Fernando Vinuela

Angioarchitectural characteristics associated with initial hemorrhagic presentation in supratentorial brain arteriovenous malformations

OBJECTIVE The difference in arterial supply, venous drainage, functional localization in supratentorial and infratentorial compartments may contribute to the conflicting results about risk factors for hemorrhage in published case series of brain arteriovenous malformation (bAVM). Further investigation focused on an individual brain compartment is thus necessary. This retrospective study aims to identify angioarchitectural characteristics associated with the initial hemorrhagic event of supratentorial bAVMs. MATERIALS AND METHODS The clinical and angiographic features of 152 consecutive patients with supratentorial bAVMs who presented to our hospital from 2005 to 2008 were retrospectively reviewed. All these patients had new diagnosis of bAVM. Univariate (χ(2) test) and multivariate analyses were conducted to assess the angiographic features in patients with and without initial hemorrhagic presentations. A probability value of less than 0.05 was considered statistically significant in each analysis. RESULTS In 152 patients with supratentorial AVMs, 70.6% of deep and 52.5% of superficial sbAVMs presented with hemorrhage. The deep location was correlated with initial hemorrhagic presentation in univariate analysis (χ(2)=3.499, p=0.046) but not in the multivariate model (p=0.144). There were 44 sbAVMs with perforating feeders, 39 (88.6%) of which bled at a significantly higher rate than those with terminal feeders (χ(2)=25.904, p=0.000). 87.5% (21/24) of exclusive deep venous drainage presented with hemorrhage, a significantly higher rate than those of the other type of venous drainage (χ(2)=11.099, p=0.004). All 10 patients with both perforating feeders and exclusive deep draining vein presented with initial hemorrhage. Hemorrhagic presentation was correlated with perforating feeders (p=0.000) and exclusive deep draining vein (p=0.007) in multivariate analysis as well. CONCLUSIONS Supratentorial bAVMs with perforating feeders and deep venous drainage have a higher risk of hemorrhage. In contrast with many previous reports, AVM location was not associated with hemorrhagic presentation in adjusted analyses. The correlation between deep location and initial hemorrhage in univariate analysis might be caused by the involved perforating feeders and deep draining vein in the deep located AVMs.

Aneurysm pressure measurement before and after placement of a Pipeline stent: feasibility study using a 0.014 inch pressure wire for coronary intervention.

Flow-diverting stents have provided a new endovascular capacity to reconstruct an intracranial aneurysm with its diseased parent artery. The results of first-generation flow diversion stents have been encouraging, with even large or giant treated aneurysms achieving complete angiographic occlusion at 12-month follow-up. Numerous clinical reports have described a slow progressive thrombosis pattern and gradual increase in rate of complete aneurysm obliteration over time. Despite promising early results, some complications specific to flow-diverting stents have been encountered. Chief among them is delayed aneurysm rupture. This complication did not emerge with stent-assisted coil embolization of intracranial aneurysms, and the underlying cause has not been established. However, new evidence suggests that persistent, or even increased, aneurysm pressure after stent placement may play a role in some delayed ruptures. We sought to evaluate this phenomenon by measuring intrasaccular pressure before and after stent placement using two different 0.014 inch coronary pressure measurement wires. Two patients with giant internal carotid artery aneurysms treated with flow-diverting stents were evaluated. Before and after stent deployment, intrasaccular aneurysm and systemic arterial pressures were recorded for 60 s and compared. In both cases, intrasaccular pressure measurement with the use of 0.014 inch pressure wire system was feasible; the pressure wires could be pushed out of the microcatheter placed in the aneurysms without friction or unexpected microcatheter motion. Despite successful flow-diverting stent deployment and angiographic flow diversion effects with excellent wall opposition across the aneurysm necks, there was no significant difference between intrasaccular and systemic pressures.

Increased affinity of endothelial cells to NiTi using ultraviolet irradiation: An in vitro study: UV-INDUCED BIOACTIVATION OF NiTi

Nickel-titanium alloy (NiTi) is one of the most popular materials used endovascularly because of its shape memory and superelasticity. The NiTi device needs to be covered by endothelial cells after being placed in the blood vessel to reduce ischemic complications. The objective of this study was to examine the impact of ultraviolet (UV) irradiation on the biocompatibility of NiTi surfaces with endothelial cells. NiTi sheets were treated with UV irradiation for 48 h and human aorta derived endothelial cells were used in this study. UV irradiation converted the NiTi surface to hydrophilic state and increased albumin adsorption. The number of endothelial cell migration, attachment, proliferation as well as their metabolic activity were significantly increased on UV treated NiTi. This study provides the first evidence of the photoactivation of NiTi surfaces by UV irradiation and demonstrates improved biocompatibility of UV-treated NiTi surfaces with vascular endothelial cells. These results suggest that UV irradiation may promote endothelialization of NiTi devices in blood vessels.

Feasibility and utility of an integrated medical imaging and informatics smartphone system for management of acute stroke

Background Rapid dissemination and coordination of clinical and imaging data among multidisciplinary team members are essential for optimal acute stroke care. Aim To characterize the feasibility and utility of the Synapse Emergency Room mobile (Synapse ERm) informatics system. Methods We implemented the Synapse ERm system for integration of clinical data, computerized tomography, magnetic resonance, and catheter angiographic imaging, and real-time stroke team communications, in consecutive acute neurovascular patients at a Comprehensive Stroke Center. Results From May 2014 to October 2014, the Synapse ERm application was used by 33 stroke team members in 84 Code Stroke alerts. Patient age was 69.6 (±17.1), with 41.5% female. Final diagnosis was: ischemic stroke 64.6%, transient ischemic attack 7.3%, intracerebral hemorrhage 6.1%, and cerebrovascular-mimic 22.0%. Each patient Synapse ERm record was viewed by a median of 10 (interquartile range 6–18) times by a median of 3 (interquartile range 2–4) team members. The most used feature was computerized tomography, magnetic resonance, and catheter angiography image display. In-app tweet team, communications were sent by median 1 (interquartile range 0–1, range 0–13) users per case and viewed by median 1 (interquartile range 0–3, range 0–44) team members. Use of the system was associated with rapid treatment times, faster than national guidelines, including median door-to-needle 51.0 min (interquartile range 40.5–69.5) and median door-to-groin 94.5 min (interquartile range 85.5–121.3). In user surveys, the mobile information platform was judged easy to employ in 91% (95% confidence interval 65%–99%) of uses and of added help in stroke management in 50% (95% confidence interval 22%–78%). Conclusion The Synapse ERm mobile platform for stroke team distribution and integration of clinical and imaging data was feasible to implement, showed high ease of use, and moderate perceived added utility in therapeutic management.

E-001 Estimation of stent conformity for cerebrovascular stent with patient-specific curved arterial model

Introduction Clinically, adaptation of an implanted stent to the vessel wall influences the development of problems such as intimal hyperplasia and in-stent-stenosis for intracranial stenting. In particular, for the stenting in a curved vessel, it was indicated that a stent deployed across an artery with angulation exerts a certain longitudinal rebounding cause of vessel straightening. For this reason, it is necessary to investigate stent-artery interaction including stress distribution and vessel deformation due to stent designs within the realistic curved arterial model. Materials and Methods The aim of this study is to analyze and evaluate the stress distribution within the stented curved artery using open and closed-cell stent designs. We focused on stent geometries and calculated the differences in stress within the realistic curved artery due to the structure and stent position using deformation analysis with finite element modeling. Results The results have different stress behavior by stent designs and its position within the parent artery. High stress values were obtained in the curved portion and at the proximal section of the parent artery with the area of contact between stent strut and the artery for all models. This behavior could be explained by differences the metal-to-artery ratio on each side of proximal and distal vessel according to stent position. Furthermore, vessel straightening was obtained for curved section with stented artery due to longitudinal rebounding force of the stent. Comparing the distribution of high stress area for stent designs, open-cell stent has lager area of high stresses than closed-cell stent at distal portion. In the other hand, the stress distribution of closed-cell was similar for different stent position. Conclusion For our simulation, stent behavior such as stress status and vessel deformation was varied by stent design and its position within the curved artery. This numerical method might be effective for designing a better stent specifically for the intracranial stenting and also to select an appropriate stent prior to the actual endovascular procedure. Competing interests None.

027 Hydrophilic surface modification of metallic endovascular devices

Background: Current endovascular procedures to treat vascular diseases use a variety of metallic devices (eg, guidewires, stents, filters and coils). One of the most popular materials used for the endovascular metallic devices is NiTi/nitinol. A nitinol endovascular device having an enhanced rate of endothelialization and neointima coverage as well as an enhanced affinity of the device with a native vascular tissue brings a positive impact on clinical practice. Materials and Methods: Nitinol sheets were treated with UV irradiation, and the surface energy of each sheet was evaluated by the contact angle …