Bilateral balloon expandable biodegradable stent (Y-stent) for postcholecystectomy perihilar biliary stricture.
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ABSTRACT:
SUBMITTER: Lakhtakia S
PROVIDER: S-EPMC7859655 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:PurposeEndoscopic bile duct decompression using bilateral self-expandable metallic stents (SEMSs) deployed via a stent-in-stent (SIS) method is considered a preferred procedure for malignant hilar biliary obstruction (MHBO). However, occlusion thereof occurs frequently. Here, we investigated stent patency duration and risk factors related to stent obstruction with bilateral SIS placement for MHBO at two large centers.Materials and methodsThe present study reviewed data on patients with MHBO who underwent endoscopic biliary drainage using the SIS method. Clinical outcomes, including stent patency duration and patient overall survival, were analyzed. Factors associated with stent patency were evaluated using Cox proportional hazards models.ResultsSeventy patients with MHBO underwent endoscopic biliary drainage using the SIS method. Median age was 68 years old, and median follow-up duration was 140 days (interquartile range, 57-329). The proportion of high-grade MHBOs (Bismuth type IV) was 57.1%. Median stent patency duration with the SIS method was 108 days according to Kaplan-Meier curves. Median patient survival analyzed by the Kaplan-Meier method was 181 days. Multivariate analysis indicated that higher baseline bilirubin (> 6.1 mg/dL) as an independent risk factor related to stent patency (p<0.05).ConclusionIn endoscopic biliary decompression using SEMS placed with the SIS method, obstructive jaundice was a risk factor for stent patency. The SIS method for high-grade MHBO showed short stent patency.
| S-EPMC6082981 | biostudies-literature
Project description:Stricture of pancreatic-enteric anastomoses is a major late complication of a pancreaticoduodenectomy for the treatment of a periampullary tumor and can lead to exocrine and endocrine insufficiency such as malnutrition and diabetes mellitus. We investigated the safety and efficacy of a biodegradable tubular stent (BTS) for preventing a pancreaticojejunostomy (PJ) anastomotic stricture in both a rat and porcine model. The BTS was manufactured using a terpolymer comprising poly p-dioxanone, trimethylene carbonate, and glycolide. A cohort of 42 rats was randomized into 7 groups of 6 animals each after BTS placement into the duodenum for the biodegradation assay. A total of 12 pigs were randomized equally into a control and BTS placement group. The effectiveness of the BTS was assessed by comparing radiologic images with histologic results. Surgical procedures and/or BTS placements were technically successful in all animals. The median mass losses of the removed BTS samples from the rat duodenum were 2.1, 6.8, 11.2, 19.4, 26.1, and 56.8% at 1, 2, 3, 4, 6, and 8 weeks, respectively. The BTS had completely degraded at 12 weeks in the rats. In the porcine PJ model, the mean luminal diameter and area of the pancreatic duct in the control group was significantly larger than in the BTS group (all p < 0.05). BTS placement thus appears to be safe and effective procedure for the prevention of PJ anastomotic stricture. These devices have the potential to be used as a temporary stent placement to treat pancreatic-enteric anastomoses, but further investigations are required for optimization in human.
| S-EPMC6992790 | biostudies-literature
Project description: Not available
| S-EPMC7650860 | biostudies-literature
Project description:OBJECTIVE: The aim of this study is to report our experience using self-expandable covered metallic stents (Wallstent) to treat different types of biliary strictures after orthotopic liver transplantation (OLT). PATIENTS AND METHODS: Between January 1999 and July 2004, 222 OLTs were performed with choledocho-choledochostomy (CC) bile duct reconstruction. An anastomotic biliary stricture was diagnosed and treated by endoscopic retrograde cholangiopancreatography (ERCP) or percutaneous procedures in 100 patients (45%). The group of 21 patients (mean age 57.0+/-5.6 years) that were eventually treated with a biliary Wallstent was studied retrospectively. RESULTS: Significant persistent proximal or anastomotic strictures were diagnosed in 4 and 17 patients, respectively. A Wallstent was inserted by ERCP or through a percutaneous route in 18 and 3 patients, respectively. The mean interval between diagnosis and Wallstent insertion was 179.7+/-292.8 (0-1113) days. The mean total number of procedures required per patient was 7.4+/-5.5. The mean stent primary patency duration was 10.8+/-7.8 (0.9-25.1) months with a 24-month primary patency rate of 26% at a mean follow-up time of 37.8+/-17.2 months. A hepatico-jejunostomy was performed in five patients (24%). Two patients (10%) underwent retransplantation for diffuse ischemic cholangitis or chronic rejection. The overall complication rate was 4%. CONCLUSION: Treatment of post-transplant biliary stenosis using a Wallstent is a valuable option for delaying or avoiding surgery in up to 70% of patients. Proximal stenosis can be treated in the same manner in selected patients with major comorbidities.
| S-EPMC2131685 | biostudies-other
Project description:Equipoise of transcatheter aortic valve replacement with surgical aortic valve replacement in intermediate-risk patients has been demonstrated. As transcatheter aortic valve replacement usage expands, questions regarding long-term durability become paramount. Valve design impacts durability with regions of increased leaflet stress being vulnerable to early failure. However, transcatheter aortic valve (TAV) leaflet stresses are unknown. The objective of this study was to determine stent and leaflet stresses of second-generation balloon-expandable TAV.Commercial 29-mm Edwards Sapien XT (Edwards Lifesciences, Irvine, CA) valves underwent high-resolution microcomputed tomography scanning to develop precise three-dimensional geometric mesh. Compressed and uncompressed TAVs were modeled under systemic pressure using finite element software. Material properties of stent were based on cobalt-chromium, whereas those for leaflets were obtained from surgical bioprostheses.Maximum and minimum principal stresses on uncompressed Sapien XT TAV were 1.63 MPa and -0.36 MPa on leaflets and 93.3 MPa and -105.6 MPa on stent at diastolic pressure. Peak leaflet stress was observed at commissural tips where leaflets connected to the stent. For compressed TAV to 26 mm, maximum and minimum principal stresses were 1.55 MPa and -0.63 MPa on leaflets and 526.1 MPa and -902.2 MPa on stent at diastolic pressure. Peak leaflet stress was located at similar position and also along the suture line with the Dacron (C. R. Bard, Haverhill, PA).Stress analysis of two extreme deployed geometries of 29-mm Edwards Sapien XT using exact geometry from high-resolution scans demonstrated that peak stresses for TAV leaflets were present at commissural tips where leaflets were attached. These regions would be mostly likely to initiate degeneration.
| S-EPMC5839641 | biostudies-literature
Project description:OBJECTIVE:Transcatheter aortic valve replacement is established therapy for high-risk and inoperable patients with severe aortic stenosis, but questions remain regarding long-term durability. Valve design influences durability. Increased leaflet stresses in surgical bioprostheses have been correlated with degeneration; however, transcatheter valve leaflet stresses are unknown. From 2007 to 2014, a majority of US patients received first-generation balloon-expandable transcatheter valves. Our goal was to determine stent and leaflet stresses in this valve design using finite element analyses. METHODS:A 26-mm Sapien Transcatheter Heart Valve (Edwards Lifesciences, Inc, Irvine, Calif) underwent high-resolution microcomputed tomography scanning to develop precise 3-dimensional geometry of the leaflets, the stent, and the polyethylene terephthalate elements. The stent was modeled using 3-dimensional elements and the leaflets were modeled using shell elements. Stent material properties were based on stainless steel, whereas those for leaflets were obtained from surgical bioprostheses. Noncylindrical Sapien valve geometry was also simulated. Pressure loading to 80 mm Hg and 120 mm Hg was performed using ABAQUS finite element software (Dassault Systèmes, Waltham, Mass). RESULTS:At 80 mm Hg, maximum principal stresses on Sapien leaflets were 1.31 megaspascals (MPa). Peak leaflet stress was observed at commissural tips where leaflets connected to the stent. Maximum principal stresses for the stent were 188.91 MPa and located at stent tips where leaflet commissures were attached. Noncylindrical geometry increased peak principal leaflet stresses by 16%. CONCLUSIONS:Using exact geometry from high-resolution scans, the 26-mm Sapien Transcatheter Heart Valve showed that peak stresses for both stent and leaflets were present at commissural tips where leaflets were attached. These regions would be prone to leaflet degeneration. Understanding stresses in first-generation transcatheter valves allows comparison to future designs for relative durability.
| S-EPMC5837867 | biostudies-literature
Project description: Not available
| S-EPMC7570430 | biostudies-literature
Project description:Common biliary tract is ≈4 mm in diameter to deliver bile from liver to small intestine to help digestion. The abnormal narrowing leads to severe symptoms such as pain and nausea. Stents are an effective treatment. Compared with non-degradable stents which require repeated removal, biodegradable stents have the advantage of reducing secondary injury related to endoscopic operation and patient burden. However, current biodegradable materials may cause tissue hyperplasia and the treatment method does not target etiology of stricture. So recurrence rates after biodegradable stent implantation are still high. Here, a biodegradable helical stent fabricated from biosynthetic P(3HB-co-4HB) is reported. Tunable properties can be acquired through altering culture substrates. Stent shows shape memory in various solvents. The stent has an optimized design with helical structure and outer track. The self-expanding of helical structure and double drainage realized by outer track greatly improve drainage of bile. Importantly, stent-loading triamcinolone acetonide can inhibit proliferation of fibroblasts and reduce incidence of restricture. Therapeutic effect is also demonstrated in minipigs with biliary stricture. The results of minipig experiments show that biliary duct in treatment group is unobstructed and tissue hyperplasia is effectively inhibited.
| S-EPMC10582434 | biostudies-literature
Project description:Endovascular treatment of arterial injuries with stent-graft is a reliable alternative approach in patients not suitable for embolization or at high risk for surgery. The aim of our study was to evaluate the efficacy and the safety of the BeGraft stent-graft, a low-profile balloon expandable covered stent, for emergency endovascular treatment of iatrogenic arterial injuries.Between August 2015 and September 2018, 34 consecutive patients (mean age 71 ± 12 years, 9 females) underwent implantation of BeGraft stent-grafts for iatrogenic arterial injuries (22 active bleedings, 11 pseudoaneurysms, and 1 enteric-iliac fistula). The primary endpoints were technical and clinical success and rates of major and minor complications. The secondary endpoint was the patency of the device during the follow-up. Imaging follow-up was performed by duplex ultrasound and/or computed tomography angiography (according to lesion site/target vessel), at 1-6-12-15 and 24 months.In all 34 patients (100%), the lesion or the defect was effectively excluded with a cumulative amount of 42 stent-grafts. The clinical success was documented in 30/34 patients (88.2%). Neither device- or procedure-related deaths, or major complications occurred. A minor complication was reported in 1 patient (2.9%), successfully treated during the same procedure. Thirty (88.2%) patients were available for a mean follow-up time of 390 ± 168 days (minimum 184, maximum 770), with no observed loss of patency, yielding a 100% Kaplan-Meier cumulative survival patency function. The percentage of patent patients was 30/30 at 6 months, 22/22 at 12 months, and 5/5 at 15 months.Endovascular treatment of iatrogenic arterial injuries with the BeGraft stent-graft is minimally invasive and effective, with good patency rate at midterm follow-up.
| S-EPMC7220351 | biostudies-literature
Project description: Not available
| S-EPMC6834977 | biostudies-literature