A pilot study of scheduled endoscopic balloon dilation with oral agent tranilast to improve the efficacy of stricture dilation after endoscopic submucosal dissection of the esophagus

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

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

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.

Strategy of targeting the tumor microenvironment via inhibition of fibroblast/fibrosis remodeling new era to cancer chemo-immunotherapy resistance

The use of repurposing drugs that may have neoplastic and anticancer effects increases the efficiency and decrease resistance to chemotherapy drugs through a biochemical and mechanical transduction mechanisms through modulation of fibroblast/fibrosis remodeling in tumor microenvironment (TME). Interestingly, fibroblast/fibrosis remodeling plays a vital role in mediating cancer metastasis and drug resistance after immune chemotherapy. The most essential hypothesis for induction of chemo-immunotherapy resistance is via activation of fibroblast/fibrosis remodeling and preventing the infiltration of T cells after is mainly due to the interference between cytoskeleton, mechanical, biochemical, metabolic, vascular, and remodeling signaling pathways in TME. The structural components of the tumor that can be targeted in the fibroblast/fibrosis remodeling include the depletion of the TME components, targeting the cancer-associated fibroblasts and tumor associated macrophages, alleviating the mechanical stress within the ECM, and normalizing the blood vessels. It has also been found that during immune-chemotherapy, TME injury and fibroblast/fibrosis remodeling causes the up-regulation of inhibitory signals and down-regulation of activated signals, which results in immune escape or chemo-resistance of the tumor. In this regard, repurposing or neo-adjuvant drugs with various transduction signaling mechanisms, including anti-fibrotic effects, are used to target the TME and fibroblast/fibrosis signaling pathway such as angiotensin 2, transforming growth factor-beta, physical barriers of the TME, cytokines and metabolic factors which finally led to the reverse of the chemo-resistance. Consistent to many repurposing drugs such as pirfenidone, metformin, losartan, tranilast, dexamethasone and pentoxifylline are used to decrease immune-suppression by abrogation of TME inhibitory signal that stimulates the immune system and increases efficiency and reduces resistance to chemotherapy drugs. To overcome immunosuppression based on fibroblast/fibrosis remodeling, in this review, we focus on inhibitory signal transduction, which is the physical barrier, alleviates mechanical stress and prevents mechano-metabolic activation.

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

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

Anti-cancer effects of Tranilast: An update

Tranilast (TRN) or (N-3,4 -dimethoxy cinnamoyl]-anthranilic acid) is an analog of a tryptophan metabolite and is identified mainly as an anti-allergic agent with limited side effects. The anti-cancer effects of tranilast either alone or in combination with chemotherapeutic drugs have been evidenced in several pre-clinical studies. The main mechanism of action of tranilast includes targeting and modulation of various signaling and immune regulatory pathways including Transforming growth factor-beta (TGF-β), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), phosphatidylinositol 3-kinase (PI3K), MAP-Kinase (MAPK), Protein kinase B (‎Akt/PKB), c-Jun N-terminal kinase, modulation of cancer stem cells, etc. Most of these pathways are involved in tumor proliferation, invasion, and metastasis and it is postulated that tranilast, with its low toxicity profile and high anti-carcinogenic abilities, can serve as a potential anti-tumorigenic agent. The main aim of this review is to provide updated information on the anti-cancer effects of tranilast and its significance as a therapeutic agent.

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.

Preventing esophageal strictures with steroids after endoscopic submucosal dissection in superficial esophageal neoplasm

OBJECTIVES

This study aimed to investigate the efficacy of prophylactic steroid administration in preventing post-endoscopic submucosal dissection (ESD) esophageal stricture and to determine risk factors for these strictures.

METHODS

Patients who underwent ESD for superficial esophageal neoplasms with a mucosal defect affecting >75% of the esophageal circumference between January 2011 and August 2016 were eligible. Patients were classified into three groups, including ESD-alone group (n = 22), oral steroid group (n = 25) and intralesional steroid injection group (n = 6). Univariate and multivariate logistic regression analyses were performed to evaluate the risk factors for esophageal stricture.

RESULTS

The stricture rate was 50.0%, 20.0% and 33.3% in the ESD-alone group, oral steroid group and steroid injection group, respectively. Patients treated with steroids had a significantly lower stricture rate than the ESD-alone group (22.6% vs 50.0%, P = 0.046). Additionally, oral steroid group had a significantly lower stricture rate than the ESD-alone group (P = 0.037). Multivariate analysis revealed that the extent of the circumferential mucosal defect was a significant risk factor for post-ESD strictures (odds ratio [OR] 13.015, 95% confidence interval [CI] 2.257-76.077, P = 0.004). The administration of steroids (OR 0.108, 95% CI 0.020-0.578, P = 0.009), specifically oral steroids (OR 0.109, 95% CI 0.019-0.622, P = 0.013), was associated with prevention of post-ESD strictures.

CONCLUSION

Oral steroid prophylaxis appears to be a safe and effective treatment in preventing post-ESD stricture and improving patients' quality of life.

Strategies to prevent stricture after esophageal endoscopic submucosal dissection

Endoscopic submucosal dissection (ESD) has been widely applied as a less invasive and more effective method for treating early esophageal cancers such as squamous cell carcinoma and dysplasia of Barrett's esophagus. However, post-ESD esophageal stricture often occurs if patients suffer circumferential mucosal defects of more than three-quarters of the circumference of the esophagus, which makes it difficult for patients to swallow and greatly reduces their quality of life. Moreover, there is currently no standard method to treat post-ESD esophageal stricture, even though it is extraordinarily important to prevent its formation. In recent years, several strategies to prevent esophageal stricture have emerged. These strategies can be classified into pharmacological, mechanical, tissue engineering, and other novel strategies, with each strategy having its own strengths and weaknesses. Although the pharmacological prophylaxis and mechanical strategies are relatively mature, they still have their drawbacks like high time-consumption, the occurrence of re-stricture, and significant side effects. Tissue engineering strategies and other novel strategies have shown promising preliminary results, but more clinical trials are needed. In this review, we discuss these strategies, with a particular focus on tissue engineering strategies and other novel strategies. It is hoped that this discussion will aid in finding more effective and safer strategies to prevent esophageal 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.

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.

Long-term efficacy and safety of intralesional steroid injection plus oral steroid administration in preventing stricture after endoscopic submucosal dissection for esophageal epithelial neoplasms

BACKGROUND

Endoscopic submucosal dissection (ESD) has been widely accepted as the treatment for early-stage esophageal epithelial neoplasms. However, stricture is a common complication after large-circumference ESD. This retrospective study is conducted to evaluate the efficacy and safety of intralesional steroid injection plus oral steroid administration in preventing esophageal stricture.

METHODS

70 patients with a mucosal defect extending over more than two-thirds of the circumference after esophageal ESD for epithelial neoplasms were enrolled in this study. Those who received intralesional triamcinolone injection combined with oral prednisolone administration were assigned to the treatment group, while those who were treated without any prophylaxis of esophageal stricture were assigned to the control group. The primary observation result was the frequency of stricture. The secondary observation results were the number of endoscopic balloon dilation (EBD) sessions and rate of complications.

RESULTS

Compared with the control group, the frequency of stricture (14.7% 5/34 patients vs. 51.5% 19/36 patients) and number of EBD sessions (mean 0.2 vs. 3.3) were significantly lower in the treatment group. One patient suffered from perforation in the treatment group and recovered with conservative treatment. None steroid-related complications were found during a long-term follow-up.

CONCLUSIONS

Intralesional steroid injection plus oral steroid administration is safe and effective in preventing stricture following esophageal ESD for esophageal epithelial neoplasms with a mucosal defect extending no less than two-thirds of the circumference in a long-term follow-up.

Progress on the Prevention of Esophageal Stricture after Endoscopic Submucosal Dissection

Endoscopic submucosal dissection (ESD) has been widely accepted as an effective, minimally invasive treatment for superficial esophageal cancers. However, esophageal stricture often occurs in patients with large mucosal defects after ESD. In this review, we discuss various approaches recently researched to prevent esophageal strictures after ESD. These approaches can be classified as pharmacological treatments, esophageal stent treatments, and tissue engineering approaches. Most of the preventive approaches still have their limitations and require further research. With the improvement of current therapies, ESD can be more widely utilized as a minimally invasive treatment with minimal complications.

Approaches for stricture prevention after esophageal endoscopic resection

BACKGROUND AND AIMS

Endoscopic resection of extensive esophageal lesions has become more common as endoscopic resection techniques and equipment have developed. However, extensive esophageal endoscopic resections can cause postoperative esophageal strictures, which have a negative impact on the quality of life of patients. We aimed to review current treatments and innovative approaches to prevent esophageal strictures after widespread endoscopic resection of esophageal lesions.

METHODS

We performed a comprehensive literature search from 2000 to 2016 using predetermined search terms to identify relevant articles and summarized their results as a narrative review.

RESULTS

A total of 21 original articles and case series were identified. A circumferential mucosal defect involving more than three fourths of the esophageal luminal circumference was the primary risk factor for developing an esophageal stricture after endoscopic resection. Oral and injectable steroid therapy demonstrated promise in preventing post-endoscopic submucosal dissection esophageal strictures, with both strategies significantly reducing the number of required endoscopic balloon dilations. More data are needed on prophylactic self-expandable metal stents, local botulinum toxin injection, and oral tranilast as a strategy to prevent post-endoscopic submucosal dissection esophageal strictures. Although preliminary studies of tissue-shielding resection sites with polyglycolic acid sheets and fibrin glue and autologous cell sheet transplantation have demonstrated promising results, additional larger validation studies are needed.

CONCLUSIONS

Oral and locally injected/administered steroids are first-line options for the prevention of esophageal strictures, but additional innovative solutions are being developed.

Feasibility of Short-Period, High-Dose Intravenous Methylprednisolone for Preventing Stricture after Endoscopic Submucosal Dissection for Esophageal Cancer: A Preliminary Study

OBJECTIVE

A wide mucosal defect after endoscopic submucosal dissection (ESD) for esophageal cancer is associated with increased risk of stricture. This study was conducted to evaluate the feasibility of short-period, high-dose intravenous methylprednisolone administration (steroid pulse therapy) in preventing post-ESD esophageal stricture.

METHODS

This prospective study examined 13 lesions in 11 consecutive patients with esophageal squamous cell carcinoma who underwent ESD that involved three-quarters or more of the circumference of the esophagus or who had a longitudinal resected specimen diameter of ≥5 cm. Steroid pulse therapy was initiated the day after ESD and continued for 3 consecutive days. The primary endpoint was the stricture rate after ESD. Secondary endpoints were adverse events (AEs) associated with steroid pulse therapy, time until the development of stricture, and the frequency and duration of endoscopic balloon dilation (EBD).

RESULTS

The stricture rate was 54.5% (6/11). The median time until stricture development was 15 days. The median number of EBD sessions required was 2.5. The median duration of EBD was 14.5 days. AEs related to steroid pulse therapy and postprocedure complications were not observed.

CONCLUSION

No preventive effect of the stricture after esophageal ESD by steroid pulse therapy was found, although the therapy was administered safely.

Risk of metachronous recurrence after endoscopic submucosal dissection of esophageal squamous cell carcinoma

Development of endoscopic submucosal dissection (ESD) improves the en bloc resection rate of superficial esophageal squamous cell carcinoma (SESCC). Although the background mucosa after ESD remains malignant potential, esophageal (sub)circumferential ESD, in cases where the mucosal defect is greater than three-fourths of the circumference, might induce refractory stricture, and it may disturb early detection of the recurrence. Therefore, we aimed to elucidate whether the patients treated by (sub)circumferential ESD for SESCC may remain at risk of metachronous recurrence. In a single-center retrospective study, we collected data from 154 consecutive patients who were treated with curative ESD for SESCC from 2002 to 2013 and followed by surveillance for longer than 12 months. Metachronous recurrence was defined as histologically proven SESCC at other site of the ESD scar or abnormal nodal swelling was detected later than 12 months after ESD. The primary endpoint was to identify the risk of metachronous recurrence using multivariate analyses. The secondary endpoint was to investigate difference in clinical pathological features between patients with and without the recurrence. The overall rate of metachronous recurrence was 14.9% during 40.5 median months after the initial ESD. 24.1% and 9.0% of overall metachronous recurrence were observed in patients treated with (sub)circumferential ESD and non-subcircumferential ESD, respectively, despite no significant difference in their observation duration. After the application of a stepwise regression model that included all variants, a Cox proportional hazards regression model identified (sub)circumferential ESD as the only risk for the recurrence (hazard ratio (HR): 1.48, 95% confidence intervals (CI): 1.04-2.08, P = 0.028). The cumulative recurrence rate revealed a significant difference between patients treated by (sub)circumferential ESD and those by nonsubcircumferential ESD (HR: 3.094, 95% CI: 1.33-7.52, P = 0.009), despite no significant difference in their cause-specific survival. Additionally, the session numbers of the follow-up endoscopy until the detection of metachronous recurrence after the non-subcircumferential ESD were significantly less than those after the (sub)circumferential ESD (7.8 ± 1.8 vs. 15.2 ± 1.5 P = 0. 005), despite no significant difference in their cancer-free duration. In conclusion, we demonstrated that patients treated by curative (sub)circumferential ESD for SESCC might be high risk for metachronous recurrence. Therefore, we should establish a risk-stratified surveillance program after (sub)circumferential ESD and preventive strategies for post-ESD stricture.

Prophylactic steroid administration for strictures after endoscopic resection of large superficial esophageal squamous cell carcinoma

Background and study aims: One of the major complications after endoscopic resection (ER) for large superficial esophageal squamous cell carcinoma (ESCC) is benign esophageal stricture, which can reduce quality of life even if ESCC achieves a cure without organ resection. Recently, steroid administration has been reported as a prophylactic treatment to prevent esophageal strictures. This retrospective study evaluated the stricture rate according to the different width of mucosal defects due to ER and compared it to that seen with prophylactic steroid administration. Patients and methods: Between June 2007 and December 2013, we enrolled patients with ESCC who had 3/4 or larger circumferential mucosal defects due to ER. In December 2009, steroid injections (triamcinolone acetonide 50 mg) into the ulcer bed due to ER were introduced. Beginning in November 2012, we commenced oral steroid administration (prednisolone 30 mg/day, tapered gradually for 8 weeks) in addition to steroid injection. Patients were classified into 3 groups according to the width of mucosal defect after ER (Group A, ≥ 3/4 and < 7/8; Group B, ≥ 7/8 and less than the entire circumference; and Group C, the entire circumference). We retrospectively evaluated the stricture rate by comparing no treatment, steroid injection, or steroid injection followed by oral steroid according to the width of mucosal defect. Results: A total of 115 patients met the selection criteria. In Group B, no treatment had a significantly higher stricture rate (100 %, vs. steroid injection: 56 % P = 0.015; vs steroid injection followed by oral steroid: 20 % P < 0.001). Conversely, in Group C, the stricture rate was high, regardless of treatment (no treatment: 100 %; steroid injection: 100 %; steroid injection followed by oral steroid: 71 %). Conclusions: Although prophylactic steroid administration is effective to prevent strictures for 7/8 circumference or larger mucosal defects, it is ineffective for whole-circumference defects. Further investigation is required.

Prevention of esophageal strictures after endoscopic submucosal dissection with the injection of botulinum toxin type A

BACKGROUND AND AIMS

The use of endoscopic submucosal dissection (ESD) for management of widespread superficial esophageal squamous carcinoma is closely associated with esophageal stenosis. We investigated the efficacy and feasibility of endoscopic injection of botulinum toxin type A (BTX-A) for preventing esophageal strictures after ESD for superficial esophageal squamous carcinoma.

METHODS

Sixty-seven patients with superficial esophageal squamous cell carcinomas with mucosal defects that exceeded one half of the circumference of the esophagus after ESD treatment were enrolled and randomly divided into 2 groups (group A, n = 33; group B, n = 34). Patients in group A (BTX-A group) were immediately injected with BTX-A after ESD, whereas patients in group B (control group) received ESD only. Endoscopy was performed when patients reported dysphagia symptoms and at 12 weeks post-ESD in patients without symptoms. Patients who experienced post-ESD esophageal strictures in both groups received bougie dilation.

RESULTS

The number of patients who experienced esophageal strictures in group A (per protocol analysis, 6.1%, 2/33; intention to treat analysis, 11.4%, 4/35) was significantly less than that seen in group B (per protocol analysis, 32.4%, 11/34; intention to treat analysis, 37.8%, 14/37) (P < .05). Moreover, the number of bougie dilation procedures was significantly lower in group A (mean, 1.5; range, 0-2) than in group B (mean, 2.8; range, 0-5) (P < .05).

CONCLUSIONS

Endoscopic injection of BTX-A was effective in preventing post-ESD esophageal strictures and decreasing the times of bougie dilation procedures. (

CLINICAL TRIAL REGISTRATION NUMBER

ChiCTR-TRC-12003188.).

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.

Esophageal Stricture Prevention after Endoscopic Submucosal Dissection

Advances in diagnostic modalities and improvement in surveillance programs for Barrett esophagus has resulted in an increase in the incidence of superficial esophageal cancers (SECs). SEC, due to their limited metastatic potential, are amenable to non-invasive treatment modalities. Endoscopic ultrasound, endoscopic mucosal resection, and endoscopic submucosal dissection (ESD) are some of the new modalities that gastroenterologists have used over the last decade to diagnose and treat SEC. However, esophageal stricture (ES) is a very common complication and a major cause of morbidity post-ESD. In the past few years, there has been a tremendous effort to reduce the incidence of ES among patients undergoing ESD. Steroids have shown the most consistent results over time with minimal complications although the preferred mode of delivery is debatable, with both systemic and local therapy having pros and cons for specific subgroups of patients. Newer modalities such as esophageal stents, autologous cell sheet transplantation, polyglycolic acid, and tranilast have shown promising results but the depth of experience with these methods is still limited. We have summarized case reports, prospective single center studies, and randomized controlled trials describing the various methods intended to reduce the incidence of ES after ESD. Indications, techniques, outcomes, limitations, and reported complications are discussed.

Prevention of esophageal stricture after endoscopic submucosal dissection: a systematic review and meta-analysis

BACKGROUND

Endoscopic submucosal dissection (ESD) of extensive superficial cancers of the esophagus may progress with high rates of postoperative stenosis, resulting in significantly decreased quality of life. Several therapies are performed to prevent this, but have not yet been compared in a systematic review.

METHODS

A systematic review of the literature and meta-analysis were performed using the MEDLINE, Embase, Cochrane, LILACS, Scopus, and CINAHL databases. Clinical trials and observational studies were searched from March 2014 to February 2015. Search terms included: endoscopy, ESD, esophageal stenosis, and esophageal stricture. Three retrospective and four prospective (three randomized) cohort studies were selected and involved 249 patients with superficial esophageal neoplasia who underwent ESD, at least two-thirds of the circumference. We grouped trials comparing different techniques to prevent esophagus stenosis post-ESD.

RESULTS

We conducted different meta-analyses on randomized clinical trials (RCT), non-RCT, and global analysis. In RCT (three studies, n = 85), the preventive therapy decreased the risk of stenosis (risk difference = -0.36, 95 % CI -0.55 to -0.18, P = 0.0001). Two studies (one randomized and one non-randomized, n = 55) showed that preventative therapy lowered the average number of endoscopy dilatations (mean difference = -8.57, 95 % CI -13.88 to -3.25, P < 0.002). There were no significant differences in the three RCT studies (n = 85) in complication rates between patients with preventative therapy and those without (risk difference = 0.02, 95 % CI -0.09 to 0.14, P = 0.68).

CONCLUSIONS

The use of preventive therapy after extensive ESD of the esophagus reduces the risk of stenosis and the number of endoscopic dilatations for resolution of stenosis without increasing the number of complications.

Efficacy and safety of endoscopic submucosal dissection for elderly patients with superficial squamous esophageal neoplasms

BACKGROUND

Little is known about the outcomes of endoscopic submucosal dissection in elderly patients with superficial squamous esophageal neoplasms.

OBJECTIVE

To assess the efficacy and safety of endoscopic submucosal dissection for superficial squamous esophageal neoplasms in elderly patients (≥65 years) compared with non-elderly patients.

METHODS

All patients with superficial squamous esophageal neoplasms receiving endoscopic submucosal dissection were retrospectively analyzed. Among them, 130 were aged 65 or older (group A), and 201 were aged younger than 65 years (group B). Therapeutic efficacy, adverse events, and follow-up data were evaluated.

RESULTS

Group A had a higher prevalence of concomitant diseases than group B (52.3% vs. 14.9%, respectively). R0 resection rate was 82.3% in group A and 84.6 % in group B (P = 0.717). The curative resection rate was 80.8% in group A and 83.6% in group B (P = 0.653). The rate of procedure-related non-cardiopulmonary adverse events was 20.8% in group A and 16.9% in group B (P = 0.377). The incidence of cardiopulmonary adverse events during or after the procedure was 6.2% in group A and 2.5% in group B (P = 0.094). No procedure-related mortality was reported in either group.

CONCLUSION

Endoscopic submucosal dissection is effective and safe for treating superficial squamous esophageal neoplasms in elderly patients.

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.

Endoscopic balloon dilatation for pharyngo-upper esophageal stricture after treatment of head and neck cancer

BACKGROUND AND AIM

Dysphagia caused by pharyngo-upper esophageal stricture is a complication of treatment for head and neck cancer. Endoscopic balloon dilation (EBD) is in widespread use as an effective and safe treatment for stricture in many areas of the gastrointestinal tract. In the present study, we investigated the efficacy and safety of EBD for pharyngo-upper esophageal strictures that developed after treatment for head and neck cancer.

METHODS

From January 2010 to December 2013, the medical records and endoscopic findings of 19 consecutive patients with pharyngo-upper esophageal strictures occurring after surgery and/or chemoradiotherapy for head and neck cancer were retrospectively examined.

RESULTS

Mean number of EBD sessions per patient was 6.6 (1-30), and mean maximum diameter of dilation was 15.8 (11-20) mm. Technical success was achieved in 16 of 19 (84.2%) patients, and only two major complications (bleeding and pha ryngeal edema) occurred in a total of 125 dilatation sessions (1.6%). Regarding the influence of chemoradiotherapy on the outcome of EBD, patients who had undergone chemoradiotherapy plus surgery experienced significantly more restenosis during the follow-up period compared to those who had undergone surgery alone (50% vs 0%, P < 0.05).

CONCLUSIONS

This retrospective analysis demonstrated the efficacy and safety of exclusive EBD for pharyngo-upper esophageal strictures occurring after treatment for head and neck cancer, indicating that the therapeutic application of EBD could be extended to such strictures. Patients who underwent chemoradiotherapy and surgery experienced more restenosis; hence, such patients should be carefully followed up after EBD treatment.

Endoscopic balloon dilatation for benign esophageal stricture after endoscopic submucosal dissection for early esophageal neoplasms

OBJECTIVE

The aim of this study was to evaluate the safety and efficacy of endoscopic balloon dilatation (EBD) for benign esophageal strictures after ESD for early esophageal neoplasms.

METHODS

Data of 335 patients who were treated with ESD for early esophageal neoplasms from October 2006 to August 2012 were retrospectively reviewed. The characteristics of the patients who underwent EBD for post-ESD stricture were analyzed.

RESULTS

A total of 117 dilatation procedures were performed in 29 patients with post-ESD esophageal stricture. The mean number of EBD sessions was 4.0 (range 1-15) and no complications occurred during the procedures. The median follow-up period for the 29 patients since their last session of EBD was 20 months (range 1-48 months). Of the 28 patients who were followed up for more than 3 months after achieving dysphagia relief, two had recurrent dysphasia and EBD was reintroduced. The treatment success rate was 92.9% (26/28).

CONCLUSION

EBD is a safe and effective modality for the treatment of benign esophageal stricture after ESD for early esophageal neoplasms.

Preventing stricture formation by covered esophageal stent placement after endoscopic submucosal dissection for early esophageal cancer

OBJECTIVE

We aimed to evaluate the efficacy and safety of fully covered esophageal stent placement for preventing esophageal strictures after endoscopic submucosal dissection (ESD).

METHODS

Twenty-two patients with a mucosal defects that exceeded 75 % of the circumference of the esophagus after ESD treatment for superficial esophageal squamous cell carcinomas were grouped according to the type of mucosal defect and randomized to undergo fully covered esophageal stent placement post-ESD (group A, n = 11) or no stent placement (group B, n = 11). In group A, the esophageal stents were removed 8 weeks post-ESD. Endoscopy was performed when patients reported dysphagia symptoms and at 12 weeks post-ESD in patients without symptoms. Savary-Gilliard dilators were used for bougie dilation in patients experiencing esophageal stricture in both groups, and we compared the rates of post-ESD strictures and the need for bougie dilation procedures.

RESULTS

The proportion of patients who developed a stricture was significantly lower in group A (18.2 %, n = 2) than in group B (72.7 %, n = 8) (P < 0.05). Moreover, the number of bougie dilation procedures was significantly lower in group A (mean 0.45, range 0-3) than in group B (mean 3.9, range 0-17) (P < 0.05). The two patients in group A who experienced stricture also had stent displacement.

CONCLUSIONS

Esophageal stents are a safe and effective method of preventing esophageal strictures in cases where >75 % of the circumference of the esophagus has mucosal defects after ESD treatment for early esophageal cancer.

Tranilast binds to aβ monomers and promotes aβ fibrillation

The antiallergy and potential anticancer drug tranilast has been patented for treating Alzheimer's disease (AD), in which amyloid β-protein (Aβ) plays a key pathogenic role. We used solution NMR to determine that tranilast binds to Aβ40 monomers with ∼300 μM affinity. Remarkably, tranilast increases Aβ40 fibrillation more than 20-fold in the thioflavin T assay at a 1:1 molar ratio, as well as significantly reducing the lag time. Tranilast likely promotes fibrillation by shifting Aβ monomer conformations to those capable of seed formation and fibril elongation. Molecular docking results qualitatively agree with NMR chemical shift perturbation, which together indicate that hydrophobic interactions are the major driving force of the Aβ-tranilast interaction. These data suggest that AD may be a potential complication for tranilast usage in elderly patients.

Endoscopic resection (endoscopic submucosal dissection/endoscopic mucosal resection) for superficial Barrett's esophageal cancer

Recently developed endoscopic resection (endoscopic submucosal dissection [ESD]/ endoscopic mucosal resection) has dramatically changed the therapeutic approach for Barrett's esophageal cancer. The rationale for endoscopic resection is that lesions confined to the mucosal layer have negligible risk for developing lymph node metastasis and can be successfully eradicated by endoscopic treatment as a curative treatment with minimal invasiveness. According to some reports that analyzed the rate of lymph-node involvement relative to the depth of mucosal or submucosal tumor infiltration, endoscopic resection is clearly indicated for intramucosal carcinoma and might be extended to lesions with invasion into the submucosa (<200 μm, sm1) because of the low risk for lymph node metastasis. Most Japanese experts recommend ESD for Barrett's esophageal cancer after accurate diagnosis of the margin of cancer using narrow band imaging with magnifying endoscopy because of its high curative rate. However, few studies have evaluated the long-term outcomes of endoscopic resection for Barrett's esophageal cancer in Japan. Further investigations should be conducted to establish endoscopic resection for Barrett's esophageal cancer.