Nitinol Stent Research Articles

IVUS Improves Outcomes With SUPERA Stents for the Treatment of Superficial Femoral-Popliteal Artery Disease.

Nitinol interwoven bare metal stents represent an advancement in stent technology; however, nominal deployment remains an area of focus. Intravascular ultrasound (IVUS) has been shown to improve outcomes in both the coronary and peripheral vasculature by providing the operator with greater vessel detail; however, the use of adjunctive IVUS with nitinol bare metal stents has not been widely studied. This studies aims to determine the effect of IVUS when used adjunctively with nitinol interwoven bare metal stents in the management of femoropopliteal lesions. Retrospective study. This study included a cohort of 200 consecutive patients with peripheral artery disease. All patients were treated with ≥1 Supera bare metal stent, and 91 received adjunctive IVUS imaging prior to stent deployment. Deployment conditions of nominal, compressed, and elongated were measured, and the primary clinical outcomes included target lesion reintervention, amputation, and mortality. This study also showed that 8.3 number needed to treat (NNT) patients must be treated with IVUS to avoid an additional revascularization event. The patients who received IVUS had a significantly greater number of nominally deployed stents (p<0.001). Patients who had IVUS imaging also had significantly lower reintervention rates compared with those who did not receive IVUS imaging (p=0.047). The IVUS and angiography decreases clinically-driven target lesion reintervention and increases nominal deployment compared with angiography alone in femoropopliteal lesions treated with interwoven bare metal nitinol stents. Endovascular surgones may conisder the adjuctive use of IVUS when using the Supera stent for the treatment of infra inguinal superficial femoral artery lesions. The adjunct use of IVUS may lead to improved sizing, vessel prep, deployment, and ultiamtely reduction in CD-TLR.

Shakedown theorems for shape memory alloys structures with functional fatigue — Application to nitinol stents

Shape memory alloys (SMAs) offer interesting perspectives in various fields such as aeronautics, robotics, biomedical sciences, or structural engineering. The distinctive properties of those materials stem from a solid/solid phase transformation occurring at a microscopic level. Modeling the rather complex behavior of SMAs is a topic of active research. Lately, SMA models coupling phase-transformation with permanent inelasticity have been proposed to capture degradation effects which are frequently observed experimentally for cyclic loadings — a phenomenon referred to as functional fatigue. In this paper, the classical static and kinematic shakedown of plasticity theory are extended to such material models. Those results give conditions for the energy dissipation to remain bounded, which is beneficial for the fatigue life. Analytical shakedown limits are obtained for a 3-bar truss example and compared with numerical results from step-by-step simulations. We consider the problem of a nitinol stent submitted to cyclic pressure and mixed pressure–bending as an application, showing how the approach presented can be combined with finite-element analysis to study shakedown of complex 3D structures.

Fortalecimento muscular e métodos profiláticos de membros inferiores em atletas de futebol para minimizar o desequilíbrio muscular

No futebol, a preparação física e fortalecimento muscular são de suma importância para maximizar o desempenho dos atletas, porém os preparadores físicos ao sistematizar e planejar o treinamento, acabam superestimando os músculos anteriores da coxa e subestimando os músculos posteriores da coxa, os quais são importantes para uma melhora do desempenho global do atleta. Assim, este estudo objetivou apresentar métodos de fortalecimento e prevenção para evitar o desequilíbrio muscular em atletas de futebol. Para a composição desta pesquisa foram consultados artigos científicos publicados entre os anos de 1994 até o mais atual 2023. As lesões decorrentes no futebol estão relacionadas ao treinamento inadequado, alterações que sobrecarregam algumas estruturas corporais, causando enfraquecimento muscular, podendo afetar os tendões e articulações. O fortalecimento muscular e os métodos de prevenção são fatores importantes para manter o equilíbrio constante da musculatura durante o treinamento e os jogos contribuindo na prevenção de lesões e aumentando o nível de competitividade nesse esporte.

Morphological and ultrastructural changes in the common bile duct wall in stenting

Aim . To carry out a comprehensive morphological study into pathological changes in the common bile duct wall following various periods of plastic and nitinol stent implantation; to examine telocytes in the common bile duct wall. Materials and methods. The study involves the material of 91 patients, who underwent surgery for periampullary carcinoma from 2014 to 2020. Plastic stents were inserted in 56 cases, nitinol stents – in 35. The study of morphological structure of the common bile duct wall took into account the type of stent and period of its implantation (14–30 days, 31–60 days, ≥ 61 days). Results . Inflammatory processes in patients with nitinol stent implantation have been revealed to prevail over fibroplastic processes, leading to hyperplasia of the common bile duct mucosa. Following plastic stents implantation, fibroplastic and atrophic changes prevailed. It was found that cases with plastic stent implantation are more often subject to damage to the telocyte ultrastructure and loss of intercellular connections. Conclusion . Structural changes in telocytes can reflect the degree of fibrosis in the common bile duct wall depending on the type of stent.

CARD11: Polymeric Endoluminal Paving for Prevention of Paravalvular Leak in Transcatheter Aortic Valve Replacement

Background: Calcific aortic valve disease and associated aortic stenosis is increasingly common, with prevalence across the age spectrum. Transcatheter aortic valve replacement (TAVR) has emerged as a life-saving, non-surgical alternative for replacement of diseased aortic valves, restoring non-obstructive blood flow from the heart. While effective, current TAVR technology remains limited by adaptability to patient-specific anatomy, leading to incomplete deployment and non-conformal fit resulting in paravalvular leak. Polymeric endoluminal paving was previously developed as a methodology allowing deployment of polymeric materials on tissue surfaces, serving as structural materials and barriers. Here we adapt the paving methodology to fill gaps and defects resulting from incomplete TAVR valve deployment to limit paravalvular leak. Specifically, we assess the efficacy pf polymeric paving in vitro as a means of gap filling and leak reduction in valves deployed in 3-D physical models of severely stenosed aortic valves. We hypothesize that applied polymeric biomaterials will fill and conform to irregular aortic valve geometries acting as a sealant to reduce paravalvular leak. Methods: Polymeric hydrogels were prepared from ABA block copolymer macromers composed of diacrylate terminated by PLA-b-PEG-b-PLA. Hydrogel networks were prepared by swelling these macromers, following the addition of free radical initiators. Hollow tubular constructs were formed via melt-processing in PDMS molds to fit as a “sleeve” around deployed PolyV® nitinol stent (Fig 1A). The sealing efficacy of polymers was examined using a silicone replica of CAVD aortic root with deployed stent + polymer construct (Fig 1B). A rubber stopper was used to fully occlude aortic lumen and restrict flow to paravalvular areas for quantitative analysis. To test sealing against hydrostatic pressure, valve construct was connected to Tygon tubing and water was added at equivalent 10 mmHg increments at 5-minute intervals. Volume from paravalvular flow was measured at each step. Experiments were performed with N = 4 polymeric sleeves. Results: We found significant reduction in paravalvular leakage with polymer sleeves compared to no polymer at all pressures tested. Figure 1C shows the mean ± standard deviation volume of water leaked over 5 minutes of corresponding hydrostatic pressure. No leakage was detected up to 60mmHg for all polymer sleeves tested. At approximately 85-90 mmHg, the rubber stopper failed, however the polymer sleeve remained intact. Conclusions: Polymeric paving utilized with TAVR is a promising combinative therapy for preventing paravalvular leakage. Our results indicate that potential polymeric biomaterials are capable of conforming to non-physiologic aortic valve morphologies, filling and sealing paravalvular gaps, while withstanding physiologic trans-aortic pressures. With further translation, polymer paving can be useful in improving TAVR outcomes.

On-demand heart valve manufacturing using focused rotary jet spinning

On-demand heart valve manufacturing using focused rotary jet spinning

Effect of laser power in laser powder bed fusion on Ni content and structure of Nitinol

Laser powder bed fusion (LPBF) additive manufacturing is capable of producing Nitinol stents of complex shapes, but a slight change of Ni content during LPBF can result in the stents not being suitable. Thus, there is a need to predict how laser power (P) and thus energy (E) affects the two important outcomes of Nitinol LPBF: defect level and Ni content. In this study, how Ni content may change during LPBF has been studied under two conditions: a sufficiently low P (thus E) but close to fully dense condition and a sufficiently high P that has caused keyhole pore formation. The loss of Ni has been found to be 0.36at% and 0.56at% for the sufficiently low and sufficiently high P conditions. Thus, 0.4–0.5at%Ni loss is expected for defect-free Nitinol LPBF. The morphological features of the melt pool affecting defect formation and relating to how P affects Ni loss will be discussed. With the significant loss of Ni due to LPBF, for the starting powder, which contains 50.5at%Ni and is fully austenitic, the LPBF as-built structure has remained mainly austenitic, but the samples also contain a small amount of martensite.

Transfistula antegrade interventions in the treatment of benign biliary strictures

Background. Primary reconstructive operations aimed at restoring the passage of bile are rather complicated due to the cicatricial process and in 1530% lead to a distant recurrence of the disease.&#x0D; Aim. To present the results of combined X-ray surgery and endoscopic transfistula antegrade interventions in the treatment of benign bile duct strictures.&#x0D; Material and methods. For the period from 2011 to 2019 31 patients with benign bile duct strictures were treated in the surgical departments of the City Clinical Hospital No. 14 in Yekaterinburg. The mean age of the patients was 60.312.7 years, the comorbidity index was 2.6. As follows from the presented data, in 13 patients the stricture developed in the area of biliodigestive anastomoses. Another 17 patients had stricture after surgery for cholelithiasis. In 1 case, there was a persistent narrowing of the lumen of the choledochus against the background of indurative pancreatitis. In 25 (80.6%) cases, the first step was percutaneous transhepatic cholangiostomy under ultrasound guidance. Another 6 (19.4%) patients had a T-shaped drainage of the choledochus.&#x0D; Results. For the treatment of strictures of the bile ducts, 97 operations were performed: an average of 3.1 operations per 1 patient. Lithoextraction with a wire basket was performed in 17 patients with calculi. 5 patients with stones larger than 10 mm required contact lithotripsy. Stricture was confirmed in 25 patients. Balloon dilatation was performed in 21 cases. In 8 cases, dilatation was supplemented with papillosphincterotomy. In 6 patients with deformation of the anastomosis zone, framed drainage was installed for 12 months. In 3 patients, bilioduodenal stenting with a nitinol stent was performed. It was not possible to recanalize the stricture in 4 (13%) cases. Complications were registered in 1 (3.2%) patient (IIIB degree according to ClavienDindo).&#x0D; Conclusion. Transfistula cholangioscopy is an effective endoscopic technology in the treatment of patients with benign bile duct strictures.

Long-Term Outcome of Bypass Surgery versus Endovascular Revascularization in Long Femoropopliteal Lesions.

Long-term follow-up data comparing surgical and endovascular revascularization of femoropopliteal lesions is rarely reported. This study presents 4-year results of revascularization for long femoropopliteal lesions (Trans-Atlantic Inter-Society Consensus Types C and D) with vein bypass (VBP), polytetrafluorethylene bypass (PTFE), and endovascular intervention with a nitinol stent (NS). Data from a randomized-controlled trial on VBP and NS was compared with a retrospective patient cohort using PTFE with the same inclusion and exclusion criteria. Primary, primary assisted, and secondary patency, as well as changes in Rutherford categories and limb salvage rates, are reported. Between 2016 and 2020, 332 femoropopliteal lesions underwent revascularization. The lesion lengths and basic patient characteristics were similar between the groups. 49% of the patients presented with chronic limb threatening ischemia at the time of revascularization. During the four-year follow-up, primary patency was comparable for all three groups. Primary assisted and secondary patency were significantly higher after VBP, while PTFE and NS had similar results. Clinical improvement was also significantly superior after VBP. After four years of follow-up, patency rates as well as the clinical outcome clearly favor VBP. If no vein is available, NS is as effective as PTFE bypass with regard to patency and clinical outcome.

Double-Barrel Nitinol Stent Placement for Iliocaval Reconstruction: The Effect of Deployment Sequence and Direction on Final Configuration

Double-barrel stent placement across the iliocaval confluence is commonly used for the treatment of chronic bilateral iliocaval occlusion. The difference in the deployment outcomes of synchronous parallel stent deployment versus asynchronous or antiparallel deployment and the underlying stent interactions are poorly understood. In this study, 3 strategies of double-barrel nitinol self-expanding stent deployment across the iliocaval confluence (synchronous parallel, asynchronous parallel, and synchronous antiparallel) were contrasted in vivo in 3 swine followed by assessment of the explanted stent construct. Synchronous parallel stent deployment achieved a desired double-barrel configuration. The asynchronous parallel and antiparallel deployment strategies both resulted in a crushed stent despite subsequent simultaneous balloon angioplasty. These animal model results suggested that in patients who undergo double-barrel iliocaval reconstruction, synchronous parallel stent deployment may provide the desired stent conformation and increase the chance for clinical success.

Treatment of Long Femoropopliteal Occlusive Lesions With Self-expanding Interwoven Nitinol Stent: 24 Month Outcomes of the STELLA-SUPERA-SIBERIA Register Trial.

The efficacy and safety of the Supera stent in superficial femoral artery (SFA) have been reported mostly in shorter lesions with relatively low proportion of occlusions. There are little data on the effectiveness of the Supera stent in long lesions. The aim of this study was to assess the clinical safety and efficiency of the Supera stent in the treatment of long femoropopliteal occlusive lesions (Trans-Atlantic Inter-Society Consensus [TASC] C/D) in patients with symptomatic peripheral artery disease. The STELLA-SUPERA-SIBERIA is a prospective, single-center, single-arm study. Patients with symptomatic (Rutherford stages 3-6) de novo and TASC C/D occlusive lesions of the femoropopliteal segment were treated with Supera stent. The primary endpoint was the 12 month rate of primary sustained clinical improvement (upward shift on the Rutherford classification to a one level without the need for repeated target lesion revascularization (TLR) in surviving patients without the need for unplanned amputation). Secondary endpoints were the 24 month of primary sustained clinical improvement, MALE, limb salvage, the primary patency, the secondary patency, 24 month MACE. Follow-up included clinical examination, duplex scan, and biplane x-ray up to 24 months. Between April 2019 and January 2020, 52 symptomatic patients with 55 long femoropopliteal occlusive lesions (52.7% TASC D lesions and 47.3% TASC C lesions) were treated. The mean target lesion length was 205±72 mm. All patients had total occlusions. The mean lesion length of the implanted Supera stents was 198±82 mm. At 12 and 24 months, the primary sustained clinical improvement rate was 80.2% and 63.6%, respectively. The Rutherford category assessment was significantly improved at 24 months compared with baseline (p=0.02). The primary patency rate at 12 and 24 months was 78.1% and 60.0%, respectively. At 12 and 24 months, freedom from TLR was 83.5% and 81.8%, respectively. There were no stent fractures at 24 months. Supera Stent implantation for TASC C/D femoropopliteal lesions revascularization appears to be a safe and efficient implant given the complexity of the treated lesions. Head-to-head studies are mandatory to establish Supera Stent as an alternative tool to open surgery for long femoropopliteal lesions. Our study indicated, that using self-expanding interwoven nitinol stent for TASC C/D femoropopliteal lesions revascularization appears to be a safe and efficient implant given the complexity of the treated lesions. Although bypass grafting is recommended for prolonged femoropopliteal lesions, open surgery is more traumatic and is associated with greater risks than endovascular procedures. Our findings suggest that the use of interwoven nitinol stents can overcome the disadvantages of traditional stents in such cases, which may help to improve patients' outcomes and reduce the risk of adverse events.

Endovascular Stent Thrombectomy in Patients With Acute Lower Limb Arterial Thrombosis on the Background of COVID-19

AIM Analysis of the outcomes of endovascular stent thrombectomy in patients with acute arterial thrombosis of the lower extremities on the background of COVID-19.MATERIAL AND METHODS This retrospective study for the period from January 1, 2020 to March 1, 2022 included 34 patients with acute lower limb ischemia who were diagnosed with the novel coronavirus infection SARS-COV-2. Endovascular stent thrombectomy was performed according to the standard technique using a Destination 8F guiding sheath (Terumo), an Advantage 0.014`` guidewire (Terumo), and a Casper stent (Microvention, Terumo) as a stent retriever. In case of fragmentation of thrombotic masses in the guide sheath, manual aspiration of thrombi was performed using a standard 50,0 ml syringe. Self-expanding nitinol stents were implanted in 11 clinical cases.RESULTS Intraoperative bleeding from the puncture site of the artery developed in 14.7% of cases, which required additional manipulation to achieve hemostasis. Every tenth (11.8%) patient developed myocardial infarction, in 2.9% of cases — ischemic stroke. In the hospital postoperative period during the first hours after surgery, 26.5% of patients developed rethrombosis which required re-intervention. In 8.8% of cases, retrombectomy was unsuccessful, and limb amputation was performed. A fatal outcome occurred in 67.6% of cases, which was due to an increase in multiple organ failure and the development of sepsis.CONCLUSION Endovascular stent thrombectomy is characterized by a low risk of rethrombosis and amputation in the context of COVID-19.

Development of innovative system of universal stent graft for endovascular treatment of aneurysm and aortic displacement in various locations

This study presents the technology of developing a universal stent graft for endovascular treatment of aneurysms and aortic dissection of various localizations, without considering the vessel diameter. A self-expanding nitinol stent was used as the frame of the main trunk of the stent graft. During the study, several variants of the aortic linear graft were manufactured and tested. The optimal stiffness and diameter of the nitinol wire were selected based on the results. When creating a bifurcation module, special attention was paid to simplifying the positioning and intravascular assembly of the structure. Implantable modules have been developed for the prosthetics of the main branches of the aorta. Dacron, optimal in terms of fiber structure, was chosen as the material of the woven shell of the graft. Linear extensibility, compactness of the pile, and tensile strength during fenestration were evaluated. To determine the heparin-controlled surgical porosity, experimental samples of stent grafts were tested on a stand simulating arterial blood flow. The wall material of the developed device had a heparin-controlled surgical porosity of 50150 mL/min/cm2 at 120 mm Hg with the possibility of maintaining a controlled endolic. The graft wall created a pressure gradient of no more than 3 mm Hg, and the flow velocity indicators were quite sufficient for adequate perfusion of vital organs. After the inactivation of heparin, blood permeability became zero. The implantation technique of the developed product was implemented on a silicone aortic phantom simulating aneurysm expansion with and without dissection. The phantom contour was filled with a solution simulating the rheological properties of native blood. Pulsating blood flow was simulated using a perfusion pump. Under X-ray control, a stent graft was installed on five large biological samples (sheep). Implantation was performed in the aortic arch with prosthetics of the brachiocephalic trunk and the suprarenal aorta with prosthetics of the visceral branches. With the experiment, we hope that the result will allow us to minimally invasively help patients suffering from aneurysms of any localization.

Migration of endothelial cells on the surface of anodized Ni-Ti stent strut.

Stent is widely regarded as the main treatment for curing cardiovascular diseases such as stenosis. Previous research has revealed that the damage of endothelial cells (EC), i.e., the components of endothelium, during stent implantation, could lead to severe complications, such as restenosis. To prevent restenosis, enhancements have been made to surface biocompatibility to accelerate the stent endothelialization process. Anodization on the Ni-Ti is a simple and efficient surface modification method to improve the biocompatibility of the Ni-Ti stent surfaces by enhancing the surface hydrophilicity, leading to an increase in the EC activities. The EC activity is known to be affected by the blood flow. Flow change by stent structure may result in EC dysfunctions, thereby leading to restenosis. It is thus essential to investigate the EC activities resulting from the anodization on the Ni-Ti surface under flow conditions. To study the influence of the endothelialization process on the Ni-Ti stent surface through anodization. The EC attachment and morphology on the anodized stent strut were observed under both with and without the flow conditions. A parallel plate flow chamber was designed to generate a constant wall shear stress (WSS) to study the flow effect on the EC behavior. The hydrophilicity of the Ni-Ti stent strut surface was enhanced by a TiO2 layer fabricated via anodization. The EC distribution on the surface of the anodized nitinol stent strut was observed after 24 h of static (without flow) and flow exposure (with flow) experiment. Under the static condition, the EC density on the surface of the anodized Ni-Ti stent strut was higher compared with the control. Under the flow condition, the enhancement of the EC density on the surface of the stent strut with anodization was reduced. The EC demonstrates a long and thin spindle-shaped morphology under the flow condition. Unlike the static condition, the EC is demonstrating a long and thin morphology in response to the flow under the flow condition. By improving the surface hydrophilicity, the anodization could enhance the EC migration onto the strut surface, and subsequently, accelerate the Ni-Ti stent endothelialization process. The improvement of the surface hydrophilicity is lower under the flow conditions when compared with the static conditions.

Not only acute respiratory failure: COVID-19 and the post-intubation/tracheostomy upper airways lesions†.

An increasing number of patients have been subjected to prolonged invasive mechanical ventilation due to COVID-19 infection, leading to a significant number of post-intubation/tracheostomy (PI/T) upper airways lesions. The purpose of this study is to report our early experience in endoscopic and/or surgical management of PI/T upper airways injuries of patients surviving COVID-19 critical illness. We prospectively collected data from patients referred to our Thoracic Surgery Unit from March 2020 to February 2022. All patients with suspected or documented PI/T tracheal injuries were evaluated with neck and chest computed tomography and bronchoscopy. Thirteen patients (8 males, 5 females) were included; of these, 10 (76.9%) patients presented with tracheal/laryngotracheal stenosis, 2 (15.4%) with tracheoesophageal fistula (TEF) and 1 (7.7%) with concomitant TEF and stenosis. Age ranged from 37 to 76 years. Three patients with TEF underwent surgical repair by double layer suture of oesophageal defect associated with tracheal resection/anastomosis (1 case) or direct membranous tracheal wall suture (2cases) and protective tracheostomy with T-tube insertion. One patient underwent redo-surgery after primary failure of oesophageal repair. Among 10 patients with stenosis, two (20.0%) underwent primary laryngotracheal resection/anastomosis, two (20.0%) had undergone multiple endoscopic interventions before referral to our Centre and, at arrival, one underwent emergency tracheostomy and T-tube positioning and one a removal of a previously positioned endotracheal nitinol stent for stenosis/granulation followed by initial laser dilatation and, finally, tracheal resection/anastomosis. Six (60.0%) patients were initially treated with rigid bronchoscopy procedures (laser and/or dilatation). Post-treatment relapse was experienced in 5 (50.0%) cases, requiring repeated rigid bronchoscopy procedures in 1 (10.0%) for definitive resolution of the stenosis and surgery (tracheal resection/anastomosis) in 4 (40.0%). Endoscopic and surgical treatment is curative in the majority of patients and should always be considered in PI/T upper airways lesions after COVID-19 illness.

Fabrication of the locally reinforced open-cell nitinol stents for intracranial vascular aneurysm

ABSTRACT Intracranial vascular stent-assisted coil embolization has been widely used for intracranial vascular aneurysm. However, there are serious complication risks, such as thromboembolism, stent migration and spring coil prolapse, due to the inappropriate radial force, poor wall apposition and oversized mesh. Therefore, a locally-reinforced intracranial vascular stent was designed to improve the radial force and wall apposition performance. Based on finite element analysis and substantial measurements, the local radial force has improved 38.9% and thestability of the coil embolism has been enhanced as well. The releasing test in vitro suggests the stent can adhere to the vascular wall very well without the ‘Gator backing’ phenomenon. Furthermore, the implanting test in vivo shows complete endothelialization without restenosis and hyperplasia in 4 weeks. The outcomes of this study provide optimal design of the locally reinforced nitinol stent used for intracranial aneurysm therapy with reduced risks of vascular embolism and haemorrhagic apoplexy after implantation.

Novel Self-Expanding Interwoven Nitinol Stent for Treating Femoropopliteal Artery Disease: 12-Month Results of Single-Center First-in-Man Study

Purpose: To evaluate the safety and efficacy of Innospring® stent, a novel self-expanding interwoven nitinol stent, in treating femoropopliteal atherosclerotic lesions. Methods: A prospective, single-center, single-arm, first-in-human study enrolled 15 patients (mean age 73.1 years; 13 men) to evaluate the safety and efficacy of the Innospring® stent monitored by core laboratories. The inclusion criteria were claudication or ischemic rest pain, de novo lesions or nonstented restenosis, >70% stenosis, lesion length <20 cm, and a reference vessel diameter of 4–7 mm. The primary safety endpoint was 30-day major adverse events. The primary efficacy end point was stent patency at 12 months. Follow-up evaluations were conducted at 30 days, 6 months, and 12 months. Results: The lesion length was 6.1 ± 3.5 mm. Fourteen (93.3%) patients had lesions of the superficial femoral artery and 3 (20.0%) patients had lesions of the popliteal artery. Nine (60.0%) patients had moderate-to-severe calcified lesion. Technical and procedural success was 100%. No patients experienced major adverse events in the first 30 days. The Rutherford category showed significant and sustained improvement at 6 and 12 months. The 12-month follow-up radiographs obtained in 13 patients confirmed the absence of stent fractures in 100% of examinations. The cumulative primary stent patency rate at 6 and 12 months were 93.3% and 84.6%, respectively. Conclusion: Stenting of the superficial femoral and popliteal arteries using the Innospring® stent is safe and effective. This competing interwoven nitinol stent may provide superior stent integrity and fracture-resistance as well as serve areas under extreme mechanical stress. Clinical Impact Endovascular recanalization is a widely accepted and recommended treatment for symptomatic peripheral artery diseases. The Innospring® stent is a novel self-expanding interwoven stent containing eight nitinol wires with additional radial force, fracture-resistance, and visibility under fluoroscopy. This first-in-human study using the Innospring® stent in patients with femoropopliteal occlusive disease reported that stenting of the superficial femoral and popliteal arteries using the Innospring® stent is safe and effective. This competing interwoven nitinol stent may provide an impressive stent integrity and fracture-resistance as well as serve areas under extreme mechanical stress.

A Giant Thoracic Aortic Aneurysm Treated by Frozen Elephant Trunk Technique

The treatment of complex aortic pathologies involving the ascending aorta, the aortic arch, and the descending aorta continues to be a challenging situation in aortic surgery. The frozen elephant trunk technique has been increasingly used but there still is an ongoing discussion within the surgical community about the optimal indications. We present herein a patient with a complex aortic aneurysm involving all three segments of the thoracic aorta. The device used is a hybrid prosthesis consisting of a proximal woven polyester graft and a distal self-expanding nitinol stent graft, which can be delivered antegrade into the descending aorta.

Wirelessly powered deformable electronic stent for noninvasive electrical stimulation of lower esophageal sphincter

Electrical stimulation is a promising method to modulate gastrointestinal disorders. However, conventional stimulators need invasive implantation and removal surgeries associated with risks of infection and secondary injuries. Here, we report a battery-free and deformable electronic esophageal stent for wireless stimulation of the lower esophageal sphincter in a noninvasive fashion. The stent consists of an elastic receiver antenna infilled with liquid metal (eutectic gallium-indium), a superelastic nitinol stent skeleton, and a stretchable pulse generator that jointly enables 150% axial elongation and 50% radial compression for transoral delivery through the narrow esophagus. The compliant stent adaptive to the dynamic environment of the esophagus can wirelessly harvest energy through deep tissue. Continuous electrical stimulations delivered by the stent in vivo using pig models significantly increase the pressure of the lower esophageal sphincter. The electronic stent provides a noninvasive platform for bioelectronic therapies in the gastrointestinal tract without the need for open surgery.

A133 PORTAL VENOUS STENTING FOR THE TREATMENT OF NON-CIRRHOTIC PORTAL HYPERTENSION-RELATED GASTRIC ANTRAL VASCULAR ECTASIA: A CASE REPORT

Abstract Background Pancreatic and hepatobiliary cancers account for 15-24% of extrahepatic portal hypertension. Treating portal hypertensive bleeding associated with these tumors has been challenging with the delayed effect of chemoradiation and patients with active bleeding being unfit for such therapies. Portal vein stenting has been described in the literature for the treatment of variceal bleeding in such patients. We present the first report of its use for the successful treatment of refractory gastric vascular ectasia (GAVE)-related bleeding. Purpose To review portal vein stenting as a treatment for non-cirrhotic portal hypertension-related GAVE bleeding. Method Chart review was performed with the patient's informed consent. Result(s) A 53-year-old female patient with locally invasive pancreatic cancer presented with one week of melena and presyncope. She had a history of gastroesophageal reflux disease. Her tumor encased the celiac trunk, hepatic and splenic arteries, and abutted the superior mesenteric artery. She had been treated with chemotherapy and radiation. On examination, she was afebrile, blood pressure was 132/87, pulse 110 beats/min, and oxygen saturation 99% on room air. Her abdomen was soft and non-tender. Her hemoglobin was 63 g/L, which represented a 64-point drop over 4 months, leukocytes 4.5 x109/L, platelets 238 x109/L, INR 1.1 and normal electrolytes and creatitine. Alkaline phosphatase was 399 U/L, aminotransferases normal, albumin 38 g/L and total bilirubin 6 umol/L. She was started on pantoprazole and octreotide. On admission, gastroscopy revealed copious blood in the stomach with no clear source despite gastric lavage; hemospray was applied. Given persistent bleeding, repeat gastroscopy the following day revealed 4 columns of Baveno grade III esophageal varices with no high-risk stigmata, as well as severe portal hypertensive gastropathy and GAVE. Argon plasma coagulation and esophageal banding were performed. Over the next month, she continued to have maroon-colored stools. CT angiogram revealed portal vein occlusion and contrast extravasation within the gastric lumen, in keeping with her known gastric antral bleed, with no evidence of lower gastrointestinal bleeding. She had 5 further gastroscopies where APC and GAVE banding were performed. Despite that, she developed hematemesis. Interventional radiology was consulted and performed transhepatic portal venous recanalization, angioplasty and stenting using a 10mm x 60mm self expandable nitinol stent from the superior mesenteric vein to the main portal vein. After stenting, previously seen collateral veins and cavernous transformation were significantly reduced on angiography. She was started on clopidogrel to maintain stent patency. Two days following stent insertion, she stopped clinically bleeding and her hemoglobin stabilized. She was discharged home one month later. Conclusion(s) In patients with GAVE-related bleeding refractory to standard therapeutics, portal venous stenting is possibly an effective treatment modality. Please acknowledge all funding agencies by checking the applicable boxes below None Disclosure of Interest None Declared