Stent Fracture Research Articles

Improvement of Cu and Zr doped Diamond-like carbon coatings on comprehensive performance of Ni-Ti alloy potentially used in braided vascular stent

Wear and corrosion between braided wires will not only release toxic nickel ions, but also cause fatigue fracture of Ni-Ti alloy-based braided stents. In this study, Cu and Zr doped Diamond-like carbon (DLC) film containing Cr intermediate layer and Cr:C gradient layer were prepared with the total thickness of about 2.17 μm and 2.05 μm, respectively. In order to study the improvement of DLC coating on the comprehensive properties of Ni-Ti based stent, the nano-mechanical, tribological, electrochemical corrosion, nickel ion release and cytotoxicity properties were all evaluated. The results showed that the nano hardness and elastic modulus for Zr-DLC film were 12.32 GPa and 138.49 GPa, respectively increased by 192% and 102% compared with bare NiTi. Cu-DLC and Zr-DLC coatings can not only significantly reduce the friction coefficient, but also greatly reduce the wear rate such as by three orders of magnitude in dry sliding condition compared with bare NiTi. Zr-DLC film reduced the icorr value with a reduction amount of 96.1%, with the values of 8.41 × 10−8 and 3.26 × 10−9 A/cm2 for NiTi and Zr-DLC, respectively. After 28 days of soak experiment in phosphate buffer solution, the total nickel ion release amount was only 5.6 ng/L for Cu-DLC and 6.9 ng/L for Zr-DLC, which was reduced by 96.1% and 95.2%, respectively. The relative cell proliferation rate results showed that NiTi and Zr-DLC were both Grade 0, which indicated good cytotoxicity result. However, the cytotoxicity of Cu-DLC reached grade 2 (the relative cell proliferation rate was 71.73%). Based on the above results, Zr-DLC showed good comprehensive performances and was expected to be used as a protective layer on the surface.

Prospective, Multicenter, Observational Study to Evaluate a Cell-Impermeable Endoprosthesis for Treatment of Stenosis or Occlusion within the Dialysis Outflow Circuit of an Arteriovenous (AV) Fistula or AV Graft (The WRAP Registry)

PurposeDysfunctional vascular access due to stenosis/occlusion within the arteriovenous fistula or graft (AVF/AVG) negatively affects the clinical management of patients undergoing hemodialysis. Results from the feasibility study of the WRAPSODY™ Cell-Impermeable Endoprosthesis demonstrated that the device can achieve high patency rates and maintain integrity of the dialysis outflow circuit. This study was designed to assess real-world evidence of safety and efficacy outcomes following device placement.Materials and MethodsThis is a prospective, multicenter, non-investigational, post-market observational study of 500 patients at up to 50 centers worldwide with a mature AVF/AVG dialysis access (≥ 1 hemodialysis session) who experience stenosis/occlusion of the outflow circuit prior to placement of WRAPSODY. Patients will be divided into the following two cohorts: peripheral or central thoracic. Primary outcome measures include target lesion primary patency (TLPP) at 6 months and procedure and/or device-related events through 30 days post-procedure. Secondary outcome measures include TLPP, safety events, and the number of interventions needed to maintain patency through the 24 month study period. Exploratory endpoints include time to access abandonment, resumption of successful dialysis, functional patency, and pending available imaging data, any incidence of stent fractures, migration, or edge stenosis. Study enrollment began in June 2022, the last patient visit is expected in 2026.DiscussionIt is expected that this study will provide real-world evidence regarding the performance of the WRAPSODY device in a diverse population of patients, which may encourage its use in the continuum of hemodialysis access management.Trial RegistrationNCT05062291Graphical

Long-term follow-up after endovascular treatment of aortic coarctation with bare and covered Cheatham platinum stents.

Endovascular treatment of aortic coarctation (CoA) in children and adults frequently requires stent implantation. The aim of this study was to analyze long-term results after CoA treatment with bare and covered Cheatham-PlatinumTM (CP) stents in our institution and to derive recommendations for the differential use of these stent types. In this retrospective single institution study, 212 patients received endovascular CoA treatment with bare (n = 71) and covered (n = 141) CP stents between September 1999 and July 2021, respectively. The indications for treatment were native CoA in 110/212 patients (51.9%) and re-coarctation after primary surgical or interventional treatment in 102/212 patients (48.1%). Median patient age at endovascular CoA treatment was 18.8 years [IQR 11.9; 35.8]. Long-term follow-up was available in 158/212 patients (74.5%) with a median follow-up of 7.3 years [IQR 4.3; 12.6]. Procedural success was achieved in 187/212 (88.2%) patients. Survival rate was 98.1% after 5, and 95.6% after 10 and 15 years, respectively. The probability of freedom from re-intervention was 93.0% after 5, 82.3% after 10 and 77.8% after 15 years, respectively. Freedom from re-interventions (44/158, 27.8%) did not differ between patients who received bare or covered CP stents (p = 0.715). Multivariable risk factor analysis identified previous CoA surgery (HR: 2.0, 95% confidence interval (CI): 1.1-3,9, p = 0.029), postdilatation (HR: 2,9, 95% CI: 1.1-6.3, p = 0.028) and age at intervention (HR: 0.96, 95% CI: 0.94-0.99, p = 0.002) as independent risk factors for re-intervention. Peri-procedural complications occurred in 15/212 (7.1%) patients (dissection/thrombosis of vascular access vessel: n = 9; bleeding: n = 1; stent dislocation: n = 2; aortic dissection/aortic wall rupture: n = 3). Long-term complications were observed in 36 patients and included stent fracture (n = 19), aneurysm formation (n = 14), endoleak (n = 1) and subclavian artery stenosis (n = 2). Peri-procedural and long-term complications did not differ between patients who received CoA treatment with bare or covered CP stents (all p > 0.05). Endovascular treatment of CoA using bare or covered CP stents can be performed safely and effectively with excellent long-term results. Survival, re-intervention and complication rate did not significantly differ between both stent types. However, individual stent selection is advisable with regard to CoA morphology and severity as well as patient age.

Mechanisms and treatment outcomes of ostial right coronary artery in-stent restenosis.

Despite a high rate of in-stent restenosis (ISR) after stenting the right coronary artery (RCA) ostium, the mechanism of ostial RCA ISR is not well understood. We aimed to clarify the cause of ostial RCA ISR using intravascular ultrasound (IVUS). Overall, 139 ostial RCA ISR lesions were identified with IVUS, pre-revascularisation. Primary ISR mechanisms were classified as follows: 1) neointimal hyperplasia (NIH); 2) neoatherosclerosis; 3) ostium not covered by the stent; 4) stent fracture or deformation; 5) stent underexpansion (old minimum stent area <4.0 mm2 or stent expansion <50%); or 6) a protruding calcified nodule. The median duration from prior stenting was 1.2 (first quartile 0.6, third quartile 3.1) years. The primary mechanisms of ISR were NIH in 25% (n=35) of lesions, neoatherosclerosis in 22% (n=30), uncovered ostium in 6% (n=9) (biological cause 53%, n=74), stent fracture or deformation in 25% (n=35), underexpansion in 11% (n=15), and protruding calcified nodules in 11% (n=15) (mechanical cause 47%, n=65). Including secondary mechanisms, 51% (n=71) of ostial RCA ISRs had stent fractures that were associated with greater hinge motion of the ostial-aorta angle during the cardiac cycle. The Kaplan-Meier rate of target lesion failure at 1 year was 11.5%. When the mechanically caused ISRs were treated without new stents, they suffered a higher subsequent event rate (41.4%) compared with non-mechanical causes or mechanical causes treated without restenting (7.8%, unadjusted hazard ratio 6.44, 95% confidence interval: 2.33-17.78; p<0.0001). Half of the ostial RCA ISRs were due to mechanical causes. Subsequent event rates were high, especially in mechanically caused ISRs treated without the implantation of a new stent.

Outcomes of Using Balloon-Expandable Covered Stent for Percutaneous Treatment of Access-Site Vascular Injury after Transfemoral Aortic Valve Implantation: A Single Center Experience

Access-site vascular injury (ASVI) remains a challenge for transfemoral transcatheter aortic valve implantation (TAVI). Although surgery is the gold standard, endovascular therapy gains growing acceptance as primary treatment option for ASVI. The aim of this study was to analyze the safety and efficacy of covered balloon-expandable stents (BXSs) placement for ASVI after transfemoral TAVI. All patients treated with a covered BXS between January 2018 and December 2020 for access-site related bleeding complications following femoral TAVI were included in this single center retrospective study. Primary measure outcome of this study was the primary patency at 12months. Technical success, limb clinical worsening and device related complications were additionally analyzed. During the study period, 576 percutaneous femoral TAVIs were performed. Of these, 36 patients (6%) underwent covered stent deployment for a femoral access-site complication (19 men, median age 83years old). Procedural success was 97%. The median follow-up was 12months (interquartile range [IQR]=9.7, range 0-36months). One patient was lost to follow-up. The primary patency rates at 6 and 12months were 100% and 95% respectively. No clinical deterioration or stent fracture was described during this period. Our results suggest that covered BXS deployment is a safe and effective alternative to surgery and may be a promising option for treating ASVI after femoral TAVI.

Fatigue strength and life prediction of lower limb venous stents under three-stage loading conditions

After the implantation of lower limb artery stents, the complex loading conditions imposed on the limb can lead to fatigue failure, which may induce inflammation and restenosis. To investigate the effect of multi-axial loading conditions on the fatigue performance of stents, five stents, namely APsolute Pro (APbott Vascular, USA), Complete SE (Medtronic, USA), Protégé EverFlex (PE3, USA), Pulsar-35 (Biotronik, Germany), and E-luminexx-B (Bard, USA), were analyzed based on the finite element method (FEM). Besides, their fatigue strength was determined under three levels of loading conditions, including tension-bending-torsion and compression-bending-torsion. Based on that, the fatigue life of these stents was predicted. The results showed that based on the nominal stress method, tension-bending-torsion loading had a more significant impact on the fatigue life of stents than compression-bending-torsion loading. Besides, two different types of initial cracks were analyzed by the fracture mechanics method. The results suggested that both the initial crack and the external load were the main causes of stent fatigue fractures. Compared with the loading nature, the influence of the initial crack on stent fatigue life was more significant. Under the same loading condition, the APsolute Pro stent had the longest fatigue life, while the E-luminexx-B stent had the shortest. Moreover, the mechanism of stent fatigue failure was revealed by exploring the fatigue performance and life prediction of stents under complex loading conditions. These findings have important implications for improving the structural design of stents and their clinical selection.

Use of Zephyr stent in congenital heart diseases: A single-center study.

Large vessel stenosis is currently successfully treated with percutaneous stent implantation. Zephyr stent is a cobalt-chromium peripheral stent specifically designed for large-vessel stenting. Its specific "S-" and "C-" shaped flexible polylinks prevent stent foreshortening and recoil. We report our experience of using Zephyr among the pediatric population and their medium-term outcome. The study included a total of 19 patients treated with 21 Zephyr stents. The indications for stenting included coarctation of the aorta (four patients), stenosed pulmonary artery (eight patients), stenosed right ventricular outflow tract (five patients) or conduit (one patient), and percutaneous Fontan (one patient). All the procedures were successful. None of the patients showed any stent-related complications. Stent fractures, foreshortening, or recoil were not seen during follow-up. Our medium-term (1-20 months) follow-up showed a favorable outcome. One patient developed restenosis. Zephyr stent is a good therapeutic option for large-vessel stenting. However, it needs large-scale studies for further confirmation.

The Use of Viatorr Stent at the Thoracic Outlet to Maintain Hemodialysis Access Function.

Venous steno-occlusive disease at the thoracic outlet affects up to 30% of the hemodialysis population [1] causing arm swelling and hemodialysis access dysfunction. Balloon angioplasty in this region can be of limited utility given the rigid compressive effect of surrounding musculoskeletal (MSK) structures. Outcomes of using the Viatorr endoprosthesis (Gore Viatorr TIPS Endoprosthesis, Gore, Flagstaff AR, USA, Viatorr ®) within this region to salvage the HD access in patients who presented with dialysis access dysfunction is presented. A retrospective chart review was performed of our tertiary and quaternary care hospital system. Hemodialysis patients were included in the study if they were using an upper extremity arteriovenous fistula or graft for access, had a Viatorr stent placed in the central (subclavian and/or brachiocephalic) veins, and had follow up. A total of nine patients were identified to meet the inclusion criteria. Four interventions were due to refractory lesions of the subclavian or brachiocephalic veins, and the other five interventions were for hemodynamically significant lesions refractory to angioplasty alone, all resulting in access dysfunction. Primary patency ranged from 36-442days (geometric mean 156.6days, range 19-442days). No stent fracture was identified on imaging at any point during follow-up of these patients out to a maximum of 2912days (Average 837days). The Viatorr stent graft used in the HD population for clinically significant lesions at the thoracic outlet (TO) showed no structural failures (fractures) in this cohort.

Aortic Coarctation Stenting in Adolescents and Adults: A Single-Center Experience.

The aim of this study was to evaluate the short and midterm results of aortic coarctation (AoCo) stenting in an adolescent and adult population. All patients with a AoCo older than 14years treated by stent placement between December 2000 and November 2016 were included in this study. Twenty-eight patients with an invasive peak systolic pressure gradient >20mmHg were identified. Number of redilations, non-invasive systolic blood pressure, peak systolic pressure gradient, antihypertensive medication intake, claudication status and complications were evaluated. Twenty-two covered and 6 uncovered stents were successfully placed. Peak systolic pressure gradient decreased immediately after stenting from a mean of 32 mmHg to 0mmHg (± 7mmHg). Mean AoCo diameter increased from 8 tot 16mm (± 4mm). Peripheral arterial injury was seen in 2 patients (7.1%). The mean follow-up time was 60 ± 49months. Redilation of the stent was required in 4 patients, 2 to accommodate for growth and 2 for restenosis. Six (35%) patients could stop all antihypertensive medication. All claudicants (6/28) became and remained asymptomatic after surgery and during their follow-up. No aneurysms, stent fractures or dissections were noticed. There were 2 stent migrations during the first procedure with only 1 needing additional stent placement. Aortic coarctation stenting is a safe and effective treatment that significantly reduces the peak systolic pressure gradient. Antihypertensive medication can be reduced, and increase of walking distance in claudicants can be obtained. Younger patients may need more frequent reinterventions to accommodate for growth.

Recurrent Stent Fracture Due to Myocardial Bridging: A Brief Report and Review of Published Cases

Recurrent Stent Fracture Due to Myocardial Bridging: A Brief Report and Review of Published Cases

Solving Intraoperative Complications During Endovascular Repair of Late Contained Ruptured Aortic Pseudoaneurysm After Surgical De-coarctation: Case Report and Systematic Review of Literature.

We present a case of successful endovascular repair of late ruptured aortic anastomotic pseudoaneurysm following previous left subclavian artery-descending thoracic aorta bypass and concomitant emergency thoracic endovascular aortic repair (TEVAR) of complicated endovascular aortic de-coarctation never previously described is also presented. A review of the intraoperative, 30-day, and follow-up morbidity, mortality, and complications of TEVAR as endovascular treatment of late aneurysm/pseudoaneurysms after surgical aortic de-coarctation was also performed. The systematic review was performed in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement and following PICO model. A literature search was conducted on MEDLINE, PubMed, EMBASE, Cochrane Library, Google Scholar, Science Direct, and Web of Science using the words "tevar of late complication of aortic coarctation surgical repair" and "endovascular repair of anastomotic pseudoaneurysm in coarctation" up to June 17, 2022. Data were extracted from study documents about study design, patient's demographics and comorbidities, details about primary surgical repair, type of late complication, time between open surgery and occurrence of complications, details of the secondary endovascular procedure with technical success, early, and follow-up mortality and morbidity. A total of 18 papers were included with 78 patients (48 men, 69.5%). The most frequent type of primary open surgical repair was patch aortoplasty (46, 58.9%). Focusing on aneurysm and pseudoaneurysm as late complications, most of the patients were asymptomatic (45, 57.7%). All patients underwent TEVAR, 14 of them (17.9%) in urgent/emergent setting. The technical success was 98.7%, with 1 intraoperative death due to rupture of the aorta. In total, 31 patients out of 78 (39.7%) showed different complications in the immediate postoperative time, with type II endoleak being the most observed (8/31, 25.8%). The mean follow-up time was about 2 years (26.5 months, range 3-92). Overall, 30-day mortality was 2.6%. Complications occurred in 30 patients (39.4%), 23 of them resolved during the follow-up period. With the limit of low-quality data, TEVAR can be considered a safe and effective option for the treatment of late complications after open surgery for aortic coarctation, even in urgent settings. Different specialists have to face the technical complexities and risks related to treatment of late complications after surgical de-coartaction, which can be either surgical or endovascular, and depend on patient's ages. Although covered stents appear to have some protection from the development of stent fractures, doesn't provide complete protection from late aneurysm formation. In this setting, TEVAR may represent a valuable option, combining the advantages of the covered stent with those of a device that can cover a wider range of aortic length, especially in adult patients. This study shows thoracic endovascular repair can be considered a safe and effective option in clincal practice for the treatment of late complications after open surgery for AC, even in urgent settings.

THE RISKS AND BENEFITS OF RENAL ARTERY STENTING IN FIBROMUSCULAR DYSPLASIA. LESSONS FROM ARCADIA-POL STUDY

Objective: Percutaneous transluminal angioplasty (PTA) is the recommended revascularization strategy in patients with renal artery stenosis (RAS) caused by fibromuscular dysplasia (FMD), limiting stenting to complications management. However this recommendation is based on cases reports and small series. The main aim of the study was to retrospectively analyze immediate and long-term results of renal stenting and PTA in FMD patients. The second aim was to evaluate the results of stenting as support of renal artery aneurysm (RAA) closure. Design and method: The study group consisted of 58 patients percutaneously treated due to significant RAS (70 arteries) and 9 patients (10 RAAs) with a history of stent implantation before aneurysm embolization, derived from 343 ARCADIA-POL registry patients. PTA was performed as initial treatment in 61 arteries (PTA-group), whereas primary stenting was done in 9 arteries (STENT-group). Stent-related complications(SRC) were defined as: in-stent restenosis (&gt;50%) or occlusion (ISR/O); stent fracture; stent underexpansion (SU) or migration. Results: In PTA-group, the first restenosis rate was 50.8%. Subsequently, 22 arteries underwent a second procedure: re-PTA(12 arteries) or stent implantation(10 arteries) . The incidence of recurrent restenosis after re-PTA was 41.7%. In the 10 arteries initially treated with PTA that underwent stenting for restenosis, complications occurred in 7 of them (70%), including 2 SUs and 5 ISR/Os . In STENT-group, SU occurred in one case (11.1%) and in-stent restenosis in 33.3% (3 of 9 stents). In combined analysis, SRC occurred following 11/19 stenting procedures (57.9%) including 3 periprocedural (SUs) and 8 late complications (ISR/Os). Finally, despite several subsequent revascularization attempts, 4 of 19 (21%) stented arteries were totally occluded and one remained significantly stenosed at follow-up imaging (Figure). In contrast to FMD-RAS procedures, there was only one intraprocedural complication (partial stent migration) and no late SRC in RAA patients. Conclusions: Renal artery stenting in FMD provides modest benefit in terms of restenosis prevention but poses high risk of immediate and late complications, including stent occlusion. Our study supports recommendations limiting stenting to the management of complications. In contrast, renal artery stenting in FMD RAA closure is associated with favorable long-term outcomes.

Fracture and embolization of a metal stent after a frozen elephant trunk procedure.

The Frozenix J graft open stent graft has been available since 2014 in Japan. This stent is widely used for the frozen elephant trunk technique in many institutions, mainly for cases of acute type A aortic dissection and also for cases of a true aneurysm and chronic aortic dissection. We treated a rare case in which the metal wires of the Frozenix J graft were broken and embolized to the periphery half a year after being implanted.

Carotid Stent Durability: The Incidence of Carotid Stent Fracture and the Associated Implications

Carotid Stent Durability: The Incidence of Carotid Stent Fracture and the Associated Implications

Novel Surgeon-Modified Fenestrated Iliac Stent Graft.

We describe the feasibility and early results of a novel endovascular approach with a surgeon-modified fenestrated iliac stent graft to preserve pelvic perfusion in patients with iliac aneurysms not suitable for iliac branch devices (IBDs). Seven high-risk patients, median age 76 years (range 63-83), with a complex aortoiliac anatomy with contraindications for commercially available IBDs were treated with a novel surgeon-modified fenestrated iliac stent graft between August 2020 and November 2021. The modified device was built using an iliac limb stent graft (Endurant II Stent Graft; Medtronic), which was partially deployed, surgically fenestrated with a scalpel, reinforced, re-sheathed, and inserted via femoral access. The internal iliac artery was cannulated and bridged with a covered stent. Technical success rate was 100%. After a median follow-up period of 10 months, there was 1 type II endoleak and no migrations, stent fractures, or loss of device integrity. One iliac limb occlusion occurred after 7 months, which needed a secondary endovascular intervention, restoring patency. Surgeon-modified fenestrated iliac stent graft is feasible and might be used as an alternative in patients with a complex iliac anatomy not suitable to commercially available IBDs. Long-term follow-up is needed to evaluate stent graft patency and potential complications. Surgeon modified fenetrated iliac stent grafts might be a promising alternative to iliac branch devices, extending endovascular solutions to a broader patient population with complex aorto-iliac anatomies preserving antegrade internal iliac artery perfusion. It is possible to treat small iliac bifurcations and large angulations of the iliac bifurcation safely and there is no need for a contralateral or upper-extremity access.

CMR and Percutaneous Treatment of Pulmonary Regurgitation: Outreach the Search for the Best Candidate.

Performance of cardiovascular magnetic resonance (CMR) in the planning phase of percutaneous pulmonary valve implantation (PPVI) is needed for the accurate delineation of the right ventricular outflow tract (RVOT), coronary anatomy and the quantification of right ventricular (RV) volume overload in patients with significant pulmonary regurgitation (PR). This helps to find the correct timings for the intervention and prevention of PPVI-related complications such as coronary artery compression, device embolization and stent fractures. A defined CMR study protocol should be set for all PPVI candidates to reduce acquisition times and acquire essential sequences that are determinants for PPVI success. For correct RVOT sizing, contrast-free whole-heart sequences, preferably at end-systole, should be adopted in the pediatric population thanks to their high reproducibility and concordance with invasive angiographic data. When CMR is not feasible or contraindicated, cardiac computed tomography (CCT) may be performed for high-resolution cardiac imaging and eventually the acquisition of complementary functional data. The aim of this review is to underline the role of CMR and advanced multimodality imaging in the context of pre-procedural planning of PPVI concerning its current and potential future applications.

Bare Stent Fracture After TEVAR With the Modified Restrictive Bare Stent (RBS) Technique in Type B Aortic Dissections.

The aim was to assess the mid-term aortic remodeling and bare-metal stent (BMS) integrity of the restricted bare stent (RBS) technique reconstruction in aortic dissections. This retrospective cohort study included prospectively collected patients treated with the modified RBS technique between 2017 and 2020. The preoperative, postoperative, and last follow-up computed tomographic (CT) scans were analyzed in the centerline at the mid-descending, celiac trunk (CeT), and the mid-abdominal levels for false lumen (FL) patency, aortic diameter, and true lumen (TL) diameter changes. Bare-metal stent integrity was assessed in the 3-dimensional multiplanar reformats. The median follow-up of the cohort (n=17) was 26 (11, 45) months. The procedure was mainly performed with the Relay NBS endograft (15/17; 88%) + E-XL BMS (17/17; 100%). Postoperative mortality, paraplegia, stroke, renovisceral vessel loss, and type I and III endoleaks were not observed. BMS fractured in 6 patients (6/17; 36%), damaged the dissection flap in 4/17 (24%), and led to the reperfusion of the FL and re-interventions with TEVAR (4/17; 24%). Two patients without FL reperfusion showed stable CT follow-ups 13 and 17 months after the fracture diagnosis. The TL expansion was seen at all landmarks and peaked in the thoracic aorta (+10; 6, 15; p<0.001). The FL thrombosis after modified RBS was only relevant in the thoracic aorta (p<0.001) and at CeT (p=0.003). The aortic diameter was stable in the thoracic aorta and increased at distal landmarks (CeT [+5; 1, 10; p=0.001]; mid-abdominal [+3; 1, 5; p=0.004]). The modified RBS technique could not stop aortic growth below the diaphragm and prevent new membrane rupture due to the fractures of the BMS and consecutive flap damage with the reperfusion of the FL. The treatment of complicated type B aortic dissections with TEVAR has become a standard. Particularly, patients with true lumen collapse and malperfusion may benefit from a more aggressive treatment strategy including proximal TEVAR and distal bare-metal stent implantation to re-open the true lumen and to prevent distal stent-induced new entry. However, this study reports the challenges of this approach with a high rate of bare-metal stent fractures during the follow-up. The fractures that occurred at the site of vertical nitinol bridges led to the dissection membrane ruptures and the reperfusion of the false lumen with consecutive dilatation. A close follow-up is mandatory to detect this complication and to treat the patients with TEVAR extension.

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.

Failure to post-dilate BeSmooth peripheral stents to adult vessel size diameters during benchside tests

Low-profile stent implantation remains a rescue treatment for aortic coarctation and branch pulmonary arteries stenosis in small children. Stent re-expansion to cope with vascular growth remains problematic. To evaluate ex vivo feasibility and mechanical behaviour of over-dilating BeSmooth peripheral stents (Bentley InnoMed, Germany). Three BeSmooth peripheral stents in diameters of 7, 8, and 10 mm were dilated to nominal pressure and then 13 atm. BeSmooth Ø7 × 23 mm was sequentially post-dilated using 12, 14, and 16 mm high-pressure balloons. BeSmooth Ø10 × 57 mm was post-dilated with a 14 mm balloon and then with a 48 mm bare-metal Optimus XXL stent hand-mounted on a 14 mm balloon (stent-in-stent). BeSmooth Ø8 × 57 mm was directly post-dilated with a 48 mm bare-metal Optimus XXL stent hand-mounted on a 16 mm balloon (stent-in-stent). The stents' diameter and length were measured. Digital inflation pressure was noted. Balloon rupture and stent fracture patterns were closely evaluated. At 20atm pressure, BeSmooth Ø7 × 23 mm shortened to 2 mm forming a 12 mm diameter solid ring circle and the woven balloon ruptured radially. At 10 atm pressure, BeSmooth Ø10 × 57 mm fractured longitudinally in various dispatched breaking points at a diameter of 13 mm without shortening and ruptured the balloon with multiple pinholes. At 10 atm pressure, BeSmooth Ø8 × 57 mm fractured centrally at three different points at a diameter of 11.5 mm without shortening and the balloon broke radially in half. In our benchmark tests, extreme shortening, severe balloon rupture, or unpredictable stent fracture patterns at small balloon diameters limits safe post-dilation of BeSmooth stents beyond 13 mm. BeSmooth stents are not ideal candidates for off-label stent interventions in smaller patients.

Efficacy of endovascular repair in the treatment of retrograde ascending aortic intramural haematoma

BackgroundThe current treatment for retrograde ascending aortic intramural hematoma (RAIMH) remains challenging. This study aims to summarize the short-term results of endovascular repair in the treatment of retrograde ascending aortic intramural hematoma.MethodsBetween June 2019 and June 2021, 21 patients (16 males and 5 females) with a retrograde ascending aortic intramural hematoma, aged 53 ± 14years, received an endovascular repair in our hospital. All cases involved an ascending aortic or aortic arch intramural hematoma. 15 patients had an ulcer on the descending aorta combined with an intramural hematoma in the ascending aorta and 6 patients had typical dissection changes on the descending aorta combined with an intramural hematoma in the ascending aorta. All patients had a successful endovascular stent-graft repair, with 10 cases operated on in the acute phase (<14 days) and 11 cases in the chronic phase (14–35 days).ResultsA single-branched aortic stent graft system was implanted in 10 cases, a straight stent in 2 cases, and a fenestrated stent in 9 cases. All surgeries were technically successful. One of the patients developed a new rupture 2 weeks after surgery and was converted to a total arch replacement. No perioperative stroke, paraplegia, stent fracture or displacement, limb or abdominal organ ischemia occurred. The intramural hematomas started being absorbed on CT angiography images before discharge. There was no incidence of postoperative 30-day mortality, and the intramural hematomas in the ascending aorta and aortic arch were fully or partly absorbed.ConclusionEndovascular repair of retrograde ascending aortic intramural hematoma was shown to be safe and effective, and correlated with favorable short-term results.