Balloon-expandable Stent Research Articles

Midterm results on a new self-expandable covered stent combined with branched stent grafts: Insights from a multicenter Italian registry

ObjectiveTo investigate the technical periprocedural and midterm outcomes of endovascular repairs with multibranched endovascular repair or iliac branch devices combined with a new self-expanding covered stent. MethodsThe COvera in BRAnch registry is a physician-initiated, multicenter, ambispective, observational registry (ClinicalTrials.gov Identifier: NCT04598802) enrolling patients receiving a multibranched endovascular repair or iliac branch devices procedure mated with Bard Covera Plus (Tempe, AZ) covered stent, designed to evaluate the outcomes of the covered stent mated with patient-specific and off-the-shelf branched stent graft. Primary end points were technical success, branch instability, and freedom from aortic and branch-related reintervention within 30 days and at follow-up. Preoperative characteristics, comorbidities, and outcomes definitions were graded according to the Society for Vascular Surgery reporting standards. ResultsTwo hundred eighty-four patients (76 years; range, 70-80 years; 79% males) in 24 centers were enrolled for a total of 708 target vessels treated. The covered stents were mated with an off-the-shelf graft in 556 vessels (79%) and a custom-made graft in 152 (21%). Three hundred seven adjunctive relining stents in 277 vessels (39%) were deployed, of which 116 (38%) were proximal, 66 (21%) intrastent, and 125 (41%) distal. Adjunctive relining stent placement was more frequent when landing in a vessel branch instead of the main trunk (59% vs 39%; P = .031), performing a percutaneous access (49% vs 35%; P < .001), using a stent with a diameter of 8 mm or greater (44% vs 36%; P = .032) and a length of 80 mm or greater (65% vs 55%; P = .005), when a post-dilatation was not performed (45% vs 29%; P < .001) and when an inner branch configuration was used (55% vs 35%; P < .001). Perioperative technical bridging success was 98%. Eight patients (3%) died in the perioperative period. Two deaths (1%) were associated with renal branch occlusion followed by acute kidney injury and paraplegia. Follow-up data were available for 638 vessels (90%) at a median of 32 months (Q1, Q3, 21, 46). Branch instability was reported in 1% of branches. Forty-six patients (17%) died during follow-up, nine (3%) of them owing to aortic-related causes. Primary patency rates at 1, 2, and 3 years were 99% (581/587), 99% (404/411), and 97% (272/279), respectively. Branch instability was associated with patient-specific devices (9% vs 4%; P = .014) and intrastent adjunctive stent placement (12% vs 2%; P = .003), especially when a bare metal balloon-expandable stent was used (25% vs 3%; P < .001). ConclusionsThe use of this new self-expanding covered stent mated with branched endografts proved to be safe and feasible with high technical procedural success rates. Low rates of branch instability were observed at midterm follow-up. Comparative studies with other commercially available covered stents are warranted.

The effect of balloon-expandable stent and self-expanding stent on changes in mitral annular motion after aortic valve replacement in patients with aortic stenosis.

The purpose of this study was to evaluate the effect of decalcification and existence of stent at the aortic annulus on mitral annular motion after surgery. Patients receiving Inspiris (Edwards, CA, USA, n = 117), Intuity (Edwards, n = 36), Perceval (Corcym, London, UK, n = 36), Evolut (Medtronics, MN, USA, n = 81) and Sapien 3 (Edwards, n = 250) were included in the study. Mitral annular motion was evaluated by E', using tissue doppler imaging. After surgery, a significant increase in E' was observed in patients receiving Inspiris (Before: 4.2 ± 1.21cm/s vs. Discharge: 5.0 ± 1.23cm/s, p < 0.001). Mid-term echocardiogram performed at 11.8 ± 2.2months after the surgery, showed a significant increase in E' in patients receiving Inspiris (Before: 4.2 ± 1.21cm/s vs. Mid-term: 5.2 ± 1.20cm/s, p < 0.001) and Perceval (Before: 3.9 ± 1.34cm/s vs. Mid-term: 4.5 ± 1.24cm/s, p = 0.008). Univariable analysis showed a higher increase in E' in patients with decalcified annulus compared to those without decalcified annulus (Decalcification: 0.15 ± 1.321cm/s vs. No Decalcification: 0.66 ± 1.420cm/s, p < 0.001). Multivariable analysis showed that balloon-expandable stent (β = -0.6960, p < 0.001) and self-expanding stent (r = -0.3592, p = 0.042) were independent limiting factors for an increase in E' at discharge. However, balloon-expandable stent (β = -0.8382, p < 0.001), and not self-expanding stent (β = -0.3682, p = 0.089), was a remaining independent factor associated with E' at mid-term follow-up. Decalcification was associated with improvement in E' after surgery. Balloon-expandable stent was an independent limiting factor for improvement in E' up to 1year after the surgery, while self-expanding stent was not a significant factor after 1year.

Midterm Outcomes of Antegrade In Situ Laser Fenestration of Polyester Endografts for Urgent Treatment of Aortic Pathologies Involving the Visceral and Renal Arteries

Aortic endografting and antegrade in situ laser fenestration of visceral arteries (LFEVAR) may be considered as an alternative to open surgery for repair of emergent complex abdominal aortic aneurysms (AAA) in fragile patients. The aim of this article is to evaluate the midterm results of LFEVAR performed with polyester endografts. From August 2015 to December 2020, all consecutive LFEVAR performed for non-deferrable treatment of complex AAA were analysed. Polyester endografts were deployed and subsequently fenestrated using an atherectomy laser probe; the fenestrations were enlarged using cutting and semicompliant balloons before implantation of balloon expandable bridging stents into the target vessels. Prospectively collected midterm survival, patency, and re-intervention rates were analysed. Forty four procedures were performed for 11 T1a endoleaks, five thoracoabdominal aneurysms, 20 pararenal aneurysms, four segmental renal artery (RA) preservations, three anastomotic aneurysms, and one aortic dissection. One hundred and eight laser fenestrations were performed (26 for the superior mesenteric artery [SMA], 13 for the coeliac trunk, 33 and 31 for the right and left RA, respectively). Median ischaemia duration was 7, 48, 48, and 45 minutes, respectively. Technical success rate was 97%, with no open surgical conversions. The 30 day mortality was 4.5% (n = 2). No spinal cord events were observed nor early stent related complications. Kaplan-Meier overall survival at two years was 73%, the aortic related re-intervention free survival was 70%, and the stent related re-intervention free survival was 90.6%. Four target vessel thromboses were detected, of which three were rescued. Three type IIIC endoleaks, one RA false aneurysm, and one SMA stenosis, required re-intervention during a median follow up of 24.7 months. Antegrade LFEVAR is feasible, safe, and provides satisfactory early and midterm outcomes for non-deferrable treatment of aortic pathologies involving the visceral segment. Long term data are mandatory to confirm the usefulness of this promising off label technique.

Drug-eluting, balloon-expandable, bioresorbable vascular scaffolds reduce neointimal thickness and stenosis in an animal model of percutaneous peripheral intervention

ObjectiveRecanalization with balloon angioplasty and/or self-expanding stents (SES) has become the endovascular treatment of choice for symptomatic femoropopliteal occlusive disease. These strategies generate suboptimal clinical results, however, because they fail to expand the artery fully and ineffectively prevent recoil, neointimal hyperplasia, and restenosis. Balloon-expandable stents, given their greater radial force and rigid structure, represent a more effective treatment strategy, but only short lengths can be implanted safely in arteries that deform and bend with skeletal motion. The purpose of this preclinical experiment was to test the hypothesis that simultaneous implantation of a series of short, resorbable, balloon-expandable, paclitaxel-eluting scaffolds would prevent neointimal hyperplasia and stenosis compared with SES in an animal model of percutaneous femoropopliteal intervention. MethodsWe extruded 6 × 60 mm Efemoral Vascular Scaffold Systems (EVSS) from copolymers of poly-L-lactic acid, coated with paclitaxel 3 μg/mm2, crimped onto a single delivery balloon, and implanted percutaneously into the iliofemoral arteries of eight Yucatan mini-swine. We implanted 7- to 8-mm × 60 mm SES into the contralateral experimental arteries. The animals were serially imaged with contrast angiography and optical coherence tomography after 30, 90, 180, 365, and 730 days. The primary end point of this study was neointimal morphometry over time. Secondary end points included acute deformation and angiographic and optical coherence tomography-derived measurements of chronic vascular response. ResultsOver the 2-year study period, one SES was found to be completely occluded at 90 days; all EVSS were widely patent at all time points. Arteries treated with SES exhibited profound neointimal hyperplasia with in-stent stenosis. In contrast, arteries treated with EVSS exhibited only modest vascular responses and minimal stenosis. After 2 years, the mean neointimal thickness (0.45 ± 0.12 vs 1.31 ± 0.91 mm; P < .05) and area (8.41 ± 3.35 vs 21.86 ± 7.37 mm2; P < .05) were significantly decreased after EVSS implantation. By 2 years, all scaffolds in all EVSS-treated arteries had resorbed fully. ConclusionsIn this preclinical animal model of peripheral endovascular intervention, the EVSS decreased neointimal hyperplasia and stenosis significantly compared with SES, then dissolved completely between the first and second years after implantation.

Microstructure and mechanical properties of the Co-Cr-W-Ni alloy tubes for balloon-expandable stents

Microstructure and mechanical properties of the Co-Cr-W-Ni alloy tubes for balloon-expandable stents

Self-Expanding Versus Balloon-Expandable Stents for treatment of Iliac Artery Occlusive Disease

Self-Expanding Versus Balloon-Expandable Stents for treatment of Iliac Artery Occlusive Disease

PERFORMANCE ANALYSIS OF HEXAGONAL UNIT CELL STENT DESIGN AND SINGLE-LAYERED MANUFACTURABILITY WITH FDM

İlaç salınımlı stentlerden sonra geliştirilen biyobozunur polimer esaslı stentler için yapılan ön klinik çalışmalardan elde edilen sonuçlara göre polimer stentlerin kullanılabilirliği sorgulanmaktadır. Polimer stentlerde strat kalınlığının yüksek olması ve mekanik özelliklerin zayıflığı nedeniyle tasarım ve malzeme iyileştirmesine gidilerek yeni modellerin ortaya çıkarılması üzerine araştırmalara devam edilmektedir. Balonla genişleyen stentlerde oluşan uç açılması arter içerisinde intimal ve medial katmanlara zarar vermektedir. Bu zarar, erken dönemde neointimal hiperplazi ve restenoza sebep olmaktadır. Metalik stent geometrilerinden biri olan Palmaz-Schatz birim hücre modelinde balonla genişleme esnasında uç açılması ve kısalma oranı meydana gelmektedir. Bu çalışmada, Palmaz-Schatz stent geometrisinin genişlemesiyle oluşturduğu geometri dikkate alınarak PLLA malzemeden altıgen birim stent geometrisinde yeni tasarım gerçekleştirilmiştir. Sonlu elemanlar simülasyonuyla, ince strat kalınlığında tasarlanan altıgen stendin genişlemesinde oluşan uç açılması ve kısalma oranı belirlenmiştir. Ayrıca, stent genişlemesinde üç katmanlı arter ve kalsifik plak yapısında meydana gelen doku hasarı ölçülmüştür. Altıgen geometrideki stentte oluşan uç açılması ve kısalma oranı Palmaz-Schatz modeline göre azaltılmıştır. Bununla birlikte, PLA/PHA karışımı malzemeden eriyik yığma modelleme ile altıgen stent geometrisinin 3B plaka baskısı tek katmanlı olarak üretilmesi sonrası ısıtıcı bir tubular tabla üzerinde sarılarak stent formuna getirilmiştir

Early and Midterm Outcomes of Endovascular Treatment in Arterial Manifestations of Vascular Behcet Disease

Behcet's disease (BD), originally described by Hulusi Behcet in 1937, is a chronic relapsing inflammatory process of an immunologic syndrome and the involvement of the vascular system is called Vasculo-Behcet Disease. This is a retrospective study evaluating 21 patients diagnosed with Vascular-Behcet's disease who underwent endovascular treatment. This single-center study was conducted between January 2016 and January 2022. Early and mid-term endovascular outcomes of a total of 21 patients (16 males, 5 females with a median age of 42 years; range, 31 to 46 years), with a diagnosis of VBD, who underwent endovascular arterial repair in our hospital, were retrospectively analyzed. Follow-ups were scheduled for the first and sixth postoperative months and every 6 months thereafter. For symptomatic patients, imaging studies and additional interventions were planned. The primary outcomes were a procedural success and the requirement for re-intervention. Secondary outcomes were complications and all-cause of mortality. Twenty-one patients underwent endovascular repair. In this study, one balloon-expandable stent for brachial artery aneurysm (4,8%), 1 Viabahn graft for femoral artery aneurysm (4,8%), 2 tube endograft for ruptured iliac artery aneurysm (9,5%), 1 tube endograft (TEVAR) insertion at the aortic bifurcation for infrarenal abdominal aortic occlusion (4,8%), one Chimney-TEVAR for saccular arcus TAA (4,8%) and 7 TEVAR for saccular TAA (33,3%), 1 EVAR for an intact and symptomatic infrarenal AAA (4,8%), 1 EVAR (aorto-uniiliac) for ruptured iliac artery aneurysm (4,8%), 6 EVAR for ruptured abdominal aortic aneurysm (28,5%) were deployed. The technical success rate was 100% with a mean follow-up period of 50,4±10,7 months (8 - 66 months). The mean aneurysm diameter was 10,7±53mm. In the follow-up period, three patients presented with a hematoma at the insertion site of the sheath (14,3%). There were no early mortalities. Three patients required re-intervention (14,3%); one of these underwent open surgical repair due to a pseudoaneurysm of the access site (4,8%). The Kaplan-Meier analysis revealed freedom from reintervention rate as 94,1±5,7% at one year, 85,6±9,7% at three years, and 68,4±17,1% at five years. Awareness of the BD especially for vascular involvements in young ages is lifesaving. Endovascular therapy with proper medical treatment seems to be the treatment of choice according to the early and midterm successful results with low morbidity and mortality.

Balloon-expandable stents for native coarctation of the aorta in children and adolescents.

Although balloon-expandable stent implantation for native aortic coarctation is a preferred method in the adolescent age group, there are insufficient data about indications for and the efficacy of the procedure in a younger age group. The aim of this study was to compare and evaluate the data of young pediatric and adolescent patients who underwent balloon-expandable stent implantation because of native aortic coarctation. The retrospective analysis included the demographic characteristics and data related to the procedure and follow-up of patients who underwent stent implantation for native aortic coarctation between August 2010 and November 2017. Patients with re-coarctation were excluded from the study. The patients were separated into 2 groups as the adolescent group (Group I: 10-18 years) and the pediatric group (Group II: ≤ 9.9 years). Group-I comprised of 18 patients and Group-II, 32 patients. Covered stent was implanted to 32 (73%) patients and uncovered stent to 12 (27%) patients. The procedural success rate was 100%. Following stent implantation, peak systolic gradient decreased significantly in both groups (P < .0001) (Group-I: from 35.9 ± 16.6 mm Hg-2.2 ± 3.4 mm Hg, Group II: from 34 ± 13.3 mm Hg-3 ± 4.09 mm Hg). Complications developed in 3 patients, and all in Group I. Femoral hematoma developed in 1 patient, balloon rupture occurred during the procedure in 1 patient, and there was temporary loss of pulse in 1 patient. All the complications were treated successfully. All the patients were taking anti-hypertensive drugs before intervention and during the mean 23-month follow-up period (range, 2-84 months), hypertension recovered in 35 (80%) patients and drugs were terminated. Stent implantation for aortic coarctation in the pediatric age group may provide pleasing results, reducing the coarctation gradient, providing effective dilatation in the lesion area and eliminating hypertension.

Improvement of mechanical properties of Co–Cr–W–Ni alloy tube suitable for balloon-expandable stent applications through heat treatment

This study focuses on the changes in the microstructure and mechanical properties of the Co–20Cr–15W–10Ni (CCWN, mass%) alloy tube, which, with heat treatment, is used as a balloon-expandable stent. To the best of our knowledge, this is the first report on the improvement of mechanical properties by microstructure control in CCWN alloy tubes. In addition, optimized heat treatment conditions are proposed for the development of next-generation small-diameter stents. The cold-worked CCWN alloy tube for stents was statically recrystallized by heat treatment at temperatures of 1373–1473 K for holding times of 60–900 s. The recrystallized alloy tubes exhibited a microstructure with a γ(fcc)-phase matrix and an average grain size of 5.8–34.1 μm. The strength and plastic elongation increased with decreasing grain size. In the coarse-grained structure, a large plate-like ε-phase formed along the twin boundary and stacking fault. The ε-phase grew to the grain boundaries, such that large cracks could form, resulting in early fracture. In the fine-grained structure, a small ε-phase formed by strain-induced martensitic transformation was uniformly dispersed, and the formation of large cracks was suppressed, leading to high ductility. The effect of low-temperature heat treatment (LTHT) at 873 K after recrystallization depended on the grain size of the alloy tube. In the alloy tube with a grain size of >15 μm, ε(hcp)-phase formation during plastic deformation was suppressed through the decrease in stacking fault density during LTHT, which resulted in improved ductility. In contrast, in the alloy tube with a grain size of <15 μm, the amount of precipitates increased during LTHT, resulting in reduced ductility.

Computational study of fenestration and parallel grafts used in TEVAR of aortic arch aneurysms.

To explore the differences between fenestration technique and parallel grafts technique of thoracic endovascular aortic repair, and evaluate the risk of complications after interventional treatment of aortic arch aneurysms. A three-dimensional aortic model was established from the follow-up imaging data of patient who reconstructed the superior arch vessel by the chimney technique, which was called the chimney model. Based on the chimney model, the geometric of the reconstructed vessel was modified by virtual surgery, and the normal model, fenestration model and periscope model were established. The blood flow waveforms measured by 2D phase contrast magnetic resonance imaging were processed as the boundary conditions of the ascending aorta inlet and the superior arch vessels outlets of the normal model. The pressure waveform of descending aorta was obtained using three-element Windkessel model, and specific pressure boundary conditions were imposed at reconstructed branches for the postoperative models. Through computational fluid dynamics simulations, the hemodynamic parameters of each model were obtained. The reconstructed vessel flow rate of the periscope model and the fenestration model are 33% and 50% of that of the normal model, respectively. The pressure difference between the inner and outer walls of the fenestration stent and periscope stent is 3.15 times and 7.56 times that of the chimney stent. The velocity in the fenestration stent and periscope stent is uneven. The high relative residence time is concentrated in the region around the branch stents, which is prone to thrombosis. The "gutter" part of the chimney model may become larger due to the effect of the stent-graft DF, increasing the risk of endoleak. For patients with incomplete circle of Willis, the periscope technique to reconstruct the supra-arch vessels may affect blood perfusion. It is recommended to use balloon-expandable stent for fenestration stent and periscope stent, and self-expanding stent for chimney stent. For patients with aortic arch aneurysms, the fenestration technique may be superior to the parallel grafts technique.

Stent imaging on a clinical dual-source photon-counting detector CT system-impact of luminal attenuation and sharp kernels on lumen visibility.

To assess the impact of scan modes and reconstruction kernels using a novel dual-source photon-counting detector CT (PCD-CT) on lumen visibility and sharpness of different stent sizes. A phantom containing six balloon-expandable stents (2.5 to 9 mm diameter) in silicone tubing was scanned on a PCD-CT with standard (0.6 mm and 0.4 mm thicknesses) and ultra-high-resolution (0.2 mm thickness) modes. With the use of increasing contrast medium concentrations, densities of 0, 200, 400, and 600 HU were achieved. Standard-resolution scans were reconstructed using increasing sharpness kernels, using both polyenergetic quantitative soft tissue "conventional" ((Qr40c(0.6 mm), Qr40c(0.4 mm), Qr72c(0.2 mm)) and vascular (Bv) virtual monoenergetic reconstructions (Bv44m(0.4 mm), Bv60m(0.4 mm)) at 70 keV. In-stent lumen visibility, sharpness (max. ΔHU of the stent measured in profile plots), and in-stent noise (standard deviation of HU) were measured. In-stent lumen visibility was highest for Qr72c(0.2 mm) (86.5 ± 2.8% to 88.3 ± 2.6%) and in Bv60m(0.4 mm) reconstructions (77.3 ± 2.9 to 82.7 ± 2.5%). Lumen visibility was lowest in the smallest stent (2.5 mm) ranging from 54.1% in Qr40c(0.6 mm) to 74.1% in Qr72c(0.2 mm) and highest in the largest stent (9 mm) ranging from 93.8% in Qr40c(0.6 mm) to 99.1% in the Qr72c(0.2 mm) series. Lumen visibility decreased by 2.1% for every 200-HU increase in lumen attenuation. Max. ΔHU between stents and stent lumen was highest in Qr72c(0.2 mm) (ΔHU 892 ± 504 to 1526 ± 517) and Bv60m(0.4 mm) series (ΔHU 480 ± 357 to 1030 ± 344). Improvement of lumen visibility and sharpness in UHR and Bv60m(0.4 mm) series was strongest in smaller stent sizes. UHR acquisition mode and sharp reconstruction kernels on a novel PCD-CT system significantly improve in-stent lumen visibility and sharpness-especially for smaller stent sizes. • In-stent lumen visibility and sharpness of stents significantly improve using sharp reconstruction kernels (Bv60) and ultra-high-resolution mode in photon-counting detector computed tomography. • The observed improvement of stent-lumen visibility was highest in smaller stent sizes.

The Iliacs and the Odyssey of Covered vs. Bare Metal Stents

In this issue of the journal, Benken et al. present the DISCOVER trial, a multicentre, randomised controlled trial (RCT) comparing covered stents (CSs) with bare metal balloon expandable stents (BMSs) for advanced common iliac artery (CIA) lesions. In total, 174 limbs were randomised between the two strategies. The main outcome was freedom from binary restenosis at two years, and it was not different between the two groups (84.7% in the BMS group and 89.1% in the CS group; p = .40).1 Secondary outcomes (especially freedom from occlusion and from target lesion revascularisation) were also not different.

Use of drug-eluting, balloon-expandable resolute onyx coronary stent as a novel treatment strategy for vertebral artery ostial stenosis: Case series.

Vertebral artery (VA) ostial stenosis is notoriously difficult to treat using bare-metal stents owing to high rates of restenosis and stent kinking and breakage. We investigated the safety and effectiveness of treatment with a drug-eluting, balloon-expandable coronary stent (Resolute Onyx, Medtronic). Our prospectively maintained database was retrospectively searched for consecutive patients diagnosed with VA ostial stenosis who underwent Resolute Onyx stenting with/without angioplasty between January 1, 2015 and January 1, 2022. Patient demographics and clinical and radiographic presentations were recorded. Occlusion location, stenosis severity, contralateral disease, devices used, and intraprocedural and postprocedural complications were noted. Outcomes were assessed based on new or recurrent stroke, transient ischemic attack (TIA), or intracranial hemorrhage (ICH). Patients were followed up clinically and with radiographic imaging for in-stent stenosis. Twenty-six patients were included in our study (21 men [80.8%]; mean age 70.3 ± 9.8 years). Symptomatic patients presented with TIA (11/26, 42.3%) and stroke (10/26; 38.5%). Mean stenosis in the study cohort was 74.9 ± 13.0%. One (3.8%) intraprocedural complication was encountered whereby the stent failed to open despite several attempts and was exchanged with a new one without issues. No in-hospital postprocedure stroke, TIA, or mortality was reported. During a mean 16.2 ± 13.6 months' follow up, two patients developed symptomatic in-stent restenosis that was treated with balloon angioplasty. We report the first case series of Resolute Onyx drug-eluting stenting including 30-day postprocedure stroke/TIA rates and clinical/radiographic follow up and demonstrate safe and effective treatment of symptomatic and asymptomatic VA ostial stenosis.

The efficacy and safety of different endovascular modalities for infrapopliteal arteries lesions: A network meta-analysis of randomized controlled trials

Endovascular treatment has become the first-line therapy for infrapopliteal artery occlusive disease (IPOD), while the optimal endovascular method remains to be determined. We performed a network meta-analysis (NWM) of randomized controlled trials (RCTs) to simultaneously compare the outcomes of different endovascular modalities for IPOD. The Pubmed, Embase, and Cochrane databases were used as data sources. The NWM approach used random-effects models based on the frequentist framework. In total, 22 eligible RCTs (44 study arms; 1,348 patients) involving nine endovascular modalities or combinations [balloon angioplasty (BA), drug-coated balloon (DCB), drug-eluting stent (DES), atherectomy device + BA (AD + BA), AD + DCB, balloon-expandable bare metal stent (BMS), self-expanding stent (SES), absorbable metal stents (AMS), and inorganics-coated stent (ICS)] were included. BA had a lower 12-month primary patency rate than DCB (RR 0.50, CI 0.27, 0.93) and AD + DCB (RR 0.34, CI 0.12, 0.93). AD + DCB decreased 6-month TLR compared with AMS (RR 0.15, CI 0.03, 0.90), and DES decreased it compared with BMS (RR 0.25, CI 0.09, 0.71). DCB had a lower 6-month TLR rate than AMS (RR 0.26, CI 0.08, 0.86) and BA (RR 0.51, CI 0.30, 0.89). BA had a higher 12-month TLR rate than DCB (RR 1.76, CI 1.07, 2.90). According to the value of the surface under the cumulative ranking curve (SUCRA), AD + DCB was considered the best treatment in terms of primary patency at 6 months (SUCRA = 87.5) and 12 months (SURCA = 91). AD + BA was considered the best treatment in terms of 6-month TLR (SUCRA = 83.1), 12-month TLR (SURCA = 75.8), and 12-month all-cause mortality (SUCRA = 92.5). In terms of 12-month major amputation, DES was considered the best treatment (SUCRA = 78.6), while AD + DCB was considered the worst treatment (SUCRA = 28.8). Moreover, AD + BA always ranks higher than AD + DCB in the comparison including these two combinations. Subgroup analyses of modalities without stenting did not significantly change the primary outcomes. ADs showed noteworthy advantages in multiple terms for IPOD except for 12-month major amputation. AD + BA may be a better method for IPOD than AD + DCB. The efficacy and safety of ADs are worthy of further investigation. [https://www.crd.york.ac.uk/prospero/], identifier [CRD42022331626].

Abstract 9613: Short- and Long-Term Vascular Responses of Stent With Biodegradable Graft for Artery Dissection in Rabbit Iliac Model

Introduction: Arterial dissection or rupture during percutaneous angioplasty is rare but can be lethal. We invented a balloon-expandable stent with a very thin membrane typed biodegradable graft for the treatment of arterial dissection (BioGard). Hypothesis: The efficacy and safety of BioGard were evaluated in the rabbit iliac artery rupture model. The devices would be helpful to seal the emergent blood extravasation due to arterial perforation and reduce unfavorable vascular events in long-term follow-up. Method: Twenty iliac arterial dissections by balloon over-inflation were induced under the guidance of angiography. Twelve rabbits with huge contrast extravasation to retroperitoneal space (Ellis type 3) were treated using BioGards. Serial histologic examinations and micro-computed tomography (CT) were performed at 1, 2, and 8 weeks and 3, 6, 9, and 12 months. Final angiography at 1 year was performed to evaluate any vascular complication. Results: There are no significant adverse cardiovascular events after one year of BioGard implantation. Micro-CT and follow-up angiography at one year revealed no case of significant in-stent restenosis and thrombotic occlusion in vivo. Early-stage histologic examination demonstrated that disrupted vessels were completely sealed up by BioGard with mural hematoma, inflammatory cell infiltration, and red thrombi. Mid- and long-term histologic examination revealed patent stents and neointimal coverage over the stents with biodegraded graft material and mild peri-strut area inflammatory response. Conclusions: Twelve months post-BioGard implantation in rabbit iliac artery dissections demonstrated good efficacy and safety. BioGard at a severely dissected artery would be an option for preventing lethal vascular events. Further clinical evaluation of this novel technology would be warranted.

Outcomes of Directional Branches of the T-Branch Off-the-Shelf Multi-Branched Stent-Graft.

A controversy on bridging covered stent (BCS) choice, between self-expanding (SECS) and balloon-expandable (BECS) stents, still exists in branched endovascular repair. This study aimed to determine the primary target vessel (TV) patency in patients treated with the t-Branch device and identify factors impairing the outcomes. A retrospective study was undertaken, including patients treated with the t-Branch (Cook Medical, Bloomington, IN, USA) between 2014 and 2019 (early 2014-2016; late 2017-2019). The endpoint was the primary patency (CT: celiac trunk, SMA, superior mesenteric artery, RRA: right renal artery, LRA: left renal artery) during the follow-up. Any branch instability event was assessed. The factors affecting the patency were determined using multivariable regression models and Kaplan-Meier analyses. In total, 2018 TVs were analyzed; 1542 SECSs and 476 BECSs. The CT patency was 99.8% (SE 0.2%) at the 1st month, with no other event. The SMA patency was 97.8% (SE 1) at the 12th month. The RRA patency was 96.7% (SE 2) at the 24th month. The LRA patency was 99% (SE 0.4) at the 6th month. Relining was the only factor independently associated with the SMA patency (OR 8.27; 95% CI 1.4-4.9; p = 0.02). The freedom from instability was 62% (SE 4.3%) and 45% (SE 5.4%) at the 24th month and 36th month. No significant difference was identified between the BECSs and SECSs in the early or late experience. BCS for the t-Branch branches performed with a good primary patency during the short-term follow-up. The type of BCS did not influence the patency. Relining might be protective for SMA patency.

A Fenestrated Balloon Expandable Stent System for the Treatment of Aortoiliac Occlusive Disease.

In aortoiliac occlusive disease, atherosclerotic plaques can occlude the distal aortic bifurcation and proximal bilateral iliac artery and thus cause ischemia in the lower extremity. This is typically treated by restoring patency with balloon expandable stents. Stents are typically deployed in a "kissing stent" configuration into the bilateral iliac arteries and into the distal aortic bifurcation lumen to restore antegrade arterial flow. However, these stents typically become re-occluded by plaques. To understand the reasons for this and look for solutions, we simulated flow dynamics in the aortic bifurcation in the presence and absence of stents using computational fluid dynamics. Results demonstrated that the kissing stent configuration was associated with high levels of vorticity and flow constriction. These prothrombotic variables were alleviated in an alternative, aortoiliac fenestrated (AIFEN), tapered, and balloon-expandable stent design. Our findings suggest that stent design can be tailored to improve flow fields for aortoiliac stenting.

A balloon-supported embolism protection technique during vertebral/subclavian artery angioplasty stenting.

A balloon-supported embolism protection technique during vertebral/subclavian artery angioplasty stenting.

Inelastic Deformation of Coronary Stents: Two-Level Model.

This study describes the internal structure of materials used to produce medical stents. A two-level elastoviscoplastic mathematical model, which sets the parameters and describes the processes at the grain level, was developed and numerically implemented. A separate study was conducted to identify the most dangerous deformation modes in the balloon-expandable stent placement using the finite-element method in COMSOL Multiphysics. As a result, the challenging strain state type required for setting the kinematic loading on a representative macrovolume in the two-level model was obtained. A yield surface for different deformation paths in the principal deformation space for stainless steel AISI 316L was obtained and the effect of grain size on the deformation behavior of this material was explored using the developed model.