Tratamiento endovascular con dispositivos ramificados ilíacos: estudio multicéntrico / Endovascular treatment with iliac branch devices: multicenter study

INTRODUCCIÓN: se estima que entre 18 y un 39 % de los pacientes con aneurismas del sector aortoilíaco sometidos a tratamiento endovascular presentan zonas no aptas para el sellado distal en arterias ilíacas comunes. Tradicionalmente, una de las opciones disponibles para abordar dicha situación consiste en realizar un sellado distal a nivel de las arterias ilíacas externas, ocluyendo las arterias hipogástricas. Sin embargo, esto conlleva la aparición de manifestaciones clínicas derivadas de la isquémica pélvica en el 28-55 % de los casos. La utilización de dispositivos ramificados ilíacos (DRI) permite mantener el flujo anterógrado a las arterias hipogástricas, lo que evita este tipo de complicaciones. El objetivo de nuestro estudio es analizar los resultados a medio plazo de la exclusión endovascular de aneurismas del sector aortoilíaco utilizando DRI. MÉTODOS: estudio descriptivo retrospectivo multicéntrico que incluye los DRI utilizados para el tratamiento endovascular de aneurismas de aorta con afectación del sector aortoilíaco entre enero de 2008 y julio de 2019. Se recogieron datos demográficos, anatómicos, intra- y perioperatorios y de seguimiento en tres centros. Las variables de interés analizadas fueron: éxito técnico, mortalidad perioperatoria, incidencia de isquemia pélvica, permeabilidad primaria de rama hipogástrica y rama ilíaca externa, reintervención relacionada con DRI y mortalidad relacionada con el aneurisma. RESULTADOS: se incluyeron 80 DRI implantados en 61 pacientes: 28 (35 %) Gore(R) Excluder(R) Iliac Branch Endoprosthesis y 52 (65 %) Cook(R) Zenith(R) Branch Endovascular Graft. Se implantaron DRI bilaterales en 18 casos (29,5 %). La tasa de éxito técnico fue del 95 % sin que existieran casos de muertes en el periodo perioperatorio. El seguimiento medio fue de 30,1 meses (± 26,3). Se presentaron seis casos de isquemia pélvica durante el seguimiento. La permeabilidad de la rama hipogástrica fue del 97,5 %, del 94,5 % y del 90,6 % a los 6, 12 y 24 meses, respectivamente. La permeabilidad de la rama ilíaca externa fue del 100 %, del 97,3 % y del 95,5 % a los 6, 12 y 24 meses, respectivamente. La tasa libre de reintervención secundaria al DRI fue del 100 %, del 96,8 % y del 94,7 % a los 6, 12 y 24 meses, respectivamente. Se produjo un caso de muerte relacionada con el aneurisma durante el seguimiento. CONCLUSIONES: en nuestra experiencia, los DRI presentan buenos resultados a medio plazo en la exclusión endovascular de aneurismas con afectación del sector aortoilíaco. Estos dispositivos permiten mantener la permeabilidad de las arterias hipogástricas, minimizando la incidencia de isquemia pélvica. A pesar de las escasas complicaciones tardías y la baja tasa de reintervenciones, es necesario realizar un seguimiento a largo plazo para mantener el éxito técnico

INTRODUCTION: it is estimated that between 18-39 % of patients with aorto-iliac aneurysms undergoing endovascular treatment have a no suitable zone for distal sealing in common iliac arteries. Traditionally, one of the options is to perform a distal seal at the external iliac arteries occluding the hypogastric arteries. However, this can lead to complications derived from pelvic ischemia in 28-55 % of cases. The use of iliac branched devices (IBD) allow to maintain the antegrade flow to the hypogastric arteries, avoiding these complications. The objective of our study is to analyze the medium-term results of endovascular exclusion of aorto-iliac aneurysms using IBD. METHODS: a descriptive multicenter retrospective study including the IBD for the endovascular treatment of aneurysms with involvement of the aorto-iliac sector was conducted between January 2008 and July 2019. Demographic, anatomical, intra-perioperative and follow-up data was collected at 3 centers. The variables of interest analyzed were: technical success, perioperative mortality, incidence of pelvic ischemia, primary patency of the hypogastric branch and external iliac branch, DRI-related reoperation, and aneurysm-related mortality. RESULTS: eighty IBDs were included from 61 patients: 28 (35 %) Gore(R) Excluder(R) Iliac Branch Endoprosthesis, and 52 (65 %) Cook(R) Zenith(R) Branch Endovascular Graft. Bilateral IBDs were implanted in 18 cases (29.5 %). The technical success was achieved in 95 % of cases, with no perioperative deaths. The mean follow-up was 30.1 (± 26.3) months. 6 patients presented pelvic ischemia during follow-up. The patency of the hypogastric side branch was 97.5 %, 94.5 %, and 90.6 %, at 6, 12, and 24 months, respectively. The patency of the external iliac side branch was 100 %, 97.3 %, and 95.5 %, at 6, 12, 24 months, respectively. Freedom from reintervention rate secondary to IBD was 100 %, 96.8 %, and 94.7 %, at 6, 12, and 24 months, respectively. There was 1 case of aneurysm-related death during follow-up. CONCLUSIONS: in our experience, IBDs show good medium-term results in endovascular treatment of aorto-iliac aneurysms. These devices allow to maintain the perfusion of the hypogastric arteries, minimizing the incidence of pelvic ischemia. Although the appearance of late complications and the need for reinterventions is low, a long-term follow-up should be carried out to maintain the success of the procedure

In vitro evaluation of a new aortic valved conduit.

BACKGROUND: This study examined whether the presence of a sinus of Valsalva equivalent in the KONECT RESILIA aortic valved conduit (Edwards Lifesciences, Irvine, Calif) improves valve hemodynamics, kinematics, and performance. METHODS: A 28-mm KONECT RESILIA aortic valved conduit was used to create an in vitro flow test model, and the same aortic valved conduit model without a sinus section was used as a control. Particle image velocimetry and hydrodynamic characterization experiments were conducted in the vicinity of the valves in a validated left-heart simulator at 3 cardiac output levels. In addition, leaflet kinematics of the valves were determined through en face high-speed imaging. RESULTS: The KONECT RESILIA aortic valved conduit model exhibited lower mean and peak transvalvular pressure gradients than the control model at all 3 cardiac outputs. In addition, its leaflets opened more fully than did those of the valved conduit without the sinuses, yielding greater effective and geometric orifice areas. It was found that the presence of the sinuses not only facilitated the development of larger and more stable vortices at the initial stages of the cardiac cycle but also helped to maintain these vortices during the late stages of the cardiac cycle, leading to smoother valve closure. CONCLUSIONS: The KONECT RESILIA aortic valved conduit reproduces the bulged section of the aortic root corresponding to the sinuses of Valsalva. With this Valsalva-type conduit, larger orifice areas were observed, improving valve hemodynamics that may enhance performance.

Comparison of PED and FRED flow diverters for posterior circulation aneurysms: a propensity score matched cohort study.

BACKGROUND: Flow diversion is a common endovascular treatment for cerebral aneurysms, but studies comparing different types of flow diverters are scarce. OBJECTIVE: To perform a propensity score matched cohort study comparing the Pipeline Embolization Device (PED) and Flow Redirection Intraluminal Device (FRED) for posterior circulation aneurysms. METHODS: Consecutive aneurysms of the posterior circulation treated at 25 neurovascular centers with either PED or FRED were collected. Propensity score matching was used to control for age, duration of follow-up imaging, adjunctive coiling, and aneurysm location, size, and morphology; previously ruptured aneurysms were excluded. The two devices were compared for the following outcomes: procedural complications, aneurysm occlusion, and functional outcome. RESULTS: A total of 375 aneurysms of the posterior circulation were treated in 369 patients. The PED was used in 285 (77.2%) and FRED in 84 (22.8%) procedures. Aneurysms treated with the PED were more commonly fusiform and larger than those treated with FRED. To account for these important differences, propensity score matching was performed resulting in 33 PED and FRED unruptured aneurysm pairs. No differences were found in occlusion status and neurologic thromboembolic or hemorrhagic complications between the two devices. The proportion of patients with favorable functional outcome was higher with FRED (100% vs 87.9%, p=0.04). CONCLUSION: Comparative analysis of PED and FRED for the treatment of unruptured posterior circulation aneurysms did not identify significant differences in aneurysm occlusion or neurologic complications. Variations in functional outcomes warrant additional investigations.

Fabricating Organized Elastin in Vascular Grafts.

Surgically bypassing or replacing a severely damaged artery using a biodegradable synthetic vascular graft is a promising treatment that allows for the remodeling and regeneration of the graft to form a neoartery. Elastin-based structures, such as elastic fibers, elastic lamellae, and laminae, are key functional components in the arterial extracellular matrix. In this review, we identify the lack of elastin in vascular grafts as a key factor that prevents their long-term success. We further summarize advances in vascular tissue engineering that are focused on either de novo production of organized elastin or incorporation of elastin-based biomaterials within vascular grafts to mitigate failure and enhance enduring in vivo performance.

Bifurcation Aneurysm Treatment with PulseRider: Technical Nuances, Device Selection, Positioning Strategies, and Overcoming Geometric Challenges.

BACKGROUND: Endovascular therapy is a viable alternative to surgical clipping for the treatment of intracranial aneurysms; however, aneurysms arising at bifurcations remain a challenge. The purpose of this technical report is to share the nuances of treating aneurysms with the PulseRider (PR), including device selection and positioning strategy, from authors who are highly experienced in its use. METHODS: We offer a comprehensive guide for neuroendovascular surgeons less experienced with PR applications to include design, general coil embolization technique, principles of deployment and detachment, positioning options, and geometric challenges and their solutions. RESULTS: In our experience, the PR is well suited for addressing the challenges of treating bifurcation aneurysms. CONCLUSIONS: PR use is intuitive and straightforward for use in bifurcation aneurysms with ideal favorable. PR can also be safely and effectively used to address a much broader and more challenging range of geometries.

Virtual simulation with Sim&Size software for Pipeline Flex Embolization: evaluation of the technical and clinical impact.

INTRODUCTION: During flow diversion, the choice of the length, diameter, and location of the deployed stent are critical for the success of the procedure. Sim&Size software, based on the three-dimensional rotational angiography (3D-RA) acquisition, simulates the release of the stent, suggesting optimal sizing, and displaying the degree of the wall apposition. OBJECTIVE: To demonstrate technical and clinical impacts of the Sim&Size simulation during treatment with the Pipeline Flex Embolization Device. METHODS: Consecutive patients who underwent aneurysm embolization with Pipeline at our department were retrospectively enrolled (January 2015-December 2017) and divided into two groups: treated with and without simulation. Through univariate and multivariate models, we evaluated: (1) rate of corrective intervention for non-optimal stent placement, (2) duration of intervention, (3) radiation dose, and (4) stent length. RESULTS: 189 patients, 95 (50.2%) without and 94 (49.7%) with software assistance were analyzed. Age, sex, comorbidities, aneurysm characteristics, and operator's experience were comparable among the two groups. Procedures performed with the software had a lower rate of corrective intervention (9% vs 20%, p=0.036), a shorter intervention duration (46 min vs 52 min, p=0.002), a lower median radiation dose (1150 mGy vs 1558 mGy, p<0.001), and a shorter stent length (14 mm vs 16 mm, p<0.001). CONCLUSIONS: In our experience, the use of the virtual simulation during Pipeline treatment significantly reduced the need for corrective intervention, the procedural time, the radiation dose, and the length of the stent.

Versatile use of catheter systems for deployment of the Pipeline embolization device: a comparison of biaxial and triaxial catheter systems.

BACKGROUND: A Pipeline embolization device (PED; Medtronic, Dublin, Ireland) can be deployed using either a biaxial or a triaxial catheter delivery system. OBJECTIVE: To compare the use of these two catheter delivery systems for intracranial aneurysm treatment with the PED. METHODS: A retrospective study of patients undergoing PED deployment with biaxial or triaxial catheter systems between 2014 and 2016 was conducted. Experienced neurointerventionalists performed the procedures. Patients who received multiple PEDs or adjunctive coils were excluded. The two groups were compared for PED deployment time, total fluoroscopy time, patient radiation exposure, complications, and cost. RESULTS: Eighty-two patients with 89 intracranial aneurysms were treated with one PED each. In 49 cases, PEDs were deployed using biaxial access; triaxial access was used in 33 cases. Time (min) from guide catheter run to PED deployment was significantly shorter in the biaxial group (24.0±18.7 vs 38.4±31.1, P=0.006) as was fluoroscopy time (28.8±23.0 vs 50.3±27.1, P=0.001). Peak radiation skin exposure (mGy) in the biaxial group was less than in the triaxial group (1243.7±808.2 vs 2074.6±1505.6, P=0.003). No statistically significant differences were observed in transient and permanent complication rates or modified Rankin Scale scores at 30 days. The triaxial access system cost more than the biaxial access system (average $3285 vs $1790, respectively). Occlusion rates at last follow-up (mean 6 months) were similar between the two systems (average 88.1%: biaxial, 89.2%: triaxial). CONCLUSION: Our results indicate near-equivalent safety and effectiveness between biaxial and triaxial approaches. Some reductions in cost and procedure time were noted with the biaxial system.

Evaluation of a modular in vitro neurovascular procedure simulation for intracranial aneurysm embolization.

BACKGROUND: Rapid development in endovascular aneurysm therapy continuously drives demand for suitable neurointerventional training opportunities. OBJECTIVE: To investigate the value of an integrated modular neurovascular training environment for aneurysm embolization using additively manufactured vascular models. METHODS: A large portfolio of 30 patient-specific aneurysm models derived from different treatment settings (eg, coiling, flow diversion, flow disruption) was fabricated using additive manufacturing. Models were integrated into a customizable neurointerventional simulator with interchangeable intracranial and cervical vessel segments and physiological circuit conditions ('HANNES'; Hamburg ANatomic Neurointerventional Endovascular Simulator). Multiple training courses were performed and participant feedback was obtained using a questionnaire. RESULTS: Training for aneurysm embolization could be reliably performed using HANNES. Case-specific clinical difficulties, such as difficult aneurysm access or coil dislocation, could be reproduced. During a training session, models could be easily exchanged owing to standardized connectors in order to switch to a different treatment situation or to change from 'treated' back to 'untreated' condition. Among 23 participants evaluating hands-on courses using a five-point scale from 1 (strongly agree) to 5 (strongly disagree), HANNES was mostly rated as 'highly suitable for practicing aneurysm coil embolization' (1.78±0.79). CONCLUSION: HANNES offers a wide variability and flexibility for case-specific hands-on training of intracranial aneurysm treatment, providing equal training conditions for each situation. The high degree of standardization offered may be valuable for analysis of device behavior or assessment of physician skills. Moreover, it has the ability to reduce the need for animal experiments.

Histological mapping of porcine carotid arteries - An animal model for the assessment of artificial conduits suitable for coronary bypass grafting in humans.

BACKGROUND: Using animal models in experimental medicine requires mapping of their anatomical variability. Porcine common carotid arteries (CCA) are often preferred for the preclinical testing of vascular grafts due to their anatomical and physiological similarity to human small-diameter arteries. Comparing the microscopic structure of animal model organs to their human counterparts reveals the benefits and limitations of translational medicine. METHODS: Using quantitative histology and stereology, we performed an extensive mapping of the regional proximodistal differences in the fractions of elastin, collagen, and smooth muscle actin as well as the intima-media and wall thicknesses among 404 segments (every 1 cm) of porcine CCAs collected from male and female pigs (n = 21). We also compared the microscopic structure of porcine CCAs with segments of human coronary arteries and one of the preferred arterial conduits used for the coronary artery bypass grafting (CABG), namely, the internal thoracic artery (ITA) (n = 21 human cadavers). RESULTS: The results showed that the histological structure of left and right porcine CCA can be considered equivalent, provided that gross anatomical variations of the regular branching patterns are excluded. The proximal elastic carotid (51.2% elastin, 4.2% collagen, and 37.2% actin) transitioned to more muscular middle segments (23.5% elastin, 4.9% collagen, 54.3% actin) at the range of 2-3 centimeters and then to even more muscular distal segments (17.2% elastin, 4.9% collagen, 64.0% actin). The resulting morphometric data set shows the biological variability of the artery and is made available for biomechanical modeling and for performing a power analysis and calculating the minimum number of samples per group when planning further experiments with this widely used large animal model. CONCLUSIONS: Comparison of porcine carotids with human coronary arteries and ITA revealed the benefits and the limitations of using porcine CCAs as a valid model for testing bioengineered small-diameter CABG vascular conduits. Morphometry of human coronary arteries and ITA provided more realistic data for tailoring multilayered artificial vascular prostheses and the ranges of values within which the conduits should be tested in the future. Despite their limitations, porcine CCAs remain a widely used and well-characterized large animal model that is available for a variety of experiments in vascular surgery.

Preliminary in vitro angiographic comparison of the flow diversion behavior of Evolve and Pipeline devices.

BACKGROUND AND PURPOSE: Flow diverters are increasingly used to treat a broad category of cerebral aneurysms. We conducted an in vitro study to angiographically compare the flow diversion effect of Surpass Evolve from Stryker Neurovascular with the Pipeline Shield Embolization Device from Medtronic Neurovascular. METHODS: Three copies each of three carotid aneurysm geometries were manufactured from silicone. Evolve and Pipeline flow diverters were deployed in one copy of each geometry; the third copy was used as Control. High-speed angiography was acquired under pulsatile flow in each replica, contrast concentration-time curves within the aneurysms were recorded, and the curves were quantified with six parameters. The parameters were statistically evaluated to compare the flow diversion effect of both devices. RESULTS: The Evolve showed greater flow diversion trends in almost all intra-geometry comparisons than the Pipeline. When aggregated over the three geometries, the Evolve was statistically significantly better than the Pipeline in four of the six parameters, and about the same or better (not statistically significant) than the Pipeline in the other two parameters. CONCLUSIONS: The Evolve device demonstrated greater in vitro flow diversion effects than Pipeline. Comparative efficacy of the devices will need to be adjudicated based on clinical outcomes.

Endosaccular Flow Disruption: A New Frontier in Endovascular Aneurysm Management.

Flow modification has caused a paradigm shift in the management of intracranial aneurysms. Since the FDA approval of the Pipeline Embolization Device (Medtronic, Dublin, Ireland) in 2011, it has grown to become the modality of choice for a range of carefully selected lesions, previously not amenable to conventional endovascular techniques. While the vast majority of flow-diverting stents operate from within the parent artery (ie, endoluminal stents), providing a scaffold for endothelial cells growth at the aneurysmal neck while inducing intra-aneurysmal thrombosis, a smaller subset of endosaccular flow disruptors act from within the lesions themselves. To date, these devices have been used mostly in Europe, while only utilized on a trial basis in North America. To the best of our knowledge, there has been no dedicated review of these devices. We therefore sought to present a comprehensive review of currently available endosaccular flow disruptors along with high-resolution schematics, presented with up-to-date available literature discussing their technical indications, procedural safety, and reported outcomes.

A Methodology to Quantify the Geometrical Complexity of the Abdominal Aortic Aneurysm.

The abdominal aortic aneurysm (AAA) anatomy influences the technical success of the endovascular aneurysm repair (EVAR), yet very few data regarding the aortic tree angles exist in the literature. This poses great limitations in the numerical analyses of endografts, constraining their design improvement as well as the identification of their operational limitations. In this study, a matrix Φ of 10 angles was constructed for the description of the pathological region and was implemented on a large dataset of anatomies. More specifically, computed tomography angiographies from 258 patients were analysed and 10 aortic angles were calculated per case, able to adequately describe the overall AAA shape. 9 dimensional variables (i.e. diameters and lengths) were also recorded. The median and extreme values of these variables were computed providing a detailed quantification of the geometrical landscape of the AAA. Moreover, statistical analysis showed that the identified angles presented no strong correlation with each other while no lateral or anterior/posterior symmetry of the AAA was identified. These findings suggest that endograft designers are free to construct any extreme case-studies with the values provided in a mix-and-match manner. This strategy can have a powerful effect in EVAR stent graft designing, as well as EVAR planning.

Opinion: Aortic Graft Infection-Any Guidelines or Just Surgeon's Experience Lines!

Aggressive strategies for thoracic aortic graft infection, including resection of all infected tissues, in situ replacement with a rifampicin-bonded graft, and omental flap installation, resulted in improved survival.

Experiments on dynamic behaviour of a Dacron aortic graft in a mock circulatory loop.

Woven Dacron grafts are currently used for the surgical treatment of aortic aneurysm and acute dissection, two otherwise fatal pathologies when aortic wall rupture occurs. While Dacron is chosen for aortic grafts because of characteristics such as biocompatibility and durability, few data are available about the dynamic response of Dacron prosthetic devices and about their side effects on the cardiovascular system. In this study, a Dacron graft was subjected to physiological flow conditions in a specifically-developed mock circulatory loop. Experiments were conducted at different physiological pulsation-per-minute rates. Results show that, in comparison to an aortic segment of the same length, the prosthesis is extremely stiffer circumferentially, thus limiting the dynamical radial expansion responsible for the Windkessel effect in human arteries. The prosthesis is instead excessively compliant in the axial direction and develops preferentially bending oscillations. This very different dynamic behaviour with respect to the human aorta can alter cardiovascular pressure and flow dynamics resulting in long-term implant complications.

Evaluation of materials used for vascular anastomoses using shear wave elastography.

Cardiovascular disease is the leading cause of mortality in the United States. Peripheral artery disease (PAD) affects a substantial portion of the elderly population (>70 years). PAD can be symptomatic or asymptomatic, and treatment is directed towards improving functional vessel patency and limb salvage. Revascularization surgical treatments are needed in some cases, and it is not always possible to use autologous veins for vascular grafting. In this case, synthetic materials may be used. Synthetic materials such as expanded polytetrafluoroethylene (ePTFE) and poly (ethylene terephthalate) (Dacron) have been used. These materials are much stiffer compared to normal arterial vessels so developing alternative materials is an active area of research. One such potential material is a p olyvinyl alcohol cryogel reinforced arterial model (PRAM). In this study we used shear wave elastography (SWE) techniques to compare the mechanical behavior of excised aortas and anastomoses formed between the aortas and the Dacron, ePTFE, and PRAM materials. Different initial longitudinal strains (0%-40%) and transmural pressures (20-180 mmHg) were used to test a wide range of parameters that are within physiological ranges. We found that the PRAM materials had similar mechanical behavior in terms of group velocity measured in the vessel wall with respect to the excised aortas compared to the Dacron and ePTFE that had higher values of group velocity. The ratios of the group velocity for the PRAM material with respect to the aortas ranged from 0.83 to 1.13 where the Dacron and ePTFE had ranges of 1.12-2.22 and 1.91-3.10 for the same stretch and pressure ranges. The PRAM materials provide an alternative vascular material with better mechanical matching with excised aortas.

Clinical and Morphological Outcomes in Endovascular Aortic Repair of Abdominal Aortic Aneurysm Using GORE C3 EXCLUDER: Comparison between Patients Treated within and Outside Instructions for Use.

BACKGROUND: The goals of this study were to evaluate mid-term outcome in endovascular aortic repair (EVAR) of abdominal aortic aneurysm (AAA) using a GORE C3 EXCLUDER and compare results between patients treated within and outside the instructions for use (IFU). METHODS: Over a 3-year period spanning October 2013 to September 2016, consecutive patients undergoing EVAR for AAA using the C3 EXCLUDER at Tokyo Medical University Hospital were registered on a prospectively maintained database. The data thus obtained were retrospectively analyzed. RESULTS: A total of 109 AAA patients underwent EVAR using the C3 EXCLUDER. The median follow-up duration was 729 days (interquartile range, 542-1,069 days). Technical success was achieved in 98.2% of cases. Adjunctive, unplanned proximal cuff-extender implantation was required in 8 patients (9.2%). Of the total number, 29 (24.8%) were categorized as being treated outside the IFU. No significant difference was observed in freedom from overall mortality or aneurysm-related mortality between patients treated within and outside the IFU. Freedom from reintervention tended to be lower in patients treated outside the IFU. There was aneurysm sac shrinkage (≥5 mm) in 30.3% and 39.1%; stable aneurysm sac in 69.7% and 56.3%; and aneurysm sac expansion (≥5 mm) in 0% and 4.7% of cases at 1 and 2 years, respectively. No significant difference was observed in aneurysm sac shrinkage between patients treated within and outside the IFU. CONCLUSIONS: The C3 EXCLUDER showed good clinical performance and aneurysm sac shrinkage, regardless of whether the patient was treated within or outside the IFU. The results suggest, however, that in those treated outside the IFU, precise planning, careful operative procedure, and subsequent follow-up are required to obtain short-term and mid- to long-term success in EVAR for AAA using the C3 EXCLUDER.

Hemodynamic analysis of a novel stent graft design with slit perforations in thoracic aortic aneurysm.

Thoracic endovascular aortic repair (TEVAR) has been introduced as a less invasive approach to the treatment of thoracic aortic aneurysm (TAA). However, the effectiveness of TEVAR in the treatment of TAA is often limited due to the complex anatomy of aortic arch. Flow preservation at the three supra-aortic branches further increases the overall technical difficulty. This study proposes a novel stent graft design with slit perforations that can positively alter the hemodynamics at the aortic arch while maintaining blood flow to supra-aortic branches. We carried out a computational fluid dynamic (CFD) analysis to evaluate flow characteristics near stented aortic arch in simplified TAA models, followed by in-vitro experiments using particle image velocimetry (PIV) in a mock circulatory loop. The hemodynamics result was studied in terms of time-averaged wall shear stress (TAWSS), oscillating shear index (OSI), and endothelial cell action potential (ECAP). The results showed that the stent graft with slit perforations can reduce the disturbed flow region considerably. Furthermore, the effect of the slits on flow preservation to the supra-aortic branches was simulated and compared with experimental results. The effectiveness of the stent graft with slit perforations in preserving flow to the branches was demonstrated by both simulated and experimental results. Low TAWSS and elevated ECAP were observed in the aortic arch aneurysm after the placement of the stent graft with slits, implying the potential of thrombus formation in the aneurysm. On the other hand, the effects of the stent grafts with full-slit design and half-slit design on the shear stress did not differ significantly. The present analysis indicated that not only could the stent graft with slit perforations shield the aneurysm from rupture, but also it resulted in a favorable environment for thrombus that can contribute to the shrinkage of the aneurysm.

Standardized End Point Definitions for Coronary Intervention Trials: The Academic Research Consortium-2 Consensus Document.

The Academic Research Consortium (ARC)-2 initiative revisited the clinical and angiographic end point definitions in coronary device trials, proposed in 2007, to make them more suitable for use in clinical trials that include increasingly complex lesion and patient populations and incorporate novel devices such as bioresorbable vascular scaffolds. In addition, recommendations for the incorporation of patient-related outcomes in clinical trials are proposed. Academic Research Consortium-2 is a collaborative effort between academic research organizations in the United States and Europe, device manufacturers, and European, US, and Asian regulatory bodies. Several in-person meetings were held to discuss the changes that have occurred in the device landscape and in clinical trials and regulatory pathways in the last decade. The consensus-based end point definitions in this document are endorsed by the stakeholders of this document and strongly advocated for clinical trial purposes. This Academic Research Consortium-2 document provides further standardization of end point definitions for coronary device trials, incorporating advances in technology and knowledge. Their use will aid interpretation of trial outcomes and comparison among studies, thus facilitating the evaluation of the safety and effectiveness of these devices.

Comparison of postsurgical clinical sequences between completely embolized and incompletely embolized patients with wide nicked intracranial aneurysms treated with stent assisted coil embolization technique: A STROBE-compliant study.

The technique of stent-assisted coil embolization has been widely used in the clinic, while its efficacy and safety have yet to be evaluated. This study investigates the values of computed tomography angiography (CTA), magnetic resonance angiography (MRA), and digital subtraction angiography (DSA) in evaluating the Enterprise stent-assisted coil embolization in the treatment of intracranial wide-necked aneurysm.A total of 578 intracranial wide-necked aneurysm patients confirmed by MRA + CTA + DSA examinations were included and treated with Enterprise stent-assisted coil embolization in this study. All patients were assigned into complete embolization (CE) group and incomplete embolization (IE) group according to the results of postoperative MRA + CTA + DSA examinations and Raymond grades. Hunt-Hess grades, incidence of complication and Glasgow Outcome Scale (GOS) grades of patients were investigated to assess the therapeutic effect of Enterprise stent-assisted coil embolization in intracranial wide-necked treatment. Multivariate logistic regression analysis was performed to assess risk factors for the therapeutic effect of Enterprise stent-assisted coil embolization in intracranial wide-necked aneurysm.CTA images offered a better and clearer view than MRA and DSA images in both the CE and IE groups. Both the sensitivity and specificity of CTA were apparently higher than those of MRA. Patients in the CE group enjoyed a higher good GOS rate but a lower incidence of complication than those in the IE group. In Enterprise stent-assisted coil embolization treatment, the Hunt-Hess grade, hypertension, and size of artery aneurysm were independent factors affecting the therapeutic effect of Enterprise stent-assisted coil embolization in intracranial wide-necked aneurysm.Compared with MRA, CTA shows a higher value in evaluating the therapeutic effect of Enterprise stent-assisted coil embolization for the treatment of intracranial wide-necked aneurysm, and can thus serve as an important means of predicting the therapeutic effect of endovascular intervention in treating patients with intracranial wide-necked aneurysm.

[Thoracoabdominal aneurysms]. / Du nouveau dans les anévrysmes thoraco-abdominaux.

Endovascular treatment of thoracoabdominal aneurysms: what's new? Thoracoabdominal aneurysms (T-AAA) are aortic aneurysms that involve both the thoracic and abdominal segments of the aorta and its associated visceral branches. Although the first successful open repair was reported over 50 years ago, the risks of treatment remain considerable. As the first generations of devices available for endovascular aneurysm repair (EVAR) were relatively simple tubes or bifurcated grafts, initial attempts to extend the benefits of EVAR to patients with T-AAA lead to "hybrid solution". Good results with hybrid repairs have not been universal and the approach does not exploit all of the potential advantages of a "pure" endovascular approach (lesser surgical insult). This unmet need, together with rapid technological advances, has encouraged the development of custom-made endografts with fenestrations and/or branches (F-BEVAR) for extension into the visceral vessel ostia. F-BEVAR requires considerably more complex device design and planning than conventional EVAR. Deployment is more technically demanding and takes longer to complete. Thus, patient, aneurysm anatomy and surgical team selection is paramount. Favorable outcomes have been widely reported following T-AAA repair with F-BEVAR in expert centers; more complex aortic lesions such as T-AAA in the context of chronic dissection or arch aneurysms are thus now also offered endovascular repair with F-BEVAR.