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Sample records for self-expandable metallic stents

  1. Functional Self-Expandable Metal Stents in Biliary Obstruction

    PubMed Central

    Kwon, Chang-Il; Ko, Kwang Hyun; Hahm, Ki Baik

    2013-01-01

    Biliary stents are widely used not only for palliative treatment of malignant biliary obstruction but also for benign biliary diseases. Each plastic stent or self-expandable metal stent (SEMS) has its own advantages, and a proper stent should be selected carefully for individual condition. To compensate and overcome several drawbacks of SEMS, functional self-expandable metal stent (FSEMS) has been developed with much progress so far. This article looks into the outcomes and defects of each stent type for benign biliary stricture and describes newly introduced FSEMSs according to their functional categories. PMID:24143314

  2. Self-expandable metal stents in malignant biliary obstruction.

    PubMed

    Jaganmohan, Sathya; Lee, Jeffrey H

    2012-02-01

    Malignant biliary obstruction can be due to direct tumor infiltration, extrinsic compression, adjacent inflammation, desmoplastic reaction from tumors or, more commonly, a combination of the above factors. Pancreatic cancer is the most common cause of malignant biliary obstruction, and jaundice occurs in 70-90% of the patients during the course of the disease. Compared with the uncovered metal stents, covered metal stents have longer patency and a lower rate of tumor ingrowth, but have a higher rate of stent migration. To combat the occlusion and provide an antitumor effect, drug-eluting stents were developed. A duodenal stricture complicates biliary stent placement in 10-20% of patients with distal biliary obstruction due to pancreatic cancer. When both strictures are considered, a biliary stent can be placed either preceding or following duodenal stent placement. Complications of self-expandable metal stents include stent occlusion, stent migration, cholecystitis and pancreatitis.

  3. Novel biliary self-expanding metal stents: indications and applications.

    PubMed

    Blero, Daniel; Huberty, Vincent; Devière, Jacques

    2015-03-01

    Endoscopic insertion of a self-expanding metal stent (SEMS) through a malignant common bile duct stricture is the first line of palliation for malignant jaundice. Patency of these stents remains a major concern. SEMS dysfunction can result from tumor ingrowth, overgrowth and/or clogging. Initial SEMS modifications involved covering the central part of the stent in order to reduce ingrowth and ultimately increase patency. Fully covered stents became available shortly after reports of their use in human patients. The potential removability and radial strength of SEMS have led to evaluation of their use in new indications including benign biliary strictures, post sphincterotomy bleeding and perforation. Other aspects of development include the addition of features such as anti-reflux valves, drug elution and spontaneous biodegradability. These aspects and their clinical implications are reviewed and discussed.

  4. Self-expandable metallic stents in nonmalignant large airway disease.

    PubMed

    Fortin, Marc; MacEachern, Paul; Hergott, Christopher A; Chee, Alex; Dumoulin, Elaine; Tremblay, Alain

    2015-01-01

    Airway self-expandable metallic stents (SEMS) were initially studied in malignant airway obstruction; however, their use in benign airway diseases has become progressively more frequent. This may be explained by their ease of insertion compared with silicone stents, which require rigid bronchoscopy for insertion. While initial experience with SEMS in benign disease suggested efficacy and promising short-term safety profile, long-term follow-up revealed significant complication rates. In addition to a high complication rate, the management of these complications is made more difficult by the semipermanent nature of these devices. Reported complications include infection, granulation tissue formation, stent migration, stent fracture, airway perforation and fistula formation, as well as extension of the initial injury, potentially eliminating other therapeutic options such as surgical resection. Therefore, SEMS should only be used in nonmalignant large airway disease as a last resort for patients in whom other endoscopic methods, including silicone stents and dilations, as well as surgical options have failed or are technically not feasible.

  5. Fractures of self-expanding metallic stents in periampullary malignant biliary obstruction.

    PubMed

    Rasmussen, I C; Dahlstrand, U; Sandblom, G; Eriksson, L G; Nyman, R

    2009-09-01

    Self-expanding metallic stents are widely used for relieving biliary duct obstruction in patients with unresectable periampullary malignancies. However, only a few studies have assessed the occurrence of fractures in these stents. To determine the prevalence and significance of stent fracture after placement of self-expanding metallic stents for periampullary malignant biliary obstruction. Over a 5-year period, 48 patients underwent placement of self-expanding metallic stents for periampullary malignant biliary obstructions. Stents were introduced 2-6 weeks after a percutaneous transhepatic biliary decompression. The medical records and relevant images were reviewed for stent patency, stent fracture, type of stent, and stent-related complications. Stent fracture was detected in four of the 48 patients (8%): in one patient at 1 month and in three patients between 10 and 21 months after stenting. All four fractures involved one type of nitinol stent used in 38 patients. In one of the patients, fracture was complicated by life-threatening gastrointestinal bleeding. The mean survival time for all patients was 251 days (standard deviation [SD]+/-275 days) and the mean overall patency time for all stents was 187 days (SD+/-205 days). Stent fracture occurs after placement of self-expanding nitinol stents for periampullary malignant biliary obstruction. The low reported incidence of this complication may be due to a lack of awareness of and difficulty in detecting stent fracture. Fracture should be considered as a possible contributing factor in recurrent biliary obstruction after self-expanding metallic stent insertion.

  6. Self-expanding metal stents in malignant esophageal obstruction: a comparison between two stent types.

    PubMed

    Schmassmann, A; Meyenberger, C; Knuchel, J; Binek, J; Lammer, F; Kleiner, B; Hürlimann, S; Inauen, W; Hammer, B; Scheurer, U; Halter, F

    1997-03-01

    Self-expanding metal stents are a promising alternative in the palliation of malignant esophageal obstruction, but the relative value of different stent types is not well established. During a 3-year enrollment period in four different centers, 82 consecutive patients with malignant dysphagia without tumor recurrence after surgery or esophagorespiratory fistulas received either an uncovered Wallstent (44 patients) or a knitted nitinol stent (38 patients). Age (median: 79 yr), sex (F:M = 33:67), dysphagia score (median: 3), Karnofsky score (median: 53), body mass index (median: 19), type of pretreatment, tumor stage, stricture length (median: 5.4 cm), and stricture location were comparable in both stent groups. After stent placement, median dysphagia score improved markedly in both groups by two points. Procedure-related mortality (16 vs 0%; p < 0.01), early complication rate (32 vs 8%; p < 0.01), and severe persistent pain after stent placement (23 vs 0%; p < 0.002) were higher in the Wallstent compared with the knitted nitinol stent group. In contrast, stent dysfunction (7 vs 32%; p < 0.005), reintervention rate (9 vs 34%; p < 0.005), and costs were lower in the Wallstent compared with the nitinol stent group. In malignant esophageal obstruction, both stents markedly improved dysphagia. Uncovered Wallstents seem to cause more early severe complications than knitted nitinol stents. In contrast, stent dysfunction, reintervention rate, and costs appear to be higher in the nitinol stent group.

  7. Comparison of Self-Expanding Polyethylene Terephthalate and Metallic Stents Implanted in Porcine Iliac Arteries

    SciTech Connect

    Wilczek, Krzysztof; Scheerder, Ivan de; Wang Kai; Verbeken, Eric; Piessens, Jan

    1996-05-15

    Purpose: Comparison of the biocompatibility of self-expanding polyethylene terephthalate (PET) stents with self-expanding metallic stents (Wallstents). Methods: Diameter- and length-matched PET stents and Wallstents were symmetrically implanted in the paired iliac arteries of 13 crossbred domestic swine. Stent deployment was studied angiographically and with intravascular ultrasound immediately after stent implantation. The angiographic stented lumen diameter was measured using quantitative vessel analysis before, immediately after stenting, and at 6-week follow-up. Cross-section histopathology and area morphometry were performed. Results: Immediately poststenting, intravascular ultrasound revealed proximal dislocation of 5 of the 13 PET stents, whereas all metal stents were firmly embedded at the implantation site. At 6-week follow-up, three of the remaining PET stents were totally or subtotally occluded by organized thrombus, whereas all metal stents were patent. Compared with immediately poststenting, the angiographic lumen diameter within the five remaining PET stents was reduced by 30%, and that of the metallic stents was virtually unaltered (p < 0.02). This observation was confirmed by postmortem morphometry, wherein the PET-stented vessel segments a diameter stenosis of 40% was measured vs only 9% in the metallic stents (p < 0.0001). Conclusion: PET-stent deployment is difficult to control due to the lack of radiopacity of this stent. PET stents seem to be more thrombogenic and lead to significantly more neointimal proliferation than metallic stents.

  8. Thoracic Discitis as a Complication of Self-Expanding Metallic Stents in Esophageal Carcinoma

    SciTech Connect

    McQueen, A. S.; Eljabu, W.; Latimer, J. Raju, P. P. J.

    2011-02-15

    The role of metallic stents in the palliation of esophageal cancer is well established. Self-expanding metal stents (SEMSs) are frequently used, as they provide an effective and safe method of relieving malignant dysphagia. A number of complications are associated with the use of SEMSs, including esophageal perforation. We report a case of thoracic discitis occurring in a patient with advanced esophageal malignancy, treated with SEMSs. We propose that the likely etiology in this patient was esophageal perforation by a metallic stent.

  9. Self-expandable metallic stents vs. plastic stents for endoscopic biliary drainage in hepatocellular carcinoma.

    PubMed

    Chung, Kwang Hyun; Lee, Sang Hyub; Park, Jin Myung; Lee, Jae Min; Ahn, Dong-Won; Ryu, Ji Kon; Kim, Yong-Tae

    2015-06-01

    The patency of self-expandable metallic stents (SEMS) is known to be better than plastic stents in the palliation of malignant biliary obstruction. However, data are scarce for obstructive jaundice caused by hepatocellular carcinoma (HCC). This study aimed to compare SEMSs and plastic stents for the palliation of obstructive jaundice in unresectable HCC. A total of 96 patients who underwent endoscopic retrograde biliary drainage with SEMSs or plastic stents were included in this retrospective analysis. The rate of successful biliary drainage, adverse events, stent patency duration, and patient survival were compared between the SEMS (n = 36) and plastic stent (n = 60) groups. The rate of successful biliary drainage was similar between the SEMS and plastic stent groups (25/36 [69.4 %] vs. 39/60 [65.0 %]; P = 0.655). Adverse events occurred in 6 patients (16.7 %) in the SEMS group and 13 patients (21.7 %) in the plastic stent group (P = 0.552). The median patency duration was also similar between the two groups (60 vs. 68 days; P = 0.396). The median patient survival was longer in the plastic stent group than in the SEMS group (123 vs. 48 days; P = 0.005). SEMSs were not superior to plastic stents for the palliation of malignant biliary obstruction in HCC with regard to successful drainage, stent patency, and adverse events. Patient survival was better in the plastic stent group. Given the lower cost, plastic stents could be a favorable option for malignant biliary obstruction caused by HCC. © Georg Thieme Verlag KG Stuttgart · New York.

  10. Polymeric photosensitizer-embedded self-expanding metal stent for repeatable endoscopic photodynamic therapy of cholangiocarcinoma.

    PubMed

    Bae, Byoung-chan; Yang, Su-Geun; Jeong, Seok; Lee, Don Haeng; Na, Kun; Kim, Joon Mee; Costamagna, Guido; Kozarek, Richard A; Isayama, Hiroyuki; Deviere, Jacques; Seo, Dong Wan; Nageshwar Reddy, D

    2014-10-01

    Photodynamic therapy (PDT) is a new therapeutic approach for the palliative treatment of malignant bile duct obstruction. In this study, we designed photosensitizer-embedded self-expanding nonvascular metal stent (PDT-stent) which allows repeatable photodynamic treatment of cholangiocarcinoma without systemic injection of photosensitizer. Polymeric photosensitizer (pullulan acetate-conjugated pheophorbide A; PPA) was incorporated in self-expanding nonvascular metal stent. Residence of PPA in the stent was estimated in buffer solution and subcutaneous implantation on mouse. Photodynamic activity of PDT-stent was evaluated through laserexposure on stent-layered tumor cell lines, HCT-116 tumor-xenograft mouse models and endoscopic intervention of PDT-stent on bile duct of mini pigs. Photo-fluorescence imaging of the PDT-stent demonstrated homogeneous embedding of polymeric Pheo-A (PPA) on stent membrane. PDT-stent sustained its photodynamic activities at least for 2 month. And which implies repeatable endoscopic PDT is possible after stent emplacement. The PDT-stent after light exposure successfully generated cytotoxic singlet oxygen in the surrounding tissues, inducing apoptotic degradation of tumor cells and regression of xenograft tumors on mouse models. Endoscopic biliary in-stent photodynamic treatments on minipigs also suggested the potential efficacy of PDT-stent on cholangiocarcinoma. In vivo and in vitro studies revealed our PDT-stent, allows repeatable endoscopic biliary PDT, has the potential for the combination therapy (stent plus PDT) of cholangiocarcinoma. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Renal Transplant Ureteral Stenosis: Treatment by Self-Expanding Metallic Stent

    SciTech Connect

    Cantasdemir, Murat; Kantarci, Fatih; Numan, Furuzan; Mihmanli, Ismail; Kalender, Betul

    2003-02-15

    We report the use of a metallic stent in a transplant ureteral stenosis. A 28-year-old man with chronic renal failure due to chronic pyelonephritis, who received a living-donor renal transplant, presented with transplant ureteral stenosis. The stenosis was unresponsive to balloon dilation and was treated by antegrade placement of a self-expanding Memotherm stent. The stentedureter stayed patent for 3 years. It may be reasonable to treat post-transplant ureteral stenosis resistant to balloon dilation with self-expanding metallic stents. However, long-term follow-up is required to evaluate the efficacy of this treatment.

  12. Feasibility of using bulk metallic glass for self-expandable stent applications.

    PubMed

    Praveen Kumar, Gideon; Jafary-Zadeh, Mehdi; Tavakoli, Rouhollah; Cui, Fangsen

    2017-10-01

    Self-expandable stents are widely used to restore blood flow in a diseased artery segment by keeping the artery open after angioplasty. Despite the prevalent use of conventional crystalline metallic alloys, for example, nitinol, to construct self-expandable stents, new biomaterials such as bulk metallic glasses (BMGs) are being actively pursued to improve stent performance. Here, we conducted a series of analyses including finite element analysis and molecular dynamics simulations to investigate the feasibility of using a prototypical Zr-based BMG for self-expandable stent applications. We model stent crimping of several designs for different percutaneous applications. Our results indicate that BMG-based stents with diamond-shaped crowns suffer from severe localization of plastic deformation and abrupt failure during crimping. As a possible solution, we further illustrate that such abrupt failure could be avoided in BMG-based stents without diamond shape crowns. This work would open a new horizon for a quest toward exploiting superior mechanical and functional properties of metallic glasses to design future stents. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1874-1882, 2017. © 2016 Wiley Periodicals, Inc.

  13. [Cost-effectiveness trial of self-expandable metal stents and plastic biliary stents in malignant biliary obstruction].

    PubMed

    Daróczi, Tímea; Bor, Renáta; Fábián, Anna; Szabó, Ella; Farkas, Klaudia; Bálint, Anita; Czakó, László; Rutka, Mariann; Szűcs, Mónika; Milassin, Ágnes; Molnár, Tamás; Szepes, Zoltán

    2016-02-14

    Self-expandable metal and plastic stents can be applied in the palliative endoscopic treatment of patients with unresectable malignant biliary obstruction. The use of metal stentsis recommended if the patient's life expectancy is more than four months. To compare the therapeutic efficacy and cost-effectiveness of metal and plastic stents in the treatment of malignant biliary obstruction. The authors retrospectively enrolled patients who received metal (37 patients) or plastic stent (37 patients). The complication rate, stent patency and cumulative cost of treatment were assessed in the two groups. The complication rate of metal stents was lower (37.84% vs. 56.76%), but the stent patency was higher compared with plastic stents (19.11 vs. 8.29 weeks; p = 0.0041). In the plastic stent group the frequency of hospitalization of patients in context with stent complications (1.18 vs. 2.32; p = 0.05) and the necessity of reintervention for stent dysfunction (17 vs. 27; p = 0.033) were substantially higher. In this group multiple stent implantation raised the stent patency from 7.68 to 10.75 weeks. There was no difference in the total cost of treatment of malignant biliary obstruction between the two groups (p = 0.848). Considering the cost of treatment and the burden of patients the authors recommend self-expandable metal sten timplantation if the life expectancy of patients is more than two months. In short survival cases multiple plastic stent implantation is recommended.

  14. Management of cervical esophageal strictures with self-expanding metalic stents.

    PubMed

    Cindoruk, Mehmet; Karakan, Tarkan

    2006-12-01

    Esophageal strictures due to malignant diseases are treated with self-expanding metalicic stents. However, experience is limited with these metalic stents in the cervical esophagus. Due to technical difficulties and procedure-related complications, the cervical esophagus has been assigned as a risky area for stenting procedures. Another encountered problem is patient discomfort after the procedure. In this case report, we present three patients with cervical esophageal strictures who were successfully treated with self-expandable metalic stents. Two of these patients had inoperable esophageal carcinoma and the third had benign stenosis due to radiotherapy of larynx carcinoma. The two patients with malignant disease survived four and six months, respectively, after the procedure. The last patient with benign disease is still alive and has been without dysphagia symptom for six months.

  15. Self-Expandable Metal Stenting of Refractory Upper Gut Corrosive Strictures: A New Role for Endoscopy?

    PubMed Central

    Manta, Raffaele; Conigliaro, Rita; Bertani, Helga; Manno, Mauro; Soliman, Ahmed; Fedeli, Paolo; Bassotti, Gabrio

    2011-01-01

    Caustic strictures of the gastrointestinal tract are often difficult to treat, since relapses are frequent after medical or endoscopic treatment. Thus, novel approaches are needed. We report here our experience with self-expandable metallic stents (SEMS) as a new endoscopic approach in three patients with corrosive strictures of the upper gastrointestinal tract. PMID:22606415

  16. Cholecystoduodenal Fistula: A Complication of Inserted Self-Expandable Metallic Biliary Stents

    SciTech Connect

    Nishida, Hirotoshi; Inoue, Hiroki; Ueno, Kazuto; Nagata, Yukitaka; Kato, Takeshi; Miyazono, Nobuaki; Nakajo, Masayuki

    1998-05-15

    We encountered a case of hepatic hilar cholangiocarcinoma resulting in cholecystoduodenal fistula after insertion of self-expandable metallic biliary stents (EMBSs). To our knowledge, there has been no report of cholecystoduodenal fistula after insertion of EMBSs. This case suggests that immediate gallbladder decompression may be necessary if acute cholecystitis occurs after insertion of EMBSs.

  17. Cholecystoduodenal fistula: A complication of inserted self-expandable metallic bilitary stents

    SciTech Connect

    Nishida, Hirotoshi; Inoue, Hiroki; Ueno, Kazuto; Nagata, Yukitaka; Kato, Takeshi; Miyazono, Nobuaki; Nakajo, Masayuki

    1998-05-15

    We encountered a case of hepatic hilar cholangiocarcinoma resulting in cholecystoduodenal fistula after insertion of self-expandable metallic biliary stents (EMBSs). To our knowledge, there has been no report of cholecystoduodenal fistula after insertion of EMBSs. This case suggests that immediate gallbladder decompression may be necessary if acute cholecystitis occurs after insertion of EMBSs.

  18. [Treatment of malignant colorectal obstruction by means of endoscopic insertion of self-expandable metallic stents].

    PubMed

    García-Cano, J; González Martín, J A; Redondo-Cerezo, E; Morillas Ariño, J; Pérez García, J I; Pérez Vigara, M G; Gómez Ruiz, C J; Pérez Sola, A

    2003-10-01

    Self-expandable metallic stents are being used increasingly to treat the obstruction of different segments of the digestive tract and biliary tree. We present our centre experience on the initial resolution of malignant colorectal obstruction by means of this type of stents. During a 18-month period, 13 patients patients suffering from malignant obstruction at the level of rectum, sigmoid or descending colon tried to be initially treated by means of endoscopic insertion of stents (non covered enteral Wallstents). Ten procedures were performed with both endoscopy and fluroscopy and three with only endoscopy. In 12 of the 13 patients (92,3%) the obstruction was solved by means of correct stent insertion. All the exclusively endoscopic procedures (without fluoroscopy) were successful. Six (50 %) patients with tumours at the rectosigmoid underwent later scheduled surgery. In the remaining six ones (a patient with an ovarian carcinoma and five with colonic adenocarcinoma) the stents were considered to be a palliative definitive treatment. Stent migration was observed in two of these patients and both were extracted endoscopically. Only one patient needed to have another stent inserted. A tumoural colo-vesical fistula developed in another patient in the palliative group, inside the previous inserted stent, and was treated by coaxial insertion of an esophageal Ultraflex. There were no other complications or mortality related to the endoscopic procedures. Self-expandable metallic stents might be considered, in general, as the initial treatment for the malignant obstruction at the level of rectum, sigmoid and descending colon

  19. Status and Literature Review of Self-Expandable Metallic Stents for Malignant Colorectal Obstruction

    PubMed Central

    Cheung, Dae Young; Lee, Yong Kook

    2014-01-01

    Use of colorectal stents has increased dramatically over the last decades. Colorectal stents offer an alternative way to relieve fatal intestinal obstruction and can take place of emergency surgery, which associated with significant morbidity and mortality and a high incidence of stoma creation, to elective resection. Although there remain a few concerns regarding the use of stents as a bridge to surgical resection, use of self-expandable metallic stents for palliation in patients with unresectable disease has come to be generally accepted. Advantages of colorectal stents include acute restoration of luminal patency and allowance of time for proper staging and surgical optimization, and the well-known disadvantages are procedure-related complications including perforation, migration, and stent failure. General indications, procedures, and clinical outcomes as well as recent evidences regarding the use of colorectal stents will be discussed in this review. PMID:24570885

  20. Malignant Gastric and Duodenal Stenosis: Palliation by Peroral Implantation of a Self-Expanding Metallic Stent

    SciTech Connect

    Pinto, Isabel T.

    1997-11-15

    Purpose: To assess the use of self-expanding metallic stents in patients with inoperable malignant antrum-pylorus-duodenal obstruction. Methods: Six patients underwent implantation of a Wallstent self-expanding metallic endoprosthesis (20 mm in five patients and 16 mm in one). In five patients a catheter (Berenstein) was introduced perorally into the stomach. A guidewire (Terumo) was introduced through the catheter and advanced through the antrum-pylorus-duodenal stenosis. The guidewire was removed and a 260-cm-long, 0.035'' superstiff guide (Amplatz) was introduced. After the catheter was removed the stent assembly was introduced. In the last patient the stent was implanted through a percutaneous gastrostomy. Results: Treatment of inoperable gastric outlet obstruction caused by tumor compression is difficult and unsatisfactory. Peroral implantation of self-expanding metallic stents resulted in successful palliative therapy of antrum-pylorus-duodenal stenosis in six patients in whom surgery was not possible because of advanced disease and poor general condition. On average, patients were able to eat during 41 days. One patient is tolerating oral intake at 3 months. Conclusion: Implantation of stents resulted in palliative relief of malignant antrum-pylorus-duodenal obstructions.

  1. Evaluation of anti-migration properties of biliary covered self-expandable metal stents.

    PubMed

    Minaga, Kosuke; Kitano, Masayuki; Imai, Hajime; Harwani, Yogesh; Yamao, Kentaro; Kamata, Ken; Miyata, Takeshi; Omoto, Shunsuke; Kadosaka, Kumpei; Sakurai, Toshiharu; Nishida, Naoshi; Kudo, Masatoshi

    2016-08-14

    To assess anti-migration potential of six biliary covered self-expandable metal stents (C-SEMSs) by using a newly designed phantom model. In the phantom model, the stent was placed in differently sized holes in a silicone wall and retracted with a retraction robot. Resistance force to migration (RFM) was measured by a force gauge on the stent end. Radial force (RF) was measured with a RF measurement machine. Measured flare structure variables were the outer diameter, height, and taper angle of the flare (ODF, HF, and TAF, respectively). Correlations between RFM and RF or flare variables were analyzed using a linear correlated model. Out of the six stents, five stents were braided, the other was laser-cut. The RF and RFM of each stent were expressed as the average of five replicate measurements. For all six stents, RFM and RF decreased as the hole diameter increased. For all six stents, RFM and RF correlated strongly when the stent had not fully expanded. This correlation was not observed in the five braided stents excluding the laser cut stent. For all six stents, there was a strong correlation between RFM and TAF when the stent fully expanded. For the five braided stents, RFM after full stent expansion correlated strongly with all three stent flare structure variables (ODF, HF, and TAF). The laser-cut C-SEMS had higher RFMs than the braided C-SEMSs regardless of expansion state. RF was an important anti-migration property when the C-SEMS did not fully expand. Once fully expanded, stent flare structure variables plays an important role in anti-migration.

  2. Difficult removal of fully covered self expandable metal stents (SEMS) for benign biliary strictures: the "SEMS in SEMS" technique.

    PubMed

    Tringali, Andrea; Blero, Daniel; Boškoski, Ivo; Familiari, Pietro; Perri, Vincenzo; Devière, Jacques; Costamagna, Guido

    2014-06-01

    Removal of biliary Fully Covered Self Expandable Metal Stents can fail due to stent migration and/or hyperplastic ingrowth/overgrowth. A case series of 5 patients with benign biliary strictures (2 post-cholecystectomy, 2 following liver transplantation and 1 related to chronic pancreatitis) is reported. The biliary stricture was treated by temporary insertion of Fully Covered Self Expandable Metal Stents. Stent removal failed due to proximal stent migration and/or overgrowth. Metal stent removal was attempted a few weeks after the insertion of another Fully Covered Metal Stent into the first one. The inner Fully Covered Self Expandable Metal Stent compressed the hyperplastic tissue, leading to the extraction of both the stents in all cases. Two complications were reported as a result of the attempt to stents removal (mild pancreatitis and self-limited haemobilia). In the present series, the "SEMS in SEMS" technique revealed to be effective when difficulties are encountered during Fully Covered Self Expandable Metal Stents removal. Copyright © 2014 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  3. A unique complication of self-expandable metal stent placement in malignant duodenal obstruction.

    PubMed

    Down, Christopher J; Kumar, Lalit; Singh, Sukhpal; Veeramootoo, Darmarajah

    2017-09-01

    Intestinal obstruction is a common complication in patients with advanced gastrointestinal malignancies. In the last two decades, endoscopic placement of duodenal stents has become a mainstay of palliative treatment in patients with unresectable obstructive duodenal pathology. Self-expandable metal stents have been reported to have excellent success rates, besides dramatically improve the patient's quality of life by reinstating the oral feeding ability. Re-intervention rates remain high, commonly as a consequence of tumour ingrowth resulting stent occlusion. We describe a unique case of duodenal stent obstruction secondary to impacted gallstones. To the best of our knowledge, this is the first case described in the literature and should alert clinicians to this unusual complication.

  4. Covered self-expandable metal stents for benign biliary tract diseases.

    PubMed

    Baron, Todd H

    2011-05-01

    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.

  5. Endoscopic treatment of benign biliary strictures using covered self-expandable metal stents (CSEMS).

    PubMed

    Irani, Shayan; Baron, Todd H; Akbar, Ali; Lin, Otto S; Gluck, Michael; Gan, Ian; Ross, Andrew S; Petersen, Bret T; Topazian, Mark; Kozarek, Richard A

    2014-01-01

    Traditional endoscopic management of benign biliary strictures (BBS) consists of placement of one or more plastic stents. Emerging data support the use of covered self-expandable metal stents (CSEMS). We sought to assess outcome of endoscopic temporary placement of CSEMS in patients with BBS. This was a retrospective study of CSEMS placement for BBS between May 2005 and July 2012 from two tertiary care centers. A total of 145 patients (81 males, median age 59 years) with BBS were identified; 73 of which were classified as extrinsic and were caused by chronic pancreatitis, and 70 were intrinsic. Main outcome measures were resolution of stricture and adverse events (AEs) due to self-expandable metal stents (SEMS)-related therapy. Fully covered and partially covered 8-10 mm diameter SEMS were placed and subsequently removed in 121/125 (97 %) attempts in BBS (failure to remove four partially covered stents). Stricture resolution occurred in 83/125 (66 %) patients after a median stent duration of 26 weeks (median follow-up 90 weeks). Resolution of extrinsic strictures was significantly lower compared to intrinsic strictures (31/65, 48 % vs. 52/60, 87 %, p = 0.004) despite longer median stent duration (30 vs. 20 weeks). Thirty-seven AEs occurred in 25 patients (17 %), with 12 developing multiple AEs including cholangitis (n = 17), pancreatitis (n = 5), proximal stent migration (n = 3), cholecystitis (n = 2), pain requiring SEMS removal and/or hospitalization (n = 3), inability to remove (n = 4), and new stricture formation (n = 3). Benign biliary strictures can be effectively treated with CSEMS. Successful resolution of biliary strictures due to extrinsic disease is seen significantly less often than those due to intrinsic disease. Removal is successful in all patients with fully covered SEMS.

  6. [Endoscopic palliation of malignant esophagus processes using a self-expanding metallic stent].

    PubMed

    Binek, J; Eigenmann, F; Hammer, B

    1995-04-15

    We investigated the palliative effect of self-expanding metallic stents on malignant obstruction of the esophagus in 10 patients. All patients had high grade dysphagia and one had an esophago-bronchial fistula. Endoscopic insertions of the prosthesis was done under sedation. Dilatation of the stricture prior to insertion was rarely necessary. Coated stents were used as secondary treatment for patients with fistulae. The procedure related morbidity was low and no mortality was observed. The stents remained patent during the residual lifetime of the patients. Dislocation or perforation did not occur. The median survival of 8 deceased patients was 3.5 months (range 1.25-14.5 months). At present 2 patients are still alive 2.7 and 1.5 months after the procedure. Self-expanding stents in the esophagus provide good palliative therapy of dysphagia or fistulae caused by malignant tumors. Insertion is relatively simple and safer than in nonexpandable types. These improvements may justify the considerably higher price of these devices.

  7. Safety and efficacy of self-expandable metallic stents in malignant small bowel obstructions

    PubMed Central

    Tsuboi, Akiyoshi; Kuwai, Toshio; Nishimura, Tomoyuki; Iio, Sumio; Mori, Takeshi; Imagawa, Hiroki; Yamaguchi, Toshiki; Yamaguchi, Atsushi; Kouno, Hirotaka; Kohno, Hiroshi

    2016-01-01

    In this report, we present 3 cases of malignant small bowel obstruction, treated with palliative care using endoscopic self-expandable metallic stent (SEMS) placement, with the aim to identify the safety and efficacy of this procedure. Baseline patient characteristics, procedure methods, procedure time, technical and clinical success rates, complications, and patient outcomes were obtained. All 3 patients had pancreatic cancer with small bowel strictures. One patient received the SEMS using colonoscopy, while the other 2 patients received SEMS placement via double balloon endoscopy using the through-the-overtube technique. The median procedure time was 104 min. The technical and clinical success rates were 100%. Post-treatment, obstructive symptoms in all patients improved, and a low-residue diet could be tolerated. All stents remained within the patients until their deaths. The median overall survival time (stent patency time) was 76 d. SEMS placement is safe and effective as a palliative treatment for malignant small bowel obstruction. PMID:27833393

  8. Understanding the Mechanical forces of Self-Expandable Metal Stents in the Biliary Ducts.

    PubMed

    Isayama, Hiroyuki; Nakai, Yousuke; Hamada, Tsuyoshi; Matsubara, Saburo; Kogure, Hirofumi; Koike, Kazuhiko

    2016-12-01

    Self-expandable metallic stent (SEMS) was an effective biliary endoprosthesis. Mechanical properties of SEMS, radial and axial force (RF, AF), may play important roles in the bile duct after placement. RF was well known dilation force and influenced on the occurrence of migration. AF, newly proposed by this author, was defined as the recovery force when the SEMS vended. AF was related with the cause of bile duct kinking, pancreatitis, and cholecystitis due to the compression of the bile duct, orifice of the cystic duct, and pancreatic orifice. Ideal SEMS may show high RF and low AF.

  9. Self-expandable metallic stents for palliative treatment of digestive cancer.

    PubMed

    Lopes, César Vivian; Pesenti, Christian; Bories, Erwan; Caillol, Fabrice; Giovannini, Marc

    2008-10-01

    BACKGROUND/GOAL: Self-expandable metallic stents can be used to reestablish luminal continuity in patients with malignancy of the esophagus, gastric outlet, or colon who are at high risk for surgical intervention. Data regarding their complication profiles remain incomplete. Our aim was to evaluate the feasibility and complications of endoscopic stenting in esophageal, gastroduodenal, and colonic malignancies. Between January 2003 and December 2005, 153 patients underwent 182 endoscopic procedures for insertion of 199 metallic stents in a single referral center. Complications were assessed retrospectively. The mean follow-up was 170 days. The mortality was 73.9% (113 patients), 105 cases between 1 and 60 weeks after the procedure (median survival, 17 wk), but none directly related to the stent placement. One single stent was required in 115 (75%) patients, and 37 (24.2%) cases required an overlapping stent. The procedure was unsuccessful in only 1 case of colonic obstruction. Thirty-eight (26.6%) patients developed 52 complications, of which 16 (9.4%) procedure-related complications (perforation, 5; migration, 5; obstruction, 3; misplacement, 2; and hemorrhage, 1) and 36 (21.3%) late complications (obstruction, 20; migration, 9; fistula, 6; and perforation, 1). Eight (5.6%) patients experienced more than 1 complication. Five (3.5%) cases required surgery (colon: 2 perforations, 1 fistula, and 1 obstruction; esophagus: 1 perforation). No significant difference on the complication rates was found for any site in which a metallic stent was inserted. Endoscopic stenting for palliation of digestive cancer, despite a reasonable complication rate, is feasible in most patients. Most dysfunctions are not life-threatening and can be managed endoscopically.

  10. Clinical effect of double coaxial self-expandable metallic stent in management of malignant colon obstruction

    PubMed Central

    Won, Yoodong; Lee, Su Lim; Ku, Young Mi; Kim, Ki Tae; Won, Hye Sung; An, Chang Hyeok

    2015-01-01

    PURPOSE We aimed to evaluate the clinical effectiveness and safety of double coaxial self-expandable metallic stent (DCSEMS) in management of malignant colonic obstruction as a bridge to surgery or palliation for inoperable patients. METHODS Between April 2006 and December 2012, 49 patients (27 males and 22 females; median age, 68 years; age range, 38–91 years) were selected to receive decompressive therapy for malignant colonic obstruction by implanting a DCSEMS. Application of DCSEMS was attempted in 49 patients under fluoroscopic guidance. The obstruction was located in the transverse colon (n=2), descending colon (n=7), sigmoid colon (n=24), rectosigmoid junction (n=6), and the rectum (n=10). The intended use of DCSEMS was as a bridge to elective surgery in 23 patients and palliation in 26 patients. RESULTS Clinical success, defined as >50% dilatation of the stent with subsequent symptomatic improvement, was achieved in 48 of 49 patients (98%). The stent was properly inserted in all patients. No immediate major procedure-related complications occurred. One patient in the bridge-to-surgery group had colon perforation three days after DCSEMS application. Four patients had late migrations of the double stent. CONCLUSION Application of DCSEMS is safe and effective in management of malignant colonic obstruction; it prevents stent migration and tumor ingrowth and lowers perforation rate during the stent application. PMID:25698096

  11. Self-Expanding Metal Stenting in the Management of a Benign Colonic Stricture

    PubMed Central

    Jessamy, Kegan; Ozden, Nuri; Simon, Howard M.; Kobrossi, Semaan; Ubagharaji, Ezinnaya

    2016-01-01

    Colonic postanastomotic strictures occur in 1.5–8% of patients following colorectal surgery. Traditionally, colonic strictures were treated by multiple modalities including endoscopic dilatation. Self-expanding metal stents (SEMS) have been indicated in the management of benign colonic strictures; however, there are limited available data with regard to their efficacy. We present the case of a 68-year-old male who had perforated sigmoid diverticulitis followed by Hartmann's procedure with eventual reanastomosis 6 months later. He subsequently developed benign colonic stricture, which was treated with a metal stent. SEMS are associated with a low mortality rate and are appropriate in treating acute colonic obstruction as a result of benign stricture in the setting of postanastomosis. PMID:27403114

  12. Outcomes of secondary self-expandable metal stents versus surgery after delayed initial palliative stent failure in malignant colorectal obstruction.

    PubMed

    Yoon, Jin Young; Park, Soo Jung; Hong, Sung Pil; Kim, Tae Il; Kim, Won Ho; Cheon, Jae Hee

    2013-01-01

    When re-intervention is required due to an occluded first colorectal self-expanding metal stent for malignant colorectal obstruction, serious controversies exist regarding whether to use endoscopic re-stenting or surgery. To compare the clinical outcomes in patients who underwent stent re-insertion versus palliative surgery as a second intervention. A total of 115 patients who received either self-expandable metal stent (SEMS) insertion or palliative surgery for treatment of a second occurrence of malignant colorectal obstruction after the first SEMS placement were retrospectively studied between July 2005 and December 2009. The median overall survival (8.2 vs. 15.5 months) and progression-free survival (4.0 vs. 2.7 months) were not significantly different between the stent and surgery groups (p = 0.895 and 0.650, respectively). The median lumen patency in the stent group was 3.4 months and that in the surgery group was 7.9 months (p = 0.003). The immediate complication rate after second stent insertion was 13.9% and late complication rate was observed in 12 of 79 (15.2%) patients. There was no mortality related to the SEMS procedure. The complication and mortality rates associated with palliative surgery were 3.5% (2/57) and 12.3% (7/57), respectively. Although there is no significant difference in the overall survival between stenting and surgery, a secondary stent insertion had a lower mortality rate despite a shorter duration of temporary colorectal decompression compared to that of palliative surgery.

  13. Small caliber covered self-expanding metal stents in the management of malignant dysphagia

    PubMed Central

    Kucera, Stephen; Barthel, James; Klapman, Jason; Shridhar, Ravi; Hoffe, Sarah; Harris, Cynthia; Almhanna, Khaldoun

    2016-01-01

    Background Use of large caliber [≥18 mm body diameter (BD)] self-expanding metal stents (SEMS) for management of malignant dysphasia is associated with substantial adverse event (AE) and mortality rates (MRs). We sought to determine dysphagia response, stent migration rates, and AE and MRs, for small caliber covered SEMS (sccSEMS) with BDs between 10–16 mm in malignant dysphagia. Methods Thirty-one patients underwent direct endoscopic placement of 50 sccSEMS between January 2008 and March 2011. Patients were monitored for change in dysphagia score (DS), stent migration, AEs, and death through May 2011. Results DS improved in 30 of 31 patients (97%). The median DS decreased from 3 to 2 (P<0.0001). The median effective duration of first sccSEMS placement was 116 (95% CI: 75–196) days. Major and minor AE rates were 6.5% and 19.4% respectively. No stent related deaths were encountered. The overall migration rate was 36% (18/50). The anticipated migration rate was 45.7% (16/35) and the unanticipated migration rate was 13.3% (2/15) (P=0.052). Positive effective clinical outcome occurred in 93.5% (29/31) of cases. Conclusions In malignant dysphagia, direct endoscopic sccSEMS placement provided acceptable dysphagia control and migration rates with substantial reductions in stent related AEs and MRs compared to those reported for large caliber SEMS. PMID:27284474

  14. Self-expandable metal stents for malignant gastric outlet obstruction: A pooled analysis of prospective literature

    PubMed Central

    van Halsema, Emo E; Rauws, Erik AJ; Fockens, Paul; van Hooft, Jeanin E

    2015-01-01

    AIM: To provide an overview of the clinical outcomes of self-expandable metal stent (SEMS) placement for malignant gastric outlet obstruction (MGOO). METHODS: A systematic literature search was performed in PubMed of the literature published between January 2009 and March 2015. Only prospective studies that reported on the clinical success of stent placement for MGOO were included. The primary endpoint was clinical success, defined according to the definition used in the original article. Data were pooled and analyzed using descriptive statistics. Subgroup analyses were performed for partially covered SEMSs (PCSEMSs) and uncovered SEMSs (UCSEMSs) using Fisher’s exact test. RESULTS: A total of 19 studies, including 1281 patients, were included in the final analysis. Gastric (42%) and pancreatic (37%) cancer were the main causes of MGOO. UCSEMSs were used in 76% of patients and PCSEMSs in 24%. The overall pooled technical success rate was 97.3% and the clinical success rate was 85.7%. Stent dysfunction occurred in 19.6% of patients, mainly caused by re-obstruction (12.6%) and stent migration (4.3%), and was comparable between PCSEMSs and UCSEMSs (21.2% vs 19.1%, respectively, P = 0.412). Re-obstruction was more common with UCSEMSs (14.9% vs 5.1%, P < 0.001) and stent migration was more frequent after PCSEMS placement (10.9% vs 2.2%, P < 0.001). The overall perforation rate was 1.2%. Bleeding was reported in 4.1% of patients, including major bleeding in 0.8%. The median stent patency ranged from 68 to 307 d in five studies. The median overall survival ranged from 49 to 183 d in 13 studies. CONCLUSION: The clinical outcomes in this large population showed that enteral stent placement was feasible, effective and safe. Therefore, stent placement is a valid treatment option for the palliation of MGOO. PMID:26604654

  15. Biliary self-expandable metal stents do not adversely affect pancreaticoduodenectomy.

    PubMed

    Cavell, Lianne K; Allen, Peter J; Vinoya, Cjloe; Eaton, Anne A; Gonen, Mithat; Gerdes, Hans; Mendelsohn, Robin B; D'Angelica, Michael I; Kingham, T Peter; Fong, Yuman; Dematteo, Ronald; Jarnagin, William R; Kurtz, Robert C; Schattner, Mark A

    2013-07-01

    Controversy exists regarding whether to place a plastic or a metal endobiliary stent in patients with resectable pancreatic cancer who require biliary drainage. Although self-expandable metal stents (SEMS) provide better drainage compared with plastic stents, concerns remain that SEMS may compromise resection and increase postoperative complications. Our objective was to compare surgical outcomes of patients undergoing pancreaticoduodenectomy (PD) with SEMS in place vs. plastic endoscopic stents (PES) and no stents (NS). We performed a retrospective analysis from a prospective database of all patients undergoing either attempted or successful PD with SEMS, PES, or NS in place at the time of operation. Patients were compared with regard to perioperative complications, margin status, and the rate of intraoperative determination of unresectability. A total of 593 patients underwent attempted PD. Of these, 84 patients were locally unresectable intraoperatively and 509 underwent successful PD, of which 71 had SEMS, 149 had PES, and 289 had NS. Among patients who had a preoperative stent, SEMS did not increase overall or serious postoperative complications, 30-day mortality, length of stay, biliary anastomotic leak, or positive margin, but was associated with more wound infections and longer operative times. In those with adenocarcinoma, intraoperative determination of local unresectability was similar in the SEMS group compared with other groups, with 16 (19.3%) in SEMS compared with 29 (17.7%) in PES (P=0.862), and 31 (17.5%) in NS (P=0.732). Placement of SEMS is not contraindicated in patients with resectable pancreatic cancer who require preoperative biliary drainage.

  16. Use of fully covered self-expanding metal stents for the management of benign biliary conditions.

    PubMed

    García-Cano, J; Taberna-Arana, L; Jimeno-Ayllón, C; Martínez-Fernández, R; Serrano-Sánchez, L; Reyes-Guevara, A K; Viñuelas-Chicano, M; Gómez-Ruiz, C J; Morillas-Ariño, M J; Pérez-García, J I; Pérez-Vigara, G; Pérez-Sola, A

    2010-09-01

    biliary self-expanding metal stents (SEMS) have the advantage of being inserted undeployed with very small sizes and provide, when fully opened, large diameters for biliary drainage. However, their use in benign conditions has been very limited, mainly because of difficulty in their extraction. We present our initial experience with a fully covered SEMS (Wallflex) for the management of benign problems of the bile duct. in a prospective study, stents of 8 mm in diameter and 4, 6 or 8 cm long were inserted by means of ERCP. These SEMS were chosen when according to medical judgement it was thought that diameters greater than 10 French (3.3 mm) were needed for proper biliary drainage. Stents were extracted also endoscopically, several months later when deemed clinically appropriate. twenty biliary SEMS were inserted. Reasons for insertion were: large intrahepatic biliary fistula after hydatid cyst surgery (1), perforation of the papillary area following endoscopic sphincterotomy (2), coaxial insertion to achieve patency in obstructed uncovered stents inserted in benign conditions (3), benign strictures (7), multiple and large common bile duct stones that could not be extracted because of tapering and stricturing of the distal common bile duct (7). In all cases, successful biliary drainage was achieved and there were no complications from insertion. Stents were easily extracted after a mean time of 132 days (36-270) in place. Complete resolution of biliary problems was obtained in 14 patients (70%). in our initial experience, the fully covered Wallflex biliary stent was removed without any complication after being in place in the common bile duct for a mean time of over four months. Therefore, it could be used in the management of benign biliary conditions.

  17. Palliation of malignant esophageal obstruction and fistulas with self expandable metallic stents

    PubMed Central

    Dobrucali, Ahmet; Caglar, Erkan

    2010-01-01

    AIM: To evaluate the efficacy of self expandable metallic stents (SEMS) in patients with malignant esophageal obstruction and fistulas. METHODS: SEMS were implanted in the presence of fluoroscopic guidance in patients suffering from advanced and non-resectable esophageal, cardiac and invasive lung cancer between 2002 and 2009. All procedures were performed under conscious sedation. All patients had esophagus obstruction and/or fistula. In all patients who required reintervention, recurrence of dysphagia, hemorrhage, and fistula formation were indications for further endoscopy. Patients’ files were scanned retrospectively and the obtained data were analyzed using SPSS 13.0 for Windows. The χ2 test was used for categorical data and was analysis of variance for non-categorical data. Patients’ long-term survival was assessed using the Kaplan-Meier method. RESULTS: Stents were successfully implanted in 90 patients using fluoroscopic guidance. Reasons for stent implantation in these patients were esophageal stricture (77/90, 85.5%), external pressure (8/90, 8.8%) and tracheo-esophageal fistula (5/90, 5.5%). Dysphagia scores (mean ± SD) were 3.37 ± 0.52 before and 0.90 ± 0.43 after stent implantation (P = 0.002). Intermittent, non-massive hemorrhage due to the erosion caused by the distal end of the stent in the stomach occurred in only one patient who received implementation at cardio-esophageal junction. Mean survival following stenting was 134.14 d (95% confidence interval: 94.06-174.21). CONCLUSION: SEMS placement is safe and effective in the palliation of dysphagia in selected patients with malignant esophageal strictures. PMID:21128325

  18. Use of fully covered self-expanding metal stents in benign biliary diseases

    PubMed Central

    García-Cano, Jesús

    2012-01-01

    Biliary fully covered self-expanding metal stents (FCSEMS) are now being used to treat several benign biliary conditions. Advantages include small predeployment and large postexpansion diameters in addition to an easy insertion technique. Lack of imbedding of the metal into the bile duct wall enables removability. In benign biliary strictures that usually require multiple procedures, despite the substantially higher cost of FCSEMS compared with plastic stents, the use of FCSEMS is offset by the reduced number of endoscopic retrograde cholangiopancreatography interventions required to achieve stricture resolution. In the same way, FCSEMS have also been employed to treat complex bile leaks, perforation and bleeding after endoscopic biliary sphincterotomy and as an aid to maintain permanent drainage tracts obtained by means of Endoscopic Ultrasound-guided biliary drainage. Good success rates have been achieved in all these conditions with an acceptable number of complications. FCSEMS were successfully removed in all patients. Comparative studies of FCSEMS and plastic stents are needed to demonstrate efficacy and cost-effectiveness PMID:22523615

  19. Clinical outcome of simultaneous self-expandable metal stents for palliation of malignant biliary and duodenal obstruction.

    PubMed

    Kaw, M; Singh, S; Gagneja, H

    2003-03-01

    Previous studies have shown that self-expanding metal stents are an effective method for palliation of malignant biliary or duodenal obstruction. We present our experience with the use of simultaneous self-expandable metal stents for palliation of malignant biliary and duodenal obstruction. We performed a retrospective review of all patients undergoing simultaneous biliary and duodenal self-expandable metal stent placement between November 98 and May 2001. All the patients had documented evidence of biliary obstruction and symptomatic duodenal obstruction. The patients received endoscopic biliary stenting with biliary Ultraflex or Wallstents, and endoscopic duodenal stenting using enteral Wallstents. They were followed until their death. We identified 18 patients (11 men and 7 women) whose mean age was 65 years, (range, 46-85 years). Malignancies included pancreatic 14 (78%), biliary 2 (11%), lymphoma 1 (5%), and metastatic 1 (5%) disorders. Ten patients previously had plastic biliary stents placed for past malignant biliary obstruction (4 patients had recurrent biliary obstruction). All the patients had evidence of duodenal obstruction. Combined metal stenting was successful in 17 patients. One procedure failed due to a tortuous duodenal stricture. All the patients had effective palliation of biliary obstruction, as evidenced by a decrease in the level of total bilirubin and alkaline phosphatase. Of the 17 patients with successful duodenal stenting, 16 had a good clinical outcome, with relief of obstructive symptoms. No immediate stent-related complications were noted. During the follow-up period, 12 patients died of progression of the underlying malignancy. None of the deaths were stent related. Median survival time was 78 days. Two patients had recurrent biliary obstruction from tumor ingrowth at 45 and 68 days, respectively. Both underwent restenting: one by endoscopic retrograde cholangiopancreatography (ERCP) and the other by percutaneous transhepatic

  20. Preoperative Drainage for Malignant Biliary Strictures: Is It Time for Self-Expanding Metallic Stents?

    PubMed Central

    Roque, Jason; Ho, Shiaw-Hooi

    2015-01-01

    Palliation of jaundice improves the general health of the patient and, therefore, surgical outcomes. Because of the complexity and location of strictures, especially proximally, drainage has been accompanied by increased morbidity due to sepsis. Another concern is the provocation of an inflammatory and fibrotic reaction around the area of stent placement. Preoperative biliary drainage with self-expanding metallic stent (SEMS) insertion can be achieved via a percutaneous method or through endoscopic retrograde cholangiopancreatography. A recently published multicenter randomized Dutch study has shown increased morbidity with preoperative biliary drainage. A Cochrane meta-analysis has also shown a significantly increased complication rate with preoperative drainage. However, few of these studies have used a SEMS, which allows better biliary drainage. No randomized controlled trials have compared preoperative deployment of SEMS versus conventional plastic stents. The outcomes of biliary drainage also depend on the location of the obstruction, namely the difficulty with proximal compared to distal strictures. Pathophysiologically, palliation of jaundice will benefit all patients awaiting surgery. However, preoperative drainage often results in increased morbidity because of procedure-related sepsis. The use of SEMS may change the outcome of preoperative biliary drainage dramatically. PMID:25674520

  1. Treatment of benign biliary leaks with transhepatic placement of coated self-expanding metallic stents.

    PubMed

    Páramo, M; García-Barquín, P; Carrillo, M; Millor Muruzábal, M; Vivas, I; Bilbao, J I

    To analyze the safety and efficacy of percutaneous placement of coated self-expanding metallic stents (SEMS) in patients with biliary leaks. This ethics committee at our center approved this study. We retrospectively reviewed all coated SEMS placed between October 2008 and September 2015. We analyzed patient-related factors such as the primary underlying disease, prior hepatic procedures, and clinical outcome. We evaluated the location, the number and type of leak (anastomotic or non-anastomotic), and the characteristics of the interventional procedure (number of stents deployed, location of the stents, technical success, and primary functionality). We recorded the complications registered. We studied 14 patients (11 men and 3 women). The mean follow-up period was 375.5 days (range 15-1920 days). Leaks were postsurgical in 12 patients. One patient developed an arteriobilioportal fistula. In another, the biliary leak occurred secondary to the rupture of the common bile duct after ERCP. A total of 23 coated SEMS were placed, including 21 Fluency(®) stents (Bard, Tempe, AZ, USA) and 2 Wallflex(®) stents (Boston Scientific, Galway, Republic of Ireland). The technical success of the procedure was considered total in 11 (78.6%) patients, partial in 2 (14.3%) patients, and null in 1 (7.2%) patient. The clinical outcome was good in 13 of the 14 patients. The mean period of primary functionality of the coated SEMS was 331 days (range 15-1920 days). No major complications were observed in 11 (78.6%) patients. Percutaneous placement of coated SEMS for the treatment of benign biliary leaks is safe and efficacious, with a high rate of technical and clinical success and a moderate rate of complications. Copyright © 2016 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

  2. Use of Fully Covered Self-Expanding Metal Biliary Stents in Pediatrics: A Case Series.

    PubMed

    Mark, Jacob A; Mack, Cara L; Marwan, Ahmed I; Kramer, Robert E

    2017-08-23

    Endoscopic retrograde cholangiopancreatography (ERCP) is used to manage biliary pathology in pediatric patients. Plastic biliary stents have been utilized in this population for obstructive lesions and bile leaks, however they are sometimes not effective due to migration, occlusion, or ineffective sealing. Fully covered self-expanding metal stents (FCSEMS) have larger diameters making them more suitable for some situations. However, their use in pediatrics has not been defined. The aim of this study is to describe our experience with FCSEMS at our institution. We present a series of all patients who underwent FCSEMS placement at Children's Hospital Colorado including three adolescents and one young adult with complex medical needs. Patient age range was 12-24 years and the weight ranged between 36-75 kg. All patients underwent previous ERCP and one or more rounds of plastic stenting without adequate clinical response prior to consideration of FCSEMS placement. Indications included: 1) Recalcitrant biliary anastomotic stricture post liver transplant, 2) Persistent bile leak after needle perforation, 3) Recurrent obstructive choledocholithiasis after cholecystectomy, and 4) Malignant biliary stricture. Sizes of FCSEMS depended on patient bile duct size and biliary pathology. Dwell time was 6-8 weeks. Three patients had resolution of biliary pathology after FCSEMS therapy. One patient had distal migration of FCSEMS necessitating repeat stenting. There were no adverse events from FCSEMS placement or removal. FCSEMS therapy should be considered in appropriate pediatric patients when plastic biliary stents are not effective. Further studies are needed to evaluate the safety and efficacy of FCSEMS in the pediatric age group.

  3. Self-Expanding Metal Stent (SEMS): an innovative rescue therapy for refractory acute variceal bleeding.

    PubMed

    Changela, Kinesh; Ona, Mel A; Anand, Sury; Duddempudi, Sushil

    2014-12-01

    Acute variceal bleeding (AVB) is a life-threatening complication of liver cirrhosis or less commonly splenic vein thrombosis. Pharmacological and endoscopic interventions are cornerstones in the management of variceal bleeding but may fail in 10 - 15 % of patients. Rescue therapy with balloon tamponade (BT) or transjugular intrahepatic portosystemic shunt (TIPS) may be required to control refractory acute variceal bleeding effectively but with some limitations. The self-expanding metal stent (SEMS) is a covered, removable tool that can be deployed in the lower esophagus under endoscopic guidance as a rescue therapy to achieve hemostasis for refractory AVB. To evaluate the technical feasibility, efficacy, and safety of SEMS as a rescue therapy for AVB. In this review article, we have performed an extensive literature search summarizing case reports and case series describing SEMS as a rescue therapy for AVB. Indications, features, technique, deployment, success rate, limitations, and complications are discussed. At present, 103 cases have been described in the literature. Studies have reported 97.08 % technical success rates in deployment of SEMS. Most of the stents were intact for 4 - 14 days with no major complications reported. Stent extraction had a success rate of 100 %. Successful hemostasis was achieved in 96 % of cases with only 3.12 % found to have rebleeding after placement of SEMS. Stent migration, which was the most common complication, was observed in 21 % of patients. SEMS is a safe and effective alternative approach as a rescue therapy for refractory AVB.

  4. Tracheal Self-Expandable Metallic Stents: A Comparative Study of Three Different Stents in a Rabbit Model.

    PubMed

    Serrano, Carolina; Lostalé, Fernando; Rodríguez-Panadero, Francisco; Blas, Ignacio de; Laborda, Alicia; de Gregorio, Miguel Angel

    2016-03-01

    The objective of this study was to assess tracheal reactivity after the deployment of different self-expandable metal stents (SEMS). Forty female New Zealand rabbits were divided into four groups. Three groups received three different SEMS: steel (ST), nitinol (NiTi), or nitinol drug-eluting stent (DES); the fourth group was the control group (no stent). Stents were deployed percutaneously under fluoroscopic guidance. Animals were assessed by multi-slice, computed tomography (CT) scans, and tracheas were collected for anatomical pathology (AP) study. Data from CT and AP were statistically analyzed and correlated. The DES group had the longest stenosis (20.51±14.08mm vs. 5.84±12.43 and 6.57±6.54mm in NiTi and ST, respectively, day 30; P<.05), and higher granuloma formation on CT (50% of cases). The NiTi group showed the lowest grade of stenosis (2.86±6.91% vs. 11.28±13.98 and 15.54±25.95% in DES and ST, respectively; P<.05). The AP study revealed that the ST group developed intense proliferative reactivity compared to the other groups. In the DES group, a destructive response was observed in 70% of the animals, while the NiTi was the least reactive stent. CT was more effective in detecting wall thickening (positive correlation of 68.9%; P<.001) than granuloma (not significant). The ST group developed granulomas and significant stenosis. NiTi was the least reactive stent, while DES caused significant lesions that may be related to drug dosage. This type of DES stent is therefore not recommended for the treatment of tracheobronchial stenosis. Copyright © 2015 SEPAR. Published by Elsevier Espana. All rights reserved.

  5. Successful management of benign biliary strictures with fully covered self-expanding metal stents.

    PubMed

    Devière, Jacques; Nageshwar Reddy, D; Püspök, Andreas; Ponchon, Thierry; Bruno, Marco J; Bourke, Michael J; Neuhaus, Horst; Roy, André; González-Huix Lladó, Ferrán; Barkun, Alan N; Kortan, Paul P; Navarrete, Claudio; Peetermans, Joyce; Blero, Daniel; Lakhtakia, Sundeep; Dolak, Werner; Lepilliez, Vincent; Poley, Jan W; Tringali, Andrea; Costamagna, Guido

    2014-08-01

    Fully covered self-expanding metal stents (FCSEMS) are gaining acceptance for the treatment of benign biliary strictures. We performed a large prospective multinational study to study the ability to remove these stents after extended indwell and the frequency and durability of stricture resolution. In a nonrandomized study at 13 centers in 11 countries, 187 patients with benign biliary strictures received FCSEMS. Removal was scheduled at 10-12 months for patients with chronic pancreatitis or cholecystectomy and at 4-6 months for patients who received liver transplants. The primary outcome measure was removal success, defined as either scheduled endoscopic removal of the stent with no removal-related serious adverse events or spontaneous stent passage without the need for immediate restenting. Endoscopic removal of FCSEMS was not performed for 10 patients because of death (from unrelated causes), withdrawal of consent, or switch to palliative treatment. For the remaining 177 patients, removal success was accomplished in 74.6% (95% confidence interval [CI], 67.5%-80.8%). Removal success was more frequent in the chronic pancreatitis group (80.5%) than in the liver transplantation (63.4%) or cholecystectomy (61.1%) groups (P = .017). FCSEMS were removed by endoscopy from all patients in whom this procedure was attempted. Stricture resolution without restenting upon FCSEMS removal occurred in 76.3% of patients (95% CI, 69.3%-82.3%). The rate of resolution was lower in patients with FCSEMS migration (odds ratio, 0.22; 95% CI, 0.11-0.46). Over a median follow-up period of 20.3 months (interquartile range, 12.9-24.3 mo), the rate of stricture recurrence was 14.8% (95% CI, 8.2%-20.9%). Stent- or removal-related serious adverse events, most often cholangitis, occurred in 27.3% of patients. There was no stent- or removal-related mortality. In a large prospective multinational study, removal success of FCSEMS after extended indwell and stricture resolution were achieved for

  6. Endosonography-guided drainage of malignant fluid collections using lumen-apposing, fully covered self-expanding metal stents.

    PubMed

    Musumba, Crispin; Tutticci, Nicholas; Nanda, Kavinderjit; Kwan, Vu

    2014-08-01

    Endosonography (EUS)-guided drainage of paragastric fluid collections using fully covered self-expanding metal stents (FCSEMS) is now a well-established procedure. Recently, new and specially designed lumen-apposing, fully-covered metal cystgastrostomy stents have been employed for this indication. In this case series, the use of these new stents for the drainage of malignant fluid collections in three symptomatic patients is described. Cases included a large pancreatic pseudocyst, secondary to underlying acute lymphoblastic leukemia, and two large collections of loculated ascites due to metastatic ovarian and cervical cancer, respectively. Technical success in inserting the new stents was achieved in all three patients, and resulted in symptomatic relief. There were no clinically significant complications directly attributed to the stents. These new lumen-apposing cystgastrostomy stents may provide a viable, minimally invasive, and effective alternative for drainage of malignant fluid collections, either for definitive treatment or for palliation of symptoms.

  7. Novel characteristics of traction force in biliary self-expandable metallic stents.

    PubMed

    Hori, Yasuki; Hayashi, Kazuki; Yoshida, Michihiro; Naitoh, Itaru; Ban, Tesshin; Miyabe, Katsuyuki; Kondo, Hiromu; Nishi, Yuji; Umemura, Shuichiro; Fujita, Yasuaki; Natsume, Makoto; Kato, Akihisa; Ohara, Hirotaka; Joh, Takashi

    2017-05-01

    In recent years, knowledge concerning the mechanical properties of self-expandable metallic stents (SEMS) has increased. In a previous study, we defined traction force and traction momentum and reported that these characteristics are important for optimal stent deployment. However, traction force and traction momentum were represented as relative values and were not evaluated in various conditions. The purpose of the present study was to measure traction force in various situations assumed during SEMS placement. Traction force and traction momentum were measured in non-stricture, stricture, and angled stricture models using in-house equipment. Stricture and angled stricture models had significantly higher traction force and traction momentum than those of the non-stricture model (stricture vs non-stricture: traction force, 7.2 N vs 1.4 N, P < 0.001; traction momentum, 237.8 Ns vs 62.3 Ns, P = 0.001; angled stricture vs non-stricture: traction force, 7.4 N vs 1.4 N, P < 0.001; traction momentum, 307.2 Ns vs 62.3 Ns, P < 0.001). Traction force was variable during SEMS placement and was categorized into five different stages, which were similar in both the stricture and angled stricture models. We measured traction force and traction momentum under simulated clinical conditions and demonstrated that strictures and the angular positioning of the stent influenced the traction force. Clinicians should be aware of the transition of the traction force and should schedule X-ray imaging during SEMS placement. © 2017 Japan Gastroenterological Endoscopy Society.

  8. Percutaneous transhepatic self-expanding metal stents for palliation of malignant biliary obstruction.

    PubMed

    Lawson, A J; Beningfield, S J; Krige, J E J; Rischbieter, P; Burmeister, S

    2012-07-11

    Malignant biliary obstruction is often inoperable at presentation and has a poor prognosis. Percutaneously placed self-expanding metal stents (SEMS) have been widely used for palliation of malignant biliary obstruction as an alternative to major bypass surgery or when endoscopic drainage is not technically feasible. The success rate, procedural complications and outcomes in patients who underwent placement of SEMS in a tertiary referral centre are presented. All patients who had percutaneous transhepatic cholangiography (PTC) and SEMS for palliation of malignant biliary obstruction between May 2008 and July 2010 at Groote Schuur Hospital, Cape Town, were reviewed. A retrospective chart review was undertaken using multidisciplinary case notes of all patients. The data analysed included demographic information, diagnosis, level of biliary obstruction, number and type of procedures, efficacy and complications of SEMS insertion. Boston Scientific 69 mm by 10 mm Wallstent SEMS were used in all patients. RESULTS; Fifty patients (28 men, 22 women, mean age 61 years, range 48 - 80 years) underwent percutaneous SEMS placement. Twenty-one patients had biliary obstruction at the level of the hilum involving the hepatic duct bifurcation, 5 in the mid-common bile duct and 24 in the low common bile duct. In 20 patients (40%) SEMS were placed at the time of initial biliary drainage (one-stage procedure), while the remaining 30 patients underwent stent placement within 2 - 23 days of biliary drainage as a two-stage procedure because of difficult access through the lesion during the initial procedure. Five patients (10%) required bilateral SEMS insertion. Stent placement was successful in all patients and biliary obstruction was relieved in all. The mean serum bilirubin level decreased by a mean of 56% from 294 µmol/l to 129 µmol/l measured 5 days after stent insertion. Mean hospital stay after stent insertion was 4.1 days. The average length of hospital stay for patients who

  9. Comparison of Endoscopic Vacuum Therapy and Endoscopic Stent Implantation With Self-Expandable Metal Stent in Treating Postsurgical Gastroesophageal Leakage

    PubMed Central

    Hwang, Jae J.; Jeong, Yeon S.; Park, Young S.; Yoon, Hyuk; Shin, Cheol M.; Kim, Nayoung; Lee, Dong H.

    2016-01-01

    Abstract The aim of the present study was to evaluate the more effective therapy for the postsurgical gastroesophageal leakage by a head-to-head comparison of endoscopic vacuum therapy (EVT) and endoscopic stent implantation with self-expandable metal stent (E-SEMS). In this hospital-based, retrospective, observative study, the patients were classified into 2 groups. Those treated with EVT were assigned to the EVT group (n = 7), and those treated with E-SMS were assigned to the E-SEMS group (n = 11). We evaluated the clinical characteristics and treatment outcomes between the 2 groups. All 7 patients (100%) were treated with EVT, but only 7 of 11 patients (63.6%) in the stenting group were treated successfully. The median time to clinical success was 19.5 (5–21) days in the EVT group and 27.0 (3–84) days in the E-SEMS group. The median hospital stay was 37.1 (13–128) days in the EVT group and 87.3 (17–366) days in the E-SEMS group. The complicaion rate was lower in the EVT group (0/7, 0.0%) than that in the E-SEMS group (6/11, 54.5%) with statistically significant difference (P = 0.042). EVT is more effective and has fewer adverse effects than E-SMS therapy as a treatment for postsurgical gastroesophageal leakage. PMID:27100431

  10. Comparison of Endoscopic Vacuum Therapy and Endoscopic Stent Implantation With Self-Expandable Metal Stent in Treating Postsurgical Gastroesophageal Leakage.

    PubMed

    Hwang, Jae J; Jeong, Yeon S; Park, Young S; Yoon, Hyuk; Shin, Cheol M; Kim, Nayoung; Lee, Dong H

    2016-04-01

    The aim of the present study was to evaluate the more effective therapy for the postsurgical gastroesophageal leakage by a head-to-head comparison of endoscopic vacuum therapy (EVT) and endoscopic stent implantation with self-expandable metal stent (E-SEMS). In this hospital-based, retrospective, observative study, the patients were classified into 2 groups. Those treated with EVT were assigned to the EVT group (n = 7), and those treated with E-SMS were assigned to the E-SEMS group (n = 11). We evaluated the clinical characteristics and treatment outcomes between the 2 groups. All 7 patients (100%) were treated with EVT, but only 7 of 11 patients (63.6%) in the stenting group were treated successfully. The median time to clinical success was 19.5 (5-21) days in the EVT group and 27.0 (3-84) days in the E-SEMS group. The median hospital stay was 37.1 (13-128) days in the EVT group and 87.3 (17-366) days in the E-SEMS group. The complicaion rate was lower in the EVT group (0/7, 0.0%) than that in the E-SEMS group (6/11, 54.5%) with statistically significant difference (P = 0.042). EVT is more effective and has fewer adverse effects than E-SMS therapy as a treatment for postsurgical gastroesophageal leakage.

  11. Partially covered self-expandable metal stents versus polyethylene stents for malignant biliary obstruction: A cost-effectiveness analysis

    PubMed Central

    Barkun, Alan N; Adam, Viviane; Martel, Myriam; AlNaamani, Khalid; Moses, Peter L

    2015-01-01

    BACKGROUND/OBJECTIVE: Partially covered self-expandable metal stents (SEMS) and polyethylene stents (PES) are both commonly used in the palliation of malignant biliary obstruction. Although SEMS are significantly more expensive, they are more efficacious than PES. Accordingly, a cost-effectiveness analysis was performed. METHODS: A cost-effectiveness analysis compared the approach of initial placement of PES versus SEMS for the study population. Patients with malignant biliary obstruction underwent an endoscopic retrograde cholangiopancreatography to insert the initial stent. If the insertion failed, a percutaneous transhepatic cholangiogram was performed. If stent occlusion occurred, a PES was inserted at repeat endoscopic retrograde cholangiopancreatography, either in an outpatient setting or after admission to hospital if cholangitis was present. A third-party payer perspective was adopted. Effectiveness was expressed as the likelihood of no occlusion over the one-year adopted time horizon. Probabilities were based on a contemporary randomized clinical trial, and costs were issued from national references. Deterministic and probabilistic sensitivity analyses were performed. RESULTS: A PES-first strategy was both more expensive and less efficacious than an SEMS-first approach. The mean per-patient costs were US$6,701 for initial SEMS and US$20,671 for initial PES, which were associated with effectiveness probabilities of 65.6% and 13.9%, respectively. Sensitivity analyses confirmed the robustness of these results. CONCLUSION: At the time of initial endoscopic drainage for patients with malignant biliary obstruction undergoing palliative stenting, an initial SEMS insertion approach was both more effective and less costly than a PES-first strategy. PMID:26125107

  12. Partially covered self-expandable metal stents versus polyethylene stents for malignant biliary obstruction: a cost-effectiveness analysis.

    PubMed

    Barkun, Alan N; Adam, Viviane; Martel, Myriam; AlNaamani, Khalid; Moses, Peter L

    2015-10-01

    BACKGROUND⁄ Partially covered self-expandable metal stents (SEMS) and polyethylene stents (PES) are both commonly used in the palliation of malignant biliary obstruction. Although SEMS are significantly more expensive, they are more efficacious than PES. Accordingly, a cost-effectiveness analysis was performed. A cost-effectiveness analysis compared the approach of initial placement of PES versus SEMS for the study population. Patients with malignant biliary obstruction underwent an endoscopic retrograde cholangiopancreatography to insert the initial stent. If the insertion failed, a percutaneous transhepatic cholangiogram was performed. If stent occlusion occurred, a PES was inserted at repeat endoscopic retrograde cholangiopancreatography, either in an outpatient setting or after admission to hospital if cholangitis was present. A third-party payer perspective was adopted. Effectiveness was expressed as the likelihood of no occlusion over the one-year adopted time horizon. Probabilities were based on a contemporary randomized clinical trial, and costs were issued from national references. Deterministic and probabilistic sensitivity analyses were performed. A PES-first strategy was both more expensive and less efficacious than an SEMS-first approach. The mean per-patient costs were US$6,701 for initial SEMS and US$20,671 for initial PES, which were associated with effectiveness probabilities of 65.6% and 13.9%, respectively. Sensitivity analyses confirmed the robustness of these results. At the time of initial endoscopic drainage for patients with malignant biliary obstruction undergoing palliative stenting, an initial SEMS insertion approach was both more effective and less costly than a PES-first strategy.

  13. Arterial bleeding during EUS-guided pseudocyst drainage stopped by placement of a covered self-expandable metal stent

    PubMed Central

    2013-01-01

    Background Hemorrhagic complications during EUS-guided pseudocyst drainage can occur, because the vessels on the internal wall of the pseudocyst might be compressed by the fluid and thus not visible on color Doppler or even power Doppler EUS. Case presentation We report a case of an immediate internal spurting arterial bleeding precipitated during EUS-guided pseudocyst drainage which stopped instantaneously by placement of a double flanged covered self-expandable metal stent through mechanical hemostasis. Conclusion In an unusual situation of bleeding from collateral circulation near the pseudocyst wall during pseudocyst drainage, the placement of an expandable metal stent proved to be useful. PMID:23706101

  14. Stent migration following endoscopic suture fixation of esophageal self-expandable metal stents: a systematic review and meta-analysis.

    PubMed

    Law, Ryan; Prabhu, Anoop; Fujii-Lau, Larissa; Shannon, Carol; Singh, Siddharth

    2017-07-19

    Covered self-expandable metal stents (SEMS) are utilized for the management of benign and malignant esophageal conditions; however, covered SEMS are prone to migration. Endoscopic suture fixation may mitigate the migration risk of covered esophageal SEMS. Hence, we conducted a systematic review and meta-analysis to evaluate the effectiveness and safety of endoscopic suture fixation for covered esophageal SEMS. Following PRISMA guidelines, we performed a systematic review from 2011 to 2016 to identify studies (case control/case series) reporting the technical success and migration rate of covered esophageal SEMS following endoscopic suture fixation. We searched multiple electronic databases and conference proceedings. We calculated pooled rates (and 95% confidence intervals [CI]) of technical success and stent migration using a random effects model. We identified 14 studies (212 patients) describing covered esophageal SEMS placement with endoscopic suture fixation. When reported, SEMS indications included leak/fistula (n = 75), stricture (n = 65), perforation (n = 10), and achalasia (n = 4). The pooled technical success rate was 96.7% (95% CI 92.3-98.6), without heterogeneity (I (2) = 0%). We identified 29 SEMS migrations at rate of 15.9% (95% CI 11.4-21.6), without heterogeneity (I (2) = 0%). Publication bias was observed, and using the trim-and-fill method, a more conservative estimate for stent migration was 17.0%. Suture-related adverse events were estimated to occur in 3.7% (95% CI 1.6-8.2) of cases. Endoscopic suture fixation of covered esophageal SEMS appears to reduce stent migration when compared to published rates of non-anchored SEMS. However, SEMS migration still occurs in approximately 1 out of 6 cases despite excellent immediate technical success and low risk of suture-related adverse events.

  15. Biliary stenting is not a prerequisite to endoscopic placement of duodenal covered self-expandable metal stents.

    PubMed

    Poincloux, L; Goutorbe, F; Rouquette, O; Mulliez, A; Goutte, M; Bommelaer, G; Abergel, A

    2016-02-01

    Duodenal covered self-expandable metal stent (cSEMS) can be used in malignant or benign gastroduodenal obstruction. The need for biliary stenting in patients with no concomitant biliary stricture, before duodenal cSEMS placement, remains unknown. The aim of this study was to determine whether cSEMS placement is responsible for biliary obstruction. This is a single-center, retrospective, case-controlled study, including 106 patients with symptomatic gastric outlet obstruction or duodenal fistula who received a covered nitinol duodenal stent by using through-the-scope/over-the-wire placement procedure. The main outcome measurement was the occurrence comparison of jaundice and bilirubin level, between patients with previous or concomitant biliary stenting (cSEMS + BS group), and patients with no biliary stent (cSEMS group) during an observational period of 90 days. Hundred and six patients underwent cSEMS placement between June 2005 and March 2014: 53 in the cSEMS group (58% male, mean age 66.4 ± 13.3 years) and 53 in cSEMS + BS group (60% male, mean age 70.4 ± 11.6 years). The obstruction was due to cancer in 45% in cSEMS group and 87% in cSEMS + BS group. No case of jaundice was reported in the cSEMS group or in the cSEMS + BS group. In cSEMS group, the mean bilirubin level (μmol/L ± SD) was 8.0 ± 4 at baseline and 8.5 ± 4.6 at day 10, while in the cSEMS + BS group it was 91.4 ± 108 at baseline and 35.3 ± 39 at day 10 (p < 0.01). Patients from the two groups were matched on age, gender and bilirubin level at baseline. Evolution of bilirubinemia was +0.98 ± 2.76 µmol/L in experimental group and +0.39 ± 522 µmol/L in the control group (p = 0.34). No significant difference was observed between the two groups in term of technical success, clinical effectiveness, migration and other complications. Previous biliary stenting is not required before endoscopic covered duodenal stent placement in patients with no associated biliary obstruction. Prospective studies

  16. Combined Placement of Covered Self-Expanding Metallic Stents and Nasojejunal Tube for Managing Large Lower Esophageal Perforations.

    PubMed

    Rana, Surinder S; Gupta, Rajesh; Dahiya, Divya; Behera, Arunanshu; Bhasin, Deepak K

    2014-02-01

    Covered self-expanding metallic stents (cSEMSs) have emerged as effective treatment option for esophageal perforations. However, the large lower esophageal perforations where the cSEMS is placed across gastroesophageal junction have lower healing rates because refluxed gastric contents constantly irritate perforation and also there is increased risk of stent migration. Moreover, gastric mucosa tends to prolapse into lumen of lower end of stent causing its obstruction, leading to seepage of saliva and fluids from upper end of stent even in the patients who are on parenteral nutrition. We present our experience of a novel technique of combined cSEMS and nasojejunal tube (NJT) placement in four patients (two males) with benign large lower esophageal perforations. The NJT was placed through the stent into the jejunum through which patients were given enteral feeding. The stents were placed 5 - 21 days after esophageal perforation with the size of perforation ranging from 4 to 6 cm. As the NJT formed a loop in stomach, it prevented migration of stent. And also its presence in lumen of stent prevented its obstruction by prolapsing gastric mucosa, thereby preventing seepage of saliva and fluids from side of stent. Both stents and NJT were removed after 6 weeks and leak closed in all patients. Combined cSEMS and NJT placement seems to be safe and effective for treating large lower esophageal perforations. NJT placement seems to decrease risk of migration, prevents seepage of fluids and permits early enteral nutrition, thereby improving the healing rates.

  17. Combined Placement of Covered Self-Expanding Metallic Stents and Nasojejunal Tube for Managing Large Lower Esophageal Perforations

    PubMed Central

    Rana, Surinder S; Gupta, Rajesh; Dahiya, Divya; Behera, Arunanshu; Bhasin, Deepak K

    2014-01-01

    Covered self-expanding metallic stents (cSEMSs) have emerged as effective treatment option for esophageal perforations. However, the large lower esophageal perforations where the cSEMS is placed across gastroesophageal junction have lower healing rates because refluxed gastric contents constantly irritate perforation and also there is increased risk of stent migration. Moreover, gastric mucosa tends to prolapse into lumen of lower end of stent causing its obstruction, leading to seepage of saliva and fluids from upper end of stent even in the patients who are on parenteral nutrition. We present our experience of a novel technique of combined cSEMS and nasojejunal tube (NJT) placement in four patients (two males) with benign large lower esophageal perforations. The NJT was placed through the stent into the jejunum through which patients were given enteral feeding. The stents were placed 5 - 21 days after esophageal perforation with the size of perforation ranging from 4 to 6 cm. As the NJT formed a loop in stomach, it prevented migration of stent. And also its presence in lumen of stent prevented its obstruction by prolapsing gastric mucosa, thereby preventing seepage of saliva and fluids from side of stent. Both stents and NJT were removed after 6 weeks and leak closed in all patients. Combined cSEMS and NJT placement seems to be safe and effective for treating large lower esophageal perforations. NJT placement seems to decrease risk of migration, prevents seepage of fluids and permits early enteral nutrition, thereby improving the healing rates. PMID:27785265

  18. Nitinol versus steel partially covered self-expandable metal stent for malignant distal biliary obstruction: a randomized trial.

    PubMed

    Soderlund, Claes; Linder, Stefan; Bergenzaun, Per E; Grape, Tomas; Hakansson, Hans-Olof; Kilander, Anders; Lindell, Gert; Ljungman, Martin; Ohlin, Bo; Nielsen, Jorgen; Rudberg, Claes; Stotzer, Per-Ove; Svartholm, Erik; Toth, Ervin; Frozanpor, Farshad

    2014-11-01

    Covered nitinol alloy self-expandable metal stents (SEMSs) have been developed to overcome the shortcomings of steel SEMS in patients with malignant biliary obstruction. In a randomized, multicenter trial, we compared stent patency, patient survival, and adverse events in patients with partly covered stents made from steel or nitinol. A total of 400 patients with unresectable distal malignant biliary obstruction were randomized at endoscopic retrograde cholangiopancreatography (ERCP) to insertion of a steel or nitinol partially covered SEMS, with 200 patients in each group. The primary outcome was confirmed stent failure during 300 days of follow-up.  At 300 days, the proportion of patients with patent stents was 77 % in the steel group, compared with 89 % in the nitinol group (P = 0.01). Confirmed stent failure occurred more often in the steel SEMS group compared with the nitinol SEMS group, in 30 versus 14 patients (P = 0.02). Stent migration occurred in 13 patients in the steel group and in 3 patients in the nitinol group (P = 0.01). Median patient survival (secondary outcome) was 137 days and 120 days in the steel SEMS and nitinol SEMS groups, respectively (P = 0.59). The nitinol SEMS showed longer patency time, and the nitinol group had fewer patients with stent failure, compared with the steel SEMS group. We could not detect any differences between the two groups regarding survival time, and regarding adverse event rate.Clinical trial registration : NCT 00980889. © Georg Thieme Verlag KG Stuttgart · New York.

  19. Definitive outcomes of self-expandable metal stents in patients with refractory post-transplant biliary anastomotic stenosis.

    PubMed

    Tarantino, Ilaria; Barresi, Luca; Curcio, Gabriele; Granata, Antonino; Ligresti, Dario; Tuzzolino, Fabio; Volpes, Riccardo; Amata, Michele; Traina, Mario

    2015-07-01

    Endoscopic retrograde cholangio-pancreatography is the gold standard of treatment in patients with biliary complications after liver transplantation. The benefits of fully covered self-expandable metal stents (FCSEMS) lie in their relative simplicity and the need for only two procedures, one for insertion, and the other for removal. Several case series have been published on such stents with generally good outcomes. Objective is to analyze definitive long-term outcomes of this treatment. Prospective, observational study in a single, tertiary-care referral centre. All consecutive patients with post-transplant biliary stenosis/leak were treated with FCSEMS after failure of conventional treatment. Recurrence was evaluated after four years. From February 2008 to April 2012, 70 patients were included. In all patients, the metal stent was successfully placed. After a mean of 86.7 ± 38.4 days, the stent was removed. Forty-six patients (65.7%) showed resolution. After a mean of 4 ± 1.2 years, 61% of patients maintained the results, but 39% showed recurrence. On the tested variables the diagnosis of stenosis, the number of previous procedures and plastic stents placed correlate with better long-term results. This series suggests a lack of long-term advantages of FCSEMS over plastic stents in the management of biliary stenosis after liver transplantation. Copyright © 2015 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  20. Self-expandable covered metal tracheal type stent for sealing cervical anastomotic leak after esophagectomy and gastric pull-up: pitfalls and possibilities.

    PubMed

    Lindenmann, Joerg; Matzi, Veronika; Porubsky, Christian; Anegg, Udo; Sankin, Oliver; Gabor, Sabine; Neuboeck, Nicole; Maier, Alfred; Smolle-Juettner, Freyja Maria

    2008-01-01

    From January 2003 to June 2006, 6 patients with leakage of the cervical esophagogastrostomy after esophagectomy and gastric pull-up underwent endoscopic stenting using the self-expandable covered tracheal type device. Anastomotic healing was satisfactory. Stent extraction was performed after an average interval of 91 days. Initial stent migration occurred in 2 patients and post-extraction stenosis developed in 3 patients. Insertion of a self-expandable covered metal tracheal stent represents a safe approach resulting in immediate closure and subsequent healing of cervical anastomotic leakage.

  1. Efficacy and safety of a new fully covered self-expandable non-foreshortening metal esophageal stent.

    PubMed

    Dua, Kulwinder S; Latif, Sahibzada U; Yang, Juliana F; Fang, Tom C; Khan, Abdul; Oh, Young

    2014-10-01

    Fully covered esophageal self-expandable metal stents (SEMSs) are potentially removable but can be associated with high migration rates. For precise positioning, non-foreshortening SEMSs are preferred. Recently, a new fully covered non-foreshortening SEMS with anti-migration features was introduced. To evaluate the efficacy and safety of this new esophageal SEMS. Retrospective study. Single, tertiary-care center. Consecutive patients with malignant and benign strictures with dysphagia grade of ≥3 and patients with fistulas/leaks were studied. Stent placement and removal. Technical success in stent deployment/removal, efficacy in relieving dysphagia and sealing fistulas/leaks, and adverse events. Forty-three stents were placed in 35 patients (mean [± standard deviation] age 65 ± 11 years; 31 male), 24 for malignant and 11 for benign (5 strictures, 6 leaks) indications. Technical success in precise SEMS placement was 100%. The after-stent dysphagia grade improved significantly (at 1 week: 1.5 ± 0.7; at 4 weeks: 1.2 ± 0.4; baseline: 3.8 ± 0.4; P < .0001). Twenty stents were removed for clinical indications, with technical success of 100%. All leaks sealed after SEMS placement and did not recur after stent removal. All benign strictures recurred after stent removal. Adverse events included migration (14%), chest pain (11%), and dysphagia from tissue hyperplasia (6%). There was no stent-related mortality. Nonrandomized, single-center study. The new esophageal SEMS was effective in relieving malignant dysphagia, allowed for precise placement, and was easily removable. It was effective in treating benign esophageal fistulas and leaks. Stent-related adverse events were acceptable. Copyright © 2014 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

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

    PubMed Central

    Sun, Ping; Yu, Qihong; Wang, Kun; Chang, Weilong; Song, Zifang; Zheng, Qichang

    2016-01-01

    Aim To 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. Methods We 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. Results The 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%). Conclusions Our 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

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

    PubMed

    Li, Jinjin; Li, Tong; Sun, Ping; Yu, Qihong; Wang, Kun; Chang, Weilong; Song, Zifang; Zheng, Qichang

    2016-01-01

    To 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. We 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. The 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%). Our 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

  4. Partially covered self-expanding metal stent for unresectable malignant extrahepatic biliary obstruction: results of a large prospective series.

    PubMed

    Gómez-Oliva, Cristina; Guarner-Argente, Carlos; Concepción, Mar; Jiménez, Francisco Javier; Rodríguez, Sarbelio; Gonzalez-Huix, Ferran; Mugica, Fernando; Cabriada, José Luis; Rodríguez, Claudio; Aguilar, Carlos Guarner

    2012-01-01

    Endoscopic biliary stenting is a well-established palliative treatment in patients with unresectable malignant biliary strictures. Obstruction of uncovered self-expanding metal stent (SEMS) due to tumor ingrowth is the most frequent complication. Partially covered SEMS might increase stent patency but could favor complications related to stent covering, such as pancreatitis, cholecystitis, and migration. The aim of this study was to evaluate the efficacy and safety of partially covered SEMS in patients with an unresectable malignant biliary stricture. Patients with malignant extrahepatic biliary obstruction treated endoscopically with partially covered SEMS were included in this multicenter, prospective, nonrandomized study. One hundred ninety-nine patients were endoscopically treated with partially covered SEMS in 32 Spanish hospitals. Clinical success after deep cannulation was 96%. Early complications occurred in 4% (3 pancreatitis, 2 cholangitis, 1 hemorrhage, 1 perforation, and 1 cholecystitis). Late complications occurred in 19.5% (18 obstructions, 10 migrations, 6 cholangitis without obstruction, 3 acute cholecystitis, and 2 pancreatitis), with no tumor ingrowth in any case. Median stent patency was 138.9 ± 112.6 days. One-year actuarial probability of stent patency was 70% and that of nonmigration was 86%. Multivariate analysis showed adjuvant radio- or chemotherapy as the only independent predictive factor of stent patency and previous insertion of a biliary stent was the only predictive factor of migration. The partially covered SEMS was easily inserted, had a high clinical success rate, and prevented tumor ingrowth. The incidence of possible complications related to stent coverage, namely, migration, pancreatitis, and cholecystitis, was lower than in previously published series.

  5. Optimum palliation of inoperable hilar cholangiocarcinoma: comparative assessment of the efficacy of plastic and self-expanding metal stents.

    PubMed

    Raju, Ramu P; Jaganmohan, Sathya R; Ross, William A; Davila, Marta L; Javle, Milind; Raju, Gottumukkala S; Lee, Jeffrey H

    2011-05-01

    Endoscopic retrograde biliary drainage (ERBD) with plastic or self-expanding metal stents (SEMS) is often performed for palliative care for cholangiocarcinoma. The objective was to compare the clinical effectiveness, including stent patency, complication rate, and need for salvage percutaneous transhepatic biliary drainage, of SEMS and plastic stents. A total of 100 patients with inoperable cholangiocarcinoma were identified from an endoscopic database from 1/1/01 to 9/30/06 at a tertiary cancer hospital and their clinical history was retrospectively reviewed. All patients were followed to death, re-intervention, or for at least one year. Stent patency and patient survival were estimated by Kaplan-Meier analysis, supplemented by the log-rank test for comparisons between groups. Forty-eight patients had SEMS placed and 52 patients had plastic stents placed. ERBD was successful in 46 (95.8%) in the SEMS group and 49 (94.2%) in the plastic group (P = 0.67). Median patency times were 1.86 months in the plastic group and 5.56 months in the SEMS group (P < 0.0001). A mean of 1.53 and 4.60 re-interventions were performed in the SEMS and plastic groups, respectively (P < 0.05). Complications occurred in 4/48 (8.3%) in the SEMS group and 4/52 (7.7%) in the plastic group (P = 0.79). Median survival was 9.08 and 8.22 months in the SEMS and plastic stent groups, respectively (P = 0.50). Metallic stent patency was superior to that of plastic stents in all Bismuth-Corlette classifications of hilar cholangiocarcinoma with similar complication rates. SEMS seem to be cost-effective and, when feasible, should be considered as an initial intervention in patients with inoperable hilar cholangiocarcinoma.

  6. Endoscopic transluminal pancreatic necrosectomy using a self-expanding metal stent and high-flow water-jet system

    PubMed Central

    Hritz, István; Fejes, Roland; Székely, András; Székely, Iván; Horváth, László; Sárkány, Ágnes; Altorjay, Áron; Madácsy, László

    2013-01-01

    Walled-off pancreatic necrosis and a pancreatic abscess are the most severe complications of acute pancreatitis. Surgery in such critically ill patients is often associated with significant morbidity and mortality within the first few weeks after the onset of symptoms. Minimal invasive approaches with high success and low mortality rates are therefore of considerable interest. Endoscopic therapy has the potential to offer safe and effective alternative treatment. We report here on 3 consecutive patients with infected walled-off pancreatic necrosis and 1 patient with a pancreatic abscess who underwent direct endoscopic necrosectomy 19-21 d after the onset of acute pancreatitis. The infected pancreatic necrosis or abscess was punctured transluminally with a cystostome and, after balloon dilatation, a non-covered self-expanding biliary metal stent was placed into the necrotic cavity. Following stent deployment, a nasobiliary pigtail catheter was placed into the cavity to ensure continuous irrigation. After 5-7 d, the metal stent was removed endoscopically and the necrotic cavity was entered with a therapeutic gastroscope. Endoscopic debridement was performed via the simultaneous application of a high-flow water-jet system; using a flush knife, a Dormia basket, and hot biopsy forceps. The transluminal endotherapy was repeated 2-5 times daily during the next 10 d. Supportive care included parenteral antibiotics and jejunal feeding. All patients improved dramatically and with resolution of their septic conditions; 3 patients were completely cured without any further complications or the need for surgery. One patient died from a complication of prolonged ventilation severe bilateral pneumonia, not related to the endoscopic procedure. No procedure related complications were observed. Transluminal endoscopic necrosectomy with temporary application of a self-expanding metal stent and a high-flow water-jet system shows promise for enhancing the potential of this endoscopic

  7. Endoscopic transluminal pancreatic necrosectomy using a self-expanding metal stent and high-flow water-jet system.

    PubMed

    Hritz, István; Fejes, Roland; Székely, András; Székely, Iván; Horváth, László; Sárkány, Agnes; Altorjay, Aron; Madácsy, László

    2013-06-21

    Walled-off pancreatic necrosis and a pancreatic abscess are the most severe complications of acute pancreatitis. Surgery in such critically ill patients is often associated with significant morbidity and mortality within the first few weeks after the onset of symptoms. Minimal invasive approaches with high success and low mortality rates are therefore of considerable interest. Endoscopic therapy has the potential to offer safe and effective alternative treatment. We report here on 3 consecutive patients with infected walled-off pancreatic necrosis and 1 patient with a pancreatic abscess who underwent direct endoscopic necrosectomy 19-21 d after the onset of acute pancreatitis. The infected pancreatic necrosis or abscess was punctured transluminally with a cystostome and, after balloon dilatation, a non-covered self-expanding biliary metal stent was placed into the necrotic cavity. Following stent deployment, a nasobiliary pigtail catheter was placed into the cavity to ensure continuous irrigation. After 5-7 d, the metal stent was removed endoscopically and the necrotic cavity was entered with a therapeutic gastroscope. Endoscopic debridement was performed via the simultaneous application of a high-flow water-jet system; using a flush knife, a Dormia basket, and hot biopsy forceps. The transluminal endotherapy was repeated 2-5 times daily during the next 10 d. Supportive care included parenteral antibiotics and jejunal feeding. All patients improved dramatically and with resolution of their septic conditions; 3 patients were completely cured without any further complications or the need for surgery. One patient died from a complication of prolonged ventilation severe bilateral pneumonia, not related to the endoscopic procedure. No procedure related complications were observed. Transluminal endoscopic necrosectomy with temporary application of a self-expanding metal stent and a high-flow water-jet system shows promise for enhancing the potential of this endoscopic

  8. Temporary placement of fully covered self-expandable metal stents for the treatment of benign biliary strictures

    PubMed Central

    Chaput, Ulriikka; Vienne, Ariane; Audureau, Etienne; Bauret, Paul; Bichard, Philippe; Coumaros, Dimitri; Napoléon, Bertrand; Ponchon, Thierry; Duchmann, Jean-Christophe; Laugier, René; Lamouliatte, Hervé; Védrenne, Bruno; Gaudric, Marianne; Chaussade, Stanislas; Robin, Françoise; Leblanc, Sarah

    2015-01-01

    Background Endoscopic treatment of benign biliary strictures (BBS) can be challenging. Objective To evaluate the efficacy of fully covered self-expandable metal stents (FCSEMS) in BBS. Methods Ninety-two consecutive patients with BBS (chronic pancreatitis (n = 42), anastomotic after liver transplantation (n = 36), and post biliary surgical procedure (n = 14)) were included. FCSEMS were placed across strictures for 6 months before endoscopic extraction. Early success rate was defined as the absence of biliary stricture or as a minimal residual anomaly on post-stent removal endoscopic retrograde cholangiopancreatography (ERCP). Secondary outcomes were the final success and stricture recurrence rates as well as procedure-related morbidity. Results Stenting was successful in all patients. Stenting associated complications were minor and occurred in 22 (23.9%) patients. Migration occurred in 23 (25%) patients. Stent extraction was successful in all but two patients with proximal stent migration. ERCP after the 6 months stenting showed an early success in 84.9% patients (chronic pancreatitis patients: 94.7%, liver transplant: 87.9%, post-surgical: 61.5%) (p = 0.01). Final success was observed in 57/73 (78.1%) patients with a median follow-up of 12 ± 3.56 months. Recurrence of biliary stricture occurred in 16/73 (21.9%) patients. Conclusions FCSEMS placement is efficient for patients with BBS, in particular for chronic pancreatitis patients. Stent extraction after 6 months indwelling, although generally feasible, may fail in a few cases. PMID:27403307

  9. Temporary placement of fully covered self-expandable metal stents for the treatment of benign biliary strictures.

    PubMed

    Chaput, Ulriikka; Vienne, Ariane; Audureau, Etienne; Bauret, Paul; Bichard, Philippe; Coumaros, Dimitri; Napoléon, Bertrand; Ponchon, Thierry; Duchmann, Jean-Christophe; Laugier, René; Lamouliatte, Hervé; Védrenne, Bruno; Gaudric, Marianne; Chaussade, Stanislas; Robin, Françoise; Leblanc, Sarah; Prat, Frédéric

    2016-06-01

    Endoscopic treatment of benign biliary strictures (BBS) can be challenging. To evaluate the efficacy of fully covered self-expandable metal stents (FCSEMS) in BBS. Ninety-two consecutive patients with BBS (chronic pancreatitis (n = 42), anastomotic after liver transplantation (n = 36), and post biliary surgical procedure (n = 14)) were included. FCSEMS were placed across strictures for 6 months before endoscopic extraction. Early success rate was defined as the absence of biliary stricture or as a minimal residual anomaly on post-stent removal endoscopic retrograde cholangiopancreatography (ERCP). Secondary outcomes were the final success and stricture recurrence rates as well as procedure-related morbidity. Stenting was successful in all patients. Stenting associated complications were minor and occurred in 22 (23.9%) patients. Migration occurred in 23 (25%) patients. Stent extraction was successful in all but two patients with proximal stent migration. ERCP after the 6 months stenting showed an early success in 84.9% patients (chronic pancreatitis patients: 94.7%, liver transplant: 87.9%, post-surgical: 61.5%) (p = 0.01). Final success was observed in 57/73 (78.1%) patients with a median follow-up of 12 ± 3.56 months. Recurrence of biliary stricture occurred in 16/73 (21.9%) patients. FCSEMS placement is efficient for patients with BBS, in particular for chronic pancreatitis patients. Stent extraction after 6 months indwelling, although generally feasible, may fail in a few cases.

  10. Endoscopic suture fixation is associated with reduced migration of esophageal fully covered self-expandable metal stents (FCSEMS).

    PubMed

    Wright, Andrew; Chang, Andrew; Bedi, Aarti Oza; Wamsteker, Erik-Jan; Elta, Grace; Kwon, Richard S; Carrott, Phillip; Elmunzer, B Joseph; Law, Ryan

    2016-12-07

    Esophageal fully covered self-expandable metal stents (FCSEMS) are indicated for the management of benign and malignant conditions of the esophagus including perforations, leaks, and strictures. FCSEMS are resistant to tissue ingrowth and are removable; however, stent migration occurs in 30-55% of cases. Endoscopic suture fixation of FCSEMS has been utilized to decrease the risk of stent migration though data supporting this practice remain limited. The primary aim of this study was to compare clinical outcomes and migration rate of patients who underwent placement of esophageal FCSEMS with and without endoscopic suture fixation. Our single-center, retrospective, cohort study includes patients who underwent esophageal FCSEMS placement with and without endoscopic suture fixation between January 1, 2012, and November 11, 2015. Baseline patient characteristics, procedural details, and clinical outcomes were abstracted. Logistic regression was performed to identify clinical and technical factors associated with outcomes and stent migration. A total of 51 patients underwent 62 FCSEMS placements, including 21 procedures with endoscopic suture fixation and 41 without. Suture fixation was associated with reduced risk of stent migration (OR 0.13, 95% CI 0.03-0.47). Prior stent migration was associated with significantly higher risk of subsequent migration (OR 6.4, 95% CI 1.6-26.0). Stent migration was associated with lower likelihood of clinical success (OR 0.21, 95% CI 0.06-0.69). There was a trend toward higher clinical success among patients undergoing suture fixation (85.7 vs. 60.9%, p = 0.07). Endoscopic suture fixation of FCSEMS was associated with a reduced stent migration rate. Appropriate patient selection for suture fixation of FCSEMS may lead to reduced migration in high-risk patients.

  11. Randomized multicenter study of multiple plastic stents vs. covered self-expandable metallic stent in the treatment of biliary stricture in chronic pancreatitis.

    PubMed

    Haapamäki, Carola; Kylänpää, Leena; Udd, Marianne; Lindström, Outi; Grönroos, Juha; Saarela, Arto; Mustonen, Harri; Halttunen, Jorma

    2015-07-01

    The use of covered self-expandable metallic stents (cSEMS) in benign biliary indications is evolving. The aim of the study was to assess the safety and feasibility of cSEMS compared with multiple plastic stents in the treatment of benign biliary stricture (BBS) caused by chronic pancreatitis. This was a prospective, multicenter, randomized study of 60 patients with BBS caused by chronic pancreatitis. All patients received an initial plastic stent before randomization. At randomization, the stent was replaced either with a single cSEMS or three plastic stents. After 3 months, the position of the cSEMS was checked or another three plastic stents were added. At 6 months after randomization, all stents were removed. Clinical follow-up including abdominal ultrasound and laboratory tests were performed at 6 months and 2 years after stent removal. Two patients dropped out of the cSEMS group before stent removal. In April 2014, the median follow-up was 40 months (range 1 - 66 months). The 2-year, stricture-free success rate was 90 % (95 % confidence interval [CI] 72 % - 97 %) in the plastic stent group and 92 % (95 %CI 70 % - 98 %) in the cSEMS group (P = 0.405). There was one late recurrence in the plastic stent group 50 months after stent removal. Stent migration occurred three times (10 %) in the plastic stent group and twice in the cSEMS group (7 %; P = 1.000). A 6-month treatment with either six 10-Fr plastic stents or with one 10-mm cSEMS produced good long-term relief of biliary stricture caused by chronic pancreatitis.Study registered at ClinicalTrials.gov (NCT01085747). © Georg Thieme Verlag KG Stuttgart · New York.

  12. Palliation of Obstructing Malignant Colonic Lesions Using Self-Expanding Metal Stents: A Single-Center Experience

    SciTech Connect

    Shrivastava, Vivek; Tariq, Omar; Tiam, ReeNee; Nyhsen, Christiane; Marsh, Ralph

    2008-09-15

    To evaluate the efficacy, risks, and survival after palliative colorectal stenting at a single center, we conducted a retrospective review of consecutive patients who had colorectal self-expanding metal stents (SEMSs) inserted over an 8-year period (September 1998 to September 2006) to relieve an obstructing colorectal tumor. All patients either had proven distant metastases or were unfit for surgical decompression. A single interventional radiologist (R.M.) inserted the stents, which were either Memotherm or WallFlex. Ninety-one patients with a median age of 73 years had a colorectal stent inserted for palliation of an obstructing colorectal malignancy. Technical success was achieved in 81 of 91 (89%) patients, and clinical success in 80 of 81 (99%). At the time of analysis (December 2006), 13 of 91 (14.2%) patients were alive. The patients who died had a median survival of 59 days, IQR 17-181 days. Seven (7/81) patients suffered stent migration, which occurred 10.3 days (IQR, 5-14 days) after the procedure. Three patients (3/81) re-presented with intestinal obstruction secondary to tumor ingrowth and 10 (10.9%) patients suffered bowel perforation. Ten patients (10.9%) had two stents inserted coaxially and overlapping in one procedure. This was performed in cases where the stricture was too long to be easily crossed by a single stent. We conclude that colorectal SEMS is a safe and effective mode of treatment for the palliation of obstructing colorectal cancers, which avoids high-risk surgery.

  13. Self-expanding metal mesh stents and laser therapy: a complementary approach for the palliation of malignant dysphagia

    NASA Astrophysics Data System (ADS)

    Madhotra, Ravi; Raouf, A.; Sturgess, R.; Krasner, Neville

    1997-12-01

    Re-establishment of the oesophageal lumen is the main focus of care in patients with inoperable oesophageal carcinomas. The self-expanding metal mesh stents (MMS) are increasingly being used. 51 patients aged 44 - 89 with inoperable oesophago-gastric carcinomas were intubated with MMS. 18 of these patients had endoscopic laser therapy (ELT) as primary palliation. 25 patients required follow-up endoscopy at variable intervals after stent insertion. 17 patients were found to have significant tumor growth (9), overgrowth (4) and both (4). All these patients were treated with Nd:YAG or diode laser for maintenance of satisfactory swallowing. 4 patients being treated with Nd:YAG laser developed deformity of MMS. This complication was not encountered with diode laser. The reblockage of MMS due to ingrowth or overgrowth of tumor is a not uncommon complication. The timing of the stent insertion should be carefully chosen since the longer the stent is in situ, the greater is the likelihood of tumor ingrowth or overgrowth. ELT can effectively deal with tumor ingrowth and overgrowth. Nd:YAG laser can cause melting of MMS. Overall the combination of ELT and MMS may offer the best palliation, particularly when patient survival of several months is anticipated.

  14. Self-expandable metal stents for obstructing colonic and extracolonic cancer: European Society of Gastrointestinal Endoscopy (ESGE) Clinical Guideline.

    PubMed

    van Hooft, Jeanin E; van Halsema, Emo E; Vanbiervliet, Geoffroy; Beets-Tan, Regina G H; DeWitt, John M; Donnellan, Fergal; Dumonceau, Jean-Marc; Glynne-Jones, Robert G T; Hassan, Cesare; Jiménez-Perez, Javier; Meisner, Søren; Muthusamy, V Raman; Parker, Michael C; Regimbeau, Jean-Marc; Sabbagh, Charles; Sagar, Jayesh; Tanis, Pieter J; Vandervoort, Jo; Webster, George J; Manes, Gianpiero; Barthet, Marc A; Repici, Alessandro

    2014-11-01

    This Guideline is an official statement of the European Society of Gastrointestinal Endoscopy (ESGE). This Guideline was also reviewed and endorsed by the Governing Board of the American Society for Gastrointestinal Endoscopy (ASGE). The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system was adopted to define the strength of recommendations and the quality of evidence. Main recommendations The following recommendations should only be applied after a thorough diagnostic evaluation including a contrast-enhanced computed tomography (CT) scan. 1 Prophylactic colonic stent placement is not recommended. Colonic stenting should be reserved for patients with clinical symptoms and imaging evidence of malignant large-bowel obstruction, without signs of perforation (strong recommendation, low quality evidence). 2 Colonic self-expandable metal stent (SEMS) placement as a bridge to elective surgery is not recommended as a standard treatment of symptomatic left-sided malignant colonic obstruction (strong recommendation, high quality evidence). 3 For patients with potentially curable but obstructing left-sided colonic cancer, stent placement may be considered as an alternative to emergency surgery in those who have an increased risk of postoperative mortality, I. e. American Society of Anesthesiologists (ASA) Physical Status ≥ III and/or age > 70 years (weak recommendation, low quality evidence). 4 SEMS placement is recommended as the preferred treatment for palliation of malignant colonic obstruction (strong recommendation, high quality evidence), except in patients treated or considered for treatment with antiangiogenic drugs (e. g. bevacizumab) (strong recommendation, low quality evidence).

  15. Short-term stenting using fully covered self-expandable metal stents for treatment of refractory biliary leaks, postsphincterotomy bleeding, and perforations.

    PubMed

    Canena, Jorge; Liberato, Manuel; Horta, David; Romão, Carlos; Coutinho, António

    2013-01-01

    Fully covered self-expandable metal stents (FCSEMS) have been used as a rescue therapy for several benign biliary tract conditions (BBC). Long-term stent placement commonly occurs, and prolonged FCSEMS placement is associated with the majority of the complications reported. This study evaluated the duration of stenting and the efficacy and safety of temporary FCSEMS placement for three BBCs: refractory biliary leaks, postsphincterotomy bleeding, and perforations. This was a retrospective case series with long-term follow-up of 25 patients who underwent FCSEMS placement for BBCs. This study included 17 patients with postcholecystectomy refractory biliary leaks who had previously undergone unsuccessful sphincterotomy and plastic stent placement, 4 patients with difficult-to-control postsphincterotomy bleeding, and 4 patients with a perforation following endoscopic sphincterotomy. Stents were removed according to clinical evidence of problem resolution. The review included stenting duration, safe FCSEMS removal, clinical efficacy, complications, and long-term outcomes. During the follow-up period, ERCP and cholangioscopy procedures were performed to exclude the possibility of bile duct lesion development. Complete resolution of the initial condition was achieved in all patients. Patients with biliary leaks had a median stent duration time of 16 days (range 7-28 days). Patients with bleeding had stents removed after a median time of 6 days (range 3-15 days). Patients with perforations had their stents removed after a median time of 29.5 days (range 21-30 days). There were no complications related to stenting. Temporary placement of a FCSEMS for 30 days or less is an effective rescue therapy for refractory biliary leaks, difficult-to-control post-endoscopic sphincterotomy bleeding, and perforations. Duration of stenting should be different for each type of condition. Stents can be safely removed, and short-term stenting is associated with the absence of early and late

  16. Clinical benefits and oncologic equivalence of self-expandable metallic stent insertion for right-sided malignant colonic obstruction.

    PubMed

    Ji, Woong Bae; Kwak, Jung Myun; Kang, Dong Woo; Kwak, Han Deok; Um, Jun Won; Lee, Sun-Il; Min, Byung-Wook; Sung, Nak Song; Kim, Jin; Kim, Seon Hahn

    2017-01-01

    The efficacy of stenting for right-sided malignant colonic obstruction is unknown. This study aimed to evaluate the safety, feasibility, and clinical benefits of self-expandable metallic stent insertion for right-sided malignant colonic obstruction. Clinical data from patients who underwent right hemicolectomy for right colon cancer from January 2006 to July 2014 at three Korea University hospitals were retrospectively reviewed. A total of 39 patients who developed malignant obstruction in the right-sided colon were identified, and their data were analyzed. Stent insertion was attempted in 16 patients, and initial technical success was achieved in 14 patients (87.5 %). No stent-related immediate complications were reported. Complete relief from obstruction was achieved in all 14 patients. Twenty-five patients, including two patients who failed stenting, underwent emergency surgery. In the stent group, 93 % (13/14) of patients underwent elective laparoscopic surgery, and only one surgery was converted to an open procedure. All patients in the emergency group underwent emergency surgery within 24 h of admission. In the emergency group, only 12 % (3/25) of patients underwent laparoscopic surgery, with one surgery converted to an open procedure. All patients in both groups underwent either laparoscopy-assisted or open right/extended right hemicolectomy with primary anastomoses as the first operation. The operative times, retrieved lymph nodes, and pathologic stage did not differ between the two groups. Postoperative hospital stay (9.4 ± 3.4 days in the stent group vs. 12.4 ± 5.9 in the emergency group, p = 0.089) and time to resume oral food intake (3.2 ± 2.1 days in the stent group vs. 5.7 ± 3.4 in the emergency group, p = 0.019) were shorter in the stent group. And there were no significant differences in disease-free survival and overall survival between the two groups. Stent insertion appears to be safe and feasible in patients with right

  17. Bronchoscopic management of critical central airway obstruction by thyroid cancer: Combination airway stenting using tracheal and inverted-Y carinal self-expanding metallic stents

    PubMed Central

    Madan, Karan; Shrestha, Prajowl; Garg, Rakesh; Hadda, Vijay; Mohan, Anant; Guleria, Randeep

    2017-01-01

    Central airway obstruction (CAO) can result from various benign and malignant etiologies. Anaplastic thyroid cancer (ATC) is the most aggressive form of thyroid cancer. Rapid airway compromise is the main cause of death in ATC. We report a patient with ATC who presented with a large neck mass leading to CAO with long segment tracheal and right main bronchial compression and respiratory failure. Urgent Rigid Bronchoscopy was performed for airway stabilization and patient was managed with a combination airway stenting approach. A combination of self expanding, metallic, covered inverted Y and straight tracheal stents was used to stabilize the near complete airway structure. We herein highlight the role of therapeutic rigid bronchoscopy with airway stenting as an efficacious treatment modality for management of malignant CAO. PMID:28360477

  18. [The application of Y-shaped self-expandable covered metal stents in the thoracostomach-airway fistula: a single center, 11 years experience].

    PubMed

    Fang, Yi; Li, Tengfei; Han, Xinwei; Wu, Gang; Ren, Jianzhuang; Ren, Kewei; Lu, Huibin; Zhang, Quanhui; Li, Zongming

    2015-08-01

    To investigate the clinical feasibility and efficacy of Y-shaped self-expandable covered metal stents (Y-stents) in the management of thoracostomach-airway fistula. Retrospective analysis was performed for 108 patients treated for thoracostomach-airway fistula with Y-shaped self-expandable coated metal stents between April 2003 and October 2014. Y-stents were designed based on the dimensions of trachea and bronchus and sites of the fistula and then were inserted under DSA monitoring. There were 65 cases with single big Y-stent placement, 26 cases with single small Y-stent placement, 23 cases with double Y-stents placement, and 1 case with 3 Y-stents placement. Stent implantation was successfully accomplished with single manipulation in all patients. Complete occlusion of the fistula was obtained in 104 patients after the primary manipulation, and 4 patients required a secondary manipulation where a double Y-stents was inserted because of failure of primary manipulate. Ninety-two patients completed the follow-up , while 16 were lost. Fifty-nine patients died while 33 were alive with marked improvement in their quality of life. The placement of Y-stents can effectively occlude the thoracostomach-airway fistula in patients who had had the esophageal tumors resected. The technique is not only feasible but reliable to improve the quality of life of the patients.

  19. Comparison between gastrostomy feeding and self-expandable metal stent insertion for patients with esophageal cancer and dysphagia.

    PubMed

    Min, Yang Won; Jang, Eun Young; Jung, Ji Hey; Lee, Hyuk; Min, Byung-Hoon; Lee, Jun Haeng; Rhee, Poong-Lyul; Kim, Jae J

    2017-01-01

    Self-expandable metal stent (SEMS) insertion and percutaneous gastrostomy (PG) feeding are commonly used for patients with esophageal cancer and dysphagia. This study aimed to compare outcomes between SEMS insertion and PG feeding for them. We retrospectively analyzed 308 patients with esophageal cancer who underwent fully covered SEMS insertion (stent group) or PG (gastrostomy group) for dysphagia due to tumor. Patients with other causes of dysphagia, such as radiation-induced or postoperative stricture, were excluded from the study. Clinical outcomes were compared between the two groups, including overall survival and need for additional intervention and postprocedural nutritional status. At baseline, the stent group (n = 169) had more stage IV patients, less cervical cancers, and received radiotherapy and esophagectomy less often than the gastrostomy group (n = 64). The Kaplan-Meier curves showed higher overall survival in the gastrostomy group than in the stent group. Multivariate analysis revealed that PG was associated with better survival compared with SEMS insertion (hazard ratio 0.541, 95% confidence interval 0.346-0.848, p = 0.007). In addition, the gastrostomy group needed additional intervention less often (3.1% vs. 21.9%, p < 0.001) and experienced less decrease in serum albumin levels (-0.15 ± 0.56 g/dL vs. -0.39 ± 0.58 g/dL, p = 0.011) than the stent group after procedure. Our data suggested that, compared with SEMS insertion, PG is associated with better overall survival in patients with esophageal cancer and dysphagia. Stabilized nutritional status by PG may play a role in improving patient survival.

  20. A fully covered self-expandable metal stent anchored by a 10-Fr double pigtail plastic stent: an effective anti-migration technique

    PubMed Central

    Katsinelos, Panagiotis; Lazaraki, Georgia; Gkagkalis, Stergios; Chatzimavroudis, Grigoris; Anastasiadou, Kiriaki; Georgakis, Nikos; Giouleme, Olga; Zavos, Christos; Kountouras, Jannis

    2017-01-01

    Background Fully covered self-expandable metal stents (FCSEMS) have been used successfully in the treatment of malignant and benign biliary strictures. However, stent migration is a major complication. We investigated the efficacy of anchoring FCSEMS with a 10-Fr double-pigtail plastic stent to prevent migration in patients with biliary strictures. Methods Between January 2012 and May 2013, 10 patients with malignant biliary strictures and one patient with a suprapapillary benign biliary stenosis were enrolled in the study. The primary endpoint of the study was to record the migration rate of FCSEMS. Results The placement of FCSEMSs and the anchoring with a 10-Fr double-pigtail plastic stent were successful in all patients. During a median follow-up period of eight months, proximal or distal migration of FCSEMS was not observed. No procedural complications related to the placement of FCSEMS and/or the anchoring plastic stent were recorded. Conclusions The placement of an anchoring 10-Fr double-pigtail stent is a simple and effective anti-migration technique for FCSEMS in patients with malignant biliary strictures. PMID:28042247

  1. Risk factors for technical failure of endoscopic double self-expandable metallic stent placement by partial stent-in-stent method.

    PubMed

    Kawakubo, Kazumichi; Kawakami, Hiroshi; Toyokawa, Yoshihide; Otani, Koichi; Kuwatani, Masaki; Abe, Yoko; Kawahata, Shuhei; Kubo, Kimitoshi; Kubota, Yoshimasa; Sakamoto, Naoya

    2015-01-01

    Endoscopic double self-expandable metallic stent (SEMS) placement by the partial stent-in-stent (PSIS) method has been reported to be useful for the management of unresectable hilar malignant biliary obstruction. However, it is technically challenging, and the optimal SEMS for the procedure remains unknown. The aim of this study was to identify the risk factors for technical failure of endoscopic double SEMS placement for unresectable malignant hilar biliary obstruction (MHBO). Between December 2009 and May 2013, 50 consecutive patients with MHBO underwent endoscopic double SEMS placement by the PSIS method. We retrospectively evaluated the rate of successful double SEMS placement and identified the risk factors for technical failure. The technical success rate for double SEMS placement was 82.0% (95% confidence interval [CI]: 69.2-90.2). On univariate analysis, the rate of technical failure was high in patients with metastatic disease and unilateral placement. Multivariate analysis revealed that metastatic disease was a significant risk factor for technical failure (odds ratio: 9.63, 95% CI: 1.11-105.5). The subgroup analysis after double guidewire insertion showed that the rate of technical success was higher in the laser-cut type SEMS with a large mesh and thick delivery system than in the braided type SEMS with a small mesh and thick delivery system. Metastatic disease was a significant risk factor for technical failure of double SEMS placement for unresectable MHBO. The laser-cut type SEMS with a large mesh and thin delivery system might be preferable for the PSIS procedure. © 2014 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

  2. Analytical Models for Predicting Mechanical Properties of Self-Expandable Metal Stents with Cover Membrane

    DTIC Science & Technology

    2007-11-02

    compressed, it elongates in its longitudinal direction. Consider the deformation of parallelogram cell as shown in Fig. 4(A). When the points A, B, and...the cell maintains a parallelogram shape during compression. The length between A and B of uncompressed stent is N klL wireAB 0 sin2 β= (14...Expansive pressure- deformation curve for bare type stent. 8 10 12 14 16 0 4 8 12 16 Experiments Pbare Pcoat Pcoated stent

  3. Reocclusion after Self-Expandable Metallic Stent Placement for Relieving Malignant Colorectal Obstruction as a Palliative Treatment

    PubMed Central

    Nitta, Toshikatsu; Fujii, Kensuke; Hirata, Yoshimasa; Tominaga, Tomo; Inoue, Yoshihiro; Kawasaki, Hiroshi; Kawakami, Ken; Ishibashi, Takashi

    2016-01-01

    Self-expandable metallic stent (SEMS) placement has been practiced in several hospitals in Japan, including ours, since January 2012. Here, we report the case of an 82-year-old Japanese man who presented to the hospital with a 1-week history of right hypochondrial pain. Computed tomography (CT) findings indicated colorectal cancer. The laboratory findings on admission indicated severe anemia (red blood cell count, 426 × 104/μL; hemoglobin, 7.9 g/dL). We performed SEMS placement because the patient refused to undergo surgery. He did not attend any of the scheduled follow-up visits after SEMS placement. However, a year and a half after the SEMS placement, the patient attended the hospital because of difficulty in passing stool. A plain abdominal CT scan showed bowel reobstruction due to the ascending colon cancer after SEMS placement. We performed an emergency operation, ascending colostomy, on the same day. Colorectal stent placement may be a good treatment option for patients who refuse to undergo conventional therapeutic treatments or in those with unresectable colorectal cancer. Patients should be carefully followed up every few months after SEMS placement because of the risk of reocclusion. PMID:28100994

  4. Y-Shaped Bilateral Self-Expandable Metallic Stent Placement for Malignant Hilar Biliary Obstruction: Data from a Referral Center for Palliative Care

    PubMed Central

    Di Mitri, R.; Mocciaro, F.

    2014-01-01

    Background and Aim. Malignant hilar strictures are a clinical challenge because of the current therapeutic approach and the poor prognosis. In recent years, self-expandable metallic stents have proven more effective than plastic stents for palliation of malignant hilar strictures, with the bilateral stent-in-stent technique registering a high success rate. We report our experience with Y-shaped endoscopic self-expandable metallic stents placement for treatment of advanced malignant hilar strictures. Methods. From April 2009 to August 2012, we prospectively collected data on patients treated with Y-shaped SEMS placement for advanced malignant hilar carcinoma. Data on technical success, clinical success, and complications were collected. Results. Twenty patients (9 males) were treated (mean age 64.2 ± 15.3 years). The grade of malignant hilar strictures according to the Bismuth classification was II in 5 patients (25%), IIIa in 1 (5%), and IV in 14 (70%). The mean bilirubin level was 14.7 ± 4.9 mg/dL. Technical success was achieved in all patients, with a significant reduction in bilirubin levels (2.9 ± 1.7 mg/dL). One patient experienced cholangitis as early complication, while in 2 patients stent ingrowth was observed. No stents migration was recorded. There was no procedure-related mortality. At the end of the follow-up (7.1 ± 3.1 months), 13 of the 20 patients (65%) had died. Conclusions. Our experience confirms endoscopic bilateral self-expandable metallic stents placement with stent-in-stent technique (Y-shaped configuration) as a feasible, effective, and safe procedure for palliation of unresectable malignant hilar strictures. PMID:24790548

  5. Self-Expanding Metal Stents for Palliative Treatment of Superior Vena Caval Syndrome

    SciTech Connect

    Oudkerk, Matthijs; Kuijpers, Theodore J.A.

    1996-05-15

    Purpose: Two stent types (a new Wallstent and a Z-stent) were investigated in 30 patients with recurrent malignant superior vena caval syndrome (SVCS). Methods: Eligibility requirements were that the patient had recurrent symptoms after appropriate radiation therapy, chemotherapy, or both; {>=}75% of the vessel was occluded; and there was collateral flow. Because of the limited availability of stents, it was not possible to perform a prospectively randomized study. Results: In the Z-stent group (17 patients), occlusion of the stent due to acute thrombosis occurred within 12 hr in 4 patients (24%), but in the other 13 patients (76%) symptoms disappeared completely. After 2 weeks the cavogram in these patients showed no signs of thrombosis, and 12 (71%) of the patients remained symptom-free. There was partial occlusion in 5 patients (29%), without relevant clinical symptoms. Of the 13 patients who received Wallstents, only 1 had an acute immediate thrombosis (8%). Symptoms disappeared completely in the other 12 patients and no signs of thrombosis were seen. However, after 2 weeks complete stent occlusion with SVCS was found in 3 patients (23%) and partial occlusion with minor clinical symptoms in 6 (46%). Only 3 patients (23%) had complete relief of their SVCS. The difference between the rates of occlusion of the two stents after 2 weeks was highly significant (p= 0.008). Conclusions: The overall clinical success rate for long-term patency was 100% for the Z-stents and 69% for the new Wallstent. These results suggest that when used for this purpose, the new Wallstent is more thrombogenic at 2 weeks than the Z-stent.

  6. Primary patency of percutaneously inserted self-expanding metallic stents in patients with malignant biliary obstruction

    PubMed Central

    Dahlstrand, Ursula; Sandblom, Gabriel; Eriksson, Lars-Gunnar; Nyman, Rickard

    2009-01-01

    Background: Effective bile duct drainage is crucial to the health-related quality of life of patients with jaundice caused by obstruction of the bile duct by inoperable malignant tumours. Methods: All patients who were treated at Uppsala University Hospital, Sweden with percutaneous stenting between 2000 and 2005 were identified retrospectively. Data on the location of the obstruction and type of stent used, date and cause of death and date of stent failure were abstracted from the patients' notes. Stent patency was defined as the duration from the insertion of the stent to the date of failure. In cases in which the cause of death was directly related to failure of the stent, the date of death was defined as the patency endpoint. Results: A total of 64 patients (34 women, 30 men) were identified. Their mean age was 71 years (standard deviation 11 years). The median length of patency was 11.4 months. Stent diameter >10 mm and distal stricture were found to be associated with significantly longer patency time in univariate Cox proportional hazard analysis. In multivariate Cox proportional hazard analysis, only location of the stricture was found to be independently and significantly associated with patency time. Discussion: Percutaneous stenting is a good alternative for patients with obstructive jaundice and a life expectancy ≤1 year. It may give instant relief from the symptoms associated with jaundice. Patency time may be prolonged by using stents with a diameter ≥10 mm. However, patency time was found to be lower for hilar tumours. PMID:19718365

  7. Self-expanding metal stents for the palliation of malignant gastric outlet obstruction in patients with peritoneal carcinomatosis

    PubMed Central

    Rademacher, Christoph; Bechtler, Matthias; Schneider, Steffen; Hartmann, Bettina; Striegel, Johannes; Jakobs, Ralf

    2016-01-01

    AIM To evaluate the efficacy of self-expanding metal stents (SEMS) for the palliation of malignant gastric outlet obstruction in patients with and without peritoneal carcinomatosis (PC). METHODS We performed a retrospective analysis of 62 patients who underwent SEMS placement for treatment of malignant gastroduodenal obstruction at our hospital over a six-year period. Stents were deployed through the scope under combined fluoroscopic and endoscopic guidance. Technical success was defined as successful stent placement and expansion. Clinical success was defined as an improvement in the obstructive symptoms and discharge from hospital without additional parenteral nutrition. According to carcinomatosis status, patients were assigned into groups with or without evidence of peritoneal disease. RESULTS In most cases, obstruction was caused by pancreatic (47%) or gastric cancer (23%). Technical success was achieved in 96.8% (60/62), clinical success in 79% (49/62) of all patients. Signs of carcinomatosis were identified in 27 patients (43.5%). The diagnosis was confirmed by pathology or previous operation in 7 patients (11.2%) and suspected by CT, MRI or ultrasound in 20 patients (32.2%). Presence of carcinomatosis was associated with a significantly lower clinical success rate compared to patients with no evidence of peritoneal disease (66.7% vs 88.6%, P = 0.036). There was no significant difference in overall survival between patients with or without PC (median 48 d vs 70 d, P = 0.21), but patients showed significantly longer survival after clinical success of SEMS placement compared to those experiencing clinical failure (median 14.5 d vs 75 d, P = 0.0003). CONCLUSION Given the limited therapeutic options and a clinical success rate of at least 66.7%, we believe that SEMS are a reasonable treatment option in patients with malignant gastric outlet obstruction with peritoneal carcinomatosis. PMID:27920476

  8. Salvage therapy using self-expandable metal stents for recalcitrant anastomotic strictures after living-donor liver transplantation

    PubMed Central

    Jang, Sung Ill; Sung, Se Yong; Park, Hyunsung; Lee, Kwang-Hun; Joo, Seung-Moon; Lee, Dong Ki

    2017-01-01

    Background: Recently, there has been an increase in clinical success rates using nonsurgical methods to resolve anastomotic biliary strictures (ABSs) that develop after liver transplantation (LT). However, some strictures are particularly refractory and cannot be completely resolved by an endoscopic or percutaneous procedure. Consequently, the aim of this study was to examine the feasibility and efficacy of using a newly designed fully covered self-expandable metal stent (FCSEMS) to resolve refractory ABS. Methods: A total of 35 patients with an ABS that developed after LT, but could not be resolved by an endoscopic or percutaneous procedure, were included in this study. FCSEMSs were positioned endoscopically and removed after 2–3 months. After stent removal, the patients were followed to assess complications, including re-stenosis. Results: The mean period from LT to stricture was 13.7 months, and the mean duration of the stricture was 31.8 months. The type and mean number of procedures previously attempted were endoscopic retrograde cholangiopancreatography (ERCP) (9.1 ± 5.1) in 19 patients and percutaneous transhepatic biliary drainage (9.2 ± 4.8) in 16 patients. All patients had successful FCSEMS insertions and removals; the mean stent indwelling time was 3.2 months. The mean follow-up period was 18.7 months (range: 6.4–37.8 months). Stricture recurrence was observed in 6 of 29 patients (recurrence rate: 20.7%). The anastomotic stricture resolved with the FCSEMS insertion in 29 of 35 patients (clinical success rate: 82.9%). Conclusions: The newly designed FCSEMS is a potentially feasible and effective treatment for anastomotic strictures that develop after LT but are not amenable to treatment by conventional procedures. PMID:28246547

  9. Antireflux versus conventional self-expanding metallic Stents (SEMS) for distal esophageal cancer: results of a multicenter randomized trial

    PubMed Central

    Coron, E.; David, G.; Lecleire, S.; Jacques, J.; Le Sidaner, A.; Barrioz, T.; Coumaros, D.; Volteau, C.; Vedrenne, B.; Bichard, P.; Boustière, C.; Touchefeu, Y.; Brégeon, J.; Prat, F.; Le Rhun, M.

    2016-01-01

    Introduction: Self-expanding metal stents (SEMS) are commonly used in the palliation of dysphagia in patients with inoperable esophageal carcinoma. However, they predispose to gastroesophageal reflux when deployed across the gastroesophageal junction. The aims of this study were to: 1) assess the influence of the antireflux valve on trans-prosthetic reflux (primary outcome); and 2) compare the results of SEMS with and without antireflux valve in terms of reflux symptoms, quality of life (QOL), improvement of dysphagia and adverse events (secondary outcomes). Patients and methods: Thirty-eight patients were enrolled in nine centers. Carcinomas were locally advanced (47 %) or metastatic. After randomization, patients received either a covered SEMS with antireflux valve (n = 20) or a similar type of SEMS with no antireflux device but assigned to standard proton pump inhibitor therapy and postural advice (n = 18). Trans-prosthetic reflux was assessed at day 2 using a radiological score based on barium esophagography performed after Trendelenburg maneuver and graded from 0 (no reflux) to 12 (maximum). Monthly telephone interviews were conducted for Organisation Mondiale de la Santé (OMS) scoring from 0 (excellent) to 5 (poor), QOL assessment (based on the Reflux-Qual Simplifié scoring system) from 0 (poor) to 100 (excellent), dysphagia scoring from 0 (no dysphagia) to 5 (complete dysphagia) and regurgitation scoring from 0 (no regurgitation) to 16 (maximum). Results: No difference was noted in terms of age, sex, size of lesion, prosthesis length or need for dilation prior to SEMS placement. No difficulty in placing SEMS nor complications were noted. Radiological scores of reflux were found to be significantly lower in patients with an antireflux stent compared to the conventional stent and associated measures. The regurgitation scores were significantly decreased in patients with antireflux stents during the first 2 months after stent placement and

  10. Plastic vs. Self-Expandable Metal Stents for Palliation in Malignant Biliary Obstruction: A Series of Meta-Analyses.

    PubMed

    Almadi, Majid A; Barkun, Alan; Martel, Myriam

    2017-02-01

    Self-expandable metal stents (SEMS) are thought to have an advantage over plastic stents in achieving biliary drainage. We performed a systematic search of MEDLINE, EMBASE, Scopus, CENTRAL, and ISI Web of knowledge databases, from January 1980 to September 2015, for randomized-controlled trials (RCTs) comparing SEMS vs. plastic stents in the palliation of malignant biliary obstruction. Primary outcomes were durations of stent patency, patient survival, and 30-day mortality. Numerous secondary outcomes were assessed, and extensive sensitivity and subgroup analyses were performed. In all, 20 RCTs totaling 1,713 patients yielded a weighted mean difference (WMD) in time to stent patency (4 studies) of 4.45 months (95% confidence interval (CI), 0.31, 8.59; GRADE=moderate) favoring SEMS. There were no differences in overall patient survival (5 studies) WMD=0.67 months (95% CI, -0.66, 1.99; GRADE=moderate), or 30-day mortality (8 studies) odds ratio (OR)=0.80 (95% CI, 0.52, 1.24; GRADE=moderate) but there was a higher symptom-free survival at 6 months (4 studies) OR=5.96 (95% CI, 1.71, 20.81; GRADE=moderate). SEMS use resulted in lower rates of late complications (11 studies) OR=0.43 (95% CI, 0.26, 0.71; GRADE=moderate), sepsis or cholangitis (14 studies) OR=0.53 (95% CI, 0.37, 0.77; GRADE=high), blocking from sludge (8 studies) OR=0.11(95% CI, 0.07, 0.17; GRADE=moderate), and mean number of re-interventions (8 studies) WMD=-0.83 interventions (95% CI, -1.64, -0.02; GRADE=moderate). There was a longer patency of SEMS for those without a prior drainage attempt (2 studies) WMD 7.70 months (95% CI, 7.14, 8.25; GRADE=high). Although a survival advantage was found when an uncovered SEMS was used (3 studies) WMD 1.31 months (95% CI, 0.30, 2.32; GRADE=high), but not partially or fully covered SEMS (2 studies) WMD -0.66 months (95% CI, -1.02, -0.30; GRADE=high) vs. plastic stents, and for SEMS in the setting of pre- or post-procedural antibiotic administration (2 studies) WMD 1

  11. Fully covered, self-expandable metal stents for first-step endoscopic treatment of biliary leaks secondary to hepato-biliary surgery: a retrospective study.

    PubMed

    Mangiavillano, Benedetto; Luigiano, Carmelo; Tarantino, Ilaria; Barresi, Luca; Dinelli, Marco; Frego, Roberto; Bassi, Marco; Fabbri, Carlo; Cennamo, Vincenzo; Viaggi, Paolo; Traina, Mario; Santoro, Tara; Masci, Enzo

    2013-05-01

    Fully covered self-expanding metal stents are now being used to treat benign biliary diseases. To assess the outcomes of these stents as first-step therapy in patients with biliary leaks secondary to hepato-biliary surgery. Thirty patients (56.7% males; mean age: 60.2 ± 13 years) were retrospectively evaluated. The data collected included technical and clinical success, adverse events and follow-up findings (1, 3 and 6 months). Technical and clinical success rates were 100%. One early mild post-procedure pancreatitis occurred and resolved spontaneously. Three late stent distal migrations occurred, however cholangiography showed correct leak sealing in all patients. Stents were removed after a mean of 55.9 days. During follow-up no other complications occurred. In our experience fully covered self-expanding metal stent placement was safe and efficacious as first-step therapy for post-operative biliary leaks. However, prospective comparative studies with plastic stents are required to validate these findings. Copyright © 2012 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  12. Placement of a new fully covered self-expanding metal stent for postoperative biliary strictures and leaks not responding to plastic stenting.

    PubMed

    Luigiano, Carmelo; Bassi, Marco; Ferrara, Francesco; Fabbri, Carlo; Ghersi, Stefania; Morace, Carmela; Consolo, Pierluigi; Maimone, Antonella; Galluccio, Gabriella; D'Imperio, Nicola; Cennamo, Vincenzo

    2013-04-01

    Fully covered self-expanding metal stents (FCSEMSs) are now being used to treat postoperative biliary strictures (BSs) and biliary leaks (BLs). The aim of this study was to assess the safety and effectiveness of a new FCSEMS (Wallflex) in patients with postoperative BSs and BLs after failure of traditional endoscopic treatment. Between January 2010 and December 2011, 16 patients (10 patients with postcholecystectomy BSs, 4 with postcholecystectomy BLs, and 2 with postorthotopic liver transplantation BSs) were enrolled. The technical and clinical success rate was 100%. All FCSEMSs were removed after a mean of 141 days. Complications occurred in 7 cases: 2 postprocedure pain, 2 mild pancreatitis, 1 early distal, and 2 late proximal FCSEMS migration. The overall long-term clinical success rate was 94% after a mean follow-up of 13 months. In our experience, the placement of FCSEMSs is an effective and secure method of treating refractory postoperative BSs or BLs.

  13. Comparison of covered and uncovered self-expandable stents in the treatment of malignant biliary obstruction.

    PubMed

    Flores Carmona, Diana Yamel; Alonso Lárraga, Juan Octavio; Hernández Guerrero, Angélica; Ramírez Solís, Mauro Eduardo

    2016-05-01

    Drainage with metallic stents is the treatment of choice in malignant obstructive jaundice. Technical and clinical success with metallic stents is obtained in over 90% and 80% of cases, respectively. There are self-expandable metallic stents designed to increase permeability. The aim of this study was to describe the results obtained with totally covered self-expandable and uncovered self-expandable metallic stents in the palliative treatment of malignant biliary obstruction. Sixty eight patients with malignant obstructive jaundice secondary to pancreatobiliary or metastatic disease not amenable to surgery were retrospectively included. Two groups were created: group A (covered self-expandable metallic stents) (n = 22) and group B (uncovered self-expandable metallic stents) (n = 46). Serum total bilirubin, direct bilirubin, alkaline phosphatase and gamma glutamyl transferase levels decreased in both groups and no statistically significant difference was detected (p = 0.800, p = 0.190, p = 0.743, p = 0.521). Migration was greater with covered stents but it was not statistically significant either (p = 0.101). Obstruction was greater in the group with uncovered stents but it was not statistically significant either (p = 0.476). There are no differences when using covered self-expandable stents or uncovered self-expandable stents in terms of technical and clinical success or complications in the palliative treatment of malignant obstructive jaundice.

  14. SU-E-T-115: Dose Perturbation Study of Self-Expandable Metal and Polyester Esophageal Stents in Proton Therapy Beams

    SciTech Connect

    Lee, S; Li, Z; Jalaj, S; McGaw, C; B K, John; J S, Scolapio; J C, Munoz

    2014-06-01

    Purpose: This work investigates dose perturbations due to Self-expandable metal and polyester esophageal stents undergoing proton radiotherapy for esophageal cancer. Methods: Five commercially available esophageal stents made of nitinol (Evolution, Wallflex and Ultraflex), stainless steel (Z-Stent) and polyester (Polyflex) were tested. Radiochromic film (GafChromic EBT3 film, Ashland, Covington, KY) wrapped around a stent and a 12cc syringe was irradiated with 2CGE (Cobalt Gray Equivalent) of proton beam in a custom fabricated acrylic phantom. An air-hollow syringe simulates the esophagus. Results: The Z-stent created the largest dose perturbations ranges from -14.5% to 6.1% due to the steel composition. The WallFlex, Evolution and Ultraflex stents produced the dose perturbation ranges of (−9.2%∼8.6%), (−6.8%∼5.7%) and (−6.2%∼6.2%), respectively. The PolyFlex stent contains the radiopaque tungsten markers located top, middle and bottom portions. When the focal cold spots induced by the markers were excluded in the analysis, the dose perturbation range was changed from (−11.6%∼6.4%) to (−0.6%∼5.0%). Conclusion: The magnitude of dose perturbation is related to material of a metallic stent. The non-metallic stent such as PolyFlex shows relatively lower dose perturbation than metallic stents except a radiopaque marker region. Overall Evolution and Ultraflex stent appear to be less dose perturbations. The largest dose perturbations (cold spots) were located at both edges of stents in distal area for the single proton beam irradiation study. The analysis of more than two proton beam which is more typical clinical beam arrangement would be necessary to minimize the doe perturbation effect in proton ratiotherapy.

  15. Efficacy and safety of limited endoscopic sphincterotomy before self-expandable metal stent insertion for malignant biliary obstruction

    PubMed Central

    Nam, Hyeong Seok; Kang, Dae Hwan; Kim, Hyung Wook; Choi, Cheol Woong; Park, Su Bum; Kim, Su Jin; Ryu, Dae Gon

    2017-01-01

    AIM To evaluate the safety and efficacy of limited endoscopic sphincterotomy (ES) before placement of self-expandable metal stent (SEMS). METHODS This was a retrospective analysis of 244 consecutive patients with unresectable malignant biliary obstruction, who underwent placement of SEMSs following limited ES from December 2008 to February 2015. The diagnosis of malignant biliary obstruction and assessment of patient eligibility for the study was established by a combination of clinical findings, laboratory investigations, imaging and pathological results. All patients were monitored in the hospital for at least 24 h following endoscopic retrograde cholangio pancreatography (ERCP). The incidence of immediate or early post-ERCP complications such as post-ERCP pancreatitis (PEP) and bleeding related to limited ES were considered as primary outcomes. Also, characteristics and complications according to the cancer type were classified. RESULTS Among the 244 patients included, the underlying diagnosis was cholangiocarcinoma in 118 patients, pancreatic cancer in 79, and non-pancreatic or non-biliary malignancies in the remaining 47 patients. Early post-ERCP complications occurred in 9 patients (3.7%), with PEP in 7 patients (2.9%; mild, 6; moderate, 1) and mild bleeding in 2 patients (0.8%). There was no significant association between the incidence of post-ERCP complications and the type of malignancy (cholangiocarcinoma vs pancreatic cancer vs others, P = 0.696) or the type of SEMS used (uncovered vs covered, P = 1.000). Patients who had more than one SEMS placed at the first instance were at a significantly higher risk of post-ERCP complications (one SEMS vs two SEMS, P = 0.031). No other factors were predictive of post-ERCP complications. CONCLUSION Limited ES is feasible and safe, and effectively facilitates the placement of SEMS, without any significant risk of PEP or severe bleeding. PMID:28321164

  16. A US Multicenter Study of Safety and Efficacy of Fully Covered Self-Expandable Metallic Stents in Benign Extrahepatic Biliary Strictures.

    PubMed

    Saxena, Payal; Diehl, David L; Kumbhari, Vivek; Shieh, Frederick; Buscaglia, Jonathan M; Sze, Wilson; Kapoor, Sumit; Komanduri, Srinadh; Nasr, John; Shin, Eun Ji; Singh, Vikesh; Lennon, Anne Marie; Kalloo, Anthony N; Khashab, Mouen A

    2015-11-01

    Endoscopic therapy is considered first line for management of benign biliary strictures (BBSs). Placement of plastic stents has been effective but limited by their short-term patency and need for repeated procedures. Fully covered self-expandable metallic stents (FCSEMSs) offer longer-lasting biliary drainage without the need for frequent exchanges. The aim of this study was to assess the efficacy and safety of FCSEMS in patients with BBS. A retrospective review of all patients who underwent ERCP and FCSEMS placement at five tertiary referral US hospitals was performed. Stricture resolution and adverse events related to ERCP and/or stenting were recorded. A total of 123 patients underwent FCSEMS placement for BBS and 112 underwent a subsequent follow-up ERCP. The mean age was 62 years (±15.6), and 57% were males. Stricture resolution occurred in 81% of patients after a mean of 1.2 stenting procedures (mean stent dwell time 24.4 ± 2.3 weeks), with a mean follow-up of 18.5 months. Stricture recurrence occurred in 5 patients, and 3 patients required surgery for treatment of refractory strictures. Stent migration (9.7%) was the most common complication, followed by stent occlusion (4.9%), cholangitis (4.1%), and pancreatitis (3.3%). There was one case of stent fracture during removal, and one stent could not be removed. There was one death due to cholangitis. Majority of BBS can be successfully managed with 1-2 consecutive FCSEMS with stent dwell time of 6 months.

  17. Endoscopic radiofrequency ablation combined with fully covered self-expandable metal stent for inoperable periampullary carcinoma in a liver transplant patient

    PubMed Central

    Tian, Qing; Wang, Guijie; Zhang, Yamin; Jin, Yan; Cui, Zilin; Sun, Xiaoye; Shen, Zhongyang

    2017-01-01

    Abstract Rationale: Postliver transplant periampullary carcinoma is an extremely uncommon disease. Patient concerns: Cutaneous jaundice in a patient who had received a liver transplant 4 years earlier. Diagnosis: Periampullary carcinoma. Interventions: Radiofrequency ablation plus fully covered self-expanding metal stents (FCSEMS). Outcomes: The treatment of malignant neoplasm of the ampulla of Vater is the patient by radiofrequency ablation plus FCSEMS placement was successful. No complications occurred. Lessons: This is the first reported case of a liver transplant patient with inoperable periampullary carcinoma successfully treated by radiofrequency ablation plus FCSEMS placement. Our experience will be useful to other surgeons in managing similar patients in the future. PMID:28151854

  18. The use of a self-expandable stent with a self-expandable stent graft in a Fontan baffle.

    PubMed

    Choi, Eun Young; Lee, Kyung Suk; Song, Jin-young

    2013-02-01

    Intravascular or intracardiac stenosis occurs in various congenital heart diseases or after surgical repair. Although balloon angioplasty is the first option for relieving stenosis, frequently restenosis occurs because of elastic recoil or kingking component. The use of a self-expandable stent and covered stent in congenital heart disease has been reported for selected cases. In general, they have been performed for coarctation of the aorta or aortic aneurysm. We now report successful implantation of a self-expandable stent with a self-expandable covered stent graft in a case of lateral tunnel dehiscence with stenosis after a Fontan operation.

  19. Self-expanding metallic stent as a bridge to surgery in the treatment of left colon cancer obstruction: Cost-benefit analysis and oncologic results.

    PubMed

    Flor-Lorente, Blas; Báguena, Gloria; Frasson, Matteo; García-Granero, Alvaro; Cervantes, Andrés; Sanchiz, Vicente; Peña, Andres; Espí, Alejandro; Esclapez, Pedro; García-Granero, Eduardo

    2017-03-01

    The use of a self-expanding metallic stent as a bridge to surgery in acute malignant left colonic obstruction has been suggested as an alternative treatment to emergency surgery. The aim of the present study was to compare the morbi-mortality, cost-benefit and long-term oncological outcomes of both therapeutic options. This is a prospective, comparative, controlled, non-randomized study (2005-2010) performed in a specialized unit. The study included 82 patients with left colon cancer obstruction treated by stent as a bridge to surgery (n=27) or emergency surgery (n=55) operated with local curative intention. The main outcome measures (postoperative morbi-mortaliy, cost-benefit, stoma rate and long-term oncological outcomes) were compared based on an "intention-to-treat" analysis. There were no significant statistical differences between the two groups in terms of preoperative data and tumor characteristics. The technically successful stenting rate was 88.9% (11.1% perforation during stent placement) and clinical success was 81.4%. No difference was observed in postoperative morbi-mortality rates. The primary anastomosis rate was higher in the bridge to surgery group compared to the emergency surgery group (77.8% vs. 56.4%; P=.05). The mean costs in the emergency surgery group resulted to be €1,391.9 more expensive per patient than in the bridge to surgery group. There was no significant statistical difference in oncological long-term outcomes. The use of self-expanding metalllic stents as a bridge to surgery is a safe option in the urgent treatment of obstructive left colon cancer, with similar short and long-term results compared to direct surgery, inferior mean costs and a higher rate of primary anastomosis. Copyright © 2017 AEC. Publicado por Elsevier España, S.L.U. All rights reserved.

  20. Multicenter trial evaluating the use of covered self-expanding metal stents in benign biliary strictures: time to revisit our therapeutic options?

    PubMed

    Kahaleh, Michel; Brijbassie, Alan; Sethi, Amrita; Degaetani, Marisa; Poneros, John M; Loren, David E; Kowalski, Thomas E; Sejpal, Divyesh V; Patel, Sandeep; Rosenkranz, Laura; McNamara, Kevin N; Raijman, Isaac; Talreja, Jayant P; Gaidhane, Monica; Sauer, Bryan G; Stevens, Peter D

    2013-09-01

    Covered self-expanding metal stents are being used more frequently in benign biliary strictures (BBS). We report the results of a multicenter study with fully covered self-expanding metal stent (FCSEMS) placement for the management of BBS. : To prospectively evaluate the efficacy and safety of FCSEMS in the management of BBS. Patients with BBS from 6 tertiary care centers who received FCSEMS with flared ends between April 2009 and October 2010 were included in this retrospective study.Efficacy was measured after removal of FCSEMS by evaluating stricture resolution on the basis of symptom resolution, imaging, laboratory studies, and/or choledochoscopy at removal. Safety profile was evaluated by assessing postprocedural complications. A total of 133 patients (78, 58.6% males) with a mean age of 59.2±14.8 years with BBS received stents. Of the 133 stents placed, 97 (72.9%) were removed after a mean stent duration of 95.5±48.7 days. Stricture resolution after FCSEMS removal was as follows: postsurgical, 11/12 (91.6%); gallstone-related disease, 16/19 (84.2%); chronic pancreatitis, 26/31 (80.7%); other etiology, 4/5 (80.0%); and anastomotic strictures, 19/31(61.2%). Ninety-four patients were included in the logistic regression analyses. Patients who had indwelling stents for >90 days were 4.3 times more likely to have resolved strictures [odds ratio, 4.3 (95% confidence interval, 1.24-15.09)] and patients with nonmigrated stents were 5.4 times more likely to have resolved strictures [odds ratio, 5.4 (95% confidence interval, 1.001-29.29)]. FCSEMS for BBS had an acceptable rate of stricture resolution for postsurgical strictures, gallstone-related strictures, and those due to chronic pancreatitis. Predictors for stricture resolution include longer indwell time and absence of migration. Further study is warranted to assess long-term efficacy in a prospective manner with longer than 3-month time of stent indwelling time.

  1. Safety and efficacy of palliative systemic chemotherapy combined with colorectal self-expandable metallic stents in advanced colorectal cancer: A multicenter study.

    PubMed

    Cézé, Nicolas; Charachon, Antoine; Locher, Christophe; Aparicio, Thomas; Mitry, Emmanuel; Barbieux, Jean-Pierre; Landi, Bruno; Dorval, Etienne; Moussata, Driffa; Lecomte, Thierry

    2016-04-01

    Self-expandable metallic stent (SEMS) placement is an accepted palliative therapy for management of acute malignant bowel obstruction in advanced colorectal cancer. Nevertheless, data are lacking on the effects of systemic chemotherapy combined with colorectal SEMS. The aim of this study was to investigate the safety and efficacy of palliative chemotherapy for advanced colorectal cancer combined with colorectal SEMS placement. This multicentre retrospective study included all consecutive advanced colorectal cancer patients who received first-line palliative chemotherapy combined with endoscopic stenting for colorectal cancer with obstruction. We analyzed the number of cycles and the type of combination used. The primary endpoint was overall survival. Secondary endpoints included progression-free survival, response rate, grade 3-4 toxicity and the outcomes of SEMS for malignant colorectal obstruction. A total of 38 patients were included. Among them, 25 patients received oxaliplatin and 5-fluorouracil combination chemotherapy. Objective response and stabilization occurred in 38 and 24% of patients, respectively. The median overall survival and progression-free survival from the start of chemotherapy were 18 and 5months, respectively. The objective response rate and overall disease control rate were 38 and 62%, respectively. Toxicity was generally acceptable. Major complications related to stenting included perforation (8%), stent migration (5%), and reobstruction secondary to tumor ingrowths (13%). Chemotherapy combined with colonic stenting as a first-line treatment seems to be a valid option in advanced colorectal cancer patients with malignant colorectal obstruction. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  2. Evolution of patency rates of self-expandable bare metal stents for endovascular treatment of femoro-popliteal arterial occlusive disease: Does stent design matter?

    PubMed

    Treitl, Karla Maria; Woerner, Benedikt; Schinner, Regina; Czihal, Michael; Notohamiprodjo, Susan; Hoffmann, Ulrich; Treitl, Marcus

    2017-09-01

    To analyse the patency rates of femoro-popliteal stenting with different self-expandable Nitinol stent-designs. Two hundred and twenty-two patients (142 (64%) male; age 72.4 ± 11.6 years) with symptomatic femoro-popliteal peripheral arterial occlusive disease (PAOD) underwent percutaneous transluminal angioplasty (PTA) and stenting with three different Nitinol stents (interwoven IW: n = 70; closed-cell CC: n = 85; open-cell OC: n = 67). One-year post-procedural target lesion revascularization (TLR_12M) rates were investigated with regard to co-morbidities: diabetes (DBM), hyperlipidaemia (HLP), hypertension (RR), coronary artery disease (CAD) and degree of calcification. Twelve-month follow-up data were available for 60, 69 and 50 patients in the IW, OC and CC groups (179 patients in total). The cumulative patency (IW: 52 (86.7%); OC: 50 (72.5%); CC: 23 (46.0%); P < 0.001) and the TLR_12M rates (IW: 8 (13.3%); OC: 19 (27.5%); CC: 27 (54.0%); P < 0.001) differed significantly, as did the subgroup analyses (DBM: P = 0.05; RR: P = 0.003; HLP: P = 0.005; CAD: P = 0.02; localization: P < 0.001; calcification: P < 0.001), with the best patency for the IW stent and the highest TLR_12M for the CC stent. The interwoven stent-design was superior to the standard open- and closed-cell stent-designs in endovascular treatment of femoro-popliteal PAOD in a follow-up period of 12 months. • Results of femoro-popliteal stenting are still unsatisfactory. • Comparative studies for currently available different Nitinol stent-designs are lacking. • This is a first comparative study on long-term patency of different Nitinol stent-designs. • Interwoven stent-design leads to improved long-term patency. • Interwoven stent-design leads to lower TLR than other stent-designs.

  3. Self-expanding metal stents (SEMS) for preoperative biliary decompression in patients with resectable and borderline-resectable pancreatic cancer: outcomes in 241 patients.

    PubMed

    Siddiqui, Ali A; Mehendiratta, Vaibhav; Loren, David; Kowalski, Thomas; Fang, John; Hilden, Kristen; Adler, Douglas G

    2013-06-01

    Obstructive jaundice caused by distal biliary obstruction can present in up to 70 % of patients with localized cancer of the head of the pancreas. The aim of this study was to report our experience in using self-expanding metal stents (SEMS) for preoperative biliary decompression in patients with resectable and borderline resectable carcinoma of the pancreatic head. We performed a retrospective study evaluating patients from two tertiary referral centers. Two-hundred and forty-one patients with resectable and borderline resectable pancreatic carcinoma underwent ERCP with metal biliary stent placement between September 2006 and August 2011. We assessed the effectiveness of SEMS to adequately decompress the biliary tree, procedural success, patient survival, stent patency, and stent-related complications. Two-hundred and forty-one patients were evaluated [123 male, mean age (± SD) 67.4 ± 9.8 years; resectable 174, borderline resectable 67]. Patients with borderline-resectable cancer underwent neoadjuvant therapy and restaging before possible curative surgery. Successful placement of a metal biliary stent was achieved in all patients and improved jaundice. Patients were followed for mean duration of 6.3 months. The overall survival was 49 % at 27 months. Fourteen (5.8 %) patients experienced stent occlusion; the mean time to stent occlusion was 6.6 (range 1-20) months. Immediate complications included: post-ERCP pancreatitis (n = 14), stent migration (n = 3), and duodenal perforation (n = 3). Long-term complications included stent migration (n = 9) and hepatic abscess (n = 1). A total of 144/174 patients deemed to have resectable cancer at time of diagnosis underwent curative surgery. Due to disease progression or the discovery of metastasis after neoadjuvant therapy, only 22/67 patients with borderline-resectable cancer underwent curative surgery. SEMS should be considered for patients with obstructive jaundice and resectable or borderline resectable pancreatic

  4. [Results of the upper digestive tract stenting with self-expanding stents].

    PubMed

    Fedorov, A G; Davydova, S V; Klimov, A E; Lebedev, N V

    2013-01-01

    The work is based on the analysis of the palliative treatment of 66 patients with malignant upper digestive tract obstruction who underwent implantation of 75 self-expanding metallic stents in the period of 2003-2012 yy. Early postoperative complications developed in 10 (15.2%) cases. Procedure-related complications were observed in 8 (12.1%) patients, non-specific complications occurred in 2 (3.0%) patients. In-hospital lethality was 4.5% (3 patients). 51 patients were followed until death. Symptomatic relapse of obstruction was observed in 4 cases. Median survival was 97 days. Stenting with self-expanding metal stents was concluded to be an effective and safe method of palliation of malignant upper digestive tract stenosis.

  5. Correction: Prospective pilot study of fully covered self-expandable metal stents for refractory benign pancreatic duct strictures: long-term outcomes

    PubMed Central

    Matsubara, Saburo; Sasahira, Naoki; Isayama, Hiroyuki; Takahara, Naminatsu; Mizuno, Suguru; Kogure, Hirofumi; Yamamoto, Natsuyo; Nakai, Yousuke; Tada, Minoru; Koike, Kazuhiko

    2016-01-01

    Background and study aims: Background and study aims: Temporary placement of a fully covered self-expandable metal stent (FCSEMS) has recently emerged as a treatment option for pancreatic duct strictures due to chronic pancreatitis refractory to conventional plastic stenting. However, there are no data about long-term outcomes with this therapeutic option. The aims of the current study were to estimate the feasibility, safety, efficacy, and long-term outcomes of temporary FCSEMS placement for refractory pancreatic duct strictures. Patients and methods: This was a prospective, single-center feasibility study. Ten patients with refractory pancreatic duct strictures due to chronic pancreatitis underwent FCSEMS placement for 3 months. We evaluated the rate of recurrent symptoms after stent removal during long-term follow-up, as well as adverse events (AEs). Results: Two patients required early (within 1 week) stent removal because of intolerable pain or pancreatitis. In the remaining 8 patients, the recurrence rate of any symptoms after FCSEMS removal was 63% during 35 months of follow up. The causes of recurrent symptoms were as follows: recurrence of stricture in 2; stent-induced stricture in 1; impaction of pancreatic stones in 1; and development of a pseudocyst in 1. When limited to stricture, the recurrence rate was 38%. Additional endoscopic treatments were required in 4 patients: a second FCSEMS placement in 1; plastic stent (PS) placement in 1; stone extraction in 1; and endoscopic ultrasound–guided pseudocyst drainage in 1. Asymptomatic stent migration occurred in 2 patients. Suppurative pancreatic ductitis due to food impaction in the FCSEMS occurred in 2 patients, and endoscopic pancreatic duct drainage was performed. Stent-induced ductal changes developed in 2 patients and PS treatment was required in 1 patient for pain relief. Conclusion: The FCSEMS appears to be a feasible and potentially effective option for the management of refractory pancreatic duct

  6. The New Nitinol Conformable Self-Expandable Metal Stents for Malignant Colonic Obstruction: A Pilot Experience as Bridge to Surgery Treatment

    PubMed Central

    2014-01-01

    Introduction. Self-expandable metal stents (SEMS) are a nonsurgical option for treatment of malignant colorectal obstruction also as a bridge to surgery approach. The new nitinol conformable stent has improved clinical outcomes in these kinds of patients. We report a pilot experience with nitinol conformable SEMS placement as bridge to surgery treatment in patients with colorectal obstruction. Materials and Methods. Between April and August 2012, we collected data on colonic nitinol conformable SEMS placement in a cohort of consecutive symptomatic patients, with malignant colorectal obstruction, who were treated as a bridge to surgery. Technical success, clinical success, and adverse events were recorded. Results. Ten patients (7 male (70%)), with a mean age of 69.2 ± 10.1, were evaluated. The mean length of the stenosis was 3.6 ± 0.6 cm. Five patients (50%) were treated on an emergency basis. The median time from stent placement to surgery was 16 days (interquartile range 7–21). Technical and clinical success was achieved in all patients with a significant early improvement of symptoms. No adverse events due to the SEMS placement were observed. Conclusion. This pilot study confirmed the important role of nitinol conformable SEMS as a bridge to surgery option in the treatment of symptomatic malignant colorectal obstruction. PMID:24526914

  7. A randomized trial comparing uncovered and partially covered self-expandable metal stents in the palliation of distal malignant biliary obstruction.

    PubMed

    Telford, Jennifer J; Carr-Locke, David L; Baron, Todd H; Poneros, John M; Bounds, Brenna C; Kelsey, Peter B; Schapiro, Robert H; Huang, Christopher S; Lichtenstein, David R; Jacobson, Brian C; Saltzman, John R; Thompson, Christopher C; Forcione, David G; Gostout, Christopher J; Brugge, William R

    2010-11-01

    The most common complication of uncovered biliary self-expandable metal stents (SEMSs) is tumor ingrowth. The addition of an impenetrable covering may prolong stent patency. To compare stent patency between uncovered and partially covered SEMSs in malignant biliary obstruction. Multicenter randomized trial. Four teaching hospitals. Adults with inoperable distal malignant biliary obstruction. Uncovered or partially covered SEMS insertion. Time to recurrent biliary obstruction, patient survival, serious adverse events, and mechanism of recurrent biliary obstruction. From October 2002 to May 2008, 129 patients were randomized. Recurrent biliary obstruction was observed in 11 of 61 uncovered SEMSs (18%) and 20 of 68 partially covered SEMSs (29%). The median times to recurrent biliary obstruction were 711 days and 357 days for the uncovered and partially covered SEMS groups, respectively (P = .530). Median patient survival was 239 days for the uncovered SEMS and 227 days for the partially covered SEMS groups (P = .997). Serious adverse events occurred in 27 (44%) and 42 (62%) patients in the uncovered and partially covered SEMS groups, respectively (P = .046). None of the uncovered and 8 (12%) of the partially covered SEMSs migrated (P = .0061). Intended sample size was not reached. Allocation to treatment groups was unequal. There was no significant difference in time to recurrent biliary obstruction or patient survival between the partially covered and uncovered SEMS groups. Partially covered SEMSs were associated with more serious adverse events, particularly migration. Copyright © 2010 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

  8. The new nitinol conformable self-expandable metal stents for malignant colonic obstruction: a pilot experience as bridge to surgery treatment.

    PubMed

    Di Mitri, Roberto; Mocciaro, Filippo

    2014-01-01

    Self-expandable metal stents (SEMS) are a nonsurgical option for treatment of malignant colorectal obstruction also as a bridge to surgery approach. The new nitinol conformable stent has improved clinical outcomes in these kinds of patients. We report a pilot experience with nitinol conformable SEMS placement as bridge to surgery treatment in patients with colorectal obstruction. Between April and August 2012, we collected data on colonic nitinol conformable SEMS placement in a cohort of consecutive symptomatic patients, with malignant colorectal obstruction, who were treated as a bridge to surgery. Technical success, clinical success, and adverse events were recorded. Ten patients (7 male (70%)), with a mean age of 69.2±10.1, were evaluated. The mean length of the stenosis was 3.6±0.6 cm. Five patients (50%) were treated on an emergency basis. The median time from stent placement to surgery was 16 days (interquartile range 7-21). Technical and clinical success was achieved in all patients with a significant early improvement of symptoms. No adverse events due to the SEMS placement were observed. This pilot study confirmed the important role of nitinol conformable SEMS as a bridge to surgery option in the treatment of symptomatic malignant colorectal obstruction.

  9. Recurrent Benign Urethral Strictures Treated with Covered Retrievable Self-Expandable Metallic Stents: Long-Term Outcomes over an 18-Year Period.

    PubMed

    Kim, Min Tae; Kim, Kun Yung; Song, Ho-Young; Park, Jung-Hoon; Tsauo, Jiaywei; Wang, Zhe; Kim, Pyeong Hwa

    2017-09-08

    To assess the long-term outcomes of covered retrievable self-expandable metallic stent (REMS) placement for recurrent benign urethral stricture and to compare the outcomes associated with 3 types of covered REMSs. A retrospective study was performed in 54 male patients in whom 114 REMSs were placed between November 1998 and December 2016. These included 26 polyurethane-covered REMSs in 13 patients (group A), 47 internally polytetrafluoroethylene (PTFE)-covered REMSs in 21 patients (group B), and 41 externally PTFE-covered REMSs in 20 patients (group C). The outcomes were analyzed and compared between the groups. Overall clinical success was achieved in 14 of the 54 patients (24%) at 5-year follow-up (group A, 12%; group B, 19%; group C, 40%). The overall complication rate was 60.5%, and the complication rate was significantly higher in group B than in groups A or C (group A vs B, P = .018; group B vs C, P = .002). The median stent indwelling time and maintained patency period were 3.1 months and 108 months, respectively. In multivariate analysis, stent indwelling time was the only significant factor associated with maintained patency. The long-term outcome of covered REMSs has not achieved the desired success rate for the standard treatment of recurrent urethral stricture. However, externally PTFE-covered REMSs showed a better long-term outcome than the other studied types. Copyright © 2017 SIR. Published by Elsevier Inc. All rights reserved.

  10. Endoscopic ultrasound-guided gallbladder drainage for acute cholecystitis: Long-term outcomes after removal of a self-expandable metal stent

    PubMed Central

    Kamata, Ken; Takenaka, Mamoru; Kitano, Masayuki; Omoto, Shunsuke; Miyata, Takeshi; Minaga, Kosuke; Yamao, Kentaro; Imai, Hajime; Sakurai, Toshiharu; Watanabe, Tomohiro; Nishida, Naoshi; Kudo, Masatoshi

    2017-01-01

    AIM To assess the long-term outcomes of this procedure after removal of self-expandable metal stent (SEMS). The efficacy and safety of endoscopic ultrasound-guided gallbladder drainage (EUS-GBD) with SEMS were also assessed. METHODS Between January 2010 and April 2015, 12 patients with acute calculous cholecystitis, who were deemed unsuitable for cholecystectomy, underwent EUS-GBD with a SEMS. EUS-GBD was performed under the guidance of EUS and fluoroscopy, by puncturing the gallbladder with a needle, inserting a guidewire, dilating the puncture hole, and placing a SEMS. The SEMS was removed and/or replaced with a 7-Fr plastic pigtail stent after cholecystitis improved. The technical and clinical success rates, adverse event rate, and recurrence rate were all measured. RESULTS The rates of technical success, clinical success, and adverse events were 100%, 100%, and 0%, respectively. After cholecystitis improved, the SEMS was removed without replacement in eight patients, whereas it was replaced with a 7-Fr pigtail stent in four patients. Recurrence was seen in one patient (8.3%) who did not receive a replacement pigtail stent. The median follow-up period after EUS-GBD was 304 d (78-1492). CONCLUSION EUS-GBD with a SEMS is a possible alternative treatment for acute cholecystitis. Long-term outcomes after removal of the SEMS were excellent. Removal of the SEMS at 4-wk after SEMS placement and improvement of symptoms might avoid migration of the stent and recurrence of cholecystitis due to food impaction. PMID:28216973

  11. Endoscopic treatment of large pancreatic fluid collections (PFC) using self-expanding metallic stents (SEMS) – a two-center experience

    PubMed Central

    Chaves, Dalton Marques; Mönkemüller, Klaus; Carneiro, Fred; Medrado, Bruno; dos Santos, Marcos; Wodak, Stephanie; Reimão, Sílvia; Sakai, Paulo; de Moura, Eduardo

    2014-01-01

    Background/study aim: During the last several years, endoscopic ultrasound (EUS)-guided pancreatic fluid collections’ (PFC) drainage has evolved into the preferred drainage technique. Recently, self-expanding metallic stents (SEMS) have been used as an alternative to double pigtail stents, with the advantage of providing a larger diameter fistula, thereby decreasing the risk of early obstruction and also allowing for direct endoscopic exploration of the cavity. The aim of this study was to evaluate the technical and clinical success, safety, and outcome of patients undergoing EUS-guided drainage of complex PFC using SEMS. Patients/materials and methods: The study was conducted at two tertiary hospitals from January 2010 to January 2013. All patients with PFC referred for endoscopic drainage were enrolled in a prospective database. The inclusion criteria were: (1) patients with pseudocysts or walled-off necrosis based on the revised Atlanta classification; (2) symptomatic patients with thick PFC; (3) PFC that persisted more than 6 weeks; and (4) large PFC diameter (≥ 9 cm). The exclusion criteria consisted of coagulation disorders, PFC bleeding or infection, and failure-to-inform written consent. Results: A total of 16 patients (9 females, 7 males; mean age 52.6, range 20 – 82) underwent EUS drainage with SEMS. There were 14 cases of pseudocysts and 2 cases of walled-off necrosis. The etiologies of the PFC were mainly gallstones (8 of 16 patients, 50 %) and alcohol (5 of 16 patients, 31 %). Technical success was achieved in 100 % of the cases. All patients had a complete resolution of the PFC. Conclusion: Transmural EUS-guided drainage of complex PFC using SEMS is feasible, appears safe, and is efficacious. However, the exchange of the UC (uncovered)-SEMS for plastic stents is mandatory within 1 week. Future prospective studies, preferably multicenter studies, comparing SEMS versus traditional plastic stents for the drainage of PFC are

  12. Square Stent: A New Self-Expandable Endoluminal Device and Its Applications

    SciTech Connect

    Pavcnik, Dusan; Uchida, Barry; Timmermans, Hans; Keller, Frederick S.; Roesch, Josef

    2001-07-15

    The square stent is a new, simply constructed, self-expanding device that has recently been described. Compared with other stents, the square stent has a minimal amount of metal and thus requires a smaller-diameter catheter for introduction. Despite the small amount of metal present, the square stent has adequate expansile force. We have been evaluating the square stent for various interventional applications. In addition to the basic square stent, combinations of square stents and coverings for square stents were developed and evaluated to expand its uses and indications. One of the coverings tested is a new biomaterial: small intestinal submucosa (SIS). This paper will discuss the various applications of the square stent, which include a retrievable inferior vena cava filter, vascular occluder, graft adapter, and venous and aortic valves. In addition, we will review the important properties of SIS as a covering for the square stent.

  13. Self-expanding nitinol stents: material and design considerations.

    PubMed

    Stoeckel, Dieter; Pelton, Alan; Duerig, Tom

    2004-02-01

    Nitinol (nickel-titanium) alloys exhibit a combination of properties which make these alloys particularly suited for self-expanding stents. Some of these properties cannot be found in engineering materials used for stents presently. This article explains the fundamental mechanism of shape memory and superelasticity, and how they relate to the characteristic performance of self-expanding stents. Nitinol stents are manufactured to a size slightly larger than the target vessel size and delivered constrained in a delivery system. After deployment, they position themselves against the vessel wall with a low, "chronic" outward force. They resist outside forces with a significantly higher radial resistive force. Despite the high nickel content of Nitinol, its corrosion resistance and biocompatibility is equal to that of other implant materials. The most common Nitinol stents are listed and described.

  14. A Case of Aorto-Bronchial Fistula After Insertion of Left Main Bronchial Self-Expanding Metallic Stent in a Patient with Recurrent Esophageal Cancer

    SciTech Connect

    Onishi, Hiroshi Kuriyama, Kengo; Komiyama, Takafumi; Tanaka, Shiho; Marino, Kan; Tsukamoto, Tatsuaki; Araki, Tsutomu

    2004-09-15

    We report a case of aorto-bronchial fistula (ABF) caused by a self-expanding metallic stent (EMS) 51 days after insertion into the left main bronchus. The patient presented with left main bronchial stenosis caused by post-operative local recurrence of esophageal cancer. Post-operative radio therapy totaling 40 Gy and post-recurrence radiotherapy totaling 34 Gy were administered, with daily fractions of 2 Gy. Stenosis of the left main bronchus improved slightly, and was followed with insertion of EMS to prevent re-stenosis. The patient experienced massive hemoptysis for 3 days before sudden death. Autopsy revealed the EMS edge perforating the descending aortic lumen. Tumor infiltration and bacterial infection were observed on the wall of the left bronchus, and atherosclerosis was present on the aortic wall around the fistula. It should be noted that the left main bronchus was at considerable risk of ABF after insertion of EMS for malignant stenosis, and prophylactic stent insertion into the bronchus without imperative need must be avoided.

  15. Three cases of endoscopic resection for synchronous early colon cancers after self-expandable metallic stent placement for obstructive colon cancer

    PubMed Central

    Moroi, Rintaro; Endo, Katsuya; Ichikawa, Ryo; Takahashi, So; Shiroki, Takeharu; Shinkai, Hirohiko; Ishiyama, Fumitake; Kayaba, Shoichi

    2016-01-01

    Background and study aims: The feasibility of endoscopic resection for synchronous early colon cancer after placement of self-expandable metallic stents (SEMS) for malignant colorectal obstruction is unknown. Herein we evaluated 3 cases of endoscopic resection for synchronous early colorectal cancers after SEMS placement. Patient 1 was an 82-year-old man with obstructive sigmoid colon cancer. We curatively treated the synchronous descending colon cancer with endoscopic submucosal dissection (ESD) and the rectal cancer with endoscopic mucosal resection (EMR) after SEMS placement. This is the first reported case of a successful ESD for synchronous early colon cancer via the use of a colonic stent. Patient 2 was an 81-year-old man with obstructive ascending colon cancer. We resected the synchronous transverse colon cancer via ESD. Histologic findings indicated that the carcinoma cells had invaded the submucosal layer. Therefore, we immediately performed expanded right-hemicolectomy. Patient 3 was an 81-year-old man with obstructive sigmoid colon cancer. We curatively treated the synchronous transverse colon cancer with EMR after SEMS placement. There were no complications associated with the endoscopic treatments in any of the cases. Our results indicate that preoperative endoscopic resection combined with the ESD technique for synchronous colorectal cancer after SEMS placement could be effective as a surgical strategy for patients with malignant colorectal obstruction. PMID:27652303

  16. Comparison of patency and cost-effectiveness of self-expandable metal and plastic stents used for malignant biliary strictures: a Polish single-center study.

    PubMed

    Budzyńska, Agnieszka; Nowakowska-Duława, Ewa; Marek, Tomasz; Hartleb, Marek

    2016-10-01

    Most patients with malignant biliary obstruction are suited only for palliation by endoscopic drainage with plastic stents (PS) or self-expandable metal stents (SEMS). To compare the clinical outcome and costs of biliary stenting with SEMS and PS in patients with malignant biliary strictures. A total of 114 patients with malignant jaundice who underwent 376 endoscopic retrograde biliary drainage (ERBD) were studied. ERBD with the placement of PS was performed in 80 patients, with one-step SEMS in 20 patients and two-step SEMS in 14 patients. Significantly fewer ERBD interventions were performed in patients with one-step SEMS than PS or the two-step SEMS technique (2.0±1.12 vs. 3.1±1.7 or 5.7±2.1, respectively, P<0.0001). The median hospitalization duration per procedure was similar for the three groups of patients. The patients' survival time was the longest in the two-step SEMS group in comparison with the one-step SEMS and PS groups (596±270 vs. 276±141 or 208±219 days, P<0.001). Overall median time to recurrent biliary obstruction was 89.3±159 days for PS and 120.6±101 days for SEMS (P=0.01). The total cost of hospitalization with ERBD was higher for two-step SEMS than for one-step SEMS or PS (1448±312, 1152±135 and 977±156&OV0556;, P<0.0001). However, the estimated annual cost of medical care for one-step SEMS was higher than that for the two-step SEMS or PS groups (4618, 4079, and 3995&OV0556;, respectively). Biliary decompression by SEMS is associated with longer patency and reduced number of auxiliary procedures; however, repeated PS insertions still remain the most cost-effective strategy.

  17. Anchoring of a fully covered self-expandable metal stent with a 5F double-pigtail plastic stent to prevent migration in the management of benign biliary strictures.

    PubMed

    Park, Jong Kyu; Moon, Jong Ho; Choi, Hyun Jong; Min, Seul Ki; Lee, Tae Hoon; Cheon, Gab Jin; Cheon, Young Koog; Cho, Young Deok; Park, Sang-Heum; Kim, Sun-Joo

    2011-10-01

    Fully covered self-expandable metal stents (FCSEMSs) can be effectively placed in patients with benign biliary stricture (BBS). However, stent migration is an inherent problem of FCSEMSs. We evaluated the efficacy of anchoring with a 5F double-pigtail plastic stent (anchoring stent) to prevent migration of an FCSEMS in patients with BBS. Between January 2007 and December 2009, 33 of 37 consecutive patients with BBS who had experienced treatment failure of at least one plastic stent placement were prospectively enrolled in this study. The patients with BBS were randomly assigned to undergo FCSEMS placement with or without an anchoring stent (anchoring group: 16 patients; non-anchoring group: 17 patients). The main outcome measures were the stent migration rate and success rates. The technical success rate was 100% in both groups. Significantly less stent migration occurred in the anchoring group (6.3%, 1/16) than in the non-anchoring group (41.2%, 7/17; P=0.024). The median indwelling time was significantly longer in the anchoring group (154 days; range, 86-176 days) than in the non-anchoring group (114 days; range, 19-162 days; P=0.010). Improvement or resolution of the BBS was confirmed in 15 of 16 patients (93.8%) in the anchoring group, and in 12 of 17 patients (70.6%) in the non-anchoring group (P=0.101). The placement of an anchoring stent appears to be a simple and effective method of preventing premature migration of FCSEMSs in patients with BBS. Appropriately powered studies are needed to confirm this finding.

  18. Anatomy-shaped design of a fully-covered, biliary, self-expandable metal stent for treatment of benign distal biliary strictures

    PubMed Central

    Weigt, Jochen; Kandulski, Arne; Malfertheiner, Peter

    2016-01-01

    Background and study aims: The treatment success of benign biliary strictures with fully covered metal stents (CSEMS) is altered by high stent dislocation rates. We aimed to evaluate a new stent design to prevent dislocation. Patients and methods: Patients with benign biliary strictures were treated with a newly designed double-coned stent (dcSEMS). Mechanical analysis of the new stent was performed and it was compared with a cylindrical stent. Results: A total of 13 dcCSEMS were implanted in 11 patients (2 female, 9 male, median age 47, range 33 – 71). All patients had distal biliary strictures due to chronic pancreatitis. No stent migration occurred. In all but one patient the stents were removed. One patient refused stent extraction and was lost to follow up. Stent occlusion occurred twice leading to cholangitis in both cases. The duration of stent treatment was 170 days (range 61 – 254). After extraction only one patient had early recurrent stricture and received the same stent again. Three stents showed minimal tissue granulation at the papilla. One stent presented ingrowth at the proximal end and was removed after implantation of a second fully covered stent. Mechanical examination revealed significantly lower radial expansion force of the new stent as compared to the cylindrical stent. Conclusions: The new stent design has a low rate of migration. Biomechanical properties may explain this effect. PMID:26793789

  19. Self-expandable biodegradable biliary stents in porcine model.

    PubMed

    Grolich, Tomáš; Crha, Michal; Novotný, Ladislav; Kala, Zdeněk; Hep, Aleš; Nečas, Alois; Hlavsa, Jan; Mitáš, Ladislav; Misík, Jan

    2015-02-01

    Treatment or prevention of a benign biliary tree stricture is an unresolved problem. A novel self-expandable biodegradable polydioxanon biliary stent in a porcine model was studied. This new stent was used in 23 pigs. Feasibility and safety of surgical stenting, time of biodegradation, and histologic reaction in 2, 8, 13, and 20 wk of a follow-up were studied. All stents were inserted into a common bile duct through a duodenal papilla following small dilatation. After surgical evaluation of abdominal cavities, the pigs were sacrificed to remove common bile ducts with the stents. All bile ducts were assessed by macroscopic and histopathologic examination. Self-expansion was correct in all cases. Neither bile duct obstruction nor postsurgical complications were observed. Macroscopic evaluation indicated lightening of the stent color in 2 wk, a partial disintegration in 8 wk, and a complete absorption in 13 and 20 wk. Histologic evaluation in general substantiated a mild-to-moderate inflammatory reaction in the lamina propria during the whole follow up and had no clinical consequences. No cholangitis, necrosis, abscess, or excessive fibroplasia was found in a hepatoduodenal ligament. Our results suggest that polydioxanon biodegradable self-expanding stents seem to be useful for biliary system implantation, offer a good biocompatibility, and completely degrade within 13 wk. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Clinical outcomes and risk factors for technical and clinical failures of self-expandable metal stent insertion for malignant colorectal obstruction.

    PubMed

    Yoon, Jin Young; Jung, Yoon Suk; Hong, Sung Pil; Kim, Tae Il; Kim, Won Ho; Cheon, Jae Hee

    2011-10-01

    Although self-expandable metal stent (SEMS) insertion is widely used for relief of malignant colorectal obstructions, the immediate technical and clinical failure rates of SEMSs and the associated risk factors remain largely unknown. To identify rates and factors predictive of technical and clinical failure of SEMSs when their use is attempted for the decompression of malignant colorectal obstruction. Retrospective chart review. A tertiary-care academic medical center in South Korea. This study involved a total of 412 patients with malignant colorectal obstruction in whom SEMS insertion was attempted. Placement of colonic SEMSs. Technical success and immediate and long-term clinical success rates. Technical and clinical failures were found in 36 of 276 patients (13.0%) and 39 of 240 patients (16.3%) in the palliative group, respectively, and in 3 of 136 patients (2.2%) and 7 of 133 patients (5.3%) in the preoperative group, respectively. Factors associated with technical failure were extracolonic origin of tumor, the presence of carcinomatosis, and a proximal obstruction site. Factors associated with long-term clinical failure in the palliative group were combined dilation procedure, no additional chemotherapy, and extracolonic origin of the tumor. In the preoperative group, only older patients had both higher technical failure and clinical failure rates. This was a single-institution, retrospective analysis. Although colorectal SEMS placement is generally safe and effective, it is associated with clinically important technical and clinical failure rates. The identification of risk factors for the failure of colorectal SEMSs found in this study might help physicians decide between surgical decompression and endoscopic stenting in patients with malignant colorectal obstruction. Copyright © 2011 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

  1. Risk factors for recurrent biliary obstruction following placement of self-expandable metallic stents in patients with malignant perihilar biliary stricture.

    PubMed

    Miura, Shin; Kanno, Atsushi; Masamune, Atsushi; Hamada, Shin; Hongou, Seiji; Yoshida, Naoki; Nakano, Eriko; Takikawa, Tetsuya; Kume, Kiyoshi; Kikuta, Kazuhiro; Hirota, Morihisa; Yoshida, Hiroshi; Katayose, Yu; Unno, Michiaki; Shimosegawa, Tooru

    2016-06-01

    Self-expandable metallic stents (SEMSs) are used for palliation in patients with malignant perihilar biliary strictures. However, recurrent biliary obstruction occasionally causes cholangitis and jaundice. This study aimed to identify risk factors for recurrent biliary obstruction in such patients. Data from consecutive patients with malignant perihilar biliary strictures treated with endoscopic placement of SEMSs between 2007 and 2014 in Tohoku University Hospital were retrospectively reviewed. Risk factors for recurrent biliary obstruction were calculated using the Cox proportional hazards models (with hazard ratios [HRs] and 95 % confidence interval [95 %CIs]), and SEMS patency period was examined using the Kaplan - Meier method. SEMS patency was defined as the period between SEMS insertion and the development of recurrent biliary obstruction. 104 patients were included. Median survival time was 281 days; and 85 patients died during a median follow-up period of 320 days. Recurrent biliary obstruction occurred in 35 patients. Median SEMS patency period was 549 days. Multivariable analyses showed that: compared with bile duct carcinoma, gallbladder carcinoma was associated with shorter SEMS patency (HR 8.18, 95 %CI 2.41 - 26.83); patency of left-sided SEMS was inferior to that of bilateral (HR 0.5, 95 %CI 0.32 - 0.93) and right-sided SEMS (HR 0.1, 95 %CI 0.02 - 0.65). Cholangitis before SEMS placement increased the risk of recurrent biliary obstruction (HR 11.44; 95 %CI 4.48 - 32.35) and reduced the SEMS patency period (746 vs. 210 days). Gallbladder carcinoma, left-sided stent placement, and cholangitis before SEMS placement are risk factors for recurrent biliary obstruction after SEMS placement. © Georg Thieme Verlag KG Stuttgart · New York.

  2. Prevalence, factors, and clinical impact of self-expanding stent fractures following iliac artery stenting.

    PubMed

    Higashiura, Wataru; Kubota, Yasushi; Sakaguchi, Shoji; Kurumatani, Norio; Nakamae, Mitsuhiro; Nishimine, Kiyoshi; Kichikawa, Kimihiko

    2009-03-01

    To evaluate the prevalence, factors, and clinical impact of self-expanding stent fracture following iliac artery stenting. A review of the endovascular registry database for our department showed 353 patients with occlusive diseases of the iliac artery who underwent stenting between 1997 and 2007. While clinical data and images were retrospectively reviewed for all patients, 165 patients who underwent self-expanding stenting and plain radiograph with >or=6-months follow-up were analyzed. Mean follow-up was 43 months for 305 stents (elgiloy, n = 83; nitinol, n = 222) implanted in 216 iliac arteries. The mean duration until the last imaging study was 38 months. Items concerning prevalence of stent fracture, factors associated with fracture, and outcomes for patients with stent fracture were analyzed. Stent fracture was detected in 11 of 216 iliac arteries (5.1%). In stent-based analysis, 11 of 305 stents (3.6%) showed stent fracture, classified as type I in 2 stents, type II in 3 stents, type III in 4 stents, type IV in 1 stent, and type V in 1 stent. Stent fracture was detected in 11 of 222 nitinol stents (5.0%), but no Elgiloy stents. Cox proportional hazards regression model indicated stenting for chronic occlusion as a risk factor associated with nitinol stent fracture (hazard ratio [HR] = 6.09, P = 0.008, 95% confidence interval [CI] 1.59-23.3). Cumulative primary patency rates in iliac arteries with and without fractured stents were 90% and 91% at 8 years (P = .80), respectively. Fracture of self-expanding stents is rare in iliac arteries, but stenting for chronic occlusion represents a risk factor for fracture. Fractures of stents placed in iliac arteries rarely affect patency.

  3. Comparing the vascular response in implantation of self-expanding, bare metal nitinol stents or paclitaxel-eluting nitinol stents in superficial femoral artery lesions: a serial optical frequency domain imaging study.

    PubMed

    Miki, Kojiro; Fujii, Kenichi; Shibuya, Masahiko; Fukunaga, Masashi; Imanaka, Takahiro; Tamaru, Hiroto; Nishimura, Machiko; Horimatsu, Tetsuo; Honda, Yasuhiro; Fitzgerald, Peter J; Masuyama, Tohru; Ishihara, Masaharu

    2016-12-20

    This study sought to investigate differences in vascular response between self-expanding bare metal nitinol stents (BMS) and paclitaxel-eluting nitinol stents (PES), in superficial femoral artery (SFA) disease, using optical frequency domain imaging (OFDI). Six months after stent implantation, follow-up quantitative vascular angiography (QVA) and OFDI assessment were scheduled to evaluate vascular response. Volume index (VI) was defined as volume divided by stent length. The primary endpoint was OFDI-derived late lumen area loss, defined as lumen VI post stent implantation minus lumen VI at follow-up. A total of 28 SFA lesions were analysed, with cases randomised to receive either BMS or PES implantation. QVA-derived diameter stenosis at six-month follow-up was lower in the PES group than in the BMS group (28.5% vs. 39.7%, p=0.04). After six months, BMS VI increased by 33.8% (20.7±3.7 to 27.7±3.5 mm3/mm), whilst PES exhibited an increase of 32.1% (19.0±2.3 to 25.1±4.7 mm3/mm). Neointimal VI was smaller (7.4±2.6 mm3/mm vs. 10.5±3.2 mm3/mm, p<0.01) and late lumen area loss was lower (2.9±1.3 mm3/mm vs. 5.6±2.8 mm3/mm, p<0.01) in the PES group. Serial volumetric OFDI analyses confirmed significantly smaller amounts of neointimal tissue and lower late lumen area loss following PES implantation for SFA lesions at short-term follow-up.

  4. Treatment of Benign Tracheal Stenosis Utilizing Self-Expanding Nitinol Stents

    SciTech Connect

    Sesterhenn, Andreas M. Wagner, Hans-Joachim; Alfke, Heiko; Werner, Jochen A.; Lippert, Burkard M.

    2004-08-15

    We assessed the results of self-expanding metallic stent insertion into benign proximal tracheal stenosis in patients not appropriate or unfit for surgical repair. Proximal benign tracheal stenoses had occurred in 11 patients (7 men, 4 women, mean age 68.8 years) after long-time intubation (n = 6), tracheostomy (n = 4), or chondropathia (n = 1). Fourteen self-expanding nitinol stents were placed in the patients under general anesthesia with endoscopical and fluoroscopical guidance. Stent insertion was successful in all cases and led to immediate relief of the morphological and functional airway obstruction. No immediate complications were noted. During the mean follow-up period of 67.5 weeks we observed one recurrent dyspnea 3 months after implantation and granuloma formation at the stent insertion site in another patient. Both complications were successfully treated with additional stent insertion in one case and laser resection of granulomas in the other. Self-expanding nitinol stents should be considered for the treatment of benign proximal tracheal obstruction in selected patients for whom surgical repair is contraindicated.

  5. Self-Expandable Nitinol Stent Placement in Homocysteinemic Porcine Aorta

    PubMed Central

    França, Luís Henrique Gil; Pereira, Adamastor Humberto; Perini, Sílvio César

    2008-01-01

    PURPOSE To compare aortic intimal thickening of normal and hyperhomocysteinemic pigs (induced with a methionine-rich diet) following placement of a self-expanding nitinol stent. METHODS Eighteen Macau pigs were used. They were older than eight weeks in age and had an average weight of 30 kg. Pigs were randomly divided into two groups. The first, Group C (control), was fed a regular diet, and the second group, Group M, was fed a methionine-rich diet for 30 days to induce hyperhomocysteinemia. The self-expandable nitinol stents were 25mm in length and 8 mm in diameter after expansion. Blood samples were collected to measure total cholesterol, triglycerides, HDL and homocysteine concentrations. All animals were subjected to angiography. Thirty days after the procedure, the animals were sacrificed, and the abdominal aorta was removed for histological and digital morphometry analysis. RESULTS Under microscopic evaluation, the intima was significantly thicker in Group C than in Group M. When groups were compared by digital morphometric analysis, intimal thickening of the vessel wall was higher in Group C than in Group M. There was no significant change in total cholesterol, triglycerides or HDL concentrations in either group. In group C the levels of plasma homocysteine ranged from 14,40 to 16,73μmol/l; in Group M, plasma homocysteine levels ranged from 17.47 to 59.80 μmol/l after 30 days of a methionine-rich diet. CONCLUSION Compared to normal pigs, less intimal hyperplasia was observed in the abdominal aortas of hyperhomocysteinemic pigs thirty days after the insertion of a self-expandable nitinol stent. PMID:18438578

  6. Covered self-expandable metal stents with an anti-migration system improve patency duration without increased complications compared with uncovered stents for distal biliary obstruction caused by pancreatic carcinoma: a randomized multicenter trial.

    PubMed

    Kitano, Masayuki; Yamashita, Yukitaka; Tanaka, Kiyohito; Konishi, Hideyuki; Yazumi, Shujiro; Nakai, Yoshitaka; Nishiyama, Osamu; Uehara, Hiroyuki; Mitoro, Akira; Sanuki, Tsuyoshi; Takaoka, Makoto; Koshitani, Tatsuya; Arisaka, Yoshifumi; Shiba, Masatsugu; Hoki, Noriyuki; Sato, Hideki; Sasaki, Yuichi; Sato, Masako; Hasegawa, Kazunori; Kawabata, Hideaki; Okabe, Yoshihiro; Mukai, Hidekazu

    2013-11-01

    The requirements of biliary stents used in the palliation of malignant biliary obstruction are a long duration of patency and minimal adverse effects. Covered self-expandable metal stents (SEMSs) have been shown to prevent tumor ingrowth, which is the most frequent complication of uncovered SEMSs. However, because they are prone to migration, the superiority of covered SEMS has yet to be convincingly demonstrated. The aim of this study was to evaluate the superiority of covered over uncovered SEMSs in the palliation of distal biliary obstruction due to unresectable pancreatic carcinoma, using both stent types with relatively low axial force and uncovered flared ends to prevent their migration. From April 2009 to December 2010, 120 patients who were admitted to 22 tertiary-care centers because of distal biliary obstruction from unresectable pancreatic carcinomas were enrolled in this prospective randomized multicenter study. Patients were randomly assigned to receive a covered or uncovered SEMS deployed at the site of the biliary stricture during endoscopic retrograde cholangiopancreatography. Stent patency time, patient survival time, patient survival time without stent dysfunction (time to stent dysfunction or patient death), cause of stent dysfunction (ingrowth, overgrowth, migration, or sludge formation), and serious adverse events were compared between covered and uncovered SEMS groups. Patient survival time in the two groups did not significantly differ (median: 285 and 223 days, respectively; P=0.68). Patient survival time without stent dysfunction was significantly longer in the covered than in the uncovered SEMS group (median: 187 vs. 132 days; P=0.043). Stent patency was also significantly longer in the covered than in the uncovered SEMS group (mean±s.d.: 219.3±159.1 vs. 166.9±124.9 days; P=0.047). Reintervention for stent dysfunction was performed in 14 of 60 patients with covered SEMSs (23%) and in 22 of 60 patients with uncovered SEMSs (37%; P=0

  7. In situ cooling with ice water for the easier removal of self-expanding nitinol stents

    PubMed Central

    Merkel, Daniel; Brinkmann, Eckhard; Wiens, Daniel; Derwahl, Karl-Michael

    2015-01-01

    Background: It is yet to be determined what effects temperature has on the properties of nitinol in order to simplify the process of removing nitinol self-expanding metal stents (SEMS). Materials and methods: We describe the procedure for removal of SEMS in a total of 11 cases with 9 patients. A study involving cooling of nitinol stents in situ with ice water just before their removal was attempted. Results: All stents were removed successfully. In partially covered and in fully covered stents, the stent rigidity was noticeably reduced following cooling. Stent removal was performed by inversion, which was achieved by pulling on the stent from its distal end. No adverse events were observed during this trial. Conclusion: The higher pliability of the stents after ice-water cooling facilitates stent removal. With this method, a mobilization of all stents by the invagination technique was achieved. The separation of the uncoated stent ends from the intestinal wall by the invagination technique, as well as the mucosal vasoconstriction resulting from the cooling, lead to an easier SEMS removal and may serve to prevent severe bleeding of the mucosal wall during this process. PMID:26134772

  8. Palliative radiotherapy in addition to self-expanding metal stent for improving dysphagia and survival in advanced oesophageal cancer (ROCS: Radiotherapy after Oesophageal Cancer Stenting): study protocol for a randomized controlled trial.

    PubMed

    Adamson, Douglas; Blazeby, Jane; Nelson, Annmarie; Hurt, Chris; Nixon, Lisette; Fitzgibbon, Jim; Crosby, Tom; Staffurth, John; Evans, Mim; Kelly, Noreen Hopewell; Cohen, David; Griffiths, Gareth; Byrne, Anthony

    2014-10-22

    The single most distressing symptom for patients with advanced esophageal cancer is dysphagia. Amongst the more effective treatments for relief of dysphagia is insertion of a self-expanding metal stent (SEMS). It is possible that the addition of a palliative dose of external beam radiotherapy may prolong the relief of dysphagia and provide additional survival benefit. The ROCS trial will assess the effect of adding palliative radiotherapy after esophageal stent insertion. The study is a randomized multicenter phase III trial, with an internal pilot phase, comparing stent alone versus stent plus palliative radiotherapy in patients with incurable esophageal cancer. Eligible participants are those with advanced esophageal cancer who are in need of stent insertion for primary management of dysphagia. Radiotherapy will be administered as 20 Gray (Gy) in five fractions over one week or 30 Gy in 10 fractions over two weeks, within four weeks of stent insertion. The internal pilot will assess rates and methods of recruitment; pre-agreed criteria will determine progression to the main trial. In total, 496 patients will be randomized in a 1:1 ratio with follow up until death. The primary outcome is time to progression of patient-reported dysphagia. Secondary outcomes include survival, toxicity, health resource utilization, and quality of life. An embedded qualitative study will explore the feasibility of patient recruitment by examining patients' motivations for involvement and their experiences of consent and recruitment, including reasons for not consenting. It will also explore patients' experiences of each trial arm. The ROCS study will be a challenging trial studying palliation in patients with a poor prognosis. The internal pilot design will optimize methods for recruitment and data collection to ensure that the main trial is completed on time. As a pragmatic trial, study strengths include collection of all follow-up data in the usual place of care, and a focus on

  9. A non-randomized study in consecutive patients with postcholecystectomy refractory biliary leaks who were managed endoscopically with the use of multiple plastic stents or fully covered self-expandable metal stents (with videos).

    PubMed

    Canena, Jorge; Liberato, Manuel; Meireles, Liliane; Marques, Inês; Romão, Carlos; Coutinho, António Pereira; Neves, Beatriz Costa; Veiga, Pedro Mota

    2015-07-01

    Endoscopic management of postcholecystectomy biliary leaks is widely accepted as the treatment of choice. However, refractory biliary leaks after a combination of biliary sphincterotomy and the placement of a large-bore (10F) plastic stent can occur, and the optimal rescue endotherapy for this situation is unclear. To compare the clinical effectiveness of the use of a fully covered self-expandable metal stent (FCSEMS) with the placement of multiple plastic stents (MPS) for the treatment of postcholecystectomy refractory biliary leaks. Prospective study. Two tertiary-care referral academic centers and one general district hospital. Forty consecutive patients with refractory biliary leaks who underwent endoscopic management. Temporary placement of MPS (n = 20) or FCSEMSs (n = 20). Clinical outcomes of endotherapy as well as the technical success, adverse events, need for reinterventions, and prognostic factors for clinical success. Endotherapy was possible in all patients. After endotherapy, closure of the leak was accomplished in 13 patients (65%) who received MPS and in 20 patients (100%) who received FCSEMSs (P = .004). The Kaplan-Meier (log-rank) leak-free survival analysis showed a statistically significant difference between the 2 patient populations (χ(2) [1] = 8.30; P < .01) in favor of the FCSEMS group. Use of <3 plastic stents (P = .024), a plastic stent diameter <20F (P = .006), and a high-grade biliary leak (P = .015) were shown to be significant predictors of treatment failure with MPS. The 7 patients in whom placement of MPS failed were retreated with FCSEMSs, resulting in closure of the leaks in all cases. Non-randomized design. In our series, the results of the temporary placement of FCSEMSs for postcholecystectomy refractory biliary leaks were superior to those from the use of MPS. A randomized study is needed to confirm our results before further recommendations. Copyright © 2015 American Society for Gastrointestinal Endoscopy

  10. Use of a novel covered self-expandable metal stent with an anti-migration system for endoscopic ultrasound-guided drainage of a pseudocyst

    PubMed Central

    Téllez-Ávila, Félix Ignacio; Villalobos-Garita, Álvaro; Ramírez-Luna, Miguel Ángel

    2013-01-01

    The development of pseudocysts in patients with chronic pancreatitis has been reported in 23%-60% of cases and drainage is indicated when they become symptomatic. Endoscopic ultrasound-guided drainage with the placement of plastic or metallic stents to create a cystogastric anastomosis has been shown to be a reliable and efficacious maneuver. Metallic stent use appears to be a safe and effective alternative that shortens the length of time of the procedure and maintains a greater diameter in the cystogastric communication. However, important migration rates have been reported. The use of new metallic stents that are specially designed to prevent migration represents a promising development in the treatment of these group of patients that appears to be safe and effective for pseudocyst drainage and could importantly reduce migration rates, while at the same time having the advantage of a single step procedure and a larger fistula diameter in the endoscopic cystogastric anastomosis. PMID:23772268

  11. Tapered self expandable bare stent to treat acute superior mesenteric artery ischemia.

    PubMed

    Martinez Miguez, Marta; Carballo-Fernandez, Coral; Mosquera-Arochena, Nilo

    2012-01-01

    This case demonstrates the use of carotid stents in off-label emergency condition where standard self-expandable stents doesn't fit to native artery and balloon-expandable stents could not be also recommended. 56 years old patient, EVAR therapy performed 2 months before, suffering acute severe abdominal pain; emergency angioCT showed oclusion of superior mesenteric artery (SMA) and no complications related to previous EVAR. A percutaneuos supraselective trombolysis was performed. After 24 hours control DSA showed partial recanalization and tight stenoses in distal SMA with poor run-off to terminal branches. A 6-8 x 40 mm Carotid Stent (Acculink®, Abbot Vascular) was implanted with good inmediate technical result. After 6 months follow up both SMA and branches remain patent and no further treatment was required. tapered self expandable uncovered stents are a good treatment option to achieve better conformability to SMA,and bare metal stents do not compromise side-branches of this artery.

  12. Self-expanding intracoronary stents in the treatment of coronary artery disease: new developments and future directions.

    PubMed

    Lu, H; Grundeken, M J; Koch, K T; Wykrzykowska, J J

    2013-10-01

    The first stent implanted in the human coronary circulation was a self-expandable (SE) stent and was introduced almost simultaneously with the first balloon-expandable (BE) stents in the late 1980s. Nowadays, the majority of the available stents are delivered by balloon expansion. While BE stents reach their final size at the time of implantation, the SE stent continues to enlarge days to weeks after implantation. Potential advantages of the self-expandable and self-apposing properties of nitinol stents, a super-elastic metallic alloy of nickel and titanium, could be reduction of acute and late acquired stent malapposition with a subsequently decreased risk of target vessel restenosis. Several nitinol stents have been developed and clinically evaluated and are now in use in daily clinical practice. However, it is important to further improve and optimize the SE stent design and apply newer strategies to the development of next generation SE stents. The present review will provide an overview of the development of these devices and the currently available clinical evidence of the contemporary SE stents.

  13. Long-Term Outcomes of Double-Layered Polytetrafluoroethylene Membrane-Covered Self-Expandable Segmental Metallic Stents (Uventa) in Patients with Chronic Ureteral Obstructions: Is It Really Safe?

    PubMed

    Kim, Myong; Hong, Bumsik; Park, Hyung Keun

    2016-12-01

    To evaluate the long-term clinical efficacy and safety of double-layered polytetrafluoroethylene membrane-covered self-expandable segmental metallic stents (Uventa) in patients with chronic ureteral obstruction. In a retrospective study, a total of 50 ureter units (44 patients) with chronic obstructions were included from July 2010 to May 2015. Indications for Uventa placement were primary stenting for malignant ureteral obstruction, failed conventional polymeric Double-J stent (PS), or percutaneous nephrostomy (PCN) technique, with comorbidities or fears limiting PS/PCN changes, or with irritation or pain due to PS/PCN. Patients underwent Uventa stent placement using the antegrade or retrograde approach. There were no immediate procedure-related complications, and all stents were placed in the proper sites. During the median follow-up of 30.9 (interquartile range [IQR], 8.1-49.0) months, the primary (no obstruction and no additional intervention) and overall success (no obstruction and no additional intervention except supplementary Uventa) was 30.0% and 34.0%, respectively. Moreover, 14 of 50 ureter units (28.0%) experienced major complications (≥Clavien-Dindo class IIIb), such as ureteroarterial fistula (three cases, 6.0%), ureteroenteric fistula (three, 6.0%), ureterovaginal fistula (one, 2.0%), ureter perforation (one, 2.0%), uncontrollable bleeding (one, 2.0%), and complete obstruction (five, 10.0%). On univariate analysis, major complications were associated with female (odds ratio [OR] = 6.000), cervical cancer (OR = 4.667), ureteral stricture length (≥6.0 cm, OR = 4.583), and placement duration (≥24.0 months, OR = 20.429; all p < 0.05). In long-term follow-up, the Uventa stent demonstrated poor treatment outcomes with frequent major complications in patients with chronic ureteral obstructions.

  14. Treatment of Pelvic Venous Spur (May-Thurner Syndrome) with Self-Expanding Metallic Endoprostheses

    SciTech Connect

    Binkert, Christoph A.; Schoch, Eric; Stuckmann, Gerd; Largiader, Jon; Wigger, Pius; Schoepke, Wolfdietrich; Zollikofer, Christoph L.

    1998-01-15

    Purpose: The application of self-expanding metallic endoprostheses (stents) to treat symptomatic pelvic venous spurs as an alternative to surgery. Methods: Wallstents with a diameter from 14 to 16 mm and one Cragg stent were placed in the left common iliac vein of eight patients (seven women, one man; mean age 42 years) with a symptomatic pelvic venous spur (left deep venous thrombosis or post-thrombotic leg swelling). Four patients had surgical thrombectomy prior to stent placement. Results: Technical success with immediate reduction of left leg circumference was achieved in all eight patients. A primary patency rate of 100% was observed during an average follow-up of 3 years (range 10-121 months). There were no procedural or stent-related complications. Conclusion: The percutaneous transfemoral placement of self-expanding metallic stents is an effective minimally invasive alternative to surgery in the treatment of symptomatic pelvic venous spur.

  15. Stent Fracture and Reocclusion After Placement of a Single Self-Expanding Stent in the Common Iliac Artery and Endovascular Treatment

    SciTech Connect

    Higashiura, Wataru Sakaguchi, Shoji; Morimoto, Kengo; Kichikawa, Kimihiko

    2008-09-15

    We present a case of fracture of a single self-expanding stent placed in the common iliac artery (CIA). An 80-year-old woman underwent placement of a self-expanding stent for CIA occlusion. Stent fracture and reocclusion were detected after 18 months. Successful revascularization was achieved using a stent-in-stent maneuver. The possibility of stent fracture with reocclusion should be considered following treatment with a single self-expanding stent for CIA occlusion.

  16. Miniaturized Self-Expanding Drug-Eluting Stent in Small Coronary Arteries: Late Effectiveness

    PubMed Central

    de Oliveira, Flavio Roberto Azevedo; Mattos, Luiz Alberto Piva e; Abizaid, Alexandre; Abizaid, Andrea S.; Costa, J. Ribamar; Costa, Ricardo; Staico, Rodolfo; Botelho, Roberto; Sousa, J. Eduardo; Sousa, Amanda

    2013-01-01

    Background Small vessels represent a risk factor for restenosis in percutaneous coronary angioplasty (PCA). The Sparrow® self-expanding drug-eluting stent, which has a lower profile than the current systems, has never been tested in this scenario. Objectives To evaluate the late effectiveness of the Sparrow® drug-eluting stent, regarding in-stent late lumen loss (LLL). Methods Patients with ischemia, symptomatic or documented, were submitted to PCA in vessels with reference diameter < 2.75 mm, divided into two groups regarding Sparrow® stent type: group 1: Sparrow® drug-eluting stent (DES), group 2: Sparrow® bare metal stent (BMS). Clinical follow-up duration was 12 months. Evaluation using quantitative coronary angiography (QCA) was performed immediately and at 8 months. A decrease of over 65% of in-stent LLL with DES was estimated to calculate sample size. IBM® SPSS software, release 19 (Chicago, Illinois, USA) was used for the statistical analysis. Results A total of 24 patients were randomized, 12 in each group. The DES and BMS groups were similar in age (63.25 ± 10.01 vs. 64.58 ± 11.54, p = 0.765), male gender (58.3% vs. 33.3%, p = 0.412), risk factors and all angiographs aspects. Immediate results were satisfactory in both groups. At 8 months in-stent late lumen loss was significantly lower in DES than in BMS group (DES vs. BMS 0.25 ± 0.16 0.97 ± 0.76, p = 0.008). Conclusion In small-vessel PCA, the Sparrow® DES determined significant reduction in in-stent LLL, when compared to Sparrow® BMS. PMID:24100691

  17. Primary Stent Placement for Recanalization of Iliac Artery Occlusions: Using a Self-Expanding Spiral Stent

    SciTech Connect

    Kim, Jae-Kyu; Kim, Yun-Hyeon; Chung, Sang-Yeung; Kang, Heoung-Keun

    1999-07-15

    Purpose: To report the clinical results for recanalizations of an occluded iliac artery by a self-expanding spiral stent. Methods: We attempted to recanalize 36 iliac artery occlusions in 34 patients [33 men, 1 woman, aged 51-75 years (average 61.6 years)]. The average lesion length was 6.92 cm (range 1-14 cm). The patients' chief complaints were intermittent claudication and resting pain. Fontaine classification was assigned before and after the procedure. Technical and clinical success were also analyzed. Results: Forty-five stents were successfully deployed in 34 patients. All 36 lesions (13 in the external iliac artery, 12 in the common iliac artery, and 11 in both) were patently recanalized on angiography. The follow-up period ranged from 6 months to 36 months (mean 11.9 months). Fourteen stents (39%) with incomplete expansion were dilated with a balloon catheter. Good technical (100%) and clinical (94%) results were obtained. The only complication was one hematoma at the puncture site. Reocclusions were noted in two lesions (5%) at 1 week and 15 months, respectively. Conclusion: A self-expanding spiral stent is a safe and effective device for recanalization of an iliac artery occlusion as the primary stent without any previous intervention.

  18. [Numerical modeling of shape memory alloy vascular stent's self-expandable progress and "optimized grid" of stent].

    PubMed

    Xu, Qiang; Liu, Yulan; Wang, Biao; He, Jin

    2008-10-01

    Vascular stent is an important medical appliance for angiocardiopathy. Its key deformation process is the expandable progress of stent in the vessel. The important deformation behaviour corresponds to two mechanics targets: deformation and stress. This paper is devoted to the research and development of vascular stent with proprietary intellectual property rights. The design of NiTinol self-expandable stent is optimized by means of finite element software. ANSYS is used to build the finite element simulation model of vascular stent; the molding material is NiTinol shape memory alloy. To cope with the factors that affect the structure of stent, the shape of grid and so on, the self-expanding process of Nitinol stent is simulated through computer. By making a comparison between two kinds of stents with similar grid structure, we present a new concept of "Optimized Grid" of stent.

  19. Tricuspid valved stent implantation: novel stent with a self-expandable super-absorbent polymer.

    PubMed

    Iino, Kenji; Lozonschi, Lucian; Metzner, Anja; Marczynski-Bühlow, Martin; Renner, Jochen; Cremer, Jochen; Lutter, Georg

    2011-08-01

    Trans-catheter aortic and pulmonary valve replacement procedures can result in favorable outcomes in selected patients. The aim of this study was to investigate the functioning of a novel self-expanding valved stent with super-absorbent polymer (SAP) for minimally invasive replacement of the tricuspid valve. A newly designed nitinol stent with SAP was specially designed for the tricuspid annulus. This device was composed of right atrial anchoring elements, a left ventricular tubular stent, and a trileaflet bovine pericardial valve. The stent was coated with a waterproof material, and a pouch containing SAP for minimizing paravalvular leakage was placed beneath the atrial element. Seven pigs underwent minimally invasive off-pump tricuspid valved stent implantation. This was performed through a lower ministernotomy using a transventricular approach under transesophageal echocardiographic guidance. After 1 and 6h, a complete echocardiographic evaluation and hemodynamics (Swan-Ganz catheter) were performed. Six of seven pigs exhibited normal hemodynamics immediately after tricuspid valved stent implantation and maintained stability for the entire period of monitoring. In one pig, a part of the atrial stent elements was deployed into the right ventricle, leading to significant paravalvular leakage, and died very soon. All subsequent animals survived with good results in the observation period. Accurate positioning of the valved stent was documented in six of seven pigs. SAP expanded and filled the gap between the stent and the native annulus in all animals. Mild paravalvular leakage was found in two of the six animals. Nevertheless, the observed leakage decreased to trace levels 6h after implantation. In the additional four pigs, only trace tricuspid regurgitation was revealed. No right ventricular outflow tract obstruction was detected. Trans-apical off-pump tricuspid valved stent implantation is feasible in an acute experimental setting, and SAP may help to reduce

  20. Clinical outcomes of self-expandable stent placement for benign esophageal diseases: A pooled analysis of the literature

    PubMed Central

    van Halsema, Emo E; van Hooft, Jeanin E

    2015-01-01

    AIM: To analyze the outcomes of self-expandable stent placement for benign esophageal strictures and benign esophageal leaks in the literature. METHODS: The PubMed, Embase and Cochrane databases were searched for relevant articles published between January 2000 and July 2014. Eight prospective studies were identified that analyzed the outcomes of stent placement for refractory benign esophageal strictures. The outcomes of stent placement for benign esophageal leaks, perforations and fistulae were extracted from 20 retrospective studies that were published after the inclusion period of a recent systematic review. Data were pooled and analyzed using descriptive statistics. RESULTS: Fully covered self-expandable metal stents (FC SEMS) (n = 85), biodegradable (BD) stents (n = 77) and self-expandable plastic stents (SEPS) (n = 70) were inserted in 232 patients with refractory benign esophageal strictures. The overall clinical success rate was 24.2% and according to stent type 14.1% for FC SEMS, 32.9% for BD stents and 27.1% for SEPS. Stent migration occurred in 24.6% of cases. The overall complication rate was 31.0%, including major (17.7%) and minor (13.4%) complications. A total of 643 patients were treated with self-expandable stents mainly for postsurgical leaks (64.5%), iatrogenic perforations (19.6%), Boerhaave’s syndrome (7.8%) and fistulae (3.7%). FC SEMS and partially covered SEMS were used in the majority of patients. Successful closure of the defect was achieved in 76.8% of patients and according to etiology in 81.4% for postsurgical leaks, 86.0% for perforations and 64.7% for fistulae. The pooled stent migration rate was 16.5%. Stent-related complications occurred in 13.4% of patients, including major (7.8%) and minor (5.5%) complications. CONCLUSION: The outcomes of stent placement for refractory benign esophageal strictures were poor. However, randomized trials are needed to put this into perspective. The evidence on successful stent placement for benign

  1. Nitinol Self-Expanding Stents for the Superficial Femoral Artery.

    PubMed

    Nathan, Ashwin; Kobayashi, Taisei; Giri, Jay

    2017-04-01

    The superficial femoral artery is a complex artery subject to a unique set of biomechanical loading conditions in its course through the leg. Plain balloon angioplasty and balloon-expandable stents had unacceptably high rates of restenosis, necessitating target vessel revascularization. Nitinol alloy is well suited to provide the strength and flexibility needed of stents to withstand the external forces posed by the environment of the superficial femoral artery. Advances in stent technology with the addition of a slow-releasing antiproliferative agent and changes in scaffold design have shown promise in reducing the rates of stent fracture and in-stent restenosis. Published by Elsevier Inc.

  2. Percutaneous treatment of symptomatic superior mesenteric vein stenosis using self-expanding nitinol stents.

    PubMed

    Beyer, L P; Wohlgemuth, W A; Uller, W; Pregler, B; Goessmann, H; Niessen, C; Haimerl, M; Stroszczynski, C; Müller-Wille, R

    2015-10-01

    To evaluate the technical and clinical success of percutaneous superior mesenteric vein (SMV) stenting in symptomatic patients using self-expanding nitinol stents. We retrospectively analyzed the technical and clinical success of percutaneous SMV stenting of 6 symptomatic patients (3 men, mean age 67 years, range 48-81 years). Stenosis of the SMV was caused by postoperative stricture (n=3), pancreas carcinoma (n=1) and pancreatitis (n=2). As a result of the stenosis, 3 patients had symptomatic ascites, 2 patients showed signs of mesenteric ischemia and 1 patient had recurrent gastrointestinal bleeding. Stenting was performed by a percutaneous transhepatic approach using self-expanding nitinol stents. Stenting of the SMV was technically and clinically successful in all patients. No peri-interventional complications occurred. The stent diameters ranged from 6 to 14 mm. During the mean follow-up of 6 months (range, 2-10 months) 1 patient presented early stent occlusion 2 weeks after placement. Stenting of a symptomatic SMV stenosis using self-expanding nitinol stents is feasible and clinically effective. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  3. Endoscopic extra-cavitary drainage of pancreatic necrosis with fully covered self-expanding metal stents (fcSEMS) and staged lavage with a high-flow water jet system

    PubMed Central

    Smith, Ioana B.; Gutierrez, Juan P.; Ramesh, Jayapal; Wilcox, C. Mel; Mönkemüller, Klaus E.

    2015-01-01

    Aim: To present a novel, less-invasive method of endoscopic drainage (ED) for walled-off pancreatic necrosis (WON).We describe the feasibility, success rate, and complications of combined ED extra-cavitary lavage and debridement of WON using a biliary catheter and high-flow water jet system (water pump). Patients and methods: Endoscopic ultrasound (EUS)-guided drainage was performed with insertion of two 7-Fr, 4-cm double pigtail stents. Subsequently a fully covered self-expanding metal stent (fcSEMS) was placed. The key aspect of the debridement was the insertion of a 5-Fr biliary catheter through or along the fcSEMS into the cavity, with ensuing saline lavage using a high-flow water jet system. The patients were then brought back for repeated, planned endoscopic lavages of the WON. No endoscopic intra-cavitary exploration was performed. Results: A total of 17 patients (15 men, 2 women; mean age 52.6, range 24 – 69; mean American Society of Anesthesiologists [ASA] score of 3) underwent ED of WON with this new method. The mean initial WON diameter was 9.5 cm, range 8 to 26 cm. The total number of ED was 84, range 2 to 13. The mean stenting period was 42.5 days. The mean follow-up was 51 days, range 3 to 370. A resolution of the WON was achieved in 14 patients (82.3 %). There were no major complications associated with this method. Conclusion: ED of complex WON with fcSEMS followed by repeated endoscopic extra-cavitary lavage and debridement using a biliary catheter and high-flow water jet system is a minimally invasive, feasible method with high technical and clinical success and minimal complications. PMID:26135660

  4. Endoscopic extra-cavitary drainage of pancreatic necrosis with fully covered self-expanding metal stents (fcSEMS) and staged lavage with a high-flow water jet system.

    PubMed

    Smith, Ioana B; Gutierrez, Juan P; Ramesh, Jayapal; Wilcox, C Mel; Mönkemüller, Klaus E

    2015-04-01

    To present a novel, less-invasive method of endoscopic drainage (ED) for walled-off pancreatic necrosis (WON).We describe the feasibility, success rate, and complications of combined ED extra-cavitary lavage and debridement of WON using a biliary catheter and high-flow water jet system (water pump). Endoscopic ultrasound (EUS)-guided drainage was performed with insertion of two 7-Fr, 4-cm double pigtail stents. Subsequently a fully covered self-expanding metal stent (fcSEMS) was placed. The key aspect of the debridement was the insertion of a 5-Fr biliary catheter through or along the fcSEMS into the cavity, with ensuing saline lavage using a high-flow water jet system. The patients were then brought back for repeated, planned endoscopic lavages of the WON. No endoscopic intra-cavitary exploration was performed. A total of 17 patients (15 men, 2 women; mean age 52.6, range 24 - 69; mean American Society of Anesthesiologists [ASA] score of 3) underwent ED of WON with this new method. The mean initial WON diameter was 9.5 cm, range 8 to 26 cm. The total number of ED was 84, range 2 to 13. The mean stenting period was 42.5 days. The mean follow-up was 51 days, range 3 to 370. A resolution of the WON was achieved in 14 patients (82.3 %). There were no major complications associated with this method. ED of complex WON with fcSEMS followed by repeated endoscopic extra-cavitary lavage and debridement using a biliary catheter and high-flow water jet system is a minimally invasive, feasible method with high technical and clinical success and minimal complications.

  5. Self-expanding stents and aortoiliac occlusive disease: a review of the literature

    PubMed Central

    Bekken, Joost A; Jongsma, Hidde; de Vries, Jean-Paul PM; Fioole, Bram

    2014-01-01

    The treatment of symptomatic aortoiliac occlusive disease has shifted from open to endovascular repair. Both short- and long-term outcomes after percutaneous angioplasty and stenting rival those after open repair and justify an endovascular-first approach. In this article, we review the current endovascular treatment strategies in patients with aortoiliac occlusive disease, indications for primary and selective stenting in the iliac artery, and physical properties and future perspectives of self-expanding stents. PMID:24833925

  6. First clinical experience with the Innova versus the Protege EverFlex self-expanding bare metal stents in superficial femoral artery occlusions.

    PubMed

    Gabrielli, Roberto; Rosati, Maria Sofia; Chiappa, Roberto; Millarelli, Massimiliano; Marcuccio, Luigi; Siani, Andrea; Caselli, Giovanni

    2015-03-01

    To evaluate outcomes of superficial femoral artery (SFA) stenting with Boston Scientific Innova stent system (Boston Scientific Corporation Place, Natick, Massachusetts, United States) compared with ev3 Protege stent system (Endovascular, Inc., Plymouth, Minnesota, United States) in terms of safety and effectiveness and to identify factors predictive of restenosis. From March 2012 to January 2013, 71 patients with SFA TASC (Trans Atlantic Inter-Societal Consensus)-II B and C occlusive lesions were treated by percutaneous transluminal angioplasty with stenting (30 patients in the Innova group and 41 cases in the Protege group) and were evaluated by retrospective observational data analysis. Chi-square tests for categorical data and time to event provided two-sided p values with a level of significance at 0.05 and 95% confidence intervals (CIs). Survival curves for primary patency were plotted using the Kaplan-Meier method. Univariate analysis for diabetes, hypercholesterolemia, smoking, hypertension, and critical limb ischemia was performed according to the Cox proportional hazards model. The mean follow-up was 14 months (range 1-18 months). The occlusive lesions treated were ≤15 cm in length. The 12-month primary patency rate was significantly higher in the Protege group (81.5%; 31/38) than the Innova group (43.3%; 13/30; hazard ratio [HR] 3.0; 95% CI: 1.38-6.8; p = 0.005. The secondary patency was similar to the primary comparison data and showed a significant advantage for the Protege stent (HR 2.9; 95% CI: 1.21-6.99; p = 0.01). Univariate analysis demonstrated that diabetes and smoking were significantly related to patency failure in both groups. SFA stenting is generally a safe procedure, but the effectiveness and patency rates are significantly lower for Innova than Protege. Furthermore, preoperative diabetes and smoking continue to be associated with low primary patency rate. These preliminary data suggest that Innova stent is not the treatment of choice

  7. Outcomes of Self-Expanding Metal Stents in Malignant Colonic Obstruction are Independent of Location or Length of the Stenosis: Results of a Retrospective, Single-Center Series.

    PubMed

    Schoonbeek, Paul K; Genzel, Pim; van den Berg, Eline H; van Dobbenburgh, O Aart; Ter Borg, Frank

    2017-08-16

    To evaluate the length and location of stenosis in the colon as predictors of technical and clinical outcomes of stent placement in patients presenting with obstructive colorectal cancer. A prospective single-center cohort study of patients treated with a colonic stent for malignant obstruction, regardless of stenosis length or location. Stenosis length was assessed globally on the appropriate CT slice as well as by 3D CT reconstruction. We analyzed whether outcomes were different in patients with a right sided-tumor and/or a stenosis >4 cm long. One hundred forty-one patients were evaluated, 63 with a stenosis >4 cm, 48 with a stenosis proximal to the splenic flexure. Technical failure (n = 9) was mainly caused because of looping or due to the difficulty in engaging the stenosis precluding analysis of the relation between the stenosis length and technical success. Both measurement methods showed good agreement. Clinical outcomes were not associated with stenosis length or location. Clinical outcomes of stenting did not differ between groups regardless of stenosis length or location. Measuring stenosis length more precisely using 3D CT reconstructions is not of help. © 2017 S. Karger AG, Basel.

  8. Evaluation of the short- and long-term effectiveness and safety of fully covered self-expandable metal stents for drainage of pancreatic fluid collections: results of a Spanish nationwide registry.

    PubMed

    Vazquez-Sequeiros, Enrique; Baron, Todd H; Pérez-Miranda, Manuel; Sánchez-Yagüe, Andres; Gornals, Joan; Gonzalez-Huix, Ferran; de la Serna, Carlos; Gonzalez Martin, Juan Angel; Gimeno-Garcia, Antonio Z; Marra-Lopez, Carlos; Castellot, Ana; Alberca, Fernando; Fernandez-Urien, Ignacio; Aparicio, Jose Ramon; Legaz, Maria Luisa; Sendino, Oriol; Loras, Carmen; Subtil, Jose Carlos; Nerin, Juan; Perez-Carreras, Mercedes; Diaz-Tasende, Jose; Perez, Gustavo; Repiso, Alejandro; Vilella, Angels; Dolz, Carlos; Alvarez, Alberto; Rodriguez, Santiago; Esteban, Jose Miguel; Juzgado, Diego; Albillos, Agustin

    2016-09-01

    Initial reports suggest that fully covered self-expandable metal stents (FCSEMSs) may be better suited for drainage of dense pancreatic fluid collections (PFCs), such as walled-off pancreatic necrosis. The primary aim was to analyze the effectiveness and safety of FCSEMSs for drainage of different types of PFCs in a large cohort. The secondary aim was to investigate which type of FCSEMS is superior. This was a retrospective, noncomparative review of a nationwide database involving all hospitals in Spain performing EUS-guided PFC drainage. From April 2008 to August 2013, all patients undergoing PFC drainage with an FCSEMS were included in a database. The main outcome measurements were technical success, short-term (2 weeks) and long-term (6 months) effectiveness, adverse events, and need for surgery. The study included 211 patients (pseudocyst/walled-off pancreatic necrosis, 53%/47%). The FCSEMSs used were straight biliary (66%) or lumen-apposing (34%). Technical success was achieved in 97% of patients (95% confidence interval [CI], 93%-99%). Short-term- and long-term clinical success was obtained in 94% (95% CI, 89%-97%) and 85% (95% CI, 79%-89%) of patients, respectively. Adverse events occurred in 21% of patients (95% CI, 16%-27%): infection (11%), bleeding (7%), and stent migration and/or perforation (3%). By multivariate analysis, patient age (>58 years) and previous failed drainage were the most important factors associated with negative outcome. An FCSEMS is effective and safe for PFC drainage. Older patients with a history of unsuccessful drainage are more likely to fail EUS-guided drainage. The type of FCSEMS does not seem to influence patient outcome. Copyright © 2016 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

  9. Efficacy and complications in the use of self-expanding colonic stents: an analysis of 15 years' experience.

    PubMed

    Samper Wamba, J D; Fernández Martínez, A; González Pastrana, L; López González, L; Balboa Arregui, Ó

    2015-01-01

    To analyze the efficacy and safety of the procedure for placing self-expanding stents in the colon. To evaluate the factors associated with complications. To analyze the dose of radiation delivered in the procedure. This was a retrospective descriptive study of 478 procedures done at a single center to place self-expanding metallic stents in the colon. A total of 423 nitinol stents and 79 stainless steel stents were placed. We included all colonic obstructions, of which 446 had malignant causes and 8 had benign causes. We excluded patients with intestinal perforation, severe colonic bleeding, short life expectancy, or lesions located less than 5 cm from the anus. We collected the dosimetric data and analyzed the technical success, clinical success, and complications during follow-up. The procedure was a technical success in 92.26% of cases (n=441) and a clinical success in 78.45% (n=375); complications occurred during follow-up in 18.5% of cases. Complications occurred more frequently with the stainless steel stents than with the nitinol stents (OR: 3.2; 95% CI: 1.8-5.7). The mean value of the dose area product was 35 Gy*cm(2). When instead of being done by the interventional radiologist working together with an endoscopist the procedure was done exclusively by the interventional radiologist, the time under fluoroscopy (p=0.001), dose area product (p=0.029), and kinetic energy released per unit mass (p=0.001) were greater. The procedure for placing self-expanding colonic stents is efficacious and safe with an acceptable rate of complications. The doses of radiation delivered were low, and the radiation doses and time under fluoroscopy were lower when the procedure was done together with an endoscopist. Copyright © 2014 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

  10. Design method of self-expanding stents suitable for the patient's condition.

    PubMed

    Yoshino, D; Inoue, K

    2010-01-01

    A medical device of mesh-shaped tubular structure, called a stent, is frequently used to expand the stenosis of a blood vessel. The stent normally has the structure of longitudinally repeated wavy wire parts and strut parts, and its mechanical properties, such as bending flexibility and rigidity in the radial direction, mainly depend on the shape of the wavy wire and the construction of the strut. This paper presents, a design support system for self-expanding stents that can design stent shape and evaluate stent performance as routine flow. A two-stage method for designing suitable stent shapes is built into this system. The mechanical properties of self-expandable stents are evaluated using a non-linear finite element method. The wire length of the stent and the wire width are adopted as design parameters, and the sensitivity of the mechanical properties to these parameters is obtained. When the patient's conditions, such as blood vessel type and the diameter of the blood vessel with stenosis, are given by medical examination, the performance of the stent in restoring blood flow has to be determined. Finally, a method is proposed for designing suitable stents with the desired performance on the basis of mechanical properties.

  11. Use of nitinol self-expandable stents in 26 dogs with tracheal collapse.

    PubMed

    Beranek, J; Jaresova, H; Rytz, U

    2014-02-01

    A study was designed to describe a novel approach to the treatment of tracheal collapse (TC) in dogs using self-expandable nitinol stents. Medical records were reviewed retrospectively for 26 client owned dogs in which nitinol stents were deployed. The entire length of trachea was supported independently of the extent of TC. Two overlapping stents were used instead of one in cases where one stent was not spanning the entire trachea adequately. The diameter of the cranial radiolucent portion of trachea, just behind the cricoid cartilage, was measured as a specific landmark to select the appropriate size of the stent. Two self-expandable nitinol stents were inserted in 9 of 26 dogs; the trachea in the rest of the cases was supported with only one stent. A follow up tracheoscopy was performed in 10 of 26 cases with recurrent clinical signs. Secondary tracheal stenosis in these cases was caused by stent fracture, granuloma or excessive stent shortening. Additional stents were placed successfully to expand the stenotic lumen. A support of the entire trachea may decrease risk of nitinol fracture at the end of the implant. Long term clinical improvement (25 of 26 dogs, 96 %) is comparable with the results of other studies.

  12. Recent advances in self-expanding stents for use in the superficial femoral and popliteal arteries.

    PubMed

    Aghel, Arash; Armstrong, Ehrin J

    2014-07-01

    Significant advances have been made in femoropopliteal stent design and clinical outcomes during the past decade. Initial randomized studies demonstrated superiority of nitinol self-expanding stents to balloon angioplasty for treatment of moderate-length superficial femoral artery stenoses. During longer-term follow-up, first generation nitinol stents were hampered by high rates of stent fracture. A number of newer nitinol stent designs have been developed with improved conformability, greater radial strength and lower rates of long-term stent fracture. These newer stent designs have demonstrated superior primary patency and decreased restenosis for the treatment of moderate-length femoropopliteal lesions relative to historical benchmarks. Recent advances in drug-eluting nitinol stents have also offered treatment options for challenging lesion subsets including very long femoropopliteal lesions and for the treatment of in-stent restenosis. This article reviews recent advances and upcoming research in nitinol self-expanding stent technology for the treatment of superficial femoral and popliteal artery stenosis.

  13. Post-biliary sphincterotomy bleeding despite covered metallic stent deployment

    PubMed Central

    Donatelli, Gianfranco; Cereatti, Fabrizio; Dumont, Jean-Loup; Dhumane, Parag; Tuszynski, Thierry; Vergeau, Bertrand Marie; Meduri, Bruno

    2016-01-01

    Objectives: Several endoscopic techniques have been proposed for the management of post-sphincterotomy bleeding. Lately, self-expandable metal stents deployment has gained popularity especially as a rescue therapy when other endoscopic techniques fail. Methods-results: We report the case report of a massive post-sphincterotomy bleeding in a patient with a self-expandable metal stent in the biliary tree. Despite the presence of a correctly positioned self-expandable metal stent, a new endoscopic session was required to control the bleeding. Conclusions: Self-expandable metal stent may be useful to manage post-endoscopic sphincterotomy bleeding. However, up to now there is no specifically designed self-expandable metal stent for such complication. Large new designed self-expandable metal stent may be a useful tool for biliary endoscopist. PMID:27489716

  14. Treatment of Malignant Biliary Obstruction with a PTFE-Covered Self-Expandable Nitinol Stent

    PubMed Central

    Kwak, Hyo-Sung; Jin, Gong-Yong; Lee, Seung-Ok; Chung, Gyung-Ho

    2007-01-01

    Objective We wanted to determine the technical and clinical efficacy of using a PTFE-covered self-expandable nitinol stent for the palliative treatment of malignant biliary obstruction. Materials and Methods Thirty-seven patients with common bile duct strictures caused by malignant disease were treated by placing a total of 37 nitinol PTFE stents. These stents were covered with PTFE with the exception of the last 5 mm at each end; the stent had an unconstrained diameter of 10 mm and a total length of 50-80 mm. The patient survival rate and stent patency rate were calculated by performing Kaplan-Meier survival analysis. The bilirubin, serum amylase and lipase levels before and after stent placement were measured and then compared using a Wilcoxon signed-rank test. The average follow-up duration was 27.9 weeks (range: 2-81 weeks). Results Placement was successful in all cases. Seventy-six percent of the patients (28/37) experienced adequate palliative drainage for the remainder of their lives. There were no immediate complications. Three patients demonstrated stent sludge occlusion that required PTBD (percutaneous transhepatic biliary drainage) irrigation. Two patients experienced delayed stent migration with stone formation at 7 and 27 weeks of follow-up, respectively. Stent insertion resulted in acute elevations of the amylase and lipase levels one day after stent insertion in 11 patients in spite of performing endoscopic sphincterotomy (4/6). The bilirubin levels were significantly reduced one week after stent insertion (p < 0.01). The 30-day mortality rate was 8% (3/37), and the survival rates were 49% and 27% at 20 and 50 weeks, respectively. The primary stent patency rates were 85%, and 78% at 20 and 50 weeks, respectively. Conclusion The PTFE-covered self-expandable nitinol stent is safe to use with acceptable complication rates. This study is similar to the previous studies with regard to comparing the patency rates and survival rates. PMID:17923784

  15. Oversizing and Restenosis with Self-Expanding Stents in Iliofemoral Arteries

    SciTech Connect

    Saguner, Ardan M. Traupe, Tobias; Raeber, Lorenz; Hess, Nina; Banz, Yara; Saguner, Arhan R.; Diehm, Nicolas; Hess, Otto M.

    2012-08-15

    Purpose: Uncoated self-expanding nitinol stents (NS) are commonly oversized in peripheral arteries. In current practice, 1-mm oversizing is recommended. Yet, oversizing of NS may be associated with increased restenosis. To provide further evidence, NS were implanted in porcine iliofemoral arteries with a stent-to-artery-ratio between 1.0 and 2.3. Besides conventional uncoated NS, a novel self-expanding NS with an antiproliferative titanium-nitride-oxide (TiNOX) coating was tested for safety and efficacy. Methods: Ten uncoated NS and six TiNOX-coated NS (5-6 mm) were implanted randomly in the iliofemoral artery of six mini-pigs. After implantation, quantitative angiography (QA) was performed for calculation of artery and minimal luminal diameter. Follow-up was performed by QA and histomorphometry after 5 months. Results: Stent migration, stent fracture, or thrombus formation were not observed. All stents were patent at follow-up. Based on the location of the stent (iliac/femoral) and the stent-to-artery-ratio, stent segments were divided into 'normal-sized' (stent-to-artery-ratio < 1.4, n = 12) and 'oversized' (stent-to-artery-ratio {>=} 1.4, n = 9). All stent segments expanded to their near nominal diameter during follow-up. Normal-sized stent segments increased their diameter by 6% and oversized segments by 29%. A significant correlation between oversizing and restenosis by both angiography and histomorphometry was observed. Restenosis rates were similar for uncoated NS and TiNOX-coated NS. Conclusions: TiNOX-coated NS are as safe and effective as uncoated NS in the porcine iliofemoral artery. All stents further expand to near their nominal diameter during follow-up. Oversizing is linearly and positively correlated with neointimal proliferation and restenosis, which may not be reduced by TiNOX-coating.

  16. Polyurethane-Covered Self-expandable Nitinol Stent for Malignant Biliary Obstruction: Preliminary Results

    SciTech Connect

    Han, Young-Min; Hwang, Seung-Bae; Lee, Soo-Teik; Lee, Jeong-Min; Chung, Gyung-Ho

    2002-10-15

    Purpose: To evaluate the immediate and long-term results in ten patients with malignant biliary obstruction using a polyurethane-covered, self-expandable nitinol stent.Methods: A nitinol stent, fully covered with high-elasticity polyurethane, with an unconstrained diameter of 10 mm and a total length of 60-80 mm, was placed transhepatically under fluoroscopic guidance in ten patients. The length of the biliary obstruction varied between 30-50 mm. The follow-up examination included a clinical assessment, serum bilirubin measurement, and ultrasound examinations at one-month intervals in all patients. Results: Initial stent deployment was successful in eight patients. Two patients experienced proximal migration,which was solved by insertion of two, uncovered Wallstents. One patient had the stent removed after two weeks because of severe nausea and vomiting. One patient had delayed migration of the covered stent after 40 weeks. The follow-up duration was 3-40 weeks (Mean: 16.9 weeks). Seven patients died(3-26 weeks) and three patients survived (24-40 weeks). The bilirubin measurements in all patients had significantly decreased one week after stent insertion. The levels of amylase and lipase had did not increase after stent insertion. Conclusions: Apolyurethane-covered, self-expandable nitinol stent can be used effectively and safely in the treatment of malignant biliary obstruction. The preliminary results are favorable, but there is a need for further large studies to determine both long-term survival and patency.

  17. The development of self-expanding peripheral stent with ion-modified surface layer

    NASA Astrophysics Data System (ADS)

    Lotkov, Alexander I.; Kashin, Oleg A.; Kudryashov, Andrey N.; Krukovskii, Konstantin V.; Kuznetsov, Vladimir M.; Borisov, Dmitry P.; Kretov, Evgenii I.

    2016-11-01

    In work researches of chemical composition of surface layers of self-expanding stents of nickel-titanium (NiTi) and their functional and mechanical properties after plasma immersion processing by ions of silicon (Si). It is established that in the treatment in the inner and outer surfaces of stents formed doped silicon layer with a thickness of 80 nm. The formation of the doped layer does not impair the functional properties of the stent. At human body temperature, the stent is fully restore its shape after removing the deforming load. The resulting graph of loading of stents during their compression between parallel plates. The research results allow the conclusion that Si-doped stents are promising for treatment of peripheral vascular disease. However, related studies on laboratory animals are required.

  18. Self-expanding stent placement for anterior circulation intracranial artery dissection presenting with ischemic symptoms.

    PubMed

    Kim, Dong Joon; Kim, Byung Moon; Suh, Sang Hyun; Kim, Dong Ik

    2015-02-01

    The prognosis of ischemic anterior circulation intracranial dissection (AC-ICD) is poor and its optimal management is still controversial. To evaluate the safety and efficacy of a self-expanding stent for ischemic AC-ICD. Eight patients (mean age, 36 years) underwent self-expanding stenting for ischemic AC-ICD. Imaging findings of ischemic AC-ICD, the reason for stenting, and the clinical and angiographic outcomes were retrospectively evaluated. AC-ICD involved intracranial internal carotid artery to middle cerebral artery (MCA) in 2, intracranial internal carotid artery alone in 3, and MCA alone in 3 patients. Six AC-ICDs showed complete or near occlusions while 2 had a severe degree of stenosis. Six AC-ICDs showed an intimal flap and 3 had intramural hematomas. Six patients underwent emergent stenting for acute stroke within 6 hours (n=2) or crescendo-type stroke within 24 hours (n=4), while 2 patients had stenting for recurrent ischemia on dual antiplatelet and/or anticoagulation after the initial attack. The mean dissection-related stenosis improved from 93.1% to 20.3% after stenting (P<.05). The mean National Institutes of Health Stroke Scale score improved from 7.5 to 1.4 (P<.05). All patients had excellent or favorable outcomes at 3 months: modified Rankin Scale score, 0 in 3, 1 in 3, and 2 in 1 patient(s). No patients had subarachnoid hemorrhage or ischemic symptom recurrence during the clinical follow-up (mean, 27 months). All stented arteries were patent without significant in-stent stenosis on angiographic follow-up (range, 3-12 months). Self-expanding stents seem to be safe and effective for AC-ICD presenting with acute/crescendo-type stroke or recurrent ischemia despite adequate medication.

  19. Covered Self-Expanding Transhepatic Biliary Stents:Clinical Pilot Study

    SciTech Connect

    Thurnher, Siegfried A.; Lammer, Johannes; Thurnher, Majda M.; Winkelbauer, Friedrich; Graf, Oswald; Wildling, Reinhard

    1996-11-15

    Purpose: We report our preliminary results with a new type of self-expanding covered stent for treatment of malignant biliary obstruction. Methods: Wallstents, fully covered with high elasticity polyurethane, with an unconstrained diameter of 10 mm and a total length of 69 mm, were placed transhepatically under fluoroscopic guidance in five patients. The length of the biliary obstruction varied between 30<+>-<+>50 mm. At 1 and 3 months (82<+>-<+>98 days) clinical assessment, serum bilirubin measurement, and ultrasound examination of the biliary tree were performed. Results: Initial uncomplicated deployment of the stents and internal drainage was possible in all patients. Distal stent migration resulted in early biliary reobstruction in one patient. At 3-month follow-up, partial reobstruction, most probably due to sludge formation, was found in another patient. Conclusion: Our initial results indicate that the covered, self-expanding Wallstent endoprosthesis can be reliably and safely deployed transhepatically for malignant biliary obstruction.

  20. In vitro comparison of self-expanding versus balloon-expandable stents in a human ex vivo model.

    PubMed

    Grenacher, Lars; Rohde, Stefan; Gänger, Ellen; Deutsch, Jochen; Kauffmann, Günter W; Richter, Götz M

    2006-01-01

    The objective was to compare the radial strength and expansile precision of self-expanding stents and balloon-expandable stents in a human cadaver bifurcation model. Seven different self-expanding (LUMINEXX, JOSTENT SelfX, JOSTENT SelfX hrf, Sinus-Repo, Sinus SuperFlex, Easy Wallstent, SMART) and four different balloon-expandable stent models (Palmaz, Sinus Stent, SAXX Medium, JOSTENT peripheral), each type 10 stents (total n = 110 stents) were implanted into the common iliac arteries of human cadaver corpses. The maximum stent diameter was 10 mm for all models. After stent implantation, the specimens were filled with silicone caoutchouc. After 24 h, the vascular walls including the stents were removed from the hardened casts. Diameters were taken and the weight of the cast cylinders was measured in air and in purified water to calculate the volume of the bodies (according to Archimedes Law) as a relative but precise degree for the radial strength of the implanted stents. The cylindrical casts of the self-expanding stents showed lower mean diameters (8.2 +/- 1.0 mm) and mean volumes (0.60 +/- 0.14 ml/cm) than in the balloon-expandable stent group (10.1 +/- 0.3 mm and 0.71 +/- 0.04 ml/cm, respectively; p < 0.01). The nominal maximum diameter of 10 mm was not achieved in any of the self-expanding stents, but this was achieved in more than 70% (29/40) of the balloon-expandable stent specimens (p < 0.05). The variation between achieved volumes was significantly larger in self-expanding (range: 0.23-0.78 ml/cm) than in balloon-expandable stents (range: 0.66-0.81 ml/cm; p < 0.05). Self-expanding stents presented considerably lower radial expansion force and lower degree of precision than balloon-expandable stents.

  1. In Vitro Comparison of Self-Expanding Versus Balloon-Expandable Stents in a Human Ex Vivo Model

    SciTech Connect

    Grenacher, Lars Rohde, Stefan Gaenger, Ellen; Deutsch, Jochen; Kauffmann, Guenter W.; Richter, Goetz M.

    2006-04-15

    The objective was to compare the radial strength and expansile precision of self-expanding stents and balloon-expandable stents in a human cadaver bifurcation model. Seven different self-expanding (LUMINEXX, JOSTENT SelfX, JOSTENT SelfX hrf, Sinus-Repo, Sinus SuperFlex, Easy Wallstent, SMART) and four different balloon-expandable stent models (Palmaz, Sinus Stent, SAXX Medium, JOSTENT peripheral), each type 10 stents (total n = 110 stents) were implanted into the common iliac arteries of human cadaver corpses. The maximum stent diameter was 10 mm for all models. After stent implantation, the specimens were filled with silicone caoutchouc. After 24 h, the vascular walls including the stents were removed from the hardened casts. Diameters were taken and the weight of the cast cylinders was measured in air and in purified water to calculate the volume of the bodies (according to Archimedes Law) as a relative but precise degree for the radial strength of the implanted stents. The cylindrical casts of the self-expanding stents showed lower mean diameters (8.2 {+-} 1.0 mm) and mean volumes (0.60 {+-} 0.14 ml/cm) than in the balloon-expandable stent group (10.1 {+-} 0.3 mm and 0.71 {+-} 0.04 ml/cm, respectively; p < 0.01). The nominal maximum diameter of 10 mm was not achieved in any of the self-expanding stents, but this was achieved in more than 70% (29/40) of the balloon-expandable stent specimens (p < 0.05). The variation between achieved volumes was significantly larger in self-expanding (range: 0.23-0.78 ml/cm) than in balloon-expandable stents (range: 0.66-0.81 ml/cm; p < 0.05). Self-expanding stents presented considerably lower radial expansion force and lower degree of precision than balloon-expandable stents.

  2. Insertion of Self-Expandable Nitinol Stents Without Previous Balloon Angioplasty Reduces Restenosis Compared with PTA Prior to Stenting

    SciTech Connect

    Harnek, Jan; Zoucas, Evita; Stenram, Unne; Cwikiel, Wojciech

    2002-10-15

    Purpose: To compare the development of intimal hyperplasia after deployment of a self-expanding nitinol stent with and without previous percutaneous transluminal balloon angioplasty (PTA), with the results after PTA alone. Methods: In nine healthy pigs, the iliac arteries were divided into three groups: group 1 (n = 6 arteries) was treated with PTA; group 2 n 6)with insertion of self-expanding stents after PTA; and group 3 (n = 6) with stent insertion without previous PTA. After 8 weeks the vessels were examined with intravascular ultrasonography,histologic examination and morphometric analysis. Results: Although the injury index in group 1 (0.17{+-} 0.57) was lower (p <0.05) than in group 2 (0.26 {+-} 0.06) and group 3 (0.26 {+-} 0.08), PTA-treated arteries showed significantly (p <0.05) reduced mean luminal gain (0.53 {+-} 2.84) compared with arteries treated with PTA prior to stenting (2.58 {+-} 1.38) and compared with stenting alone (4.65 {+-}5.34). Stenting after PTA resulted in a higher (p<0.05) restenosis index (2.63 {+-} 1.06) compared with stenting without PTA (1.35 {+-} 0.59). Group 2 also had a significantly thicker intimap <0.05) and 83% and 74% higher intima/mediaratio (p <0.05) compared with groups 1 and 3, respectively. Conclusion: Insertion of a self-expandable nitinol stent without previous PTA results in less intimalhyperplasia than if PTA is performed prior to stenting, suggesting that direct stenting can be used in angioplasty sessions with a favorable outcome.

  3. A Word of Caution for Extra Large Self-expandable Nitinol Stents.

    PubMed

    Reyes Valdivia, Andrés; Duque Santos, Africa; Alvarez Marcos, Francisco; Romero Lozano, Asunción; Ocaña Guaita, Julia; Gandarias Zúñiga, Claudio

    2017-07-01

    To report an unsuccessful use of large nitinol stent to prevent proximal endoleak in endograft treatment for juxtarenal aortic aneurysm. An 82-year-old male presented coronary disease and severe chronic obstructive pulmonary disease requiring oxygen support. A large 80-mm juxtarenal aneurysm was found on routine urological examination. Neck features were as follows: 7 mm and high anterior-posterior angulation. ASA risk score IV was given. Patient wanted to be treated. We decided a 1-shot intervention based on self-expandable suprarenal fixation endograft with adjunctive extra large self-expandable (high radial force) nitinol stent. Control computed tomography scan demonstrates nitinol stent severe infolding and a possible perforation of the primary endograft. At 6-month follow-up, sac reveals enlargement of 5 mm and 6% volume increase. Patient does not want further treatments due to high risk of procedures. Extreme caution should be taken when using self-expandable extra large nitinol stents for preventive matters. Oversizing should be carefully considered, not necessarily reaching the endograft chosen size. When short and angulated neck morphology co-exists, other devices or procedures may be a better option. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Carotid Artery Stenting Using a Novel Self-Expanding Braided Nickel-Titanium Stent: Feasibility and Safety Porcine Trial

    SciTech Connect

    Ahlhelm, Frank Kaufmann, Ralf; Ahlhelm, Dirk Ong, Mai Fang; Roth, Christian Reith, Wolfgang

    2009-09-15

    We studied the deliverability and safety of a braided, self-expanding, closed-cell nickel-titanium (NiTi) stent (E-volution, Jotec GmbH, Hechingen, Germany) especially designed for the endovascular treatment of carotid artery bifurcation stenosis with special regard to in-stent stenosis and thrombosis compared with a laser-cut reference nitinol stent in a porcine model of percutaneous vascular interventions. We aimed to assess histopathologic response in minipig carotid and subclavian arteries. Eight minipigs received a total of 42 stents: 14 reference stents and 28 E-volution stents. Eleven of the E-volution stents were additionally coated with heparin. Control angiography was obtained immediately before and after vascular intervention as well as 4 weeks after the procedure. Primary endpoints were 28 days of angiographic analyses as well as histomorphometric analysis, including injury score, inflammation score, luminal diameter, vessel diameter, maximal neointimal thickness, and area of in-stent stenosis. Secondary end points were procedural success, 28-day mortality, and stent thrombosis. All stents could be delivered successfully without procedural complications, morbidity, or mortality during our observation time. As confirmed by histology, no in-stent thrombosis was observed. Compared with common carotid arteries, subclavian arteries are significantly more vulnerable to developing in-stent stenosis caused by neointima proliferation (p < 0.05). Compared with the use of 1 single stent/artery, serial application of two stents leads to a more excessive but not significantly different neointimal proliferation (p > 0.05). The E-volution stent, especially when heparin coated, is in line with the comparison to the laser-cut reference stent displaying similar results of angiographic, histologic, and histomorphometric analyses (p > 0.05). Compared with the reference laser-cut stent, the self-expanding nitinol stent (E-volution) with its advanced braiding technology is

  5. A comparison of temporary self-expanding plastic and biodegradable stents for refractory benign esophageal strictures.

    PubMed

    van Boeckel, Petra G A; Vleggaar, Frank P; Siersema, Peter D

    2011-08-01

    It is a challenge to manage refractory benign esophageal strictures (RBES). We compared the efficacy and safety of self-expanding plastic stents (SEPSs) with placement of biodegradable stents for the treatment of RBES. We studied 2 groups of consecutive patients with RBES who received temporary placement (6 weeks) of SEPSs (n = 20) or biodegradable stents (n = 18). Data were collected with respect to clinical outcome, complications, recurrent dysphagia, and reinterventions. SEPSs were removed in 16 (80%) patients. Stent placement was not successful in 1 patient, while stent removal was not performed in another 3 patients. Six (30%) patients with an SEPS were dysphagia-free after a median follow-up of 385 days (range, 77-924 days). Ten (50%) developed recurrent dysphagia. Major complications occurred in 2 patients (10%; 1 with hemorrhage and 1 with perforation). Six patients (33%) with a biodegradable stent were dysphagia-free after a median follow-up of 166 days (range 21-559 days) (P = .83 compared with SEPS). Twelve patients (67%) had recurrent dysphagia. Major complications occurred in 4 patients (22%; 2 with hemorrhage, 2 with severe retrosternal pain) with a biodegradable stent (P = .30 compared with SEPS). Reinterventions were less frequently indicated after biodegradeble stent than after SEPS placement (15 [mean, 0.8 ± 0.6 per stent placed] vs 21 [mean, 1.3 ± 0.4 per stent placed], respectively; P = .03). Placement of SEPSs or biodegradable stents provides long-term relief of dysphagia in 30% and 33%, respectively, of patients with RBES. Biodegradable stents require fewer procedures than SEPSs, offering an advantage. Although stent placement is a viable strategy in patients with RBES, the ideal strategy still needs to be defined. Copyright © 2011 AGA Institute. Published by Elsevier Inc. All rights reserved.

  6. Use of self-expanding nitinol stents in the pediatric management of refractory esophageal caustic stenosis.

    PubMed

    Alonso, Verónica; Ojha, Devicka; Nalluri, Harsha; de Agustín, Juan Carlos

    2017-10-01

    The treatment of recurrent esophageal stricture secondary to the ingestion of a caustic agent is an arduous task. Self-expanding esophageal stents may be an alternative to repeated endoscopic esophageal dilations. We present the case of a two-year-old male with a severe and long esophageal stricture successfully treated by the combination of dilations and stent placement. After five months of serial pneumatic dilations, three self-expanding nitinol stents internally coated with silicone were introduced through a gastrostomy, covering the entire esophagus. The procedure was performed under endoscopic and radiological guidance. Three months later, the treatment was repeated with a single stent. A new stenosis in the proximal esophagus required surgical resection, and anastomosis followed by two pneumatic dilations for five months resulted in longer intervals where the patient was asymptomatic. The results obtained were satisfactory, allowing the patient to conserve and use his own esophagus. However, this is a unique case and the optimal maintenance time and withdrawal time of the stent must be determined.

  7. Mechanical modeling of self-expandable stent fabricated using braiding technology.

    PubMed

    Kim, Ju Hyun; Kang, Tae Jin; Yu, Woong-Ryeol

    2008-11-14

    The mechanical behavior of a stent is one of the important factors involved in ensuring its opening within arterial conduits. This study aimed to develop a mechanical model for designing self-expandable stents fabricated using braiding technology. For this purpose, a finite element model was constructed by developing a preprocessing program for the three-dimensional geometrical modeling of the braiding structure inside stents, and validated for various stents with different braiding structures. The constituent wires (Nitinol) in the braided stents were assumed to be superelastic material and their mechanical behavior was incorporated into the finite element software through a user material subroutine (VUMAT in ABAQUS) employing a one-dimensional superelastic model. For the verification of the model, several braided stents were manufactured using an automated braiding machine and characterized focusing on their compressive behavior. It was observed that the braided stents showed a hysteresis between their loading and unloading behavior when a compressive load was applied to the braided tube. Through the finite element analysis, it was concluded that the current mechanical model can appropriately predict the mechanical behavior of braided stents including such hysteretic behavior, and that the hysteresis was caused by the slippage between the constituent wires and their superelastic property.

  8. Implantation study of a tissue-engineered self-expanding aortic stent graft (bio stent graft) in a beagle model.

    PubMed

    Kawajiri, Hidetake; Mizuno, Takeshi; Moriwaki, Takeshi; Iwai, Ryosuke; Ishibashi-Ueda, Hatsue; Yamanami, Masashi; Kanda, Keiichi; Yaku, Hitoshi; Nakayama, Yasuhide

    2015-03-01

    The use of stent grafts for endovascular aortic repair has become an important treatment option for aortic aneurysms requiring surgery. This treatment has achieved excellent outcomes; however, problems like type 1 endoleaks and stent graft migration remain. Bio stent grafts (BSGs), which are self-expanding stents covered with connective tissue, were previously developed using "in-body tissue architecture" technology. We assessed their early adaptation to the aorta after transcatheter implantation in a beagle model. BSGs were prepared by subcutaneous embedding of acryl rods mounted with self-expanding nitinol stents in three beagles for 4 weeks (n = 3/dog). The BSGs were implanted as allografts into infrarenal abdominal aortas via the femoral artery of three other beagles. After 1 month of implantation, aortography revealed no stenosis or aneurysmal changes. The luminal surface of the BSGs was completely covered with neointimal tissue, including endothelialization, without any thrombus formation. The cover tissue could fuse the luminal surface of the native aorta with tight conjunctions even at both ends of the stents, resulting in complete impregnation of the strut into the reconstructed vascular wall, which is expected to prevent endoleaks and migration in clinical applications.

  9. Effect of Self-Expanding Carotid Stents on Plaque Thickness and Vessel Diameter.

    PubMed

    Martínez-Pérez, Rafael; Marchuk, Graeme; Lee, Donald H; Pelz, David M; Lownie, Stephen P

    2017-09-01

    In vitro models have suggested that stents affect atherosclerotic plaques symmetrically because of their outward radial forces. We evaluated the effects of stents on carotid plaque and the arterial wall using carotid ultrasound in carotid stenting patients to see whether these effects were borne out in vivo. From a carotid stent database, 30 consecutive patients were selected. All had carotid Doppler ultrasound performed pre- and poststenting. The diameters of the lumen at the level of stenotic plaque pre- and poststenting, the dorsal and ventral plaque thickness, and of the outer arterial wall diameter were measured. Plaque thickness was measured at the level of maximal stenosis. Nonparametric tests were used to determine whether the stent effect and luminal enlargement were based on wall remodeling or on total arterial expansion. The patients were followed for an average of 22 months. Eighteen patients were male, with an average age of 70 years. A total of 87% of patients were symptomatic ipsilateral to the side of stenosis. Nine patients had angioplasty intraprocedurally. The luminal diameter increased poststenting in the region of severe stenosis. Plaque thickness, both ventrally and dorsally, decreased poststenting, with no significant difference between the ventral and dorsal plaque effects. The outer arterial wall diameters did not change. The measured lumen in the stent increased over time poststenting. Self-expanding nitinol stents alter the baseline ventral and dorsal plaque to a significant degree and do not significantly affect the native arterial wall and the overall arterial diameter.

  10. Fatigue-Life Computational Analysis for the Self-Expanding Endovascular Nitinol Stents

    NASA Astrophysics Data System (ADS)

    Grujicic, M.; Pandurangan, B.; Arakere, A.; Snipes, J. S.

    2012-11-01

    Self-expanding endovascular stents made of Nitinol (a Ni-Ti intermetallic compound possessing superelastic and shape-memory properties) are being widely used to treat a common circulatory problem in which narrowed arteries, primarily due to fatty deposits, hamper blood flow to the extremities (the problem commonly referred to as "peripheral artery disease"). The stents of this type unfortunately occasionally fail structurally (and, in turn, functionally) rendering the stenting procedure ineffective. The failure is most often attributed to the fatigue-induced damage since over its expected ten-year life span, the stent will normally experience 370-400 million pulsating-blood flow-induced loading cycles. Redesign/redevelopment of the stents using the conventional make-and-test approaches is quite expensive and time consuming and therefore is being increasingly complemented by computational engineering methods and tools. In the present study, advanced structural and fluid-structure interaction finite element computational methods are combined with the advanced fatigue-based durability analysis techniques to further enhance the use of the computational engineering analysis tools in the development of vascular stents with improved high-cycle fatigue life.

  11. Comparison of Drug-eluting Coronary Stents, Bare Coronary Stents and Self-expanding Stents in Angioplasty of Middle Cerebral Artery Stenoses

    PubMed Central

    Lee, Jong-Hyeog; Jo, Sung-Min; Jo, Kwang-Deog; Kim, Moon-Kyu; Lee, Sang-Youl

    2013-01-01

    Objective The purpose of this study is to investigate the results of treatment using stent-angioplasty for symptomatic middle cerebral arterial (MCA) stenosis and comparison of in-stent restenosis between drug-eluting stents (DES), bare metal coronary stents (BMS) and self-expanding stents (SES). Materials and Methods From Jan. 2007 to June. 2012, 34 patients (mean age ± standard deviation: 62.9 ± 13.6 years) with MCA stenosis were treated. Inclusion criteria were acute infarction or transient ischemic attacks (TIAs) and angiographically proven symptom related severe stenosis. Stents used for treatment were DES (n = 8), BMS (n = 13) and SES (n = 13). National Institutes of Health Stroke Scale (NIHSS) at admission was 2.5 ± 3.1 and mean stenosis rate was 79.0 ± 8.2%. Assessment of clinical and angiographic results was performed retrospectively. Results Among 34 patients, periprocedural complications occurred in four cases (11.8%), however, only two cases (6.0%) were symptomatic. All patients were followed clinically (mean follow-up period; 40.7 ± 17.7 months) and 31 were followed angiographically (91.2%. 13.4 ± 8.5 months). There was no occurrence of repeat stroke in all patients; however, mild TIAs related to restenosis occurred in three of 34 patients (8.8%). The mean NIHSS after stent-angioplasty was 1.7 ± 2.9 and 0.8 ± 1.1 at discharge. The modified Rankin score (mRS) at discharge was 0.5 ± 0.9 and 0.3 ± 0.8 at the last clinical follow-up. In-stent restenosis over 50% occurred in five of 31 angiographically followed cases (16.1%), however, all of these events occurred only in patients who were treated with BMS or SES. Restenosis rate was 0.0% in the DES group and 20.8% in the other group (p = 0.562); it did not differ between BMS and SES (2/11 18.2%, 3/13 23.1%, p = 1.000). Conclusion Stent-angioplasty appears to be effective for symptomatic MCA stenosis. As for restenosis, in our study, DES was presumed to be more effective than BMS and SES; meanwhile

  12. Hepatic venous outflow obstruction after transplantation: outcomes for treatment with self-expanding stents.

    PubMed

    Viteri-Ramírez, G; Alonso-Burgos, A; Simon-Yarza, I; Rotellar, F; Herrero, J I; Bilbao, J I

    2015-01-01

    To evaluate the safety and patency of self-expanding stents to treat hepatic venous outflow obstruction after orthotopic liver transplantation. To evaluate differences in the response between patients with early obstruction and patients with late obstruction. This is a retrospective analysis of 16 patients with hepatic venous outflow obstruction after liver transplantation treated with stents (1996-2011). Follow-up included venography/manometry, ultrasonography, CT, and laboratory tests. We did a descriptive statistical analysis of the survival of patients and stents, technical and clinical success of the procedure, recurrence of obstruction, and complications of the procedure. We also did an inferential statistical analysis of the differences between patients with early and late obstruction. The mean follow-up period was 3.34 years (21-5,331 days). The technical success rate was 93.7%, and the clinical success rate was 81.2%. The rate of complications was 25%. The survival rates were 87.5% for patients and 92.5% for stents. The rate of recurrence was 12.5%. The rate of primary patency was 0.96 (95% CI 0.91-1) at 3 months, 0.96 (95% CI 0.91-1) at 6 months, 0.87 (95% CI 0.73-1) at 12 months, and 0.87 (95% CI 0.73-1) at 60 months. There were no significant differences between patients with early and late obstruction, although there was a trend toward higher rates of primary patency in patients with early obstruction (P=.091). Treating hepatic venous outflow obstruction after orthotopic transplantation with self-expanding stents is effective, durable, and effective. There are no significant differences between patients with early obstruction and those with late obstruction. Copyright © 2013 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

  13. Radial forces of stents used in thoracic endovascular aortic repair and bare self-expanding nitinol stents measured ex vivo - Rapid rescue for obstruction of the innominate artery using bare self-expanding nitinol stents.

    PubMed

    Matsumoto, Takuya; Inoue, Kentaro; Tanaka, Shinichi; Aoyagi, Yukihiko; Matsubara, Yutaka; Matsuda, Daisuke; Yoshiya, Keiji; Yoshiga, Ryosuke; Ohkusa, Tomoko; Maehara, Yoshihiko

    2017-02-01

    Purpose Our objective was to compare the radial forces of several stents ex vivo to identify stents suitable for rescue of the unexpected coverage of aortic arch branches in thoracic endovascular aortic repair. Methods We measured the radial forces of two types of self-expanding bare nitinol stents (E-luminexx and Epic) used singly or as double-walled pairs, and of three endoprostheses used in thoracic endovascular aortic repair (TEVAR, Gore c-TAG, Relay, and Valiant) by compressing the stent using an MTS Instron universal testing machine (model #5582). We also examined the compressive effects of the TEVAR endoprostheses and the bare nitinol stents on each other. Results The radial force was greater in the center than at the edge of each stent. In all stents tested, the radial force decreased incrementally with increasing stent diameter. The radial force at the center was two times greater when using two stents than with a single stent. In the compression test, only E-luminexx used as a pair was not compressed after compressing a Relay endoprosthesis by 12 mm. Conclusion Two E-luminexx stents are appropriate to restore the blood flow if a TEVAR endoprosthesis covers the innominate artery following innominate-carotid-left subclavian arterial bypass.

  14. The Safety and efficacy of a new self-expandable intratracheal nitinol stent for the tracheal collapse in dogs

    PubMed Central

    Kim, Joon-young; Han, Hyun-jung; Yun, Hun-young; Lee, Bora; Jang, Ha-young; Eom, Ki-dong; Park, Hee-myung

    2008-01-01

    To evaluate the potential utility of a self-expandable intratracheal nitinol stent with flared ends for the treatment of tracheal collapse in dogs, endotracheal stenting therapy was performed under fluoroscopic guidance in four dogs with severe tracheal collapse. During the 4 to 7 month follow-up, after stent implantation, clinical signs, including dyspnea and respiratory distress, dramatically improved in all dogs. The radiographs showed that the implanted stents improved the tracheal collapse, and there were no side effects such as collapse, shortening or migration of the stents. In conclusion, the self-expandable intratracheal nitinol stents provided adequate stability to the trachea and were effective for attenuating the clinical signs associated with severe tracheal collapse. PMID:18296893

  15. The Results of Self-Expandable Kissing Stents in Aortic Bifurcation.

    PubMed

    Moon, Jae Young; Hwang, Hong Pil; Kwak, Hyo Sung; Han, Young Min; Yu, Hee Chul

    2015-03-01

    Kissing stent reconstruction is a widely used technique for the management of aortoiliac occlusive disease involving the aortic bifurcation or proximal common iliac arteries. The purpose of this study was to evaluate the results of self-expandable kissing stents in the aortic bifurcation. We reviewed medical records of the patients treated with a kissing stent retrospectively from January 2007 to December 2012. The primary and secondary patencies were determined with Kaplan-Meier analysis, and Cox regression was used to determine the factors associated with patency. A total of 21 patients were included, and all were male (median age 53±15 years, range 48-78 years). Major symptoms were claudication (n=16, 61.9%), rest pain (n=5, 23.8%) and gangrene (n=5, 23.8%). Tans-Atlantic Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC) II classification was A 2 (9.5%), B 5 (23.8%), C 7 (33.3%) and D 8 (38%). The mean follow-up was 40.7 months. Major complication occurred in only one case which consisted of distal limb ischemia by emboli. Six patients developed symptomatic restenosis or occlusion. There was no major amputation, but minor amputation occurred in 3 patients. There were 2 mortalities not associated with the procedure (lung cancer and intracranial hemorrhage). Primary patency was 89.6% at 1 year, 74.7% at 3 years and 64.0% at 5 years. Secondary patency was 94.1% at 1 year, 88.2% at 3 years and 68.6% at 5 years. No risk factors for restenosis or occlusion were identified. Self-expandable kissing stents can be used successfully with comparable patency for endovascular treatment of symptomatic atherosclerotic occlusive lesions in the aortic bifurcation area.

  16. The varying porosity of braided self-expanding stents and flow diverters: an experimental study.

    PubMed

    Makoyeva, A; Bing, F; Darsaut, T E; Salazkin, I; Raymond, J

    2013-03-01

    Braided self-expandable stents and flow diverters of uniform construction may develop zones of heterogeneous porosity in vivo. Unwanted stenoses may also occur at the extremities of the device. We studied these phenomena in dedicated benchtop experiments. Five braided devices of decreasing porosity were studied. To simulate discrepancies in diameters between the landing zones of the parent vessel and the aneurysm neck area, device extremities were inserted into silicone tubes of various diameters (2-3 mm), leaving the midportion free to react to experimental manipulations, which included axial approximation of the tubes (0-7 mm), and curvature (0-135°), with or without axial compression (0-2 mm). The length of the landing zone was sequentially decreased to study terminal device stenosis. All devices adopted a conformation characterized by 3 different zones: bilateral landing zones, a middle compaction zone, and 2 transition zones. It is possible, during deployment, to compact stents and FDs to decrease porosity, but a limiting factor was the transition zone, which remained relatively unchanged and of higher porosity than the expansion zone. Length of the transition zone increased when devices were constrained in smaller tubes. Heterogeneities in porosity with compaction and curvatures were predictable and followed simple geometric rules. Extremity stenoses occurred increasingly with decreasing length of the landing zone. Braided self-expandable devices show predictable changes in porosity according to device size, vessel diameter, and curvature. Adequate landing zones are required to prevent terminal device stenosis.

  17. Esophageal self-expandable stent material and mesh grid density are the major determining factors of external beam radiation dose perturbation: results from a phantom model.

    PubMed

    Abu Dayyeh, B K; Vandamme, J J; Miller, R C; Baron, T H

    2013-01-01

    Self-expandable esophageal stents are increasingly used for palliation or as an adjunct to chemoradiation for esophageal neoplasia. The optimal esophageal stent design and material to minimize dose perturbation with external beam radiation are unknown. We sought to quantify the deviation from intended radiation dose as a function of stent material and mesh density design. A laboratory dosimetric film model was used to quantify perturbation of intended radiation dose among 16 different esophageal stents with varying material and stent mesh density design. Radiation dose enhancement due to stent backscatter ranged from 0 % to 7.3 %, collectively representing a standard difference from the intended mean radiation dose of 1.9 (95 % confidence interval [CI] 1.5 - 2.2). This enhancement was negligible for polymer-based stents and approached 0 % for the biodegradable stents. In contrast, all metal alloy stents had significant radiation backscatter; this was largely determined by the density of mesh design and not by the type of alloy used. Stent characteristics should be considered when selecting the optimal stent for treatment and palliation of malignant esophageal strictures, especially when adjuvant or neo-adjuvant radiotherapy is planned. © Georg Thieme Verlag KG Stuttgart · New York.

  18. Feasibility study for the investigation of Nitinol self-expanding stents by neutron techniques

    NASA Astrophysics Data System (ADS)

    Rogante, M.; Pasquini, U.; Rosta, L.; Lebedev, V.

    2011-02-01

    In this paper, neutron techniques - in particular, small angle neutron scattering (SANS) and neutron diffraction (ND) - are considered for the non-destructive characterization of Nitinol artery stents. This roughly equiatomic (50Ni-50Ti at%) shape memory alloy (SMA) exhibits significant properties of superelasticity and biocompatibility that make it suitable to be typically used as smart material for medical implants and devices. Nitinol self-expanding artery stents, as permanent vascular support structures, supply an ideal option to bypass surgery, but they are submitted for the whole of patient's life to the dynamical stress of the artery pulsation and the aggression from the biological environment. These stents, consequently, can suffer from wear and fracture occurrence likely due to a variety of cyclic fatigue, overload conditions and residual stresses. Neutrons have recently become a progressively more important probe for various materials and components and they allow achieving information complementary to those obtained from the traditional microstructural analyses. The outputs from the preliminary works already carried out in this field consent to consider neutron techniques capable to contribute to the development of these crucial medical implants. The achievable results can yield trends adoptable in monitoring of the stent features.

  19. Differences in Endothelial Injury After Balloon Angioplasty, Insertion of Balloon-Expanded Stents or Release of Self-Expanding Stents: An Electron Microscopic Experimental Study

    SciTech Connect

    Harnek, Jan; Zoucas, Evita; Carlemalm, Erik; Cwikiel, Wojciech

    1999-01-15

    Purpose: To evaluate which of six different commonly available stents inserted into an artery without percutaneous transluminal angioplasty (PTA) causes the least endothelial damage. To compare the degree of endothelial injury after insertion of such a stent with injury caused by PTA. Methods: Twelve healthy pigs were used in the experiments. In the first part of the study six different types of stents were inserted into the common iliac arteries. In the second part of the study self-expanding stents with large spaces between the wires were used. PTA was performed in the contralateral iliac artery. The pigs were killed immediately after the procedure and resected specimens examined after fixation, using scanning electron microscopy. Results: All procedures but two were accomplished successfully. More endothelium was preserved after insertion of self-expanding stents with large spaces between the wires, compared with stents with small spaces and balloon-expanded stents. After insertion of self-expanding stents with large spaces, 50.1% {+-} 16.4% of the endothelium remained intact, compared with only 5.6% {+-} 7.7% after PTA. The difference was statistically significant (p < 0.001). Conclusion: Self-expanding stents with large spaces between the wires, inserted without PTA, cause less damage to the endothelium than other stents and significantly less damage than PTA.

  20. Biodegradable shape-memory block co-polymers for fast self-expandable stents.

    PubMed

    Xue, Liang; Dai, Shiyao; Li, Zhi

    2010-11-01

    Block co-polymers PCTBVs (M(n) of 36,300-65,300 g/mol, T(m) of 39-40 and 142 degrees C) containing hyperbranched three-arm poly(epsilon-caprolactone) (PCL) as switching segment and microbial polyester PHBV as crystallizable hard segment were designed as biodegradable shape-memory polymer (SMP) for fast self-expandable stent and synthesized in 96% yield by the reaction of three-arm PCL-triol (M(n) of 4200 g/mol, T(m) of 47 degrees C) with methylene diphenyl 4,4'-diisocyanate isocynate (MDI) to form the hyperbrached MDI-linked PCL (PTCM; M(n) of 25,400 g/mol and a T(m) of 38 degrees C), followed by further polymerization with PHBV-diol (M(n) of 2200 g/mol, T(m) of 137 and 148 degrees C). The polymers were characterized by (1)H NMR, GPC, DSC, tensile test, and cyclic thermomechanical tensile test. PCTBVs showed desired thermal properties, mechanical properties, and ductile nature. PCTBV containing 25 wt% PHBV (PCTBV-25) demonstrated excellent shape-memory property at 40 degrees C, with R(f) of 94%, R(r) of 98%, and shape recovery within 25s. PCTBV-25 was also shown as a safe material with good biocompatibility by cytotoxicity tests and cell growth experiments. The stent made from PCTBV-25 film showed nearly complete self-expansion at 37 degrees C within only 25 s, which is much better and faster than the best known self-expandable stents.

  1. Determination of coefficient of friction for self-expanding stent-grafts.

    PubMed

    Vad, Siddharth; Eskinazi, Amanda; Corbett, Timothy; McGloughlin, Tim; Vande Geest, Jonathan P

    2010-12-01

    Migration of stent-grafts (SGs) after endovascular aneurysm repair of abdominal aortic aneurysms is a serious complication that may require secondary intervention. Experimental, analytical, and computational studies have been carried out in the past to understand the factors responsible for migration. In an experimental setting, it can be very challenging to correctly capture and understand the interaction between a SG and an artery. Quantities such as coefficient of friction (COF) and contact pressures that characterize this interaction are difficult to measure using an experimental approach. This behavior can be investigated with good accuracy using finite element modeling. Although finite element models are able to incorporate frictional behavior of SGs, the absence of reliable values of coefficient of friction make these simulations unreliable. The aim of this paper is to demonstrate a method for determining the coefficients of friction of a self-expanding endovascular stent-graft. The methodology is demonstrated by considering three commercially available self-expanding SGs, labeled as A, B, and C. The SGs were compressed, expanded, and pulled out of polymeric cylinders of varying diameters and the pullout force was recorded in each case. The SG geometries were recreated using computer-aided design modeling and the entire experiment was simulated in ABAQUS 6.8/STANDARD. An optimization procedure was carried out for each SG oversize configuration to determine the COF that generated a frictional force corresponding to that measured in the experiment. The experimental pullout force and analytically determined COF for SGs A, B, and C were in the range of 6-9 N, 3-12 N, and 3-9 N and 0.08-0.16, 0.22-0.46, and 0.012-0.018, respectively. The computational model predicted COFs in the range of 0.00025-0.0055, 0.025-0.07, and 0.00025-0.006 for SGs A, B, and C, respectively. Our results suggest that for SGs A and B, which are exoskeleton based devices, the pullout forces

  2. Use of self-expanding stents for better intracranial flow diverter wall apposition.

    PubMed

    Kühn, Anna Luisa; Wakhloo, Ajay K; Gounis, Matthew J; Kan, Peter; de Macedo Rodrigues, Katyucia; Lozano, J Diego; Marosfoi, Miklos G; Perras, Mary; Brooks, Christopher; Howk, Mary C; Rex, David E; Massari, Francesco; Puri, Ajit S

    2017-04-01

    Background Flow diverter (FD) malapposition is associated with stroke-related complications. We document the use of self-expanding nitinol stents to remove/reduce the ledge of a FD deployed for aneurysm treatment. Methods We identified five patients who were treated with the Pipeline embolization device (PED) in conjunction with a Neuroform EZ stent for inadequate wall apposition of the ends of the FD at our institution between May 2014 and July 2015. Among other parameters, angiographic results, cone-beam computed tomography assessment of wall apposition and patient clinical outcome were evaluated. Results Incomplete device end apposition was seen in three cases, and precarious positioning of the distal end of the PED over the aneurysm neck was seen in two cases. In all five cases, successful treatment with good wall apposition and proper pinning of the PED distal edge was achieved using an additional Neuroform EZ stent. Appropriate aneurysm neck coverage and flow stagnation was seen in all cases. The combination of high radial outward force and open-cell design permits the Neuroform EZ stent to jail the malappositioned edges of the FD while maintaining good vessel-wall apposition itself and prevent migration of the PED. Short-term follow-up angiography showed device patency and complete aneurysm obliteration in all cases. Conclusions Preliminary results of this small case series suggest that the Neuroform EZ stent allows for effective treatment of FD malapposition in selected patients amenable for this endovascular approach. Long-term and larger cohort studies are needed to validate these results.

  3. Bronchobiliary Fistula Treated by Self-expanding ePTFE-Covered Nitinol Stent-Graft

    SciTech Connect

    Gandini, Roberto; Konda, Daniel Tisone, Giuseppe; Pipitone, Vincenzo; Anselmo, Alessandro; Simonetti, Giovanni

    2005-12-15

    A 71-year-old man, who had undergone right hepatectomy extended to the caudate lobe with terminolateral Roux-en-Y left hepatojejunostomy for a Klatskin tumor, developed bilioptysis 3 weeks postoperatively due to bronchobiliary fistula. Percutaneous transhepatic cholangiography revealed a non-dilated biliary system with contrast medium extravasation to the right subphrenic space through a resected anomalous right posterior segmental duct. After initial unsuccessful internal-external biliary drainage, the fistula was sealed with a VIATORR covered self-expanding nitinol stent-graft placed with its distal uncovered region in the hepatojejunal anastomosis and the proximal ePTFE-lined region in the left hepatic duct. A 10-month follow-up revealed no recurrence of bilioptysis and confirmed the complete exclusion of the bronchobiliary fistula.

  4. Endovascular Treatment for Infra-inguinal Autologous Saphenous Vein Graft Occlusion Using Self Expanding Nitinol Stents.

    PubMed

    Yanagiuchi, T; Kimura, M; Shiraishi, J; Sawada, T

    2016-01-01

    For patients with infra-inguinal autologous vein bypass graft occlusion, conventional open surgical repair or endovascular treatment (EVT) for native vessel occlusion have generally been performed. A 73 year old female with non-healing ulcer and gangrene of the left lower leg was diagnosed as having infra-inguinal autologous saphenous vein graft occlusion. In this case, surgical repair such as patch angioplasty, interposition graft, or replacement graft did not seem promising because of repeated previous infection in the polytetrafluoroethylene (PTFE) vascular prosthesis and absence of available autologous vein due to past surgery. Moreover, there was no chance of crossing the native vessel, since the proximal superficial femoral artery (SFA) had already been resected. Thus, EVT was performed for the occluded autologous vein graft, implanting multiple self expanding bare nitinol stents throughout the vein graft achieving complete revascularization, good medium term patency, and dramatically improved wound healing. Endovascular recanalization using multiple bare stents could be an alternative treatment for infra-inguinal autologous vein graft occlusion.

  5. A comparison of the temporary placement of 3 different self-expanding stents for the treatment of refractory benign esophageal strictures: a prospective multicentre study

    PubMed Central

    2012-01-01

    Background Refractory benign esophageal strictures (RBESs) have been treated with the temporary placement of different self-expanding stents with conflicting results. We compared the clinical effectiveness of 3 types of stents: self-expanding plastic stents (SEPSs), biodegradable stents, and fully covered self-expanding metal stents (FCSEMSs), for the treatment of RBES. Methods This study prospectively evaluated 3 groups of 30 consecutive patients with RBESs who underwent temporary placement of either SEPSs (12 weeks, n = 10), biodegradable stents (n = 10) or FCSEMSs (12 weeks, n = 10). Data were collected to analyze the technical success and clinical outcome of the stents as evaluated by recurrent dysphagia, complications and reinterventions. Results Stent implantation was technically successful in all patients. Migration occurred in 11 patients: 6 (60%) in the SEPS group, 2 (20%) in the biodegradable group and 3 (30%) in the FCSEMS group (P = 0.16). A total of 8/30 patients (26.6%) were dysphagia-free after the end of follow-up: 1 (10%) in the SEPS group, 3 (30%) in the biodegradable group and 4 (40%) in the FCSEMS group (P = 0.27). More reinterventions were required in the SEPS group (n = 24) than in the biodegradable group (n = 13) or the FCSEMS group (n = 13) (P = 0.24). Multivariate analysis showed that stricture length was significantly associated with higher recurrence rates after temporary stent placement (HR = 1.37; 95% CI = 1.08-1.75; P = 0.011). Conclusions Temporary placement of a biodegradable stent or of a FCSEMS in patients with RBES may lead to long-term relief of dysphagia in 30 and 40% of patients, respectively. The use of SEPSs seems least preferable, as they are associated with frequent stent migration, more reinterventions and few cases of long-term improvement. Additionally, longer strictures were associated with a higher risk of recurrence. PMID:22691296

  6. [The palliation of dysphagia secondary to esophageal-cardial carcinoma with self-expandable metal prostheses. The authors' personal experience with 92 patients].

    PubMed

    De Palma, G D; Sivero, L; Galloro, G; Siciliano, S; Pigna, F; Catanzano, C

    1999-04-01

    Endoscopic insertion of a stent is an important option in the palliative management of esophageal obstruction and esophagorespiratory fistula. Plastic stents have been available for over 20 years. A new class of self-expanding metal stents for palliation of esophageal and cardial cancer is now available. Between September 1992 and October 1997, 92 patients underwent implantation of self-expanding metal stents for palliation of dysphagia due to inoperable esophageal or cardial cancer (65 patients) or for locally recurrent carcinoma after surgery (12 patients), laser-therapy (11 patients) or radiotherapy (4 patients). Successful stent implantation was achieved in 89/92 patients (96.7%). After stent implantation the dysphagia score improved from 3.0, on average, to 0.5, on average. Early complications were observed in 4.5% and peroperative mortality was 2.1%. Late complications were observed in 25.6%, with a mortality rate of 1.1%. The mean survival time was 6.9 months. Self-expanding metal stents are a new effective alternative for palliation of dysphagia due to esophageal and cardial cancers.

  7. Self-expanding plastic stent removed after radiochemotherapy for advanced esophageal cancer.

    PubMed

    Laquière, A; Grandval, P; Heresbach, D; Prat, F; Arpurt, J P; Bichard, P; D'Halluin, P-N; Berthillier, J; Boustière, C; Laugier, R

    2014-01-01

    Endoscopic evaluation after chemoradiotherapy (CR) is impossible with an esophageal stent in place. The main study objective was to evaluate self-expanding plastic stent (SEPS) removal post-CR. Secondary end-points were the improvement of dysphagia and patients' quality of life. From October 2008 to March 2011, 20 dysphagic patients who suffered from advanced esophageal cancer were enrolled in a multicenter, prospective study. SEPS was inserted prior to CR and then removed endoscopically. SEPS efficiency (dysphagia score) and tolerance, as well as the patients' quality of life (European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire validated for the esophagus), were monitored. Continuous variables were compared using a paired t-test analysis for matched data. A P-value of less than 0.05 was considered statistically significant. Twenty patients (15 men and 5 women), aged 61.5 years (±9.88) (range 43-82 years), with adenocarcinoma (n = 12) and squamous cell carcinoma (n = 8), were enrolled. SEPS were successfully inserted in all patients (100%). There was one perforation and three episodes of migration. All of these complications were medically treated. The mean dysphagia score at the time of stent placement was 2.79 (0.6). Mean dysphagia scores obtained on day 1 and day 30 post-SEPS placement were 0.7 (0.9) (P < 0.0001) and 0.45 (0.8) (P < 0.0001), respectively. Quality of Life Questionnaire validated for the esophagus score showed an improvement in dysphagia (P = 0.01) and quality of oral feeding (P = 0.003). All SEPS were removed endoscopically without complications. In two patients, the stent was left in place due to metastatic disease. SEPS are extractable after CR of esophageal cancer. Early stenting by SEPS prior to and during CR may reduce dysphagia and improve quality of oral alimentation. © 2013 Wiley Periodicals, Inc. and the International Society for Diseases of the Esophagus.

  8. New treatment of iliac artery disease: focus on the Absolute Pro® Vascular Self-Expanding Stent System

    PubMed Central

    Gates, Lindsay; Indes, Jeffrey

    2013-01-01

    Management of iliac artery disease has evolved over the years, from a surgical-only approach to a primarily endovascular-only approach as the first line treatment option. This has been continuously improved upon with the advent of new devices and applied technologies. Most recently in particular, the literature has shown good, reliable outcomes with the use of self-expandable stents in iliac artery atherosclerotic lesions. Nevertheless, no device is without its limitations, and the Absolute Pro® Vascular Self-Expanding Stent System was designed with the intent of overcoming some of the shortcomings of other available stents while maintaining acceptable postprocedural outcomes. Based on preliminary industry-acquired data, it has achieved these goals and appears to be an emergent competitor for the treatment of both focal and complex iliac artery lesions. PMID:24049463

  9. Balloon-expandable Metallic Stents for Airway Diseases.

    PubMed

    Ohki, Takashi; Sugimoto, Seiichiro; Kurosaki, Takeshi; Otani, Shinji; Miyoshi, Kentaroh; Yamane, Masaomi; Miyoshi, Shinichiro; Oto, Takahiro

    2016-10-01

    Stent placement is an essential treatment for airway diseases. Although self-expandable metallic stents and silicone stents are commonly applied for the treatment of airway diseases, these stents are unsuitable for the treatment of small airway diseases encountered in pediatric patients and lung transplant recipients with airway complications. Currently, only vascular balloon-expandable metallic stents are available for the treatment of small airway diseases; however, little research has been conducted on the use of these stents in this field. We have launched a prospective feasibility study to clarify the safety and efficacy of balloon-expandable metallic stents for the treatment of airway diseases.

  10. ALD mediated heparin grafting on nitinol for self-expanded carotid stents.

    PubMed

    Wang, Fei; Zhang, Yan; Chen, Xiumian; Leng, Bing; Guo, Xin; Zhang, Tao

    2016-07-01

    Carotid-artery atherosclerosis is a common cause of ischemic stroke. Carotid-artery stenting (CAS) is one of the most effective treatments. However, In-stent restenosis (ISR) and re-endothelialization delay are two major issues of intravascular stent which affect clinical safety and reduce effects. In this study, atomic layer deposition (ALD) technology was applied to deposit a layer (10nm) of Al2O3 on Nitinol surface as an intermediate functional layer. The alumina covered surface was then modified with a coupling agent 3-aminopropyltriethoxysilane (APS) and heparin sequentially in order to improve the hemocompatibility of Nitinol stents. The successful graft of APS and heparin onto Nitinol was proven by X-ray photoelectron spectroscopy. Furthermore, the predicted improvement in the biocompatibilities of modified Nitinol was confirmed by water contact angle measurement, protein adsorption, platelet adhesion, and plasma recalcification time determination. The results of hemolysis assay, cell proliferation and cytotoxicity tests revealed that the grafting of heparin on NiTi kept the original positive performance of nitinol material. The results indicate that ALD technology is of great potential for the manufacture of medical devices, especially for surface modifications and functionalization. ALD technology can help with modifications of inert metallic surfaces and therefore benefit implantable medical devices, especially intravascular stents.

  11. Development of tissue-engineered self-expandable aortic stent grafts (Bio stent grafts) using in-body tissue architecture technology in beagles.

    PubMed

    Kawajiri, Hidetake; Mizuno, Takeshi; Moriwaki, Takeshi; Ishibashi-Ueda, Hatsue; Yamanami, Masashi; Kanda, Keiichi; Yaku, Hitoshi; Nakayama, Yasuhide

    2015-02-01

    In this study, we aimed to describe the development of tissue-engineered self-expandable aortic stent grafts (Bio stent graft) using in-body tissue architecture technology in beagles and to determine its mechanical and histological properties. The preparation mold was assembled by insertion of an acryl rod (outer diameter, 8.6 mm; length, 40 mm) into a self-expanding nitinol stent (internal diameter, 9.0 mm; length, 35 mm). The molds (n = 6) were embedded into the subcutaneous pouches of three beagles for 4 weeks. After harvesting and removing each rod, the excessive fragile tissue connected around the molds was trimmed, and thus tubular autologous connective tissues with the stent were obtained for use as Bio stent grafts (outer diameter, approximately 9.3 mm in all molds). The stent strut was completely surrounded by the dense collagenous membrane (thickness, ∼150 µm). The Bio stent graft luminal surface was extremely flat and smooth. The graft wall of the Bio stent graft possessed an elastic modulus that was almost two times higher than that of the native beagle abdominal aorta. This Bio stent graft is expected to exhibit excellent biocompatibility after being implanted in the aorta, which may reduce the risk of type 1 endoleaks or migration.

  12. Finite Element Modeling of A Novel Self-Expanding Endovascular Stent Method in Treatment of Aortic Aneurysms

    NASA Astrophysics Data System (ADS)

    Arokiaraj, Mark C.; Palacios, Igor F.

    2014-01-01

    A novel large self-expanding endovascular stent was designed with strut thickness of 70 μm × 70 μm width. The method was developed and investigated to identify a novel simpler technique in aortic aneurysm therapy. Stage 1 analysis was performed after deploying it in a virtual aneurysm model of 6 cm wide × 6 cm long fusiform hyper-elastic anisotropic design. At cell width of 9 mm, there was no buckling or migration of the stent at 180 Hg. Radial force of the stents was estimated after parametric variations. In stage 2 analysis, a prototype 300 μm × 150 μm stent with a cell width of 9 mm was chosen, and it was evaluated similarly after embedding in the aortic wall, and also with a tissue overgrowth of 1 mm over the stent. The 300/150 μm stent reduced the peak wall stress by 70% in the aneurysm and 50% reduction in compliance after embedding. Stage 3 analysis was performed to study the efficacy of stents with struts (thickness/width) 70/70, 180/100 and 300/150 μm after embedding and tissue overgrowth. The adjacent wall stresses were very minimal in stents with 180/100 and 70/70 μm struts after embedding. There is potential for a novel stent method in aortic aneurysm therapy.

  13. Bench-top Comparison of Physical Properties of 4 Commercially-Available Self-Expanding Intracranial Stents

    PubMed Central

    Cho, Su-hee; Jo, Won-il; Jo, Ye-eun; Yang, Ku Hyun; Park, Jung Cheol

    2017-01-01

    Purpose To better understand the performance of four commercially available neurovascular stents in intracranial aneurysm embolization, the stents were compared in terms of their basic morphological and mechanical properties. Materials and Methods Four different types of stents that are currently being used for cerebral aneurysm embolization were prepared (two stents per type). Two were laser-cut stents (Neuroform and Enterprise) and two were braided from a single nitinol wire (LEO and LVIS stents). All were subjected to quantitative measurements of stent size, pore density, metal coverage, the force needed to load, push, and deploy the stent, radial force on deployment, surface roughness, and corrosion resistance. Results Compared to their nominal diameters, all stents had greater diameters after deployment. The length generally decreased after deployment. This was particularly marked in the braided stents. The braided stents also had higher pore densities than the laser-cut stents. Metal coverage was highest in the LEO stent (14%) and lowest in the Enterprise stent (5%). The LIVS stent had the highest microcatheter loading force (81.5 gf). The LEO stent had the highest passage force (55.0 gf) and deployment force (78.9 gf). The LVIS and LEO stents had the highest perpendicular (37.1 gf) and circumferential (178.4 gf) radial forces, respectively. The Enterprise stent had the roughest stent wire, followed by the LVIS, LEO, and Neuroform stents. Conclusion The four neurovascular stent types differed in terms of morphological and physical characteristics. An understanding of this diversity may help to decide which stent is most suitable for specific clinical situations. PMID:28316867

  14. Endovascular Repair of Arterial Iliac Vessel Wall Lesions with a Self-Expandable Nitinol Stent Graft System

    PubMed Central

    Mensel, Birger; Kühn, Jens-Peter; Hoene, Andreas; Hosten, Norbert; Puls, Ralf

    2014-01-01

    Objective To assess the therapeutic outcome after endovascular repair of iliac arterial lesions (IALs) using a self-expandable Nitinol stent graft system. Methods Between July 2006 and March 2013, 16 patients (13 males, mean age: 68 years) with a self-expandable Nitinol stent graft. A total of 19 lesions were treated: nine true aneurysms, two anastomotic aneurysms, two dissections, one arteriovenous fistula, two type 1B endoleaks after endovascular aneurysm repair, one pseudoaneurysm, and two perforations after angioplasty. Pre-, intra-, and postinterventional imaging studies and the medical records were analyzed for technical and clinical success and postinterventional complications. Results The primary technical and clinical success rate was 81.3% (13/16 patients) and 75.0% (12/16), respectively. Two patients had technical failure due to persistent type 1A endoleak and another patient due to acute stent graft thrombosis. One patient showed severe stent graft kinking on the first postinterventional day. In two patients, a second intervention was performed. The secondary technical and clinical success rate was 87.5% (14/16) and 93.8% (15/16). The minor complication rate was 6.3% (patient with painful hematoma at the access site). The major complication rate was 6.3% (patient with ipsilateral deep vein thrombosis). During median follow-up of 22.4 months, an infection of the aneurysm sac in one patient and a stent graft thrombosis in another patient were observed. Conclusion Endovascular repair of various IALs with a self-expandable Nitinol stent graft is safe and effective. PMID:25119346

  15. Reversal of Transjugular Intrahepatic Portosystemic Shunt (TIPS)-Induced Hepatic Encephalopathy Using a Strictured Self-Expanding Covered Stent

    SciTech Connect

    Cox, Mitchell W.; Soltes, George D.; Lin, Peter H. Bush, Ruth L.; Lumsden, Alan B.

    2003-11-15

    Hepatic encephalopathy is a known complication following percutaneous transjugular intrahepatic portosystemic shunt (TIPS) placement. We describe herein a simple and effective strategy of TIPS revision by creating an intraluminal stricture within a self-expanding covered stent, which is deployed in the portosystemic shunt to reduce the TIPS blood flow. This technique was successful in reversing a TIPS-induced hepatic encephalopathy in our patient.

  16. Long-Term Results after Placement of Aortic Bifurcation Self-Expanding Stents: 10 Year Mortality, Stent Restenosis, and Distal Disease Progression

    SciTech Connect

    Houston, J. Graeme Bhat, Raj; Ross, Rose; Stonebridge, Peter A.

    2007-02-15

    Purpose. To retrospectively evaluate the 10 year follow-up results in patients who had 'kissing' self-expanding stent aortic bifurcation reconstruction. Methods. Forty-three patients were treated with 'kissing' self-expanding stents for aortoiliac occlusive disease. Early follow-up with clinical and ankle brachial pressure indices (ABPI) was performed at 3, 6, 12, and 24 months and with intra-arterial digital subtraction angiography at 12-24 months; clinical and angiographic follow-up was performed for symptom recurrence up to 10 years after treatment. Retrospective record review was performed to assess mortality, clinical patency, angiographic patency, and secondary assisted patency of both stents and downstream peripheral vessels at 5 and 10 years follow-up. Results. The 2 year primary angiographic and secondary assisted stent patencies were 89% and 93%, respectively. At 10 years follow-up in 40 patients the mortality was 38% (due to myocardial infarction, stroke, chronic renal failure, malignancy, and liver failure). At 5 and 10 years follow-up the primary clinical stent patency was 82% and 68%, and the secondary assisted stent patency 93% and 86%, respectively. At 5 and 10 years, the distal vessel patency was 86% and 72%, and the secondary assisted distal vessel patency treated by surgical or endovascular techniques was 94% and 88%, respectively. At 10 years there was no limb loss. Conclusion. The long-term (10 year) results of aortic bifurcation arterial self-expanding stent placement in patients with arterial occlusive disease show a 10 year primary stent patency rate of 68% but a secondary assisted patency rate of 86%. In addition there is a high overall mortality due to other cardiovascular causes and the rate of distal disease progression and loss of patency is similar to the loss of stent patency rate.

  17. Current Status of Biliary Metal Stents

    PubMed Central

    Nam, Hyeong Seok; Kang, Dae Hwan

    2016-01-01

    Many advances have been achieved in biliary stenting over the past 30 years. Endoscopic stent placement has become the primary management therapy to relieve obstruction in patients with benign or malignant biliary tract diseases. Compared with plastic stents, a self-expandable metallic stent (SEMS) has been used for management in patients with malignant strictures because of a larger lumen and longer stent patency. Recently, SEMS has been used for various benign biliary strictures and leaks. In this article, we briefly review the characteristics of SEMS as well as complications of stent placement. We review the current guidelines for managing malignant and benign biliary obstructions. Recent developments in biliary stenting are also discussed. PMID:26911896

  18. Cefotaxime-eluting covered self-expandable stents in a canine biliary model: scanning electron microscopic study of biofilm formation.

    PubMed

    Gwon, Dong Il; Lee, Sang Soo; Kim, Eun-Young

    2012-12-01

    As bacterial attachment and subsequent biofilm formation on the surface of a stent lumen may be important in initiating sludge formation and subsequent stent blockage, there is a need for antibiotic-eluting stents to prevent sludge formation by bacterial attachment and colonization. To evaluate the antimicrobial effects of cefotaxime-eluting covered self-expandable stents (CE-CSEMS) in a canine biliary model by using scanning electron microscopy (SEM) to analyze biofilm formation on the inner surface of the stents. Three 10% (wt/vol) CE-CSEMS, three 20% (wt/vol) CE-CSEMS, and three control stents (CS) were endoscopically inserted into the bile ducts of nine mongrel dogs, which were followed up for 8 weeks. Gross and SEM examinations were performed to access the development and degree of biofilm formation in dogs with CS and CE-CSEMS. All stents were successfully inserted into canine bile ducts without any procedure-related complications. All nine dogs remained in good health without jaundice over the next 8 weeks. The degree of biofilm was similar in dogs implanted with CS and CE-CSEMS using two concentrations of cefotaxime either by gross inspection or SEM. All stent types showed a similar biofilm structure with relatively uniform thickness on SEM. Cefotaxime does not prevent biofilm development in a canine biliary model. Biofilm formation on the inner surface of biliary stents may be prevented by using broad-spectrum antimicrobial agents and stents that maintain a steady release of these agents for a long time, thus prolonging stent patency.

  19. The first clinical experience with a peripheral, self-expanding nitinol stent in the treatment of saphenous vein graft disease: angiographic evidence of late expansion.

    PubMed

    Bokhari, Syed W; Vahdat, Omid; Winters, Rex J

    2003-07-01

    The ideal intervention for degenerated saphenous vein grafts (SVG) is still controversial. We report the first use of a peripheral, self-expanding nitinol stent in the treatment of a patient with symptomatic SVG disease. The procedure was well tolerated, without any short- or long-term complications. Quantitative coronary analysis of a 3-month follow-up angiogram revealed a continued expansion of the nitinol stent. Larger scale trials are warranted to evaluate whether the self-expanding nitinol stents can be used alone or in adjunct to other modalities for the treatment of SVG disease. The case report is followed by a literature review of SVG stenting.

  20. The use of self-expanding silicone stents in esophageal cancer care: optimal pre-, peri-, and postoperative care.

    PubMed

    Martin, Robert; Duvall, Ryan; Ellis, Susan; Scoggins, Charles R

    2009-03-01

    Preoperative nutritional supplementation, management of esophageal leaks, and postoperative anastomotic strictures still remain common problems in the management of esophageal cancer. Jejunal feeding tubes, total parenteral nutrition (TPN) with nasogastric suction, and repeated esophageal dilations remain the most common treatments, respectively. The aim of this study was to evaluate the use of removable silicone stents in (1) the preoperative nutritional optimization during neoadjuvant therapy, (2) the management of perioperative anastomotic leak, and (3) the management of postoperative anastomotic strictures. Review of our prospectively maintained esophageal database identified 15 patients who had removable self-expanding silicone stents placed in the management of one of these three management problems from July 2004 to August 2006. Preoperative therapy: Five patients underwent initial stent placement in preparation for neoadjuvant therapy. Dysphagia relief was seen in 100% of patients, with optimal caloric needs taken within 24 h of placement. All patients tolerated neoadjuvant therapy without delay from dehydration or malnutrition. One stent migration was found at the time of operation, which was removed without sequelae. Perioperative therapy: Five patients developed delayed (>10 days) esophageal leaks that were managed with removable esophageal stent and percutaneous drainage (in three patients). All patients had successful exclusion of the leak on the day of the procedure with resumption of oral intake on the evening of procedure. All five healed leaks without sequelae. Postoperative therapy: Five patients developed postoperative anastomotic strictures that required dilation and placement of removable esophageal stent. The median number of dilations was 1 (range 1-2), with all stents placed for approximate 3 months duration. All patients had immediate dysphagia relief after stent placement. Removable esophageal stents are novel treatment option to optimize

  1. Study of the Behavior of a Bell-Shaped Colonic Self-Expandable NiTi Stent under Peristaltic Movements

    PubMed Central

    Puértolas, José A.; López, Enrique

    2013-01-01

    Managing bowel obstruction produced by colon cancer requires an emergency intervention to patients usually in poor conditions, and it requires creating an intestinal stoma in most cases. Regardless of that the tumor may be resectable, a two-stage surgery is mandatory. To avoid these disadvantages, endoscopic placement of self-expanding stents has been introduced more than 10 years ago, as an alternative to relieve colonic obstruction. It can be used as a bridge to elective single-stage surgery avoiding a stoma or as a definitive palliative solution in patients with irresectable tumor or poor estimated survival. Stents must be capable of exerting an adequate radial pressure on the stenosed wall, keeping in mind that stent must not move or be crushed, guaranteeing an adequate lumen when affected by peristaltic waves. A finite element simulation of bell-shaped nitinol stent functionality has been done. Catheter introduction, releasing at position, and the effect of peristaltic wave were simulated. To check the reliability of the simulation, a clinical experimentation with porcine specimens was carried out. The stent presented a good deployment and flexibility. Stent behavior was excellent, expanding from the very narrow lumen corresponding to the maximum peristaltic pressure to the complete recovery of operative lumen when the pressure disappears. PMID:23841067

  2. Impact of stent diameter on vascular response after self-expanding paclitaxel-eluting stent implantation in the superficial femoral artery.

    PubMed

    Miki, Kojiro; Fujii, Kenichi; Shibuya, Masahiko; Fukunaga, Masashi; Imanaka, Takahiro; Kawai, Kenji; Tamaru, Hiroto; Sumiyoshi, Akinori; Nishimura, Machiko; Horimatsu, Tetsuo; Saita, Ten; Yoshihara, Nagataka; Kimura, Takumi; Honda, Yasuhiro; Fitzgerald, Peter J; Masuyama, Tohru; Ishihara, Masaharu

    2017-10-01

    The optimal sizing of self-expanding paclitaxel-eluting stents (PES) in the treatment for superficial femoral artery (SFA) lesions is unclear. This study sought to investigate the influence of PES diameter on stent patency in SFA lesions using optical frequency domain imaging (OFDI). A total of 20 de novo SFA lesions were randomized 1:1 to receive either self-expanding PES with a nominal diameter of 6mm or 8mm. Follow-up angiography and OFDI was scheduled six months after stent implantation, and volumetric OFDI analysis was performed to evaluate vascular response to the stents. Volume index (VI) was defined as the volume divided by the stent length. The primary end point was lumen VI at the 6-month follow-up. Secondary end point was minimum lumen diameter (MLD) by quantitative vascular angiography (QVA) at the follow-up. Stent length was 78.0±23.9mm in the 6-mm group and 70.0±23.6mm in the 8-mm group (p=0.46). Baseline QVA data were also similar between the two groups. MLD immediately after stent implantation was similar between the two groups (4.2±0.5mm in the 6-mm group and 3.9±0.5mm in the 8-mm group, p=NS). At the 6-month follow-up, MLD was greater in the 8-mm group compared to the 6-mm group (4.0±1.0mm vs. 3.2±0.4mm, p<0.05). Stent VI was larger in the 8-mm group (28.4±6.7mm(3)/mm vs. 22.2±1.2mm(3)/mm, p=0.01). Neointimal VI was similar between the two groups (5.8±2.9mm(3)/mm vs. 5.2±2.6mm(3)/mm, p=0.68). Lumen VI was greater in the 8-mm group (23.2±7.6mm(3)/mm vs. 17.3±2.6mm(3)/mm, p=0.04). Chronic stent enlargement resulted in greater lumen area after implantation of self-expanding PES with a large diameter at the mid-term follow-up. Stent diameter might be important for stent patency in procedure with PES for SFA lesions. Copyright © 2017 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

  3. Partially covered versus uncovered self-expandable nitinol stents with anti-migration properties for the palliation of malignant distal biliary obstruction: A randomized controlled trial.

    PubMed

    Yang, Min Jae; Kim, Jin Hong; Yoo, Byung Moo; Hwang, Jae Chul; Yoo, Jun Hwan; Lee, Ki Seong; Kang, Joon Koo; Kim, Soon Sun; Lim, Sun Gyo; Shin, Sung Jae; Cheong, Jae Youn; Lee, Kee Myung; Lee, Kwang Jae; Cho, Sung Won

    2015-01-01

    Covered self-expandable metal stents (SEMSs) are increasingly used as alternatives to uncovered SEMSs for the palliation of inoperable malignant distal biliary obstruction to counteract tumor ingrowth. We aimed to compare the outcomes of partially covered and uncovered SEMSs with identical mesh structures and anti-migration properties, such as low axial force and flared ends. One hundred and three patients who were diagnosed with inoperable malignant distal biliary obstruction between January 2006 and August 2013 were randomly assigned to either the partially covered (n = 51) or uncovered (n = 52) SEMS group. There were no significant differences in the cumulative stent patency, overall patient survival, stent dysfunction-free survival and overall adverse events, including pancreatitis and cholecystitis, between the two groups. Compared to the uncovered group, stent migration (5.9% vs. 0%, p = 0.118) and tumor overgrowth (7.8% vs. 1.9%, p = 0.205) were non-significantly more frequent in the partially covered group, whereas tumor ingrowth showed a significantly higher incidence in the uncovered group (5.9% vs. 19.2%, p = 0.041). Stent migration in the partially covered group occurred only in patients with short stenosis of the utmost distal bile duct (two in ampullary cancer, one in bile duct cancer), and did not occur in any patients with pancreatic cancer. For the palliation of malignant distal biliary obstruction, endoscopic placement of partially covered SEMSs with anti-migration designs and identical mesh structures to uncovered SEMSs failed to prolong cumulative stent patency or reduce stent migration.

  4. Self-Expanding Nitinol Renal Artery Stents: Comparison of Safety and Efficacy of Bare Versus Polyzene-F Nanocoated Stents in a Porcine Model

    SciTech Connect

    Kurz, P.; Stampfl, U.; Christoph, P.; Henn, C.; Satzl, S.; Radeleff, B.; Berger, I.; Richter, G. M.

    2011-02-15

    Objective: To investigate the safety and efficacy of a Polyzene-F nanocoat on new low-profile self-expandable nitinol stents in minipig renal arteries. Materials and Methods: Ten bare nitinol stents (BNS) and 10 stents coated with a 50 nm-thin Polyzene-F coating were randomly implanted into renal arteries of 10 minipigs (4- and 12-week follow-up, 5 animals/group). Thrombogenicity, on-stent surface endothelialization, vessel wall injury, late in-stent stenosis, and peristrut vessel wall inflammation were determined by quantitative angiography and postmortem histomorphometry. Results: In 6 of 10 BNS, >50% stenosis was found, but no stenosis was found in stents with a nanothin Polyzene-F coating. Histomorphometry showed a statistically significant (p < 0.05) different average maximum luminal loss of 55.16% {+-} 8.43% at 12 weeks in BNS versus 39.77% {+-} 7.41% in stents with a nanothin Polyzene-F coating. Stents with a nanothin Polyzene-F coating had a significantly (p < 0.05) lower inflammation score after 12 weeks, 1.31 {+-} 1.17 versus 2.17 {+-} 0.85 in BNS. The results for vessel wall injury (0.6 {+-} 0.58 for Polyzene-F-coated stents; 0.72 {+-} 0.98 for BNS) and re-endothelialization, (1.16 {+-} 0.43 and 1.23 {+-} 0.54, respectively) were not statistically significant at 12-week follow-up. No thrombus deposition was observed on the stents at either follow-up time point. Conclusion: Nitinol stents with a nanothin Polyzene-F coating successfully decreased in-stent stenosis and vessel wall inflammation compared with BNS. Endothelialization and vessel wall injury were found to be equal. These studies warrant long-term pig studies ({>=}120 days) because 12 weeks may not be sufficient time for complete healing; thereafter, human studies may be warranted.

  5. An Efficient Finite Element Framework to Assess Flexibility Performances of SMA Self-Expandable Carotid Artery Stents

    PubMed Central

    Ferraro, Mauro; Auricchio, Ferdinando; Boatti, Elisa; Scalet, Giulia; Conti, Michele; Morganti, Simone; Reali, Alessandro

    2015-01-01

    Computer-based simulations are nowadays widely exploited for the prediction of the mechanical behavior of different biomedical devices. In this aspect, structural finite element analyses (FEA) are currently the preferred computational tool to evaluate the stent response under bending. This work aims at developing a computational framework based on linear and higher order FEA to evaluate the flexibility of self-expandable carotid artery stents. In particular, numerical simulations involving large deformations and inelastic shape memory alloy constitutive modeling are performed, and the results suggest that the employment of higher order FEA allows accurately representing the computational domain and getting a better approximation of the solution with a widely-reduced number of degrees of freedom with respect to linear FEA. Moreover, when buckling phenomena occur, higher order FEA presents a superior capability of reproducing the nonlinear local effects related to buckling phenomena. PMID:26184329

  6. Percutaneous cholangioscopy in obstructed biliary metal stents

    SciTech Connect

    Hausegger, Klaus A.; Mischinger, Hans J.; Karaic, Radenko; Klein, Guenther E.; Kugler, Cristian; Kern, Robert; Uggowitzer, Martin; Szolar, Dieter

    1997-05-15

    Purpose. To reevaluate the reasons for the occlusion of self-expanding biliary metal stents, on the basis of cholangioscopic findings. Methods. Percutaneous transhepatic cholangioscopy (PTCS) was performed in 15 patients with obstructed biliary Wallstents. The reason for stent insertion was a malignant obstruction in 14 patients; 1 had a benign biliary stricture. Conventional noncovered stents had been inserted in 12 patients; in 3 cases a polyurethane-covered prototype Wallstent had been used. Stent occlusions occurred after 1-55 months. PTCS was performed with a 2.3-mm endoscope through an 11 Fr sheath. Biopsies were taken via the working channel of the endoscope. Results. In all patients with noncovered stents the inner surface of the stent was highly irregular with seaweed-like protrusions (biopsy-proven granulation tissue). Stent incorporation varied from absent (n=1) to subtotal (n=8), but was always incomplete, no matter how long the stent had been in place. Tumor ingrowth was histologically proven in 2 patients. One patient had a large occluding concrement at the proximal end of the stent. In patients with covered stents, the inner surface appeared more regular; however, viable granulation tissue was found inside two stents and tumor ingrowth in one of them. Conclusion. PTCS showed that incorporation of the stent is virtually always incomplete. The factors contributing most to stent occlusion are the buildup of granulation tissue, bile sludge, and tumor overgrowth. Stone formation and tumor ingrowth can also be important, although less common causes of occlusion. A polyurethane stent covering could not prevent tumor ingrowth in one patient and the buildup of viable granulation tissue inside the stent in two further patients; mean stent patency in the three patients with such a stent was 3 months.

  7. Influence of different self-expanding stent-graft types on remodeling of the aortic neck after endovascular aneurysm repair.

    PubMed

    Oberhuber, Alexander; Schwarz, Alexander; Hoffmann, Martin H; Klass, Oliver; Orend, Karl-Heinz; Mühling, Bernd

    2010-12-01

    To evaluate aortic neck changes, specifically aortic neck dilatation, over a 10-year period in patients undergoing endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm. All patients who underwent elective EVAR at our institution from 1998 through 2007 were analyzed retrospectively. Among these, 103 patients (96 men; mean age 71 years, range 35-84) who received the 3 most frequently implanted self-expanding stent-grafts (35 Talent, 39 Excluder, and 29 Zenith) and had a minimum 3-month imaging follow-up at our department were selected for this study. All diameters were measured perpendicular to the centerline of flow on computed tomography; baseline data were derived from the first postoperative scan. Stent-graft migration was measured from the lowermost renal artery to the first strut of the stent-graft. Based on intra- and interobserver error measurements, a minimum change of 2 mm defined aortic neck dilatation. During a mean follow-up of 39.4 months (range 3-108.8), infrarenal aortic neck dilatation (>2 mm) was found in 10 patients (28.6%, 95% CI 14.6-46.3) in the Talent group, 4 (10.3%, 95% CI 2.9-24.2) in the Excluder group, and 9 (31.0%, 95% CI 15.3-50.8) in the Zenith group (p=0.299). In 7 (31%) of the 23 patients with neck dilatation, additional therapy was necessary. Suprarenal changes were found in 6 patients (17.1%, 95% CI 6.6-33.6), 8 patients (20.5%, 95% CI 9.3-36.5), and 5 patients (17.2%, 95% CI 5.8-35.8), respectively (p=0.218). Stent-graft migration >2 mm was seen in 2 (1.9%) of the 103 patients in follow-up. The overall endoleak rates were 37.1% for Talent, 30.8% for Excluder, and 37.9% for Zenith (p>0.05). Two patients were converted to open repair owing to Talent stent-graft migration and persistent type I leak (Zenith). The overall reintervention rate was 13.6% (13/103). Only a small number of the patients treated with self-expanding stent-grafts show notable infrarenal aortic neck dilatation, which does not appear to be related to

  8. Prevention of Intracranial In-stent Restenoses: Predilatation with a Drug Eluting Balloon, Followed by the Deployment of a Self-Expanding Stent

    SciTech Connect

    Vajda, Zsolt Guethe, Thomas Perez, Marta Aguilar Kurre, Wiebke; Schmid, Elisabeth Baezner, Hansjoerg; Henkes, Hans

    2013-04-15

    Stenting in intracranial atherosclerotic disease (ICAD) is increasingly debated, due to issues of procedural safety, technical efficacy, and in-stent recurrent stenoses (ISR). In the present study, feasibility, safety, and efficacy of angioplasty using a drug-eluting balloon (DEB) followed by the implantation of a self-expanding stent (Enterprise) were evaluated for the treatment of ICAD lesions. Fifty-two patients (median age: 71 years; range: 54-86 years; male/female ratio 37:15) underwent stenting of high-grade ICAD lesions between February 2010 and November 2011 in a single center. Angioplasty using a paclitaxel coated SeQuent Please (B. Braun, Germany) or DIOR (Eurocor, Germany) coronary PTCA balloon, followed by the implantation of a self-expanding stent (Enterprise, Codman, USA) was performed in 54 lesions. Angiographic and clinical follow-up was performed at 6 and 12 weeks, 6 and 12 months, and yearly thereafter. Technical success rate, periprocedural complications, occurrence of recurrent ischemic symptoms, and the development of an ISR were analyzed. Angioplasty using a DEB followed by stent implantation was successfully performed in 44 (81 %) cases. DEB insertion failed in 19 % of the cases and angioplasty was finally performed using a conventional PTCA balloon. The combined procedure related permanent neurologic morbidity and mortality rate (stroke, ICH, and subarachnoid hemorrhage) at 30 days and beyond was 5 %. Angiographic and clinical follow-up were obtained in 33 (61 %) lesions in 32 patients. Recurrent stenosis was seen in one (3 %) lesion. Angioplasty and stenting using a DEB is safe and yields encouragingly low ISR rates. Further technical developments to improve lesion accessibility are, nevertheless, mandatory.

  9. Five-year outcomes of self-expanding nitinol stent implantation for chronic total occlusion of the superficial femoral and proximal popliteal artery.

    PubMed

    Sakamoto, Yasunari; Hirano, Keisuke; Iida, Osamu; Soga, Yoshimitsu; Suzuki, Kenji; Muramatsu, Toshiya; Tsukahara, Reiko

    2013-09-01

    To investigate the 5-year patency rates and predictors of restenosis after self-expanding nitinol stent implantation for chronic total occlusion (CTO) in superficial femoral and proximal popliteal artery (SFPA) lesions. Outcomes and long-term patency rates after self-expanding nitinol stent for CTO in the SFPA lesions have not been clarified. From January 2004 to December 2009, 861 serial arteriosclerosis obliterans patients, 1,017 limbs, underwent endovascular therapy with implantation of a self-expanding nitinol stent for SFPA lesions at four institutions in Japan. Of the cohort, 352 patients, 383 limbs, had self-expanding nitinol stents implanted for CTOs in the SFPA and were followed for 5 years. We retrospectively investigated patency rate and multivariate predictors associated with restenosis. Mean age was 72 ± 9 years and 31% were female patients. In total, 58% of the patients had diabetes mellitus and 25% were patients with critical limb ischemia. Occluded length was 194 ± 89 mm, mean total stent length was 198 ± 7 mm, and mean stent diameter was 7.1 ± 0.9 mm. Five-year primary and secondary patency rates were 51.8 and 79.5%, respectively, and the rates of freedom from bypass surgery, major or minor amputation, and all-cause death were 96.1, 96.2, and 78.4%, respectively. Female gender (odds ratio, 1.95; P = 0.0051) and mean stent diameter (odds ratio, 0.77; P = 0.0324) were factors strongly associated with restenosis. Women and patients requiring small stents failed to maintain primary patency when treated with self-expanding nitinol stents for CTO lesions in the SFPA. Although primary patency was low, the secondary patency rate was acceptable. Copyright © 2013 Wiley Periodicals, Inc.

  10. Chronic vascular response after self-expanding nitinol stent implantation in superficial femoral arteries: a serial intravascular ultrasound analysis.

    PubMed

    Nishimura, Machiko; Fujii, Kenichi; Fukunaga, Masashi; Kawasaki, Daizo; Miki, Kojiro; Saita, Ten; Horimatsu, Tetsuo; Tamaru, Hiroto; Imanaka, Takahiro; Naito, Yoshiro; Masuyama, Tohru

    2016-10-01

    The mechanical properties of the self-expanding nitinol stents (SENS) and chronic biological stimulation on the wall from the SENS have not been fully investigated. This study evaluated the mechanical vascular response to SENS implantation in superficial femoral artery (SFA) lesions using serial volumetric intravascular ultrasound (IVUS). Twenty-five symptomatic patients due to de novo SFA lesions scheduled for SENS placement were prospectively enrolled. Serial IVUS studies were performed immediately after crossing with a guidewire, immediately after the procedure, and at a 8-month follow-up. Serial IVUS volumetric analysis was conducted after stent deployment and at follow-up. Mean stent, lumen and neointimal areas were calculated as the volume divided by the stent length, and the calcium arc was measured. At follow-up, SENS had increased 40.6 % in overall volume. The chronic stent expansion tended to be larger, and the mean neointimal area at the 8-month follow-up was significantly larger in less calcified lesions compared to heavily calcified lesions. As a result, the mean late lumen area loss was significantly larger in lesions with calcium arcs of 0° and in the first and second quadrants than in those with calcium arcs in the third and fourth quadrants (2.8 ± 7.2, 1.3 ± 5.6, 0.6 ± 5.9, 1.2 ± 5.4, -0.8 ± 5.2 mm(2), respectively; p < 0.001). SENSs continued to enlarge with intimal proliferation over 8 months in all lesions. Although arterial calcium affected the degree of chronic stent expansion during the follow-up period, neointimal proliferation was smaller in heavily calcified lesion compared to less calcified lesion following SENS implantation.

  11. Esophagojejunal Anastomosis Fistula, Distal Esophageal Stenosis, and Metalic Stent Migration after Total Gastrectomy

    PubMed Central

    Al Hajjar, Nadim; Popa, Calin; Al-Momani, Tareg; Margarit, Simona; Graur, Florin; Tantau, Marcel

    2015-01-01

    Esophagojejunal anastomosis fistula is the main complication after a total gastrectomy. To avoid a complex procedure on friable inflamed perianastomotic tissues, a coated self-expandable stent is mounted at the site of the anastomotic leak. A complication of stenting procedure is that it might lead to distal esophageal stenosis. However, another frequently encountered complication of stenting is stent migration, which is treated nonsurgically. When the migrated stent creates life threatening complications, surgical removal is indicated. We present a case of a 67-year-old male patient who was treated at our facility for a gastric adenocarcinoma which developed, postoperatively, an esophagojejunostomy fistula, a distal esophageal stenosis, and a metallic coated self-expandable stent migration. To our knowledge, this is the first reported case of an esophagojejunostomy fistula combined with a distal esophageal stenosis as well as with a metallic coated self-expandable stent migration. PMID:25945277

  12. Esophagojejunal anastomosis fistula, distal esophageal stenosis, and metalic stent migration after total gastrectomy.

    PubMed

    Al Hajjar, Nadim; Popa, Calin; Al-Momani, Tareg; Margarit, Simona; Graur, Florin; Tantau, Marcel

    2015-01-01

    Esophagojejunal anastomosis fistula is the main complication after a total gastrectomy. To avoid a complex procedure on friable inflamed perianastomotic tissues, a coated self-expandable stent is mounted at the site of the anastomotic leak. A complication of stenting procedure is that it might lead to distal esophageal stenosis. However, another frequently encountered complication of stenting is stent migration, which is treated nonsurgically. When the migrated stent creates life threatening complications, surgical removal is indicated. We present a case of a 67-year-old male patient who was treated at our facility for a gastric adenocarcinoma which developed, postoperatively, an esophagojejunostomy fistula, a distal esophageal stenosis, and a metallic coated self-expandable stent migration. To our knowledge, this is the first reported case of an esophagojejunostomy fistula combined with a distal esophageal stenosis as well as with a metallic coated self-expandable stent migration.

  13. Impact on the quality of remaining life of treatment with self-expandable metal prostheses in patients with inoperable esophago-cardial cancer. Results of a study of 107 consecutive patients treated with Ultraflex-type prostheses.

    PubMed

    De Palma, G D; Siciliano, S; Sivero, L; Galloro, G; Donisi, M; Catanzano, C

    1999-06-01

    Self-expanding metal stents are a new alternative for palliation of esophagocardial malignancies. We evaluated the impact of these stents on the quality of remaining life in patients affected by inoperable esophago-cardial cancer. Between September 1992 and September 1997, 102 patients underwent implantation of self expanding metal stents for palliation of dysphagia due to esophagene or cardial cancer (76 patients), or for locally recurrent carcinoma after surgery (14 patients), lasertherapy (13 patients) or radiotherapy (5 patients). Stents were implanted under radiological and endoscopic control in patients under mild sedation. Successful stent implantation was achieved in 102/107 patients (95.3%). Early complications were observed in 4.9% and per-operative mortality was 1.96%. After stent implantation the dysphagia score improved from 3.0, on average, to 0.5, on average. Late complications were evidenced in 25.5%. Weight gain was evidenced in 24.5% and the performance status improved in 14.3%. The mean survival time was 6.9 months. Self expanding metal stents are an effective alternative for palliation of malignant dysphagia due to esophageal and cardial cancers.

  14. Self expandable stents for relief of venous baffle obstruction after the Mustard operation.

    PubMed

    Brown, S C; Eyskens, B; Mertens, L; Stockx, L; Dumoulin, M; Gewillig, M

    1998-03-01

    Obstruction of the venous pathways after Mustard repair for transposition of the great arteries is associated with an increased risk of arrhythmia and sudden death. The purpose of this study was to assess the effectiveness of the largest (tracheal 22 x 40 mm) Wallstents in treating baffle obstructions. Retrospective analysis of patients with stented venous pathways. Eleven patients with baffle obstruction after Mustard repair for transposition of the great arteries. Stenoses were dilated with an 18 or 20 mm balloon. However, recoil was noticed in 11 patients: immediately (n = 7) or on repeat angiography (n = 4). Eighteen stents were implanted (mean (SD)) 18 (3.3) years postoperatively. After dilatation a tracheal Wallstent (11.5 F) was deployed. Relief of obstruction, haemodynamic improvement. In the inferior vena cava, 10 stents were deployed in seven baffle obstructions with an increase in diameter from 9.8 (2.4) mm to 16.5 (1.4) mm (p < 0.01) and a mean (SD) pressure gradient decrease from 5.1 (3.6) mm Hg to 1.4 (2.0) mm Hg; in the superior vena cava, eight stents were implanted increasing the diameter from 9.1 (3.7) mm to 15.6 (3.8) mm (p < 0.001) with a decrease in mean pressure gradient from 5.1 (2.7) mm Hg to 1.9 (1.5) mm Hg. No complications were experienced during implantation. No anticoagulation was prescribed. During follow up (1.7 (0.6) years; range, 0.9-2.6) no problems were noted; five patients were re-catheterised without change in measurements. There was no evidence of peal formation in any of the stents. It is concluded that Wallstents are safe, easy to use, and effective in relieving baffle obstruction. Anticoagulation does not seem necessary.

  15. Self expandable stents for relief of venous baffle obstruction after the Mustard operation

    PubMed Central

    Brown, S; Eyskens, B; Mertens, L; Stockx, L; Dumoulin, M; Gewillig, M

    1998-01-01

    Objective—Obstruction of the venous pathways after Mustard repair for transposition of the great arteries is associated with an increased risk of arrhythmia and sudden death. The purpose of this study was to assess the effectiveness of the largest (tracheal 22 × 40 mm) Wallstents in treating baffle obstructions.
Design—Retrospective analysis of patients with stented venous pathways.
Subjects—Eleven patients with baffle obstruction after Mustard repair for transposition of the great arteries.
Interventions—Stenoses were dilated with an 18 or 20 mm balloon. However, recoil was noticed in 11 patients: immediately (n = 7) or on repeat angiography (n = 4). Eighteen stents were implanted (mean (SD)) 18 (3.3) years postoperatively. After dilatation a tracheal Wallstent (11.5 F) was deployed.
Main outcome measures—Relief of obstruction, haemodynamic improvement.
Results—In the inferior vena cava, 10 stents were deployed in seven baffle obstructions with an increase in diameter from 9.8 (2.4) mm to 16.5 (1.4) mm (p < 0.01) and a mean (SD) pressure gradient decrease from 5.1 (3.6) mm Hg to 1.4 (2.0) mm Hg; in the superior vena cava, eight stents were implanted increasing the diameter from 9.1 (3.7) mm to 15.6 (3.8) mm (p < 0.001) with a decrease in mean pressure gradient from 5.1 (2.7) mm Hg to 1.9 (1.5) mm Hg. No complications were experienced during implantation. No anticoagulation was prescribed. During follow up (1.7 (0.6) years; range, 0.9-2.6) no problems were noted; five patients were re-catheterised without change in measurements. There was no evidence of peal formation in any of the stents.
Conclusion—It is concluded that Wallstents are safe, easy to use, and effective in relieving baffle obstruction. Anticoagulation does not seem neccessary.

 Keywords: Mustard procedure;  venous baffle obstruction;  stent PMID:9602654

  16. Safety and biocompatibility of a novel self-expanding nitinol carotid stent with hybrid cell design in a porcine model of neointimal hyperplasia.

    PubMed

    Janas, Adam; Milewski, Krzysztof; Buszman, Piotr P; Nowakowski, Przemysław; Jelonek, Michał; Orlik, Bartłomiej; Krauze, Agata; Samborski, Stefan; Beaudry, Diane; Lecelrc, Guy; Król, Marek; Lapointe, Jean Martin; Wojakowski, Wojciech; Turek, Anna; Kiesz, Radosław S; Buszman, Paweł E

    2015-01-01

    Stent design may influence the outcomes, suggesting that adverse event rates vary according to free cell area and cell design. Open cell design technology of self-expandable stents, dedicated for carotid revascularisation has better deliverability, although closed cell technology is expected to cause fewer thromboembolic events. To evaluate the feasibility and vascular response of novel, hybrid cell, self-expandable nitinol stents (MER®, Balton, Poland) implanted into porcine carotid arteries. Hybrid cell design combines open and closed cell technology. All tested stents were implanted with 10% overstretch into 10 carotid segments of Polish domestic pigs. Control angiography was obtained immediately before and after vascular interventions as well as 28 days after the procedure. Thereafter, animals were sacrificed, and the treated segments were harvested and evaluated in the independent histopathology laboratory. All stents were easily introduced and implanted, showing good angiographic acute outcome. At 28 days, in the angiography, all vessels were patent with no signs of thrombi or excessive neointimal formation, with the late lumen loss of -0.11 ± 0.3 mm and percentage diameter stenosis 10.18 ± 8.1%. There was a 10% increase in the vessel reference diameter when compared to baseline (4.57 ± 0.5 vs. 4.96 ± 0.3 mm, p < 0.01). In the histopathology, mean area stenosis was 17.4% and mean intimal thickness was 0.20 mm. At histopathology, the mean injury, inflammation, and fibrin scores were low. Endothelialisation was complete in all stents, and neointimal tissue appeared moderately mature as shown by the moderate mean neointimal smooth muscle score. Nonetheless, histopathology shows one stent affected by peri-strut granulomas and one stent affected by marked mineralisation. The novel Polish self-expandable nitinol carotid stent with hybrid cell technology shows optimal biocompatibility and a vascular healing profile, and therefore may be introduced for first

  17. Effect of Early Use of Covered Self-Expandable Endoscopic Stent on the Treatment of Postoperative Stapler Line Leaks.

    PubMed

    Quezada, Nicolás; Maiz, Cristóbal; Daroch, David; Funke, Ricardo; Sharp, Allan; Boza, Camilo; Pimentel, Fernando

    2015-10-01

    Postoperative leaks are a dreaded complication after bariatric surgery (BS). Its treatment is based on nutritional support and sepsis control by antibiotics, collections drainage and/or prosthesis, and/or surgery. The aim of this study is to report our experience with coated self-expandable endoscopic stents (SEES) for leaks treatment. This study was performed in a University Hospital, (censored). We performed a retrospective analysis of our BS database from January 2007 to December 2013. All patients with leak after BS treated with SEES were included. We identified 29 patients; 17 (59%) were women, with median age of 37 (19-65) years, and preoperative body mass index of 40 (28.7-56-6) kg/m(2). Nineteen (65.5%) patients had a sleeve gastrectomy and 10 (34.5%) a Roux-en-Y gastric bypass. All patients had a leak in the stapler line. Median time from surgery to leak diagnosis was 7 (1-51) days, and SEES were installed 8 (0-104) days after diagnosis. Twenty-one (72%) patients also had abdominal exploration. Median length of SEES use was 60 (1-299) days. Patients who had SEES as primary treatment (with or without simultaneous reoperation) had a shorter leak closure time (50 [6-112] vs 109 [60-352] days; p = 0.008). Twenty-eight (96.5%) patients successfully achieved leak closure with SEES. There were 16 migrations in 10 (34%) patients, 1 (3%) stent fracture, 1 opening of the blind end of alimentary limb (3%), and 5 patients (17%) required a second stent due to leak persistence. SEES is a feasible, safe, and effective management of post BS leaks, although patients may also require prosthesis revision and abdominal exploration. Primary SEES placement is associated with a shorter leak resolution time.

  18. Midterm to long-term safety and efficacy of self-expandable nitinol stent implantation for coarctation of aorta in adults.

    PubMed

    Haji Zeinali, Ali Mohammad; Sadeghian, Mohammad; Qureshi, Shakeel A; Ghazi, Payam

    2017-09-01

    Endovascular treatment of coarctation of aorta (CoA) by self-expandable Nitinol stents is one of the recognized treatment methods and may be an alternative to surgery or balloon-expandable stent implantation for CoA but there is little information about midterm to long term results of self-expandable stents. Sixty-two patients with CoA (40 men), with a mean age of 30.7 ± 11 years, (range 17-63 years) underwent stent implantation with Optimed self-expandable Nitinol stents between 2005 and 2014. Successful outcome was defined as peak systolic pressure gradient ≤20 mmHg after stent implantation. The patients were followed-up clinically and by echocardiography and in patients, in whom there was suspicion of recoarctation, CT angiography or recatheterization was performed. 65 stents were successfully implanted in all 62 patients. Peak systolic pressure gradient decreased from mean 62.4 ± 18 mmHg (range 35-100 mmHg) to mean 2.8 ± 5 mmHg (range 0-15 mmHg; P < 0.001). Stent displacement occurred in 3 patients during the procedure. These were managed successfully by an overlapping second stent. None of the patients had major complications such as aortic dissection, rupture, or vascular access problems. In follow up, only three patients had recoarctation, and two of these were managed successfully by balloon redilation or further stenting 16 and 18 months after the first procedure and one patient refused reintervention. There were two deaths, unrelated to the procedure, 12 and 78 months after the initial intervention. Follow-up of a mean of 45.5 ± 17 months (range 12-105 months) demonstrated no evidence of aneurysm formation or stent fracture. Self-expandable nitinol stents for the treatment of native and recurrent CoA is safe and has good efficacy with acceptable midterm to long-term outcome. © 2017 Wiley Periodicals, Inc.

  19. An instant rare complication: a fractured metallic pyloric stent

    PubMed Central

    Javaid, Mahvesh Rana; Yusuf, Aasim Mohammad

    2013-01-01

    Metallic pyloric stenting (also termed as metallic enteral stenting) performed endoscopically, stands as first-line treatment for malignant gastric outlet obstruction. With reported evidence, these self-expandable metallic stents (SEMS) re-enable oral food intake, preventing patients having to face invasive techniques such as surgical gastroenterostomy. We report a patient having received a covered pyloric SEMS insertion following a tumour growth causing stenosis in the gastric antropyloric region. After 3 weeks, the patient presented with a fracture of the pyloric SEMS, a rare complication, resulting in a second pyloric SEMS insertion. PMID:23345482

  20. Novel Use of a Uniquely Designed, Lumen-Apposing, Metal Stent in Benign Gastric Outlet Obstruction in Two Patients

    PubMed Central

    Pathirana, Induruwa; Magulick, John; Domanski, Jeremy; Okoh, Emuejevoke; Womeldorph, Craig

    2017-01-01

    Current guidelines recommend management of benign gastric outlet obstruction (GOO) with serial dilations. Self-expanding metal stents are effective, but their use is complicated by high rates of migration. We present two cases from our institution where a uniquely designed, lumen-apposing metal stent (LAMS) was successfully used to alleviate benign GOO without stent migration. PMID:28184377

  1. Simulations of Self-Expanding Braided Stent Using Macroscopic Model of NiTi Shape Memory Alloys Covering R-Phase

    NASA Astrophysics Data System (ADS)

    Frost, M.; Sedlák, P.; Kruisová, A.; Landa, M.

    2014-07-01

    Self-expanding stents or stentgrafts made from Nitinol superelastic alloy are widely used for a less invasive treatment of disease-induced localized flow constriction in the cardiovascular system. The therapy is based on insertion of a stent into a blood vessel to maintain the inner diameter of the vessel; it provides highly effective results at minimal cost and with reduced hospital stays. However, since stent is an external mechanical healing tool implemented into human body for quite a long time, information on the mechanical performance of it is of fundamental importance with respect to patient's safety and comfort. Advantageously, computational structural analysis can provide valuable information on the response of the product in an environment where in vivo experimentation is extremely expensive or impossible. With this motivation, a numerical model of a particular braided self-expanding stent was developed. As a reasonable approximation substantially reducing computational demands, the stent was considered to be composed of a set of helical springs with specific constrains reflecting geometry of the structure. An advanced constitutive model for NiTi-based shape memory alloys including R-phase transition was employed in analysis. Comparison to measurements shows a very good match between the numerical solution and experimental results. Relation between diameter of the stent and uniform radial pressure on its surface is estimated. Information about internal phase and stress state of the material during compression loading provided by the model is used to estimate fatigue properties of the stent during cyclic loading.

  2. Self-expanding nitinol stents in recanalisation of long-length superficial femoral artery occlusions in patients with critical limb ischaemia.

    PubMed

    Taneja, M; Tay, K H; Sebastian, M; Pasupathy, S; Lin, S E; Teo, T; Low, R; Irani, F G; Chng, S P; Dewan, A; Tan, B S

    2009-12-01

    This study aims to evaluate our experience with self-expanding nitinol stent- enabled recanalisation of long-length occlusions (30 cm or more) of the superficial femoral artery (SFA). 573 patients underwent 842 lower limb interventions from August 2006 to December 2008. A retrospective review of patients undergoing recanalisation of long-length SFA occlusions with self-expanding nitinol stents and an evaluation of their patency and impact on limb salvage, were done. 22 patients (mean age 62.5 years, male: female ratio 11:11) underwent 22 long-length SFA stenting procedures. The spectrum of critical limb ischaemia included rest pain (five), ulcer (six) and gangrene (11). Length of occlusions varied from 30 cm to 45 cm (average length 36.4 cm). Five patients had stents placed through the ipsilateral popliteal artery approach, and the rest had stents placed through the femoral artery approach. All patients were followed up over an average duration of 12 months. One patient died due to associated medical conditions during this period. Six out of 21 (28.6 percent) of the stents thrombosed completely on one year follow-up. Of these, two patients underwent amputation, one patient had a bypass, and the stent in two patients were recanalised with balloon angioplasty. All remaining patent stents showed varying degrees of stenoses at one year. The overall limb salvage rate at one year following stent placement was 81 percent. Our experience showed the beneficial result of long-length SFA stent placement with good limb salvage outcome. Repeat interventions may be required to maintain the patency of stents in these patients.

  3. Stent-Assisted Coil Embolization of a Mycotic Renal Artery Aneurysm by Use of a Self-Expanding Neurointerventional Stent

    SciTech Connect

    Rabellino, Martin; Garcia-Nielsen, Luis; Zander, Tobias Baldi, Sebastian; Llorens, Rafael; Maynar, Manuel

    2011-02-15

    Mycotic aneurysms are uncommon, especially those located in visceral arteries. We present a case of a patient with two visceral mycotic aneurysms due to bacterial endocarditis, one located in right upper pole renal artery and the second in the splenic artery. Both aneurysms were treated as endovascular embolization using microcoils. In the aneurysm located at the renal artery, the technique of stent-assisted coils embolization was preferred to avoid coils migration due to its wide neck. The stent used was the Solitaire AB, which was designed for the treatment of intracranial aneurysms and was used recently in acute stroke as a mechanical thrombectomy device. Complete embolization of the aneurysm was achieved, preserving all the arterial branches without nephrogram defects in the final angiogram.

  4. Complication rates using balloon-expandable and self-expanding stents for the treatment of intracranial atherosclerotic stenoses : analysis of the INTRASTENT multicentric registry.

    PubMed

    Kurre, Wiebke; Brassel, Friedhelm; Brüning, Roland; Buhk, Jan; Eckert, Bernd; Horner, Susanna; Knauth, Michael; Liebig, Thomas; Maskova, Jana; Mucha, Dirk; Sychra, Vojtech; Sitzer, Matthias; Sonnberger, Michael; Tietke, Marc; Trenkler, Johannes; Turowski, Bernd; Berkefeld, Joachim

    2012-01-01

    Using balloon-expandable stents (BES) for treatment of intracranial stenoses, high inflation pressures and rigidity of the device are regarded as major drawbacks limiting feasibility and safety of the procedure. Self-expanding stents (SES) were developed to facilitate lesion access and to allow for less aggressive dilatation. We analyzed data of the INTRASTENT multicentric registry to assess whether self-expanding stents significantly reduced peri-interventional complication rates. Records of intracranial stent procedures were entered consecutively into the registry. Datasets were divided into two groups according to the type of stent used. For outcome measurement, we chose three categories: TIA/minor stroke [modified Rankin score (mRS) <2], disabling stroke, and patient death. Clinical outcome was compared between BES and SES. We analyzed types of adverse events occurring in each group in addition. Of 409 atherosclerotic lesions, 254 were treated with BES and 155 with SES. Technical success rates were 97.6% and 98.7%, respectively. Adverse event rates were 4.9%, 3.7%, and 0.8% for TIA/nondisabling stroke, disabling stroke, and death in the BES group compared with 5.3%, 6.0%, and 4.0% in the SES group. The differences were not statistically significant. We observed more perforator strokes after use of BES, but thromboembolic events occurred more often in the SES treatment group. Data of the INTRASTENT registry do not support the hypothesis that introduction of SES lowered the overall complication rate of intracranial stent procedures. There might be an advantage using self-expanding stents in vessel segments with important perforating arteries.

  5. Self-Expandable Stent for Repairing Coarctation of the Left-Circumferential Aortic Arch with Right-sided Descending Aorta and Aberrant Right Subclavian Artery with Kommerell's Aneurysm.

    PubMed

    Khajali, Zahra; Sanati, Hamid Reza; Pouraliakbar, Hamidreza; Mohebbi, Bahram; Aeinfar, Kamran; Zolfaghari, Reza

    2017-01-01

    Endovascular treatment offers a great advantage in the management of main arteries stenoses. However, simultaneous presence of a group of anomalies may complicate the situation. Here we present a case of 21-year-old man with aortic coarctation. Radiographic imaging and angiography demonstrated aortic coarctation of the left-circumferential aortic arch, right-sided descending aorta, and Kommerell's diverticulum at the origin of right subclavian artery. These anomalies have rarely been reported to concurrently exist in the same case and the treatment is challenging. Percutaneous treatment for repair of aortic coarctation was successfully performed with deployment of self-expanding nitinol stents. Follow-up demonstrated the correction of blood pressure and improvement of the symptoms. It appears that deployment of self-expandable nitinol stents present a viable option for the management of coarcted aorta in patients having all or some of these anomalies together.

  6. Successful Endovascular Repair of an Iatrogenic Perforation of the Superficial Femoral Artery Using Self-Expanding Nitinol Supera Stents in a Patient with Acute Thromboembolic Limb Ischemia.

    PubMed

    Eisele, Tom; Muenz, Benedikt M; Korosoglou, Grigorios

    2016-01-01

    The treatment of acute thromboembolic limb ischemia includes well-established surgical thrombectomy procedures and, in recent times, also percutaneous rotational thrombectomy using Straub Rotarex® system. This modality not only enables efficient treatment of such thrombotic occlusion but also in rare cases may imply the risk of perforation of the occluded artery. Herein, we report the case of a perforation of the superficial femoral artery (SFA) in an elderly female patient with thromboembolic limb ischemia. The perforation was successfully treated by implantation of self-expanding nitinol Supera stents and without the need for implantation of a stent graft.

  7. Successful Endovascular Repair of an Iatrogenic Perforation of the Superficial Femoral Artery Using Self-Expanding Nitinol Supera Stents in a Patient with Acute Thromboembolic Limb Ischemia

    PubMed Central

    Eisele, Tom; Muenz, Benedikt M.

    2016-01-01

    The treatment of acute thromboembolic limb ischemia includes well-established surgical thrombectomy procedures and, in recent times, also percutaneous rotational thrombectomy using Straub Rotarex® system. This modality not only enables efficient treatment of such thrombotic occlusion but also in rare cases may imply the risk of perforation of the occluded artery. Herein, we report the case of a perforation of the superficial femoral artery (SFA) in an elderly female patient with thromboembolic limb ischemia. The perforation was successfully treated by implantation of self-expanding nitinol Supera stents and without the need for implantation of a stent graft. PMID:27213074

  8. Two-year Clinical Outcomes Post Implantation of Epic(TM) Self-Expanding Nitinol Stents for the Aortoiliac Occlusive Disease in Patients with Peripheral Arterial Disease.

    PubMed

    Tsujimura, Takuya; Iida, Osamu; Fujita, Masashi; Masuda, Masaharu; Okamoto, Shin; Ishihara, Takayuki; Nanto, Kiyonori; Kanda, Takashi; Okuno, Shota; Matsuda, Yasuhiro; Fujihara, Masahiko; Yokoi, Yoshiaki; Mano, Toshiaki

    2017-10-05

    We investigated 2-year clinical outcomes after implantaton of Epic(TM) self-expanding nitinol stents for patients with peripheral artery disease (PAD) due to the aortoiliac occlusive disease (AIOD). This study was a multicenter and retrospective study. From February 2013 through October 2014, 292 lesions (chronic total occlusion, 21%; TASC Ⅱ C/D, 35%) in 217 consecutive patients (74±8 years; male, 81%; diabetes mellitus, 47%; dialysis, 21%; critical limb ischemia, 29%) who had undergone endovascular therapy (EVT) with Epic(TM) self-expanding nitinol stents for PAD with AIOD were analyzed. The primary endpoints were 2-year primary patency and target lesion revascularization (TLR)-free rate. The primary patency and freedom from TLR were determined by Kaplan-Meier analysis. Additionally, predictors for loss of patency were estimated by Cox proportional hazard model. The mean follow-up duration was 19.1±8.5 months. Primary patency was 87.3% at 2 years. Freedom from TLR rate was 94.1% at 2 years. Multivariate analysis revealed that the presence of diabetes mellitus was associated with a loss of patency. The Epic(TM) self-expanding nitinol stent was demonstrated to be safe and effectivene for AIOD when tested for two years in patients with PAD.

  9. Experimental off-pump transventricular pulmonary valve replacement using a self-expandable valved stent: A new approach for pulmonary incompetence after repaired tetralogy of Fallot?

    PubMed

    Godart, François; Bouzguenda, Ivan; Juthier, Francis; Wautot, Fabrice; Prat, Alain; Rey, Christian; Corseaux, Delphine; Ung, Alexandre; Jude, Brigitte; Vincentelli, André

    2009-05-01

    Off-pump valve replacement using self-expandable stents is an emerging technique for pulmonary valve disease. However, significant limitations are the lack of easily available valve substitute to be inserted within the stent and, in the setting of repaired tetralogy of Fallot, the existence of huge pulmonary trunk. We report the first experimental results of a transventricular approach using a decellularized porcine xenograft mounted in a self-expandable stent. Pulmonary valve replacement was realized in 15 lambs by direct access of the infundibulum through a left thoracotomy, combined with pulmonary artery banding. Animals were followed by transthoracic echocardiography and, after control hemodynamic study, were electively killed either at day 7, month 1, or month 4 after implantation. Implantation succeeded in all lambs. Two animals died after implantation (1 pneumothorax and 1 endocarditis). Doppler echocardiographic follow-up did not show any significant transvalvular gradient and showed only mild pulmonary regurgitation. The hemodynamic control before termination revealed a systolic pulmonary valve gradient of 18.5 +/- 12.4 mm Hg at 1 week (n = 4), 13.5 +/- 10.6 mm Hg at 1 month (n = 4), and 4.3 +/- 4.9 mm Hg at 4 months (n = 5). Gross examination demonstrated the presence of connective tissue between the valved stent and pulmonary wall, which increased with time. Fifteen lambs underwent successful deployment of a self-expandable valved stent in the pulmonary position using a transventricular approach. This technique combined with pulmonary artery banding could be a therapeutic option for pulmonary insufficiency after repair of tetralogy of Fallot with a transannular patch.

  10. Implantability, Complications, and Follow-Up After Transjugular Intrahepatic Portosystemic Stent-Shunt Creation With the 6F Self-Expanding Sinus-SuperFlex-Visual Stent

    PubMed Central

    Spira, Daniel; Wiskirchen, Jakub; Lauer, Ulrich; Ketelsen, Dominik; Nikolaou, Konstantin; Wiesinger, Benjamin

    2016-01-01

    Background The transjugular intrahepatic portosystemic stent-shunt (TIPSS) builds a shortcut between the portal vein and a liver vein, and represents a sophisticated alternative to open surgery in the management of portal hypertension or its complications. Objectives To describe clinical experiences with a low-profile nitinol stent system in TIPSS creation, and to assess primary and long-term success. Patients and Methods Twenty-six patients (5 females, 21 males; mean age 54.6 years) were treated using a low-profile 6F self-expanding sinus-SuperFlex-Visual stent system. The indication for TIPSS creation was refractory bleeding in 9 of the 26 patients, refractory ascites in 18 patients, and acute thrombosis of the portal vein confluence in one patient. Portosystemic pressure gradients before and after TIPSS, periprocedural and long-term complications, and the time to orthotopic liver transplantation (OLT) or death were recorded. Results The portosystemic pressure gradient was significantly reduced, from 20.9 ± 6.3 mmHg before to 8.2 ± 2.3 mmHg after TIPSS creation (P < 0.001). Procedure-related complications included acute tract occlusion (n = 2), liver hematoma (n = 1), hepatic encephalopathy (n = 1), and cardiac failure (n = 1). Three of the 26 patients had late-onset TIPSS occlusion (at 12, 12, and 39 months after TIPSS creation). Three patients died within one week after the procedure due to their poor general condition (multiorgan failure, acute respiratory distress syndrome, necrotizing pancreatitis, and aspiration pneumonia). Another four patients succumbed to their underlying advanced liver disease within one year after TIPSS insertion. Seven patients underwent OLT at a mean time of 9.4 months after TIPSS creation. Conclusion The sinus-SuperFlex-Visual stent system can be safely deployed as a TIPSS device. The pressure gradient reduction was clinically sufficient to treat the patients’ symptoms, and periprocedural complications were due to the TIPSS

  11. Comparison of drug-eluting balloon angioplasty with self-expanding interwoven nitinol stent deployment in patients with complex femoropopliteal lesions.

    PubMed

    Teymen, Burak; Akturk, Suleyman; Akturk, Ulku; Tdjani, Muhammed

    2017-01-01

    Objective The aim of this study was to compare the drug-eluting balloon with self-expanding interwoven nitinol stent deployment in patients with complex femoropopliteal lesions. Methods We retrospectively identified patients at our clinic with complex femoropopliteal artery lesions treated either with self-expanding interwoven nitinol stent or drug-eluting balloon. All patients had ankle-brachial index measured before and after the intervention, and regular clinical follow-up with Doppler ultrasonography was performed at six months and one year. Patients underwent peripheral angiography if needed. Results From April 2012 to July 2015, 107 patients with complex femoropopliteal lesions treated with using self-expanding interwoven nitinol stent ( N = 49, mean length 143.5 mm, mean follow-up of 14.1 ± 3.7 months) or drug-eluting balloon ( N = 58, mean length 140.6 mm, mean follow-up of 13.8 ± 4.1 months). The technical success rate was 100% in Supera® and 96.6% in drug-eluting balloon group. There were seven restenosis in self-expanding interwoven nitinol stent (SUS) group (84.8% patency) and 11 restenosis in drug-eluting balloon group (79.2% patency). A significant increase in the ankle-brachial index in both groups after intervention demonstrated a hemodynamic success (SUS group 0.45 ± 0.06, drug-eluting balloon group 0.43 ± 0.07). The mean Rutherford Becker Class significantly decreased in both groups after a follow-up of 12 months (SUS group 0.70 ± 0.73, drug-eluting balloon group 0.74 ± 0.75). Conclusion Deploying drug-eluting balloon or self-expanding interwoven nitinol stent in patients with complex femoropopliteal lesions are both safe and effective with high patency rates with no statistical difference for one-year primary patency rates between them.

  12. Role of metallic stents in benign esophageal stricture

    NASA Astrophysics Data System (ADS)

    Shim, Chan Sup

    2012-10-01

    Simple esophageal strictures, which are focal, straight, and large in diameter, usually require 1 - 3 dilation sessions to relieve symptoms. However, complex strictures, which are long, tortuous, or associated with a severely compromised luminal diameter, are usually more difficult to treat with conventional bougie or balloon dilation techniques, and often have high recurrence rates. Although the permanent placement of self-expandable metal stents (SEMS) has been used to manage refractory benign esophageal strictures, this procedure is associated with additional problems, such as stricture from tissue hyperplasia, stent migration, and fistula formation. Thus, several new types of stents have been developed, including temporary SEMS, self-expandable plastic stents (SEPS), and biodegradable stents. The use of these new products has produced varied results. Temporary SEMS that have been used to relieve benign esophageal conditions have caused granulation tissue at both ends of the stent because of contact between the mucosa and the exposed metal components of the stent, thus hindering stent removal. We examined the tissue response to two new types of SEMS, a flange-type and a straighttype, each coated with a silicone membrane on the outside of the metal mesh. These two SEMS were evaluated individually and compared with a conventional control stent in animal experiments. Although the newly designed stents resulted in reduced tissue hyperplasia, and were thus more easily separated from the esophageal tissue, some degree of tissue hyperplasia did occur. We suggest that newly designed DES (drug-eluting stents) may provide an alternative tool to manage refractory benign esophageal stricture.

  13. Primary Self-EXPANDing Nitinol Stenting vs Balloon Angioplasty With Optional Bailout Stenting for the Treatment of Infrapopliteal Artery Disease in Patients With Severe Intermittent Claudication or Critical Limb Ischemia (EXPAND Study).

    PubMed

    Schulte, Karl-Ludwig; Pilger, Ernst; Schellong, Sebastian; Tan, Kong Ten; Baumann, Frederic; Langhoff, Ralf; Torsello, Giovanni; Zeller, Thomas; Amendt, Klaus; Brodmann, Marianne

    2015-10-01

    To compare primary placement of a self-expanding nitinol stent to percutaneous transluminal angioplasty (PTA) with bailout stenting in infrapopliteal arteries of patients with severe intermittent claudication or critical limb ischemia (CLI). In the EXPAND trial (ClinicalTrials.gov; identifier NCT00906022), 92 patients (mean age 72.9±9.5 years; 62 men) undergoing treatment for infrapopliteal stenosis in 11 European centers were randomized 1:1 to either self-expanding nitinol stenting with the Astron Pulsar/Pulsar-18 nitinol stent or PTA with bailout stenting. The primary endpoint was sustainable clinical improvement after 12 months, defined as a ≥1-category increase for Rutherford category 3 patients or a ≥2-category increase for CLI patients (Rutherford categories 4/5) compared with baseline. Furthermore, target lesion revascularization (TLR), mortality, and amputation were assessed after 12 months. Sustained clinical improvement at 1 year was observed in 74.3% of the patients treated with primary stenting and in 68.6% of the patients treated with PTA and bailout stenting (p>0.05). Kaplan-Meier estimates of freedom from TLR (76.6% and 77.6%), mortality (7.4% vs 2.1%), and amputation [8.9% (major 6.7%) vs 13.2% (major 8.7%)] at 1 year were not significantly different. Primary self-expanding nitinol stenting did not show statistically different clinical outcomes compared to angioplasty with bailout stenting for infrapopliteal lesions. © The Author(s) 2015.

  14. Covered versus uncovered self-expandable nitinol stents in the palliative treatment of malignant distal biliary obstruction: results from a randomized, multicenter study.

    PubMed

    Kullman, Eric; Frozanpor, Farshad; Söderlund, Claes; Linder, Stefan; Sandström, Per; Lindhoff-Larsson, Anna; Toth, Ervin; Lindell, Gert; Jonas, Eduard; Freedman, Jacob; Ljungman, Martin; Rudberg, Claes; Ohlin, Bo; Zacharias, Rebecka; Leijonmarck, Carl-Eric; Teder, Kalev; Ringman, Anders; Persson, Gunnar; Gözen, Mehmet; Eriksson, Olle

    2010-11-01

    Covered biliary metal stents have been developed to prevent tumor ingrowth. Previous comparative studies are limited and often include few patients. To compare differences in stent patency, patient survival, and complication rates between covered and uncovered nitinol stents in patients with malignant biliary obstruction. Randomized, multicenter trial conducted between January 2006 and October 2008. Ten sites serving a total catchment area of approximately 2.8 million inhabitants. A total of 400 patients with unresectable distal malignant biliary obstruction. ERCP with insertion of covered or uncovered metal stent. Follow-up conducted monthly for symptoms indicating stent obstruction. Time to stent failure, survival time, and complication rate. The patient survival times were 116 days (interquartile range 242 days) and 174 days (interquartile range 284 days) in the covered and uncovered stent groups, respectively (P = .320). The first quartile stent patency time was 154 days in the covered stent group and 199 days in the uncovered stent group (P = .326). There was no difference in the incidence of pancreatitis or cholecystitis between the 2 groups. Stent migration occurred in 6 patients (3%) in the covered group and in no patients in the uncovered group (P = .030). Randomization was not blinded. There were no significant differences in stent patency time, patient survival time, or complication rates between covered and uncovered nitinol metal stents in the palliative treatment of malignant distal biliary obstruction. However, covered stents migrated significantly more often compared with uncovered stents, and tumor ingrowth was more frequent in uncovered stents. Copyright © 2010 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

  15. Management of occluded metal stents in malignant biliary obstruction: similar outcomes with second metal stents compared to plastic stents.

    PubMed

    Shah, Tilak; Desai, Svetang; Haque, Mahfuzul; Dakik, Hassan; Fisher, Deborah

    2012-11-01

    Covered or uncovered self expandable metallic stents (SEMS) placed in patients with malignant biliary obstruction can occlude in 19-40 %, but optimal management is unclear. We sought to summarize current evidence regarding management of occluded SEMS in patients with malignant biliary obstruction. Two investigators independently searched Pubmed, Embase, and Web of Science using pre-defined search criteria, and reviewed bibliographies of included studies. Data were independently abstracted by two investigators, and analyzed using RevMan. We compared strategies of second SEMS versus plastic stents with respect to the following outcomes: rate of second stent re-occlusion, duration of second stent patency, and survival. Ten retrospective studies met inclusion criteria for the systematic review. Management options described were placement of an uncovered SEMS (n = 125), covered SEMS (n = 106), plastic stent (n = 135), percutaneous biliary drain (n = 7), mechanical cleaning (n = 18), or microwave coagulation (n = 7). Relative risk of re-occlusion was not significantly different in patients with second SEMS compared to plastic stents (RR 1.24, 95 % CI 0.92, 1.67, I(2) = 0, p 0.16). Duration of second stent patency was not significantly different between patients who received second SEMS versus plastic stents (weighted mean difference 0.46, 95 % CI -0.30, 1.23, I(2) = 83 %). Survival was not significantly different among patients who received plastic stents versus SEMS (weighted mean difference -1.13, 95 % CI -2.33, 0.07, I(2) 86 %, p = 0.07). Among patients with malignant biliary obstruction and occluded SEMS, available evidence suggests a strategy of placing a plastic stent may be as effective as second SEMS. Limitations of these findings were that all studies were retrospective and heterogeneity between studies was detected for two of the outcomes.

  16. Metallic stents for airway complications after lung transplantation: long-term follow-up.

    PubMed

    Abdel-Rahman, Nader; Kramer, Mordechai R; Saute, Milton; Raviv, Yael; Fruchter, Oren

    2014-05-01

    Bronchial stenosis is still a significant source of morbidity and mortality following lung transplantation (LTX) and often mandating placement of a bronchial stent. It has been suggested that although self-expanding metal stents offer excellent early palliation, their long-term complication rates are unacceptably high, and hence, their usage in many transplantation centres has been nearly abandoned. The aim of the study was to assess short- and long-term complication rates and survival in LTX patients with bronchial stenosis treated with insertion of self-expanding metal stents. From January 1997 to March 2013, 435 patients underwent LTX (325 single-LTX and 110 bilateral LTX). Of 503 actual anastomoses at risk (derived by subtracting the number of anastomoses in 30 patients who died within 30 days of LTX), 60 airway complications (11.9%) in 47 patients required self-expanding metal stent insertion. We assessed the early results and long-term outcomes and survival compared with LTX patients in whom stents were not required. The median follow-up period ranged from 1 to 132 (median 54) months. Immediate relief of symptoms was achieved in the vast majority of patients (95%). One-, three- and five-year survival in patients who required self-expanding metal stent placement were 77.7, 66.6 and 55.5%, respectively. The corresponding survival rates in LTX patients without stents were 69, 64.9 and 61.1% (P > 0.05). Self-expanding metal stents are safe and effective tools in the management of airway complications post-LTX and provide immediate improvement in symptoms and pulmonary function tests in the vast majority of cases. The long-term complication rate is low, and mortality is similar to that in LTX patients who did not require stent insertion.

  17. Endoscopic management of malignant biliary obstruction by means of covered metallic stents: primary stent placement vs. re-intervention.

    PubMed

    Kida, M; Miyazawa, S; Iwai, T; Ikeda, H; Takezawa, M; Kikuchi, H; Watanabe, M; Imaizumi, H; Koizumi, W

    2011-12-01

    Recent progress in chemotherapy has prolonged the survival of patients with malignant biliary strictures, leading to increased rates of stent occlusion. Occlusion of covered metallic stents now occurs in about half of all patients with malignant biliary strictures. The removal of metallic stents followed by placement of a second stent has been attempted, but outcomes remain controversial. The aim of the current study was to evaluate the effectiveness and safety of the primary placement and secondary placement (re-intervention) of covered metallic stents and to assess the feasibility and safety of stent removal. The study included 186 patients with unresectable malignant biliary strictures who underwent primary stent placement between October 2001 and March 2010.  Covered biliary self-expandable metal stents (SEMSs) were removed in 39 of these patients, and 36 underwent re-intervention. The patency times, occlusion rates of the first stent and re-intervention, success rates of stent removal, and complications were investigated. Covered SEMSs were placed in 186 patients. The median patency time of the first stent was 352 days. Stent occlusion occurred in 48.9 % of the patients and was mainly caused by debris or food residue (37 %), dislocation (19 %), and migration with hyperplasia (19 %). Stent removal was attempted in 50 patients and was successful without complication in 39 (78 %). Most of the patients in whom stent removal was unsuccessful had migration with hyperplasia. The median patency time of the second stent was 263 days. The stent patency time did not significantly differ between the first and the second stent. Covered SEMSs could be safely removed at the time of stent occlusion. Patency rates were similar for initial stent placement and re-intervention. © Georg Thieme Verlag KG Stuttgart · New York.

  18. Feasibility, safety, and preliminary efficacy of a novel ePTFE-covered self-expanding stent in saphenous vein graft lesions: the Symbiot II trial.

    PubMed

    Laarman, Gerrit J; Kiemeneij, Ferdinand; Mueller, Ralf; Guagliumi, Giuglio; Cobaugh, Michael; Serruys, Patrick W

    2005-03-01

    Compared with percutaneous interventions in native coronary arteries, revascularization of saphenous vein graft (SVG) lesions is associated with increased rates of immediate and long-term major adverse cardiac events (MACE). The Symbiot II trial was a multicenter prospective study designed to evaluate the feasibility and safety of a novel self-expanding polytetrafluoroethylene (ePTFE)-covered stent in the treatment of de novo and restenotic SVG lesions. The primary endpoint was MACE through 30 days postprocedure. Successful Symbiot stent deployment was achieved in 75 of 77 patients (97.4%) with SVG lesions < or = 35 mm in length (visual assessment). The procedural success rate (defined as < 30% residual stenosis at the target site and no clinical complications) was 83%, and all study device procedures provided grade 3 TIMI flow postprocedure. Within the first 30 days postprocedure, four patients (5.2%) experienced MACE (defined as death, Q-wave or non-Q-wave myocardial infarction, and clinically driven target vessel revascularization), of whom three patients (3.9%) experienced periprocedural non-Q-wave myocardial infarction. No subacute stent thrombosis was observed over the 6-month follow-up period. No relevant luminal loss at the target site (mean, 0.3 +/- 0.9 mm) was observed in the 58 patients (77.3% of enrolled patients) who underwent quantitative coronary angiography at 6 months. The incidences of binary in-stent restenosis, in-segment restenosis, and target vessel failure (defined as acute and late-term MACE through 6 months postprocedure) were low (7.0%, 8.6%, and 14.3%, respectively). The Symbiot self-expanding ePTFE membrane-covered stent was associated with a high procedural success rate (97.4%), low incidences of MACE at 30 days (5.2%) and 6 months (14.3%), suggesting that it is safe and effective in the treatment of SVG disease.

  19. Use of an ePTFE-covered nitinol self-expanding stent graft for the treatment off pre-closure device failure during transcatheter aortic valve replacement.

    PubMed

    Steinvil, Arie; Bernardo, Nelson; Rogers, Toby; Koifman, Edward; Buchanan, Kyle; Alraies, M Chadi; Shults, Christian; Torguson, Rebecca; Okubagzi, Petros G; Pichard, Augusto D; Satler, Lowell F; Ben-Dor, Itsik; Waksman, Ron

    2017-03-01

    Our aim was to describe our experience with the use of an ePTFE-covered nitinol self-expanding stent graft (GORE® VIABAHN® Endoprosthesis, Gore Medical, USA) placed in the common femoral artery for the treatment of suture-mediated pre-closure device failure following transcatheter aortic valve replacement (TAVR). Access site-related vascular complications (VC) following sheath removal related to pre-closure device failure during TAVR are common and treatment options may vary. We performed an observational study on a series of consecutive patients who underwent TAVR between 2013 and 2015. Included were 25 patients at a mean (±SD) age of 82±9. Failure of the closure device resulted in overt bleeding in 19 patients, dissection or no flow in 5 patients, and angiographic pseudoaneurysm in 1. Overall 29 stents were deployed with diameters ranging from 8 to 11mm and a length of 50mm (26, 90%). All stent-graft deployments achieved complete hemostasis of the arteriotomy site and resulted in normal flow to the distal vessels. None of the patients required open surgical repair. The mean hemoglobin drop was 2.6±1.3g/dl. Blood transfusions were used in 15 (60%) patients. Acute kidney injury occurred in 4 (16%) patients, none of whom was treated with dialysis. Length of hospital stay was 9±5days. All patients survived during a 30-day follow-up period, and none had VC related to the stented site. The use of an ePTFE-covered Nitinol self-expanding stent graft is a feasible, safe, and effective treatment modality for access site-related VC following TAVR. The use of an ePTFE-covered nitinol self-expanding stent graft placed in the common femoral artery for the treatment of suture-mediated pre-closure device failure following transcatheter aortic valve replacement (TAVR) is described in 25 patients. Its use was found to be feasible, safe, and an effective treatment modality for access site-related vascular complications following TAVR. Copyright © 2016 Elsevier Inc. All

  20. Long-Term Primary Patency Rate After Nitinol Self-Expandable Stents Implantation in Long, Totally Occluded Femoropopliteal (TASC II C & D) Lesions.

    PubMed

    Elmahdy, Mahmoud Farouk; Buonamici, Piergiovanni; Trapani, Maurizio; Valenti, Renato; Migliorini, Angela; Parodi, Guido; Antoniucci, David

    2017-06-01

    Endovascular therapy for long femoropopliteal lesions using percutaneous transluminal balloon angioplasty or first-generation of peripheral stents has been associated with unacceptable one-year restenosis rates. However, with recent advances in equipment and techniques, a better primary patency rate is expected. This study was conducted to detect the long-term primary patency rate of nitinol self-expandable stents implanted in long, totally occluded femoropopliteal lesions TransAtlantic Inter-Society Census (TASC II type C & D), and determine the predictors of reocclusion or restenosis in the stented segments. The demographics, clinical, anatomical, and procedural data of 213 patients with 240 de novo totally occluded femoropopliteal (TASC II type C & D) lesions treated with nitinol self-expandable stents were retrospectively analysed. Of these limbs, 159 (66.2%) presented with intermittent claudication, while 81 (33.8%) presented with critical limb ischaemia. The mean-time of follow-up was 36±22.6 months, (range: 6.3-106.2 months). Outcomes evaluated were, primary patency rate and predictors of reocclusion or restenosis in the stented segments. The mean age of the patients was 70.9±9.3 years, with male gender 66.2%. Mean pre-procedural ABI was 0.45±0.53. One-hundred-and-seventy-five (73%) lesions were TASC II type C, while 65 (27%) were type D lesions. The mean length of the lesions was 17.9±11.3mm. Procedure related complications occurred in 10 (4.1%) limbs. There was no periprocedural mortality. Reocclusion and restenosis were detected during follow-up in 45 and 30 limbs respectively, and all were re-treated by endovascular approach. None of the patients required major amputation. Primary patency rates were 81.4±1.1%, 77.7±1.9% and 74.4±2.8% at 12, 24, and 36 months respectively. Male gender, severe calcification, and TASC II D lesion were independent predictors for reocclusion, while predictors of restenosis were DM, smoking and TASC II D lesions

  1. Novel use of a peripheral, self-expanding nitinol stent in adjunct to excimer laser coronary atherectomy in the treatment of degenerated vein graft disease.

    PubMed

    Gim, Ronald D; Bokhari, Syed W; Winters, Rex J

    2005-01-01

    Decades of successful surgical revascularization of coronary artery disease have led to a growing population with saphenous vein graft disease. However, the treatment of degenerated saphenous vein graft still remains controversial. We report a novel but successful use of a peripheral, self-expanding nitinol stent in adjunct to excimer laser coronary atherectomy (ELCA) in the treatment of symptomatic, degenerated saphenous vein graft disease. The procedure was tolerated well without any short- or long-term complications. The case report is followed by a review of the literature on the treatment of vein graft disease.

  2. Bare metal stent versus paclitaxel eluting stent for intermediate length femoropopliteal arterial lesions (BATTLE trial): study protocol for a randomized controlled trial.

    PubMed

    Gouëffic, Yann; Kaladji, Adrien; Guyomarch, Béatrice; Montagne, Carine; Fairier, Damien; Gestin, Simon; Riche, Valéry-Pierre; Vent, Pierre Alexandre; Chaillou, Philippe; Costargent, Alain; Patra, Philippe

    2014-10-30

    Currently, endovascular treatment is indicated to treat femoropopliteal lesions ≤15 cm. However, the Achilles' heel of femoropopliteal endovascular repair remains restenosis. Paclitaxel eluting stents have shown promising results to prevent restenosis in femoropopliteal lesions compared to percutaneous transluminal angioplasty. A recently released prospective registry using a newer generation of self-expandable nitinol stents (Misago®; Terumo Corp., Tokyo, Japan) supports primary bare metal stenting as a first-line treatment for femoropopliteal lesions. To date, no studies have been designed to compare bare metal stents to paclitaxel eluting stents for the treatment of femoropoliteal lesions. The BATTLE trial was designed to compare paclitaxel eluting stents (Zilver® PTX®) and a last generation bare self-expandable nitinol stents (Misago® RX, Terumo Corp., Tokyo, Japan) in the treatment of intermediate length femoropopliteal lesions (≤14 cm). A prospective, randomized (1:1), controlled, multicentric and international study has been designed. One hundred and eighty-six patients fulfilling the inclusion criteria will be randomized to one of the two assessments of endovascular repair to treat de novo femoropopliteal lesions ≤14 cm in symptomatic patients (Rutherford 2 to 5): bare stent group and paclitaxel eluting stent group. The primary endpoint is freedom from in-stent restenosis at 1 year defined by a peak systolic velocity index >2.4 (restenosis of >50%) at the target lesion and assessed by duplex scan. Our main objective is to demonstrate the clinical superiority of primary stenting using Zilver® PTX® stent system versus bare metal self-expandable stenting in the treatment of femoropopliteal lesions in patients with symptomatic peripheral arterial disease. This is the first randomized and controlled study to compare the efficacy of bare metal stents and paclitaxel eluting stents for the treatment of femoropopliteal lesions. It may clarify the

  3. Supera self-expanding stents for endovascular treatment of femoropopliteal disease: a review of the clinical evidence.

    PubMed

    Bishu, Kalkidan; Armstrong, Ehrin J

    2015-01-01

    Femoropopliteal lesions account for a significant proportion of endovascular interventions for peripheral artery disease in patients with disabling claudication or chronic limb ischemia. The femoropopliteal artery crosses two joint structures (hip and knee joints) and courses through the muscular adductor canal in the thigh, which places the artery at increased biomechanical stress. There is a critical need for stent platforms with a reduced risk of stent fracture while maintaining patency during long-term follow-up. The Supera peripheral stent system has a braided nickel-titanium alloy stent designed to withstand the unique stressors along the course of the femoropopliteal artery. This design may be associated with improved patency in association with reduced stent fracture rates on short- and medium-term follow-up. Further studies, including randomized controlled studies, comparing the Supera interwoven nickel-titanium alloy stent system with other stent platforms and angioplasty alone are needed.

  4. Palliative Treatment of Malignant Colorectal Strictures with Metallic Stents

    SciTech Connect

    Paul Diaz, Laura; Pinto Pabon, Isabel; Fernandez Lobato, Rosa; Montes Lopez, Carmen

    1999-01-15

    Purpose: To assess the effectiveness and safety of self-expanding metallic stents as a primary palliative treatment for inoperable malignant colorectal strictures. Methods: Under radiological guidance 20 self-expanding metallic Wallstents were implanted in 16 consecutive patients with colorectal stenoses caused by malignant neoplasms, when surgical treatment of the condition had been ruled out. The patients were followed up clinically for 1-44 months, until death or termination of this study. Results: The stents were successfully implanted in all cases and resolved the clinical obstruction in all the patients except one, who underwent subsequent colostomy. During follow-up of the remaining 15 patients, clinical complications arising from the procedure were pain (two patients), minor rectal bleeding (one patient), and severe rectal bleeding (one patient) (26%). There were three cases of stent migration and three cases of stent occlusion, and reintervention by us was necessary in 20% of cases (3/15). The mean life span following the procedure was 130 days, and none of the patients exhibited clinical symptoms of obstruction at the time of death (12 patients) or termination of the study (3 patients). Conclusion: Deployment of metallic stents under radiologic guidance is an effective alternative as a primary palliative measure in malignant colorectal obstruction, though the possible clinical complications and need for repeat intervention during follow-up should be taken into account.

  5. Understanding the requirements of self-expandable stents for heart valve replacement: Radial force, hoop force and equilibrium.

    PubMed

    Cabrera, María Sol; Oomens, Cees W J; Baaijens, Frank P T

    2017-04-01

    A proper interpretation of the forces developed during stent crimping and deployment is of paramount importance for a better understanding of the requirements for successful heart valve replacement. The present study combines experimental and computational methods to assess the performance of a nitinol stent for tissue-engineered heart valve implantation. To validate the stent model, the mechanical response to parallel plate compression and radial crimping was evaluated experimentally. Finite element simulations showed good agreement with the experimental findings. The computational models were further used to determine the hoop force on the stent and radial force on a rigid tool during crimping and self-expansion. In addition, stent deployment against ovine and human pulmonary arteries was simulated to determine the hoop force on the stent-artery system and the equilibrium diameter for different degrees of oversizing.

  6. Evaluation of the medtronic exponent self-expanding carotid stent system with the medtronic guardwire temporary occlusion and aspiration system in the treatment of carotid stenosis: combined from the MAVErIC (Medtronic AVE Self-expanding CaRotid Stent System with distal protection In the treatment of Carotid stenosis) I and MAVErIC II trials.

    PubMed

    Higashida, Randall T; Popma, Jeffrey J; Apruzzese, Patricia; Zimetbaum, Peter

    2010-02-01

    Embolic protection devices and improved stent technology have advanced the endovascular treatment of carotid artery disease. A combined analysis was performed of the MAVErIC (Medtronic AVE Self-expanding CaRotid Stent System with distal protection) I and II trials to evaluate the safety and feasibility of this system among patients at high risk for surgical endarterectomy. Four hundred ninety-eight patients were enrolled in the MAVErIC I (99 patients) and MAVErIC II (399 patients) studies from June 2001 to October 2004. The results were pooled for statistical analysis of a common primary end point, the 365-day rate of major adverse events. Clinical follow-up took place at 30 days, 6 months, and 365 days postprocedure. The 365-day major adverse event rate, defined as death, stroke, or myocardial infarction within 30 days, and death, ipsilateral stroke, or myocardial infarction from days 31 to 365 was 12.5%. The incidence of neurological death through 365 days was 1.1%. The 30-day major adverse event rate was 5.4%. Subgroup analyses showed no notable differences in the 365-day major adverse event rate for symptomatic patients compared with asymptomatic patients. Treatment of carotid artery disease with carotid artery stenting with a self-expanding stent and distal embolic protection results in a low 30-day adverse event rate, including the occurrence of stroke in patients at high risk for carotid endarterectomy.

  7. Self-Expandable Stent Placement in Infrapopliteal Arteries After Unsuccessful Angioplasty Failure: One-Year Follow-up

    SciTech Connect

    Peregrin, J. H. Smirova, S.; Koznar, B.; Novotny, J.; Kovac, J.; Lastovickova, J.; Skibova, J.

    2008-09-15

    The purpose of this prospective study was to evaluate whether stent placement in infrapopliteal arteries is helpful in failed percutaneous transluminal angioplasty (PTA). Infrapopliteal PTA was performed in 70 arteries of 66 patients with chronic critical lower limb ischemia. The group comprised 55 males and 11 females, with an average age of 63.4 (range, 42-82) years. Diabetes mellitus was present in 92.4% of patients. Only the palpable anterior tibial and posterior tibial arteries were evaluated. Stents (Xpert stent; Abbot Vascular, Redwood City, CA, USA) were placed in 16 arteries where PTA was not successful (the failure was defined as residual stenosis >30% after PTA). In 54 arteries simple PTA was performed and was technically successful. Twenty-four nondilated arteries with no significant stenosis served as a comparison group. The 12-month patency rate was evaluated according to a combination of palpation and Doppler ultrasound. In all cases stent placement restored the flow in the artery immediately after unsuccessful PTA. Twelve-month follow-up showed a patency rate of 82% in the PTA group, 78% in the stent group, and 69% in the comparison group. We conclude that stent placement in the case of unsuccessful infrapopliteal PTA changed technical failure to success and restored flow in the dilated artery. At 12-month follow-up the patency rate of infrapopliteal arteries stented for PTA failure did not differ significantly either from nonstented arteries with an optimal PTA result or from a comparison group of nonintervened arteries.

  8. Role of laser photoablative therapy and expandable metal stents in colorectal carcinoma

    NASA Astrophysics Data System (ADS)

    Chennupati, Raja S.; Trowers, Eugene A.

    2000-05-01

    Metallic stents are effective in relieving colorectal obstruction in more than 80% of cases. Self expanding metallic stents allow for decompression of the proximal colon and preoperative bowel cleansing. Hence, emergent surgery for large bowel obstruction with its associated high morbidity and mortality might be avoided. Endoscopic laser photoablation and stent placement may successfully palliate inoperable colorectal cancer patients by maintaining luminal patency and avoiding the need for a colostomy. Major complications associated with metallic stents include pressure necrosis, perforation, bleeding and migration. The effectiveness of expandable metallic stents in obstructive colorectal carcinoma is critically reviewed. The authors present a concise review of the effectiveness of endoscopic laser photoablation and expandable metal stent placement.

  9. Self-expandable stent before elective surgery vs. emergency surgery for the treatment of malignant colorectal obstructions: comparison of primary anastomosis and morbidity rates.

    PubMed

    Martinez-Santos, Cristina; Lobato, Rosa F; Fradejas, José Manuel; Pinto, Isabel; Ortega-Deballón, Pablo; Moreno-Azcoita, Mariano

    2002-03-01

    At present there are not enough studies that demonstrate the usefulness of self-expandable stents in patients with left-sided malignant colon and rectal obstruction. We evaluated primary anastomosis and morbidity rates obtained with this method in comparison with the results of the emergency surgical treatment. From February 1994 to November 1999, 72 consecutive patients with left-sided malignant colorectal obstruction were enrolled. Forty-three patients were assigned to the study group (preoperative stent and elective surgical treatment or palliative stent, depending on the assessment of the stage of the tumor) and 29 to the control group (emergency surgical treatment). The resection was not indicated in 18 cases in the study group (after preoperative staging in 17 and intraoperative staging in 1) and in 3 cases in the control group. In the study group, the obstruction was relieved in 41 cases (95 percent) after the stent placement. Of 26 patients who underwent surgical treatment, a primary anastomosis was possible in 22 (84.6 vs. 41.4 percent in the control group, P = 0.0025), with lower need for a colostomy (15.4 vs. 58.6 percent in the control group). The anastomotic failure rate was similar and the reintervention rate was lower (0 vs. 17 percent, P = 0.014). The total stay (14.23 vs. 18.52 days; P = 0.047), the intensive care unit stay (0.3 vs. 2.9 days; P = 0.015), and the number of patients with severe complications (11.6 vs. 41.2 percent; P = 0.008) were significantly lower in the study group. In our patients with left-sided malignant colon and rectal obstruction, placement of a preoperative stent prevented 17 (94 percent) of 18 of unnecessary operations and a large number of colostomies after elective surgery. These results were obtained with a lower severe complication rate as well as a shorter hospital stay.

  10. Treatment for long-segment femoro-popliteal obstructions: initial experience with a 4-F compatible self-expanding nitinol stent and review of the literature.

    PubMed

    Baumann, F; Do, D-D; Willenberg, T; Baumgartner, I; Diehm, N

    2012-08-01

    The aim of this paper was to evaluate the efficacy of a novel 4-F compatible self-expanding Nitinol stent for the treatment of long femoro-popliteal obstructions. This retrospective analysis includes patients with femoro-popliteal obstructions ≥ 120 mm in length, treated with a novel Nitinol stent (Pulsar-18) between February 2010 and December 2011. Patients were categorized as either intermittent claudication (IC) or critical limb ischemia (CLI). Primary endpoint was primary patency, secondary endpoints were target lesion revascularization (TLR). A total of 31 patients (IC: N=18 and CLI: N=13) were included in the present series. Mean age was 73.3 ± 10.1 years and 71% (22/31) of the patients were male. Primary intervention was performed in 77.4% (24/31) of the patients and re-do revascularization in the remaining. Mean lesion length of femoro-popliteal obstructions was 163.5 ± 32.5 mm. Technical success was obtained in all patients. Mean follow-up duration was 316 ± 198 days. Primary patency rates were 83.3% in IC and 80.0% in CLI patients at 6 months and 64.1% and 54.9% at 12 months, respectively (P=0.84). Target lesion revascularization occurred in 5.6% of IC and 20.0% of CLI patients at 6 months and in 14.1% and 36.0% at 12 months, respectively (P=0.43). Endovascular stenting of long femoro-popliteal lesions using the Pulsar-18 stent provides acceptable results with patency and restenosis rates comparable with data from literature for stenting of long femoro-popliteal obstructions.

  11. On the role of SMA modeling in simulating NiTinol self-expanding stenting surgeries to assess the performance characteristics of mechanical and thermal activation schemes.

    PubMed

    Saleeb, A F; Dhakal, B; Owusu-Danquah, J S

    2015-09-01

    The work is focused on a detailed simulation of the key stages involved in the NiTinol self-expanding stenting surgical procedure; i.e., crimping, deployment, SMA activation, as well as post-surgery steady-state cyclic behavior mimicking the systolic-to-diastolic pressure oscillations. To this end, a general multi-mechanism SMA model was utilized, whose calibration was completed using the test data from simple isothermal uniaxial tension experiments. The emphasis in the study was placed on the comparison of two alternative SMA activation protocols, in terms of both the immediate and long-term (post-surgery) performance characteristics. The first is 'hard' mechanical activation utilizing superelasticity, and the second is 'soft' thermal activation relying upon the combined one-way shape memory effect and constrained-recovery characteristics of the NiTinol material. The important findings are (1) the thermal activation protocol is far superior compared to the mechanical counterpart, from the point of view of lower magnitudes of the induced outward chronic forces, lesser developed stresses in the host tissue, as well as higher compression ratio with lesser crimping force for the same geometry of initial stent memory configuration, (2) the thermal activation protocol completely bypassed the complications of maintaining the high restraining force during deployment of the stent, and (3) there is no indication of any detrimental functional fatigue/degradation in the cured stenotic artery during cyclic pressure oscillations.

  12. Clinical application of metallic stents in treatment of esophageal carcinoma

    PubMed Central

    Yang, Hai-Shan; Zhang, Lin-Bo; Wang, Tian-Wei; Zhao, Yong-Sheng; Liu, Lin

    2005-01-01

    AIM: To evaluate the effects of self-expanding metal stents (SEMS) in patients with malignant esophageal obstruction and to analyze their prognosis and complications. METHODS: Seventy-four metallic stents were placed under fluoroscopic guidance in 66 patients with esophageal obstruction secondary to carcinoma, of whom, 6 cases were complicated by fistula. RESULTS: After seventy-two stents were successfully used in 66 cases without any severe complications (technical successful rate was 97%), the dysphagia score improved from 3.3±0.6 to 0.8±0.5 (P<0.01), and life quality improved significantly in all these patients. All fistulae were sealed immediately after coated stents were inserted in the six patients. New stents were placed in two patients: the stent migrated more than 2 cm, in one patient and the stent slipped into stomach in the other. Minor bleeding was found only in 28 patients during the operation. Reobstruction was found in 12 patients, but was successfully cured under endoscopy. The survival rate was 78%, 57% and 11% for 6 mo, 1 year and 2 years respectively. CONCLUSION: Placement of SEMS is a simple, safe, quick and efficient surgical method for treating esophageal carcinoma obstruction. It may be used mainly as a palliative treatment of esophageal obstruction secondary to carcinoma. PMID:15637767

  13. Developments in metallic biodegradable stents.

    PubMed

    Hermawan, H; Dubé, D; Mantovani, D

    2010-05-01

    Interest in metallic degradable biomaterials research has been growing in the last decade. Both scientific journals and patent databases record a high increase in publications in this area. Biomedical implants with temporary function, such as coronary stents, are the targeted applications for this novel class of biomaterials. It is expected that stents made of degradable biomaterials, named biodegradable stents, will provide a temporary opening into a narrowed arterial vessel until the vessel remodels and will progressively disappear thereafter. Biodegradable stents made of metal have recently been progressed into preclinical tests in humans after their first introduction in early 2000s. By referring to patents and journal publications, this paper reviews the developments in biodegradable stents, with emphasis on those made of metals, starting from the first design ideas to validation testing.

  14. Hepatocellular Carcinoma Complicated by Gastroduodenal Obstruction: Palliative Treatment with Metallic Stent Placement

    SciTech Connect

    Lee, Ye Jin; Kim, Jin Hyoung Song, Ho-Young; Park, Jung-Hoon; Na, Han Kyu; Kim, Pyeong Hwa; Fan, Yong

    2012-10-15

    Purpose: To evaluate the clinical effectiveness of self-expandable metallic stents in seven patients with malignant gastroduodenal obstruction caused by inoperable hepatocellular carcinoma (HCC). Methods: Seven patients with gastroduodenal obstruction caused by advanced HCC underwent metallic stent placement from 2003 to 2010. These patients had total dysphagia (n = 5) or were able to eat only liquids (n = 2) before stent placement. Patients had Eastern Cooperative Oncology Group performance scores of 2 or 3, and Child-Pugh classification B or C. Results: Stent placement was technically successful in all seven patients (100%) and clinically successful in six (86%). Five patients could eat a soft diet, and one patient tolerated regular diet after stent placement. Stent-related obstructive jaundice occurred in one patient. One patient had hematemesis 11 days after stent placement. Overall mean survival was 51 days (range, 10-119 days). Stent patency was preserved in six patients with clinical success until death. Conclusion: Placement of a covered self-expandable metallic stent may offer good palliation in patients with gastroduodenal obstruction due to advanced HCC.

  15. Malignant Gastroduodenal Obstruction: Treatment with Self-Expanding Uncovered Wallstent

    SciTech Connect

    Gutzeit, Andreas Binkert, Christoph A.; Schoch, Eric; Sautter, Thomas; Jost, Res; Zollikofer, Christoph L.

    2009-01-15

    Purpose: To retrospectively evaluate the clinical effectiveness of a self-expanding uncovered Wallstent in patients with malignant gastroduodenal obstruction. Materials and Methods: Under combined endoscopic and fluoroscopic guidance, 29 patients with a malignant gastroduodenal stenosis were treated with a self-expanding uncovered metallic Wallstent. A dysphagia score was assessed before and after the intervention to measure the success of this palliative therapy. The dysphagia score ranged between grade 0 to grade 4: grade 0 = able to tolerate solid food, grade 1 = able to tolerate soft food, grade 2 = able to tolerate thick liquids, grade 3 = able to tolerate water or clear fluids, and grade 4 = unable to tolerate anything perorally. Stent patency and patients survival rates were calculated. Results: The insertion of the gastroduodenal stent was technically successful in 28 patients (96.5%). After stenting, 25 patients (86.2%) showed clinical improvement by at least one score point. During follow-up, 22 (78.5%) of 28 patients showed no stent occlusion until death and did not have to undergo any further intervention. In six patients (20.6%), all of whom were treated with secondary stent insertions, occlusion with tumor ingrowth and/or overgrowth was observed after the intervention. The median period of primary stent patency in our study was 240 days. Conclusion: Placement of an uncovered Wallstent is clinically effective in patients with malignant gastroduodenal obstruction. Stent placement is associated with high technical success, good palliation effect, and high durability of stent function.

  16. Percutaneous Placement of Permanent Metallic Stents in the Cystic Duct to Treat Obstructive Cholecystitis.

    PubMed

    Brown, Nicholas I; Jhamb, Ashu; Brooks, Duncan M; Little, Andrew F

    2015-12-01

    This report presents a series of five patients unsuitable for surgery who had nonretrievable self-expanding metallic stents deployed along the cystic duct as treatment for benign and malignant causes of gallbladder obstruction. Techniques are described for draining cholecystitis, removing gallstones, bypassing gallbladder obstructions, and inserting metallic stents across the cystic duct to restore permanent antegrade gallbladder drainage in acute and chronic cholecystitis. Symptoms resolved in all cases, and stents remained patent for as long as 22 months. This procedure may be an effective alternative to cholecystectomy or long-term gallbladder drainage for patients in inoperable condition.

  17. Intra-aneurysmal hemodynamic alterations by a self-expandable intracranial stent and flow diversion stent: high intra-aneurysmal pressure remains regardless of flow velocity reduction.

    PubMed

    Shobayashi, Yasuhiro; Tateshima, Satoshi; Kakizaki, Ryuichi; Sudo, Ryo; Tanishita, Kazuo; Viñuela, Fernando

    2013-11-01

    Little is known about how much protection a flow diversion stent provides to a non-thrombosed aneurysm without the adjunctive use of coils. A three-dimensional anatomically realistic computation aneurysm model was created from the digital subtraction angiogram of a large internal carotid artery-ophthalmic artery aneurysm which could have been treated with either a neck bridging stent or a flow diversion stent. Three-dimensional computational models of the Neuroform EZ neck bridging stent and Pipeline embolization device were created based on measurements with a stereo-microscope. Each stent was placed in the computational aneurysm model and intra-aneurysmal flow structures were compared before and after placement of the stents. Computational fluid dynamics were performed by numerically solving the continuity and Navier-Stokes momentum equations for a steady blood flow based on the finite volume method. Blood was assumed as an incompressible Newtonian fluid. Vessel walls were assumed to be rigid, and no-slip boundary conditions were applied at the lumens. To estimate the change in the intra-aneurysmal pressures we assumed that, at the inlets, the intra-arterial pressure at peak systole was 120 mm Hg both before and after stent placement Without any stent, the blood flow entered into the aneurysm dome from the mid to proximal neck area and ascended along the distal wall of the aneurysm. The flow then changed its direction anteriorly and moved along the proximal wall of the aneurysm dome. In addition to the primary intra-aneurysmal circulation pattern, a counterclockwise vortex was observed in the aneurysm dome. The placement of a Neuroform EZ stent induced a mean reduction in flow velocity of 14% and a small change in the overall intra-aneurysmal flow pattern. The placement of a Pipeline device induced a mean reduction in flow velocity of 74% and a significant change in flow pattern. Despite the flow velocity changes, Neuroform EZ and Pipeline devices induced

  18. Early clinical experience with a novel self-expanding percutaneous stent-valve in the native right ventricular outflow tract.

    PubMed

    Cao, Qi-Ling; Kenny, Damien; Zhou, Daxin; Pan, Wenzhi; Guan, Lihua; Ge, Junbo; Hijazi, Ziyad M

    2014-12-01

    Balloon expandable transcatheter pulmonary valve systems are not applicable to the large majority of patients with chronic severe pulmonary regurgitation (PR) following surgical right ventricular outflow tract (RVOT) rehabilitation. This report describes the clinical use and short-term follow-up of a novel transcatheter self-expanding pulmonary valve system (Venus P Valve) for rehabilitation of the RVOT in patients with chronic severe PR. Patients with native RVOT and severe PR were selected on a case-by-case basis as part of early clinical experience with this valve. Patient demographics and pre-procedural, intra-procedural, and follow-up data were reviewed. Five patients (four females) with a mean weight of 54.8 ± 11.4 kg were selected for attempted valve deployment. Patients were either NYHA class II (n = 3) or class III (n = 2) at baseline. PR was grade 4 in all cases with mean right ventricular end-diastolic volumes of 155.0 ± 16.6 ml/m(2) on cardiac MRI. Mean minimum "annular" diameter on transthoracic echocardiogram was 22.8 ± 2.5 mm and mean RVOT diameter was 31.8 ± 5.1 mm. Uncomplicated successful valve delivery was achieved in all five cases with a mean fluoroscopy time of 22.8 ± 8.8 min. Valve sizes used were 26 (n = 3), 30 (n = 1), and 32 (n = 1). Mean pulmonary artery diastolic pressure increased from 3 ± 3.7 mm Hg to 9.9 ± 6.9 mm Hg (P = 0.06). On mean follow-up of 3.4 ± 2.5 months PR grade is 0 (n = 3) or 1 (n = 2) in all cases. NYHA class has improved at least one class in all cases and right ventricular volumes assessed by echocardiography have normalized in all three patients with follow-up to 3 months. The Venus P Valve provides excellent short-term pulmonary valvar function in the native RVOT of patients with surgically induced chronic severe PR. © 2014 Wiley Periodicals, Inc.

  19. Comparison of outcomes among secondary covered metallic, uncovered metallic, and plastic biliary stents in treating occluded primary metallic stents in malignant distal biliary obstruction.

    PubMed

    Cho, Jae Hee; Jeon, Tae Joo; Park, Jeong Youp; Kim, Hee Man; Kim, Yoon Jae; Park, Seung Woo; Chung, Jae Bock; Song, Si Young; Bang, Seungmin

    2011-02-01

    The self-expandable metallic stent (SEMS) has been widely used for unresectable malignant biliary obstruction but eventually becomes occluded by tumor ingrowth/overgrowth and sludge. Therefore, we aimed to determine the therapeutic effectiveness of secondary stents and to find differences according to various combinations of the first and second stents for the management of occluded SEMSs in patients with malignant distal biliary obstruction. Between 1999 and November 2008, 77 patients with malignant biliary obstruction underwent secondary biliary stent placement as "stent-in-stent" at three university hospitals in Korea (40 covered, 26 uncovered, and 11 plastic stents). The membrane of the covered SEMS was regarded as the barrier against tumor ingrowth. We categorized the patients into three groups based on whether the covered SEMS was either the first or the second stent: membrane-SEMS (18 covered-covered; 9 covered-uncovered; 22 uncovered-covered SEMS), bare-SEMS (17 uncovered-uncovered SEMS), and plastic stent (3 covered-plastic; 8 uncovered-plastic). The median patency of second stents was 138, 109, and 88 days (covered, uncovered, and plastic stents). The second covered SEMSs had a significantly longer patency than plastic stents (p=0.047). In a multivariate analysis including membrane-SEMS, bare-SEMS, and plastic stent groups, the bare-SEMS had a worse cumulative stent patency (HR=2.04, CI=1.08-3.86) and survival time (HR=2.37, CI=1.25-4.49) than the membrane-SEMS. Patients with ampulla of Vater cancer had better stent patency (HR=0.27, CI=0.08-0.98) and survival (HR=0.17, CI=0.04-0.77) than those with other pancreatobiliary malignancies. In addition, antitumor treatment prolonged survival time (HR=0.50, CI=0.26-0.99). The placement of additional biliary stents using the "stent-in-stent" method is an effective treatment for an occluded metallic primary stent. In addition, double biliary SEMS placement using at least one covered SEMS (in the primary and

  20. Biliary metal stents are superior to plastic stents for preoperative biliary decompression in pancreatic cancer.

    PubMed

    Decker, Christopher; Christein, John D; Phadnis, Milind A; Wilcox, C Mel; Varadarajulu, Shyam

    2011-07-01

    It is unclear whether plastic or metal stents are more suitable for preoperative biliary decompression in pancreatic cancer. The objective of this study was to compare the rate of endoscopic reinterventions in patients with pancreatic cancer undergoing plastic or self-expandable metal stent (SEMS) placements for preoperative biliary decompression. This was a retrospective study of all patients with obstructive jaundice secondary to pancreatic head cancer who underwent their index endoscopic retrograde cholangiopancreatography (ERCP) and all follow-up biliary stent placements at our center before undergoing pancreaticoduodenectomy. Plastic or SEMS were placed at ERCP for biliary decompression. The main outcome measure was to compare the rate of endoscopic reinterventions between the plastic and SEMS cohorts. 29 patients who underwent pancreaticoduodenectomy had preoperative biliary stent placement (18 plastic, 11 SEMS) at our center. Whereas none of the 11 patients who underwent SEMS placement had stent dysfunction, 7 of 18 (39%) patients with plastic stents required endoscopic reintervention before surgery (P=0.02). Reinterventions were due to cholangitis (n=1) or persistent elevation in serum bilirubin levels (n=6). Two patients with SEMS underwent EUS-guided fine-needle aspiration after ERCP, which yielded a positive diagnosis of cancer in all cases; SEMS did not impair visualization of the tumor mass at EUS. Pancreaticoduodenectomy was undertaken successfully in all 29 patients and the presence of a SEMS did not interfere with biliary anastomosis. On univariate logistic regression, only SEMS placement was associated with less need for endoscopic reintervention (P=0.02). SEMS are superior to plastic stents for preoperative biliary decompression in pancreatic cancer.

  1. Pneumoperitoneum Caused by Transhepatic Air Leak After Metallic Biliary Stent Placement

    SciTech Connect

    Lee, Jei Hee; Lee, Deok Hee; Yu, Jeong-Sik; Lee, Se Joon; Kwon, Woo-Cheol; Kim, Ki Whang

    2000-11-15

    A self-expanding metallic biliary stent was placed for palliation of a common bile duct obstruction in a 68-year-old male with unresectable pancreatic head cancer 3 days after initial percutaneous right transhepatic catheter decompression. The stent crossed the ampulla of Vater. Three days later, the stent was balloon-dilated and the percutaneous access was removed. At removal, a small contrast leak from the transhepatic tract was seen. Three days later, pneumoperitoneum was found with symptoms of peritoneal irritation and fever. A widely open sphincter of Oddi caused by the metallic stent, accompanied by delayed sealing of the transhepatic tract, may have caused the air and bile leakage into the peritoneal space. This case shows that pneumoperitoneum may occur without ductal tear or bowel injury, with a biliary stent crossing the ampulla of Vater.

  2. Covered metal stents in endoscopic therapy of biliary complications after liver transplantation.

    PubMed

    Cantù, Paolo; Tenca, Andrea; Parzanese, Ilaria; Penagini, Roberto

    2016-08-01

    There is growing interest in using covered self-expandable metal stents for the treatment of benign biliary conditions, and the presence of anastomotic biliary strictures and leaks after liver transplantation provide a valuable opportunity for testing them. The performance of the stents is encouraging, and the technical success rate is high. They provide larger diameter dilation and are easily removed, and can potentially limit costs by reducing the number of procedures needed to treat anastomotic biliary strictures. However, drawbacks such as sub-optimal tolerability and migration may affect both patient management and costs. New stent designs are currently being evaluated. Randomized controlled trials and cost-effectiveness analyses comparing covered metal stents with multiple plastic stent endotherapy are warranted in order to define the role of the former as first-line or rescue treatment. Copyright © 2016 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  3. Temporary endoscopic metallic stent for idiopathic esophageal achalasia.

    PubMed

    Coppola, Franco; Gaia, Silvia; Rolle, Emanuela; Recchia, Serafino

    2014-02-01

    Idiopathic achalasia is a motor disorder of the esophagus of unknown etiology caused by loss of motor neurons determining an altered motility. It may determine severe symptoms such as progressive dysphagia, regurgitations, and pulmonary aspirations. Many therapeutic options may be offered to patients with achalasia, from surgery to endoscopic treatments such as pneumatic dilation, botulinum injection, peroral endoscopic myotomy, or endoscopic stenting. Recently, temporary placement of a stent was proposed by Cheng as therapy for achalasia disorders, whereas no Western authors have dealt with it up to date. The present study reports our preliminary experience in 7 patients with achalasia treated with a temporary stent. Partially covered self-expanding metallic stents (Micro-Tech, Nanjin, China) 80 mm long and 30 mm wide were placed under fluoroscopic control and removed after 6 days. Clinical follow-up was scheduled to check endoscopic success, symptoms release, and complications. The placement and the removal of the stents were obtained in all patients without complications. Mean clinical follow-up was 19 months. Five out of 7 patients referred total symptoms release and 2 experienced significant improvement of dysphagia. The procedure was not time consuming and was safe; no mild or severe complications were registered. In conclusion, our results may suggest a possible safe and effective endoscopic alternative treatment in patients with achalasia; however, further larger studies are necessary to confirm these promising, but very preliminary, data.

  4. The Primary Patency and Fracture Rates of Self-Expandable Nitinol Stents Placed in the Popliteal Arteries, Especially in the P2 and P3 Segments, in Korean Patients

    PubMed Central

    Chang, Il Soo; Park, Sang Woo; Yun, Ik Jin; Hwang, Jae Joon; Lee, Song Am; Kim, Jun Seok; Chang, Seong-Hwan; Jung, Hong Geun

    2011-01-01

    Objective We wanted to evaluate the status of self-expandable nitinol stents implanted in the P2 and P3 segments of the popliteal artery in Korean patients. Materials and Methods We retrospectively analyzed 189 consecutive patients who underwent endovascular treatment for stenoocclusive lesions in the femoropopliteal artery from July 2003 to March 2009, and 18 patients who underwent stent placement in popliteal arterial P2 and P3 segments were finally enrolled. Lesion patency was evaluated by ultrasound or CT angiography, and stent fracture was assessed by plain X-rays at 1, 3, 6 and 12 months and annually thereafter. Results At the 1-month follow-up, stent fracture (Type 2) was seen in one limb (up to P3, 1 of 18, 6%) and it was identified in seven limbs at the 3-month follow-up (Type 2, Type 3, Type 4) (n = 1: up to P2; n = 6: P3). At the 6-month follow-up, one more fracture (Type 1) (up to P3) was noted. At the 1-year follow-up, there were no additional stent fractures. Just four limbs (up to P2) at the 2-year follow-up did not have stent fracture. The primary patency was 94%, 61% and 44% at 1, 3 and 6 months, respectively, and the group with stent implantation up to P3 had a higher fracture rate than that of the group that underwent stenting up to P2 (p < 0.05). Conclusion We suggest that stent placement up to the popliteal arterial P3 segment and over P2 in an Asian population can worsen the stent patency owing to stent fracture. It may be necessary to develop a stent design and structure for the Asian population that can resist the bending force in the knee joint. PMID:21430937

  5. Air cholangiography in endoscopic bilateral stent-in-stent placement of metallic stents for malignant hilar biliary obstruction.

    PubMed

    Lee, Jae Min; Lee, Sang Hyub; Jang, Dong Kee; Chung, Kwang Hyun; Park, Jin Myung; Paik, Woo Hyun; Lee, Jun Kyu; Ryu, Ji Kon; Kim, Yong-Tae

    2016-03-01

    Although endoscopic bilateral stent-in-stent (SIS) placement of self-expandable metallic stents (SEMS) is one of the major palliative treatments for unresectable malignant hilar biliary obstruction, post-endoscopic retrograde cholangiopancreatography (ERCP) cholangitis can occur frequently due to inadequate drainage, especially after contrast injection into the biliary tree. The aim of this study is to evaluate the efficacy and safety of air cholangiography-assisted stenting. This study included 47 patients with malignant hilar biliary obstruction who underwent endoscopic bilateral SEMS placement using the SIS technique. They were divided into two groups, air (n = 23) or iodine contrast (n = 24) cholangiography. We retrospectively compared comprehensive clinical and laboratory data of both groups. There were no significant differences found between the two groups with respect to technical success (87% versus 87.5%, air versus contrast group, respectively), functional success (95% versus 95.2%), 30-day mortality (8.3% versus 8.7%) and stent patency. Post-ERCP adverse events occurred in 5 (21.7%) of the patients in the air group and 8 (33.3%) of the patients in the contrast group. Among these, the rate of cholangitis was significantly lower in the air group (4.8% versus 29.2%, p = 0.048). In multivariate analysis, air cholangiography, technical success and a shorter procedure time were significantly associated with a lower incidence of post-ERCP cholangitis. Air cholangiography-assisted stenting can be a safe and effective method for endoscopic bilateral SIS placement of SEMS in patients with malignant hilar biliary obstruction.

  6. Self-expanding plastic esophageal stents versus jejunostomy tubes for the maintenance of nutrition during neoadjuvant chemoradiation therapy in patients with esophageal cancer: a retrospective study.

    PubMed

    Siddiqui, A A; Glynn, C; Loren, D; Kowalski, T

    2009-01-01

    In patients undergoing chemoradiotherapy for esophageal cancer, the inability to eat may severely impair nutritional status. We conducted a retrospective study to compare the efficacy of the Polyflex self-expanding silicone stent (PS) versus a jejunostomy tube (JT) for maintaining nutrition during neoadjuvant chemoradiation therapy in patients with esophageal cancer who were scheduled for resectional surgery. Thirty-six patients were treated either with PS placement (12 patients) or JT placement (24 patients) prior to receiving an 8-week course of chemoradiation therapy. Patients were interviewed weekly until cessation of therapy. Patient data were collected on procedural success and complication rates, nutritional status, and dysphagia scores. PS placement was successful in 11 of 12 patients (92%), and those 11 patients were able to resume oral nutrition. Dysphagia scores improved from a mean of 3 to 1 in the PS group (P < 0.005) but did not change significantly in the JT group. PS were removed endoscopically without complications prior to the esophagectomies. Albumin levels and weight increased significantly in both the PS and JT groups. There were no significant differences between groups in the procedural success rates (PS 92% vs. JT 100%, P = 0.33), complication rates (PS 22% vs. JT 4%, P = 0.11), mean increase in weight (PS 4.4 kg vs. JT 4.2 kg, P = 0.59), and mean increase in serum albumin (PS 0.62 g/dL vs. JT 0.44 g/dL, P = 0.05). PS is a safe and effective alternative to a surgical JT for maintaining nutrition in this subset of patients.

  7. Benign and malignant esophageal strictures: treatment with a polyurethane-covered retrievable expandable metallic stent.

    PubMed

    Song, H Y; Park, S I; Jung, H Y; Kim, S B; Kim, J H; Huh, S J; Kim, T H; Kim, Y K; Park, S; Yoon, H K; Sung, K B; Min, Y I

    1997-06-01

    To evaluate the clinical effectiveness of a polyurethane-covered, retrievable, self-expandable metallic stent and hook catheter in the treatment of esophageal strictures. Stents were constructed of 0.4-mm stainless steel wire in a cylindric zig-zag configuration of six to nine bends. Four to eight stents were connected in tandem by dipping in a polyurethane solution. A nylon loop was hooked inside to each bend of the proximal portion of the stent and strung with a thread. Under fluoroscopic guidance, 22 stents were placed in 16 patients with a malignant stricture and five patients with a benign stricture. The stent was removed with a hook catheter 2 months after placement in patients with a benign stricture and when complications occurred in patients with a malignant stricture. All patients had dysphagia with ingestion of soft foods or liquids. Stent placement was technically successful and well tolerated in 20 patients. In one patient, the stent was misplaced but relocated successfully. After stent placement, all patients were able to ingest solid and/or soft foods without dysphagia. After stent removal, strictures showed improvement but recurred in two patients. Use of polyurethane-covered, retrievable expandable stents seems to be a feasible and effective method of treatment of benign and malignant esophageal strictures.

  8. An Update to Hepatobiliary Stents

    PubMed Central

    Moy, Brian T.; Birk, John W.

    2015-01-01

    Endoscopic stent placement is a common primary management therapy for benign and malignant biliary strictures. However, continuous use of stents is limited by occlusion and migration. Stent technology has evolved significantly over the past two decades to reduce these problems. The purpose of this article is to review current guidelines in managing malignant and benign biliary obstructions, current endoscopic techniques for stent placement, and emerging stent technology. What began as a simple plastic stent technology has evolved significantly to include uncovered, partially covered, and fully covered self-expanding metal stents (SEMS) as well as magnetic, bioabsorbable, drug-eluting, and antireflux stents.1 PMID:26357636

  9. Mechanisms of Biliary Plastic Stent Occlusion and Efforts at Prevention

    PubMed Central

    Kwon, Chang-Il; Lehman, Glen A.

    2016-01-01

    Biliary stenting via endoscopic retrograde cholangiopancreatography has greatly improved the quality of patient care over the last 30 years. Plastic stent occlusion limits the life span of such stents. Attempts to improve plastic stent patency duration have mostly failed. Metal stents (self-expandable metal stents [SEMSs]) have therefore replaced plastic stents, especially for malignant biliary strictures. SEMS are at least 10 times more expensive than plastic stents. In this focused review, we will discuss basic mechanisms of plastic stent occlusion, along with a systematic summary of previous efforts and related studies to improve stent patency and potential new techniques to overcome existing limitations. PMID:27000422

  10. Endoscopic laser fragmentation and removal of a nonremovable metal esophageal stent for persistent dysphagia: a technical note.

    PubMed

    Coomber, Ross S; Patel, Pranav H; Dhir, Anubhav; Livingstone, Jeremy I

    2012-06-01

    Self-expanding metal stents are widely used in the palliation of esophageal diseases (Todd, N Engl J Med 344(22):1681-1687, 2001). The majority are inserted for end-stage malignancy and are not designed to be removed. We report the first recorded successful endoscopic removal of an "irremovable" stent by laser fragmentation after its placement became redundant. A 72-year-old man who had persistent dysphagia after esophageal stent insertion for Boerhaave's syndrome had his stent removed by Nd-YAG laser fragmentation at staged endoscopies. The stent was removed in its entirety and the patients' symptoms resolved. We describe a successful technique for the removal of a nonretrievable stent using laser fracture and endoscopic retrieval. This method of stent removal has not been previously reported.

  11. Photodynamic therapy for occluded biliary metal stents

    NASA Astrophysics Data System (ADS)

    Roche, Joseph V. E.; Krasner, Neville; Sturgess, R.

    1999-02-01

    In this abstract we describe the use of photodynamic therapy (PDT) to recanalize occluded biliary metal stents. In patients with jaundice secondary to obstructed metal stents PDT was carried out 72 hours after the administration of m THPC. Red laser light at 652 nm was delivered endoscopically at an energy intensity of 50 J/cm. A week later endoscopic retrograde cholangiogram showed complete recanalization of the metal stent.

  12. Long-Term Outcomes of Self-Expandable Nitinol Stent Implantation With Intraluminal Angioplasty to Treat Chronic Total Occlusion in the Superficial Femoral Artery (TransAtlantic Inter-Society Consensus Type D Lesions).

    PubMed

    Matsumi, Junya; Ochiai, Tomoki; Tobita, Kazuki; Shishido, Koki; Sugitatsu, Kazuya; Mizuno, Shingo; Yamanaka, Futoshi; Murakami, Masato; Tanaka, Yutaka; Takahashi, Saeko; Akasaka, Takeshi; Saito, Shigeru

    2016-02-01

    To evaluate the long-term outcomes of self-expandable nitinol stent implantation with intraluminal angioplasty for chronic total occlusion (CTO) in the superficial femoral artery (SFA) of patients with TransAtlantic Inter-Society Consensus (TASC) D lesions. From 2004 to 2011, self-expandable nitinol stent implantation in SFA was performed successfully in 72 consecutive limbs of 68 patients with TASC D lesions. These patients were assessed for an average of 38.8 ± 25.6 months. The procedure was performed using a 0.014" or 0.018" guidewire and intraluminal angioplasty. Patients with hemodialysis constituted 20.6% of cases. The mean occlusion length was 244.6 ± 34.1 mm. A bidirectional approach was performed in 69.4% of cases. Primary patency rates were 77.9%, 71.9%, 67.2%, and 51.5% at 1 year, 2 years, 3 years, and 5 years, respectively. Secondary patency rates were 88.6%, 78.7%, 71.1%, and 56.0% at 1 year, 2 years, 3 years, and 5 years, respectively. Cox regression multivariate analysis for hemodialysis pertaining to loss of primary and secondary patency resulted in hazard ratio = 2.555 (95% confidence interval, 1.108-5.891; P=.03) for loss of primary patency and hazard ratio = 3.615 (95% confidence interval, 1.380-9.471; P=.01) for loss of secondary patency. Long-term patency of self-expandable nitinol intraluminal stent implantation with intraluminal angioplasty to treat CTO (TASC D) in SFA is promising. Hemodialysis was the only independent predictor for loss of primary and secondary patency.

  13. Comparison of the utility of covered metal stents versus uncovered metal stents in the management of malignant biliary strictures in 749 patients.

    PubMed

    Lee, Jeffrey H; Krishna, Somashekar G; Singh, Amanpal; Ladha, Harshad S; Slack, Rebecca S; Ramireddy, Srinivas; Raju, Gottumukkala S; Davila, Marta; Ross, William A

    2013-08-01

    Self-expandable metal stents (SEMSs) are used to relieve malignant biliary obstruction. To compare outcomes between covered self-expandable metal stents (CSEMSs) and uncovered self-expandable metal stents (USEMSs) in malignant biliary obstruction. Retrospective cohort study. Tertiary cancer center. Patients with malignant biliary obstruction. Placement of CSEMS or USEMS. Time to recurrent biliary obstruction (TRO), overall survival (OS), and adverse events. From January 2000 to June 2011, 749 patients received SEMSs: 171 CSEMSs and 578 USEMSs. At 1 year, there was no significant difference in the percentage of patients with recurrent obstruction (CSEMSs, 35% vs USEMSs, 38%) and survival (CSEMSs, 45% vs USEMSs, 49%). There was no significant difference in the median OS (CSEMSs, 10.4 months vs USEMSs, 11.8 months; P = .84) and the median TRO (CSEMSs, 15.4 months vs USEMSs, 26.3 months; P = .61). The adverse event rate was 27.5% for the CSEMS group and 27.7% for the USEMS group. Although tumor ingrowth with recurrent obstruction was more common in the USEMS group (76% vs 9%, P < .001), stent migration (36% vs 2%, P < .001) and acute pancreatitis (6% vs 1%, P < .001) were more common in the CSEMS group. Retrospective study. There was no significant difference in the patency rate or overall survival between CSEMSs and USEMSs for malignant distal biliary strictures. The CSEMS group had a significantly higher rate of migration and pancreatitis than the USEMS group. No significant SEMS-related adverse events were observed in patients undergoing neoadjuvant chemoradiation or surgical resection. Copyright © 2013 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

  14. Fluorocopolymer-coated nitinol self-expanding paclitaxel-eluting stent: pharmacokinetics and vascular biology responses in a porcine iliofemoral model.

    PubMed

    Hou, Dongming; Huibregtse, Barbara A; Eppihimer, Michael; Stoffregen, William; Kocur, Gordon; Hitzman, Cory; Stejskal, Elizabeth; Heil, John; Dawkins, Keith D

    2016-08-20

    Our aim was to evaluate arterial responses to paclitaxel and a novel fluorocopolymer-coated nitinol low-dose paclitaxel-eluting stent (FP-PES). Human smooth muscle cell (SMC) migration was assessed after exposure to paclitaxel in vitro. For pharmacokinetics and vascular response, FP-PES or bare metal stents (BMS) were implanted in porcine iliofemoral arteries. Paclitaxel significantly inhibited human coronary and femoral artery SMC migration at doses as low as 1 pM. Inhibition was significantly greater for femoral compared with coronary artery SMCs from 1 pM to 1 μM. Pharmacokinetics showed consistent paclitaxel release from FP-PES over the study duration. The peak arterial wall paclitaxel level was 3.7 ng/mg at 10 days, with levels decreasing to 50% of peak at 60 days and 10% at 180 days. Paclitaxel was not detected in blood or remote organs. Arteriogram and histomorphometry analyses showed FP-PES significantly inhibits neointimal proliferation versus BMS at 30 and 90 days. Re-endothelialisation scores were not different between groups. Paclitaxel affected femoral artery SMC migration at lower concentrations and to a greater degree than it did coronary artery SMCs. The novel FP-PES used in this preclinical study demonstrated a vascular healing response similar to BMS, while significantly inhibiting neointimal formation up to 90 days.

  15. Endoscopic management of occluded biliary uncovered metal stents: A multicenter experience

    PubMed Central

    Katsinelos, Panagiotis; Beltsis, Athanasios; Chatzimavroudis, Grigoris; Paikos, Dimitris; Paroutoglou, George; Kapetanos, Dimitris; Terzoudis, Sotiris; Lazaraki, Georgia; Pilpilidis, Ioannis; Fasoulas, Kostas; Atmatzidis, Stefanos; Zavos, Christos; Kountouras, Jannis

    2011-01-01

    AIM: To compare diverse endoscopic interventions in the management of occluded uncovered self-expanding metal stents (SEMSs) that had been placed for palliative treatment of unresectable malignant biliary obstruction. METHODS: A retrospective review was undertaken in 4 tertiary endoscopic centers to determine optimal management of different types of occluded SEMSs. The technical success of performed treatment in occluded SEMSs, the patency of the stent, the need for re-intervention and the financial costs of each treatment were analyzed. RESULTS: Fifty four patients were included in the analysis; 21 received Hanaro, 19 Wallstent and 14 Flexus. For the relief of obstruction, a plastic stent was inserted in 24 patients, a second SEMS in 25 and mechanical cleaning was performed in 5 patients. The overall median second patency rates between second SEMSs and plastic stents did not differ (133 d for SEMSs vs 106 d for plastic stents; P = 0.856). Similarly, no difference was found between the overall survival of SEMS and plastic stent groups, and no procedure-related complications occurred. Incremental cost analysis showed that successive plastic stenting was a cost-saving strategy at least in Greece. CONCLUSION: Insertion of uncovered SEMSs or plastic stents is a safe and effective treatment for occluded uncovered SEMSs; insertion of plastic stents appears to be the most cost-effective strategy. PMID:21218089

  16. Endoscopic management of occluded biliary uncovered metal stents: a multicenter experience.

    PubMed

    Katsinelos, Panagiotis; Beltsis, Athanasios; Chatzimavroudis, Grigoris; Paikos, Dimitris; Paroutoglou, George; Kapetanos, Dimitris; Terzoudis, Sotiris; Lazaraki, Georgia; Pilpilidis, Ioannis; Fasoulas, Kostas; Atmatzidis, Stefanos; Zavos, Christos; Kountouras, Jannis

    2011-01-07

    To compare diverse endoscopic interventions in the management of occluded uncovered self-expanding metal stents (SEMSs) that had been placed for palliative treatment of unresectable malignant biliary obstruction. A retrospective review was undertaken in 4 tertiary endoscopic centers to determine optimal management of different types of occluded SEMSs. The technical success of performed treatment in occluded SEMSs, the patency of the stent, the need for re-intervention and the financial costs of each treatment were analyzed. Fifty four patients were included in the analysis; 21 received Hanaro, 19 Wallstent and 14 Flexus. For the relief of obstruction, a plastic stent was inserted in 24 patients, a second SEMS in 25 and mechanical cleaning was performed in 5 patients. The overall median second patency rates between second SEMSs and plastic stents did not differ (133 d for SEMSs vs 106 d for plastic stents; P=0.856). Similarly, no difference was found between the overall survival of SEMS and plastic stent groups, and no procedure-related complications occurred. Incremental cost analysis showed that successive plastic stenting was a cost-saving strategy at least in Greece. Insertion of uncovered SEMSs or plastic stents is a safe and effective treatment for occluded uncovered SEMSs; insertion of plastic stents appears to be the most cost-effective strategy.

  17. Excimer laser with adjunctive balloon angioplasty and heparin-coated self-expanding stent grafts for the treatment of femoropopliteal artery in-stent restenosis: twelve-month results from the SALVAGE study.

    PubMed

    Laird, John R; Yeo, Khung Keong; Rocha-Singh, Krishna; Das, Tony; Joye, James; Dippel, Eric; Reddy, Bhagat; Botti, Charles; Jaff, Michael R

    2012-11-01

    The aim of the study is to evaluate the safety and effectiveness of treating femoropopliteal in-stent restenosis (ISR) with debulking with excimer laser followed by implantation of a VIABAHN endoprosthesis. The optimal treatment strategy for femoropopliteal ISR is unclear. The SALVAGE study is a multicenter prospective registry involving nine US centers. Patients with femoropopliteal ISR with moderate to severe intermittent claudication or critical limb ischemia (Rutherford categories 2-5) and an ankle-brachial index (ABI) =0.8 were treated with excimer laser and the VIABAHN endoprosthesis. The primary efficacy endpoint is primary patency at 12 months as measured by duplex ultrasonography. The primary safety endpoint is the major adverse event (MAE) rate at 30 days. Twenty-seven patients were enrolled. The mean lesion length was 20.7 ± 10.3 cm. The majority of lesions were TASC (TASC I) C and D (81.4%). All lesions were pretreated with excimer laser and percutaneous transluminal angioplasty (PTA) prior to VIABAHN implantation. Technical success was achieved in 100% of cases. There were no MAE at 30 days. Primary patency at 12 months was 48%. The ankle brachial index increased from 0.58 ± 0.24 at baseline to 0.90 ± 0.17 at 12 months. There was improvement in all quality-of-life parameters. The 12-month TLR rate was 17.4%. The strategy of excimer laser atherectomy and PTA followed by implantation of a self-expanding stent graft for the treatment of femoropopliteal ISR is safe and associated with high procedural success. Primary patency rate at 12-months was suboptimal; however, the TLR rate was low. Copyright © 2012 Wiley Periodicals, Inc.

  18. Enteral metallic stenting by balloon enteroscopy for obstruction of surgically reconstructed intestine.

    PubMed

    Nakahara, Kazunari; Okuse, Chiaki; Matsumoto, Nobuyuki; Suetani, Keigo; Morita, Ryo; Michikawa, Yosuke; Ozawa, Shun-ichiro; Hosoya, Kosuke; Kobayashi, Shinjiro; Otsubo, Takehito; Itoh, Fumio

    2015-06-28

    We present three cases of self-expandable metallic stent (SEMS) placement using a balloon enteroscope (BE) and its overtube (OT) for malignant obstruction of surgically reconstructed intestine. A BE is effective for the insertion of an endoscope into the deep bowel. However, SEMS placement is impossible through the working channel, because the working channel of BE is too small and too long for the stent device. Therefore, we used a technique in which the BE is inserted as far as the stenotic area; thereafter, the BE is removed, leaving only the OT, and then the stent is placed by inserting the stent device through the OT. In the present three cases, a modification of this technique resulted in the successful placement of the SEMS for obstruction of surgically reconstructed intestine, and the procedures were performed without serious complications. We consider that the present procedure is extremely effective as a palliative treatment for distal bowel stenosis, such as in the surgically reconstructed intestine.

  19. Future developments in biliary stenting

    PubMed Central

    Hair, Clark D; Sejpal, Divyesh V

    2013-01-01

    Biliary stenting has evolved dramatically over the past 30 years. Advancements in stent design have led to prolonged patency and improved efficacy. However, biliary stenting is still affected by occlusion, migration, anatomical difficulties, and the need for repeat procedures. Multiple novel plastic biliary stent designs have recently been introduced with the primary goals of reduced migration and improved ease of placement. Self-expandable bioabsorbable stents are currently being investigated in animal models. Although not US Food and Drug Administration approved for benign disease, fully covered self-expandable metal stents are increasingly being used in a variety of benign biliary conditions. In malignant disease, developments are being made to improve ease of placement and stent patency for both hilar and distal biliary strictures. The purpose of this review is to describe recent developments and future directions of biliary stenting. PMID:23837001

  20. Effect of Covered Metallic Stents Compared With Plastic Stents on Benign Biliary Stricture Resolution

    PubMed Central

    Coté, Gregory A.; Slivka, Adam; Tarnasky, Paul; Mullady, Daniel K.; Elmunzer, B. Joseph; Elta, Grace; Fogel, Evan; Lehman, Glen; McHenry, Lee; Romagnuolo, Joseph; Menon, Shyam; Siddiqui, Uzma D.; Watkins, James; Lynch, Sheryl; Denski, Cheryl; Xu, Huiping; Sherman, Stuart

    2017-01-01

    IMPORTANCE Endoscopic placement of multiple plastic stents in parallel is the first-line treatment for most benign biliary strictures; it is possible that fully covered, self-expandable metallic stents (cSEMS) may require fewer endoscopic retrograde cholangiopancreatography procedures (ERCPs) to achieve resolution. OBJECTIVE To assess whether use of cSEMS is noninferior to plastic stents with respect to stricture resolution. DESIGN, SETTING, AND PARTICIPANTS Multicenter (8 endoscopic referral centers), open-label, parallel, randomized clinical trial involving patients with treatment-naive, benign biliary strictures (N = 112) due to orthotopic liver transplant (n = 73), chronic pancreatitis (n = 35), or postoperative injury (n = 4), who were enrolled between April 2011 and September 2014 (with follow-up ending October 2015). Patients with a bile duct diameter less than 6 mm and those with an intact gallbladder in whom the cystic duct would be overlapped by a cSEMS were excluded. INTERVENTIONS Patients (N = 112) were randomized to receive multiple plastic stents or a single cSEMS, stratified by stricture etiology and with endoscopic reassessment for resolution every 3 months (plastic stents) or every 6 months (cSEMS). Patients were followed up for 12 months after stricture resolution to assess for recurrence. MAIN OUTCOMES AND MEASURES Primary outcome was stricture resolution after no more than 12 months of endoscopic therapy. The sample size was estimated based on the noninferiority of cSEMS to plastic stents, with a noninferiority margin of −15%. RESULTS There were 55 patients in the plastic stent group (mean [SD] age, 57 [11] years; 17 women [31%]) and 57 patients in the cSEMS group (mean [SD] age, 55 [10] years; 19 women [33%]). Compared with plastic stents (41/48, 85.4%), the cSEMS resolution rate was 50 of 54 patients (92.6%), with a rate difference of 7.2% (1-sided 95% CI, −3.0% to ∞; P < .001). Given the prespecified noninferiority margin of −15%, the

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

    PubMed

    Lee, Hyun Jik; Chung, Moon Jae; Park, Jeong Yup; Park, Seung Woo; Nam, Chung Mo; Song, Si Young; Bang, Seungmin

    2017-08-01

    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 66.6 years (range, 35-83), and 42 (59.2%) were male. The mean duration of stent patency was 212 days (±152) in the DBS group (n = 24) compared with 124 days (±98) in the SBSs group (n = 23; P = 0.022 for noninferiority) and 116 days (±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.

  2. Effect of Covered Metallic Stents Compared With Plastic Stents on Benign Biliary Stricture Resolution: A Randomized Clinical Trial.

    PubMed

    Coté, Gregory A; Slivka, Adam; Tarnasky, Paul; Mullady, Daniel K; Elmunzer, B Joseph; Elta, Grace; Fogel, Evan; Lehman, Glen; McHenry, Lee; Romagnuolo, Joseph; Menon, Shyam; Siddiqui, Uzma D; Watkins, James; Lynch, Sheryl; Denski, Cheryl; Xu, Huiping; Sherman, Stuart

    Endoscopic placement of multiple plastic stents in parallel is the first-line treatment for most benign biliary strictures; it is possible that fully covered, self-expandable metallic stents (cSEMS) may require fewer endoscopic retrograde cholangiopancreatography procedures (ERCPs) to achieve resolution. To assess whether use of cSEMS is noninferior to plastic stents with respect to stricture resolution. Multicenter (8 endoscopic referral centers), open-label, parallel, randomized clinical trial involving patients with treatment-naive, benign biliary strictures (N = 112) due to orthotopic liver transplant (n = 73), chronic pancreatitis (n = 35), or postoperative injury (n = 4), who were enrolled between April 2011 and September 2014 (with follow-up ending October 2015). Patients with a bile duct diameter less than 6 mm and those with an intact gallbladder in whom the cystic duct would be overlapped by a cSEMS were excluded. Patients (N = 112) were randomized to receive multiple plastic stents or a single cSEMS, stratified by stricture etiology and with endoscopic reassessment for resolution every 3 months (plastic stents) or every 6 months (cSEMS). Patients were followed up for 12 months after stricture resolution to assess for recurrence. Primary outcome was stricture resolution after no more than 12 months of endoscopic therapy. The sample size was estimated based on the noninferiority of cSEMS to plastic stents, with a noninferiority margin of -15%. There were 55 patients in the plastic stent group (mean [SD] age, 57 [11] years; 17 women [31%]) and 57 patients in the cSEMS group (mean [SD] age, 55 [10] years; 19 women [33%]). Compared with plastic stents (41/48, 85.4%), the cSEMS resolution rate was 50 of 54 patients (92.6%), with a rate difference of 7.2% (1-sided 95% CI, -3.0% to ∞; P < .001). Given the prespecified noninferiority margin of -15%, the null hypothesis that cSEMS is less effective than plastic stents was rejected. The

  3. Stenting as a palliative method in the management of advanced squamous cell carcinoma of the oesophagus and gastro-oesophageal junction

    PubMed Central

    Kużdżał, Jarosław

    2016-01-01

    Advanced squamous cell carcinoma of the oesophagus and gastroesophageal junction usually requires palliative treatment, and the method of choice is stenting. There are several types of stents currently available, including: self-expandable metallic stents (fully or partially covered); self-expandable plastic stents; biodegradable stents. Each of the mentioned stents has its advantages and limitations, and requires a proper, patient-tailored selection. Due to the close anatomical relationship between the oesophagus and bronchial tree, some patients may require bilateral stenting. Oesophageal stenting may not only be considered as a palliative procedure, but can also be implemented to alleviate dysphagia during preoperative chemotherapy and/or radiotherapy. PMID:28133493

  4. Metal versus plastic stents for drainage of malignant biliary obstruction before primary surgical resection.

    PubMed

    Song, Tae Jun; Lee, Jae Hoon; Lee, Sang Soo; Jang, Ji Woong; Kim, Jung Wook; Ok, Tae Jin; Oh, Dong Wook; Park, Do Hyun; Seo, Dong Wan; Lee, Sung Koo; Kim, Myung-Hwan; Kim, Song Cheol; Kim, Chul Nam; Yun, Sung Cheol

    2016-11-01

    Preoperative biliary drainage (PBD) with stent placement has been commonly used for patients with malignant biliary obstruction. In PBD, the placement of fully covered self-expandable metal stents (FCSEMSs) may provide better patency duration and a lower incidence of cholangitis compared with plastic stents. We aimed to evaluate which type of stent showed better outcomes in PBD. In this multicenter, prospective randomized trial, we compared PBD with FCSEMSs versus plastic stents in 86 patients with malignant biliary obstruction between January 2012 and December 2014. Patients with obstructive jaundice were randomly assigned to undergo PBD either with plastic stents or FCSEMS placement. Baseline characteristics were not significantly different between the 2 groups. Endoscopic stent placement was technically successful in all patients. Procedure-related adverse events were not significantly different between the 2 groups (plastic vs FCSEMS group; 16.3% vs 16.3%, P = 1.0). Reintervention was required in 16.3% of the plastic stent group and 14.0% of the FCSEMS group (P = .763). The interval to surgery after PBD (plastic vs FCSEMS group; 14.2 ± 8.3 vs 12.3 ± 6.9 days, P = .426) was not significantly different between groups. Surgery-related adverse events occurred in 43.6% of the plastic stent group and 40.0% of the FCSEMS group (P = .755). In patients with resectable malignant biliary obstruction, the outcomes of PBD with plastic stents and FCSEMSs were similar. Considering the cost-effectiveness, PBD with plastic stents may be preferable to FCSEMS placement. (Clinical trial registration number: NCT01789502.). Copyright © 2016 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

  5. Metal or plastic stents for preoperative biliary drainage in resectable pancreatic cancer.

    PubMed

    Tol, J A M G; van Hooft, J E; Timmer, R; Kubben, F J G M; van der Harst, E; de Hingh, I H J T; Vleggaar, F P; Molenaar, I Q; Keulemans, Y C A; Boerma, D; Bruno, M J; Schoon, E J; van der Gaag, N A; Besselink, M G H; Fockens, P; van Gulik, T M; Rauws, E A J; Busch, O R C; Gouma, D J

    2016-12-01

    In pancreatic cancer, preoperative biliary drainage (PBD) increases complications compared with surgery without PBD, demonstrated by a recent randomised controlled trial (RCT). This outcome might be related to the plastic endoprosthesis used. Metal stents may reduce the PBD-related complications risk. A prospective multicentre cohort study was performed including patients with obstructive jaundice due to pancreatic cancer, scheduled to undergo PBD before surgery. This cohort was added to the earlier RCT (ISRCTN31939699). The RCT protocol was adhered to, except PBD was performed with a fully covered self-expandable metal stent (FCSEMS). This FCSEMS cohort was compared with the RCT's plastic stent cohort. PBD-related complications were the primary outcome. Three-group comparison of overall complications including early surgery patients was performed. 53 patients underwent PBD with FCSEMS compared with 102 patients treated with plastic stents. Patients' characteristics did not differ. PBD-related complication rates were 24% in the FCSEMS group vs 46% in the plastic stent group (relative risk of plastic stent use 1.9, 95% CI 1.1 to 3.2, p=0.011). Stent-related complications (occlusion and exchange) were 6% vs 31%. Surgical complications did not differ, 40% vs 47%. Overall complication rates for the FCSEMS, plastic stent and early surgery groups were 51% vs 74% vs 39%. For PBD in pancreatic cancer, FCSEMS yield a better outcome compared with plastic stents. Although early surgery without PBD remains the treatment of choice, FCSEMS should be preferred over plastic stents whenever PBD is indicated. Dutch Trial Registry (NTR3142). Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

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

    PubMed Central

    Kim, Eui Joo; Kim, Yoon Jae

    2016-01-01

    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. PMID:26811630

  7. Management of Biliary Neoplastic Obstruction with Two Different Metallic Stents Implanted in One Session

    SciTech Connect

    Gandini, Roberto; Fabiano, S. Pipitone, Vincenzo; Spinelli, Alessio; Reale, Carlo Andrea; Colangelo, Vittorio; Pampana, Enrico; Romagnoli, Andrea; Simonetti, Giovanni

    2005-01-15

    The efficacy of the 'one-step' technique using two different metallic stents (Wallstent and Ultraflex) and associated rate of complications was studied in 87 patients with jaundice secondary to malignant biliary obstruction, with bilirubin level less than 15 mg/dl and Bismuth type 1 or 2 strictures. The study group, composed of 40 men and 47 women with a mean age of 59.4 years (range 37-81 years), was treated with a 'one-step' percutaneous transhepatic implantation of self-expanding stents. The cause of the obstruction was pancreatic carcinoma in 38 patients (44%), lymph node metastasis in 20 patients (23%), gallbladder carcinoma in 13 patients (15%), cholangiocarcinoma in 12 patients (14%) and ampullary carcinoma in four patients (5%). A significant reduction in jaundice was obtained in all but one patient, with a drop of total serum bilirubin level from a mean of 13.7 mg/dl to 4.3 mg/dl within the first 4 days. The mean postprocedural hospitalization period was 5.4 days in the Wallstent group and 6.4 days in the Ultraflex group. Mean survival rate was 7.8 months (Wallstent group) and 7.1 months (Ultraflex group). The use of both stents did not reveal any significant difference in parameters tested. The implantation of these self-expandable stents in one session, in selected patients, is clinically effective, devoid of important complications and cost-effective due to the reduction in hospitalization.

  8. The effect of paclitaxel-eluting covered metal stents versus covered metal stents in a rabbit esophageal squamous carcinoma model

    PubMed Central

    Zhang, Yin; Ma, Limei; Huang, Jin; Shuang, Jinquan

    2017-01-01

    Background The use of self-expanding metallic stents (SEMSs) is the current treatment of choice for malignant gastrointestinal obstructions. However, these stents can promote only drainage and have no antitumor effect. Some studies have reported that drug-eluting SEMSs may have tumor inhibition potential. The aim of this study was to evaluate the efficiency and safety of paclitaxel-eluting SEMSs (PEMSs) in rabbit esophageal cancer models. Materials and methods A PEMS was covered with a paclitaxel-incorporated membrane, in which the concentration of paclitaxel was 10% (wt/vol). The rabbit models were created endoscopically. Then, a PEMS or SEMS was endoscopically inserted into the rabbit esophagus. Two weeks after stent placement, the rabbits were sacrificed, and we evaluated the tumor volume, area of the wall defect, area of the tumor under endoscopic ultrasound (EUS) before and after stent placement, status of the proximal esophageal obstruction, tumor metastasis food-intake and weight loss. Results A total of 26 rabbits received stent insertion and survived until sacrifice, and migration occurred in 4 cases, 3 in SEMS group and 1 in PEMS group. For the remaining 22 rabbits, at the sacrificed time, the average tumor volume was 7.00±4.30 cm3 in the SEMS group and 0.94±1.51 cm3 in the PEMS group (P<0.05). The area of the esophageal wall defect was 0.70±0.63 cm2 in the SEMS group and 0.17±0.16 cm2 in the PEMS group (P<0.05). The tumor area under EUS was 4.40±1.47 cm2 in the SEMS group and 1.30±1.06 cm2 in the PEMS group (P<0.05). At the time of stent placement, tumor area under EUS was comparable in the two groups. Other indices did not significantly differ between the two groups. Conclusions SEMS and PEMS are both safe and effective to relieve dysphagia in rabbit esophageal cancer models. A PEMS can serve as an alternative tool for advanced esophageal cancer that may inhibit tumor growth by serving as a drug sustained-release platform. Clinical trials of the

  9. Placement of multiple metal stents for malignant intrahepatic biliary obstruction via an endoscopic ultrasound-guided choledochoduodenostomy fistula.

    PubMed

    Akiyama, Dai; Hamada, Tsuyoshi; Nakai, Yousuke; Isayama, Hiroyuki; Takagi, Kaoru; Mizuno, Suguru; Koike, Kazuhiko

    2015-01-01

    Endoscopic ultrasound-guided choledochoduodenostomy (EUS-CDS) using a fully-covered self-expandable metal stent (SEMS) is increasingly used as an alternative to failed endoscopic retrograde cholangiopancreatography. An EUS-CDS fistula can provide endoscopists with a new approach route for intrahepatic bile ducts. Here, we present successful placement of multiple SEMS for intrahepatic biliary obstruction via an EUS-CDS fistula.

  10. Clinical experience with ureteral metal stents

    PubMed Central

    Al Aown, Abdulrahman; Iason, Kyriazis; Panagiotis, Kallidonis; Liatsikos, Evangelos N.

    2010-01-01

    Ureteral metal stents (MSs) present a minimally invasive tool to preserve the drainage of renal pelvis whenever ureteral patency is at risk to be obstructed due to extrinsic or intrinsic etiologies. Clinical experience with these stents demonstrates that they impose a promising alternative treatment option in ureteral pathologies that are difficult to be treated via common polymeric stents. Current application of MSs in the treatment of both benign and malignant ureteral obstruction reveals quite promising results. Nevertheless, the ideal MS that would provide uncomplicated long-term effectiveness is still lucking and current MS usage is facing several adverse effects between which stent obstruction, encrustation, infection, migration, and patient discomfort. Ongoing attempts to create more inert stent with sophisticated novel designs are expected to improve current MS efficiency. MSs will play a major role in the future as a routine management of a variety of ureteral pathologies. PMID:21369375

  11. Fluoroscopy Guided Transurethral Placement of Ureteral Metallic Stents

    PubMed Central

    Myung Gyu, Song; Seo, Tae Seok; Park, Cheol Min; Choi, Jae Woong; Lee, Jong Mee; Park, Yang Shin

    2015-01-01

    Ureteral stent exchange is usually performed under both fluoroscopic and cystoscopic guidance. We experienced two cases with retrograde placement of metallic ureteral stent via urethra under fluoroscopic guidance. When patients with double-J ureteral stent (DJUS)have symptom and want to change DJUS to metallic stent, fluoroscopic guided transurethral placement of ureteral metallic stent is a good option as alternative of cystoscopic procedure or percutaneous procedure through percutaneous nephrostomy tract. PMID:26557281

  12. Endoscopic esophageal self-expanding stent implantation WallFlex™ (Boston Scientific) in the management of a gastrocutaneous fistula, as a complication of sleeve bariatric gastrectomy.

    PubMed

    Janczak, Dariusz; Pawłowski, Wiktor; Ziomek, Agnieszka; Dorobisz, Tadeusz; Janczak, Dawid; Janus, Werner; Chabowski, Mariusz

    2015-06-01

    The study presented a case of a gastrocutaneous fistula, as a result of bariatric sleeve gastrectomy. The discussion considered the main pathogenesis, etiology, diagnostics and endoscopic treatment using the implantation of covered esophageal stents. Special attention was placed upon the multifactorial origin of this life-threatening clinical condition, typical for bariatric surgery.

  13. Stent-in-stent through a side hole to prevent biliary metallicstent migration.

    PubMed

    Ridtitid, Wiriyaporn; Rerknimitr, Rungsun; Amornsawadwattana, Surachai; Ponauthai, Yuwadee; Kullavanijaya, Pinit

    2011-03-16

    The covered self-expandable metallic stent (SEMS) has been developed to overcome the problem of tissue in-growth, However, stent migration is a well-known com--plication of covered SEMS placement. Use of a double pigtail stent to lock the movement of the SEMS and prevent migration has been advised by many ex-perts. Unfortunately, in our case this technique led to an in-cidental upward migration of the SEMS. We used APC to create a side hole in the SEMS for plastic stent insertion as stent-in-stent. This led to a successful pre-ven-tion of stent migration.

  14. Successful biliary drainage using a metal stent through the gastric stoma

    PubMed Central

    Matsumoto, Kazuyuki; Kato, Hironari; Tsutsumi, Koichiro; Akimoto, Yutaka; Uchida, Daisuke; Tomoda, Takeshi; Yamamoto, Naoki; Noma, Yasuhiro; Horiguchi, Shigeru; Okada, Hiroyuki; Yamamoto, Kazuhide

    2015-01-01

    We report a case of biliary drainage for malignant stricture using a metal stent with an ultrathin endoscope through the gastric stoma. A 78-year-old female was referred to our hospital for jaundice and fever. She had undergone percutaneous endoscopic gastrostomy (PEG) for esophageal obstruction after radiation therapy for cancer of the pharynx. Abdominal contrast-enhanced computed tomography showed a 3-cm enhanced mass in the middle bile duct and dilatation of the intra-hepatic bile duct. We initially performed endoscopic retrograde cholangiopancreatography (ERCP) with a trans-oral approach. However, neither the side-viewing endoscope nor the ultrathin endoscope passed through the esophageal orifice. Thus, we eventually performed ERCP via the PEG stoma using an ultrathin endoscope. We performed biliary drainage with a 6F introducer self-expanding metal stent. The cytology findings obtained by brush cytology showed malignancy. Her laboratory results were restored to normal levels after drainage and no complication occurred. PMID:26140009

  15. Complete Obliteration of a Basilar Artery Aneurysm after Insertion of a Self-Expandable Leo Stent into the Basilar Artery without Coil Embolization

    PubMed Central

    Nowak, Stanisław; Wieloch, Michał; Zarzecka, Anna

    2008-01-01

    We report a case of a 45-year-old man who underwent endovascular treatment in the acute setting of a subarachnoid hemorrhage due to rupture of a wide-necked basilar trunk aneurysm. The patient was treated with stent implantation without coiling. A control angiographic scan obtained immediately after the procedure revealed significantly decreased intraaneurysmal flow. Follow-up angiography performed after one month demonstrated total aneurysm occlusion. PMID:18682676

  16. Complete obliteration of a basilar artery aneurysm after insertion of a self-expandable Leo stent into the basilar artery without coil embolization.

    PubMed

    Juszkat, Robert; Nowak, Stanisław; Wieloch, Michał; Zarzecka, Anna

    2008-01-01

    We report a case of a 45-year-old man who underwent endovascular treatment in the acute setting of a subarachnoid hemorrhage due to rupture of a wide-necked basilar trunk aneurysm. The patient was treated with stent implantation without coiling. A control angiographic scan obtained immediately after the procedure revealed significantly decreased intraaneurysmal flow. Follow-up angiography performed after one month demonstrated total aneurysm occlusion.

  17. In vitro evaluation of stent patency and in-stent stenoses in 10 metallic stents using MR angiography.

    PubMed

    Hamer, O W; Borisch, I; Paetzel, C; Nitz, W R; Seitz, J; Feuerbach, S; Zorger, N

    2006-08-01

    In vitro study to investigate the suitability of contrast enhanced magnetic resonance angiography (CEMRA) for determination of stent patency and grading of in-stent stenoses in 10 metallic stents. The Acculink carotid, DynaLink, Easy Wallstent, JostentSelfX XF, Luminexx, Omnilink, sinus-SuperFlex, SMART, Symphony and ZA stent were separately placed in a vascular phantom. Dedicated stenoses inside the stents generated a concentric lumen narrowing of 50%. CEMRA was performed for each stent. Signal loss inside the stents and artificial lumen narrowing were assessed objectively using the evaluation software of the MR imager. Moreover, three blinded observers determined visibility of stent patency and in-stent stenoses subjectively on a 3-point scale and graded in-stent stenoses. Loss of signal intensity within the stent lumen ranged between 90% (Wallstent) and 5% (ZA), artificial lumen narrowing between 56% (Symphony) and 22% (ZA). For the Symphony and Wallstent, visibility of patency and in-stent stenoses was impaired and the observers' grading exaggerated the degree of stenoses (by 23% and 33%, respectively). For the remainder of stents, patency and stenoses were visible and stenoses were graded accurately (less than 10% discrepancy from reference standard). In this in vitro study, eight of 10 stents presented with MRI characteristics which enabled determination of stent patency and accurate grading of clinically relevant in-stent stenoses.

  18. Effect of a paclitaxel-eluting metallic stent on rabbit esophagus

    PubMed Central

    Zhang, Yin; Gao, Ying; Chen, Jianping; Ma, Limei; Liu, Li; Wang, Xiang; Fan, Zhining

    2016-01-01

    The use of self-expanding metallic stents (SEMS) is the current treatment of choice for malignant gastrointestinal obstructions. A paclitaxel-eluting metallic SEMS (PEMS) may have an antitumor effect on esophageal tissue. PEMS with 10% paclitaxel or conventional SEMS were inserted into the lower esophagus of rabbits. Following the insertion of the stents for 1, 2, 4 and 6 weeks, the rabbits were sacrificed and the status of the stent insertion was examined, as well as any macroscopic or microscopic mucosal changes in the esophageal tissue. All the rabbits survived until death without any complications. No migration following stent insertion occurred. The number of cases with proximal obstruction increased in a time-dependent manner, and no significant difference was observed between the two groups. Gross histological examination showed similar tissue reaction to the stents at 1, 2 and 4 weeks, and inflammatory cell infiltrating was higher in the SEMS group at 1 and 2 weeks. However, inflammatory cell infiltration was markedly higher in the PEMS group at 4 and 6 weeks. Food-intake and weight were similar in the two groups. The results of the present study demonstrated that PEMS may serve as a safe alternative treatment strategy for esophageal obstruction. Furthermore, PEMS may inhibit the tumor growth of the esophageal wall through inflammatory infiltration and targeted drug delivery. A tumor model will be required in the future for evaluating the prognosis of patients with advanced esophageal carcinoma. PMID:27882097

  19. Acute Duodenal Obstruction After Percutaneous Placement of Metallic Biliary Stents: Peroral Treatment with Enteral Stents

    SciTech Connect

    Lopera, Jorge E. Alvarez, Oscar A.; Perdigao, Joseph; Castaneda-Zuniga, Wilfrido

    2003-09-15

    Three patients with malignant biliary obstruction were treated with placement of metallic biliary stents. Two patients had known partial duodenal stenosis but had no symptoms of gastrointestinal obstruction. The patients developed symptomatic duodenal obstruction early after biliary metallic stent placement. The symptomatic duodenal obstructions were successfully treated with peroral placement of duodenal stents, which obviated the need for surgical intervention.

  20. Mechanical Properties of Metallic Stents: How Do These Properties Influence the Choice of Stent for Specific Lesions?

    SciTech Connect

    Dyet, John F.; Watts, William G.; Ettles, Duncan F.; Nicholson, Anthony A.

    2000-01-15

    Purpose: To assess selected balloon-expandable and self-expanding stents for radial force, flexibility, radio-opacity, and trackability, and to relate these physical characteristics to potential indications for placement.Methods: Force-strain curves were plotted for each stent and the force required to produce 50% luminal narrowing was recorded. The ability of the stent to show elastic recoil following deformation was also noted. Flexibility was measured by bending the stents against a force transducer and recording the force required per degree of flexion. Radio-opacity was measured by comparing each stent against a standard aluminum step wedge. Trackability was measured by testing the ability of the stent on its delivery system to track over angles of 90 deg. and 60 deg. Results: The balloon-expandable stents showed greater radial strength and radio-opacity but, apart from the AVE Iliac Bridge stent, showed poorer flexibility and trackability. The self-expanding stents showed less radial force but were able to re-expand following deformity. They were generally more flexible and had better trackability but lower radio-opacity.Conclusion: There is no stent which exhibits all the ideal properties required and therefore the interventionist will need to keep a range of stents available if all lesions are to be addressed.

  1. Metallic Stents for Tracheobronchial Pathology Treatment

    SciTech Connect

    Serrano, Carolina; Laborda, Alicia; Lozano, Juan M.; Caballero, Hugo; Sebastian, Antonio; Lopera, Jorge; Gregorio, Miguel Angel de

    2013-12-15

    Purpose: To present the 7-year experience of the treatment of benign and malignant tracheobronchial stenoses using metallic stents. Patients and Methods: One hundred twenty-three stents were inserted in 86 patients (74 benign and 12 malignant stenoses). Ninety-seven stents were placed in the trachea and 26 in the bronchi. The procedures were performed under fluoroscopic and flexible bronchoscopic guidance with the patient under light sedation. In cases of severe stenotic lesions or obstructions, laser resection was performed before stent placement. Clinical and functional pulmonary data were recorded before and 3 months after the procedure. Follow-up involved clinical data and radiographic techniques at 48 h and at 1-, 3-, 6-, and 12-month intervals. Results: The technical success was 100 %. Dyspnea disappearance, forced expiratory volume in the first second, and pulmonary functional data improvement was observed in all patients (p < 0.001). Complications were detected in 23 patients (26.7 %). Mean follow-up time was 6.3 {+-} 1.2 months in patients with malignant lesions and 76.2 {+-} 2.3 months patients with in benign lesions. By the end of the study, 100 % of patients with malignant pathology and 6.7 % of patients with benign lesions had died. Conclusion: Endoluminal treatment of tracheobronchial stenosis with metallic stents is a therapeutic alternative in patients who are poor candidates for surgery. In unresectable malignant lesions, the benefit of metallic stenting is unquestionable. In benign lesions, the results are satisfactory, but sometimes other interventions are required to treat complications. New stent technology may improve these results.

  2. Gastrointestinal Stent Update

    PubMed Central

    2010-01-01

    The use of self-expanding metallic stents in the upper gastrointestinal tract, placed under radiologic imaging or endoscopic guidance, is the current treatment of choice for the palliation of malignant gastrointestinal outlet obstructions. Advances in metallic stent design and delivery systems have progressed to the stage where this treatment is now considered a minimally invasive therapy. Metallic stent placement will broaden further into the field of nonsurgical therapy for the gastrointestinal tract. To date, metallic stents placed in the esophagus, gastric outlet, colorectum, and bile ducts are not intended to be curative, but rather to provide a palliative treatment for obstructions. The evolution of metallic stent technology will render such procedures not only palliative but also therapeutic, by enabling local drug delivery, and the use of biodegradable materials will reduce procedure-related complications. PMID:21103290

  3. Metallic stents are more efficacious than plastic stents in unresectable malignant hilar biliary strictures: a randomized controlled trial.

    PubMed

    Mukai, Tsuyoshi; Yasuda, Ichiro; Nakashima, Masanori; Doi, Shinpei; Iwashita, Takuji; Iwata, Keisuke; Kato, Tomohiro; Tomita, Eiichi; Moriwaki, Hisataka

    2013-02-01

    Endoscopic biliary stenting is a well-established palliative treatment for unresectable malignant biliary strictures, for which plastic tube stents (PSs) and self-expandable metallic stents (SEMSs) are most commonly used. The efficacy of these stents has been extensively described in distal biliary strictures, but not in hilar biliary strictures. The present study aimed to compare the efficacy of PSs and SEMSs for unresectable malignant hilar biliary strictures. From June 2004 to November 2008, 60 patients were enrolled and prospectively randomized into the PS or SEMS group. The 6-month patency rate was significantly higher in the SEMS group than in the PS group (81 vs. 20%; p = 0.0012). Kaplan-Meier analysis showed significantly longer patency in the SEMS group than in the PS group (p = 0.0002); the 50% patency period was 359 days in the SEMS group and 112 days in the PS group. There was no significant difference in the overall survival period between the PS and SEMS groups (p = 0.2834). The mean number of reinterventions for stent failures was significantly lower in the SEMS group (0.63 times/patient) than in the PS group (1.80 times/patient) (p = 0.0008). The overall total cost for the treatment was significantly lower in the SEMS group than in the PS group (p = 0.0222). SEMSs were associated with a longer patency than PSs in patients with unresectable hilar biliary stricture. SEMSs were also more advantageous in reducing the number of reintervention sessions and the overall treatment cost.

  4. Biocompatible metallic stent for medical therapy

    NASA Astrophysics Data System (ADS)

    Kathuria, Yash P.

    2003-12-01

    In the stent theory for the medical applications, especially in coronary heart disease, the metallic stent of high quality demands the ability for precision micromaterial processing. It possesses an inherent advantage of adequate radio opacity. This paper describes the current status as well as fabrication of such metallic stent of length 20 mm and dia. 2.1 mm with an annular tube thickness of 0.2 mm, by using the short pulse Nd-YAG laser. Fine structures with slit width of 0.1 mm and pitch better than 0.2 mm are created with sharpness and low roughness in the cut surface. Some features of the reduced heat affected zone and dross removal process of the cut surfaces are also discussed.

  5. Fabrication of a silver particle-integrated silicone polymer-covered metal stent against sludge and biofilm formation and stent-induced tissue inflammation

    PubMed Central

    Lee, Tae Hoon; Jang, Bong Seok; Jung, Min Kyo; Pack, Chan Gi; Choi, Jun-Ho; Park, Do Hyun

    2016-01-01

    To reduce tissue or tumor ingrowth, covered self-expandable metal stents (SEMSs) have been developed. The effectiveness of covered SEMSs may be attenuated by sludge or stone formation or by stent clogging due to the formation of biofilm on the covering membrane. In this study, we tested the hypothesis that a silicone membrane containing silver particles (Ag-P) would prevent sludge and biofilm formation on the covered SEMS. In vitro, the Ag-P-integrated silicone polymer-covered membrane exhibited sustained antibacterial activity, and there was no definite release of silver ions from the Ag-P-integrated silicone polymer membrane at any time point. Using a porcine stent model, in vivo analysis demonstrated that the Ag-P-integrated silicone polymer-covered SEMS reduced the thickness of the biofilm and the quantity of sludge formed, compared with a conventional silicone-covered SEMS. In vivo, the release of silver ions from an Ag-P-integrated silicone polymer-covered SEMS was not detected in porcine serum. The Ag-P-integrated silicone polymer-covered SEMS also resulted in significantly less stent-related bile duct and subepithelium tissue inflammation than a conventional silicone polymer-covered SEMS. Therefore, the Ag-P-integrated silicone polymer-covered SEMS reduced sludge and biofilm formation and stent-induced pathological changes in tissue. This novel SEMS may prolong the stent patency in clinical application. PMID:27739486

  6. Endoscopic management of unresectable malignant gastroduodenal obstruction with a nitinol uncovered metal stent: A prospective Japanese multicenter study

    PubMed Central

    Sasaki, Reina; Sakai, Yuji; Tsuyuguchi, Toshio; Nishikawa, Takao; Fujimoto, Tatsuya; Mikami, Shigeru; Sugiyama, Harutoshi; Yokosuka, Osamu

    2016-01-01

    AIM: To determine the safety and efficacy of endoscopic duodenal stent placement in patients with malignant gastric outlet obstruction. METHODS: This prospective, observational, multicenter study included 39 consecutive patients with malignant gastric outlet obstruction. All patients underwent endoscopic placement of a nitinol, uncovered, self-expandable metal stent. The primary outcome was clinical success at 2 wk after stent placement that was defined as improvement in the Gastric Outlet Obstruction Scoring System score relative to the baseline. RESULTS: Technical success was achieved in all duodenal stent procedures. Procedure-related complications occurred in 4 patients (10.3%) in the form of mild pneumonitis. No other morbidities or mortalities were observed. The clinical success rate was 92.3%. The mean survival period after stent placement was 103 d. The mean period of stent patency was 149 d and the patency remained acceptable for the survival period. Stent dysfunction occurred in 3 patients (7.7%) on account of tumor growth. CONCLUSION: Endoscopic management using duodenal stents for patients with incurable malignant gastric outlet obstruction is safe and improved patients’ quality of life. PMID:27076769

  7. Bronchial artery aneurysm suggested to be caused by metalic tracheal stent migration.

    PubMed

    Sato, Kiyoshi; Fumimoto, Satoshi; Fukada, Takehisa; Ochi, Kaoru; Kataoka, Takayuki; Ichihashi, Yoshio; Satomi, Hidetoshi; Morita, Takuya; Hanaoka, Nobuharu; Okada, Yoshikatsu; Katsumata, Takahiro

    2016-12-01

    Occurrence of bronchial artery aneurysm is rare, and it has been detected in less than 1 % of all selective bronchial arteriography cases. Here, we present a case of a bronchial artery aneurysm caused by a tracheal stent migration. A 59-year-old man was operated on for esophageal cancer, where an esophageal-tracheal fistula occurred 1 week after operation. Surgical repair of the esophageal-tracheal fistula was performed using a muscle flap, but this not results in fistula closure. Consequently, a self-expanding covered metallic tracheal stent was implanted for rescue, and this resulted in fistula closure. After 1 year, there was frequent hemoptysis caused by migration of the stent. He was referred to our hospital where removal of the stent was planned. A sudden occurrence of massive bleeding from trachea occurred, and extracorporeal membrane oxygenation (ECMO) was used. Although removal of tracheal stent was performed successfully, the patient subsequently died from multi-organ failure. Post-mortem autopsy revealed that the massive bleeding is originated from the rupture of a bronchial artery aneurysm.

  8. Analysis of endoscopic management of occluded metal biliary stents at a single tertiary care center.

    PubMed

    Rogart, Jason N; Boghos, Ara; Rossi, Federico; Al-Hashem, Hashem; Siddiqui, Uzma D; Jamidar, Priya; Aslanian, Harry

    2008-10-01

    A significant number of self-expandable metal stents (SEMSs) placed to palliate malignant biliary obstruction will occlude. Few data exist as to what constitutes optimal management. Our purpose was to review the management and outcomes of patients with biliary SEMS occlusion. Retrospective chart review at a single tertiary care hospital. From January 1999 to October 2005, a total of 90 patients had SEMSs placed for malignant biliary obstruction, and 27 of these occluded. Technical success of treating SEMS occlusion, stent patency and need for reintervention, and incremental cost analysis. A total of 60 ERCPs were performed to treat SEMS occlusions in 27 patients. The success rate was 95%; however, 52% of patients eventually required more than 1 intervention. Placing a second SEMS through the existing SEMS (n = 14) provided the lowest reocclusion rate (43% vs 55% and 100%), the longest time to reintervention (172 days vs 66 and 43 days, P = .03), and a trend toward longer survival (285 days vs 188 and 194 days) compared with plastic stent and mechanical balloon cleaning, respectively. Incremental cost analysis showed both uncovered SEMSs and plastic stents to be cost effective strategies. Small number of patients, retrospective study. Treatment of biliary SEMS occlusion with SEMS insertion provides for longer patency and survival, decreases the number of subsequent ERCPs by 50% compared with plastic stents, and is cost-effective.

  9. Evaluation of the compressive mechanical properties of endoluminal metal stents.

    PubMed

    Schrader, S C; Beyar, R

    1998-06-01

    The mechanical properties of metal stents are important parameters in the consideration of stent design, matched to resist arterial recoil and vascular spasm. The purpose of this study was to develop a system for a standardized quantitative evaluation of the mechanical characteristics of various coronary stents. Several types of stents were compressed by external hydrostatic pressure. The stent diameter was assessed by placing a pair of small ultrasonic sono-crystals on the stent. From pressure-strain diagrams the ultimate strength and radial stiffness for each stent were determined. For all stents, except the MICRO-II and the Wiktor stent, the diameter decreased homogeneously until an ultimate compressive strength was exceeded, causing an abrupt collapse. Expanded to 3 mm, the mechanical behavior of the beStent, the Crown and the Palmaz-Schatz stent (PS153-series) were comparable. The spiral articulated Palmaz-Schatz stent showed twice the strength (1.26 atm) of the PS-153 (0.65 atm). The NIR stent yielded a maximum strength of 1.05 atm. The MICRO-II and the Wiktor stent did not collapse abruptly but rather showed a continuous decline of diameter with increasing external pressure. The Cardiocoil stent behaved in a fully elastic manner and showed the largest radial stiffness. Difference in mechanical properties between stents were documented using a new device specifically developed for that purpose. These mechanical stent parameters may have important clinical implications.

  10. Upper Gastrointestinal Stent Insertion in Malignant and Benign Disorders

    PubMed Central

    Kang, Hyoun Woo

    2015-01-01

    Upper gastrointestinal (GI) stents are increasingly being used to manage upper GI obstructions. Initially developed for palliative treatment of esophageal cancer, upper GI stents now play an emerging role in benign strictures of the upper GI tract. Because recurrent obstruction and stent-related complications are common, new modifications of stents have been implemented. Self-expandable metal stents (SEMS) have replaced older plastic stents. In addition, newly designed SEMS have been developed to prevent complications. This review provides an overview of the various types, indications, methods, complications, and clinical outcomes of upper GI stents in a number of malignant and benign disorders dividing the esophagus and gastroduodenum. PMID:26064817

  11. Higher quality of life after metal stent placement compared with plastic stent placement for malignant extrahepatic bile duct obstruction: a randomized controlled trial.

    PubMed

    Walter, Daisy; van Boeckel, Petra G A; Groenen, Marcel J M; Weusten, Bas L A M; Witteman, Ben J; Tan, Gi; Brink, Menno A; Nicolai, Jan; Tan, Adriaan C; Alderliesten, Joyce; Venneman, Niels G; Laleman, Wim; Jansen, Jeroen M; Bodelier, Alexander; Wolters, Frank L; van der Waaij, Laurens A; Breumelhof, Ronald; Peters, Frans T M; Scheffer, Robbert C H; Steyerberg, Ewout W; May, Anne M; Leenders, Max; Hirdes, Meike M C; Vleggaar, Frank P; Siersema, Peter D

    2017-02-01

    For palliation of extrahepatic bile duct obstruction, self-expandable metal stents (SEMS) are superior to plastic stents in terms of stent patency and occurrence of stent dysfunction. We assessed health-related quality of life (HRQoL) after stent placement to investigate whether this also results in a difference in HRQoL between patients treated with a plastic stent or SEMS. This randomized multicenter trial included 219 patients who were randomized to receive plastic stent (n=73) or SEMS [uncovered (n=75) and covered (n=71); n=146] placement. HRQoL was assessed with two general questionnaires (EQ-5D-3L and QLQ-C30) and one disease-specific questionnaire (PAN-26). Scores were analyzed using linear mixed model regression and included all patients with baseline and at least one follow-up measurement. HRQoL data were available in 140 of 219 patients (64%); 71 patients (32%) declined participation and in eight patients (4%) only baseline questionnaires were available. On the QLQ-C30, the interaction between follow-up time and type of stent was significantly different on two of five functional scales [physical functioning (P=0.004) and emotional functioning (P=0.01)] in favor of patients with a SEMS. In addition, patients with SEMS reported significantly less frequent symptoms of fatigue (P=0.01), loss of appetite (P=0.02), and nausea and vomiting (0.04) over time. The EQ-VAS score decreased with time in both treatment groups, indicating a statistically significant decrease in HRQoL over time. In patients with inoperable malignant extrahepatic bile duct obstruction, SEMS placement results in better scores for general and disease-specific HRQoL over time compared with plastic stent placement.

  12. Fracture of Memotherm Metallic Stents in the Biliary Tract

    SciTech Connect

    Peck, Robert; Wattam, John

    2000-01-15

    In a series of 66 patients who had palliation of malignant obstructive jaundice by percutaneous placement of Memotherm expanding metal stents, we report four cases of stent fracture. This has not been reported previously.

  13. Trimming a Metallic Biliary Stent Using an Argon Plasma Coagulator

    SciTech Connect

    Rerknimitr, Rungsun Naprasert, Pisit; Kongkam, Pradermchai; Kullavanijaya, Pinit

    2007-06-15

    Background. Distal migration is one of the common complications after insertion of a covered metallic stent. Stent repositioning or removal is not always possible in every patient. Therefore, trimming using an argon plasma coagulator (APC) may be a good alternative method to solve this problem. Methods. Metallic stent trimming by APC was performed in 2 patients with biliary Wallstent migration and in another patient with esophageal Ultraflex stent migration. The power setting was 60-100 watts with an argon flow of 0.8 l/min. Observations. The procedure was successfully performed and all distal parts of the stents were removed. No significant collateral damage to the nearby mucosa was observed. Conclusions. In a patient with a distally migrated metallic stent, trimming of the stent is possible by means of an APC. This new method may be applicable to other sites of metallic stent migration.

  14. Palliation of Postoperative Gastrointestinal Anastomotic Malignant Strictures with Flexible Covered Metallic Stents: Preliminary Results

    SciTech Connect

    Lee, Jeong-Min; Han, Young Min; Lee, Sang Yong; Kim, Chong Soo; Yang, Doo Hyun; Lee, Seung Ok

    2001-01-15

    Purpose: To evaluate the efficacy of the placement of covered metallic stents for palliation of gastrointestinal anastomotic strictures secondary to recurrent gastric cancer.Methods: Under fluoroscopic guidance, placement of one or two self-expandable covered metallic stents was attempted perorally in 11 patents (aged 48-76 years) with anastomotic stenoses due to recurrent gastric malignancies. The strictures involved both the afferent and efferent loops in three patients. All patients had poor peroral food intake with severe nausea and vomiting after ingestion. The technical and clinical success was evaluated.Results: Placement of the covered stent was technically successful in 13 of 15 (87%) attempts in ten patients. After the procedure, 9 of 11 (82%) patients overall were able to ingest at least a liquid diet and had markedly decreased incidence of vomiting. During the follow-up of 2-31 weeks (mean 8.5 weeks) there were no major complications.Conclusion: These preliminary results suggest that flexible, covered stents may provide effective palliation of malignant anastomotic stricture secondary to recurrent gastric cancer.

  15. Metallic stents in malignant biliary obstruction

    SciTech Connect

    Rieber, Andrea; Brambs, Hans-Juergen

    1997-01-15

    Purpose. Retrospective analysis of our results with metallic stent placement for malignant biliary strictures. We sought to determine parameters that influence stent patency. Methods. A total of 95 Wallstents were implanted in 65 patients (38 men, 27 women; mean age, 65.1 years) with malignant biliary obstruction. Serum bilirubin levels were assessed in 48 patients; the mean value prior to intervention was 15.0 mg/dl. Results. In 12 patients (21%) complications occurred as a result of percutaneous transhepatic drainage. Stent implantation was complicated in 13 patients, but was possible in all patients. A significant decrease in bilirubin level was seen in 83.3% of patients following stent implantation. Approximately 30% of patients developed recurrent jaundice after a mean 97.1 days. In 9 patients (15%) the recurrent jaundice was caused by stent occlusion due to tumor growth. The mean follow-up was 141.8 days, the mean survival 118.7 days. Patients with cholangiocarcinomas and gallbladder carcinomas had the best results. Worse results were seen in patients with pancreatic tumors and with lymph node metastases of colon and gastric cancers. Conclusions. The main predictive factors for occlusion rate and survival are the type of primary tumor, tumor stage, the decrease in bilirubin level, and the general condition of the patient.

  16. Primary and revision efficacy of cross-wired metallic stents for endoscopic bilateral stent-in-stent placement in malignant hilar biliary strictures.

    PubMed

    Lee, T H; Moon, J H; Kim, J H; Park, D H; Lee, S S; Choi, H J; Cho, Y D; Park, S H; Kim, S J

    2013-01-01

    Endoscopic bilateral drainage for inoperable malignant hilar biliary strictures (HBS) using metal stents is considered to be technically difficult. Furthermore, endoscopic revision of bilateral stenting after occlusion can be challenging. This study was performed to evaluate the long-term efficacy of endoscopic bilateral stent-in-stent placement of cross-wired metallic stents in high-grade malignant HBS and planned endoscopic bilateral revision. A total of 84 patients with inoperable high-grade malignant HBS were enrolled from three academic tertiary referral centers. Two cross-wired metal stents were inserted using a bilateral stent-in-stent placement method. Bilateral endoscopic revision was also performed during follow-up using either identical metal stents or plastic stents. The main outcome measurements were technical and functional success, complications, stent patency, and endoscopic revision efficacy. The technical and clinical success rates of endoscopic bilateral stent-in-stent placement of cross-wired metallic stents were 95.2% (80/84) and 92.9% (78/84), respectively. Median patency (range) and survival were 238 days (10-429) and 256 days (10-1130), respectively. Obstruction of primary bilateral stents occurred in 30.8% (24/78) of patients with functionally successful stent placement. The technical and clinical success rates of planned bilateral endoscopic revision for occluded stents were 83.3% (20/24) and 79.2% (19/24), respectively. For revision, bilateral metallic stents were placed in 11 patients (55.0%); the remaining patients received plastic stents. Palliative endoscopic bilateral stent-in-stent placement of cross-wired metallic stents was effective in patients with inoperable HBS. Revision endoscopic bilateral stenting may be feasible and successful in cases where the primary deployed metal stents are occluded. © Georg Thieme Verlag KG Stuttgart · New York.

  17. Role of Stent Grafts and Helical-Woven Bare-Metal Stents in the Superficial Femoral and Popliteal Arteries.

    PubMed

    Madassery, Sreekumar; Turba, Ulku C; Arslan, Bulent

    2016-06-01

    Peripheral vascular disease (PVD) is a devastating medical problem that may lead to significant life alterations for patients, from simply limiting their daily activities to potential loss of limbs and eventual demise. Superficial femoral and popliteal arteries are significantly common locations for PVD sequelae to present itself, and owing to their length and mobile nature, treatment of these segments are quite challenging. Indications for PVD treatment include lifestyle-limiting claudication that is not responding to medical management, ischemic rest pain, nonhealing ulcers, and lower extremity gangrene. There is a wide variety of treatment options that include medical management, interventional, and surgical techniques. Interventional techniques include plain old balloon angioplasty, cryoplasty, drug-coated balloon angioplasty, self-expanding bare-nitinol stents, self-expanding covered stents, self-expanding drug-eluding stents, and a number of atherectomy devices (ie, laser, rotational, orbital, and excisional). The scope of this article is to review indications, patient selection, and deployment techniques of Viabahn and Supera self-expanding stents. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Biodegradable biliary stents have a different effect than covered metal stents on the expression of proteins associated with tissue healing in benign biliary strictures.

    PubMed

    Siiki, Antti; Jesenofsky, Ralf; Löhr, Matthias; Nordback, Isto; Kellomäki, Minna; Gröhn, Heidi; Mikkonen, Joonas; Sand, Juhani; Laukkarinen, Johanna

    2016-07-01

    Benign biliary strictures (BBS) are primarily treated endoscopically with covered self-expandable metal stents (CSEMS). Biodegradable biliary stents (BDBS) may be the future of endoscopic therapy of BBS. The aim was to assess the expression of proteins related to tissue healing in BBS compared with the intact bile duct (BD), and to study the protein expression after therapy with CSEMS or BDBS. Pigs with ischemic BBS were endoscopically treated either with BDBS or CSEMS. Samples were harvested from pigs with intact BD (n = 5), untreated BBS (n = 5), and after six months of therapy with BDBS (n = 4) or CSEMS (n = 5) with subsequent histologic analysis. Two-dimensional electrophoresis with protein identification was performed to evaluate protein expression patterns. In BBS, the expression of galectin-2 and annexin-A4 decreased, compared to intact BD. Treatment with biodegradable stents normalized galectin-2 level; with CSEMS therapy it remained low. Transgelin expression of intact BD and BBS remained low after BDBS treatment but increased after CSEMS therapy. Histologic analysis did not show unwanted foreign body reaction or hyperplasia in the BD in either group. The expression of proteins related to tissue healing in BBS is different after treatment with biodegradable stents and CSEMS. Treatment with biodegradable stents may bring protein expression towards what is seen in intact BD. BDBS seem to have a good biocompatibility.

  19. Endoscopic stenting for hilar cholangiocarcinoma: efficacy of unilateral and bilateral placement of plastic and metal stents in a retrospective review of 480 patients

    PubMed Central

    2012-01-01

    Background Endoscopic biliary drainage of hilar cholangiocarcinoma is controversial with respect to the optimal types of stents and the extent of drainage. This study evaluated endoscopic palliation in patients with hilar cholangiocarcinoma using self-expandable metallic stents (SEMS) and plastic stents (PS).We also compared unilateral and bilateral stent placement according to the Bismuth classification. Methods Data on 480 patients receiving endoscopic biliary drainage for hilar cholangiocarcinoma between September 1995 and December 2010 were retrospectively reviewed to evaluate the following outcome parameters: technical success (TS), functional success (FS), early and late complications, stent patency and survival. Patients were followed from stent insertion until death or stent occlusion. Patients were divided into 3 groups according to the Bismuth classification (Group 1, type I; Group 2, type II; Group 3, type > III). Results The initial stent insertion was successful in 450 (93.8%) patients. TS was achieved in 204 (88.3%) patients treated with PS and in 246 (98.8%) patients palliated with SEMS (p < 0.001). In the intention-to-treat (ITT) analysis, the FS in patients treated with SEMS (97.9%) was significantly higher than in patients treated with PS (84.8%) (p < 0.001). Late complications occurred in 115 (56.4%) patients treated with PS and 60 (24.4%) patients treated with SEMS (p < 0.001). The median duration of stent patency in weeks (w) were as follows: 20 w in patients palliated with PS and 27 w in patients treated with SEMS (p < 0.0001). In Group 2, the median duration of PS patency was 17 w and 18 w for unilateral and bilateral placement, respectively (p = 0.0004); the median duration of SEMS patency was 24 w and 29 w for unilateral and bilateral placement, respectively (p < 0.0001). Multivariate analysis using the Poisson regression showed that SEMS placement (B = 0.48; P < 0.01) and bilateral deployment (B = 0

  20. Comparison of a New Polytetrafluoroethylene-Covered Metallic Stent to a Noncovered Stent in Canine Ureters

    SciTech Connect

    Chung, Hwan-Hoon Lee, Seung Hwa; Cho, Sung Bum; Park, Hong Suk; Kim, Young Sik; Kang, Byung Chul; Frisoli, Joan K.; Razavi, Mahmood K.

    2008-05-15

    The aim of this study was to determine the feasibility of using a newly designed polytetrafluoroethylene (PTFE)-covered metallic stent in the ureter by comparing its effectiveness with that of the noncovered stent in a canine model. We placed 14 stents in the ureters of seven mongrel dogs that weighed 30-40 kg each. The covered and noncovered stents were deployed in the right and left ureters, respectively, of six dogs. In the seventh dog, a covered stent and a double-J catheter were inserted in the right ureter, and a covered stent only was inserted in the left ureter. The first six dogs were sacrificed at 5, 10, and 15 weeks after deployment of the stents (two for each follow-up period), and the seventh dog was sacrificed at 30 weeks. There was no migration or poor expansion of any of the stents observed on plain radiography. On intravenous pyelogram and retrograde pyelogram, all of the covered stents at each follow-up period had patent lumens at the stented segments without hydronephrosis, and the passage of contrast material through it was well preserved. The noncovered stents in the dogs sacrificed at 5 and 10 weeks and one of the two dogs sacrificed at 15 weeks showed near-complete occlusion of the stent lumen due to ingrowth of the soft tissue, and severe hydronephrosis was also noted. The noncovered stent in the other dog sacrificed at 15 weeks showed the passage of contrast material without hydronephrosis, but the lumen of the stent was still nearly occluded by the soft tissue. There was no evidence of hydronephrosis or passage disturbance of the contrast material in both ureters of the dog sacrificed at 30 weeks. We conclude that the newly designed PTFE-covered stent effectively prevented the luminal occlusion caused by urothelial hyperplasia compared to the near-total occlusion of the noncovered stents, and no migration of the covered stents was noted.

  1. Self-expanding wallstent endoprosthesis for malignant ureteral obstruction.

    PubMed

    Díaz-Lucas, E F; Martínez-Torres, J L; Fernández Mena, J; Carazo Martínez, O; de la Fuente Serrano, A; Zuluaga Gómez, A

    1997-12-01

    We present our experience with the self-expanding Wallstent endoprosthesis for ureteral recanalization in obstructive uropathy secondary to malignant pelvic disease. In total, 19 stents were inserted in 14 ureters. The follow-up included 100% of the patients. To date, except for one case, the patency of the stent has always persisted for the period of the survival of the patients, the longest ones being 4 and 4.1 years.

  2. Initial Experience with the Resonance Metallic Stent for Antegrade Ureteric Stenting

    SciTech Connect

    Wah, Tze M. Irving, Henry C.; Cartledge, Jon

    2007-07-15

    Background and purpose. We describe our initial experience with a new metallic ureteric stent which has been designed to provide long-term urinary drainage in patients with malignant ureteric strictures. The aim is to achieve longer primary patency rates than conventional polyurethane ureteric stents, where encrustation and compression by malignant masses limit primary patency. The Resonance metallic double-pigtail ureteric stent (Cook, Ireland) is constructed from coiled wire spirals of a corrosion-resistant alloy designed to minimize tissue in-growth and resist encrustation, and the manufacturer recommends interval stent change at 12 months. Methods. Seventeen Resonance stents were inserted via an antegrade approach into 15 patients between December 2004 and March 2006. The causes of ureteric obstruction were malignancies of the bladder (n = 4), colon (n = 3), gynecologic (n = 5), and others (n = 3). Results. One patient had the stent changed after 12 months, and 3 patients had their stents changed at 6 months. These stents were draining adequately with minimal encrustation. Four patients are still alive with functioning stents in situ for 2-10 months. Seven patients died with functioning stents in place (follow-up periods of 1 week to 8 months). Three stents failed from the outset due to bulky pelvic malignancy resulting in high intravesical pressure, as occurs with conventional plastic stents. Conclusion. Our initial experience with the Resonance metallic ureteric stent indicates that it may provide adequate long-term urinary drainage (up to 12 months) in patients with malignant ureteric obstruction but without significantly bulky pelvic disease. This obviates the need for regular stent changes and would offer significant benefit for these patients with limited life expectancy.

  3. Y-configured metallic stent combined with 125I seed strands cavity brachytherapy for a patient with type IV Klatskin tumor

    PubMed Central

    Dechao, Jiao; Yanli, Wang; Zhen, Li

    2016-01-01

    We report a case in an inoperable patient with type IV Klatskin tumor treated by the use of a novel, two piece, Y-configured self-expandable metallic stent (SEMS) combined with two 125I seed strands via bilateral approach. The placement of the Y-shaped SEMS was successful and resulted in adequate biliary drainage. After 2 months of intraluminal brachytherapy (ILBT), both 125I seed strands and temporary drainage catheter were removed after patency of the expanded stents was confirmed by the cholangiogram. This technique was feasible and could be considered for the treatment of patients with Bismuth type IV Klatskin tumors. PMID:27648091

  4. Biodegradable stents for the treatment of refractory or recurrent benign esophageal stenosis.

    PubMed

    Imaz-Iglesia, Iñaki; García-Pérez, Sonia; Nachtnebel, Anna; Martín-Águeda, Belén; Sánchez-Piedra, Carlos; Karadayi, Bilgehan; Demirbaş, Ali Rıza

    2016-06-01

    Esophageal stents are used for the treatment of refractory and recurrent dyphagias. In 2007, esophageal biodegradable stents (EBS) were authorised as an alternative to existing metal and plastic stents in Europe. The advantages claimed for EBS are fewer complications concerning tissue ingrowth, stent migration and stent removal. We performed a systematic review to evaluate the efficacy and safety of EBS compared to fully-covered self-expanding metal stents, self-expanding plastic stents, and esophageal dilation for the treatment of refractory or recurrent benign esophageal stenosis. Three comparative studies (one randomized controlled trial and two cohort studies) were assessed. The studies used different inclusion criteria, had a very small (sample) size and the quality of the evidence was very low. Expert commentary: The current evidence is insufficient to determine the relative efficacy or safety of esophageal biodegradable stents. The results of this systematic review should be updated once new evidence is available.

  5. Intra-channel stent release technique for fluoroless endoscopic ultrasound-guided lumen-apposing metal stent placement: changing the paradigm

    PubMed Central

    Anderloni, Andrea; Attili, Fabia; Carrara, Silvia; Galasso, Domenico; Di Leo, Milena; Costamagna, Guido; Repici, Alessandro; Kunda, Rastislav; Larghi, Alberto

    2017-01-01

    Background Recently, a novel lumen-apposing fully covered self-expanding metal stent (LA-FCSEMS) mounted on an electrocautery-enhanced delivery system has been developed to perform endoscopic ultrasound (EUS)-guided transluminal drainage. From early experience, however, release of the proximal flange of the stent has mostly been done using endoscopic view guidance to ensure proper positioning. Aim We describe a new technique that we have named the Intra-Channel Stent Release Technique (ICSRT) to perform stent placement under complete EUS control, without the use of either fluoroscopic or endoscopic views. Material and methods Data on all consecutive patients who underwent EUS-guided drainage using the new ICSRT between June 2014 and April 2016 were retrospectively retrieved from two institution databases. All EUS procedures were performed by experienced endoscopists with the patient under conscious or deep sedation. The total procedure and stent deployment time, and adverse events related to stent positioning with the ICSRT were evaluated. Results One hundred consecutive patients (51 women; mean age ± SD, 66 ± 15.2 years, range 34 – 95) underwent EUS-guided transluminal drainage with the Hot AXIOS™ device using the new ICSRT. The procedure was technically successful in all but one patient (1 %). The mean total procedural time was 21.9 minutes (range 7 – 50), while the mean time for stent placement was 3.2 minutes (range 1 – 15). No major adverse events occurred. Discussion The ICSRT has been used to deploy the newly developed lumen-apposing FCSEMS under complete EUS guidance without fluoroscopic and/or endoscopic assistance. The technique appears to be safe and highly effective and should be learned by all interventional endosonographers in order to be able to perform drainage in all clinical scenarios.

  6. Aspirin Use Is Associated With Reduced Risk of Occlusion of Metallic Biliary Stents.

    PubMed

    Jang, Sunguk; Stevens, Tyler; Parsi, Mansour A; Lopez, Rocio; Vargo, John J

    2017-03-01

    Biliary self-expandable metallic stents (SEMSs) are widely used to treat malignant and benign conditions of bile duct. Despite their lower rate of occlusion and longer patency than plastic stents, SEMSs still have significant rates of occlusion. We aimed to identify factors associated with occlusion of biliary SEMS. We performed a retrospective study of consecutive patients who underwent endoscopic retrograde cholangiopancreatography with biliary SEMS placement at the Cleveland Clinic Foundation from March 2011 to April 2016. We collected clinical, endoscopic, radiographic, and surgical data from medical records and performed multivariable analysis to identify factors associated with SEMS patency. Subjects that received minimal daily dose of 81 mg at the time of stent placement until the end of follow-up were assigned to the aspirin exposure group (n = 157) and compared with subjects with no aspirin exposure (n = 436). Patients were followed for a median 81 days. The primary outcome was hazard ratio for SEMS occlusion requiring an interventional maneuver for biliary drainage. We analyzed data from patients receiving a total of 593 biliary SEMS for treatment of malignant and benign conditions of bile duct. Stent occlusion was observed in 126 cases. Multivariable analysis showed that daily use of aspirin (81 mg or more) was associated with 51% lower risk of stent occlusion than in patients without daily use of aspirin (hazard ratio, 0.49; 95% confidence interval, 0.32-0.75). Furthermore, SEMSs had a longer duration of stent patency in patients in the aspirin exposure group (434.4 days) versus the no aspirin exposure group (339.9 days) (P < .001). Stricture location limited to distal bile duct (in comparison with strictures involving proximal extrahepatic duct) was associated with lower risk of stent occlusion (hazard ratio, 0.39; 95% CI, 0.22-0.71). In an analysis of a large cohort of subjects with metallic biliary stent placement for malignant and benign

  7. Malignant tracheal-mediastinal-parenchymal-pleural fistula after chemoradiation plus bevacizumab: management with a Y-silicone stent inside a metallic covered stent.

    PubMed

    Machuzak, Michael S; Santacruz, Jose F; Jaber, Wissam; Gildea, Thomas R

    2015-01-01

    Tracheal or bronchial-mediastinal fistulas are a rare entity associated to high mortality. We report a case of a 58-year-old man with an unresectable non-small cell carcinoma of the lung, treated with chemoradiation followed by bevacizumab. Approximately, 6 weeks after starting bevacizumab he developed a severe cough with copious secretions He could not lie supine due to the feeling of drowning. Investigations revealed a large tracheo-mediastinal-parenchymal-pleural fistula. Palliative management was offered with interventional bronchoscopic techniques. He was found to have a large central airway defect that obliterated almost 40% of the trachea. Under general anesthesia and positive pressure ventilation, a unique approach was used to rebuild an eroded tracheal and right main stem bronchial wall. A self-expanding metallic stent (SEMS) was placed to provide a scaffold of support, whereas a Dumon Y-stent was placed inside the SEMS. This combination allowed for a patent, stable airway; recreating the normal anatomy in a minimally invasive manner walling off the fistula. The patient was discharged 2 days after the bronchoscopic intervention, with significant palliation of his symptomatology. Eighteen months later, the upper lobe cavity persists with a stable airway and stents perfectly positioned with clinically insignificant evidence of stent related granulation in the upper trachea.

  8. Biodegradable Metals for Cardiovascular Stent Application: Interests and New Opportunities

    PubMed Central

    Moravej, Maryam; Mantovani, Diego

    2011-01-01

    During the last decade, biodegradable metallic stents have been developed and investigated as alternatives for the currently-used permanent cardiovascular stents. Degradable metallic materials could potentially replace corrosion-resistant metals currently used for stent application as it has been shown that the role of stenting is temporary and limited to a period of 6–12 months after implantation during which arterial remodeling and healing occur. Although corrosion is generally considered as a failure in metallurgy, the corrodibility of certain metals can be an advantage for their application as degradable implants. The candidate materials for such application should have mechanical properties ideally close to those of 316L stainless steel which is the gold standard material for stent application in order to provide mechanical support to diseased arteries. Non-toxicity of the metal itself and its degradation products is another requirement as the material is absorbed by blood and cells. Based on the mentioned requirements, iron-based and magnesium-based alloys have been the investigated candidates for biodegradable stents. This article reviews the recent developments in the design and evaluation of metallic materials for biodegradable stents. It also introduces the new metallurgical processes which could be applied for the production of metallic biodegradable stents and their effect on the properties of the produced metals. PMID:21845076

  9. Biodegradable metals for cardiovascular stent application: interests and new opportunities.

    PubMed

    Moravej, Maryam; Mantovani, Diego

    2011-01-01

    During the last decade, biodegradable metallic stents have been developed and investigated as alternatives for the currently-used permanent cardiovascular stents. Degradable metallic materials could potentially replace corrosion-resistant metals currently used for stent application as it has been shown that the role of stenting is temporary and limited to a period of 6-12 months after implantation during which arterial remodeling and healing occur. Although corrosion is generally considered as a failure in metallurgy, the corrodibility of certain metals can be an advantage for their application as degradable implants. The candidate materials for such application should have mechanical properties ideally close to those of 316L stainless steel which is the gold standard material for stent application in order to provide mechanical support to diseased arteries. Non-toxicity of the metal itself and its degradation products is another requirement as the material is absorbed by blood and cells. Based on the mentioned requirements, iron-based and magnesium-based alloys have been the investigated candidates for biodegradable stents. This article reviews the recent developments in the design and evaluation of metallic materials for biodegradable stents. It also introduces the new metallurgical processes which could be applied for the production of metallic biodegradable stents and their effect on the properties of the produced metals.

  10. Paraffin processing of stented arteries using a postfixation dissolution of metallic and polymeric stents.

    PubMed

    Fishbein, Ilia; Welch, Tre; Guerrero, David T; Alferiev, Ivan S; Adamo, Richard F; Chorny, Michael; Gupte, Rohit K; Tang, Yanqing; Levy, Robert J

    Studying the morphology of the arterial response to endovascular stent implantation requires embedding the explanted stented artery in rigid materials such as poly(methyl methacrylate) to enable sectioning through both the in situ stent and the arterial wall, thus maintaining the proper anatomic relationships. This is a laborious, time-consuming process. Moreover, the technical quality of stained plastic sections is typically suboptimal and, in some cases, precludes immunohistochemical analysis. Here we describe a novel technique for dissolution of metallic and plastic stents that is compatible with subsequent embedding of "destented" arteries in paraffin, fine sectioning, major staining protocols, and immunohistochemistry.

  11. Outcomes, health-care resources use, and costs of endoscopic removal of metallic airway stents.

    PubMed

    Alazemi, Saleh; Lunn, William; Majid, Adnan; Berkowitz, David; Michaud, Gaetane; Feller-Kopman, David; Herth, Felix; Ernst, Armin

    2010-08-01

    The use of self-expandable metallic airway stents (SEMAS) for airway compromise may be associated with significant complications requiring their removal/replacement. The aim of this study is to describe the complications, health-care resources use (HRU), and costs associated with endoscopic removal of SEMAS. A retrospective analysis of patients who underwent endoscopic removal of SEMAS during a 10-year period (January 2000-August 2009) was performed. HRU was analyzed in terms of the number of endoscopic procedures, hospital and ICU stay, need for mechanical ventilation and airway restenting, and estimation of respective hospital costs. Fifty-five SEMAS were removed from 46 patients with a mean age of 58.6 +/- 15.8 years. Eighty percent of the stents were placed for benign airway disorders with an average stent in situ duration of 292 days. The median number of removal and total procedures during each encounter was one and two, respectively. Patients required hospitalization and ICU admission in 78% and 39% of the encounters with a median length of stay of 3.5 and 0 days, respectively. The estimated median total cost per encounter to remove the stents was $10,700, ranging from $3,700 to $69,800. The measured outcomes were statistically significantly better when in situ stent duration was

  12. Impact of anticancer treatment on recurrent obstruction in covered metallic stents for malignant biliary obstruction.

    PubMed

    Nakai, Yousuke; Isayama, Hiroyuki; Mukai, Tsuyoshi; Itoi, Takao; Maetani, Iruru; Kawakami, Hiroshi; Yasuda, Ichiro; Maguchi, Hiroyuki; Ryozawa, Shomei; Hanada, Keiji; Hasebe, Osamu; Ito, Kei; Kawamoto, Hiorofumi; Mochizuki, Hitoshi; Igarashi, Yoshinori; Irisawa, Atsushi; Sasaki, Tamito; Togawa, Osamu; Hara, Taro; Kamada, Hideki; Toda, Nobuo; Hamada, Tsuyoshi; Kogure, Hirofumi

    2013-11-01

    In patients with unresectable malignant biliary obstruction (MBO), anticancer treatment is often administered. The impact of anticancer treatment on recurrent biliary obstruction in covered self-expandable metallic stents (SEMS) has not been fully elucidated. Data on 279 patients enrolled in a multicenter prospective cohort study of two different covered SEMS for distal MBO, WATCH study (141 partially covered WallFlex stents and 138 partially covered Wallstents) were retrospectively analyzed. The rates and causes of recurrent biliary obstruction (stent occlusion or migration) were compared between anticancer treatment group (n = 173) and best supportive care alone (BSC) group (n = 106). Cumulative time and prognostic factors for recurrent biliary obstruction were analyzed, using a proportional hazards model with death without recurrent biliary obstruction as a competing risk. The overall rate (43 vs. 25%, P = 0.002) and the cumulative incidence (16.1 vs. 8.2, 27.9 vs. 18.9 and 44.1 vs. 26.6% at 3, 6 and 12 months, P = 0.030 by Gray's test) of recurrent biliary obstruction were significantly higher in anticancer treatment group compared with BSC group. The multivariate analysis revealed anticancer treatment [subdistribution hazard ratio (SHR) 1.93, P = 0.007) as well as the use of a partially covered WallFlex stent (SHR 0.65, P = 0.049) as prognostic factors. Anticancer treatment was a risk factor for recurrent biliary obstruction in covered SEMS for distal MBO. The superiority of a partially covered WallFlex stent was again confirmed in this competing risk analysis; UMIN-CTR: UMIN000002293.

  13. Paclitaxel-eluting stents versus bare-metal stents in acute myocardial infarction.

    PubMed

    Stone, Gregg W; Lansky, Alexandra J; Pocock, Stuart J; Gersh, Bernard J; Dangas, George; Wong, S Chiu; Witzenbichler, Bernhard; Guagliumi, Giulio; Peruga, Jan Z; Brodie, Bruce R; Dudek, Dariusz; Möckel, Martin; Ochala, Andrzej; Kellock, Alison; Parise, Helen; Mehran, Roxana

    2009-05-07

    There is no consensus regarding the safety and efficacy of drug-eluting stents, as compared with bare-metal stents, in patients with ST-segment elevation myocardial infarction who are undergoing primary percutaneous coronary intervention (PCI). We randomly assigned, in a 3:1 ratio, 3006 patients presenting with ST-segment elevation myocardial infarction to receive paclitaxel-eluting stents (2257 patients) or otherwise identical bare-metal stents (749 patients). The two primary end points of the study were the 12-month rates of target-lesion revascularization for ischemia (analysis powered for superiority) and a composite safety outcome measure of death, reinfarction, stroke, or stent thrombosis (powered for noninferiority with a 3.0% margin). The major secondary end point was angiographic evidence of restenosis at 13 months. Patients who received paclitaxel-eluting stents, as compared with those who received bare-metal stents, had significantly lower 12-month rates of ischemia-driven target-lesion revascularization (4.5% vs. 7.5%; hazard ratio, 0.59; 95% confidence interval [CI], 0.43 to 0.83; P=0.002) and target-vessel revascularization (5.8% vs. 8.7%; hazard ratio, 0.65; 95% CI, 0.48 to 0.89; P=0.006), with noninferior rates of the composite safety end point (8.1% vs. 8.0%; hazard ratio, 1.02; 95% CI, 0.76 to 1.36; absolute difference, 0.1 percentage point; 95% CI, -2.1 to 2.4; P=0.01 for noninferiority; P=0.92 for superiority). Patients treated with paclitaxel-eluting stents and those treated with bare-metal stents had similar 12-month rates of death (3.5% and 3.5%, respectively; P=0.98) and stent thrombosis (3.2% and 3.4%, respectively; P=0.77). The 13-month rate of binary restenosis was significantly lower with paclitaxel-eluting stents than with bare-metal stents (10.0% vs. 22.9%; hazard ratio, 0.44; 95% CI, 0.33 to 0.57; P<0.001). In patients with ST-segment elevation myocardial infarction who were undergoing primary PCI, implantation of paclitaxel

  14. Stenting of the Upper Gastrointestinal Tract: Current Status

    SciTech Connect

    Katsanos, Konstantinos; Sabharwal, Tarun Adam, Andreas

    2010-08-15

    Minimally invasive image-guided insertion of self-expanding metal stents in the upper gastrointestinal tract is the current treatment of choice for palliation of malignant esophageal or gastroduodenal outlet obstructions. A concise review is presented of contemporary stenting practice of the upper gastrointestinal tract, and the procedures in terms of appropriate patient evaluation, indications, and contraindications for treatment are analyzed, along with available stent designs, procedural steps, clinical outcomes, inadvertent complications, and future technology. Latest developments include biodegradable polymeric stents for benign disease and radioactive or drug-eluting stents for malignant obstructions.

  15. Endoscopic ultrasound-guided gastrojejunostomy with a lumen-apposing metal stent: a multicenter, international experience

    PubMed Central

    Tyberg, Amy; Perez-Miranda, Manuel; Sanchez-Ocaña, Ramon; Peñas, Irene; de la Serna, Carlos; Shah, Janak; Binmoeller, Kenneth; Gaidhane, Monica; Grimm, Ian; Baron, Todd; Kahaleh, Michel

    2016-01-01

    Background: Surgical gastrojejunostomy and enteral self-expanding metal stents are efficacious for the management of gastric outlet obstruction but limited by high complication rates and short-term efficacy. Endoscopic ultrasound-guided gastrojejunostomy (EUS-GJ) is a novel alternative option. Patients and methods: Patients who underwent EUS-GJ between March 2014 and September 2015 as part of a prospective multicenter registry at four academic centers in two countries were included. Technical success was defined as successful placement of a gastrojejunal lumen-apposing metal stent. Clinical success was defined as the ability of the patient to tolerate an oral diet. Post-procedural adverse events were recorded. Results: The study included 26 patients, of whom 11 (42 %) were male. Technical success was achieved in 24 patients (92 %). Clinical success was achieved in 22 patients (85 %). Of the 4 patients in whom clinical success was not achieved, 2 had persistent nausea and vomiting despite a patent EUS-GJ and required enteral feeding for nutrition, 1 died before the initiation of an oral diet, and 1 underwent surgery for suspected perforation. Adverse events, including peritonitis, bleeding, and surgery, occurred in 3 patients (11.5 %). Conclusion: EUS-GJ is an emerging procedure that has efficacy and safety comparable with those of current therapies and should hold a place as a new minimally invasive option for patients with gastric outlet obstruction. Clinical trial identification number: NCT01522573 PMID:27004243

  16. Impact of stent strut design in metallic stents and biodegradable scaffolds.

    PubMed

    Foin, Nicolas; Lee, Renick D; Torii, Ryo; Guitierrez-Chico, Juan Luis; Mattesini, Alessio; Nijjer, Sukhjinder; Sen, Sayan; Petraco, Ricardo; Davies, Justin E; Di Mario, Carlo; Joner, Michael; Virmani, Renu; Wong, Philip

    2014-12-20

    Advances in the understanding of healing mechanisms after stent implantation have led to the recognition of stent strut thickness as an essential factor affecting re-endothelialization and overall long term vessel healing response after Percutaneous Coronary Interventions (PCI). Emergence of Drug-eluting stents (DESs) with anti-proliferative coating has contributed to reducing the incidence of restenosis and Target Lesion Revascularization (TVR), while progress and innovations in stent materials have in the meantime facilitated the design of newer platforms with more conformability and thinner struts, producing lesser injury and improving integration into the vessel wall. Recent advances in biodegradable metal and polymer materials now also allow for the design of fully biodegradable platforms, which are aimed at scaffolding the vessel only temporarily to prevent recoil and constrictive remodeling of the vessel during the initial period required, and are then progressively resorbed thereby avoiding the drawback of leaving an unnecessary implant permanently in the vessel. The aim of this article is to review recent evolution in stent material and stent strut design while understanding their impact on PCI outcomes. The article describes the different metallic alloys and biodegradable material properties and how these have impacted the evolution of stent strut thickness and ultimately outcomes in patients. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  17. Comparison of the influence of plastic and fully covered metal biliary stents on the accuracy of EUS-FNA for the diagnosis of pancreatic cancer.

    PubMed

    Siddiqui, Ali A; Fein, Michael; Kowalski, Thomas E; Loren, David E; Eloubeidi, Mohamad A

    2012-09-01

    Prior 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. We conducted a retrospective study evaluating 677 patients with solid pancreatic head/uncinate lesions and a previous biliary stent in whom EUS-FNA was performed. The patients were stratified into two groups: (1) those with a plastic stents and (2) those with CSEMS. Performance characteristics of EUS-FNA including the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were compared between the two groups. The frequency of obtaining an adequate cytology by EUS-FNA was similar in both the CSEMS group and the plastic stent group (97 vs. 97.1 % respectively; p = 1.0). The sensitivity, specificity, and accuracy of EUS-FNA was not significantly different between patients with CSEMS and plastic stents (96.8, 100, 100 % and 97.3, 98, 99.8 %, respectively). The negative predictive value for EUS-FNA was lower in the CSEMS group compared to the plastic stent group (66.6 vs. 78.1 % respectively; p = 0.42). There was one false-positive cytology in the plastic stent group compared to none in the CSEMS group. In a retrospective cohort trial, EUS-FNA was found to be highly accurate and safe in diagnosing patients with suspected pancreatic cancer, even in the presence of a plastic or metallic biliary stent. The presence of a stent did not contribute to a higher false-positive cytology rate.

  18. Biliary metal stents for proximal esophageal or hypopharyngeal strictures.

    PubMed

    Bechtler, Matthias; Wagner, Florian; Fuchs, Erik-Sebastian; Jakobs, Ralf

    2015-11-01

    Endoscopic dilation is the standard of care for stenoses of the cervical esophagus, but refractory strictures require some form of stenting. Most endoscopists avoid the placement of metal stents near the upper esophageal sphincter as they can cause major problems like severe cervical pain and globus sensation. We report our results with the use of biliary SEMS in the upper esophagus, which have a smaller diameter than regular esophageal stents and therefore exert less expansive force. We retrospectively reviewed all patients in our center between July 2011 and June 2014 who received a biliary metal stent because of a refractory stricture in the cervical esophagus. We implanted biliary SEMS (Wallflex, Boston Scientific) with a diameter of 1 cm and length of 6-8 cm. Technical and clinical success, adverse events and duration of stenting were evaluated. Ten patients were treated with biliary SEMS in the upper esophagus. Strictures were located between 10 and 19 cm from incisor teeth. Stent placement was successful in all (10/10) patients. One stent had to be extracted because of pain and globus sensation. Apart from that stent tolerability was good. All remaining patients (9/9) reported improvement of dysphagia with a decrease in mean dysphagia score from 3.2 to 1.78. Mean duration of stenting was 68 days. Because of a high clinical success rate and good tolerability, biliary metal stents are a reasonable alternative for difficult strictures in the cervical esophagus, especially in the palliative setting.

  19. Bare metal stents, durable polymer drug eluting stents, and biodegradable polymer drug eluting stents for coronary artery disease: mixed treatment comparison meta-analysis

    PubMed Central

    Toklu, Bora; Amoroso, Nicholas; Fusaro, Mario; Kumar, Sunil; Hannan, Edward L; Faxon, David P; Feit, Frederick

    2013-01-01

    Objective To compare the efficacy and safety of biodegradable polymer drug eluting stents with those of bare metal stents and durable polymer drug eluting stents. Design Mixed treatment comparison meta-analysis of 258 544 patient years of follow-up from randomized trials. Data sources and study selection PubMed, Embase, and Central were searched for randomized trials comparing any of the Food and Drug Administration approved durable polymer drug eluting stents (sirolimus eluting, paclitaxel eluting, cobalt chromium everolimus eluting, platinum chromium everolimus eluting, zotarolimus eluting-Endeavor, and zotarolimus eluting-Resolute) or biodegradable polymer drug eluting stents, with each other or against bare metal stents. Outcomes Long term efficacy (target vessel revascularization, target lesion revascularization) and safety (death, myocardial infarction, stent thrombosis). Landmark analysis at more than one year was evaluated to assess the potential late benefit of biodegradable polymer drug eluting stents. Results From 126 randomized trials and 258 544 patient years of follow-up, for long term efficacy (target vessel revascularization), biodegradable polymer drug eluting stents were superior to paclitaxel eluting stents (rate ratio 0.66, 95% credibility interval 0.57 to 0.78) and zotarolimus eluting stent-Endeavor (0.69, 0.56 to 0.84) but not to newer generation durable polymer drug eluting stents (for example: 1.03, 0.89 to 1.21 versus cobalt chromium everolimus eluting stents). Similarly, biodegradable polymer drug eluting stents were superior to paclitaxel eluting stents (rate ratio 0.61, 0.37 to 0.89) but inferior to cobalt chromium everolimus eluting stents (2.04, 1.27 to 3.35) for long term safety (definite stent thrombosis). In the landmark analysis after one year, biodegradable polymer drug eluting stents were superior to sirolimus eluting stents for definite stent thrombosis (rate ratio 0.29, 0.10 to 0.82) but were associated with increased

  20. Bare metal stents, durable polymer drug eluting stents, and biodegradable polymer drug eluting stents for coronary artery disease: mixed treatment comparison meta-analysis.

    PubMed

    Bangalore, Sripal; Toklu, Bora; Amoroso, Nicholas; Fusaro, Mario; Kumar, Sunil; Hannan, Edward L; Faxon, David P; Feit, Frederick

    2013-11-08

    To compare the efficacy and safety of biodegradable polymer drug eluting stents with those of bare metal stents and durable polymer drug eluting stents. Mixed treatment comparison meta-analysis of 258,544 patient years of follow-up from randomized trials. PubMed, Embase, and Central were searched for randomized trials comparing any of the Food and Drug Administration approved durable polymer drug eluting stents (sirolimus eluting, paclitaxel eluting, cobalt chromium everolimus eluting, platinum chromium everolimus eluting, zotarolimus eluting-Endeavor, and zotarolimus eluting-Resolute) or biodegradable polymer drug eluting stents, with each other or against bare metal stents. Long term efficacy (target vessel revascularization, target lesion revascularization) and safety (death, myocardial infarction, stent thrombosis). Landmark analysis at more than one year was evaluated to assess the potential late benefit of biodegradable polymer drug eluting stents. From 126 randomized trials and 258,544 patient years of follow-up, for long term efficacy (target vessel revascularization), biodegradable polymer drug eluting stents were superior to paclitaxel eluting stents (rate ratio 0.66, 95% credibility interval 0.57 to 0.78) and zotarolimus eluting stent-Endeavor (0.69, 0.56 to 0.84) but not to newer generation durable polymer drug eluting stents (for example: 1.03, 0.89 to 1.21 versus cobalt chromium everolimus eluting stents). Similarly, biodegradable polymer drug eluting stents were superior to paclitaxel eluting stents (rate ratio 0.61, 0.37 to 0.89) but inferior to cobalt chromium everolimus eluting stents (2.04, 1.27 to 3.35) for long term safety (definite stent thrombosis). In the landmark analysis after one year, biodegradable polymer drug eluting stents were superior to sirolimus eluting stents for definite stent thrombosis (rate ratio 0.29, 0.10 to 0.82) but were associated with increased mortality compared with cobalt chromium everolimus eluting stents (1.52, 1

  1. Biliary stenting in patients with malignant biliary obstruction: comparison of double layer, plastic and metal stents.

    PubMed

    Elwir, Saleh; Sharzehi, Kaveh; Veith, Joshua; Moyer, Mathew T; Dye, Charles; McGarrity, Thomas; Mathew, Abraham

    2013-07-01

    The double layer stent (DLS) has a unique design and has been used for palliation of malignant biliary obstruction, but literature on this stent is limited. Our aim was to compare plastic (PS), DLS and metal stents (MS) in terms of complication rates, time to occlusion, and patency rate in patients with malignant biliary obstruction (MBO). A retrospective review of stents placed for MBO at our institution in the period between January 2009 and April 2011 was conducted. A total of 114 stents were identified, of which 44 were MS (39 %), 37 DLS (32 %), and 33 PS (29 %). A stent was considered occluded when an unplanned stent removal or intervention occurred due to clinical suspicion of biliary obstruction. Stents remained patent for 95 days (range 7-359 days) in the DLS group and 59 days (range 7-228 days) in the PS group (P = 0.014) and 128.7 days (range 4-602 days) in the metal stent group. Twenty-seven percent (n = 9) of PS occluded after a mean of 60 days while 16 % (n = 7) of MS occluded after a mean of 87 days and 5 % (n = 2) of DLS occluded after a mean of 85 days (DLS vs. PS P = 0.012, DLS vs. MS P = 0.13, MS vs. PS P = 0.22). DLS are superior to PS in patients with MBO and appear to be comparable to MS. MS had a longer patency rate but were comparable to DLS in early and late complications. We speculate that the less expensive DLS may be a cost effective alternative in the palliation of MBO.

  2. Role of stents and laser therapy in biliary strictures

    NASA Astrophysics Data System (ADS)

    Chennupati, Raja S.; Trowers, Eugene A.

    2001-05-01

    The most frequent primary cancers causing malignant obstructive jaundice were pancreatic cancer (57%), hilar biliary cancer (19% including metastatic disease), nonhilar biliary cancer (14%) and papillary cancer (10%). Endoscopic stenting has widely replaced palliative surgery for malignant biliary obstruction because of its lower risk and cost. Self-expandable metal stents are the preferred mode of palliation for hilar malignancies. Plastic stents have a major role in benign biliary strictures. Major complications and disadvantages associated with metallic stents include high cost, cholangitis. malposition, migration, unextractability, and breakage of the stents, pancreatitis and stent dysfunction. Dysfunction due to tumor ingrowth can be relieved by thermal methods (argon plasma coagulator therapy). We present a concise review of the efficacy of metallic stents for palliation of malignant strictures.

  3. EUS-guided drainage of hepatic abscess and infected biloma using short and long metal stents (with videos).

    PubMed

    Tonozuka, Ryosuke; Itoi, Takao; Tsuchiya, Takayoshi; Sofuni, Atsushi; Ishii, Kentaro; Ikeuchi, Nobuhito; Umeda, Junko; Tanaka, Reina; Mukai, Shuntaro; Gotoda, Takuji; Moriyasu, Fuminori

    2015-01-01

    Currently, few reports exist on EUS-guided hepatic abscess drainage (EUS-HAD) and EUS-guided biloma drainage (EUS-BLD) using a metal stent. We evaluated the technical success rate and efficacy of EUS-HAD and EUS-BLD for patients with hepatic abscess (HA) and infected biloma. Retrospective case series. Single tertiary referral medical center. We evaluated 7 HA and 6 infected biloma patients who were treated between August 2013 and August 2014 at Tokyo Medical University Hospital. EUS-HAD or EUS-BLD using a short (length, 2 or 3 cm) or long (length, 6 or 8 cm) self-expandable fully covered metal stent. Technical success, clinical success, and adverse event. The overall technical success rate was 100% in both EUS-HAD and EUS-BLD. The clinical success rates of EUS-HAD and EUS-BLD at the first session were 71.4% and 83.3%, respectively. Direct endoscopic necrosectomy was required in 1 case each of HA and infected biloma. The final clinical success rate was 100%. There were no procedure-related adverse events or cases of recurrence during the follow-up period (median, 83.5 days; range, 24-396 days). Small sample size and no control group. EUS-HAD and EUS-BLD using a metal stent can be performed safely and effectively for HA and infected biloma. Copyright © 2015 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

  4. The Casper carotid artery stent: a unique all metal micromesh stent designed to prevent embolic release.

    PubMed

    Diaz, Orlando; Lopez, Gloria; Roehm, John O F; De la Rosa, Ginna; Orozco, Fernando; Almeida, Rafael

    2017-04-24

    Stroke due to the release of embolic debris during the placement of a stent to correct carotid artery stenosis is a constant procedural and peri-procedural threat. The new all metal Casper stent has been created with two layers of nitinol, the inner layer of which has pores diminutive enough to prevent embolic release. To evaluate the safety, effectiveness, and utility of the double layer nitinol Casper carotid artery stent in the treatment of patients with severe carotid artery stenosis. 19 patients with severe internal carotid artery stenosis, 14 symptomatic and 5 asymptomatic, were treated with the Casper stent. After stent placement, angiographic and cone beam CT images were recorded in all patients. The unique low profile delivery system allowed for easy stent placement, re-sheathing, and repositioning of the stent. The large cell external layer produced excellent apposition to the artery wall. The inner layer prevented prolapse of atherosclerotic debris through the device. Plaque coverage was achieved; residual stenosis ranged from 0% to 20%. Long term angiographic follow-up in 5 patients showed wall apposition of the device covering the lesion and no restenosis. There were no procedure related complications. Two patients experienced a delayed ischemic stroke, likely related to inconsistent medical management. The Casper has been an excellent stent for the treatment of internal carotid artery stenosis and its internal micromesh layer has been effective in preventing plaque prolapse. It provides the flexibility of large cell stents and the inner layer provides maximum protection against plaque prolapse. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  5. Bare Metal Stenting for Endovascular Exclusion of Aortic Arch Thrombi

    SciTech Connect

    Mahnken, Andreas H.; Hoffman, Andras; Autschbach, Ruediger; Damberg, Anneke L. M.

    2013-08-01

    BackgroundAortic thrombi in the ascending aorta or aortic arch are rare but are associated with a relevant risk of major stroke or distal embolization. Although stent grafting is commonly used as a treatment option in the descending aorta, only a few case reports discuss stenting of the aortic arch for the treatment of a thrombus. The use of bare metal stents in this setting has not yet been described.MethodsWe report two cases of ascending and aortic arch thrombus that were treated by covering the thrombus with an uncovered stent. Both procedures were performed under local anesthesia via a femoral approach. A femoral cutdown was used in one case, and a total percutaneous insertion was possible in the second case.ResultsBoth procedures were successfully performed without any periprocedural complications. Postoperative recovery was uneventful. In both cases, no late complications or recurrent embolization occurred at midterm follow-up, and control CT angiography at 1 respectively 10 months revealed no stent migration, freely perfused supra-aortic branches, and no thrombus recurrence.ConclusionTreating symptomatic thrombi in the ascending aorta or aortic arch with a bare metal stent is feasible. This technique could constitute a minimally invasive alternative to a surgical intervention or complex endovascular therapy with fenestrated or branched stent grafts.

  6. Current state of the absorbable metallic (magnesium) stent.

    PubMed

    Waksman, Ron

    2009-12-15

    BIOTRONIK's absorbable metal stent technology is based ona magnesium alloy that offers superior stent mechanics and biocompatibility. The first generation (AMS-1) showed promising results regarding mechanical properties as well as feasibility and safety in several human applications (150 cases). The second generation (AMS-2.1) shows improved scaffolding and efficacy in animals due to a more slowly degrading magnesium alloy and an optimised stent design. The preclinical results of the drug-eluting AMS-3 are encouraging and the clinical investigational program will resume in 2010.

  7. Laser microfabrication of biocompatible metallic stent for medical therapy

    NASA Astrophysics Data System (ADS)

    Kathuria, Yash P.

    2003-10-01

    In the stent theory for the medical applications, especially in coronary heart disease, the metallic stent of high quality demands the ability for precision micromaterial processing. It possesses an inherent advantage of adequate radiopacity. This paper describes the current status as well as fabrication of such metallic stent of length 20 mm and dia. 2.1 mm with an annular tube thickness of 0.2 mm, by using the short pulse Nd-YAG laser. Fine structures with slit width of 0.1 mm and pitch better than 0.2 mm are created with sharpness and low roughness in the cut surface. Some features on the reduced heat affected zone and dross removal process of the cut surfaces of the stent as well as a few techniques on preventing restenosis are well documented.

  8. Drug-eluting stents versus bare-metal stents for acute coronary syndrome.

    PubMed

    Feinberg, Joshua; Nielsen, Emil Eik; Greenhalgh, Janette; Hounsome, Juliet; Sethi, Naqash J; Safi, Sanam; Gluud, Christian; Jakobsen, Janus C

    2017-08-23

    Approximately 3.7 million people died from acute coronary syndrome worldwide in 2012. Acute coronary syndrome, also known as myocardial infarction or unstable angina pectoris, is caused by a sudden blockage of the blood supplied to the heart muscle. Percutaneous coronary intervention is often used for acute coronary syndrome, but previous systematic reviews on the effects of drug-eluting stents compared with bare-metal stents have shown conflicting results with regard to myocardial infarction; have not fully taken account of the risk of random and systematic errors; and have not included all relevant randomised clinical trials. To assess the benefits and harms of drug-eluting stents versus bare-metal stents in people with acute coronary syndrome. We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, LILACS, SCI-EXPANDED, and BIOSIS from their inception to January 2017. We also searched two clinical trials registers, the European Medicines Agency and the US Food and Drug Administration databases, and pharmaceutical company websites. In addition, we searched the reference lists of review articles and relevant trials. Randomised clinical trials assessing the effects of drug-eluting stents versus bare-metal stents for acute coronary syndrome. We included trials irrespective of publication type, status, date, or language. We followed our published protocol and the methodological recommendations of Cochrane. Two review authors independently extracted data. We assessed the risks of systematic error by bias domains. We conducted Trial Sequential Analyses to control the risks of random errors. Our primary outcomes were all-cause mortality, major cardiovascular events, serious adverse events, and quality of life. Our secondary outcomes were angina, cardiovascular mortality, and myocardial infarction. Our primary assessment time point was at maximum follow-up. We assessed the quality of the evidence by the GRADE approach. We included 25

  9. Are Covered Stents Really Effective at Closing Esophagotracheal Fistulas? Results of an Animal Study

    SciTech Connect

    Wagner, Hans-Joachim; Stinner, Benno; Barth, Peter; Klose, Klaus-Jochen

    2000-07-15

    Purpose: To determine whether covered self-expanding metal stents successfully exclude experimentally created esophagotracheal fistulas.Methods: Esophagotracheal fistulas were surgically created in the upper third of the esophagus in 12 minipigs and immediately sealed by implantation of a covered self-expanding metal stent (20 mm expanded diameter) in the esophagus. Before the animals were killed, after 3, 7, 14, 28, 30, and 36 days, the position of the stent and the sealing of the fistula were monitored fluoroscopically. The esophagus, trachea, and both lungs were examined histologically.Results: Creation of an esophagotracheal fistula was successful in all cases. All fistulas were widely patent at autopsy. The technical success rate for stent deployment and initial sealing of the fistula was 100%. During follow-up, five stents migrated distally, but none into the stomach. Therefore, the fistula was no longer excluded in five animals. In seven animals the stent sealed the fistula until the death of the animal. Tracheal narrowing necessitated additional tracheal stenting in three animals. Two minipigs died due to aspiration of food. Histologic examination showed signs of aspiration in all animals with stents in place for longer than 2 weeks.Conclusion: This experimental animal study revealed worse results for sealing of esophagotracheal fistulas with covered self-expanding metal stents than have been reported for the clinical use of these devices.

  10. Hemodynamic analysis of edge stenosis in peripheral artery stent grafts.

    PubMed

    Al-Hakim, R; Lee, E W; Kee, S T; Seals, K; Varghese, B; Chien, A; Quirk, M; McWilliams, J

    2017-10-01

    The purpose of this study was to characterize the hemodynamics of peripheral artery stent grafts to guide intelligent stent redesign. Two surgically explanted porcine arteries were mounted in an ex vivo system with subsequent deployment of an Xpert self-expanding nitinol stent or Viabahn stent graft. The arteries were casted with radiopaque resin, and the cast then scanned using micro-computed tomography at 8μm isotropic voxel resolution. The arterial lumen was segmented and a computational mesh grid surface generated. Computational fluid dynamics (CFD) analysis was subsequently performed using COMSOL Multiphysics 5.1. CFD analysis demonstrated low endothelial shear stress (ESS) involving 9.4 and 63.6% surface area of the central stent graft and bare metal stent, respectively. Recirculation zones were identified adjacent to the bare metal stent struts, while none were identified in the central stent graft. However, the stent graft demonstrated malapposition of the proximal stent graft edge with low velocity flow between the PTFE lining and arterial wall, which was associated with longitudinally and radially oriented recirculation zones and low ESS. Computational hemodynamic analysis demonstrates that peripheral artery stent grafts have a superior central hemodynamic profile compared to bare metal stents. Stents grafts, however, suffer from malapposition at the proximal stent edge which is likely a major contributor to edge stenosis. Copyright © 2017 Editions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

  11. Malignant Ureteral Obstruction: Functional Duration of Metallic versus Polymeric Ureteral Stents

    PubMed Central

    Chow, Po-Ming; Chiang, I-Ni; Chen, Chia-Yen; Huang, Kuo-How; Hsu, Jui-Shan; Wang, Shuo-Meng; Lee, Yuan-Ju; Yu, Hong-Jeng; Pu, Yeong-Shiau; Huang, Chao-Yuan

    2015-01-01

    Background Ureteral obstruction caused by extrinsic compression is often associated with intra-abdominal cancers. Internal drainage with ureteral stents is typically the first-line therapy to relieve such obstructions. Novel designs of ureteral stents made of different materials have been invented to achieve better drainage. In this study, we described the functional outcomes of a Resonance metallic ureteral stent (Cook Medical, Bloomington, Indiana, USA) in patients with malignant ureteral obstruction and compare the functional duration of Resonance stents with regular polymeric stents in the same cohort. Methods Cancer patients who received polymeric stents and subsequent Resonance stents for ureteral obstruction between July 2009 and November 2012 were included in a chart review. Stent failure was detected by clinical symptoms, imaging studies, and renal function tests. The functional durations of each stent were calculated, and possible factors affecting stent patency were investigated. Results A total of 50 stents were successfully inserted into 50 ureteral units in 42 patients with malignant ureteral obstruction. There were 7 antegrade stents and 43 retrograde stents. There were no major complications. Stent-related symptoms were similar in both kinds of stents. After polymeric stents were replaced with Resonance metallic stents, hydronephrosis subsided or remained stable in 90% (45/50) of the ureteral units. Serum creatinine decreased or remained stable in 90% (38/42) of these patients. The Resonance stent exhibited a mean increase in functional duration of 4 months compared with the polymeric stents (p<0.0001), and 50% (25/50) of the Resonance stents exhibited a significant increase in functional duration (more than 3 months). Pre-operative serum creatinine < 2 was associated with a substantial increase in stent duration. Conclusions Resonance stents are effective and safe in relieving malignant ureteral obstructions after polymeric stents failure

  12. Management of Failing Prosthetic Bypass Grafts with Metallic Stent Placement

    SciTech Connect

    Siskin, Gary P.; Stainken, Brian F.; Mandell, Valerie S.; Darling, R. Clement; Dowling, Kyran; Herr, Allen

    1999-09-15

    Purpose: To evaluate the role of metallic stents in treating stenoses involving prosthetic arterial bypass grafts. Methods: Patients undergoing stent placement within a failing prosthetic bypass graft, during a 41-month period, were reviewed for treatment outcome and complications. The indications for stent placement in 15 patients included severe claudication (n= 3), rest pain (n= 9), and minor or major tissue loss (n= 3). Lesions were at the proximal anastomosis (n= 6), the distal anastomosis (n= 3), or within the graft (n= 6). Results: Treatment with metallic stents was successful in all patients. There was one acute stent thrombosis, successfully treated with thrombolytic therapy. Follow-up data are available for a mean duration of 12.3 months. The mean duration of primary patency was 9.4 months with 6- and 12-month primary patency rates of 51.9% and 37.0%, respectively. The mean duration of secondary patency was 12.1 months with 6- and 12-month secondary patency rates of 80.0% and 72.7%, respectively. Two patients with discontinuous runoff and preexisting gangrene required a below-knee amputation. Six patients were revised surgically after stent placement (at a mean of 10.8 months). Three late deaths occurred during follow-up. Conclusion: Given the mortality risks of surgical revision and the reduced life expectancy of this patient population, metallic stent placement represents a viable, short-term treatment option for stenoses within or at the anastomoses of prosthetic grafts. Further evaluation is warranted to compare intragraft stent placement with surgical graft revision.

  13. Drug-eluting versus bare-metal coronary stents: where are we now?

    PubMed

    Amoroso, Nicholas S; Bangalore, Sripal

    2012-11-01

    Drug-eluting stents have dramatically reduced the risk of restenosis, but concerns of an increased risk of stent thrombosis have provided uncertainty about their use. Recent studies have continued to show improved procedural and clinical outcomes with drug-eluting stents both in the setting of acute coronary syndromes and stable coronary artery disease. Newer generation drug-eluting stents (especially everolimus-eluting stents) have been shown to be not only efficacious but also safe with reduced risk of stent thrombosis when compared with bare-metal stents, potentially changing the benchmark for stent safety from bare-metal stents to everolimus-eluting stents. While much progress is being made in the development of bioabsorbable polymer stents, nonpolymer stents and bioabsorbable stent technology, it remains to be seen whether these stents will have superior safety and efficacy outcomes compared with the already much improved rates of revascularization and stent thrombosis seen with newer generation stents (everolimus-eluting stents and resolute zotarolimus-eluting stents).

  14. Antireflux Metal Stent as a First-Line Metal Stent for Distal Malignant Biliary Obstruction: A Pilot Study

    PubMed Central

    Hamada, Tsuyoshi; Isayama, Hiroyuki; Nakai, Yousuke; Togawa, Osamu; Takahara, Naminatsu; Uchino, Rie; Mizuno, Suguru; Mohri, Dai; Yagioka, Hiroshi; Kogure, Hirofumi; Matsubara, Saburo; Yamamoto, Natsuyo; Ito, Yukiko; Tada, Minoru; Koike, Kazuhiko

    2017-01-01

    Background/Aims In distal malignant biliary obstruction, an antireflux metal stent (ARMS) with a funnel-shaped valve is effective as a reintervention for metal stent occlusion caused by reflux. This study sought to evaluate the feasibility of this ARMS as a first-line metal stent. Methods Patients with nonresectable distal malignant biliary obstruction were identified between April and December 2014 at three Japanese tertiary centers. We retrospectively evaluated recurrent biliary obstruction and adverse events after ARMS placement. Results In total, 20 consecutive patients were included. The most common cause of biliary obstruction was pancreatic cancer (75%). Overall, recurrent biliary obstruction was observed in seven patients (35%), with a median time to recurrent biliary obstruction of 246 days (range, 11 to 246 days). Stent occlusion occurred in five patients (25%), the causes of which were sludge and food impaction in three and two patients, respectively. Stent migration occurred in two patients (10%). The rate of adverse events associated with ARMS was 25%: pancreatitis occurred in three patients, cholecystitis in one and liver abscess in one. No patients experienced non-occlusion cholangitis. Conclusions The ARMS as a first-line biliary drainage procedure was feasible. Because the ARMS did not fully prevent stent dysfunction due to reflux, further investigation is warranted. PMID:27282268

  15. Self-expanding/shrinking structures by 4D printing

    NASA Astrophysics Data System (ADS)

    Bodaghi, M.; Damanpack, A. R.; Liao, W. H.

    2016-10-01

    The aim of this paper is to create adaptive structures capable of self-expanding and self-shrinking by means of four-dimensional printing technology. An actuator unit is designed and fabricated directly by printing fibers of shape memory polymers (SMPs) in flexible beams with different arrangements. Experiments are conducted to determine thermo-mechanical material properties of the fabricated part revealing that the printing process introduced a strong anisotropy into the printed parts. The feasibility of the actuator unit with self-expanding and self-shrinking features is demonstrated experimentally. A phenomenological constitutive model together with analytical closed-form solutions are developed to replicate thermo-mechanical behaviors of SMPs. Governing equations of equilibrium are developed for printed structures based on the non-linear Green-Lagrange strain tensor and solved implementing a finite element method along with an iterative incremental Newton-Raphson scheme. The material-structural model is then applied to digitally design and print SMP adaptive lattices in planar and tubular shapes comprising a periodic arrangement of SMP actuator units that expand and then recover their original shape automatically. Numerical and experimental results reveal that the proposed planar lattice as meta-materials can be employed for plane actuators with self-expanding/shrinking features or as structural switches providing two different dynamic characteristics. It is also shown that the proposed tubular lattice with a self-expanding/shrinking mechanism can serve as tubular stents and grippers for bio-medical or piping applications.

  16. European Experience with the Self-Expanding Nitinol Coil: Pilot Phase Evaluation in Cardiovascular Applications.

    PubMed

    Beyar; Roguin

    1997-03-01

    BACKGROUND: The Cardiocoil (InStent) is a self-expanding nitinol coil that is restrained on a delivery catheter in a compressed state and deployed by a wire based release mechanism. We provide the initial data on the acute results of the use of this stent in a multi-center study in Europe. We also briefly review the other non-coronary applications of this stent. METHODS: One-hundred two stents were implanted in 76 patients for suboptimal results or dissections. There were 39 LAD lesions, 28 RCA lesions and 9 Circumflex lesions. There were eight total occlusions. Lesions were short in 41% (< 10 mm), tubular (between 10 and 20 mm) in 37%, and diffuse (> 20%) in 22%. Stent deployment included predilatation to the reference arterial side and post dilatation after stent deployment. RESULTS: Stent deployment was successful in all cases in which lesions could be crossed. In cases where the stent did not cross the lesion (n=3) it was removed uneventfully. There were no stent losses. Complications included subacute thrombosis in 4/76 (5.3%) patients (1- a long total RCA lesion, 2- diffuse proximal LAD diseases). There were no late acute events after stenting and no stent related mortality. Angiographic quantitative analysis showed that the stent expands by both its intrinsic self-expanding properties and by post deployment balloon assistance. CONCLUSIONS: The self-expanding coil stent for cardiovascular interventions is safe and effective in treating a variety of complex lesions. It provides adequate support to the arterial wall, preventing acute recoil and tacking dissections to the arterial wall. The long-term efficiency of this stent awaits further clinical testing.

  17. Economic analysis of esophageal stenting for management of malignant dysphagia.

    PubMed

    Rao, C; Haycock, A; Zacharakis, E; Krasopoulos, G; Yakoub, D; Protopapas, A; Darzi, A; Hanna, G B; Athanasiou, T

    2009-01-01

    Over half of patients diagnosed with esophageal cancer are unsuitable for curative resection. A significant proportion of these patients will subsequently require palliative stenting to alleviate dysphagia. There is growing consensus in the literature that the deployment of a Self-Expanding Metal Stent is the optimum stenting strategy; however, it remains unclear whether covered or uncovered metal stents are more cost-effective. In order to determine which type of prosthesis is more cost-effective, we compared the different stenting strategies in terms of 1-year stent-related mortality, health-related quality of life, and cost. A decision analytical model was constructed to compare the 1-year stent-related mortality, health-related quality of life, and cost between covered and uncovered stents. Probabilistic sensitivity analysis was performed to quantify the uncertainty associated with our results. Value of Information analysis was performed to assess the value of further research. In order to fully characterize the uncertainty associated with this decision, plastic stents were included in our analysis. Stent-related mortality was slightly lower following covered stent deployment compared with uncovered stent deployment (1.00% vs. 1.26%). Covered stents were more effective by 0.0013 Quality-Adjusted Life Years (Standard Deviation [SD] 0.0013 Quality-Adjusted Life Years). They were also less expensive by $729.58 (SD $390.63). Probabilistic sensitivity analysis suggested that these results were not sensitive to model parameter uncertainty. Plastic stents deployment was $2832.64 (SD $1182.72) more expensive than uncovered metal stent deployment. Value of Information analysis suggests that the maximum value of further research in the UK is $61,124.30. The results of this study represent strong evidence for the cost-effectiveness of covered compared with uncovered self-expanding metal stents for the palliation of patients with malignant dysphagia. The findings support

  18. Diamond stents for palliation of malignant bile duct obstruction: a prospective multicenter evaluation.

    PubMed

    Ferlitsch, A; Oesterreicher, C; Dumonceau, J M; Deviere, J; Leban, T; Born, P; Rösch, T; Suter, W; Binek, J; Meyenberger, C; Müllner, M; Schneider, B; Schöfl, R

    2001-08-01

    Various types of self-expandable metal stents have been introduced for biliary drainage in patients with malignant jaundice, showing prolonged patency compared with plastic endoprostheses. However, there has only been prolonged experience with a meaningful number of patients using the Wallstent. We evaluated the Diamond stent, a self-expanding uncoated biliary metal stent, in a prospective uncontrolled multicenter setting. The eligibility criterion was obstructive jaundice due to inoperable malignant disease. Between August 1995 and January 2000, 126 patients, who received a total of 134 Diamond stents in four European centers, were followed prospectively. Technical and clinical success rates were 96 % and 98 %, respectively. No major procedure-related complications occurred. The 30-day mortality rate was 13 %. Stent occlusion occurred in 28 patients (22 %). Overall median stent patency was 477 days; overall median survival was 173 days. Stent occlusion, confirmed by endoscopic retrograde cholangiopancreatography, was successfully treated with plastic stents in all patients. Cost analysis revealed estimated costs of 3440 euros per patient for palliative treatment with the Diamond stent. The Diamond stent compares favorably with other biliary metal stents for patients requiring biliary drainage of malignant jaundice.

  19. Will absorbable metal stent technology change our practice?

    PubMed

    Bosiers, M; Deloose, K; Verbist, J; Peeters, P

    2006-08-01

    Peripheral stents aim to support revascularization procedures of intravascular stenoses by mechanically preventing vessel recoil and counteracting pathophysiologic processes of luminal re-narrowing triggered by procedural injury of the vessel wall. Despite improvements in stenting techniques and concomitant medication, repeated intervention due to target lesion re-stenosis is necessary on a significant percentage of patients. The permanent presence of an artificial implant plays a prominent role in the discussion of mechanisms causing in-stent restenosis. Permanent metallic implants pose the risk of a continuous interaction between non-absorbable stent and surrounding tissue, leading to physical irritation, long-term endothelial dysfunction, or chronic inflammatory reactions. In addition, there is a risk of stent fracture due to external mechanical forces. To overcome these shortcomings, technology of stenting has moved towards the development of temporary implants composed of biocompatible materials which mechanically support the vessel during the period of high risk for recoil and then completely degrade in the long-term perspective. This removes a potential trigger for late restenosis.

  20. Endoscopic bilio-duodenal bypass: outcomes of primary and revision efficacy of combined metallic stents in malignant duodenal and biliary obstructions.

    PubMed

    Canena, Jorge; Coimbra, João; Carvalho, Diana; Rodrigues, Catarina; Silva, Mário; Costa, Mariana; Horta, David; Mateus Dias, António; Seves, Isabel; Ramos, Gonçalo; Ricardo, Leonel; Coutinho, António Pereira; Romão, Carlos; Veiga, Pedro Mota

    2014-11-01

    Self-expandable metal stents (SEMSs) can be used for palliation of combined malignant biliary and duodenal obstructions. However, the results of the concomitant stent placement for the duration of the patients' lives, as well as the need for and efficacy of endoscopic revision, are unclear. This study evaluated the clinical effectiveness of SEMS placement for combined biliary and duodenal obstructions throughout the patients' lives and the need for endoscopic revision. This study is a retrospective multicenter study of 50 consecutive patients who underwent simultaneous or sequential SEMS placement for malignant biliary and duodenal obstructions. The data were collected to analyze the sustained relief of obstructive symptoms until the patients' death and the efficacy of endoscopic revision, as well as stent patency, adverse events, survival and prognostic factors for stent patency. Technical and immediate clinical success was achieved in all of the patients. Duodenal stricture occurred before the papilla in 35 patients (70 %), involved the papilla in 11 patients (22 %) and was observed distal to the papilla in four patients (8 %). Initial biliary stenting was performed endoscopically in 42 patients (84 %) and percutaneously in eight patients. After combined stenting, 30 patients (60 %) required no additional intervention until the time of their death. The remaining 20 patients were successfully treated using endoscopic stent reinsertion: nine patients needed biliary revision, three patients needed duodenal restenting and eight patients needed both biliary and duodenal reinsertion. The median duodenal stent patency and median biliary stent patency were 34 and 27 weeks, respectively. The median survival after combined stent placement was 18 weeks. A Cox multivariate analysis showed that duodenal stent obstruction after combined stenting was a risk factor for biliary stent obstruction (hazard ratio 6.85; 95 % confidence interval 1.43-198.98; P = 0

  1. Coating bioabsorption and chronic bare metal scaffolding versus fully bioabsorbable stent.

    PubMed

    Waksman, Ron; Pakala, Rajbabu

    2009-12-15

    Advances in coronary stent technology, including refinement of the stent alloy, strut thickness, stent geometry, passive coating, and drug elution, have dramatically enhanced the safety and efficacy of percutaneous coronary intervention (PCI) with stenting. Stents are currently used in over 90% of coronary interventions and the use of drug-eluting stents (DES) has been disseminated to more complex lesion subsets such as total occlusions, long lesions, bifurcation lesions, and for patients with acute myocardial infarction. DES continue to demonstrate reduction in restenosis and the need for repeat revascularisation but are associated with delayed healing and re-endothelialisation, which have led to an increased rates of late stent thrombosis, dependency on prolonged dual antiplatelet therapy, impaired in-vessel reactivity, and chronic inflammation. As scientists and clinicians better understand the mechanism for late restenosis and stent thrombosis, a variety of solutions in regard to stent technology have been proposed, including stent coating, polymer bioabsorption, and fully biodegradable stents. Bare metal stents were improved by the reduction of strut thickness, changes in stent geometry, and the addition of passive coating, which lead to improvements in efficacy and reduction of restenosis. In addition, there is continued improvement in the polymer technology for DES, including new biocompatible, thinner durable polymers, and bioabsorbable polymers that completely bioabsorb within 3-12 months after stent implantation. These features potentially minimise the chronic inflammatory response and late stent thrombosis. Finally, fully bioabsorbable stents, both polymeric and metallic, continue to be developed in order to eliminate any late stenting effects and potentially may enable complete vessel restoration. This manuscript will discuss the wide variety of new stent technologies and compare and contrast durable metallic and polymeric stents to current

  2. Stent selection in patients with myocardial infarction: drug eluting, biodegradable polymers or bare metal stents?

    PubMed

    Mieres, Juan; Rodríguez, Alfredo E

    2012-08-01

    Percutaneous coronary intervention (PCI) has been increasingly used in the last years during interventional procedures in patients with acute coronary syndromes (ACS) including ST elevation myocardial infarction (STEMI) and non-ST elevation myocardial infarction (NSTEMI). In patients with either STEMI, NSTEMI, high risk ACS with EKG changes or cardiac enzymes rises; PCI with bare metal stent (BMS) implantation has been associated with a significant improvement in clinical outcome. Therefore, BMS implantation during primary PCI in STEMI has become a standard of practice. With the introduction of drug eluting stents (DESs) in this decade, the use of these new devices instead of BMSs in patients with STEMI has emerged as a rational PCI alternative in this particular subgroup of patients. In spite of the unquestionable benefits of DESs in terms of reduction of restenosis and TVR, specific concerns have arisen with regard to their long-term safety. High incidence of very late stent thrombosis has been described with these devices, and special attention should be paid in patients with unstable coronary lesions, in which plaque composition and remodeling may play a main role in their safety and long-term outcome. Intraluminal thrombus caused by plaque rupture is the most frequent mechanism of STEMI, in which the necrotic core and thin fibrous cap play a major role. In this context, the use of first DESs designs may be futile or even unsafe because delayed healing may further contribute to plaque instability. Adjunctive invasive imaging tools can improve stent deployment and safety outcome in these lesions with intravascular findings of plaque instability. Recently, other players such as new dedicated antithrombotic BMS designs, including selfexpanding stents or drug-eluting coated balloons, are exploring their potential indications in patients with ACS and myocardial infarction. This paper reports and discusses new stent devices and adjunctive pharmacologic agents. It

  3. The Integrity bare-metal stent made by continuous sinusoid technology.

    PubMed

    Turco, Mark A

    2011-05-01

    The Integrity Coronary Stent System (Medtronic Vascular, CA, USA) is a low-profile, open-cell, cobalt-chromium-alloy advanced bare-metal iteration of the well-known Driver/Micro-Driver Coronary Stent System (Medtronic Vascular). The Integrity stent is made with a process called continuous sinusoid technology. This process allows stent construction via wrapping a single thin strand of wire around a mandrel in a sinusoid configuration, with laser fusion of adjacent crowns. The wire-forming process and fusion pattern provide the stent with a continuous preferential bending plane, intended to allow easier access to, and smoother tracking within, distal and tortuous vessels while radial strength is maintained. Continuous sinusoid technology represents innovation in the design of stent platforms and will provide a future stent platform for newer technology, including drug-eluting stent platforms, drug-filled stents and core wire stents.

  4. The use of cold sprayed alloys for metallic stents

    NASA Astrophysics Data System (ADS)

    AL-Mangour, Bandar

    With the invention of the coronary stent, which is a wire metal mesh tube designed to keep the arteries open in the treatment of heart diseases, promising clinical outcomes were generated. However, the long term successes of stents have been delayed by significant in-stent restenosis (blockages) and stent fracture. In this research work, it has been proposed to use Cold Gas Dynamic Spraying (CGDS) coating material as an alternative choice to manufacture metallic stent. In CGDS, fine particles are accelerated to a high velocity and undergo solid-state plastic deformation upon impact on the substrate, which leads to particle-particle bonding. The feature of CGDS distinct from other thermal spray techniques is that the processing gas temperature is below the melting point of the feedstock. Therefore, unwanted effects of high temperatures, such as oxidation, grain growth and thermal stresses, are absent. In response to the fact that the majority of stents are made from stainless steel (316L) or Co-Cr alloy (L605), this study specifically addresses the development and characterization of 316L and 316L mixed with L605 coatings produced by the CGDS process. Scanning electron microscopy and electron backscatter diffraction were used to investigate the microstructural changes of these coatings before and after annealing. The effect of gas type on the microstructure of 316L coatings and the role of post-heat treatment in the microstructure and properties are also studied. Of particular interest are grain refinement, heat treatment, mechanical properties and corrosion behavior of the cold sprayed material.

  5. Elastic Deformation Properties of Implanted Endobronchial Wire Stents in Benign and Malignant Bronchial Disease: A Radiographic In Vivo Evaluation

    SciTech Connect

    Hautmann, Hubert; Rieger, Johannes; Huber, Rudolf M.; Pfeifer, Klaus J.

    1999-03-15

    Purpose: To evaluate the long-term mechanical behavior in vivo of expandable endobronchial wire stents, we imaged three different prostheses in the treatment of tracheobronchial disease. Methods: Six patients with bronchial stenoses (three benign, three malignant) underwent insertion of metallic stents. Two self-expandable Wallstents, two balloon-expandable tantalum Strecker stents and two self-expandable nitinol Accuflex stents were used. Measurements of deformation properties were performed during voluntary cough by means of fluoroscopy, at 1 month and 7-10 months after implantation. The procedures were videotaped, their images digitized and the narrowing of stent diameters calculated at intervals of 20 msec. Results: After stent implantation all patients improved with respect to ventilatory function. Radial stent narrowing during cough reached 53% (Wallstent), 59% (tantalum Strecker stent), and 52% (nitinol Accuflex stent) of the relaxed post-implantation diameter. Stent compression was more marked in benign compared with malignant stenoses. In the long term permanent deformation occurred with the tantalum Strecker stents; the other stents were unchanged. Conclusion: Endobronchial wire stents can be helpful in the treatment of major airway collapse and obstructing bronchial lesions. However, evidence of material fatigue as a possible effect of exposure to recurrent mechanical stress on the flexible mesh tube may limit their long-term use. This seems to be predominantly important in benign bronchial collapse.

  6. A new removable airway stent

    PubMed Central

    Amundsen, Tore; Sørhaug, Sveinung; Leira, Håkon Olav; Tyvold, Stig Sverre; Langø, Thomas; Hammer, Tommy; Manstad-Hulaas, Frode; Mattsson, Erney

    2016-01-01

    Background Malignant airway obstruction is a feared complication and will most probably occur more frequently in the future because of increasing cancer incidence and increased life expectancy in cancer patients. Minimal invasive treatment using airway stents represents a meaningful and life-saving palliation. We present a new removable airway stent for improved individualised treatment. Methods To our knowledge, the new airway stent is the world's first knitted and uncovered self-expanding metal stent, which can unravel and be completely removed. In an in vivo model using two anaesthetised and spontaneously breathing pigs, we deployed and subsequently removed the stents by unravelling the device. The procedures were executed by flexible bronchoscopy in an acute and a chronic setting – a ‘proof-of-principle’ study. Results The new stent was easily and accurately deployed in the central airways, and it remained fixed in its original position. It was easy to unravel and completely remove from the airways without clinically significant complications. During the presence of the stent in the chronic study, granulation tissue was induced. This tissue disappeared spontaneously with the removal. Conclusions The new removable stent functioned according to its purpose and unravelled easily, and it was completely removed without significant technical or medical complications. Induced granulation tissue disappeared spontaneously. Further studies on animals and humans are needed to define its optimal indications and future use. PMID:27608269

  7. Novel biodegradable polydioxanone stents in a rabbit airway model.

    PubMed

    Novotny, Ladislav; Crha, Michal; Rauser, Petr; Hep, Ales; Misik, Jan; Necas, Alois; Vondrys, David

    2012-02-01

    This study was undertaken to evaluate safety and biocompatibility of a novel biodegradable polydioxanone stent in a rabbit tracheal model. Metallic and silicone stents represent standard therapeutic approaches for hollow organ stenosis, although complications have been reported repeatedly. Biodegradable stents could reduce the risks associated with this procedure while still achieving the purpose of maintaining lumen patency. A commercially available polydioxanone suture strand with a long safety record was used to manufacture the self-expanding stents. The polydioxanone stents were then implanted bronchoscopically and under fluoroscopic guidance into the tracheas of white rabbits (N = 25). Periodic clinical examination was performed. Histopathologic examination concluded the study for the 5 experimental groups at 3, 4, 5, 10, and 15 weeks after implantation. There were no unexpected deaths and no stent displacements during the study. The animals remained in good condition, without stent debris expectoration. Macroscopic examination revealed that the tracheal lumen stayed open. Histologic examination showed that tracheal damage score was highest 5 weeks after stenting, including in-stent necrosis of the epithelium. Stent degradation was complete with no remnants after 10 weeks, leaving the trachea completely healed at 15 weeks after implantation. This animal airway model has demonstrated acceptable safety and biocompatibility of this novel biodegradable polydioxanone stent. We suggest that polydioxanone stenting be used for further clinical studies for cases in which complete stent degradation after temporary airway treatment is desirable. Copyright © 2012 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

  8. A novel biodegradable esophageal stent: results from mechanical and animal experiments

    PubMed Central

    Liu, Jin; Shang, Liang; Liu, Jiyong; Qin, Chengyong

    2016-01-01

    Biodegradable esophageal stents eliminate stent retrieval, but usually induce hyperplasia. This study investigated the properties of a novel biodegradable stent in vitro and in vivo. The degradation of the novel stent was observed in phosphate buffered saline (PBS) for 8 weeks. The radial forces, pH values, morphology, and retention rate of the intrinsic viscosity (R[η]) of the new biodegradable stent were all evaluated. In vitro, the pH values remained constant for 4 weeks and declined from weeks 4 to 8. The biodegradable threads degraded and ruptured at 6 weeks. Consequently, the radial force of the stent decreased to zero at that time. The curve of R[η] decreased with time linearly in PBS. To study the stents in vivo, we used a stricture model in which the middle esophagus of rabbits was damaged by alkali burn. Stents were inserted 2 weeks after injury and observed for 8 weeks. We assessed complications related to stent insertion, degradation of the stent, and survival of the rabbits. Two stents migrated, and one rabbit died. In the other rabbits, two stents degraded and moved into the stomach during the sixth week, five during the seventh week and one during the eighth week, respectively. One stent remained in position until the end of the study. In conclusion, our newly designed stent retained the strong radial force of self-expandable metal stents (SEMSs) and maintained the biodegradable properties of biodegradable (BD) stents. PMID:27158397

  9. A novel biodegradable esophageal stent: results from mechanical and animal experiments.

    PubMed

    Liu, Jin; Shang, Liang; Liu, Jiyong; Qin, Chengyong

    2016-01-01

    Biodegradable esophageal stents eliminate stent retrieval, but usually induce hyperplasia. This study investigated the properties of a novel biodegradable stent in vitro and in vivo. The degradation of the novel stent was observed in phosphate buffered saline (PBS) for 8 weeks. The radial forces, pH values, morphology, and retention rate of the intrinsic viscosity (R[η]) of the new biodegradable stent were all evaluated. In vitro, the pH values remained constant for 4 weeks and declined from weeks 4 to 8. The biodegradable threads degraded and ruptured at 6 weeks. Consequently, the radial force of the stent decreased to zero at that time. The curve of R[η] decreased with time linearly in PBS. To study the stents in vivo, we used a stricture model in which the middle esophagus of rabbits was damaged by alkali burn. Stents were inserted 2 weeks after injury and observed for 8 weeks. We assessed complications related to stent insertion, degradation of the stent, and survival of the rabbits. Two stents migrated, and one rabbit died. In the other rabbits, two stents degraded and moved into the stomach during the sixth week, five during the seventh week and one during the eighth week, respectively. One stent remained in position until the end of the study. In conclusion, our newly designed stent retained the strong radial force of self-expandable metal stents (SEMSs) and maintained the biodegradable properties of biodegradable (BD) stents.

  10. Novel stent in the palliation of malignant esophageal strictures: a retrospective study.

    PubMed

    Chen, H; Ni, Z; Jing, D; He, L; Qiao, L; Liu, L; Wei, X; Jiang, M; Tang, S; Xu, H

    2017-02-01

    The placement of metal stents is often used as a palliative treatment for malignant esophageal stenosis. We designed a novel stent that has been used clinically since 2011, and we therefore performed a retrospective study to compare the therapeutic effects of this novel metal stent to a conventional partially covered metal stent in patients with malignant esophageal strictures. The records of 201 consecutive patients who underwent placement of either the conventional partially covered metal stents (Group A, n = 92) or the new metal stents (Group B, n = 109) in the Endoscopy Center of General Hospital of Chengdu Military Command from October 2008 to March 2013 were reviewed. The median dysphagia score significantly improved in both groups 1 week following stent placement (P < 0.001). No significant differences were observed in success rate (P = 0.910) or the complication rate (P = 0.426) between groups. Six months after stent placement, recurrent dysphagia due to stent migration, tissue ingrowth or overgrowth or food obstruction occurred in 45% and 29% of patients in the conventional stent and new stent groups, respectively. The results of this retrospective study indicate that the new modified self-expandable metal stents (SEMS) is at least as safe and effective as the conventional partially covered SEMS in treatment of malignant esophageal strictures. © 2015 International Society for Diseases of the Esophagus.

  11. Plastic and Biodegradable Stents for Complex and Refractory Benign Esophageal Strictures

    PubMed Central

    Ham, Young Hee

    2014-01-01

    Endoscopic stent placement is a well-accepted and effective alternative treatment modality for complex and refractory esophageal strictures. Among the currently available types of stents, the partially covered self-expanding metal stent (SEMS) has a firm anchoring effect, preventing stent migration and ensuring effective covering of a narrowed segment. However, hyperplastic tissue reaction driven by the uncovered mesh may prevent easy and safe stent removal. As an alternative, a fully covered SEMS decreases the recurrence of dysphagia caused by hyperplastic tissue ingrowth; however, it has a high migration rate. Likewise, although a self-expanding plastic stent (SEPS) reduces reactive hyperplasia, the long-term outcome is disappointing because of the high rate of stent migration. A biodegradable stent has the main benefit of not requiring stent removal in comparison with SEMS and SEPS. However, it still has a somewhat high rate of hyperplastic reaction, and the long-term outcome does not satisfy expectations. Up to now, the question of which type of stent should be recommended for the effective treatment of complex and refractory benign strictures has no clear answer. Therefore, the selection of stent type for endoscopic treatment should be individualized, taking into consideration the endoscopist's experience as well as patient and stricture characteristics. PMID:25133114

  12. Interventional radiology and the use of metal stents in nonvascular clinical practice: a systematic overview.

    PubMed

    Pron, G; Common, A; Simons, M; Ho, C S

    1999-05-01

    The intent of this systematic overview was to describe the clinical role of metal stents in nonvascular health care interventions and the level of evidence supporting their use. Structured searches of Medline were conducted and limited to original peer-reviewed articles published in English. Clinical practice involving metal stents was reported in more than 109 clinical series involving 4,753 patients. Stents were placed mainly for palliation of malignant biliary, esophageal, and airway obstruction in patients who were untreatable or had surgically unresectable lesions. Assessment of these interventions has so far centered on safety and technical success. Efficacy, quality of life, and costing factors were not routinely reported. Randomized trial evidence was available but limited; six randomized trials involving metal stents have been reported. Three trials involved biliary malignant obstruction, and all three reported metal stent (132 patients) palliation to be superior to plastic stent palliation (136 patients) based on longer patency and lower reintervention costs. Safety and complication differences between stents, however, were inconsistent across trials. In three trials involving esophageal malignant obstruction, metal stent (82 patients) palliation was reported to be superior to plastic stent (41 patients), based on lower complication and reintervention rates, and superior to laser therapy (18 patients), based on better dysphagia relief. Use of metal stents has been reported for obstructed ducts and passageways of most body systems. There is, however, limited controlled trial evidence confirming the advantages of their use over plastic stents or other forms of treatment.

  13. Primary Patency of Wallstents in Malignant Bile Duct Obstruction: Single vs. Two or More Noncoaxial Stents

    SciTech Connect

    Maybody, Majid Brown, Karen T.; Brody, Lynn A.; Covey, Anne M.; Sofocleous, Constantinos T.; Thornton, Raymond H.; Getrajdman, George I.

    2009-07-15

    The purpose of this study was to determine the primary patency of two or more noncoaxial self-expanding metallic Wallstents (Boston Scientific, Natick, MA) and to compare this with the primary patency of a single stent in malignant bile duct obstruction. From August 2002 to August 2004, 127 patients had stents placed for malignant bile duct obstruction. Forty-five patients were treated with more than one noncoaxial self-expanding metallic stents and 82 patients had a single stent placed. Two patients in the multiple-stent group were lost to follow-up. The primary patency period was calculated from the date of stenting until the first poststenting intervention for stent occlusion, death, or the time of last documented follow-up. The patency of a single stent was significantly different from that of multiple stents (P = 0.0004). In the subset of patients with high bile duct obstruction, the patency of a single stent remained significantly different from that of multiple stents (P = 0.02). In the single-stent group, there was no difference in patency between patients with high vs. those with low bile duct obstruction (P = 0.43). The overall median patency for the multistent group and the single-stent group was 201 and 261 days, respectively. In conclusion, the patency of a single stent placed for malignant low or high bile duct obstruction is similar, and significantly longer than, that of multiple stents placed for malignant high bile duct obstruction. Given the median patency of 201 days, when indicated, percutaneous stenting of multiple bile ducts is an effective palliative measure for patients with malignant high bile duct obstruction.

  14. Metallic stents in the management of ureteric strictures

    PubMed Central

    Kulkarni, Ravi

    2014-01-01

    Management of ureteric strictures is a challenging task. Subtle presentation, silent progression and complex aetiology may delay diagnosis. A wide range of available treatment options combined with the lack of adequate randomised trials has led to the introduction of personal bias in the management of this difficult group of patients. Metallic ureteric stents offer an alternative to the conventional treatment modalities. A review of the currently available metallic stents and their role in the long-term management of ureteric strictures is presented. Materials used in the manufacture of indwelling urological devices are evolving all the time. Improved endo-urological techniques combined with new devices made from better compounds will continue to improve patient experience. PMID:24497686

  15. Late Migration of Covered Metal Stent to the Stomach Through a Spontaneous Choledochoduodenal Fistula in a Patient With Malignant Biliary Obstruction.

    PubMed

    Katakura, Yoshiki; Asaki, Tsutoshi; Adachi, Seitaro; Yasuda, Ikuma; Toyomizu, Michifumi; Fukita, Yosho

    2012-06-01

    We report a case in which a spontaneous choledochoduodenal fistula occurred after biliary covered self-expanding metal stent (SEMS) placement and a late transfistula migration of the stent in a patient with malignant distal biliary obstruction. A partially covered WallFlex biliary stent (Boston Scientific) was appropriately implanted in the common bile duct. Subsequently the patient received chemotherapy with gemcitabine. After 7 months of the SEMS insertion, the patient presented with frequent vomiting. Abdominal computed tomography revealed the obstruction of the duodenal descending part and the migrated stent in the stomach. A choledochoduodenal fistula was observed endoscopically at the proximal point of the duodenal obstruction. These findings can cleanly account for the SEMS migration through the fistula. The mechanism of formation of the fistula is mostly associated with a mechanical contact between the bile duct wall and the SEMS edge, which is pushed up in the direction of the duodenum because of the enlargement of the primary tumor, finally penetrating through the duodenal wall. To our knowledge, this is an extreme unusual case, which has been unreported previously. Therefore, we emphasize the necessity of being alert to the potential for such complications in cases involving placement of SEMS for malignant biliary obstruction.

  16. Stent Angioplasty of Closed Mesocaval Shunt in a Patient with Budd-Chiari Syndrome

    SciTech Connect

    Sancak, Tanzer; Karagulle, Ayse Tuba; Bilgic, Sadik; Sanlidilek, Umman; Yerdel, Mehmet Ali

    2002-08-15

    Budd-Chiari syndrome (BCS) is an uncommon disorder caused by hepatic venous outflow obstruction. It is characterized by ascites, hepatomegaly and abdominal pain. Percutaneous intervention shave recently been used for the treatment of BCS. We present a case of BCS with a closed mesocaval shunt which was reopened with a self-expandable metallic stent.

  17. [A case of severe motor and intellectual disability with tracheal stenosis due to granulation caused by metal stents treated successfully by silicone stents].

    PubMed

    Kotani, Haruko; Hino, Hiroyuki; Shiraishi, Taisuke; Ogura, Hideo

    2002-11-01

    A silicone stent (Dumon stent) was used in a severe motor and intellectual disability with severe tracheal stenosis due to granulation caused by an implanted the expanded metal stent (Ultraflex Nitinol Stent). To treat tracheobronchial malacia, diagnosed in infancy, expanded metalic stent was implanted at the ages of 30 and 32 years. However, a few months after the second implantation, progressive dyspnea appeared, and he had to use a respirator under intravenous anesthesia. Bronchoscopy showed re-stenosis of the trachea due to a granulation tissue within the stent. A Dumon stent was applied to control the re-stenosis. He was successfully weaned from a respirator. Since granulation tissue had recurred at the end of the Dumon stent after 3 months, a long term care of the airway and regular observation is necessary after implantation of stents.

  18. A new polymer-free drug-eluting stent with nanocarriers eluting sirolimus from stent-plus-balloon compared with bare-metal stent and with biolimus A9 eluting stent in porcine coronary arteries

    PubMed Central

    Galon, Micheli Z.; Gutierrez, Paulo S.; Sojitra, Prakash; Vyas, Ashwin; Doshi, Manish; Lemos, Pedro A.

    2015-01-01

    Background Permanent polymers in first generation drug-eluting stent (DES) have been imputed to be a possible cause of persistent inflammation, remodeling, malapposition and late stent thrombosis. We aim to describe the in vivo experimental result of a new polymer-free DES eluting sirolimus from stent-plus-balloon (Focus np stent, Envision Scientific) compared with a bare-metal stent (BMS) (Amazonia CroCo, Minvasys) and with a biolimus A9 eluting stent (Biomatrix, Biosensors). Methods In 10 juvenile pigs, 23 coronary stents were implanted in the coronary arteries (8 Amazonia CroCo, 8 Focus np, and 7 Biomatrix). At 28-day follow-up, optical coherence tomography (OCT) and histology were used to evaluate neointimal hyperplasia and healing response. Results According to OCT analysis, Focus np stents had a greater lumen area and less neointimal hyperplasia response than BMS and Biomatrix had. Histomorphometry results showed less neointimal hyperplasia in Focus np than in BMS. Histology showed a higher fibrin deposition in Biomatrix stent compared to Focus np and BMS. Conclusions The new polymer-free DES with sirolimus eluted from stent-plus-balloon demonstrated safety and reduced neointimal proliferation compared with the BMS and Biomatrix stents at 28-day follow-up in this porcine coronary model. This new polymer-free DES is promising and warrants further clinical studies. PMID:25984451

  19. Gastric and Duodenal Stents: Follow-Up and Complications

    SciTech Connect

    Pinto Pabon, Isabel Teresa; Paul Diaz, Laura; Ruiz de Adana, Juan Carlos; Lopez Herrero, Julio

    2001-05-15

    Purpose: To assess the efficacy of self-expanding metallic stents in treating inoperable gastric and duodenal stenoses during follow-up and to evaluate the complications encountered.Methods: A total of 31 patients suffering from gastroduodenal obstruction (29 malignant, 2 benign) were treated with a self-expanding metallic stent (Wallstent). In 24 cases insertion was by the peroral route, in seven cases via gastrostomy.Results: All the strictures were successfully negotiated under fluoroscopic guidance without having to resort to endoscopy. A total of 27 patients (87%) were able to resume a regular diet, a soft diet, or a liquid diet orally. Complications included one case of stent malpositioning, one case of leakage of ascitic fluid through the gastrostomy orifice, one case of perforation and fistula to the biliary tree, and two cases of hematemesis. In two patients (6%) additional stents were implanted to improve patency. In all patients follow-up was maintained until death. Recurrence of symptoms immediately before death occurred in seven cases (23%). Mean survival time of patients was 13.3 weeks (SE {+-} 4.6).Conclusions: The deployment of gastroduodenal stents resulted in good palliation of inoperable gastric and duodenal stenoses. Certain technical aspects, e.g., adaptation of stents to bowel morphology, is critical to proper stent function and avoidance of complications.

  20. Palliative Airway Stenting Performed Under Radiological Guidance and Local Anesthesia

    SciTech Connect

    Profili, Stefano; Manca, Antonio; Feo, Claudio F. Padua, Guglielmo; Ortu, Riccardo; Canalis, Giulio C.; Meloni, Giovanni B.

    2007-02-15

    Purpose. To assess the effectiveness of airway stenting performed exclusively under radiological guidance for the palliation of malignant tracheobronchial strictures. Methods. We report our experience in 16 patients with malignant tracheobronchial stricture treated by insertion of 20 Ultraflex self-expandable metal stents performed under fluoroscopic guidance only. Three patients presented dysphagia grade IV due to esophageal malignant infiltration; they therefore underwent combined airway and esophageal stenting. All the procedures were performed under conscious sedation in the radiological room; average procedure time was around 10 min, but the airway impediment never lasted more than 40 sec. Results. We obtained an overall technical success in 16 cases (100%) and clinical success in 14 patients (88%). All prostheses were successfully placed without procedural complications. Rapid clinical improvement with symptom relief and normalization of respiratory function was obtained in 14 cases. Two patients died within 48 hr from causes unrelated to stent placement. Two cases (13%) of migration were observed; they were successfully treated with another stent. Tumor overgrowth developed in other 2 patients (13%); however, no further treatment was possible because of extensive laryngeal infiltration. Conclusions. Tracheobronchial recanalization with self-expandable metal stents is a safe and effective palliative treatment for malignant strictures. Airway stenting performed exclusively under fluoroscopic view was rapid and well tolerated.

  1. A physical corrosion model for bioabsorbable metal stents.

    PubMed

    Grogan, J A; Leen, S B; McHugh, P E

    2014-05-01

    Absorbable metal stents (AMSs) are an emerging technology in the treatment of heart disease. Computational modelling of AMS performance will facilitate the development of this technology. In this study a physical corrosion model is developed for AMSs based on the finite element method and adaptive meshing. The model addresses a gap between currently available phenomenological corrosion models for AMSs and physical corrosion models that have been developed for more simple geometries than those of a stent. The model developed in this study captures the changing surface of a corroding three-dimensional AMS structure for the case of diffusion-controlled corrosion. Comparisons are made between model predictions and those of previously developed phenomenological corrosion models for AMSs in terms of predicted device geometry and mechanical performance during corrosion. Relationships between alloy solubility and diffusivity in the corrosion environment and device performance during corrosion are also investigated.

  2. Metallic Zinc Exhibits Optimal Biocompatibility for Bioabsorbable Endovascular Stents

    PubMed Central

    Bowen, Patrick K.; Guillory, Roger J.; Shearier, Emily R.; Seitz, Jan-Marten; Drelich, Jaroslaw; Bocks, Martin; Zhao, Feng; Goldman, Jeremy

    2015-01-01

    Although corrosion resistant bare metal stents are considered generally effective, their permanent presence in a diseased artery is an increasingly recognized limitation due to the potential for long-term complications. We previously reported that metallic zinc exhibited an ideal biocorrosion rate within murine aortas, thus raising the possibility of zinc as a candidate base material for endovascular stenting applications. This study was undertaken to further assess the arterial biocompatibility of metallic zinc. Metallic zinc wires were punctured and advanced into the rat abdominal aorta lumen for up to 6.5 months. This study demonstrated that metallic zinc did not provoke responses that often contribute to restenosis. Low cell densities and neointimal tissue thickness, along with tissue regeneration within the corroding implant, point to optimal biocompatibility of corroding zinc. Furthermore, the lack of progression in neointimal tissue thickness over 6.5 months or the presence of smooth muscle cells near the zinc implant suggest that the products of zinc corrosion may suppress the activities of inflammatory and smooth muscle cells. PMID:26249616

  3. Clinical utility of platinum chromium bare-metal stents in coronary heart disease

    PubMed Central

    Jorge, Claudia; Dubois, Christophe

    2015-01-01

    Coronary stents represent a key development for the treatment of obstructive coronary artery disease since the introduction of percutaneous coronary intervention. While drug-eluting stents gained wide acceptance in contemporary percutaneous coronary intervention practice, further developments in bare-metal stents remain crucial for patients who are not candidates for drug-eluting stents, or to improve metallic platforms for drug elution. Initially, stent platforms used biologically inert stainless steel, restricting stent performance due to limitations in flexibility and strut thickness. Later, cobalt chromium stent alloys outperformed steel as the material of choice for stents, allowing latest generation stents to be designed with significantly thinner struts, while maintaining corrosion resistance and radial strength. Most recently, the introduction of the platinum chromium alloy refined stent architecture with thin struts, high radial strength, conformability, and improved radiopacity. This review will provide an overview of the novel platinum chromium bare-metal stent platforms available for coronary intervention. Mechanical properties, clinical utility, and device limitations will be summarized and put into perspective. PMID:26345228

  4. A Novel Method for Insertion of the Straight Metallic Tracheal Stent.

    PubMed

    Prasad, Kuruswamy Thurai; Ram, Babu; Sehgal, Inderpaul Singh; Dhooria, Sahajal; Agarwal, Ritesh

    2016-10-01

    A straight metallic tracheal stent can be inserted either during flexible or rigid bronchoscopy. However, in patients with significant airway obstruction or those requiring tumor debulking, rigid bronchoscopy is the method of choice. A tracheoscope size 12 or larger is generally required for the introduction of the straight metallic tracheal stent. Herein, we describe a novel method that facilitates the introduction of the straight metallic tracheal stent through a size 8.5 tracheoscope by using the introducer tube of the silicone stent applicator. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  5. Treatment of cuff-related tracheal stenosis with a fully covered retrievable expandable metallic stent.

    PubMed

    Chen, G; Wang, Z; Liang, X; Wang, Y; Wang, Y; Wang, Z; Xian, J

    2013-04-01

    To investigate the clinical effectiveness, complications, and optimal duration of use of covered retrievable expandable metallic stents in the management of cuff-related tracheal stenosis. Twenty-one patients with cuff-related tracheal stenosis, Meyer-Cotton grade II (29%) and III (71%), who underwent fluoroscopically guided placement of covered retrievable expandable metallic stents were studied. Sixty-four-section computed tomography (CT) and bronchovideoscopy were performed prior to stent insertion, 1 month after stent insertion, in the case of stent-related complications, and after stent removal. Clinical manifestations, Hugh-Jones classification, and forced expiratory volume in 1 s (FEV1) were used to evaluate respiratory function before and after stent insertion and removal. The diameter of the stricture and FEV1 changes before insertion and after removal were analysed using the paired samples t-test. A p-value of ≤0.05 was considered statistically significant. Twenty-one patients had 27 covered retrievable expandable metallic stents placed. Stents were electively removed from 20 patients. The median duration of stent placement was 5 months (range 4-12 months). One stent was not removed due to mucopolysaccharidosis type II (MPS II or Hunter syndrome) with tracheomalacia. After stent removal, airway dimensions increased and airway occlusion was symptomatically relieved in all patients. CT and bronchovideoscopy showed patent lumens with increased dimensions. Stent-related complications occurred in 19 (91%) patients, including granulation tissue formation (n = 18, 86%), stent migration and stent expectoration (n = 2, 10%), mucus plugging (n = 1, 5%), and halitosis (n = 6, 29%). Some patients experienced multiple complications, which were all managed effectively while the stent was still in place. There was a statistically significant difference in the diameter of the stricture and FEV1 between the time of stent insertion and removal. An improvement in

  6. Novel method of stent insertion for malignant lower rectal obstruction with proximal releasing delivery system (with video).

    PubMed

    Lee, Kee Myung; Lim, Sun Gyo; Shin, Sung Jae; Kim, Jin Hong; Kang, Dae Hwan; Kim, Jae Keun; Hwang, Jae Chul; Kwon, Chang-Il; Cheong, Jae Yeon; Yoo, Byung Moo

    2013-12-01

    Self-expandable metal stents are an alternative to preoperative and palliative colostomy for patients with malignant colorectal obstruction. However, self-expandable metal stent placement is considered unsuitable or contraindicated for patients with malignant lower rectal obstruction within 5 cm of the anal verge because the exposed stent portion can irritate the distal rectum and cause anal pain and a foreign body sensation. To describe our experience with 6 patients with malignant lower rectal obstruction who underwent stent insertion with a proximal releasing delivery system (PRDS). Prospective clinical series outcome study. A tertiary-care referral university hospital. This study involved all patients at our center who had a malignant lower rectal obstruction within 5 cm of the anal verge caused by rectal cancer and bladder cancer. Uncovered stent with the PRDS with endoscopic and fluoroscopic guidance. Technical and clinical success rate, adverse event rate, and stent migration rate. All stents were placed at the expected location. Technical and clinical success rates were 100%. Two patients reported anal pain, which was controlled with analgesics. One case of tumor ingrowth occurred after 5 months and was treated with reinsertion of a stent with the PRDS. After stent insertion, the patients received chemotherapy, chemoradiotherapy, or conservative care. Small number of patients and no comparison group. Further prospective, randomized, controlled trials are needed. Uncovered stent insertion with the PRDS is a feasible, safe, and effective treatment for the patient with malignant lower rectal obstruction within 5 cm from the anal verge. Copyright © 2013. Published by Mosby, Inc.

  7. Biodegradable metals for cardiovascular stents: from clinical concerns to recent Zn - alloys

    PubMed Central

    Bowen, Patrick K.; Shearier, Emily R.; Zhao, Shan; Guillory, Roger J.; Zhao, Feng; Goldman, Jeremy; Drelich, Jaroslaw W.

    2016-01-01

    Metallic stents are commonly used to promote revascularization and maintain patency of plaqued or damaged arteries following balloon angioplasty. To mitigate the long-term side effects associated with corrosion-resistant stents (i.e. chronic inflammation and late stage thrombosis), a new generation of so-called “bioabsorbable” stents is currently being developed. The bioabsorbable coronary stents will corrode and be absorbed by the artery after completing their task as vascular scaffolding. Research spanning the last two decades has focused on biodegradable polymeric, iron-based, and magnesium-based stent materials. The inherent mechanical and surface properties of metals make them more attractive stent material candidates than their polymeric counterparts. Unfortunately, iron produces a voluminous, retained oxide product in the arterial wall, whereas magnesium and its alloys corrode too rapidly. A third class of metallic bioabsorbable materials that are based on zinc has been introduced in the last few years. As summarized in this contribution, this new zinc-based class of materials demonstrates the potential for an absorbable metallic stent with the mechanical and biodegradation characteristics required for optimal stent performance. They appear to be free of flaws that limit the application of iron- and magnesium-based alloys, and polymers. This review compares bioabsorbable materials and summarizes progress towards bioabsorbable stents. It emphasizes on current understanding of physiological and biological benefits of zinc and its biocompatibility. Finally, the review provides an outlook on challenges in designing zinc-based stents of optimal mechanical properties and biodegradation rate. PMID:27094868

  8. Biodegradable Metals for Cardiovascular Stents: from Clinical Concerns to Recent Zn-Alloys.

    PubMed

    Bowen, Patrick K; Shearier, Emily R; Zhao, Shan; Guillory, Roger J; Zhao, Feng; Goldman, Jeremy; Drelich, Jaroslaw W

    2016-05-01

    Metallic stents are used to promote revascularization and maintain patency of plaqued or damaged arteries following balloon angioplasty. To mitigate the long-term side effects associated with corrosion-resistant stents (i.e., chronic inflammation and late stage thrombosis), a new generation of so-called "bioabsorbable" stents is currently being developed. The bioabsorbable coronary stents will corrode and be absorbed by the artery after completing their task as vascular scaffolding. Research spanning the last two decades has focused on biodegradable polymeric, iron-based, and magnesium-based stent materials. The inherent mechanical and surface properties of metals make them more attractive stent material candidates than their polymeric counterparts. A third class of metallic bioabsorbable materials that are based on zinc has been introduced in the last few years. This new zinc-based class of materials demonstrates the potential for an absorbable metallic stent with the mechanical and biodegradation characteristics required for optimal stent performance. This review compares bioabsorbable materials and summarizes progress towards bioabsorbable stents. It emphasizes the current understanding of physiological and biological benefits of zinc and its biocompatibility. Finally, the review provides an outlook on challenges in designing zinc-based stents of optimal mechanical properties and biodegradation rate.

  9. Feasibility of one-step endoscopic metal stenting for distal malignant biliary obstruction.

    PubMed

    Shimizu, Shuya; Naitoh, Itaru; Nakazawa, Takahiro; Hayashi, Kazuki; Miyabe, Katsuyuki; Kondo, Hiromu; Yoshida, Michihiro; Yamashita, Hiroaki; Ohara, Hirotaka; Joh, Takashi

    2014-03-01

    We aimed to clarify the clinical usefulness of one-step self-expandable metal stent (SEMS) placement for distal malignant biliary obstruction by comparing with two-step SEMS placement. We retrospectively compared early complications, bilirubin level decreasing rate, and period of hospitalization between 40 patients with one-step SEMS and 52 patients with two-step SEMS. We also evaluated the complications in patients with two-step SEMS by classifying them into first drainage (ERBD or ENBD) and second drainage (SEMS). The total incidence of early complications was significantly higher in patients with one-step SEMS than the second drainage of two-step SEMS (42.5% [17/40] vs. 13.5% [7/52]; P = 0.004). However, there was no significant difference in the early complications between one-step SEMS and two-step SEMS (total of first and second drainage) (42.5% [17/40] vs. 36.5% [19/52]; P = 0.561). The period required to reach the bilirubin level (<3 mg/dL) after initial drainage was significantly shorter in one-step SEMS than in two-step SEMS (5.7 vs. 10.1 days; P = 0.025). Similar results were observed in the period of hospitalization for patients without chemotherapy (22.2 vs. 37.3 days; P = 0.004). One-step SEMS placement is the alternative option of drainage method for distal malignant biliary obstruction. © 2013 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

  10. Endoscopic Management of Post-Liver Transplantation Biliary Strictures With the Use of Fully Covered Metallic Stents.

    PubMed

    Jiménez-Pérez, M; Melgar Simón, J M; Durán Campos, A; González Grande, R; Rodrigo López, J M; Manteca González, R

    2016-09-01

    The aim of this work was to evaluate the safety and efficacy of a fully covered self-expandable metal stent (FCSEMS) in the treatment of post-liver transplantation biliary strictures. From October 2009 to October 2014, 44 patients with post-liver transplantation biliary stenosis were treated with the use of endoscopic retrograde cholangiography and placement of FCSEMS after informed consent. The FCSEMS was scheduled to remain in situ for 3-6 months. Patients were followed at regular intervals to evaluate for symptoms and liver function tests. Technical success, complications, and patient outcome were analyzed. All of the strictures were anastomotic, 52% having occurred within the 1st year following the transplantation. Placement of the FCSEMS was possible on the 1st attempt in 54% of patients. Stricture resolution at the time of stent removal was seen in 100% of the cases. During an average follow-up of 27.83 ± 18.3 months after stent removal, stenosis recurred in 9 out of 41 patients (21.9%). The average time of recurrence was 11.78 ± 13.3 months. In all of these cases, the recurrence was resolved by means of placement of another FCSEMS. In 4 cases, the recurrence was associated with a migration of the prosthesis, partial in 2 cases and total in 2 cases. Stent migration occurred in a total of 17 of the 41 patients (41.4%), in 13 of the 32 (40.6%) who had no recurrence of stenosis and in 4 of the 9 (44.4%) of those who experienced recurrence. The average numbers of endoscopic retrograde cholangiography studies required per patient were 2.8 in those with no recurrence and 3.3 in those with recurrence. No death was associated with the process. FCSEMS is a safe effective alternative to plastic stents in the treatment of post-transplantation biliary strictures, resulting in a lower risk of complications and better patient acceptance. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Efficacy of Retrievable Metallic Stent with Fixation String for Benign Stricture after Upper Gastrointestinal Surgery

    PubMed Central

    Kim, Jeong-Eun; Lee, Myungsu; Hur, Saebeom; Kim, Minuk; Lee, Sang Hwan; Cho, Soo Buem; Kim, Chan Sun; Han, Joon Koo

    2016-01-01

    Objective To determine the efficacy of retrievable metallic stent with fixation string for benign anastomotic stricture after upper gastrointestinal (UGI) surgery. Materials and Methods From June 2009 to May 2015, a total of 56 retrievable metallic stents with fixation string were placed under fluoroscopy guidance in 42 patients who were diagnosed with benign anastomotic stricture after UGI surgery. Clinical success was defined as achieving normal regular diet (NRD). Results The clinical success rate after the first stent placement was 57.1% (24/42). After repeated stent placement and/or balloon dilation, the clinical success rate was increased to 83.3% (35/42). Six (14.3%) patients required surgical revision to achieve NRD. One (2.4%) patient failed to achieve NRD. Stent migration occurred in 60.7% (34/56) of patients. Successful rate of removing the stent using fixation string and angiocatheter was 94.6% (53/56). Distal migration occurred in 12 stents. Of the 12 stents, 10 (83.3%) were successfully removed whereas 2 could not be removed. No complication occurred regarding distal migration. Conclusion Using retrievable metallic stent with a fixation string is a feasible option for managing early benign anastomotic stricture after UGI surgery. It can reduce complications caused by distal migration of the stent. PMID:27833405

  12. Effective treatment of post-pneumonectomy bronchopleural fistula by conical fully covered self-expandable stent†

    PubMed Central

    Andreetti, Claudio; D'Andrilli, Antonio; Ibrahim, Mohsen; Ciccone, Anna Maria; Maurizi, Giulio; Mattia, Antonio; Venuta, Federico; Rendina, Erino A.

    2012-01-01

    The aim of the study was to assess the feasibility, efficacy and safety of the use of a conical self-expandable stent for the treatment of post-pneumonectomy bronchopleural fistula (PPBPF). Between April 2008 and November 2010, six patients underwent treatment for the PPBPF by the introduction of a tracheobronchial conical fully covered self-expandable nitinol stent with the aim of excluding the bronchial dehiscence from the airflow. We secured the prosthesis to the tracheal mucosa with titanium helical fasteners tacks. Five patients presented with a bronchial fistula larger than 5 mm following right (4) or left (1) pneumonectomy. One patient had an anastomotic dehiscence after right tracheal sleeve pneumonectomy. A chest tube showed the absence of empyema in all cases. Immediate resolution of the bronchial air leak was obtained in all the patients. Permanent closure of the bronchial dehiscence without recurrence was achieved in all the patients at a mean follow-up time of 13 months (range 3–32). The bronchial stent was successfully removed in all patients without sequelae 71–123 days after its implantation. The use of the conical self-expandable Silmet® stent has proved to be an effective, safe and fast method to treat even large PPBPFs. PMID:22268070

  13. Outcomes of Prosthetic Hemodialysis Grafts after Deployment of Bare Metal versus Covered Stents at the Venous Anastomosis

    SciTech Connect

    Kim, Charles Y. Tandberg, Daniel J.; Rosenberg, Michael D.; Miller, Michael J.; Suhocki, Paul V.; Smith, Tony P.

    2012-08-15

    Purpose: To compare postintervention patency rates after deployment of bare metal versus covered stents across the venous anastomosis of prosthetic arteriovenous (AV) grafts. Methods: Review of our procedural database over a 6 year period revealed 377 procedures involving stent deployment in an AV access circuit. After applying strict inclusion criteria, our study group consisted of 61 stent deployments in 58 patients (median age 58 years, 25 men, 33 women) across the venous anastomosis of an upper extremity AV graft circuit that had never been previously stented. Both patent and thrombosed AV access circuits were retrospectively analyzed. Within the bare metal stent group, 20 of 32 AV grafts were thrombosed at initial presentation compared to 18 of 29 AV grafts in the covered stent group. Results: Thirty-two bare metal stents and 29 covered stents were deployed across the venous anastomosis. The 3, 6, and 12 months primary access patency rates for bare metal stents were not significantly different than for covered stents: 50, 41, and 22 % compared to 59, 52, and 29 %, respectively (p = 0.21). The secondary patency rates were also not significantly different: 78, 78, and 68 % for bare metal stents compared to 76, 69, and 61 % for covered stents, respectively (p = 0.85). However, covered stents demonstrated a higher primary stent patency rate than bare metal stents: 100, 85, and 70 % compared to 75, 67, and 49 % at 3, 6, and 12 months (p < 0.01). Conclusion: The primary and secondary access patency rates after deployment of bare metal versus covered stents at the venous anastomosis were not significantly different. However, bare metal stents developed in-stent stenoses significantly sooner.

  14. Metal versus plastic stents for malignant biliary obstruction: an update meta-analysis.

    PubMed

    Hong, Wan-dong; Chen, Xiao-wei; Wu, Wen-Zhi; Zhu, Qi-huai; Chen, Xiang-rong

    2013-11-01

    The data on comparisons of stent patency, re-intervention rate and patient survival between metal and plastic stents in palliation of malignant biliary obstruction have never been pooled. We carry out a meta-analysis to summarise current evidence for clinical efficacy of metal and plastic stents in the treatment of malignant biliary obstruction. A comprehensive search of several databases was conducted. A fixed-effects or random-effects model was used to pool data of all study endpoints. Sensitivity analysis and subgroup analysis (distal vs. hilar biliary obstruction) were also performed. Ten randomized clinical trials were identified. Compared with plastic stents, metal stents were associated with a significantly longer stent patency (HR=0.36; 95% CI: 0.28-0.47; I(2)=0%), fewer numbers of re-intervention (WMD=0.59; 95% CI: 0.28-0.90; I(2)=76.4%) and longer patient survival (HR=0.74; 95% CI: 0.64-0.85; I(2)=16.0%). These results were still significant by sensitivity analysis. All outcomes reached statistical significance except of the pooled WMD of number of re-intervention in the studies with hilar biliary obstruction. No publication bias was observed. Metal stents were associated with a significantly longer stent patency, lower re-intervention rate and longer patient survival in palliation of malignant biliary obstruction when compared to plastic stents. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  15. Response of Balloon-Expandable Endoprosthetic Metallic Stents Subjected to Over-Expansion In Vitro

    SciTech Connect

    Montague, B. J.; Kakimoto, W. M.; Arepally, A.; Razavi, M.; Dake, M. D.; Hofmann, L. V.

    2004-03-15

    We attempted to evaluate the in vitro behavior and performance of balloon-expandable endoprosthetic metallic stents subjected to over-expansion (OE). Seventy-two balloon-expandable endoprosthetic stents, representing 22 models from six manufacturers, were over- expanded in vitro. Stents were initially expanded to their maximum manufacturer- recommended diameter and then over-expanded incrementally to their endpoints. Endpoints for OE were either stent disarticulation or an inability to undergo further expansion despite balloon insufflation to maximum burst pressure. Measurements of stent dimensions were recorded at each overexpanded diameter and comparisons were made to manufacturer's specifications. A total of 288 balloon-driven expansions were performed on 72 stents. Sixteen stents were expanded to large diameters ({>=} 16 mm), 20 stents underwent OE of 50% or greater. One model tended to disarticulate after OE greater than 50%. There were five models that had a tendency to disarticulate after minimal OE. Five models were resistant to OE (25% or less OE) but did not disarticulate. Nearly all stents showed some degree of foreshortening with OE, while 36 stents underwent foreshortening of 30% or more. Models that are not recommended for OE include Intrastent, Intrastent DoubleStrut, NIR Royale and Omniflex. Good candidates for OE include Intrastent DoubleStrut LD, Palmaz large, Medtronic Extra Support Biliary Plus and Medtronic Flexible Biliary. Palmaz XL remains the only model available for expansion from 20 to 28 mm in diameter. For the remaining stents, OE is possible, however, caution should be used.

  16. High single-session success rate of endoscopic bilateral stent-in-stent placement with modified large cell Niti-S stents for malignant hilar biliary obstruction.

    PubMed

    Kogure, Hirofumi; Isayama, Hiroyuki; Nakai, Yousuke; Tsujino, Takeshi; Matsubara, Saburo; Yashima, Yoko; Ito, Yukiko; Hamada, Tsuyoshi; Takahara, Naminatsu; Miyabayashi, Koji; Mizuno, Suguru; Mohri, Dai; Kawakubo, Kazumichi; Sasaki, Takashi; Yamamoto, Natsuyo; Hirano, Kenji; Sasahira, Naoki; Tada, Minoru; Koike, Kazuhiko

    2014-01-01

    Endoscopic bilateral self-expandable metallic stent (SEMS) placement in a stent-in-stent method for malignant hilar biliary obstruction is technically challenging. Technical difficulties in the initial placement and reinterventions for stent occlusion are disadvantages inherent to this stent-in-stent method. We previously reported the feasibility of Niti-S large cell D-type biliary stents (LCD). This multicenter prospective consecutive study evaluated the efficacy of bilateral SEMS placement using modified LCD with large and uniform cells, a slimmer delivery system and high radial force. From July 2010 to June 2011, 26 consecutive patients with unresectable malignant hilar biliary obstruction underwent endoscopic bilateral placement of modified LCD in a stent-in-stent method at three tertiary hospitals. Ten patients had gallbladder cancer, eight had cholangiocarcinoma, four had lymph node metastasis, two had intrahepatic cholangiocarcinoma, and two had liver metastasis. Single-session and final technical success rate was 96% and 100%, respectively. Functional success rate was 89%. Stent occlusion occurred in 11 patients (42%) because of sludge (n = 7) or tumor ingrowth (n = 4). Endoscopic bilateral reintervention was technically easy and successful: six patients had stent clearance by balloon sweeping and five had plastic stent placement. According to Kaplan-Meier analysis, median survival and stent patency were 220 days and 157 days, respectively. Modified LCD achieved a high technical success rate both in the initial stent-in-stent placement and in bilateral reinterventions in patients with malignant hilar biliary obstruction. © 2013 The Authors. Digestive Endoscopy © 2013 Japan Gastroenterological Endoscopy Society.

  17. Aortic neck dilatation and endograft migration are correlated with self-expanding endografts.

    PubMed

    Dalainas, Ilias; Nano, Giovanni; Bianchi, Paolo; Ramponi, Fabio; Casana, Renato; Malacrida, Giovanni; Tealdi, Domenico G

    2007-06-01

    To compare self-expanding and balloon-expandable stent-grafts in terms of aortic neck dilatation and endograft migration. Two-hundred and forty-two patients (178 men; mean age 68 years, range 56-91) underwent elective endovascular repair of abdominal aortic aneurysm. Two-hundred self-expanding (115 Excluder, 48 Endologix, 23 Vanguard, 10 Anaconda, and 4 Talent) and 42 balloon-expandable (Lifepath) endografts were used. All patients underwent contrast-enhanced computed tomography (CT) prior to the intervention, at 1, 3, and 6 months after the procedure, and annually thereafter. Comparison was made between the first and the last follow-up CT scans. Fifty-five (27.5%) of the 200 patients treated with self-expanding endografts had aortic neck dilatation compared to only 3 (7.1%) of the 42 patients treated with balloon-expandable endografts (p = 0.023). Forty-nine (24.5%) patients in the self-expanding group versus only 3 (7.1%) patients of the balloon-expandable group presented with endograft migration (p = 0.034); all had dilated necks. The difference between the means of neck dilatation for the Lifepath balloon-expandable stent-graft and the Excluder self-expanding endoprosthesis was statistically significant (p = 0.011, 95% CI 0.07 to 0.91). Aortic neck dilatation following endovascular AAA repair appears to be correlated with self-expanding endografts, which may contribute to a higher incidence of graft migration compared to that occurring with balloon-expandable endografts.

  18. Infections of intravascular bare metal stents: a case report and review of literature.

    PubMed

    Bosman, W M P F; Borger van der Burg, B L S; Schuttevaer, H M; Thoma, S; Hedeman Joosten, P Ph

    2014-01-01

    The objective of the paper is to present a case of an infected bare metal stent in the left common iliac artery that was removed by an urgent operation, and to review the literature on diagnosis and outcome of infected coronary and non-coronary metal stents. A systematic search of the Medline database was performed with the purpose of identifying risk factors, signs and symptoms, imaging strategies, and treatment modalities of bare metal stent infections, both coronary and peripheral. In total, 76 additional studies/case reports (48 non-coronary; 29 coronary) were included and analyzed. Intravascular bare metal stent infections are a rare but serious complication, often leading to emergency surgery (overall: 75.3%; non-coronary cases: 83.3%; coronary cases: 62.1%). In 25.0% of the non-coronary cases, infection led to amputation of an extremity or removal of viscera. Reported mortality was up to 32.5% of the cases (non-coronary: 22.9%; coronary 48.3%). Physicians should always be suspicious of a stent infection when patients present with aspecific symptoms such as fever and chills after stent placement. Additional imaging can be used to detect the presence of a pseudoaneurysm. A PET-CT is an ideal medium for identification of a stent infection. Intravascular stent infection is associated with a high risk of morbidity and mortality. Surgery is the preferred treatment option, but not always possible, especially in patients with a coronary stent. In selected cases, bare metal stent infections may be prevented by the use of prophylactic antibiotics at stent placement. Copyright © 2013 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

  19. Analysis of risk factors associated with complications of colonic stenting for malignant obstruction.

    PubMed

    Dindar, Gokhan; Ustundag, Yucel; Karakan, Tarkan

    2014-07-21

    Self expanding metalic stent (SEMS) application can cause serious problems up to one third of the patients and some studies reported negative effect of SEMSs on survival in patients with malignancy. The SEMS type especially the rigid one like Wall-stent rather than more flexible type Ultraflex was also reported to have bad impact on the risk of perforation we believe that stent based management protocol for patients with non-perforating left sided obstructing colorectal cancer is a complex method that needs qualified medical and technical team.

  20. Analysis of risk factors associated with complications of colonic stenting for malignant obstruction

    PubMed Central

    Dindar, Gokhan; Ustundag, Yucel; Karakan, Tarkan

    2014-01-01

    Self expanding metalic stent (SEMS) application can cause serious problems up to one third of the patients and some studies reported negative effect of SEMSs on survival in patients with malignancy. The SEMS type especially the rigid one like Wall-stent rather than more flexible type Ultraflex was also reported to have bad impact on the risk of perforation we believe that stent based management protocol for patients with non-perforating left sided obstructing colorectal cancer is a complex method that needs qualified medical and technical team. PMID:25083098

  1. Very Late Stent Thrombosis After Primary Percutaneous Coronary Intervention With Bare-Metal and Drug-Eluting Stents for ST-Segment Elevation Myocardial Infarction

    PubMed Central

    Brodie, Bruce; Pokharel, Yashashwi; Fleishman, Nathan; Bensimhon, Adam; Kissling, Grace; Hansen, Charles; Milks, Sally; Cooper, Michael; McAlhany, Christopher; Stuckey, Tom

    2011-01-01

    Objectives The purpose of this study was to assess the frequency of very late stent thrombosis (VLST) after stenting with bare-metal stents (BMS) and drug-eluting stents (DES) for ST-segment elevation myocardial infarction (STEMI). Background Stent thrombosis occurs more frequently after stenting for STEMI than after elective stenting, but there are little data regarding VLST. Methods Consecutive patients (n = 1,463) who underwent stenting for STEMI were prospectively enrolled in our database. BMS were implanted exclusively from 1995 to 2002, and DES and BMS were implanted from 2003 to 2009. Follow-up was obtained at 1 to 15 years. Results Bare-metal stent patients (n = 1,095) were older and had more shock, whereas DES patients (n = 368) had more diabetes and smaller vessels. Stent thrombosis occurred in 107 patients, of which 42 were VLST (>1 year). Stent thrombosis continued to increase to at least 11 years with BMS and to at least 4.5 years with DES. Stent thrombosis rates with BMS versus DES were similar at 1 year (5.1% and 4.0%, respectively) but increased more with DES after the first year (1.9%/year vs. 0.6%/year, respectively). Landmark analysis (>1 year) found DES had a higher frequency of VLST (p < 0.001) and reinfarction (p = 0.003). Drug-eluting stent was the only significant independent predictor of VLST (hazard ratio: 3.79, 95% confidence interval: 1.64 to 8.79, p = 0.002). Conclusions Very late stent thrombosis after primary PCI for STEMI occurs with relatively high frequency to at least 11 years with BMS and to at least 4.5 years with DES. Very late stent thrombosis and reinfarction (>1 year) were more frequent with DES. New strategies are needed to manage this problem. PMID:21251626

  2. The first use of Resonance® metallic ureteric stent in a case of obstructed transplant kidney

    PubMed Central

    Abdulmajed, Mohamed I.; Jones, Vaughan W.; Shergill, Iqbal S.

    2014-01-01

    INTRODUCTION To date, double JJ stent is the mainstay ureteric stent used in a transplant kidney. We herein report the first use of Resonance® metallic ureteric stent to manage ureteric obstruction in a transplant kidney. PRESENTATION OF CASE A 45-year-old lady underwent an uneventful living related donor renal transplantation. Due to post-operative pelvi-ureteric obstruction and recurrent obstruction following multiple distal stent migration and expulsion necessitated frequent nephrostomy insertion and antegrade stenting, she underwent challenging but successful retrograde insertion of a 12 centimetres long and size 6.0 French Cook Resonance® metallic ureteric stent which was performed under general anaesthesia. DISCUSSION Metallic ureteric stents are a fairly recent introduction to modern urology and they have been successfully used in the management of benign and malignant obstruction of ureter. CONCLUSION This is the first case of therapeutic metallic ureteric stent insertion in a transplant kidney. PMID:24858983

  3. Are “Treatment” Bare Metal Stents Superior to “Control” Bare Metal Stents? A meta-analytic approach

    PubMed Central

    Kent, David M; Trikalinos, Thomas A

    2011-01-01

    Background It has been suggested that the benefits of drug-eluting stents compared to bare metal stents (BMS) have been over-estimated in part because target lesion/vessel revascularization (TLR/TVR) rates in the BMS control group of these trials were spuriously high. Methods We used meta-analytic techniques to systematically compare clinical event rates among patients treated with BMS in trials where BMS were the experimental (BMSexperimental) rather than the control (BMScontrol) intervention. MEDLINE searches were performed to identify eligible randomized trials comparing either drug-eluting stents with BMScontrol, or BMSexperimental with balloon angioplasty in patients with non-acute coronary artery disease. Trial characteristics and 6 to 12 month rates for death, myocardial infarction, TLR/TVR and major adverse cardiac events (MACE) were extracted and assessed. Results Eligible trials yielded 50 BMS cohorts: 19 in the BMScontrol group (4 046 patients) and 31 in the BMSexperimental group (5 068 patients). Summary death and infarction rates did not differ between groups. The summary TLR/TVR rates were 16.2% (95% confidence interval, CI: 13.5, 19.3) versus 13.8% (95% CI: 12.0, 15.7) in BMScontrol versus BMSexperimental groups, respectively (p=0.15). Among 39 BMS cohorts with ≤250 patients, TLR/TVR rates were significantly higher in BMScontrol versus BMSexperimental groups (18.9% [95% CI: 16.0, 22.2] versus 13.7% [95% CI: 11.5, 16.3], p=0.01). There were no between-group differences among larger BMS cohorts (p=0.98). Conclusions While overall clinical event rates did not differ in the BMScontrol and the BMSexperimental groups, a higher rate of TVR/TLR was seen in the BMScontrol group among smaller trials. PMID:18371468

  4. Combined Arterial Infusion and Stent Implantation Compared with Metal Stent Alone in Treatment of Malignant Gastroduodenal Obstruction

    SciTech Connect

    Wang Zhongmin; Chen Kemin; Gong Ju; Zheng Yunfeng; Wang Tianxiang

    2009-09-15

    Many patients with malignant gastroduodenal obstruction have an unresectable primary lesion and distant metastases, which may prompt palliative management to allow the patient to eat and to improve the quality of life. Intraluminal metallic stent implantation (MSI) under fluoroscopic guidance has been reported to be an effective option for symptomatic relief in these patients, with a good safety record. An alternative, dual interventional therapy (DIT), has been used during the last decade, in which prosthesis insertion is followed by intra-arterial chemotherapy via the tumor-feeding arteries. The aim of this study was to compare success rates, complication rates, and survival time between MSI and DIT in patients who presented with gastroduodenal obstruction from advanced upper gastrointestinal tract cancer. All consecutive patients with malignant gastroduodenal obstruction seen at our center between October 2002 and August 2007 were retrospectively studied. Patients were treated palliatively by either MSI or DIT by the patient's or the next of kin's decision. Outcomes included technical and clinical success, complication rates, and survival. Of the 164 patients with malignant gastric and duodenal outlet obstructions, 80 (49%) underwent stent insertion as the primary therapy, while the remaining 84 (51%) received DIT. Clinical characteristics were similar between the two groups. In the MSI cohort initial stent implantation was successful in 73 patients (91%), two stents were used in 5 patients, and delayed additional stent insertion for stent obstruction related to tumor overgrowth was required in 3 patients during follow-up. In the DIT cohort the technical success rate was 94%, 3 patients required two stents, and stent obstruction occurred in 2 patients after initial stent placement. Early postprocedural clinical success, indicated by average dysphagia score, improved significantly in both groups: MSI group, from 4.56 to 1.51 (P < 0.01); and DIT group, from 4

  5. Atherosclerotic plaque behind the stent changes after bare-metal and drug-eluting stent implantation in humans: implications for late stent failure?

    PubMed Central

    Andreou, Ioannis; Takahashi, Saeko; Tsuda, Masaya; Shishido, Koki; Antoniadis, Antonios P.; Papafaklis, Michail I.; Mizuno, Shingo; Coskun, Ahmet U.; Saito, Shigeru; Feldman, Charles L.; Edelman, Elazer R.; Stone, Peter H.

    2016-01-01

    Background and aims The natural history and the role of atherosclerotic plaque located behind the stent (PBS) are still poorly understood. We evaluated the serial changes in PBS following bare-metal (BMS) compared to first-generation drug-eluting stent (DES) implantation and the impact of these changes on in-stent neointimal hyperplasia (NIH). Methods Three-dimensional coronary reconstruction by angiography and intravascular ultrasound was performed after intervention and at 6–10-month follow-up in 157 patients with 188 lesions treated with BMS (n=89) and DES (n=99). Results There was a significant decrease in PBS area (−7.2%; p<0.001) and vessel area (−1.7%; p<0.001) after BMS and a respective increase in both areas after DES implantation (6.1%; p<0.001 and 4.1%; p<0.001, respectively). The decrease in PBS area significantly predicted neointimal area at follow-up after BMS (β: 0.15; 95% confidence interval [CI]: 0.10–0.20, p<0.001) and DES (β: 0.09; 95% CI: 0.07–0.11; p<0.001) implantation. The decrease in PBS area was the most powerful predictor of significant NIH after BMS implantation (odds ratio: 1.13; 95% CI: 1.02–1.26; p=0.02). Conclusions The decrease in PBS area after stent implantation is significantly associated with the magnitude of NIH development at follow-up. This finding raises the possibility of a communication between the lesion within the stent and the underlying native atherosclerotic plaque, and may have important implications regarding the pathobiology of in-stent restenosis and late/very late stent thrombosis. PMID:27494445

  6. Surgical failure after colonic stenting as a bridge to surgery

    PubMed Central

    Kim, Jung Ho; Kwon, Kwang An; Lee, Jong Joon; Lee, Won-Suk; Baek, Jeong-Heum; Kim, Yoon Jae; Chung, Jun-Won; Kim, Kyoung Oh; Park, Dong Kyun; Kim, Ju Hyun

    2014-01-01

    AIM: To identify risk factors for surgical failure after colonic stenting as a bridge to surgery in left-sided malignant colonic obstruction. METHODS: The medical records of patients who underwent stent insertion for malignant colonic obstruction between February 2004 and August 2012 were retrospectively reviewed. Patients with malignant colonic obstruction had overt clinical symptoms and signs of obstruction. Malignant colonic obstruction was diagnosed by computed tomography and colonoscopy. A total of 181 patients underwent stent insertion during the study period; of these, 68 consecutive patients were included in our study when they had undergone stent placement as a bridge to surgery in acute left-sided malignant colonic obstruction due to primary colon cancer. RESULTS: Out of 68 patients, forty-eight (70.6%) were male, and the mean age was 64.9 (range, 38-89) years. The technical and clinical success rates were 97.1% (66/68) and 88.2% (60/68), respectively. Overall, 85.3% (58/68) of patients underwent primary tumor resection and primary anastomosis. Surgically successful preoperative colonic stenting was achieved in 77.9% (53/68). The mean duration, defined as the time between the SEMS attempt and surgery, was 11.3 d (range, 0-26 d). The mean hospital stay after surgery was 12.5 d (range, 6-55 d). On multivariate analysis, the use of multiple self-expanding metal stents (OR = 28.872; 95%CI: 1.939-429.956, P = 0.015) was a significant independent risk factor for surgical failure of preoperative stenting as a bridge to surgery. Morbidity and mortality rates in surgery after stent insertion were 4.4% (3/68) and 1.5% (1/68), respectively. CONCLUSION: The use of multiple self-expanding metal stents appears to be a risk factor for surgical failure. PMID:25206288

  7. New stents for SFA.

    PubMed

    MINAR, E; SCHILLINGER, M

    2009-10-01

    Endovascular stent implantation was introduced to femoropopliteal procedures almost two decades ago. Initial results with balloon-expandable stainless steel stents and self expanding Elgiloy stents, however, were disappointing. In particular, recurrence rates after long-segment femoropopliteal stenting were rather high, in the range of 60% to 80% at 1 year. After years of stagnation, recent developments in femoropopliteal stent technology have been promising. Self-expanding nitinol stents have been evaluated in several prospective studies. Initial problems with stent fractures seem to be resolved using second-generation devices. The second generation of Nitinol stents have an enhanced flexibility particularly also in axial direction due to a reduction of cell interconnections and a more spiral orientation of the interconnections. However, until now there is no proof of any impact of the stent design on restenosis rate. Otherwise, stenting has been shown to be beneficial compared to balloon angioplasty especially in longer femoropopliteal lesions. The superior fracture resistance of the latest stent generation in combination with the production of long nitinol stents of up to 20 cm in length allow that more difficult and complex lesions can be treated endovascularly. The main unresolved problem with femoropopliteal stenting is the treatment of instent restenosis. Future concepts to further improve long-term patency after femoropopliteal stenting are therefore under investigation, including drug-eluting stents (DES), biodegradable stents, and coated stent-grafts. Stent grafts appear to be a viable option for the treatment of complex superficial femoral artery lesions, with comparable outcomes to prosthetic above-knee femoropopliteal bypass surgery. Concerning DES, we have to wait for the results of the ongoing studies.

  8. Ferromagnetic Bare Metal Stent for Endothelial Cell Capture and Retention

    PubMed Central

    Uthamaraj, Susheil; Tefft, Brandon J.; Hlinomaz, Ota; Sandhu, Gurpreet S.; Dragomir-Daescu, Dan

    2015-01-01

    Rapid endothelialization of cardiovascular stents is needed to reduce stent thrombosis and to avoid anti-platelet therapy which can reduce bleeding risk. The feasibility of using magnetic forces to capture and retain endothelial outgrowth cells (EOC) labeled with super paramagnetic iron oxide nanoparticles (SPION) has been shown previously. But this technique requires the development of a mechanically functional stent from a magnetic and biocompatible material followed by in-vitro and in-vivo testing to prove rapid endothelialization. We developed a weakly ferromagnetic stent from 2205 duplex stainless steel using computer aided design (CAD) and its design was further refined using finite element analysis (FEA). The final design of the stent exhibited a principal strain below the fracture limit of the material during mechanical crimping and expansion. One hundred stents were manufactured and a subset of them was used for mechanical testing, retained magnetic field measurements, in-vitro cell capture studies, and in-vivo implantation studies. Ten stents were tested for deployment to verify if they sustained crimping and expansion cycle without failure. Another 10 stents were magnetized using a strong neodymium magnet and their retained magnetic field was measured. The stents showed that the retained magnetism was sufficient to capture SPION-labeled EOC in our in-vitro studies. SPION-labeled EOC capture and retention was verified in large animal models by implanting 1 magnetized stent and 1 non-magnetized control stent in each of 4 pigs. The stented arteries were explanted after 7 days and analyzed histologically. The weakly magnetic stents developed in this study were capable of attracting and retaining SPION-labeled endothelial cells which can promote rapid healing. PMID:26436434

  9. Prophylactic stenting for esophageal stricture prevention after endoscopic submucosal dissection

    PubMed Central

    Shi, Ke-Da; Ji, Feng

    2017-01-01

    Endoscopic submucosal dissection (ESD) of superficial esophageal cancer has been increasingly used as an alternative to surgery because it is minimally invasive and has a high rate of en bloc resection. However, a high rate of esophageal stricture is observed after ESD for large lesions, which can dramatically decrease the patient’s quality of life. Stricture prevention is necessary to allow for endoscopic therapy to expand. We, herein, review the most recent evidence and discuss the role of the metallic self-expandable stent and the biodegradable stent in esophageal stricture prevention. Limited studies suggested that prophylactic stenting could reduce the stricture rate without increasing the number of complications. In addition, the number of bougie dilation procedures was significantly lower with stent placement. Esophageal stenting is a promising option for post-ESD stricture prevention. However, current evidence is too preliminary to formulate practice standards. Future studies are needed to further validate the efficacy and safety of prophylactic stenting and determine the best strategy for stricture prevention. Stent migration is the most common complication. A new stent that has advantages of a low migration rate and minimal tissue reaction will need to be developed. Therefore, randomized controlled trials with long-term follow-up periods are required before prophylactic stenting could be considered a valid option to prevent post-ESD stricture. PMID:28246466

  10. Transapical implantation of a novel self-expanding sutureless aortic valve prosthesis.

    PubMed

    Stalder, Mario; Suri, Rakesh M; Kraehenbuehl, Eva S; Hellige, Gerrit; Wenaweser, Peter; Zobrist, Claudia; Schaff, Harzell V; Carrel, Thierry P

    2010-03-01

    To date, transapical aortic valve implantation has required a balloon-expandable stented valve prosthesis. More recently, a novel self-expanding sutureless stented bovine pericardial prosthesis has been developed which allows rapid aortic valve replacement via an open transaortic approach in humans. The aim of this animal study was to develop a reliable protocol to facilitate the transapical implantation of this self-expanding valve in a porcine model. Off-pump transapical aortic valve implantation was performed through a left mini-thoracotomy using a bovine pericardial valve mounted on a self-expandable nitinol stent of size 21 mm and 23 mm in 11 pigs (average weight 60 kg). The crimped valve was introduced through the left ventricular apex using a fle