• Clinical Endoscopy
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• v.57 no.5
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• pp.588-594
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• 2024

Endoscopic ultrasound (EUS)-guided interventions have evolved rapidly in recent years, with dedicated metal stents playing a crucial role in this process. Specifically, the invention of biflanged short metal-covered stents, including lumen-apposing metal stents (LAMS), and modifications in a variety of tubular self-expandable metal stents (SEMS), have led to innovations in EUS-guided interventions. LAMS or non-LAMS stents are commonly used in the EUS-guided drainage of pancreatic fluid collections, especially in cases of walled-off necrosis. Additionally, LAMS is commonly considered for drainage of the EUS-guided gallbladder or dilated common bile duct and EUS-guided gastroenterostomy. Fully or partially covered tubular SEMS with several new designs are being considered for EUS-guided biliary drainage. This review focuses on advances in SEMS for EUS-guided interventions and discusses related research results.

• Journal of Digestive Cancer Research
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• v.12 no.1
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• pp.15-22
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• 2024

Malignant colorectal obstructions urgently require decompression therapy to prevent the severe risks of intestinal ischemia and bowel perforation. In managing malignant colonic strictures endoscopically, the use of self-expandable metal stents (SEMS) is the predominant approach. Colonic SEMs are primarily used in preoperative decompression therapy before curative surgery and palliative treatment in patients with advanced disease stages. Furthermore, the stenting process, which requires rigorous clinical supervision, can lead to complications. This review endeavors to concisely review the clinical considerations associated with the SEMS procedure, with a focus on its indications, technical aspects, and potential complications that may arise during the procedure.

• Clinical Endoscopy
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• v.57 no.5
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• pp.628-636
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• 2024

Background/Aims: Advanced pancreatic and biliary tract cancers can invade the duodenum and cause duodenal hemorrhagic stenosis. This study aimed to evaluate the efficacy of covered self-expandable metal stents in the treatment of cancer-related duodenal hemorrhage with stenosis. Methods: Between January 2014 and December 2016, metal stents were placed in 51 patients with duodenal stenosis. Among these patients, a self-expandable covered metal stent was endoscopically placed in 10 patients with hemorrhagic duodenal stenosis caused by pancreatobiliary cancer progression. We retrospectively analyzed the therapeutic efficacy of the stents by evaluating the technical and clinical success rates based on successful stent placement, degree of oral intake, hemostasis, stent patency, and overall survival. Results: The technical and clinical success rates were 100%. All 10 patients achieved a gastric outlet obstruction scoring system score of three within two weeks after the procedure and had no recurrence of melena. The median stent patency duration and overall survival after stent placement were 52 days (range, 20-220 days) and 66.5 days (range, 31-220 days), respectively. Conclusions: Endoscopic placement of a covered metal stent for hemorrhagic duodenal stenosis associated with pancreatic or biliary tract cancer resulted in duodenal hemostasis, recanalization, and improved quality of life.

• Clinical Endoscopy
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• v.56 no.2
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• pp.135-142
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• 2023

Endoscopic biliary drainage strategies for managing unresectable malignant hilar biliary obstruction differ in terms of stent type, drainage area, and deployment method. However, the optimal endoscopic drainage strategy remains unclear. Uncovered self-expandable metal stents (SEMS) are the preferred type because of their higher functional success rate, longer time to recurrent biliary obstruction (RBO), and fewer cases of reintervention than plastic stents (PS). Other PS subtypes and covered SEMS, which feature a longer time to RBO than PS, can be removed during reintervention for RBO. Bilateral SEMS placement is associated with a longer time to RBO and a longer survival time than unilateral SEMS placement. Unilateral drainage is acceptable if a drainage volume of greater than 50% of the total liver volume can be achieved. In terms of deployment method, no differences were observed in clinical outcomes between side-by-side (SBS) and stent-in-stent deployment. Simultaneous SBS boasts a shorter procedure time and higher technical success rate than sequential SBS. This review of previous studies aimed to clarify the optimal endoscopic biliary drainage strategy for unresectable malignant hilar biliary obstruction.

• Journal of Digestive Cancer Research
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• v.10 no.2
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• pp.92-98
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• 2022

Self-expandable metal stent (SEMS) is effective for biliary drainage, especially in pancreaticobiliary cancer. The mechanical properties, material, and design of SEMS are important in preventing recurrent biliary obstruction and complication. Radial and chronic expansion forces play roles in preventing stent migration and collapse. Complications, such as stent impaction, cholecystitis, and pancreatitis, were related to the axial force. The nickel-titanium alloy shows more flexibility, conformability, and optimal axial force compared to previously used stainless steel. Additionally, the stent structure affected the mechanical properties of SEMS. Therefore, understanding the mechanical properties, material, and design of SEMS will provide the best outcome for biliary drainage, as well as better SEMS development.

• Clinical Endoscopy
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• v.55 no.3
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• pp.369-371
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• 2022

• Clinical Endoscopy
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• v.57 no.4
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• pp.515-526
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• 2024

Background/Aims: The optimal length of the uncovered portion of partially covered self-expandable metal stents (PCSEMSs) used in endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) remains unclear. This study investigated the safety and efficacy of PCSEMSs with different uncovered lengths, with a focus on stent migration and time to recurrent biliary obstruction (RBO). Methods: Outcomes of patients undergoing EUS-HGS using PCSEMSs with 5-mm and 20-mm uncovered portions at our institution from January 2016 to December 2021 were compared. Results: Sixty-two patients underwent EUS-HGS using PCSEMS (5/20-mm uncovered portions: 32/30). Stent migration occurred only in the 5-mm group. There were no differences in RBO rates (28.1% vs. 40.0%) or median time to RBO (6.8 vs. 7.1 months) between the two groups. Median overall survival (OS) was longer in the 20-mm group (3.1 vs. 4.9 months, p=0.037) due to the higher number of patients that resumed chemotherapy after EUS-HGS (56.7% vs. 28.1%, p=0.029). Good performance status, absence of hepatic metastases, and chemotherapy after EUS-HGS were independent predictors of longer OS. Conclusions: No migration was observed in patients treated with PCSEMS with 20-mm uncovered portions. Patients treated with PCSEMS with 20-mm uncovered portions performed at least as well as those treated with 5-mm uncovered portions in all material respects.

• Clinical Endoscopy
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• v.55 no.6
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• pp.793-800
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• 2022

Background/Aims: Fully covered self-expanding metal stents (FCSEMSs) are a relatively novel option for treating painful main pancreatic duct refractory strictures in patients with chronic pancreatitis. Herein, we aimed to assess the efficacy, feasibility, and safety of FCSEMSs in this patient group. Methods: This prospective single-center study included patients who underwent endoscopic retrograde pancreatography with FCSEMS placement. The primary endpoints were the technical and clinical success rates. A reduction in visual analog scale pain score of >50% compared with that before stent placement was defined as clinical success. Secondary endpoints were resolution of pancreatic strictures on fluoroscopy during endoscopic retrograde pancreatography and the development of stent-related adverse events. Results: Thirty-six patients were included in the analysis. The technical success rate was 100% (n=36) and the clinical success rate was 86.1% (n=31). There was a significant increase in stricture diameter from 1.7 mm to 3.5 mm (p<0.001) after stent removal. The mean visual analog scale pain score showed statistically significant improvement. At 19 months of follow-up, 55.6% of the patients were asymptomatic. Stent migration (16.7%), intolerable abdominal pain (8.3%), development of de novo strictures (8.3%), and mild pancreatitis (2.8%) were the most common adverse events. Conclusions: FCSEMS placement showed good technical and clinical success rates for achieving pain relief in patients with refractory main pancreatic duct strictures.

• Clinical Endoscopy
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• v.55 no.1
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• pp.150-155
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• 2022

We reviewed 7 patients with unsuccessful endoscopic hemostasis using covered self-expandable metal stent (CSEMS) placement for post-endoscopic sphincterotomy (ES) bleeding. ES with a medium incision was performed in 6 and with a large incision in 1 patient. All but 1 of them (86%) showed delayed bleeding, warranting second endoscopic therapies followed by CSEMS placement 1-5 days after the initial ES. Subsequent CSEMS placement did not achieve complete hemostasis in any of the patients. Lateral-side incision lines (3 or 9 o'clock) had more frequent bleeding points (71%) than oral-side incision lines (11-12 o'clock; 29%). Additional endoscopic hemostatic procedures with hemostatic forceps, hypertonic saline epinephrine, or hemoclip achieved excellent hemostasis, resulting in complete hemostasis in all patients. These experiences provide an alert: CSEMS placement is not an ultimate treatment for post-ES bleeding, despite its effectiveness. The lateral-side of the incision line, as well as the oral-most side, should be carefully examined for bleeding points, even after the CSEMS placement.

• Clinical Endoscopy
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• v.55 no.4
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• pp.564-569
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• 2022

A lumen-apposing metal stent (LAMS) is a saddle-shaped stent with large flanges at both ends, thereby preventing stent migration and helping with approximation of the adjacent structures. We report the case of a 25-year-old female with remnant choledochal cyst which was successfully treated with LAMS after initial treatment failure with a plastic stent. Although complete excision of the cyst is the definite treatment of choledochal cysts, endoscopic ultrasonography-guided cystoduodenostomy can be considered in cases wherein surgery is not feasible and dysplasia is not present. LAMS may be preferred to plastic stents for effective resolution of remnant choledochal cyst and prevention of ascending infection.