Plastic and biodegradable stents for complex and refractory benign esophageal strictures

Lumen-apposing metal stents provide early and late clinical benefits for the management of benign gastrointestinal strictures: Is there a role for definitive therapy?

Objectives

This study aimed to characterize the clinical outcomes, safety, and efficacy of lumen-apposing metal stents (LAMS) in treating benign gastrointestinal strictures.

Methods

A single-center retrospective review of all patients who underwent LAMS placement for benign strictures from June 2017 to July 2023. Primary outcomes were technical success, early clinical success, late clinical success (LCS), and sustained post-LAMS clinical success (SPLCS). Secondary outcomes included stent dwell time, stenosis changes, adverse events, reintervention rates, and symptomatology evaluation.

Results

Thirty-five patients underwent placement of 42 LAMS (74% female, mean age: 54.2 ± 11.7 years). Anastomotic strictures accounted for 64% of cases (N = 27, 45% at the gastrojejunal anastomosis). The median STD was 91.0 days (interquartile range [IQR]: 55.0-132.0). Technical success was obtained in all cases. Early clinical successand LCS were achieved in 80% of cases overall. SPLCS was achieved in 45% (n = 15) of cases. The overall reintervention rate was 63%, with a median time to reintervention being 50.5 days (IQR: 24-105). adverse events occurred in 28% (n = 12) overall, with a 24% migration rate (n = 10). Follow-up was completed in 83% of cases with a median duration of 629 days (range: 192.0-1297.0). Overall symptom improvement occurred in 79% (n = 27) during indwelling LAMS versus 58% and 56% at 30- and 60-days post-removal, respectively.

Conclusions

LAMS for benign gastrointestinal strictures are associated with high technical and early clinical success/LCS rates, positive quality-of-life metrics, and a tolerable adverse event rate. Overall, recurrence of symptoms and high reintervention rates post-LAMS removal reinforce the difficulty in managing benign gastrointestinal strictures but also argue for LAMS as a definitive therapy in select cases.

Innovative Design of a 3D Printed Esophageal Stent Inspired by Nature: Mitigating Migration Challenges in Palliative Esophageal Cancer Therapy

Esophageal cancer is a complex and challenging tumor to treat, with esophageal stenting being used as a palliative measure to improve the quality of life of patients. Self-expandable metal stents (SEMS), self-expandable plastic stents (SEPS), and biodegradable stents are the most commonly used types of stents. However, complications can arise, such as migration, bleeding, and perforation. To address issues of migration, this study developed a novel 3D printed bioinspired esophageal stent utilizing a highly flexible and ductile TPU material. The stent was designed to be self-expanding and tubular with flared ends to provide secure anchorage at both the proximal and distal ends of the structure. Suction cups were strategically placed around the shaft of the stent to prevent migration. The stent was evaluated through compression-recovery, self-expansion, and anti-migration tests to evaluate its recovery properties, self-expansion ability, and anchoring ability, respectively. The results indicated that the novel stent was able to recover its shape, expand, keep the esophagus open, and resist migration, demonstrating its potential for further research and clinical applications. Finite element analysis (FEA) was leveraged to analyze the stent's mechanical behavior, providing insights into its structural integrity, self-expansion capability, and resistance against migration. These results, supported by FEA, highlight the potential of this innovative stent for further research and its eventual application in preclinical settings.

Comprehensive review of materials, applications, and future innovations in biodegradable esophageal stents

Esophageal stricture (ES) results from benign and malignant conditions, such as uncontrolled gastroesophageal reflux disease (GERD) and esophageal neoplasms. Upper gastrointestinal endoscopy is the preferred diagnostic approach for ES and its underlying causes. Stent insertion using an endoscope is a prevalent method for alleviating or treating ES. Nevertheless, the widely used self-expandable metal stents (SEMS) and self-expandable plastic stents (SEPS) can result in complications such as migration and restenosis. Furthermore, they necessitate secondary extraction in cases of benign esophageal stricture (BES), rendering them unsatisfactory for clinical requirements. Over the past 3 decades, significant attention has been devoted to biodegradable materials, including synthetic polyester polymers and magnesium-based alloys, owing to their exceptional biocompatibility and biodegradability while addressing the challenges associated with recurring procedures after BES resolves. Novel esophageal stents have been developed and are undergoing experimental and clinical trials. Drug-eluting stents (DES) with drug-loading and drug-releasing capabilities are currently a research focal point, offering more efficient and precise ES treatments. Functional innovations have been investigated to optimize stent performance, including unidirectional drug-release and anti-migration features. Emerging manufacturing technologies such as three-dimensional (3D) printing and new biodegradable materials such as hydrogels have also contributed to the innovation of esophageal stents. The ultimate objective of the research and development of these materials is their clinical application in the treatment of ES and other benign conditions and the palliative treatment of malignant esophageal stricture (MES). This review aimed to offer a comprehensive overview of current biodegradable esophageal stent materials and their applications, highlight current research limitations and innovations, and offer insights into future development priorities and directions.

Caustic esophageal stenosis: A case report of endoscopic dilatation with nasogastric tubes

The management of the esophageal strictures that may result from caustic ingestion has evolved over time, from surgical to endoscopic management. Dilation with nasogastric tubes may be a valuable alternative in places with limited resources.

Lumen-apposing metal stents for the treatment of benign gastrointestinal tract strictures: a single-center experience and proposed treatment algorithm

BACKGROUND

Lumen-apposing metal stents (LAMS) are an alternative therapeutic option for benign gastrointestinal (GI) tract strictures. Our study aimed to evaluate the safety and efficacy of LAMS for the management of benign GI strictures.

METHODS

Consecutive patients who underwent a LAMS placement for benign luminal GI strictures at a tertiary care center between January 2014 and July 2021 were reviewed. Primary outcomes included technical success, early clinical success, and adverse events (AEs). Other outcomes included rates of stent migration and re-intervention after LAMS removal.

RESULTS

One hundred and nine patients who underwent 128 LAMS placements (67.9% female, mean age of 54.3 ± 14.2 years) were included, and 70.6% of the patients had failed prior endoscopic treatments. The majority of strictures (83.5%) were anastomotic, and the most common stricture site was the gastrojejunal anastomosis (65.9%). Technical success was achieved in 100% of procedures, while early clinical success was achieved in 98.4%. The overall stent-related AE rate was 25%. The migration rate was 27.3% (35/128). Of these, five stents were successfully repositioned endoscopically. The median stent dwell time was 119 days [interquartile range (IQR) 68-189 days], and the median follow-up duration was 668.5 days [IQR: 285.5-1441.5 days]. The re-intervention rate after LAMS removal was 58.3%.

CONCLUSIONS

LAMS is an effective therapeutic option for benign GI strictures, offering high technical and early clinical success. However, the re-intervention rate after LAMS removal was high. In select cases, using LAMS placement as destination therapy with close surveillance is a reasonable option.

Managing esophageal strictures following endoscopic resection of superficial neoplastic lesions

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

Mechanical properties and degradation process of biliary self-expandable biodegradable stents

OBJECTIVES

The clinical outcomes and prevalence of adverse events associated with biliary biodegradable stents (BS) can differ according to degradation process and time. The aim of this study was to observe the degradation process and time of different BS prototypes, and to evaluate sequential changes in their mechanical properties.

METHODS

Using an in vitro bile flow phantom model, we compared degradation time, radial force changes, and morphologic changes among four different BS prototypes: polydioxanone (PDO) BS, polyglycolide (PGA) BS, polydioxanone/poly-l-lactic acid (PDO/PLLA) sheath-core BS, and polydioxaone/magnesium (PDO/Mg) sheath-core BS. Using an in vivo swine bile duct dilation model, we performed a direct peroral cholangioscopy (DPOC) examination to observe the biodegradation process and related adverse events at regular intervals.

RESULTS

In the bile flow phantom model, the PGA BS and PDO/Mg BS prototypes showed rapid radial force reduction and morphological changes and complete degradation within six weeks. PDO/PLLA BS maintained high radial force and kept their original shape for longer than the PDO BS, up to 16 weeks. A total of 24 BS were inserted into the dilated bile ducts of 12 swine. In this animal model, DPOC examination revealed that PDO BS and PDO/PLLA BS maintained their original shapes for approximately 12 weeks, but PDO BS showed a greater degree of fragmentation and induced biliary stones and bile duct obstruction.

CONCLUSION

Our results showed that PDO/PLLA BS maintained their original shape and radial force for a relatively long time and minimized adverse events.

[Palliative endoscopy]

Endoscopy is the leading method in the diagnostics of gastrointestinal malignancies. With the increasing incidences of various tumor entities, a palliative treatment situation is already present in many patients despite an increasing number of screening strategies. Palliative endoscopy can make an essential contribution to alleviation of tumor-related symptoms, such as dysphagia, malnutrition, cholestasis, ileus and pain. Various approaches can be offered to safeguard the nutrition, e.g. percutaneous endoscopic gastrostomy (PEG) and percutaneous endoscopic jejunostomy (PEJ), for maintenance of the gastrointestinal passage (stents) and secretion drainage or to drain congested hollow organs. Furthermore, in cases of inaccessibility or impassability of stenoses due to tumors, endosonographically assisted punctures offer the possibility to guarantee new drainage options or continuities by stent placement. In all interventions possible contraindications and complications must be taken into account.

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.

Management of tracheo-oesophageal fistula in adults

Tracheo-oesophageal fistula (TOF) is a pathological connection between the trachea and the oesophagus that is associated with various underlying conditions including malignancies, infections, inhalation injuries and traumatic damage. As the condition spans multiple organ systems with varying aetiologies and acuities, TOF poses unique diagnostic and management challenges to pulmonologists, gastroenterologists and thoracic surgeons alike. Although stents have been a cornerstone in the management of TOF, there exists a large gap in our understanding of their efficacy and precise methodology, making stenting procedure both art and science. TOFs relating to underlying oesophageal or tracheal malignancies require advanced understanding of the airway and digestive tract anatomy, dimensions of the fistula, stent characteristics and types, and the interplay between the oesophageal stent and the airway stent if dual stenting procedure is elected. In this review article, we review the most up-to-date data on risk factors, clinical manifestations, diagnostic approaches, management methods and prognosis. Consequently, this article serves to evaluate current therapeutic strategies and the future directions in the areas of 3D-printed stents, over-the-scope clipping systems, tissue matrices and atrial septal closure devices.

Corrosive injury of the upper gastrointestinal tract: the evolving role of a radiologist

Corrosive injury is a devastating injury which carries significant morbidity. The upper gastrointestinal tract is predominantly affected with severity ranging from mild inflammation to full thickness necrosis which may result in perforation and death. Among the complications, stricture formation is most common, causing dysphagia and malnutrition. Endoscopy has a pivotal role in the diagnosis and management, with a few shortcomings. Imaging has an important role to play. Besides radiography, there is an increasing role of CT scan in the emergency setting with good accuracy in identifying patients who are likely to benefit from surgery. Further, CT scan has a role in the diagnosis of complications. Oral contrast studies help in assessing the severity and extent of stricture formation and associated fistulous complications in the subacute and chronic phase. The scope of intervention radiology for this condition is increasing. Fluoroscopy-guided balloon dilatation, drainage of collections or mucoceles, endovascular embolization of point bleeders, placement of feeding jejunostomy and image-guided biopsy are among the procedures that are being performed. Through this review we aim to stress the role the radiologist plays in the diagnosis and follow-up of these patients and in performing radiological interventions. Besides this, we have also highlighted few salient points to help understand the pathophysiology and management of such injuries which is paramount to ensure a good long-term outcome.

Alternative uses of lumen apposing metal stents

The advent of lumen apposing metal stents (LAMS) has revolutionized the management of many complex gastroenterological conditions that previously required surgical or radiological interventions. These procedures have garnered popularity due to their minimally invasive nature, higher technical and clinical success rate and lower rate of adverse events. By virtue of their unique design, LAMS provide more efficient drainage, serve as conduit for endoscopic access, are associated with lower rates of leakage and are easy to be removed. Initially used for drainage of pancreatic fluid collections, the use of LAMS has been extended to gallbladder and biliary drainage, treatment of luminal strictures, creation of gastrointestinal fistulae, pancreaticobiliary drainage, improved access for surgically altered anatomy, and drainage of intra-abdominal and pelvic abscesses as well as post-surgical fluid collections. As new indications of endosonographic techniques and LAMS continue to evolve, this review summarizes the current role of LAMS in the management of these various complex conditions and also highlights clinical pearls to guide successful placement of LAMS.

Clinical outcomes of lumen-apposing metal stent in the management of benign gastrointestinal strictures: a systematic review and meta-analysis

Background and aims: Lumen-apposing metal stent (LAMS) have been considered as a viable alternative to treat benign gastrointestinal (GI) strictures. We aimed to determine the efficacy and safety of LAMS for benign GI strictures. Methods: Medline, Embase, Cochrane, and PubMed databases were searched using the keywords 'benign stricture', 'gastrointestinal stricture', 'lumen-apposing metal stent' and related terms on December 2018. Articles were selected for review by two authors independently according to predefined inclusion criteria and exclusion criteria. A meta-analysis using a random effects model was performed. Results: Six studies with a total of 144 patients were included in the final analysis (60 males, 41.7%). Overall, the pooled technical success rate was 98.3% [95% confidence interval (CI): 0.962-1.004], clinical success rate was 73.8% (95% CI: 0.563-0.912) and adverse events rate was 30.6% (95% CI: 0.187-0.425). The most common complication associated with LAMS for benign GI strictures was migration, and the pooled events rate was 10.9% (95% CI: 0.058-0.160). According to locations of stricture, subgroup analysis was performed in terms of clinical success [Esophagogastric: 63.9% (95% CI: 0.365-0.914); Gastroduodenal: 67.4% (95% CI: 0.421-0.927); Gastrojejunal: 78% (95% CI: 0.638-0.922); Pylorus: 77.6% (95% CI: 0.551-1.002); Colonic: 85.3% (95% CI: 0.515-1.191)]. Conclusions: Although the safety of LAMS placement in benign GI strictures is not very satisfactory, it is associated with a low migration rate. LAMS can achieve clinical symptom improvement or resolution in most patients with benign GI strictures, and it might be an alluring prospect for treating patients with this difficult condition.

A Review of Self-Expanding Esophageal Stents for the Palliation Therapy of Inoperable Esophageal Malignancies

Esophageal cancer is a very deadly disease, killing more than 15,000 people in the United States annually. Almost 400,000 new cases happen in the worldwide every year. More than 50% esophageal cancer patients are diagnosed at an advanced stage when they need an esophageal stent to open the blocked esophagus for feeding and drinking. Esophageal stents have evolved in stages over the years. Current clinically used stents commonly include stainless steel or nitinol self-expandable metallic stent (SEMS) and self-expandable plastic stent (SEPS). There are many choices of different types of stents and sizes, with fierce competition among manufacturers. However, current stent technology, whether uncovered, partially covered, fully covered SEMS or SEPS, has their own advantages to solve the dysphagia, stricture, and fistula problems, but they also cause some clinical complications. The ideal stent remains elusive. New 3D printing technique may bring new promising potential to manufacturing personalized esophageal stents. Drug-eluting stents could be the new avenue to do more than just pry open a stricture or cover a defect in the esophageal lumen, a possibility of proving local anticancer therapy simultaneously. Additionally, the lack of esophageal cancer animal models also hinders the progress of stent development. This paper reviews these topics for a comprehensive understanding of this field. In a conclusion, the ultimate goal of the future esophageal stent would have multifunction to treat the underlying conditions and restore esophageal function to near normal.

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.

3D-printed flexible polymer stents for potential applications in inoperable esophageal malignancies

Palliation therapy for dysphagia using esophageal stents is the current treatment of choice for those patients with inoperable esophageal malignancies. However, the metallic and plastic stents currently used in the clinical setting may cause complications, such as tumor ingrowth and stent migration into the stomach. To effectively reduce/overcome these complications, we designed a tubular, flexible polymer stent with spirals. The parameters of the spirals were computationally optimized by using a finite element analysis. The designed polymer stents with optimized spirals were then printed by a 3D printing technique. 3D-printed tubular polymer stents without spirals served as controls. The self-expansion and anti-migration properties of the printed stent were characterized in an ex vivo normal porcine esophagus. The biodegradability test of the stent was performed in a neutral buffer and acidic gastric buffer. The cytotoxicity of the new stent was examined through the viability test of human esophagus epithelial cells. Results showed the self-expansion force of the 3D-printed polymer stent with spirals was higher than the stent without spirals. The anti-migration force of the 3D-printed stent with spirals was significantly higher than that of the stent without spirals. Furthermore, the stent with spirals significantly decreased the migration distance compared to the non-spiral 3D-printed polymer stent. Degradation study showed that the polymer materials started to degrade after six weeks and the compressive strength of the stent was not significantly decreased with time. In vitro cell viability results further indicated that the polymer stent does not have any cytotoxicity. Together, these results showed that the 3D-printed stent with spirals has potential applications in the treatment of inoperable esophageal malignancies. STATEMENT OF SIGNIFICANCE: In this study, we developed a new 3D-printed flexible tubular polymeric stent with spirals. The mechanical properties of the 3D-printed polymer stent are modulated by changing the ratios of PLA to TPU. The stent is flexible enough to be compressed in a clinically available stent delivery system, and can self-expand after it is released. The self-expansion force of the stent with spirals is higher than that of non-spiral stents. The spirals on the outside of the stent significantly increased the anti-migration force compared to non-spiral stents in an ex vivo normal pig esophagus. Together, the 3D-printed stent with spirals will bring promising potential in the treatment of inoperable esophagus malignancies or benign strictures.

Efficacy and safety of lumen-apposing metal stent for benign gastrointestinal stricture

Management of benign gastrointestinal (GI) strictures refractory to primary (balloon and savary dilation) and secondary (steroid injection, fully covered self-expanding metal stent, incision therapy) treatment modalities remains a challenge. Lumen-apposing metal stents (LAMSs), originally designed for the management of pancreatic fluid collections, are an attractive option for GI stricture because of their anti-migratory property, attributable to their saddle-shaped design. In this article, we reviewed 70 patients from 12 original studies who received LAMS for refractory (68/70) or treatment-naïve (2/70) benign GI stricture. The technical and clinical success rates were 98.6% (69/70) and 79.7% (55/69), respectively. Endoscopic placement, with or without fluoroscopic guidance, was generally successful, with only a minority requiring endoscopic ultrasound (EUS) guidance where the lumen was completely obscured. The majority of the strictures were short (≤1 cm), but comparable technical and clinical success was noted in isolated cases with long strictures, where 2 overlapping LAMSs were placed. For the overall population, a failure rate of 21.5% (14/69) was noted and was attributed to either lack of follow up, or to persistent or de novo symptoms requiring stent removal/exchange or surgical referral. One perforation (1.4%), five stent migration events (7.1%), two bleeding events (2.9%) and two de novo strictures proximal to the LAMS (2.9%) were reported for the entire study cohort. No mortality was attributable to LAMS placement. Although experience is still evolving, LAMS placement guided by esophagogastroduodenoscopy or EUS is a technically feasible and safe procedure with good clinical outcomes for benign refractory GI strictures.

Novel Uses of Lumen-Apposing Metal Stents

The lumen apposing metal stent (LAMS) has historically been used for drainage of pancreatic fluid collections. The unique design of this stent has allowed endoscopists to develop novel uses, including drainage of abscesses adjacent to gastrointestinal lumens, maintaining patency in gastrointestinal strictures, and creating a fistulous tract to bypass altered or compromised anatomy. These alternative uses for the LAMS take advantage of its ability to form a sealed, well-approximated anastomosis. Future applications of the LAMS are continuously being developed as clinicians provide minimally invasive approaches for management of these disease processes.

Self-Expanding Biodegradable Stents for Postoperative Upper Gastrointestinal Issues

BACKGROUND AND OBJECTIVES

Endoscopic stenting is a minimally invasive treatment modality for patients with various gastrointestinal conditions. We evaluated the safety and efficacy of uncovered biodegradable stents for postoperative leaks and strictures in the upper gastrointestinal tract.

METHODS

This was a retrospective study of patients treated endoscopically with biodegradable stents from January 2010 through November 2017.

RESULTS

Thirteen patients were enrolled, 7 of whom were men. Their mean age was 46 (range, 21-82) years. The indications for stent placement were postoperative leakage and stricture in 9 and 4 patients, respectively. The primary diagnoses were obesity in 7 patients, gastric cancer in 5, and peptic ulcer in 1. The average time to stent placement after surgery was 35 (range, 17-125) and 166 (range, 153-185) days for patients with postoperative leakage and stricture, respectively. Stent insertion was successful at the first attempt in all patients. Complete resolution of the leak and stricture was achieved after stent application in 11 patients, for a clinical success rate of 85%. The mean follow-up duration was 50 (range, 24-76) months. There were no major complications.

CONCLUSIONS

Compared to self-expanding metal and plastic stents, the main advantages of uncovered biodegradable stents are that they do not have to be removed and have a low migration rate. Our results suggest that these stents have promise for management of postoperative gastrointestinal complications. Further randomized trials with larger sample sizes are necessary to determine the role of biodegradable stents in the treatment algorithm.

Use of a lumen-apposing metal stent to treat GI strictures (with videos)

BACKGROUND AND AIMS

Benign GI strictures occur typically in the esophagus and pyloric channel but can occur anywhere in the GI tract and at anastomotic sites. Such strictures can be treated with dilation, incisional therapy, steroid injection, and stents. Our aim was to describe the use of a lumen-apposing metal stent (LAMS) to treat short, benign GI strictures.

PATIENTS AND METHODS

Consecutive patients who underwent LAMS placement for various benign strictures at 2 tertiary care centers from August 2014 to November 2015 were reviewed retrospectively. The main outcome measures were technical success, clinical success, stent migration, and adverse events.

RESULTS

Twenty-five patients (7 males, 18 females) with a median age of 54 years (33-85 years) underwent 28 LAMS placements to treat various benign strictures. The location of the strictures included esophagogastric anastomoses (n=4), gastrojejunal anastomoses (n=13), pylorus (n=6), vertical banded gastroplasty (n=1), and ileocolonic anastomosis (n=1). Twenty patients had been previously treated with dilation alone (9 patients with ≥3 dilations), 11 patients with dilation and steroid injection, 2 patients with additional needle-knife therapy, and 1 patient with placement of a traditional fully covered self-expandable metal stent. A 15-mm internal diameter LAMS was placed in all patients; 3 patients had been treated previously with a 10-mm LAMS. Technical success was achieved in all patients, whereas clinical success was achieved in 15 of 25 patients (60%) who completed a minimum of 6 months of follow-up after placement. Median stent dwell time was 92 days (range, 3-273 days). Stent migration was seen in 2 of 28 stent placements (7%). Four of 25 patients (16%) developed 5 moderate adverse events (pain requiring removal, 2; new stricture formation, 2; bleeding, 1). Median follow-up was 301 days after stent placement. Study limitations include the small, select group of patients, the retrospective study design, and short follow-up.

CONCLUSIONS

LAMS placement for benign GI strictures is technically easy and safe with low migration rates and may be an option to treat selected patients with short-length strictures.

Management of esophageal caustic injury

Ingestion of caustic substances and its long-term effect on the gastrointestinal system maintain its place as an important public health issue in spite of the multiple efforts to educate the public and contain its growing number. This is due to the ready availability of caustic agents and the loose regulatory control on its production. Substances with extremes of pH are very corrosive and can create severe injury in the upper gastrointestinal tract. The severity of injury depends on several aspects: Concentration of the substance, amount ingested, length of time of tissue contact, and pH of the agent. Solid materials easily adhere to the mouth and pharynx, causing greatest damage to these regions while liquids pass through the mouth and pharynx more quickly consequently producing its maximum damage in the esophagus and stomach. Esophagogastroduodenoscopy is therefore a highly recommended diagnostic tool in the evaluation of caustic injury. It is considered the cornerstone not only in the diagnosis but also in the prognostication and guide to management of caustic ingestions. The degree of esophageal injury at endoscopy is a predictor of systemic complication and death with a 9-fold increase in morbidity and mortality for every increased injury grade. Because of this high rate of complication, prompt evaluation cannot be overemphasized in order to halt development and prevent progression of complications.

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.

Silicone-covered biodegradable magnesium-stent insertion in the esophagus: a comparison with plastic stents

BACKGROUND

We determined the feasibility of, and tissue response to silicone-covered biodegradable magnesium- and plastic-stent insertion into the esophagus in rabbits.

METHODS

The mechanical compression-recovery characteristics and degradation behaviors of the magnesium stent were investigated in vitro. A total of 45 rabbits were randomly divided into a magnesium- (n = 15) and a plastic- (n = 15) stent group, and underwent stent insertion into the lower third of the esophagus under fluoroscopic guidance; a control group (n = 15) did not undergo the intervention. Esophagography was performed at 1, 2, and 4 weeks. Five rabbits in each group were euthanized at each time point for histological examination.

RESULTS

Silicone-covered magnesium stents showed similar radial force to plastic stents (p > 0.05). The magnesium stents degraded rapidly in an acidic solution, but 90.2% ± 3.1% of the residual mass was maintained after a 2-week degradation in a solution with a pH of 4.0. All stent insertions were well tolerated. Magnesium stents migrated in six rabbits (one at 1 week, one at 2 weeks and four at 4 weeks), and plastic stents migrated in three rabbits (one at 2 weeks and two at 4 weeks; p > 0.05). Esophageal wall remodeling (thinner epithelial and smooth muscle layers) was similar in both stented groups (p > 0.05), and the esophagus wall was found to be significantly thinner in the stented groups than in the control group (p < 0.05). Esophageal injury and collagen deposition following stent insertion were similar and did not differ from the control group (p > 0.05).

CONCLUSIONS

Esophageal silicone-covered magnesium stents provided reliable support for at least 2 weeks, with acceptable migration rates and without causing severe injury or tissue reaction compared with plastic stents.

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

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

Technical feasibility and tissue reaction after silicone-covered biodegradable magnesium stent insertion in the oesophagus: a primary study in vitro and in vivo

OBJECTIVES

Determine the feasibility of and tissue response to biodegradable magnesium-silicone stent insertion into the oesophagus of rabbits.

METHODS

Mechanical compression-recovery and degradation behaviours of the stents were investigated in vitro. Thirty rabbits were randomly divided into a magnesium-silicone stent group (n = 15) that received stent insertion into the lower 1/3 of the oesophagus under fluoroscopic guidance and a control group (n = 15). Oesophagography was performed at 1, 2 and 4 weeks. Five rabbits in each group were euthanized at each time point for histological examination.

RESULTS

Magnesium-silicone stents showed good flexibility and elasticity, and degraded more slowly than bare stents at pH 4.0 and 7.4. All stent insertions were well tolerated. The oesophageal diameters at 1, 2 and 4 weeks were 9.7 ± 0.7, 9.6 ± 0.8 and 9.6 ± 0.5 mm, respectively (vs. 9.2 ± 0.8 mm before intervention; P > 0.05). Stent migration occurred in six rabbits (one at 1 week, one at 2 and four at 4). Microscopy demonstrated dilation of the oesophageal wall within 1 week of insertion. Oesophageal injury and collagen deposition following stent insertion were similar to control (P > 0.05).

CONCLUSIONS

Oesophageal magnesium-silicone stent insertion was feasible and provided reliable support for 2 weeks without causing oesophageal injury or collagen deposition.

KEY POINTS

• Mg stent provided apparently adequate radial force and silicone membrane reduced magnesium biodegradation • Stent insertion provided good support for at least 2 weeks before biodegradation • Stenting effectively resulted in oesophageal wall remodelling, without demonstrable injury.

A Comparison of a Fully Covered and an Uncovered Segmented Biodegradable Esophageal Stent in a Porcine Model: Preclinical Evaluation of Degradation, Complications, and Tissue Reactions

Aims. This study was to compare the degradation, complications, and tissue reactions of two segmented biodegradable esophageal stents in a porcine model. Methods. Uncovered biodegradable segmented stents and fully covered biodegradable segmented stents (FCBDS) were transplanted into the porcine esophagus lumen. Data on biodegradation, complications, and tissue reactions were collected and compared. Results. All animals kept good general conditions. No severe complications and stents migration occurred. Stents degradation commenced at week 3. Compared with uncovered stents, stents structure breakage and complete stents absorption in FCBDS were postponed for 1-2 weeks. Hyperplasia was prominent at early stage and ameliorated at late stage after stents insertion. Tissue reactions in FCBDS were milder than those in uncovered stents in the early stage. A longer degradation period was present in FCBDS than in uncovered stents, while FCBDS induced tissue reaction at late stage was mild. Conclusions. Biodegradable esophageal stents with a segmented trunk may be further evaluated in refractory benign esophagus strictures. This FCBDS may be advantageous compared with uncovered stents for a longer degradation period.

Caustic Esophageal Stenosis: A Case Report of Endoscopic Dilation With a Dynamic Stent

INTRODUCTION

The management of esophageal strictures has evolved from surgical treatment to the endoscopic dilation and, more recently, esophageal stenting.

CLINICAL CASE

We describe a case of a two-year-old boy with a double stenosis of the esophagus resulting from accidental ingestion of strong alkaline liquid. After several unsuccessful endoscopic dilations for three years and even topical mitomicin, it was decided to place a dynamic stent developed by the Digestive Surgery and Endoscopic Unit of the Bambino Gesù Hospital, Rome. The stent is a custom silicon device built coaxially on a nasogastric tube that is inserted after stricture dilations, by endoscopic guidance, and then fixed outside the nose. The device was removed after seven weeks with good clinical outcome (no dysphagia more than a year of follow-up).

CONCLUSION

This case confirms that the dynamic stent is a simple device that may avoid aggressive surgical substitution in cases of refractory strictures.

Endoscopic incisional therapy for benign esophageal strictures: Technique and results

Benign esophageal strictures refractory to the conventional balloon or bougie dilatation may be subjected to various adjunctive modes of therapy, one of them being endoscopic incisional therapy (EIT). A proper delineation of the stricture anatomy is a prerequisite. A host of electrocautery and mechanical devices may be used, the most common being the use of needle knife, either standard or insulated tip. The technique entails radial incision and cutting off of the stenotic rim. Adjunctive therapies, to prevent re-stenosis, such as balloon dilatation, oral or intralesional steroids or argon plasma coagulation can be used. The common strictures where EIT has been successfully used are Schatzki’s rings (SR) and anastomotic strictures (AS). Short segment strictures (< 1 cm) have been found to have the best outcome. When compared with routine balloon dilatation, EIT has equivalent results in treatment naïve cases but better long term outcome in refractory cases. Anecdotal reports of its use in other types of strictures have been noted. Post procedure complications of EIT are mild and comparable to dilatation therapy. As of the current evidence, incisional therapy can be used for management of refractory AS and SR with relatively short stenosis (< 1 cm) with good safety profile and acceptable long term patency.

Therapy of caustic ingestion: new treatment considerations

PURPOSE OF REVIEW

This review will focus on therapeutic considerations and recent advances in treatment of caustic ingestion injuries.

RECENT FINDINGS

A retrospective study suggests that it may be safe to advance the endoscope beyond the first circumferential burn to allow for a more complete assessment of extent of injury. A randomized controlled prospective study suggested that a 3-day course of high-dose methylprednisolone might reduce the occurrence of esophageal stricture formation. Balloon dilatation has been shown to be as effective as other bougienage techniques with lower risk of perforations. Recent studies indicate that esophageal dilatation can be safely performed as early as 5-15 days after initial ingestion and may decrease risk for long-term stricture formation. The use of adjunctive treatment, such as topical mitomycin C and esophageal stents, shows promise in reducing the reoccurrence of stricture formation after dilatation.

SUMMARY

Caustic ingestion remains a significant problem in children, despite continued efforts to educate the public about ways to avoid this preventable accident. Because there are few good quality therapeutic trials in children, many of the current recommendations regarding treatment are based on expert opinion. Large, prospective, multicenter, controlled treatment trials are needed to identify the best protocols to prevent serious complications.

Stent-in-stent technique for removal of embedded partially covered self-expanding metal stents

BACKGROUND

Removal of embedded partially covered self-expanding metal stents (PCSEMS) is associated with an increased risk of adverse events compared with removal of fully covered self-expanding stents (FCSES) due to tissue ingrowth. Successful removal of embedded PCSEMS has been described by the stent-in-stent (SIS) technique.

AIMS

To report the first US experience from three high-volume quaternary care centers on the safety and efficacy of the SIS technique for removal of embedded PCSEMS.

METHODS

Retrospective study of outcomes for consecutive patients who underwent the SIS for removal of embedded PCSEMS over a 5-year period.

RESULTS

Twenty-seven embedded PCSEMS were successfully removed using the SIS technique (100 %) from 25 patients (11 males), median age 65 (range 37-80). All stents were successfully removed in one endoscopic session (no repeat SIS procedures were required for persistently embedded stents). The embedded PCSEMS had been in situ for a median of 76 days (range 26-501). Median SIS dwell time (FCSES in situ of PCSEMS) was 13 days (interquartile range 8-16 days; range 4-212 days). One adverse event (self-limited bleeding) occurred during a median follow-up period of 3 months (range 1-32). No patients died, required surgery, or had long-term disability due to adverse events attributed to the SIS technique. Twelve patients required additional interventions following SIS procedure for persistence or recurrence of the underlying pathology.

CONCLUSION

When performed by experienced endoscopists, safe and effective removal of embedded PCSEMS can be achieved via the SIS technique.

Foregut caustic injuries: results of the world society of emergency surgery consensus conference

INTRODUCTION

Lesions of the upper digestive tract due to ingestion of caustic agents still represent a major medical and surgical emergency worldwide. The work-up of these patients is poorly defined and no clear therapeutic guidelines are available.

PURPOSE OF THE STUDY

The aim of this study was to provide an evidence-based international consensus on primary and secondary prevention, diagnosis, staging, and treatment of this life-threatening and potentially disabling condition.

METHODS

An extensive literature search was performed by an international panel of experts under the auspices of the World Society of Emergency Surgery (WSES). The level of evidence of the screened publications was graded using the Oxford 2011 criteria. The level of evidence of the literature and the main topics regarding foregut caustic injuries were discussed during a dedicated meeting in Milan, Italy (April 2015), and during the 3rd Annual Congress of the World Society of Emergency Surgery in Jerusalem, Israel (July 2015).

RESULTS

One-hundred-forty-seven full papers which addressed the relevant clinical questions of the research were admitted to the consensus conference. There was an unanimous consensus on the fact that the current literature on foregut caustic injuries lacks homogeneous classification systems and prospective methodology. Moreover, the non-standardized definition of technical and clinical success precludes any accurate comparison of therapeutic modalities. Key recommendations and algorithms based on expert opinions, retrospective studies and literature reviews were proposed and approved during the final consensus conference. The clinical practice guidelines resulting from the consensus conference were approved by the WSES council.

CONCLUSIONS

The recommendations emerging from this consensus conference, although based on a low level of evidence, have important clinical implications. A world registry of foregut caustic injuries could be useful to collect a homogeneous data-base for prospective clinical studies that may help improving the current clinical practice guidelines.

Recent advancement of therapeutic endoscopy in the esophageal benign diseases

Over the past 30 years, the field of endoscopy has witnessed several advances. With the advent of endoscopic mucosal resection, removal of large mucosal lesions have become possible. Thereafter, endoscopic submucosal resection was refined, permitting en bloc removal of large superficial neoplasms. Such techniques have facilitated the development of antireflux mucosectomy, a promising novel treatment for gastroesophageal reflux. The introduction and use of over the scope clips has allowed for endoscopic closure of defects in the gastrointestinal tract, which were traditionally treated with surgical intervention. With the development of per-oral endoscopic myotomy (POEM), the treatment of achalasia and spastic disorders of the esophagus have been revolutionized. From the submucosal tunnelling technique developed for POEM, Per oral endoscopic tumor resection of subepithelial tumors was made possible. Simultaneously, advances in biotechnology have expanded esophageal stenting capabilities with the introduction of fully covered metal and plastic stents, as well as biodegradable stents. Once deemed a primarily diagnostic tool, endoscopy has quickly transcended to a minimally invasive intervention and therapeutic tool. These techniques are reviewed with regards to their application to benign disease of the esophagus.

Refractory esophageal strictures: what to do when dilation fails

Benign esophageal strictures arise from a diversity of causes, for example esophagogastric reflux, esophageal resection, radiation therapy, ablative therapy, or the ingestion of a corrosive substance. Most strictures can be treated successfully with endoscopic dilation using bougies or balloons, with only a few complications. Nonetheless, approximately one third of patients develop recurrent symptoms after dilation within the first year. The majority of these patients are managed with repeat dilations, depending on their complexity. Dilation combined with intra lesional steroid injections can be considered for peptic strictures, while incisional therapy has been demonstrated to be effective for Schatzki rings and anastomotic strictures. When these therapeutic options do not resolve the stenosis, stent placement should be considered. Self bougienage can be proposed to a selected group of patients with a proximal stenosis. As a final step surgery is an option, but even then the risk of stricture formation at the anastomotic site remains. This chapter reviews refractory benign esophageal strictures and the treatment options that are currently available.

Caustic injury of the oesophagus

Caustic ingestion continues to be a significant problem world-wide especially in developing countries and particularly in the under 6 years age group. The presence or absence of symptoms or oral lesions does not reliably predict the existence or severity of oesophageal lesions. Upper endoscopy remains the mainstay diagnostic modality for evaluation to define the extent and severity of the injury. The best predictor of morbidity and mortality is the extent of injury as assessed during initial evaluation. Early management strategies for caustic ingestion are well defined. Controversy still surrounds the use of steroids, antibiotics, antacid therapy in the acute phase, and the use of oesophageal stents and the frequency, timing and method of dilatation in the prevention and management of oesophageal strictures. There is a pressing need for non-invasive diagnostic modalities and effective therapeutic options to evaluate and treat the complications associated with caustic ingestion. Indications for definitive surgery or bypass and the type of procedure to use are also subject to ongoing debate.