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Abstract Background Malignant ureteral obstruction (MUO) is a frequent challenge for urologists. Patients have poor prognoses, treatment aims to improve quality‐of‐life while optimising renal function. Standard practice in the United Kingdom is to use polyurethane stents, which require frequent surgical replacements for blockages and encrustation. More durable metallic stents are available, although these incur an increased initial purchase price. Aims We aim to assess whether the use of polyurethane double‐J (JJ) or metallic stent, Resonance® is more cost‐effective for managing MUO in the UK healthcare setting. Methods A Markov model was parameterised to 5 years with costs and health‐related quality‐of‐life consequences for treating MUO with Resonance metallic stent (Cook Medical), versus standard JJ stents, from the UK care system perspective, with 3.5% discounting. Deterministic and probabilistic sensitivity analyses were undertaken to assess the effect of uncertainty. Results Over 5 years, approximately four fewer repeat surgical interventions were estimated in the metallic stent arm compared with the JJ stent, driving a 23.4% reduction in costs. The mean estimates of costs and benefits indicate that treatment of MUO with Resonance for 5 years is dominant over JJ stents. Over 5 years a cost‐saving of £2164.74 and a health gain of +0.046 quality‐adjusted life years (QALYs) per patient is estimated. With a maximum willingness to pay of £20 k per QALY, a net monetary benefit (NMB) of £3077.83 is estimated. Probabilistic sensitivity analysis at a willingness to pay threshold of £20 000 indicates an 89.3% probability of Resonance being cost‐effective over JJ stents. Within 1‐year savings of £726.53 are estimated driven by a reduction of two fewer repeat surgical interventions when using the metallic stent. Conclusions Resonance metallic stents for the treatment of MUO reduce the number of repeat procedures and could be a cost‐effective option for the treatment, potentially offering efficiencies to the healthcare system.

An ongoing debate exists regarding the feasibility of placing self-expanding metallic stents (SEMS) within 5 cm of the anal verge. Traditionally, SEMS have been considered contraindicated for patients with a malignant rectal obstruction within this region due to potential impact on the anorectal ring or anal canal, which can cause incontinence, proctalgia, and tenesmus. However, in the case of a 63-year-old female who presented with distention, abdominal pain, and diminishing stool output, the rectal exam identified a bulky fixed mass. Imaging studies revealed large bowel obstruction and high-grade stricture, with a minuscule residual lumen. Endoscopy identified a bulky mass obscuring the lumen at 5 cm from the anal verge, and biopsy confirmed adenocarcinoma. Despite the traditionally held contraindication, a 2.5 cm × 9.0 cm colonic stent was successfully deployed, leading to brisk colonic decompression. This allowed the patient to promptly undergo chemoradiotherapy. [ABSTRACT FROM AUTHOR]

The first dedicated tracheobronchial silicone stent was designed by the French pulmonologist Jean‐Paul Dumon. The most common indications for stenting are to minimise extrinsic airway compression from mass effect, maintain airway patency due to intrinsic obstruction or treat significant nonmalignant airway narrowing or fistulae. Silicone stents require rigid bronchoscopy for insertion; however, they are more readily repositioned and removed compared with metallic stents. Metallic stents demonstrate luminal narrowing when loads are applied to their ends, therefore stents should either be reinforced at the ends or exceed the area of stenosis by a minimum of 5 mm. Nitinol, a nickel‐titanium metal alloy, is currently the preferred material used for airway stents. Airway stenting provides effective palliation for patients with severe symptomatic obstruction. Drug‐eluting and three‐dimensional printing of airway stents present promising solutions to the challenges of the physical and anatomical constraints of the tracheobronchial tree. Biodegradable stents could also be a solution for the treatment of nonmalignant airway obstruction. [ABSTRACT FROM AUTHOR]

Objective: The main goal of the study is to show the indications of the fully covered self-expandable metallic stents used in our unit. Method: Patients who underwent fully covered self-expandable metallic stents between January 1, 2018, and December 31, 2019, in our unit were included in the study. Endoscopic procedure reports were found by searching for "covered metallic stent" from the EndoCam operating system. Result: There were a total of 149 patients in the study. The mean age of the patients was 57.44 ± 16.86 years. About 46.3% of the patients were women. Benign biliary stenosis in the common bile duct was the first with a rate of 36.2% in indications. Malignant biliary stenosis was in the second place at 11.4%, and posttransplant anastomotic stenosis was in the third place at 8.7%. The median time between insertion and removal sessions was 34 days (min: 5 days, max: 417 days) in patients (80%) whose fully covered self-expandable metallic stents were removed in our center. Conclusion: Fully covered self-expandable metallic stents are used to treat a variety of benign and malignant biliary pathological conditions. However, fully covered self-expandable metallic stents may face stent migration issues that can be addressed with modifications. [ABSTRACT FROM AUTHOR]

Abstract Objectives Advancements in the endoscopic management of walled‐off necrosis using lumen apposing metal stents have improved outcomes over its surgical and percutaneous alternatives. The ideal procedural technique and timing of direct endoscopic necrosectomy (DEN) have yet to be clarified. Methods From November 2015 to June 2021, a retrospective comparative cohort analysis was performed comparing clinical outcomes for patients undergoing immediate DEN (iDEN) versus delayed DEN (dDEN). Subgroups were identified based on the quantification of necrosis. Wilcoxon two‐sample tests were used to compare continuous variables and Fisher's exact test was used to compare categorical variables. Results A total of 80 patients underwent DEN for management of walled‐off necrosis (iDEN = 43, dDEN = 37). Technical success was achieved in all patients. Clinical success was seen in 39 (91%) patients in the iDEN group and 34 (92%) in the dDEN group. Amongst iDEN patients, the mean number of necrosectomies was 2.5 (standard deviation [SD] 1.4) in comparison to 1.5 (SD 1.0) for dDEN (p‐value = 0.0011). The median index hospital length of stay was longer with iDEN than dDEN (7.5 days vs. 3.0 days respectively, p‐value = 0.010). Subgroup analysis was performed based on the percentage of necrosis (25% necrosis). iDEN was associated with more necrosectomies than dDEN regardless of the percentage of necrosis (p = 0.017 and 0.0067, respectively). Conclusion Patients undergoing dDEN had a shorter index hospital stay and fewer necrosectomies than iDEN. The large diameter of lumen apposing metal stents permits adequate drainage allowing a less aggressive approach thereby improving clinical outcomes and avoiding unnecessary interventions.

Obstructive jaundice caused by malignant distal biliary obstruction is a common clinical symptom in patients with inoperable biliary–pancreatic cancer. Endoscopic retrograde cholangiopancreatography (ERCP)-guided stent implantation is an effective treatment for obstructive jaundice. Internal stent drainage is more physiologic and associated with a better quality of life than external stent drainage methods such as percutaneous transhepatic gallbladder drainage or percutaneous transhepatic cholangiodrainage. Self-expanding metallic stents, which may be covered and uncovered, are commonly used. However, some uncertainties remain regarding the selection of metallic stents, including drainage patency time, clinical effect, stent migration, and post-operative complications such as pancreatitis, bleeding, and cholecystitis. This review aims to summarize the current progress and controversies surrounding the use of covered or uncovered metallic stents in inoperable common biliary obstruction via ERCP. [ABSTRACT FROM AUTHOR]

Abstract Background Post-variceal band ligation bleeding ulcer is a severe complication with considerable mortality. We tried evaluating self-expandable metallic stent (SEMS) with concern to the ulcer morphology not well studied. Results We did a retrospective analysis of patients with bleeding post-band ulcers and treated by SEMS with concern to control bleeding and 6 weeks survival. Twenty-eight patients studied had their age (mean ± S.D.) 57.8 ± 8.6 years, and 85.7% were males. The Child-Pugh score range was 5–12]. Control of bleeding by SEMS was achieved in 23 (82.1%) patients, and overall, 6-week survival was 75%. Both post-band ulcer types B (oozing blood and type C (active spurted) were a risk for 6 weeks mortality (P = 0.04, OR 1.58, CI 95% 1.12–2.23). Conclusion SEMS is considered an excellent choice to control esophageal post-banding ulcer bleeding and a definite treatment bridge.

Metallic ureteric stents are increasingly used for the management of malignant ureteric obstruction, a commonly encountered complication in urological and other malignancies. However, there has been limited evaluation of complications associated with these stents, including those that might arise from the use of magnetic resonance imaging (MRI). While most devices are deemed nominally “MRI-safe,” their implication on the quality of imaging produced has not been evaluated in clinical trials, and in our practice, significant artefact has been encountered with some ureteric stents—specifically, the Teleflex Rüsch DD tumour stent—compromising image quality and diagnostic certainty.

Background: Self-expandable metallic stents have not only largely replaced surgical gastrojejunostomy for unresectable gastric cancers, but their role as bridging therapy for resectable obstructing tumours is also evolving. Objective: To evaluate the efficacy and safety of pyloric stents in gastric outlet obstruction in patients with gastric cancer and assess survival in patients with resectable obstructing gastric tumours in whom stents were inserted as a bridge to surgery. Methods: We retrospectively reviewed the electronic medical records of patients who underwent self-expandable metallic stent insertion for gastric outlet obstruction due to gastric cancer from January 2014 to March 2019. Results: Out of 161 patients, clinical improvement was observed in 159 (99%) and 156 (97%) at 1 and 12 weeks of stent placement, respectively. None of these patients experienced serious complications, such as perforation or aspiration pneumonia. Of these 161 patients, enteral stents were placed as bridging therapy prior to surgery in 40 (24.8%). Among these, 35 (87.5%) of 40 underwent neo-adjuvant chemotherapy followed by curative surgery. Of the 35 patients, 3 failed to follow-up. One-year survival following curative surgery was 87.5%. Stent helped to reduce vomiting and improve nutrition, measured by the body mass index (p = 0.36) and serum albumin (p = 0.05), over a 4-week period following stent insertion. Conclusion: Pyloric stents are useful in relieving malignant gastric outlet obstruction, maintaining nutrition during neo-adjuvant treatment and improving survival without additional risk of postoperative complications. They have traditionally been used for palliation, but should also be considered as bridging therapy for obstructing resectable gastric tumours during neo-adjuvant treatment. [ABSTRACT FROM AUTHOR]

Objective: To define which long-term stent would work best in malignant ureteral obstruction (MUO) and benign ureteral obstruction (BUO), focusing on their mechanisms of action, price and insertion approach. Methods: A systematic review was developed using the MEDLINE and Scopus databases and in accordance with the PRISMA checklist. There were no language restrictions for the search. Studies describing the use of metallic ureteric stents for MUO and for BUO in humans were included. Results: We analyzed five types of metallic stents (35 papers) and also the experience with the tumor and extra-anatomical stents. The Resonance, Memokath and Allium ureteral stents were found to be useful in BUO and MUO. The Uventa stent performed well in chronic ureteral obstruction. The Detour bypass stent was a recommended option in those patients who had complete obstruction of the ureter and were unfit for reconstructive surgery. There was no difference with regard to the insertion technique and both antegrade and retrograde approaches were equally successful. Although tumor stents showed a good performance, there were very few published studies on it. Conclusion: Metallic stents are a suitable option for MUO and BUO. When compared to standard double J stents, although they are relatively high priced, they show a financial benefit in the long-term. The Detour bypass stent seems to be an effective alternative for complete ureteral obstruction or patients unfit for surgery. Further prospective randomized studies should be done on the effectiveness of tumor stents versus metallic stents. [ABSTRACT FROM AUTHOR]

This paper focuses on microstructural and mechanical characterization of metallic thin-walled tube produced with additive manufacturing (AM), as a promising alternative technique for the manufacturing of tubes as a feedstock for stents micromachining. Tubes, with a wall thickness of 500 μm, were made of 316L stainless steel using selective laser melting. Its surface roughness, constituting phases, underlying microstructures and chemical composition were analyzed. The dependence of hardness and elastic modulus on the crystallographic orientation were investigated using electron backscatter diffraction and nanoindentation. Spherical nanoindentation was performed to extract the indentation stress–strain curve from the load–displacement data. The obtained results were compared with those for a commercial 316L stainless steel stent. Both tube and commercial stent samples were fully austenitic, and the as-fabricated surface finish for the tube was much rougher than the stent. Microstructural characterization revealed that the tube had a columnar and coarse grain microstructure, compared to equiaxed grains in the commercial stent. Berkovich nanoindentation suggested an effect for the grain orientation on the hardness and Young's modulus. The stress–strain curves and the indentation yield strength for the tube and stent were similar. The work is an important step toward AM of patient-specific stents. [ABSTRACT FROM AUTHOR]

Ureteric stents are fundamental to modern-day urological practice. This article aims to chronicle their development over the last century and the key individuals whose efforts have made their development possible. Early stents were ureteric catheters that were exteriorised outside the body and were associated with complications including migration, infection and encrustation.The use of polyethylene stents in humans was first reported by Tulloch in 1952. Polyethylene was thought to be a promising material due to its durability and water-repellent nature. It would, however, suffer the problems that would become associated with stents over the following decades mentioned above.The first silicone ureteric stents were developed in the 1960s by Zimskind and provided prolonged, efficient drainage but were complicated with stent migration. Collars, wings, flanges and barbs were developed to help prevent migration. Finney developed a double ‘pig-tail’ stent in the 1970s which helped to prevent both proximal and distal migration and the modern-day ureteric stent was born.Modern polymers have been developed such as polyurethane or styrene ethylene-butylene (C-flex®). Metal stents have also been used over the last three decades including the Wallstent™, Resonance® and Memokath™ stents. They have shown promising results particularly when long-term relief of ureteric obstruction is needed.Various strategies are available for removal including cystoscopically, stents with a metallic end that can be removed by using a catheter with a magnet at the proximal end, tethered stents that can be removed noninvasively either by the urologist, nurse or even by the patient and dissolvable stents which are in development. [ABSTRACT FROM AUTHOR]

Objective: The aim of the present study was to share our experiences of the use of self-expandable metallic stent for the upper gastrointestinal tract disease. Material and Methods: We retrospectively reviewed the medical records of 18 patients who underwent self-expandable metallic stent implantation procedure for anastomosis stricture, anastomosis leak, or spontaneous fistula of the upper gastrointestinal tract at two different surgery clinics. Self-expandable metallic stent implantation procedures were performed while keeping the patient under sedation and the correct stent localization was verified using fluoroscopy. The stent localization and possible stent migration were checked using X-ray films taken a few days after the stenting procedure. Results: Overall, 25 self-expandable metallic stents were implanted in 18 patients (malignant, 13; benign, 5) aged between 19 and 89 years. The indications for self-expandable metallic stent implantation were as follows: malignant gastric stricture (inoperable; n=6), malignant esophageal stricture (inoperable; n=4), staple line leak (laparoscopic sleeve gastrectomy; n=4), esophagojejunostomy anastomotic leak (total gastrectomy+Roux-en-Yesophagojejunostomy; n=2), and stricture (total gastrectomy+Roux-en-Yesophagojejunostomy; n=1), and esophagopleural fistula (pulmonary tuberculosis; n=1). A favorable outcome was achieved in a single session in 15 patients, whereas more than two sessions of stenting were necessary in the remaining three patients. Among the patients who underwent esophagojejunal anastomosis (n=3), self-expandable metallic stents were successfully deployed in a single session in two patients to relieve anastomosis leak (n=1) and anastomosis stricture (n=1); the remaining patients underwent four self-expandable metallic stent implantation procedures to relieve anastomosis leak and subsequent recurrent strictures. No complications developed during the stenting procedure. Three of the four patients who developed mortality had advanced stage esophageal cancer, whereas one patient had morbid obesity and developed staple line leakage. Conclusion: Endoscopic self-expandable metallic stent implantation under fluoroscopic guidance is a low-morbidity and effective procedure for the management of advanced stage tumors of the gastrointestinal tract and the elimination of postoperative complications. [ABSTRACT FROM AUTHOR]

Background and Aim: Endoscopic biliary drainage (EBD) is the mainstay treatment for inoperable malignant distal biliary obstruction (MDBO). Some authorities suggest that metallic stents are more cost-effective than plastic stents in patients with expected survival of at least 6 months. However, studies attempting to define the predictive factors for such survival times are limited. This study aims to develop a scoring system for predicting a survival time of <24 weeks in these patients.Method: Patients with MDBO from inoperable periampullary cancers who underwent EBD at Songklanagarind Hospital during 2004-2009 were retrospectively analyzed. Baseline clinical, laboratory, and imaging data were retrieved. The survival time data were retrieved from the medical records and Thailand’s civil registration database. Multivariate Cox regression model coefficients were used in the development of a survival time prediction scoring system.Results: Ninety-eight patients were included. The overall median survival was 17.6 weeks. Fifty-seven (58.1%) survived <24 weeks. By multivariate analysis, cancer type and liver metastasis were significant predictive factors. The Simple Clinical Score (SCS) was calculated from (2× liver metastasis) + (1× pancreatic cancer) − (2× ampullary cancer) − (1× cholangiocarcinoma), when 1 and 0 were used for the presence and absence of each factor, respectively. The cutoff value of the score ≥0 had a sensitivity and specificity of 0.77 and 0.63, respectively, for predicting a survival time of <24 weeks, with AUC of 0.76. The median survival of patients with SCS <0 and ≥0 was 36.6 and 13.1 weeks, respectively.Conclusion: The scoring system from this study may be beneficial for clinicians to select the appropriate stents in endoscopic biliary drainage in inoperable MDBO patients. [ABSTRACT FROM AUTHOR]

The review concerns the problem of late thromboses of drug-eluting stents and their influence on late prognosis of the patients; presents long-term results of the trial of sirolimus-eluting stents implanted to patients with coronary heart disease; analyses mechanisms of development of late stent thrombosis, data from different meta-analyses and registers comparing long-term outcomes in patients with implanted sirolimus-eluting stents and metallic stents; suggests risk factors of late thromboses of drug-eluting stents; presents original evidence on 3.5-year follow-up of patients with implanted sirolimus-eluting stents and metallic stents.

Background: Self-expandable metallic stents (SEMS) can be used to treat malignant obstructions and fistulas of the central airways. SEMS can be placed using different methods. Recently, a rigid bronchoscope has been used for stent placement without the need for fluoroscopy. We retrospectively evaluated patients for whom SEMS were placed using a rigid bronchoscope, without employing guidewires or fluoroscopy. We describe the intra- and post-procedural complications of the method. Methods: Data collected between January 2014 and July 2015 were retrospectively evaluated by reference to hospital records. Results: The mean patient age was 58.14 ± 8.48 years (44-72 years) and 13 out of the 14 patients were male. Twelve had lung cancer, one a thyroid papillary carcinoma with a bronchomediastinal fistula, and one an esophageal carcinoma with a tracheoesophageal fistula. Covered metallic Y-shaped stents were placed in all patients. Before placement, argon plasma coagulation was performed on two patients, diode laser treatment on four, and de-obstruction on nine. No procedure-related mortality was noted. Only two patients required follow-up in the intensive care unit; they were moved to a regular ward after two days. No patient required stent replacement or repositioning. The most common early complication was mucus plugs. Conclusion: Endobronchial placement of covered self-expandable metallic stents was safe and readily performed in patients with airway obstructions. Neither fluoroscopic nor guidewire guidance was required. Neither patients nor staff were exposed to radiation, and costly guidewire guidance was not necessary. The procedure is cost-effective. [ABSTRACT FROM AUTHOR]