Thomas R. Marotta
Thomas R. Marotta, Thorsteinn Gunnarsson, Ian Penn, Donald R. Ricci, Ian Mcdougall, Alexei Marko, Gyasi Bourne and Leodante Da Costa
The authors describe a novel device for the endovascular treatment of intracranial aneurysms, the endovascular clip system (eCLIPs). Descriptions of the device and its delivery system as well as the results of flow model tests and the treatment of experimental aneurysms are provided.
The eCLIPs comprises a flexible hybrid implantable device (an anchor and a covered leaf) and a balloon catheter delivery system, designed to be positioned and activated in the parent vessel in such a way that the covered portion will abut the aneurysm neck. The eCLIPs was subjected to testing in glass, elastomeric, and cadaveric flow models to determine its navigability, orientation, and activation compared with commercially available stents. In a second experiment, 8 carotid artery sidewall aneurysms in swine were treated using eCLIPs. The degree of occlusion was observed on angiography immediately following and 30 days after device activation, and a histological analysis was performed at 30 days.
The device could navigate tortuous glass models and human cadaveric vessels. Compared with commercially available stents, the eCLIPs performed well. It could be navigated, oriented, and activated easily and reliably. With regard to the 8 porcine experimental aneurysms, immediate postactivation angiograms confirmed complete occlusion of 4 lesions and near occlusion of the other 4. Angiographic follow-up at 30 days postactivation showed occlusion of all 8 aneurysms and patency of all parent vessels. Histopathological analysis revealed aneurysm healing, with smooth-muscle cells growing across the lesion neck to allow reendothelialization.
Aneurysm occlusion with a single extrasaccular endovascular device has potential advantages. The authors believe that eCLIPs may prove to be a useful tool in the endovascular treatment of cerebral aneurysms. The system should reduce risks associated with coiling, procedure time, costs, and radiation exposure. The device satisfactorily occluded 8 experimental sidewall aneurysms. The observed healing pattern is similar to that seen after microsurgical clipping.
Thomas R. Marotta, Howard A. Riina, Ian McDougall, Donald R. Ricci and Monika Killer-Oberpfalzer
Intracranial bifurcation aneurysms are complex lesions for which current therapy, including simple coiling, balloon- or stent-assisted coiling, coil retention, or intrasaccular devices, is inadequate. Thromboembolic complications due to a large burden of intraluminal metal, impedance of access to side branches, and a high recurrence rate, due largely to the unmitigated high-pressure flow into the aneurysm (water hammer effect), are among the limitations imposed by current therapy. The authors describe herein a novel device, eCLIPs, and its use in a preclinical laboratory study that suggests the device's design and functional features may overcome many of these limitations.
A preclinical model of wide-necked bifurcation aneurysms in rabbits was used to assess functional features and efficacy of aneurysm occlusion by the eCLIPs device.
The eCLIPs device, in bridging the aneurysm neck, allows coil retention, disrupts flow away from the aneurysm, leaves the main vessel and side branches unencumbered by intraluminal metal, and serves as a platform for endothelial growth across the neck, excluding the aneurysm from the circulation.
The eCLIPs device permits physiological remodeling of the bifurcation.
Christoph J. Griessenauer, Christopher S. Ogilvy, Nimer Adeeb, Adam A. Dmytriw, Paul M. Foreman, Hussain Shallwani, Nicola Limbucci, Salvatore Mangiafico, Ashish Kumar, Caterina Michelozzi, Timo Krings, Vitor Mendes Pereira, Charles C. Matouk, Mark R. Harrigan, Hakeem J. Shakir, Adnan H. Siddiqui, Elad I. Levy, Leonardo Renieri, Thomas R. Marotta, Christophe Cognard and Ajith J. Thomas
Flow diversion for posterior circulation aneurysms performed using the Pipeline embolization device (PED) constitutes an increasingly common off-label use for otherwise untreatable aneurysms. The safety and efficacy of this treatment modality has not been assessed in a multicenter study.
A retrospective review of prospectively maintained databases at 8 academic institutions was performed for the years 2009 to 2016 to identify patients with posterior circulation aneurysms treated with PED placement.
A total of 129 consecutive patients underwent 129 procedures to treat 131 aneurysms; 29 dissecting, 53 fusiform, and 49 saccular lesions were included. At a median follow-up of 11 months, complete and near-complete occlusion was recorded in 78.1%. Dissecting aneurysms had the highest occlusion rate and fusiform the lowest. Major complications were most frequent in fusiform aneurysms, whereas minor complications occurred most commonly in saccular aneurysms. In patients with saccular aneurysms, clopidogrel responders had a lower complication rate than did clopidogrel nonresponders. The majority of dissecting aneurysms were treated in the immediate or acute phase following subarachnoid hemorrhage, a circumstance that contributed to the highest mortality rate in those aneurysms.
In the largest series to date, fusiform aneurysms were found to have the lowest occlusion rate and the highest frequency of major complications. Dissecting aneurysms, frequently treated in the setting of subarachnoid hemorrhage, occluded most often and had a low complication rate. Saccular aneurysms were associated with predominantly minor complications, particularly in clopidogrel nonresponders.
Albert H. Chiu, Joost De Vries, Cian J. O'Kelly, Howard Riina, Ian McDougall, Jonathan Tippett, Martina Wan, Airton Leonardo de Oliveira Manoel and Thomas R. Marotta
Treatment of wide-necked intracranial aneurysms is associated with higher recanalization and complication rates; however, the most commonly used methods are not specifically designed to work in bifurcation lesions. To address these issues, the authors describe the evolution in the design and use of the eCLIPs (Endovascular Clip System) device, a novel hybrid stent-like assist device with flow diverter properties that was first described in 2008.
A registry was established covering 13 international centers at which patients were treated with the second-generation eCLIPs device. Aneurysm morphology and rupture status, device neck coverage, coil retention, and procedural and late morbidity and mortality were recorded. For those patients who had undergone successful implantation more than 6 months earlier, the final imaging and clinical follow-up results and need for re-treatment were recorded.
Thirty-three patients were treated between June 2013 and September 2015. Twenty-five (76%) patients had successful placement of an eCLIPs device; 23 (92%) of these 25 patients had complete data. Eight cases of nondeployment occurred during the 1st year of use, consistent with a learning curve; no failures of deployment occurred thereafter. Two periprocedural transient ischemic attacks and 2 asymptomatic thrombotic events occurred. Twenty-one (91%) of 23 patients underwent follow-up at an average of 8 months (range 3–18 months); 9 (42.9%) of these 21 patients demonstrated an improvement in Raymond grade at follow-up; no cases of worsening Raymond grade were recorded, and 17 (81.0%) patients sustained a modified Raymond-Roy Classification class of I or II angiographic result at follow-up. Two delayed ruptures were recorded, both in previously coiled, symptomatic giant aneurysms where the device was used as a part of a salvage strategy.
The second-generation eCLIPs device is a viable treatment option for bifurcation aneurysms. The aneurysm occlusion rates in this initial clinical series are comparable to the initial experience with other bifurcation support devices.