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51 result(s) for "Lopes, Demetrius K."
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Long-Term Clinical and Angiographic Outcomes Following Pipeline Embolization Device Treatment of Complex Internal Carotid Artery Aneurysms: Five-Year Results of the Pipeline for Uncoilable or Failed Aneurysms Trial
Abstract BACKGROUND: Early and mid-term safety and efficacy of aneurysm treatment with the Pipeline Embolization Device (PED) has been well demonstrated in prior studies. OBJECTIVE: To present 5-yr follow-up for patients treated in the Pipeline for Uncoilable or Failed Aneurysms clinical trial. METHODS: In our prospective, multicenter trial, 109 complex internal carotid artery (ICA) aneurysms in 107 subjects were treated with the PED. Patients were followed per a standardized protocol at 180 d and 1, 3, and 5 yr. Aneurysm occlusion, in-stent stenosis, modified Rankin Scale scores, and complications were recorded. RESULTS: The primary endpoint of complete aneurysm occlusion at 180 d (73.6%) was previously reported. Aneurysm occlusion for those patients with angiographic follow-up progressively increased over time to 86.8% (79/91), 93.4% (71/76), and 95.2% (60/63) at 1, 3, and 5 yr, respectively. Six aneurysms (5.7%) were retreated. New serious device-related events at 1, 3, and 5 yr were noted in 1% (1/96), 3.5% (3/85), and 0% (0/81) of subjects. There were 4 (3.7%) reported deaths in our trial. Seventy-eight (96.3%) of 81 patients with 5-yr clinical follow-up had modified Rankin Scale scores ≤2. No delayed neurological deaths or hemorrhagic or ischemic cerebrovascular events were reported beyond 6 mo. No recanalization of a previously occluded aneurysm was observed. CONCLUSION: Our 5-yr findings demonstrate that PED is a safe and effective treatment for large and giant wide-necked aneurysms of the intracranial ICA, with high rates of complete occlusion and low rates of delayed adverse events.
Analysis of neointima development in flow diverters using optical coherence tomography imaging
BackgroundFlow diverters are used for the treatment of intracranial aneurysms. Surface modification may decrease the thrombogenicity of flow diverters but the details are unknown. Optical coherence tomography (OCT) is an intravascular imaging test with high resolution which identifies neointimal growth over stents. We compared the development of neointima in a flow diverter and stents with and without surface modification in a swine model.MethodsIn this study we implanted four devices (two in each carotid artery) in four pigs. The devices used were the Pipeline Flex embolization device (PED Flex, n=6), PED with Shield technology (PED Shield, n=6), and Solitaire AB (n=4). Serial carotid angiographic and OCT images were obtained on days 0, 7, 14, and 21. The data analyzed included: neointimal area (lumen area − stent area), neointimal ratio ([lumen area − stent area]/stent area), and the neointimal thickness ratio (minimum neointimal thickness/maximum neointimal thickness).ResultsThere was no significant difference in where neointima formation was initiated in relation to the implanted device (distal vs middle vs proximal). The PED Shield had a trend towards earlier endothelial formation at day 7. By day 21 the neointimal ratio was significantly higher for the PED Flex and PED Shield devices than for Solitaire (p<0.05 and p<0.01, respectively). The neointimal thickness ratio was significantly higher with PED Shield than with PED Flex and Solitaire (p<0.05 and p<0.01, respectively).ConclusionsOCT enabled us to follow and compare in vivo the development of neointima over implants. PED Shield showed a similar neointimal volume to PED Flex and more concentric neointima.
A neurovascular high-frequency optical coherence tomography system enables in situ cerebrovascular volumetric microscopy
Intravascular imaging has emerged as a valuable tool for the treatment of coronary and peripheral artery disease; however, no solution is available for safe and reliable use in the tortuous vascular anatomy of the brain. Endovascular treatment of stroke is delivered under image guidance with insufficient resolution to adequately assess underlying arterial pathology and therapeutic devices. High-resolution imaging, enabling surgeons to visualize cerebral arteries' microstructure and micron-level features of neurovascular devices, would have a profound impact in the research, diagnosis, and treatment of cerebrovascular diseases. Here, we present a neurovascular high-frequency optical coherence tomography (HF-OCT) system, including an imaging console and an endoscopic probe designed to rapidly acquire volumetric microscopy data at a resolution approaching 10 microns in tortuous cerebrovascular anatomies. Using a combination of in vitro, ex vivo, and in vivo models, the feasibility of HF-OCT for cerebrovascular imaging was demonstrated. High resolution intravascular imaging in the brain is limited by the high tortuosity of the vasculature. Here the authors present a fiber optic imaging technology using high-frequency optical coherence tomography (HF-OCT) to provide volumetric high resolution images in the highly tortuous cerebral vasculature.
Results of the ANSWER Trial Using the PulseRider for the Treatment of Broad-Necked, Bifurcation Aneurysms
Abstract BACKGROUND: The safety and probable benefit of the PulseRider (Pulsar Vascular, Los Gatos, California) for the treatment of broad-necked, bifurcation aneurysms was studied in the context of the prospective, nonrandomized, single arm clinical trial—the Adjunctive Neurovascular Support of Wide-neck aneurysm Embolization and Reconstruction (ANSWER) Trial. OBJECTIVE: To present the results of the United States cases employing the PulseRider device as part of the ANSWER clinical trial. METHODS: Aneurysms treated with the PulseRider device among sites enrolling in the ANSWER trial were prospectively studied and the results are summarized. Aneurysms arising at either the carotid terminus or basilar apex that were relatively broad necked were considered candidates for inclusion into the ANSWER study. RESULTS: Thirty-four patients were enrolled (29 female and 5 male) with a mean age of 60.9 years (27 basilar apex and 7 carotid terminus). Mean aneurysm height ranged from 2.4 to 15.9 mm with a mean neck size of 5.2 mm (range 2.3-11.6 mm). In all patients, the device was delivered and deployed. Immediate Raymond I or II occlusion was achieved in 82.4% and progressed to 87.9% at 6-month follow-up. A modified Rankin Score of 2 or less was seen in 94% of patients at 6 months. CONCLUSION: The results from the ANSWER trial demonstrate that the PulseRider device is safe and offers probable benefit as for the treatment of bifurcation aneurysms arising at the basilar apex or carotid terminus. As such, it represents a useful addition to the armamentarium of the neuroendovascular specialist.
The safety and effectiveness of the LVIS stent system for the treatment of wide-necked cerebral aneurysms: final results of the pivotal US LVIS trial
IntroductionThe LVIS stent system (LVIS and LVIS Junior) is a self-expanding, retrievable, microstent system indicated for the treatment of wide-necked cerebral aneurysms (WNAs). The present pivotal study was performed to evaluate the safety and effectiveness of this device.MethodsThe US LVIS pivotal trial was a prospective, multicenter, single-arm, interventional study conducted at 21 US centers. The study enrolled 153 adults with WNAs of the anterior and posterior circulations. The study was conducted under good clinical practices and included independent adjudication of all adverse events. The primary effectiveness endpoint was defined as successful aneurysm treatment with the LVIS System as evidenced by complete (100%) aneurysm occlusion at 12 months on conventional angiography without retreatment and without significant (≥50%) stenosis of the treated artery at 12 months as determined by an independent core laboratory. The primary safety endpoint was defined as the rate of stroke or death within 30 days, or ipsilateral stroke or neurologic death with 12 months.ResultsOne hundred and fifty-three patients enrolled at 21 investigational sites underwent attempted LVIS-assisted coil embolization. The mean age was 58.3±10.5 years and the majority of the participants (110/153, 71.9%) were female. Fifty-seven aneurysms (57/153, 37.3%) arose from the anterior cerebral artery, 43 (43/153, 28.1%) from the internal carotid artery, 17 (17/153, 11.1%) from the middle cerebral artery, 27 (27/153, 17.6%) from the basilar artery, six (6/153,3.9 %) from the PCA, and two from the vertebral artery. A single aneurysm arose from the superior cerebellar artery. The mean aneurysm dome height was 6.0±2.2 mm and mean width 5.5±2.3 mm. Mean neck width was 4.2±1.4 mm. A total of 22 participants presented for re-treatment of a previously ruptured (>30 days prior to treatment) target aneurysm. The primary effectiveness endpoint was observed in 70.6% (108/153) in the intent to treat population (ITT). Of the evaluable participants with follow-up 12-month angiography, 79.1 % (110/139) demonstrated complete occlusion– 92.1% (128/139) in this population demonstrated ≥95% occlusion and 95% demonstrated ≥90% occlusion (132/139). Eight participants (5.2%, 8/153) had at least one primary safety event in the ITT population.ConclusionThe LVIS stent system allows safe and highly effective coil embolization of WNAs.Clinical registration numberNCT01793792.
Multicenter Study of Pipeline Flex for Intracranial Aneurysms
Abstract Background The Pipeline Flex (PED Flex; Medtronic, Dublin, Ireland) was designed to facilitate deployment and navigation compared to its previous iteration to reduce the rate of technical events and complications. OBJECTIVE To assess the neurological morbidity and mortality rates of the PED Flex at 30 d. Methods Information from 9 neurovascular centers was retrospectively obtained between July 2014 and March 2016. Data included patient/aneurysm characteristics, periprocedural events, clinical, and angiographic outcomes. Multivariate logistic regression was performed to determine predictors of unfavorable clinical outcome (modified Rankin Scale [mRS] > 2). Results A total of 205 patients harboring 223 aneurysms were analyzed. The 30-d neurological morbidity and mortality rates were 1.9% (4/205) and 0.5% (1/205), respectively. The rate of intraprocedural events without neurological morbidity was 6.8% (14/205), consisting of intraprocedural ischemic events in 9 patients (4.5%) and hemorrhage in 5 (2.4%). Other technical events included difficulty capturing the delivery wire in 1 case (0.5%) and device migration after deployment in another case (0.5%). Favorable clinical outcome (mRS 0-2) was achieved in 186 patients (94.4%) at discharge and in 140 patients (94.5%) at 30 d. We did not find predictors of clinical outcomes on multivariate analysis. Conclusion The 30-d rates of neurological morbidity and mortality in this multicenter cohort using the PED Flex for the treatment of intracranial aneurysms were low, 1.9% (4/205) and 0.5% (1/205), respectively. In addition, technical events related to device deployment were also low, most likely due to the latest modifications in the delivery system.
Arteriovenous malformation embocure score: AVMES
BackgroundCerebral arteriovenous malformations (CAVMs) may be treated with microsurgery, radiosurgery, endovascular surgery, or a combination of these modalities. Grading scales are available to aid the assessment of curative risk for microsurgery and radiosurgery. No grading system has been developed to assess the curative risk of endovascular surgery.ObjectiveTo report our retrospective application of the AVM embocure score to patients treated at our institution between 2005 and 2011MethodsWe performed a retrospective review of 39 patients with CAVM treated at our institution between 2005 and 2011 with the primary aim of achieving a curative embolization. After reviewing all the different variables associated with the conventional Onyx embolization technique for CAVMs, we identified the following as the most relevant characteristics influencing the chances for complete angiographic embolization and complication risk: the number of arterial pedicles and draining veins, size of AVM nidus, and vascular eloquence. We sought to develop a scoring system to assess the complication risk for a curative embolization of CAVM with liquid embolic Onyx (Covidien, Irvine, California, USA). We developed the AVM embocure score (AVMES). This scoring system ranges from 3 to 10 and is the arithmetic sum of the number of arterial pedicles feeding the AVM (≤3, 4–6, >6), the number of draining veins (≤3, 4–6, >6), the size of the AVM nidus in centimeters (≤3, 4–6, >6), and the vascular eloquence (0–1). We applied AVMES to the same cohort of patients and validated the predictability of complete angiographic embolization and expected clinical risk of complication.ResultsIn lesions with an AVMES of 3 (n=8), there was a 100% rate of complete AVM obliteration and 0% rate of major complications. In AVMES 4 (n=12) lesions, there was 75% complete obliteration rate, with 8% major morbidity. In AVMES 5 (n=9) lesions, there was 78% complete obliteration and 11% major morbidity. In AVMES >5 (n=10) there was 20% complete obliteration and 30% major morbidity. Receiver-operator curve analysis showed that this scoring system was robust in its discriminative ability, with an area under the curve (AUC) of 0.8356 for complete obliteration without complication, AUC=0.8240 for complete obliteration regardless of the presence of major morbidity, and AUC=0.7529 for major morbidity.ConclusionsThe AVMES complements existing scoring systems for microsurgery and radiosurgery. It provides a valuable tool for risk assessment during the complex decision-making process in treating AVMs that accounts for angioarchitectural features of particular relevance to endovascular surgeons.
Utilization of Pipeline embolization device for treatment of ruptured intracranial aneurysms: US multicenter experience
ObjectiveUtilization of the Pipeline embolization device (PED) in complex ruptured aneurysms has not been well studied. We evaluated the safety and effectiveness data from five participating US centers.MethodsRecords of patients with ruptured cerebral aneurysms who underwent PED treatment between 2011 and 2013 were retrospectively reviewed.Results26 patients with ruptured aneurysms underwent PED treatment (mean age 51.4±13.2 years;16 women). At presentation, 8 patients (30.8%) had a Hunt–Hess grade of IV or above; 11 required extraventricular drain placement. Aneurysm morphologies were: 8 dissecting, 8 blister-like, 6 fusiform, and 4 saccular. There were 22 anterior circulation and 4 posterior circulation aneurysms. PED deployment was successful in all patients, with adjunctive coiling utilized in 12. Periprocedural complications occurred in 5 (19.2%), including 3 inhospital deaths. 23 patients (88.5%) had postoperative angiography at a mean of 5.9 months: 18 aneurysms (78.3%) were completely occluded, 3 (13.0%) had residual neck filling, and 2 (8.7%) had residual dome filling. All blister-type aneurysms were completely occluded at follow-up. Clinical follow-up was available for an average of 10.1 months (range 2–21 months), with one asymptomatic in-stent stenosis and one asymptomatic thromboembolic stroke noted. Good outcome (modified Rankin Scale (mRS) score of 0–2) was achieved in 20 patients (76.9%), fair (mRS 3–4) in 3 (11.5%), and 3 died (11.5%).ConclusionsThe PED can be utilized for ruptured aneurysms and is a good option for blister-type aneurysms. However, due to periprocedural complications, it should be reserved for lesions that are difficult to treat by conventional clipping or coiling.
Stent-Retriever Thrombectomy after Intravenous t-PA vs. t-PA Alone in Stroke
In acute ischemic stroke, thrombectomy with a stent retriever plus intravenous t-PA was more effective than t-PA in improving functional outcomes. At 90 days, 60% of patients in the intervention group were functionally independent, as compared with 35% in the control group. Intravenous tissue plasminogen activator (t-PA) administered within 4.5 hours after the onset of acute ischemic stroke improves outcomes. 1 – 3 However, intravenous t-PA has multiple constraints, including unresponsiveness of large thrombi to rapid enzymatic digestion, a narrow time window for administration, and the risk of cerebral and systemic hemorrhage. Among patients with occlusions of the intracranial internal carotid artery or the first segment of the middle cerebral artery (or both), intravenous t-PA results in early reperfusion in only 13 to 50%. 4 – 7 Neurovascular thrombectomy is a reperfusion strategy that is distinct from pharmacologic fibrinolysis. Endovascular mechanical treatments can remove large, proximal . . .
Predictors of incomplete aneurysm occlusion after treatment with the Pipeline Embolization Device: PREMIER trial 1 year analysis
BackgroundFlow diverters have revolutionized the treatment of intracranial aneurysms. Nevertheless, some aneurysms fail to occlude with flow diversion. The Prospective Study on Embolization of Intracranial Aneurysms with the Pipeline Device (PREMIER) was a prospective, multicenter and single-arm trial of small and medium wide-necked unruptured aneurysms. In the current study, we evaluate the predictors of treatment failure in the PREMIER cohort.MethodsWe analyzed PREMIER patients who had incomplete occlusion (Raymond-Roy >1) at 1 year angiographic follow-up and compared them with those who achieved Raymond-Roy 1, aiming to identify predictors of treatment failure.Results25 aneurysms demonstrated incomplete occlusion at 1 year. There was a median reduction of 0.9 mm (IQR 0.41–2.43) in maximum diameter between pre-procedure and 1 year measurements, with no aneurysmal hemorrhage. Patients with incomplete occlusion were significantly older than those with complete occlusion (p=0.011). Smoking (p=0.045) and C6 segment location (p=0.005) were significantly associated with complete occlusion, while location at V4 (p=0.01) and C7 (p=0.007) and involvement of a side branch (p<0.001) were significantly associated with incomplete occlusion. In multivariable logistic regression, significant predictors of incomplete occlusion were non-smoker status (adjusted OR 4.49, 95% CI 1.11 to 18.09; p=0.03) and side branch involvement (adjusted OR 11.68, 95% CI 3.84 to 35.50; p<0.0001), while C6 location had reduced odds of incomplete occlusion (adjusted OR 0.29, 95% CI 0.10 to 0.84; p=0.02).ConclusionsThe results of our study are consistent with previous retrospective series and warrant consideration for technique adaptations to achieve higher occlusion rates. Further follow-up is needed to assess progression of aneurysm occlusion and clinical behavior in these cases.