Temporary metallic stent placement in the treatment of refractory benign esophageal strictures: results and factors associated with outcome in 55 patients

Hydrogel-Impregnated Robust Interlocking Nano Connector (HiRINC) for Noninvasive Anti-Migration of Esophageal Stent

Migration of implanted self-expandable metallic stent (SEMS) in the malignant or benign esophageal stricture is a common complication but not yet resolved. Herein, this research develops a hydrogel-impregnated robust interlocking nano connector (HiRINC) to ensure adhesion and reduce the mechanical mismatch between SEMSs and esophageal tissues. Featuring a network-like porous layer, HiRINC significantly enhances adhesion and energy dissipation during esophageal peristalsis by utilizing mechanical interlocking and increasing hydrogen bonding sites, thereby securing SEMS to tissues. The anti-swelling property of HiRINC prevents excessive hydrogel expansion, avoiding esophageal blockage. Ex vivo and in vivo adhesion tests confirm that the HiRINC outperforms flat surfaces without RINC structures and effectively prevents stent migration. HiRINC-coated SEMS maintains its position and luminal patency, minimizing stent-induced tissue hyperplasia and inflammatory responses in rat and porcine esophageal models during the 4-week follow-up. This novel HiRINC-SEMS can ensure anti-migration and prolonged stent patency in the rat and porcine esophagus and seems to be expanded to other nonvascular luminal organs and various implantable metallic devices.

Small Balloon Dilation Versus Bougie Dilation Versus Large Balloon Dilation for the Treatment of Benign Esophageal Strictures in Adult Patients

RATIONALE AND OBJECTIVES

The optimal treatment for benign esophageal strictures (BES) is still unknown, small balloon dilation (6-24mm in diameter) and bougie dilator dilation (5-17mm in diameter) are usually used clinically, while large balloon dilation (25-30mm in diameter) is rarely used due to the potential risk of esophageal rupture and massive bleeding. According to the different choices of treatment, we grouped the patients into three groups and compared their safety and effectiveness to explore the optimal treatment of BES.

MATERIALS AND METHODS

Between July 2016 and March 2024, 104 consecutive patients with BES who underwent dilation of small balloon (Group S, n=30), bougie dilator (Group B, n=38) or large balloon (Group L, n=36) were retrospectively evaluated. Data were collected to analyze the technical success, safety and clinical outcome of the dilations as evaluated by dysphagia score, complications and recurrence.

RESULTS

Technically success rates of Group S, Group B and Group L were 97.0%, 96.7% and 89.9%, respectively (P=0.0507). Recurrence of stricture and esophageal rupture were the reasons for technical failures in balloon and bougie dilation. Esophageal ruptures occurred in 11 dilations as follows: 4 (3.0%) in the Group S, 2 (1.7%) in the Group B and 5 (7.2%) in the Group L (P=0.1184). Among them, two patients with type III rupture had temporary removable esophageal stent placed, and rupture healed after stents removal. Two patients with type II rupture had the rupture clamped with titanium clips. A total of 55/104 patients (52.9%) were cured with no dysphagia after the end of follow-up as follows: 12 (40.0%) in the Group S, 18 (47.4%) in the Group B and 25 (69.4%) in the Group L (P=0.0385). Less No. of dilation sessions and shorter duration of treatment were required in the Group L than in the Group S or the Group B (P<0.05). Total hospitalization cost was higher in the Group S than in the Group B or the Group L (P<0.05).

CONCLUSION

Both balloon dilation and bougie dilation are safe and effective for patients with benign esophageal strictures. Large balloon dilation seems to be preferable to small balloon dilation and bougie dilation regardless of the condition of adult BES, as they are associated with higher clinical effectiveness, less required dilation, and reduced duration of treatment.

A comparison of three kinds of balloon dilatations for patients with benign esophageal strictures

Benign esophageal strictures (BES) have been usually treated with balloon dilatation with occasionally drug-coated balloon (DCB) or large balloon dilatation. We compared the clinical outcomes of 3 types of dilatations: small balloon dilatation, DCB dilatation, and large balloon dilatation for the treatment of BES. This retrospective study evaluated 3 groups of 82 consecutive patients with BES who underwent dilatation of either small balloon (Group S, n = 25), DCB (Group D, n = 22) or large balloon (Group L, n = 35). Technical success, dysphagia score, safety and recurrence of stricture were collected and evaluated. Technical success rates of dilatation procedure were 88.7%, 87.1% and 89.7% in Group S, Group D and Group L, respectively (P = 0.9291). Rupture occurred in 8 dilatations: two (2.8%) in the Group S, one (3.2%) in the Group D and 5 (7.4%) in the Group L (P = 0.4109). The final scores in Group L (0.4 ± 0.9) was significantly lower than that in Group S (1.3 ± 1.5) or Group D (1.3 ± 1.4; P < 0.01). A total of 44/82 patients (53.7%) were cured with no dysphagia after the end of follow-up: 10 (40.0%) in the Group S, 9 (40.9%) in the Group D and 25 (71.4%) in the Group L. Group L showed the best clinical effectiveness among the three groups (P = 0.0272). Longer hospitalization was required in the Group D (median 21.0, interquartile range [IQR] 10.0-49.5) than in the Group S (median 14.0, IQR 9.0-24.0) or the Group L (median 12.0, IQR 8.0-24.0, P = 0.0112). More hospitalization cost was required in the Group D (median 6.9 months, IQR 3.7-11.2 months) than in the Group S (median 4.0 months, IQR 2.6-6.8 months) or the Group L (median 3.1, IQR 2.1-6.3, P = 0.0006). In conclusion, large balloon dilatation is a safe and effective treatment for BES, with higher clinical effectiveness, shorter hospitalization and lower hospitalization cost. The use of DCB seems least preferable, as they are associated with more hospitalization cost and few cases of clinical improvement.

TGF-β1 inhibitor P144 protects against benign restenosis after esophageal stenting through TGF-β1/Smads signaling pathway inhibition

BACKGROUND AND STUDY AIMS

Esophageal restenosis is a serious complication after esophageal stent placement, which influences the clinical prognosis of stent implantation and the patient's quality of life. TGF-β1/Smads signaling pathway plays an important role in the development of the eosinophilic esophagitis and scar repair after skin trauma. However, the role of TGF-β1/Smads in the development of esophageal restenosis after esophageal stent placement remains unknown. Our study aimed to investigate whether TGF-β1/Smads plays an important role in the development of esophageal restenosis after esophageal stent, and whether the exogenous TGF-β1 inhibitor supplement could ameliorate the esophageal restenosis after esophageal stent.

MATERIAL AND METHODS

We established the model of esophageal restenosis after esophageal stenting in rats, and determined the expression levels of TGF-β1/Smads signaling pathway and the relevant markers of fibroblast activation by immunochemistry (IHC), Western Blot and real time qPCR. Those all the indicators were also determined in esophageal fibroblast when exposed to rhTGF-β1 with or without TGF-β1 inhibitor P144.

RESULTS

The serum level of IL-1β and TNFα were significantly increased in stent implantation group compared to blank control group, and obviously ameliorated when treated with P144. The TGF-β1/Smads signaling pathway and the relevant markers of fibroblast activation were significantly increased in stent implantation group compared to blank control group, and obviously ameliorated when treated with P144. Those all the indicators were significantly increased when exposed to rhTGF-β1, and obviously decreased when treated with P144.

CONCLUSIONS

TGF-β1 Inhibitor P144 could protect against benign restenosis after esophageal stenting by down-regulating the expression levels of relevant markers of fibroblast activation through TGF-β1/Smads signaling pathway inhibition, and may be used as a novel therapy for benign restenosis after esophageal stenting.

A Functional Stent Encapsulating Radionuclide in Temperature-Memory Spiral Tubes for Malignant Stenosis of Esophageal Cancer

Stent implantation is a commonly used palliative treatment for alleviating stenosis in advanced esophageal cancer. However, tissue proliferation induced by stent implantation and continuous tumor growth can easily lead to restenosis. Therefore, functional stents are required to relieve stenosis while inhibiting tissue proliferation and tumor growth, thereby extending the patency. Currently, no ideal functional stents are available. Here, iodine-125 (125 I) nuclides are encapsulated into a nickel-titanium alloy (NiTi) tube to develop a novel temperature-memory spiral radionuclide stent (TSRS). It has the characteristics of temperature-memory, no cold regions at the end of the stent, and a uniform spatial dose distribution. Cell-viability experiments reveal that the TSRS can reduce the proliferation of fibroblasts and tumor cells. TSRS implantation is feasible and safe, has no significant systemic radiotoxicity, and can inhibit in-stent and edge stenosis caused by stent-induced tissue proliferation in healthy rabbits. Moreover, TSRS can improve malignant stenosis and luminal patency resulting from continuous tumor growth in a VX2 esophageal cancer model. As a functional stent, the TSRS combines the excellent properties of NiTi with brachytherapy of the 125 I nuclide and will make significant contributions to the treatment of malignant esophageal stenosis.

Silver nanoparticle-coated self-expandable metallic stent suppresses tissue hyperplasia in a rat esophageal model

BACKGROUND

To evaluate the efficacy of a silver nanoparticle (AgNP)-coated self-expandable metallic stent (SEMS) for suppressing tissue hyperplasia in a rat esophageal model.

METHODS

Twenty-four male Sprague-Dawley rats were randomly assigned to four groups. Animals in group A underwent uncoated SEMS placement, whereas animals in groups B, C, and D underwent 6, 12, and 24 mg/mL AgNP-coated SEMS placement, respectively. All animals were euthanized 4 weeks after SEMS placement, and a gross examination and histological analyses were performed.

RESULTS

All rats achieved technical success and survived until the end of the study. The gross examination showed moderate to severe tissue hyperplasia in 5 rats in group A and 2 rats in group B. In contrast, no animals in groups C and D had moderate or severe tissue hyperplasia. The gross examination revealed no complications. The percentage of granulation tissue area, number of epithelial layers, thickness of submucosal fibrosis, percentage of connective tissue area, inflammatory cell infiltration grade, degree of collagen deposition, and degrees of Ki67, TUNEL, and α-SMA-positive deposition were significantly lower in groups C and D than in group A (all p < 0.05). However, only the percentage of granulation tissue area, number of epithelial layers, thickness of submucosal fibrosis, and percentage of connective tissue area were significantly lower in group B than in group A (all p < 0.05). No histological parameters were significantly different between group D and group C (all p > 0.05).

CONCLUSION

AgNP-coated SEMSs suppressed tissue hyperplasia in a rat esophageal model.

Progress of esophageal stricture prevention after endoscopic submucosal dissection by regenerative medicine and tissue engineering

Endoscopic submucosal dissection (ESD) has been widely accepted as an effective treatment for early esophageal cancer. However, post-ESD esophageal stricture remains a thorny issue. We herein review many strategies for preventing post-ESD esophageal stricture, as well as discuss their strengths and weaknesses. These strategies include pharmacological prophylaxis, esophageal stent and tissue engineering and regenerative medicine treatment. In this review, we summarize these studies and discuss the underlying progress and future directions of tissue engineering and regenerative medicine treatment.

Photothermal therapy via a gold nanoparticle-coated stent for treating stent-induced granulation tissue formation in the rat esophagus

Minimally invasive therapies using stent technology are currently limited by stent-induced granulation tissue formation adjacent to the stent. The effectiveness of photothermal therapy (PTT) using a gold nanoparticle (AuNP)-coated stent for treating stent-induced granulation tissue formation in the rat esophagus was investigated. All experiments were approved by the animal research committee of our institution. An AuNP-coated, self-expandable metallic stent (SEMS) was produced to conduct PTT under near-infrared laser irradiation. Forty rats were randomly divided into four groups (10 rats each). The animals in group A (non-coated SEMS) and group B (AuNP-coated SEMS with local heating at 65 °C at 4 weeks) were sacrificed 4 weeks after stent placement. The rats in group C (AuNP-coated SEMS with local heating at 65 °C at 4 weeks) and group D (AuNP-coated SEMS with local heating at 65 °C at 4 and 8 weeks) were sacrificed 8 weeks after stent placement. The effectiveness of local heating was assessed by histopathology. All procedures were successful in all of the animals. Seven rats were excluded because of stent migration (n = 2) and death (n = 5). Granulation tissue formation-related variables were significantly higher in group A than in groups B-D (all p < 0.05). Heat-shock protein 70 (HSP70) and TUNEL expression were significantly lower in group A than in groups B-D (all p < 0.05). Granulation tissue formation-related variables were significantly higher in group C than in groups B and D (all p < 0.05). PTT using AuNP-coated SEMS successfully treated granulation tissue formation after stent placement in the rat esophagus.

Assessment of long-term results of repeated dilations and impact of a scheduled program of dilations for refractory esophageal strictures: a retrospective case-control study

INTRODUCTION

In patients with benign and refractory esophageal strictures (BES), repeating initial dilations in short intervals could be recommended, but little data are available to validate this strategy. Our aim was to evaluate long-term results of a scheduled program of repeated and sustained esophageal dilations in patients with refractory strictures.

METHODS

Patients with BES requiring five or more dilations were retrospectively included and divided in two groups for analysis: a SCHEDULED group (SDG) where patients were systematically rescheduled for the 5 first dilations; ON-DEMAND group (ODG) where patients were dilated only in case of recurrence of the dysphagia. Comparison between SDG and ODG was done with a 1:1 matching analysis and etiology of stricture. Clinical success was defined as the absence of dysphagia for more than a year.

RESULTS

39 patients with refractory BES were included with post-operative stenosis in 51.2% and post-caustic injury 28.2%; 10 were in SDG and 29 in ODG. In overall analysis (39 patients), the follow-up was 64.4 ± 32 months, success rate was 79.5% and duration of treatment was 27.3 ± 20 months, and mean number of dilations was 11.7 per patient. The need for dilations decreased significantly after 18 months of treatment with an average of 0.56 dilations per semester. Self-expandable metallic stent insertion was associated with an increased rate of complications (5.9% vs 59.1% p = 0.001). In matched analysis (10 ODG vs 10 SDG patients), the duration of treatment was lower in SDG (18.8 vs 41.4 months, p = 0,032) with a higher probability of remission (survival analysis, Log-rank: p = 0,019) and the success rate did not differ between ODG and SDG patients (80% vs 90%; NS).

CONCLUSION

Overall, long-term esophageal dilations resulted in a 79.5% success rate and the need for further dilatations decreased significantly in both groups after 18-month follow-up. A scheduled dilation program was associated with a higher probability of final success and lower treatment duration.

Endoscopic management of benign recalcitrant esophageal strictures

Benign esophageal strictures are one of the common clinical conditions managed by endoscopists. Nearly 90% of the benign esophageal strictures respond to endoscopic dilation. However, a small percentage of patients progress to recalcitrant strictures. The benign recalcitrant esophageal strictures are difficult to manage both medically and endoscopically as they do not respond to conventional treatment with proton pump inhibitors and esophageal dilations. Patients with benign recalcitrant esophageal strictures are at a high risk of developing debilitating malnutrition and morbidity due to severe dysphagia. This condition is associated with psychological trauma to patients as treatments are usually prolonged with poor outcomes. Also, this can be a financial burden on the healthcare industry due to several sessions of treatment. In this article, we discuss the classification of benign esophageal strictures, evidence-based treatment strategies, endoscopic procedural techniques, and complications of endoscopic interventions. We aim to guide providers in managing benign esophageal strictures with a focus on endoscopic management of benign recalcitrant esophageal strictures.

Micro-endoscopy for Live Small Animal Fluorescent Imaging

Intravital microscopy has emerged as a powerful technique for the fluorescent visualization of cellular- and subcellular-level biological processes in vivo. However, the size of objective lenses used in standard microscopes currently makes it difficult to access internal organs with minimal invasiveness in small animal models, such as mice. Here we describe front- and side-view designs for small-diameter endoscopes based on gradient-index lenses, their construction, their integration into laser scanning confocal microscopy platforms, and their applications for in vivo imaging of fluorescent cells and microvasculature in various organs, including the kidney, bladder, heart, brain, and gastrointestinal tracts, with a focus on the new techniques developed for each imaging application. The combination of novel fluorescence techniques with these powerful imaging methods promises to continue providing novel insights into a variety of diseases.

Novel detachable stents for the treatment of benign esophageal strictures

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

Lumen-apposing Metal Stents, Fully Covered Self-expanding Metal Stents, and Biodegradable Stents in the Management of Benign of GI Strictures: A Systematic Review and Meta-Analysis

BACKGROUND

Refractory benign gastrointestinal (GI) strictures are difficult to treat and placement of a stent is a commonly sought resort. Stents used for this purpose are fully covered self-expanding metal stent (FCSEMS), a biodegradable stent (BDS) and recently, a lumen-apposing metal stent (LAMS). There is no data comparing these stents to this end.

METHODS

We conducted a comprehensive search of multiple electronic databases and conference proceedings (from inception through October 2018) to identify studies that reported on the performance of FCSEMS, BDS, and LAMS in the treatment of refractory benign GI strictures. Our goals were to evaluate the pooled rate of technical success, clinical success, and adverse events with these stents and compare the outcomes between them.

RESULTS

A total of 31 studies were analyzed. In total, 14 (342 patients), 11 (226 patients), and 8 studies (192 patients) reported the use of FCSEMS, BDS, and LAMS, respectively. The pooled rate of technical success was 96.5% [95% confidence interval (CI): 93.5-98.1], 91.9% (95% CI: 85.6-95.6), and 97.6% (95% CI: 94.0-99.0) with FCSEMS, BDS, and LAMS respectively. No statistical significance to the difference was noted. The pooled rate of clinical success was 48.4% (95% CI: 37.1-59.8), 34.9% (95% CI: 23.6-48.1), and 78.8% (95% CI: 65.8-87.8) with FCSEMS, BDS, and LAMS, respectively. Statistical significance was noted in LAMS versus FCSEMS (P=0.001) and LAMS versus BDS (P=0.001). LAMS demonstrated statistically better outcomes in regards to stent migration and postprocedure pain when compared with FCSEMS and BDS.

CONCLUSION

Our study demonstrates that LAMS gives better clinical outcomes in the treatment of refractory benign GI strictures when compared with FCSEMS and BDS. Variability in the site, as well as the length of stricture, indirect comparison, and heterogeneity, were the limitations of our study.

Silicone-covered biodegradable magnesium stent for treating benign esophageal stricture in a rabbit model

BACKGROUND

Stent insertion can effective alleviate the symptoms of benign esophageal strictures (BES). Magnesium alloy stents are a good candidate because of biological safety, but show a poor corrosion resistance and a quick loss of mechanical support in vivo.

AIM

To test the therapeutic and adverse effects of a silicone-covered magnesium alloy biodegradable esophageal stent.

METHODS

Fifteen rabbits underwent silicone-covered biodegradable magnesium stent insertion into the benign esophageal stricture under fluoroscopic guidance (stent group). The wall reconstruction and tissue reaction of stenotic esophagus in the stent group were compared with those of six esophageal stricture models (control group). Esophagography was performed at 1, 2, and 3 weeks. Four, six, and five rabbits in the stent group and two rabbits in the control groups were euthanized, respectively, at each time point for histological examination.

RESULTS

All stent insertions were well tolerated. The esophageal diameters at immediately, 1, 2 and 3 wk were 9.8 ± 0.3 mm, 9.7 ± 0.7 mm, 9.4 ± 0.8 mm, and 9.2 ± 0.5 mm, respectively (vs 4.9 ± 0.3 mm before stent insertion; P < 0.05). Magnesium stents migrated in eight rabbits [one at 1 wk (1/15), three at 2 wk (3/11), and four at 3 wk (4/5)]. Esophageal wall remodeling (thinner epithelial and smooth muscle layers) was found significantly thinner in the stent group than in the control group (P < 0.05). Esophageal injury and collagen deposition following stent insertion were similar and did not differ compared to rabbits with esophageal stricture and normal rabbits (P > 0.05).

CONCLUSION

Esophageal silicone-covered biodegradable magnesium stent insertion is feasible for BES without causing severe injury or tissue reaction. Our study suggests that insertion of silicone-covered magnesium esophageal stent is a promising approach for treating BES.

Fluoroscopic self-expandable metallic stent placement for treating post-operative nonanastomotic strictures in the proximal small bowel: a 15-year single institution experience

OBJECTIVE

To evaluate the efficacy and safety of fluoroscopic self-expandable metallic stent (SEMS) placement for treating postoperative nonanastomotic strictures in the proximal small bowel.

METHODS

Data from 8 consecutive patients (mean age, 63.8 ± 6.9 years; 7 males and 1 female) who underwent 17 fluoroscopic SEMS placement procedures in total for treating postoperative nonanastomotic strictures in the proximal jejunum were retrospectively reviewed. The most recent surgery for all the patients was total gastrectomy with esophagojejunostomy. Strictures were located in the proximal jejunum in all patients. The mean length of the strictures was 5.8 ± 2.0 cm. Five patients with comorbidities were poor surgical candidates. Four patients underwent fluoroscopic balloon dilation, three of whom showed no resolution of obstructive symptoms and one demonstrated recurrence of symptoms.

RESULTS

Technical and clinical success was achieved in 100% (17/17) SEMS procedures. Complete resolution of obstructive symptoms and improvement in oral intake status occurred within 3 days after all procedures, rendering a clinical success rate of 100% (17/17). No complication occurred during or after the procedures. The median follow-up duration was 167 [interquartile range (IQR), 48-576] days. Stent malfunction occurred after 58.8% (10/17) of the procedures, including six occurrences of stent migration and four of benign tissue hyperplasia. Surgical removal of the migrated stents was performed in two patients. Recurrence of symptoms occurred after 64.7% (11/17) of the procedures. The median stent dwell and recurrence-free times were 32 (IQR, 20-193) and 68 (IQR, 38-513) days, respectively.

CONCLUSION

Fluoroscopic SEMS placement may be effective and safe for treating postoperative nonanastomotic strictures, but stent malfunction and recurrence are major drawbacks.

ADVANCES IN KNOWLEDGE

SEMS placement is effective and relatively safe in patients with postoperative nonanastomotic strictures in the proximal small bowel. Patients section and counseling is highly encouraged.

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.

Biodegradable Stents in Resistant Peptic Oesophageal Stricture: Is It the Right Way to Go?

Peptic oesophageal stricture can be considered as the end result of prolonged gastro-oesophageal reflux. The 'gold standard' treatment for peptic stricture is endoscopic dilatation with balloon or bougie. It is predicted that up to 40% of patients remain symptomatic with dysphagia due to refractory (resistant to treatment) or recurrent strictures, needing frequent interventions at short intervals. Such patients have poor nutritional status due to the primary disease and are susceptible to complications related to repeated endoscopic dilatation such as bleeding and perforation. This general review aims to analyse existing published evidence and address the role of biodegradable stents in resistant peptic strictures as an alternative treatment to provide long-term dysphagia-free intervals.

In Vivo Fluorescence Microendoscopic Monitoring of Stent-Induced Fibroblast Cell Proliferation in an Esophageal Mouse Model

PURPOSE

To evaluate the feasibility of self-expanding metal stent (SEMS) placement and fluorescence microendoscopic monitoring for determination of fibroblast cell proliferation after stent placement in an esophageal mouse model.

MATERIALS AND METHODS

Twenty fibroblast-specific protein (FSP)-1 green fluorescent protein (GFP) transgenic mice were analyzed. Ten mice (Group A) underwent SEMS placement, and fluoroscopic and fluorescence microendoscopic images were obtained biweekly until 8 weeks thereafter. Ten healthy mice (Group B) were used for control esophageal values.

RESULTS

SEMS placement was technically successful in all mice. The relative average number of fibroblast GFP cells and the intensities of GFP signals in Group A were significantly higher than in Group B after stent placement. The proliferative cellular response, including granulation tissue, epithelial layer, submucosal fibrosis, and connective tissue, was increased in Group A. FSP-1-positive cells were more prominent in Group A than in Group B.

CONCLUSIONS

SEMS placement was feasible and safe in an esophageal mouse model, and proliferative cellular response caused by fibroblast cell proliferation after stent placement was longitudinally monitored using a noninvasive fluorescence microendoscopic technique. The results have implications for the understanding of proliferative cellular response after stent placement in real-life patients and provide initial insights into new clinical therapeutic strategies for restenosis.

Nanofunctionalized Stent-Mediated Local Heat Treatment for the Suppression of Stent-Induced Tissue Hyperplasia

Current therapeutic strategies are insufficient for suppressing stent-induced restenosis. Here, branched gold nanoparticles (BGNP)-coated self-expandable metallic stents (SEMSs) were developed for a local heat-induced suppression of stent-related tissue hyperplasia. Our polydopamine (PDA) coating on SEMS allowed BGNP crystal growth on the surface of SEMSs. The prepared BGNP-coated SEMS showed effective local heating under near-infrared laser irradiation. The effectiveness of BGNP-coated SEMSs for suppressing stent-related tissue hyperplasia was demonstrated in a rat esophageal model ( n = 52). BGNP-coated SEMS placement under fluoroscopic guidance was technically successful in all rats. The placed BGNP-coated SEMS in rat esophagus achieved three different local heat dose ranges (50, 65, and 80 °C) under fluoroscopic image-guided local irradiation. Follow-up endoscopic examination readily monitored the local heating and observed significantly decreased tissue hyperplasia at 4 weeks of local heat treatments (50 and 65 °C). Finally, Western blot, histology, immunohistochemistry (HSP70, αSMA, and TUNEL), and immunofluorescence (Ki67 and BrdU) analyses along with the statistical analysis confirmed that optimized BGNP-coated SEMS-mediated local heat treatments inducing the expression of anti-inflammatory HSP70 effectively suppresses tissue hyperplasia after stent placement in the esophagus. Our local heating with nanofunctionalized stents represents a promising new approach for suppressing stent-related tissue hyperplasia.

UK guidelines on oesophageal dilatation in clinical practice

These are updated guidelines which supersede the original version published in 2004. This work has been endorsed by the Clinical Services and Standards Committee of the British Society of Gastroenterology (BSG) under the auspices of the oesophageal section of the BSG. The original guidelines have undergone extensive revision by the 16 members of the Guideline Development Group with representation from individuals across all relevant disciplines, including the Heartburn Cancer UK charity, a nursing representative and a patient representative. The methodological rigour and transparency of the guideline development processes were appraised using the revised Appraisal of Guidelines for Research and Evaluation (AGREE II) tool.Dilatation of the oesophagus is a relatively high-risk intervention, and is required by an increasing range of disease states. Moreover, there is scarcity of evidence in the literature to guide clinicians on how to safely perform this procedure. These guidelines deal specifically with the dilatation procedure using balloon or bougie devices as a primary treatment strategy for non-malignant narrowing of the oesophagus. The use of stents is outside the remit of this paper; however, for cases of dilatation failure, alternative techniques-including stents-will be listed. The guideline is divided into the following subheadings: (1) patient preparation; (2) the dilatation procedure; (3) aftercare and (4) disease-specific considerations. A systematic literature search was performed. The Grading of Recommendations Assessment, Develop-ment and Evaluation (GRADE) tool was used to evaluate the quality of evidence and decide on the strength of recommendations made.

Preserving the Mucosa to the Maximum Possible Extent for Endoscopic Submucosal Dissection of Subcircumferential Superficial Esophageal Carcinoma

AIM

To show our unique strategy of endoscopic submucosal dissection (ESD) for esophageal squamous cell carcinoma larger than the subcircumference.

METHODS

From April 2011, we used a mucosal preservation method called the log bridge (LB) method for the lesion larger than the subcircumference. The patients in whom the circumference of the mucosal defect was 5/6 to <1 were classified into the LB group; those who underwent whole circumferential ESD were classified into the non-LB group. The data were collected retrospectively and were compared between the two groups.

RESULTS

Eighteen patients into the LB group and 7 into the non-LB group were classified. The median number of endoscopic balloon dilation sessions after ESD in the LB group tended to be lower than that in the non-LB group. The mean period until complete epithelialization after ESD was significantly shorter in the LB group. The rates of curative resection were 100% (7/7) in the non-LB group and 61.1% (11/18) in the LB group. However, there was no local recurrence in either group for approximately two years.

CONCLUSION

In cases involving subcircumferential esophageal lesions, the LB method is useful for achieving rapid healing and might be related to a reduced degree of esophageal stricture.

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.

Radiation-induced esophageal strictures treated with fluoroscopic balloon dilation: clinical outcomes and factors influencing recurrence in 62 patients

Background Balloon dilation is safe and effective for the treatment of radiation-induced esophageal stricture (RIES), with favorable short-term and mid-term outcomes; however, few reports of long-term outcomes exist. Few studies have evaluated factors associated with recurrence after balloon dilation. Purpose To evaluate the long-term outcome of balloon dilation in patients with RIES and to identify factors associated with stricture recurrence. Material and Methods The medical records of 62 consecutive patients who had undergone fluoroscopic balloon dilation for RIES at our institution between December 1998 and June 2016 were reviewed. Results One hundred and twenty balloon dilation sessions were performed in 62 patients (mean = 1.9 sessions per patient). Clinical success was achieved in 53 (86%) patients after single (n = 37) or multiple (n = 16) dilation sessions. Complications occurred in 27% of the dilation sessions. The primary patency rates at one, two, three, and five years were 60%, 56%, 52%, and 52%, respectively. Secondary patency rates at one, two, three, and five years were 87%, 85%, 85%, and 80%, respectively. Multivariate logistic regression analysis identified an interval from radiation therapy (RT) to stricture of ≥6 months (hazard ratio [HR] = 0.205; P < 0.001), strictures located at the cervical esophagus (HR = 5.846; P < 0.001), and stricture length of ≥2 cm (HR = 2.923; P = 0.006) as significant predictors of recurrence. Conclusion Despite the high incidence of ruptures and recurrences, fluoroscopic balloon dilation is valuable as an initial therapeutic option for patients with RIES.

Esophageal triamcinolone acetonide-filling method: a novel procedure to prevent stenosis after extensive esophageal endoscopic submucosal dissection (with videos)

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) for extensive esophageal carcinomas may cause severe stenosis requiring endoscopic balloon dilations (EBDs). A standard prevention method has not been established. We propose the esophageal triamcinolone acetonide (TA)-filling method as a novel local steroid administration procedure.

METHODS

We enrolled 22 consecutive patients with early esophageal cancer who were treated using either subcircumferential or circumferential ESD (15 and 7 procedures, respectively) in this case series. Esophageal TA filling was performed on the day after ESD and 1 week later and was performed again if mild stenosis was found on follow-up. EBD with TA filling was performed only for severe stenosis that prevented endoscope passage. The primary endpoint was the incidence of severe stenosis. Secondary endpoints were the total number of EBDs and additional TA filling, dysphagia score, time to stenosis and to complete re-epithelialization, and any adverse events.

RESULTS

The incidence of severe stenosis was 4.5% (1/22; confidence interval, .1%-22.8%), and EBD was performed 2 times in 1 patient. Mild stenosis was found in 9 patients. Additional TA filling was performed in 45.5% of patients (10/22; median, 5 times; range, 1-13). The dysphagia score deteriorated to 1 to 2 in 31.8% (7/22) but showed a final score of 0 after complete re-epithelialization in 90.9% (20/22). The median time to stenosis was 3 weeks (range, 3-4) and that to complete re-epithelialization was 7 weeks (range, 4-36). No severe adverse events occurred.

CONCLUSIONS

The esophageal TA-filling method is highly effective for preventing severe stenosis after extensive esophageal ESD.

EW-7197, an activin-like kinase 5 inhibitor, suppresses granulation tissue after stent placement in rat esophagus

BACKGROUND AND AIMS

Self-expanding metallic stent (SEMS) placement is a well-established method for treating malignant esophageal strictures; however, this procedure has not gained widespread acceptance for treating benign esophageal strictures because of granulation tissue formation. The aim of the present study was to investigate whether EW-7197, a novel per-oral transforming growth factor-β type I receptor kinase inhibitor, suppressed granulation tissue formation after SEMS placement in the rat esophagus.

METHODS

Sixty rats underwent SEMS placement and were randomly divided into 4 groups. Group A (n = 20) received vehicle-treated control for 4 weeks. Group B (n = 20) received 20 mg/kg/day EW-7197 for 4 weeks. Group C (n = 10) received 20 mg/kg/day EW-7197 for 4 weeks followed by vehicle-treated control for 4 weeks. Group D (n = 10) received 20 mg/kg/day EW-7197 for 8 weeks.

RESULTS

SEMS placement was technically successful in all rats. Eleven rats, however, were excluded because of stent migration (n = 9) and procedure-related death (n = 2). The luminal diameter in group A was significantly smaller than those in groups B, C, and D (all P < .001). The percentage of granulation tissue area, number of epithelial layers, thickness of submucosal fibrosis, percentage of connective tissue area, and degree of collagen deposition were significantly higher in group A than in groups B, C, and D (all P < .001); however, there were no significant differences among groups B, C, and D. EW-7197 decreased the expression levels of phospho-Smad 3, N-cadherin, fibronectin, α-smooth muscle actin, and transforming growth factor-β1 and increased the expression level of E-cadherin (all P < .01).

CONCLUSIONS

EW-7197 suppressed granulation tissue formation after SEMS placement in the rat esophagus.

Endoscopic treatment of benign esophageal strictures: a literature review

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

Efficacy of Retrievable Metallic Stent with Fixation String for Benign Stricture after Upper Gastrointestinal Surgery

Objective

To determine the efficacy of retrievable metallic stent with fixation string for benign anastomotic stricture after upper gastrointestinal (UGI) surgery.

Materials and Methods

From June 2009 to May 2015, a total of 56 retrievable metallic stents with fixation string were placed under fluoroscopy guidance in 42 patients who were diagnosed with benign anastomotic stricture after UGI surgery. Clinical success was defined as achieving normal regular diet (NRD).

Results

The clinical success rate after the first stent placement was 57.1% (24/42). After repeated stent placement and/or balloon dilation, the clinical success rate was increased to 83.3% (35/42). Six (14.3%) patients required surgical revision to achieve NRD. One (2.4%) patient failed to achieve NRD. Stent migration occurred in 60.7% (34/56) of patients. Successful rate of removing the stent using fixation string and angiocatheter was 94.6% (53/56). Distal migration occurred in 12 stents. Of the 12 stents, 10 (83.3%) were successfully removed whereas 2 could not be removed. No complication occurred regarding distal migration.

Conclusion

Using retrievable metallic stent with a fixation string is a feasible option for managing early benign anastomotic stricture after UGI surgery. It can reduce complications caused by distal migration of the stent.

Removal of Retrievable Self-Expandable Metallic Tracheobronchial Stents: An 18-Year Experience in a Single Center

PURPOSE

The purpose of the study was to retrospectively evaluate the technical outcomes of removal of retrievable self-expandable metallic stents (REMSs) and identify predictors of technical failure in 81 patients with benign and malignant tracheobronchial strictures.

MATERIALS AND METHODS

A total of 98 REMSs were removed under fluoroscopic guidance in 81 patients with benign (n = 48) or malignant (n = 33) tracheobronchial strictures. Primary and secondary technical success rates and complication rate were evaluated. Technical outcomes with regard to underlying diseases were also evaluated. Logistic regression models were constructed to identify predictors of primary technical success.

RESULTS

Primary and secondary technical success rates were 86.7 and 94.9 %, respectively. Stent removal-related complication rate was 7.1 % (7/98) and all were bleeding after stent removal. All bleeding complications were minor and managed conservatively. Primary technical success rate for benign strictures was significantly lower compared with that for malignant strictures (80.9 vs. 97.1 %, P = 0.029), but secondary technical success rate (93.7 vs. 97.1 %, P = 0.652) did not differ between the two groups. Granulation tissue formation was identified as an independent predictor of primary technical success (odds ratio 0.249, 95 % CI 0.071-0.874, P = 0.030).

CONCLUSION

Removal of REMSs in patients with benign and malignant tracheobronchial strictures is safe and technically feasible. Bronchoscopic guidance may be required when the removal using a hook wire fails. The presence of granulation tissue was the negative predictor of primary technical success.

Polymeric Biodegradable Stent Insertion in the Esophagus

Esophageal stent insertion has been used as a well-accepted and effective alternative to manage and improve the quality of life for patients diagnosed with esophageal diseases and disorders. Current stents are either permanent or temporary and are fabricated from either metal or plastic. The partially covered self-expanding metal stent (SEMS) has a firm anchoring effect and prevent stent migration, however, the hyperplastic tissue reaction cause stent restenosis and make it difficult to remove. A fully covered SEMS and self-expanding plastic stent (SEPS) reduced reactive hyperplasia but has a high migration rate. The main advantage that polymeric biodegradable stents (BDSs) have over metal or plastic stents is that removal is not require and reduce the need for repeated stent insertion. But the slightly lower radial force of BDS may be its main shortcoming and a post-implant problem. Thus, strengthening support of BDS is a content of the research in the future. BDSs are often temporarily effective in esophageal stricture to relieve dysphagia. In the future, it can be expect that biodegradable drug-eluting stents (DES) will be available to treat benign esophageal stricture, perforations or leaks with additional use as palliative modalities for treating malignant esophageal stricture, as the bridge to surgery or to maintain luminal patency during neoadjuvant chemoradiation.

Endoscopic Management of Anastomotic Esophageal Strictures Secondary to Esophageal Atresia

The reported incidence of anastomotic stricture after esophageal atresia repair has varied in case series from as low as 9% to as high as 80%. The cornerstone of esophageal stricture treatment is dilation with either balloon or bougie. The goal of esophageal dilation is to increase the luminal diameter of the esophagus while also improving dysphagia symptoms. Once a stricture becomes refractory to esophageal dilation, there are several treatment therapies available as adjuncts to dilation therapy. These therapies include intralesional steroid injection, mitomycin C, esophageal stent placement, and endoscopic incisional therapy.

Newly designed “pieced” stent in a rabbit model of benign esophageal stricture

AIM: To investigate a newly designed stent and its dilatation effect in a rabbit model of benign esophageal stricture.

METHODS: Thirty-four New Zealand white rabbits underwent a corrosive injury in the middle esophagus for esophageal stricture formation. Thirty rabbits with a successful formation of esophageal strictures were randomly allocated into two groups. The control group (n = 15) was implanted with a conventional stent, and the study group (n = 15) was implanted with a detachable “pieced” stent. The study stent (30 mm in length, 10 mm in diameter) was composed of three covered metallic pieces connected by surgical suture lines. The stent was collapsed by pulling the suture lines out of the mesh. Two weeks after stricture formation, endoscopic placement of a conventional stent or the new stent was performed. Endoscopic extraction was carried out four weeks later. The extraction rate, ease of extraction, migration, complications, and survival were evaluated.

RESULTS: Stent migration occurred in 3/15 (20%) animals in the control group and 2/15 (13%) animals in the study group; the difference between the two groups was not statistically significant. At the end of four weeks, the remaining stents were successfully extracted with the endoscope in 100% (11/11) of the animals in the study group, and 60% (6/10) of the animals in the control group; this difference was statistically significant (P < 0.05). There was no difference in the mean number of follow-up days between the control and study groups (25.33 vs 25.85). Minor bleeding was reported in five cases in the study group and four in the control group. There were no severe complications directly associated with stent implantation or extraction in either of the two groups.

CONCLUSION: In this experimental protocol of benign esophageal strictures, the novel “pieced” stent demonstrated a superior removal rate with a similar migration rate compared to a conventional stent.

Literature Analysis of the Treatment of Benign Esophageal Disease with Stent

To analyze the efficacy and safety of benign esophageal disease used biodegradable (BD) stent or metal stent. The English literatures of benign esophageal disease that were treated by biodegradable or metal stents implantation were retrieved and summarized. In all 323 benign esophageal disease, the most common etiologies were benign refractory stricture, surgical anastomotic stricture and esophageal fistula/leak/perforation, but the main characteristics between the two groups were not significantly different. One hundred fifty-four cases were completely healed by using BD stents or self-expandable metal stents (SEMS) (47.7 %). Clinical success was achieved in 47.7 % of all patients and there was no significant difference between BD stents (51 %) and SEMS (46.2 %) (P = 0.472), while stent migration occurred more frequently with SEMS (33.9 %) than with BD stent (19.6 %) (P ≤ 0.05), and tissue in- or overgrowth occurred more frequently with SEMS (22.2 %) than with BD stents (8.8 %) (P ≤ 0.05). Furthermore, the time about degradation of BD stents in esophageal was longer than removal of SEMS from the esophagus (P ≤ 0.05). Placement of BD stents or SEMS provides effective and safe relief for benign esophageal disease. Clinical success and mortality were not significantly different. BD stents offers an advantage of fewer complications. Although stent placement is a viable strategy in patients with benign esophageal disease, the ideal treatment strategy and further randomized trials with large number of patients are needed.

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.

Esophagojejunal anastomosis fistula, distal esophageal stenosis, and metalic stent migration after total gastrectomy

Esophagojejunal anastomosis fistula is the main complication after a total gastrectomy. To avoid a complex procedure on friable inflamed perianastomotic tissues, a coated self-expandable stent is mounted at the site of the anastomotic leak. A complication of stenting procedure is that it might lead to distal esophageal stenosis. However, another frequently encountered complication of stenting is stent migration, which is treated nonsurgically. When the migrated stent creates life threatening complications, surgical removal is indicated. We present a case of a 67-year-old male patient who was treated at our facility for a gastric adenocarcinoma which developed, postoperatively, an esophagojejunostomy fistula, a distal esophageal stenosis, and a metallic coated self-expandable stent migration. To our knowledge, this is the first reported case of an esophagojejunostomy fistula combined with a distal esophageal stenosis as well as with a metallic coated self-expandable stent migration.

The application of linear endoscopic ultrasound in the patients with esophageal anastomotic strictures

OBJECTIVES

To evaluate the role of linear endoscopic ultrasound (EUS) in the diagnosis and treatment of the anastomotic stricture after esophagectomy for locally advanced esophageal cancer (EC).

MATERIALS AND METHODS

A retrospective analysis was performed in patients undergone EUS assessment and endoscopic treatment for anastomotic stricture after esophagectomy for locally advanced EC from January 2010 to December 2014 at Shengjing Hospital. The linear EUS was performed in all the patients to assess the thickness of the esophageal wall, the length and width of the lesion, and to evaluate the severity of anastomotic stricture. According to the EUS features of the lesion, different endoscopic therapy were performed.

RESULTS

There were 92 patients enrolled in this study. All the lesions of the patients were assessed by EUS. Eighty-six patients had cicatricial stricture of the esophagus confirmed by EUS, and were treated by endoscopic balloon dilation. Five patients were suspected to have tumor relapses, and the other one had lymphatic metastasis. All the six patients were undergone endoscopic metal stent implantation. The EUS diagnoses of all the patients were confirmed by pathological biopsy.

CONCLUSION

Linear EUS is safe and effective for distinguishing the nature of the anastomotic stricture, and should be performed before endoscopic or surgical treatment.

Clinical outcomes of self-expandable stent placement for benign esophageal diseases: A pooled analysis of the literature

AIM

To analyze the outcomes of self-expandable stent placement for benign esophageal strictures and benign esophageal leaks in the literature.

METHODS

The PubMed, Embase and Cochrane databases were searched for relevant articles published between January 2000 and July 2014. Eight prospective studies were identified that analyzed the outcomes of stent placement for refractory benign esophageal strictures. The outcomes of stent placement for benign esophageal leaks, perforations and fistulae were extracted from 20 retrospective studies that were published after the inclusion period of a recent systematic review. Data were pooled and analyzed using descriptive statistics.

RESULTS

Fully covered self-expandable metal stents (FC SEMS) (n = 85), biodegradable (BD) stents (n = 77) and self-expandable plastic stents (SEPS) (n = 70) were inserted in 232 patients with refractory benign esophageal strictures. The overall clinical success rate was 24.2% and according to stent type 14.1% for FC SEMS, 32.9% for BD stents and 27.1% for SEPS. Stent migration occurred in 24.6% of cases. The overall complication rate was 31.0%, including major (17.7%) and minor (13.4%) complications. A total of 643 patients were treated with self-expandable stents mainly for postsurgical leaks (64.5%), iatrogenic perforations (19.6%), Boerhaave's syndrome (7.8%) and fistulae (3.7%). FC SEMS and partially covered SEMS were used in the majority of patients. Successful closure of the defect was achieved in 76.8% of patients and according to etiology in 81.4% for postsurgical leaks, 86.0% for perforations and 64.7% for fistulae. The pooled stent migration rate was 16.5%. Stent-related complications occurred in 13.4% of patients, including major (7.8%) and minor (5.5%) complications.

CONCLUSION

The outcomes of stent placement for refractory benign esophageal strictures were poor. However, randomized trials are needed to put this into perspective. The evidence on successful stent placement for benign esophageal leaks, perforations and fistulae is promising.

Preventive effects of ¹²⁵I seeds on benign restenosis following esophageal stent implantation in a dog model

The present study aimed to evaluate the effects of iodine-125 (¹²⁵I) seeds on the proliferation of primary esophageal fibroblasts in dogs, and to assess the safety and preventive efficacy of ¹²⁵I seed-pre-loaded esophageal stents in benign restenosis following implantation. Primary fibroblasts were cultured with various ¹²⁵I seed activities, which were then evaluated using cell proliferation and apoptosis assays as well as cell cycle analysis using Annexin V/propidium iodide (PI) double staining and PI staining. Prior to sacrification, animals were submitted to esophageal radiography under digital subtraction angiography. Esophageal tissues were collected and examined for macroscopic, microscopic and pathological alterations. The results demonstrated a significant and dose-dependent inhibition of fibroblast proliferation and increased apoptosis following exposure to ¹²⁵I seeds. G0/G1 fibroblast populations increased in a dose-dependent manner following treatment with ¹²⁵I seeds, in contrast to cells in S phase. Four weeks following implantation, α-smooth muscle actin and proliferating cell nuclear antigen expression levels in the experimental group were significantly lower compared with those in the control group; in addition, eight weeks following implantation, esophageal inner diameters were increased in the experimental group. ¹²⁵I seeds inhibited proliferation of dog esophageal fibroblasts via cell cycle arrest and apoptosis. In conclusion, ¹²⁵I seed-pre-loaded esophageal stents inhibited benign hyperplasia in the upper edge of the stent to a certain extent, which relieved benign restenosis following implantation with a good safety profile.

Stricture occurring after endoscopic submucosal dissection for esophageal and gastric tumors

Endoscopic submucosal dissection (ESD) is a widely accepted treatment for early gastric and esophageal cancer. Compared to endoscopic mucosal resection, ESD has the advantage of enabling en bloc removal of tumors regardless of their size. However, ESD can result in a large artificial ulcer, which may lead to a considerable deformity. Circumferential mucosal defects of more than three-fourths the esophageal circumference, long longitudinal mucosal defects (>30 mm), and lesions in the upper esophagus are significant risk factors for the development of post-ESD strictures of the esophagus. In the stomach, a circumferential mucosal defects more than three-fourths in extent and longitudinal mucosal defects >5 cm are risk factors of post-ESD stricture. If scheduled early, regular endoscopic balloon dilation is effective in controlling and preventing post-ESD stricture. Moreover, intralesional steroid injections or oral steroids can achieve remission of dysphagia or reduce the need for repeated endoscopic balloon dilation. However, further study is needed to improve the prevention of stricture formation.

Prevention and treatment of esophageal stenosis after endoscopic submucosal dissection for early esophageal cancer

Endoscopic submucosal dissection (ESD) for the treatment of esophageal mucosal lesions is associated with a risk of esophageal stenosis, especially for near-circumferential or circumferential esophageal mucosal defects. Here, we review historic and modern studies on the prevention and treatment of esophageal stenosis after ESD. These methods include prevention via pharmacological treatment, endoscopic autologous cell transplantation, endoscopic esophageal dilatation, and stent placement. This short review will focus on direct prevention and treatment, which may help guide the way forward.

Externally removable stents in the treatment of benign recalcitrant strictures and esophageal perforations in pediatric patients with esophageal atresia

BACKGROUND

We investigated whether removable stents, such as self-expandable plastic stents (SEPSs) and fully covered self-expandable metal stents (FCSEMSs) could provide an alternative treatment for recalcitrant strictures and esophageal perforations after esophageal atresia (EA) repair.

OBJECTIVE

The primary aim of our study was to evaluate technical feasibility. Secondary aims were to evaluate safety and procedural success.

DESIGN

Retrospective study.

SETTING

Tertiary-care referral center.

PATIENTS

A total of 24 children with EA.

INTERVENTIONS

Retrospective review of all children with EA who underwent dilation and esophageal stent placement from January 2010 to February 2013 at our institution.

MAIN OUTCOME MEASUREMENTS

Healing of perforation and stricture resolution at 30 and 90 days.

RESULTS

A total of 41 stents (SEPSs 14, FCSEMSs 27) were placed in 24 patients with EA during the study period, including 14 who had developed esophageal leaks. Procedural success of esophageal stent placement in the treatment of refractory strictures was 39% at 30 days and 26% at 90 days. The success rate was 80% for closure of esophageal perforations with stent therapy after dilation and 25% for perforations associated with surgical repair. Adverse events of stent placement included migration (21% of SEPSs and 7% of FCSEMSs), granulation tissue (37% of FCSEMSs), and deep ulcerations (22% of FCSEMSs).

LIMITATIONS

Retrospective study with small sample size.

CONCLUSION

SEPSs and FCSEMSs can be placed successfully in small infants and children with a history of EA repair. The stents appear to be safe and beneficial in closing esophageal perforations, especially post-dilation. However, a high stricture recurrence rate after stent removal may limit their usefulness in treating recalcitrant esophageal anastomotic strictures.

Benign esophageal stricture after thermal injury treated with esophagectomy and ileocolon interposition

Thermal injuries of the esophagus are rare causes of benign esophageal stricture, and all published cases were successfully treated with conservative management. A 28-year-old Japanese man with a thermal esophageal injury caused by drinking a cup of hot coffee six months earlier was referred to our hospital. The hot coffee was consumed in a single gulp at a party. Although the patient had been treated conservatively at another hospital, his symptoms of dysphagia gradually worsened after discharge. An upper gastrointestinal endoscopy and computed tomography revealed a pin-hole like area of stricture located 19 cm distally from the incisors to the esophagogastric junction, as well as circumferential stenosis with notable wall thickness at the same site. The patient underwent a thoracoscopic esophageal resection with reconstruction using ileocolon interposition. The pathological findings revealed wall thickening along the entire length of the esophagus, with massive fibrosis extending to the muscularis propria and adventitia at almost all levels. Treatment with balloon dilation for long areas of stricture is generally difficult, and stent placement in patients with benign esophageal stricture, particularly young patients, is not yet widely accepted due to the incidence of late adverse events. Considering the curability and quality-of-life associated with a long expected prognosis, we determined that surgery was the best treatment option for this young patient. In this case, we decided to perform an esophagectomy and reconstruction with ileocolon interposition in order to preserve the reservoir function of the stomach and to avoid any problems related to the reflux of gastric contents. In conclusion, resection of the esophagus is a treatment option in patients with benign esophageal injury, especially in cases involving young patients with refractory esophageal stricture. In addition, ileocolon interposition may help to improve the quality-of-life of patients.

Plastic and biodegradable stents for complex and refractory benign esophageal strictures

Endoscopic stent placement is a well-accepted and effective alternative treatment modality for complex and refractory esophageal strictures. Among the currently available types of stents, the partially covered self-expanding metal stent (SEMS) has a firm anchoring effect, preventing stent migration and ensuring effective covering of a narrowed segment. However, hyperplastic tissue reaction driven by the uncovered mesh may prevent easy and safe stent removal. As an alternative, a fully covered SEMS decreases the recurrence of dysphagia caused by hyperplastic tissue ingrowth; however, it has a high migration rate. Likewise, although a self-expanding plastic stent (SEPS) reduces reactive hyperplasia, the long-term outcome is disappointing because of the high rate of stent migration. A biodegradable stent has the main benefit of not requiring stent removal in comparison with SEMS and SEPS. However, it still has a somewhat high rate of hyperplastic reaction, and the long-term outcome does not satisfy expectations. Up to now, the question of which type of stent should be recommended for the effective treatment of complex and refractory benign strictures has no clear answer. Therefore, the selection of stent type for endoscopic treatment should be individualized, taking into consideration the endoscopist's experience as well as patient and stricture characteristics.

Comparison of a standard fully covered stent with a super-thick silicone-covered stent for the treatment of refractory esophageal benign strictures: A prospective multicenter study

BACKGROUND

Some esophageal strictures resist endoscopic treatments. There is a need for new treatments, such as specifically designed stents.

OBJECTIVE

Our study sought to compare the results achieved with a standard, fully covered metallic stent (FCMS) and those achieved using a stent designed specifically for benign strictures (BS-FCMS).

PATIENTS AND METHODS

The study used a prospective, multicenter, controlled design, with patients recruited from tertiary referral centers. Patients with refractory esophageal strictures were included. Standard FCMS were used in group 1 (N = 24), and BS-FCMS were used in group 2 (N = 17). Patients were followed for 24 months after stent removal. The main outcomes measured were stricture resolution rate, 24 months' recurrence rate and stent-related morbidity.

RESULTS

Early stent migrations occurred in one (4.1%) patient from group 1 and five (29.4%) from group 2 (p < 0.05). During esophageal stenting, complications occurred in six patients (25%) in group 1 and six patients (35.3%) in group 2 (p = 0.47), respectively. Fifty percent of complications were attributed to migration. There was no procedure-related morbidity associated with the extraction of the stent. The stricture resolution rate was, respectively, 95.2% in group 1 and 87.5% in group 2 (the difference between the two groups is not significant). During follow-up, stricture recurrence occurred in 15/19 patients (group 1, 79%) and 7/8 patients (group 2, 87.5%; p = 1.0). The median time to recurrence of esophageal stricture was 1.7 months (group 1, 0.6-12 months) and 1 month (group 2, 0.1-6 months). Study limitations include its nonrandomized design.

CONCLUSION

The stricture resolution rate was high at the end of the stenting period for both types of stents without any statistical difference between the two groups, but the long-term results were disappointing, with stricture recurring frequently and rapidly in both groups.

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.