Penumbra (United States)

IntroductionMRI-guided intervention provides valuable functional information such as perfusion and diffusion that standard fluoroscopic guidance lacks. Recent studies have demonstrated utility in stroke treatment for multimodality X-ray and MR imaging suites. Yet, clinical adoption of MRI-guided intervention has lagged, and an absence of appropriate tooling could be a contributing factor. Prior work described a polymeric catheter featuring radiopaque markers doped with iron oxide nanoparticles (IONPs) as low-profile, MRI-visible passive markers. Here, we further investigate susceptibility artifacts in vitro at 0° and 90° with respect to B0. Marker separation was evaluated to identify a potential format for full-length visibility at 3.0T.MethodsPolymeric, 6.6 Fr guide catheter segments were built in a fabrication facility (Penumbra, Inc., Alameda, CA). Epoxy-based radiopaque ink was mixed with 9.1 wt% (w/w) iron(III) oxide (Fe2O3) nanoparticles of 20–40 nm diameter. Four circumferential marker bands ranging from 5 to 20 mm apart were applied in series starting 1 cm from the distal tip and cured at 20°C.15-cm segments submerged in copper sulfate solution (CuSO4, 1–2 g/L) were oriented parallel (0°) and orthogonal (90°) with respect to B0. At 0°, images were acquired in coronal/sagittal slice orientations on a 3.0T MRI scanner (MAGNETOM Skyra, Siemens Healthcare, Erlangen, Germany). At 90°, images were acquired in coronal/axial orientations to match image acquisition of 0°. Phase encoding direction was maintained parallel to the catheter major axes. T2-weighted turbo spin echo (TSE) and gradient echo (GRE) sequences were collected. Maximum artifact widths were evaluated per ASTM F2119–07, using ImageJ (http://imagej.nih.gov/ij).ResultsSusceptibility artifacts induced by the IONP-doped markers are shown (FIG. 1). 90° orientation produced worst-case artifacts in all sequences except the axial TSE. Furthermore, some artifacts could not be discerned at 90°. 20-mm separation yielded distinct artifacts without overlapping. E-205 Figure 1Susceptibility artifacts were assessed in vitr. Artifacts were evaluated per ASTM F2119–07 and measured with ImageJ software (red outlines). The phase encoding direction, as indicated by the black arrow, was oriented parallel to the major axis of the catheter segments. Blue dashed line = superimposed catheter onto MR images. Artifacts were measured while oriented parallel to B0 on a A) spin echo and B) gradient echo. The same measurement were collected at 90° with respect to B0 on a C) spin echo and D) gradient echo. E) Global artifact widths fro, all slices are presentedConclusionAlthough worst-case artifacts were observed at 90°, they remained acceptable for use in guide catheters. Additionally, 20-mm marker separation could provide distinct artifacts down the length of a catheter during MRI-guided interventions, despite anatomic tortuosity. The phantom used in this study was shallow, which limited the ability to distinguish between real artifacts and those arising from the solution-air interface. Hence, accuracy of the degree of increased artifact may warrant further investigation. This study simulated worst-case orientations in vitro; more data should be collected in vivo using real-time sequences to best evaluate artifacts during clinical use.DisclosuresB. Kilbride: None. C. Jordan: None. S. Ahn: 5; C; Siemens Medical Solutions USA Inc. K. Mueller: 5; C; Siemens Medical Solutions USA Inc. A. Chu: 5; C; Penumbra Inc. D. Barry: 5; C; Penumbra Inc.. T. Moore: None. A. Martin: None. M. Wilson: None. S. Hetts: None.

A major challenge for stroke rehabilitation and recovery research is the recruitment and retention of participants. Our prior challenges and successes have influenced our team to rethink our approach and the potential for large-scale stroke recruitment. In this special interest article, we highlight how the adoption and implementation of recruitment strategies such as physician engagement and a streamlined "customer service" approach helped us improve our enrollment and maximize efficiency. Another positive outcome of enrollment was increased representation of those who identify as underrepresented minority or live in rural areas. Rethinking our recruitment processes and infrastructure allowed for greater interprofessional interactions, minimal burden for our stroke physician team members, and maximized enrollment into our stroke studies.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A324).

Approaches to economic evaluations of stroke therapies are varied and inconsistently described. An objective of the European Stroke Organisation (ESO) Health Economics Working Group is to standardise and improve the economic evaluations of interventions for stroke. The ESO Health Economics Working Group and additional experts were contacted to develop a protocol and a guidance document for data collection for economic evaluations of stroke therapies. A modified Delphi approach, including a survey and consensus processes, was used to agree on content. We also asked the participants about resources that could be shared to improve economic evaluations of interventions for stroke. Of 28 experts invited, 16 (57%) completed the initial survey, with representation from universities, government, and industry. More than half of the survey respondents endorsed 13 specific items to include in a standard resource use questionnaire. Preferred functional/quality of life outcome measures to use for economic evaluations were the modified Rankin Scale (14 respondents, 88%) and the EQ-5D instrument (11 respondents, 69%). Of the 12 respondents who had access to data used in economic evaluations, 10 (83%) indicated a willingness to share data. A protocol template and a guidance document for data collection were developed and are presented in this article. The protocol template and guidance document for data collection will support a more standardised and transparent approach for economic evaluations of stroke care.

Introduction: A recent meta-analysis of four randomized controlled trials (RCTs) concluded that mechanical thrombectomy using Solitaire for large vessel ischemic stroke was effective with significantly reduced disability. Hypothesis: Our hypothesis was that treatment with the Penumbra Aspiration System and the novel 3D Stent Retriever would demonstrate similar angiographic and functional outcomes compared to use of Solitaire. Methods: The 3D trial was a RCT to compare the safety and effectiveness of the 3D Stent Retriever when used with the Penumbra Aspiration System (3D/PS) compared to the PS alone. Inclusion criteria for the 3D RCT included presentation with NIH Stroke Scale ≥ 8 and refractory to or not eligible for IV rtPA. Analysis compared reperfusion to mTICI 2b or 3 and functional independence (mRS 0-2 at 90 days) in a 3D Trial cohort with ASPECTS 8-10 vs the meta-analysis data reported by Campbell et al ( Stroke 2016). Results: One hundred four (104) of 198 patients met analysis criteria. Baseline ASPECTS (median [IQR]) were similar between the 3D Trial ASPECTS 8-10 cohort (3D/PS, PS, combined: 9 [8,10]) and Campbell group (9 [7,10]). Substantial reperfusion (mTICI 2b or 3) was experienced in 84.6% (44/52) of 3D/PS and 75.0% (39/52) of PS alone cases, similar to the Campbell group (76.6%). When both arms were pooled, results (79.8%) were also similar to Campbell. With regards to functional independence, both 3D cohorts and pooled trial results showed similar rates compared with Campbell (Figure). Conclusions: The novel 3D Stent Retriever + Penumbra System and the Penumbra Aspiration System alone showed similar reperfusion and functional outcomes compared to Solitaire.

Purpose The utility of the Penumbra Coil 400 (PC400) System in embolization of aneurysms in smaller caliber arteries has yet to be characterized. The goal was to assess the safety and effectiveness of the PC400 with the use of the 0.025” ID PXSLIM microcatheter in the anterior communicating artery. Reported herein are the initial clinical experience and long-term results in a subset of the Aneurysm Coiling Efficiency (ACE) registry. Results from conventional coils published in peer-reviewed journals are used as historical controls. Methods Our treatment cohort consisted of 46 aneurysms ranging between 3.5–17 mm in diameter. Patients were treated between March 2012–January 2015 at 16 high volume centers. Six-month follow-up data were assessed. Data on angiographic results and procedural complications were collected prospectively and analyzed. Results The mean aneurysm size was 6.3 ± 2.8 mm, 22 ruptured and 24 unruptured. All aneurysms were treated entirely with PC400 coils, with a mean of 5.0 ± 3.5 coils placed. Sixty-two percent of the cases achieved an initial Raymond Scale of 1, and 28.9% achieved a Raymond scale of 2 post-procedure. Mean packing density was 38.8%±18.5 at immediate post-procedure. The rate of retreatment at 6 months was 0%, while the overall rate of morbidity/mortality caused by stroke at 30 days was 6.5%. Comparison with a recently published meta-analysis of conventional coils showed similar or superior outcomes with lower procedural complication rates, most notably lower overall vasospasm rate of 4% vs. 13%, permanent procedure-related morbidity rate of 2% vs. 6%, lower retreatment rate of 0% vs. 7% and higher long-term (6 months or more) complete and near-complete occlusion of 96% vs. 85% with PC400 coils (Tables 1, 2). Conclusion Initial multicenter experience demonstrates that embolization using the PC400 System and 0.025” ID PXSLIM microcatheter in the small caliber vessel AcomA aneurysms leads to safe and effective short- and long-term outcomes. Disclosures B. Baxter: None. O. Zaidat: None. E. Deshaies: None. M. Kabbani: None. J. Lynch: None. D. Lopes: 4; C; Penumbra, Inc.. A. Turk: None. C. Roth: None. A. Chowdhary: None. G. Rappard: None. M. Knauth: None. P. Schramm: None. F. Hui: None. M. Ollenschleger: None. J. Jacobson: None. A. Shhadeh: None. R. Pergolizzi: None. S. Prothmann: None. A. Khaldi: None. E. Luong: 5; C; Penumbra, Inc. S. Hak: 5; C; Penumbra, Inc. S. Kuo: 5; C; Penumbra, Inc. N. Nguyen: 5; C; Penumbra, Inc. D. Ueda: 5; C; Penumbra, Inc. S. Sit: 4; C; Penumbra, Inc. 5; C; Penumbra, Inc.

Purpose: Final ASPECTS has been shown to predict patient outcomes after endovascular therapy in stroke. The goal of this study was to compare sequential ASPECTS imaging pre-treatment and post-treatment in predicting outcome. Methods: The PICS Study is a prospective registry of clinical and imaging data in proximal artery occlusion patients treated with the Penumbra System. In multivariate analysis, variables assessed for relationship to 90 day mRS included age, gender, time to reperfusion, occlusion location, ASPECTS, and NIHSS. ASPECTS scores were assessed by a central core laboratory, blinded except for stroke side. Results: In this study, 141 patients with mean age 67.9 ± 15.6 and median admission NIHSS score 16.0 (IQR 12.0-21.0) met study criteria. Univariate predictors of 90 day mRS included age, baseline NIHSS, 7 day/discharge NIHSS as well as post-treatment ASPECTS. After adjusting for age and baseline NIHSS, post procedure ASPECTS showed a stronger relationship with good outcome (p<0.0001) than pre-treatment ASPECTS (p=0.0520). Change in ASPECTS was also a significant predictor of 90 day mRS (p=0.0046) in the multivariate analysis. Conclusion: Sequential and post procedure ASPECTS are better predictors of clinical outcome following endovascular therapy than pre-ASPECTS. Final infarct volume quantified using ASPECTS serves as a surrogate biomarker for long-term functional outcome.

Purpose: Pre-treatment NIHSS has been shown to be the strongest predictor of outcome after endovascular therapy in acute ischemic stroke. However, it is not clear if sequential changes in NIHSS scores have any predictive value after mechanical thrombectomy cases. Methods: Prospective (Pivotal N=119, PICS N=219, START N=124) and retrospective/registry (POST N=95, RetroSTART N=168) cases using the Penumbra System were pooled. All were IV tPA-ineligible or refractory with treatment at <8 h. The association of NIHSS pre- and post-treatment and good clinical outcome (mRS 0-2 at 90 days) was tested. Results: Among 725 patients, mean age was 66 ± 15 and median admission NIHSS score was 17 (IQR 13-21). Median NIHSS improved to 11 at 7 days. NIHSS scores at 7 days showed a stronger relationship with good outcome (correlation 0.84; p<0.001) than baseline (correlation 0.37; p<0.001). Furthermore, serial NIHSS scores (baseline minus 7 day) also predicted good outcome (correlation -0.69; p<0.001). Age (correlation 0.39, p < 0.001), pre-treatment ASPECTS score (correlation -0.19; p < 0.001) but not reperfusion to TIMI 2-3/TICI 2b-3 also demonstrated associations with good outcome. Conclusion: In this pooled Penumbra cohort, post treatment improvement in neurological status significantly predicted good clinical and functional outcomes, independent of reperfusion status.

BackgroundEndovascular treatment of wide necked and large/giant intracranial aneurysms is challenging. The goal of this study was to evaluate the Liberty stent system in the rabbit elastase aneurysm model for 30, 90, and 180 days.MethodsThe Altes elastase model was used to create aneurysms in the right common carotid artery in New Zealand White rabbits. Safety was assessed by angiographic and histopathological data from treated wide necked aneurysms, treated subclavian arteries, and related vasculature immediately post-treatment and at scheduled end points.ResultsIn this study, stenting of wide necked aneurysms demonstrated excellent results in all 35 animals. The Liberty could be tracked to the final position across an aneurysm neck precisely, without changing microcatheter position. After device deployment, no significant changes in vessel contour and no stent migration were observed. Coil mass was well supported in all aneurysms and high packing densities were achieved. In addition, follow-up angiograms showed stable coil masses and persistent occlusion in all animals, without any recanalization of the neck or aneurysmal sac. Furthermore, there was no evidence of coil compaction or protrusion of coil loop through the stent struts. None of the immediate post-coiling angiograms revealed evidence of vasospasm, dissection, or in-stent thrombosis.DiscussionThis animal study demonstrated promising results with the novel Liberty stent system. The Liberty showed consistent precise positioning and accurate deployment. The stent revealed good compatibility with embolic coiling procedures, while morbidity and mortality were negligible. In addition, persistent occlusion of aneurysms without recanalization or in-stent stenosis was observed at the 180 day follow-up.

Data from recent reports have indicated that mechanical thrombectomy may have potential as a treatment for acute ischemic stroke. The purpose of this study was to assess the safety and performance of the Penumbra System (PS): a novel mechanical device designed to reduce clot burden in acute stroke due to large-vessel occlusive disease. A prospective, single arm, independently monitored and core laboratory adjudicated trial enrolled subjects with an acute neurologic deficit consistent with acute stroke, presenting within 8 hours of symptom onset and an angiographically verified occlusion (Thrombolysis in Myocardial Infarction [TIMI] grade 0 or 1) of a treatable intracranial vessel. The primary end point was revascularization of the target vessel to TIMI grade 2 or 3. Secondary end points were the proportion of subjects who achieved a modified Rankin Scale (mRS) score of 2 or less or a 4-point improvement on the National Institutes of Health Stroke Scale (NIHSS) score at 30-day follow-up, as well as all-cause mortality. Twenty-three subjects were enrolled, and 21 target vessels were treated in 20 subjects by the PS. At baseline, mean age was 60 years, mean mRS score was 4.6, and mean NIHSS score was 21. Postprocedure, all 21 of the treated vessels (100%) were successfully revascularized by the PS to TIMI 2 or 3. At 30-day follow-up, 9 subjects (45%) had a 4-point or more NIHSS improvement or an mRS of 2 or less. The all-cause mortality rate was 45% (9 of 20), which is lower than expected in this severe stroke cohort, where 70% of the subjects at baseline had either an NIHSS score of more than 20 or a basilar occlusion. Thus, early clinical experience suggests that the PS allows revascularization in certain subjects experiencing acute ischemic stroke.