon/stent time compared with ASGS group (p < 0.001). Comparison of relevant stricture factors between the stricture group and non-stricture group revealed that longer longitudinal length of ulceration (> 60 mm) accounted for a higher proportion in stricture groups (p = 0.035).

CONCLUSION

Both the SHIB and ASGS had high efficacy and safety in preventing strictures in patients with mucosal defects no longer than 100 mm in length after esophageal cESD. The longitudinal length of ulceration > 60 mm was the independent factor for predicting stricture.

Endoscopic submucosal dissection techniques and technology: European Society of Gastrointestinal Endoscopy (ESGE) Technical Review

ESGE suggests conventional endoscopic submucosal dissection (ESD; marking and mucosal incision followed by circumferential incision and stepwise submucosal dissection) for most esophageal and gastric lesions. ESGE suggests tunneling ESD for esophageal lesions involving more than two-thirds of the esophageal circumference. ESGE recommends the pocket-creation method for colorectal ESD, at least if traction devices are not used. The use of dedicated ESD knives with size adequate to the location/thickness of the gastrointestinal wall is recommended. It is suggested that isotonic saline or viscous solutions can be used for submucosal injection. ESGE recommends traction methods in esophageal and colorectal ESD and in selected gastric lesions. After gastric ESD, coagulation of visible vessels is recommended, and post-procedural high dose proton pump inhibitor (PPI) (or vonoprazan). ESGE recommends against routine closure of the ESD defect, except in duodenal ESD. ESGE recommends corticosteroids after resection of  > 50 % of the esophageal circumference. The use of carbon dioxide when performing ESD is recommended. ESGE recommends against the performance of second-look endoscopy after ESD. ESGE recommends endoscopy/colonoscopy in the case of significant bleeding (hemodynamic instability, drop in hemoglobin > 2 g/dL, severe ongoing bleeding) to perform endoscopic hemostasis with thermal methods or clipping; hemostatic powders represent rescue therapies. ESGE recommends closure of immediate perforations with clips (through-the-scope or cap-mounted, depending on the size and shape of the perforation), as soon as possible but ideally after securing a good plane for further dissection.

Outcomes for endoscopic submucosal dissection of pathologically staged T1b esophageal cancer: a multicenter study

BACKGROUND AND AIMS

The outcomes of endoscopic submucosal dissection (ESD) for T1b esophageal cancer (EC) and its recurrence rates remain unclear in the West. Using a multicenter cohort, we evaluated technical outcomes and recurrence rates of ESD in the treatment of pathologically staged T1b EC.

METHODS

We included patients who underwent ESD of T1b EC at 7 academic tertiary referral centers in the United States (n = 6) and Brazil (n = 1). We analyzed demographic, procedural, and histopathologic characteristics and follow-up data. Time-to-event analysis was performed to evaluate recurrence rates.

RESULTS

Sixty-six patients with pathologically staged T1b EC after ESD were included in the study. A preprocedure staging EUS was available in 54 patients and was Tis/T1a in 27 patients (50%) and T1b in 27 patients (50%). En-bloc resection rate was 92.4% (61/66) and R0 resection rate was 54.5% (36/66). Forty-nine of 66 patients (74.2%) did not undergo surgery immediately after resection and went on to surveillance. Ten patients had ESD resection within the curative criteria, and no recurrences were seen in a 13-month (range, 3-18.5) follow-up period in these patients. Ten of 39 patients (25.6%) with noncurative resections had residual/recurrent disease. Of the 10 patients with noncurative resection, local recurrence alone was seen in 5 patients (12.8%) and metastatic recurrence in 5 patients (12.8%). On univariate analysis, R1 resection had a higher risk of recurrent disease (hazard ratio, 6.25; 95% confidence interval, 1.29-30.36; P = .023).

CONCLUSIONS

EUS staging of T1b EC has poor accuracy, and a staging ESD should be considered in these patients. ESD R0 resection rates were low in T1b EC, and R1 resection was associated with recurrent disease. Patients with noncurative ESD resection of T1b EC who cannot undergo surgery should be surveyed closely, because recurrent disease was seen in 25% of these patients.

Clinical effectiveness of short course oral prednisone for stricture prevention after semi-circumferential esophageal endoscopic submucosal dissection

Background and study aims  Esophageal strictures (ES) occur frequently after semi-circumferential endoscopic submucosal dissection (ESD) for the eradication of superficial esophageal neoplasms and negatively impact a patient's quality of life. Oral corticosteroids have been shown to be clinically effective, but the most appropriate drug, dose and duration is yet to be determined. The aim of the study was to investigate the clinical effectiveness and safety of 30 mg prednisone with a shortened tapering schedule on ES after semi-circumferential ESD. Patients and methods  This was a retrospective observational study that analyzed consecutive patients with esophageal neoplasms who underwent semi-circumferential ESD with a resection defect greater than 75 % of the circumference that received a protocol of oral steroids for stricture prevention. On postoperative day 3, 30 mg prednisone was prescribed, tapering weekly to 20 mg/10 mg/5 mg over 4 weeks. Follow-up included clinic consultation and endoscopic review at weeks 2 and 4. Effectiveness outcomes included ES rates, safety, tolerability, resection, dilatation and recurrence rates. Results  Ninety ESD procedures were carried out during the specified time period and 18 patients met the inclusion criteria for the final analysis. The mean age was 61.5 years, lesion size was 52.5 mm, and final histology was squamous cell carcinoma in all patients. Incidence of intra-procedure complications was: bleeding 5.5 % (1/18) and ES 5.5 % (1/18), requiring a median two endoscopic dilatations. En bloc, R0 and curative resection rates were 88.8 %, 72.2 %, and 55.5 %, respectively. Conclusions  The short tapering schedule of 30 mg oral prednisone is clinically efficacious and safe for prevention of ES after semi-circumferential ESD in Latin American patients.

Flexible 3D Nanonetworked Silica Film as a Polymer-Free Drug-Eluting Stent Platform to Effectively Suppress Tissue Hyperplasia in Rat Esophagus

Loading and eluting drugs on self-expandable metallic stents (SEMSs) can be challenging in terms of fabrication, mechanical stability, and therapeutic effects. In this study, a flexible 3D nanonetworked silica film (NSF) capable of withstanding mechanical stress during dynamic expansion is constructed to function as a drug delivery platform on an entire SEMS surface. Despite covering a broad curved area, the synthesized NSF is defect-free and thin enough to increase the stent strut diameter (110 µm) by only 0.4 percent (110.45 µm). The hydrophobic modification of the surface enables loading of 4.7 times the sirolimus (SRL) concentration in NSF than Cypher, polymer-coated commercial stent, which is based on the same thickness of coating layer. Furthermore, SRL-loaded NSF exhibits a twofold delay in release compared to the control group without NSF. The SRL-loaded NSF SEMS significantly suppresses stent-induced tissue hyperplasia than the control SEMS in the rat esophagus (all variables, p < 0.05). Thus, the developed NSF is a promising polymer-free drug delivery platform to efficiently treat esophageal stricture.

Endoscopic submucosal dissection vs. endoscopic mucosal resection for early Barrett's neoplasia in the West: a retrospective study

BACKGROUND

The difference in clinical outcomes after endoscopic submucosal dissection (ESD) and endoscopic mucosal resection (EMR) for early Barrett's esophagus (BE) neoplasia remains unclear. We compared the recurrence/residual tissue rates, resection outcomes, and adverse events after ESD and EMR for early BE neoplasia.

METHODS

We included patients who underwent EMR or ESD for BE-associated high grade dysplasia (HGD) or T1a esophageal adenocarcinoma (EAC) at eight academic hospitals. We compared demographic, procedural, and histologic characteristics, and follow-up data. A time-to-event analysis was performed to evaluate recurrence/residual disease and a Kaplan-Meier curve was used to compare the groups.

RESULTS

243 patients (150 EMR; 93 ESD) were included. EMR had lower en bloc (43 % vs. 89 %; P < 0.001) and R0 (56 % vs. 73 %; P = 0.01) rates than ESD. There was no difference in the rates of perforation (0.7 % vs. 0; P > 0.99), early bleeding (0.7 % vs. 1 %; P > 0.99), delayed bleeding (3.3 % vs. 2.1 %; P = 0.71), and stricture (10 % vs. 16 %; P = 0.16) between EMR and ESD. Patients with non-curative resections who underwent further therapy were excluded from the recurrence analysis. Recurrent/residual disease was 31.4 % [44/140] for EMR and 3.5 % [3/85] for ESD during a median (interquartile range) follow-up of 15.5 (6.75-30) and 8 (2-18) months, respectively. Recurrence-/residual disease-free survival was significantly higher in the ESD group. More patients required additional endoscopic resection procedures to treat recurrent/residual disease after EMR (EMR 24.2 % vs. ESD 3.5 %; P < 0.001).

CONCLUSIONS

ESD is safe and results in more definitive treatment of early BE neoplasia, with significantly lower recurrence/residual disease rates and less need for repeat endoscopic treatments than with EMR.

Artificial Intelligence for Detecting and Delineating Margins of Early ESCC Under WLI Endoscopy

INTRODUCTION

Conventional white light imaging (WLI) endoscopy is the most common screening technique used for detecting early esophageal squamous cell carcinoma (ESCC). Nevertheless, it is difficult to detect and delineate margins of early ESCC using WLI endoscopy. This study aimed to develop an artificial intelligence (AI) model to detect and delineate margins of early ESCC under WLI endoscopy.

METHODS

A total of 13,083 WLI images from 1,239 patients were used to train and test the AI model. To evaluate the detection performance of the model, 1,479 images and 563 images were used as internal and external validation data sets, respectively. For assessing the delineation performance of the model, 1,114 images and 211 images were used as internal and external validation data sets, respectively. In addition, 216 images were used to compare the delineation performance between the model and endoscopists.

RESULTS

The model showed an accuracy of 85.7% and 84.5% in detecting lesions in internal and external validation, respectively. For delineating margins, the model achieved an accuracy of 93.4% and 95.7% in the internal and external validation, respectively, under an overlap ratio of 0.60. The accuracy of the model, senior endoscopists, and expert endoscopists in delineating margins were 98.1%, 78.6%, and 95.3%, respectively. The proposed model achieved similar delineating performance compared with that of expert endoscopists but superior to senior endoscopists.

DISCUSSION

We successfully developed an AI model, which can be used to accurately detect early ESCC and delineate the margins of the lesions under WLI endoscopy.

AGA Clinical Practice Update on Surveillance After Pathologically Curative Endoscopic Submucosal Dissection of Early Gastrointestinal Neoplasia in the United States: Commentary

The purpose of this American Gastroenterological Association (AGA) Institute Clinical Practice Update was to review the available evidence and provide expert advice regarding surveillance using endoscopy and other relevant modalities after removal of dysplastic lesions and early gastrointestinal cancers with endoscopic submucosal dissection deemed to be pathologically curative. This Clinical Practice Update was commissioned and approved by the AGA Institute Clinical Practice Updates Committee and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership, and underwent internal peer review by the Clinical Practice Updates Committee and external peer review through standard procedures of Gastroenterology. This expert commentary incorporates important as well as recently published studies in this field, and it reflects the experiences of the authors, who are advanced endoscopists with high-level expertise in performing endoscopic submucosal dissection to treat dysplasia and early cancers in the luminal gastrointestinal tract.

Managing esophageal strictures following endoscopic resection of superficial neoplastic lesions

Over the last few years early esophageal tumors, whether squamous-cell or associated with Barrett's esophagus, have been excised using endoscopic resection techniques, primarily endoscopic submucosal dissection (ESD). Esophageal surgery-associated morbidity and mortality are thus avoided with similar oncologic outcomes. ESD is not without complications, many of which arise and are endoscopically solved during the procedure itself (bleeding, perforation, etc.). Other complications develop within days or weeks after resection, these including mainly esophageal stricture. Esophageal strictures following ESD are initially managed with endoscopic balloon dilation (EBD). Preventive measures have been suggested to alleviate this complication, primarily by using local or systemic steroids in association with early dilation. Even so, not always may they be prevented. Such complications are called refractory strictures, which require either esophageal stents (in a majority of cases) or surgery.

Extracellular vesicles from adipose stromal cells combined with a thermoresponsive hydrogel prevent esophageal stricture after extensive endoscopic submucosal dissection in a porcine model

In this study, we investigated the combination of extracellular (nano) vesicles (EVs) from pig adipose tissue-derived stromal cells (ADSCs) and a thermoresponsive gel, Pluronic® F-127 (PF-127), to prevent stricture formation after endoscopic resection in a porcine model. ADSC EVs were produced at a liter scale by a high-yielding turbulence approach from ADSCs 3D cultured in bioreactors and characterized in terms of size, morphology and membrane markers. The thermoresponsive property of the PF-127 gel was assessed by rheology. The pro-regenerative potency of ADSC EVs was investigated ex vivo in esophageal biopsies under starvation. In vivo tests were performed in a porcine model after extended esophageal endoscopic mucosal dissection (ESD). Pigs were randomized into 3 groups: control (n = 6), gel (n = 6) or a combination of 1.45 × 1012 EVs + gel (n = 6). Application of gel ± EVs was performed just after ESD with a follow-up finalized on day 21 post-ESD. There was a trend towards less feeding disorder in the EV + gel group in comparison with the gel and the control groups (16.67% vs. 66.7% vs. 83.33%, respectively) but without reaching a statistically significant difference. A significant decrease in the esophageal stricture rate was confirmed by endoscopic, radiological and histological examination for the EV + gel group. A decrease in the mean fibrosis area and larger regenerated muscularis mucosae were observed for the EV + gel group. In summary, the application of EVs + gel after extended esophageal endoscopic resection succeeded in preventing stricture formation with an anti-fibrotic effect. This nano-therapy may be of interest to tackle an unmet medical need considering that esophageal stricture is the most challenging delayed complication after extended superficial cancer resection by endoscopy.

Pathogenesis and management of gastrointestinal inflammation and fibrosis: from inflammatory bowel diseases to endoscopic surgery

Gastrointestinal fibrosis is a state of accumulated biological entropy caused by a dysregulated tissue repair response. Acute or chronic inflammation in the gastrointestinal tract, including inflammatory bowel disease, particularly Crohn’s disease, induces fibrosis and strictures, which often require surgical or endoscopic intervention. Recent technical advances in endoscopic surgical techniques raise the possibility of gastrointestinal stricture after an extended resection. Compared to recent progress in controlling inflammation, our understanding of the pathogenesis of gastrointestinal fibrosis is limited, which requires the development of prevention and treatment strategies. Here, we focus on gastrointestinal fibrosis in Crohn’s disease and post-endoscopic submucosal dissection (ESD) stricture, and we review the relevant literature.

Novel hybrid endoscopy-assisted larynx-preserving esophagectomy for cervical esophageal cancer (with video)

Hybrid endoscopy-assisted larynx-preserving esophagectomy is developed for cervical esophageal squamous cell carcinoma encroaching or extending above the upper esophageal sphincter. First, a cervical incision was surgically performed followed by cervical lymph node dissection. Second, the margin of cervical esophageal squamous cell carcinoma was endoscopically identified with iodine staining and marked endoscopically followed by semi-circumferential or circumferential endoscopic full-thickness excision around the lumen of the esophagus. The distal margin was surgically resected and reconstruction was performed. Among six consecutive patients with cervical esophageal squamous cell carcinoma undergoing hybrid endoscopy-assisted larynx-preserving esophagectomy, proximal surgical margin was histologically negative in five patients. During a median follow-up period of 15.5 months, all patients tolerated oral intake and were alive without evidence of recurrence. None of the patients experienced aspiration pneumonia, vocal disorder or postoperative anastomotic stricture. Hybrid endoscopy-assisted larynx-preserving esophagectomy could be a clinically feasible treatment for cervical esophageal squamous cell carcinoma providing accurate proximal resection margin with the benefit of laryngeal function preservation.

A Review of Endoscopic Full-thickness Resection, Submucosal Tunneling Endoscopic Resection, and Endoscopic Submucosal Dissection for Resection of Subepithelial Lesions

Gastrointestinal subepithelial tumors (SETs) are often found while performing routine endoscopy. Recently, there has been the development of new endoscopic techniques such as endoscopic submucosal dissection, submucosal tunnel endoscopic resection, and endoscopic full-thickness resection, all minimally invasive approaches which have made it possible to resect SETs that were previously resected with surgery. This review discusses the endoscopic treatment of patients with SETs, outcomes for endoscopic treatment, procedure-related complications, and advantages and disadvantages of these endoscopic techniques.

Clinical outcomes of endoscopic resection of preoperatively diagnosed non-circumferential T1a-muscularis mucosae or T1b-submucosa 1 esophageal squamous cell carcinoma

In Japan, preoperatively diagnosed T1a-muscularis mucosae or T1b-submucosa 1 (MM/SM1) esophageal squamous cell carcinoma (ESCC) is a relative indication for endoscopic resection (ER). We evaluated long-term outcomes in patients after ER for non-circumferential ESCC with a preoperative diagnosis of MM/SM1 invasion. We retrospectively reviewed 66 patients with a preoperative diagnosis of non-circumferential MM/SM1 ESCC endoscopically resected between 2010 and 2015. Patients were divided into low- (adequate follow-up) and high-risk (requiring additional treatment) groups for lymph node metastasis according to risk factors (submucosal invasion, lymphovascular invasion, or droplet infiltration) and long-term outcomes were analyzed. Pathological invasion to T1a-lamina propria mucosa, MM/SM1, and T1b-SM2 was seen in 22, 38, and 6 lesions, respectively. Overall, 71.2% patients were classified into the "adequate follow-up" group. Of these, only one patient had a lymph node recurrence, which was successfully treated by additional therapy. The remaining 28.8% patients were classified into the "requiring additional treatment" group, where no recurrences were observed after additional treatments. After a median follow-up of 58.6 months, no deaths happened due to ESCC. The 3- and 5-year overall survival rates were 93.6% and 88.7%, respectively. ER is a valid initial treatment for non-circumferential ESCC with preoperatively diagnosed MM/SM1 invasion.

Efficacy of oral steroid gel in preventing esophageal stricture after extensive endoscopic submucosal dissection: a randomized controlled trial

BACKGROUND AND AIMS

Esophageal stricture is a distressing issue for patients with early esophageal cancer following extensive endoscopic submucosal dissection (ESD), and the current steroid-based approaches are unsatisfactory for stricture prophylaxis. We evaluated the efficacy of oral hydrocortisone sodium succinate and aluminum phosphate gel (OHA) for stricture prophylaxis after extensive ESD.

METHODS

Patients undergoing > 3/4 circumferential ESD were randomized to either the endoscopic loco-regional triamcinolone acetonide injection (ETI) plus oral prednisone group or the OHA group. The primary endpoint was incidence of esophageal stricture, and the secondary endpoints included adverse events (AEs) and endoscopic balloon dilations (EBDs).

RESULTS

The incidence of esophageal stricture in OHA group (per-protocol analysis, 9.4%, 3/32; intention-to-treat analysis, 12.1%, 4/33) was significantly less than that of control group (per-protocol analysis, 35.5%, 11/31, P = 0.013; intention-to-treat analysis, 39.4%, 13/33, P = 0.011). Two sessions of EBD were necessary to release all strictures in the OHA group, while the similar EBDs (median 2, range 1-4) for 11 of the control. Operation-related AEs included infection (control vs. OHA group = 9.7% vs. 31.3%, P = 0.034), operation-related hypokalemia (19.4% vs. 31.3%, P = 0.278), perforation (3.2% vs. 3.1%), post-ESD hemorrhage (6.5% vs. 0%), and cardiac arrhythmia (0% vs. 6.3%). Steroid-related AEs included steroid-related hypokalemia (16.1% vs. 25%) and bone fracture (3.2% vs. 0%). Multivariate logistic regression analysis demonstrated that OHA was an independent protective factor for stricture (OR 0.079; 95%CI 0.011, 0.544; P = 0.01) and mucosal defect > 11/12 circumference was an independent risk factor (OR 49.91; 95%CI 6.7, 371.83; P < 0.001).

CONCLUSIONS

OHA showed significantly better efficacy in preventing esophageal stricture after > 3/4 circumferential ESD compared to ETI plus oral prednisone.

Prevention of Stricture after Endoscopic Submucosal Dissection for Superficial Esophageal Cancer: A Review of the Literature

Endoscopic resection has been the standard treatment for intramucosal esophageal cancers (ECs) because of the low risk of lymph node metastases in the lesions. In recent years, endoscopic submucosal dissection (ESD), which can resect large ECs, has been performed. However, the risk of esophageal stricture after ESD is high when the mucosal defect caused by the treatment exceeds 3/4 of the circumference of the lumen. Despite the subsequent high risk of luminal stricture, ESD has been performed even in cases of circumferential EC. In such cases, it is necessary to take measures to prevent stricture. Therefore, in this review, we aimed to clarify the current status of stricture prevention methods after esophageal ESD based on previous literature. Although various prophylactic methods have been reported to have stricture-preventing effects, steroid injection therapy and oral steroid administration are mainstream. However, in cases of circumferential EC, both steroid injection therapy and oral steroid administration cannot effectively prevent luminal stricture. To solve this issue, clinical applications, such as tissue shielding methods with polyglycolic acid sheet, autologous oral mucosal epithelial sheet transplantation, and stent placement, have been developed. However, effective prophylaxis of post-ESD mucosal defects of the esophagus is still unclear. Therefore, further studies in this research field are needed.

Advances in the Prevention and Treatment of Esophageal Stricture after Endoscopic Submucosal Dissection of Early Esophageal Cancer

Endoscopic submucosal dissection (ESD) has become the main treatment for early esophageal cancer. While treating the disease, ESD may also cause postoperative esophageal stricture, which is a global issue that needs resolution. Various methods have been applied to resolve the problem, such as mechanical dilatation, glucocorticoids, anti-scarring drugs, and regenerative medicine; however, no standard treatment regimen exists. This article describes and evaluates the strengths and limitations of new and promising potential strategies for the treatment and prevention of esophageal strictures.

Effectiveness of fibrin sealant as a hemostatic technique in accelerating endoscopic submucosal dissection-induced ulcer healing and preventing stricture in the esophagus: A retrospective study

The aim of the present retrospective study was to evaluate the effectiveness of conservative electrocoagulation followed by porcine fibrin sealant (FS) as a protective hemostatic technique for wounded microvessels in promoting the healing of endoscopic submucosal dissection (ESD)-induced ulcer, and preventing esophageal strictures that follow ESD. A total of 203 patients with early esophageal cancer or precancerous lesions were retrospectively analyzed. The 1-month ulcer healing and stricture rates were compared between the two groups (combined hemostats and electrocautery groups). The 1-month complete healing rate was 77.0% in the combined hemostats group and 52.6% in the electrocautery group (P=0.003). The use of FS and a smaller resected range (<3/4 circumference) was associated with a better 1-month healing rate. For patients with a ≥3/4 circumference mucosal defect, the esophageal stricture rate was 31.6% (6/19) in the combined hemostats group and 25.0% (2/8) in the electrocautery group. There was no difference in the stricture rate (P=0.737) and dilation time (P=0.733) between the two groups. In conclusion, the application of conservative electrocoagulation followed by porcine FS as a wound-protection technique promoted ESD-induced ulcer healing in the esophagus. However, this combined hemostatic technique was not superior to the conventional hemostatic method in preventing post-ESD stricture in patients with large esophageal mucosal defects.

Esophageal regenerative therapy using cell sheet technology

We have been conducting research on esophageal regenerative therapy using cell sheet technology. In particular, in the endoscopic field, we have pushed forward clinical research on endoscopic transplantation of cultured autologous oral mucosal epithelial cell sheets to esophageal ulcer after endoscopic submucosal dissection (ESD). We started research in this direction using animal models in 2004 and performed clinical research in 2012 in collaboration with Nagasaki University and Karolinska Institute. Although in full-circumferential cases it was difficult to prevent esophageal stricture after ESD, there were no complications and stricture could be suppressed. The cell sheet technology is still in its infancy. However, we are convinced that it has a high potential for application in various areas of gastrointestinal science. In this review, we focus on the pre-clinical and clinical trial results obtained and on the theoretical aspects of (1) stricture prevention, (2) esophageal tissue engineering research, and (3) endoscopic transplantation, and review the esophageal regenerative therapy by cell sheet technology.

Risk factors and clinical outcomes of endoscopic dilation in benign esophageal strictures: a long-term follow-up study

BACKGROUND AND AIMS

Endoscopic dilation (ED) is still the mainstay of therapeutic management of benign esophageal strictures (BESs). This study aimed to establish risk factors for refractory BESs and assess long-term clinical outcomes of ED.

METHODS

We performed a retrospective study in 891 patients who underwent ED from 2003 to 2018 for BESs. We searched electronic medical records in 6 tertiary care centers in the Netherlands for data on clinical outcome of ED. Median follow-up was 39 months. The primary endpoint was risk factors for refractory BESs, defined as factors associated with an increased number of ED sessions during follow-up. Secondary endpoints were time from first to last ED session and adverse events.

RESULTS

Dilation up to 13 to 15 mm was associated with a higher number of ED sessions than dilation up to 16 to 18 mm (5.0 vs 4.1; hazard ratio [HR], 1.4; P = .001). Compared with peptic strictures, anastomotic (4.9 vs 3.6; HR, 2.1; P < .001), radiation (5.0 vs 3.6; HR, 3.0; P < .001), caustic (7.2 vs 3.6; HR, 2.7; P < .001), and postendotherapy (3.9 vs 3.6; HR, 1.8; P = .005) strictures were associated with a higher number of ED sessions. After 1 year of follow-up, the proportions of patients who remained free of ED was 75% in anastomotic, 71% in radiation, 70% in peptic, 83% in postendotherapy, and 62% in caustic strictures. Esophageal perforation occurred in 23 ED sessions (.4%) in 22 patients (2.4%).

CONCLUSIONS

More than 60% of patients with BESs remain free of ED after 1 year of follow-up. Because dilation up to 16 to 18 mm diameter was associated with fewer ED sessions during follow-up, we suggest that clinicians should consider dilation up to at least 16 mm to reduce the number of ED sessions in these patients.

Efficacy and safety of endoscopic submucosal tunnel dissection for superficial esophageal neoplastic lesions: a systematic review and meta-analysis

Background

Presently, endoscopic submucosal tunnel dissection (ESTD) has been a novel therapy for superficial esophageal neoplastic lesions (SENL), especially for circumferential neoplastic lesions. A number of studies have reported the clinical application of ESTD with promising outcomes. Therefore, we conducted a systematic review and meta-analysis to evaluated the efficacy and safety of ESTD for SENL .

Methods

From 2013 to November 2018, Pubmed, Embase and Cochrane databases were searched to determine studies reporting ESTD treatment of SENL. Weighted pooled rates (WPR) were calculated for en bloc resection, R0 resection and complication of ESTD. Risk ratios (RR) were calculated and pooled to compare the clinical outcomes of ESTD with ESD for SENL.

Results

A total of 9 studies involving 494 patients with 518 esophageal neoplastic lesions were included in our study. WPR for en bloc resection and R0 resection of ESTD was 97.0% (95% CI: 94.7–98.3%) and 84.1% (95% CI: 80.5–87.1%), respectively. WPR for complication was 40.0% (95% CI: 25.8–56.1%). Two studies with 265 patients compared the performance of ESTD with ESD. Pooled RR for en bloc resection and R0 resection was 1.04 (95% CI: 0.95–1.14, P = 0.42) and 1.01 (95% CI: 0.93–1.10, P = 0.73), respectively. Pooled RR for complication was 0.68 (95% CI: 0.46–1.01, P = 0.05).

Conclusion

Our study showed that ESTD is effective for treating SENL with high en bloc resection rate and R0 resection rate, but accompanying by a relatively high complications.

Clinical relevance of fluorodeoxyglucose positron emission tomography/computed tomography and magnifying endoscopy with narrow band imaging in decision-making regarding the treatment strategy for esophageal squamous cell carcinoma

BACKGROUND

Recent advances in endoscopic technology, especially magnifying endoscopy with narrow band imaging (ME-NBI) enable us to detect superficial esophageal squamous cell carcinoma (ESCC), but determining the appropriate method of resection, endoscopic resection (ER) vs surgical resection, is often challenging. Recently, several studies have reported that ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET) is a useful indicator for decision-making regarding treatment for superficial ESCC. Although, there are not enough reports on association between FDG-PET uptake and clinicopathological characteristics of superficial ESCC. And, there are not enough reports on evaluating the usefulness of combination of FDG-PET and ME-NBI for determining the treatment strategy for superficial ESCC. This study evaluated clinical relevance of FDG-PET and ME-NBI in decision-making regarding the treatment strategy for ESCC.

AIM

To investigate the association between FDG uptake and the clinicopathological characteristics of superficial ESCC and its usefulness of combination of FDG-PET and ME-NBI for determining the treatment strategy for superficial ESCC.

METHODS

A database of all patients with superficial ESCC who had undergone both ME-NBI and FDG-PET for pre-treatment staging at Aichi Cancer Center Hospital between January 2008 and November 2018 was retrospectively analyzed. FDG uptake was defined positive or negative whether the primary lesion was visualized or could be distinguished from the background, or not. The invasion depth of ESCC was classified according to the Japan Esophageal Society. Primary endpoint is to evaluate the association between FDG uptake and clinicopathological characteristics of superficial ESCC. Secondary endpoint is to investigate the efficacy of combination of FDG-PET and ME-NBI for determining the treatment strategy for superficial ESCC.

RESULTS

A total of 82 lesions in 82 patients were included. FDG-PET showed positive uptake in 29 (35.4%) lesions. Univariate analysis showed that uptake of FDG-PET had significant correlations with circumferential extension (P = 0.014), pathological depth of tumor invasion (P < 0.001), infiltrative growth pattern (P < 0.001), histological grade (P = 0.002), vascular invasion (P = 0.001), and lymphatic invasion (P < 0.001). On multivariate analysis, only depth of tumor invasion was independently correlated with FDG-PET/computed tomography visibility (P = 0.018). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of Type B2 in ME-NBI for the invasion depth of T1a muscularis mucosae and T1b upper submucosal layer were 68.4%/79.4%/50.0%/89.3%/76.8%, respectively, and those of Type B3 for the depth of T1b middle and deeper submucosal layers (SM2 and SM3) were 46.7%/100%/100%/89.3%/90.2%, respectively. On the other hand, those of FDG-PET for SM2 and SM3 were 93.3%/77.6%/48.2%/98.1%/80.5%, respectively, whereas, if the combination of positive FDG uptake and type B2 and B3 was defined as an indicator for radical esophagectomy or definitive chemoradiotherapy, the sensitivity, specificity, PPV, NPV, and accuracy were 78.3%/91.5%/78.3%/91.5%/87.8%, respectively.

CONCLUSION

FDG uptake was correlated with the invasion depth of superficial ESCC. Combined use of FDG-PET and ME-NBI, especially with the microvascular findings of Type B2 and B3, is useful to determine whether ER is indicated for the lesion.

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.

Stricture Prevention after Extensive Endoscopic Submucosal Dissection of Neoplastic Barrett's Esophagus: Individualized Oral Steroid Prophylaxis

Introduction

Endoscopic resection (ER) exceeding ≥75% of the esophageal circumference is accompanied with a high stricture risk regardless of the resection method. The ideal strategy for stricture prevention is not well defined today. Different approaches have been reported but data are limited to the resection of squamous cell neoplasia. The aim of this study was to assess the efficacy of an individualized oral steroid regimen to prevent strictures after extensive ER in neoplastic Barrett's esophagus (NBE).

Materials and Methods

Over a 50-month period, endoscopic submucosal dissection (ESD) was performed in 193 patients with NBE. 23 patients with resections exceeding 75% of the circumference were included. 19 resection ulcers were noncircumferential (NCR) while 4 were circumferential (CR). Stricture prevention was performed using oral prednisolone starting with a daily dose of 50 mg and standard tapering over 8 weeks (50/40/30/25/20/15/10/5 mg). Tapering was individualized according to the ulcer healing process (assessed endoscopically in the first tapering period and before stopping the steroids). Data were analyzed retrospectively.

Results

Stricture rates were 5.3% (1/19) for NCR and 100% (4/4) for CR (p < 0.001). The only stricture in the NCR group was seen in a patient who had stopped steroids without any reason after few days. 12/19 patients received standard tapering over 8 weeks (63.1%). According to the individual ulcer healing, treatment was prolonged to 9-10 weeks in 4/19 (21.1%) and shortened to 7 weeks in another 2/19 (10.5%). After CR, all patients needed endoscopic balloon dilatation (median 6.5 sessions; range 3-14 sessions for 8-40 weeks). Side effects of the steroid therapy were not noted.

Conclusion

Oral prednisolone therapy with an endoscopy-based individualized tapering regimen is effective in avoiding strictures after NCR of Barrett's neoplasia. After CR, the stricture risk is not sufficiently decreased. CR should be restricted to circumferential neoplasia which is a very rare scenario in neoplastic BE.

Clinical feasibility of endoscopic submucosal dissection with minimum lateral margin of superficial esophageal squamous cell carcinoma

Background  Esophageal stricture following endoscopic submucosal dissection (ESD) for superficial esophageal squamous cell cancer (SESCC) has been associated with wide mucosal defects greater than three-quarters of the luminal circumference. Some patients developed dysphagia and required repeated endoscopic balloon dilation even after steroid therapy. As iodine staining clearly visualized the margin of SESCC, we made a longitudinal mucosal incision close to the margin of the lesion to avoid a mucosal defect involving over three-quarters of the luminal circumference for large lesions. This retrospective study aimed to clarify the clinical feasibility of ESD with minimum lateral margin of SESCC. Patients and methods  Between 2005 and 2013, 94 patients with 94 initial SESCCs had lesions greater than half of the luminal circumference. Of those, 70 patients with 70 SESCCs had achieved endoscopic clearance for the initial SESCC. In this study, endoscopic clearance was defined as en bloc resection of SESCC histologically confined to the mucosa without lymphovascular invasion and with a free deep margin regardless of the lateral margin. This study evaluated the short- and long-term outcomes in patients undergoing endoscopic clearance. Results  In total, 61.4 % (43/70) of the patients had mucosal defects involving over three-quarters of the luminal circumference and 38.5 % (27/70) had a positive or indeterminate lateral margin. However, there was no local or nodal recurrence during the median follow-up period of 3.8 years; the 3-year overall survival rate was 98.5 % and the 3-year disease-free survival rate was 100 %. Conclusion  Using our institutions' strategy, ESD for SESCCs with minimum lateral margins was oncologically acceptable; this approach could reduce the known risk factor of post-ESD stricture.

Management of adverse events related to endoscopic resection of upper gastrointestinal neoplasms: Review of the literature and recommendations from experts

Prevention therapy is recommended for lesions >1/2 of the esophageal circumference. Locoregional steroid injection is recommended for lesions >1/2-3/4 of the esophageal circumference and oral steroids are recommended for lesions >1/2 of the subtotal circumference. For lesions of the entire circumference, oral steroid combined with injection steroid is considered. Endoscopic balloon dilatation (EBD) is the first choice of treatment for stricture after esophageal endoscopic submucosal dissection (ESD). Radical incision and cutting or self-expandable metallic stent can be considered for refractory stricture after EBD. In case of intraoperative perforation during esophageal ESD, endoscopic clip closure should be initially attempted. Surgery is considered for treatment of delayed perforation. Current standard practice for prevention of delayed bleeding after gastric ESD includes prophylactic coagulation of vessels on post-ESD ulcers and giving proton pump inhibitors. Chronic kidney disease stage 4 or 5, multiple antithrombotic drug use, anticoagulant use, and heparin bridging therapy are high-risk factors for delayed bleeding after gastric ESD. Intraoperative perforation during gastric ESD is initially managed by endoscopic clip closure. If endoscopic clip closure is difficult, other methods such as over-the-scope clip (OTSC), polyglycolic acid (PGA) sheet shielding etc. are attempted. Delayed perforation usually requires surgical intervention, but endoscopic closure by OTSC or PGA sheet may be considered. Resection of three-quarters of the circumference is a risk factor for stenosis after gastric ESD. Giving prophylactic local steroid injection and/or oral steroid is reported, but effectiveness has not been fully verified as has been done for esophageal stricture. The main management method for gastric stenosis is EBD but it may cause perforation.

Roles of Steroids in Preventing Esophageal Stricture after Endoscopic Resection

BACKGROUND AND PURPOSES

Endoscopic resection has been worldwide recognized as a treatment strategy for early esophageal lesions. The occurrence of esophageal stricture after endoscopic resection will reduce the quality of life of patients. This study will evaluate the efficacy and safety of steroids in the prevention of esophageal stricture after endoscopic resection and the influence of different steroid administration methods.

METHODS

In the relevant literature database, literature from 2008 to 2018 is retrieved by using preset keywords, the search results are carefully screened, and the conclusion of the literature is synthesized to form arguments and draw conclusions.

RESULTS

73 articles met our requirements. Oral steroid administration, not prophylactic endoscopic balloon dilation alone, was effective in preventing esophagostenosis after esophagoscopic treatment and reducing the number of repeated endoscopic balloon dilations even after extensive endoscopic resection. Local steroid injection is useful and economy for preventing esophageal stricture, even though it may raise the risk of perforation during dilations. A wider range of circumferential mucosal defects is an independent predictor for stricture formation for patents given preventive steroid injections after endoscopic submucosal dissection. For complete circular mucosal defect, the further researches are essential to investigate the role of local steroid injection. The effect of other methods such as steroid gel, intravenous infusion of steroid, and novel steroid filling methods require more confirmation.

CONCLUSIONS

Therefore, steroids play an irreplaceable role in preventing esophageal stricture after endoscopic resection. Oral and local injections of steroids are the two most acceptable methods and more prospective studies are needed to compare the effectiveness and safety of these two 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.

Efficacy of triamcinolone-soaked polyglycolic acid sheet plus fully covered metal stent for preventing stricture formation after large esophageal endoscopic submucosal dissection

Esophageal stricture is a major problem for patients with large superficial esophageal squamous cell neoplasms (SESCNs) after endoscopic submucosal dissection (ESD). Although many measures could be used as prophylaxis for post-ESD strictures, a well-accepted method has not yet been established. We propose using a triamcinolone-soaked polyglycolic acid sheet plus fully covered metal stent (TS-PGA+FCMS) as a novel method to prevent stricture formation after large esophageal ESD. From June 2016 to May 2017, nine patients with SESCNs (≥3/4 of the esophageal circumference) who underwent TS-PGA+FCMS placement immediately after ESD and did not require additional surgical resection were enrolled in this case series. All stents were removed 4-6 weeks post-ESD. The sizes of mucosal defects in 9 patients were 3/4 (n = 1), 4/5 (n = 2), 1/1 (n = 6). The average size of resection was 90.0 mm (range: 60-140 mm). The incidence of stricture was 33.3% (3/9) of patients. No stricture occurred in 3 patients with noncircumferential resection, while stricture occurred in 50% (3/6) patients with circumferential resection. The median number of EBD sessions was 4 (range: 3-4 sessions). No adverse events or recurrences were observed during the median follow-up period of 15.2 months (range: 12-22 months). The TS-PGA+FCMS method is safe and may decrease the incidence of esophageal stricture and the number of EBD sessions after large esophageal ESD.

Autologous Flap Transfer for Esophageal Stricture Prevention After Endoscopic Submucosal Dissection in a Porcine Model

BACKGROUND

Esophageal stricture caused by endoscopic submucosal dissection for a mucosal defect that covers more than three quarters of the circumference of the esophagus has a high incidence. To date, no method for preventing such strictures has been widely recognized as effective in clinical practice.

AIMS

We examined whether esophageal stricture caused by circumferential endoscopic submucosal dissection could be prevented by autologous flap transfer.

METHODS

Six pigs (N = 6) underwent circumferential esophageal endoscopic submucosal dissection under general anesthesia. For animals in the flap group (N = 3), an autologous flap was constructed and then placed at the resection site and secured with metal clips. Animals in the control group (N = 3) underwent endoscopic submucosal dissection only. Endoscopy was performed 3 weeks postoperative to evaluate the effects of flap transfer.

RESULTS

Animals in the flap group gained more weight than animals in the control group. At 3 weeks postoperative, animals in the flap group developed clinically slight stricture; in these animals, an endoscope could be passed through the stricture with slight resistance. In contrast, in the control group, significant stricture was observed, and the stricture was difficult to cross with an endoscope.

CONCLUSION

Autologous flap transfer after circumferential esophageal endoscopic submucosal dissection is a novel approach that remarkably decreases the degree of esophageal stricture that arises.

Deployment of carboxymethyl cellulose sheets to prevent esophageal stricture after full circumferential endoscopic submucosal dissection: A porcine model

BACKGROUND AND AIM

Esophageal stricture is a serious adverse event secondary to extensive endoscopic submucosal dissection (ESD). The present study aimed to investigate the efficacy of carboxymethyl cellulose (CMC) sheets for the prevention of esophageal stricture after full circumferential ESD in an animal model.

METHODS

Fourteen porcine models were randomized into a control group (n = 7) and a CMC group (n = 7). Five-centimeter-long circumferential esophageal ESD was carried out at a distance of 40 to 45 cm from the incisors in all models. In the CMC group, CMC sheets were placed over the mucosal defect completely after ESD, whereas the control group underwent routine ESD only. Endoscopic examination was conducted after the first and second week post-ESD. Esophageal specimens were harvested during post-mortem and were evaluated for macroscopic and histological appearance. Blood serum levels of four pro-inflammatory or profibrotic cytokines were measured quantitatively.

RESULTS

The CMC group had better food tolerability during the second week post-ESD. The CMC group showed a significantly lower esophageal mucosal stricture rate compared to the control group. Histological assessments showed less fibrosis in the submucosal layer, milder damage to the muscularis propria, and enhanced re-epithelization in the CMC group. Serum transforming growth factor beta 1 levels were significantly lower in the CMC group post-ESD.

CONCLUSION

Deployment of CMC sheets on the mucosal defect appears to be a promising method for preventing esophageal strictures after extensive ESD.

Endoscopic submucosal dissection for superficial esophageal cancer

Endoscopic submucosal dissection (ESD) has evolved into a viable treatment modality for superficial esophageal cancer. ESD offers a distinct advantage given the ability to perform en bloc resection enabling accurate histopathologic assessment. Data from published literature has established ESD as the preferred option in the treatment of superficial squamous cell carcinoma with complete resection rates of 78-100%, and a low rate recurrence of 0-2.6%. En bloc resection for esophageal SCC is curative for tumors with M1 (intrapethelial) or M2 (invasion into the lamina propria) involvement with no lymphovascular invasion. Tumors that contain lymphovascular invasion or submucosal invasion greater than 200 μm should be treated as advanced carcinomas due to the increased risk of lymph node metastasis. In contrast, the role of ESD in Barrett's esophagus is more limited due to the high rate of efficacy of EMR. A randomized control trial comparing EMR and ESD strategies found a higher R0 resection rate for ESD, but no significant difference in complete remission from neoplasia at 3 month follow up. Endoscopic ultrasound (EUS) has a limited role in the evaluation of superficial esophageal cancer. Alternatively, detailed endoscopic assessment along with magnification endoscopy or narrow band imaging, may provide greater utility than EUS. The most common adverse events of ESD in the esophagus include perforation and stricture. Perforation can often be managed by defect closure along with non-operative conservative management. Steroid administration with either topical or local injection can be effective management in stricture prevention. Continued refinement of ESD technique and innovation will overcome some of the current limitations of ESD and enable curative resection of superficial esophageal cancer as an alternative to invasive surgery.