Embolization before Gamma Knife radiosurgery for cerebral arteriovenous malformations does not negatively impact its obliteration rate: a series of 190 patients.

PURPOSE: Embolization of arteriovenous malformations (AVMs) before radiosurgery has been reported to negatively impact the obliteration rate. This study aims to assess treatment outcomes in a series of 190 patients treated by Gamma Knife radiosurgery (GKRS) for previously embolized AVMs. METHODS: The institutional database of AVMs was retrospectively reviewed between January 2004 and March 2018. The clinical and radiological data of patients treated with GKRS for previously embolized AVMs were analyzed. Predicting factors of obliteration and hemorrhage following GKRS were assessed with univariate and multivariate regression analyses. RESULTS: The mean AVM size was significantly reduced after embolization (p < 0.001). The obliteration rate was 78.4%. Multivariate analyses showed that a lower Spetzler-Martin grade (p = 0.035) and a higher marginal dose (p = 0.007) were associated with obliteration. Post-GKRS hemorrhages occurred in 14 patients (7.4%). A longer time between diagnosis and GKRS was the only factor associated with post-GKRS hemorrhages in multivariate analysis (p = 0.022). Complications related to the combined treatment were responsible for a new permanent neurological disability in 20 patients (10.5%), and a case of death (0.5%). CONCLUSIONS: This study shows that the embolization of AVMs does not have a negative impact on the obliteration rate after radiosurgery. Embolization reduces the AVM size to a treatable volume by GKRS. However, the combined treatment results in an increased complication rate related to the addition of the risks of each treatment modality.

European Multicenter Study of ET-COVID-19.

BACKGROUND AND PURPOSE: Acute ischemic stroke and large vessel occlusion can be concurrent with the coronavirus disease 2019 (COVID-19) infection. Outcomes after mechanical thrombectomy (MT) for large vessel occlusion in patients with COVID-19 are substantially unknown. Our aim was to study early outcomes after MT in patients with COVID-19. METHODS: Multicenter, European, cohort study involving 34 stroke centers in France, Italy, Spain, and Belgium. Data were collected between March 1, 2020 and May 5, 2020. Consecutive laboratory-confirmed COVID-19 cases with large vessel occlusion, who were treated with MT, were included. Primary investigated outcome: 30-day mortality. SECONDARY OUTCOMES: early neurological improvement (National Institutes of Health Stroke Scale improvement ≥8 points or 24 hours National Institutes of Health Stroke Scale 0-1), successful reperfusion (modified Thrombolysis in Cerebral Infarction grade ≥2b), and symptomatic intracranial hemorrhage. RESULTS: We evaluated 93 patients with COVID-19 with large vessel occlusion who underwent MT (median age, 71 years [interquartile range, 59-79]; 63 men [67.7%]). Median pretreatment National Institutes of Health Stroke Scale and Alberta Stroke Program Early CT Score were 17 (interquartile range, 11-21) and 8 (interquartile range, 7-9), respectively. Anterior circulation acute ischemic stroke represented 93.5% of cases. The rate modified Thrombolysis in Cerebral Infarction 2b to 3 was 79.6% (74 patients [95% CI, 71.3-87.8]). Thirty-day mortality was 29% (27 patients [95% CI, 20-39.4]). Early neurological improvement was 19.5% (17 patients [95% CI, 11.8-29.5]), and symptomatic intracranial hemorrhage was 5.4% (5 patients [95% CI, 1.7-12.1]). Patients who died at 30 days exhibited significantly lower lymphocyte count, higher levels of aspartate, and LDH (lactate dehydrogenase). After adjustment for age, initial National Institutes of Health Stroke Scale, Alberta Stroke Program Early CT Score, and successful reperfusion, these biological markers remained associated with increased odds of 30-day mortality (adjusted odds ratio of 2.70 [95% CI, 1.21-5.98] per SD-log decrease in lymphocyte count, 2.66 [95% CI, 1.22-5.77] per SD-log increase in aspartate, and 4.30 [95% CI, 1.43-12.91] per SD-log increase in LDH). CONCLUSIONS: The 29% rate of 30-day mortality after MT among patients with COVID-19 is not negligible. Abnormalities of lymphocyte count, LDH and aspartate may depict a patient's profiles with poorer outcomes after MT. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT04406090.

Safety and efficacy of a pre-treatment antiplatelet regimen of unruptured intracranial aneurysms: a single-center experience.

PURPOSE: Endovascular treatment of unruptured intracranial aneurysms with stent-assisted coiling or flow diverter stents requires a prophylactic antiplatelet premedication to avoid thrombo-embolic complications. Guidelines for optimal antiplatelet regimens are poorly defined. The aim of this study is to report our experience using a high dosage antiplatelet premedication regimen for patients with unruptured intracranial aneurysms undergoing endovascular treatment by stent-assisted coiling or flow diverter stents. METHODS: From a retrospective analysis of a prospectively maintained database, we collected clinical and angiographic data of 400 procedures in 362 patients treated by stent-assisted coiling or flow diverter stents for 419 unruptured intracranial aneurysms. Descriptive and analytic statistics were performed to report morbidity, mortality, and complication rates and to demonstrate associations between variables and outcomes. Logistic multivariable regression was performed to rule out confounding factors between subgroups. RESULTS: Thrombo-embolic complications occurred in 23/400 procedures (5.75%) and hemorrhagic complications in 19/400 procedures (4.75%). The majority of complications were minor and transient with overall procedure-related morbidity and mortality rates of 1.75% (n = 7/400) and 1.25% (n = 5/400) respectively. The co-existence of multiple cardiovascular risk factors among smoking, hypertension, dyslipidemia, and age > 65 years old was significantly associated with permanent procedure-related morbidity (p = 0.006) and thrombo-embolic complications occurrence (p = 0.034). Age alone was associated with higher permanent morbidity (p = 0.029) and was the only variable associated with higher hemorrhagic complication (p = 0.024). CONCLUSION: In this study, the use of a high dosage antiplatelet premedication was safe and effective for the treatment of unruptured intracranial aneurysms with stent-assisted coiling or flow diverter stents. Mortality and morbidity rates compare favorably with the current literature. The thrombo-embolic complications rate is low and most of them were clinically silent. However, the hemorrhagic complications rate was substantial and a significant proportion of them were associated with mortality.

Leo stent for endovascular treatment of intracranial aneurysms: very long-term results in 50 patients with 52 aneurysms and literature review.

INTRODUCTION: The Leo stent was the first retrievable stent for endovascular treatment of intracranial aneurysms (IAs). We report our experience with this device with emphasis on very long-term follow-up. METHODS: This study was approved by authors' ethical committee. A retrospective review of our prospectively maintained database identified all patients treated for a saccular IA with this stent in our institution. Technical issues and immediate and long-term outcomes (at least 12 months) were evaluated. RESULTS: Between 2004 and 2015, 50 patients with 52 IAs were identified. In two patients, the stent could not safely be placed (failure rate = 3.8%). Among 48 treated patients with 50 IAs, there were 44 women and 4 men (mean age, 53 years). Mean aneurysm diameter was 7.2 mm. All IAs but six were wide-necked. There was no immediate morbidity or mortality. Anatomical results included 76% complete occlusions, 22% neck remnants, and 2% incomplete occlusions. Mean follow-up was 50.2 months (range, 12-139 months). Two patients had delayed TIAs but long-term morbidity rate remained = 0%. At follow-up, occlusion was stable in 68% IAs, showed thrombosis in 12%, and recanalization in 20% IAs. Complementary treatment was required in 8% IAs. Final results showed 70% complete occlusions, 24% neck remnants, and 6% incomplete occlusions. Asymptomatic stent occlusion and significant stenosis occurred in one and two cases, respectively. CONCLUSION: The Leo stent is safe and effective for treatment of wide-necked saccular IAs. Very long-term results show high rates of adequate and stable occlusion. Moreover, the stent is well tolerated.

Endovascular treatment of intracranial aneurysms with the p64 flow diverter stent: mid-term results in 35 patients with 41 intracranial aneurysms.

INTRODUCTION: The p64 flow diverter (FD) device is a fully resheathable and detachable stent dedicated for endovascular treatment (EVT) of intracranial aneurysms (IAs). We report our mid-term experience with this device. METHODS: Between January 2015 and February 2016, we retrospectively identified, in our prospectively maintained database, all patients treated with p64 FDs in two institutions. Independent clinical follow-up was performed by a vascular neurologist. Imaging follow-up included a digitalized subtraction angiography (DSA) at 3, 6, and 12 months and a magnetic resonance angiography (MRA) at 12 months. RESULTS: Thirty-nine patients (22 women/17 men; median age 54 years) with 48 IAs (median aneurysm size 6.2 mm; mean neck size 3.4 mm) were identified. All IAs were saccular and unruptured. Failure of safe stent delivery occurred in 15% of cases (7/48 IAs) which were excluded. Transient neurological morbidity occurred in 2/35 patients (5.7%) including one delayed thromboembolic complication. No permanent morbidity or mortality was encountered. Complete aneurysmal occlusion at 3, 6, and 12 months was 20/30 (66.6%), 18/27 (66.6%), and 24/28 (85.7%), respectively. Intra-stent stenosis was observed in 9/29 patients (31%) and classified as moderate in 4/29 (13.7%) and mild in 5/29 patients (17.2%). These stenoses gradually improved over time, with only mild stenoses being identified at 6 months and at 12 months. CONCLUSION: In our small case series, the p64 FD stent appears safe and effective for EVT of IAs. A high occlusion rate and a low morbidity rate were observed.

Stent-assisted coiling of wide-neck bifurcation aneurysms with a branch incorporated in the aneurysm base: long-term follow-up in 49 patients with 53 aneurysms.

PURPOSE: Wide-neck bifurcation intracranial aneurysms (WNBA) with a branch incorporated in the aneurysm base remain difficult to treat by embolization. We aim to report our long-term follow-up of stent-assisted coiling (SAC) in this subgroup of patients. METHODS: This study was approved by our local ethical committee. A retrospective review of our prospectively maintained database identified all patients treated in our institution by SAC for a WNBA with a branch incorporated in the aneurysm base. Technical issues, immediate, long-term outcomes were evaluated. RESULTS: Between 2007 and 2015, 49 patients with 53 intracranial aneurysms (IAs) (52 unruptured, 1 ruptured) were identified and successfully treated. No morbidity/mortality occurred. The incorporated branch was preserved in all patients but one who was treated during a vasospasm phase. At the first 6-month imaging control, the branch was patent. Immediate occlusion was near-complete in 11/53 aneurysms (20.8%), neck remnant in 20/53 aneurysms (37.7%), and incomplete in 22/53 aneurysms (41.5%). Available imaging follow-up of 47 IAs, ranging from 3 to 84 months (mean 26 months ± 19.6 months), showed 27 progressive thrombosis (57.4%), 17 stable occlusions (36.2%), 1 minor recanalization (2.1%), and 2 significant recanalizations that were retreated (4.3%). The latest imaging control showed 30 near-complete occlusions (63.8%), 13 neck remnants (27.7%), and 4 incomplete occlusions (8.5%). CONCLUSION: Stent-assisted coiling is safe and effective for the treatment of WNBA with a branch incorporated in the aneurysm base. Despite poor immediate anatomical results, long-term follow-up shows a high rate of progressive thrombosis achieving adequate and stable occlusion in most patients.

Stent-assisted coiling of intracranial aneurysms located on small vessels: midterm results with the LVIS Junior stent in 40 patients with 43 aneurysms.

INTRODUCTION: The Low-profile Visualized Intraluminal Support (LVIS) Junior stent is dedicated for endovascular treatment of wide-neck intracranial aneurysms located on small-diameter vessels (2-3.5 mm). This study reports midterm clinical and anatomical results of this device. METHODS: This study was approved by authors' ethical committees. A retrospective review of our prospectively maintained database identified all patients treated by this stent in three institutions. Technical issues and immediate and mid-term anatomical and clinical outcomes were evaluated. RESULTS: Forty patients (30 women/10 men, mean age of 55 years) with 43 aneurysms were identified. Mean aneurysm diameter was 5.6 mm (range, 2-13 mm). In all patients, treatment was successful and the stent could be precisely placed. There were three procedure-related complications, one stent thrombosis and two aneurysm ruptures, leading to immediate morbidity in one patient. Delayed ischemic events occurred in three patients including two transient attacks and one permanent deficit. The overall permanent morbidity rate was thus 5 %. No mortality occurred. Immediate aneurysm occlusion consisted of 36 complete occlusions (83.7 %), five neck remnants (11.6 %), and two incomplete occlusions (4.7 %). Twenty-seven patients (29 aneurysms) and 11 patients (11 aneurysms) had a 12- and 6-month angiographic follow-up, respectively. Final anatomical results included 36 complete occlusions (90 %) and four neck remnants (10 %). Two minor recanalizations were seen but did not require retreatment. Non-significant intrastent stenosis occurred in 7/40 followed-up cases (17.5 %). CONCLUSION: The LVIS Junior stent appears safe and effective for endovascular treatment of wide-neck intracranial aneurysms located on small vessels. Midterm results show high rates of adequate and stable occlusion.

Detection and characterization of unruptured intracranial aneurysms: Comparison of 3T MRA and DSA.

PURPOSE: To compare magnetic resonance angiography (MRA) at 3 Tesla (3T) and digital subtraction angiography (DSA) for the detection and characterization of unruptured intracranial aneurysms (UIA). MATERIALS AND METHODS: This study has been approved by our local ethical committee. From February to August 2010, 40 consecutive patients with UIA contemporarily underwent MRA at 3T including time-of-flight (TOF-MRA) and contrast enhanced (CE-MRA) techniques and DSA. MR images were independently reviewed by 3 radiologists and DSA images were reviewed by 2 radiologists together. Interobserver and intertechnique agreements were assessed for aneurysm detection and characterization including maximal diameter, neck width and the presence of a bleb or a branch arising from the sac. RESULTS: DS angiography revealed 56 aneurysms. Mean sensitivity and positive predictive value of MRA were 91.4% and 93.4% respectively. For UIA < 3 mm and those ≥ 3 mm, MRA had a mean sensitivity of 74.1% and 100% respectively. Intertechnique and interobserver agreements were substantial for the measurement of UIA maximal diameter (mean κ, 0.607 and 0.601 respectively) and were moderate and fair for neck width measurement respectively (mean κ, 0.456 and 0.285 respectively). For bleb detection, intertechnique and interobserver agreements were fair and slight respectively (mean κ, 0.312 and 0.116 respectively) whereas both were slight for detection of branches arising from the sac (mean κ, 0.151 and 0.070 respectively). CONCLUSION: MR angiography at 3T has a high sensitivity for the detection of UIA. However, it remains significantly inferior to DSA for morphological characterization of UIA.

Stent-assisted coiling of unruptured intracranial aneurysms: long-term follow-up in 164 patients with 183 aneurysms.

PURPOSE: Stent-assisted coiling (SAC) is increasingly used to treat complex unruptured intracranial aneurysms (UIA) including wide-necked and fusiform IA. However, few data are available over the long-term results of this technique. We report our 9-year-experience of SAC of UIA. METHODS: A retrospective review of our prospectively maintained database identified all patients treated by SAC for an UIA in 2 institutions. The clinical charts, procedural data and angiographic results were reviewed. RESULTS: Between 2004 and 2012, we identified 164 patients with 183 UIA. There were 115 women and 49 men with a mean age of 46 years. Embolization was successful in all patients. Procedural morbidity and mortality rates were 2.2% and 0% respectively. Immediate anatomical outcome included 54 complete occlusion (29.5%), 43 neck remnants (23.5%) and 86 incomplete occlusions (47%). Imaging follow-up was available in 137 patients (mean=26 months, range 3 to 99 months) and it showed 104 complete occlusions (75.9%), 23 neck remnants (16.8%) and 10 incomplete occlusions (7.3%). At follow-up, only 3 patients developed a significant intrastent stenosis, one of which was induced by radiosurgery. One of these patients had a symptomatic thrombo-embolic complication 3 years after stent placement. CONCLUSION: SAC of complex UIA is effective and associated with low complication rates. Even if immediate anatomical results are relatively unsatisfying, mid- and long-term follow-up show a major improvement with a high rate of adequate occlusion that is stable over time. Moreover, the long-term clinical and angiographic tolerance of intracranial stents is excellent.

Treatment of Cerebral Vasospasm Following Aneurysmal Subarachnoid Hemorrhage using the Neurospeed Semi-compliant Balloon.

BACKGROUND AND PURPOSE: Cerebral vasospasm (CV) following aneurysmal subarachnoid hemorrhage (aSAH) may lead to morbidity and mortality. Endovascular mechanical angioplasty may be performed if symptomatic CV is refractory to noninvasive medical management. Off-label compliant remodelling balloons tend to conform to the course of the vessel, contrary to noncompliant or semi-compliant balloons. Our objective is to describe our initial experience with the semi-compliant Neurospeed balloon (approved for intracranial stenosis) in cerebral vasospasm treatment following aSAH. METHODS: All patients included in the prospective observational SAVEBRAIN PWI (NCT05276934 on clinicaltrial.gov) study who underwent cerebral angioplasty using the Neurospeed balloon for the treatment of medically refractory and symptomatic CV after aSAH were identified. Patient demographic information, procedural details and outcomes were obtained from electronic medical records. RESULTS: Between February 2022 and June 2023, 8 consecutive patients underwent CV treatment with the Neurospeed balloon. Angioplasty of 48 arterial segments (supraclinoid internal carotid artery, A1 and A2 segments of the anterior cerebral artery, M1 and M2 segments of the middle cerebral artery) was attempted and 44/48 (92%) were performed. The vessel diameter significantly improved following angioplasty (+81%), while brain hypoperfusion decreased (-81% of the mean TMax). There was no long-term clinical complication, 4% periprocedural complications occurred. CONCLUSION: The semi-compliant Neurospeed balloon is effective in the treatment of cerebral vasospasm following aSAH, bringing a new device into the armamentarium of the neurointerventionalist to perform intracranial angioplasty.

Endoscope-integrated ICG technology: first application during intracranial aneurysm surgery.

Microscopic indocyanine green videoangiography (mICG-VA) has gained wide acceptance during intracranial aneurysm surgery by lowering rates of incomplete clipping and occlusion of surrounding vessels. However, mICG-VA images are limited to the microscopic view and some deeper areas, including the aneurysm sac/neck posterior side, cannot be efficiently assessed as they are hidden by the aneurysm, clips, or surrounding structures. Contrarily, endoscopes allow a wider area of visualization, but neurosurgical endoscopes to date only provided visual data. We describe the first application of endoscope ICG-integrated technology (eICG) applied in an initial case of anterior communicating artery aneurysm clipping. This new technique provided also relevant information regarding aneurysm occlusion and patency of parent and branching vessels and small perforating arteries. eICG-VA provided additional information compared to mICG-VA by magnifying areas of interest and improving the ability to view less accessible regions, especially posterior to the aneurysm clip. Obtaining eICG sequences required currently the microscope to be moved away from the operating field. eICG-VA was only recorded under infrared illumination which prevented tissue handling, but white-infrared light views could be interchanged instantaneously. Further development of angled endoscopes integrating the ICG technology and dedicated filters blocking the microscopic light could improve visualization capacities even further. In conclusion, as a result of its ability to reveal structures around corners, the eICG-VA technology could be beneficial when used in combination with mICG-VA to visualize and confirm vessel patency in areas that were previously hidden from the microscope.

Severely Hypoperfused Brain Tissue Correlates with Final Infarct Volume Despite Recanalization in DMVO Stroke.

Objectives: We sought to assess whether there were any parameter(s) on baseline computed-tomography-perfusion (CTP) strongly correlating with final-infarct-volume, and infarct volume progression after endovascular recanalization of acute ischemic stroke (AIS) with primary distal, medium vessel occlusion (DMVO). Materials and Methods: We performed a retrospective analysis of consecutive AIS patients who were successfully recanalized by thrombectomy for DMVO. By comparing baseline CTP and follow-up MRI, we evaluated the correlation between baseline infarct and hypoperfusion volumes, and final infarct volume and infarct volume progression. We also examined their effect on good clinical outcome at 3 months (defined as an mRS score of 0 to 2). Results: Between January 2018 and January 2021, 38 patients met the inclusion criteria (76% [29/38] female, median age 75 [66-86] years). Median final infarct volume and infarct volume progression were 8.4 mL [IQR: 5.2-44.4] and 7.2 mL [IQR: 4.3-29.1] respectively. TMax > 10 sec volume was strongly correlated with both (r = 0.831 and r = 0.771 respectively, p < 0.0001), as well as with good clinical outcome (-0.5, p = 0.001). A higher baseline TMax > 10 sec volume increased the probability of a higher final-infarct-volume (r2 = 0.690, coefficient = 0.83 [0.64-1.00], p < 0.0001), whereas it decreased the probability of good clinical outcome at 3 months (odds ratio = -0.67 [-1.17 to -0.18], p = 0.008). Conclusion: TMax > 10 sec volume on baseline CTP correlates strongly with final infarct volume as well as with clinical outcome after mechanical thrombectomy for an AIS with DMVO.

Endovascular treatment of proximal superior middle cerebral artery aneurysms.

INTRODUCTION: Aneurysms superiorly located on the proximal segment of the middle cerebral artery (PMCAA) are rare and challenging to treat. No information is available regarding their management by endovascular approach. The aim of this study was to report our experience with endovascular treatment (EVT) of PMCAA. METHODS: A retrospective review of our prospectively maintained database identified all PMCAA treated in our institution. The clinical charts, procedural data, and angiographic results were reviewed. RESULTS: From April 2004 to December 2011, 17 patients were identified including six who presented with subarachnoid hemorrhage (SAH) and 11 with an unruptured PMCAA. All aneurysms were small (<6 mm) and had a branch arising from the neck or the sac, and 15/17 were wide-necked. All patients were successfully treated by balloon-assisted coiling (n = 10), stent-assisted coiling (n = 5), and coiling (n = 2). No technical or clinical complication occurred. Fifteen patients showed an excellent clinical outcome, and two kept a slight or a significant deficit that were both SAH-related. Immediate anatomical outcome includes nine complete occlusions and eight neck remnants. Imaging follow-up in 11 patients (mean = 21, range, 6 to 60 months) showed stable or improved results in all cases. CONCLUSION: Our study is the first reported series of patients with PMCAA treated by selective embolization. It suggests that EVT is a safe and effective alternative to surgery for the management of PMCAA. Balloon- or stent-assisted coiling are needed in most cases because of PMCAA morphological characteristics.

Endovascular Treatment of Patients with Ruptured Intracranial Aneurysms: A Series of 468 Patients Treated Over a 14-Year Period.

Purpose: Non-traumatic subarachnoid hemorrhage (SAH) is an emergency usually caused by the rupture of a saccular intracranial aneurysm. Endovascular treatment (EVT) is now considered as the first therapeutic option. The aim of our study is to evaluate, over a 14-year period in a single center, the result of EVT of ruptured intracranial aneurysms. Methods: From the retrospective analysis of our prospectively maintained database, we collected data of 457 patients successfully treated by endovascular approach for a SAH. Descriptive statistics and percentages were used to report clinical and anatomical outcomes, procedure-related complications, post procedural events, morbidity and mortality. Results: EVT was unsuccessful in eleven patients but effective in 457 patients with two patients who experienced a rebleeding (0.4%). In 6.3% of cases, a second EVT was necessary. The final aneurysm occlusion was complete (65.7%), with a neck remnant (28.2%) or incomplete (6.1%). Procedure-related complications occurred in 5.9% of patients and were associated with five clinical worsening and one death. Overall EVT-related morbidity and mortality were thus of 1.3% and 0.4% respectively. At discharge, 71% of patients had a good recovery (mRS 0-2), 11.2% had a poor outcome (mRS 3-5), and 17.8% died. Conclusion: This study seems to prove that high-volume centers with experienced interventional neuroradiologists carry low rates of technical failure and complication from EVT of ruptured intracranial aneurysm.

Stroke Core Volume Weighs More Than Recanalization Time for Predicting Outcome in Large Vessel Occlusion Recanalized Within 6 h of Symptoms Onset.

Introduction: Current guidelines suggest that perfusion imaging should only be performed > 6 h after symptom onset. Pathophysiologically, brain perfusion should matter whatever the elapsed time. We aimed to compare relative contribution of recanalization time and stroke core volume in predicting functional outcome in patients treated by endovascular thrombectomy within 6-h of stroke-onset. Methods: Consecutive patients presenting between January 2015 and June 2021 with (i) an acute ischaemic stroke due to an anterior proximal occlusion, (ii) a successful thrombectomy (TICI >2a) within 6-h of symptom-onset and (iii) CT perfusion imaging were included. Core stroke volume was automatically computed using RAPID software. Two linear regression models were built that included in the null hypothesis the pre-treatment NIHSS score and the hypoperfusion volume (Tmax > 6 s) as confounding variables and 24 h post-recanalization NIHSS and 90 days mRS as outcome variables. Time to recanalization was used as covariate in one model and stroke core volume as covariate in the other. Results: From a total of 377 thrombectomies, 94 matched selection criteria. The Model null hypothesis explained 37% of the variability for 24 h post-recanalization NIHSS and 42% of the variability for 90 days MRS. The core volume as covariate increased outcome variability prediction to 57 and 56%, respectively. Time to recanalization as covariate marginally increased outcome variability prediction from 37 and 34% to 40 and 42.6%, respectively. Conclusion: Core stroke volume better explains outcome variability in comparison to the time to recanalization in anterior large vessel occlusion stroke with successful thrombectomy done within 6 h of symptoms onset. Still, a large part of outcome variability prediction fails to be explained by the usual predictors.

Long-term follow-up of the pCONus device for the treatment of wide-neck bifurcation aneurysms.

PURPOSE: Wide-neck bifurcation aneurysms remain challenging for the neurointerventionist and/or neurosurgeon despite many recent advances. The pCONus (Phenox, Bochum, Germany) is an emerging device for endovascular neck protection, we report the first long-term results of this device. METHODS: We performed a retrospective analysis of all consecutive intracranial wide-neck bifurcation aneurysms treated with the pCONus. Patients' characteristics were reviewed, procedural complications, angiographic (Roy-Raymond scale) and clinical outcomes were documented. RESULTS: Between January 2016 and September 2019, 43 patients (74% female, median age 56 [49-66] years) with 43 wide-neck bifurcation aneurysms (mean width of 6.8 ± 2.1 mm, dome/neck ratio of 1.3 ± 0.2 and neck of 5.2 ± 1.3 mm) were included. A procedural angiographic complication was reported in five patients (12%), no patient presented a post-operative neurological deficit or long-term complication, mortality rate was 0%. At last follow-up (median of 46.5 months [38.3-51.7]), an adequate occlusion (complete and neck remnant) was observed in 37/43 patients (86%) and an aneurysm remnant in 6/43 (14%). Four patients (9%) needed retreatment. No in-stent stenosis or branch occlusion was depicted. CONCLUSION: pCONus device provides a safe and efficient alternative for endovascular wide-neck bifurcation aneurysms management, with long-term stability.

Thrombectomy for distal medium vessel occlusion with a new generation of Stentretriever (Tigertriever 13).

PURPOSE: To evaluate the safety and efficacy of the Tigertriever 13 (Rapid Medical, Yoqneam, Israel) stent retriever in acute ischemic stroke (AIS) patients with primary or secondary distal, medium vessel occlusions (DMVO). METHODS: We performed a retrospective analysis of all consecutive AIS patients who underwent thrombectomy with the Tigertriever13 for DMVO. Patients' characteristics were reviewed, procedural complications, angiographic (modified thrombolysis in cerebral infarction score [mTICI]) and clinical (modified Rankin Scale [mRS]) outcomes were documented. RESULTS: Between November 2019 and November 2020, 16 patients with 17 DMVO were included (40% female, median age 60 [50-65] years). The Tigertriever13 was used in 11/17 (65%, median NIHSS of 8 [6-15]) primary DMVO and in 6/17 (35%, median NIHSS of 20 [13-24]) cases of secondary DMVO after a proximal thrombectomy. The successful reperfusion rate (mTICI 2b, 2c, 3) was 94% (16/17) for the dedicated vessel. At day 1, CT imaging showed a subarachnoid hemorrhage in 29% of the cases and a parenchymal hematoma in 12%. At 3 months, 65% of the patients (11/17) had a favorable outcome (mRS 0-2). CONCLUSION: Mechanical thrombectomy using the Tigertriever13 appears to be safe and effective for DMVO. Clinical and anatomical results are in line with those of patients with proximal occlusions.

The Anch'Or Harpoon Technique With a Manually Expandable Stentretriever (Tigertriever 13), a Technical Note.

Background and purpose: Stent and balloon anchor techniques have been described to obtain distal support and straighten catheter loops, stabilize microcatheters in giant aneurysms, or access distal tortuous anatomy during thrombectomy. These techniques require catheterization of distal arteries with a microcatheter but tortuosity and length issues may render it challenging, precluding the distal unsheathing of a classical auto-expandable stentretriever with the anchor technique. Methods: Therefore, we developed the so-called Anch'Or Harpoon Technique using a manually expandable stent retriever, the Tigertriever 13 (Rapid Medical, Yoqneam, Israel). Here, the stent retriever is not unsheathed but pushed out of a microcatheter, and then advanced as far as possible before manual opening. Results and conclusion: This technique may be used in 2 different situations. First, in the case of vessel tortuosity if the microcatheter can't be advanced as far as the physician wants: the Tigertriever 13 could be delivered through the microcatheter without having to unsheathe it, and be advanced and opened distally to its microcatheter to establish a stable anchor prior to advancing the guiding, intermediate, and micro-catheters (Anchor technique). The second situation is when distal occlusions lead to length issues; the microcatheter may be too short to cross a distal clot: the Tigertriever 13 could then be pushed out of the microcatheter, and be used to cross a sub-occlusive clot as it has a soft shaped distal tip and the physician has a visual on the artery beyond the sub-occlusion. Then, the Tigertriever would be manually expanded through the clot and retrieved (Harpoon technique) to obtain a recanalization.

Hypoperfusion Intensity Ratio Predicts Infarct Growth After Successful Thrombectomy for Distal Medium Vessel Occlusion.

BACKGROUND AND PURPOSE: This study evaluated whether quantitative measurement of collaterals by the hypoperfusion intensity ratio (HIR) on baseline computed tomography perfusion (CTP) correlated with infarct growth and clinical outcome after successful endovascular recanalization of acute ischemic stroke (AIS) caused by primary distal medium vessel occlusions (DMVO). METHODS: We performed a retrospective analysis of consecutive AIS patients who underwent an initial CTP and were successfully recanalized by thrombectomy (modified thrombolysis In cerebral infarction 2b or 3) for DMVO. We evaluated the association of baseline HIR with infarct growth and clinical outcome. RESULTS: Between January 2018 and January 2021, 40 patients with an AIS caused by a DMVO were successfully recanalized by MT (65%, 26/40 female, median age 72 years, range 65-83 years). Baseline HIR was strongly correlated with infarct growth after successful recanalization (r = 0.501, p = 0.001). An HIR<0.3 was the optimal threshold for good collaterals using ROC analysis. Patients with HIR ≥ 0.3 had higher infarct growth compared to HIR < 0.3 (23.8 mL, IQR: 9.1-45.1 vs. 7.2 mL, interquartile range (IQR): 4.2-11.7, relative risk 7.9, p = 0.024 in multivariate analysis); their clinical outcome was poorer in univariate analysis (75%, 21/28 patients with a 3 months modified Rankin scale of 0-2 vs. 33%,4/12, p < 0.017, odds ratio (OR) 6.0, 1.37-26.20) but it did not remain significant in multivariate analysis (p = 0.107). CONCLUSION: Good collaterals on initial CTP assessed by an HIR < 0.3 are associated with less infarct growth after successful recanalization of AIS caused by a DMVO.

Early Neurological Improvement Predicts Clinical Outcome After Thrombectomy for Distal Medium Vessel Occlusions.

Background and Purpose: Good clinical outcome predictors have been established in mechanical thrombectomy (MT) for acute ischemic stroke (AIS) caused by large vessel occlusion (LVO). An early neurological improvement (ENI), defined as a reduction of ≥8 on the National Institutes of Health Stroke Scale (NIHSS), compared with the baseline score or an NIHSS of 0 or 1 at 24 h after MT, is a strong predictor of favorable outcome. We aimed to study the impact of ENI after MT for distal medium vessel occlusions (DMVO). Methods: We retrospectively analyzed the data of consecutive patients who underwent MT for a primary DMVO in one large academic center. We compared clinical outcomes between patients with DMVO stratified by ENI. Multivariate analyses were performed to determine the impact of ENI on good 90-day outcome (modified Rankin scale of 0-2) and identify factors contributing to ENI. Results: Between January 2018 and January 2021, 61 patients underwent an MT for an AIS with a primary DMVO. An ENI was seen in 24 (39%) patients (ENI+). Outcomes were significantly better in ENI+ patients, with 83% achieving a good outcome at 3 months vs. 43% for patients without ENI (ENI-; p = 0.019). ENI was an independent predictive factor of good clinical outcome even after adjusting for potential confounding factors [odds ratio 12.49 (1.49-105.01), p = 0.020]. The use of intravenous tissue plasminogen activator [IVtPA; Odds-ratio 6.59 (1.82-23.89), p = 0.004] was a positive predictor of ENI. Conclusion: ENI at day 1 following MT for DMVO stroke is a strong independent predictor of good to excellent 3-month clinical outcome.