Removable self-expanding metal stents insertion for the treatment of perforations and postoperative leaks of the esophagus.

PubMed

Nasa, Mukesh; Sharma, Zubin Dev; Choudhary, Narendra S; Puri, Rajesh; Sud, Randhir

2016-03-01

Esophageal rupture, spontaneous or iatrogenic, is associated with significant morbidity and mortality. The current study aims at highlighting the various clinical scenarios, where esophageal fully covered self-expanding removable metal stents (FCSEMS) can be used in esophageal rupture. In patients who underwent insertion of FCSEMS between January 2013 and June 2014, all data regarding demographics, indications, insertion, removal, and outcomes were studied retrospectively. Seven patients underwent the placement of esophageal covered SEMS. Two patients had Boerhaave syndrome, two had leak following the repair of aortic aneurysm, one had extensive esophageal injury following transesophageal echocardiography, one had carcinoma esophagus with tracheaesophageal fistula, and one had dehiscence of esophagogastric anastomosis. Stent insertion was successful in all the patients; one had stent migration which was managed endoscopically. Two patients died due to underlying illness; the rest had successful removal of stents after 8-10 weeks and good outcomes. Esophageal FCSEMS placement is safe and effective modality in management of patients with esophageal rupture.

Pancreatic stents for the prevention of post-endoscopic retrograde cholangiopancreatography pancreatitis should be inserted up to the pancreatic body or tail.

PubMed

Sugimoto, Mitsuru; Takagi, Tadayuki; Suzuki, Rei; Konno, Naoki; Asama, Hiroyuki; Sato, Yuki; Irie, Hiroki; Watanabe, Ko; Nakamura, Jun; Kikuchi, Hitomi; Waragai, Yuichi; Takasumi, Mika; Hikichi, Takuto; Ohira, Hiromasa

2018-06-14

To investigate the location to which a pancreatic stent should be inserted to prevent post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP). Over a ten-year period at our hospital, 296 patients underwent their first ERCP procedure and had a pancreatic stent inserted; this study included 147 patients who had ERCP performed primarily for biliary investigation and had a pancreatic stent inserted to prevent PEP. We divided these patients into two groups: 131 patients with a stent inserted into the pancreatic head (head group) and 16 patients with a stent inserted up to the pancreatic body or tail (body/tail group). Patient characteristics and ERCP factors were compared between the groups. Pancreatic amylase isoenzyme (p-AMY) levels in the head group were significantly higher than those in the body/tail group [138.5 (7.0-2086) vs 78.5 (5.0-1266.5), P = 0.03] [median (range)]. No cases of PEP were detected in the body/tail group [head group, 12 (9.2%)]. Of the risk factors for post-ERCP hyperamylasemia (≥ p-AMY median, 131 IU/L), procedure time ≥ 60 min [odds ratio (OR) 2.65, 95%CI: 1.17-6.02, P = 0.02) and stent insertion into the pancreatic head (OR 3.80, 95%CI: 1.12-12.9, P = 0.03) were identified as independent risk factors by multivariate analysis. Stent insertion up to the pancreatic body or tail reduces the risk of post-ERCP hyperamylasemia and may reduce the risk of PEP.

'Stent in a stent'--an alternative technique for removing partially covered stents following sleeve gastrectomy complications.

PubMed

Vasilikostas, Georgios; Sanmugalingam, Nimalan; Khan, Omar; Reddy, Marcus; Groves, Chris; Wan, Andrew

2014-03-01

Endoscopic stenting is a relatively new technique for the treatment of post sleeve gastrectomy complications. Partially covered stents are used in this method to minimise the risk of migration but they are associated with difficulties with removal. Patients requiring emergency stenting following sleeve gastrectomy underwent insertion of a partially covered metallic stent. One month later, if the stent was not easily removable, a fully covered overlapping stent was inserted and the patient was readmitted 2 weeks later for removal of both stents. Four patients required stenting following sleeve gastrectomy leaks, and one patient required stenting for a stricture. In these cases, a 'stent in a stent' technique was used for removal. This technique allows the safe removal of partially covered stents inserted following sleeve gastrectomy complications.

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

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

PubMed

Jung, Kyoungwon; Ahn, Ji Yong; Jung, Hwoon-Yong; Cho, Charles J; Na, Hee Kyong; Jung, Kee Wook; Lee, Jeong Hoon; Kim, Do Hoon; Choi, Kee Don; Song, Ho June; Lee, Gin Hyug; Kim, Jin-Ho

2016-09-01

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

Late-onset severe biliary bleeding after endoscopic pigtail plastic stent insertion.

PubMed

Yasuda, Muneji; Sato, Hideki; Koyama, Yuki; Sakakida, Tomoki; Kawakami, Takumi; Nishimura, Takeshi; Fujii, Hideki; Nakatsugawa, Yoshikazu; Yamada, Shinya; Tomatsuri, Naoya; Okuyama, Yusuke; Kimura, Hiroyuki; Ito, Takaaki; Morishita, Hiroyuki; Yoshida, Norimasa

2017-01-28

Here, we report our experience with a case of severe biliary bleeding due to a hepatic arterial pseudoaneurysm that had developed 1 year after endoscopic biliary plastic stent insertion. The patient, a 78-year-old woman, presented with hematemesis and obstructive jaundice. Ruptured hepatic arterial pseudoaneurysm was diagnosed, which was suspected to have been caused by long-term placement of an endoscopic retrograde biliary drainage (ERBD) stent. This episode of biliary bleeding was successfully treated by transarterial embolization (TAE). Pseudoaneurysm leading to hemobilia is a rare but potentially fatal complication in patients with long-term placement of ERBD. TAE is a minimally invasive procedure that offers effective treatment for biliary bleeding.

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

The insertion of self expanding metal stents with flexible bronchoscopy under sedation for malignant tracheobronchial stenosis: a single-center retrospective analysis.

PubMed

McGrath, Emmet E; Warriner, David; Anderson, Paul

2012-02-01

To describe a 10-year experience of inserting Ultraflex™ self-expanding metal stents (SEMS) under sedation using flexible bronchoscopy for the treatment of malignant tracheobronchial stenosis in a tertiary referral centre. Medical notes were retrospectively reviewed for all patients who underwent SEMS insertion between 1999 and 2009. A data analysis of 68 patients who had Ultraflex™ SEMS inserted under sedation was completed. Thirty three males and 35 females with a mean age of 67.9 years (range 35-94) presented with features including dyspnea/respiratory distress (39 patients), stridor (16 patients) and hemoptysis/dyspnea (13 patients). Etiology of stenosis included lung cancer (46 patients) esophageal cancer (14 patients) and other malignancies (8 patients). Mean dose of midazolam administered was 5mg (range 0-10mg). The trachea was the most common site of stent insertion followed by the right and left main bronchus, respectively. Adjuvant laser therapy was applied at some stage in 31% of all cases, and chemotherapy and/or radiotherapy was administered to at least 64% of patients with malignant disease. Hemoptysis and stent migration were the most frequent complications (5 and 4 patients, respectively). The mean survival time of stented non-small cell lung cancer (NSCLC) patients was 214 days (range 5-1233) and that of esophageal malignancy was 70 days (range 12-249). Mean pack-year history of individuals with lung cancer requiring stent insertion was 37 (range 2-100). Ultraflex stents offer a safe and effective therapy for patients who are inoperable or unresectable that otherwise would have no alternative therapy. It has an immediate beneficial effect upon patients, not only through symptom relief but, in some, through prolongation of life. Survival data is no worse than other studies using different varieties of stents and insertion techniques indicating its longer-term efficacy. Moreover, this report highlights the feasibility of performing this procedure

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

Treatment of Biliary Stricture After Live Donor Liver Transplantation With Combined Metal and Plastic Stent Insertion: A Feasibility and Safety Study.

PubMed

Parlak, Erkan; Koksal, Aydin Seref; Eminler, Ahmet Tarik; Toka, Bilal; Uslan, Mustafa Ihsan

2017-08-01

Fully covered self-expandable metal stents (Fc-SEMSs) have a challenging use in the treatment of anastomosis strictures after live donor liver transplantation (LDLT) because they can occlude secondary branch biliary ducts when placed above the biliary bifurcation. In this study, we evaluated the technical feasibility and safety of combining Fc-SEMSs with plastic stent(s) inserted to the secondary branch biliary ducts for the treatment of anastomosis stricture after LDLT. The study group included 22 patients (12 men, aged 51±11 years) with anastomotic biliary stricture after LDLT. A Fc-SEMS, 8 to 10 mm in diameter, was inserted to the straight, dilated main duct and plastic stent(s) were inserted to the secondary branches to avoid their occlusion. Stents were left in place for 2 months and removed with a stent retrieving forceps. Technical feasibilities, including technical success, successful removal, and adverse events of this novel strategy, were evaluated. Fc-SEMSs were successfuly deployed and removed in all of the cases. Three (13.6%) patients had pain requiring intravenous analgesia and Fc-SEMS had to be removed because of unbearable pain in one of them. Three (13.6%) patients developed cholangitis due to occlusion of unrecognized secondary branch biliary ducts. Primary stricture resolution rate was achieved in 17 (89.5%) of 19 patients. Recurrence was observed in 3 (17.6%) patients after a mean follow-up duration of 154.3±52.6 (range, 104-304) days. Combination of Fc-SEMS and plastic stent(s) is technically feasible and safe for the treatment of anastomotic biliary strictures after LDLT.

Symptomatic stent cast.

PubMed

Keohane, John; Moore, Michael; O'Mahony, Seamus; Crosbie, Orla

2008-02-01

Biliary stent occlusion is a major complication of endoscopic stent insertion and results in repeat procedures. Various theories as to the etiology have been proposed, the most frequently studied is the attachment of gram negative bacteria within the stent. Several studies have shown prolongation of stent patency with antibiotic prophylaxis. We report the case of stent occlusion from a cast of a previously inserted straight biliary stent; a "stent cast" in an 86-year-old woman with obstructive jaundice. This was retrieved with the lithotrypter and she made an uneventful recovery. This is the first reported case of a biliary stent cast.

Metallic ureteral stents in malignant ureteral obstruction: clinical factors predicting stent failure.

PubMed

Chow, Po-Ming; Hsu, Jui-Shan; Huang, Chao-Yuan; Wang, Shuo-Meng; Lee, Yuan-Ju; Huang, Kuo-How; Yu, Hong-Jheng; Pu, Yeong-Shiau; Liang, Po-Chin

2014-06-01

To provide clinical outcomes of the Resonance metallic ureteral stent in patients with malignant ureteral obstruction, as well as clinical factors predicting stent failure. Cancer patients who have received Resonance stents from July 2009 to March 2012 for ureteral obstruction were included for chart review. Stent failure was detected by clinical symptoms, image studies, and renal function tests. Survival analysis for stent duration was used to estimate patency rate and factors predicting stent failure. A total of 117 stents were inserted successfully into 94 ureteral units in 79 patients. There were no major complications. These stents underwent survival analysis and proportional hazard regression. The median duration for the stents was 5.77 months. In multivariate analysis, age (P=0.043), preoperative serum creatinine level (P=0.0174), and cancer type (P=0.0494) were significant factors associated with stent failure. Cancer treatment before and after stent insertion had no effect on stent duration. Resonance stents are effective and safe in relieving malignant ureteral obstructions. Old age and high serum creatinine level are predictors for stent failure. Stents in patients with lower gastrointestinal cancers have longer functional duration.

[The Predictive Factors of Stent Failure in the Treatment of Malignant Extrinsc Ureteral Obstruction Using Internal Ureteral Stents].

PubMed

Matsuura, Hiroshi; Arase, Shigeki; Hori, Yasuhide; Tochigi, Hiromi

2017-12-01

In this study, we retrospectively reviewed the experiences at our single institute in the treatment of malignant extrinsic ureteral obstruction (MUO) using ureteral stents to investigate the clinical outcomes and the predictive factors of stent failure. In 52 ureters of 38 patients who had radiologically significant hydronephrosis due to MUO, internal ureteral stents (The BARD(R) INLAY(TM) ureteral stent set) were inserted. The median follow-up interval after the initial stent insertion was 124.5 days (4-1,120). Stent failure occurred in 8 ureters (15.4%) of the 7 patients. The median interval from the first stent insertion to stent failure was 88 days (1-468). A Cox regression multivariate analysis showed that the significant predictors of stent failure were bladder invasion. Based on the possibility of stent failure, the adaptation of the internal ureteral stent placement should be considered especially in a patient with MUO combined with bladder invasion.

The forgotten ureteric JJ stent and its prevention: a prospective audit of the value of a ureteric stent logbook.

PubMed

Thomas, A Z; Casey, R G; Grainger, R; McDermott, T; Flynn, R; Thornhill, J A

2007-01-01

Temporary ureteric stent insertion is an integral part of modern endo-urological practice. Delayed stent removal or forgotten stents are associated with increased patient morbidity and complications which are often difficult to manage. We prospectively audited our ureteric stent insertion and removal logbook system to determine the value and effectiveness of our stent follow-up. Over a 1-year period, 210 ureteric stents were inserted in our urological unit. Of these, 47 (22.4%) patients were unaccounted as having their stents removed within the stent logbooks. One patient was lost to follow-up and re-presented with stent encrustation 10 months later. Our results in this audit suggest that our system of ureteric stent follow-up is not effective. We have now introduced a new system that we feel is a safer and a satisfactory alternative to the stent logbooks. This includes a patient education leaflet and removal date scheduling prior to discharge from hospital.

Antegrade Ureteral Stenting is a Good Alternative for the Retrograde Approach

PubMed Central

van der Meer, Rutger W.; Weltings, Saskia; van Erkel, Arian R.; Roshani, Hossain; Elzevier, Henk W.; van Dijk, Lukas C.; van Overhagen, Hans

2017-01-01

Background/Aims Double J (JJ) stents for treating obstructive ureteral pathology are generally inserted through a retrograde route with cystoscopic guidance. Antegrade percutaneous insertion using fluoroscopy can be performed alternatively but is less known. Indications, success rate and complications of antegrade ureteral stenting were evaluated. Methods Data of consecutive patients in which antegrade ureteral stenting was performed were retrospectively analysed using the radiology information system and patient records. Patient characteristics, details of the antegrade JJ stent insertion procedure and registered complications were collected. Furthermore, it was investigated if prior to the antegrade procedure a retrograde attempt for JJ stent insertion was performed. Results Total 130 attempts for antegrade JJ stent insertion were performed in 100 patients. A percutaneous nephrostomy catheter had already been placed in the majority of kidneys (n = 109) for initial treatment of hydronephrosis. Most prevelant indication for a JJ stent was obstructive ureteral pathology due to malignancy (n = 63). A JJ stent was successfully inserted in 125 of 130 procedures. In 21 cases, previous retrograde ureteral stenting had failed but, subsequent antegrade ureteral stenting was successful. There were 8 procedure related complications; 6 infections, 1 false tract and 1 malposition. Conclusion Antegrade percutaneous insertion of a JJ stent is a good alternative for retrograde insertion. PMID:28785193

Antegrade Ureteral Stenting is a Good Alternative for the Retrograde Approach.

PubMed

van der Meer, Rutger W; Weltings, Saskia; van Erkel, Arian R; Roshani, Hossain; Elzevier, Henk W; van Dijk, Lukas C; van Overhagen, Hans

2017-07-01

Double J (JJ) stents for treating obstructive ureteral pathology are generally inserted through a retrograde route with cystoscopic guidance. Antegrade percutaneous insertion using fluoroscopy can be performed alternatively but is less known. Indications, success rate and complications of antegrade ureteral stenting were evaluated. Data of consecutive patients in which antegrade ureteral stenting was performed were retrospectively analysed using the radiology information system and patient records. Patient characteristics, details of the antegrade JJ stent insertion procedure and registered complications were collected. Furthermore, it was investigated if prior to the antegrade procedure a retrograde attempt for JJ stent insertion was performed. Total 130 attempts for antegrade JJ stent insertion were performed in 100 patients. A percutaneous nephrostomy catheter had already been placed in the majority of kidneys (n = 109) for initial treatment of hydronephrosis. Most prevelant indication for a JJ stent was obstructive ureteral pathology due to malignancy (n = 63). A JJ stent was successfully inserted in 125 of 130 procedures. In 21 cases, previous retrograde ureteral stenting had failed but, subsequent antegrade ureteral stenting was successful. There were 8 procedure related complications; 6 infections, 1 false tract and 1 malposition. Antegrade percutaneous insertion of a JJ stent is a good alternative for retrograde insertion.

A systematic review of biodegradable biliary stents: promising biocompatibility without stent removal.

PubMed

Siiki, Antti; Sand, Juhani; Laukkarinen, Johanna

2018-05-18

Biodegradable self-expanding stents are an emerging alternative to standard biliary stents as the development of endoscopic insertion devices advances. The aim was to systematically review the existing literature on biodegradable biliary stents. In-vivo studies on the use of biodegradable stents in the biliary duct were systematically reviewed from 1990 to 2017. Despite extensive research on the biocompatibility of stents, the experience so far on their clinical use is limited. A few favorable reports have recently been presented on endoscopically and percutaneously inserted self-expanding biodegradable polydioxanone stents in benign biliary strictures. Another potential indication appears to be postcholecystectomy leak of the cystic duct. The main benefit of biodegradable stents is that stent removal can be avoided. The biocompatibility of the current biodegradable stent materials, most prominently polydioxanone, is well documented. In the few studies currently available, biodegradable stents are reported to be feasible and safe, also in humans. The initial results of the endoscopic use of these stents in benign biliary stricture management and for treating postcholecystectomy bile leaks are promising. Further controlled studies on long-term clinical results and cost-effectiveness are needed.

Preliminary study for a newly designed silicone stent and delivery system for canine obstructive tracheal disease.

PubMed

Kim, Dae-Hyun; Choi, Chi-Bong; Chung, Wook-Hun; Lee, Sung-Ho; Lee, A-Jin; Jeong, Jae-Seung; Kim, Ho-Joong; Kim, Hwi-Yool

2012-10-01

The goal of this study was to prove the possibility of using silicone stents broadly used for human medicine in canine obstructive tracheal disease. A silicone stent anatomically designed for canine trachea was tested on 5 beagle dogs for 8 weeks. The stent was carefully inserted using a newly developed delivery device under fluoroscopic guidance. There were no technical difficulties in placing the stent during the procedure. Previously reported complications of airway stenting such as stent migration or granulation tissue formation did not occur in any of the cases. In addition, removal of the stent was as simple as inserting it, and complications were absent. The stent introduced in this study could possibly be applied to various canine obstructive tracheal diseases.

Complications and management of forgotten long-term biliary stents.

PubMed

Sohn, Se Hoon; Park, Jae Hyun; Kim, Kook Hyun; Kim, Tae Nyeun

2017-01-28

To evaluate complications and management outcomes of retained long-term plastic biliary stents. Endoscopic plastic biliary stent placement was performed in 802 patients at Yeungnam University Hospital between January 2000 and December 2014. Follow-up loss with a subsequently forgotten stent for more than 12 mo occurred in 38 patients. We retrospectively examined the cause of biliary stent insertion, status of stents, complications associated with biliary stents and management outcomes of long-term plastic biliary stents. Continuous variables were analyzed using the t test. Observed frequencies in subsets of the study population were compared using Fisher's exact test and χ 2 tests. Statistical significance was defined as P < 0.05 (two-tailed). Mean age of patients was 73.7 ± 12 years and male-to-female ratio was 2.2:1. Indications of plastic biliary stent insertion were bile duct stones (63.2%, 24/38) and benign bile duct stricture (52.6%, 20/38). Mean duration of retained plastic stent was 22.6 ± 12.2 mo, and in 10 cases (26.3%), stents were retained for more than 24 mo. Common bile duct (CBD) stones or sludge were found in most cases (92.1%, 35/38). The most common complication was acute cholangitis (94.7%, 36/38). Stent removal by endoscopic approach was successfully performed in 92.1% (35/38) of the cases. In 3 cases, an additional plastic stent was inserted alongside the previous stent due to failure of the stent removal. Endoscopic removal of bile duct stones was successful in 73.7% (28/38) of the cases. When patients were divided into two groups by duration of stent placement (12 to 24 mo vs over 24 mo), there were no differences in the development of cholangitis, presence of biliary stones, and success rate of endoscopic removal of stones and biliary stents. The most common complication of retained long-term plastic biliary stents was acute cholangitis associated with CBD stones. Endoscopic management was successfully performed in most cases.

Complications and management of forgotten long-term biliary stents

PubMed Central

Sohn, Se Hoon; Park, Jae Hyun; Kim, Kook Hyun; Kim, Tae Nyeun

2017-01-01

AIM To evaluate complications and management outcomes of retained long-term plastic biliary stents. METHODS Endoscopic plastic biliary stent placement was performed in 802 patients at Yeungnam University Hospital between January 2000 and December 2014. Follow-up loss with a subsequently forgotten stent for more than 12 mo occurred in 38 patients. We retrospectively examined the cause of biliary stent insertion, status of stents, complications associated with biliary stents and management outcomes of long-term plastic biliary stents. Continuous variables were analyzed using the t test. Observed frequencies in subsets of the study population were compared using Fisher’s exact test and χ2 tests. Statistical significance was defined as P < 0.05 (two-tailed). RESULTS Mean age of patients was 73.7 ± 12 years and male-to-female ratio was 2.2:1. Indications of plastic biliary stent insertion were bile duct stones (63.2%, 24/38) and benign bile duct stricture (52.6%, 20/38). Mean duration of retained plastic stent was 22.6 ± 12.2 mo, and in 10 cases (26.3%), stents were retained for more than 24 mo. Common bile duct (CBD) stones or sludge were found in most cases (92.1%, 35/38). The most common complication was acute cholangitis (94.7%, 36/38). Stent removal by endoscopic approach was successfully performed in 92.1% (35/38) of the cases. In 3 cases, an additional plastic stent was inserted alongside the previous stent due to failure of the stent removal. Endoscopic removal of bile duct stones was successful in 73.7% (28/38) of the cases. When patients were divided into two groups by duration of stent placement (12 to 24 mo vs over 24 mo), there were no differences in the development of cholangitis, presence of biliary stones, and success rate of endoscopic removal of stones and biliary stents. CONCLUSION The most common complication of retained long-term plastic biliary stents was acute cholangitis associated with CBD stones. Endoscopic management was successfully

Forgotten/retained double J ureteric stents: A source of severe morbidity in children

PubMed Central

Nerli, Rajendra B.; Magdum, Prasad V.; Sharma, Vikas; Guntaka, Ajay Kumar; Hiremath, Murigendra B.; Ghagane, Shridhar

2016-01-01

Background: The increase in the usage of double J (DJ) ureteral stents in the management of a variety of urinary tract disease processes mandates familiarity with these devices, their consequences and their potential complications, which at times can be devastating. We retrospectively reviewed our series of children with forgotten/retained DJ ureteric stents. Materials and Methods: Hospital records of all patients’ <18 years old who underwent removal of forgotten/retained DJ ureteral stent at our hospital were reviewed for age, gender, indication for insertion of DJ stent, duration of stent insertion, radiological images and surgical procedures performed. Results: During the study period, January 2000 to December 2014 (a 15-year period), a total of 14 children underwent removal of forgotten/retained DJ ureteral stent. A combination of extracorporeal shock wave lithotripsy, cystolitholapaxy and percutaneous nephrolithotomy was done to free the DJ stent and extract it. Conclusions: Forgotten/retained stents in children are a source of severe morbidity, additional/unnecessary hospitalisation and definitely financial strain. PMID:27251521

Ureteric stent dwelling time: a risk factor for post-ureteroscopy sepsis.

PubMed

Nevo, Amihay; Mano, Roy; Baniel, Jack; Lifshitz, David A

2017-07-01

To evaluate the association between stent dwelling time and sepsis after ureteroscopy, and identify risk factors for sepsis in this setting. The prospectively collected database of a single institution was queried for all patients who underwent ureteroscopy for stone extraction between 2010 and 2016. Demographic, clinical, preoperative and operative data were collected. The primary study endpoint was sepsis within 48 h of ureteroscopy. Logistic regressions were performed to identify predictors of post-ureteroscopy sepsis in the ureteroscopy cohort and specifically in patients with prior stent insertion. Between October 2010 and April 2016, 1 256 patients underwent ureteroscopy for stone extraction. Risk factors for sepsis included prior stent placement, female gender and Charlson comorbidity index. A total of 601 patients had a ureteric stent inserted before the operation and were included in the study cohort, in which the median age was 56 years, 90 patients were women (30%), and 97 patients were treated for positive preoperative urine cultures (16.1%). Postoperative sepsis, <48 h after surgery, occurred in eight (1.2%) non-stented patients and in 28 patients (4.7%) with prior stent insertion. Sepsis rates after stent dwelling times of 1, 2, 3 and >3 months were 1, 4.9, 5.5 and 9.2%, respectively. On multivariate analysis, stent dwelling time, stent insertion because of sepsis, and female gender were significantly associated with post-ureteroscopy sepsis in patients with prior stent placement. Patients who undergo ureteroscopy after ureteric stent insertion have a higher risk of postoperative sepsis. Prolonged stent dwelling time, sepsis as an indication for stent insertion, and female gender are independent risk factors. Stent placement should be considered cautiously, and if inserted, ureteroscopy should be performed within 1 month. © 2017 The Authors BJU International © 2017 BJU International Published by John Wiley & Sons Ltd.

Expandable stents.

PubMed

Nesbitt, J C; Carrasco, H

1996-05-01

Expandable metallic stents are effective in selected patients with malignant or benign airway stenoses. When used for malignant lesions, the primary purpose of the stent is to improve the quality of life; stents are usually chosen for palliation of symptoms in recognition of the low likelihood of success for other therapy. For patients with benign stenoses, the stents provide a permanent source of structural support to alleviate the narrowed segment. The advantages of the expandable metallic stents are as follows: (1) they can be inserted through an endotracheal tube or under local anesthesia with relative simplicity under fluoroscopic guidance; (2) they do not impair the drainage of sputum because ciliary movement is not interrupted; (3) over a period of a few weeks, the meshwork is gradually covered with mucosa as the stent becomes incorporated into the airway wall; (4) ventilation usually is not impaired if the metallic mesh stent covers another nonstenosed bronchus, because the interstices of the stent are nonobstructive; and (5) they are dynamic and continue to expand over time, particularly if concurrent treatment achieves an effect on the lesion that caused stenosis. Disadvantages of the expandable stent include (1) they often are only temporarily effective for tracheobronchial stenosis due to intraluminal tumor or granulation tissue, both of which can grow between the wires; (2) they are considered permanent stents because removal is difficult; and (3) they can be poorly positioned during placement or can become displaced by progressive migration after placement, and they cannot be repositioned. A relative contraindication to insertion is an inflammatory process or infection that can predispose to granulation formation, particularly at the points of maximal contact pressure of the stent to the airway mucosa. In the presence of inflammation, it may be better to use a silicone prosthesis until the inflammatory process subsides and fibrosis occurs. Granulation

Semi-Automatic Electronic Stent Register: a novel approach to preventing ureteric stents lost to follow up.

PubMed

Macneil, James W H; Michail, Peter; Patel, Manish I; Ashbourne, Julie; Bariol, Simon V; Ende, David A; Hossack, Tania A; Lau, Howard; Wang, Audrey C; Brooks, Andrew J

2017-10-01

Ureteric stents are indispensable tools in modern urology; however, the risk of them not being followed-up once inserted poses medical and medico-legal risks. Stent registers are a common solution to mitigate this risk; however, manual registers are logistically challenging, especially for busy units. Western Sydney Local Health District developed a novel Semi-Automatic Electronic Stent Register (SAESR) utilizing billing information to track stent insertions. To determine the utility of this system, an audit was conducted comparing the 6 months before the introduction of the register to the first 6 months of the register. In the first 6 months of the register, 457 stents were inserted. At the time of writing, two of these are severely delayed for removal, representing a rate of 0.4%. In the 6 months immediately preceding the introduction of the register, 497 stents were inserted, and six were either missed completely or severely delayed in their removal, representing a rate of 1.2%. A non-inferiority analysis found this to be no worse than the results achieved before the introduction of the register. The SAESR allowed us to improve upon our better than expected rate of stents lost to follow up or severely delayed. We demonstrated non-inferiority in the rate of lost or severely delayed stents, and a number of other advantages including savings in personnel costs. The semi-automatic register represents an effective way of reducing the risk associated with a common urological procedure. We believe that this methodology could be implemented elsewhere. © 2017 Royal Australasian College of Surgeons.

Bacteriology of urinary tract infection associated with indwelling J ureteral stents.

PubMed

Kehinde, Elijah O; Rotimi, Vincent O; Al-Hunayan, Adel; Abdul-Halim, Hamdy; Boland, Fareeda; Al-Awadi, Khaleel A

2004-11-01

To investigate the microorganisms responsible for urinary tract infection (UTI) and stent colonization in patients with indwelling J ureteral stents and to compare the antimicrobial susceptibility pattern of the isolates from urine and J stents in order to establish the etiologic agents of bacteriuria and colonized stents in such patients and provide baseline data on an antibiotic policy for the urology unit. Midstream urine from 250 patients requiring J stent insertion was investigated microbiologically prior to stent insertion and on the day of stent removal. After stent removal, 3 to 5 cm of the tip located in the bladder was also sent for culture. Patients' bio-data and underlying diseases were documented. Those with no known systemic diseases ("normal patients") were also studied as controls. Of the 250 patients studied, 152 (61%) were normal, while 27 (11%), 53 (21%), and 18 (7%) had diabetes mellitus (DM), chronic renal failure (CRF), and diabetic nephropathy (DN), respectively. The mean duration of stent retention was 27 days. All microbial isolates were tested for their susceptibility to a panel of 10 antibiotics. Twelve patients (5%) before stent insertion and 42 patients (17%; P < 0.001) on the day of stent removal had positive urine cultures. One hundred four stents (42%) were culture positive. Of the 104 patients with positive stent cultures, in 62 patients (60%), urine culture was sterile. The commonest isolates were Escherichia coli, Enterococcus spp., Staphylococcus spp., Pseudomonas, and Candida spp. On the day of stent removal, urine culture was positive in 28% of the normal patients compared with 57% (P = 0.11), 78% (P < 0.001), and 62% (P < 0.001) of patients with CRF, DM, and DN, respectively. Stent isolates were more resistant to antibiotics than the organism isolated before stent insertion. An indwelling J ureteral stent carries a significant risk of bacteriuria and stent colonization. The sensitivity of urine culture to stent colonization is

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.

Use of percutaneous nephrostomy and ureteral stenting in management of ureteral obstruction

PubMed Central

Hsu, Linda; Li, Hanhan; Pucheril, Daniel; Hansen, Moritz; Littleton, Raymond; Peabody, James; Sammon, Jesse

2016-01-01

The management options for ureteral obstruction are diverse, including retrograde ureteral stent insertion or antegrade nephrostomy placement, with or without eventual antegrade stent insertion. There is currently no consensus on the ideal treatment or treatment pathway for ureteral obstruction owing, in part, to the varied etiologies of obstruction and diversity of institutional practices. Additionally, different clinicians such as internists, urologists, oncologists and radiologists are often involved in the care of patients with ureteral obstruction and may have differing opinions concerning the best management strategy. The purpose of this manuscript was to review available literature that compares percutaneous nephrostomy placement vs ureteral stenting in the management of ureteral obstruction from both benign and malignant etiologies. PMID:26981442

Safety and efficacy of self-expandable metal stents for obstructive proximal and distal large bowel cancer.

PubMed

Mitra, V; Hu, M; Majumdar, D; Krishnan, V; Chaudhury, B; Hancock, J; Dwarakanath, D

2017-03-01

Self-expandable metal stents are often used to treat obstructive large bowel cancers. This study assessed the safety and efficacy of colonic stent insertion carried out in a district general hospital. Methods A retrospective review was carried out between 1 January 2007 and 28 February 2014 to identify patients who underwent stent insertion for malignant colorectal obstruction. Results Seventy-five patients (median age 75.2 years, 70.6% male) with primary colorectal cancer underwent stent insertion - 53 underwent semi-elective self-expanded metal stent insertion (for subacute bowel obstruction) and 22 had emergency stent inserted (for acute bowel obstruction). The majority (88%) had self-expanded metal stents inserted for palliation. Technical and clinical success rates were 98.7% and 91.2%, respectively. One patient had stent-related perforation; there was no procedure-related mortality. Conclusion This study shows that self-expanded metal stent insertion in malignant colorectal obstruction is safe and effective and can be successfully delivered in a district general hospital with high technical and clinical success rates.

Silicone tracheobronchial stent: A rare cause for bronchoesophageal fistula and distortion of airway anatomy.

PubMed

Kumar, Bhupesh; Munirathinam, Ganesh Kumar; Puri, Goverdhan Dutt; Mishra, Anand Kumar; Arya, Virendra Kumar

2017-01-01

Silicone tracheobronchial stents are being increasingly used in a large number of patients for the treatment of tracheal stenosis. One very rare complication due to tracheobronchial stenting is bronchoesophageal fistula (BEF), which has been associated with the use of metallic stents. We report intraoperative management of a patient undergoing repair of a BEF, following previous insertion of a silicone Y-stent that is soft in texture and has not been implicated for this complication till date. In addition, misalignment of this silicone tracheobronchial Y-stent resulted in a tracheal mucosal bulge proximal to the stent that vanished after its removal.

Silicone Tracheobronchial Stent: A Rare Cause for Bronchoesophageal Fistula and Distortion of Airway Anatomy

PubMed Central

Kumar, Bhupesh; Munirathinam, Ganesh Kumar; Puri, Goverdhan Dutt; Mishra, Anand Kumar; Arya, Virendra Kumar

2017-01-01

Silicone tracheobronchial stents are being increasingly used in a large number of patients for the treatment of tracheal stenosis. One very rare complication due to tracheobronchial stenting is bronchoesophageal fistula (BEF), which has been associated with the use of metallic stents. We report intraoperative management of a patient undergoing repair of a BEF, following previous insertion of a silicone Y-stent that is soft in texture and has not been implicated for this complication till date. In addition, misalignment of this silicone tracheobronchial Y-stent resulted in a tracheal mucosal bulge proximal to the stent that vanished after its removal. PMID:28701606

Comparison of nitinol urethral stent infections with indwelling catheter-associated urinary-tract infections.

PubMed

Egilmez, Tulga; Aridogan, I Atilla; Yachia, Daniel; Hassin, David

2006-04-01

To determine the efficacy of intraurethral metal stents in preventing or eradicating urinary-tract infections (UTI) during the management of bladder outlet obstruction (BOO) by comparing the frequency and nature of the infections with indwelling-catheter-associated UTI. The SAS relative-risk test was used to compare the risks of UTI in 76 patients with temporary urethral stents, 60 patients with BOO who had never been catheterized nor stented, and 34 patients with a permanent indwelling urethral catheter (PIUC). Infection was assessed 1 month after placement of the devices. Scanning electron microscopy (SEM) of the proximal and distal pieces of the stents removed from five patients with and five patients without UTI was carried out in a search for predisposing changes on the surfaces. After insertion of the catheter, UTI developed in 79.4% of the patients who originally had sterile urine. However, after insertion of the stent, UTI developed in only 40.9% of the patients with sterile urine. In 21 (44.6%) of the catheterized patients who had infected urine, UTI was eradicated after stent insertion. The SEM analysis of the stents showed that a thick organic layer had formed only on the infected devices but with no sign of erosion. Urinary infection is a significant problem in patients with PIUC but is significantly less frequent and less severe in patients with urethral stents. This advantage of stents over the conventional urethral catheter, in addition to their obvious convenience for the patient, make them good alternatives to reduce the risk of UTI.

The Glasgow Prognostic Score at the Time of Palliative Esophageal Stent Insertion is a Predictive Factor of 30-Day Mortality and Overall Survival.

PubMed

Driver, Robert J; Handforth, Catherine; Radhakrishna, Ganesh; Bennett, Michael I; Ford, Alexander C; Everett, Simon M

2018-03-01

Optimizing the timing of esophageal stent insertion is a challenge, partly due to difficulty predicting survival in advanced malignancy. The Glasgow prognostic score (GPS) is a validated tool for predicting survival in a number of cancers. To assess the utility of the GPS in predicting 30-day mortality and overall survival postesophageal stent insertion. Patients at a tertiary referral center who had received an esophageal stent for palliation of dysphagia were included if they had a measurement of albumin and C-reactive protein (CRP) in the week preceding the procedure (n=209). Patients with both an elevated CRP (>10 mg/L) and hypoalbuminemia (<35 g/L) were given a GPS score of 2 (GPS2). Patients with only one of these abnormalities were assigned as GPS1 and those with normal CRP and albumin were assigned as GPS0. Clinical and pathologic parameters were also collected to assess for potential confounding factors in the survival analysis. Increasing GPS was associated with 30-day mortality; for patients with GPS0, 30-day mortality was 5% (2/43), for GPS1 it was 23% (26/114), and for GPS2 it was 33% (17/52). The adjusted hazard ratio for overall poststent mortality was 1.6 (95% confidence interval, 1.1-2.4; P=0.02) for GPS1 and 2.4 (95% confidence interval, 1.5-3.8; P<0.001) for GPS2 patients compared with GPS0. GPS is an independent prognostic factor of 30-day mortality and overall survival after esophageal stent insertion. It is a potential adjunct to clinical assessment in identifying those patients at high-risk of short-term mortality poststent.

First Experience of Inserting a Metallic Mesh Stent (Uventa Stent) in Malignant Ureteral Obstruction in Iran.

PubMed

Ghaed, Mohammad Ali; Daniali, Maziar; Ebrahimian, Mohammad

2018-05-03

Malignant ureteral obstruction is usually caused by an extrinsic compression including intra-abdominal cancers. One of the treatment modalities decompressing the obstruction is applying stent to open the ureter. Metallic Stent is an effective instrument which we used for the first time in Iran in our patient who had a metastatic colon cancerwith a single kidney and we used a Novel, Double-Layered, Coated, Self-expandable Metallic Mesh Stent (Uventa Stent) to keep the ureter open. After six months of follow up with ureteroscopy, there was no obstruction any more.

Obstruction after Self-expanding Metallic Stents in Tuberculous Bronchial Stenosis

PubMed Central

Kim, Won; Lee, Youg Chul; Rhee, Yang Keun

1995-01-01

Expandable metallic stents seemed to be a good method in tuberculous bronchial stenosis that does not respond to medical therapy. But there was no long-term follow-up study after stents insertion in tuberculous bronchial stenosis. We report a case of obstruction after successful Gianturco metallic stents insertion due to tuberculous bronchial stenosis. PMID:7542914

Development and evaluation of a centralised computerised registry for ureteric stents: completing the audit cycle.

PubMed

Davis, N F; Murray, G; O'Connor, T; Browne, C; MacCraith, E; Galvin, D; Mulvin, D; Quinlan, D; Lennon, G

2017-11-01

A forgotten ureteric stent may result in severe renal impairment leading to nephrectomy. To compare the effectiveness of a centralised computerised registry for monitoring ureteric stent activity with a previously established theatre stent logbook system. This prospective audit was performed in two 9-monthly intervals. During the first interval, insertion/removal of a ureteric stent was documented in a specific theatre stent logbook. In the second interval, an electronic centralised computerised registry was developed to document insertion/removal of a ureteric stent onto an accessible hospital server. A computerised traffic-light system was also developed to identify patients with an indwelling stent for >3 months. The primary outcome variable was the number of prolonged indwelling ureteric stents in both groups. During the first time interval, 188 ureteric stents were inserted and 182 (96%) were removed or changed. Six (4%) patients underwent insertion of a ureteric stent for a prolonged period of time (>6 months). This subgroup required complex endourological intervention for stent removal due to encrustation. During the second time interval, 157 ureteric stents were inserted and all patients had their stent removed or changed within 6 months. No patients in this group were lost to follow-up. This study demonstrates that a centralised computerised ureteric stent registry is superior to a conventional logbook for monitoring ureteric stent activity. We propose the introduction a centralised nationalised ureteric stent registry for eliminating the potential for prolonged or forgotten ureteric stents.

Plastic Biliary Stent Migration During Multiple Stents Placement and Successful Endoscopic Removal Using Intra-Stent Balloon Inflation Technique: A Case Report and Literature Review.

PubMed

Calcara, Calcedonio; Broglia, Laura; Comi, Giovanni; Balzarini, Marco

2016-02-05

Late migration of a plastic biliary stent after endoscopic placement is a well known complication, but there is little information regarding migration of a plastic stent during multiple stents placement. A white man was hospitalized for severe jaundice due to neoplastic hilar stenosis. Surgical eligibility appeared unclear on admission and endoscopy was carried out, but the first stent migrated proximally at the time of second stent insertion. After failed attempts with various devices, the migrated stent was removed successfully through cannulation with a dilation balloon. The migration of a plastic biliary stent during multiple stents placement is a possible complication. In this context, extraction can be very complicated. In our patient, cannulation of a stent with a dilation balloon was the only effective method.

Combined Arterial Infusion and Stent Implantation Compared with Metal Stent Alone in Treatment of Malignant Gastroduodenal Obstruction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang Zhongmin, E-mail: wzm0722@hotmail.co; Chen Kemin, E-mail: ckm0722@hotmail.co; Gong Ju

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 timemore » 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

Management of complex benign post-tracheostomy tracheal stenosis with bronchoscopic insertion of silicon tracheal stents, in patients with failed or contraindicated surgical reconstruction of trachea.

PubMed

Tsakiridis, Kosmas; Darwiche, Kaid; Visouli, Aikaterini N; Zarogoulidis, Paul; Machairiotis, Nikolaos; Christofis, Christos; Stylianaki, Aikaterini; Katsikogiannis, Nikolaos; Mpakas, Andreas; Courcoutsakis, Nicolaos; Zarogoulidis, Konstantinos

2012-11-01

Tracheal stenosis is a potentially life-threatening condition. Tracheostomy and endotracheal intubation remain the commonest causes of benign stenosis, despite improvements in design and management of tubes. Post-tracheostomy stenosis is more frequently encountered due to earlier performance of tracheostomy in the intensive care units, while the incidence of post-intubation stenosis has decreased with application of high-volume, low-pressure cuffs. In symptomatic benign tracheal stenosis the gold standard is surgical reconstruction (often after interventional bronchoscopy). Stenting is reserved for symptomatic tracheal narrowing deemed inoperable, due to local or general reasons: long strictures, inflammation, poor respiratory, cardiac or neurological status. When stenting is decided, silicone stent insertion is considered the treatment of choice in the presence of inflammation and/or when removal is desirable. We inserted tracheal silicone stents (Dumon) under general anaesthesia through rigid bronchoscopy in two patients with benign post-tracheostomy stenosis: a 39-year old woman with failed initial operation, and continuous relapses with proliferation after multiple bronchscopic interventions, and a 20-year old man in a poor neurological status, with a long tracheal stricture involving the subglottic larynx (lower posterior part), and inflamed tracheostomy site tissues (positive for methicillin resistant staphylococcus aureus). The airway was immediately re-establish, without complications. At 15- and 10-month follow-up (respectively) there was no stent migration, luminal patency was maintained without: adjacent structure erosion, secretion adherence inside the stents, granulation at the ends. Tracheostomy tissue inflammation was resolved (2(nd) patient), new infection was not noted. The patients maintain good respiratory function and will be evaluated for scheduled stent removal. Silicone stents are removable, resistant to microbial colonization and are

Management of complex benign post-tracheostomy tracheal stenosis with bronchoscopic insertion of silicon tracheal stents, in patients with failed or contraindicated surgical reconstruction of trachea

PubMed Central

Tsakiridis, Kosmas; Darwiche, Kaid; Visouli, Aikaterini N.; Machairiotis, Nikolaos; Christofis, Christos; Stylianaki, Aikaterini; Katsikogiannis, Nikolaos; Mpakas, Andreas; Courcoutsakis, Nicolaos; Zarogoulidis, Konstantinos

2012-01-01

Tracheal stenosis is a potentially life-threatening condition. Tracheostomy and endotracheal intubation remain the commonest causes of benign stenosis, despite improvements in design and management of tubes. Post-tracheostomy stenosis is more frequently encountered due to earlier performance of tracheostomy in the intensive care units, while the incidence of post-intubation stenosis has decreased with application of high-volume, low-pressure cuffs. In symptomatic benign tracheal stenosis the gold standard is surgical reconstruction (often after interventional bronchoscopy). Stenting is reserved for symptomatic tracheal narrowing deemed inoperable, due to local or general reasons: long strictures, inflammation, poor respiratory, cardiac or neurological status. When stenting is decided, silicone stent insertion is considered the treatment of choice in the presence of inflammation and/or when removal is desirable. We inserted tracheal silicone stents (Dumon) under general anaesthesia through rigid bronchoscopy in two patients with benign post-tracheostomy stenosis: a 39-year old woman with failed initial operation, and continuous relapses with proliferation after multiple bronchscopic interventions, and a 20-year old man in a poor neurological status, with a long tracheal stricture involving the subglottic larynx (lower posterior part), and inflamed tracheostomy site tissues (positive for methicillin resistant staphylococcus aureus). The airway was immediately re-establish, without complications. At 15- and 10-month follow-up (respectively) there was no stent migration, luminal patency was maintained without: adjacent structure erosion, secretion adherence inside the stents, granulation at the ends. Tracheostomy tissue inflammation was resolved (2nd patient), new infection was not noted. The patients maintain good respiratory function and will be evaluated for scheduled stent removal. Silicone stents are removable, resistant to microbial colonization and are

Internal stenting in malignant biliary obstruction.

PubMed

Cowling, M G; Adam, A N

2001-03-01

Internal stenting in inoperable malignant biliary obstruction plays an important role in patient management. Surgical bypass may still be undertaken where there is also duodenal obstruction, though the need for gastroenterostomy may be reduced with the increasing use of metallic stents for the relief of malignant gastric outlet obstruction. Stents may be placed endoscopically or percutaneously, though in most centers the endoscopic route is usually tried first, with the percutaneous route being reserved for endoscopic failures. Plastic and self-expanding metallic biliary stents are available, each with its own advantages and disadvantages. In general, longer periods of patency are observed with metallic stents, though they are more expensive. Plastic stents can be changed endoscopically relatively easily when they have blocked, and in practice it is common for plastic stents to be inserted via this route for initial biliary drainage. If there is prolonged survival thereafter, many workers insert a metallic stent in an attempt to reduce the number of interventions required. If the percutaneous route is being employed, the histologic diagnosis has been confirmed, and the malignancy is inoperable, our practice is to use a self-expanding metallic stent, as the delivery system is relatively small and subsequent occlusion less likely.

Drug treatment of bothersome lower urinary tract symptoms after ureteric JJ-stent insertion: A contemporary, comparative, prospective, randomised placebo-controlled study, single-centre experience.

PubMed

Hekal, Ihab A

2016-12-01

To provide a guide for medication to alleviate bothersome lower urinary tract symptoms (LUTS) in patients after JJ ureteric stenting. Between June 2011 and June 2015, a prospective randomised placebo-controlled study was conducted on 200 consecutive cases of ureteric stones that required JJ stents. All patients had signed informed consent and JJ-stent placement confirmed by X-ray. The patients were randomised into five groups: A, solifenacin 5 mg; B, trospium chloride 20 mg; C, antispasmodic; and E, α-blocker; and a placebo group (D). A standard model was created to lessen patient selection bias. Eligible patients were enrolled and assessed for side-effects and bothersome LUTS using the validated Ureteric Stent Symptoms Questionnaire. Appropriate statistical analysis was carried out. In all, 150 male patients in the five groups were compared. LUTS were less in groups A and B ( P  < 0.05), while dry mouth was significantly reported in Group A. Individual comparisons with the placebo group showed a non-significant difference with Group C, while Group E had significant nocturia improvement. Selective comparison of two best groups (A and B) showed less frequency in Group B, while the other LUTS were less in Group A with comparable side-effects. In symptomatic patients following JJ-stent insertion, anti-muscarinic medication, namely solifenacin 5 mg or trospium chloride 20 mg, was the best. The advantage of trospium over solifenacin is in the control of frequency rather than the other symptoms. Addition of an α-blocker (alfuzosin 10 mg) is valuable when nocturia is the predominant symptom.

Microvascular stent anastomosis using N-fibroin stents: feasibility, ischemia time, and complications.

PubMed

Smeets, Ralf; Vorwig, Oliver; Wöltje, Michael; Gaudin, Robert; Luebke, Andreas M; Beck-Broichsitter, Benedicta; Rheinnecker, Michael; Heiland, Max; Grupp, Katharina; Gröbe, Alexander; Hanken, Henning

2016-05-01

To evaluate a novel microvascular anastomosis technique using N-fibroin stents. Cylinder stents of 1 mm diameter and 5 mm length were fabricated using N-fibroin from silkworms. In 22 rats, aortas were dissected, and the stent was inserted into the two ends of the aorta and fixed using methylmethacrylate. Stent anastomosis was successful in 21 (96%) rats. The mean ischemia time was 7.4 minutes, significantly shorter than the 15.9 minutes in the control group with conventional sutures (P < .0001). After 4 months, anastomosis was functionally patent in all cases. However, elastic fibers remained interrupted in all stent anastomosis cases, and marked host rejection was evident at the stent anastomosis sites. Around the stents, thrombi were frequent (52%). Our study demonstrated the basic feasibility of stent anastomosis using N-fibroin stents and reduced ischemia time. However, thrombus formation, frequent and severe abdominal infections, and heavy host rejection remain critical issues. Copyright © 2016 Elsevier Inc. All rights reserved.

Preventing the forgotten ureteral stent: implementation of a web-based stent registry with automatic recall application.

PubMed

Lynch, Mark F; Ghani, Khurshid R; Frost, Ian; Anson, Ken M

2007-09-01

To describe and analyze a unique computerized system that tracks ureteral stents and automatically sends a notice by e-mail to clinical staff if a stent becomes overdue for removal. We have developed an electronic stent register (ESR) and stent extraction reminder facility (SERF) located within our hospital computer network. After stent insertion, a stent "episode" is created in the ESR with a mandatory maximal stent life (MSL). The SERF interrogates the ESR on a daily basis and identifies stents that have breached its MSL, generating daily e-mail notices to personnel until the stent is removed and the ESR updated. The episode data capture initially employing manual entry was changed to barcode technology acquisition. We analyzed the success of patient recall and conducted a prospective, blinded review to determine the success of the data acquisition. A total of 293 episodes were created within 2.4 years. Of the 241 (86%) episodes that were closed, 123 (51%) went beyond the MSL. The mean delay from designated MSL to stent removal was 20.89 days (SD 19.71). In the 7 months before barcode data acquisition, 43 of 71 stents were entered into the ESR (data capture rate 61%). In the 7 months after barcode data acquisition, 52 of 60 stents were entered (data capture rate 87%; P = 0.0009). The results of our study have shown the ESR and SERF to be robust and valuable tools for the treatment of patients with ureteral stents. Barcode acquisition significantly improved the stent insertion capture rate. This system ensures improved patient safety with an element of protection from potential litigation.

Expandable metallic stents for tracheobronchial stenoses in esophageal cancer.

PubMed

Takamori, S; Fujita, H; Hayashi, A; Tayama, K; Mitsuoka, M; Ohtsuka, S; Shirouzu, K

1996-09-01

Tracheobronchial stenosis in patients with esophageal cancer can be life threatening. Few reports have discussed use of expandable metallic stents for central airway stenoses in patients with esophageal cancer. Twelve patients with esophageal cancer underwent placement of expandable metallic stents for respiratory distress caused by tracheobronchial stricture. Single or double metallic stents were placed in the stenotic airways under fluoroscopic guidance. Improvement in respiratory symptoms and clinical outcome were assessed. Most stenoses were located in the trachea or the left main bronchus. From one to four expandable metallic stents were placed in each stricture site, with immediate relief of respiratory symptoms in 8 patients. One patient with tracheomalacia in alive 3 years after stent placement and another is alive 6 months after stent insertion. The other 10 patients lived from 10 to 70 days (mean; survival, 35 days) after stent placement. Death was due to progression of disease. Although metallic stents are useful for relieving respiratory distress in patients with advanced esophageal cancer, additional therapies should be considered.

[Expandable stents and composite prosthesis].

PubMed

Baldeyrou, P

1999-11-01

Today, numerous expandable and mixed silicone metallic stents for trachea and bronchi are available. Among the many technical propositions, Nitinol is a new alloy with promising potential, offering the advantage of shape memory. The right stent is the one which best meets the needs of the individual stenotic situation as evaluated by endoscopy and CT. Sufficient experience has been acquired only with the Dumon stent, giving exact information about its qualities and possible complications. The new stents are thinner. Some can be inserted under fluoroscopic and fibroscopic control. They are presumed to produce fewer complications an provide answers to some still unresolved questions such as dyskinesia or stenosis on short bronchi. They appear to be more easily inserted on the tracheo-bronchial tree. More experience is needed to satisfactorily identify specific indications and contraindications. A prospective registry will be important to obtain comparative information more quickly.

Management of occluded self-expanding biliary metal stents in malignant biliary disease.

PubMed

Nennstiel, Simon; Tschurtschenthaler, Isolde; Neu, Bruno; Algül, Hana; Bajbouj, Monther; Schmid, Roland M; von Delius, Stefan; Weber, Andreas

2018-02-01

Occlusion of self-expanding metal stents (SEMS) in malignant biliary obstruction occurs in up to 40% of patients. This study aimed to compare the different techniques to resolve stent occlusion in our collective of patients. Patients with malignant biliary obstruction and occlusion of biliary metal stent at a tertiary referral endoscopic center were retrospectively identified between April 1, 1994 and May 31, 2014. The clinical records were further analyzed regarding the characteristics of patients, malignant strictures, SEMS, management strategies, stent patency, subsequent interventions, survival time and case charges. A total of 108 patients with biliary metal stent occlusion were identified. Seventy-nine of these patients were eligible for further analysis. Favored management was plastic stent insertion in 73.4% patients. Second SEMS were inserted in 12.7% patients. Percutaneous transhepatic biliary drainage and mechanical cleansing were conducted in a minority of patients. Further analysis showed no statistically significant difference in median overall secondary stent patency (88 vs. 143 days, P = 0.069), median survival time (95 vs. 192 days, P = 0.116), median subsequent intervention rate (53.4% vs. 40.0%, P = 0.501) and median case charge (€5145 vs. €3473, P = 0.803) for the treatment with a second metal stent insertion compared to plastic stent insertion. In patients with survival time of more than three months, significantly more patients treated with plastic stents needed re-interventions than patients treated with second SEMS (93.3% vs. 57.1%, P = 0.037). In malignant biliary strictures, both plastic and metal stent insertions are feasible strategies for the treatment of occluded SEMS. Our data suggest that in palliative biliary stenting, patients especially those with longer expected survival might benefit from second SEMS insertion. Careful patient selection is important to ensure a proper decision for either management

Use of biliary stent in laparoscopic common bile duct exploration.

PubMed

Lyon, Matthew; Menon, Seema; Jain, Abhiney; Kumar, Harish

2015-05-01

It is well supported in the literature that laparoscopic common bile duct exploration (LCBDE) for choledocholithiasis has equal efficacy when compared to ERCP followed by laparoscopic cholecystectomy. Decompression after supra-duodenal choledochotomy is common practice as it reduced the risk of bile leaks. We conducted a prospective non-randomized study to compare outcomes and length of stay in patients undergoing biliary stent insertion versus T-tube drainage following LCBDE via choledochotomy. The study involved 116 patients with choledocholithiasis who underwent LCBDE and decompression of the biliary system by either ante-grade biliary stent or T-tube insertion. A 7 French straight/duodenal curve biliary Diagmed™ stent (9-11 cm) was placed in 82 patients (Biliary Stent Group). T-tube insertion was used for 34 patients (T-tube group). The length of hospital stay and complications for the selected patients were recorded. All trans-cystic common bile duct explorations were excluded from the study. The mean hospital stay for patients who underwent ante-grade biliary stent or T-tube insertion after LBCDE were 1 and 3.4 days, respectively. This is a statistically significant result with a p value of less than 0.001. Of the T-tube group, two patients required laparoscopic washout due to bile leaks, one had ongoing biliary stasis and one reported ongoing pain whilst the T-tube was in situ. A complication rate of 11.2%, this was a significant finding. There were no complications or concerns reported for the Biliary Stent Group. Our results show that there is a significant reduction in length of hospital stay and morbidity for patients that have ante-grade biliary stent decompression of the CBD post laparoscopic choledochotomy when compared T-tube drainage. This implies that ante-grade biliary stent insertion is likely to reduce costs and increase overall patient satisfaction. We support the use of ante-grade biliary stent insertion during LCBDE when primary closure is

Endoscopic management of occluded metal biliary stents: metal versus 10F plastic stents.

PubMed

Yoon, Won Jae; Ryu, Ji Kon; Lee, Jung Won; Ahn, Dong-Won; Kim, Yong-Tae; Yoon, Yong Bum; Woo, Sang Myung; Lee, Woo Jin

2010-11-14

To compare the efficacy of self-expandable metal stents (SEMSs) with 10F plastic stents (PSs) in the endoscopic management of occluded SEMSs. We retrospectively reviewed the medical records of 56 patients who underwent SEMS insertion for palliation of unresectable malignant biliary obstruction between 2000 and 2007 and subsequent endoscopic retrograde biliary drainage (ERBD) with SEMS or PS for initial SEMS occlusion between 2000 and 2008. Subsequent ERBD with SEMS was performed in 29 patients and with PS in 27. The median time to stent occlusion after subsequent ERBD was 186 d in the SEMS group and 101 d in the PS group (P = 0.118). Overall median stent patency was 79 d for the SEMS group and 66 d for the PS group (P = 0.379). The mean number of additional biliary drainage procedures after subsequent ERBD in patients that died (n = 50) during the study period was 2.54 ± 4.12 for the SEMS group and 1.85 ± 1.95 for the PS group (P = 0.457). The mean total cost of additional biliary drainage procedures after the occlusion of subsequent SEMS or PS was $410.04 ± 692.60 for the SEMS group and $630.16 ± 671.63 for the PS group (P = 0.260). Tumor ingrowth as the cause of initial SEMS occlusion was the only factor associated with a shorter time to subsequent stent occlusion (101 d for patients with tumor ingrowth vs 268 d for patients without tumor ingrowth, P = 0.008). Subsequent ERBD with PSs offered similar patency and number of additional biliary drainage procedures compared to SEMSs in the management of occluded SEMS.

Comparison of a New Polytetrafluoroethylene-Covered Metallic Stent to a Noncovered Stent in Canine Ureters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chung, Hwan-Hoon, E-mail: chungmic@korea.ac.kr; Lee, Seung Hwa; Cho, Sung Bum

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 sixmore » 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.« less

Initial experience with a new biodegradable airway stent in children: Is this the stent we were waiting for?

PubMed

Antón-Pacheco, Juan L; Luna, Carmen; García, Enrique; López, María; Morante, Rocío; Tordable, Cristina; Palacios, Alba; de Miguel, Mónica; Benavent, Isabel; Gómez, Andrés

2016-06-01

To report our experience with a new type of biodegradable airway stent in the setting of severe tracheobronchial obstruction in children. We conducted a retrospective and prospective (since June 2014) study of pediatric patients with severe airway obstruction treated with biodegradable stents in our institution between 2012 and 2015. The following data were collected: demographics, indication for stenting, bronchoscopic findings, insertion technique complications, clinical outcome, stent related complications, re-stenting, and time of follow-up. Thirteen custom-made polydioxanone stents were placed in four infants (mean age, 4 months) with severe tracheobronchial obstruction: tracheomalacia (two patients), bronchomalacia (1), and diffuse tracheal stenosis (1). All the stents were bronchoscopically inserted uneventfully. Immediate and maintained clinical improvement was observed in every case. No major stent related complications have occurred and only mild or moderate granulation tissue was observed during surveillance bronchoscopy. Two patients required repeated stenting as expected. All the patients are alive and in a good respiratory condition with a follow-up ranging from 5 to 40 months. Biodegradable airway stents seem to be safe, effective, and cause fewer complications than other types of stents. They can be an alternative to the classic metallic or plastic stents for severe tracheal stenosis or malacia in small children. More experience is needed in order to establish the definite clinical criteria for their use in pediatric patients. Pediatr Pulmonol. 2016;51:607-612. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Angulated Stents-A Novel Stent Improvisation to Manage Difficult Post-tuberculosis Bronchial Stenosis.

PubMed

Tay, Chee Kiang; Jeong, Byeong-Ho; Kim, Hojoong

2017-10-18

Post-tuberculosis bronchostenosis (PTBS), a complication of endobronchial tuberculosis is currently treated by bronchial stenting. However, in cases of angulated bronchial stenoses, difficulty is often encountered in stent insertion and maintenance, resulting in stent migration, granulation tissue overgrowth, and restenosis. To accommodate the angulated alignment of the stenosis, we devised an "angulated stent"-a novel improvisation of the conventional stent via splicing and suturing to achieve a resultant angulated shape. A retrospective review was undertaken to evaluate the performance of this stent. Among 283 PTBS patients who underwent interventional bronchoscopy at our center from 2004 to 2014, 21 were treated with at least one angulated stent. Clinical outcomes, including the stenting duration were investigated. After a median follow-up of 26 months, stent removal was successful in 7 (33.3%) out of 21 patients. In patients managed with angulated stents, the median duration to stent change or eventual removal was longer than those treated with straight tube stents (392 days vs. 86 days; p < 0.05). Angulated stents are a feasible treatment option in patients with angulated PTBS by reducing complications and prolonging the stent-changing interval.

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.

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

Temporary placement of a paclitaxel or rapamycin-eluting stent is effective to reduce stenting induced inflammatory reaction and scaring in benign cardia stricture models.

PubMed

Wang, Lin; Zhu, Yue-Qi; Cheng, Ying-Sheng; Cui, Wen-Guo; Chen, Ni-Wei

2014-12-01

To investigate whether temporary placement of a paclitaxel or rapamycin eluting stent is more effective to reduce stenting induced inflammatory reaction and scaring than a bared stent in benign cardia stricture models. Eighty dog models of stricture were randomly divided into a control group (CG, n=20, no stent insertion), a bare stent group (BSG, n=20), a paclitaxel eluting (Pacl-ESG, n=20) and a rapamycin eluting stent group (Rapa-ESG, n=20), with one-week stent retention. Lower-oesophageal-sphincter pressure (LOSP), 5-minute barium height (5-mBH) and cardia diameter were assessed before, immediately after the procedure, and regularly for 6 months. Five dogs in each group were euthanized for histological examination at each follow-up assessment. Stent insertion was well tolerated, with similar migration rates in three groups. At 6 months, LOSP and 5-mBH improved in Pacl-ESG and Rapa-ESG compared to BSG (p<0.05), with no difference between Pacl-ESG and Rapa-ESG (p>0.05). Cardia kept more patency in the Pacl-ESG and Rapa-ESG than in BSG (p<0.05). Reduced peak inflammatory reactions and scarring occurred in the Pacl-ESG and Rapa-ESG compared to BSG (p<0.05), with a similar outcome in the Pacl-ESG and Rapa-ESG (p>0.05). Paclitaxel or rapamycin-eluting stents insertion led to better outcomes than bare stents in benign cardia stricture models.

Angioplasty and stent placement - peripheral arteries - discharge

MedlinePlus

... medlineplus.gov/ency/patientinstructions/000234.htm Angioplasty and stent placement - peripheral arteries - discharge To use the sharing ... peripheral artery). You may have also had a stent placed. To perform the procedure: Your doctor inserted ...

Endoscopic management of occluded metal biliary stents: Metal versus 10F plastic stents

PubMed Central

Yoon, Won Jae; Ryu, Ji Kon; Lee, Jung Won; Ahn, Dong-Won; Kim, Yong-Tae; Yoon, Yong Bum; Woo, Sang Myung; Lee, Woo Jin

2010-01-01

AIM: To compare the efficacy of self-expandable metal stents (SEMSs) with 10F plastic stents (PSs) in the endoscopic management of occluded SEMSs. METHODS: We retrospectively reviewed the medical records of 56 patients who underwent SEMS insertion for palliation of unresectable malignant biliary obstruction between 2000 and 2007 and subsequent endoscopic retrograde biliary drainage (ERBD) with SEMS or PS for initial SEMS occlusion between 2000 and 2008. RESULTS: Subsequent ERBD with SEMS was performed in 29 patients and with PS in 27. The median time to stent occlusion after subsequent ERBD was 186 d in the SEMS group and 101 d in the PS group (P = 0.118). Overall median stent patency was 79 d for the SEMS group and 66 d for the PS group (P = 0.379). The mean number of additional biliary drainage procedures after subsequent ERBD in patients that died (n = 50) during the study period was 2.54 ± 4.12 for the SEMS group and 1.85 ± 1.95 for the PS group (P = 0.457). The mean total cost of additional biliary drainage procedures after the occlusion of subsequent SEMS or PS was $410.04 ± 692.60 for the SEMS group and $630.16 ± 671.63 for the PS group (P = 0.260). Tumor ingrowth as the cause of initial SEMS occlusion was the only factor associated with a shorter time to subsequent stent occlusion (101 d for patients with tumor ingrowth vs 268 d for patients without tumor ingrowth, P = 0.008). CONCLUSION: Subsequent ERBD with PSs offered similar patency and number of additional biliary drainage procedures compared to SEMSs in the management of occluded SEMS. PMID:21072899

Antegrade jj stenting after percutaneous renal procedures: The 'pull and push' technique.

PubMed

Ratkal, Jaideep M; Sharma, Elias

2015-06-01

A JJ stent is inserted antegradely after percutaneous renal procedures like percutaneous nephrolithotomy (PCNL) for renal calculus disease, and for endopyelotomy for pelvi-ureteric junction obstruction. We describe a technique for antegrade stent insertion after PCNL.

Fluoroscopically guided placement of self-expandable metallic stents and stent-grafts in the treatment of acute malignant colorectal obstruction.

PubMed

Kim, Honsoul; Kim, Seung Hyoung; Choi, Sun Young; Lee, Kwang-Hun; Won, Jong Yoon; Lee, Do Yun; Lee, Jong Tae

2008-12-01

To evaluate the technical feasibility and clinical effectiveness of fluoroscopically guided placement of self-expandable metallic stents and stent-grafts for acute malignant colorectal obstruction. Radiologic images and clinical reports of 42 patients (22 men, 20 women; age range, 28-93 years; median age, 65.5 years) who underwent fluoroscopically guided colorectal stent insertion without endoscopic assistance for acute malignant obstruction were reviewed retrospectively. Eighteen patients received bare stents as a bridge to surgery. Twenty-four patients received 27 insertions of either a bare stent (n = 15) or a stent-graft (n = 12) for palliation. The obstruction was located in the rectum (n = 8), sigmoid (n = 17), descending colon (n = 8), splenic flexure (n = 3), and transverse colon (n = 6). Clinical success, defined as more than 50% dilatation of the stent with subsequent symptomatic improvement, was achieved in 41 of the 42 patients (98%). No major procedure-related complications occurred. Minor complications occurred in eight of the 45 procedures (18%). No perioperative mortalities occurred within 1 month after surgery. In the palliative group, the median stent patency was 62 days (range, 0-1,014 days). There was no statistically significant difference in stent patency between the bare stents (range, 0-855 days; median, 68 days) and stent-grafts (range, 1-1,014 days; median, 81 days). Fluoroscopically guided placement of self-expandable metallic stents and stent-grafts for the relief of acute malignant colorectal obstruction was technically feasible without endoscopic assistance-even in lesions proximal to the splenic flexure and transverse colon-and clinically effective in both bridge to surgery and palliative management.

Filling cystoureterography facilitates stone visualization in patients with previously inserted double-J ureteral stents.

PubMed

Kravchick, Sergey George; Shumalinsky, Dmitry; Jeshurun-Koren, Michael; Stepnov, Eugen; Cytron, Shmuel

2005-06-01

In our study, we assessed the ability of a filling cystogram to induce vesicoureteral reflux (VUR) and to evaluate its role in stone targeting during ESWL in the presence of a double-J ureteral stent (JJ-S). Filling cystoureterography was performed during ESWL in 17 patients with previously inserted 4.7 F JJ-S. The examination ended with stone localization. In every procedure, 3,500 shock waves were delivered with an energy range of 18-23 kV. Patients were evaluated 4 weeks after ESWL. A stone-free result was defined as no evidence of calculi in the first or second visits. Because contrast material was employed in this study, we also evaluated its possible interference with the results of lithotripsy. All radiolucent or poorly calcified stones were successfully localized. In four patients, rhythmic suprapubic manual pressure was performed to initiate VUR. Reflux was low grade in 35% and high grade in 65% of renal units. The efficiency quotient reached 59%. In vitro artificial stones were successfully disintegrated both in water and solutions of Ultravist. In the presence of a JJ-S, filling cystography can easily localize radiolucent stones during SWL. No special catheters or stents are required for this technique. Ultravist in particular does not affect the results of ESWL unfavorably.

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

Additive Manufacturing for Highly Efficient Window Inserts CRADA Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roschli, Alex C.; Chesser, Phillip C.; Love, Lonnie J.

ORNL partnered with the Mackinac Technology Company to demonstrate how additive manufacturing can be used to create highly energy efficient window inserts for retrofit in pre-existing buildings. Many early iterations of the window inserts were fabricated using carbon fiber reinforced thermoplastics and polycarbonate films as a stand in for the low-e coated films produced by the Mackinac Technology Company. After demonstration of the proof of concept, i.e. custom window inserts with tensioned film, the materials used for the manufacture of the frames was more closely examined. Hollow particle-filled syntactic foam and low-density polymer composites formed by expandable microspheres were exploredmore » as the materials used to additively manufacture the frames of the inserts. It was concluded that low-cost retrofit window inserts in custom sizes could be easily fabricated using large scale additive manufacturing. Furthermore, the syntactic and expanded foams developed and tested satisfy the mechanical performance requirements for the application.« less

Nitinol stents in the treatment of benign proximal tracheal stenosis or tracheomalacia.

PubMed

Isa, A Y; Macandie, C; Irvine, B W

2006-01-01

Nitinol stents have been used in the treatment of benign tracheal stenosis. A retrospective review of five patients treated at Stobhill Hospital over the last six and a half years is presented. Age at presentation ranged from 17 to 76 years. The minimum follow-up period was 23 months and the maximum was 78 months. All our patients were successfully decannulated, with none requiring recannulation. Four patients developed granulation tissue related to the stent at intervals ranging from three weeks to 41 months post stenting. Topical mitomycin C application has been useful after resection of granulations using the carbon dioxide (CO2) laser. Stent migration occurred in one patient three weeks after insertion. Nitinol stents are easy to insert and effective in the treatment of tracheal stenosis, but can have associated morbidity. Their use should be considered carefully, as insertion should be regarded as permanent. Publications reporting experience and outcome with the use of Nitinol stents in the trachea are reviewed.

[Sixteen Cases of Colon Stenting as a Bridge to Surgery(BTS)for Obstructive Colorectal Cancer].

PubMed

Otsuka, Ryo; Saito, Shuji; Hirayama, Ryouichi; Miura, Yasuaki; Sasaki, Kazunori; Miyajima, Ayako; Kuwamoto, Nobutsuna; Kataoka, Ryoko; Shindo, Yukito; Fujita, Rikiya

2017-11-01

Colonic stent insertion is widely used as a bridge to surgery(BTS)for obstructive colorectal cancer. Stenting can shorten hospitalization and decrease complication and colostomy rates in comparison with emergency surgery. We investigated patients who underwent colonic stent insertion for BTS in our hospital. Sixteen patients(8 men, 8 women) with a colorectal obstruction score of 0 or 1 who underwent colonic stent insertion as a BTS between April 2015 and April 2017 period were investigated. Mean patient age was 68.2(45-94)years. Technical success was obtained in all patients, and clinical success in 14(87%). Total colonoscopy was possible via stent in 10 patients. Nine patients were temporarily discharged from the hospital, and median time to operation was 18(2-43)days. Laparoscopic resection was performed in 14 patients, and anastomotic leakage was a postoperative complication in 1 patient. Colostomy was performed in only 1 patient with anastomotic leakage. Good results were obtained with careful patient selection and safe colonic stent insertion.

Management of JJ stent-related symptoms.

PubMed

Papatsoris, Athanasios; Dellis, Athanasios; Daglas, George; Sanguedolce, Francesco

2014-01-01

Ureteric JJ stents are inserted in numerous pa- tients as a routine procedure. Nevertheless, the ideal JJ stent that does not cause any lower urinary tract symptoms has not been developed yet. Even special validated ques- tionnaires have been used for the assessment of JJ stent-related symtoms. For the management of such symtoms usually alpha-blockers are admin- istered. Also, studies have examined the efficacy and safety of anticholinergics and calcium channel blo- ckers. In this article we review the literature upon the management of JJ stent-related symptoms.

Metallic ureteral stents in malignant ureteral obstruction: short-term results and radiological features predicting stent failure in patients with non-urological malignancies.

PubMed

Chow, Po-Ming; Hsu, Jui-Shan; Wang, Shuo-Meng; Yu, Hong-Jheng; Pu, Yeong-Shiau; Liu, Kao-Lang

2014-06-01

To provide short-term result of the metallic ureteral stent in patients with malignant ureteral obstruction and identify radiological findings predicting stent failure. The records of all patients with non-urological malignant diseases who have received metallic ureteral stents from July 2009 to March 2012 for ureteral obstruction were reviewed. Stent failure was detected by clinical symptoms and imaging studies. Survival analysis was used to estimate patency rates and factors predicting stent failure. A total of 74 patients with 130 attempts of stent insertion were included. A total of 113 (86.9 %) stents were inserted successfully and 103 (91.2 %) achieved primary patency. After excluding cases without sufficient imaging data, 94 stents were included in the survival analysis. The median functional duration of the 94 stents was 6.2 months (range 3-476 days). Obstruction in abdominal ureter (p = 0.0279) and lymphatic metastasis around ureter (p = 0.0398) were risk factors for stent failure. The median functional durations of the stents for abdominal and pelvic obstructions were 4.5 months (range 3-263 days) and 6.5 months (range 4-476 days), respectively. The median durations of the stents with and without lymphatic metastasis were 5.3 months (range 4-398 days) and 7.8 months (range 31-476 days), respectively. Metallic ureteral stents are effective and safe in relieving ureteral obstructions resulting from non-urological malignancies, and abdominal ureteral obstruction and lymphatic metastasis around ureter were associated with shorter functional duration.

Treatment of tracheomalacia with Palmaz stent: a case report.

PubMed

Inan, Mustafa; Ayvaz, Süleyman; Basaran, Umit Nusret

2005-01-01

Tracheomalacia is a potentially life-threatening clinical problem. The expandable Palmaz stent can be used for the treatment of tracheomalacia. We describe a female infant with tracheomalacia who showed respiratory distress the day after birth. Tracheomalacia was diagnosed by bronchoscopic examination, computed tomography and bronchography. At 75 days of age, an expandable metallic stent (Palmaz stent) was inserted into the trachea under fluoroscopic control. The patient's respiratory status improved rapidly. Bronchoscopic examination 6 months after the insertion did not show any granulation tissue. However, in bronchoscopic examination carried out two years later, we detected invasion of the Palmaz stent to the trachea and development of granulation tissue. We think that expandable metallic stent placement should be considered in patients who show intractable respiratory symptoms caused by tracheomalacia in the earlier stages of the treatment. But long-term complications of this procedure are crucial.

Wall shear stress distributions on stented patent ductus arteriosus

NASA Astrophysics Data System (ADS)

Kori, Mohamad Ikhwan; Jamalruhanordin, Fara Lyana; Taib, Ishkrizat; Mohammed, Akmal Nizam; Abdullah, Mohammad Kamil; Ariffin, Ahmad Mubarak Tajul; Osman, Kahar

2017-04-01

A formation of thrombosis due to hemodynamic conditions after the implantation of stent in patent ductus arteriosus (PDA) will derived the development of re-stenosis. The phenomenon of thrombosis formation is significantly related to the distribution of wall shear stress (WSS) on the arterial wall. Thus, the aims of this study is to investigate the distribution of WSS on the arterial wall after the insertion of stent. Three dimensional model of patent ductus arteriosus inserted with different types of commercial stent are modelled. Computational modelling is used to calculate the distributions of WSS on the arterial stented PDA. The hemodynamic parameters such as high WSS and WSSlow are considered in this study. The result shows that the stented PDA with Type III stent has better hemodynamic performance as compared to others stent. This model has the lowest distributions of WSSlow and also the WSS value more than 20 dyne/cm2. From the observed, the stented PDA with stent Type II showed the highest distributions area of WSS more than 20 dyne/cm2. This situation revealed that the high possibility of atherosclerosis to be developed. However, the highest distribution of WSSlow for stented PDA with stent Type II indicated that high possibility of thrombosis to be formed. In conclusion, the stented PDA model calculated with the lowest distributions of WSSlow and WSS value more than 20dyne/cm2 are considered to be performed well in stent hemodynamic performance as compared to other stents.

Natural stent in the management of post-intubation tracheal stenosis.

PubMed

Park, Hye Yun; Kim, Hojoong; Koh, Won-Jung; Suh, Gee Young; Chung, Man Pyo; Kwon, O Jung

2009-05-01

The treatment choice for post-intubation tracheal stenosis (PITS) in patients for whom surgery is not initially feasible is bronchoscopic silicone stenting. A new silicone stent, called the Natural stent (N stent), was investigated for its clinical efficacy and safety in patients with PITS. A retrospective review was conducted of 32 patients with PITS who underwent N stenting between November 2001 and December 2006 and were followed for at least 12 months. Airway dilatation with combined modalities such as Nd:YAG laser, ballooning or bougienage was followed by N stent insertion. After intervention, all patients had symptomatic and spirometric improvement without immediate complications. Removal of the stent without re-stenosis was successful in 38% of the patients at a median time of 7 months after insertion. The stent could not be removed or needed reinsertion in 31% of patients, and 16% of patients underwent surgery after initial stabilization by stenting. Late complications were stent migration (34%), mucostasis (31%), granulation tissue formation (38%) and re-stenosis (40%). All patients tolerated the management of complications during a median follow up of 22 months. Bronchoscopic N stenting is an effective treatment for patients with PITS in whom surgery is not feasible on initial presentation. Further stent development is necessary to reduce the late complication rate.

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.

Antegrade jj stenting after percutaneous renal procedures: The ‘pull and push’ technique

PubMed Central

Ratkal, Jaideep M.; Sharma, Elias

2014-01-01

A JJ stent is inserted antegradely after percutaneous renal procedures like percutaneous nephrolithotomy (PCNL) for renal calculus disease, and for endopyelotomy for pelvi-ureteric junction obstruction. We describe a technique for antegrade stent insertion after PCNL. PMID:26413327

Percutaneous biliary drainage using open cell stents for malignant biliary hilar obstruction.

PubMed

Ahn, Sun Jun; Bae, Jae Ik; Han, Tae Sun; Won, Je Hwan; Kim, Ji Dae; Kwack, Kyu-Sung; Lee, Jae Hee; Kim, Young Chul

2012-01-01

To evaluate the feasibility, safety and the effectiveness of the complex assembly of open cell nitinol stents for biliary hilar malignancy. During the 10 month period between January and October 2007, 26 consecutive patients with malignant biliary hilar obstruction underwent percutaneous insertion of open cell design nitinol stents. Four types of stent placement methods were used according to the patients' ductal anatomy of the hilum. We evaluated the technical feasibility of stent placement, complications, patient survival, and the duration of stent patency. Bilobar biliary stent placement was conducted in 26 patients with malignant biliary obstruction-T (n = 9), Y (n = 7), crisscross (n = 6) and multiple intersecting types (n = 4). Primary technical success was obtained in 24 of 26 (93%) patients. The crushing of the 1st stent during insertion of the 2nd stent occurred in two cases. Major complications occurred in 2 of 26 patients (7.7%). One case of active bleeding from hepatic segmental artery and one case of sepsis after procedure occurred. Clinical success was achieved in 21 of 24 (87.5%) patients, who were followed for a mean of 141.5 days (range 25-354 days). The mean primary stent patency period was 191.8 days and the mean patient survival period was 299 days. Applying an open cell stent in the biliary system is feasible, and can be effective, especially in multiple intersecting stent insertions in the hepatic hilum.

Retrograde exchange of heavily encrusted ureteric stents via the ileal conduit: a technical report.

PubMed

Tapping, Charles Ross; Boardman, Phil

2014-02-01

We describe two cases of retrograde ureteric stent exchange of heavily encrusted ureteric stents (JJ) via tortuous ileal conduits. The blocked ureteric stents were snared from inside the conduit so they could be accessed and a wire inserted. The lumens of the stents were unblocked with a wire but the stents could not be withdrawn due to heavy encrustation of the ureteric stent in the renal pelvis. A stiff wire was inserted to provide support and a 9 French peel away sheath was used to remove the encrustations allowing the stents to be withdrawn and exchanged. This is a safe and successful technique allowing ureteric stents to be removed when heavily encrusted. © 2013 The Royal Australian and New Zealand College of Radiologists.

Plastic biliary stents for benign biliary diseases.

PubMed

Perri, Vincenzo; Familiari, Pietro; Tringali, Andrea; Boskoski, Ivo; Costamagna, Guido

2011-07-01

Biliary plastic stenting plays a key role in the endoscopic management of benign biliary diseases. Complications following surgery of the biliary tract and liver transplantation are amenable to endoscopic treatment by plastic stenting. Insertion of an increasing number of plastic stents is currently the method of choice to treat postoperative biliary strictures. Benign biliary strictures secondary to chronic pancreatitis or primary sclerosing cholangitis may benefit from plastic stenting in select cases. There is a role for plastic stent placement in nonoperative candidates with acute cholecystitis and in patients with irretrievable bile duct stones. Copyright © 2011 Elsevier Inc. All rights reserved.

Endoscopic biliary stenting in irretrievable common bile duct stones: stent exchange or expectant management-tertiary-centre experience and systematic review.

PubMed

Mohammed, Noor; Pinder, Matthew; Harris, Keith; Everett, Simon M

2016-07-01

Conventional endoscopic duct clearance may not be possible in up to 10%-15% of common bile duct stones (CBDS). Sphincterotomy and biliary drainage by endoprosthesis have for many years been the mainstay of management in irretrievable stones. Recent years have seen the advent of sphincteroplasty or cholangioscopically-guided electrohydraulic lithotripsy (EHL) permitting duct clearance in majority of cases. However, when bile duct clearance is not possible, options include long-term stenting followed by elective stent exchange (ESE) 6-12 monthly or permanent stent insertion (PSI) in selected cases, but it is not clear which management strategy among ESE and PSI is preferable. A retrospective review of all patients in Leeds Teaching Hospitals NHS Trust who underwent plastic stent insertion for biliary access for difficult CBDS from January 2006 to December 2011 was undertaken. Adult patients with irretrievable CBDS who had plastic stent insertions throughout the follow-up period were included. Patients who underwent PSI and ESE annually were retrospectively reviewed to determine the long-term outcomes. A detailed systematic review was also performed, examining the outcomes of CBDS managed with stents. During the study period, 674 patients underwent 1769 biliary-stent-related procedures; of which, 246 patients met our inclusion criteria. 201 patients had subsequent duct clearance. 45 patients were, therefore, included in the final analysis, 28 of whom underwent annual ESEs and 17 PSIs. Patients in the PSI group had higher American Society of Anesthesiologists (ASA) scores compared with the ESE group. In the PSI group, 9/17 patients presented acutely with blocked stents, 5 of whom presented within 12 months. 2/9 patients were severely ill and died within a fortnight following the repeat endoscopic retrograde cholangiopancreatography (ERCP). In the ESE group, 4/28 patients had duct clearance in subsequent ERCPs, 1/28 patient presented with a blocked stent, and no

Permanent stenting in "unextractable" common bile duct stones in high risk patients. A prospective randomized study comparing two different stents.

PubMed

Pisello, Franco; Geraci, Girolamo; Li Volsi, Francesco; Modica, Giuseppe; Sciumè, Carmelo

2008-11-01

Endoscopic sphincterotomy (ES) and stone extraction is the treatment of choice for bile duct stones. Therefore, if ES and conventional stone extraction fail, further treatment is mandatory. Insertion of a biliary endoprosthesis is an effective option. We treated 30 high-risk patients (17 women and 13 men, mean age 82 years) affected by difficult common bile duct stones. The patients were randomly assigned preoperatively using closed envelopes (blind randomization) into two groups to receive insertion of polyethylene or hydrophilic hydromer-coated polyurethane stent, respectively. Follow-up was achieved by contacting referring physicians and patient's relatives. Biliary drainage was established in all patients. Early minor complications occurred in 28%. In all these patients, the stent was a definitive measure. Median follow-up was 38 months. Late complications occurred in 34%. Cholangitis was the most frequent. During follow up, 11 patients died, two as result of a biliary-related cause. No statistically significant difference was observed on different stents patency. Endoprosthesis insertion as a permanent therapy is an effective alternative to surgery or dissolution therapy. Therefore, biliary stenting should preferably be restricted to high-risk patients unfit for operative treatment and with a short life expectancy.

Stenting of the Upper Gastrointestinal Tract: Current Status

DOE Office of Scientific and Technical Information (OSTI.GOV)

Katsanos, Konstantinos; Sabharwal, Tarun, E-mail: tarun.sabharwal@gstt.nhs.uk; 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.

A comparative evaluation of early stent occlusion among biliary conventional versus wing stents.

PubMed

Khashab, Mouen A; Hutfless, Susan; Kim, Katherine; Lennon, Anne Marie; Canto, Marcia I; Jagannath, Sanjay B; Okolo, Patrick I; Shin, Eun Ji; Singh, Vikesh K

2012-06-01

Conventional plastic stents with a lumen typically have limited patency. The lumenless wing stent was engineered to overcome this problem. The objective of this study was to compare the incidence of early stent occlusion (symptomatic occlusion/cholangitis necessitating re-insertion within 90 days) for wing stents and conventional plastic stents. Patients with biliary pathology treated with plastic biliary stenting during the period 2003-2009 comprised the study cohort. Patients who had at least one biliary wing stent placed comprised the wing stent group, whereas patients who underwent only conventional stent plastic placement comprised the conventional stent group. Patients were stratified by indication: benign biliary strictures (group 1), malignant biliary strictures (group 2), or benign biliary non-stricture pathology (group 3). The association of stent type with the occurrence of primary outcome by indication was analyzed by use of multivariable logistic regression. Three-hundred and forty-six patients underwent 612 ERCP procedures with placement of plastic biliary stent(s). On multivariate analysis, early stent occlusion did not differ between the wing and conventional groups in groups 1, 2, and 3. Among patients who achieved primary outcome in group 2, significantly fewer patients in the wing group had cholangitis (6.7% vs. 39.1%, P = 0.03). Among patients who achieved primary outcome in group 3, significantly fewer patients in the wing group had cholangitis (10% vs. 50%, P = 0.03). Early stent occlusion was similar for wing stents and conventional plastic stents. Wing stents, however, were associated with a lower incidence of cholangitis in patients with malignant biliary obstruction and benign non-stricturing biliary pathology.

Management of endoscopic biliary stenting for choledocholithiasis: Evaluation of stent-exchange intervals.

PubMed

Tohda, Gen; Dochin, Masaki

2018-01-16

To evaluate the best management of plastic stents in patients with choledocholithiasis who were unfit for endoscopic stone removal or surgery. Between April 2007 and September 2017, 87 patients (median age 83.7 years) with symptomatic choledocholithiasis were treated with insertion of 7-Fr plastic stents because complete endoscopic stone retrieval was difficult, and their general condition was not suitable for surgery. Seventy of these patients agreed to regular stent management and stent exchange was carried out at every 6 mo (Group A, n = 35) or every 12 mo (Group B, n = 35). The remaining 17 patients did not accept regular stent exchange, and stents were replaced when clinical symptoms appeared (Group C). We evaluated the frequency of biliary complication and stent patency rate during follow-up periods. The patency rate of biliary plastic stents was 91.4% at 6 mo (Group A) and 88.6% at 12 mo (Group B), respectively. Acute cholangitis occurred in 2.9% of Group A patients and in 8.6% of Group B patients. In Group C, median stent patency was 16.3 mo, and stent exchange was carried out in 70.6% of cases because of acute cholangitis or obstructive jaundice. Although a high incidence of acute cholangitis occurred, there was no biliary-related mortality. Plastic stent exchange at 12-mo intervals is considered a safe procedure for patients with choledocholithiasis. Long-term biliary stenting increases biliary complications, but it can be an acceptable option for select patients who are medically unfit for further invasive procedures.

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.

Peri-interventional antibiotic prophylaxis only vs continuous low-dose antibiotic treatment in patients with JJ stents: a prospective randomised trial analysing the effect on urinary tract infections and stent-related symptoms.

PubMed

Moltzahn, Felix; Haeni, Katharina; Birkhäuser, Frédéric D; Roth, Beat; Thalmann, George N; Zehnder, Pascal

2013-02-01

To evaluate the antibiotic treatment regime in patients with indwelling JJ stents, the benefits and disadvantages of a peri-interventional antibiotic prophylaxis were compared with those of a continuous low-dose antibiotic treatment in a prospective randomised trial. In all, 95 patients were randomised to either receive peri-interventional antibiotic prophylaxis during stent insertion only (group A, 44 patients) or to additionally receive a continuous low-dose antibiotic treatment until stent removal (group B, 51). Evaluations for urinary tract infections (UTI), stent-related symptoms (SRSs) and drug side-effects were performed before stent insertion and consecutively after 1, 2 and 4 weeks and/or at stent withdrawal. All patients received a peri-interventional antibiotic prophylaxis with 1.2 g amoxicillin/clavulanic acid. Amoxicillin/clavulanic acid (625 mg) once daily was administered for continuous low-dose treatment (group B). Primary endpoints were the overall rates of UTIs and SRSs. Secondary endpoints were the rates and severity of drug side-effects. Neither the overall UTI rates (group A: 9% vs group B: 10%), nor the rates of febrile UTIs (group A: 7% vs group B: 6%) were different between the groups. Similarly, SRS rates did not differ (group A: 98% vs group B: 96%). Antibiotic side-effect symptoms were to be increased in patients treated with low-dose antibiotics. A continuous antibiotic low-dose treatment during the entire JJ stent-indwelling time does not reduce the quantity or severity of UTIs and has no effect on SRSs either compared with a peri-interventional antibiotic prophylaxis only. © 2012 BJU International.

[How to prevent tissue overgrowth and incrustation of metal stents in the urinary tract in patients with pelvic malignancy] b ].

PubMed

Marković, Z; Masulović, D; Markovic, B; Anojcić, P; Mladenović, A

2009-01-01

At the current level of stent application in urology each irreversible urostasis contraindicated for surgical therapy implies consideration of indications for metal stent insertion. Stent incrustation which leads directly into a new uroobstruction is a characteristic complication of this method. Available experience in different uroobstructive conditions has shown that very different clinical aspects of stent usage may directly determine the possibility of their incrustation. Stent incrustation may occur in the early postprocedural course or several months later. After that, prevention of stent incrustation starts with postprocedural evaluation, selection of the stent type, and it is subsequently continued by insertion technique and lasts practically permanently after the insertion (infection control, promotion of diuresis and maintenance of normal urodynamics). Authors present own experianse in clinical aplication of metal stents in uroradiology strictures for period of last 15 years.

Mechanical properties of different airway stents.

PubMed

Ratnovsky, Anat; Regev, Noa; Wald, Shaily; Kramer, Mordechai; Naftali, Sara

2015-04-01

Airway stents improve pulmonary function and quality of life in patients suffering from airway obstruction. The aim of this study was to compare main types of stents (silicone, balloon-dilated metal, self-expanding metal, and covered self-expanding metal) in terms of their mechanical properties and the radial forces they exert on the trachea. Mechanical measurements were carried out using a force gauge and specially designed adaptors fabricated in our lab. Numerical simulations were performed for eight different stent geometries, inserted into trachea models. The results show a clear correlation between stent diameter (oversizing) and the levels of stress it exerts on the trachea. Compared with uncovered metal stents, metal stents that are covered with less stiff material exert significantly less stress on the trachea while still maintaining strong contact with it. The use of such stents may reduce formation of mucosa necrosis and fistulas while still preventing stent migration. Silicone stents produce the lowest levels of stress, which may be due to weak contact between the stent and the trachea and can explain their propensity for migration. Unexpectedly, stents made of the same materials exerted different stresses due to differences in their structure. Stenosis significantly increases stress levels in all stents. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

The role of biodegradable stents in the management of benign and malignant oesophageal strictures: A cohort study.

PubMed

McCain, Stephen; McCain, Scott; Quinn, Barry; Gray, Ronan; Morton, Joan; Rice, Paul

2016-12-01

Oesophageal strictures can be caused by benign or malignant processes. Up to 10% of patients with a benign stricture are refractory to pneumatic dilatation and may benefit from biodegradable stent (BD) insertion. Biodegradable stents also have a role in malignant oesophageal strictures to facilitate enteral nutrition while staging or neo-adjuvant treatment is completed. The aim of this study was to review the safety and efficacy of BD stents in the management of benign or malignant oesophageal strictures. A single centre retrospective cohort study was performed. Dysphagia was graded before and after stenting using a validated score. All patients were followed up for at least 30 days and all adverse events were recorded. Twenty eight stents were inserted in 20 patients; 11 for malignant and 17 for benign disease. One further attempted stenting was impossible due to a high benign stricture. There were no perforations and the 30-day mortality rate was zero. Mean dysphagia scores improved from 2.65 to 1.00 (p value <0.001) in benign disease and from 3.27 to 1.36 (p value <0.001) in patients with malignant disease. Surgical resection was not compromised following stent insertion in the malignant group. Biodegradable stent insertion is a safe and efficacious adjunct in the treatment of benign and malignant oesophageal strictures. In malignant disease, BD stent insertion can maintain enteral nutrition while staging or neo-adjuvant therapy is completed without adversely impacting on surgical resection. Copyright © 2015 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.

Treatment of Intra- and Extracranial Arterial Dissections Using Stents and Embolization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Joo, Jin Yang; Ahn, Jung Yong, E-mail: jyahn@cha.ac.kr; Chung, Young Sun

2005-06-15

Purpose. To evaluate the safety and efficacy of stent placement for extracranial and intracranial arterial dissections. Methods. Eighteen patients underwent endovascular treatment of carotid and vertebral dissections using intraluminal stent placement. Five patients with arterial dissection were treated, 2 using one insertion of a single stent and 3 using placement of two stents. Patients with a dissecting aneurysm were treated as follows: 7 patients with insertion of one stent, 4 with placement of two stents, and 2 by stent-assisted Guglielmi detachable coil embolization. In the 18 patients in whom stenting was attempted, the overall success in reaching the target lesionmore » was 94.4%. Of the 17 patients treated with stents, stent release and positioning were considered optimal in 16 (94%) and suboptimal in one (6%). In patients who underwent a successful procedure, all parent arteries were preserved. There were no instances of postprocedural ischemic attacks, new neurologic deficits, or new minor or major strokes prior to patient discharge. In follow up, all patients were assessed, using the modified Rankin scale, as functionally improved or of stable clinical status. The reduction in dissection-induced stenosis or pseudoaneurysm, the patency rate obtained at follow-up, and the lack of strokes (ischemic or hemorrhagic) suggest that stent placement offers a viable alternative to complex surgical bypass or reconstructive procedures. The long-term efficacy and durability of stent placement for arterial dissection remain to be determined in a larger series.« less

An approach to tracheostomy in a patient with an expandable metallic tracheal stent.

PubMed

Madden, Brendan P; Sheth, Abhijat

2005-09-01

With increasing use of expandable metallic stents to manage patients with a variety of endobronchial pathologies, some will have a subsequent need for tracheostomy insertion. We describe a successful technique to insert a tracheostomy using rigid and fibre-optic bronchoscopy in a patient who had an 8 cm expandable metallic tracheal stent deployed previously on account of tracheomalacia.

Double Y-stenting for tracheobronchial stenosis.

PubMed

Oki, Masahide; Saka, Hideo

2012-12-01

The purpose of the present study was to evaluate the feasibility, efficacy and safety of the double Y-stenting technique, by which silicone Y-stents are placed on both the main carina and another peripheral carina, for patients with tracheobronchial stenosis. Under general anaesthesia, using rigid and flexible bronchoscopes, a Dumon™ Y-stent (Novatech, La Ciotat, France) was first placed on the primary right or secondary left carina followed by another Y-stent on the main carina so as to insert the bronchial limb of the stent into the first Y-stent. Patients who underwent double Y-stent placement during 3 yrs and 1 month in a single centre were retrospectively reviewed. In the study period, 93 patients underwent silicone stent placement and 12 (13%) underwent double Y-stent placement (11 for right and one for left bronchus). A combination of Y-stents, 14 × 10 × 10 mm and 16 × 13 × 13 mm in outer diameter, were most frequently used. Dyspnoea was relieved in all patients. Six out of seven patients with supplemental oxygen before stent placement could be discharged without supplemental oxygen. Median survival after stenting was 94.5 days. One pneumothorax and one granuloma formation occurred. Double Y-stent placement for patients with tracheobronchial stenosis was technically feasible, effective and acceptably safe.

Self-expanding Y stents in the treatment of central airway stenosis: a retrospective analysis.

PubMed

Gompelmann, Daniela; Eberhardt, Ralf; Schuhmann, Maren; Heussel, Claus P; Herth, Felix J F

2013-10-01

Central airway obstruction (CAO) is a life-threatening situation. Stent insertion re-establishes patency of the central airways. Self-expanding metallic Y stents have been available since 2005, widening the spectrum of interventional bronchoscopic techniques. Retrospective analysis of all patients treated for CAO with a self-expanding metallic Y stent at the Thoraxklinik Heidelberg between May 2005 and January 2009. A total of 43 patients aged 26-81 had a metallic Y stent inserted endoscopically for the treatment of CAO; 39 of these patients (90.7%) had CAO due to malignant disease, four patients (9.3%) due to benign disease. In all 43 patients, the Y stent was deployed without any complications. A longitudinal follow up was possible in 32 of the 43 patients. The stents remained in situ for an average of 107.1 days (range 1-640 days). In 29 patients with malignant CAO the stenosis was successfully overcome with a Y stent; 11 of these patients died within 6 weeks following stent insertion. On follow up the remaining 18 patients showed immediate improvement of dyspnoea. Eight out of the 18 patients (44.4%) tolerated the stent without problems, two (11.1%) required further stenting, six (33.3%) had complications such as increased secretions, cough, dyspnoea or granulation tissue formation. The stent was removed in one patient (5.6%) due to increased secretions, and in another (5.6%) as the stent was no longer required due to successful tumour-specific therapy. Placement of Y stents in symptomatic CAO allows for quick relief of symptoms. Severe complications are rare. Stent removal is possible after successful treatment of the primary tumour. However, the prognostic indicator for survival is the underlying malignancy.

Successful silicon stent for life-threatening tracheal wall laceration.

PubMed

Yamamoto, Shinichi; Endo, Shunsuke; Endo, Tetsuya; Mitsuda, Sayaka

2013-01-01

We report an 86-year-old woman with a large tracheal laceration caused by tracheal intubation at cardiopulmonary arrest who underwent a successful stent procedure. Tracheal laceration developed in the membranous portion longitudinally 6 cm in length to 2 cm above the carina. Following 9 days' tracheal intubation, a Y-shaped silicon stent was inserted over the lacerated trachea. Four months after the stenting procedure, we removed the Y-shaped silicon stent from the healed membranous wall. The patient returned to daily life without requiring thoracotomy.

Biofilm Quantification on Nasolacrimal Silastic Stents After Dacryocystorhinostomy.

PubMed

Murphy, Jae; Ali, Mohammed Javed; Psaltis, Alkis James

2015-01-01

Biofilms are now recognized as potential factors in the pathogenesis of chronic inflammatory and infective diseases. The aim of this study was to examine the presence of biofilms and quantify their biomass on silastic nasolacrimal duct stents inserted after dacryocystorhinostomy (DCR). A prospective study was performed on a series of patients undergoing DCR with O'Donoghue stent insertion. After removal, the stents were subjected to biofilm analysis using standard protocols of confocal laser scanning microscopy (CLSM) and scanning electron microscopy. These stents were compared against negative controls and positive in vitro ones established using Staphylococcus aureus strain ATCC 25923. Biofilm quantification was performed using the COMSTAT2 software and the total biofilm biomass was calculated. A total of nine consecutive patient samples were included in this prospective study. None of the patients had any evidence of postoperative infection. All the stents demonstrated evidence of biofilm formation using both imaging modalities. The presence of various different sized organisms within a common exopolysaccharide matrix on CLSM suggested the existence of polymicrobial communities. The mean biomass of patient samples was 0.9385 μm³/μm² (range: 0.3901-1.9511 μm³/μm²). This is the first study to report the quantification of biomass on lacrimal stents. The presence of biofilms on lacrimal stents after DCR is a common finding but this need not necessarily translate to postoperative clinical infection.

Transjugular Insertion of Bare-Metal Biliary Stent for the Treatment of Distal Malignant Obstructive Jaundice Complicated by Coagulopathy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsauo Jiaywei, E-mail: 80732059@qq.com; Li Xiao, E-mail: simonlixiao@gmail.com; Li Hongcui, E-mail: lihongcui520@126.com

This study was designed to investigate retrospectively the feasibility of transjugular insertion of biliary stent (TIBS) for the treatment of distal malignant obstructive jaundice complicated by coagulopathy. Between April 2005 and May 2010, six patients with distal malignant obstructive jaundice associated with coagulopathy that was unable to be corrected underwent TIBS at our institution for the palliation of jaundice. Patients' medical record and imaging results were reviewed to obtain information about demographics, procedure details, complications, and clinical outcomes. The intrahepatic biliary tract was successfully accessed in all six patients via transjugular approach. The procedure was technically successfully in five ofmore » six patients, with a bare-metal stent implanted after traversing the biliary strictures. One procedure failed, because the guidewire could not traverse the biliary occlusion. One week after TIBS, the mean serum bilirubin in the five successful cases had decreased from 313 {mu}mol/L (range 203.4-369.3) to 146.2 {mu}mol/L (range 95.8-223.3) and had further decreased to 103.6 {mu}mol/L (range 29.5-240.9) at 1 month after the procedure. No bleeding, sepsis, or other major complications were observed after the procedure. The mean survival of these five patients was 4.5 months (range 1.9-5.8). On imaging follow-up, there was no evidence of stent stenosis or migration, with 100 % primary patency. When the risks of hemorrhage from percutaneous transhepatic cholangiodrainage are high, TIBS may be an effective alternative for the treatment of distal malignant obstructive jaundice.« less

Preventing intra-urethral migration of a guidewire during antegrade placement of a JJ stent: a technical modification

PubMed Central

Bansal, Ankur; Gupta, Piyush; Dalela, Disha; Dalela, Diwakar

2016-01-01

A JJ stent is usually inserted in antegrade fashion after percutaneous renal surgery. We describe a new technical modification for antegrade stent insertion that prevents intraoperative intra-urethral migration of the guidewire and saves operative time and cost. PMID:26951444

Evaluation of Ureteral Stent Colonization in Live-Donor Renal Transplant Recipients.

PubMed

Sarier, M; Demir, M; Duman, I; Yuksel, Y; Demirbas, A

2017-04-01

Ureteral stent insertion during kidney transplantation is a matter of debate. Stenting has been proven to reduce the risk of surgical complications. In addition, it has been reported to increase risks such as urinary tract infections especially after operation. Ureteral stent colonization (USC) is known to play a role in the pathogenesis of stent related-infections. The aim of this study was (1) to assess the frequency of USC and values of urine cultures in identifying colonizing bacteria; (2) to assess the importance of indwelling time for USC in live-donor renal transplant recipients; and (3) to evaluate the biomarker role of neutrophil-to-lymphocyte ratio (NLR) on USC. A total of 107 live-donor kidney transplant patients were included in the study (76 men and 31 women). The mean age was 43.7 years, and average indwelling time of the ureteral stent was 24.7 days. Patients were divided into three groups according to indwelling stent time as group 1: 15 to 21 days (3rd week), group 2: 22 to 28 days (4th week), and group 3: 29 to 35 days (5th week). The decision to remove the stent was primarily based on clinical judgment. Ureteral stents were removed with the use of flexible cystoscopy. Midstream urine for urine culture and blood samples for NLR were taken prior to stent removal. The removed stents were divided into three parts and taken for bacteriological investigation. Of 107 patients, USC was detected in 24 (22.4%) patients, whereas urinary proliferation was observed in 8 (7.4%) patients. The most common microorganisms found in USC was the Enterecoccus species. The most common microorganisms in urinary culture were Enterecoccus spp. and Klebsiella pnemoniae. All patients with isolated microorganisms in the urine had USC (P < .001). On the other hand, proliferation in urinary culture was observed only in 30% of patients. Urine culture was not significant in identification of USC (P = .063). The three patient groups that were determined according to

Drug-eluting stent in malignant biliary obstruction

NASA Astrophysics Data System (ADS)

Lee, Dong-Ki; Jang, Sung Ill

2012-10-01

Endoscopic stent insertion is the treatment of choice for patients with malignant biliary obstruction. However, conventional stents enable only mechanical palliation of the obstruction, without any anti-tumor effects. Drugeluting stent (DES), which was first introduced in coronary artery disease, are currently under investigation for sustaining stent patency and prolonging patient survival by inhibiting tumor ingrowth in malignant biliary obstruction. Many factors affecting efficient drug delivery have been studied to determine how drugs with antitumor effects suppress tumor ingrowth, including the specific drugs incorporated, means of incorporating the drugs, mode of drug release, and stent structure. Advances have resulted in the construction of more effective non-vascular DES and ongoing clinical research. Non-vascular DES is expected to play a vital role in prolonging the survival of patients with malignant biliary obstruction.

Percuflex Helical Ureteral Stents Significantly Reduce Patient Analgesic Requirements Compared to Control Stents.

PubMed

Chew, Ben H; Rebullar, Karla A; Harriman, David; McDougall, Elspeth; Paterson, Ryan F; Lange, Dirk

2017-12-01

Ureteral stent symptoms are experienced by the majority of patients with ureteral stents. No one stent or technology has shown a clear advantage. The Helical™ stent, a spirally cut stent made of proprietary Percuflex™ material, was designed to conform to the shape of the ureter and better accommodate patient movement. We prospectively sought to compare unscheduled visits, analgesic use, and pain scores in patients who received a Percuflex Helical ureteral stent following ureteroscopy compared to a historical control group. Fifteen (n = 15) patients undergoing ureteroscopy for the treatment of kidney stones were consented for study. A Percuflex Helical ureteral stent was inserted after treating the urinary stone. The historical control group consisted of 30 patients, from a previous (ketorolac eluting) ureteral stent study utilizing the same protocol and clinical monitoring forms, who received a regular Percuflex ureteral stent. The control patients were matched by age and sex. The primary study outcome was to compare unscheduled visits. Secondary outcomes included comparison of Visual Pain Analog Scale (VPAS) scores and analgesic use between the two groups. There were no differences in the gender, age, BMI, or stone characteristics between groups. Both groups underwent retrograde ureteroscopy using holmium:YAG laser lithotripsy and stone fragmentation. There was a significant reduction in the amount of analgesics required in the Helical stent group (4.4 ± 7.99 mg morphine equivalents) compared to controls (16.75 ± 18.31 mg, p = 0.0035) to achieve similar VPAS scores. There was no difference in unscheduled visits (20%) or VPAS scores (13.84 ± 13.68 helical vs 14.29 ± 11.58 control, p = 0.7910) between groups. Patients who received a Percuflex Helical ureteral stent required significantly fewer analgesics than those who received a Percuflex stent and both had equivalent pain scores.

Multi-stage surgery for airway patency after metallic stent removal in benign laryngotracheal airway disease in two adolescents.

PubMed

Coordes, Annekatrin; Todt, Ingo; Ernst, Arne; Seidl, Rainer O

2013-05-01

Laryngotracheal stents may damage the highly complex laryngeal structures, impair voice and swallowing functions and cause tissue ingrowths, thereby necessitating airway patency interventions. In benign airway disease, the number of adolescents with laryngotracheal stents is therefore limited. We present two cases of laryngeal metallic stent placement following benign airway disease. Two adolescents presented with severe dyspnea and self-expandable metallic stent placement after benign laryngotracheal stenoses. Granulation tissue ingrowths required additional surgical interventions every 6-8 weeks to recanalize the stent lumen. We performed multi-stage surgery including removal of the embedded stent, segmental resection of the stenotic area, end-to-end-anastomosis and laryngotracheal reconstruction respectively, to achieve patent airway without tracheal cannulation. Montgomery T-tubes were temporarily inserted to bridge the complex reconstructions. In both adolescents, we achieved successful removal of the embedded stent and patent airway. Bilateral vocal fold paralysis required additional surgery to improve the final airway patency and vocal rehabilitation. Stent removal, segmental resection and laryngotracheal reconstruction provide the achievement of patent airway and allow decannulation. Temporary Montgomery T-tubes bridge complex laryngotracheal reconstructions. In benign laryngeal airway disease, stent placement should be avoided, especially in adolescents. Transfer to a specialist center should be considered prior to metallic stent implantation. In general, self-expanding tracheobronchial stents can be placed in selected patients where surgical interventions are limited. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Preventing intra-urethral migration of a guidewire during antegrade placement of a JJ stent: a technical modification.

PubMed

Bansal, Ankur; Gupta, Piyush; Dalela, Disha; Dalela, Diwakar

2016-03-07

A JJ stent is usually inserted in antegrade fashion after percutaneous renal surgery. We describe a new technical modification for antegrade stent insertion that prevents intraoperative intra-urethral migration of the guidewire and saves operative time and cost. 2016 BMJ Publishing Group Ltd.

Urinary tract infections associated with ureteral stents: A Review.

PubMed

Liaw, A; Knudsen, B

2016-10-01

We review the literature on infections associated with ureteral stents and new technologies aimed at preventing them. Ureteral stent placement is one of the most common urologic procedures, but carries a comparatively high morbidity. Infection is one of the most common stent-associated morbidities. Several new stent materials and coatings have been proposed and tested to reduce stent-associated infections. We review the current methods of preventing bacterial infection, including antibiotic prophylaxis and minimising dwell time. We look at the science underlying infection and biofilm formation on stents. Several new stent materials and coatings are described, as well as the studies underlying their mechanism of action. While many promising ideas for new stent coatings and materials have been tested, no significant improvement to current polyurethane stent technology is commonly available or used. The basic principles of antibiotic prophylaxis at time of insertion, avoiding contamination, and minimising dwell times remain the best methods to prevent stent-associated infections.

Engineering solutions to ureteral stents: material, coating and design

PubMed Central

Mosayyebi, Ali; Vijayakumar, Aravinthan; Yue, Qi Y.; Bres-Niewada, Ewa; Manes, Costantino; Carugo, Dario

2017-01-01

Introduction An ideal stent would offer simple insertion and removal with no discomfort and/or migration, it would have no biofilm formation or encrustation and would also maintain the patient's quality of life. Material and methods In this mini-review, we outlined the engineering developments related to stent material, design and coating. Results There have been a wide variety of in-vitro, model-based, animal-based and clinical studies using a range of commercial and non-commercial stents. Ureteric stents have evolved since their first usage with a wider range of stent design, material and coating available for laboratory and clinical use. Conclusions While engineering innovations have led to the evolution of stents, more work needs to be done to address the issues relating to stent encrustation and biofilm formation. PMID:29104790

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

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

Self-expandable macroporous nitinol stents for transfemoral exclusion of aortic aneurysms in dogs: preliminary results.

PubMed

Hagen, B; Harnoss, B M; Trabhardt, S; Ladeburg, M; Fuhrmann, H; Franck, C

1993-01-01

This experimental study evaluated the feasibility of excluding artificially created aortic aneurysms in dogs with transfemorally inserted nitinol stents, serving as intraluminal bypass. Infrarenal aortic aneurysms were created in eleven dogs (28-35 kg) by end-to-end anastomosis of sacciform conduits. Single and double wire-knitted, macroporous, superelastic, self-expanding nitinol stents without any additional wrapping or in-between fabrics served as endovascular grafts. The pore size of the double-knitted stents was less than 0.7 mm2. Angiography following stent placement showed immediate exclusion of the aneurysms for the double-knitted stents. For the single-knitted stents (2 cases), partial exclusion was achieved only after considerable delay. CT studies in the dogs with the double-knitted stents revealed patency of the grafts after 3 to 5 weeks with the aneurysms totally thrombosed. So far gross pathology of 1 dog at 24 h and 1 at 12 months revealed patency of the stents. At 12 months histopathology showed a neointima covering the inner stent surface with the aneurysm filled by an organized thrombus. It is concluded, that an "open" stent with a tight meshwork appears to be a suitable device to instantly exclude artificial aneurysms of the canine aorta.

The Comparison of Double J Stent Insertion and Conservative Treatment Alone in Severe Pure Gestational Hydronephrosis: A Case Controlled Clinical Study

PubMed Central

Çeçen, Kürşat; Ülker, Kahraman

2014-01-01

Objective. Management options of gestational hydronephrosis are based on the coexisting stone disease, pyelonephritis, and renal disease. However, the management option and its consequences in the absence of a coexisting disease state are not clear. In this study we aimed to compare the effectiveness of conservative treatment and double J insertion in symptomatic pure gestational hydronephrosis. Material and Methods. The data of the women with severe pure gestational hydronephrosis over a nine-year period was collected retrospectively. The included women were grouped into two according to receiving double J stent insertion or conservative treatments. Results. Double J insertion and conservative treatment groups included 24 and 29 women, respectively. Hydronephrosis was demonstrated on the right, left, or both kidneys in 37 (70%), 13 (24%), and 3 (6%) women, respectively. None of the participants gave birth prior to the 37th week. The demographics, initial pain scores, the severity of the hydronephrosis during first admission, and pain scores one week after the interventions did not differ significantly between groups (P > 0.05). Similarly, the rates of complications, postpartum pain scores, and permanent hydronephrosis did not differ between groups (P > 0.05). Conclusion. Double J insertion in symptomatic pure gestational hydronephrosis adds no benefit to conservative treatment. PMID:24574939

An uncommon case of antegrade stent causing serious persistent haematuria

PubMed Central

Ejikeme, Chidozie M.

2015-01-01

Introduction Transient minor bleeding after nephrostomy tube placement is very common, occurring in up to 95% of cases. Often this is due to small vessel or venous bleeding. Severe post procedure bleeding requiring transfusion or other intervention is RARE. Presentation of case A case of a 79 year old man, who had antegrade stent insertion for 10 mm left upper ureteric stone. He was alright for up to one week but developed severe haemturia requiring three way catheter. Catheter was blocking regularly and needed to go to theatre for bladder washout. No source of bleeding was found in bladder. CT renal angiogram revealed his stent has migrated into the nephrostomy tract. He was taken to theatre and had his stent changed. His haematuria settled. Discussion The severe bleeding recorded in this case could not have been attributed to the stent, though the initial bleeding following the procedure has settled it seemed likely to blame vascular injury following PCN as the cause of bleeding. Subsequent CT scan was able to point at the right source of bleeding. Conclusion All possibilities should be considered when presented with a case severe bleeding following antegrade stent insertion. PMID:25797353

An uncommon case of antegrade stent causing serious persistent haematuria.

PubMed

Ejikeme, Chidozie M

2015-01-01

Transient minor bleeding after nephrostomy tube placement is very common, occurring in up to 95% of cases. Often this is due to small vessel or venous bleeding. Severe post procedure bleeding requiring transfusion or other intervention is RARE. A case of a 79 year old man, who had antegrade stent insertion for 10mm left upper ureteric stone. He was alright for up to one week but developed severe haemturia requiring three way catheter. Catheter was blocking regularly and needed to go to theatre for bladder washout. No source of bleeding was found in bladder. CT renal angiogram revealed his stent has migrated into the nephrostomy tract. He was taken to theatre and had his stent changed. His haematuria settled. The severe bleeding recorded in this case could not have been attributed to the stent, though the initial bleeding following the procedure has settled it seemed likely to blame vascular injury following PCN as the cause of bleeding. Subsequent CT scan was able to point at the right source of bleeding. All possibilities should be considered when presented with a case severe bleeding following antegrade stent insertion. Copyright © 2015 The Author. Published by Elsevier Ltd.. All rights reserved.

[Complications and the management of fully covered retrievable metal stent placement in benign tracheal stenosis].

PubMed

Wang, Zheng-yu; Wang, Yong-li; Chen, Guang-li; Liang, Xi-hong; Wang, Zhen-chang; Ma, Jian-zhong; Wu, Guang-zhong; Zhang, Xiao-ping

2012-11-01

To study complications and the management of the use of covered retrievable expandable metallic stents in the treatment of benign tracheal stenosis. Fully covered retrievable metal stents were placed in 21 patients with benign tracheal stenosis. Stent-related complications and the management were reviewed and analysed. Twenty-eight fully covered retrievable metallic stents were successfully placed fluoroscopically in 21 patients. Stents were removed 4 - 12 months [mean (5.5 ± 2.2) mouths] after placement in all patients. Stent-related complications included granulation tissue (n = 18), stent migration (n = 4), stent expectoration (n = 2), halitosis (n = 8), mucous retention (n = 21) and mucus plugging (n = 1). Granulation tissue was removed with a carbon dioxide laser in 2 patients. Stents were replaced for 2 times and 3 times respectively in 2 patients after stent migration and stent expectoration. An additional stent was placed in 2 patients after stent migration. Symptom of halitosis was relieved after prolonged course of systemic antibiotics treatment in 8 patients. Symptom of mucous retention was relieved with nebulized saline and N-acetylcysteine saline inhalation. Mucous plug was expelled after severe coughing after suctioning using an aspirator in one patient. There were statistically significant differences in stricture diameter, rank of tachypnea and pulmonary function (FEV(1)) in all 21 patients before stent insertion and after stents removal. No patient has experienced recurrence during the follow-up period of 1 - 36 months [mean (23.2 ± 8.0) months]. Fully covered retrievable metallic stent may be a safe and effective in benign tracheal stenosis. Stent-related complications may be effectively managed.

Endoscopic removal of malfunctioning biliary self-expandable metallic stents.

PubMed

Familiari, Pietro; Bulajic, Milutin; Mutignani, Massimiliano; Lee, Linda S; Spera, Gianluca; Spada, Cristiano; Tringali, Andrea; Costamagna, Guido

2005-12-01

Endoscopic removal of malfunctioning self-expandable metallic biliary stents (SEMS) is difficult and not well described. The aim of this study is to review the indications, the techniques, and the results of SEMS removal in a cohort of patients with malfunctioning stents. All patients who underwent an attempt at endoscopic removal of biliary SEMS over a 5-year period were retrospectively identified. The main indications for SEMS removal were the following: distal migration of the stent or impaction to the duodenum, impaction into the bile-duct wall, tissue ingrowth, and inappropriate length of the stent causing occlusion of intrahepatic ducts. SEMS were removed by using foreign-body forceps or polypectomy snares. Endoscopic removal of 39 SEMS (13 uncovered and 26 covered) was attempted in 29 patients (17 men; mean age, 66 years). SEMS extraction was attempted after a mean of 7.5 months (8.75 months standard deviation) post-SEMS insertion. Removal was successful in 20 patients (68.9%) and in 29 SEMS (74.3%). Covered SEMS were effectively removed more frequently than uncovered ones: 24 of 26 (92.3%) and 5 of 13 (38.4%), respectively (p < 0.05). No major complications were recorded. Multivariate analysis showed that the time interval between insertion and removal, SEMS length, stent-mesh design (zigzag vs. interlaced), and indication for removal were not predictive of success at stent removal. Endoscopic removal of biliary SEMS is feasible and safe in more than 70% of cases. Because only 38% of uncovered SEMS were removable, the presence of a stent covering is the only factor predictive of successful stent extraction. The presence of diffuse and severe ingrowth was the main feature limiting SEMS removal.

[Tracheobronchial stents: a retrospective analysis of indications, results and in particular complications].

PubMed

Tonn, H; Mall, W; Schneider, K-D; Schönhofer, B

2008-10-01

Tracheobronchial stents are inserted mainly in cases of malignant and benign airway stenosis. Further indications are esophago-tracheal fistulas, mediastinal fistulas and tracheomalacia. A retrospective analysis was conducted on patients' records, information provided by the general practitioners and relatives of the patients from July 1993 to December 2006 in the Department of Pneumology of the Heidehaus Hospital Hannover (since 6/05 Department of Pneumology and Internal Intensive Care Medicine, Oststadt-Heidehaus Hospital). During the observation period of 13 years a total of 269 stents (177 permanent, 92 temporary) were implanted in 207 patients (1.3 stents per patient). The vast majority of patients (173/207) suffered from an underlying malignancy. About half of the stents were deployed in the trachea. The median length of placement was 116 days in patients with malignancies and 313 days in patients with benign diseases. In about 40 % of the patients notable complications were observed which were directly or indirectly associated with the stents. These findings show the importance of a critical indication for stent implantation. In benign diseases a stent can remain for years inside the tracheobronchial system, if it is well tolerated in the beginning. In malignant diseases the result depends decisively on the stage of the tumour: has the stent been implanted before any other tumour therapy is started or is it an end-stage tumor with no other therapeutic option? In general, complications of stents occur quite frequently. The analysis of stent data leads to some aspects for the prevention of stent-related complications. There should be a strict indication and appropriate choice of stent material. Nevertheless, there remains an ethical dilemma in patients with end-stage disease as to whether to implant a stent or to do nothing against the tumor, because the benefit immediately after stent insertion vanishes with progression of the tumour, so causing extra

Fiber-reinforced silicone for tracheobronchial stents: An experimental study.

PubMed

Vearick, Samanta Bianchi; Demétrio, Kétner Bendo; Xavier, Rogério Gastal; Moreschi, Alexandre Heitor; Muller, André Frotta; Sanches, Paulo Roberto Stefani; Dos Santos, Luis Alberto Loureiro

2018-01-01

A trachea is a tubular structure composed of smooth muscle that is reinforced with cartilage rings. Some diseases can cause sagging in smooth muscle and cartilaginous tissue. The end result is reduction (narrowing) of the trachea diameter. A solution to this problem is the use of tracheal stents, which are small tubular devices made of silicone. One is inserted into the trachea to prevent or correct its constriction. The purpose of tracheal stent use is to maintain cartilage support that would otherwise be lost in the airway. Current tracheal stent models present limitations in terms of shape and characteristics of the silicone used in their production. One of the most important is the large thickness of the wall, which makes its placement difficult; this mainly applies to pediatric patients. The wall thickness of the stent is closely related to the mechanical properties of the material. This study aims to test the reinforcement of silicone with three kinds of fibers, and then stents that were produced using fiber with the best compressive strength characteristics. Silicone samples were reinforced with polypropylene (PP), polyamide (PA), and carbon fiber (CF) at concentrations of 2% and 4% (vol%), which then underwent tensile strength and Shore A hardness testing. Samples with fiber showed good characteristics; surface analyses were carried out and they were used to produce stents with an internal diameter of 11 or 13mm and a length of 50mm. Stents underwent compression tests for qualitative evaluation. Samples with 2% and 4% CF blends showed the best mechanical performance, and they were used to produce stents. These samples presented similar compressive strengths at low deformation, but stents with a 4% CF blend exhibited improved compressive strength at deformations greater than 30-50% of their diameter (P ≤ 0.05). The addition of 2% and 4% CF blends conferred greater mechanical strength and resistance to the silicone matrix. This is particularly true at low

Biodegradable braided poly(lactic-co-glycolic acid) urethral stent combined with dutasteride in the treatment of acute urinary retention due to benign prostatic enlargement: a pilot study.

PubMed

Kotsar, Andres; Isotalo, Taina; Juuti, Hanne; Mikkonen, Joonas; Leppiniemi, Jenni; Hänninen, Venla; Kellomäki, Minna; Talja, Martti; Tammela, Teuvo L J

2009-03-01

To evaluate, in a pilot study, the efficacy and safety of combining a braided poly(lactic-co-glycolic acid) (PLGA, a copolymer of l-lactide and glycolide) urethral stent and dutasteride in the treatment of acute urinary retention (AUR) due to benign prostatic enlargement (BPE). Ten men with AUR due to BPE were treated as outpatients. A biodegradable braided PLGA urethral stent was inserted into the prostatic urethra, using a specially designed insertion device under visual control. Dutasteride treatment was started and the patients were followed up for 3 months after insertion of the stents. In all patients the stents were placed successfully with the new insertion device. All men were able to void after inserting the stent. At 1 month five patients voided freely with a low residual urine volume (<150 mL), two voided but had a high residual urine volume and a suprapubic catheter was placed, and three needed a suprapubic or an indwelling catheter before 1 month, due to AUR or comorbidities. At 3 months five patients were voiding with no problems. We have developed a new and effective insertion device for biodegradable braided prostatic stents. The new braided-pattern stent overcomes the earlier problems of migration and sudden breakage into large particles associated with biodegradable spiral stents. However, the mechanical properties of the new stent need to be improved and tested in a longer follow-up. We consider that this new biodegradable braided-pattern urethral stent could provide a new option in the future treatment of AUR.

Plastic Biliary Stent Occlusion: Factors Involved and Possible Preventive Approaches

PubMed Central

Donelli, Gianfranco; Guaglianone, Emilio; Di Rosa, Roberta; Fiocca, Fausto; Basoli, Antonio

2007-01-01

Endoscopic biliary stenting is today the most common palliative treatment for patients suffering from obstructive jaundice associated with malignant hepatobiliary tumors or benign strictures. However, recurrent jaundice, with or without cholangitis, is a major complication of a biliary endoprosthesis insertion. Thus, stent removal and replacement with a new one frequently occurs as a consequence of device blockage caused by microbial biofilm growth and biliary sludge accumulation in the lumen. Factors and mechanisms involved in plastic stent clogging arising from epidemiological, clinical and experimental data, as well as the possible strategies to prevent biliary stent failure, will be reviewed and discussed. PMID:17456835

Efficacy and tolerance of a new silicone stent for the treatment of benign tracheal stenosis: preliminary results.

PubMed

Vergnon, J M; Costes, F; Polio, J C

2000-08-01

In inoperable patients with tracheal stenosis who are treated using silicone stents, stent migration occurs in 18.6% of cases. To decrease the migration rate, we have designed a new silicone stent with narrow central and larger distal parts. This study analyzes the stability and tolerance of this new stent. Preliminary prospective study conducted in two French university hospitals. Thirteen inoperable patients with benign complex tracheal stenosis due to intubation or tracheotomy. Tracheal stent insertion was performed under general anesthesia with a rigid bronchoscope. The patients were followed up clinically up to stent removal, which was planned at 18 months. Stent insertion or removal was very simple and did not differ from other silicone stents. No migration occurred after a mean follow-up of 22.8 months. Minimal granuloma formation occurred in only one patient (7.7%). Sputum retention remained similar to that with other silicone stents and could be improved by a smoother internal wall. Stents have been removed in seven patients after a mean duration of 19.6 months, with a complete stenosis cure in four cases. This new stent combines the excellent stability of the metallic stents and the tolerance and easy removal of straight silicone stents. This allows a prolonged use in order to obtain curative action.

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.

Treatment of congenital tracheal stenosis by balloon-expandable metallic stents in paediatric intensive care unit

PubMed Central

Xu, Xuan; Li, Dandan; Zhao, Shuyu; Liu, Xicheng; Feng, Zhichun; Ding, Hui

2012-01-01

The aim of this study was to evaluate the use of balloon-expandable metallic stents in the treatment of children with congenital tracheal stenosis in whom conventional therapy has failed. From 2010 to 2011, balloon-expandable metallic stents were implanted into the trachea of eight infants aged 2–20 months in the paediatric intensive care unit. The infants had severe airway obstruction caused by congenital tracheal stenosis. Tracheal stents were placed after intraluminal balloon dilatation of the tracheal stenosis, inserted with balloon catheters and implanted into the desired position bronchoscopically. The stents were 12 to 29 mm long and 4 mm in diameter. Seven children were relieved of airway obstruction after this procedure. However, a child died due to severe sepsis after the placement of bronchial stents. No granulation tissue developed over the stents in any of the children. Stents have been in place for 1–6 months after insertion without any other complication. Balloon-expandable metallic stents are effective in relieving airway obstruction by congenital tracheal stenosis in children. This technique may provide an important remedy for congenital tracheal stenosis in children. PMID:22361127

Covered Balloon-Expanding Stents in Airway Stenosis.

PubMed

Majid, Adnan; Kheir, Fayez; Chung, Jey; Alape, Daniel; Husta, Bryan; Oh, Scott; Folch, Erik

2017-04-01

The balloon-expanding stents are widely available but rarely described for use within the tracheobronchial tree. This report describes our experience with these stents in airway stenosis particularly as a lobar salvage therapy. This was a retrospective review of all records in which the balloon-expanding stents were used at a tertiary medical center. Ages, sex, location of stenosis, etiology of stenosis, stent size, duration of stent placement and associated interventions for airway stenosis were recorded. Patient's self-reported respiratory symptoms, dyspnea scale, and radiographic imaging at baseline and after stent placement were also reported. Twenty-one Atrium iCAST stents were inserted in 18 patients with malignant and benign airway disease. The median age was 69.5 years (interquartile range, 53.5 to 74). Most stents (n=20, 95%) were deployed in the lobar airways. There was a significant improvement in the modified Medical Research Council dyspnea scale from median of 3 to 2 (P<0.05). Self-reported respiratory symptoms improved in 14 patients (78%, P<0.05). Radiographic improvement post Atrium iCAST stent placement was achieved in 15 patients (83%). No deaths were related to airway stenting complications. Adverse events related to stents included migration (n=2, 9.5%), granulation tissue formation (n=2, 9.5%) and mucus plugging (n=1, 4.8%). Lobar stenting with balloon-expanding metallic stents appears feasible, safe and improves symptoms as well as radiographic atelectasis in patients with lobar airway stenosis in this small case series. Larger studies are needed to confirm this observation and to address long-term safety.

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. © 2014 Wiley Periodicals, Inc.

Allium™ TPS--A New Prostatic Stent for the Treatment of Patients with Benign Prostatic Obstruction: The First Report.

PubMed

Yildiz, Guner; Bahouth, Zaher; Halachmi, Sarel; Meyer, Gil; Nativ, Ofer; Moskovitz, Boaz

2016-03-01

Several prostatic stents were developed in the last three decades, none of which were able to provide a real alternative in patients unfit or unwilling to undergo classical prostatic surgeries. In this study, we report the results of the use of a newly developed prostatic stent--the Allium™ Triangular Prostatic Stent (TPS). The Allium TPS is a highly flexible, nitinol-built polymer-covered stent, which prevents tissue ingrowth and reduces encrustations. Between 2008 and 2014, at two centers (Israel and Turkey), the stent was inserted under local or regional anesthesia in 51 patients with benign prostatic obstruction (BPO) who are unwilling or unfit for surgery. Patients were followed for 12 months from surgery. The primary outcome was symptom improvement as measured by the international prostate symptom score (IPSS) and improvement in peak urinary flow. Stent insertion was successful in all patients. The mean IPSS decreased from 26.4 to 7.7 on the last follow-up. The mean peak flow increased from 5.5 mL/second before stent insertion to 16.0 mL/second 1 year thereafter. The main adverse effect was transient pain in nine patients. No stent migration or obstruction was seen. Patients reported satisfaction and improvement in quality of life. Our short-term results show that Allium TPS is safe and effective for the treatment of patients with BPO.

Self-Expandable Metallic Stent Placement in Malignant Gastric Outlet Obstruction: A Comparison Between 2 Brands of Stents.

PubMed

Ye, Bing-Wei; Lee, Kuei-Chuan; Hsieh, Yun-Cheng; Li, Chung-Pin; Chao, Yee; Hou, Ming-Chih; Lin, Han-Chieh

2015-07-01

Malignant gastric outlet obstruction is a late complication of intraabdominal malignancy. Self-expandable metallic stent placement has been a safe palliative treatment to relieve obstructive symptoms. We aimed to assess the efficacy and safety of metallic stents in our patients and analyzed the clinical outcome of different brands. Seventy-one patients with inoperable gastric outlet obstruction receiving WallFlex enteral stents (WallFlex group) or Bonastents (Bonastent group) since April 2010 were analyzed retrospectively. The overall technical and clinical success rates of stent placement were 100% and 93%, respectively. The baseline characteristics and clinical outcomes including procedure-related complications, restenosis, and reintervention rates were comparable between the 2 groups. However, the Bonastent group had a higher rate of stent fracture than the WallFlex group (13.3% vs 0%, P = 0.03). The mean duration of overall stent patency was 132.7 days. The mean duration of survival was 181.9 days. Resumption of regular diet or low residual diet at day 7 after stent insertion predicted stent patency (hazard ratio [HR]: 0.28, P = 0.01). Cancer with gastric origin (HR: 0.25, P = 0.045) and poststent chemotherapy (HR: 0.38, P = 0.006) predicted lower mortality; however, peritoneal carcinomatosis (HR: 3.09, P = 0.04) correlated with higher mortality. Metallic stent placement is a safe and effective method for relieving gastric outlet obstruction. Except higher rate of stent fracture in the Bonastent group, there is no significant difference in clinical outcomes between the Bonastent group and the WallFlex group.

Ureteric stents vs percutaneous nephrostomy for initial urinary drainage in children with obstructive anuria and acute renal failure due to ureteric calculi: a prospective, randomised study.

PubMed

ElSheemy, Mohammed S; Shouman, Ahmed M; Shoukry, Ahmed I; ElShenoufy, Ahmed; Aboulela, Waseem; Daw, Kareem; Hussein, Ahmed A; Morsi, Hany A; Badawy, Hesham

2015-03-01

To compare percutaneous nephrostomy (PCN) tube vs JJ ureteric stenting as the initial urinary drainage method in children with obstructive calcular anuria (OCA) and post-renal acute renal failure (ARF) due to bilateral ureteric calculi, to identify the selection criteria for the initial urinary drainage method that will improve urinary drainage, decrease complications and facilitate the subsequent definitive clearance of stones, as this comparison is lacking in the literature. A series of 90 children aged ≤12 years presenting with OCA and ARF due to bilateral ureteric calculi were included from March 2011 to September 2013 at Cairo University Pediatric Hospital in this randomised comparative study. Patients with grade 0-1 hydronephrosis, fever or pyonephrosis were excluded. No patient had any contraindication for either method of drainage. Stable patients (or patients stabilised by dialysis) were randomised (non-blinded, block randomisation, sealed envelope method) into PCN-tube or bilateral JJ-stent groups (45 patients for each group). Initial urinary drainage was performed under general anaesthesia and fluoroscopic guidance. We used 4.8-6 F JJ stents or 6-8 F PCN tubes. The primary outcomes were the safety and efficacy of both groups for the recovery of renal functions. Both groups were compared for operative and imaging times, complications, and the period required for a return to normal serum creatinine levels. The secondary outcomes included the number of subsequent interventions needed for clearance of stones. Additional analysis was done for factors affecting outcome within each group. All presented patients completed the study with intention-to-treat analysis. There was no significant difference between the PCN-tube and JJ-stent groups for the operative and imaging times, period for return to a normal creatinine level and failure of insertion. There were significantly more complications in the PCN-tube group. The stone size (>2 cm) was the only factor

[Use of esophageal small balloon or papillary sphincter knife in the treatment of stent implantation 
for colorectal malignant obstruction].

PubMed

Xiao, Dinghua; Liu, Shaojun; Yan, Hanguang; Wang, Xiaoyan

2018-05-28

To explore the function of esophageal small balloon or papillary sphincter knife in the treatment of stent implantation for colorectal malignant obstruction, and to improve the success rate of colonic stent placement in such patients.
 Methods: A total of 49 patients with colorectal cancer complicated with almost complete obstruction or colorectal cancer were enrolled for this study. The esophageal small balloon or papillary sphincter knife was used in the guide wires. The guide wires gradually crossed the tumor gap and they were placed in the contralateral intestinal cavity with balloon progression. X-ray was then used to confirm whether the guide wire was inserted in the lesion intestinal cavity, and then the metal bare stent was inserted.
 Results: The guide wires was successfully inserted with conventional methods in these 49 cases, while they were also successfully placed the guide wire and the stent in the new way.
 Conclusion: For the patients with colorectal cancer complicated with complete obstruction or colorectal cancer located in obviously angled location, the use of esophageal small balloon or papillary sphincter knife can help the guide wire insert. They greatly improve the success rate of stent implantation.

Evaluation of symptoms and patients' comfort for JJ-ureteral stents with and without antireflux-membrane valve.

PubMed

Ecke, Thorsten H; Bartel, Peter; Hallmann, Steffen; Ruttloff, Jürgen

2010-01-01

To evaluate safety and patients' comfort by using the ureteral stent symptom questionnaire. Ureteral stents are used to provide upper urinary-tract drainage. A total of 133 JJ-ureteral stents with and without antireflux-membrane valve as consecutive referrals for therapy of hydronephrosis have been inserted. Four weeks after insertion of the ureteral stent, the patients were asked about pain while urination, flank pain due to reflux, and the comparison with former stents. Ultrasound of the kidney for hydronephrosis grade and creatinine value as follow-up have been documented. Statistical analysis included chi(2) test after Pearson correlation computed and performed by SPSS software. We found a high correlation between the JJ-ureteral stent used and the detection of a hydronephrosis (P = .004). More patients who had a JJ-ureteral stent without valve complained of flank pain (P <.0005) and pain in the bladder (P <.0005). Patients who had a ureteral stent before were asked to compare new stents with the former ones. No patients with a JJ-ureteral stent with valve found this one to be worse than what they had before. JJ-stent related symptoms are a major problem for these patients. New stent designs and materials will be developed in the future to reduce stent-related morbidity and improve patient comfort. JJ-ureteral stents with an antireflux-membrane valve have a lower complication rate and provide a higher patient comfort compared with stents without valve. Crown Copyright 2010. Published by Elsevier Inc. All rights reserved.

Use of covered self-expandable stents for benign colorectal disorders in children.

PubMed

Lange, Bettina; Sold, Moritz; Kähler, Georg; Wessel, Lucas M; Kubiak, Rainer

2017-01-01

There is a lack of experience with covered self-expandable stents for benign colorectal disorders in children. Five children (4M, 1F) with a median age of 5years (range, 6months-9years) who underwent treatment with covered self-expandable plastic (SEPSs) or self-expandable metal stents (SEMSs) for a benign colorectal condition between April 2005 and November 2013 were recruited to this retrospective study. Etiologies included: anastomotic stricture with (n=1) or without (n=3) simultaneous enterocutaneous fistula, as well as an anastomotic leak associated with enterocutaneous fistula (n=1). All children suffered from either Hirschsprung's disease (n=3) or total colonic aganglionosis (Zuelzer-Wilson syndrome) (n=2). Median duration of individual stent placement was 23days (range, 1-87days). In all cases up to five different stents were placed over time. At follow-up two patients were successfully treated without further intervention. In another patient the anastomotic stricture resolved fully, but a coexisting enterocutaneous fistula persisted. Overall, three patients did not improve completely following stenting and required definite surgery. Stent-related problems were noted in all cases. There was one perforation of the colon at stent insertion. Further complications consisted of stent dislocation (n=4), obstruction (n=1), formation of granulation tissue (n=1), ulceration (n=1) and discomfort (n=3). Covered self-expandable stents enrich the armamentarium of interventions for benign colorectal disorders in children including anastomotic strictures and intestinal leaks. A stent can be applied either as an emergency procedure (bridge to surgery) or as an adjuvant treatment further to endoscopy and dilatation. Postinterventional problems are frequent but there is a potential for temporary or definite improvement following stent insertion. Copyright © 2017. Published by Elsevier Inc.

Experimental use of new absorbable tracheal stent.

PubMed

Schopf, Luciano F; Fraga, José Carlos; Porto, Rodrigo; Santos, Luis A; Marques, Douglas R; Sanchez, Paulo R; Meyer, Fabíola S; Ulbrich, Jane M

2017-11-16

Silicone and metallic stents are not effective in children with tracheobronchial stenosis or tracheomalacia. Herein, we aimed to evaluate the clinical manifestations and histological reaction of rabbit trachea to the presence of a new poly(lactic-co-glycolic acid) with polyisoprene (PLGA/PI) polymer absorbable stent. Fourteen adult white rabbits (weight, 3.0-3.5kg) were randomly assigned to three groups: Group I (n=6): PLGA/PI spiral stent; Group II (n=6): PLGA/PI fragment; and Group III (n=2): controls. After a longitudinal incision on three cervical tracheal rings, the stents and fragments were inserted into the trachea and fixed onto the lateral wall with nonabsorbable sutures. The stented group showed significantly more stridor at rest (p=0.0041), agitation (p=0.014), and use of accessory muscles (p=0.0002) and required more emergency endoscopies than the fragment group. Further, it showed significantly more remarkable histological inflammatory damage than the fragment and control groups (p=0.002). The new PLGA/PI polymeric stent implanted into the trachea of rabbits caused more clinical manifestations and histologically verified inflammatory reaction than the PLGA/PI polymeric fragment. Future studies should be aimed at reducing the stent-wall thickness. Copyright © 2017 Elsevier Inc. All rights reserved.

Use of self-expandable plastic stents for the treatment of esophageal perforations and symptomatic anastomotic leaks.

PubMed

Gelbmann, C M; Ratiu, N L; Rath, H C; Rogler, G; Lock, G; Schölmerich, J; Kullmann, F

2004-08-01

Extensive anastomotic leaks after esophageal resection and esophageal perforations are a therapeutic challenge. The aim of the present study was to assess the potential of the self-expandable Polyflex plastic stent for the treatment of these conditions. Between January 2002 and March 2003, nine patients were treated with a self-expandable Polyflex plastic stent for sealing of thoracic esophagoenteric anastomotic leaks following surgical resection (n = 5) or esophageal perforation (n = 4). In all patients the stents were inserted successfully without technical problems. In all but two patients complete sealing of the leak was achieved as demonstrated by radiography with water-soluble contrast media. The stent migration rate was 30 % and repositioning of the migrated stents was possible in all cases. Complete mucosal healing of the esophageal leaks and stent extraction was achieved in six patients. The stents were in situ for an average period of 135 +/- 78 days. Two critically ill patients with anastomotic leaks died in spite of stent insertion due to sepsis and one patient with esophageal perforation died due to the underlying malignant disease. Our preliminary experience with the self-expanding and removable Polyflex plastic stent for the sealing of anastomotic leaks and esophageal perforations suggests that this stent is a feasible treatment option, in particular, for more extensive esophageal defects, patients with co-morbid conditions, and critically ill patients.

Late peripheral stent thrombosis due to stent fracture, vigorous exercise and hyporesponsiveness to clopidogrel.

PubMed

Linnemann, Birgit; Thalhammer, Axel; Wolf, Zsuzsanna; Tirneci, Vanessa; Vogl, Thomas J; Edelgard Lindhoff-Last, And

2012-03-01

Late peripheral arterial stent thrombosis usually occurs due to haemodynamically relevant in-stent restenosis. However, late stent thrombosis may be multicausal. We report here the well-documented case of a 69-year-old man with acute thrombosis of the stented superficial femoral artery after a long-distance bicycle tour. Catheter-directed thrombolysis revealed a residual stenosis located at a stent fracture site. In addition, platelet function tests revealed an inadequate platelet response to clopidogrel. In conclusion, stent fracture, strenuous exercise and hyporesponsiveness to clopidogrel may have contributed to the development of late peripheral stent thrombosis.

French experience of silicone tracheobronchial stenting in children.

PubMed

Fayon, Michael; Donato, Lionel; de Blic, Jacques; Labbé, André; Becmeur, François; Mely, Laurent; Dutau, Hervé

2005-01-01

Silicone stents were inserted into the trachea or left main-stem bronchus in 14 children aged 2-69 months (median, 7 months). Indications were as follows: tracheomalacia or airway kinking (7 cases), vascular compression (5 cases), and surgically corrected congenital tracheal stenoses (2 cases). The best results were obtained in tracheomalacia. Overall, 6 cases out of 14 (43%) were considered successful, with a stent placement duration of 3-15 months (median, 7 months). Two cases were considered a technical success, although they were clinical failures. Five cases were considered failures primarily due to stent migration. A retrospective analysis of failures suggests that most of these could have been avoided by the use of larger stents. One patient died of stent obstruction. No wall erosion was observed, and the development of granulation tissue was infrequent. Endoscopic removal of the prostheses was uneventful. The biocompatibility of silicone stents appears to be better than what is reported for metal ones, although the stability of the former is less satisfactory. The present study shows the feasibility of silicone stent placement in infants. These stents should be considered as a possible therapeutic option in certain types of childhood airway disorders, although further studies are required.

Management of post-gastrectomy anastomosis site obstruction with a self-expandable metallic stent.

PubMed

Cha, Ra Ri; Lee, Sang Soo; Kim, Hyunjin; Kim, Hong Jun; Kim, Tae-Hyo; Jung, Woon Tae; Lee, Ok Jae; Bae, Kyung Soo; Jeong, Sang-Ho; Ha, Chang Yoon

2015-04-28

Post-gastrectomy anastomosis site obstruction is a relatively rare complication after a subtotal gastrectomy. We present a case of a 75-year-old man who underwent a truncal vagotomy, omental patch, gastrojejunostomy, and Braun anastomosis for duodenal ulcer perforation and a gastric outlet obstruction. Following the 10(th) postoperative day, the patient complained of abdominal discomfort and vomiting. We diagnosed post-gastrectomy anastomosis site obstruction by an upper gastrointestinal series and an upper endoscopic examination. We inserted a self-expandable metallic stent (SEMS) at the anastomosis site. The stent was fully expanded after deployment. On the day following the stent insertion, the patient began to eat, and his abdominal discomfort was resolved. This paper describes the successful management of post-gastrectomy anastomosis site obstruction with temporary placement of a SEMS.

Comparison of expandable endotracheal stents in the treatment of surgically induced piglet tracheomalacia.

PubMed

Mair, E A; Parsons, D S; Lally, K P; Van Dellen, A F

1991-09-01

Present surgical alternatives for pediatric tracheobronchomalacia are limited and associated with many potentially undesirable complications. The feasibility of different intraluminal expandable endotracheal stents for the treatment of surgically induced tracheomalacia was analyzed in 27 piglets. A potentially fatal tracheomalacia was surgically created. Either a stainless steel "zig-zag" stent or a woven polymeric stent was then implanted. Tracheal patency, mucosal function, histopathologic respiratory tract changes, and effects of the stent on esophageal motility were evaluated over a 16-week period. Piglets with steel stents uniformly experienced intense inflammation leading to tracheal dysfunction and death. Piglets with polymeric stents experienced minimal respiratory symptoms. Expandable polymeric endotracheal stents alleviate surgically induced piglet tracheomalacia, were easy to insert, allowed for tracheal growth, and reduced the need for high-risk surgical procedures with prolonged ventilatory support.

Wing-shaped plastic stents vs. self-expandable metal stents for palliative drainage of malignant distal biliary obstruction: a randomized multicenter study.

PubMed

Schmidt, Arthur; Riecken, Bettina; Rische, Susanne; Klinger, Christoph; Jakobs, Ralf; Bechtler, Matthias; Kähler, Georg; Dormann, Arno; Caca, Karel

2015-05-01

Previous studies have shown superior patency rates for self-expandable metal stents (SEMS) compared with plastic stents in patients with malignant biliary obstruction. The aim of this study was to compare stent patency, patient survival, and complication rates between a newly designed, wing-shaped, plastic stent and SEMSs in patients with unresectable, malignant, distal, biliary obstruction. A randomized, multicenter trial was conducted at four tertiary care centers in Germany. A total of 37 patients underwent randomization between March 2010 and January 2013. Patients underwent endoscopic retrograde cholangiography with insertion of either a wing-shaped, plastic stent without lumen or an SEMS.  Stent failure occurred in 10/16 patients (62.5 %) in the winged-stent group vs. 4/18 patients (22.2 %) in the SEMS group (P = 0.034). The median time to stent failure was 51 days (range 2 - 92 days) for the winged stent and 80 days (range 28 - 266 days) for the SEMS (P = 0.002). Early stent failure (< 8 weeks after placement) occurred in 8 patients (50 %) vs. 2 patients (11.1 %), respectively (P = 0.022). After obtaining the results from this interim analysis, the study was discontinued because of safety concerns. The frequency of stent failure was significantly higher in the winged-stent group compared with the SEMS group. A high incidence of early stent failure within 8 weeks was observed in the winged-stent group. Thus, the winged, plastic stent without central lumen may not be appropriate for mid or long term drainage of malignant biliary obstruction. Study registration ClinicalTrials.gov (NCT01063634). © Georg Thieme Verlag KG Stuttgart · New York.

Drug- and Gene-eluting Stents for Preventing Coronary Restenosis

PubMed Central

Lekshmi, Kamali Manickavasagam; Che, Hui-Lian; Cho, Chong-Su

2017-01-01

Coronary artery disease (CAD) has been reported to be a major cause of death worldwide. Current treatment methods include atherectomy, coronary angioplasty (as a percutaneous coronary intervention), and coronary artery bypass. Among them, the insertion of stents into the coronary artery is one of the commonly used methods for CAD, although the formation of in-stent restenosis (ISR) is a major drawback, demanding improvement in stent technology. Stents can be improved using the delivery of DNA, siRNA, and miRNA rather than anti-inflammatory/anti-thrombotic drugs. In particular, genes that could interfere with the development of plaque around infected regions are conjugated on the stent surface to inhibit neointimal formation. Despite their potential benefits, it is necessary to explore the various properties of gene-eluting stents. Furthermore, multifunctional electronic stents that can be used as a biosensor and deliver drug- or gene-based on physiological condition will be a very promising way to the successful treatment of ISR. In this review, we have discussed the molecular mechanism of restenosis, the use of drug- and gene-eluting stents, and the possible roles that these stents have in the prevention and treatment of coronary restenosis. Further, we have explained how multifunctional electronic stents could be used as a biosensor and deliver drugs based on physiological conditions. PMID:28184335

The BioStent: novel concept for a viable stent structure.

PubMed

Weinandy, Stefan; Rongen, Lisanne; Schreiber, Fabian; Cornelissen, Christian; Flanagan, Thomas Cormac; Mahnken, Andreas; Gries, Thomas; Schmitz-Rode, Thomas; Jockenhoevel, Stefan

2012-09-01

Percutaneous stenting of occluded peripheral vessels is a well-established technique in clinical practice. Unfortunately, the patency rates of small-caliber vessels after stenting remain unsatisfactory. The aim of the BioStent concept is to overcome in-stent restenosis by excluding the diseased vessel segment entirely from the blood stream, in addition to providing an intact endothelial cell layer. The concept combines the principles of vascular tissue engineering with a self-expanding stent: casting of the stent within a cellularized fibrin gel structure, followed by bioreactor conditioning, allows complete integration of the stent within engineered tissue. Small-caliber BioStents (Ø=6 mm; n=4) were produced by casting a nitinol stent within a thin fibrin/vascular smooth muscle cell (vSMC) mixture, followed by luminal endothelial cell seeding, and conditioning of the BioStent within a bioreactor system. The potential remodeling of the fibrin component into tissue was analyzed using routine histological methods. Scanning electron microscopy was used to assess the luminal endothelial cell coverage following the conditioning phase and crimping of the stent. The BioStent was shown to be noncytotoxic, with no significant effect on cell proliferation. Gross and microscopic analysis revealed complete integration of the nitinol component within a viable tissue structure. Hematoxylin and eosin staining revealed a homogenous distribution of vSMCs throughout the thickness of the BioStent, while a smooth, confluent luminal endothelial cell lining was evident and not significantly affected by the crimping/release process. The BioStent concept is a platform technology offering a novel opportunity to generate a viable, self-expanding stent structure with a functional endothelial cell lining. This platform technology can be transferred to different applications depending on the luminal cell lining required.

The effect of stent coating on stent deliverability: direct randomised comparison of drug eluting and bare metal stents using the same stent platform.

PubMed

Siminiak, Tomasz; Link, Rafał; Wołoszyn, Maciej; Kałmucki, Piotr; Baszko, Artur

2012-01-01

There is certain experimental and clinical evidence indicating that the covering of bare metal stents (BMS) with drug eluting polymers to produce drug eluting stents (DES) results in increased stent stiffness and modifies the mechanical properties of the stent platform. In addition, it has been speculated that the mechanical performance of DES, compared to BMS, may be related to the type of polymer used to cover stents. We aimed at evaluating the deliverability of DES with a lactate based biodegradable polymer and BMS in patients with stable coronary artery disease in a prospective randomised study. One hundred eleven consecutive patients (age: 36-77, mean 58.8 years) scheduled for routine angioplasty due to stable coronary disease were randomised to receive BMS (Chopin II(TM), Balton, Poland) or paclitaxel eluting stent (Chopin Luc(TM), Balton, Poland) using the same metal platform. Only patients scheduled for angioplasty using the direct implantation technique of a single stent were randomised. The exclusion criteria included patients 〉 80 years, multivessel disease and reference diameter of the target vessel 〉 3.5 mm. In the BMS group (n = 55; 35 males and 20 females), the mean diameter of implanted stents was 3.09 ± 0.40 and the mean length was 11.37 ± 2.80, whereas in the DES group (n = 56; 34 males and 22 females) the mean stent sizes were 3.02 ± 0.34 and 17.90 ± 7.38 mm, respectively (p 〉 0.05 for length). The groups did not significantly differ regarding the frequency of stent implantation to particular coronary vessels. The direct stenting technique was attempted and failed, leading to the stents' implantation after predilatation in five patients in the BMS group and six patients in the DES group. Failure of stent implantation and subsequent implantation of another stent type was observed in no BMS patients and in one DES patient (NS). Although stent covering with lactate based drug eluting polymer may increase its stiffness, it does not affect

Application of memory metallic stents to urinary tract disorders in pediatric patients.

PubMed

Kamata, Shinkichi; Usui, Noriaki; Kamiyama, Masafumi; Yoneda, Akihiro; Tazuke, Yuko; Ooue, Takaharu

2005-03-01

The use of memory metallic stents for the urinary tract in pediatric patients has not been reported. The authors report on 2 patients with urinary tract disorders who were successfully treated with a memory metallic stent. A thermoexpandable, nickel-titanium alloy stent was placed at the urethroureteral junction of a 4-year-old boy with ureteral stenosis associated with cloacal exstrophy for 18 months and at the urethra of a 2-year-old girl with ischuria after a repair of cloacal anomaly for 6 months. Temporary insertion of a memory metallic stent is a safe and effective alternative for organic stricture or functional obstruction of the urinary tract in pediatric patients.

Comparison of covered versus uncovered wire mesh stents in the canine biliary tract.

PubMed

Silvis, S E; Sievert, C E; Vennes, J A; Abeyta, B K; Brennecke, L H

1994-01-01

Self-expanding wire mesh stents have been developed for endoscopic placement across malignant biliary strictures, but tumor ingrowth may limit the usefulness of open mesh stents. We reasoned that coating the wire mesh might prevent tumor ingrowth. Tissue response to covered and uncovered stents was compared in dogs. Stents were surgically placed in the bile ducts of 22 mongrel dogs through the sphincter of Oddi. Either a silicone-covered stent or an uncovered stent was inserted. Liver function test values remained normal throughout a 1- or 3-month study. Necropsy revealed that all ducts were unobstructed. Bile duct histologic examination revealed mild-to-moderate cellular infiltration in all animals. Mucosal hyperplasia was more marked in the animals with uncovered stents and the bare wires became deeply embedded in bile duct epithelium, whereas the wires of covered stents did not. We conclude that covered stents are well tolerated by the canine bile duct. These results suggest that such stents may be removable, making self-expanding metal stents an appropriate treatment for both benign and malignant biliary strictures.

Stenting of the Cystic Duct in Benign Disease: A Definitive Treatment for the Elderly and Unwell

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hersey, N., E-mail: naomi.hersey@sth.nhs.uk; Goode, S. D., E-mail: s.goode@sheffield.sc.uk; Peck, R. J., E-mail: robert.peck@sth.nhs.uk

PurposeThere have been few case reports describing cystic duct stent insertion in the management of acute cholecystitis secondary to benign disease with no case series published to date. We present our series demonstrating the role of cystic duct stents in managing benign gallbladder disease in those patients unfit for surgery.Materials and MethodsThirty three patients unfit for surgery in our institution underwent cystic duct stent insertion for the management of acute cholecystitis in the period June 2008 to June 2013. Patients underwent a mixture of transperitoneal and transhepatic gallbladder puncture. The cystic duct was cannulated with a hydrophilic guidewire which wasmore » subsequently passed through the common bile duct and into the duodenum. An 8Fr 12-cm double-pigtail stent was placed with the distal end lying within the duodenum and the proximal end within the gallbladder.ResultsTen patients presented with gallbladder perforation, 21 patients with acute cholecystitis, 1 with acute cholangitis and 1 with necrotising pancreatitis. The technical success rate was 91 %. We experienced a 13 % complication rate with 3 % mortality rate at 30 days.ConclusionCystic duct stent insertion can be successfully used to manage acute cholecystitis, gallbladder empyema or gallbladder perforations in those unfit for surgery and should be considered alongside external gallbladder drainage as a definitive mid-term treatment option.« less

Automated detection of a prostate Ni-Ti stent in electronic portal images.

PubMed

Carl, Jesper; Nielsen, Henning; Nielsen, Jane; Lund, Bente; Larsen, Erik Hoejkjaer

2006-12-01

Planning target volumes (PTV) in fractionated radiotherapy still have to be outlined with wide margins to the clinical target volume due to uncertainties arising from daily shift of the prostate position. A recently proposed new method of visualization of the prostate is based on insertion of a thermo-expandable Ni-Ti stent. The current study proposes a new detection algorithm for automated detection of the Ni-Ti stent in electronic portal images. The algorithm is based on the Ni-Ti stent having a cylindrical shape with a fixed diameter, which was used as the basis for an automated detection algorithm. The automated method uses enhancement of lines combined with a grayscale morphology operation that looks for enhanced pixels separated with a distance similar to the diameter of the stent. The images in this study are all from prostate cancer patients treated with radiotherapy in a previous study. Images of a stent inserted in a humanoid phantom demonstrated a localization accuracy of 0.4-0.7 mm which equals the pixel size in the image. The automated detection of the stent was compared to manual detection in 71 pairs of orthogonal images taken in nine patients. The algorithm was successful in 67 of 71 pairs of images. The method is fast, has a high success rate, good accuracy, and has a potential for unsupervised localization of the prostate before radiotherapy, which would enable automated repositioning before treatment and allow for the use of very tight PTV margins.

Efficacy and safety of biodegradable stents for refractory benign esophageal strictures: the BEST (Biodegradable Esophageal Stent) study.

PubMed

Repici, Alessandro; Vleggaar, Frank P; Hassan, Cesare; van Boeckel, Petra G; Romeo, Fabio; Pagano, Nicola; Malesci, Alberto; Siersema, Peter D

2010-11-01

Benign esophageal strictures refractory to standard dilation therapy present a challenging problem. Temporary plastic and metal stents have been proposed with inconclusive results. To evaluate the efficacy and safety of a new biodegradable stent for the treatment of refractory benign esophageal strictures (RBESs). Prospective study from 2 European endoscopy centers. Twenty-one patients (11 men/10 women, mean age 60.2 ± 17.6 years) with RBESs defined according to the Kochman criteria treated by placement of a biodegradable stent (Ella stent). Clinical and endoscopic follow-up was scheduled at 1, 2, 3, and 6 months and later only in case of dysphagia recurrence. Pre- and poststenting dysphagia status was graded according to a 5-point scale. Minor and major complication rates were prospectively assessed. Stent insertion was technically successful in all of the patients. At 4 and 7 weeks, stent migration occurred in 2 patients (9.5%). At 3-month endoscopy, the stent appeared to be almost completely fragmented in all remaining patients. The median pre- and poststenting dysphagia scores were 3 (range 3-4) and 1 (range 0-2), respectively (P < .01), with a median follow-up of 53 weeks (range 25-88 weeks). In detail, 9 of 20 patients (45%) were dysphagia free at the end of the follow-up. No major complications occurred. Severe poststenting pain requiring analgesics developed in 3 patients, and minor bleeding was observed in 1 patient. Limited follow-up; nonrandomized study. In this preliminary study, the biodegradable stent showed a favorable risk/benefit ratio, achieving complete relief of dysphagia in nearly 50% of RBES patients without the occurrence of major complications. The use of this stent may be a valuable alternative to repeat endoscopic dilation. Larger studies with longer follow-up are needed. Copyright © 2010 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

New developments in the use of prostatic stents

PubMed Central

Papatsoris, Athanasios G; Junaid, Islam; Zachou, Alexandra; Kachrilas, Stefanos; Zaman, Faruquz; Masood, Junaid; Buchholz, Noor

2011-01-01

Bladder outflow obstruction is a very common age-related clinical entity due to a variety of benign and malignant diseases of the prostate. Surgical treatment under general or regional anesthesia is not suitable for high-risk elderly patients who seek minimally invasive management. Unfortunately, for patients who are not fit for transurethral and/or laser prostatectomy, few treatment options remain, other than long-term catheterization and insertion (under local anesthesia) of a prostatic stent. In this review, we present developments in the use of prostatic stents. PMID:24198637

Metallic stents for tracheobronchial pathology treatment.

PubMed

Serrano, Carolina; Laborda, Alicia; Lozano, Juan M; Caballero, Hugo; Sebastián, Antonio; Lopera, Jorge; de Gregorio, Miguel Ángel

2013-12-01

To present the 7-year experience of the treatment of benign and malignant tracheobronchial stenoses using metallic stents. 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. 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. 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.

Metallic Stents for Tracheobronchial Pathology Treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Serrano, Carolina, E-mail: carolina.serrano@unizar.es; Laborda, Alicia, E-mail: alaborda@unizar.es; Lozano, Juan M., E-mail: juamauloz@gmail.com

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 techniquesmore » 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.« less

Meta-Analysis of Stenting versus Non-Stenting for the Treatment of Ureteral Stones

PubMed Central

Wang, Hai; Man, Libo; Li, Guizhong; Huang, Guanglin; Liu, Ning; Wang, Jianwei

2017-01-01

Background and aim Ureteroscopic lithotripsy (URL) and extracorporeal shock wave lithotripsy (ESWL) are two widely used methods for the treatment of ureteral stones. The need for ureteral stenting during these procedures is controversial. In this meta-analysis, we evaluated the benefits and disadvantages of ureteral stents for the treatment of ureteral stones. Methods Databases including PubMed, Embase and Cochrane library were selected for systematic review of randomized controlled trials (RCTs) comparing outcomes with or without stenting during URL and ESWL. Meta-analysis was performed using RevMan 5.3 and STATA 13.0 software. Results We identified 22 RCTs comparing stenting and non-stenting. The stented group was associated with longer operation time (WMD: 4.93; 95% CI: 2.07 to 7.84; p < 0.001), lower stone-free rate (OR: 0.55; 95% CI: 0.34 to 0.89; p = 0.01). In terms of complications, the incidence of hematuria (OR: 3.68; 95% CI: 1.86 to 7.29; p < 0.001), irritative urinary symptoms (OR: 4.40; 95% CI: 2.19 to 9.10; p < 0.001), urinary infection (OR: 2.23; 95% CI: 1.57 to 3.19; p < 0.001), and dysuria (OR: 3.90; 95% CI: 2.51 to 6.07; p < 0.001) were significantly higher in the stented group. No significant differences in visual analogue score (VAS), stricture formation, fever, or hospital stay were found between stenting and non-stenting groups. The risk of unplanned readmissions (OR: 0.63; 95% CI: 0.41 to 0.97; p = 0.04) was higher in the non-stented group. Conclusions Our analysis showed that stenting failed to improve the stone-free rate, and instead, it resulted in additional complications. However, ureteral stents are valuable in preventing unplanned re-hospitalization. Additional randomized controlled trials are still required to corroborate our findings. PMID:28068364

Cephalic Arch Stenosis in Autogenous Haemodialysis Fistulas: Treatment With the Viabahn Stent-Graft

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shawyer, Andrew, E-mail: andrew.shawyer@bartsandthelondon.nhs.uk; Fotiadis, Nicos I., E-mail: fotiadis.nicholas@gmail.com; Namagondlu, Girish, E-mail: girish.namagondlu@bartsandthelondon.nhs.uk

2013-02-15

Cephalic arch stenosis (CAS) is an important and common cause of dysfunction in autogenous haemodialysis fistulas that requires multiple reinterventions and aggressive surveillance. We evaluated the safety and efficacy of the Viabahn stent-graft for the management of CAS. Between April 2005 and October 2011, 11 consecutive patients [four men and seven women (mean age 56.7 years)] with CAS and dysfunctional fistulas were treated with insertion of 11 Viabahn stent-grafts. Six stent-grafts were inserted due to residual stenosis after angioplasty and five for fistuloplasty-induced rupture. No patient was lost to follow-up. The technical and clinical success rate was 100 %. Primarymore » access patency rates were 81.8 % [95 % confidence interval (CI) 0.482-0.977] at 6 months and 72.7 % (95 % CI 0.390-0.939) at 12 months. Secondary access patency rates were 90.9 % at 6 months (95 % CI 0.587-0.997). There were no procedure-related complications. Mean follow-up was 543.8 days (range 156-2,282). The use of the Viabahn stent-graft in the management of CAS is technically feasible and, in this small series, showed patency rates that compare favorably with historical data of angioplasty and bare stents.« less

Routine short-term ureteral stent in living donor renal transplantation: introduction of a simple stent removal technique without using anesthesia and cystoscope.

PubMed

Dong, J; Lu, J; Zu, Q; Yang, S; Sun, S; Cai, W; Zhang, L; Zhang, X

2011-12-01

We evaluated routine short-time insertion of ureteral stent in living donor renal transplant at a single center. It was easy to remove the stent without cystoscopy and anesthesia. Between October 2007 and July 2010, a single surgeon performed 76 living donor renal transplantations at one institute. All recipients underwent extravesical ureteroneocystostomy with a 2-0 silk suture passed through the venting side hole of the double-J stent into the bladder; a quadruple knot prevented the suture's slippage or distraction from the stent. After removal of the indwelling catheter at 5 days posttransplantation, the 2-0 silk passed with the urinary stream within 72 hours. The double-J stent was removed at 7 to 10 (mean 8.4) days after kidney transplantation by pulling the 2-0 silk out of the urethral orifice without anesthesia or cystoscopy. There was only one case of stenosis, which was resolved by surgery. No patient developed urinary leakage. There were three episodes of urinary tract infection in 70 patients during first 6 months' follow-up. Routine short-term stenting is a safe and effective technique in living donor renal transplantation. Removal of the stent is feasible without cystoscopy or anesthesia. Copyright © 2011 Elsevier Inc. All rights reserved.

Long-term outcome of self expandable metal stents for biliary obstruction in chronic pancreatitis.

PubMed

Waldthaler, Alexander; Schütte, Kerstin; Weigt, Jochen; Kropf, Siegfried; Malfertheiner, Peter; Kahl, Stefan

2013-01-10

Insertion of a self-expandable metal stent is still controversial for treatment of benign common bile duct stenosis but can be a valuable alternative to surgical treatment. Aim of our study was to analyze the efficacy of covered and uncovered self-expandable metal stent in patients with chronic pancreatitis and common bile duct stenosis. Twenty patients with common bile duct stenosis due to alcoholic chronic pancreatitis were retrospective analyzed. All patients had advanced chronic pancreatitis, presenting with calcifications in pancreatic head. Uncovered self-expandable metal stent (uSEMS) were used in 11 patients (3 females, 8 males) while in 9 patients (3 females, 6 males) partially covered self-expandable metal stent (cSEMS) were inserted. All patients treated with self-expandable metal stent had contraindications for surgery. Overall mean follow up time was 155 weeks: 206 (52-412) weeks in uSEMS, and 93 (25-233) weeks in cSEMS, respectively. Stent patency was in mean 118 weeks: 159 (44-412) weeks in uSEMS and 67 (25-150) weeks in cSEMS (P=0.019). In the uSEMS group, reintervention was necessary in 5 patients (45%) due to stent obstruction, whereas in the cSEMS group 4 patients (44%) needed reintervention (2 obstructions, 2 migration). Stent migration is an early complication, compared to obstruction (P<0.05), and in cSEMS obstruction occurred significantly earlier compared to uSEMS (P<0.05). Patency of uSEMS was significantly longer compared to partially cSEMS. Available self-expandable metal stent, unfortunately, do not meet the demands on successful treatment of benign common bile duct stenosis.

Management of acute cholangitis as a result of occlusion from a self-expandable metallic stent in patients with malignant distal and hilar biliary obstructions.

PubMed

Shiomi, Hideyuki; Matsumoto, Kazuya; Isayama, Hiroyuki

2017-04-01

Acute cholangitis as a result of common bile duct stones can be managed; however, cholangitis caused by occlusion with a biliary self-expandable metallic stent (SEMS) in patients with an unresectable malignant biliary obstruction has not been fully discussed. The acute cholangitis clinical guidelines (Tokyo Guidelines 2013) recommend following the same procedure as that used for cholangitis; however, the patient's condition, including performance status, tumor extension or staging, and prognosis must be considered. Most physicians manage cholangitis from a SEMS occlusion using a two-step procedure. They insert endoscopic drainage with a plastic stent or insert a nasobiliary drainage tube, which does not exacerbate sepsis. Addition or replacement of a biliary SEMS is required in many cases depending on the cause of the occlusion. Tumor ingrowth through the stent mesh is common in uncovered SEMS and requires placement of another stent in an in-stent method. However, covered SEMS tends to be occluded by sludge, so it must be replaced because of the bacterial biofilm that forms on the covering membrane. The location of the biliary stricture (hilar or distal) should also be considered. Strategies for managing cholangitis as a result of occlusion by a biliary SEMS remain controversial, so prospective clinical trials are needed. © 2017 The Authors. Digestive Endoscopy © 2017 Japan Gastroenterological Endoscopy Society.

Timing of silicone stent removal in patients with post-tuberculosis bronchial stenosis.

PubMed

Eom, Jung Seop; Kim, Hojoong; Park, Hye Yun; Jeon, Kyeongman; Um, Sang-Won; Koh, Won-Jung; Suh, Gee Young; Chung, Man Pyo; Kwon, O Jung

2013-10-01

In patients with post-tuberculosis bronchial stenosis (PTBS), the severity of bronchial stenosis affects the restenosis rate after the silicone stent is removed. In PTBS patients with incomplete bronchial obstruction, who had a favorable prognosis, the timing of stent removal to ensure airway patency is not clear. We evaluated the time for silicone stent removal in patients with incomplete PTBS. A retrospective study examined PTBS patients who underwent stenting and removal of a silicone stent. Incomplete bronchial stenosis was defined as PTBS other than total bronchial obstruction, which had a luminal opening at the stenotic segment on bronchoscopic intervention. The duration of stenting was defined as the interval from stent insertion to removal. The study included 44 PTBS patients and the patients were grouped at intervals of 6 months according to the duration of stenting. Patients stented for more than 12 months had a significantly lower restenosis rate than those stented for less than 12 months (4% vs. 35%, P = 0.009). Multiple logistic regression revealed an association between stenting for more than 12 months and a low restenosis rate (odds ratio 12.095; 95% confidence interval 1.097-133.377). Moreover, no restenosis was observed in PTBS patients when the stent was placed more than 14 months previously. In patients with incomplete PTBS, stent placement for longer than 12 months reduced restenosis after stent removal.

Prospective Evaluation of Two iStent® Trabecular Stents, One iStent Supra® Suprachoroidal Stent, and Postoperative Prostaglandin in Refractory Glaucoma: 4-year Outcomes.

PubMed

Myers, Jonathan S; Masood, Imran; Hornbeak, Dana M; Belda, Jose I; Auffarth, Gerd; Jünemann, Anselm; Giamporcaro, Jane Ellen; Martinez-de-la-Casa, Jose M; Ahmed, Iqbal Ike K; Voskanyan, Lilit; Katz, L Jay

2018-03-01

This study evaluates long-term outcomes of two trabecular micro-bypass stents, one suprachoroidal stent, and postoperative prostaglandin in eyes with refractory open angle glaucoma (OAG). Prospective ongoing 5-year study of 80 eligible subjects (70 with 4-year follow-up) with OAG and IOP ≥ 18 mmHg after prior trabeculectomy and while taking 1-3 glaucoma medications. Subjects received two iStent ® trabecular micro-bypass stents, one iStent Supra ® suprachoroidal stent, and postoperative travoprost. Postoperative IOP was measured with medication and annually following medication washouts. Performance was measured by the proportion of eyes with ≥ 20% IOP reduction on one medication (the protocol-specified prostaglandin) versus preoperative medicated IOP (primary outcome); and the proportion of eyes with postoperative IOP ≤ 15 and ≤ 18 mmHg on one medication (secondary outcome). Additional clinical and safety data included medications, visual field, pachymetry, gonioscopy, adverse events, visual acuity, and slit-lamp and fundus examinations. Preoperatively, mean medicated IOP was 22.0 ± 3.1 mmHg on 1.2 ± 0.4 medications, and mean unmedicated IOP was 26.4 ± 2.4 mmHg. Postoperatively, among eyes without later cataract surgery, mean medicated IOP at all visits through 48 months was ≤ 13.7 mmHg (≥ 37% reduction), and annual unmedicated IOP was ≤ 18.4 mmHg (reductions of ≥ 30% vs. preoperative unmedicated IOP and ≥ 16% vs. preoperative medicated IOP). At all postoperative visits among eyes without additional surgery or medication, ≥ 91% of eyes had ≥ 20% IOP reduction on one medication versus preoperative medicated IOP. At month 48, 97 and 98% of eyes achieved IOP ≤ 15 and ≤ 18 mmHg, respectively, on one medication. Six eyes required additional medication, no eyes required additional glaucoma surgery, and safety measurements were favorable throughout follow-up. IOP control was achieved safely with two

Dilatation by Soehendra stent retriever is feasible and effective in multiple deployment of metallic stents to malignant hilar biliary strictures.

PubMed

Kato, Hironari; Kawamoto, Hirofumi; Noma, Yasuhiro; Sonoyama, Takayuki; Tsutsumi, Koichiro; Fujii, Masakuni; Okada, Hiroyuki; Yamamoto, Kazuhide

2013-01-01

The endoscopic management of malignant hilar biliary strictures using multiple metallic stents (MS) is technically demanding, in the initial deployment of MS and the recovery from MS occlusion with deployment of multiple plastic stents (PS). We evaluated the outcomes of the application of a Soehendra stent retriever (SSR) as a dilator of intractable strictures. Fifty-nine patients with malignant hilar biliary strictures had multiple MS inserted using a partial stent-in-stent procedure. When we encountered intractable strictures, we adopted SSR to dilate the stricture and the interstice of the MS. We evaluated the success rate of MS or PS deployment after SSR application and procedural complications. Five of 59 patients (8%) were subjected to SSR application for the initial MS deployment. MS were successfully deployed in all of these patients (100%). MS occlusion was noted in 27 patients. We applied SSR to seven patients (26%) for the deployment of multiple PS after MS occlusion. In five patients (71%), successful PS deployment was achieved after the SSR application. No complications related to dilatation using SSR occurred in any patient. SSR proved to be a potent dilator of difficult strictures in the management of malignant hilar biliary strictures.

Endoscopic stenting for benign upper gastrointestinal strictures and leaks.

PubMed

Sharaiha, Reem Z; Kim, Katherine J; Singh, Vikesh K; Lennon, Anne Marie; Amateau, Stuart K; Shin, Eun Ji; Canto, Marcia Irene; Kalloo, Anthony N; Khashab, Mouen A

2014-01-01

Self-expandable metal stents (SEMS) and self-expandable plastic stents (SEPS) maybe used for the treatment of benign upper gastrointestinal (GI) leaks and strictures. This study reviewed our experience with stent insertions in patients with benign upper GI conditions. Patients who underwent stent placement for benign upper GI strictures and leaks between March 2007 and April 2011 at a tertiary referral academic center were studied using an endoscopic database and electronic patient records. The technical success, complications, and clinical improvement after stent removal were compared according to type of stent. The outcomes measured were clinical response, adverse events, and predictors of stent migration. Thirty-eight patients (50 % male, mean age = 54 years, range = 12-82) underwent 121 endoscopic procedures. Twenty patients had stents placed for strictures, and 18 had stents placed for leaks. Stent placement was technically successful in all patients. The average duration of stent placement was 54 days (range = 18-118). Clinical improvement immediately after stent placement was seen in 29 of the 38 patients (76.3 %). Immediate post-procedure adverse events occurred in 8 patients. Late adverse events were seen in 18 patients. Evidence of stent migration occurred in 16 patients and was seen in 42 of the 118 successfully placed stents (35.5 %). Migration was more frequent with fully covered SEMS (p = 0.002). After stent removal, 27 patients were evaluable for long-term success (median follow-up time of 283 days, IQR 38-762). Resolution of strictures or leaks was seen in 11 patients (40.7 %). Predictors for long-term success included increasing age and if the stent did not cross the GE junction. Placement of SEPS and SEMS for benign refractory strictures and fistulas has modest long-term clinical efficacy and is limited by a significant migration rate. Stent migration is common and frequent with fully covered SEMS compared to other types of stents, regardless of

Feasibility study using a Ni-Ti stent and electronic portal imaging to localize the prostate during radiotherapy.

PubMed

Carl, Jesper; Lund, Bente; Larsen, Erik Hoejkjaer; Nielsen, Jane

2006-02-01

A new method for localization of the prostate during external beam radiotherapy is presented. The method is based on insertion of a thermo-expandable Ni-Ti stent. The stent is originally developed for treatment of bladder outlet obstruction caused by benign hyperplasia. The radiological properties of the stent are used for precise prostate localization during treatment using electronic portal images. Patients referred for intended curative radiotherapy and having a length of their prostatic urethra in the range from 25 to 65 mm were included. Pairs of isocentric orthogonal portal images were used to determine the 3D position at eight different treatment sessions for each patient. Fourteen patients were enrolled in the study. The data obtained demonstrated that the stent position was representative of the prostate location. The stent may also improve delineation of the prostate GTV, and prevent obstruction of bladder outlet during treatment. Precision in localization of the stent was less than 1 mm. Random errors in stent position were left-right 1.6 mm, cranial-caudal 2.2 mm and anterior-posterior 3.2 mm. In four of 14 patients a dislocation of the stent to the bladder occurred. Dislocation only occurred in patients with length of prostatic urethra less than 40 mm. A new method for radiological high precision localization of the prostate during radiotherapy is presented. The method is based on insertion of a standard Ni-Ti thermo-expandable stent, designed for treatment of benign prostate hyperplasia.

Accuracy of a cone beam computed tomography-guided surgical stent for orthodontic mini-implant placement.

PubMed

Yu, Jae-Jung; Kim, Gyu-Tae; Choi, Yong-Suk; Hwang, Eui-Hwan; Paek, Janghyun; Kim, Seong-Hun; Huang, John C

2012-03-01

To validate the accuracy of a cone-beam computed tomography (CBCT)-guided surgical stent for orthodontic mini-implant (OMI) placement by quantitatively evaluating the difference between CBCT-prescribed and actual position of mini-implants in preoperative and postoperative CBCT images. A surgical stent was fabricated using Teflon-Perfluoroalkoxy, which has appropriate biological x-ray attenuation properties. Polyvinylsiloxane impression material was used to secure the custom-made surgical stent onto swine mandibles. CBCT scanning was done with the stent in place to virtually plan mini-implants using a three-dimensional (3D) software program. An appropriate insertion point was determined using 3D reconstruction data, and the vertical and horizontal angulations were determined using four prescribed angles. A custom-designed surveyor was used to drill a guide hole within the surgical stent as prescribed on the CBCT images for insertion of 32 OMIs. The mandibles with a surgical stent in place were rescanned with CBCT to measure the deviations between the virtual planning data and surgical results. The difference between the prescribed and actual vertical angle was 1.01 ± 7.25, and the horizontal difference was 1.16 ± 6.08. The correlation coefficient confirms that there was no intrarater variability in either the horizontal (R  =  .97) or vertical (R  =  .74) vectors. The surgical stent in this study guides mini-implants to the prescribed position as planned in CBCT. Since the statistical difference was not significant, the surgical stent can be considered to be an accurate guide tool for mini-implant placement in clinical use.

[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.

Characterization of biofilms in biliary stents and potential factors involved in occlusion.

PubMed

Vaishnavi, Chetana; Samanta, Jayanta; Kochhar, Rakesh

2018-01-07

To quantify the components in biofilms and analyze the predisposing factors involved in occlusion of biliary stents. In a prospective study conducted from April 2011 to March 2014 at a tertiary care hospital, all consecutive patients who required endoscopic biliary stent exchange/removal were included. Etiology of the biliary disease was diagnosed by imaging, cytology and on follow-up. Clinical details of patients with biliary stent retrieval were noted. All extracted stents were collected in sterile containers and immediately processed for quantification of biofilm proteins and polysaccharides. Molecular identification of commonly known and unknown bacteria was performed by polymerase chain reaction and density gradient gel electrophoresis methods. Eighty one patients (41 males) with age range of 20-86 years were studied. The underlying causes for stent insertion were bile duct stones ( n = 46; 56.8%) benign stricture ( n = 29; 35.8%) and malignancy ( n = 6; 7.4%) with cholangitis in 50 (61.7%) patients. The retrieved stent sizes were 7 Fr ( n = 62; 76.5%) and 10 Fr ( n = 19; 23.5%) with 65 days median insertion duration. Polybacterial consortia were detected in 90.1% of the stents. The most common bacteria identified by polymerase chain reaction alone and/or sequencing were Pseudomonas ( n = 38), Citrobacter ( n = 23), Klebsiella ( n = 22), Staphylococcus ( n = 20), Serratia ( n = 16), Escherichia coli ( n = 14), Streptococcus ( n = 13), Enterococcus ( n = 13), Aeromonas ( n = 12), Proteus ( n = 10) and Enterobacter ( n = 9). Protein concentration according to gender (0.547 ± 0.242 mg/mL vs 0.458 ± 0.259 mg/mL; P = 0.115) as well as age > 60 years and < 60 years (0.468 ± 0.295 mg/mL vs 0.386 ± 0.238 mg/mL; P = 0.205) was non-significant. However, polysaccharide concentration was significant both according to gender (0.052 ± 0.021 mg/mL vs 0.049 ± 0.016 mg/mL; P < 0.0001) and age (0.051 ± 0.026 mg/mL vs 0.038 ± 0.016 mg/mL; P < 0.011). Protein

Characterization of biofilms in biliary stents and potential factors involved in occlusion

PubMed Central

Vaishnavi, Chetana; Samanta, Jayanta; Kochhar, Rakesh

2018-01-01

AIM To quantify the components in biofilms and analyze the predisposing factors involved in occlusion of biliary stents. METHODS In a prospective study conducted from April 2011 to March 2014 at a tertiary care hospital, all consecutive patients who required endoscopic biliary stent exchange/removal were included. Etiology of the biliary disease was diagnosed by imaging, cytology and on follow-up. Clinical details of patients with biliary stent retrieval were noted. All extracted stents were collected in sterile containers and immediately processed for quantification of biofilm proteins and polysaccharides. Molecular identification of commonly known and unknown bacteria was performed by polymerase chain reaction and density gradient gel electrophoresis methods. RESULTS Eighty one patients (41 males) with age range of 20-86 years were studied. The underlying causes for stent insertion were bile duct stones (n = 46; 56.8%) benign stricture (n = 29; 35.8%) and malignancy (n = 6; 7.4%) with cholangitis in 50 (61.7%) patients. The retrieved stent sizes were 7 Fr (n = 62; 76.5%) and 10 Fr (n = 19; 23.5%) with 65 days median insertion duration. Polybacterial consortia were detected in 90.1% of the stents. The most common bacteria identified by polymerase chain reaction alone and/or sequencing were Pseudomonas (n = 38), Citrobacter (n = 23), Klebsiella (n = 22), Staphylococcus (n = 20), Serratia (n = 16), Escherichia coli (n = 14), Streptococcus (n = 13), Enterococcus (n = 13), Aeromonas (n = 12), Proteus (n = 10) and Enterobacter (n = 9). Protein concentration according to gender (0.547 ± 0.242 mg/mL vs 0.458 ± 0.259 mg/mL; P = 0.115) as well as age > 60 years and < 60 years (0.468 ± 0.295 mg/mL vs 0.386 ± 0.238 mg/mL; P = 0.205) was non-significant. However, polysaccharide concentration was significant both according to gender (0.052 ± 0.021 mg/mL vs 0.049 ± 0.016 mg/mL; P < 0.0001) and age (0.051 ± 0.026 mg/mL vs 0.038 ± 0.016 mg/mL; P < 0.011). Protein

Assessment of bio-safety of low-cost polyurethane urologic stents used in developing countries.

PubMed

Roy, Nobhojit; Waingankar, Santosh; Aggarwal, Gaurav

2012-04-01

Ureteral stents, despite their ubiquitous use, have not been evaluated for their safety and strength after removal from the patient. While literature is available from the industry with regards to manufacturing and specifications of stents, what happens to a stent after it is inserted into the body, still needs to be explored. We conducted a methodical study of 153 consecutive patients with urological problems who were stented with inexpensive polyurethane stents. Once removed from the patients, the stents were analyzed for breakload, tensile strength, elongation, pH, decomposition temperature, residue as well as diameter change. There was no significant change in the physical and mechanical properties of the stent after clinical use and the variance was within the acceptable range of biomaterials. There was minimal leaching of material and color change in all stents. The cheap polyurethane stents were found to be safe for use in patients, for the short time periods of in situ stenting. The degradation of physical and chemical properties of the stent was not significant. Thus it can be safely said that the stents currently in widespread use are cost-effective and physically safe for short spans of time.

Direct Primary or Secondary Percutaneous Ureteral Stenting: What Is the Most Compliant Option in Patients with Malignant Ureteral Obstructions?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carrafiello, Gianpaolo, E-mail: gcarraf@tin.it; Lagana, Domenico; Lumia, Domenico

2007-09-15

The objective of this study was to analyze three ureteral stenting techniques in patients with malignant ureteral obstructions, considering the indications, techniques, procedural costs, and complications. In the period between June 2003 and June 2006, 45 patients with bilateral malignant ureteral obstructions were evaluated (24 males, 21 females; average age, 68.3; range, 42-87). All of the patients were treated with ureteral stenting: 30 (mild strictures) with direct stenting (insertion of the stent without predilation), 30 (moderate/severe strictures) with primary stenting (insertion of the stent after predilation in a one-stage procedure), and 30 (mild/moderate/severe strictures with infection) with secondary stenting (insertionmore » of the stent after predilation and 2-3 days after nephrostomy). The incidence of complications and procedural costs were compared by a statistical analysis. The primary technical success rate was 98.89%. We did not observe any major complications. The minor complication rate was 11.1%. The incidence of complications for the various techniques was not statistically significantly. The statistical analysis of costs demonstrated that the average cost of secondary stenting ( Euro 637; SD, Euro 115) was significantly higher than that of procedures which involved direct or primary stenting ( Euro 560; SD, Euro 108). We conclude that one-step stenting (direct or primary) is a valid option to secondary stenting in correctly selected patients, owing to the fact that when the procedure is performed by expert interventional radiologists there are high technical success rates, low complication rates, and a reduction in costs.« less

Application of self-expandable metal stents for ureteroileal anastomotic strictures: long-term results.

PubMed

Liatsikos, Evangelos N; Kagadis, George C; Karnabatidis, Dimitrios; Katsanos, Konstantinos; Papathanassiou, Zafiria; Constantinides, Constantinos; Perimenis, Petros; Nikiforidis, George C; Stolzenburg, Jens-Uwe; Siablis, Dimitrios

2007-07-01

We report our long-term experience with the management of benign ureteroileal anastomotic strictures using self-expandable metal stents. A total of 16 male and 2 female patients with a mean+/-SD age of 72+/-7 years (range 66 to 78) with benign fibrotic strictures at the site of ureteroileal anastomosis underwent implantation of self-expandable metal stents with a nominal diameter of 6 to 8 mm. A total of 24 ureteroileal conduits were treated. The external nephrostomy tubes were removed after fluoroscopic validation of ureteral patency. Patients were followed with blood biochemistry, ultrasonography, urography and/or virtual endoscopy. Retrograde external-internal catheter insertion through the cutaneous stoma was performed in cases of recalcitrant stricture. The technical success rate of ureteroileal stricture crossing and stenting was 100% (24 of 24 cases). Mean followup was 21 months (range 7 to 50). The clinical success rate during the immediate post-stenting period was 70.8% (17 of 24 cases). The 1 and 4-year primary patency rates were 37.8% and 22.7%, respectively. Secondary interventions included repeat balloon dilation in 15 ureters, of which 8 also underwent subsequent coaxial stent placement. The 1 and 4-year secondary patency rates were 64.8% and 56.7%, respectively. Except in 2 patients who died external-internal Double-J catheters continued to be inserted retrograde in 6 ureteroileal conduits. They are periodically exchanged to prevent mucous inspissation and stent encrustation. Metal stents served as the definitive treatment for stricture in more than half of the cases, whereas in the remainder the stents allowed the uncomplicated and regular exchange of Double-J catheters in retrograde fashion. This combined, less invasive treatment for ureteroileal anastomotic strictures may help patients avoid surgical revision and preserve quality of life.

Management of pancreatic collections with a novel endoscopically placed fully covered self-expandable metal stent: a national experience (with videos).

PubMed

Chandran, Sujievvan; Efthymiou, Marios; Kaffes, Arthur; Chen, John Wei; Kwan, Vu; Murray, Michael; Williams, David; Nguyen, Nam Quoc; Tam, William; Welch, Christine; Chong, Andre; Gupta, Saurabh; Devereaux, Ben; Tagkalidis, Peter; Parker, Frank; Vaughan, Rhys

2015-01-01

Recent medical literature on novel lumen-apposing stents for the treatment of pancreatic fluid collections (PFCs) is limited by small numbers, solo operators, and single-center experience. To evaluate a recently developed lumen-apposing, fully covered self-expandable metal stent (FCSEMS) in the management of PFCs. Retrospective case series. Thirteen tertiary and private health care centers across Australia. Forty-seven patients (median age 51 years) who underwent endoscopic management of PFCs. Insertion of FCSEMS after PFC puncture under EUS guidance. A subgroup of 9 patients underwent direct endoscopic necrosectomy. Technical and clinical success rate, adverse event rate. The technical success rate was 53 of 54 patients (98.1%), and the initial clinical success rate was 36 of 47 (76.6%), which was sustained for more than 6 months in 34 of 36 (94.4%). Early adverse events included 4 cases (7.4%) of stent migration during direct endoscopic necrosectomy, 4 cases (7.4%) of sepsis, 1 case (1.9%) of bleeding, and 1 case (1.9%) of stent migration into the fistula tract. Late adverse events were 6 (11.1%) spontaneous stent migrations, 3 (5.6%) recurrent stent occlusions, 3 (5.6%) tissue ingrowth/overgrowth, and 2 (3.7%) bleeding into PFC. The majority of stents inserted (48 of 54, 88.9%) and removed (31 of 35, 88.6%) in our study were described by the operator as superior to pigtail stents with regard to ease of use. Retrospective study. Although FCSEMSs are technically easier to insert and remove compared with traditional pigtail stents, there are significant limitations to the widespread use of FCSEMSs in the management of PFCs. These include cost, adverse events, and lower-than-expected resolution rates. Copyright © 2015 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

Successful management of multiple esophagorespiratory fistulas using two types of stent: report of a case.

PubMed

Hamai, Yoichi; Hihara, Jun; Emi, Manabu; Okita, Riki; Shimizu, Katsuhiko; Okada, Morihito

2011-04-01

We herein describe a 41-year-old man with esophageal cancer who developed three esophagorespiratory fistulas (ERFs) that were successfully treated using one esophageal and three airway stents. A self-expandable metallic stent (SEMS) was initially inserted into the esophagus to close an ERF in the right bronchus. However, two new ERFs developed in the trachea and the left main bronchus 3 months later because of pressure necrosis and penetration of the esophageal SEMS. These secondary ERFs were subsequently closed using two silicone stents, together with one SEMS in the airway. This experience suggests that appropriate stenting can control multiple and large ERFs.

Biofilms and Physical Deposits on Nasolacrimal Silastic Stents Following Dacryocystorhinostomy: Is There a Difference Between Ocular and Nasal Segments?

PubMed

Ali, Mohammad Javed; Baig, Farhana; Lakshman, Mekala; Naik, Milind N

2015-01-01

The aims of this study were to examine the presence of biofilms and physical deposits on ocular and nasal segments of silastic nasolacrimal duct stents inserted after dacryocystorhinostomy and to document any differences. A prospective interventional study was performed on a series of patients undergoing dacryocystorhinostomy with Crawford stent insertion. All the patient samples were retrieved 4 weeks after an endoscopic dacryocystorhinostomy. None of the patients had any evidence of postoperative infection. The ocular and nasal segments were separated during retrieval. After removal, the stent segments were subjected to biofilm and physical deposit analysis using standard protocols of scanning electron microscopy. These stent segments were compared against sterile stents which acted as controls. A total of 11 stents were studied. Nine were consecutive patient samples and 2 were sterile stents. The ocular and nasal segments of all the stents demonstrated evidence of biofilm formation and physical deposits. However, the deposits and biofilms were thicker and extensive in the ocular segment, although more focal in nature. In contrast, the nasal segments showed thinner biofilms and sparser deposits but were more diffuse in nature. The presence of different-sized organisms within the exopolysaccharide matrix and in between the deposits suggests the existence of polymicrobial communities. This is the first study to report the differences between ocular and nasal segments of lacrimal stents. These differences could propel further studies on stent biomechanics and their interactions with ocular and nasal tissues, following a dacryocystorhinostomy.

Timing of silicone stent removal in patients with post-tuberculosis bronchial stenosis

PubMed Central

Eom, Jung Seop; Kim, Hojoong; Park, Hye Yun; Jeon, Kyeongman; Um, Sang-Won; Koh, Won-Jung; Suh, Gee Young; Chung, Man Pyo; Kwon, O. Jung

2013-01-01

CONTEXT: In patients with post-tuberculosis bronchial stenosis (PTBS), the severity of bronchial stenosis affects the restenosis rate after the silicone stent is removed. In PTBS patients with incomplete bronchial obstruction, who had a favorable prognosis, the timing of stent removal to ensure airway patency is not clear. AIMS: We evaluated the time for silicone stent removal in patients with incomplete PTBS. SETTINGS AND DESIGN: A retrospective study examined PTBS patients who underwent stenting and removal of a silicone stent. METHODS: Incomplete bronchial stenosis was defined as PTBS other than total bronchial obstruction, which had a luminal opening at the stenotic segment on bronchoscopic intervention. The duration of stenting was defined as the interval from stent insertion to removal. The study included 44 PTBS patients and the patients were grouped at intervals of 6 months according to the duration of stenting. RESULTS: Patients stented for more than 12 months had a significantly lower restenosis rate than those stented for less than 12 months (4% vs. 35%, P = 0.009). Multiple logistic regression revealed an association between stenting for more than 12 months and a low restenosis rate (odds ratio 12.095; 95% confidence interval 1.097-133.377). Moreover, no restenosis was observed in PTBS patients when the stent was placed more than 14 months previously. CONCLUSIONS: In patients with incomplete PTBS, stent placement for longer than 12 months reduced restenosis after stent removal. PMID:24250736

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

Comparison of Temporary Open Arterial Revascularization Using Stent Grafts vs. Standard Vascular Shunts in a Porcine (Sus scrofa) Model

DTIC Science & Technology

2017-01-24

Objectives: Open surgical reconstruction using expanded polytetrafluoroethylene stent grafts to create a sutureless anastomosis is an alternative to...French Argyle shunt was inserted into one randomly assigned artery, with a self-expanding ePTFE stent deployed in the other. Arterial flow measurements...for histopathology were obtained during the terminal procedure. Results: Angiography revealed no difference in patency at 72 hours. The stent grafts

Endoscopic placement of double-J ureteric stents in children as a treatment for primary hydronephrosis.

PubMed

Pogorelić, Zenon; Brković, Tomislava; Budimir, Dražen; Todorić, Jakov; Košuljandić, Đurđica; Jerončić, Ana; Biočić, Mihovil; Saraga, Marijan

2017-06-01

The aim of this study was to determine the efficacy and potential complications of double-J ureteric stents in the treatment of primary hydronephrosis in pediatric patients. A retrospective case-records review of 133 patients (45 girls and 88 boys) treated because of primary hydronephrosis with double-J ureteric stents, in Department of Pediatric Surgery, Split University Hospital, between December 1997 and December 2014, was performed. Success of treatment, results of follow up investigations and complications were recorded. Patients were followed up clinically and radiologically for a minimum of 2 years following stent insertion. In all, 133 endoscopic double-J ureteric stents insertions were performed. Of the total number of patients, left-sided hydronephrosis was found in 82 patients, right-sided in 38, and bilateral in 13 patients. The median age of children was 2 years (range 0-17 years). Mean hospital stay was 2 days (range 1-10 days). In primary hydronephrosis, double-J ureteric stenting alone was effective with resolution of hydronephrosis in 73% of cases (97/133 insertions). Regarding the age of the patients the highest success of 83.5% was achieved in age group 0-4 years. Success in groups 5-9 years; 10-14 years and 15-17 years were 47%; 33.5% and 0%, respectively. Several complications have been recorded: symptomatic infections, migration in the renal pelvis and bladder, progression of hydronephrosis, spontaneously prolapse of prosthesis, bleeding and perforation of the renal pelvis. A significant, decreasing trend in success rates by age of participants was observed (p < 0.001). Ureteric stenting is minimally invasive procedure that provides an alternative to open surgery in patients with primary hydronephrosis. Endoscopic placement of ureteric double-J stents should be considered as a first-line treatment in the management of primary hydronephrosis especially in children till 4 years of age, with success rate of 83.5% and without the need for

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.

Is pre-shock wave lithotripsy stenting necessary for ureteral stones with moderate or severe hydronephrosis?

PubMed

El-Assmy, Ahmed; El-Nahas, Ahmed R; Sheir, Khaled Z

2006-11-01

We performed a prospective, randomized clinical trial to evaluate the outcome of ureteral stents for solitary ureteral stones 2 cm or less in moderately or severely obstructed systems using shock wave lithotripsy. Between 2001 and 2004, 186 patients who met study criteria were randomized into 2 groups. Group 1 received a pre-shock wave lithotripsy 6Fr Double-J stent and group 2 had no stent. Patients were treated with a Dornier MFL 5000 lithotripter. Results were compared in terms of clearance rates, number of shock waves and sessions, irritative voiding symptoms, incidence of complications and secondary interventions. Failure was defined as the need for additional procedure(s) for stone extraction. Overall 164 patients (88.2%) became stone-free after shock wave lithotripsy. Complete stone fragmentation was achieved after 1 to 3 and more than 3 session in 108 (58.1%), 30 (16.1%), 13 (7%) and 14 patients (7.5%), respectively. Ureteral stent insertion did not affect the stone-free rate, which was 84.9% and 91.4% in groups 1 and 2, respectively (p = 0.25). There was no statistical difference in the re-treatment rate, flank pain or temperature in the 2 groups. However, all patients in the stented group significantly complained of side effects attributable to the stent, including dysuria, suprapubic pain, hematuria, pyuria and positive urinary culture. Pretreatment stenting provides no advantage over in situ shock wave lithotripsy for significantly obstructing ureteral calculi. Shock wave lithotripsy is reasonable initial therapy for ureteral stones 2 cm or less that cause moderate or severe hydronephrosis.

The use of expandable metallic airway stents for tracheobronchial obstruction in children.

PubMed

Filler, R M; Forte, V; Fraga, J C; Matute, J

1995-07-01

Expandable metallic angioplasty stents (Palmaz stent) have been implanted in the trachea and/or bronchi of seven children. Three children had severe tracheal stenosis after tracheoplasty for congenital tracheal stenosis repair, and four had tracheomalacia or bronchomalacia with or without vascular compression. The mean age at stenting was 9.7 months (range, 2 to 15 months). Balloon expandable stents were inserted into the trachea or bronchus through a 3.5-mm bronchoscope under fluoroscopic control. Initially a single tracheal stent was used for all patients except for one with obstruction in the trachea and both bronchi, in whom three stents were implanted. Three children had recurrent airway obstruction 1 month later; one was cured with a second stent; one child died 1 year later; and the other is being treated for heart disease. The others have no serious respiratory problems. The stents in all have been in place for 1 to 25 (mean, 11) months. No immediate complications were noted. Early and late bronchoscopy showed incomplete epithelialization of the stent and patches of granulation tissue on it. Two stents were removed bronchoscopically, one at the completion of treatment for tracheomalacia and the other at the time of recurrent airway obstruction. This preliminary experience indicates that expandable metallic stents have a useful role in the treatment of selected lower airway obstructions.

Endoscopic Removal of a Nitinol Mesh Stent from the Ureteropelvic Junction after 15 Years

PubMed Central

Smrkolj, Tomaž; Šalinović, Domagoj

2015-01-01

We report a rare case of a patient with a large stone encrusted on a nitinol mesh stent in the ureteropelvic junction. The stent was inserted in the year 2000 after failure of two pyeloplasty procedures performed due to symptomatic ureteropelvic junction stenosis. By combining minimally invasive urinary stone therapies—extracorporeal shock wave lithotripsy, semirigid ureterorenoscopy with laser lithotripsy, and percutaneous nephrolithotomy—it was possible to completely remove the encrusted stone and nitinol mesh stent that was implanted for 15 years, rendering the patient symptom and obstruction free. PMID:26697258

iStent with Phacoemulsification versus Phacoemulsification Alone for Patients with Glaucoma and Cataract: A Meta-Analysis

PubMed Central

Malvankar-Mehta, Monali S.; Iordanous, Yiannis; Chen, Yufeng Nancy; Wang, Wan Wendy; Patel, Sangita Shantilal; Costella, John; Hutnik, Cindy M. L.

2015-01-01

Background Minimally invasive glaucoma surgeries (MIGS) have attracted significant attention, as they have been reported to lower intra-ocular pressure (IOP) and have an excellent safety profile. The iStent is an example of a minimally invasive glaucoma device that has received particular attention due to its early and wide spread utilization. There is a growing body of evidence supporting its use at the time of phacoemulsification to help lower IOP. However, it is still not clear how much of the IOP lowering effect can be attributed to the iStent, the crystalline lens extraction or both when inserted concurrently at the time of phacoemulsification. This has been an important issue in understanding its potential role in the glaucoma management paradigm. Purpose To conduct a systematic review and meta-analysis comparing the IOP lowering effect of iStent insertion at the time of phacoemulsification versus phacoemulsification alone for patients with glaucoma and cataracts. Methods A systematic review was conducted utilizing various databases. Studies examining the IOP lowering effect of iStent insertion in combination with phacoemulsification, as well as studies examining the IOP lowering effect of phacoemulsification alone were included. Thirty-seven studies, reporting on 2495 patients, met the inclusion criteria. The percentage reduction in IOP (IOPR%) and mean reduction in topical glaucoma medications after surgery were determined. The standardized mean difference (SMD) was computed as a measure of the treatment effect for continuous outcomes taking into account heterogeneity. Fixed-effect and random-effect models were applied. Results A 4% IOP reduction (IOPR%) from baseline occurred following phacoemulsification as a solo procedure compared to 9% following an iStent implant with phacoemulsification, and 27% following 2 iStents implants with phacoemulsification. Compared with cataract extraction alone, iStent with phacoemulsification resulted in significant

Comparison of self-expandable and balloon-expanding stents for hybrid ductal stenting in hypoplastic left heart complex.

PubMed

Goreczny, Sebastian; Qureshi, Shakeel A; Rosenthal, Eric; Krasemann, Thomas; Nassar, Mohamed S; Anderson, David R; Morgan, Gareth J

2017-07-01

We aimed to compare the procedural and mid-term performance of a specifically designed self-expanding stent with balloon-expandable stents in patients undergoing hybrid palliation for hypoplastic left heart syndrome and its variants. The lack of specifically designed stents has led to off-label use of coronary, biliary, or peripheral stents in the neonatal ductus arteriosus. Recently, a self-expanding stent, specifically designed for use in hypoplastic left heart syndrome, has become available. We carried out a retrospective cohort comparison of 69 neonates who underwent hybrid ductal stenting with balloon-expandable and self-expanding stents from December, 2005 to July, 2014. In total, 43 balloon-expandable stents were implanted in 41 neonates and more recently 47 self-expanding stents in 28 neonates. In the balloon-expandable stents group, stent-related complications occurred in nine patients (22%), compared with one patient in the self-expanding stent group (4%). During follow-up, percutaneous re-intervention related to the ductal stent was performed in five patients (17%) in the balloon-expandable stent group and seven patients (28%) in self-expanding stents group. Hybrid ductal stenting with self-expanding stents produced favourable results when compared with the results obtained with balloon-expandable stents. Immediate additional interventions and follow-up re-interventions were similar in both groups with complications more common in those with balloon-expandable stents.

An effective technique to facilitate radiographic stone visualization with an internal stent during shock wave lithotripsy.

PubMed

Sundaram, C P; Saltzman, B

1998-10-01

We describe a simple method to assist stone localization during shock wave lithotripsy in the presence of a Double J stent. A 4F whistle tip ureteral catheter is passed alongside a previously inserted 6F Double J stent. The tip of the ureteral stent is positioned in the lower or mid third of the ureter. Contrast material is injected through the ureteral catheter during lithotripsy to assist stone localization. This technique has been successful in localization of poorly opacified renal stones during lithotripsy. Radiolucent and poorly calcified renal stones can be easily localized during shock wave lithotripsy, despite the presence of a Double J stent. No special catheters or stents are required for this technique.

Self-Expandable Metallic Stent Placement in Malignant Gastric Outlet Obstruction

PubMed Central

Ye, Bing-Wei; Lee, Kuei-Chuan; Hsieh, Yun-Cheng; Li, Chung-Pin; Chao, Yee; Hou, Ming-Chih; Lin, Han-Chieh

2015-01-01

Abstract Malignant gastric outlet obstruction is a late complication of intraabdominal malignancy. Self-expandable metallic stent placement has been a safe palliative treatment to relieve obstructive symptoms. We aimed to assess the efficacy and safety of metallic stents in our patients and analyzed the clinical outcome of different brands. Seventy-one patients with inoperable gastric outlet obstruction receiving WallFlex enteral stents (WallFlex group) or Bonastents (Bonastent group) since April 2010 were analyzed retrospectively. The overall technical and clinical success rates of stent placement were 100% and 93%, respectively. The baseline characteristics and clinical outcomes including procedure-related complications, restenosis, and reintervention rates were comparable between the 2 groups. However, the Bonastent group had a higher rate of stent fracture than the WallFlex group (13.3% vs 0%, P = 0.03). The mean duration of overall stent patency was 132.7 days. The mean duration of survival was 181.9 days. Resumption of regular diet or low residual diet at day 7 after stent insertion predicted stent patency (hazard ratio [HR]: 0.28, P = 0.01). Cancer with gastric origin (HR: 0.25, P = 0.045) and poststent chemotherapy (HR: 0.38, P = 0.006) predicted lower mortality; however, peritoneal carcinomatosis (HR: 3.09, P = 0.04) correlated with higher mortality. Metallic stent placement is a safe and effective method for relieving gastric outlet obstruction. Except higher rate of stent fracture in the Bonastent group, there is no significant difference in clinical outcomes between the Bonastent group and the WallFlex group. PMID:26200641

Intralacrimal migration of Masterka® stents.

PubMed

Fayet, B; Racy, E; Katowitz, W R; Katowitz, J A; Ruban, J-M; Brémond-Gignac, D

2018-03-01

Tearing and conjunctivitis in children are commonly due to lacrimal drainage system obstruction. Congenital nasolacrimal obstruction is a common pathology treated by probing with or without silicone stent insertion, depending upon the age of the child. The silicone stent is self-retaining and placed for at least one month. Masterka ® is a recent version of Monoka ® , which may lead to the same surgical complications, such as intralacrimal migration. The medical records of two patients surgically treated with the Masterka ® probe for nasolacrimal duct obstruction, who developed intralacrimal migration of the stent, were retrospectively reviewed and analyzed. A 41-month-old child and an 18-month-old child presented with disappearance of the silicone tube after 7 days and 2 years respectively. In the first case, the tube migrated completely within the lacrimal system and became externalized through the nose at 2 years, while in the second case, the Masterka ® was retrieved through a canalicular approach. In both cases, infants had no further tearing. The frequency self-retaining stent disappearance is estimated at 15%. Among these cases, intralacrimal migration is only reported in 0.5% of cases. To prevent intralacrimal migration, the surgical technique must follow a certain number of rules. Management, based on residual epiphora, is discussed. Prevention of intralacrimal migration of self-retaining stents involves a rigorous analysis of the relationship between the meatus and the fixation head at the time of placement. After lacrimal intubation, scheduled monitoring is necessary to screen for stent disappearance. Management is based on clinical findings, anterior rhinoscopy and even exploratory canaliculotomy. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Silver-nanoparticle-coated biliary stent inhibits bacterial adhesion in bacterial cholangitis in swine.

PubMed

Wen, Wei; Ma, Li-Mei; He, Wei; Tang, Xiao-Wei; Zhang, Yin; Wang, Xiang; Liu, Li; Fan, Zhi-Ning

2016-02-01

One of the major limitations of biliary stents is the stent occlusion, which is closely related to the over-growth of bacteria. This study aimed to evaluate the feasibility of a novel silver-nanoparticle-coated polyurethane (Ag/PU) stent in bacterial cholangitis model in swine. Ag/PU was designed by coating silver nanoparticles on polyurethane (PU) stent. Twenty-four healthy pigs with bacterial cholangitis using Ag/PU and PU stents were randomly divided into an Ag/PU stent group (n=12) and a PU stent group (n=12), respectively. The stents were inserted by standard endoscopic retrograde cholangiopancreatography. Laboratory assay was performed for white blood cell (WBC) count, alanine aminotransferase (ALT), interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha) at baseline time, 8 hours, 1, 2, 3, and 7 days after stent placements. The segment of bile duct containing the stent was examined histologically ex vivo. Implanted biliary stents were examined by a scan electron microscope. The amount of silver release was also measured in vitro. The number of inflammatory cells and level of ALT, IL-1beta and TNF-alpha were significantly lower in the Ag/PU stent group than in the PU stent group. Hyperplasia of the mucosa was more severe in the PU stent group than in the Ag/PU stent group. In contrast to the biofilm of bacteria on the PU stent, fewer bacteria adhered to the Ag/PU stent. PU biliary stents modified with silver nanoparticles are able to alleviate the inflammation of pigs with bacterial cholangitis. Silver-nanoparticle-coated stents are resistant to bacterial adhesion.

Drug eluting stents and modern stent technologies for in-stent restenosis.

PubMed

Werner, Martin

2017-08-01

The implantation of metallic stents has become a standard procedure to improve the outcome after angioplasty of peripheral vessels. However, the occurrence of in-stent restenosis is hampering the long-term efficacy of these procedures and is associated with re-occurrence of symptoms. The optimal treatment modality for in-stent-restenosis in the peripheral vasculature is not well examined. This review discusses the existing evidence for the treatment of in-stent restenosis with drug eluting stents and modern stent technologies.

New dedicated bifurcated silicone stent placement for stenosis around the primary right carina.

PubMed

Oki, Masahide; Saka, Hideo

2013-08-01

Silicone stenting has been widely used to palliate respiratory symptoms in patients suffering from airway stenosis. Although many types and shapes of stents have been developed, there is no ideal stent for stenosis around the carina between the bronchus to the right upper lobe and the bronchus intermedius (primary right carina). The purpose of this study was to evaluate the feasibility, efficacy, and safety of a new silicone stent designed for treating airway stenosis around the primary right carina. We recruited 16 patients with suspected stenosis around the primary right carina. Ten of the patients met the inclusion criteria for inserting the study stent. All stenting procedures were performed with a rigid and flexible bronchoscope under general anesthesia. The study stent could be mounted successfully on the primary right carina in all 10 patients. Five patients underwent stenting using only the new stent, and the other five underwent stenting with it on the primary right carina and a silicone Y stent on the main carina. The dyspnea index improved in eight of the 10 patients, including one who was mechanically ventilated. Early complications developed in three patients (temporary pneumonia in two and retention of secretions in one), and late complications occurred in two patients (granuloma formation in one and hemoptysis in one). Stent placement with the new silicone stent designed to fit on the primary right carina is feasible, effective, and acceptably safe. UMIN-Clinical Trials Registry; No.: UMIN000001776; URL: www.umin.ac.jp/ctr.

Ureteric catheterization via an ileal conduit: technique and retrieval of a JJ stent.

PubMed

Wah, T M; Kellett, M J

2004-11-01

Retrograde ureteric catheterization of a patient with an ileal conduit is difficult, because guide wires and catheters coil in the conduit. A modified loopogram, using a Foley catheter as a fulcrum through which catheters can be advanced to the ureteric anastomosis, is described. This technique was used to remove a JJ stent, which had been inserted previously across a stricture in one ureter, the stent crossing from one kidney to the other.

Palliative Airway Stenting Performed Under Radiological Guidance and Local Anesthesia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Profili, Stefano; Manca, Antonio; Feo, Claudio F.

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 technicalmore » 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.« less

Bare Metal Stenting for Endovascular Exclusion of Aortic Arch Thrombi

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mahnken, Andreas H., E-mail: mahnken@med.uni-marburg.de; Hoffman, Andras; Autschbach, Ruediger

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.more » 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.« less

[Clinical application of a fully covered self-expandable metallic stent in treatment of airway fistula].

PubMed

Zhu, Qiang; Zang, Qi; Jiang, Zhong-min; Wang, Wei; Cao, Ming

2013-06-01

To assess the feasibility, safety and efficacy of the use of a fully covered self-expandable stent for the treatment of airway fistula. From August 2005 to November 2011, 9 patients underwent treatment by the introduction of a tracheo-bronchial or bronchial fully covered self-expandable metallic stent. There were 7 males and 2 females, aged from 28-65 years with a mean of 46 years. In this group, 7 cases were diagnosed as bronchopleural fistula, 1 case as tracheopleural fistula, 1 case as broncho-esophageal fistula, 8 cases with thoracic empyema. The fistula orifices were from 3.5-25.0 mm in diameter with a mean 8.4 mm. All patients received topical anesthesia, and L-shaped stent was placed in 6 patients and I-shaped stent in 3 patients under fluoroscopic guidance. After the stent placement, the patients with empyema were treated with continual irrigation of the empyema cavity. Stent placement in the tracheo-bronchial tree was technically successful in all patients, without procedure-related complications. The operating time was from 5-16 minutes, mean time (10 ± 4) minutes. Except for 1 patient, immediate closure of the airway fistula was achieved in the other patients after the procedure, as shown by the immediate cessation of bubbling in the chest drain system or the contrast examination. In this study, 1 patient coughed the inserted stent out due to irritable cough on the 5th day and had to receive repositioning of a new stent. Among the patients who were with empyema, 1 patient died of septicemia on the 8th day and 1 patient died of brain metastases from lung cancer 6 months after the stent insertion with empyema not cured, the other 6 patients' empyema healed from 2-5 months, mean time 3.7 months. Seven patients were followed from 3 to 36 months with a median of 13.5 months. During follow-up, 1 stent was removed from a patient 8 months after the stent implantation without empyema recurred. The remaining patient presented good tolerability to the existence of

Placement of percutaneous transhepatic biliary stent using a silicone drain with channels

PubMed Central

Yoshida, Hiroshi; Mamada, Yasuhiro; Taniai, Nobuhiko; Mineta, Sho; Mizuguchi, Yoshiaki; Kawano, Yoichi; Sasaki, Junpei; Nakamura, Yoshiharu; Aimoto, Takayuki; Tajiri, Takashi

2009-01-01

This report describes a method for percutaneous transhepatic biliary stenting with a BLAKE Silicone Drain, and discusses the usefulness of placement of the drain connected to a J-VAC Suction Reservoir for the treatment of stenotic hepaticojejunostomy. Percutaneous transhepatic biliary drainage was performed under ultrasonographic guidance in a patient with stenotic hepaticojejunostomy after hepatectomy for hepatic hilum malignancy. The technique used was as follows. After dilatation of the drainage root, an 11-Fr tube with several side holes was passed through the stenosis of the hepaticojejunostomy. A 10-Fr BLAKE Silicone Drain is flexible, which precludes one-step insertion. One week after insertion of the 11-Fr tube, a 0.035-inch guidewire was inserted into the tube. After removal of the 11-Fr tube, the guidewire was put into the channel of a 10-Fr BLAKE Silicone Drain. The drain was inserted into the jejunal limb through the intrahepatic bile duct and was connected to a J-VAC Suction Reservoir. Low-pressure continued suction was applied. Patients can be discharged after insertion of the 10-Fr BLAKE Silicone Drain connected to the J-VAC Suction Reservoir. Placement of a percutaneous transhepatic biliary stent using a 10-Fr BLAKE Silicone Drain connected to a J-VAC Suction Reservoir is useful for the treatment of stenotic hepaticojejunostomy. PMID:19725159

Scanning Electron Microscopic Features of Nasolacrimal Silastic Stents Retained for Prolong Durations Following Dacryocystorhinostomy.

PubMed

Ali, Mohammad Javed; Baig, Farhana; Lakshman, Mekala; Naik, Milind N

2016-01-01

The aims of this study were to examine the scanning electron microscopic features of silastic nasolacrimal duct stents retained for long durations following a dacryocystorhinostomy. A prospective interventional study was performed on stents retrieved from patients who were lost to follow up after a dacryocystorhinostomy with Crawford stent insertion. Long duration was defined as stents retrieved at a minimum of 1 year following a dacryocystorhinostomy. None of the patients had any evidence of postoperative infection. After removal, the stent segments were subjected to biofilm and physical deposit analysis using standard protocols of scanning electron microscopy. These stent segments were compared against sterile stents which acted as controls. A total of 7 stents were studied. Five were consecutive patient samples, and 2 were sterile stents. All the 5 stents were retrieved from patients who were lost to follow up for a minimum of 12 months following surgery. The mean duration of intubation at retrieval was 21 months. All the stents demonstrated evidence of biofilm formation and physical deposits. However, as the duration of retention increased, the deposits and biofilms were noted to be progressively denser, multilayered and extensive. Certain areas demonstrated thick biofilm integration with the deposits. Polymicrobial communities were noted within the exopolysaccharide matrix. This is the first study to exclusively report on scanning electron microscopic features of lacrimal stents retained for long durations. Further studies on physical elements within the deposits and protein analysis would provide more insights into stent-tissue interactions.

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

A new thermal shape memory Ti-Ni alloy stent covered with silicone.

PubMed

Nakamura, T; Shimizu, Y; Ito, Y; Matsui, T; Okumura, N; Takimoto, Y; Ariyasu, T; Kiyotani, T

1992-01-01

An attempt was made to develop an airway stent for nonsurgical transluminal implantation using a bronchofiberscope. The stent is composed of a single wire with a diameter of 0.5 mm. The wire is made of thermal shape memory titanium nickel alloy, with a transition temperature of 25-30 degrees C. To avoid direct contact between the metal and the tissue, the wire is covered with a 300 microns thick coating of silicone. The stent is horseshoe shaped in cross-section. It is 15 mm in outer transverse diameter and 40 mm long. Ten stents were implanted in 10 dogs whose tracheal cartilages had been previously broken. The stents were first cooled in ice water to reduce their diameter and then inserted into the target site. The wire was warmed to body temperature and recovered its initial shape within 10 sec. The dogs were killed for examination between 1 week and 6 months after implantation. All the stents were located at the implantation sites and were patent. Tissue reactions, such as ulceration and granulation formation, were less severe than in those with previously implanted non-silicone covered stents. Microscopic observation showed that the wires became gradually covered with epithelium within 2 months. This transluminal technique for preserving airway patency shows promise for clinical application.

SX-Ella Danis stent in massive upper gastrointestinal bleeding in cirrhosis - a case series.

PubMed

Jain, Mayank; Balkrishanan, Mahadevan; Snk, Chenduran; Cgs, Sridhar; Ramakrishnan, Ravi; Venkataraman, Jayanthi

2018-06-01

We report our experience of three cases of decompensated cirrhosis with massive upper gastrointestinal bleeding, which required insertion of an SX-Ella Danis stent for hemostasis. The procedure is safe and effective.

Spectral Imaging for Intracranial Stents and Stent Lumen.

PubMed

Weng, Chi-Lun; Tseng, Ying-Chi; Chen, David Yen-Ting; Chen, Chi-Jen; Hsu, Hui-Ling

2016-01-01

Application of computed tomography for monitoring intracranial stents is limited because of stent-related artifacts. Our purpose was to evaluate the effect of gemstone spectral imaging on the intracranial stent and stent lumen. In vitro, we scanned Enterprise stent phantom and a stent-cheese complex using the gemstone spectral imaging protocol. Follow-up gemstone spectral images of 15 consecutive patients with placement of Enterprise from January 2013 to September 2014 were also retrospectively reviewed. We used 70-keV, 140-keV, iodine (water), iodine (calcium), and iodine (hydroxyapatite) images to evaluate their effect on the intracranial stent and stent lumen. Two regions of interest were individually placed in stent lumen and adjacent brain tissue. Contrast-to-noise ratio was measured to determine image quality. The maximal diameter of stent markers was also measured to evaluate stent-related artifact. Two radiologists independently graded the visibility of the lumen at the maker location by using a 4-point scale. The mean of grading score, contrast/noise ratio and maximal diameter of stent markers were compared among all modes. All results were analyzed by SPSS version 20. In vitro, iodine (water) images decreased metallic artifact of stent makers to the greatest degree. The most areas of cheese were observed on iodine (water) images. In vivo, iodine (water) images had the smallest average diameter of stent markers (0.33 ± 0.17mm; P < .05) and showed the highest mean grading score (2.94 ± 0.94; P < .05) and contrast/noise ratio of in-stent lumen (160.03 ±37.79; P < .05) among all the modes. Iodine (water) images can help reduce stent-related artifacts of Enterprise and enhance contrast of in-stent lumen. Spectral imaging may be considered a noninvasive modality for following-up patients with in-stent stenosis.

Plastic strains during stent deployment have a critical influence on the rate of corrosion in absorbable magnesium stents.

PubMed

Galvin, Emmet; Cummins, Christy; Yoshihara, Shoichiro; Mac Donald, Bryan J; Lally, Caitríona

2017-08-01

Magnesium stents are a promising candidate in the emerging field of absorbable metallic stents (AMSs). In this study, the mechanical and corrosion performance of dog-bone specimens and a specific stent design of a magnesium alloy, WE43, are assessed experimentally in terms of their corrosion behaviour and mechanical integrity. It is shown that plastic strains that are induced in the struts of the stent during stent deployment have a critical influence in directing subsequent corrosion behaviour within the material. In addition, the deployment and scaffolding characteristics of the magnesium stent are elucidated and contrasted with those of a commercial stainless steel stent. The magnesium stent is found to support higher levels of cyclic strain amplitude than the stainless steel stent, even prior to degradation, and this may play a role in reducing in-stent restenosis. This study provides new insights into the experimental performance of a current AMS design and material whilst demonstrating the critical influence of plastic strain on the corrosion performance and scaffolding ability of an AMS.

Placement of retrievable self-expandable metallic stents with barbs into patients with obstructive prostate cancer.

PubMed

Song, Ho-Young; Kim, Choung Soo; Jeong, In Gab; Yoo, Dalsan; Kim, Jin Hyoung; Nam, Deok Ho; Bae, Jae-Ik; Park, Jung-Hoon

2013-03-01

To evaluate the technical feasibility and clinical effectiveness of retrievable self-expandable metallic stents with barbs in patients with obstructive prostate cancer. Retrievable self-expandable metallic stents with eight barbs each were inserted into eight consecutive patients with obstructive prostate cancer. Patient ages ranged from 55 to 76 years (mean, 69 years). All eight patients had previously received hormone therapy, and three had undergone palliative transurethral prostatectomy. Stents were removed using a 21-F stent removal set if they caused complications. Stent placement was technically successful and well tolerated in all patients. One had severe incontinence, which improved spontaneously, and two had gross haematuria, which disappeared spontaneously within 4 days. Peak urine flow rates and post-void residual urine volumes 1 month after stent placement were 5.6-10.2 ml/s (mean, 8.3 ml/s), and 5-45 ml (mean, 27 ml), respectively. During a mean follow-up of 192 days (range, 39-632 days), one patient required stent removal after 232 days because of stone formation within the stent. No further intervention was required because the mass improved after stent removal. These preliminary results suggest that retrievable stents with eight barbs are both feasible to place and effective in patients with obstructive prostate cancer.

Critical appraisal of the Spanner™ prostatic stent in the treatment of prostatic obstruction

PubMed Central

McKenzie, Patrick; Badlani, Gopal

2011-01-01

The Spanner™ stent was first used in patients to relieve bladder outlet obstruction (BOO), and has recently been used in patients following transurethral microwave thermotherapy and men unfit for surgical intervention. We review the current literature on the role of the Spanner stent in treating prostatic obstruction compared to previously reported cases involving the use of temporary stents. The Spanner stent has been found to be successful in treating patients with bladder outlet obstruction from benign prostatic hyperplasia and following high-energy transurethral microwave thermotherapy (TUMT). Patients with the Spanner stent had an increase in peak flow rate and a decrease in post void residual and International Prostate Symptom Scores. In patients treated with TUMT, quality of life measures indicate that the Spanner stent shows increased ease of bladder drainage, decreased leakage, and no adverse effect on daily activities. In patients unfit for surgery, however, there was increased retention and pain requiring stent removal in 63% of cases. The Spanner stent offers ease of insertion with a decrease in voiding symptoms in selected patients. Based on limited data, the Spanner stent has been recommended as a treatment option for men with BOO following TUMT. However, it is not a good treatment option for men unfit for surgery based on an increased incidence of urinary retention and dysuria. The Spanner stent is the only currently approved temporary stent and, based on a literature review, it does not offer significant advantage over previously used temporary stents. It is notable that most researchers have not evaluated the role of detrusor function on the outcomes. PMID:22915927

Fully Covered Metallic Stents for the Treatment of Benign Airway Stenosis

PubMed Central

Ocak, Sebahat; Gourdin, Maximilien; d'Odémont, Jean-Paul

2016-01-01

Introduction. We herein report our experience with new fully covered self-expanding metallic stents in the setting of inoperable recurrent benign tracheobronchial stenosis. Methods. Between May 2010 and July 2014, 21 Micro-Tech® FC-SEMS (Nanjing Co., Republic of Korea) were placed in our hospital in 16 patients for inoperable, recurrent (after dilatation), and symptomatic benign airway stenosis. Their medical files were retrospectively reviewed in December 2014, with focus on stent's tolerance and durability data. Results. Twenty-one stents were inserted: 13 for posttransplant left main bronchus anastomotic stricture, seven for postintubation tracheal stenosis, and one for postlobectomy anastomotic stricture. Positioning was easy for all of them. Stents were in place for a mean duration of 282 days. The most common complications were granulation tissue development (35%), migration (30%), and sputum retention (15%). Fifty-five % of the stents (11/20) had to be removed because of various complications, without difficulty for all of them. None of the patients had life-threatening complications. Conclusion. Micro-Tech FC-SEMS were easy to position and to remove. While the rate of complications requiring stent removal was significant, no life-threatening complication occurred. Further studies are needed to better define their efficacy and safety in the treatment of benign airway disease. PMID:27777507

Fully Covered Metallic Stents for the Treatment of Benign Airway Stenosis.

PubMed

Dahlqvist, Caroline; Ocak, Sebahat; Gourdin, Maximilien; Dincq, Anne Sophie; Putz, Laurie; d'Odémont, Jean-Paul

2016-01-01

Introduction. We herein report our experience with new fully covered self-expanding metallic stents in the setting of inoperable recurrent benign tracheobronchial stenosis. Methods. Between May 2010 and July 2014, 21 Micro-Tech® FC-SEMS (Nanjing Co., Republic of Korea) were placed in our hospital in 16 patients for inoperable, recurrent (after dilatation), and symptomatic benign airway stenosis. Their medical files were retrospectively reviewed in December 2014, with focus on stent's tolerance and durability data. Results. Twenty-one stents were inserted: 13 for posttransplant left main bronchus anastomotic stricture, seven for postintubation tracheal stenosis, and one for postlobectomy anastomotic stricture. Positioning was easy for all of them. Stents were in place for a mean duration of 282 days. The most common complications were granulation tissue development (35%), migration (30%), and sputum retention (15%). Fifty-five % of the stents (11/20) had to be removed because of various complications, without difficulty for all of them. None of the patients had life-threatening complications. Conclusion. Micro-Tech FC-SEMS were easy to position and to remove. While the rate of complications requiring stent removal was significant, no life-threatening complication occurred. Further studies are needed to better define their efficacy and safety in the treatment of benign airway disease.

Similarities and differences in coatings for magnesium-based stents and orthopaedic implants

PubMed Central

Ma, Jun; Thompson, Marc; Zhao, Nan; Zhu, Donghui

2016-01-01

Magnesium (Mg)-based biodegradable materials are promising candidates for the new generation of implantable medical devices, particularly cardiovascular stents and orthopaedic implants. Mg-based cardiovascular stents represent the most innovative stent technology to date. However, these products still do not fully meet clinical requirements with regards to fast degradation rates, late restenosis, and thrombosis. Thus various surface coatings have been introduced to protect Mg-based stents from rapid corrosion and to improve biocompatibility. Similarly, different coatings have been used for orthopaedic implants, e.g., plates and pins for bone fracture fixation or as an interference screw for tendon-bone or ligament-bone insertion, to improve biocompatibility and corrosion resistance. Metal coatings, nanoporous inorganic coatings and permanent polymers have been proved to enhance corrosion resistance; however, inflammation and foreign body reactions have also been reported. By contrast, biodegradable polymers are more biocompatible in general and are favoured over permanent materials. Drugs are also loaded with biodegradable polymers to improve their performance. The key similarities and differences in coatings for Mg-based stents and orthopaedic implants are summarized. PMID:27695671

Infrapopliteal stenting with silicon carbide-coated stents in critical limb ischemia: a 12 month follow-up study.

PubMed

Atar, Eli; Avrahami, Ram; Koganovich, Yuri; Litvin, Sergey; Knizhnik, Michael; Belenky, Alexander

2009-10-01

Critical limb ischemia is an increasingly common condition that has high surgical morbidity and limited non-surgical options. To evaluate the use of silicon carbide-coated Motion stents, as compared to reported data for bare metal stents, in elderly patients with infrapopliteal artery stenoses causing critical limb ischemia after failed or complicated percutaneous transluminal angioplasty. Between January 2003 and March 2004, 41 stents were inserted into 17 consecutive patients (11 males, 6 females, mean age 82 years, range 75-93) following unsuccessful or complicated PTA. Seven patients had one-vessel run-off, six had two-vessel and four had three vessel run-off. All patients suffered from CLI, had up to three lesions and more than one co-morbid condition, and were considered at high surgical risk. Silicon carbide-coated Motion coronary stents, 2.5-4 mm diameterand 25 and 30 mm length, were used. Pre-intervention assessment included clinical condition, ankle brachial index, Doppler ultrasound and digital subtracted angiography. Postintervention evaluation included clinical condition, ABI and Doppler ultrasound at 3, 6 and 12 months. The technical success rate per lesion was 100% (41/41). Two patients died of unrelated causes after 2 and 8 months respectively. Primary patency rates with duplex ultrasound were 68.7% (11/16) at 3 months, 43.7% (7/16) at 6 months and 40% (6/15) after 12 months. Nine patients developed complete occlusion in 13 stents; three of these patients underwent a below-knee amputation and two patients a partial foot amputation. Re-intervention (PTA only) was performed in 7 patients (43.7%). Secondary patency rate was 81.2% (13/16) at 6 months and 60% (9/15) at one year. Mean ABI index had improved at 6 months from 0.32 to 0.67, and to 0.53 at one year. Clinical improvement was evident in 87.5% (14/16) at 6 months and in 66.6% (10/15) at one year. Silicon carbide-coated stents are comparable to bare metal stents after 6 and 12 months in

Fluoroscopic Placement of Double-Pigtail Ureteral Stents

PubMed Central

Chen, Gregory L.

2001-01-01

Purpose: Double-pigtail ureteral stent is placed cystoscopically after ureteroscopy. We describe a technique for fluoroscopic placement of ureteral stents and demonstrate its use in a non-randomized prospective study. Materials and methods: Double-pigtail stents were placed either fluoroscopically or cystoscopically in 121 consecutive patients. In the fluoroscopic method, the stent was placed over a guide wire using a stent pusher without the use of cystoscopy. Conversely, stents were placed through the working channel of the cystoscope under vision. The procedure, stent length, width, type, method, ureteral dilation, and use of a retrieval string were noted. Results: A wide range of stent sizes were used. The success with fluoroscopic placement of double-pigtail ureteral stents was 100% (89 of 89 cases). No stents migrated or required replacement. Stents were placed after ureteroscopic laser lithotripsy (53/89) and ureteroscopic tumor treatment (22/89). Cystoscopic visualization was used in 32 additional procedures requiring precise control (15 ureteral strictures and nine retrograde endopyelotomy). Conclusions: The fluoroscopic placement of ureteral stents is a safe and simple technique with a very high success rate. We have used cystoscopic placement only after incisional procedures such as retrograde endopyelotomy, stricture or ureterotomy. PMID:18493562

Predictors of early stent occlusion among plastic biliary stents.

PubMed

Khashab, Mouen A; Kim, Katherine; Hutfless, Susan; Lennon, Anne Marie; Kalloo, Anthony N; Singh, Vikesh K

2012-09-01

A major disadvantage of plastic biliary stents is their short patency rates. The aim of this study was to identify predictors of early stent occlusion among patients receiving conventional plastic biliary stents. Early stent occlusion was defined as worsening cholestatic liver test results of a severity sufficiently significant to warrant ERCP with stent exchange prior to the planned stent exchange, or as symptoms of cholangitis. The association of cumulative stent diameter, demographics, stricture location, procedure indication, Charlson comorbidity index, history of prior early stent occlusion, presence of gallbladder, and performance of sphincteromy with the occurrence of early stent occlusion was studied using logistic regression and multivariate analysis. Our patient cohort comprised 343 patients (mean age 59.3 years) who underwent 561 ERCP procedures with the placement of one or more plastic biliary stents (mean number of stents per procedure 1.2, mean total diameter of stents per procedure 12 Fr). Early stent occlusion occurred in 73 (13 %) procedures. Female gender was protective against early stent occlusion (adjusted OR 0.54, 95 % CI 0.32-0.90, p = 0.02), while hilar stricture location was independently associated with a significantly increased risk of early stent occlusion (adjusted OR 3.41, 95 % CI 1.68-6.90, p = 0.0007). Early occlusion of conventional biliary stents occurred in 13 % of cases. While female gender decreased the risk of early stent occlusion, hilar stricture location was a significant predictor of early stent occlusion. Our results suggest that physicians should consider early elective stent exchange in patients with hilar strictures.

Mechanical Characteristics of Composite Knitted Stents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tokuda, Takanori, E-mail: tkdtknr@gmail.com; Shomura, Yuzo; Tanigawa, Noboru

2009-09-15

We used metal wires and fibers to fabricate a composite knitted stent and then compare the mechanical characteristics of this stent with those of a pure metallic stent of the same construction in order to develop a stent that offers a comparable degree of expandability as metallic stents but can be used for highly curved lesions that cannot be treated using metallic stents. We fabricated two types of composite knitted stent (N-Z stents), using nitinol wire with a diameter of 0.12 mm and polypara-phenylene-benzobisoxazole (PBO) multifilament fiber (Zyron AS; Toyobo, Osaka, Japan). Stents were knitted into a cylindrical shape usingmore » the same textile pattern as a Strecker stent. Two loop lengths (L) of nitinol wire were used in the N-Z stents: L = 1.84 mm (N-Z stent L = 1.84) and L = 2.08 mm (N-Z stent L = 2.08). For the sake of comparison, we fabricated a metallic stent of nitinol using the same textile pattern (N-N stent L = 1.92). We applied a radial compression force diametrically to each stent and applied a bending force diametrically at the free end of a stent with one end fixed in order to evaluate the relationship between stent elasticity and load values. In addition, we macroscopically evaluated the generation of kinks when the stent was bent 180{sup o}. The radial compressive force when the stent diameter was reduced by 53% was 6.44 N in the case of N-Z stent L = 1.84, 6.14 N in the case of N-Z stent L = 2.08, and 4.96 N in the case of N-N stent L = 1.92 mm. The composite stent had a radial compressive force higher than that of a metallic stent. The restoring force to longitudinal direction at a 90{sup o} bending angle was 0.005 N for N-Z stent L = 1.84, 0.003 N for N-Z stent L = 2.08, and 0.034 N for N-N stent L = 1.92. The restoring force of the composite stent was significantly lower. Finally, the composite stent generated no definitive kinks at a bending angle of 180{sup o}, regardless of loop length. However, the N-N stent clearly produced kinks

Application of Y-shaped, coated self-expandable metallic stents for anastomotic stenosis after gastrojejunostomy (Billroth II).

PubMed

Li, Teng-Fei; Wu, Gang; Han, Xin-Wei; Shui, Shao-Feng; Ren, Jian-Zhuang; Li, Zhen; Ren, Ke-Wei

2017-01-01

Anastomotic stenosis is an infrequent but life-threatening complication after gastrojejunostomy (Billroth II). Tubular or single tubular stents have limited efficacy due to the particular anatomy. To assess the feasibility of a Y-shaped, fully-coated, self-expandable, metallic stent (SEMS) for anastomotic stenosis after gastrojejunostomy (Billroth II). Between January 2008 and August 2014, 14 patients (10 with gastric carcinoma and four with duodenal ulcers) had anastomotic stenoses following Billroth II reconstructions. Eight patients with gastric cancer had tumor recurrence near the anastomosis; two had benign strictures. The four duodenal ulcer patients had benign stenoses. An integrated Y-shaped, fully coated SEMS was designed to accord with the anatomy of residual gastrojejunal anastomotic strictures. Fourteen stents were inserted under fluoroscopic control. Follow-up was at 1, 3, 9, and 12 months, and then annually. All 14 stents were inserted successfully at the first attempt with a technical success rate of 100%. After stenting, abdominal symptoms resolved in all patients. All patients were followed up for 4-27 months (mean, 13.9 months). One of the eight recurrent cases died of multiple tumor metastases and liver failure after 7 months, without obstruction symptoms. In all six patients with benign anastomotic stenosis, the stents were removed successfully without complication and with no evidence of restenosis based on clinical evaluation and imaging. A Y-shaped, fully-coated SEMS proved to be a feasible and minimally invasive procedure for treating anastomotic stenosis after gastrojejunostomy (Billroth II). © The Foundation Acta Radiologica 2016.

Delayed complications after flow-diverter stenting: reactive in-stent stenosis and creeping stents.

PubMed

Cohen, José E; Gomori, John Moshe; Moscovici, Samuel; Leker, Ronen R; Itshayek, Eyal

2014-07-01

We assessed the frequency and severity of changes in stent configuration and location after the treatment of intracranial aneurysms, and patterns of in-stent stenosis. We retrospectively reviewed data for consecutive aneurysm patients managed with endovascular implantation of flow-diverter stents (Silk Flow Diverter [Balt Extrusion, Montmorency, France] and Pipeline Embolization Device [ev3/Coviden, Minneapolis, MN, USA]) from October 2011 to July 2012. Routine 2, 6, 9-12, and 16-20 month follow-up angiograms were compared, with a focus on changes in stent configuration and location from immediately after deployment to angiographic follow-up, and the incidence and development of in-stent stenosis. Thirty-four patients with 42 aneurysms met inclusion criteria. The Silk device was implanted in 16 patients (47%, single device in 15), the Pipeline device in 18 (53%, single device in 16). On first follow-up angiography, in-stent stenosis was observed in 38% of Silk devices and 39% of Pipeline devices. In-stent stenosis was asymptomatic in 12 of 13 patients. One woman presented with transient ischemic attacks and required stent angioplasty due to end tapering and mild, diffuse in-stent stenosis. Configuration and location changes, including stent creeping and end tapering were seen in 2/16 patients (13%) with Silk devices, and 0/18 patients with Pipeline devices. We describe stent creeping and end tapering as unusual findings with the potential for delayed clinical complications. In-stent stenosis, with a unique behavior, is a frequent angiographic finding observed after flow-diverter stent implant. The stenosis is usually asymptomatic; however, close clinical and angiographic monitoring is mandatory for individualized management. Copyright © 2013 Elsevier Ltd. All rights reserved.

[Retrieval of a migrated plastic stent in a 51-year-old man].

PubMed

Poszler, A; Klare, P; Weber, A; Abdelhafez, M; Holzapfel, K; Schmid, R M; von Delius, S

2018-04-16

Endosonographically guided transgastric drainage is the first-line interventional therapy of walled-off necrosis and symptomatic pancreatic pseudocysts in necrotizing pancreatitis. Plastic stents or lumen apposing metal stents are commonly used. A possible complication of endoscopic therapy is stent migration. We report upon a 51-year-old man who presented with acute necrotizing pancreatitis. Transgastric necrosectomy was performed and 5 transmural double-pigtail stents (DPS) were left in situ to drain the residual retroperitoneal cavity. The patient recovered and 4 stents were endoscopically removed 5 weeks later on an outpatient basis, whereas the fifth stent was suspected to have passed spontaneously via the natural route. The asymptomatic patient presented 3 months later for follow-up computed tomography. The necrosis had healed but one DPS was seen beyond the gastric wall near the kidney. Transmural access to the stent could be achieved by an endosonographically guided puncture toward the proximal portion of the stent followed by placement of a hydrophilic guidewire alongside the stent. A new gastrostomy was created by using a 6F cystotome followed by wire-guided dilation with a 12 mm balloon. The stent could then be grasped with transmurally inserted rat-tooth forceps and repositioned across the gastrostomy site. The patient was given prophylactic antibiotics. After removal of the stent, the patient could be discharged. Herein, we present the successful endosonographically guided transmural removal of a retroperitoneally migrated plastic stent. Of note, in our patient we had to rely completely on endosonography and radiography for localization and targeting of the stent, since the former necrotic cavity had meanwhile completely healed.

[Neoplasic colonic obstruction: resolution with self-expanding metallic stents].

PubMed

Jury, Gastón; Amieva, Leandro; Dolan, Martín; Fagalde, Rafael López; Naiderman, Diego; Pastorino, Martín; Jury, Rubén

2014-03-01

The endoscopic placement of self-expanding metallic stents (SEMS) emerges as a therapeutic option for neoplastic colonic obstruction in two situations: as palliative treatment and as a bridge to surgery. The latter can avoid emergency surgery, thus decreasing the rate of ostomies and the mortality and morbidity associated with them. To evaluate the feasibility, safety and benefits of SEMS placement for the treatment of neoplastic colorectal obstruction. Between August 2008 and June 2012, we included in this prospective, longitudinal, descriptive and observational study all the patients suffering from colorectal neoplasia who were subjected to SEMS placement by the same group ofendoscopists. Nitinol SEMS were inserted under endoscopic vision and radioscopic control. Twenty seven SEMS were inserted in 27 patients, 61% of them were male and the average age was 70 years old. Symptoms of colonic suboclussion or obstruction were found in 92% of patients, 88% of the lesions were located in the left-side colon, 41% of cases were performed on an ambulatory basis and 65% of stenting was carried out for palliative purposes. The average time of hospitalization was 6,46 days. Technical and clinical success were 93% and 100%, respectively. Minor complications were observed in 11% of patients. Colonic stenting was followed by elective surgery within one month, by a laparoscopic technique in most cases. The placement of SEMS arises as a safe and effective alternative to palliative surgery or as a bridge to elective surgery.

Biodegradable stents for the treatment of benign stenoses of the small and large intestines.

PubMed

Rejchrt, S; Kopacova, M; Brozik, J; Bures, J

2011-10-01

Biodegradable stents, which are made of various synthetic polymers, such as polylactide or polyglycolide, or co-polymers, such as polydioxanone, can be used for the treatment of benign refractory stenoses of the gastrointestinal tract. Here we report 11 patients (median age 41) with stenosing Crohn's disease of the small and/or large intestine. Endoscopic insertion of a biodegradable stent was successful at the first attempt in all patients except one. Subsequent follow-up was for a mean of 16 months, median 17 months, range 12-29 months. Early stent migration (between 2 days and 8 weeks) was seen in three patients. Mucosal overgrowth (epithelial hyperplasia) was not observed in any of the patients during the follow-up period. The high rate of early stent migration might be solved by appropriate tailoring and further improvements in the design of the biodegradable stents. Proof of long-term efficacy and safety requires further studies. © Georg Thieme Verlag KG Stuttgart · New York.

The full metallic double-pigtail ureteral stent: Review of the clinical outcome and current status

PubMed Central

Kallidonis, Panagiotis S.; Georgiopoulos, Ioannis S.; Kyriazis, Iason D.; Kontogiannis, Stavros; Al-Aown, Abdulrahman M.; Liatsikos, Evangelos N.

2015-01-01

The full metallic double-J ureteral stent (MS) was introduced as a method for providing long-term drainage in malignant ureteral obstruction. Experimental evaluation of the MS revealed that its mechanical features allow efficient drainage in difficult cases, which could not be managed by the insertion of a standard polymeric double-J stent. Clinical experience with the MS showed controversial results. Careful patient selection results in efficient long-term management of malignant ureteral obstruction. The use of the MS should also be considered in selected benign cases. Major complications are uncommon and the minor complications should not hinder its use. Experience in pediatric patients is limited and warrants additional study. The cost-effectiveness of the MS seems to be appropriate for long-term treatment. Further investigation with comparative clinical trials would document the outcome more extensively and establish the indications as well as the selection criteria for the MS. PMID:25624569

Urethroplasty after Urethral Urolume Stent: an International Multicenter Experience.

PubMed

Angulo, Javier C; Kulkarni, Sanjay; Pankaj, Joshi; Nikolavsky, Dmitriy; Suarez, Pedro; Belinky, Javier; Virasoro, Ramón; DeLong, Jessica; Martins, Francisco E; Lumen, Nicolaas; Giudice, Carlos; Suárez, Oscar A; Menéndez, Nicolás; Capiel, Leandro; López-Alvarado, Damian; Ramirez, Erick A; Venkatesan, Krishnan; Husainat, Maha M; Esquinas, Cristina; Arance, Ignacio; Gómez, Reynaldo; Santucci, Richard

2018-05-08

To evaluate the outcomes and factors affecting success of urethroplasty in patients with stricture recurrence after Urolume® urethral stent. Retrospective international multicenter study on patients treated with urethral reconstruction after Urolume® stent. Stricture and stent length, time between urethral stent insertion and urethroplasty, age, mode of stent retrieval, type of urethroplasty, complications and baseline and post-urethroplasty voiding parameters were analyzed. Successful outcome was defined as standard voiding, without need of any postoperative adjunctive procedure. Sixty-three patients were included. Stent was removed at urethroplasty in 61 patients. Reconstruction technique was excision and primary anastomosis in 14(22.2%), dorsal onlay buccal mucosa graft (BMG) 9(14.3%), ventral onlay BMG 6(9.5%), dorso-lateral onlay BMG 9(14.3%), ventral onlay plus dorsal inlay BMG 3(4.8%), augmented anastomosis 5(7.9%), pedicled flap urethroplasty 6(9.5%), 2-stage procedure 4(6.4%) and perineal urethrostomy 7(11.1%). Success rate was 81% at a mean 59.7+63.4months. Dilatation and/or internal urethrotomy was performed in 10(15.9%), redo-urethroplasty in 5(7.9%). Total IPSS, QoL, Qmax and PVR significantly improved (p<.0001). Complications occurred in 8(12.7%), all Clavien-Dindo <2. Disease-free survival rate after reconstruction was 88.1%,79.5% and 76.7% at 1,3 and 5-years respectively. Explant of individual strands followed by onlay BMG is the most common approach and was significantly advantageous over the other techniques (p=.018). Urethroplasty in patients with Urolume® urethral stents is a viable option of reconstruction with a high success rate and very acceptable complication rate. Numerous techniques are viable, however, urethral preservation, tine-by-tine stent extraction and use of BMG augmentation produced significantly better outcomes. Copyright © 2018 Elsevier Inc. All rights reserved.

Temporary placement of stent grafts in postsurgical benign biliary strictures: a single center experience.

PubMed

Vellody, Ranjith; Willatt, Jonathon M; Arabi, Mohammad; Cwikiel, Wojciech B

2011-01-01

To evaluate the effect of temporary stent graft placement in the treatment of benign anastomotic biliary strictures. Nine patients, five women and four men, 22-64 years old (mean, 47.5 years), with chronic benign biliary anastomotic strictures, refractory to repeated balloon dilations, were treated by prolonged, temporary placement of stent-grafts. Four patients had strictures following a liver transplantation; three of them in bilio-enteric anastomoses and one in a choledocho-choledochostomy. Four of the other five patients had strictures at bilio-enteric anastomoses, which developed after complications following laparoscopic cholecystectomies and in one after a Whipple procedure for duodenal carcinoma. In eight patients, balloon-expandable stent-grafts were placed and one patient was treated by insertion of a self-expanding stent-graft. In the transplant group, treatment of patients with bilio-enteric anastomoses was unsuccessful (mean stent duration, 30 days). The patient treated for stenosis in the choledocho-choledochostomy responded well to consecutive self-expanding stent-graft placement (total placement duration, 112 days). All patients with bilio-enteric anastomoses in the non-transplant group were treated successfully with stent-grafts (mean placement duration, 37 days). Treatment of benign biliary strictures with temporary placement of stent-grafts has a positive effect, but is less successful in patients with strictures developed following a liver transplant.

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.

Stent-thrombus interaction and the influence of aspiration on mechanical thrombectomy: evaluation of different stent retrievers in a circulation model.

PubMed

Madjidyar, Jawid; Hermes, Julian; Freitag-Wolf, Sandra; Jansen, Olav

2015-08-01

Different devices and techniques are available for endovascular treatment of ischemic stroke. In this in vitro study, we examined the stent-thrombus interaction and the influence of additional aspiration on the efficiency of mechanical thrombectomy with established stent retrievers. Human blood thrombi were made in a Chandler loop. The thrombi were placed into the middle cerebral artery of a vascular silicon phantom. A programmable piston pump was used to acquire physiological flow in the model. Resistances were interposed to gain physiological pressure. The stent retrievers Trevo, Solitaire FR, Separator 3D, and Aperio were used to perform thrombectomy under direct visual control. For the additional aspiration, we used intermediate catheters. Ten attempts per device were made with and without aspiration under standardized conditions, a total of n = 80. For all thrombectomy maneuvers, it was demonstrated that the thrombus was pushed by the stent struts against the vessel wall and was retracted along it. The stent-thrombus interaction was only superficial for all devices. Using additional distal aspiration, the amount of distal embolism and rate of embolism in new territories was significantly lower than without. Moreover, additional aspiration reduced the number of recanalization maneuvers and the recanalization time. Distal aspiration with intermediate catheters increases the efficacy of mechanical thrombectomy with stent retrievers significantly. In contrary to earlier suggestions, the interaction between the thrombus and the stent retriever is only superficial, rather than an integration of the thrombus into the retriever. No significant differences between the proven devices could be shown in our model.

Bile Flow Phantom Model and Animal Bile Duct Dilation Model for Evaluating Biliary Plastic Stents with Advanced Hydrophilic Coating

PubMed Central

Kwon, Chang-Il; Kim, Gwangil; Jeong, Seok; Lee, Won Seop; Lee, Don Haeng; Ko, Kwang Hyun; Hong, Sung Pyo; Hahm, Ki Baik

2016-01-01

Background/Aims The efforts to improve biliary plastic stents (PSs) for decreasing biofilm formation and overcome short patency time have been continued. The aim of this study is to evaluate the effect of advanced hydrophilic coating for patency and biodurability of PS. Methods Using an in vitro bile flow phantom model, we compared patency between prototype PS with hydrophilic coating (PS+HC) and prototype PS without hydrophilic coating (PS−HC). We performed an analysis of the degree of luminal narrowing by microscopic examination. Using an in vivo swine bile duct dilation model made by endoscopic papillary closure and stent insertion, we evaluated biodurability of hydrophilic coating. Results In the phantom model, PS+HC showed less biofilm formation and luminal narrowing than PS−HC at 8 weeks (p<0.05). A total of 31 stents were inserted into the dilated bile duct of seven swine models, and 24 stents were successfully retrieved 8 weeks later. There was no statistical difference of stent patency between the polyethylene PS+HC and the polyurethane PS+HC. The biodurability of hydrophilic coating was sustained up to 8 weeks, when assessing the coating layer by scanning electron microscopy examination. Conclusions Advanced hydrophilic coating technology may extend the patency of PS compared to uncoated PS. PMID:27021507

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahlhelm, Frank, E-mail: frah1@gmx.de; Kaufmann, Ralf, E-mail: ralf.kaufmann@vascomed.d; Ahlhelm, Dirk, E-mail: ahlhelmd@gmx.de

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 interventionmore » 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

A review of the iStent® trabecular micro-bypass stent: safety and efficacy

PubMed Central

Wellik, Sarah R; Dale, Elizabeth A

2015-01-01

There is a significant demand for procedures that can effectively treat glaucoma with low risk and good visual outcomes. To fill this void, procedures termed “minimally invasive glaucoma surgery”, are gaining in popularity. This review will focus on the safety and efficacy of one such minimally invasive glaucoma surgery procedure, the trabecular micro-bypass stent. This stent is intended to lower intraocular pressure by directly cannulating Schlemm’s canal and thereby enhancing aqueous outflow. Recent randomized controlled trials and case series have demonstrated the micro-bypass stent to be a relatively safe procedure, with limited complications and no serious adverse sequelae. The most common complication across all studies was stent obstruction or malposition, which generally did not result in any adverse outcome in vision or pressure control. In addition, increased rates of hypotony, choroidal hemorrhage, or infection were not seen with the micro-bypass stent in comparison to cataract surgery alone. PMID:25931808

Magnetic Ureteral Stent Removal Without Cystoscopy: A Randomized Controlled Trial.

PubMed

Rassweiler, Marie-Claire; Michel, Maurice-Stephan; Ritter, Manuel; Honeck, Patrick

2017-08-01

Ureteral stenting is a common procedure in urology. The cystoscopic removal of Double-J stents (DJ) causes unpleasant side effects with a negative impact on patient's quality of life. The aim of our study was to evaluate this newly developed magnetic DJ and compare it with a standard DJ regarding quality of life with indwelling DJs as well as discomfort during the removal. The magnetic DJ (Blackstar, Urotech [Achenmühle, Germany]) is a standard 7F ureteral stent with a small magnetic cube fixed through a string on the loop of the distal part of the stent. For DJ removal, a special catheter-like retrieval instrument with a magnetic tip is inserted, the two magnets connect and the retrieval instrument is removed with the DJ. We first tested this DJ in 20 cases. Afterward we evaluated 40 consecutive cases that required a DJ placement after ureterorenoscopy in a prospective randomized manner. The quality of life was assessed by the ureteral stent symptom questionnaire. A visual analogue scale was used to document the pain by DJ removal. There was a significant difference regarding the pain location with the indwelling DJ (p = 0.038). The maximum pain was located in the lower abdomen and/or around the bladder (48%) with the magnetic DJ, whereas the standard DJ caused flank pain in 54% of the patients. The mean time for the magnetic DJ removal including preparation and cleaning as for a transurethral catheter insertion was 9.55 [7-14] minutes, whereas the mean time for the cystoscopic DJ removal was 21.35 [18-30] minutes. The pain caused by the removal of the magnetic DJ was significantly less than that caused by the cystoscopic DJ removal (p = 0.019). The discomfort caused by the indwelling magnetic DJ is comparable with that caused by the standard DJ. However, the magnetic DJ removal is less painful and faster.

The German linguistic validation of the Ureteral Stent Symptoms Questionnaire (USSQ).

PubMed

Abt, Dominik; Dötzer, Kristina; Honek, Patrick; Müller, Karolina; Engeler, Daniel Stephan; Burger, Maximilian; Schmid, Hans-Peter; Knoll, Thomas; Sanguedolce, Francesco; Joshi, Hrishi B; Fritsche, Hans-Martin

2017-03-01

We developed and validated the German version of the Ureteral Stent Symptoms Questionnaire (USSQ) for male and female patients with indwelling ureteral stents. The German version of the USSQ was developed following a well-established multistep process. A total of 101 patients with indwelling ureteral stents completed the German USSQ as well as the validated questionnaires International Prostate Symptom Score (IPSS) or International Consultation on Incontinence Questionnaire (ICIQ) and the Short Form Health Survey (SF-36). Patients completed questionnaires at 1 and 2-4 weeks after stent insertion and 4 weeks after stent removal. Statistical analyses were performed to assess the psychometric properties of the questionnaire. The German version of the USSQ showed good internal consistency (Cronbach's α = .72-.88) and test-retest reliability [intraclass correlation coefficient (ICC) = .81-.92]. Inter-domain associations within the USSQ showed substantial correlations between different USSQ domains, indicating a high conceptual relationship of the domains. Except from urinary symptoms and general quality of life, German USSQ showed good convergent validity with the corresponding validated questionnaires. All USSQ domains showed significant sensitivity to change (p ≤ .001). The new German version of the USSQ proved to be a reliable and robust instrument for the evaluation of ureteral stent-associated morbidity for both male and female patients. It is expected to be a valid outcome measure in the future stent research.

Medium-term follow-up after deployment of ultraflex expandable metallic stents to manage endobronchial pathology.

PubMed

Madden, Brendan P; Park, John E S; Sheth, Abhijat

2004-12-01

Between March 1997 and March 2004 we deployed 80 Ultraflex metallic expandable stents (Boston Scientific, Waterson, MA) in 69 patients under direct vision using rigid bronchoscopy. We report our medium- to long-term experience in patients for whom these stents were deployed. To date 15 patients have been followed for more than 1 year (median 41 months, range 12 to 83 months) after stent deployment. Indications for stenting in these patients were neoplasia (5), stricture (5), airway malacia (1), iatrogenic tracheal tear (1), and compression from an aortic aneurysm (1), a right interrupted aortic arch (1), and a right brachiocephalic artery aneurysm with tracheomalacia (1). Ten tracheal stents (9 covered, 1 uncovered) and 10 bronchial stents (8 uncovered, 2 covered) were inserted, and 5 patients received two stents. Five of these patients experienced no long-term problems. Complications included troublesome halitosis (5), which was difficult to treat despite various antibiotic regimes; granulation tissue formation above and below the stent that was successfully treated with low-power Nd:YAG laser therapy (7); and metal fatigue (1). We did not encounter stent migration. We conclude that Ultraflex expandable metallic stents have an important role in the management of selected patients with diverse endobronchial pathologies and are well tolerated in the long-term. Although associated granulation tissue can be successfully treated with Nd:YAG laser, halitosis can be a difficult problem to address.

Percutaneous intraductal radiofrequency ablation for treatment of biliary stent occlusion: A preliminary result.

PubMed

Xia, Ning; Gong, Ju; Lu, Jian; Chen, Zhi-Jin; Zhang, Li-Yun; Wang, Zhong-Min

2017-03-14

To assess the feasibility and effectiveness of a novel application of percutaneous intraductal radiofrequency (RF) for the treatment of biliary stent obstruction. We specifically report a retrospective study presenting the results of percutaneous intraductal RF in patients with biliary stent occlusion. A total of 43 cases involving biliary stent obstruction were treated by placing an EndoHPB catheter and percutaneous intraductal RF was performed to clean stents. The stent patency was evaluated by cholangiography and follow-up by contrast enhanced computed tomography or ultrasound after the removal of the drainage catheter. Following the procedures, of the 43 patients, 40 survived and 3 died with a median survival of 80.5 (range: 30-243) d. One patient was lost to follow-up. One patient had the stent patent at the time of last follow-up. Two patients with stent blockage at 35 d and 44 d after procedure underwent percutaneous transhepatic drain insertion only. The levels of bilirubin before and after the procedure were 128 ± 65 μmol/L and 63 ± 29 μmol/L, respectively. There were no related complications (haemorrhage, bile duct perforation, bile leak or pancreatitis) and all patients' stent patency was confirmed by cholangiography after the procedure, with a median patency time of 107 (range: 12-180) d. This preliminary clinical study demonstrated that percutaneous intraductal RF is safe and effective for the treatment of biliary stent obstruction, increasing the duration of stent patency, although randomized controlled trials are needed to confirm the effectiveness of this approach.

Percutaneous intraductal radiofrequency ablation for treatment of biliary stent occlusion: A preliminary result

PubMed Central

Xia, Ning; Gong, Ju; Lu, Jian; Chen, Zhi-Jin; Zhang, Li-Yun; Wang, Zhong-Min

2017-01-01

AIM To assess the feasibility and effectiveness of a novel application of percutaneous intraductal radiofrequency (RF) for the treatment of biliary stent obstruction. METHODS We specifically report a retrospective study presenting the results of percutaneous intraductal RF in patients with biliary stent occlusion. A total of 43 cases involving biliary stent obstruction were treated by placing an EndoHPB catheter and percutaneous intraductal RF was performed to clean stents. The stent patency was evaluated by cholangiography and follow-up by contrast enhanced computed tomography or ultrasound after the removal of the drainage catheter. RESULTS Following the procedures, of the 43 patients, 40 survived and 3 died with a median survival of 80.5 (range: 30-243) d. One patient was lost to follow-up. One patient had the stent patent at the time of last follow-up. Two patients with stent blockage at 35 d and 44 d after procedure underwent percutaneous transhepatic drain insertion only. The levels of bilirubin before and after the procedure were 128 ± 65 μmol/L and 63 ± 29 μmol/L, respectively. There were no related complications (haemorrhage, bile duct perforation, bile leak or pancreatitis) and all patients’ stent patency was confirmed by cholangiography after the procedure, with a median patency time of 107 (range: 12-180) d. CONCLUSION This preliminary clinical study demonstrated that percutaneous intraductal RF is safe and effective for the treatment of biliary stent obstruction, increasing the duration of stent patency, although randomized controlled trials are needed to confirm the effectiveness of this approach. PMID:28348491

A retrospective study of silicone stent placement for management of anastomotic airway complications in lung transplant recipients: short- and long-term outcomes.

PubMed

Dutau, Hervé; Cavailles, Arnaud; Sakr, Lama; Badier, Monique; Gaubert, Jean-Yves; Boniface, Stéphanie; Doddoli, Christophe; Thomas, Pascal; Reynaud-Gaubert, Martine

2010-06-01

Airway anastomotic complications remain a major cause of morbidity and mortality after lung transplantation (LT). Few data are available with regard to the use of silicone stents for these airway disorders. The aim of this retrospective study was to evaluate the clinical efficacy and safety of silicone stents for such an indication. Data of adult lung transplant recipients who had procedures performed between January 1997 and December 2007 at our institution were reviewed retrospectively. We included patients with post-transplant airway complications who required bronchoscopic intervention with a silicone stent. In 17 of 117 (14.5%) LT recipients, silicone stents were inserted at a mean time of 165 (range 5 to 360) days after surgery in order to palliate 23 anastomotic airway stenoses. Symptomatic improvement was noted in all patients, and mean forced expiratory volume in 1 second (FEV(1)) increased by 672 +/- 496 ml (p < 0.001) after stent insertion. The stent-related complication rate was 0.13/patient per month. The latter consisted of obstructive granulomas (n = 10), mucus plugging (n = 7) and migration (n = 7), which were of mild to moderate severity and were successfully managed endoscopically. Mean stent duration was 266 days (range 24 to 1,407 days). Successful stent removal was achieved in 16 of 23 cases (69.5%) without recurrence of stenosis. Overall survival was similar in patients with and without airway complications (p = 0.36). Silicone stents allow clinical and lung function improvement in patients with LT-related airway complications. Stent-related complications were of mild to moderate severity, and were appropriately managed endoscopically. Permanent resolution of airway stenosis was obtained in most patients, allowing definitive stent removal without recurrence. Copyright 2010 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

A Spanner in the works: the use of a new temporary urethral stent to relieve bladder outflow obstruction after prostate brachytherapy.

PubMed

Henderson, Alastair; Laing, Robert W; Langley, Stephen E M

2002-01-01

Assessment of the Spanner, a new temporary urethral stent to relieve bladder outflow obstruction and urinary symptoms after brachytherapy. Five patients with unusually severe urinary morbidity after (125)I brachytherapy were recruited. The mean time after implant was 40 days (range 25-90). Spanner intraprostatic stents were introduced using topical anesthetic without complication. All patients were able to void spontaneously with no post-void residual volume of urine. The flow rates increased in all cases (p=0.03) and the International Prostate Symptom Scores were significantly improved after stent insertion in all patients (p=0.03). All patients experienced some degree of pain or dysuria during stent use. Bladder outflow obstruction was effectively treated with the Spanner intraprostatic stent, however pain limited the use of the device in the early post-brachytherapy patient group. Pharmacotherapy, stent design modification, or smaller stent diameter may increase the utility of stents after brachytherapy.

Evaluation of a bifurcation drug-eluting stent system versus provisional T-stenting in a perfused synthetic coronary artery model.

PubMed

Rizik, David G; Klag, Joseph M; Tenaglia, Alan; Hatten, Thomas R; Barnhart, Marianne; Warnack, Boris

2009-12-01

Provisional T-stenting is a widely used strategy for the treatment of coronary artery bifurcation lesions. However, the use of conventional stents in this setting is limited by multiple factors; this includes technical considerations such as wire wrap when accessing the involved vessel, and stent overlap at or near the carina of the lesion. In addition, current slotted tube stent technology tends to be associated with gaps in the coverage of the side branch ostium, which may result in restenosis in that segment of the lesion. The Pathfinder device, now more commonly referred to as the Xience Side Branch Access System (Xience SBA) is a drug-eluting stent (DES) designed specifically to assist in the treatment of bifurcation lesions by allowing wire access into the side branch, irrespective of the treatment strategy to be employed. The Xience SBA drug-eluting stent was compared with the standard Vision coronary stent system using a provisional T-stenting strategy in a perfused synthetic model of the coronary vasculature with side branch angulations of 30 degrees , 50 degrees , 70 degrees , and 90 degrees . Stent delivery was performed under fluoroscopic guidance. Following the procedure, high-resolution 2D Faxitron imaging was used to evaluate deployment accuracy of the side branch stent relative to the main branch stent. Deployment of the Xience SBA was accomplished in the same total time as the standard stents in a provisional T-stenting approach (14.9 vs. 14.6 minutes). However, the time required to achieve stent deployment in the main branch was less with the Xience SBA (4.0 vs. 6.6 minutes), and as a result, total contrast usage (49.4 vs. 69.4 cm(3)) and fluoroscopy time (5.1 vs. 6.2 minutes) was lower. Additionally, the Xience SBA had a lower incidence of wire wrap (22% vs. 89%) and less distal protrusion of the side branch stent into the main branch (0.54 vs. 1.21 mm). Significant gaps in ostial side branch coverage were not seen in either group. The Xience

Retreatment of recanalized aneurysms after Y-stent-assisted coil embolization with double enterprise stents: case report and systematic review of the literature.

PubMed

Kono, Kenichi; Shintani, Aki; Terada, Tomoaki

2014-01-01

It is necessary to consider possibility of recanalization and retreatment after coil embolization for cerebral aneurysms. There is concern that retreatment for recanalized aneurysms after Y-stent-assisted coil embolization may be difficult because of double stents, especially in Y-stents with double closed-cell stents owing to narrowed structures. However, no detailed reports of retreatment after Y-stent have been reported. Between July 2010 and June 2013, we treated four aneurysms with Y-stent-assisted coil embolization using Enterprise closed-cell stents. Recanalization occurred in one case (25%), and retreatment was performed. We easily navigated a microcatheter into the target portions of the aneurysm through the Y-stent and occluded the aneurysm with coils. Additionally, by systematically searching in PubMed, we found 105 cases of Y-stent-assisted coil embolization using Enterprise stents or Neuroform stents with more than 6 months of follow-up. Among them, retreatment was performed in 10 cases (9.5%). There were no significant differences in retreatment rates among different stent combinations (P=0.91; Fisher's exact test). In conclusion, navigation of a microcatheter into the aneurysm through the Y-stent with double Enterprise stents was feasible, and retreatment rates after Y-stent-assisted coiling may not depend on stent combinations.

Newly designed plastic stent for endoscopic placement above the sphincter of Oddi in patients with malignant hilar biliary obstruction.

PubMed

Ishiwatari, Hirotoshi; Hayashi, Tsuyoshi; Ono, Michihiro; Sato, Tsutomu; Kato, Junji

2013-05-01

Plastic stent (PS) occlusion occurs as a result of bacterial adherence to the stent's inner wall. To retain the bacteriological barrier, placing a PS above the sphincter of Oddi ('inside stent') has been investigated. We designed a new PS (inside stent with thread [IT] stent) with attachable nylon thread for use as an inside stent and for easy retrieval. The present study evaluated the IT stent's technical feasibility and efficacy for malignant hilar biliary obstruction. A total of 26 consecutive patients with unresectable malignant hilar biliary obstruction underwent placement of IT stents from August 2007 to February 2011. IT stents were placed across the strictures without sphincterotomy to achieve bilateral drainage. The overall technical success rate of the IT stent was 100% for one session. Multiple IT stents were inserted in 25 cases(two stents in 15 patients, three stents in 10 patients). No stent-related early complications occurred. The functional success rate was 92% (24/26). The rate of reintervention because of stent malfunction was 50% (13/26). In all 16 patients who underwent stent removal, IT stents were easily retrieved using the nylon thread. According to Kaplan-Meier analysis, the median stent patency period was 136 days. IT stents for endoscopic placement above the sphincter of Oddi can be used safely and effectively for malignant hilar biliary obstruction. © 2013 The Authors. Digestive Endoscopy © 2013 Japan Gastroenterological Endoscopy Society.

Fabrication of a Delaying Biodegradable Magnesium Alloy-Based Esophageal Stent via Coating Elastic Polymer

PubMed Central

Yuan, Tianwen; Yu, Jia; Cao, Jun; Gao, Fei; Zhu, Yueqi; Cheng, Yingsheng; Cui, Wenguo

2016-01-01

Esophageal stent implantation can relieve esophageal stenosis and obstructions in benign esophageal strictures, and magnesium alloy stents are a good candidate because of biodegradation and biological safety. However, biodegradable esophageal stents show a poor corrosion resistance and a quick loss of mechanical support in vivo. In this study, we chose the elastic and biodegradable mixed polymer of Poly(ε-caprolactone) (PCL) and poly(trimethylene carbonate) (PTMC) as the coated membrane on magnesium alloy stents for fabricating a fully biodegradable esophageal stent, which showed an ability to delay the degradation time and maintain mechanical performance in the long term. After 48 repeated compressions, the mechanical testing demonstrated that the PCL-PTMC-coated magnesium stents possess good flexibility and elasticity, and could provide enough support against lesion compression when used in vivo. According to the in vitro degradation evaluation, the PCL-PTMC membrane coated on magnesium was a good material combination for biodegradable stents. During the in vivo evaluation, the proliferation of the smooth muscle cells showed no signs of cell toxicity. Histological examination revealed the inflammation scores at four weeks in the magnesium-(PCL-PTMC) stent group were similar to those in the control group (p > 0.05). The α-smooth muscle actin layer in the media was thinner in the magnesium-(PCL-PTMC) stent group than in the control group (p < 0.05). Both the epithelial and smooth muscle cell layers were significantly thinner in the magnesium-(PCL-PTMC) stent group than in the control group. The stent insertion was feasible and provided reliable support for at least four weeks, without causing severe injury or collagen deposition. Thus, this stent provides a new stent for the treatment of benign esophageal stricture and a novel research path in the development of temporary stents in other cases of benign stricture. PMID:28773505

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.

[Experimental study of an intratracheal stent made of shape memory alloy].

PubMed

Yoshimura, M; Tsugawa, C; Tsubota, N

1994-11-01

To develop a new prosthesis for treating tracheal stenosis and tracheobronchomalacia, we examined the usefulness of an intratracheal stent made of shape memory alloy (SMA), a titanium-nickel alloy composed of 50% of each metal. At its recovery temperature (37 degrees C), the SMA stent was designed to recall the memorized shape of a coil with a diameter of 5 or 6 mm and a length of 10 mm. For the present experiment, it was transformed to a smaller coil 3 mm in diameter at a low temperature (-50 degrees C) and then loaded into the prosthesis introducer tube. An experimental model of potentially fatal tracheomalacia was made surgically by cutting and fracturing the tracheal cartilages of rabbits and tracheal collapse was confirmed by rigid bronchoscope. The introducer tube with the SMA stent was inserted and then the prosthesis was advanced into the collapsed segment of the trachea using the stent pusher. The SMA stent warmed bo body temperature and recovered its memorized shape after 1-2 min. In 3 out of 8 rabbits, follow-up bronchoscopy performed at 6, 8, and 10 months after implantation revealed satisfactory patency of the SMA stent and the trachea. After follow-up, 3 animals were sacrificed for histological observation, which showed little proliferation of granulation tissue and no dislocation of the SMA stent from the malacic portion. The remaining 5 rabbits have been followed for 18-24 months and are doing well. We conclude that the SMA stent maintains good tracheal patency, causes little reaction in the tracheal wall, and is easy to handle. Thus, it shows the potential for clinical application.

A shape memory airway stent for tracheobronchomalacia in children: an experimental and clinical study.

PubMed

Tsugawa, C; Nishijima, E; Muraji, T; Yoshimura, M; Tsubota, N; Asano, H

1997-01-01

The authors have designed a coil airway stent using a thermal shape-memory titanium-nickel alloy (SMA) to relieve airway collapse in children. A characteristic of alloy allowed the stent to be enclosed in the thin introducer tube and to position it bronchoscopically in the collapsed airway. When the stent is warmed to 37 to 40 degrees C, it expands to the memorized diameter and stents the airway. In eight rabbits, an experimental model of potentially fatal tracheomalacia was created by fracturing the tracheal cartilages. The stents of 6 mm in diameter and 15 mm in length were placed, and then the stents were recovered to their original shape within 1 minute. All rabbits except one showed no respiratory symptoms during the follow-up period. Results of bronchoscopy performed 6 and 10 months after implantation showed satisfactory patency of the trachea. The rabbits were killed for histological evaluation 6 to 28 months after implantation. The specimens showed little proliferation of granulation and no dislodgement of the stents. This procedure was attempted in two children who had severe bronchomalacia. One 5-year-old patient underwent implantation with a stent of 5 mm in diameter and 25 mm in length into the left main bronchus. The patient was relieved from apneic attacks. The stent was removed 2 years after implantation after a remarkable improvement of ventilation. The other patient with left bronchomalacia, age 1 year 2 months, underwent implantation with a 5-mm x 20-mm stent. The animal experiment and clinical experience indicated that (1) this stent can be easily inserted and removed bronchoscopically, (2) the stent has good tissue compatibility and little interference of mucociliary function, and (3) the SMA stent is a promising therapeutic adjunct in the management of children with severe tracheobronchomalacia.

Correction of Stent Distortion and Overhanging Stent Struts during Left Main Bifurcation Stenting by Selective Distal Stent Cell Re-Wiring: A Novel Guidewire Approach

PubMed Central

Sabbah, Mahmoud; Kadota, Kazushige; Fuku, Yasushi; Mitsudo, Kazuaki

2015-01-01

Stent malapposition and overhanging stent struts in front of the side branch (SB) ostium are not uncommon following bifurcation stenting that might lead to stent thrombosis. We herein present 2 cases, in which optical frequency domain imaging and intravascular ultrasound effectively revealed stent malapposition and overhanging struts inside the ostium of the SB following left main coronary artery stenting. Therefore, we introduced a novel technique for rectification of these incidental findings by selective SB re-wiring through the most distal stent cell with the adjunctive help of a double lumen microcatheter. PMID:27122906

A new intratracheal stent made from nitinol, an alloy with "shape memory effect".

PubMed

Vinograd, I; Klin, B; Brosh, T; Weinberg, M; Flomenblit, Y; Nevo, Z

1994-05-01

Temporary or permanent tracheal splinting in pediatric patients may be indicated in tracheomalacia or bronchomalacia, repair of congenital tracheal stenosis, and after tracheal resection. This study presents the results of the development of a new intraluminal airway stent made from titanium alloy, a metal with "shape memory effect". At low temperatures (martensitic state) the titanium alloy stent can be fashioned into a specific shape; then when heated to a higher temperature (austenitic state) the stent alters its shape, only to regain its original shape when recooled to the lower temperature. The stent, connected to a small electric power supply, was introduced into 20 young rabbits with the use of a 2.5 cm rigid bronchoscope. After implantation in the martensitic state the stent was warmed to 40 degrees C, the austenitic state, by an electric current of 1.5 to 3 ampere for 1 to 2 seconds. After a period of 8 to 10 weeks the stent was removed (in its martensitic state) through the same-sized bronchoscope after being cooled with 3 to 4 ml of 80% alcohol solution at 6 degrees C. No signs of airway obstruction developed in any of the animals after implantation or extraction of the stent. The biomechanical properties of the trachea, as shown by strain measurements with the use of incremental forces, showed significant differences between the stented and unstented segments (p < 0.005). The titanium alloy intratracheal stent adequately fulfilled the requirements of a temporary intraluminal airway splint, and because of its unique feature of shape memory effect the stent could be inserted, fixed, and removed easily, even in very small airways.

Self-Expanding Metal Stents for the Treatment of Post-Surgical Esophageal Leaks: A Tertiary Referral Center Experience.

PubMed

Anderloni, Andrea; Genco, Chiara; Massidda, Marco; Di Leo, Milena; Fumagalli, Uberto Romario; Rosati, Riccardo; Correale, Loredana; Maselli, Roberta; Ferrara, Elisa Chiara; Jovani, Manol; Repici, Alessandro

2018-06-05

The study aimed to evaluate the effectiveness and safety of self-expanding metal stents (SEMS) in the management of post-surgical esophageal leaks. Retrospective data of consecutive patients with a post-surgical esophageal leak treated by means of a metal stent between January 2008 and December 2014 at the Humanitas Research Hospital (Milan, Italy) were extracted from a prospectively maintained register of SEMS used for benign indications, such as post-surgical benign esophageal strictures and/or leaks. The primary outcome of the study was to assess the rate of successful leak closure and to identify the variables associated with its achievement. As a secondary outcome, we evaluated the overall safety of SEMS placement and the efficacy and safety for different types of SEMS in this specific setting of patients. Leak resolution was documented with endoscopic and/or imaging studies. In the case of leak persistence, further attempts of esophageal stenting were carried out at the discretion of both endoscopists and surgeons. A total of 49 patients were included in the study (men 41 of 49, 83.7%, mean age 62.4 ± 11.9). One patient was excluded from analysis, because of death 1 day after stent insertion due to worsening of pre-existing mediastinitis. A total number of 82 stents were placed (mean number of stents per patient: 1.7) in 49 patients: 35 patients (71.4%) received a partially covered SEMS (PCSEMS) as the first stent positioned, while the remaining 14 (28.6%) received a fully covered SEMS (FCSEMS); but 1 patient (2%) died following stent insertion; therefore, data regarding therapeutic success were available for 48 patients. Stents were left in place for a mean period of 21.9 ± 15.2 days. Leak closure after the first stent placement was achieved in 22 of 48 (45.8%) patients. Of the 26 patients with failure of index stent placement, 18 patients underwent further stenting attempts (69.2%), and secondary closure of leak was achieved in 7 (38.9%) of these 18

Microstructure evolution of the Ir-inserted Ni silicides with additional annealing

NASA Astrophysics Data System (ADS)

Yoon, Kijeong; Song, Ohsung

2009-02-01

Thermally-evaporated 10 nm-Ni/1 nm-Ir/(poly)Si structures were fabricated in order to investigate the thermal stability of Ir-inserted nickel silicide after additional annealing. The silicide samples underwent rapid thermal annealing at 300 ° C to 1200 ° C for 40 s, followed by 30 min annealing at the given RTA temperatures. Silicides suitable for the salicide process were formed on the top of the single crystal and polycrystalline silicon substrates, mimicking actives and gates. The sheet resistance was measured using a four-point probe. High resolution x-ray diffraction and Auger depth profiling were used for phase and chemical composition analysis, respectively. Transmission electron microscope and scanning probe microscope were used to determine the cross-section structure and surface roughness. The silicide, which formed on single crystal silicon substrate with surface agglomeration after additional annealing, could defer the transformation of Ni(Ir)Si to Ni(Ir)Si2 and was stable at temperatures up to 1200 °C. Moreover, the silicide thickness doubled. There were no outstanding changes in the silicide thickness on polycrystalline silicon. However, after additional annealing, the silicon-silicide mixing became serious and showed high resistance at temperatures >700 °C. Auger depth profiling confirmed the increased thickness of the silicide layers after additional annealing without a change in composition. For a single crystal silicon substrate, the sheet resistance increased slightly due to the significant increases in surface roughness caused by surface agglomeration after additional annealing. Otherwise, there were almost no changes in surface roughness on the polycrystalline silicon substrate. The Ir-inserted nickel monosilicide was able to maintain a low resistance in a wide temperature range and is considered suitable for the nano-thick silicide process.

Single-stage intraoperative transhepatic biliary stenting in patients with unresectable hepatobiliary pancreatic tumors.

PubMed

Iwasaki, Yoshimi; Kubota, Keiichi; Kita, Junji; Katoh, Masato; Shimoda, Mitsugi; Sawada, Tokihiko; Iso, Yukihiro

2013-02-01

The current study was conducted to evaluate the safety and utility of intraoperative transhepatic biliary stenting (ITBS) in patients with unresectable malignant biliary obstruction (UMBO) diagnosed intraoperatively. In this study, 50 patients who underwent ITBS for UMBO between April 2001 and May 2009 were retrospectively reviewed. For 26 patients who underwent preoperative percutaneous transhepatic biliary drainage (PTBD), the expandable metallic stent (EMS) was inserted intraoperatively by the PTBD route in a single stage. For 24 patients, the intrahepatic bile ducts were intentionally dilated by injection of saline via the endoscopic nasobiliary drainage or the percutaneous transhepatic gallbladder drainage route, and the puncture was performed under intraoperative ultrasound guidance followed by guidewire and catheter insertion. Thereafter, the EMS was placed in the same manner. The initial postoperative complications and long-term results of ITBS were evaluated. In all cases, ITBS was technically successful. Stenting alone was performed in 22 patients and stenting combined with other procedures in 28 patients. Hospital mortality occurred for three patients (6 %), and complication-related mortality occurred in two cases (4 %). There were nine cases (18 %) of postoperative complications. The median survival time was 179 days, and the EMS patency time was 137 days. During the follow-up period, EMS occlusion occurred in 23 cases (46 %). Best supportive care was a significant independent risk factor for early mortality within 100 days after ITBS (p = 0.020, odds ratio, 9.398). Single-stage ITBS is feasible for palliation of UMBO and seems to have a low complication rate.

Subintimal Recanalization of Occluded Stents: The Substent Technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Diamantopoulos, Athanasios, E-mail: adiamant@upatras.gr; Katsanos, Konstantinos; Spiliopoulos, Stavros

2013-08-01

PurposeApplication of metal stents is complicated by neointimal hyperplasia leading to vessel restenosis and reocclusion. Treatment options in cases presenting with complete occlusion of the stented segment and recurrent critical limb ischemia (CLI) are limited. We present the option of the subintimal/substent technique in dealing with occluded stents.MethodsThe study included patients presenting with recurrent CLI due to impaired blood flow as a result of complete occlusion of previously inserted metal stents and unsuccessful intraluminal crossing of the lesion via either the antegrade or retrograde approach. In these cases, crossing the occlusion through the subintimal/substent plane was attempted. Primary end pointsmore » included technical success, safety of the procedure, clinical improvement, and limb salvage, while secondary end points were patient survival, primary patency, and vessel restenosis rates at 1-year follow-up. Study end points were calculated by Kaplan-Meier survival analysis.ResultsBetween July 2006 and October 2011, a total of 14 patients (mean age 69.14 {+-} 12.59 years, 12 men) were treated with the substent technique and included in the analysis. Technical success rate was 85.71 % (12 of 14), with a total lesion length of 193.57 {+-} 90.78 mm. The mean occluded stented segment length was 90.21 {+-} 44.34 mm. In 10 (83.33 %) of 12 cases, a new stent had to be placed by the side of the old occluded one, while the remaining two cases (16.67 %) were treated only with balloon angioplasty. No serious adverse events were noted during the immediate postprocedural period. All successfully treated patients improved clinically. Estimated limb salvage was 90.9 %, and patient survival rate was 90.0 % at 1 year's follow-up. Primary patency was 45.50 % and vessel restenosis 77.30 %.ConclusionSubintimal recanalization of occluded metal stents through the substent plane is a valuable alternative treatment option, especially in patients with recurrent CLI

Radioactive self-expanding stents for palliative management of unresectable esophageal cancer: a systematic review and meta-analysis.

PubMed

Chen, Hong-Lin; Shen, Wang-Qin; Liu, Kun

2017-05-01

Stent insertion is a feasible and safe palliative management for advanced unresectable esophageal cancer. The aim of this study is to assess the efficacy of radioactive stent for unresectable esophageal cancer compared with conventional stent. Systematic searches of the PubMed and Web of science are dated from their beginning to January 25, 2016. Studies that compared radioactive stent with conventional stent for unresectable esophageal cancer were included. The outcomes were postimplantation survival, relief of dysphagia, and complications related to stent implant. Six studies with 539 patients were included. All of them used stent equipped with radioactive iodine beads as a radioactive stent. The pooled weighted mean difference for median survival was 2.734 months (95% CI 1.710-3.775; Z = 5.21, P = 0.000) between two groups. The 1,3,6 month survival rates were higher in radioactive stents than conventional stent, with the pooled ORs 3.216 (95% CI 1.293-7.999; Z = 2.51, P = 0.012), 3.095 (95% CI 1.908-5.020; Z = 4.58, P = 0.000), and 7.503 (95% CI 2.206- 25.516; Z = 3.23, P = 0.001, respectively). The pooled hazard ratio was 0.464 (95% CI 0.328-0.655; Z = 4.35, P = 0.000) between two groups. For relief of dysphagia, two stents all have good relief of the dysphagia effect, but radioactive stent showed a better effect at 3, 6 months follow-up after implantation. For complications related to stent implant, no significant differences were found between two stents in terms of severe chest pain (30.0% vs. 35.7%, OR 0.765, 95% CI 0.490-1.196), gastroesophageal reflux (18.6% vs. 16.1%, OR 1.188, 95% CI 0.453-3.115), fever (12.1% vs. 12.1%, OR 1.014, 95% CI 0.332-3.097), bleeding (16.7% vs. 14.2%, OR 1.201, 95% CI 0.645-2.236), perforation or fistula (6.1% vs. 9.0%, OR 0.658, 95% CI 0.291-1.486), pneumonia (10.7% vs. 14.1%, OR 0.724, 95% CI 0.343-1.526), stent migration (7.0% vs. 10.2%, OR 0.651, 95% CI 0.220-1.924), and restenosis (24.2% vs. 20.6%, OR 1.228, 95% CI 0

Long-term Outcome of Short Metallic Stents for Lobar Airway Stenosis.

PubMed

Fruchter, Oren; Abed El Raouf, Bayya; Rosengarten, Dror; Kramer, Mordechai R

2017-07-01

Whereas stents are considered an excellent treatment for proximal central major airway stenosis, the value of stenting for distal lobar airway stenosis is still controversial. Our aim was to explore the short-term and long-term outcome of metallic stents placed for benign and malignant lobar airway stenosis. Between July 2007 and July 2014, 14 patients underwent small airway stent insertion. The clinical follow-up included serial semiannual physical examinations, pulmonary function tests, imaging, and bronchoscopy. The etiologies for airway stenosis were: early post-lung transplantation bronchial stenosis (N=5), sarcoidosis (N=1), amyloidosis (N=1), anthracofibrosis (N=1), right middle lobe syndrome due to external lymph node compression (N=1), lung cancer (N=4), and stenosis of the left upper lobe of unknown etiology (N=1). Stents were placed in the right upper lobe bronchus (N=2), right middle lobe bronchus (N=6), left upper lobe bronchus (N=4), linguar bronchus (N=1), and left lower lobe bronchus (N=1). The median follow-up period ranged from 2 to 72 months (median 18 mo). Immediate relief of symptoms was achieved in the vast majority of patients (13/14, 92%). Out of 10 patients with benign etiology for stenosis, 9 (90%) experienced sustained and progressive improvement in pulmonary function tests and clinical condition. We describe our positive experience with small stents for lobar airway stenosis; further prospective trials are required to evaluate the value of this novel modality of treatment.

Endovascular Gene Delivery from a Stent Platform: Gene- Eluting Stents

PubMed Central

Fishbein, Ilia; Chorny, Michael; Adamo, Richard F; Forbes, Scott P; Corrales, Ricardo A; Alferiev, Ivan S; Levy, Robert J

2015-01-01

A synergistic impact of research in the fields of post-angioplasty restenosis, drug-eluting stents and vascular gene therapy over the past 15 years has shaped the concept of gene-eluting stents. Gene-eluting stents hold promise of overcoming some biological and technical problems inherent to drug-eluting stent technology. As the field of gene-eluting stents matures it becomes evident that all three main design modules of a gene-eluting stent: a therapeutic transgene, a vector and a delivery system are equally important for accomplishing sustained inhibition of neointimal formation in arteries treated with gene delivery stents. This review summarizes prior work on stent-based gene delivery and discusses the main optimization strategies required to move the field of gene-eluting stents to clinical translation. PMID:26225356

Characterization and assessment of a novel poly(ethylene oxide)/polyurethane composite hydrogel (Aquavene) as a ureteral stent biomaterial.

PubMed

Gorman, S P; Tunney, M M; Keane, P F; Van Bladel, K; Bley, B

1998-03-15

The effective long-term use of indwelling ureteral stents is often hindered by the formation of encrusting deposits which may cause obstruction and blockage of the stent. Development of improved ureteral stent biomaterials capable of preventing or reducing encrustation is therefore particularly desirable. In this study, the suitability as a ureteral stent biomaterial of Aquavene, a novel poly(ethylene oxide)/polyurethane composite hydrogel was compared with that of silicone and polyurethane, two materials widely employed in ureteral stent manufacture. Examination of Aquavene in dry and hydrated states by confocal laser scanning microscopy, scanning electron microscopy, and atomic force microscopy showed the presence of numerous channels within a cellular matrix structure. The channel size increased considerably to as much as 10 microm in diameter in the hydrated state. Aquavene provided superior resistance to encrustation and intraluminal blockage over a 24-week period in a simulated urine flow model. Unobstructed urine flow continued with Aquavene at 24 weeks, whereas silicone and polyurethane stents became blocked with encrustation at 8 and 10 weeks, respectively. Weight loss within Aquavene on the order of 9% (w/w) over the 24-week flow period indicates that extraction of the noncrosslinked poly(ethylene oxide) hydrogel may be responsible for the prevention of encrustation blockage of this biomaterial. In the dry state, Aquavene was significantly harder than either silicone or polyurethane, as shown by Young's modulus, and rapidly became soft on hydration. These additional properties of Aquavene would facilitate ease of stent insertion in the dry state past obstructions in the ureter and provide improved patient comfort on subsequent biomaterial hydration in situ. Aquavene is a promising candidate for use in the urinary tract, as it is probable that effective long-term urine drainage would be maintained in vivo. Further evaluation of this novel biomaterial is

Endoscopic control of enterocutaneous fistula by dual intussuscepting stent technique.

PubMed

Melich, George; Pai, Ajit; Balachandran, Banujan; Marecik, Slawomir J; Prasad, Leela M; Park, John J

2016-09-01

Large high-output enterocutaneous fistulas pose great difficulties, especially in the setting of recent surgery and compromised skin integrity. This video demonstrates a new technique of endoscopic control of enterocutaneous fistula by using two covered overlapping stents. In brief, the two stents are each inserted endoscopically, one proximal, and the other distal to the fistula with 2 cm of each stent protruding cutaneously. Following this, the proximal stent is crimped and intussuscepted into the distal stent with an adequate overlap. A prolene suture is passed through the anterior wall of both stents to prevent migration. The two stents used were evolution esophageal stents-10 cm long, fully covered, double-flared with non-flared and flared diameters being 20 and 25 mm, respectively (product number EVO-FC-20-25-10-E, Cook Medical, Bloomington, IN, USA). The patient featured in this video developed a high-output enterocutaneous fistula proximal to a loop ileostomy, which was created following a small bowel leak after a curative surgery for bladder cancer. Using the technique featured in this video (schematic depicted in Fig. 1), the patient was nutritionally optimized with oral feeds from albumin of 0.9-3.4 g/dl within 2 months despite prior failure to achieve nutrition optimization and adequate skin protection with combination of oral and/or parenteral nutrition. Three months after stenting, following nutritional optimization and improvement of skin coverage, definitive procedure consisted of uncomplicated fistula resection with primary stapled side-to-side functional end-to-end anastomosis. The stents were not completely incorporated into the mucosa and were rather easily pulled through the residual fistula opening just prior to the surgery. Only minimal fibrosis was noted and less than 20 cm of involved small bowel needed to be resected. Had the fistula have closed completely, the options would have included (1) proceeding to bowel resection with

Fenestrated endovascular repair of aortic arch aneurysm in patients with bovine arch using the Najuta stent graft.

PubMed

Toya, Naoki; Ohki, Takao; Fukushima, Soichiro; Shukuzawa, Kota; Ito, Eisaku; Akiba, Tadashi

2018-06-01

We describe the case of a 74-year-old man with a thoracic aortic aneurysm with a bovine arch who underwent fenestrated endovascular repair of aortic arch aneurysm using the Najuta stent graft (Kawasumi Laboratories, Inc, Tokyo, Japan). He has had a previous endovascular aneurysm repair and femoropopliteal bypass for abdominal aortic aneurysm combined with peripheral arterial disease. The Najuta stent graft was inserted and deployed at zone 0 with delicate positional adjustment of the fenestration of the stent graft to the brachiocephalic trunk. There was no endoleak or complication. His postoperative course was uneventful. At 7-month follow-up, complete exclusion of the aneurysm was noted. The Najuta stent graft repair of aortic arch aneurysms is a safe and effective treatment option for patients with a bovine arch.

Elastic Deformation Properties of Implanted Endobronchial Wire Stents in Benign and Malignant Bronchial Disease: A Radiographic In Vivo Evaluation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hautmann, Hubert; Rieger, Johannes; Huber, Rudolf M.

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 implantationmore » 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.« less

Stent fabric fatigue of grafts supported by Z-stents versus ringed stents: an in vitro buckling test.

PubMed

Lin, Jing; Wang, Lu; Guidoin, Robert; Nutley, Mark; Song, Ge; Zhang, Ze; Du, Jia; Douville, Yvan

2014-03-01

Stent-grafts externally fitted with a Z-shaped stents were compared to devices fitted with ringed stents in an in vitro oscillating fatigue machine at 200 cycles per minute and a pressure of 360 mmHg for scheduled durations of up to 1 week. The devices fitted with Z-stents showed a considerably lower endurance limit to buckling compared to the controls. The contact between the apexes of adjacent Z-stents resulted in significant damage to the textile scaffolds and polyester fibers due to the sharp angle of the Z-stents. The ringed stents did not cause any fraying in the textile scaffolds.

Assessment of vesicoureteral reflux in patients with self-retaining ureteral stents: implications for upper urinary tract instillation.

PubMed

Yossepowitch, Ofer; Lifshitz, David A; Dekel, Yoram; Ehrlich, Yaron; Gur, Uri; Margel, David; Livne, Pinhas M; Baniel, Jack

2005-03-01

Conservative treatment of upper urinary tract tumors has been popularized during the last decade. Like in bladder cancer management, localized adjuvant therapy has been advocated to reduce the risk of disease recurrence or progression. In this study we tested the feasibility of creating vesicoureteral reflux (VUR) using a Double-J stent (Medical Engineering Corp., New York, New York) as a measure of efficacy for intravesical adjuvant treatment of the ureter and renal collecting system. The cohort included 100 consecutive patients in whom a Double-J stent was inserted for renal obstruction. All the patients underwent cystography in the supine position by retrograde filling of the bladder with a 50% dilute solution of 300 mgI/ml iopromide in serial increments of 50 ml up to a maximum of 350 ml. A total of 41 patients underwent cystography immediately following stent insertion (early group) and 59 patients with indwelling stents underwent cystography before further endourological intervention (late group). The presence of VUR and the level along the ureter and renal collecting system were assessed fluoroscopically. Overall VUR was detected in 56 patients (56%), specifically 11 of the 41 (27%) in the early group and 45 of the 59 (76%) in the late group (p <0.001). There was no correlation between stent diameter or length and VUR, or between patient sex, age or particular side and the likelihood of reflux. Mean minimal intravesical volume required to obtain reflux was 171 +/- 11 ml, which was significantly higher in the early (255 +/- 21 ml) than in the late (146 +/- 11 ml) cystogram group. In 24 of the 56 patients (43%) with VUR, there was complete visualization of the entire ureter and renal collecting system. However, 15 patients (26%) had opacified renal pelves and calices without concomitant visualization of the ureters, whereas 7 patients (31%) had reflux to the ureter without opacification of the renal pelvis. VUR is not a guaranteed consequence of Double-J stent

Drug-eluting stents to prevent stent thrombosis and restenosis.

PubMed

Im, Eui; Hong, Myeong-Ki

2016-01-01

Although first-generation drug-eluting stents (DES) have significantly reduced the risk of in-stent restenosis, they have also increased the long-term risk of stent thrombosis. This safety concern directly triggered the development of new generation DES, with innovations in stent platforms, polymers, and anti-proliferative drugs. Stent platform materials have evolved from stainless steel to cobalt or platinum-chromium alloys with an improved strut design. Drug-carrying polymers have become biocompatible or biodegradable and even polymer-free DES were introduced. New limus-family drugs (such as everolimus, zotarolimus or biolimus) were adopted to enhance stent performances. As a result, these new DES demonstrated superior vascular healing responses on intracoronary imaging studies and lower stent thrombotic events in actual patients. Recently, fully-bioresorbable stents (scaffolds) have been introduced, and expanding their applications. In this article, the important concepts and clinical results of new generation DES and bioresorbable scaffolds are described.

One Year Outcomes of 101 BeGraft Stent Grafts used as Bridging Stents in Fenestrated Endovascular Repairs.

PubMed

Spear, Rafaelle; Sobocinski, Jonathan; Hertault, Adrien; Delloye, Matthieu; Azzauiu, Richard; Fabre, Dominique; Haulon, Stéphan

2018-04-01

To evaluate the outcomes of the second generation BeGraft balloon expandable covered stent Graft System (Bentley InnoMed, Hechingen, Germany) implanted as bridging stent grafts during fenestrated endovascular aortic repair (FEVAR) of complex aneurysms. This was a single centre prospective study including all consecutive patients treated by FEVAR performed with second generation BeGraft stent grafts as bridging stents. Demographics of patients, diameter and length of the bridging stent grafts, technical success, re-interventions, occlusions, post-operative events, and imaging (Cone Beam CT and/or CT scan, and contrast enhanced ultrasound) were prospectively collected in an electronic database. Duplex ultrasound was performed before discharge and at 6 month follow-up. At 1 year, patients were evaluated clinically and by imaging (CT and ultrasound). Between November 2015 and September 2016, 39 consecutive patients (one woman) were treated with custom made fenestrated endografts (2-5 fenestrations) for complex aneurysms or type 1 endoleak after EVAR, using a variety of bridging stents including the BeGraft. All 101 BeGraft stent grafts were successfully delivered and deployed. There was no in hospital mortality. Early fenestration patency rate was 99% (96/97); the sole target vessel post-operative occlusion was secondary to a dissection of the renal artery distal to the stent. Complementary stenting was unsuccessful in recovering renal artery patency; bilateral renal stent occlusion was observed in the same patient on a CT scan performed 2 months after the procedure. He required post-operative dialysis. No additional renal impairment was observed. During follow-up (median 13 months [11-15]), all fenestrations stented with BeGraft stent grafts remained patent (95/97, 98%). One type 1b endoleak was detected and treated (2.6%). BeGraft stent grafts used as bridging stents during FEVAR are associated with favourable outcomes at 1 year follow-up. Long-term follow-up is

Doxazosin oral intake therapy to relieve stent - related urinary symptoms and pain: a prospective, randomized, controlled study.

PubMed

Zhang, Long; Li, Junping; Pan, Minjie; Han, Weiwei; Liu, Shucheng; Xiao, Yajun

2016-01-01

To assess the impact of Doxazosin Oral Intake Therapy on urinary symptoms and pain in patients with indwelling ureteral stents Patients and Methods: A total of 239 patients with ureteral stone-related hydronephrosis who underwent a double-J stent insertion after ureteroscopic lithotripsy were enrolled. Patients were randomized to receive doxazosin cotrolled release 4 mg once daily for 4 weeks or matching placebo. Patients completed the brief-form Chinese version Ureteric Stent Symptom Questionnaire (USSQ) and quality of life (QoL) score 2 weeks and 4 weeks after stent placement and 4 weeks after stent withdrawal. The analgesic use was also recorded during the stenting period. Patients in Doxazosin Oral Intake Therapy group, in the first 2 weeks and second 2 weeks with the stent in situ, expressed significant lower daytime frequency (p=0.028 and p=0.038), nocturia (p=0.021 and p=0.008) and urgency (p=0.012 and p=0.014), respectively. Similarly, flank pain score, QoL score and analgesic use were also significant less in the stenting period. There was no significant difference in scores of urinary symptoms, pain and QoL during the post-stent period between two cohorts. Doxazosin Oral Intake Therapy reduced stent-related urinary symptoms, pain and the negative impact on QoL. Copyright© by the International Brazilian Journal of Urology.

An in Vitro Twist Fatigue Test of Fabric Stent-Grafts Supported by Z-Stents vs. Ringed Stents.

PubMed

Lin, Jing; Guidoin, Robert; Du, Jia; Wang, Lu; Douglas, Graeham; Zhu, Danjie; Nutley, Mark; Perron, Lygia; Zhang, Ze; Douville, Yvan

2016-02-16

Whereas buckling can cause type III endoleaks, long-term twisting of a stent-graft was investigated here as a mechanism leading to type V endoleak or endotension. Two experimental device designs supported with Z-stents having strut angles of 35° or 45° were compared to a ringed control under accelerated twisting. Damage to each device was assessed and compared after different durations of twisting, with focus on damage that may allow leakage. Stent-grafts with 35° Z-stents had the most severe distortion and damage to the graft fabric. The 45° Z-stents caused less fabric damage. However, consistent stretching was still seen around the holes for sutures, which attach the stents to the graft fabric. Larger holes may become channels for fluid percolation through the wall. The ringed stent-graft had the least damage observed. Stent apexes with sharp angles appear to be responsible for major damage to the fabrics. Device manufacturers should consider stent apex angle when designing stent-grafts, and ensure their devices are resistant to twisting.

An in Vitro Twist Fatigue Test of Fabric Stent-Grafts Supported by Z-Stents vs. Ringed Stents

PubMed Central

Lin, Jing; Guidoin, Robert; Du, Jia; Wang, Lu; Douglas, Graeham; Zhu, Danjie; Nutley, Mark; Perron, Lygia; Zhang, Ze; Douville, Yvan

2016-01-01

Whereas buckling can cause type III endoleaks, long-term twisting of a stent-graft was investigated here as a mechanism leading to type V endoleak or endotension. Two experimental device designs supported with Z-stents having strut angles of 35° or 45° were compared to a ringed control under accelerated twisting. Damage to each device was assessed and compared after different durations of twisting, with focus on damage that may allow leakage. Stent-grafts with 35° Z-stents had the most severe distortion and damage to the graft fabric. The 45° Z-stents caused less fabric damage. However, consistent stretching was still seen around the holes for sutures, which attach the stents to the graft fabric. Larger holes may become channels for fluid percolation through the wall. The ringed stent-graft had the least damage observed. Stent apexes with sharp angles appear to be responsible for major damage to the fabrics. Device manufacturers should consider stent apex angle when designing stent-grafts, and ensure their devices are resistant to twisting. PMID:28787913

Stent selection for both biliary and pancreatic strictures caused by chronic pancreatitis: multiple plastic stents or metallic stents?

PubMed

Gupta, Rajesh; Reddy, D Nageshwar

2011-09-01

Endoscopic stenting is an effective treatment option in the management of both benign biliary strictures and pancreatic ductal strictures. Plastic stents and self-expandable metal stents have been used with variable success for the management of both benign biliary strictures and pancreatic ductal strictures caused by chronic pancreatitis. Fully covered self-expandable metal stents of improved design represent a major technological advance which has added to the endoscopic armamentarium. Both multiple plastic stents and covered self-expandable metal stents have shown promising results. However, data to support the use of self-expandable metal stents over multiple plastic stents or vice versa are still lacking.

Use of a Palmaz stent for tracheomalacia: case report of an infant with esophageal atresia.

PubMed

Tazuke, Y; Kawahara, H; Yagi, M; Yoneda, A; Soh, H; Maeda, K; Yamamoto, T; Imura, K

1999-08-01

A male infant with congenital cardiac anomalies and esophageal atresia with tracheoesophageal fistula (EA-TEF) showed intractable respiratory symptoms after delayed primary repair of EA-TEF. Computed tomography demonstrated that the trachea was compressed by the enlarged aorta. Artificial ventilation was necessary even after aortopexy performed at 2 months of age. At 140 days of age, an expandable metallic stent (Palmaz stent) was inserted through a rigid bronchoscope into the trachea underfluoroscopic control. His respiratory status improved dramatically, and he was extubated in 18 hours. Although the follow-up period has been 9 months, the short-term result is satisfactory. The expandable metallic stent placement should be considered in patients with EA-TEF who show intractable respiratory symptoms caused by tracheomalacia.

Large Bariatric-Specific Stents and Over-the-Scope Clips in the Management of Post-Bariatric Surgery Leaks.

PubMed

Shehab, Hany; Abdallah, Emad; Gawdat, Khaled; Elattar, Inas

2018-01-01

Endoscopic stents are successful in the management of surgical leaks; however, stent migration remains a significant problem. In this study, we present our approach depending on a large bariatrics-specific stent (Mega stent) and over-the-scope clips in the management of post-bariatric surgery leaks. A retrospective analysis of all patients with post-bariatric surgery leaks treated at our institution using an approach reliant on Mega stents and over-the-scope clips was conducted. Potential factors associated with procedure success and occurrence of complications were also evaluated. A total of 81 stents were inserted in 62 patients with post-bariatric surgery leaks, 46 sleeve gastrectomies (73%) and 16 Roux-en-Y gastric bypass (27%). Over-the-scope clips were applied in 29 patients (46%). Leak closure was achieved in 51 patients (82%). Median number of procedures per patient was 3 (range 2-8). Complications included the following: stent migration (11/62, 18%), intolerance necessitating premature removal (7/62, 11%), esophageal stricture (8/62, 13%), bleeding (4/62, 6%), perforation (4/62, 6%). One stent-induced mortality was encountered (bleeding). The presence of open surgery (vs laparoscopic) was significantly associated with the occurrence of stent-induced complications (p 0.002). The approach combining Mega stents and over-the-scope clips is highly effective in the management of post-bariatric surgery leaks and is associated with a low rate of stent migration and a low number of procedures and stents per patient. Mega stents, however, should be used with great caution due to the significant morbidity associated with their use.

Clinical outcome after intrahepatic venous stent placement for malignant inferior vena cava syndrome.

PubMed

Brountzos, Elias N; Binkert, Christoph A; Panagiotou, Irene E; Petersen, Bryan D; Timmermans, Hans; Lakin, Paul C

2004-01-01

We evaluated the clinical outcome of malignant inferior vena cava (IVC) syndrome after intrahepatic IVC stent placement by retrospective analysis of 50 consecutive patients (25 men, 25 women, age 32-83 years) with malignant IVC syndrome who were treated with intrahepatic stent placement. Gianturco-Rosch-Z (GRZ) stents (n = 45), and Wallstents (n = 5) were inserted. Clinical outcome was assessed from patients' records using a score based on leg swelling, scrotal/vulvar edema, ascites and anasarca before and after stent placement, as well as at last follow-up visit before death. Clinical follow-up was supplemented by duplex sonography in 36 patients. Inferior venocavography was performed in 5 patients prior to re- intervention. Follow-up time ranged from 1 to 932 days (mean 62 days). Mean pressure gradient in the IVC was reduced from 14 +/- 4.1 mmHg before to 2.9 +/- 3.2 mmHg after stent placement (p < 0.001). Four patients had stent occlusion, 2 of whom were successfully re-stented. Primary and secondary patency was 59% and 100%, respectively at 540 days. Immediate clinical data were available in 44 patients: 38 improved; 6 did not respond. Last follow-up visit data were available in 36 patients: 24 showed persistent symptom relief till death. All symptom scores were significantly improved after stent placement (p < 0.001) and with the exception of ascites, remained significantly improved (p < 0.05) until the last follow-up. Increased serum bilirubin was a common characteristic of clinical failures and recurrences. Intrahepatic IVC stent placement resulted in significant symptomatic relief in patients with malignant IVC syndrome. Palliation was effective even in patients with a very short life expectancy.

Safety and Efficacy of a Fully Covered Self-Expandable Metallic Stent in Benign Airway Stenosis.

PubMed

Fortin, Marc; Lacasse, Yves; Elharrar, Xavier; Tazi-Mezalek, Rachid; Laroumagne, Sophie; Guinde, Julien; Astoul, Philippe; Dutau, Hervé

2017-01-01

The use of self-expandable metallic stents (SEMS) in benign airway disease was the object of a boxed warning from the United States Food and Drug Administration in 2005 due to the risk of stent-related complications and difficulties associated with their removal. Third-generation fully covered SEMS have been commercialized since this warning and theoretically should not present the same difficulties associated with removal as they cannot become embedded in the airway mucosa. We aimed to examine the safety and efficacy of a specific third-generation SEMS, the Silmet stent. We reviewed the records of all patients treated for benign airway stenosis with third-generation Silmet SEMS from January 2011 to December 2015 at the North Hospital of Marseilles, France. Forty SEMS were inserted in 30 patients over this period. Twenty (50.0%) stents were removed because of stent-related complications after a median of 77.0 ± 96.6 days (migration 32.5%, granulation tissue formation 7.5%, subjective intolerance 5.0%, mucus plugging 2.5%, laryngeal edema 2.5%). There were no cases of stent-related mortality. All complications were managed successfully endoscopically. Thirty-six stents (90.0%) were removed successfully after a median of 122.0 ± 113.2 days without any complications. The clinical success rate of stent treatment was 40.7%. Third-generation SEMS are a safe treatment option for complex benign airway stenosis, but complications requiring stent removal are frequent. Further studies are needed to compare the performance of third-generation SEMS and silicone stents in benign airway stenosis. © 2017 S. Karger AG, Basel.

Solifenacin improves double-J stent-related symptoms in both genders following uncomplicated ureteroscopic lithotripsy.

PubMed

Lee, Yuan-Ju; Huang, Kuo-How; Yang, Hung-Ju; Chang, Hong-Chiang; Chen, Jun; Yang, Teng-Kai

2013-06-01

The objective of this study is to evaluate the effects of solifenacin on double-J stent-related symptoms following uncomplicated ureterosocpic lithotripsy (URSL). A total of 70 patients who underwent double-J ureteral stent insertion following URSL were consecutively recruited and received solifenacin postoperatively. Another 70 age- and sex-matched subjects without solifenacin therapy were enrolled as a control group. The clinical data including stone and stent characteristics were collected. All subjects completed the brief-form Ureteral Symptom Score Questionnaire (Chinese-version) to assess the lower urinary tract symptoms, stent-related body pain and hematuria 2 weeks after operation. The severity of stent-related symptoms was compared between two groups. The mean age was 53.8 in solifenacin group and 53.4 years in the control group (p = 0.87). The stone characteristics, stent size, position and curl completeness were similar in both groups. Compared to the control group, solifenacin group had significantly lower total symptom score, urgency and urge incontinence scores. As for stent-related body pain, solifenacin group had significantly less flank, abdominal, urethral pain and hematuria scores (all p < 0.05). The solifenacin versus control group showed significant benefits in lower urinary tract symptoms, stent-related pain and hematuria in both genders (all p < 0.05). Four subjects encountered minor adverse events (5.7 %) and one had urinary retention (1.4 %) in solifenacin group. For patients undergoing URSL and double-J stent indwelling, postoperative solifenacin use was effective and well-tolerated for the treatment of lower urinary tract symptoms, stent-related body pain and hematuria irrespective of genders.

Percutaneous intraductal radiofrequency ablation for clearance of occluded metal stent in malignant biliary obstruction: feasibility and early results.

PubMed

Pai, Madhava; Valek, Vlastimil; Tomas, Andrasina; Doros, Attila; Quaretti, Pietro; Golfieri, Rita; Mosconi, Cristina; Habib, Nagy

2014-02-01

The major complication occurring with biliary stents is stent occlusion, frequently seen because of tumour in-growth, epithelial hyperplasia, and sludge deposits, resulting in recurrent jaundice and cholangitis. We report a prospective study with the results of first in man percutaneous intraductal radiofrequency (RF) ablation to clear the blocked metal stents in patients with malignant biliary obstruction using a novel bipolar RF catheter. Nine patients with malignant biliary obstruction and blocked metal stents were included. These patients underwent intraductal biliary RF ablation through the blocked metal stent following external biliary decompression with an internal-external biliary drainage. All nine patients had their stent patency restored successfully without the use of secondary stents. Following this intervention, there was no 30-day mortality, haemorrhage, bile duct perforation, bile leak, or pancreatitis. Of the nine patients, six are alive and three patients are dead with a median follow-up of 122 (range 50-488) days and a median stent patency of 102.5 (range 50-321) days. Six patients had their stent patent at the time of last follow-up or death. Three patients with stent blockage at 321, 290, and 65 days postprocedure underwent percutaneous transhepatic drain insertion and repeat ablation. In this selective group of patients, it appears that this new approach is safe and feasible. Efficacy remains to be proven in future, randomized, prospective studies.

Analysis of trends and prospects regarding stents for human blood vessels.

PubMed

Lee, Jeong Hee; Kim, Eung Do; Jun, Eun Jung; Yoo, Hyoung Sun; Lee, Joon Woo

2018-01-01

The purpose of this paper is to provide technology trends and information regarding market and prospects in stents used for human blood vessels in Korea and the world.A stent is a medical device in the form of a cylindrical metal net used to normalize flow when blood or other bodily fluids such as biliary fluids are obstructed in blood vessels, gastrointestinal tracts, etc. by inserting the stent into a narrowed or clogged area. Stents are classified into vascular and non-vascular stents. The coronary artery stent is avascular stent that is used for coronary atherosclerosis.The demand is increasing for stents to treat diseases such as those affecting the heart and blood vessels of elderly and middle-aged patients. Due to the current shift in the demographic structure caused by an aging society, the prospect for stents seems to be very bright.The use of a stent designed to prevent acute vascular occlusion and restenosis, which is a side effect of conventional balloon angioplasty, has rapidly become popular because it can prevent acute complications and improve clinical outcomes. Since the initial release of this stent, there have been significant developments in its design, the most notable of which has been the introduction of drug-eluting stents (DES). Bioresorbable scaffolds (BRS) have the potential to introduce a paradigm shift in interventional cardiology, a true anatomical and functional "vascular restoration" instead of an artificial stiff tube encased by a persistent metallic foreign body. Data for this research were gathered from primary and secondary sources as well as the databases of the Korea Institute of Science Technology Information (KISTI) located in Seoul, Korea like KISTI Market Report. The sources used for primary research included the databases available from the Korea Institute of Science Technology Information, past industry research services/studies, economic and demographic data, and trade and industry journals. Secondary research was used

Double stenting with silicone and metallic stents for malignant airway stenosis.

PubMed

Matsumoto, Keitaro; Yamasaki, Naoya; Tsuchiya, Tomoshi; Miyazaki, Takuro; Kamohara, Ryotaro; Hatachi, Go; Nagayasu, Takeshi

2017-08-01

For severe malignant airway stenosis, there are several types of commercially available airway stents, and each has its own advantages and disadvantages. We herein describe the safety and efficacy of combination stenting with silicone and metallic stents for patients with extended malignant airway stenosis. Seven patients with malignant airway stenosis were treated via combination stenting with a silicone stent and a metallic stent for extended airway stenosis from the central to peripheral airways. Five patients were diagnosed with advanced esophageal cancer, two of whom had tracheoesophageal fistulas. One patient had adenoid cystic carcinoma, and another had mediastinal tumor. There were no specific complications related to the double stenting. Combination stenting with silicone and metallic stents proved to be a safe option for patients with severe, extended, and complicated malignant airway stenosis.

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

PubMed

Hori, Yasuki; Naitoh, Itaru; Hayashi, Kazuki; Ban, Tesshin; Natsume, Makoto; Okumura, Fumihiro; Nakazawa, Takahiro; Takada, Hiroki; Hirano, Atsuyuki; Jinno, Naruomi; Togawa, Shozo; Ando, Tomoaki; Kataoka, Hiromi; Joh, Takashi

2017-10-01

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

Association between silent embolic cerebral infarction and continuous increase of P2Y12 reaction units after neurovascular stenting.

PubMed

Kim, Bum Joon; Kwon, Joo Y; Jung, Jin-Man; Lee, Deok Hee; Kang, Dong-Wha; Kim, Jong S; Kwon, Sun U

2014-10-01

Endovascular procedures are one of the important treatment options for steno-occlusive arteries in ischemic stroke patients. However, embolic complications after such procedures are always a concern. The authors investigated the association between serial change of residual platelet reactivity and silent embolic cerebral infarction (SECI) after endovascular treatment. Ischemic stroke patients undergoing stenting of intra- or extracranial arteries were recruited prospectively. Residual platelet reactivity, represented by aspirin reaction units (ARUs) and P2Y12 reaction units (PRUs), was measured serially (6 hours before, immediately after, and 24 hours after the procedure). A loading dosage of aspirin (500 mg) and/or clopidogrel (300 mg) was given 24 hours before the procedure to patients naïve to antiplatelet agents, whereas the usual dosage (aspirin 100 mg and clopidogrel 75 mg) was continued for patients who had previously been taking these agents for more than a week. Diffusion-weighted MRI was performed before and 24 hours after the procedure to detect new SECIs. Clinical characteristics, baseline ARU and PRU values, and the change in ARU and PRU values after stenting were compared between patients with and without SECIs. Among 69 consecutive patients who underwent neurovascular stent insertion, 41 patients (59.4%) had poststenting SECIs. The lesion was located only at the vascular territory of the stented vessel in 21 patients (51.2%), outside the stented vessel territory in 8 patients (19.5%), and both inside and outside in 12 patients (29.3%). The occurrence of SECIs was not associated with the baseline ARU or PRU value, but was associated with PRU increase after stenting (36 ± 73 vs -12 ± 59, p = 0.007), deployment of a longer stent (31.1 ± 16.5 mm vs 21.8 ± 9.9 mm, p = 0.01), and stent insertion in extracranial arteries (78.1% vs 45.2%, p = 0.008). Stent length (OR 1.066, p = 0.01) and PRU change (OR 1.009, p = 0.04) were independently associated with

Treatment of esophagopleural fistulas using covered retrievable expandable metallic stents.

PubMed

Kim, Tae-Hyung; Shin, Ji Hoon; Kim, Kyung Rae; Park, Jung-Hoon; Kim, Jin Hyoung; Song, Ho-Young

2014-04-01

To evaluate the clinical efficacy of placement of covered retrievable expandable metallic stents for esophagopleural fistulas (EPFs). During the period 1997-2013, nine patients with EPF were treated using covered retrievable expandable metallic stents. The underlying causes of EPF were esophageal carcinoma (n = 6), lung cancer (n = 2), and postoperative empyema for Boerhaave syndrome (n = 1). Technical success was achieved in eight patients (88.9%). In one patient, incomplete EPF closure was due to incomplete stent expansion. Clinical success, defined as complete EPF closure within 7 days, was achieved in five patients (55.6%). Overall fistula persistence (n = 1) or reopening (n = 4) occurred in five patients (55.6%) 0-15 days after stent placement. The causes of reopening were due to the gap between the stent and the esophagus (n = 3) or stent migration (n = 1). For fistula persistence or reopening, additional interventional management, such as gastrostomy, stent removal, or stent reinsertion, was performed. Stent migration occurred as a complication in one patient with EPF from a benign cause secondary to postoperative empyema. In the eight patients who died during the follow-up period, the mean and median survival times were 78.8 days and 46 days, respectively. Placement of a covered expandable metallic esophageal stent for the palliative treatment of EPF is technically feasible, although the rate of clinical success was poor secondary to fistula persistence or reopening. Fistula reopening was caused by the gap between the stent and the esophagus or by stent migration, and additional interventional treatment was useful to ensure enteral nutritional support. Copyright © 2014 SIR. Published by Elsevier Inc. All rights reserved.

Airway stents

PubMed Central

Keyes, Colleen

2018-01-01

Stents and tubes to maintain the patency of the airways are commonly used for malignant obstruction and are occasionally employed in benign disease. Malignant airway obstruction usually results from direct involvement of bronchogenic carcinoma, or by extension of carcinomas occurring in the esophagus or the thyroid. External compression from lymph nodes or metastatic disease from other organs can also cause central airway obstruction. Most malignant airway lesions are surgically inoperable due to advanced disease stage and require multimodality palliation, including stent placement. As with any other medical device, stents have significantly evolved over the last 50 years and deserve an in-depth understanding of their true capabilities and complications. Not every silicone stent is created equal and the same holds for metallic stents. Herein, we present an overview of the topic as well as some of the more practical and controversial issues surrounding airway stents. We also try to dispel the myths surrounding stent removal and their supposed use only in central airways. At the end, we come to the long-held conclusion that stents should not be used as first line treatment of choice, but after ruling out the possibility of curative surgical resection or repair. PMID:29707506

To stent or not to stent: the use of transanastomotic biliary stents in liver transplantation and patient outcomes.

PubMed

Ong, Michelle; Slater, Kellee; Hodgkinson, Peter; Dunn, Nathan; Fawcett, Jonathan

2018-06-01

There is no substantial evidence for the use of biliary stents in bile duct reconstruction during liver transplantation. A longitudinal, retrospective cohort study was performed to compare biliary complications between stented and non-stented patients between 2011 and 2015 at the Princess Alexandra Hospital, Brisbane, Australia. We found no significant difference in biliary complications between stented and non-stented groups. Stented patients were 3.31 times as likely to require subsequent intervention, mainly in the form of stent removal. These results suggest that there is limited benefit in the placement of endobiliary stents in liver transplantation. Given that this was purely an observational study, causality cannot be proven and a prospective cohort trial would be beneficial in further defining these relationships. © 2018 Royal Australasian College of Surgeons.

Behaviour of two typical stents towards a new stent evolution.

PubMed

Simão, M; Ferreira, J M; Mora-Rodriguez, J; Fragata, J; Ramos, H M

2017-06-01

This study explores the analysis of a new stent geometry from two typical stents used to treat the coronary artery disease. Two different finite element methods are applied with different boundary conditions to investigate the stenosis region. Computational fluid dynamics (CFD) models including fluid-structure interaction are used to assess the haemodynamic impact of two types of coronary stents implantation: (1) type 1-based on a strut-link stent geometry and (2) type 2-a continuous helical stent. Using data from a recent clinical stenosis, flow disturbances and consequent shear stress alterations introduced by the stent treatment are investigated. A relationship between stenosis and the induced flow fields for the two types of stent designs is analysed as well as the correlation between haemodynamics and vessel wall biomechanical factors during the initiation and development of stenosis formation in the coronary artery. Both stents exhibit a good performance in reducing the obstruction artery. However, stent type 1 presents higher radial deformation than the type 2. This deformation can be seen as a limitation with a long-term clinical impact.

Fully covered self-expandable metal stent in tracheobronchial disorders: clinical experience.

PubMed

Marchese, Roberto; Poidomani, Grazia; Paglino, Giuseppe; Crimi, Claudia; Lo Nigro, Chiara; Argano, Vincenzo

2015-01-01

The third-generation fully covered self-expandable metallic stent (SEMS) has been developed to solve the problems of difficult removal and in-stent granuloma formation related to the uncovered or partially covered type. There are few written reports about the performance of this type of stents with early encouraging results. To report and analyse our experience with the Silmet® stent in the management of malignant and benign tracheobronchial disorders. We retrospectively reviewed medical records of patients who underwent fully covered SEMS Silmet placement at the Interventional Pulmonology Unit, La Maddalena Cancer Center, Palermo, Italy, between May 2010 and August 2013. Stents were placed in 52 patients with malignant (n = 49) and benign airway obstruction (n = 2) and broncho-oesophageal fistula (n = 1). SEMSs were inserted into the trachea (n = 19), the main bronchi (n = 21) and the peripheral bronchi (n = 31). Besides 1 procedural dislocation, the deployment was successful in all patients with an immediate significant improvement of symptoms (Barthel Index p < 0.001; Medical Research Council score p < 0.001). A radiographic improvement was detected in 48% of patients. The mean follow-up duration was 119 ± 120 days (range 22-549 days). Complications observed were: migration (7.6%), tumour overgrowth (15%), infections (5.7%), granulation tissue formation (3.8%) and mucus plug (3.8%). The Silmet stent is effective, safe and simple to implant and remove. We suggest its use in cases of tight stenoses, in the treatment of small- to medium-caliber airways or in cases of tortuous airways. © 2015 S. Karger AG, Basel.

Magnesium alloy covered stent for treatment of a lateral aneurysm model in rabbit common carotid artery: An in vivo study

NASA Astrophysics Data System (ADS)

Wang, Wu; Wang, Yong-Li; Chen, Mo; Chen, Liang; Zhang, Jian; Li, Yong-Dong; Li, Ming-Hua; Yuan, Guang-Yin

2016-11-01

Magnesium alloy covered stents have rarely been used in the common carotid artery (CCA). We evaluated the long-term efficacy of magnesium alloy covered stents in a lateral aneurysm model in rabbit CCA. Magnesium alloy covered stents (group A, n = 7) or Willis covered stents (group B, n = 5) were inserted in 12 New Zealand White rabbits and they were followed up for 12 months. The long-term feasibility for aneurysm occlusion was studied through angiograms; the changes in vessel area and lumen area were assessed with IVUS. Complete aneurysmal occlusion was achieved in all aneurysms. Angiography showed that the diameter of the stented CCA in group A at 6 and 12 months was significantly greater than the diameter immediately after stent placement. On intravascular ultrasound (IVUS) examination, the mean lumen area of the stented CCA in group A was significantly greater at 6 and 12 months than that immediately after stent placement; the mean lumen area was also significantly greater in group A than in group B at the same time points. The magnesium alloy covered stents proved to be an effective approach for occlusion of lateral aneurysm in the rabbit CCA; it provides distinct advantages that are comparable to that obtained with the Willis covered stent.

Development of asymmetric stent for treatment of eccentric plaque.

PubMed

Syaifudin, Achmad; Takeda, Ryo; Sasaki, Katsuhiko

2018-01-01

The selection of stent and balloon type is decisive in the stenting process. In the treatment of an eccentric plaque obstruction, a symmetric expansion from stent dilatation generates nonuniform stress distribution, which may aggravate fibrous cap prone to rupture. This paper developed a new stent design to treat eccentric plaque using structural transient dynamic analysis in ANSYS. A non-symmetric structural geometry of stent is generated to obtain reasonable stress distribution safe for the arterial layer surrounding the stent. To derive the novel structural geometry, a Sinusoidal stent type is modified by varying struts length and width, adding bridges, and varying curvature width of struts. An end ring of stent struts was also modified to eliminate dogboning phenomenon and to reduce the Ectropion angle. Two balloon types were used to deploy the stent, an ordinary cylindrical and offset balloon. Positive modification results were used to construct the final non-symmetric stent design, called an Asymmetric stent. Analyses of the deformation characteristics, changes in surface roughness and induced stresses within intact arterial layer were subsequently examined. Interaction between the stent and vessel wall was implemented by means of changes in surface roughness and stress distribution analyses. The Palmaz and the Sinusoidal stent were used for a comparative study. This study indicated that the Asymmetric stent types reduced the central radial recoiling and the dogboning phenomenon. In terms of changes in surface roughness and induced stresses, the Asymmetric stent has a comparable effect with that of the Sinusoidal stent. In addition, it could enhance the distribution of surface roughening as expanded by an offset balloon.

Effects of the temporary placement of a self-expandable metallic stent in benign pyloric stenosis.

PubMed

Choi, Won Jae; Park, Jong-Jae; Park, Jain; Lim, Eun-Hye; Joo, Moon Kyung; Yun, Jae-Won; Noh, Hyejin; Kim, Sung Ho; Choi, Woo Seok; Lee, Beom Jae; Kim, Ji Hoon; Yeon, Jong Eun; Kim, Jae Seon; Byun, Kwan Soo; Bak, Young-Tae

2013-07-01

The use of self-expandable metallic stents (SEMS) is an established palliative treatment for malignant stenosis in the gastrointestinal tract; therefore, its application to benign stenosis is expected to be beneficial because of the more gradual and sustained dilatation in the stenotic portion. We aimed in this prospective observational study to evaluate the efficacy and safety of temporary SEMS placement in benign pyloric stenosis. Twenty-two patients with benign stenosis of the prepylorus, pylorus, and duodenal bulb were enrolled and underwent SEMS placement. We assessed symptom improvement, defined as an increase of at least 1 degree in the gastric-outlet-obstruction scoring system after stent insertion. No major complications were observed during the procedures. After stent placement, early symptom improvement was achieved in 18 of 22 patients (81.8%). During the follow-up period (mean 10.2 months), the stents remained in place successfully for 6 to 8 weeks in seven patients (31.8%). Among the 15 patients (62.5%) with stent migration, seven (46.6%) showed continued symptomatic improvement without recurrence of obstructive symptoms. Despite the symptomatic improvement, temporary SEMS placement is premature as an effective therapeutic tool for benign pyloric stenosis unless a novel stent is developed to prevent migration.

Effects of the Temporary Placement of a Self-Expandable Metallic Stent in Benign Pyloric Stenosis

PubMed Central

Choi, Won Jae; Park, Jain; Lim, Eun-Hye; Joo, Moon Kyung; Yun, Jae-Won; Noh, Hyejin; Kim, Sung Ho; Choi, Woo Seok; Lee, Beom Jae; Kim, Ji Hoon; Yeon, Jong Eun; Kim, Jae Seon; Byun, Kwan Soo; Bak, Young-Tae

2013-01-01

Background/Aims The use of self-expandable metallic stents (SEMS) is an established palliative treatment for malignant stenosis in the gastrointestinal tract; therefore, its application to benign stenosis is expected to be beneficial because of the more gradual and sustained dilatation in the stenotic portion. We aimed in this prospective observational study to evaluate the efficacy and safety of temporary SEMS placement in benign pyloric stenosis. Methods Twenty-two patients with benign stenosis of the prepylorus, pylorus, and duodenal bulb were enrolled and underwent SEMS placement. We assessed symptom improvement, defined as an increase of at least 1 degree in the gastric-outlet-obstruction scoring system after stent insertion. Results No major complications were observed during the procedures. After stent placement, early symptom improvement was achieved in 18 of 22 patients (81.8%). During the follow-up period (mean 10.2 months), the stents remained in place successfully for 6 to 8 weeks in seven patients (31.8%). Among the 15 patients (62.5%) with stent migration, seven (46.6%) showed continued symptomatic improvement without recurrence of obstructive symptoms. Conclusions Despite the symptomatic improvement, temporary SEMS placement is premature as an effective therapeutic tool for benign pyloric stenosis unless a novel stent is developed to prevent migration. PMID:23898381

Radial force measurement of endovascular stents: Influence of stent design and diameter.

PubMed

Matsumoto, Takuya; Matsubara, Yutaka; Aoyagi, Yukihiko; Matsuda, Daisuke; Okadome, Jun; Morisaki, Koichi; Inoue, Kentarou; Tanaka, Shinichi; Ohkusa, Tomoko; Maehara, Yoshihiko

2016-04-01

Angioplasty and endovascular stent placement is used in case to rescue the coverage of main branches to supply blood to brain from aortic arch in thoracic endovascular aortic repair. This study assessed mechanical properties, especially differences in radial force, of different endovascular and thoracic stents. We analyzed the radial force of three stent models (Epic, E-Luminexx and SMART) stents using radial force-tester method in single or overlapping conditions. We also analyzed radial force in three thoracic stents using Mylar film testing method: conformable Gore-TAG, Relay, and Valiant Thoracic Stent Graft. Overlapping SMART stents had greater radial force than overlapping Epic or Luminexx stents (P < 0.01). The radial force of the thoracic stents was greater than that of all three endovascular stents (P < 0.01). Differences in radial force depend on types of stents, site of deployment, and layer characteristics. In clinical settings, an understanding of the mechanical characteristics, including radial force, is important in choosing a stent for each patient. © The Author(s) 2015.

The use of JJ stent in the management of deep endometriosis lesion, affecting or potentially affecting the ureter: a review of our practice.

PubMed

Weingertner, A S; Rodriguez, B; Ziane, A; Gibon, E; Thoma, V; Osario, F; Haddad, C; Wattiez, A

2008-08-01

With the increasing number of operative laparoscopies performed for the treatment of deep pelvic endometriosis, technical difficulties and risk of complications inevitably increase. We report our experience using JJ stents, in women treated for deep pelvic endometriosis, with regard to prevention and management of ureteral lesions. Descriptive retrospective analysis between March 2004 and March 2007. Department of Obstetrics and Gynaecology, University Hospital, Strasbourg, France. Cases of women who underwent laparoscopic surgery for severe endometriosis and who needed a JJ stent in their management were recorded. Laparoscopic surgery was performed at the Department of Obstetrics and Gynaecology at CMCO-SIHCUS and Hautepierre Hospitals, Strasbourg, which are referral centres in the treatment of deep endometriosis. To evaluate the contribution of JJ stent in the prevention and management of ureteral lesions from endometriotic origin and/or iatrogenic origin in women treated for deep pelvic endometriosis. A total of 145 women had surgery for deep pelvic endometriosis. Seventeen (11.7%) women had a JJ ureteral stent inserted. In 82.4% of women, the stent was inserted pre- or peroperatively. We noted three ureteral complications, of which only one needed management by laparotomy. Except in extreme cases, management of ureteral endometriosis should be performed laparoscopically. Ureteral lesions whether iatrogenic, or secondary to endometriotic disease, can be treated by cystoscopy, JJ stent and laparoscopy. The combination of these three elements is the optimal management and is unlikely to cause subsequent complications. Laparotomy and its associated morbidity should be avoided.

Role of Montgomery T-tube stent for laryngotracheal stenosis.

PubMed

Prasanna Kumar, Saravanam; Ravikumar, Arunachalam; Senthil, Kannan; Somu, Lakshman; Nazrin, Mohd Ismail

2014-04-01

To identify the indications, complications and outcome of patients of LTS managed with Montgomery T-tube stenting and review the current literature about the role of stenting in LTS. Retrospective chart reviews of 39 patients of laryngotracheal stenosis managed by T-tube stenting for temporary or definitive treatment during the period 2004-2011 were considered. The data on indications for stenting, type of stent, problems/complications of stenting, duration of stenting, additional intervention and outcome of management were collected, tabulated and analyzed. Of the 51 cases of laryngotracheal stenosis 39 patients were treated by Montgomery T-tube stenting. There was no mortality associated with the procedure or stenting. 82% of the patients were successfully decannulated. The problems and complications encountered were crusting within the tube in 44% and granulation at the subglottis in 33%. Two patients had complication due to T-tube itself: One patient developed tracheomalacia and the other had stenosis at both ends of the T-tube. Stenting still has a role in management of inoperable or in some deadlock situations where resection anastomosis is not feasible. It is easier to introduce the stent and to maintain it. Complications are minor and can be managed easily. It is safe for long term use. We emphasize that the treating surgeon needs to use prudence while treating stenosis using stents. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Clinical results from first use of prostate stent as fiducial for radiotherapy of prostate cancer.

PubMed

Carl, Jesper; Nielsen, Jane; Holmberg, Mats; Larsen, Erik Hoejkjaer; Fabrin, Knud; Fisker, Rune V

2011-05-01

A clinical feasibility study using a removable prostate stent as fiducial for image-guided radiotherapy (IGRT) of localized prostate cancer (PC). The study included patients with local or locally advanced PC. The clinical target volume (CTV) was outlined on magnetic resonance (MR) images co-registered to planning computer tomography (CT) images. Daily online IGRT was delivered using the stent as fiducial. Risk of migration was estimated using multiple MR. Acute urinary toxicity was scored using the international prostate symptom score (IPSS). Late gastro-intestinal (GI) and genito-urinary (GU) toxicity was scored using the Radio Therapy Oncology Group (RTOG) score, biochemical failure (BF) was defined as an elevation of prostate specific antigen (PSA) above nadir plus 2 ng/ml after radiotherapy. One hundred men were enrolled in the study. Ninety completed radiotherapy with the stent as fiducial. No migration of the stent was seen, but three cases of dislocation of the stent to the bladder were observed. Acute urinary toxicity based on IPSS was comparable to toxicity in patients who had gold markers (GM) as fiducials. Removal of the stent was associated with a high frequency of urinary retention. Late GI and GU toxicity and BF were comparable to those of other studies, but longer observation time is needed. This study reports the first clinical results of using a prostate stent as fiducial. No migration of the stent observed. Dislocation of the stent to the urinary bladder was observed in three cases, requiring removal of the stent and insertion of a new fiducial. Acute toxicity during radiotherapy evaluated from IPSS was comparable to toxicity in patients with GM. Removal of the stent was associated with a high frequency of post procedural urinary retention. Late toxicity and BF were comparable to those of other studies, though longer observation time is needed.

In Situ Fracture of Stents Implanted for Relief of Pulmonary Arterial Stenosis in Patients with Congenitally Malformed Hearts

PubMed Central

McElhinney, Doff B.; Bergersen, Lisa; Marshall, Audrey C.

2014-01-01

Background One of the most common uses of stents in patients with congenitally malformed hearts is treatment of pulmonary arterial stenosis. Although there are reports of fractured pulmonary arterial stents, little is known about the risk factors for, and implications of, such fractures. Methods We reviewed angiograms to identify fractures in stents previously inserted to relieve stenoses in pulmonary arteries from 1990 through 2001 in patients who also underwent follow-up catheterization at least 3 years after placement of the stent. We undertook matched cohort analysis, matching a ratio of 2 fractured to 1 unfractured stent. Results Overall, 166 stents meeting the criterions of our study had been placed in 120 patients. We identified fractures in 35 stents (21%) in 29 patients. All fractured stents were in the central pulmonary arteries, 24 (69%) in the central part of the right pulmonary artery, and all were complete axial fractures, or complex fractures along at least 2 planes. Stent-related factors associated with increased risk of fracture identified by multivariable logistic regression included placement in close apposition to the ascending aorta (p = 0.001), and a larger expanded diameter (p = 0.002). There was obstruction across 28 of 35 fractured stents, which was severe in 11. We re-stented 21 of the fractured stents, and recurrent fracture was later diagnosed in 3 of these. A fragment of the fractured stent embolized distally in 2 patients, without clinically important effects. Conclusions In situ fracture of pulmonary arterial stents is relatively common, and in most cases is related to compression by the aorta. There is usually recurrent obstruction across the fractured stent, but fractured stents rarely embolize, and are not associated with other significant complications. PMID:18559137

The Impact of Preoperative α-Adrenergic Antagonists on Ureteral Access Sheath Insertion Force and the Upper Limit of Force Required to Avoid Ureteral Mucosal Injury: A Randomized Controlled Study.

PubMed

Koo, Kyo Chul; Yoon, Jun-Ho; Park, No-Cheol; Lee, Hye Sun; Ahn, Hyun Kyu; Lee, Kwang Suk; Kim, Do Kyung; Cho, Kang Su; Chung, Byung Ha; Hong, Chang Hee

2018-06-01

Excessive bulking force during primary access of the ureteral access sheath may induce ureteral injury. We investigated the efficacy of preoperative α-blockade to reduce ureteral access sheath insertion force and determine the upper limit required to avoid ureteral injury. In this randomized controlled trial 135 patients from a single institution who had ureteropelvic junction or renal pelvis stones and were scheduled to undergo retrograde intrarenal surgery were prospectively enrolled from December 2015 to January 2017. Of the patients 41 and 42 were randomly assigned to the control and experimental groups, respectively. The experimental group received α-blockade preoperatively. The 21 patients who were pre-stented were assessed separately. We developed a homemade device to measure maximal ureteral access sheath insertion force. Our ureteral access sheath insertion force measurement device showed excellent reproducibility. Higher insertion velocity resulted in greater maximal sheath insertion force. Maximal insertion force in the α-blockade group was significantly lower than in the control group at the ureterovesical junction (p = 0.008) and the proximal ureter (p = 0.036). Maximal insertion force in the α-blockade group was comparable to that in pre-stented patients. Female patients and patients 70 years old or older showed a lower maximal ureteral access sheath insertion force than their counterparts. The rate of grade 2 or greater ureteral injury was lower in the α-blockade group than in controls (p = 0.038). No injury occurred in any case in which ureteral access sheath insertion force did not exceed 600 G. Preoperative α-blockade and slow sheath placement may reduce maximal ureteral access sheath insertion force. If the force exceeds 600 G, a smaller diameter sheath may be an alternative. Alternatively the procedure can be terminated and followed later by pre-stented retrograde intrarenal surgery. Copyright © 2018 American Urological Association

A simple three-dimensional stent for proper placement of mini-implant

PubMed Central

2013-01-01

Background This paper deals with the fabrication of a three-dimensional stent which is simple in design but provides an accurate placement of a mini-implant in three planes of space, namely, sagittal (root proximity), vertical (attached gingiva/alveolar mucosa) and transverse (angulation). Findings The stent is made of 0.018 × 0.025 in. stainless steel archwire which consists of a ‘u loop’ angulated at 20°, a vertical limb, a horizontal limb and a stop. The angulation of the ‘u’ helps in the placement of the mini-implant at 70° to the long axis of the tooth. The vertical height is determined such that the mini-implant is placed at the mucogingival junction. The mini-implant is placed with the aid of the stent, and its angulation and proximity to the adjacent roots are checked with a cone beam computed tomography image. The cone beam computed tomography image showed the mini-implant at an angle of 70° to the long axis of the tooth. There is no contact between mini-implant and the roots of the adjacent teeth. Conclusion This stent is simple, easy to fabricate, cost-effective, and provides ease of insertion/removal, and three-dimensional orientation of the mini-implant. PMID:24326158

[Characterization of urinary tract symptoms and quality of life in patients with double-pig-tailed ureteral stents].

PubMed

Vega Vega, A; García Alonso, D; García Alonso, C J

2007-01-01

To prospectively assess the prevalence of urinary tract symptoms caused by indwelling ureteral stents and how they affect their quality of life using an specific questionnaire. A total of 100 patients with unilateral indwelling ureteral stents were asked to complete an specific questionnaire that include questions on urinary symptoms: dysuria, frequency of urination, incomplete empting, urgency, incontinence, haematuria and bother or pain associated with urinary stents affecting the daily activities of the patients. They were also asked to compete International Prostate Symptoms Score questionnaire and a question on quality of life. Pain was assessed from 0 to 10 using a VAS (visual analogic scale). 46 men and 54 women, mean age 54 years, completed the study. Mean time after stent insertion was 6.5 weeks. The cause of the insertion was in 40% due to the size of the stone, previous to ESWL, 33% due to urinary tract obstruction, 25% due to infection, and the others after a surgical procedure. 95% of patients with stent positioning without general anesthesia complaint of pain during the procedure. 89% of patients reported bothersome urinary symptoms, named in order of frequence: nycturia, frequence voiding, incomplete empting, dysuria, urgence, haematuria and incontinence. More than 70% of patients experienced pain that impaired daily activities, in 52% pain was located at the flank and in 47% at the bladder. 60% of patients signalled that they were not satisfied with their quality of life with the indwelling catheter. Urinary symptoms and pain related to indwelling double pig tailed ureteral stens affect the daily activities and reduces the quality of life of 60% of patients.

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

Endoscopic bilateral stent-in-stent placement for malignant hilar obstruction using a large cell type stent.

PubMed

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

2016-12-01

Bilateral stent-in-stent (SIS) self-expandable metal stent placement is technically challenging for palliation of unresectable malignant hilar obstruction. In the SIS technique, the uniform large cell type biliary stent facilitates contralateral stent deployment through the mesh of the first metallic stent. This study aimed to assess the technical success and clinical effectiveness of this technique with a uniform large cell type biliary stent. Thirty-one patients who underwent bilateral SIS placement using a large cell type stent were reviewed retrospectively. All patients showed malignant hilar obstruction (Bismuth types II, III, IV) with different etiologies. Sixteen (51.6%) patients were male. The mean age of the patients was 67.0+/-14.0 years. Most patients were diagnosed as having hilar cholangiocarcinoma (58.1%) and gallbladder cancer (29.0%). Technical success rate was 83.9%. Success was achieved more frequently in patients without masses obstructing the biliary confluence (MOC) than those with MOC (95.2% vs 60.0%, P=0.03). Functional success rate was 77.4%. Complications occurred in 29.0% of the patients. These tended to occur more frequently in patients with MOC (50.0% vs 19.0%, P=0.11). Median time to recurrent biliary obstruction was 188 days and median survival was 175 days. The large cell type stent can be used efficiently for bilateral SIS placement in malignant hilar obstruction. However, the risk of technical failure increases in patients with MOC, and caution is needed to prevent complications for these patients.

Self-Expandable Metal Stents and Trans-stent Light Delivery: Are Metal Stents and Photodynamic Therapy Compatible?

PubMed Central

Wang, Luo-Wei; Li, Li-Bo; Li, Zhao-Shen; Chen, Yang K; Hetzel, Fred W.; Huang, Zheng

2008-01-01

Background and Objectives: Obstructive non-small cell lung cancer and obstructive esophageal cancer are US FDA approved indications of photodynamic therapy (PDT). The usefulness of PDT for the treatment of cholangiocarcinoma is currently under clinical investigation. Endoscopic stenting for lumen restoration is a common palliative intervention for those indications. It is important to assess whether self-expandable metal stents are compatible with trans-stent PDT light delivery. Study Design/Materials and Methods: Direct effects of various components of metal biliary (n = 2), esophageal (n = 2), and bronchial (n = 1) stents on PDT light transmittance and distribution were examined using a point or linear light source (630 or 652 nm diode laser). Resected pig biliary duct and esophageal wall tissues were used to examine the feasibility of PDT light delivery through the fully expanded metal stents. Results: While using a point light source, the metal components (thread and joint) of the stent could cause a significant shadow effect. The liner material (polytetrafluoroethylene or polyurethane) could cause various degrees of light absorption. When the stent was covered with a thin layer of biliary duct and esophageal tissues containing all wall layers, the shadow effect could be mitigated due to tissue scattering. Conclusions: This study clearly demonstrates that it is feasible to combine stenting and PDT for the treatment of luminal lesions. PDT light dose should be adjusted to counteract the reduction of light transmittance caused by the metal and liner materials of stent. PMID:18951422

A combined technique using a muscular flap and endobronchial stent to repair complex broncho-oesophageal fistulae supported by ECMO.

PubMed

Baste, Jean-Marc; Haddad, Laura; Philouze, Guillaume

2018-02-01

Certain broncho-oesophageal fistulae require surgical repair. Herein, we describe an innovative surgical technique combining intercostal flap and endobronchial stenting. Two patients, each with a with complex broncho-oesophageal fistula 2 years after radio-chemotherapy, were hospitalised for severe respiratory infection and extension of the fistula despite previous endoscopic treatment. The first patient presented with respiratory distress (ARDS). She had emergency surgery under extra corporeal membrane oxygenation: oesophagectomy and reconstruction of the left bronchus by a vascularised intercostal flap. Stenting was performed on day 10, due to persistence of the fistula. At 3 months the bronchus was healed, but the patient died of cerebral bleeding. For the second patient, repair was proposed before severe ARDS with the same surgical and ventilatory strategy and a stent was preventively inserted after surgery. After 3 months, the stent was removed and the left bronchus was healed. Complex post-radiotherapy broncho-oesophageal fistulae should be treated surgically before respiratory complications arise, by combining reconstruction with a vascularised flap and transient stenting.

Initial study of sediment antagonism and characteristics of silver nanoparticle-coated biliary stents in an experimental animal model.

PubMed

Tian, Yigeng; Xia, Mingfeng; Zhang, Shuai; Fu, Zhen; Wen, Qingbin; Liu, Feng; Xu, Zongzhen; Li, Tao; Tian, Hu

2016-01-01

Plastic biliary stents used to relieve obstructive jaundice are frequently blocked by sediment, resulting in loss of drainage. We prepared stents coated with silver nanoparticles (AgNPs) and compared their ability to resist sedimentation with Teflon stents in a beagle model of obstructive jaundice. AgNP-coated Teflon biliary stents were prepared by chemical oxidation-reduction and evaluated in an obstructive jaundice model that was produced by ligation of common bile duct (CBD); animals were randomized to two equal groups for placement of AgNP-coated or Teflon control stents. Liver function and inflammatory index were found to be similar in the two groups, and the obstruction was relieved. Stents were removed 21 days after insertion and observed by scanning and transmission electron microscopy. The AgNP coating was analyzed by energy dispersive X-ray analysis (EDXA), and the composition of sediment was assayed by Fourier-transform infrared (FTIR) spectroscopy. Electron microscopy revealed a black, closely adherent AgNP stent coating, with thicknesses of 1.5-6 µm. Sediment thickness and density were greater on Teflon than on AgNP-coated stents. EDXA confirmed the stability and integrity of the AgNP coating before and after in vivo animal experimentation. FTIR spectroscopy identified stent sediment components including bilirubin, cholesterol, bile acid, protein, calcium, and other substances. AgNP-coated biliary stents resisted sediment accumulation in this canine model of obstructive jaundice caused by ligation of the CBD.

Initial study of sediment antagonism and characteristics of silver nanoparticle-coated biliary stents in an experimental animal model

PubMed Central

Tian, Yigeng; Xia, Mingfeng; Zhang, Shuai; Fu, Zhen; Wen, Qingbin; Liu, Feng; Xu, Zongzhen; Li, Tao; Tian, Hu

2016-01-01

Objective Plastic biliary stents used to relieve obstructive jaundice are frequently blocked by sediment, resulting in loss of drainage. We prepared stents coated with silver nanoparticles (AgNPs) and compared their ability to resist sedimentation with Teflon stents in a beagle model of obstructive jaundice. Methods AgNP-coated Teflon biliary stents were prepared by chemical oxidation–reduction and evaluated in an obstructive jaundice model that was produced by ligation of common bile duct (CBD); animals were randomized to two equal groups for placement of AgNP-coated or Teflon control stents. Liver function and inflammatory index were found to be similar in the two groups, and the obstruction was relieved. Stents were removed 21 days after insertion and observed by scanning and transmission electron microscopy. The AgNP coating was analyzed by energy dispersive X-ray analysis (EDXA), and the composition of sediment was assayed by Fourier-transform infrared (FTIR) spectroscopy. Results Electron microscopy revealed a black, closely adherent AgNP stent coating, with thicknesses of 1.5–6 µm. Sediment thickness and density were greater on Teflon than on AgNP-coated stents. EDXA confirmed the stability and integrity of the AgNP coating before and after in vivo animal experimentation. FTIR spectroscopy identified stent sediment components including bilirubin, cholesterol, bile acid, protein, calcium, and other substances. Conclusion AgNP-coated biliary stents resisted sediment accumulation in this canine model of obstructive jaundice caused by ligation of the CBD. PMID:27217749

Therapeutic efficacy and stent patency of transhepatic portal vein stenting after surgery

PubMed Central

Jeon, Ung Bae; Kim, Chang Won; Kim, Tae Un; Choo, Ki Seok; Jang, Joo Yeon; Nam, Kyung Jin; Chu, Chong Woo; Ryu, Je Ho

2016-01-01

AIM To evaluate portal vein (PV) stenosis and stent patency after hepatobiliary and pancreatic surgery, using abdominal computed tomography (CT). METHODS Percutaneous portal venous stenting was attempted in 22 patients with significant PV stenosis (> 50%) - after hepatobiliary or pancreatic surgery - diagnosed by abdominal CT. Stents were placed in various stenotic lesions after percutaneous transhepatic portography. Pressure gradient across the stenotic segment was measured in 14 patients. Stents were placed when the pressure gradient across the stenotic segment was > 5 mmHg or PV stenosis was > 50%, as observed on transhepatic portography. Patients underwent follow-up abdominal CT and technical and clinical success, complications, and stent patency were evaluated. RESULTS Stent placement was successful in 21 patients (technical success rate: 95.5%). Stents were positioned through the main PV and superior mesenteric vein (n = 13), main PV (n = 2), right and main PV (n = 1), left and main PV (n = 4), or main PV and splenic vein (n = 1). Patients showed no complications after stent placement. The time between procedure and final follow-up CT was 41-761 d (mean: 374.5 d). Twenty stents remained patent during the entire follow-up. Stent obstruction - caused by invasion of the PV stent by a recurrent tumor - was observed in 1 patient in a follow-up CT performed after 155 d after the procedure. The cumulative stent patency rate was 95.7%. Small in-stent low-density areas were found in 11 (55%) patients; however, during successive follow-up CT, the extent of these areas had decreased. CONCLUSION Percutaneous transhepatic stent placement can be safe and effective in cases of PV stenosis after hepatobiliary and pancreatic surgery. Stents show excellent patency in follow-up abdominal CT, despite development of small in-stent low-density areas. PMID:27956806

A Double-Layered Covered Biliary Metal Stent for the Management of Unresectable Malignant Biliary Obstruction: A Multicenter Feasibility Study.

PubMed

Park, Jin-Seok; Jeong, Seok; Lee, Don Haeng; Moon, Jong Ho; Lee, Kyu Taek; Dong, Seok Ho

2016-11-15

The covered self-expandable metal stent (CMS) was developed to prevent tumor ingrowth-induced stent occlusion during the treatment of malignant biliary obstruction. However, complications such as cholecystitis, pancreatitis, and stent migration can occur after the endoscopic insertion of CMSs. The aim of the present study was to assess the efficacy and safety of a double-layered CMS (DCMS) for the management of malignant bile duct obstruction. DCMSs were endoscopically introduced into 59 patients with unresectable malignant extrahepatic biliary obstruction at four tertiary referral centers, and the patient medical records were retrospectively reviewed. Both the technical and functional success rates were 100%. Procedure-related complications including pancreatitis, cholangitis, stent migration, and liver abscess occurred in five patients (8.5%). The median follow-up period was 265 days (range, 31 to 752 days). Cumulative stent patency rates were 68.2% and 40.8% at 6 and 12 months, respectively. At the final follow-up, the rate of stent occlusion was 33.9% (20/59), and the median stent patency period was 276 days (range, 2 to 706 days). The clinical outcomes of DCMSs were comparable to the outcomes previously reported for CMSs with respect to stent patency period and complication rates.

Mechanical behavior of peripheral stents and stent-vessel interaction: A computational study

NASA Astrophysics Data System (ADS)

Dottori, Serena; Flamini, Vittoria; Vairo, Giuseppe

2016-05-01

In this paper stents employed to treat peripheral artery disease are analyzed through a three-dimensional finite-element approach, based on a large-strain and large-displacement formulation. Aiming to evaluate the influence of some stent design parameters on stent mechanics and on the biomechanical interaction between stent and arterial wall, quasi-static and dynamic numerical analyses are carried out by referring to computational models of commercially and noncommercially available versions of both braided self-expandable stents and balloon-expandable stents. Addressing isolated device models, opening mechanisms and flexibility of both opened and closed stent configurations are numerically experienced. Moreover, stent deployment into a stenotic peripheral artery and possible postdilatation angioplasty (the latter for the self-expandable device only) are simulated by considering different idealized vessel geometries and accounting for the presence of a stenotic plaque. Proposed results highlight important differences in the mechanical response of the two types of stents, as well as a significant influence of the vessel shape on the stress distributions arising upon the artery-plaque system. Finally, computational results are used to assess both the stent mechanical performance and the effectiveness of the stenting treatment, allowing also to identify possible critical conditions affecting the risk of stent fracture, tissue damage, and/or pathological tissue response.

Removable esophageal stents have poor efficacy for the treatment of refractory benign esophageal strictures (RBES).

PubMed

Dan, D T; Gannavarapu, B; Lee, J G; Chang, K; Muthusamy, V R

2014-08-01

With the recent availability of removable esophageal stents, endoscopic stenting has been utilized to treat refractory benign esophageal strictures (RBES). The objective of this study was to review the feasibility and effectiveness of removable esophageal stents to treat RBES. Patients who received removable esophageal stents for the treatment of RBES at the institution between 2004-2010 using its stent implantation logs and endoscopic database were retrospectively identified. Patient demographics, stricture etiology and location, stent and procedure characteristics, and clinical outcomes were obtained. Twenty-five patients with a mean age of 70 (72% male) underwent initial stent placement; 24 were successful. Overall clinical success was achieved in five of the 19 patients (26%) ultimately undergoing stent removal. RBES etiologies included anastomotic (13), radiation (5), peptic (3), chemotherapy (1), scleroderma (1), and unknown (2). Alimaxx-E (Merit-Endotek, South Jordan, UT, USA) stents were placed in 20 patients and Polyflex (Boston Scientific, Natick, MA, USA) stents were used in five patients. Immediate complications included failed deployment (1) and chest pain (7). Five patients died prior to stent removal. Stent migration was found in 53% (10/19) of patients who underwent stent removal: nine required additional therapy and one had symptom resolution. Out of the nine patients without stent migration, five required additional therapy and four had symptom resolution. Although placement of removable esophageal stents for RBES is technically feasible, it is frequently complicated by stent migration and chest pain. In addition, few patients achieved long-term stricture resolution after initial stenting. In this study, most patients ultimately required repeated stenting and/or dilations to maintain relief of dysphagia. © 2012 Copyright the Authors. Journal compilation © 2012, Wiley Periodicals, Inc. and the International Society for Diseases of the Esophagus.

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.

Risk of stent thrombosis among bare-metal stents, first-generation drug-eluting stents, and second-generation drug-eluting stents: results from a registry of 18,334 patients.

PubMed

Tada, Tomohisa; Byrne, Robert A; Simunovic, Iva; King, Lamin A; Cassese, Salvatore; Joner, Michael; Fusaro, Massimiliano; Schneider, Simon; Schulz, Stefanie; Ibrahim, Tareq; Ott, Ilka; Massberg, Steffen; Laugwitz, Karl-Ludwig; Kastrati, Adnan

2013-12-01

This study sought to compare the risk of stent thrombosis among patients treated with bare-metal stents (BMS), first-generation drug-eluting stents (G1-DES), and second-generation drug-eluting stents (G2-DES) for a period of 3 years. In patients undergoing coronary stenting, there is a scarcity of long-term follow-up data on cohorts large enough to compare rates of stent thrombosis across the stent generations. A total of 18,334 patients undergoing successful coronary stent implantation from 1998 to 2011 at 2 centers in Munich, Germany, were included in this study. Patients were stratified into 3 groups according to treatment with BMS, G1-DES, and G2-DES. The cumulative incidence of definite stent thrombosis at 3 years was 1.5% with BMS, 2.2% with G1-DES, and 1.0% with G2-DES. On multivariate analysis, G1-DES compared with BMS showed a significantly higher risk of stent thrombosis (odds ratio [OR]: 2.05; 95% confidence interval [CI]: 1.47 to 2.86; p < 0.001). G2-DES were associated with a similar risk of stent thrombosis compared with BMS (OR: 0.82; 95% CI: 0.56 to 1.19; p = 0.30). Beyond 1 year, the risk of stent thrombosis was significantly increased with G1-DES compared with BMS (OR: 4.72; 95% CI: 2.01 to 11.1; p < 0.001), but not with G2-DES compared with BMS (OR: 1.01; 95% CI: 0.32 to 3.25; p = 0.98). In a large cohort of unselected patients undergoing coronary stenting, compared with BMS, there was a significant excess risk of stent thrombosis at 3 years with G1-DES, driven by an increased risk of stent thrombosis events beyond 1 year. G2-DES were associated with a similar risk of stent thrombosis compared with BMS. Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Angiographic CT: in vitro comparison of different carotid artery stents-does stent orientation matter?

PubMed

Lettau, Michael; Bendszus, Martin; Hähnel, Stefan

2013-06-01

Our aim was to evaluate the in vitro visualization of different carotid artery stents on angiographic CT (ACT). Of particular interest was the influence of stent orientation to the angiography system by measurement of artificial lumen narrowing (ALN) caused by the stent material within the stented vessel segment to determine whether ACT can be used to detect restenosis within the stent. ACT appearances of 17 carotid artery stents of different designs and sizes (4.0 to 11.0 mm) were investigated in vitro. Stents were placed in different orientations to the angiography system. Standard algorithm image reconstruction and stent-optimized algorithm image reconstruction was performed. For each stent, ALN was calculated. With standard algorithm image reconstruction, ALN ranged from 19.0 to 43.6 %. With stent-optimized algorithm image reconstruction, ALN was significantly lower and ranged from 8.2 to 18.7 %. Stent struts could be visualized in all stents. Differences in ALN between the different stent orientations to the angiography system were not significant. ACT evaluation of vessel patency after stent placement is possible but is impaired by ALN. Stent orientation of the stents to the angiography system did not significantly influence ALN. Stent-optimized algorithm image reconstruction decreases ALN but further research is required to define the visibility of in-stent stenosis depending on image reconstruction.

Coronary and peripheral stenting in aorto-ostial protruding stents: The balloon assisted access to protruding stent technique.

PubMed

Helmy, Tarek A; Sanchez, Carlos E; Bailey, Steven R

2016-03-01

Treatment of aorto-ostial in-stent restenosis lesions represents a challenge for interventional cardiologists. Excessive protrusion of the stent into the aorta may lead to multiple technical problems, such as difficult catheter reengagement of the vessel ostium or inability to re-wire through the stent lumen in repeat interventions. We describe a balloon assisted access to protruding stent technique in cases where conventional coaxial engagement of an aorto-ostial protruding stent with the guide catheter or passage of the guide wire through the true lumen is not feasible. This technique is applicable both in coronary and peripheral arteries. © 2015 Wiley Periodicals, Inc.

Low symptomatic premature stent occlusion of multiple plastic stents for benign biliary strictures: comparing standard and prolonged stent change intervals.

PubMed

Lawrence, Christopher; Romagnuolo, Joseph; Payne, K Mark; Hawes, Robert H; Cotton, Peter B

2010-09-01

Benign biliary strictures are typically managed endoscopically whereby an increasing size or number of plastic stents is placed at ERCP. Stents are often changed every 3 to 4 months based on the known median patency of a single biliary stent, but patency data for multiple biliary stents are lacking. To assess the incidence of occlusion-free survival of multiple plastic biliary stents and the rate of premature occlusion if left in longer than 6 months. Retrospective. Tertiary-care medical center (Charleston, SC). Consecutive patients who received multiple plastic stents for benign nonhilar biliary strictures from 1994 to 2008 were identified. Exchange of multiple plastic biliary stents within 6 months (group 1) or 6 months or longer (group 2) after placement. Symptomatic stent occlusion. Seventy-nine patients with nonhilar extrahepatic benign biliary stricture underwent 125 ERCPs with multiple plastic biliary stents. Stents were scheduled for removal/exchange within 6 months in 52 patients (86 ERCPs) compared with after 6 months in 22 patients (26 ERCPs). The median interval between multiple stent placement and removal/exchange was 90 days for group 1 and 242 days for group 2. Premature stent occlusion occurred in 4 of 52 (7.7%) patients in group 1 versus 1 of 22 (4.5%) in group 2, with significantly longer occlusion-free survival in group 2 (log-rank P < .0001). Retrospective study at a single tertiary referral center. Multiple plastic biliary stents for benign nonhilar strictures were associated with a low rate of premature symptomatic stent occlusion at more than 6 months and a longer occlusion-free survival. Copyright 2010 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

Influence of strut cross-section of stents on local hemodynamics in stented arteries

NASA Astrophysics Data System (ADS)

Jiang, Yongfei; Zhang, Jun; Zhao, Wanhua

2016-05-01

Stenting is a very effective treatment for stenotic vascular diseases, but vascular geometries altered by stent implantation may lead to flow disturbances which play an important role in the initiation and progression of restenosis, especially in the near wall in stented arterial regions. So stent designs have become one of the indispensable factors needed to be considered for reducing the flow disturbances. In this paper, the structural designs of strut cross-section are considered as an aspect of stent designs to be studied in details. Six virtual stents with different strut cross-section are designed for deployments in the same ideal arterial model. Computational fluid dynamics (CFD) methods are performed to study how the shape and the aspect ratio (AR) of strut cross-section modified the local hemodynamics in the stented segments. The results indicate that stents with different strut cross-sections have different influence on the hemodynamics. Stents with streamlined cross-sectional struts for circular arc or elliptical arc can significantly enhance wall shear stress (WSS) in the stented segments, and reduce the flow disturbances around stent struts. The performances of stents with streamlined cross-sectional struts are better than that of stents with non-streamlined cross-sectional struts for rectangle. The results also show that stents with a larger AR cross-section are more conductive to improve the blood flow. The present study provides an understanding of the flow physics in the vicinity of stent struts and indicates that the shape and AR of strut cross-section ought to be considered as important factors to minimize flow disturbance in stent designs.

A prospective, randomized study of the patency period of the plastic antireflux biliary stent: an interim analysis.

PubMed

Leong, Quan Wai; Shen, Mira L; Au, Kim W; Luo, Derek; Lau, James Y; Wu, Justin C; Chan, Francis K; Sung, Joseph J

2016-02-01

There is as yet no ideal design of a plastic biliary stent with the longest patency period. To study the safety and effective patency period of a new plastic antireflux biliary stent in the clinical setting. We conducted a prospective, randomized trial to compare the patency of 2 similar plastic biliary stents, one of which has an antiduodenobiliary reflux property. The study was conducted at 2 separate tertiary centers in 2 countries. Patients with inoperable distal malignant biliary obstruction were recruited. One of the 2 types of plastic stents under study was randomly chosen and inserted in the common bile duct of the study subjects. The subjects were followed until the end of study or occlusion occurrence. Our primary endpoint was the time to stent occlusion in days, with stent-related adverse events and all-cause mortality the secondary endpoints. A total of 16 subjects were recruited for the study; 7 were allocated to group A (ordinary Tannenbaum stent) and 9 to group B (antireflux biliary stent). Five of 7 subjects (71%) in group B had stent occlusion within 8 days, and the primary end point was reached in all 7 subjects within 30 days, whereas the primary endpoint was not reached within 30 days in any of the subjects in group A. Our data showed a significantly shorter stent patency period in group B compared with group A (P < .003). Small sample size. Routine use of antireflux plastic biliary stents in the palliative management of malignant biliary obstructions cannot be recommended at present. (Clinical trial registration number: NCT01142921.). Copyright © 2016 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

Numerical analysis of urine flow through the side holes of a double J stent in a ureteral stenosis.

PubMed

Kim, Hyoung-Ho; Choi, Young Ho; Lee, Seung Bae; Baba, Yasutaka; Kim, Kyung-Wuk; Suh, Sang-Ho

2017-07-20

Ureteral stenosis presents with a narrowing in the ureter, due to an intrinsic or extrinsic ureteral disease, such as ureter cancer or retroperitoneal fibrosis. The placement of a double J stent in the upper urinary system is one of the most common treatments of ureteral stenosis, along with the insertion of a percutaneous nephrostomy tube into the renal pelvis. The effect that the side holes in a double J stent have on urine flow has been evaluated in a few studies using straight ureter models. In this study, urine flow through a double J stent's side holes was analyzed in curved ureter models, which were based on human anatomy. In ureteral stenosis, especially in severe ureteral stenosis, a stent with side holes had a positive effect on the luminal and total flow rates, compared with the rates for a stent without side holes. The more side holes a stent has, the greater the luminal and total flow rates. However, the angular positions of the side holes did not affect flow rate. In conclusion, the side holes in a double J stent had a positive effect on ureteral stenosis, and the effect became greater as the ureteral stenosis became more severe.

Expandable metal stents for endoscopic bilateral stent-within-stent placement for malignant hilar biliary obstruction.

PubMed

Chahal, Prabhleen; Baron, Todd H

2010-01-01

Placement of biliary stents is effective for palliation of unresectable hilar malignant biliary obstruction. However, when bilateral self-expandable metal stents (SEMSs) are used, placement can be technically challenging. In many studies, side-by-side placement is performed, although it is unclear whether this is the most anatomical and functional approach. We sought to assess the technical feasibility and effectiveness of deploying bilateral SEMSs with a stent-within-stent approach using commercially available stents with a large cell width. Retrospective study. Tertiary care medical center. Patients with malignant biliary hilar obstruction referred for endoscopic palliation of obstructive jaundice. Technical success, ie, successful bilateral SEMS placement across the stricture; functional success, ie, decrease in pretreatment bilirubin level; early and late complications; and stent patency. Bilateral biliary drainage was attempted and successfully established in 21 patients with malignant hilar obstruction (15 men, 6 women; mean age 63.7 [standard deviation 13.9] years), resulting in clinical improvement of obstructive symptoms. Median follow-up was 6.14 months (interquartile range 3.5-9.5 months). There were 1 (5%) early and 7 (33%) late stent occlusions that required endoscopic reintervention. The 30-day mortality rate was 10% (2 deaths). Retrospective study of a series of cases treated at a tertiary care center by expert endoscopists. This simple technique was performed by using an open-cell expandable metal stent is technically feasible and easy and allows bilateral placement of SEMSs in patients with unresectable hilar malignancy. 2010 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

Effects of specific alpha-1A/1D blocker on lower urinary tract symptoms due to double-J stent: a prospectively randomized study.

PubMed

Wang, Chung-Jing; Huang, Shi-Wei; Chang, Chien-Hsing

2009-06-01

The aim of our study was to evaluate the effect of tamsulosin in improving symptoms in patients with indwelling double-J ureteral stents. This prospective study lasted from April 2006 to March 2008. All the patients with symptomatic lower ureteral stones with <15 mm diameter were enrolled, and were prospectively randomized (random numbers table) into two groups. A total of 154 patients, with insertion of a double-J ureteral stent after ureteroscopic stone removal. In group 1, 75 patients were enrolled and received placebo for 2 weeks. Group 2 included 79 patients who received 0.4 mg of tamsulosin, once daily for 2 weeks. All patients completed the validated ureteral stent symptom questionnaire (USSQ) and quality of life of international prostate symptom scale (IPSS) for evaluating the symptoms of double-J stents and quality of life after double-J stent insertion and removal, respectively. The analysis of the questionnaire at W1 revealed a significant difference in the main score index of urinary symptoms, body pain and general health between groups 1 and 2. When comparing W1 evaluation with that of W4 after double-J removal, both groups showed significant worsening of urinary symptoms, body pain, general health and work performance, except sexual performance. The mean score of quality of life in IPSS was 4.21 in group 1 and 1.6 in group 2. Tamsulosin can improve a subset of stent-related urinary symptoms and quality of life effectively and may be applied in routine clinical practice.

Has the pelvic renal stone position inside the upper loop of JJ stent any influence on the extracorporeal shock wave lithotripsy results?

PubMed

Pricop, Catalin; Serban, Dragomir N; Serban, Ionela Lacramioara; Cumpanas, Alin-Adrian; Gingu, Constantin-Virgil

2016-01-01

JJ stents are often encountered in patients with pelvic renal stones referred for shock wave lithotripsy, most of them being placed either for obstructive renal pelvic stones or for ureteric stones mobilized retrograde during the JJ stent insertion. The aim of the study was to determine whether the relative stone position in the upper loop of the JJ stent during extracorporeal shock wave lithotripsy (SWL) influences the efficiency of the procedure. The study was designed as a prospective cohort study on 162 patients addressing the same urological department, with single renal pelvic stone (primary or mobilized to the renal pelvis during the insertion of JJ stent), smaller than 15 mm, with JJ stent, treated by SWL using a second generation spark gap lithotripter, 18 kV, 3000 waves/session. Patients were divided in three groups according to the relative position of the stone to the upper loop of the JJ stent as appears on plain X-ray: stone-inside-loop, loop-crossing-stone and stone-outside the loop. The SWL success rate was the primary outcome of the study. p Value, Chi square and Kruskal-Wallis tests were used for statistical analysis. For stone-inside-loop cases, SWL efficiency was 22.7 versus 42 % for all the other cases (p = 0.002). Other factors for decreased SWL success rate were: higher stone radio-opacity, larger JJ of stent and obese patients. Study limitation is represented by the relative small study group and by the evaluation of stone density using plain X-ray instead of computer tomography. For pelvic renal stones having the same density characteristics studied by plain X-ray, the SWL efficiency is lower in stone-inside-loop cases comparing with the other positions. The overall stone free rate for renal pelvic stones could be explained by the second generation lithotripter used for all procedures.

A Wireless Pressure Sensor Integrated with a Biodegradable Polymer Stent for Biomedical Applications

PubMed Central

Park, Jongsung; Kim, Ji-Kwan; Patil, Swati J.; Park, Jun-Kyu; Park, SuA; Lee, Dong-Weon

2016-01-01

This paper describes the fabrication and characterization of a wireless pressure sensor for smart stent applications. The micromachined pressure sensor has an area of 3.13 × 3.16 mm2 and is fabricated with a photosensitive SU-8 polymer. The wireless pressure sensor comprises a resonant circuit and can be used without the use of an internal power source. The capacitance variations caused by changes in the intravascular pressure shift the resonance frequency of the sensor. This change can be detected using an external antenna, thus enabling the measurement of the pressure changes inside a tube with a simple external circuit. The wireless pressure sensor is capable of measuring pressure from 0 mmHg to 230 mmHg, with a sensitivity of 0.043 MHz/mmHg. The biocompatibility of the pressure sensor was evaluated using cardiac cells isolated from neonatal rat ventricular myocytes. After inserting a metal stent integrated with the pressure sensor into a cardiovascular vessel of an animal, medical systems such as X-ray were employed to consistently monitor the condition of the blood vessel. No abnormality was found in the animal blood vessel for approximately one month. Furthermore, a biodegradable polymer (polycaprolactone) stent was fabricated with a 3D printer. The polymer stent exhibits better sensitivity degradation of the pressure sensor compared to the metal stent. PMID:27271619

A Wireless Pressure Sensor Integrated with a Biodegradable Polymer Stent for Biomedical Applications.

PubMed

Park, Jongsung; Kim, Ji-Kwan; Patil, Swati J; Park, Jun-Kyu; Park, SuA; Lee, Dong-Weon

2016-06-02

This paper describes the fabrication and characterization of a wireless pressure sensor for smart stent applications. The micromachined pressure sensor has an area of 3.13 × 3.16 mm² and is fabricated with a photosensitive SU-8 polymer. The wireless pressure sensor comprises a resonant circuit and can be used without the use of an internal power source. The capacitance variations caused by changes in the intravascular pressure shift the resonance frequency of the sensor. This change can be detected using an external antenna, thus enabling the measurement of the pressure changes inside a tube with a simple external circuit. The wireless pressure sensor is capable of measuring pressure from 0 mmHg to 230 mmHg, with a sensitivity of 0.043 MHz/mmHg. The biocompatibility of the pressure sensor was evaluated using cardiac cells isolated from neonatal rat ventricular myocytes. After inserting a metal stent integrated with the pressure sensor into a cardiovascular vessel of an animal, medical systems such as X-ray were employed to consistently monitor the condition of the blood vessel. No abnormality was found in the animal blood vessel for approximately one month. Furthermore, a biodegradable polymer (polycaprolactone) stent was fabricated with a 3D printer. The polymer stent exhibits better sensitivity degradation of the pressure sensor compared to the metal stent.

After urgent drainage of an obstructed kidney by internal ureteric stenting; is ureteroscopic stone extraction always needed?

PubMed Central

Taha, Diaa-Eldin; Elshal, Ahmed M.; Zahran, Mohamed H.; Harraz, Ahmed M.; El-Nahas, Ahmed R.; Shokeir, Ahmed A.

2015-01-01

Objectives To assess the probability of spontaneous stone passage and its predictors after drainage of obstructed kidney by JJ stent, as insertion of an internal ureteric stent is often used for renal drainage in cases of calcular ureteric obstruction. Patients and methods Between January 2011 and June 2013, patients for whom emergent drainage by ureteric stents were identified. The patients’ demographics, presentation, and stone characteristics were reviewed. The primary endpoint for this study was stone-free status at the time of stent removal, where all patients underwent non-contrast spiral computed tomography (NCCT) before stent removal. Ureteroscopic stone extraction was performed for CT detectable ureteric stones at the time of stent removal. Potential factors affecting the need for ureteroscopic stone extraction at the time of stent removal were assessed using univariate and multivariate statistical analyses. Results Emergent ureteric stents were undertaken in 196 patients (112 males, 84 females) with a mean (SD) age of 53.7 (16.2) years, for renal obstruction drainage. At the time of stent removal, 83 patients (42.3%) were stone free; with the remaining 113 patients (57.7%) undergoing ureteroscopic stone extraction. On multivariate analysis, stone width [odds ratio (OR) 15.849, 95% confidence interval (CI) 2.83; P = 0.002) and radio-opaque stones (OR 12.035, 95% CI 4.65; P < 0.001) were independent predictors of the need for ureteroscopic stone extraction at the time of stent removal. Conclusion Spontaneous ureteric stone passage is possible after emergent drainage of an obstructed kidney by ureteric stenting. Stone opacity, larger stone width, and positive preoperative urine culture are associated with a greater probability of requiring ureteroscopic stone extraction after emergent drainage by ureteric stenting. PMID:26609444

Fast Virtual Stenting with Active Contour Models in Intracranical Aneurysm

PubMed Central

Zhong, Jingru; Long, Yunling; Yan, Huagang; Meng, Qianqian; Zhao, Jing; Zhang, Ying; Yang, Xinjian; Li, Haiyun

2016-01-01

Intracranial stents are becoming increasingly a useful option in the treatment of intracranial aneurysms (IAs). Image simulation of the releasing stent configuration together with computational fluid dynamics (CFD) simulation prior to intervention will help surgeons optimize intervention scheme. This paper proposed a fast virtual stenting of IAs based on active contour model (ACM) which was able to virtually release stents within any patient-specific shaped vessel and aneurysm models built on real medical image data. In this method, an initial stent mesh was generated along the centerline of the parent artery without the need for registration between the stent contour and the vessel. Additionally, the diameter of the initial stent volumetric mesh was set to the maximum inscribed sphere diameter of the parent artery to improve the stenting accuracy and save computational cost. At last, a novel criterion for terminating virtual stent expanding that was based on the collision detection of the axis aligned bounding boxes was applied, making the stent expansion free of edge effect. The experiment results of the virtual stenting and the corresponding CFD simulations exhibited the efficacy and accuracy of the ACM based method, which are valuable to intervention scheme selection and therapy plan confirmation. PMID:26876026

Treatment of central venous in-stent restenosis with repeat stent deployment in hemodialysis patients.

PubMed

Ronald, James; Davis, Bradley; Guevara, Carlos J; Pabon-Ramos, Waleska M; Smith, Tony P; Kim, Charles Y

2017-05-15

To report patency rates for stent deployment for treatment of in-stent stenosis of the central veins of the chest in hemodialysis patients. A retrospective analysis was performed on 29 patients who underwent 35 secondary percutaneous transluminal stent (PTS) deployments for in-stent stenosis within the central veins that were refractory to angioplasty and ipsilateral to a functioning hemodialysis access (in-stent PTS group). For comparison, patency data were acquired for 47 patients who underwent 78 successful percutaneous transluminal angioplasty (PTA) procedures for in-stent stenosis (in-stent PTA group) and 55 patients who underwent 55 stent deployments within native central vein stenosis refractory to angioplasty (native vein PTS group). The 3-, 6-, and 12-month primary lesion patency for the in-stent PTS group was 73%, 57%, and 32%, respectively. The 3-, 6-, and 12-month primary patency for the in-stent PTA group was 70%, 38%, and 17% and for the native vein PTS group was 78%, 57%, and 26%, which were similar to the in-stent PTS group (p = 0.20 and 0.41, respectively). The 3-, 6-, and 12-month secondary access patency was 91%, 73%, and 65% for the in-stent PTS group. Sub-analysis of the in-stent PTS group revealed no difference in primary (p = 0.93) or secondary patency rates (p = 0.27) of bare metal stents (n = 23) compared with stent grafts (n = 12). Stent deployment for central vein in-stent stenosis refractory to angioplasty was associated with reasonable patency rates, which were similar to in-stent PTA and native vein PTS.

Cost analysis of prophylactic intraoperative cystoscopic ureteral stents in gynecologic surgery.

PubMed

Fanning, James; Fenton, Bradford; Jean, Geraldine Marie; Chae, Clara

2011-12-01

Prophylactic intraoperative ureteral stent placement is performed to decrease operative ureteric injury, though few data are available on the effectiveness of this procedure, and no data are available on its cost. To analyze the cost of prophylactic intraoperative cystoscopic ureteral stents in gynecologic surgery. All cases of prophylactic ureteral stent placement performed in gynecologic surgery during a 1-year period were identified and retrospectively reviewed through the electronic medical records database of Summa Health System. Costs were obtained through the Healthcare Cost Accounting System. The principles of cost-effective analysis were used (ie, explicit and detailed descriptions of costs and cost-effectiveness statistics). Importantly, we evaluated cost and not charges or financial model estimates. In addition, we obtained the contribution margins (ie, the hospital's net profit or loss) for prophylactic ureteral stent placement. Other gynecologic procedures were also analyzed. Among 792 major inpatient gynecologic procedures, 18 cases of prophylactic intraoperative ureteral stents were identified. Median costs were as follows: additional cost of prophylactic intraoperative ureteral stenting, $1580; additional cost of surgical resources, $770; cost of ureteral catheters, $427; cost of surgeons, $383. The contribution margins per case for various gynecologic surgical procedures were as follows: oophorectomy, $2804 profit; abdominal hysterectomy, $2649 profit; laparoscopically assisted vaginal hysterectomy (LAVH), $1760 profit. When intraoperative ureteral stenting was added, the contribution margins changed to the following: oophorectomy, $782 profit; abdominal hysterectomy, $627 profit; LAVH, $262 loss. Overall, the contribution margin profit was decreased by about 85%, from $2400 to $380. Prophylactic intraoperative ureteral stenting in gynecologic surgery decreases a hospital's contribution margin. Because of the expense of this procedure, as well as

iStent trabecular micro-bypass stent for open-angle glaucoma

PubMed Central

Le, Kim; Saheb, Hady

2014-01-01

Trabecular micro-bypass stents, commonly known as iStents, are micro-invasive glaucoma surgery (MIGS) devices used to treat open-angle glaucoma. Like other MIGS procedures that enhance trabecular outflow, the iStent lowers intraocular pressure (IOP) by creating a direct channel between the anterior chamber and Schlemm’s canal. iStents are typically implanted at the time of phacoemulsification for patients with open-angle glaucoma and visually significant cataracts. This review summarizes the published data regarding the efficacy, safety, and cost considerations of trabecular micro-bypass stents. Most studies found statistically significant reductions in mean IOP and ocular medication use after combined phacoemulsification with single or double iStent implantation. The devices were found to be very safe, with a safety profile similar to that of cataract surgery. Complications were infrequent, with the most common complications being temporary stent obstruction or malposition, which resolved with observation or secondary procedures. Future studies are needed to evaluate long-term outcomes, patient satisfaction, cost effectiveness, and expanded indications. PMID:25284980

Shrinking the Supply Chain for Implantable Coronary Stent Devices.

PubMed

Moore, Sean S; O'Sullivan, Kevin J; Verdecchia, Francesco

2016-02-01

Stenting treatments for the management of disease in the heart, arterial and venous systems, biliary ducts, urethras, ureters, oesophageal tract and prostate have made enormous technical advances since their introduction into clinical use. The progression from metallic to polymer based bio-absorbable stents, coupled with the advances in additive manufacturing techniques, present a unique opportunity to completely re-envision the design, manufacture, and supply chain of stents. This paper looks at current stenting trends and proposes a future where the stent supply chain is condensed from ~150 days to ~20 min. The Cardiologist therefore has the opportunity to become a designer, manufacturer and user with patients receiving custom stents specific to their unique pathology that will be generated, delivered and deployed in the Cath-lab. The paper will outline this potentially revolutionary development and consider the technical challenges that will need to be overcome in order to achieve these ambitious goals. A high level overview of the generating eluting stents in situ program-GENESIS-is outlined including some early experimental work.

Clinical Application of Fully Covered Self-Expandable Metal Stents in the Treatment of Bronchial Fistula.

PubMed

Cao, Ming; Zhu, Qiang; Wang, Wei; Zhang, Tian Xiao; Jiang, Min Zhong; Zang, Qi

2016-09-01

Background The study was designed to access the feasibility, safety, and efficacy of fully covered self-expandable metal stents in the treatment of bronchial fistula. Methods Clinical data of nine patients (seven males and two females) who were treated with placement of tracheobronchial or bronchial fully covered self-expandable metal stents from August 2005 to November 2011 were analyzed retrospectively. Among these patients, seven were diagnosed with bronchopleural fistula, one with tracheopleural fistula, and one with left main bronchoesophageal fistula. Eight had accompanying thoracic empyema. The fistula orifices ranged from 3.5 mm to 25 mm in diameter. All patients received topical anesthesia. L-shaped stents were placed in six patients and I-shaped stents in three under fluoroscopic guidance. After stent placement, patients with empyema were treated with pleural lavage. Results Stent placement in the tracheobronchial tree was successful in all patients, without procedure-related complications. The operating time was 5 to 16 minutes. A small amount of bubble overflowed from the intrathoracic drainage tube of only one patient. In the other patients, the bubble in the intrathoracic drainage tube disappeared immediately or angiography showed no overflow of contrast agent from the fistula orifice. The effective rate of fistula orifice closure after stent placement was 100%, with 88.9% rated as excellent. One patient coughed the stent out 5 days after placement and hence a new stent was placed. Among the patients with empyema, one died of septicemia arising from empyema on day 8 and another died of brain metastases of lung cancer 6 months after stent insertion with persistent empyema. In the other six patients, empyema resolved after 2 to 5 months (cure rate 75%). Seven patients were followed up for 3 to 36 months. During follow-up, one stent was removed 8 months after implantation due to difficult expectoration, without recurrent empyema. The remaining

Forgotten CBD stent (102 months) with stone-stent complex: A case report.

PubMed

Barai, Varsha; Hedawoo, Jagadish; Changole, Sanjay

2017-01-01

Choledocholithiasis is presence of stone in Common bile duct (CBD) which can be treated by endoscopy or surgery [1]. Retained foreign bodies like stents forms a nidus for stone formation resulting in pain, fever, jaundice. 60 years female patient admitted in surgery ward with features of cholangitis with computed tomography showing cholangitic abscess with dilated common bile duct and sludge around stent in situ. Stone was found at proximal end of stent during surgery. Stents may remain without complications or may migrate, and rarely form nidus for stone formation. If kept for long time they lead to bacterial proliferation, biofilm formation and precipitation of calcium bilirubinate presenting as fever, pain, jaundice. Stent-stone complex can be treated endoscopically and surgically [6,7]. As stent can cause stone formation, infection and other complications, timely removal of stent should advised. III-effects of stent in-situ should be explained, record should be maintained [8] and patient should be advised regular follow up and stent removal after 6 weeks. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

TIPS stent migration into the heart with 6-year follow-up.

PubMed

Fehervari, Imre; Szonyi, Laszlo; Fazakas, Janos; Gerlei, Zsuzsa; Lazar, Istvan

2011-01-01

The transjugular intrahepatic portosystemic shunt (TIPS) is widely used for the treatment of portal hypertension in adults, but no studies have defined the best approach to treat portal hypertension in pediatric patients. Pediatric use of TIPS is rare even in large centers of adult practice. The migration of stents has also been reported as a complication in adults. There is no standard way to treat this type of complication, and it is not always clear whether immediate removal or watchful waiting is safer for the patient. We report the case of an 11-year-old patient who underwent urgent TIPS implantation due to variceal bleeding, after unsuccessful sclerotherapy. During the procedure, due to the deep impact of the stent, a second, telescopic, stent was inserted. The portal pressure decreased, no further bleeding occurred, and the patient was listed for transplantation. Three weeks later a routine chest X-ray discovered the migration of the second stent into the right ventricle. No interventional radiological removal or open heart surgery was available for the transplant waiting list patient. The patient underwent uneventful combined liver-kidney transplantation. During the 6-year follow-up period the child had no signs of hemodynamic instability, and his somatic and mental development were appropriate. To our knowledge this case is the first publication on a heart-impacted TIPS stent in a child. The watchful waiting was justified by uneventful combined liver-kidney transplantation and long-term follow-up. This case also underlines the need for best practice guidelines in pediatric portal hypertension.

Oxygen Mass Transport in Stented Coronary Arteries.

PubMed

Murphy, Eoin A; Dunne, Adrian S; Martin, David M; Boyle, Fergal J

2016-02-01

Oxygen deficiency, known as hypoxia, in arterial walls has been linked to increased intimal hyperplasia, which is the main adverse biological process causing in-stent restenosis. Stent implantation has significant effects on the oxygen transport into the arterial wall. Elucidating these effects is critical to optimizing future stent designs. In this study the most advanced oxygen transport model developed to date was assessed in two test cases and used to compare three coronary stent designs. Additionally, the predicted results from four simplified blood oxygen transport models are compared in the two test cases. The advanced model showed good agreement with experimental measurements within the mass-transfer boundary layer and at the luminal surface; however, more work is needed in predicting the oxygen transport within the arterial wall. Simplifying the oxygen transport model within the blood flow produces significant errors in predicting the oxygen transport in arteries. This study can be used as a guide for all future numerical studies in this area and the advanced model could provide a powerful tool in aiding design of stents and other cardiovascular devices.

Clinical remission following endoscopic placement of retrievable, fully covered metal stents in patients with esophageal achalasia.

PubMed

Zeng, Y; Dai, Y-M; Wan, X-J

2014-01-01

Metal stents may represent an alternative therapy in the treatment of achalasia. We therefore evaluated the effectiveness of retrievable, fully covered metal stents in patients with achalasia. Fifty-nine patients with achalasia were treated with retrievable, fully covered metal stents. Symptoms using a global symptom score (0-10), lower esophageal sphincter (LES) resting pressure, LES relaxation, and simultaneous contraction of the esophagus were analyzed before and 1 week and 1 month after intervention. Complications and treatment outcomes were followed up at 6, 12, 18, and 24 months postoperatively. Stent placement was successful, and clinical symptoms resolved (P < 0.01) in all patients. Regurgitation, dysphagia and chest pain improved significantly (all P < 0.01). Therapy improved LES resting pressure (51.4 ± 9.7 mmHg pretherapy vs. 20.9 ± 8.1 mmHg post-therapy), LES relaxation (58.1 ± 17.1% pretherapy vs. 84.5 ± 18.9% post-therapy), and simultaneous contraction of the esophagus (36.1 ± 8.6% pretherapy vs. 69.4 ± 23.1% post-therapy) 1 month after stent placement (all P < 0.01). The cumulative clinical remission rates 6, 12, 18, 24, 30, and 36 months after stent removal were 90.9%, 81.8%, 76.4%, 69.1%, 65.5%, and 49.1%, respectively. All patients tolerated stent placement. Twelve patients (25.5%) complained of substernal pain and five (10.6%) had substernal burning. Stents migrated in four patients (8.5%). Insertion of retrievable, fully covered metal stents is an effective and safe treatment in patients with achalasia. © 2013 Wiley Periodicals, Inc. and the International Society for Diseases of the Esophagus.

Lower urinary tract infection and bacterial colonization in patient with double J ureteral stent.

PubMed

Joshi, R; Singh, D R; Sharma, S

2011-10-01

The aim of this study is to investigate the bacteriology of urinary tract infection associated with indwelling DJ stent. A total of 60 patients were included and 14 lost during follow up. Study period was for 6 months carried out in the department of surgery, Kathmandu Medical College. Prophylactic antibiotic was given at the time of intervention. Mid stream urine samples for routine and culture were sent before intervention. Urine samples during DJ removal and DJ tip cultures were also sent. All patients were "stented" during the various open and endourolgical procedures. Patients were clinically followed for a period till the DJ was removed. Statistical Package for Scientific Study (SPSS) 11, Chi square Test was used for statistical analysis. A total of 46 cases were included. Mean age in years was 35.70 (10-78 years). Male were 22 and female 24. Eleven patients (23.91%) had stent placed less than 30 days and 35 patients (76.08%) had it for equal or more than 30 days. DJ indwelling time was in between 12-86 days. Bacterial colonies were found in 28.3% (13 of 46) of the urine samples and 30.4% (14 of 46) from the tip of the DJ stent segment. Of the pathogens identified, E. coli was found to be the most common. An increased stent colonization rate was associated with implantation time, female sex. On urine culture 70.21% had no growth, 14.89% E. coli, 4.25% Klebsiella, Actinobacter, 2.12% E. coli/kleb, multiple org, psuedomonas. Ten patients (21.7%) had positive urine culture before stent insertion. Thirteen patients (28.3%) were shown to have positive urine culture on stent removal. Fourteen patients (30.4%) had positive DJ stent culture. Positive urine culture and positive DJ tip cultures had strong correlation. Longer duration of placement of stent showed stent colonization. The commonest pathogen was E. coli.

[Stents in urology].

PubMed

Mattei, A; Danuser, H

2003-04-01

Ureteral stents are employed in the upper and urethral stents in the lower urinary tract for restitution or maintenance of urinary drainage. Placement of ureteral stents is indicated as an adjuvant measure prior to extracorporal disintegration (ESWL) of large kidney stones to insure urinary drainage and enhance expulsion of fragments and disintegrate. Also, obstruction by very small urinary tract stones that are not treatable by ESWL because they cannot be localized can be relieved by placement of a double-J-stent with immediate elimination of colic. If the cause of urinary tract obstruction is external ureteral compression (retroperitoneal mass), placement of a special tumor stent is one possibility. This, however, has the danger of becoming reobstructed with detritus and blockage of the drainage holes in the stent. In these cases the essential drainage along the stent is blocked by the mass. Therefore, a percutaneous nephrostomy providing direct drainage is easier to control and preferable. Obstructive pyelonephritis is an absolute indication for drainage of the upper urinary tract with a double-J-stent, or even better by percutaneous nephrostomy. If pyeloureteral or ureteral stenoses of the upper urinary tract are opened endoscopically, then the double-J-stent serves to maintain and insure drainage until the new lumen is reepithelialized. In patients with prostatic hyperplasia who no longer respond to medical treatment and who are not candidates for more invasive surgical treatment, a stent can be placed in the prostatic urethra under local anesthesia as a last resort. This procedure is seldom used but, in view of the satisfactory long-term results, it provides a true alternative to bladder drainage by transurethral catheter or percutaneous cystostomy. The same stents may be used in the bulbar urethra to reduce restricture rates following endoscopic treatment of strictures.

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

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

PubMed

van Halsema, Emo E; van Hooft, Jeanin E

2015-02-16

To analyze the outcomes of self-expandable stent placement for benign esophageal strictures and benign esophageal leaks in the literature. 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. 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. 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 esophageal leaks, perforations and

Novel use of a percutaneous endoscopic gastrostomy tube fastener for securing silicone tracheal stents in patients with benign proximal airway obstruction.

PubMed

Musani, Ali I; Jensen, Kurt; Mitchell, John D; Weyant, Michael; Garces, Katherine; Hsia, David

2012-04-01

Benign tracheal obstruction occurs for a variety of reasons. Bronchoscopic intervention includes silicone stent placement, which effectively maintains airway patency. Stent migration is a common complication, particularly when placed in the proximal trachea. We used a novel technique of securing tracheal stents with a percutaneous endoscopic gastrostomy tube fastener (PEG-TF) to prevent stent migration. The purpose of this study was to determine the feasibility of securing silicone stents in the proximal trachea with PEG-TF. Silicone stents were placed under general anesthesia by rigid bronchoscopy in 7 consecutive patients with inoperable benign proximal tracheal obstruction. PEG-TFs were placed under sterile conditions with direct bronchoscopic visualization. A needle was inserted through the anterior neck and silicone stent wall allowing stylet introduction of a T-fastener into the interior of the stent. The T-fastener was secured externally by a metal clamp and cotton pledget at the surface of the neck. Patients had routine outpatient follow-up and covered the external portion of the PEG-TF with a waterproof dressing when showering. All 7 PEG-TFs were placed without complications. The PEG-TFs were left in for 1 to 25 weeks. Complications of the PEG-TF included localized cellulitis and suture breakage. No stent migration occurred while the fastener was in place. Two stents were removed within 2 weeks due to patient's difficulty tolerating the stent. Securing silicone stents in the proximal trachea is feasible and may prevent stent migration, but further study and possible modification of the PEG-TF device are needed.

Impact of loop-tail ureteral stents on ureteral stent-related symptoms immediately after ureteroscopic lithotripsy: Comparison with pigtail ureteral stents

PubMed Central

Inoue, Takaaki; Muguruma, Kouei; Murota, Takashi; Kinoshita, Hidefumi; Matsuda, Tadashi

2017-01-01

Purpose To evaluate urination-related quality of life (QoL) in patients with an indwelling ureteral stent immediately after ureteroscopic lithotripsy (URSL) for upper urinary calculi. We compared the effects of loop-tail and pigtail ureteral stents on urination-related QoL. Materials and Methods Of 135 patients who underwent URSL between May 2014 and March 2015 at our hospital, we retrospectively analyzed the records of 70 patients (42 men, 28 women; median age, 63 years) in whom the stent tail was positioned inside the bladder without crossing the midline and who completed the core lower urinary tract symptoms score (CLSS) questionnaire pre- and postoperatively. Results There were significant differences in incomplete emptying (p=0.048) and bladder pain (p=0.041) between patients with loop-tail versus pigtail ureteral stents after URSL. In the multivariate analysis, stent type had a stronger association with incomplete emptying (p=0.022) and bladder pain (p=0.018) than age, sex, body mass index, stent side, operation time, diameter of ureteral access sheath, and stent type. Conclusions Patients with loop-tail ureteral stents had better urination-related QoL in the immediate post-URSL stage than patients with pigtail stents. PMID:29124244

Stent Coating Integrity of Durable and Biodegradable Coated Drug Eluting Stents.

PubMed

Yazdani, Saami K; Sheehy, Alexander; Pacetti, Stephen; Rittlemeyer, Brandon; Kolodgie, Frank D; Virmani, Renu

2016-10-01

Coatings consisting of a polymer and drug are widely used in drug-eluting stents (DES) and are essential in providing programmable drug release kinetics. Among other factors, stent coating technologies can influence blood compatibility, affect acute and sub-acute healing, and potentially trigger a chronic inflammatory response. The aim of this study was to investigate the short-term (7 and 28 days) and long-term (90 and 180 days) coating integrity of the Xience Prime Everolimus-Eluting Stent (EES), Resolute Zotarolimus-Eluting Stent (ZES), Taxus Paclitaxel-Eluting Stent (PES), and Nobori Biolimus A9-Eluting Stent (BES) in a rabbit ilio-femoral stent model. Stented arteries (n = 48) were harvested and the tissue surrounding the implanted stents digested away with an enzymatic solution. Results demonstrated that the majority of struts of EES were without any coating defects with a few struts showing minor defects. Similarly, for the ZES, most of the struts were without coating defects at all time points except at 180 days. The majority of PES demonstrated mostly webbing and uneven coating. In the BES group, the majority of strut coating showed polymer cracking. Overall, the EES and ZES had fewer coating defects than the PES and BES. Coating defects, however increase over time for the ZES, whereas the percent of coating irregularities remained constant for the EES. These results provide, for the first time, a comparison of the long-term durability of these drug-eluting stent coatings in vivo. © 2016, Wiley Periodicals, Inc.

Very late stent thrombosis in a bare-metal stent, 9 years after implantation.

PubMed

Almasswary, Adel A

2009-06-01

Very late bare-metal stent thrombosis occurring beyond one year after stenting is uncommon. We report a case of bare-metal stent thrombosis presenting as acute myocardial infarction. The patient's stent was implanted 9 years ago, however, he was not adherent to his antiplatelet therapy (aspirin). This case highlights the importance of antiplatelet therapy in patients with stents even many years after implantation.

Mechanisms and Patterns of Intravascular Ultrasound In-Stent Restenosis Among Bare Metal Stents and First- and Second-Generation Drug-Eluting Stents.

PubMed

Goto, Kosaku; Zhao, Zhijing; Matsumura, Mitsuaki; Dohi, Tomotaka; Kobayashi, Nobuaki; Kirtane, Ajay J; Rabbani, LeRoy E; Collins, Michael B; Parikh, Manish A; Kodali, Susheel K; Leon, Martin B; Moses, Jeffrey W; Mintz, Gary S; Maehara, Akiko

2015-11-01

The most common causes of in-stent restenosis (ISR) are intimal hyperplasia and stent under expansion. The purpose of this study was to use intravascular ultrasound (IVUS) to compare the ISR mechanisms of bare metal stents (BMS), first-generation drug-eluting stents (DES), and second-generation DES. There were 298 ISR lesions including 52 BMS, 73 sirolimus-eluting stents, 52 paclitaxel-eluting stents, 16 zotarolimus-eluting stents, and 105 everolimus-eluting stent. Mean patient age was 66.6 ± 1.1 years, 74.2% were men, and 48.3% had diabetes mellitus. BMS restenosis presented later (70.0 ± 66.7 months) with more intimal hyperplasia compared with DES (BMS 58.6 ± 15.5%, first-generation DES 52.6 ± 20.9%, second-generation DES 48.2 ± 22.2%, p = 0.02). Although reference lumen areas were similar in BMS and first- and second-generation DES, restenotic DES were longer (BMS 21.8 ± 13.5 mm, first-generation DES 29.4 ± 16.1 mm, second-generation DES 32.1 ± 18.7 mm, p = 0.003), and stent areas were smaller (BMS 7.2 ± 2.4 mm(2), first-generation DES 6.1 ± 2.1 mm(2), second-generation DES 5.7 ± 2.0 mm(2), p <0.001). Stent fracture was seen only in DES (first-generation DES 7 [5.0%], second-generation DES 8 [7.4%], p = 0.13). In conclusion, restenotic first- and second-generation DES were characterized by less neointimal hyperplasia, smaller stent areas, longer stent lengths, and more stent fractures than restenotic BMS. Copyright © 2015 Elsevier Inc. All rights reserved.

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

PubMed

Mukai, Tsuyoshi; Yasuda, Ichiro; Isayama, Hiroyuki; Iwashita, Takuji; Itoi, Takao; Kawakami, Hiroshi; Kogure, Hirofumi; Nakai, Yousuke

2016-09-01

In patients with unresectable malignant distal biliary obstruction, covered self-expandable metallic stents (CSEMS) may remain patent longer than uncovered self-expandable metallic stents as a result of tumor ingrowth prevention. One main cause of recurrent biliary obstruction (RBO) in CSEMS is sludge formation, which can be prevented using a large-bore stent. Therefore, we developed a novel, 12-mm diameter fully covered SEMS (FCSEMS) and investigated its clinical safety, efficacy, and rate of adverse events. This prospective, multicenter pilot study, which ran between June 2011 and November 2012, included 38 consecutive patients with unresectable malignant distal biliary obstruction. All patients underwent endoscopic insertion of our novel stent. Primary endpoint was non-RBO rate 6 months after placement. Technical and functional success rates of the procedures were 100%. Six-month non-RBO rate was 50%, and median time to RBO was 184 days. Median survival time was 241 days. Twelve patients died within 6 months after stent placement without RBO. RBO was observed in 10 patients (26%), with seven experiencing stent occlusion and three experiencing stent migration. Adverse events other than RBO (at <30 days) developed in six patients (16%; cholecystitis, one; pancreatitis, one; hyperamylasemia, one; pancreatic ductitis, one; abdominal pain, two). Stent removal for reintervention was successfully completed in eight patients. Our novel FCSEMS may be safe and effective for managing malignant distal obstruction with an acceptable incidence of adverse events. © 2016 Japan Gastroenterological Endoscopy Society.

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

Takimura, Celso K; Galon, Micheli Z; Gutierrez, Paulo S; Sojitra, Prakash; Vyas, Ashwin; Doshi, Manish; Lemos, Pedro A

2015-04-01

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). 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. 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. 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.

4D phase contrast flow imaging for in-stent flow visualization and assessment of stent patency in peripheral vascular stents--a phantom study.

PubMed

Bunck, Alexander C; Jüttner, Alena; Kröger, Jan Robert; Burg, Matthias C; Kugel, Harald; Niederstadt, Thomas; Tiemann, Klaus; Schnackenburg, Bernhard; Crelier, Gerard R; Heindel, Walter; Maintz, David

2012-09-01

4D phase contrast flow imaging is increasingly used to study the hemodynamics in various vascular territories and pathologies. The aim of this study was to assess the feasibility and validity of MRI based 4D phase contrast flow imaging for the evaluation of in-stent blood flow in 17 commonly used peripheral stents. 17 different peripheral stents were implanted into a MR compatible flow phantom. In-stent visibility, maximal velocity and flow visualization were assessed and estimates of in-stent patency obtained from 4D phase contrast flow data sets were compared to a conventional 3D contrast-enhanced magnetic resonance angiography (CE-MRA) as well as 2D PC flow measurements. In all but 3 of the tested stents time-resolved 3D particle traces could be visualized inside the stent lumen. Quality of 4D flow visualization and CE-MRA images depended on stent type and stent orientation relative to the magnetic field. Compared to the visible lumen area determined by 3D CE-MRA, estimates of lumen patency derived from 4D flow measurements were significantly higher and less dependent on stent type. A higher number of stents could be assessed for in-stent patency by 4D phase contrast flow imaging (n=14) than by 2D phase contrast flow imaging (n=10). 4D phase contrast flow imaging in peripheral vascular stents is feasible and appears advantageous over conventional 3D contrast-enhanced MR angiography and 2D phase contrast flow imaging. It allows for in-stent flow visualization and flow quantification with varying quality depending on stent type. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Time Sequence Evaluation of Biliary Stent Occlusion by Dissection Analysis of Retrieved Stents.

PubMed

Kwon, Chang-Il; Gromski, Mark A; Sherman, Stuart; Easler, Jeffrey J; El Hajj, Ihab I; Watkins, James; Fogel, Evan L; McHenry, Lee; Lehman, Glen A

2016-08-01

Multiple factors can affect the occlusion of plastic stents. Previous data demonstrate that side holes may induce more biofilm formation probably via microturbulence and bile flow disturbances that could lead to occlusion. These results, however, have not been replicated in subsequent clinical studies with different methods. The objective of this study is to evaluate the physical characteristics of plastic stent occlusion over time. This is a plastic stent sequential analysis study. Biliary stents removed via ERCP from February 24, 2015, to June 2, 2015, were included. One hundred and forty-eight retrieved straight-type plastic stents were longitudinally cut by a custom-made cutting device. These dissected stents were then evaluated in detail with regard to the location of stent occlusion and the stent patency period. Location of stent occlusive debris was the primary outcome in this study. Biofilm formations and occlusions by debris were sequentially but separately tallied. Biofilm formations were initially seen around the side hole areas within 30 days and spread to the entire stent by 60 days. Then, occlusion process by debris was mainly initiated by 80 days and progressed to full occlusion by median of 90 days. Although some occlusions were also observed around the side hole areas within 30 days, affected areas were more widely observed after biofilm formation. This study is the first to attempt to describe the distribution of stent occlusions over time. These observations may help guide future stent development.

The burden of chronic ureteral stenting in cervical cancer survivors

PubMed Central

Fan, Yunhua; Jarosek, Stephanie; Elliott, Sean P.

2017-01-01

ABSTRACT Purpose Ureteral obstruction in cervical cancer occurs in up to 11% of patients, many of whom undergo ureteral stenting. Our aim was to describe the patient burden of chronic ureteral stenting in a population-based cohort by detailing two objectives: (1) the frequency of repeat procedures for ureteral obstruction; and, (2) the frequency of urinary adverse effects (UAEs) (e.g., lower urinary tract symptoms, flank pain). Materials and Methods From SEER-Medicare, we identified 202 women who underwent ureteral stent placement prior to or following cervical cancer treatment. The frequency of repeat procedures and rate ratios were compared between treatment modalities. The rates and rate ratios of UAEs were compared between our primary cohort (stent + cervical cancer) and the following groups: no stent + cervical cancer, stent + no cancer, and no stent + no cancer. The “no cancer” group was drawn from the 5% Medicare sample. Results 117/202 women (58%) underwent >1 stent procedure. The frequency of additional procedures was significantly higher in patients who received radiation as part of their treatment. UAEs were very common in women with stent + cancer. The rate of UTI was 190 (per 100 person-years), 67 for LUTS, 42 for stones, and 6 for flank pain. These rates were 3-10 fold higher than in the no stent + no cancer control group; rates were also higher than in the no stent + cancer and the stent + no cancer women. Conclusions The burden of disease associated with ureteral stents is higher than expected and urologists should be actively involved in stent management, screening for associated symptoms and offering definitive reconstruction when appropriate. PMID:27649113

Stent longitudinal integrity bench insights into a clinical problem.

PubMed

Ormiston, John A; Webber, Bruce; Webster, Mark W I

2011-12-01

Standardized bench-top compression and elongation testing was undertaken to assess the longitudinal strength of contemporary stents. Insights gained may improve clinical stent choice and deployment techniques, and facilitate future stent design improvements. The hoops of coronary stents provide radial support, and connectors hold hoops together. Strut material, shape, and thickness, along with connector number and configuration, provide the balance between stent flexibility and longitudinal integrity. Longitudinal distortion manifests as length change, strut overlap, strut separation, malapposition, and luminal obstruction. These may predispose to restenosis and stent thrombosis, obstruct passage of devices, be misinterpreted as strut fracture, and require additional stenting. The force required to compress and to elongate 7 contemporary stents was measured with an Instron universal testing machine (Norwood, Massachusetts). Stents deployed in a silicone phantom damaged by a balloon or guide catheter were imaged by microcomputed tomography to understand better the appearances and effects of longitudinal distortion. Stents with 2 connectors (Boston Scientific [Natick, Massachusetts] Omega and Medtronic [Santa Rosa, California] Driver) required significantly less force to be compressed up to 5 mm and elongated by 1 mm than designs with more connectors. The 6-connector Cypher Select required significantly more force to be elongated 5 mm than other designs. Stents with 2 connectors between hoops have less longitudinal strength when exposed to compressing or elongating forces than those with more connectors. This independent, standardized study may assist stent selection in clinical situations where longitudinal integrity is important, and may aid future design improvements. Stent longitudinal strength, the resistance to shortening or elongation, appears related to the number of connectors between hoops. Using a standardized testing protocol, designs with 2 connectors

Percutaneous stent placement for the treatment of malignant biliary obstruction: nitinol versus elgiloy stents.

PubMed

Zurstrassen, Charles Edouard; Bitencourt, Almir Galvão Vieira; Guimaraes, Marcos Duarte; Cavalcante, Aline Cristine Barbosa Santos; Tyng, Chiang Jeng; Amoedo, Mauricio Kauark; Matsushita Junior, João Paulo Kawaoka; Szklaruk, Janio; Marchiori, Edson; Chojniak, Rubens

2017-01-01

This study aimed to compare two self-expanding stents, a nitinol stent and an elgiloy stent, both placed percutaneously, in terms of their efficacy in palliating inoperable malignant biliary obstruction. We retrospectively investigated 99 patients with unresectable malignant biliary obstruction treated with percutaneous placement of a self-expanding metallic stent at our institution between May 2007 and January 2010. Serum bilirubin and liver enzyme levels were measured before and 30 days after stenting. For all procedures using elgiloy or nitinol stents, stent occlusion and patient survival rates were calculated using Kaplan-Meyer analysis. All of the patients showed clinical improvement after stent placement, with no difference between the two groups. In both groups, the occlusion-free survival rate was 67% at 30 days, 37% at 90 days, 25% at 180 days, and 10% at 360 days, with no significant difference in relation to the type of stent. The two stents evaluated showed comparable efficacy for the percutaneous treatment of unresectable biliary malignancy, with good clinical results.