Uncovered Stents Research Articles

Delayed Hemobilia Caused by Penetration of Biliary Plastic Stent into Portal Vein

Biliary stent migration is one of the late complications of endoscopic retrograde cholangiopancreatography. Most of the biliary stent migration is asymptomatic and successfully managed by stent removal. A 66-year-old man with unresectable pancreatic cancer, common bile duct obstruction, and duodenal third portion obstruction underwent endoscopic plastic biliary stent placement and duodenal uncovered metallic stent placement in two separate sessions. After 3 weeks from the duodenal stenting, he presented with hematemesis. Urgent esophagogastroduodenoscopy and magnetic resonance imaging showed hemobilia. The patient recovered with conservative managements. Cross-sectional imagings done 2 months later demonstrated the penetration of the biliary stent into portal vein. Here, we present a case of delayed hemobilia caused by penetration of biliary plastic stent into the portal vein.

Management of distal benign biliary stricture

Endoscopic treatment consists of passing the stricture and placement of at least one large bore plastic stent, followed by further sessions of stenting with multiple plastic stents. Temporary placement of multiple plastic stents is the recommended approach in patients with benign biliary strictures. Self-expandable metal stents have a larger diameter compared to plastic stents and can be covered and uncovered. Placement of uncovered metal stents in patients with benign biliary strictures is strongly discouraged. However, covered self-expandable metal stents can be safely placed in selected patients.

Successful removal of an uncovered metallic stent using peroral direct cholangioscopy and the stent-in-stent technique.

Successful removal of an uncovered metallic stent using peroral direct cholangioscopy and the stent-in-stent technique.

Impact of endobiliary radiofrequency ablation on biliary drainage in patients with malignant biliary strictures treated with uncovered self-expandable metal stents: a randomized controlled multicenter trial

Endobiliary radiofrequency ablation (RFA), usually combined with endoscopic stent insertion, is a simple procedure with the potential to improve stent patency and patient survival for malignant biliary obstruction. We conducted this randomized multicenter trial to evaluate the impact of RFA on stent patency. Eighty-six patients with malignant biliary obstruction and nonresectable tumors (pancreatic carcinoma, cholangiocarcinoma, or metastases) were included and randomly assigned to receive a self-expandable metal stent (SEMS) only (n= 44) or RFA followed by SEMS insertion (RFA+SEMS, n= 42). The primary outcome measure was stent patency after 3 and 6 months; secondary outcome measures were patient survival and early adverse events within 30 days. Technical success rates for RFA and stent insertion were 100% and 98.8%, respectively. Stent patency after 3 and 6 months did not differ significantly between groups (RFA+SEMS group, 73.1% and 33.3%, respectively; SEMS-only group, 81.8% and 52.4%, respectively; P= .6). Similarly, the addition of RFA did not impact overall survival (hazard ratio, .72; P= .389 for RFA+SEMS). The adverse event rate in the RFA+SEMS group was 10.5% compared with 2.3% in the SEMS-only group, without a statistically significant difference (P= .18). RFA as an addition to SEMS implantation had no positive impact on patency rate or survival. (Clinical trial registration number: DRKS00018993.).

Endoscopic management of perihilar cholangiocarcinoma.

Endoscopic management for perihilar cholangiocarcinoma (PHCC) is evolving toward more accurate diagnosis and safer drainage. In imaging, it is important to diagnose the entire lesion using multidetector-row computed tomography to determine resectability and optimal surgical planning, followed by local diagnosis using endoscopic retrograde cholangiopancreatography. Video peroral cholangioscopy and probe-based confocal laser endomicroscopy have been newly introduced as diagnostic imaging methods and are being applied clinically. In transpapillary forceps biopsy for PHCC diagnosis, the location in the bile duct (for mapping biopsy) and the number of biopsy samples should be determined depending on resectability, the morphological type, and future surgical planning. Preoperative drainage has shifted from percutaneous transhepatic biliary drainage to endoscopic nasobiliary drainage given the possibility of seeding metastasis. In addition, considering potential patient discomfort from a nasal tube, the usefulness of the placement of a plastic stent above the papilla (inside stent) as a bridging therapy for surgery has been reported. For drainage of unresectable PHCC, the improved prognosis due to advances in chemotherapy has necessitated a strategy that accounts for reintervention. Thus, in addition to uncovered self-expandable metallic stents (SEMS), exchangeable slim fully covered SEMS and inside stents have started to be used. In addition to the conventional transpapillary approach, an endoscopic ultrasonography-guided approach has been introduced, and a combination of both methods has also been proposed. To improve the quality of life and prognosis of PHCC patients, endoscopists need to understand and be able to use the various methods of endoscopic management for PHCC.

PARTIALLY COVERED VERSUS UNCOVERED SELF-EXPANDIBLE METAL STENTS IN THE PALLIATIVE TREATMENT OF MALIGNANT DISTAL BILIARY OBSTRUCTION

Kyo-Sang Yoo: NO financial relationship with a commercial interest Background/Aims: Self-expandable metal stents (SEMSs) are commonly used to relieve malignant biliary obstruction. Covered self-expandable metal stents (CSEMSs) were introduced to improve the patency of SEMSs by preventing tissue ingrowth. Unlike uncovered self-expandable metal stents (USEMSs), which are integrated into the tumor or duct wall, CSEMSs do not embed, but has an increased risk of migration. Although several retrospective studies comparing these two types of stents for malignant biliary obstruction have shown longer patency with CSEMSs, prospective, randomized trials have not been able to confirm these results.

Efficacy of a novel large-cell Niti-S stent with a slim delivery system for hilar biliary obstruction: a preliminary study

Objectives The large-cell Niti-S stent is useful for multiple stenting in patients with malignant hilar biliary obstruction (MHBO). Recently, a novel uncovered self-expandable metallic stent (USEMS) (a Niti-S large-cell SR slim delivery system) was developed. In this study, we aimed to evaluate the efficacy of this USEMS slim delivery system in MHBO patients. Materials and methods Outcomes related to USEMS placement, the clinical course, and the period to recurrent biliary obstruction (RBO) were evaluated in MHBO patients who received multiple USEMSs with the Niti-S large-cell SR slim delivery system. Results Twenty-two MHBO patients underwent the placement of multiple USEMSs, including the novel slim-delivery stent. Six patients had a past history of upper gastrointestinal reconstruction (Billroth I: 1, Billroth II: 4, Roux-en-Y: 1). The number of USEMSs placed in each patient was 2-6. Three procedures were reinterventions. The new slim delivery system was placed as the first stent in ten patients and as an additional stent in the remaining patients. Seven patients were drained using only Niti-S large-cell SR slim delivery stents. The technical and clinical success rates were both 100%. Conclusions Placing multiple USEMSs in patients with a past history of abdominal surgery or in reintervention is difficult. Although difficult cases were included in this study, stent-in-stent placement with the novel Niti-S large-cell SR slim delivery system was useful in treating MHBO patients. In addition, this novel stent might be the first choice for MHBO patients. KEY MESSAGES Endoscopic multistenting for MHBO is challenging. In addition, reintervention or multistenting for MHBO patients with a past history of abdominal surgery becomes more difficult. The novel Niti-S large-cell SR slim delivery USEMS is useful as an additional stent because the delivery system is thin and suitable for a 0.025 guidewire. In addition, the novel stent is of the braided type and has a large mesh. Therefore, the novel stent is expected to have strong radial force and can be used as the first SEMS. The Niti-S large-cell SR slim delivery stent is long enough to be used in patients with upper gastrointestinal reconstruction. Although this study included patients with reintervention or a past history of upper gastrointestinal reconstruction, the technical success rate of multiple stenting for MHBO patients was 100%. The slim-delivery stent might overcome several difficulties of endoscopic multistenting.

Covered versus uncovered metal stent for endoscopic drainage of a malignant distal biliary obstruction: Meta‐analysis

ObjectivesThe role of a covered vs. an uncovered self‐expandable metal stent (SEMS) for malignant distal biliary obstruction (MDBO) is not clear. This meta‐analysis compared the efficacy of covered vs. uncovered SEMS for patients with MDBO after endoscopic insertion.MethodsA systematic meta‐analysis of all relevant articles listed in PubMed, the Cochrane Library, and Google Scholar databases was performed. Fixed effects or random effects models were used to investigate pooled effects with 95% confidence intervals (CIs).ResultsThe meta‐analysis included 2358 patients from 12 eligible studies. Time to recurrent biliary obstruction (RBO) was significantly longer for covered SEMS (mean difference, 45.51 days; 95% CI 11.79–79.24). Although there was no significant difference in the RBO rate, subgroup analysis in pancreatic cancer occupying more than 90% (PC) revealed that the RBO rates were significantly lower for covered SEMS (odds ratio [OR] 0.43, 95% CI 0.25–0.74). Stent migration, sludge formation, and overgrowth were significantly more common with a covered SEMS (OR 7.92, 95% CI 4.01–15.64; OR 3.25, 95% CI 1.89–5.59; OR 2.03, 95% CI 1.20–3.43, respectively). The rate of ingrowth was significantly lower for covered SEMS. There was no significant difference in total procedure‐related adverse events between the two types of SEMS.ConclusionsA covered SEMS is superior to an uncovered SEMS with respect to prevention of RBO in patients with MDBO, particularly those caused by PC.

Jailbreaking a metal biliary stent through a duodenal stent.

Video 1.

Urethral stenting in a dog due to compression and invasion by a liposarcoma

AbstractAn approximately 10‐year‐old, mixed breed, entire male dog was referred for acute onset of urethral obstruction. Abdominal ultrasound was unremarkable, complete blood count, serum biochemical analysis and urine analysis were all unremarkable. A retrograde urethrogram demonstrated narrowing of the urethral lumen caudal to the ischiadic arc. Urethral stenting with a self‐expanding nitinol stent was performed and the patient was without symptoms over a 6‐month period. After that time, ingrowth of tissue into the stent lumen could be seen via a new retrograde urethrogram; therefore, a covered stent was placed into the previously placed uncovered stent. Clinical signs resolved immediately. Another contrast study 4 months later demonstrated almost complete obstruction at the distal end of the stent. Scrotal ablation with perineal urethrostomy was performed and tissue samples submitted for histopathology. Liposarcoma was diagnosed. The patient was urinating without problems, but suddenly died at home 1 week after the last surgery.

Rupture of a pseudoaneurysm after uncovered self-expanding biliary metallic stent placement.

Watch a video of this article.

Two approaches in the treatment of malignant obstructive jaundice using nitinol stents

The article presents our experience of observing two different approaches for endoscopic retrograde drainage in patients with malignant pathology of the pancreatobiliary zone, complicated by the bile duct obstruction. In one case, in case of dysfunction of the installed uncovered stent as a result of incrustation with bile salts and/or tumor invasion, stent-to-stent restenting was performed. In the second case, if it was impossible to pass the guidewire retrogradely beyond the area of the tumor narrowing, an alternative method was used – bringing it down by percutaneous transhepatic access towards the endoscope to install a retrograde stent delivery system along it using the "Rendezvous" method.

Endoscopic bilateral revision after metal stent deployment for hepatic hilar obstruction using molting technique (with videos).

Background:After multiple uncovered self-expandable metal stent (UCSEMS) deployments, endoscopic revision becomes complex and potentially challenging. A novel stent delivery system with a dilation function has recently been developed in Japan. This study evaluated the technical feasibility of this device for patients with unresectable malignant hilar biliary obstruction (MHO) after multiple UCSEMS deployments.Method:Participants comprised consecutive patients with unresectable MHO who had undergone multiple UCSEMS deployments and required endoscopic revision for the right or left hepatic bile ducts, as decided by cholangiography under endoscopic retrograde cholangiopancreatography (ERCP) guidance.Results:A total of 14 patients requiring endoscopic revision of right and left hepatic bile ducts were enrolled in this study. Among these 14 patients, guidewire insertion through the mesh of previously placed stents failed in 2 patients. As a result, these two patients underwent only unilateral UCSEMS deployment. Because clinical success was not obtained, transmural placement of the UCSEMS under Endoscopic Ultrasound (EUS) guidance to the segment of the liver not being drained was performed in those patients. The molting technique was attempted in 12 patients, proving successful in all patients. The technical success rate was therefore 92.8% (12/14). Mean procedure time was 23.2 min.Conclusion:This novel stent delivery system with a dilation function may be useful in endoscopic revision techniques for bilateral UCSEMS deployment.

Optimization of Biliary Drainage in Inoperable Distal Malignantstrictures

Intoduction: Given most patients with distal malignant biliary obstruction present in the nonresectable stage, palliative endoscopic biliary drainage with fully covered metal stent (FCMS) or uncovered metal stent (UCMS) is the only available measure to improve patients’ quality of life. Half covered metal stent (HCMS) has been recently introduced commercially. The adverse effects and stent function between FCMS and UCMS have been extensively discussed. To study the duration of stent patency of HCMS and compare it with FCMS and UCMS to optimize biliary drainage in inoperable patients with distal malignant obstruction.

Ten-Year Experience in the Treatment of Coarctation of the Aorta through Endovascular Stenting in Patients of Different Age Groups

The aim. To analyze the 10-year experience in aortic coarctation endovascular stenting in patients of different age groups.
 Materials and methods. Examination and endovascular treatment of 194 patients aged 3 days to 60 years with coarctation of the aorta (CoA) with different anatomical and morphological variants was performed. According to the age criterion, the examined patients were divided into 4 study groups. The first group consisted of 84 patients (43.3%) over 25 years of age, group 2 included 33 patients (17.0%) aged 19 to 25 years, group 3 included 71 patients (36.6%) aged 5 to 18 years, and group 4 included 6 patients (3.1%) under 1 year of age.
 Results and discussion. We presented the clinical features of different anatomical and morphological variants of CoA. Endovascular treatment of CoA with stenting is considered the best method for adolescents and adults, due to the lower risk of aneurysm formation compared to balloon angioplasty. We were able to successfully reduce the invasive pressure gradient in patients of different ages and to establish the dependence of complication rate on the stent type used. The most common complications were aneurysm formation (2.1%) and stent migration (2.1%). Complications occurred more often in cases of uncovered stents compared to stent grafts (5.3% and 2.1%, respectively, p <0.05). No cases of hospital mortality were recorded in patients older than 5 years. Seven endovascular procedures were performed in 5 patients aged 3 days to 11 months (mean age 3.5 ± 1.6 months) with combined heart defects. Complications were documented in 1 child (20.0%). Endovascular intervention in pregnant women is indicated in refractory hypertension. We performed endovascular CoA stenting in 4 pregnant women at 15–23 weeks of gestation (average, 19.8 ± 3.1 weeks), and in 6 women with well-controlled hypertension stenting was performed within 48 hours to 5 years after delivery. In all the presented cases, successful revascularization was achieved. During follow-up (from 2 months to 10 years), all 10 women are alive, did not develop recoarctation or complications.
 Conclusions. The results of the analysis of CoA endovascular treatment showed that the chosen method and technique of intervention is appropriate and safe for patients of all ages, including pregnant women. Based on the results obtained, we have developed an algorithm for the management of patients who, according to clinical examination and echocardiography, were diagnosed with CoA during pregnancy.

Quadruple, 4-segment, triple sector "Y-shaped stents" in complex hilar cholangiocarcinoma after cholangitis from plastic stents.

Video 1Video showing successful placement of 4 uncovered self-expanding metal stents in a stent-in-stent, Y-shaped configuration for cholangitis from plastic stents in a patient with unresectable cholangiocarcinoma.

Covered vs. uncovered self-expandable metal stents for palliation of malignant afferent loop obstruction: a multicenter study

Background and aims Endoscopic stent placement is a palliative therapy for malignant digestive tract obstruction. However, its use for malignant afferent loop obstruction (mALO) has not been adequately investigated. Methods From March 2009 to December 2020, 137 patients with mALO who underwent endoscopic stent placement at three tertiary care centers were retrospectively enrolled. The primary aim of this study was to compare stent dysfunction (SD) between the covered self-expandable metal stent (CSEMS) and uncovered self-expandable metal stent (UCSEMS) groups, with subgroup analysis among patients with extrinsic and intrinsic tumors separately. Results Twenty-three patients developed SD in the CSEMS group and 29 patients in the UCSEMS group (log-rank p = .974). The primary contributors to SD included a higher risk of stent migration in the CSEMS group and stent ingrowth in the UCSEMS group (p = .003; p < .001). Among patients with extrinsic tumors, the CSEMS group showed a significantly higher probability of overall SD (p = .008) and stent migration (p = .001) with a shorter time to SD (log-rank p = .006) than the UCSEMS group. Among patients with intrinsic tumors, the CSEMS group showed a significantly lower incidence of overall SD (p < .001) and stent ingrowth (p < .001) with a longer time to SD (log-rank p = .011) than the UCSEMS group. Conclusions Our results showed no significant difference in SD between the CSEMS and UCSEMS groups for palliation of mALO. Furthermore, subgroup analysis suggested using CSEMSs for patients with intrinsic tumors, and UCSEMSs for those with extrinsic tumors.

Endoscopic removal of biliary uncovered self-expandable metal stents in one patient placed 15years ago.

Before: 51 W: We removed two biliary uncovered SEMSs from one patient using stent-in-stent technique with a fully covered biliary stent, one of which was placed for up to 15 years. That is rare and also meaningful. Maybe,we should have a new understanding of uncovered SEMS in management of benign biliary strictures. After: 50 W: Yu and colleagues removed two biliary uncovered self-expandable metal stents, one of which had been in place for 15 years, from one patient using the stent-in-stent technique with a fully covered biliary stent. A new understanding of uncovered self-expandable metal stents in the management of benign biliary strictures is needed.

Stent-in-stent technique for removal of the tracheal stent in patients with severe granulation tissue hyperplasia

A tracheal stent implantation is an effective treatment for benign or malignant tracheal stenosis and tracheal fistula (1-6). Currently, covered self-expanding metal stents (SEMS) are generally used in benign cases and uncovered SEMS for treating malignant tracheal stenosis. However, the radial force of the stent on the trachea and the friction between the stent and the tracheal wall during coughing often provoke granulation tissue hyperplasia (7,8). This hyperplasia, which appears at the ends of covered stents or over the entire stented area in the case of uncovered stents, results in incarceration of the stent and tracheal restenosis (9,10). Removal of the stent is then necessary (11,12). Tracheal stent removal can result in complications such as a tracheal mucosal tear, tracheal perforation, mediastinal abscess, massive hemorrhage, and asphyxia (13-15). When the SEMS is embedded in hyperplastic granulation tissue, tracheal perforation and hemorrhage risks are especially high (16-18). Despite advances in interventional techniques and bronchoscopy, both stent removal and treatment of related complications remain difficult. Inspired by the success of the stent-in-stent (SIS) technique for esophageal stent removal (19,20), we applied it to the removal of tracheal SEMS in four patients with severe proliferative stenosis. We describe our technique and report the outcomes.

The Great Stent Graft Escape

A 72 year old male presented with a six week history of two purulent wounds on the medial aspect of his right transfemoral amputation stump (performed in 2015), and a chronic sinus distally. A computed tomography scan showed a kinked right superficial femoral artery (arrow) with an uncovered stent and Gore Viabahn endoprosthesis (WL Gore & Associates, Flagstaff, AZ, USA) inserted in 2015 for chronic limb threatening ischaemia and dissection during angioplasty. Despite initial conservative antibiotic management, the wounds deteriorated so the endoprostheses were explanted. Staphylococcus aureus was cultured and a two week course of intravenous flucloxacillin was given.Image 1