Uncovered Self-expandable Metal Stents Research Articles

Predictors of stent dysfunction after self-expandable metal stent placement for malignant gastric outlet obstruction: tumor ingrowth in uncovered stents and migration of covered stents.

Endoscopic metallic stenting is widely accepted as a palliation therapy for malignant gastric outlet obstruction (GOO). However, the predictors of stent dysfunction have not been clarified. We aimed to evaluate the predictors, especially tumor ingrowth in uncovered self-expandable metallic stents (U-SEMS) and migration of covered self-expandable metallic stents (C-SEMS), which are the main causes related to the stent characteristics. In this multicenter retrospective study, we compared patients with U-SEMS and C-SEMS in terms of clinical outcomes, and predictors of stent dysfunction. In total, 252 patients (126 with U-SEMS and 126 with C-SEMS) were enrolled. There were no significant differences in technical success, clinical success, GOO score, or time to stent dysfunction. Tumor ingrowth was significantly more frequent in U-SEMS (U-SEMS, 11.90% vs. C-SEMS, 0.79%; p = 0.002), and stent migration was significantly more frequent for C-SEMS (C-SEMS, 8.73% vs. U-SEMS, 0.79%; p = 0.005). Karnofsky performance status (p = 0.04), no presence of ascites (p = 0.02), and insufficient (<30%) stent expansion (p = 0.003) were significantly associated with tumor ingrowth in U-SEMS. Meanwhile, a shorter stent length (p = 0.05) and chemotherapy (p = 0.03) were predictors of C-SEMS migration. Both U-SEMS and C-SEMS are effective with comparable patencies. Tumor ingrowth and stent migration are the main causes of stent dysfunction for U-SEMS and C-SEMS, respectively. With regard to stent dysfunction, U-SEMS might be a good option for patients receiving chemotherapy, while C-SEMS with longer stents for patients in good condition. (Clinical trial registration number: UMIN000024059).

Covered versus uncovered metal stents for malignant gastric outlet obstruction: Systematic review and meta-analysis.

Self-expandable metal stents (SEMS) are used for non-resectable malignant gastric outlet obstruction (GOO). Studies of covered versus uncovered SEMS have yielded inconsistent results as a result of heterogeneity in design and patient population. We carried out a meta-analysis to compare covered and uncovered gastroduodenal SEMS. Using MEDLINE, Embase, and the Cochrane database, we identified 1624 patients from 13 prospective and retrospective studies that evaluated covered and uncovered SEMS for malignant GOO and were published until October 2016. We pooled data on SEMS dysfunction, technical and clinical success, and adverse events using the fixed-effect or random-effects model. Compared with uncovered SEMS, covered SEMS did not show any significant difference in stent dysfunction risk (risk ratio [RR], 1.02; 95% confidence interval [CI], 0.79-1.32). A subgroup analysis of five randomized trials suggested a trend toward a lower dysfunction risk in covered SEMS (RR, 0.63; 95% CI, 0.45-0.88). Covered SEMS were associated with a lower occlusion risk (RR, 0.44; 95% CI, 0.28-0.68), but with a higher migration risk (RR, 4.28; 95% CI, 2.89-6.34). Technical and clinical success rates were comparable between the groups. Overall adverse events tended to be more frequent in covered SEMS (RR, 1.75; 95% CI, 1.09-2.83). Outcomes of covered and uncovered gastroduodenal SEMS were comparable, although the lower dysfunction rate of covered SEMS observed in the analysis of randomized trials needs further investigation. Antimigration mechanisms for covered SEMS and identification of patients who can achieve longer patency from uncovered SEMS would help improve the outcomes of gastroduodenal SEMS.

Percutaneous Transhepatic Biliary Stenting with Uncovered Self-Expandable Metallic Stents in Patients with Malignant Biliary Obstruction – Efficacy and Survival Analysis

SummaryBackgroundThe aim of this study was to assess short- and long-term outcomes of malignant biliary obstruction (MBO) treatment by percutaneous transhepatic biliary stenting (PTBS) with uncovered selfexpandable metallic stents (SEMS), and to identify predictors of survival.Material/MethodsA nine-year, single-centre study from a prospectively collected database included 222 patients with inoperable MBO treated by PTBS with uncovered nitinol SEMS.ResultsTechnical and clinical success rates were 95.9% and 82.4%, respectively. The total rate of postprocedural complications was 14.4%. The mean durations of the primary and secondary stent patency were 114.7±15.1 and 146.4±21.2 days, respectively. The 30-day mortality rate was 15.3% with no procedure-related deaths. The mean estimated length of survival was 143.3±20.6 days. Independent predictors increasing the risk of death included higher than 115 μmol/L serum bilirubin 2–5 days after biliary stenting (HR 3.274, P=0.019), distal (non-hilar) obstruction of the bile ducts (HR 3.711, P=0.008), Bismuth-Corlette type IV stricture (HR 2.082, P=0.008), obstruction due to gallbladder cancer (HR 31.029, P=0.012) and only partial drainage of liver parenchyma (HR 4.158, P=0.040).ConclusionsPTBS with uncovered SEMS is an effective and safe method for palliative treatment of MBO. Serum bilirubin higher than 115 μmol/L 2–5 days after the procedure has a significant negative impact on patients’ survival. Lower survival is also determined by distal bile duct obstruction, Bismuth– Corlette type IV stricture, biliary obstruction caused by gallbladder cancer and when only partial liver drainage is applied.

Erosion of esophageal stent into left main bronchus causing airway compromise.

Covered or uncovered self-expanding metal stents are currently used for the palliative treatment of neoplastic esophageal strictures or compressions and esophageal leaks or fistulas due to malignancies. Erosion of esophageal stents into the respiratory tract is a rare complication and that too has been reported mostly as an early complication within few days or weeks. Here, we present the case of a 31-year-old female, who presented with a late complication of an esophageal stent eroding into the left main bronchus causing respiratory distress. She was stented for a benign corrosive esophageal stricture following caustic soda ingestion 3 years ago. She underwent a thoracotomy and closure of esophagobronchial fistula along with laparoscopic esophagectomy and gastric pull through. Postoperatively, patient developed an anastomotic leak which was corrected by placing a temporary stent.

A prospective randomized study for efficacy of an uncovered double bare metal stent compared to a single bare metal stent in malignant biliary obstruction.

A biliary self-expandable metal stent (SEMS) is commonly used to relieve malignant biliary obstruction. The aim of this study was to compare the efficacy of a conventional uncovered SEMS with that of a newly developed uncovered double bare metal stent in reducing the risk of stent occlusion caused by tumor ingrowth. We performed a prospective, open-labeled, randomized trial in 71 patients at Severance Hospital, Yonsei University College of Medicine from June 2013 to June 2014. Patients with inoperable malignant biliary obstruction were included and randomized to receive an uncovered single bare metal stent (SBSs; S&G Biotech Inc.), an uncovered single bare metal stent (SBSt; Taewoong Medical), or an uncovered double bare metal stent (DBS; S&G Biotech Inc.). The mean age was 66.6years (range, 35-83), and 42 (59.2%) were male. The mean duration of stent patency was 212days (±152) in the DBS group (n=24) compared with 124days (±98) in the SBSs group (n=23; P=0.022 for noninferiority) and 116days (±79) in the SBSt group (n=24; P=0.010 for noninferiority). There were no differences in the incidences of early and delayed complications or migration. The newly developed DBS is noninferior to the conventional uncovered SEMSs on duration of stent patency and tumor ingrowth occurred less frequently in the DBS group. This might decrease the need for reintervention and offer a better quality of life. The trial is registered with Clinicaltrials.gov no: NCT01869894.

Short-Term Use of Uncovered Self-Expanding Metallic Airway Stents for Severe Expiratory Central Airway Collapse

Background: Patients with severe symptomatic expiratory central airway collapse (ECAC) undergo a stent trial to determine whether they are candidate for tracheobronchoplasty. Most stent trials were done using silicone stents. However, there was a higher number of silicone stent-related complications. Objectives: The aim of this study was to evaluate the safety and efficacy of short-term uncovered self-expanding metallic airway stents (USEMAS) in patients with ECAC. Methods: This was a retrospective review. Baseline measurements were compared to those obtained after 7-14 days. Measurements included: Modified Medical Research Council (mMRC), Cough Quality of Life Questionnaire (CQLQ), spirometry testing, and 6-Minute Walk Test (6MWT). Stent- and procedure-related complications were reported. Results: 33 patients (median age, 52 years) underwent the USEMAS trial. Presenting symptoms were dyspnea in 100%, intractable cough in 90.3%, recurrent infection in 42.2%, and inability to clear secretions in 21.4%. Dyspnea, cough, and secretion clearance improved in 88, 70, and 57%, respectively. Overall, there was a significant improvement in mMRC (p < 0.001), CQLQ (p = 0.015), and 6MWT (p = 0.015). There was 1 airway infection, 1 stent migration, and 1 pneumothorax. The median duration of USEMAS was 7 days. All stents were removed without any complications. At the time of stent removal, no granulation tissue was observed in 30.9%, and mild granulation tissue was observed in 69.1%. Conclusion: The short-term USEMAS trial improves respiratory symptoms, quality of life, and exercise capacity with few complications in patients with severe symptomatic ECAC when performed by a multidisciplinary airway team in highly specialized centers with experience in the evaluation and treatment of this patient population.

Intraductal Fenestration of Biliary Metal Stents Using Argon Plasma to Facilitate Bilateral Hilar Stenting

Background: When placed across the biliary confluence, uncovered self-expanding metal stents (SEMS) may impede access to the contralateral intrahepatic ducts. In particular it is difficult to place additional plastic or metal stents across multiple adjacent cells of a hilar SEMS. Argon plasma has been used to trim biliary SEMS. However, the use of argon plasma for intraductal fenestration of biliary metal stents has not been described. Case report: A 38-year-old man with hilar cholanogiocarcinoma presented with cholangitis and right lobe liver abscesses. He had been previously treated with placement of multiple closed-cell, uncovered SEMS extending from duodenum to left hepatic duct. A percutaneous transhepatic catheter was placed into an abscess cavity, which communicated with right hepatic ducts. Subsequently a percutaneous transhepatic guidewire was advanced through the hilar SEMS interstices and into the duodenum. During ERCP a temporary plastic stent was placed into the left main duct for venting of argon gas. The percutaneous guidewire was then grasped with a snare and brought out via the mouth. Choledochoscopy was then performed using a pediatric gastroscope which was advanced over the guidewire into the existing SEMS up to the level of the hilum. Metal struts of the embedded SEMS were seen crisscrossing over the right duct orifice. The visible SEMS wires were fenestrated using a pediatric argon plasma coagulation probe at power of 80 W and flow 0.3 L/min, and further unwoven with a pediatric biopsy forceps. Argon gas vented from the percutaneous biliary sheath as well as the left hepatic duct stent. Subsequently plastic stents were placed via a duodenoscope into 4 separate right intrahepatic ducts, each of which was accessed across adjacent interstices of the SEMS. The patient had rapid clinical improvement and a follow-up computed tomography at 4 weeks showed resolution of liver abscesses. Conclusion: Fenestration of hilar biliary SEMS using argon plasma under direct endoscopic visualization can facilitate bilateral hilar stent placement in patients with complex malignant obstruction of the central intrahepatic ducts. Argon plasma has been used to trim biliary and rectal SEMS. The use of argon plasma for endoscopic fenestration of duodenal stents to facilitate ERCP has also been reported. Our case extends the application of this technique by describing intraductal fenestration of an indwelling biliary SEMS to accomplish bilateral hilar stenting.

Partially Covered versus Uncovered Self-expandable Metal Stents in the Palliative Treatment of Malignant Distal Biliary Obstruction

Introduction: Self-expandable metal stents (SEMSs) are commonly used to relieve malignant biliary obstruction. Covered self-expandable metal stents (CSEMSs) were introduced to improve the patency of SEMSs by preventing tissue ingrowth. Unlike uncovered self-expandable metal stents (USEMSs), which are integrated into the tumor or duct wall, CSEMSs do not embed, but have an increased risk of migration. Although several retrospective studies comparing these two types of stents for malignant biliary obstruction have shown longer patency with CSEMSs, prospective, randomized trials have not been able to confirm these results. Partially covered self-expandable metal stents (PCSEMSs) has been introduced to reduce migration with advantage of CSEMSs preventing tumor ingrowth. The aim of this study was to compare stent patency and clinical outcomes between PCSEMSs and USEMSs in malignant biliary obstruction. Methods: A total of 36 patients with malignant biliary obstruction were randomly assigned to either PCSEMSs (n=16) or USEMSs (n=20) for palliation of biliary obstruction. Duration of stent patency, procedure-related adverse events and intervention for stent occlusion were evaluated. Results: The mean period of follow-up was 105.3±100.8 days for the PCSEMSs group and 180.8±123.3 days for the USEMSs group (P=0.056). Stent occlusion occurred in only 1 patient after 84 days in the PCSEMSs group and in 6 patients after a mean of 146 days in the USEMSs group (P=0.104). Cumulative stent patency estimated by the Kaplan-Meier method showed no significant difference between PCSEMSs group and USEMSs group (P=0.20). There was no procedure-related adverse event in both groups. Additionally, there was no migration of stent in the CSEMSs group. Conclusion: There was no significant difference in stent patency time between PCSEMSs and USEMSs in the palliative treatment of malignant distal biliary obstruction, although there was trend that more stent occlusion occurred in USEMSs group than PCSEMSs group. There was no migration of stent in the CSEMSs group. Further studies with large population are warranted to validate these results.

Through-the-scope enteral metal stent placement using a short-type single-balloon enteroscope for malignant surgically reconstructed jejunal stenosis (with video).

Self-expandable metal stent (SEMS) placement in surgically reconstructed intestine is technically challenging, and only a few reports have been published.1, 2 Here, we describe a case of successful SEMS placement for surgically reconstructed jejunal stenosis using a newly developed short-type single-balloon enteroscope (sSBE). A 70-year-old man presented to our hospital with fever and jaundice. Six months earlier, he had undergone subtotal stomach-preserving pancreatoduodenectomy with PD-II reconstruction for duodenal cancer. Computed tomography revealed a dilated intrahepatic bile duct as a result of stenosis in the surgically reconstructed jejunal loop caused by cancer recurrence (Fig. 1a). We could reach the stenosis using a sSBE (SIF-H290S; channel diameter, 3.2 mm; Olympus, Tokyo, Japan); however, it was impossible to pass beyond the stenosis (Fig. 1b). Because of the advanced stage of cancer, palliative through-the-scope (TTS) SEMS placement was attempted. A 0.035-inch guidewire was advanced beyond the stenosis, and an uncovered SEMS (18-mm wide, 80-mm long; Niti-S Enteral Colonic Stent; Taewoong Medical, Gimpo, Korea) was deployed (Fig. 2, Video S1). The postoperative period was uneventful. Jaundice and cholangitis resolved in a few days. Abdominal X-ray revealed that the stent was well expanded. The sSBE is compatible with the use of various interventional devices through its large working channel. To date, there is only one report on TTS SEMS placement, but it used a short-type double-balloon enteroscope (DBE).3 In comparison with DBE, SBE was assumed to be more disadvantageous in carrying out deep insertion.4 Having been equipped with a passive bending part, the sSBE has an increased endoscope flexibility. A recent article using sSBE showed its success rate of insertion to the blind end to be 92%.5 Although the safety of SEMS placement in the jejunum is yet to be established, TTS SEMS placement using sSBE could be an effective, minimally invasive treatment option for patients with advanced cancer. Authors declare no conflicts of interest for this article. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Predictors of outcomes in patients undergoing covered and uncovered self-expandable metal stent placement for malignant gastric outlet obstruction: a multicenter study

Uncovered self-expandable metal stents (U-SEMSs) and covered self-expandable metal stents (C-SEMSs) are available for palliative therapy for malignant gastric outlet obstruction (GOO). However, clinical differences and indications between the 2 types of SEMSs have not been elucidated. We retrospectively compared 126 patients with U-SEMS and 126 patients with C-SEMSs with regard to clinical outcome and factors predictive of clinical improvement after SEMSs placement. No significant difference was observed between the U-SEMS and C-SEMS groups with respect to technical success, clinical success, GOO score, or time to stent dysfunction. Stent migration was significantly more frequent in patients with C-SEMSs (U-SEMSs, .79%; C-SEMSs, 8.73%; P= .005). Karnofsky performance status, chemotherapy, peritoneal dissemination, and stent expansion≤ 30% were associated significantly with poor GOO score improvement in multivariable analyses, but stent type was not (P= .213). In subgroup analyses, insufficient (≤30%) stent expansion was an independent factor in patients with U-SEMSs (P= .041) but not C-SEMSs. In the insufficient stent expansion subgroup, C-SEMSs was associated significantly with superior clinical improvement compared with U-SEMSs (P= .01). Insufficient stent expansion was observed more frequently in patients with GI obstruction because of anastomotic sites or metastatic cancer (44.8% [13/29], P= .001). No clinical difference, apart from stent migration, was observed between patients with U-SEMSs and C-SEMSs. GI obstruction because of an anastomotic site or metastatic cancer may be an indication for C-SEMS use to improve oral intake after SEMSs placement.

Is There Room for Improvement in Increasing the Stent Patency of Biliary Plastic Stents?

Is There Room for Improvement in Increasing the Stent Patency of Biliary Plastic Stents?

Pilot study of a novel, large‐bore, fully covered self‐expandable metallic stent for unresectable distal biliary malignancies

In patients with unresectable malignant distal biliary obstruction, covered self-expandable metallic stents (CSEMS) may remain patent longer than uncovered self-expandable metallic stents as a result of tumor ingrowth prevention. One main cause of recurrent biliary obstruction (RBO) in CSEMS is sludge formation, which can be prevented using a large-bore stent. Therefore, we developed a novel, 12-mm diameter fully covered SEMS (FCSEMS) and investigated its clinical safety, efficacy, and rate of adverse events. This prospective, multicenter pilot study, which ran between June 2011 and November 2012, included 38 consecutive patients with unresectable malignant distal biliary obstruction. All patients underwent endoscopic insertion of our novel stent. Primary endpoint was non-RBO rate 6 months after placement. Technical and functional success rates of the procedures were 100%. Six-month non-RBO rate was 50%, and median time to RBO was 184 days. Median survival time was 241 days. Twelve patients died within 6 months after stent placement without RBO. RBO was observed in 10 patients (26%), with seven experiencing stent occlusion and three experiencing stent migration. Adverse events other than RBO (at <30 days) developed in six patients (16%; cholecystitis, one; pancreatitis, one; hyperamylasemia, one; pancreatic ductitis, one; abdominal pain, two). Stent removal for reintervention was successfully completed in eight patients. Our novel FCSEMS may be safe and effective for managing malignant distal obstruction with an acceptable incidence of adverse events.

Tu1554 Partially Covered Versus Uncovered Self-Expandable Metal Stents in the Palliative Treatment of Malignant Distal Biliary Obstruction

Tu1554 Partially Covered Versus Uncovered Self-Expandable Metal Stents in the Palliative Treatment of Malignant Distal Biliary Obstruction

Feasibility of the placement of a novel 6-mm diameter threaded fully covered self-expandable metal stent for malignant hilar biliary obstructions (with videos)

Uncovered self-expandable metal stents (USEMSs) are used to treat unresectable malignant hilar biliary obstructions (MHBOs). However, ingrowth is not prevented, and reintervention is often troublesome. A novel 6-mm threaded fully covered self-expandable metal stent (T-FCSEMS) is available that may mitigate these issues. We aimed to clarify the safety and efficacy of T-FCSEMS placement for MHBO. Thirty patients underwent T-FCSEMS placements for MHBOs between 2014 and 2015. T-FCSEMSs were used for initial stenting in 17 patients (initial group) and for reinterventions for USEMS occlusions caused by ingrowth in 13 patients (reintervention group). The technical success rates, times to recurrent biliary obstruction, and the reintervention success rates were evaluated. The technical success rates were 94% (16/17) and 92% (12/13) in the initial group and reintervention group, respectively. Intrahepatic bile duct occlusions caused liver abscesses 8 days and 22 days after T-FCSEMS placements in 2 cases (7%) in the initial group, in which T-FCSEMSs were placed across the intrahepatic bile duct bifurcation. The median times to recurrent biliary obstruction were 210 days in the initial group after bilateral placement and 112 days and 152 days in the reintervention group after bilateral and unilateral placements, respectively. During reintervention, T-FCSEMS removal was successful in all patients in whom it was attempted, and the success rate of endoscopic reintervention was 100% in both groups. T-FCSEMS placement is a promising option for both initial stenting and reintervention for MHBO. However, we should consider the possibility of intrahepatic bile duct occlusion.

Stent for Crohn's disease strictures: Which one and when?

Stent for Crohn's disease strictures: Which one and when?

Covered versus Uncovered Self-Expandable Metal Stents for Managing Malignant Distal Biliary Obstruction: A Meta-Analysis.

AimTo compare the efficacy of using covered self-expandable metal stents (CSEMSs) and uncovered self-expandable metal stents (UCSEMSs) to treat objective jaundice caused by an unresectable malignant tumor.MethodsWe performed a comprehensive electronic search from 1980 to May 2015. All randomized controlled trials comparing the use of CSEMSs and UCSEMSs to treat malignant distal biliary obstruction were included.ResultsThe analysis included 1417 patients enrolled in 14 trials. We did not detect significant differences between the UCSEMS group and the CSEMS group in terms of cumulative stent patency (hazard ratio (HR) 0.93, 95% confidence interval (CI) 0.19–4.53; p = 0.93, I2 = 0%), patient survival (HR 0.77, 95% CI 0.05–10.87; p = 0.85, I2 = 0%), overall stent dysfunction (relative ratio (RR) 0.85, M-H, random, 95% CI 0.57–1.25; p = 0.83, I2 = 63%), the overall complication rate (RR 1.26, M-H, fixed, 95% CI 0.94–1.68; p = 0.12, I2 = 0%) or the change in serum bilirubin (weighted mean difference (WMD) -0.13, IV fixed, 95% CI 0.56–0.3; p = 0.55, I2 = 0%). However, we did detect a significant difference in the main causes of stent dysfunction between the two groups. In particular, the CSEMS group exhibited a lower rate of tumor ingrowth (RR 0.25, M-H, random, 95% CI 0.12–0.52; p = 0.002, I2 = 40%) but a higher rate of tumor overgrowth (RR 1.76, M-H, fixed, 95% CI 1.03–3.02; p = 0.04, I2 = 0%). Patients with CSEMSs also exhibited a higher migration rate (RR 9.33, M-H, fixed, 95% CI 2.54–34.24; p = 0.008, I2 = 0%) and a higher rate of sludge formation (RR 2.47, M-H, fixed, 95% CI 1.36–4.50; p = 0.003, I2 = 0%).ConclusionsOur meta-analysis indicates that there is no significant difference in primary stent patency and stent dysfunction between CSEMSs and UCSEMSs during the period from primary stent insertion to primary stent dysfunction or patient death. However, when taking further management for occluded stents into consideration, CSEMSs is a better choice for patients with malignant biliary obstruction due to their removability.

Endoscopic palliative treatment using a metallic stent in a patient with an obstructive jejunal metastasis

A 42-year-old man, receiving palliative treatment for lung cancer, presented with hyperemesis, abdominal pain, and intestinal subocclusion. Endoscopy showed a large volume of liquid stasis and gastric lesions compatible with metastasis (Video 1, available at www.giejournal.org). Computed tomography revealed intussusception in the jejunal loop. Single-balloon endoscopy demonstrated multiple metastatic lesions throughout the small bowel. At the midjejunum level, a 5-cm vegetative lesion was found, which partially prevented the endoscope transposition. It was decided to insert an uncovered self-expandable metal stent (SEMS) (22 mm × 9 cm, Wallflex duodenal stent, Boston Scientific, Natick, Mass). The obstructive lesion was demarcated with clips. After removal of the enteroscope, the overtube was kept in place with the inflated balloon, and the SEMS was deployed under fluoroscopy. The stent delivery system was 255-cm long, and the overtube was 140-cm long. On endoscopic review, immediate expansion of the stent was confirmed with a contrast-free flow through the lumen (Fig. 1). In the following days, the patient was able to consume an oral diet and had normal bowel movements until he died a month later. With the development of deep enteroscopy and the use of stent deployment through the overtube, patients with small-bowel neoplasia unreachable by conventional endoscopes have become eligible for endoscopic palliation.

Stents for colorectal obstruction: Past, present, and future.

Since the development of uncovered self-expanding metal stents (SEMS) in the 1990s, endoscopic stents have evolved dramatically. Application of new materials and new designs has expanded the indications for enteral SEMS. At present, enteral stents are considered the first-line modality for palliative care, and numerous types of enteral stents are under development for extended clinical usage, beyond a merely palliative purpose. Herein, we will discuss the current status and the future development of lower enteral stents.

Choice of plastic or metal stent for patients with jaundice with pancreaticobiliary malignancy using simple clinical tools: a prospective evaluation

Background and aimAlthough plastic stents have been recommended for patients with pancreaticobiliary malignancy and an expected survival of less than 6 months, no study has developed criteria to assess survival...

Outcomes of endoscopically inserted self-expandable metal stents in malignancy according to the type of stent and the site of obstruction.

Self-expandable metal stents (SEMSs) can be used for the palliation of malignant obstruction in the upper gastrointestinal tract. This study assessed the feasibility and efficacy of endoscopically inserted SEMSs for the palliation of malignant obstruction in the stomach and duodenum. Between January 2011 and April 2014, 220 patients with gastric or duodenal obstruction due to malignancy underwent endoscopic SEMS insertion at Asan Medical Center. The associations of technical/clinical outcomes and complications with the type of stent and site of obstruction were analyzed. The 220 patients included 125 men (56.8%) and 95 women (43.2%); median patient age was 63years. Fully covered, partially covered, and uncovered SEMSs were inserted into 16, 77, and 120 patients, respectively. Obstructions were located in the gastric outlet, including the duodenal bulb, in 106 patients, and in the duodenal second and third portions in 114 patients. Technical success was achieved in 213 of 220 patients (96.8%) and clinical success in 184 of 213 (86.4%). Clinical success rates were similar to the type of stent, but were significantly greater for gastric outlet (95/104, 91.3%) than for duodenal (89/109, 81.7%) obstructions (p=0.039). Stent migration was observed in 20 patients (9.1%) and stent obstruction in 51 (23.2%). Rates of stent migration were significantly higher for fully covered (6/16, 37.5%) than for partially covered (7/77, 9.1%) and uncovered (7/120, 5.8%) SEMSs (p<0.001) and were significantly higher for gastric outlet (16/104, 15.4%) than for duodenal (4/109, 1.2%) obstructions (p=0.003). Rates of stent obstruction were similar for fully covered (2/16, 12.5%), partially covered (17/77, 22.1%), and uncovered (32/120, 26.7%) SEMSs (p=0.409) and in patients with gastric outlet (26/104, 25.0%) and duodenal (25/109, 22.9%) obstruction (p=0.724). SEMS selection for malignant obstruction of the upper gastrointestinal tract depends on the site of obstruction.