Endoscopic luminal stenting: Current applications and future perspectives

Endoscopic luminal stenting (ELS) represents a minimally invasive option for the management of malignant obstruction along the gastrointestinal tract. Previous studies have shown that ELS can provide rapid relief of symptoms related to esophageal, gastric, small intestinal, colorectal, biliary, and pancreatic neoplastic strictures without compromising cancer patients’ overall safety. As a result, in both palliative and neoadjuvant settings, ELS has largely surpassed radiotherapy and surgery as a first-line treatment modality. Following the abovementioned success, the indications for ELS have gradually expanded. To date, ELS is widely used in clinical practice by well-trained endoscopists in managing a wide variety of diseases and complications, such as relieving non-neoplastic obstructions, sealing iatrogenic and non-iatrogenic perforations, closing fistulae and treating post-sphincterotomy bleeding. The abovementioned development would not have been achieved without corresponding advances and innovations in stent technology. However, the technological landscape changes rapidly, making clinicians’ adaptation to new technologies a real challenge. In our mini-review article, by systematically reviewing the relevant literature, we discuss current developments in ELS with regard to stent design, accessories, techniques, and applications, expanding the research basis that was set by previous studies and highlighting areas that need to be further investigated.

Use of double-layered covered esophageal stents in post-surgical esophageal leaks and esophageal perforation: Our experience

INTRODUCTION

The use of esophageal stents for the endoscopic management of esophageal leaks and perforations has become a usual procedure. One of its limitations is its high migration rate. To solve this incovenience, the double-layered covered esophageal stents have become an option.

OBJECTIVES

To analyse our daily practice according to the usage of double-layered covered esophageal metal stents (DLCEMS) (Niti S™ DOUBLE™ Esophageal Metal Stent Model) among patients diagnosed of esophageal leak or perforation.

METHODS

Retrospective, descriptive and unicentric study, with inclusion of patients diagnosed of esophageal leak or perforation, from November 2010 until October 2018. The main aim is to evaluate the efficacy of DLCEMS, in terms of primary success and technical success. The secondary aim is to evaluate their (the DLCEMS) safety profile.

RESULTS

Thirty-one patients were firstly included. Among those, 8 were excluded due to mortality not related to the procedure. Following stent placement, technical success was reached in 100% of the cases, and primary success, in 75% (n=17). Among the complications, stent migration was present in 21.7% of the patients (n=5), in whom the incident was solved by endoscopic means.

CONCLUSIONS

According to our findings, DLCEMS represent an alternative for esophageal leak and perforation management, with a high success rate in leak and perforation resolutions and low complication rate, in contrast to the published data. The whole number of migrations were corrected by endoscopic replacement, without the need of a new stent or surgery.

Biodegradable esophageal stents for the treatment of refractory benign esophageal strictures

This review attempts to present the available evidence regarding the use of biodegradable stents in refractory benign esophageal strictures, especially highlighting their impact on clinical success and complications. A comprehensive literature search was conducted in PubMed, using the terms "biodegradable" and "benign"; evidence from cohort and comparative studies, as well as data from one pooled analysis and one meta-analysis are presented. In summary, the results from these studies indicate that the effectiveness of biodegradable stents ranges from more than one third to a quarter of cases, fairly similar to other types of stents used for the same indication. However, their implementation may reduce the need for re-intervention during follow up. Biodegradable stents also seem to reduce the need for additional types of endoscopic therapeutic modalities, mostly balloon or bougie dilations. Results from pooled data are consistent, showing moderate efficacy along with a higher complication rate. Nonetheless, the validity of these results is questionable, given the heterogeneity of the studies included. Finally, adverse events may occur at a higher rate but are most often minor. The lack of high-quality studies with sufficient patient numbers mandates further studies, preferably randomized, to elucidate the exact role of biodegradable stents in the treatment of refractory benign esophageal strictures.

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.

Treatment of refractory post-esophagectomy anastomotic esophageal strictures using temporary fully covered esophageal metal stenting compared to repeated bougie dilation: results of a randomized controlled trial

Background and study aims  Fully covered self-expanding metal stents (FCSEMS) provide an alternative to bougie dilation (BD) for refractory benign esophageal strictures. Controlled studies comparing temporary placement of FCSES to repeated BD are not available. Patients and methods  Patients with refractory anastomotic esophageal strictures, dysphagia scores ≥ 2, and two to five prior BD were randomized to 8 weeks of FCSEMS or to repeated BD. The primary endpoint was the number of BD during the 12 months after baseline treatment. Results  Eighteen patients were included (male 67 %, median age 66.5; 9 received metal stents, 9 received BD). Technical success rate of stent placement and stent removal was 100 %. Recurrent dysphagia occurred in 13 patients (72 %) during follow-up. No significant difference was found between the stent and BD groups for mean number of BD during follow-up (5.4 vs. 2.4, P  = 0.159), time to recurrent dysphagia (median 36 days vs. 33 days, Kaplan-Meier: P  = 0.576) and frequency of reinterventions per month (median 0.3 vs. 0.2, P  = 0.283). Improvement in quality of life score was greater in the stent group compared to the BD group at month 12 (median 26 % vs. 4 %, P  = 0.011). Conclusions  The current data did not provide evidence for a statistically significant difference between the two groups in the number of BD during the 12 months after initial treatment. Metal stenting offers greater improvement in quality of life from baseline at 12 months compared to repeated BD for patients with refractory anastomotic esophageal strictures.

In-vivo oesophageal regeneration in a human being by use of a non-biological scaffold and extracellular matrix

BACKGROUND

Tissue-engineered extracellular matrix populated with autologous pluripotent cells can result in de-novo organogenesis, but the technique is complex, not widely available, and has not yet been used to repair large oesophageal defects in human beings. We aimed to use readily available stents and extracellular matrix to regenerate the oesophagus in vivo in a human being to re-establish swallowing function.

METHODS

In a patient aged 24 years, we endoscopically placed a readily available, fully covered, self-expanding, metal stent (diameter 18 mm, length 120 mm) to bridge a 5 cm full-thickness oesophageal segment destroyed by a mediastinal abscess and leading to direct communication between the hypopharynx and the mediastinum. A commercially available extracellular matrix was used to cover the stent and was sprayed with autologous platelet-rich plasma adhesive gel. The sternocleidomastoid muscle was placed over the matrix. After 4 weeks, stent removal was needed due to stent migration, and was replaced with three stents telescopically aligned to improve anchoring. The stents were removed after 3·5 years and the oesophagus was assessed by endoscopy, biopsy, endoscopic ultrasonography, and high-resolution impedance manometry.

FINDINGS

After stent removal we saw full-thickness regeneration of the oesophagus with stratified squamous epithelium, a normal five-layer wall, and peristaltic motility with bolus transit. 4 years after stent removal, the patient was eating a normal diet and maintaining a steady weight.

INTERPRETATION

Maintenance of the structural morphology of the oesophagus with off-the-shelf non-biological scaffold and stimulation of regeneration with commercially available extracellular matrix led to de-novo structural and functional regeneration of the oesophagus.

FUNDING

None.

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.

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.

Highlights of international digestive endoscopy network 2013

Rapid advances in the technology of gastrointestinal endoscopy as well as the evolution of science have made it necessary for us to continue update in either various endoscopic techniques or state of art lectures relevant to endoscopy. International Digestive Endoscopy Network (IDEN) 2013 was held in conjunction with Korea-Japan Joint Symposium on Gastrointestinal Endoscopy (KJSGE) during June 8 to 9, 2013 at Seoul, Korea. Two days of impressive scientific program dealt with a wide variety of basic concerns from upper gastrointestine (GI), lower GI, pancreaticobiliary endoscopy to advanced knowledge including endoscopic submucosal dissection forum. IDEN seems to be an excellent opportunity to exchange advanced information of the latest issues on endoscopy with experts from around the world. In this special issue of Clinical Endoscopy, we prepared state of art review articles from contributing authors and the current highlights will skillfully deal with very hot spots of each KJSGE, upper GI, lower GI, and pancreaticobiliary sessions by associated editors of Clinical Endoscopy.