Self-expanding Metal Stents Research Articles

Endoscopic removal of a deteriorated fully-covered self-expandable metal stent using an endoscopic retrograde cholangiopancreatography guide sheath

Endoscopic removal of a deteriorated fully-covered self-expandable metal stent using an endoscopic retrograde cholangiopancreatography guide sheath

Predictors of symptom recurrence and survival in patients with malignant gastric outlet obstruction treated with self-expanding metal stents.

Malignant gastric outlet obstruction (GOO) poses a substantial symptomatic burden. While various therapeutic options exist, self-expanding metal stents (SEMS) are a common palliative choice for patients who are ineligible for surgery. We studied SEMS outcomes to identify factors influencing stent dysfunction and patient survival. A multi-centre, retrospective review of 190 patients with GOO undergoing SEMS at three tertiary hospitals was performed over 2016-2022. Technical success, clinical success and adverse outcomes were recorded. Predictors of stent dysfunction and survival were evaluated using multivariate regression. Technical success was achieved in 186/190 (97.9%) and clinical success in 156/186 (83.9%), defined as post-procedural gastric outlet obstruction symptom score (GOOSS) ≥2. Eighty-two (44.1%) patients experienced an adverse event with stent occlusion the most common (23.1%). Approximately one-third (32.3%) underwent a repeat intervention. Mean stent patency time was 67 days (standard deviation=76), and median post-stent survival was 95 days (37-197). Covered and partially covered SEMS carried three times the risk of stent dysfunction compared to uncovered SEMS (odds ratio 3.06, p=0.008). Mortality predictors were Eastern Cooperative Oncology Group score ≥2 (p=0.03), extrinsic outlet obstruction (p=0.05) and presence of ascites (p=<0.001). SEMS demonstrated technical and clinical success but posed a high risk of recurrence, with stent patency time falling short of survival in our cohort. With an evolving landscape of therapeutics for GOO, appropriate patient selection is paramount. Individuals with reduced performance status, extrinsic obstruction and/or ascites may be better candidates for SEMS due to more limited life expectancy. In this setting, uncovered SEMS carry the lowest risk of reintervention.

Low-pressure self-expandable metal stent insertion for obstructive colon cancer using water and gel immersion.

Low-pressure self-expandable metal stent insertion for obstructive colon cancer using water and gel immersion.

Prognostic value of carcinoembryonic antigen (CEA) and CA 19-9 levels in patients with obstructive colorectal cancer treated with a self-expandable metallic stent and curative surgery.

The importance of tumor markers is well established; yet little is known about their prognostic value for patients with obstructive colorectal cancer (OCRC). We investigated the clinical significance of carcinoembryonic antigen (CEA) and CA 19-9 levels in patients with non-metastatic OCRC, who underwent insertion of a self-expandable metallic stent and curative surgery. Clinical data on 91 patients with OCRC were analyzed retrospectively to evaluate the associations of preoperative serum values of tumor makers with short- and long-term outcomes. The 91 patients comprised 53 men and 38 women, with a median age of 71years. Twelve patients had an elevated preoperative CA 19-9 level. Multivariate analyses revealed that an elevated CA 19-9 level was independently associated with poor disease-free survival (DFS) [hazard ratio (HR) = 4.57, 95% confidence interval (CI) 2.06-10.14, P < 0.001] and overall survival (HR = 4.06, 95% CI 1.46-11.24, P = 0.007). A CEA level > 5ng/ml had no prognostic value, whereas a CEA level > 10.8ng/ml was significantly associated with worse DFS (P = 0.032). Measuring the CA 19-9 level concomitantly with the CEA level for patients with advanced CRC, including OCRC, may provide a valuable means to improve prognostication.

Impact of a novel-covered colonic stent in obstructive colon cancer.

Although the short-term outcomes of bridge-to-surgery (BTS) procedures using self-expandable metal stents are favorable, concerns remain regarding worsened prognosis due to tissue injury in the tumor area. Herein, we describe a newly developed covered stent, the Kawasumi Jabara colonic stent™, designed to reduce tissue damage/injury associated with stent-related complications in BTS procedures. This study aimed to evaluate the efficacy and safety of the Kawasumi Jabara colonic stent as a BTS for obstructive colorectal cancer (OCC). This multicenter retrospective observational study included 44 OCC patients who underwent BTS with stents at four facilities between September 2020 and November 2022. The groups of patients receiving the Kawasumi Jabara and non-covered colonic stents were designated Groups C and NC, respectively. Treatment outcomes related to stent placement and surgery were compared using propensity score matching (PSM) analysis. Groups NC and C (n = 34 and 10, respectively) showed no significant differences in sex, age, tumor location, histological type, Colorectal Obstruction Scoring System (CROSS) score, or cStage; however, the stent placement duration was shorter in Group C. No significant differences were found in terms of the technical and clinical success rates for stent placement. Stent dislocation was observed in 0 and 2 cases in Groups C and NC, respectively. PSM analysis between eight cases, each from Groups C and NC, revealed no significant differences in stent-related or surgical outcomes between the groups. However, regarding the gross injury score in the resected specimens, Group C had a lower score than Group NC (1.8 vs. 5.5), and the proportion of pathological tissue injury involving deeper layers was also lower in Group C (37.5% vs. 100%). Compared to conventional non-covered stents, the Kawasumi Jabara colonic stent™ demonstrated favorable safety during stent insertion, retention, and surgery, with only mild tissue injury.

Endoscopic sphincterotomy to prevent post-ERCP pancreatitis after self-expandable metal stent placement for distal malignant biliary obstruction (SPHINX): a multicentre, randomised controlled trial

BackgroundEndoscopic retrograde cholangiopancreatography (ERCP) with fully covered self-expandable metal stent (FCSEMS) placement is the preferred approach for biliary drainage in patients with suspected distal malignant biliary obstruction (MBO). However, FCSEMS...

Novel self-expandable metallic stent with dumbbell-shape and spiral outer cover for malignant distal biliary obstruction.

Novel self-expandable metallic stent with dumbbell-shape and spiral outer cover for malignant distal biliary obstruction.

Feasibility of Double-Deployment Small-Diameter Covered Metallic Stent for Malignant Distal Biliary Obstruction (with Video)

Background/Objectives: Covered self-expandable metallic stents (CSEMS) are commonly used to treat malignant distal biliary obstructions. A 10-mm CSEMS carries the risk of obstructing the pancreatic and cystic duct orifices by adhering to the bile duct; therefore, postoperative pancreatitis and cholecystitis are reported to occur at a certain frequency. We have adopted a new drainage technique for malignant distal biliary obstruction called ‘‘double-slim SEMS stenting” (DSS), where two small-diameter CSEMS are placed side-by-side. We aimed to compare the efficacy and safety of biliary drainage using DSS with those of conventional CSEMS. Methods: In total, 50 patients who underwent endoscopic biliary drainage for malignant distal biliary obstructions between April 2019 and March 2022 at Hyogo Medical University Hospital were enrolled. Patients were divided into DSS and Conventional groups, and the technical success rate, clinical success rate, adverse events, success rate for reintervention, recurrent biliary obstruction (RBO) rate, and time to RBO (TRBO) were evaluated. Results: There were no significant differences in patient characteristics between the DSS (n = 20) and Conventional groups (n = 30). The technical and clinical success rates were 100% in the DSS group. The incidence of adverse events was not significantly different between the two groups (DSS/Conventional: 10.0% [2/20]/20.0% [6/30]) (p = 0.34). No acute cholecystitis was observed in the DSS group. The incidence rates of RBO were 30% (6/20) and 43% (13/30) in the DSS and Conventional groups, respectively (p = 0.92). The median TRBO in the DSS group was 378 days, while the TRBO in the Conventional group was 195 days (p = 0.03), resulting in significantly longer TRBO in the DSS group. Conclusions: DSS emerges as a viable and safe approach for biliary drainage in malignant distal biliary obstruction, demonstrating a lower incidence of adverse events and longer TRBO compared to conventional CSEMS.

Self-expanding metal stent for relieving the stricture after endoscopic injection for esophageal varices.

Esophageal stricture is one of the complications after esophageal varices sclerotherapy injection (ESI), and the incidence rate is between 2%-10%. To explore the efficacy of self-expanding metal stent (SEMS) for the stricture after endoscopic injection with cyanoacrylate (CYA) and sclerotherapy for esophageal varices. We retrospectively analyzed the efficacy of SEMS to improve the stricture after endoscopic injection with CYA and sclerotherapy for esophageal varices in 4 patients from February 2023 to June 2023. The strictures were improved in four patients after stenting. The stent was removed after two weeks because of chest pain with embedding into esophageal mucosa in one patient. The stent was removed after one month, however, the stent was reinserted because of the strictures happening again in two patients. The stent was removed after three months, however, the stent was reinserted because of the strictures happening again in one patient. The stent embedded into esophageal mucosa in three patients. There were 3 patients suffered reflux esophagitis, and the acid reflux was relieved by taking hydrotalcite. There was no other complication of esophageal perforation, bleeding from varices or infection. SEMS may relieve the stricture which happened after endoscopic injection with CYA and sclerotherapy for esophageal varices. However, when we should remove the stent still needs to be explored.

Radiation Exposure with Self-Expandable Metallic Stent versus Transanal Decompression Tube for Malignant Colorectal Obstruction: A Post Hoc Propensity Score Matched Analysis.

Background: Although several reports have compared the outcomes of self-expandable metallic stent (SEMSs) and transanal decompression tube (TDT) placement for malignant colorectal obstruction (MCO), few studies have compared the radiation exposure (RE) associated with these two procedures. Consequently, we aimed to compare the RE of SEMS and TDT placements for MCO using propensity score matching (PSM) in a multi-center, prospective observational study. Methods: This study investigated the clinical data of 236 patients who underwent SEMS or TDT placement. The air kerma at the patient entrance reference point (Ka,r: mGy) and air kerma-area product (PKA; Gycm2) were measured and compared between SEMS and TDT groups after PSM. Results: After PSM, 61 patients were identified in each group. The median Ka,r in the SEMS group was significantly greater than that in the TDT group (77.4 vs. 55.6 mGy; p = 0.025) across the entire cohort. With respect to subgroup analyses by location, in the rectum, the median Ka, r and PKA were significantly greater in the SEMS group than in the TDT group (172.9 vs. 34.6 mGy; p = 0.001; and 46.0 vs. 18.1 Gycm2; p = 0.006, respectively). However, in the colon, the RE parameters did not significantly differ between the two groups. Conclusions: TDT might be a more suitable option for decompression in patients with malignant rectal obstruction due to its lower RE and technical advantages. Conversely, SEMS placement is recommended as the first decompression method to treat malignant colonic obstruction, in line with the current guidelines.

Endoscopic Removal of Uncovered Metallic Airway Stents.

Self-expandable uncovered metallic stents (SEUMS) have been used in benign tracheobronchial stenosis. Stent complications may require risky removal due to SEUMS integration in the tracheobronchial wall. Our study aims to report techniques, including a novel one, and outcomes of SEUMS removal by rigid bronchoscopy. We studied a case series of 7 patients from a tertiary medical center, who underwent SEUMS removal from 2017 to 2022. SEUMS removals were performed through rigid bronchoscopy. We used a new technique with bronchoscopic hook scissors to gradually dissect the stent from the airway wall. Nine SEUMS were removed from 7 patients. The mean duration of stenting was 7 years (5 to 12y). Indications for stent removal included mostly recurrent pulmonary infections, obstructive granulation tissue, and stents' fractures. We used the usually described technique in the literature known as the "piecemeal fashion" without dissection in 4 SEUMS removals and a new dissection technique in 5 procedures. We reported one major intraoperative complication using the former technique in the form of tracheal tear with mediastinal breach, while we did not experience any major complications with the later one. One patient died 8 days after surgery from respiratory failure. Dissection and "piecemeal fashion techniques" can be used to remove SEUMS by rigid bronchoscopy even after long-term stenting. SEUMS removal is a very risky procedure and must be performed by a trained operator. Patients should be aware of possible severe complications.

Optimizing EUS-guided choledochoduodenostomy with lumen-apposing metal stents for primary drainage of malignant distal biliary obstruction (SCORPION-IIp): a prospective pilot study

Background and AimsBiliary drainage by endoscopic retrograde cholangiography (ERCP) in patients with malignant distal bile duct obstruction (MBO) is frequently associated with complications, such as pancreatitis, hampering patient outcome. EUS-guided choledochoduodenostomy (EUS-CDS) with a lumen-apposing metal stent (LAMS) is a promising alternative in patients with MBO but is associated with a worrisome risk of stent dysfunction. Placement of a fully covered self-expandable metal stent (FCSEMS) through the LAMS, thereby changing the axis of biliary drainage towards the descending duodenum, may decrease the risk of stent dysfunction while maintaining high technical success and low adverse event rates. MethodsProspective single center pilot study in patients with a pathology confirmed MBO without gastric-outlet obstruction. Primary outcome was stent dysfunction, defined as recurrent jaundice after initial clinical success, ongoing jaundice in combination with persistent bile duct dilatation, or cholangitis. The study was registered in clinicaltrials.gov (registry number NCT05595122). ResultsOverall, 27 consecutive patients eligible for EUS-CDS were enrolled. The placement of a LAMS was successful in 24/27 patients (89%), and placement of FCSEMS through the LAMS was successful in 20/24 (83%), in the remaining 4 patients a coaxial double-pigtail plastic stent was placed. In 2 of these 20 patients there was persistent jaundice requiring stent revision (10%), leading to a clinical success rate of 90%. No patients developed stent dysfunction after initial clinical success. ConclusionsThis study showed a stent dysfunction rate of 10% following technically successful EUS-CDS with placement of a FCSEMS through the LAMS. Improving the design of LAMS may further reduce the rate of stent dysfunction.

S1586 Covered Self-Expandable Metallic Stents versus Multiple Plastic Stents for Benign Biliary Strictures

S1586 Covered Self-Expandable Metallic Stents versus Multiple Plastic Stents for Benign Biliary Strictures

A case of successful endoscopic hemostasis with a covered self-expandable metal stent for the treatment of spurting hemobilia

A case of successful endoscopic hemostasis with a covered self-expandable metal stent for the treatment of spurting hemobilia

Safety and efficacy of conventional compared to segmented esophageal fully covered self-expanding metal stents: a retrospective multicenter case-control study.

Segmented self-expanding metal stents (SEMS) are an alternative to conventional unsegmented SEMS in the treatment of esophageal strictures. Due to their segmented design, they may adapt better to the surrounding structures making them less likely to migrate or cause trauma. We examined if there are clinically relevant differences between segmented and conventional esophageal SEMS in benign and malignant stenosis in terms of their functionality and safety. We performed a multicenter, retrospective case-control study of segmented and conventional SEMS implantations in esophageal stenosis. Outcome parameters were adverse events such as migration, occlusion, and severe complications (i.e., bleeding and perforation). 79 segmented SEMS were identified and compared to 79 conventional SEMS implantations. Groups were similar in terms of age, gender, and etiology. We observed 13.9% severe complications (SEMS-associated clinically significant bleeding or perforation) in the conventional SEMS group compared to 3.8% in the segmented SEMS group. This difference was statistically significant (p = 0.025). Rates of migration and occlusion were similar between both groups. Likewise, there was no significant difference in terms of short-term (30days) clinical success. In this first controlled analysis, segmented SEMS were associated with fewer severe clinical complications compared to conventional SEMS.

Manufacturing, Processing, and Characterization of Self-Expanding Metallic Stents: A Comprehensive Review.

This paper aims to review the State of the Art in metal self-expanding stents made from nitinol (NiTi), showing shape memory and superelastic behaviors, to identify the challenges and the opportunities for improving patient outcomes. A significant contribution of this paper is its extensive coverage of multidisciplinary aspects, including design, simulation, materials development, manufacturing, bio/hemocompatibility, biomechanics, biomimicry, patency, and testing methodologies. Additionally, the paper offers in-depth insights into the latest practices and emerging trends, with a special emphasis on the transformative potential of additive manufacturing techniques in the development of metal stents. By consolidating existing knowledge and highlighting areas for future innovation, this review provides a valuable roadmap for advancing nitinol stents.

Endoscopic biliary drainage for distal bile duct obstruction due to pancreatic cancer.

Approximately 60% of pancreatic cancers occur in the pancreatic head and may present as obstructive jaundice due to bile duct invasion. Obstructive jaundice often leads to poor general conditions and acute cholangitis, interfering with surgery and chemotherapy and requiring biliary drainage. The first choice of treatment for biliary drainage is the endoscopic transpapillary approach. In unresectable tumors, self-expandable metal stents (SEMSs) are most commonly used and are classified into uncovered and covered SEMSs. Recently, antireflux metal stents and large- or small-diameter SEMSs have become commercially available, and their usefulness has been reported. Plastic stents are infrequently used in patients with resectable biliary obstruction; however, owing to the recent trend in preoperative chemotherapy, SEMSs are frequently used because of the long time to recurrent biliary obstruction. Endoscopic ultrasound-guided biliary drainage (EUS-BD) is often performed in patients who are not eligible for the transpapillary approach, and favorable outcomes have been reported. Different EUS-BD techniques and specialized stents have been developed and can be safely used in high-volume centers. The indications for EUS-BD are expected to further expand in the future.

Endoscopic interventions in patients with bronchial tumors

Analysis of the results of endoscopic diagnosis and treatment of patients with bronchial tumors. Material and methods. Endoscopic diagnosis and interventions were perfomed in 56 patients with benign - 39 (70.7%) and malignant - 17 (29.3%) bronchial tumors. There were 38 men and 18 women aged from 17 to 70 years (average age of patients 52.1 ± 14.6 years). Results. In patients with benign bronchial tumors, mechanical removal or excision by using polypectomy share was more often performed. In cases malignant tumors (10 patients) stent insertion was performed to ensure long-term maintenance of the bronchial lumen. In two cases - silicone stents were inserted; in eight cases - metal self-expanding stents were inserted. There were no complications during the intervention or in the postoperative period. Repeated interventions due to tumor recurrence were performed in 3 (5.4%) patients. Conclusion. Endoscopic interventions in patients with benign and malignant bronchial tumors can effectively and relatively safely restore and maintain airway patency. The choice of tumor removal method is multifactorial. It depends on the equipment of the medical institution and the endoscopist preference. To maintain bronchial patency in patients with malignant bronchial tumors, stenting is indicated, which avoids staged endoscopic interventions, each of which can be potentially dangerous due to possible complications.

Outcomes of multi-hole self-expandable metal stents versus fully covered self-expandable metal stents for malignant distal biliary obstruction in unresectable pancreatic cancer.

The multi-hole self-expandable metal stent (MHSEMS) is a novel SEMS with multiple small side holes on the covering membrane to prevent stent migration while minimizing tumor ingrowth. This study aimed to evaluate the clinical outcomes of MHSEMS in comparison with conventional covered SEMS (c-CMS). Consecutive patients with unresectable pancreatic cancer who underwent initial SEMS placement (MHSEMS or c-CMS) for malignant distal biliary obstruction were analyzed. Technical success, clinical success, causes of recurrent biliary obstruction (RBO), non-RBO adverse events, time to RBO (TRBO), and endoscopic reintervention were compared between groups. A total of 65 patients were included (MHSEMS: 27, c-CMS: 38). The technical success, clinical success, and non-RBO adverse event rates were similar between groups. Although stent migration was less frequently observed in the MHSEMS group (0% vs. 17.6%, p = 0.032), overall RBO rates were similar between groups (53.8% vs. 55.9%, p > 0.99). The most common cause of RBO within 14 days in the MHSEMS group was non-occlusion cholangitis. Median TRBO was significantly shorter in the MHSEMS group (101 vs. 227 days, p = 0.030) and MHSEMS was an independent predictor for shorter TRBO in multivariate analysis (hazard ratio, 2.27; 95% confidence interval, 1.06-4.86; p = 0.034). Outcomes after endoscopic interventio were not significantly different between groups. Stent removal was successful in all attempted cases in both groups. MHSEMS was associated with a significantly shorter TRBO compared to c-CMS. Further modifications of the present MHSEMS may be needed.

Radiation-Emitting metallic stent for unresectable bismuth type III or IV perihilar cholangiocarcinoma: a multicenter randomized trial

Background &amp; Aims: Self-expandable metallic stents (SEMSs) have been recommended for patients with unresectable malignant biliary obstruction while radiation-emitting metallic stents (REMSs) loaded with 125I seeds have recently been approved to provide longer patency and overall survival in malignant biliary tract obstruction. This trial is to evaluate the efficacy and safety of REMS plus hepatic arterial infusion chemotherapy (REMS-HAIC) versus SEMS plus HAIC (SEMS-HAIC) for unresectable perihilar cholangiocarcinoma (pCCA). Methods: This multicenter randomized controlled trial recruited patients with unresectable Bismuth type III or IV pCCA between March 2021 and January 2023. Patients were randomly assigned (1:1 ratio) to receive either REMS-HAIC or SEMS-HAIC using permuted block randomization, with a block size of six. The primary endpoint was overall survival (OS). The secondary endpoints were time to symptomatic progression (TTSP), stent patency, relief of jaundice, quality of life, and safety. Results: A total of 126 patients were included in the intent-to-treat population, with 63 in each group. The median OS was 10.2 months versus 6.7 months (P=0.002). The median TTSP was 8.6 months versus 5.4 months (P=0.003). The median stent patency was longer in the REMS-HAIC group than in the SEMS-HAIC group (P=0.001). The REMS-HAIC group showed better improvement in physical functioning scale (P&lt;0.05) and fatigue symptoms (P&lt;0.05) when compared to the SEMS-HAIC group. No significant differences were observed in relief of jaundice (85.7% vs. 84.1%; P=0.803) or the incidence of grade 3 or 4 adverse events (9.8% vs. 11.9%; P=0.721). Conclusion: REMS plus HAIC showed better OS, TTSP, and stent patency compared with SEMS plus HAIC in patients with unresectable Bismuth type III or IV pCCA with an acceptable safety profile.