Covered Self-expandable Metal Stents Research Articles

Comparison of partially covered nitinol stents with partially covered stainless stents as a historical control in a multicenter study of distal malignant biliary obstruction: the WATCH study

Covered self-expandable metal stents (CSEMSs) were developed to prevent tumor ingrowth, but stent migration is one of the problems with CSEMSs. To evaluate a new, commercially available CSEMS with flared ends and low axial force compared with a commercially available CSEMS without the anti-migration system and high axial force. Multicenter, prospective study with a historical cohort. Twenty Japanese referral centers. This study involved patients with unresectable distal malignant biliary obstruction. Placement of a new, commercially available, partially covered SEMS. Recurrent biliary obstruction rate, time to recurrent biliary obstruction, stent-related complications, survival. Between April 2009 and March 2010, 141 patients underwent partially covered nitinol stent placement, and between May 2001 and January 2007, 138 patients underwent placement of partially covered stainless stents as a historical control. The silicone cover of the partially covered nitinol stents prevented tumor ingrowth. There were no significant differences in survival (229 vs 219 days; P = .250) or the rate of recurrent biliary obstruction (33% vs 38%; P = .385) between partially covered nitinol stents and partially covered stainless stents. Stent migration was less frequent (8% vs 17%; P = .019), and time to recurrent biliary obstruction was significantly longer (373 vs 285 days; P = .007) with partially covered nitinol stents. Stent removal was successful in 26 of 27 patients (96%). Nonrandomized, controlled trial. Partially covered nitinol stents with an anti-migration system and less axial force demonstrated longer time to recurrent biliary obstruction with no tumor ingrowth and less stent migration.

Mo1311 Late Recurrence of Biliary Anastomotic Strictures (BAS) in Liver Transplant Patients Initially Responding to Covered Self-Expandable Metal Stents (CSEMS)

Standard endoscopic management of benign biliary strictures with periodic multiple plastic stent (PS) replacement is less effective in post-transplant BAS. CSEMS appear to improve BAS resolution rates over PS. However, the risk of stricture recurrence after CSEMS removal is not yet known.

Sa1526 Comparison of the Influence of Plastic and Fully Covered Metal Biliary Stents on the Accuracy of EUS-FNA for the Diagnosis of Pancreatic Cancer

Studies have reported that the presence of prior biliary stent may interfere with EUS visualization of pancreatic tumors. We aimed to compare the influence of the biliary plastic and fully covered self expanding metal stents (CSEMS) on the accuracy of EUS-FNA cytology in patients with solid pancreatic masses.

Tu1522 Comparing Plastic Versus Covered Self Expandable Metallic Stent (CSEMS) in Endoscopic Ultrasound-Guided Transmural Drainage for Peripancreatic Fluid Collections, Which Is Better?; A Pilot Study

Single-step EUS-guided peripancreatic fluid collections (PFCs) drainage has been widely used. This procedure usually needs to insert multiple plastic stents for adequate drainage, which may cumbersome and take a long time. Recently some reports introduced the usefulness of metal stent for this procedure. However, there was no comparative study between multiple plastic stents and metal stent for drainage of PFCs. We, therefore, conducted pilot study to compare the procedure time, technical success and clinical outcomes.

Mo1338 Use of Covered Self Expandable Metal Stents (CSEMS) for Endoscopic Management of Non-Stricture Related Benign Biliary Diseases

Mo1338 Use of Covered Self Expandable Metal Stents (CSEMS) for Endoscopic Management of Non-Stricture Related Benign Biliary Diseases

Mo1329 Endoscopic Treatment of Benign Biliary Diseases Using Covered Self- Expandable Metal Stents (CSEMS)

Mo1329 Endoscopic Treatment of Benign Biliary Diseases Using Covered Self- Expandable Metal Stents (CSEMS)

Su1360 Covered Self-Expandable Metal Stent Deployment Promises Safe Neoadjuvant Chemotherapy in Patients With Borderline Resectable Pancreatic Head Cancer

Neoadjuvant chemotherapy (NAC) may lead to successful margin-negative resection (R0) in patients with borderline resectable pancreatic head cancer (BRPHC). NAC using a metallic stent has been attempted in patients with BRPHC, however, the efficacy of this therapy and the influence of use of a covered self-expanding metal stent (CSEMS) for its delivery in the treatment of BRPHC has not been evaluated yet.

Endoscopic ultrasound-guided transmural drainage of infected pancreatic fluid collections with placement of covered self-expanding metal stents: a case series

Endoscopic ultrasound-guided transmural drainage (EUS-GTD) has become the standard procedure for treating symptomatic pancreatic fluid collections. The aim of this series was to evaluate the efficacy and safety of covered self-expanding metal stent (CSEMS) placement for treating infected pancreatic fluid collections. From January 2007 to May 2010, 22 patients (18 M/4F; mean age 56.9) with infected pancreatic fluid collections (mean size, 13.2 cm) at two Italian centers were evaluated for EUS-GTD. In 20 of the 22 patients, EUS-GTD with CSEMS placement was indicated. Early complications occurred in two patients: one patient developed a superinfection, which was managed conservatively, and one experienced stent migration and superinfection, and was managed surgically. The CSEMSs were removed without difficulty in 18 patients after a median of 26 days, while stent removal failed in one patient due to inflammatory tissue ingrowth; instead it was removed during surgery performed for renal cancer. Clinical success was achieved without additional intervention in 17 patients during a mean follow-up of 610 days; only one symptomatic recurrence was observed. In our experience, EUS-GTD with CSEMS placement appears safe for the treatment of infected pancreatic fluid collections.

Covered self expandable metallic stent with flared plastic one inside for pancreatic pseudocyst avoiding stent dislodgement

Endoscopic ultrasound-guided drainage has recently been recommended for increasing the drainage rate of endoscopically managed pancreatic fluid collections and decreasing the morbidity associated with conventional endoscopic trans-mural drainage. The type of stent used for endoscopic drainage is currently a major area of interest. A covered self expandable metallic stent (CSEMS) is an alternative to conventional drainage with plastic stents because it offers the option of providing a larger-diameter access fistula for drainage, and may increase the final success rate. One problem with CSEMS is dislodgement, so a metallic stent with flared or looped ends at both extremities may be the best option. An 85-year-old woman with severe co-morbidity was treated with percutaneous approach for a large (20 cm) pancreatic pseudocyst with corpuscolated material inside. This approach failed. The patient was transferred to our institute for EUS-guided transmural drainage. EUS confirmed a large, anechoic cyst with hyperechoic material inside. Because the cyst was large and contained mixed and corpusculated fluid, we used a metallic stent for drainage. To avoid migration of the stent and potential mucosal growth above the stent, a plastic prosthesis (7 cm, 10 Fr) with flaps at the tips was inserted inside the CSEMS. Two months later an esophagogastroduodenoscopy was done, and showed patency of the SEMS and plastic stents, which were then removed with a polypectomy snare. The patient experienced no further problems.

Role of Fully Covered Self-Expandable Metal Stent for Treatment of Benign Biliary Strictures and Bile Leaks

Endoscopic therapy by balloon dilation and placement of multiple large-bore plastic stents is the treatment of choice for benign biliary stricture. This approach is effective but it typically requires multiple endoscopic sessions given the short duration of stent patency. The endoscopic approach for treatment of bile leak involves the placement of a stent with or without biliary sphincterotomy. The self-expandable metal stent (SEMS) has traditionally been used for palliation of malignant biliary strictures given the long duration of stent patency owing to their larger stent diameter. Recently, SEMS has been used in a variety of benign biliary strictures and leaks, especially with the design of the covered self-expandable metal stent (CSEMS), which permits endoscopic-mediated stent removal. The use of CSEMS in benign biliary stricture could potentially result in a decrease in endoscopic sessions and it is technically easier when compared to placement of multiple plastic stents. However, complications such as cholecystitis due to blockage of cystic duct, stent migration, infection and pancreatitis have been reported. The potential subsegmental occlusion of contralateral intrahepatic ducts also limits the use of CSEMS in hilar stricture. Certain techniques and improvement of stent design may overcome these challenges in the future. Thus, CSEMS may be appropriate in only highly selected conditions, such as refractory benign biliary stricture, despite multiple plastic stent placement or difficult to treat bile duct stricture from chronic pancreatitis, and should not be used routinely. This review focuses on the use of fully covered self-expandable metal stent for benign biliary strictures and bile leaks.

Fully covered self-expandable metal stents for treatment of malignant and benign biliary strictures

To present a series of covered self-expandable metal stents (CSEMS) placed for different indications and to evaluate the effectiveness, complications and extractability of these devices. We therefore retrospectively reviewed the courses of patients who received CSEMS due to malignant as well as benign biliary strictures and post-sphincterotomy bleeding in our endoscopic unit between January 2010 and October 2011. Twenty-six patients received 28 stents due to different indications (20 stents due to malignant biliary strictures, six stents due to benign biliary strictures and two stents due to post-sphincterotomy bleeding). Biliary obstruction was relieved in all cases, regardless of the underlying cause. Hemostasis could be achieved in the two patients who received the stents for this purpose. Complications occurred in five patients (18%). Two patients (7%) developed cholecystitis, stents dislocated/migrated in other two patients (7%), and in one patient (3.6%) stent occlusion was documented during the study period. Seven stents were extracted endoscopically. Removal of stents was easily possible in all cases in which it was desired using standard forceps. Twelve patients underwent surgery with pylorus preserving duodenopancreatectomy. In all patients stents could be removed during the operation without difficulties. Despite the higher costs of these devices, fully covered self-expanding metal stents may be suitable to relief biliary obstruction due to bile duct stenosis, regardless of the underlying cause. CSEMS may also represent an effective treatment strategy of severe post-sphincterotomy bleeding, not controlled by other measures.

Endoscopic placement of fully covered self expanding metal stents for management of post-operative foregut leaks

BACKGROUND:Fully covered self-expanding metal stent (SEMS) placement has been successfully described for the treatment of malignant and benign conditions. The aim of this study is to evaluate our experience of fully covered SEMS placement for post-operative foregut leaks.MATERIALS AND METHODS:Retrospective analysis was done for indications, outcomes and complications of SEMS placed in homogeneous population of 15 patients with post-operative foregut leaks in our tertiary-care centre from December 2008 to December 2010. Stent placement and removal, clinical and radiological evidence of leak healing, migration and other complications were the main outcomes analyzed.RESULTS:Twenty-three HANAROSTENT® SEMS were successfully placed in 14/15 patients (93%) with post-operative foregut leaks for an average duration of 28.73 days (range=1-42 days) per patient and 18.73 days per SEMS. Three (20%) patients needed to be re-stented for persistent leaks ultimately resulting in leak closure. Total 5/15 (33.33%) patients and 7/23 (30.43%) stents showed migration; 5/7 (71.42%) migrated stents could be retrieved endoscopically. There were mucosal ulceration in 2/15 (13.33%) and pain in 1/15 (6.66%) patients.CONCLUSIONS:Stenting with SEMS seems to be a feasible option as a primary care modality for patients with post-operative foregut leaks.

Feasibility and safety of EUS-guided cholecystoenterostomy with a modified covered self-expandable metal stent for patients with acute cholecystitis, who are unsuitable for cholecystectomy

Percutaneous cholecystostomy has been conducted as the choice of treatment for high risk patients with acute cholecystitis, who are unsuitable for cholecystectomy because of high operative mortality and morbidity. Percutaneous cholecystostomy, however, has several disadvantages such as patient discomfort and catheter dislodgement as well as complications including bleeding, bile leakage, and pneumoperitoneum. Recently, endoscopic ultrasound (EUS)-guided cholecystoente-rostomy with a modified covered self-expandable metal stent (CSEMS) is being attempted as an alternative treatment for those patients.

Intraductal vs. Transpapillary FCSEMS Placement- Does It Make a Difference?

Purpose: Fully covered self-expanding metal stents are used more frequently in benign and malignant biliary strictures. Stent patency is a determinant to stent efficacy; we report upon whether patency is affected by trans-papillary (TP) vs. intra-ductal (ID) placement. Methods: Two hundred and one patients with benign or malignant biliary strictures from a single university based medical center undergoing Fully Covered Self Expanding Metal Stent (FCSEMS) (Gore, Viabil) placement between November 2006-November 2009 were retrospectively analyzed to assess whether stent patency was affected by trans-papillary vs. intra-ductal placement. Patency was assessed by stent appearance at removal as well as the need for re-intervention due cholestasis or cholangitis. Results: A total of 201 patients; 120 males (59.7%) (mean age 67.1 ± 12.2 yrs.) with benign as well as malignant strictures were retrospectively analyzed. Benign etiologies (98) (48.8%) mainly consisted of choledocholithiasis (24) (24.5%), chronic pancreatitis (20) (20.4%), post-operative biliary leaks (16) (16.3%), post OLT anastomotic strictures (14) (14.3%) and post ampullary adenoma resection (11) (11.2%). Malignant etiologies (103) (51%) primarily consisted of strictures secondary to pancreatic cancer (68) (66.1%), cholangiocarcinoma (10) (9.7%), metastatic disease (7) (6.8%) and gallbladder cancer (2) (1.9%). A total of 121 (60.2%) stents were placed ID and 80 (39.8%) TP. Of the 121 placed ID, 50(41.3%) were used for benign indications and 71 (58.6%) for malignant. Of the 80 placed TP, 49 (61.3%) were for benign and 31 (38.8%) for malignant indications. Of the 80 TP stents, 35 (43.8%) were removed in an anticipated fashion. Of these, 10 (28.6%) (p = 0.002) were partially occluded with stent revision carried out in 5. Six patients (7.5%) presented with cholangitis (4 requiring stent revision) and 7 (8.8%) with cholestasis (6 requiring stent revision) (p = 0.028). Of the 121 ID stents, 42 (34.7%) were removed. Of these, 6 (14.3%) (p = 0.002) were occluded at removal. Seven patients (5.8%) presented with cholangitis (4 requiring stent revision) and 3 (2.5%) (p = 0.028) with worsening cholestasis. The biliary sphincterotomies that were carried out were partial and had no impact on the rate of stent occlusion in intraductal stents. Conclusion: The role of duodeno-biliary reflux has been implicated in stent occlusion due to bacterial bio-film formation and de-conjugation of bile acids. Intraductally placed stents may potentially negate or minimize this effect for both benign as well as malignant indications even in the presence of a partial sphincterotomy. Further study is warranted to assess long term efficacy in a prospective fashion.

Complex biliary stones: treatment with removable self-expandable metal stents: a new approach (with videos)

Complex biliary stones often require temporary stent placement before a repeat attempt at extraction. To date, covered self-expandable metal stents (CSEMSs) have not been formally investigated for this indication. To evaluate the efficacy and safety of CSEMSs in patients with retained complex biliary stones. Retrospective case series. Large quaternary-care center. Thirty-six patients (24 women) with complex biliary stones with incomplete stone clearance after endoscopic retrograde cholangiography (ERC) with biliary sphincterotomy. Patients with incomplete stone clearance after ERC with biliary sphincterotomy underwent temporary placement of CSEMSs, with subsequent removal before repeat stone extraction. Success achieving immediate biliary drainage and eventual complete duct clearance. Procedure-related complications were also assessed. CSEMS placement was successful in establishing immediate biliary drainage in all 36 patients. Complete duct clearance at repeat ERC was achieved in 29 of 35 patients after a mean duration of 6.4 weeks. Four of the remaining 6 patients underwent sequential CSEMS placement, with eventual duct clearance after multiple ERCPs. There were no complications related to biliary obstruction. One patient died of a nonbiliary cause. Of the total 42 CSEMSs placed, there were 4 cases (9.5%) of clinically insignificant stent migration. Single-center experience, retrospective design. CSEMSs permit management of complex biliary stones, but require multiple sessions. The cost-effectiveness of this technique needs further investigation.

Feasibility and safety of EUS-guided transgastric/transduodenal gallbladder drainage with single-step placement of a modified covered self-expandable metal stent in patients unsuitable for cholecystectomy

Although early laparoscopic cholecystectomy is the treatment of choice for patients with acute cholecystitis, percutaneous cholecystostomy has been performed in patients unsuitable for cholecystectomy. EUS-guided transgastric/transduodenal gallbladder drainage by using a plastic stent and/or nasobiliary drainage may be an alternative effective treatment for these patients, but bile leakage into the peritoneal space causing bile peritonitis is not uncommon during placement of a plastic stent. To evaluate the technical feasibility and safety of EUS-guided transgastric/transduodenal gallbladder drainage with single-step placement of a modified covered self-expandable metal stent (CSEMS) in patients with acute cholecystitis who are unsuitable for cholecystectomy. Prospective feasibility study. Tertiary-care referral center. This study involved 15 patients with acute cholecystitis who did not respond to initial medical treatment and were unsuitable for cholecystectomy. EUS-guided transgastric/transduodenal gallbladder drainage with single-step placement of a modified CSEMS. Technical success, functional success, complications associated with the placement of a metal stent, and recurrence of acute cholecystitis. Modified CSEMSs were successfully placed in all patients through the stomach (n = 10) or duodenum (n = 5). All patients achieved functional success within 3 days of metal stent placement. Pneumoperitoneum occurred in two patients during or after the procedure, but both patients improved with conservative management. During follow-up (median 145 days, range 60-297 days), no patient experienced recurrent cholecystitis. Small patient population without long-term follow-up. Placement of a modified CSEMS after EUS-guided transgastric/transduodenal gallbladder drainage may be a feasible and safe alternative to treatments such as percutaneous cholecystostomy in patients with acute cholecystitis who are unsuitable for cholecystectomy.

Meta-analysis of randomized trials comparing the patency of covered and uncovered self-expandable metal stents for palliation of distal malignant bile duct obstruction

Self-expandable metal stents (SEMSs) are used for palliation of malignant biliary obstruction. We performed a meta-analysis to compare stent patency and stent survival of covered SEMSs (CSEMSs) and uncovered SEMSs (USEMSs) in patients with unresectable distal malignant biliary obstruction. Meta-analysis. Tertiary-care facility. A comprehensive search of several databases (from each database's earliest inclusive dates to November 2010, any language, and any population) was conducted. The search identified 337 potential abstracts and titles, of which 16 were retrieved in full text. Review of references identified 17 additional studies. We found 5 multicenter, randomized trials involving 781 patients. Placement of covered and uncovered SEMSs for treatment of distal malignant biliary obstruction. Stent patency, stent survival, patient survival, and cause for stent dysfunction (ingrowth, overgrowth, migration, and sludge formation). The median length of follow-up was 212 days. Compared with USEMSs, CSEMSs were associated with significantly prolonged stent patency (weighted mean difference [WMD] 60.56 days; 95% confidence interval [CI], 25.96, 95.17; I² = 0%) and longer stent survival (WMD 68.87 days; 95% CI, 25.64, 112.11; I(2) = 79%). Stent migration, tumor overgrowth, and sludge formation were significantly higher with CSEMSs (relative risk [RR] 8.11; 95% CI, 1.47, 44.76; I² = 0%), (RR 2.02; 95% CI, 1.08, 3.78; I² = 0%), (RR 2.89; 95% CI, 1.27, 6.55; I² = 0%). Relatively low number of studies available and the fact that 2 of the 5 studies were from one institution. Also, the limited availability of some stents used in the trials may limit the applicability of these results. CSEMSs have a significantly longer duration of patency compared with USEMSs in patients with distal malignant biliary obstruction. Stent dysfunction occurs at a similar rate, although there is a trend toward later obstruction with CSEMSs.

Covered self-expandable metal stents for benign biliary tract diseases

Benign biliary diseases are often managed endoscopically using plastic stents. Benign biliary strictures (BBS) respond to placement of multiple large-bore plastic stents, though requiring multiple procedures to place stents, and to exchange stents to prevent and/or treat stent occlusion. Bile leaks close using plastic stents, which divert bile away from the leak into the duodenum. Covered self-expandable metal stents (CSEMS), intended for palliation of malignant biliary obstruction, have been used to treat benign biliary diseases. Advantages include small predeployment and large postexpansion diameters. Lack of imbedding of the metal into the bile duct wall enables removability. For strictures, one CSEMS is inserted without need for dilation and remains in place for up to 6 months. Successful removal has been reported in all cases. Long-term stricture resolution is achieved in up to 92%. Adverse events include migration and new stricture formation. For treatment of complex bile leaks, the covering and large diameter allow successful closure in nearly all cases. Other uses of CSEMS include treatment of postsphincterotomy bleeding and closure of perforations. CSEMS show promise for treatment of BBS and complex biliary leaks. Successful resolution can be achieved in the majority of patients with the advantage of fewer procedures, which offsets their higher cost.

Su1450 Feasibility of a Modified Fully Covered Self-Expandable Metallic Stents Placement Above the Papilla to Minimize Stent-Induced Bile Duct Injury for Benign Biliary Strictures

Endoscopic placement of fully covered self expandable metallic stent (FCSEMS) has been tried to manage refractory benign biliary strictures (BBS). However, currently available FCSEMS may be associated with unintended complications such as a de novo stricture by tissue hyperplasia, or reflux of duodenal content. To be a novel stent for BBS, we modified FCSEMS to minimize stent-induced complications. The aim of this study was to evaluate the success rates, safety, and removability of modified FCSEMS with placement above the papilla for the patients with benign biliary strictures.

384 Transmural Access and Therapy of Bile-Duct Disease in Patients With Complex Anatomy Using Temporary Covered Self-Expandable Metal Stents (CSEMS)

cSEMS can be removed endoscopically from the GI or biliary tract. Experience with EUS-guided transluminal (TL) biliary drainage with cSEMS is growing. Percutaneous (PC) transenteric ERCP w/o surgical assistance poses risks. We hypothesized 1) TL-EUS-guided cSEMS insertion into the bileduct could ease iterative endoscopy while providing internal drainage; 2) cSEMS could be removed once therapy was performed: 3) cSEMS could similarly be used to protect a PC transenteric endoscopic access tract.