Satoshi Tateshima

Novel aneurysm neck reconstruction device: initial experience in an experimental preclinical bifurcation aneurysm model.

Introduction Treatment of wide-necked bifurcation aneurysms often poses procedural and long-term outcome challenges. The initial preclinical experience with the Pulsar Vascular Aneurysm Neck Reconstruction Device (PVANRD) in a canine bifurcation model is described. Methods Experimental bifurcation vein pouch aneurysms were surgically created in the carotid arteries of eight dogs. Endovascular coiling of the aneurysms with assistance of the PVANRD was performed in all cases with acute performance compared with Y-stenting. Results Twelve devices were deployed in the eight cases. Deployment of the devices was straightforward and successfully protected the parent artery and maintained patency of the bifurcation in all cases, despite the use of oversized coils. Conclusion The PVANRD is a novel bifurcation stent that facilitates treatment of wide-necked bifurcation aneurysms compared with currently available adjunctive devices.

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 0.014u2005inch 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 60u2005s and compared. In both cases, intrasaccular pressure measurement with the use of 0.014u2005inch 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.

O-017 Preliminary Experience with a New Barrel Shaped Bifurcation Aneurysm Bridging Device

Purpose To test the feasibility of a novel fully retrievable barrel-shaped vascular reconstruction device for stent assisted endovascular treatment of wide-necked bifurcation aneurysms. Methods 16 Canine were utilised to assess the acute technical feasibility and the chronic in vivo performance of the Barrel™ Bifurcation Vascular Reconstruction Device (Reverse Medical Corporation, Irvine, CA). The degree of angiographic aneurysm occlusion and the ability of the barrel device to support an embolic coil mass in both surgically created wide-necked (> 4 mm/dome to neck ratio < 2) bifurcation (n =16) and lateral wall (n =16) aneurysms were evaluated. Diagnostic angiography was performed during the procedure, immediately post procedure, and at 1, 2, 3, and 6 months post implantation. Histological analyses to evaluate vessel wall injury, inflammation, and neointimal response, were performed after 3 months on a subset of canines. Results 32 surgically created wide necked (5.20 ± 0.61 mm/dome to neck ratio 1.47 ± 0.18) bifurcation and lateral wall aneurysms were successfully embolised with Barrel Vascular Reconstruction devices and embolic coils. All embolisations were deemed clinically acceptable with angiographic fills of 92% ± 10.2% and Coil packing densities of 49 ± 9%. Coil Protrusion was noted in 2/32 (6%) with small neck remnants seen in 13/32 (41%). Acute results demonstrated the device to be easily delivered through a microcatheter with excellent fluoroscopic visualisation of the device including the barrel segment. In all cases the device was easy to position with good coil mass support and device stability. As the device is resheathable, it could be placed into either the contralateral or ipso-lateral vessel of the bifurcation aneurysm, depending on which vessel position offered the best neck coverage. Additionally the device could be manipulated in situ to further gain optimal neck coverage. The 1, 2, 3 and 6-month angiographic follow-ups confirmed that the device continued to provide both coil mass stability and neck coverage. 3-month histology was conducted and demonstrated that the device had zero or minimal vessel wall damage, with mature, stable and endothelialised neointima at aneurysmal necks. Additionally device struts were associated with zero or minimal inflammatory reaction. Conclusions The acute technical feasibility and chronic durability of the novel the Barrel™ Bifurcation Vascular Reconstruction Device has been demonstrated and may offer a new tool for the endovascular treatment of wide-necked bifurcation and branching type aneurysms. Disclosures S. Tateshima: 2; C; Reverse Medical. 4; C; Reverse Medical. D. Niemann: 2; C; Reverse Medical. S. Moskowitz: 2; C; Reverse Medical. B. Baxter: 2; C; Reverse Medical. D. Frei: 2; C; Reverse Medical. Abstract O-017 Figure 1

O-031 Preliminary Experience with the MVP™ Device, a New Microcatheter-Deliverable Vascular Plug for Rapid Endovascular Vessel Occlusion and Flow Control

Purpose To test the feasibility of a novel microcatheter-deliverable self-expanding vascular plug for use in endovascular flow control and vessel occlusion. Methods 40 peripheral vessels in 10 canines were utilised to assess acute technical feasibility and chronic in vivo performance of the Reverse Medical™ Corporation MVP™ Micro Vascular Plug System (MVP-3) compared to Covidien ® Axium™ embolisation coils (5mm X 15cm helical) and St. Jude Medical® Amplatzer® Vascular Plug 4 (AVP-4 4mm x 10mm). In this study, arteries 1.5 - 3.0 mm in diameter were targeted for embolisation. Four vessel sites were chosen: left and right subclavian, and left and right internal thoracic arteries. Within each subject a single MVP-3 device was placed in three vessels and one control (a single AVP-4 or Axium coil) in the fourth vessel. Angiography was conducted 1,3,5 and 10 minutes post device implantation and a quantitative flow grade was given (TIMI Grade 0, 1, 2, or 3). If complete flow stasis (Grade 0) was achieved prior to 10 minutes, no further angiographies were performed for that vessel/device. Acute endpoints included system preparation, access, vessel embolisation and system performance/clinical acceptability. Post implantation each canine was given 80mg/day aspirin to create a worst-case recanalisation scenario. Chronic study endpoints include 1, 2, 3 and 6 months follow up for efficacy: patency, blood flow (occlusion), migration and re-canalisation; and safety: absence of adverse events associated with the device and/or delivery system, and histological and pathological evaluations including local foreign body reactions. Results 40 target vessels, average diameter 2.55mm (range 1.86–2.89 mm), were successfully implanted with embolisation devices. MVP-3 devices and Axium coils were delivered through .021 microcatheter and AVP-4 devices were delivered through guide catheter. Flow reduction or occlusion within 10 minutes (TIMI Flow Grade 0, 1, or 2) was achieved 30/30 (100%) with a single MVP-3 device, versus 33% (2/6) with a single AVP–4 device, and versus 0% (0/4) with a single Axium Coil. Complete vessel occlusion was demonstrated in 17/30 (57%) target vessels with a single MVP-3 versus 0/6 (0%) for a single AVP–4 device vs 0/4 (0%) for a single Axium Coil. At 1, 2, 3 and 6 month follow up and histopathology, the MVP-3 had superior durability and neointimal coverage, less recanalisation compared to the control devices and demonstrated no migration. Conclusions The novel MVP Micro Vascular Plug System demonstrated superior performance and clinical acceptability and provides for better occlusion/flow reduction compared to control devices. Abstract O-031 Figure 1 Disclosures S. Tateshima: 2; C; Reverse Medical. 4; C; Reverse Medical. D. Niemann: 2; C; Reverse Medical. S. Moskowitz: 2; C; Reverse Medical. B. Baxter: 2; C; Reverse Medical. D. Frei: 2; C; Reverse Medical.

Nature’s Wastebasket: The Role of the External Carotid Artery in Acute Stroke

We describe a novel technical approach to acute stroke illustrated by the case of a 41 year old male who presented with tandem right common carotid artery (CCA) and M1 occlusions. His NIHSS was 17 and Alberta stroke programe early CT score (ASPECTs) was 8. Thrombectomy initially proved challenging due to large volume CCA thrombus that repeatedly occluded the aspiration catheters. However, by inflating a balloon distally and pulling clot into the adjacent ECA, we were able to quickly restore distal contrast flow to the intracranial circulation and achieve Thrombolysis In Cerebral Infarction/Arterial Occlusive Lesion (TICI2C/AOL3) revascularization.

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.

P-018 Parent Artery Curvature and Angle of Incidence of Blood Flow Affect Flow Diversion Effect of Pipeline

Introduction Pipeline flow diversion stent is often placed in a tortuous anatomy. Nevertheless, effect of parent artery curvature on the flow diversion effect from Pipeline stent is poorly understood. The flow diversion effect could be enhanced or diminished depending on the curvature of Pipeline or the angle at which blood flow strikes the Pipeline (angle of incidence). These variations may explain why not all aneurysms are obliterated after Pipeline treatment despite its high efficacy. We evaluated the flow diversion effect of Pipeline in various parent artery curvatures and angle of incidence in in-vitro models. Methods Four acrylic prototypes of curved tube with a side branch were constructed with circular cross section with the inner diameter of 3.8 mm. The variation among the prototypes was made in terms of the radius of curvature R (R = 25 mm and 50 mm), and the relative angle θ of the side branch (θ = 60, 90, and 120). The angle θ of the side branch determines the angle of incidence. The identical Pipeline of diameter 4.75 mm were placed to each prototype and the pressure loss (K) occurring in the flow through the Pipeline mesh was measured for the Reynolds numbers ranging from 100 to 800. Careful error analysis on the measured data made it possible to quantify weak change of the flow resistance due to the geometrical variations. Results The parent artery curvature and angle of incidence of the blood flow clearly affect the flow diversion effect (K) of Pipeline (Figure 1). Flow diversion effect diminishes in tighter curvature. Also noted is higher angle of incidence reduces flow diversion effect.Abstract P-018 Figure 1 Conclusion The parent artery curvature and angle of incidence are important parameters that may affect the efficacy of Pipeline. Disclosures S. Tateshima: 1; C; Material Support/Medtronic. 2; C; Consultant/Medtronic, Consultant/Stryker, Consultant/Blockade Medical, Consultant/PulsarVascular, Consultant/Century Medical Inc., Consultant/Penumbra. 4; C; PulsarVascular, Blockade Medical. 6; C; Microvention/Fellowship Support Grant. R. Sagas: None. C. Kularni: None. D. Duong: None. S. Obi: None.

O-006 A novel microcatheter based device for endovascular mechanical thrombectomy/flow restoration

Purpose To evaluate the performance of a new microcatheter based device (ReStore, Reverse Medical, Irvine, California, USA) for endovascular mechanical thrombectomy/flow restoration in a swine thromboembolic model and to compare its efficacy over other available devices for mechanical thromboembolectomy. Method We investigated the use of ReStore for thrombectomy treatment against similar control devices. The cerebral vasculature swine model was utilized in which 12 of each carotid artery branches were prepared with prophylactic papaverine due to the vasospastic nature of the swine model and occluded with radio-opacified blood thrombi. The thrombi were prepared in such a way to represent characteristics of those found in acute stroke patients. The thrombi were injected into target arteries via a 6u2005Fr guiding catheter. The thrombi were allowed to set up in situ for at least 15u2005min until complete localized occlusion of the target vessels were confirmed by angiography. Once the occlusion was confirmed, ReStore or a control device was advanced via a 6u2005Fr guide catheter and precisely positioned across the target thrombi over a microguide wire. No flow arresting means was utilized during retrieval or recanalization attempts. Only localized aspiration was conducted via the 6u2005Fr guide catheter, once the ReStore or control device holding retrieved thrombi was pulled down to the tip of the guide catheter. Parameters collected for this assessment study were TIMI score, number of retrieval attempts, per cent clot retrieved, time to recanalization, thrombus fragmentation and loss of thrombus at the tip of the guide catheter. Results We found higher TIMI scores (OR 9; 95% CI 0.28 to 285.3), recanalization on the first attempt (9/10 vs 0/2; p<0.01) and per cent clot retrieved (74% vs 20%; p=0.06) with ReStore over the control devices while procedure times for ReStore appeared to be the same as that of the control device. Despite the use of prophylactic papaverine, vasospasm was still prevalent in all cases, even during guidewire and catheter manipulations. No vessel dissections or device failures were encountered during this study. Study recanalization rates for ReStore (9/10, 90%) in the swine model, which is much less tortuous than humans, and the radio-opacified thrombi allowed for more accurate target positioning and retrieval. Conclusion ReStore is effective in removal of thrombi and recanalization of blood flow within the swine cranial arteries.Abstract O-006 Figure 1

008 Biomechanical design of the intracranial stent for the cerebral aneurysm treatment

Introduction: The mechanical characteristic required for an aneurysm stent is high longitudinal flexibility and low radial stiffness. Longitudinal flexibility is necessary to navigate the tortuous shape inherent to the intracranial circulation to reach lesions beyond the carotid siphon. Low radial stiffness is necessary to reduce the risk of vascular damage. However, mechanical behavior such as stress distribution and deformation by finite element method (FEM) and experiments of cerebrovascular stent has not yet been studied. The aim of this study is to …

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.nnMaterials and Methods: Nitinol sheets were treated with UV irradiation, and the surface energy of each sheet was evaluated by the contact angle …