Self-expanding Plastic Stents Research Articles

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 3decades, 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.

Covered self-expandable metallic stent versus plastic stent for preoperative endoscopic biliary drainage in patients with pancreatic cancer: a multi-center retrospective cohort study

Background Expanding indications for neoadjuvant chemotherapy (NAC) for resectable pancreatic cancer prolong the period from diagnosis to surgery. In resectable pancreatic cancer with malignant biliary obstruction (MBO), the biliary drainage method without any biliary events is ideally required to safely perform NAC as planned. Plastic stents (PS) have been traditionally used for preoperative biliary drainage; however, recently, covered self-expandable metallic stents (CSEMS) have emerged as a tool for preoperative biliary drainage. Aims To compare CSEMS with PS for preoperative biliary drainage in the management of resectable pancreatic cancer with MBO. Methods In this multicenter retrospective cohort study, we compared CSEMS with PS for preoperative biliary drainage in patients with pancreatic cancer at three tertiary care centers between 2008 and 2019. Results Of the 120 enrolled patients, 45 underwent CSEMS and 75 underwent PS. No significant difference was observed in the basic characteristics between the groups. The rate of recurrent biliary obstruction (RBO) was significantly lower and the time to RBO was significantly longer in the CSEMS group. In multivariate analysis, CSEMS was an independent factor for a longer RBO. However, pancreatitis and cholecystitis were more common in the CSEMS group. The surgery-related adverse events were not significantly different between the two groups, except for longer surgery time and time to discharge in the CSEMS group. Conclusions CSEMS for preoperative endoscopic biliary drainage in patients with pancreatic cancer reduced RBO, although the risk for pancreatitis or cholecystitis could be increased.

Banded RYGB Ring Slippage Endoscopic Removal with Self-expandable Stents: a Comparative Study Between Metallic and Plastic One.

Banded Roux-en-Y gastric bypass (RYGB) was a common bariatric procedure in the 2000s, and the ring slippage is one of its late adverse events. Both plastic and metallic stents have been reported as adjunct methods to induce erosion and facilitate endoscopic removal of the ring. To compare the safety and effectiveness of self-expanding metallic stents (SEMS) and plastic stents (SEPS) to treat ring slippage. We conducted a retrospective longitudinal study analyzing consecutive patients with ring dysfunction treated with stents plus endoscopic removal. Ninety patients were enrolled (36 SEMS vs. 54 SEPS). The mean age was 48.56 ± 13.07 and 45.6 ± 12.1 in the SEMS and SEPS groups, respectively. All patients had band slippage, but 24 from SEMS group and 23 from SEPS group had further complications. There were more complications in metallic stent concerning mean absolute number of therapy-related adverse events (1.33 ± 0.48 vs. 1.72 ± 0.5, p > 0.05) and time until erosion (14.9 ± 1.6 vs. 13.8 ± 1.4days, p > 0.05). Female sex and age > 41years old correlated with longer time to band erosion and higher incidence of adverse events in SEMS patients. In SEPS group, only female sex was a risk factor for adverse events. Both procedures were efficient at inducing band erosion with similar safety profiles. Older and female patients are at a higher risk of treatment-related adverse events, especially those receiving SEMS.

Long-term outcomes of fully covered self-expandable metal stents versus plastic stents in chronic pancreatitis

Chronic pancreatitis (CP) related main pancreatic duct (MPD) stricture has been a challenge for endoscopists. Fully covered self-expandable metal stents (FC-SEMS) has been tried in CP patients, but the efficacy and safety are still controversial. Thus, we aim to compare the long-term clinical efficacy of FC-SEMS vs. plastic stent placement in persistent MPD strictures secondary to CP. Between 2007 and 2018, 80 chronic pancreatitis patients (58 males, median age 49 years), who underwent endoscopic placement of FC-SEMS (n = 26) and plastic stent (n = 54) for persistent MPD strictures after at least 3 months of initial single plastic stenting, were retrospectively analyzed during a median follow-up duration of 33.7 months. As a result, MPD stricture resolution rate was statistically higher in FC-SEMS group (87.0% vs. 42.0%, p < 0.001). Although immediate complications occurred similarly (38.5% vs. 37.0%, p = 0.902), spontaneous migration (26.9%) and de novo strictures (23.1%) were pronounced delayed complications in FC-SEMS group. Pain relief during follow-up was significantly higher in FC-SEMS group (76.9% vs. 53.7%, p = 0.046). The total procedure cost was similar in both groups ($1,455.6 vs. $1,596.9, p = 0.486). In comparison with plastic stent, FC-SEMS placement for persistent MPD strictures had favorable long-term clinical efficacy, with its typical complications like spontaneous migration and de novo strictures.

Successful Surgical Removal of Firmly Impacted Pancreatic Duct Stent: Two Case Report

Successful surgical removal of firmly impacted pancreatic duct stent: Two case report Recently, the self-expandable metallic and plastic stents are increasingly being used for management of different pancreatic disorders. The major indications for pancreatic stent placement are: pancreatic duct stones, chronic pancreatitis, pancreatic strictures, unresectable pancreatic cancer, preventing POPF and post-ERCP pancreatitis, papillary adenoma. Stent placement or retrieval and exchange is difficult process and sometimes it could be the serious clinical challenge. We report two cases of successful removal of firmly impacted pancreatic duct stent by open surgical intervention and transduodenal approach with lateral “side-to-side” pancreaticojejunostomy to prevent the risk of main pancreatic duct restenosis in the first case and with the sphincteroplasty in the second. Therefore, in these challenging cases of firmly impacted pancreatic duct stents, our choice seems to be the most optimal and effective surgical procedure, which could be considered like “parachute” option after failed attempts of stents removal by endoscopic and radiological procedures.

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.

Laryngeal Descent: A Novel Complication of Self-expanding Plastic Stents

Laryngeal Descent: A Novel Complication of Self-expanding Plastic Stents

The current status of biodegradable stent to treat benign luminal disease

Stent implantation is a well-accepted alternative to treat benign luminal disease (BLD). Current stents are often fabricated from plastic, mental and biodegradable materials, and the latter two have wider clinical application. Self-expanding plastic and mental stents possessed many disadvantages such as stent migration, tissue hyperplasia, in-stent restenosis and are difficult to remove, which catalyzes the development of biodegradable stent (BDS). In fact, BDS are not required to be removed upon implementation and leaves no residues in tissue after complete biodegradation compared to metallic or plastic stents. In vascular system, BDS, also termed bioresorbable vascular scaffold (BVS) have also been used to treat luminal stenotic or occlusive lesions in cardiovascular system, peripheral arteries system and veins. In nonvascular system, BDS, with either bare or covered designs, was employed for the treatment of occlusion, stenosis, anastomosis, leak, fistula or perforation of digestive (esophagus, gastrointestinal, biliary, pancreatobiliary, hepatobiliary), respiratory (airway), and urinary (ureteral, urethral). However, the weak radial force, in-stent thrombosis and restenosis become main issues of BDS or BVS and restrict its further clinical application. Therefore, more intensive researches are expected on the strengthening of the radial force of BDS and development of novel drug eluting techniques on its surface to prevent thrombus or restenosis. In this review it is given an updated outline of the use of BDS to treat BLD in a minimal invasive way and explore its advantages and disadvantages for a vast range of fields ranging from cardiovascular to digestive and urinary system. Further discussion to foster the investigation and development of this approach in clinical is also provided.

Su1300 Cost-Effectiveness of Fully Covered Self-Expanding Metal Stents, Lumen-Apposing Fully Covered Self-Expanding Metal Stents and Plastic Stents for Endoscopic Drainage of Pancreatic Walled-Off Necrosis in a Large Multicenter United States Study

Su1300 Cost-Effectiveness of Fully Covered Self-Expanding Metal Stents, Lumen-Apposing Fully Covered Self-Expanding Metal Stents and Plastic Stents for Endoscopic Drainage of Pancreatic Walled-Off Necrosis in a Large Multicenter United States Study

Use of self-expandable plastic stents (SEPS) in management of refractory benign esophageal strictures: a single center experience

Back ground Benign esophageal stricture is a common cause for dysphagia in adults. It can negatively affect the quality of patient’s life and may cause many complications. Benign esophageal strictures are caused by different procedures and disorders, such as gastroesophageal reflux disease, post-surgery anastomotic stricture, radiation, ablative therapy or caustic ingestion. The aim of the study was to assess the efficacy of Polyflex stent insertion in refractory benign esophageal strictures in patients admitted to the endoscopy unit of the Medical Research Institute hospital, Alexandria University, Alexandria, Egypt.

Self-expanding plastic stent for esophageal leaks and fistulae.

Self-expanding plastic stents (SEPS) have emerged as a good alternative to surgery in esophageal leaks and fistulae. There is scarce published literature regarding its efficacy in these conditions. We present our experience with SEPS in treatment of esophageal leaks and fistulae. Consecutive patients admitted in a tertiary referral center who underwent SEPS placement for esophageal leak or fistula between February 2012 and February 2015 were retrospectively evaluated. Patients underwent prior assessment with upper gastrointestinal endoscopic and thoracic contrast-enhanced computed tomography assessment. SEPS (25-mm flares, 21-mm diameter) were placed under fluoroscopic guidance. A silk thread tied to upper end was routed through nostril and fixed to prevent stent migration. Nasojejunal tube was inserted in all patients. Intercostal drain was inserted in the case of hydro/pyopneumothorax. Twelve patients [eight male, median age 45.3years (19 to 65years)] were included. Etiologies were spontaneous leaks due to Boerhaave syndrome (n=2), corrosive fistulae (n=2), tubercular fistulae (n=4), invasive Candida esophagitis-induced fistula (n=1), iatrogenic leaks (n=2; one achalasia dilatation, one obesity surgery), and pancreaticoesophageal fistula due to ruptured pancreatic pseudocyst (n=1). Stent placement was successful in all patients with no immediate postprocedure complications. Successful healing was seen in nine patients (75%). Stents were removed after a median time of 83.5days (13-190days). Stent migration was seen in four patients (33.3%), and in two of them, it was retrieved and redeployed; none had early migration (<72h). Reasons for SEPS failure in our cohort were failure of effective sepsis control in two patients and poor wound healing seen in one patient having multiple tubercular fistulae. SEPS is a safe, well-tolerated treatment with good success rate (75%) in treatment of esophageal leaks and fistulae.

Su1312 Cost Effectiveness and Clinical Efficacy of Lumen Apposing Covered Self-Expanding Metal vs Plastic Stents for the Treatment of Walled off Pancreatic Necrosis

Su1312 Cost Effectiveness and Clinical Efficacy of Lumen Apposing Covered Self-Expanding Metal vs Plastic Stents for the Treatment of Walled off Pancreatic Necrosis

Tu1570 Fully Covered Self-Expandable Metal Stents Outperform Straight Plastic Stents in Management of Benign Anastomotic Biliary Strictures following Orthotopic Liver Transplantation

Tu1570 Fully Covered Self-Expandable Metal Stents Outperform Straight Plastic Stents in Management of Benign Anastomotic Biliary Strictures following Orthotopic Liver Transplantation

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.

Update on Enteral Stents.

The recent advances in enteral stents design and composition introduced novel usage and indications, heading to a continuous addition of prostheses application in clinical practice. Since the first use to palliate malignant diseases, improving patient's quality of life, in the last decades we assisted to a large spread, often becoming a first choice treatment in GI disorders. Indeed, the clinical indication of gastrointestinal stents includes endoscopic treatment of fistula and leaks besides the well-established role of restoring lumen patency in benign and malignant conditions. Several different kind of stents have been developed, each one with its own characteristics and benefits, including self-expandable plastic and metal stents, available as uncovered, partially covered, and fully covered as well as biodegradable stents. Recently, new drug-eluting stents, working both as palliative treatment and as local chemotherapy, are under evaluation. This review aims to critically evaluate the most recently published literature about enteral stents and to address endoscopists' choice for a better patient management.

Endoscopic treatment of food intolerance after a banded gastric bypass: inducing band erosion for removal using a plastic stent.

Ring complications after a banded Roux-en-Y gastric bypass (RYGB) are usually managed surgically. The aim of this study was to analyze the safety and effectiveness of endoscopic removal of noneroded rings after banded-RYGB, by inducing intragastric erosion of the ring using a self-expandable plastic stent (SEPS). A total of 41 patients with banded RYGB who had noneroded rings and food intolerance were prospectively enrolled. Patients were treated with endoscopic SEPS placement and ring removal. Data from time of stenting, resolution of symptoms, need for endoscopic dilation, and complications were recorded. Successful ring removal was possible in all patients. In 21 cases, the SEPS induced complete erosion, and in 17 cases the ring was removed a month later because of incomplete erosion at the time of SEPS removal. Nine patients (22.0 %) needed endoscopic dilation after stent removal in order to treat fibrotic strictures. Food tolerance was observed in 32 patients (78.0 %) after the procedure. No patient needed surgery and there were no deaths. Endoscopic removal of the ring using SEPS appeared to be safe and effective after a banded RYGB.

Use of covered self-expandable stents for benign colorectal disorders in children

PurposeThere is a lack of experience with covered self-expandable stents for benign colorectal disorders in children. MethodsFive children (4M, 1F) with a median age of 5years (range, 6months–9years) who underwent treatment with covered self-expandable plastic (SEPSs) or self-expandable metal stents (SEMSs) for a benign colorectal condition between April 2005 and November 2013 were recruited to this retrospective study. Etiologies included: anastomotic stricture with (n=1) or without (n=3) simultaneous enterocutaneous fistula, as well as an anastomotic leak associated with enterocutaneous fistula (n=1). All children suffered from either Hirschsprung's disease (n=3) or total colonic aganglionosis (Zuelzer–Wilson syndrome) (n=2). ResultsMedian duration of individual stent placement was 23days (range, 1–87days). In all cases up to five different stents were placed over time. At follow-up two patients were successfully treated without further intervention. In another patient the anastomotic stricture resolved fully, but a coexisting enterocutaneous fistula persisted. Overall, three patients did not improve completely following stenting and required definite surgery. Stent-related problems were noted in all cases. There was one perforation of the colon at stent insertion. Further complications consisted of stent dislocation (n=4), obstruction (n=1), formation of granulation tissue (n=1), ulceration (n=1) and discomfort (n=3). ConclusionsCovered self-expandable stents enrich the armamentarium of interventions for benign colorectal disorders in children including anastomotic strictures and intestinal leaks. A stent can be applied either as an emergency procedure (bridge to surgery) or as an adjuvant treatment further to endoscopy and dilatation. Postinterventional problems are frequent but there is a potential for temporary or definite improvement following stent insertion.

Stenting as a palliative method in the management of advanced squamous cell carcinoma of the oesophagus and gastro-oesophageal junction.

Advanced squamous cell carcinoma of the oesophagus and gastroesophageal junction usually requires palliative treatment, and the method of choice is stenting. There are several types of stents currently available, including: self-expandable metallic stents (fully or partially covered); self-expandable plastic stents; biodegradable stents. Each of the mentioned stents has its advantages and limitations, and requires a proper, patient-tailored selection. Due to the close anatomical relationship between the oesophagus and bronchial tree, some patients may require bilateral stenting. Oesophageal stenting may not only be considered as a palliative procedure, but can also be implemented to alleviate dysphagia during preoperative chemotherapy and/or radiotherapy.

Clinical outcomes following stent placement in refractory benign esophageal stricture: a systematic review and meta-analysis.

The management of refractory benign esophageal strictures (RBESs) is challenging. Stent placement has been proposed as a possible rescue strategy. We performed a systematic review and meta-analysis to examine the efficacy of this strategy in the long-term resolution of dysphagia. PubMed, SCOPUS, and Google Scholar were searched (up to January 2015). Studies recruiting adults with RBES treated with stent placement were eligible. The success, adverse event, and migration rates were pooled by means of a random-effect model to obtain odds with a 95 % confidence interval (CI). Eighteen studies (444 patients) were eligible for inclusion. The pooled clinical success rate was 40.5 % (95 %CI 31.5 % - 49.5 %), yielding odds of 0.68 (95 %CI 0.46 - 0.98) with high heterogeneity (I(2) = 65.0 %). The meta-regression analysis showed stricture etiology as the only influencing factor. Treatment with self-expanding plastic (SEPSs) and metal stents (SEMSs) did not result in significantly higher success rates than treatment with biodegradable stents (BDSs) (46.2 % vs. 40.1 % vs. 32.9 %, respectively). The migration rate was 28.6 % (95 %CI 21.9 % - 37.1 %), yielding odds of 0.40 (95 %CI 0.28 - 0.59), with migration rates for SEPSs and SEMSs reported as being not significantly higher than BDSs (33.3 % vs. 31.5 % vs. 15.3 %, respectively). The adverse event rate was 20.6 % (95 %CI 15.3 % - 28.1 %), yielding odds of 0.26 (95 %CI 0.18 - 0.39) with no significant difference between stent types (19.4 % vs. 21.9 % vs. 21.9 %, respectively). Stent placement in patients with RBES is effective in about 40 % of cases. Further studies should investigate whether the clinical success rate varies according to the stricture etiology.(PROSPERO registration number: CRD42015019017.).

Stent-in-stent, a safe and effective technique to remove fully embedded esophageal metal stents: case series and literature review

Background: Endoscopic stenting is a widely used method for managing esophageal anastomotic leaks and perforations. Self-expanding metal stents (SEMSs) have proved effective in sealing these defects, with a lower rate of displacement than that of self-expanding plastic stents (SEPSs) as a result of tissue proliferation and granulation tissue ingrowth at the uncovered portion of the stent, which anchor the prosthesis to the esophageal wall. Removal of a fully embedded stent is challenging because of the risk of bleeding and tears. Materials and methods: Temporary placement of a new stent within the first stent (stent-in-stent technique) may facilitate the mobilization and safe removal of both stents by inducing pressure ischemia of the granulation tissue. We report our own experience with the stent-in-stent technique in five consecutive patients in whom a partially covered Ultraflex stent had previously been implanted and compare our results with those in the current literature. Results: The first SEMSs remained in place for a median of 40 days (range 18 – 68) without displacement. Placement of the new stent was technically successful in all patients. All stents were left in place for a median of 9 days. The overall stent-in-stent success rate was 100 % for the removal of embedded stents. No serious adverse events related to the procedure occurred. Conclusion: The procedure was safe, well tolerated, and effective. The use of a partially covered Ultraflex stent of the same size as the old stent for a limited time (≤ 6 days) was consistently successful.