M1 Segment Research Articles

Early experience with the Aristotle Colossus 0.035' macrowire for mechanical thrombectomy in 30 consecutive cases.

Recent literature continues to demonstrate the successful role of large-bore aspiration catheters in thrombus ingestion during mechanical thrombectomy. However catheter-to-microwire step-off and distal navigation are ongoing challenges in thrombectomy. A new to market 0.035' macrowire (Aristotle 35 Colossus Guidewire, Scientia Vascular, West Vale City, UT) may address such challenges. We report here our early experience in 30 mechanical thrombectomy cases. We analyzed a prospectively maintained database of the senior authors to identify cases utilizing a 0.035' macrowire with 0.035' aspiration catheters for mechanical thrombectomy. Thirty consecutive cases were identified. Seventeen (57%) patients were female with an average age of 75.3 ± 2.2 years (range 55-97). Average presenting NIHSS was 13.0 ± 1.7. Thrombus locations included 7% (n = 2) in the cervical ICA, 47% (n = 14) in the M1, 43% (n = 13) in the M2, and 3% (n = 1) in the P1. An 088' ID aspiration catheter was navigated to at least the M1 segment in all anterior circulation cases and the basilar in the posterior circulation case. The 0.035' macrowire was placed proximal to the occlusion in all cases allowing coaxial 035' and 071' catheter aspiration passes. TICI 2C/3 was achieved in 87% of cases (n = 26) and TICI 2B in the remaining cases. There were no wire-related perforations or vessel dissections. The Colossus 0.035' macrowire may offer advantages over its smaller counterparts by reducing ledge effect and the need to cross the thrombus. Further comparative studies against currently available microwires in various anatomies are warranted.

Clinical Outcome of Intravenous Alteplase Treatment in Patients With Acute Mild Cerebral Infarction

ABSTRACTBackgroundThe efficacy of intravenous alteplase therapy for acute cerebral infarction is well established, regardless of the ischemic stroke subtype. However, its effectiveness in patients with mild cerebral infarction remains controversial, raising concerns about the significance of the treatment.AimTo retrospectively evaluate the efficacy of intravenous alteplase in patients with mild cerebral infarction and other factors affecting the outcome.MethodsA total of 527 patients received intravenous alteplase (0.6 mg/kg) at our hospital between October 2012 and March 2023. Of these, 118 patients with mild cerebral infarction (National Institutes of Health Stroke Scale [NIHSS] ≤ 5) who were treated with intravenous alteplase without mechanical thrombectomy were retrospectively evaluated for treatment efficacy and the factors affecting the efficacy.ResultsThe modified Rankin scale (mRS) outcome at 90 days was good (mRS: 0–1) in 85 (72%) patients and poor (mRS: 2–5) in 33 (28%) patients. Branch atheromatous disease (BAD) and proximal anterior circulation large vessel occlusion (proximal LVO: internal carotid artery and M1 segment of middle cerebral artery) were observed more frequently in the poor outcome group than in the good outcome group. Multivariate analysis, adjusted for age and sex, identified BAD and proximal LVO as factors associated with poor outcomes after intravenous alteplase treatment for mild cerebral infarction. Symptomatic intracranial hemorrhage was observed in one patient with BAD.ConclusionMost patients with mild cerebral infarction who were treated with intravenous alteplase alone had good outcomes. BAD and proximal LVO were other factors influencing poor outcomes.

Elucidation of the Cranial Arterial Anatomy Using the Transorbital Endoscopic Approach.

New surgical techniques that access the orbit and intracranial cavity have been developed in recent years called transorbital neuroendoscopic surgery. The superior eyelid route, as a transorbital corridor, is a clinically feasible route to access selected anterior and middle skull base pathologies. However, studies regarding the suitability of this approach in vascular surgery are lacking. In this study, transorbital endoscopic dissections were performed bilaterally in 4 cadavers through the superior eyelid approach. The authors aimed to define the arterial vascular structures that can be accessed through this approach. In this study, the M1 and M2 segments of the middle cerebral artery and the branches originating from it were accessible with a 0 degree endoscope after an appropriate dissection. Thus, the endoscopic superior eyelid approach may be a novel alternative approach for some cranial pathologies.

Soft partial release of non-aggressive stent retriever technique for very distal arterial occlusion stroke.

Endovascular thrombectomy (EVT) for very distal vessel occlusion (DVO) stroke is increasingly performed but there is insufficient evidence on the efficacy and safety of distal EVT techniques. We hypothesized that the technique of soft partial release of non-aggressive stent retrievers (SPORNS) reduces friction on the perforating vessels during thrombectomy and thereby reduces bleeding complications. Retrospective study including consecutive DVO patients who were treated with the SPORNS technique between 1 January 2022 and 31 December 2022 at two tertiary stroke centers. DVOs were defined as isolated occlusions of the M3 and M4 segments of the middle cerebral artery, occlusions of the A2 and A3 segments of the anterior cerebral artery, and occlusions of the P2 and P3 segments of the posterior cerebral artery or of the superior cerebellar artery. The technique is described in detail and procedural and clinical outcomes are given. Twenty-four patients were treated with the SPORNS technique of whom 22 (92%) had complete or near complete recanalization (eTICI 2c/3). National Institutes of Health Stroke Scale (NIHSS) decreased from a median of nine (IQR 7-13) at admission to three (1-5) at discharge and 18 patients (75%) achieved a good outcome (modified Rankin scale 0-2) at day 90 post-stroke. Two patients (8%) had a small subarachnoid hemorrhage and two patients (8%) had a symptomatic intracerebral hemorrhage on follow-up imaging. For the treatment of very distal arterial occlusions, the SPORNS technique employing a soft partial release of a non-aggressive stent retriever is safe and effective for the thrombectomy of small clots. The technique potentially yields a lower rate of subarachnoid hemorrhages while achieving an excellent rate of complete and first-pass recanalization.

Perfusion-Based Relative Cerebral Blood Volume Is Associated With Functional Dependence in Large-Vessel Occlusion Ischemic Stroke.

Pretreatment computed tomography perfusion parameter relative cerebral blood volume (rCBV) lesion volume has been shown to predict 90-day modified Rankin Scale score in small-core strokes with Alberta Stroke Program Early Computed Tomography Score ≥5, including those with medium-vessel occlusions (mid and distal M2 segment occlusions). Hence, in this study we aim to assess the performance of different rCBV lesion volume thresholds (rCBV <42%, rCBV <38%, and rCBV <34%) with 90-day modified Rankin Scale score including patients with large core (Alberta Stroke Program Early Computed Tomography Score <5) and strictly including only patients with anterior circulation large-vessel occlusion. In this retrospective evaluation of our prospectively collected database, inclusion criteria were (1) Computed tomographic angiography confirmed anterior circulation large-vessel occlusion from September 1, 2017, to October 1, 2023; and (2) diagnostic computed tomography perfusion. Student t test, Mann-Whitney U test, and χ2 test were used in the univariate data analysis. Spearman's rank correlation analysis was used to assess correlations. Outcome measure was dichotomized into good functional outcome (90-day modified Rankin Scale score, 0-2) and poor functional outcome (90-day modified Rankin Scale score, 3-6) for logistic regression and receiver operating characteristic analysis. P≤0.05 was considered significant. In total, 229 patients met our inclusion criteria. The majority of the patients (n=161) in our cohort had M1 occlusion. All the rCBV thresholds were significantly higher in patients with poor 90-day functional outcomes and were independently associated with the outcome. Spearman's rank correlation analysis revealed a slightly stronger correlation of rCBV <42% (ρ=0.27, P<0.001), as compared with rCBV <38% (ρ=0.25, P<0.001) and rCBV <34% (ρ=0.24, P<0.001) with functional outcome. Receiver operating characteristic analysis revealed that rCBV <42% (area under the curve, 0.67 [95% CI, 0.60-0.74]; P<0.001) performed marginally better than rCBV <38% (area under the curve, 0.66 [95% CI, 0.59-0.73]; P<0.001), and rCBV <34% (area under the curve, 0.65 [95% CI, 0.58-0.72]; P<0.001). All the rCBV thresholds were independently associated with poor 90-day functional outcome; however, the rCBV <42% marginally outperformed rCBV <38% and rCBV <34% lesion volumes.

Association of Pretreatment Perfusion Imaging Parameters With 90-Day Excellent Functional Outcomes in Anterior Circulation Distal Medium Vessel Occlusion Stroke.

Acute ischemic strokes caused by distal medium vessel occlusions (DMVO) represent a significant proportion of all stroke cases, yet the predictors of excellent functional outcomes in these patients remain poorly understood. This study aims to identify pretreatment computed tomography perfusion (CTP) parameters associated with excellent functional outcomes, defined as a modified Rankin Scale (mRS) score of 0-1 at 90 days, in patients with anterior circulation DMVO. We conducted a retrospective multicenter study involving patients with anterior DMVO, from three stroke centers within the Johns Hopkins Medical Enterprise. Baseline demographic, clinical, and imaging data were collected, with CTP parameters analyzed using RAPIDAI software. Univariable and multivariable logistic regression models were used to identify predictors of excellent outcomes. Receiver operating characteristic (ROC) curves were constructed to assess the predictive accuracy of CTP parameters. Among the 82 patients (median age, 71 years; 57% female), occlusions were located in the M2 segment in 89%, M3 in 8.5%, and A2 in 2.4%. IVT was administered to 37% of patients, and EVT was attempted in 59%. Excellent outcomes at 90 days were achieved in 45% of patients. In univariate analysis, white race (OR, 4.14; 95% CI, 1.66-10.9; P=0.003), higher CBV index (OR per 0.1-unit change, 1.45; 95% CI, 1.08-2.05; P=0.022), and lower relative cerebral blood flow (rCBF < 20%) volumes (OR, 0.91; 95% CI, 0.81-0.98; P=0.038) were significantly associated with excellent outcomes. In multivariate analysis adjusting for age, sex, race, IVT administration, EVT attempted, dyslipidemia, and premorbid mRS, higher CBV index remained a significant independent predictor (OR per 0.1-unit change, 1.72; 95% CI, 1.14-2.81; P=0.017), and lower rCBF < 20% volume was associated with better outcomes (OR, 0.91; 95% CI, 0.80-0.98; P=0.05). The multivariate model demonstrated good predictive performance (area under the ROC curve, 80%; 95% CI, 70%-90%; P < 0.001). In patients with anterior circulation DMVO, a higher CBV index on pretreatment CTP is an independent predictor of excellent functional outcomes at 90 days. These findings suggest that CTP parameters, particularly the CBV index, may be useful in prognostic assessment for this stroke population. Further studies are needed to validate these results and optimize therapeutic approaches. ABC＝ definition; XYZ＝ definition.

SURGICAL CHALLENGES IN CLIPPING LARGE ANEURYSMS IN DISTAL ARTERIAL TERRITORIES

Background By distal arterial territories we mean the arteries located after the main bifurcations of the cerebral arteries. They can occur at multiple sites throughout the course of distal arteries, but most often are found after the bifurcation of the M1 segment of the middle cerebral artery. Methods A retrospective review of 18 consecutive patients with large aneurysms located in distal arterial territories, treated by surgical clipping between 2019-2023, was performed. We consider aneurysm larger than 10 mm in diameter as large aneurysm. The data of all our consecutive patients were searched to obtain patient characteristics, details of the aneurysm size and orientation, treatment details, complications and follow up. At admission, the clinical condition of all patients was classified according to the Hunt and Hess scale. Clinical outcome was graded according to the modified Rankin scale. The follow-up period varied widely from 6 to 54 months (mean 24 months). Results Surgical clipping was performed for all aneurysms; only in 2 cases the aneurysm was unruptured. Three patients presented with significant hematoma which required the evacuation of the clot. Most large aneurysms were located in M2 or M3 segments of the MCA (16 patients). Post-operative control angiography was performed in 11 patients (61%), from which we reported a full occlusion of the aneurysm in 10 patients (90%). No perioperative mortality was recorded. The outcome was graded mRankin 0–2 in 83% of the cases (15 patients) at the end of the first postoperative months, and 94.4% (17 patients) at six months follow-up. The most important improvement was recorded for patients graded mRankin 1-2 at the first month follow-up. Conclusions The large size of the aneurysm, the size of the neck, as well as the reduced diameter of the parent vessel, represent important trials for the neurosurgeon in the correct clipping of the aneurysm. In some cases, sectioning of the aneurysm dome was necessary for successful clipping.

Two Novel Variants in the CHRNA2 and SCN2A Genes in Italian Patients with Febrile Seizures.

Febrile seizures (FSs) are the most common form of epilepsy in children aged between six months and five years. The exact cause is unknown, but several studies have demonstrated the importance of genetic predisposition, with increasing involvement of receptors and ion channels. The present study aims to identify novel pathogenic variants in Italian patients with FSs. We performed targeted panel sequencing in a cohort of 21 patients with FSs. In silico analysis was performed to predict the pathogenic role of the resulting variants. We found two novel variants segregating in two families with FSs: c.1021C>G (p.Leu341Val) in the CHRNA2 gene and c.140A>G (p.Glu47Gly) in SCN2A. The c.1021C>G (p.Leu341Val) variant leads to a codon change of highly conserved leucine to valine at position 341 and is located in segments M3 of the subunit, which is important for channel gating. The c.140A>G (p.Glu47Gly) variant causes a substitution of glutamic acid with glycine at position 47 of the protein, which is highly conserved across the species. Moreover, it is located in the N-terminal domain, a region commonly affected in ASD, which impacts the inactivation kinetics and voltage dependence of steady-state activation. Further analyses are needed to better explain the role of CHRNA2 and SCN2A in the development of febrile seizures.

Emergency microsurgical trapping, decompression, and revascularization of a middle cerebral artery dissecting aneurysm using a minipterional approach in a pediatric patient: illustrative case.

Pediatric intracranial aneurysms present unique diagnostic and therapeutic challenges due to their rarity and their distinct anatomical and physiological considerations compared with those of adult intracranial aneurysms. The authors present the case of a symptomatic pediatric patient who required emergency microsurgical treatment after a thrombosed dissecting aneurysm was identified in the right M1 segment of the middle cerebral artery. The lesion completely occluded its parent vessel, although distal blood flow was reconstituted through leptomeningeal collaterals. However, aneurysm wall contrast enhancement and signs of early perfusion changes were noticed, which prompted emergency treatment consisting of microsurgical aneurysm trapping, decompression, and extracranial/intracranial revascularization to be successfully performed through a minipterional craniotomy. After 1 year, the bypass occluded, although the patient remained asymptomatic. A slight enlargement of the ipsilateral anterior cerebral artery suggested the possibility of a benign hemodynamic rearrangement. Emergency treatment may be necessary when signs of lesion instability or hemodynamic compromise are present; however, a comprehensive multidisciplinary evaluation is required. Treatment of complex vascular lesions using a minipterional approach is feasible even in pediatric patients, and delayed bypass occlusion may be a benign phenomenon reflecting gradual blood flow reorganization. https://thejns.org/doi/10.3171/CASE24484.

Clinical Impact of Reperfusion Techniques and Occlusion Sites in Thrombectomy: Insights from the ASSIST Stroke Registry

Background Mechanical thrombectomy has changed the landscape of acute ischemic stroke treatment, offering improved outcomes for patients with large vessel occlusions. The interplay between reperfusion techniques and occlusion sites remains a critical consideration in treatment decisions. This study investigates the impact of primary reperfusion techniques—stent retriever classic, stent retriever combination with aspiration, and direct aspiration—on procedural and clinical outcomes at different occlusion sites. Methods Using data from the ASSIST registry, a prospective multinational initiative, patients with anterior circulation acute ischemic stroke with large vessel occlusions (n = 1477) were included. Three primary occlusion sites—M1 segment of the middle cerebral artery, M2 segment of the middle cerebral artery, and the internal carotid artery—were studied. Univariate tests and multivariable logistic regression models were used to assess associations between reperfusion techniques and procedural and clinical outcomes, including the expanded thrombolysis in cerebral infarction score and the modified Rankin Scale, stratified by occlusion site. Results Achieving expanded thrombolysis in cerebral infarction ≥2c after first pass was lower in internal carotid artery occlusions (18.2%, P &lt;0.0001) with direct aspiration alone compared with stent retriever classic (38.2%) or stent retriever combination with aspiration (43.3%), while no differences were seen for M1 segment of the middle cerebral artery ( P = 0.77) and M2 segment of the middle cerebral artery ( P = 0.29) occlusions. Bailout maneuvers, which were more frequent in the direct aspiration group for all occlusion sites, did not result in longer procedure times or different final recanalization outcomes in direct aspiration compared with stent retriever classic or stent retriever combination with aspiration. Overall, there were no differences in the rate of patients with modified Rankin Scale scores of 0–2 at 90 days. No differences in safety outcomes were observed. Conclusions This study provides insight into the complex relationship between reperfusion techniques and occlusion sites in patients with acute ischemic stroke and shows that certain techniques have advantages in certain occlusion sites. As the field evolves, further research is warranted to refine our understanding of these dynamics and inform clinical practice.

Treatment of Cerebral Vasospasm after Aneurysmal Subarachnoid Hemorrhage Using the Compliant Manually Adjustable Mesh Comaneci.

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. Compliant and noncompliant balloons and manually adjustable mesh may be used in this indication. We describe our initial experience with the Comaneci (Rapid Medical, Yokneam, Israel) 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 Comaneci device 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, seven consecutive patients underwent CV treatment with the Comaneci. Angioplasty of 37 arterial segments (supraclinoid internal carotid artery, A1, A2, and A3 segments of the anterior cerebral artery and M1 and M2 segments of the middle cerebral artery) was attempted, and 35/37 (95%) were performed. The vessel diameter improved significantly following angioplasty (+64%), while brain hypoperfusion decreased (-45% of the mean T Max). There was no long-term clinical complication, and 6% per-procedural complications occurred. Conclusions: The Comaneci is effective in the treatment of cerebral vasospasm following aSAH, bringing a new device in the armamentarium of the neurointerventionalist to perform intracranial angioplasty.

Ophthalmic artery originating from anterior inferior cerebellar artery: a rare variation.

The variations of origin of ophthalmic artery are extremely rare. Here, we aimed to present a patient had a rare variation of the ophthalmic artery. The patient had a history of Moyamoya disease. The imaging studies revealed ophthalmic artery origination from basillar artery. In addition, M1-segment fusiform aneurysm, vasculitis and, as a variation, middle meningeal artery originating from the ophthalmic artery were also detected. We presented this case report as it is the first case with ophthalmic artery originating from anterior inferior cerebellar artery. In our case we reported, M1 segment fusiform aneurysm, vasculitis, and as a variation, middle meningeal artery originating from the ophthalmic artery and anterior inferior cerebellar artery as ophthalmic artery origin and hereby present it for inclusion into the literature. Ophthalmic artery anatomical abnormalities occupies so little place in existing literature when nominating rare variations. Ophtalmic artery originating from anterior inferior cerebellar artery firstly defined as an ophthalmic artery variation including its way-out branch structures.

Poor venous outflow is associated with hyperintense acute reperfusion marker on follow-up MRI in patients with acute ischemic stroke with a large vessel occlusion

BackgroundHyperintense acute reperfusion marker (HARM) refers to delayed enhancement in the subarachnoid or subpial space on post-contrast fluid attenuated inversion recovery (FLAIR) images. HARM is a measure of blood–brain barrier...

Subacute in-stent thrombosis after carotid artery stenting in a patient with gene polymorphisms associated with aspirin and clopidogrel resistance: a case report

BackgroundCarotid artery stenting (CAS) is a key treatment option for moderate to severe carotid artery stenosis. Carotid stent thrombosis (CST), a rare complication of CAS, has gained significant attention because of its catastrophic nature. More evidences are needed to guide the diagnosis and treatment of CST.Case presentationThis study reports a rare case of sub-acute CST following CAS in a 50-year-old male patient who had experienced repeated cerebrovascular events on the premise of taking antiplatelet drugs. He also suffered an occlusion of the left middle cerebral artery (MCA) in the M2 segment, likely caused by an embolus detached from the stent thrombus. The cause of CST in this patient was presumed to be dual antiplatelet resistance (AR), as indicated by genetic testing. After treated with guide catheter-directed thrombolysis, thrombus aspiration, and a second round of thrombolysis, his in-stent thrombus was basically cleared. His M2 occlusion was resolved by mechanical thrombectomy using the Solitaire FR/Stent with Intermediate Catheter Assisting technique. The patient recovered well after replacement of antiplatelet drugs, and no new thromboembolic event occurred during the 13-month follow-up period.ConclusionsThe occurrence rate of AR-related CST may be underestimated as the cause of majority CST cases remains unclear. Implementation of genetic test for aspirin and clopidogrel resistance may be helpful to find the possible cause of CST and to avoid future repeated cerebrovascular events by replacement of antiplatelet drugs.

Effect of occlusion site on the effectiveness and safety of endovascular thrombectomy for large ischemic cores: A cohort study.

Recent clinical trials have shown that patients with large ischemic cores have better outcomes with endovascular thrombectomy (EVT) compared with standard medical treatment (SMT) alone.We aim to assess whether the relationship between EVT and improvements in clinical outcomes varies depending on the location of the occlusive sites. This study is a subgroup analysis conducted within a prospective, nationwide, multi-center registry. The cohort included patients with acute large vessel occlusion in the anterior circulation and an Alberta Stroke Program Early Computed Tomography Score of 0 to 5 within 24 hours from last known well. We utilized the adjusted common odds ratio for a shift toward better outcome on the modified Rankin Scale after EVT compared with SMT alone as the primary outcome. Safety outcomes included symptomatic intracranial hemorrhage (sICH). A total of 745 patients with large ischemic cores were included: 272(36.5%) with internal carotid artery occlusion, 392(52.6%) with M1 segment of the middle cerebral artery occlusion, and 81(11.0%) with M2 segment of the middle cerebral artery occlusion. The adjusted common odds ratios were as follows: 1.98 (95% CI, 1.01-3.89) for ICA occlusions, 2.09 (95% CI, 1.35-3.23) for M1 occlusions, and 1.13 (95% CI, 0.43-2.94) for M2 occlusions. There was no significant treatment-by-occlusion site interaction observed (P=0.69). However, the incidence of sICH was significantly greater in all groups receiving EVT than in those receiving SMT alone. Additionally, we observed that the secondary outcomes and subgroup analyses were generally consistent with the main outcomes. In this study, we found that patients with internal carotid artery and M1 occlusion demonstrated a better outcome with EVT, while the benefit for patients with M2 occlusion remains uncertain.

Measurement of transcranial Doppler insonation angles from three-dimensional reconstructions of CT angiography scans.

Blood velocities measured by Transcranial Doppler (TCD) are dependent on the angle between the incident ultrasound beam and the direction of blood flow (known as the Doppler angle). However, when TCD examinations are performed without imaging the Doppler angle for each vessel segment is not known. We have measured Doppler angles in the basal cerebral arteries examined with TCD using three-dimensional (3D) vessel models generated from computed tomography angiography (CTA) scans. This approach produces angle statistics that are not accessible during non-imaging TCD studies. We created 3D models of the basal cerebral arteries for 24 vasospasm patients. Standard acoustic windows were mapped to the specific anatomy of each patient. Virtual ultrasound transmit beams were generated that originated from the acoustic window and intersected the centerline of each arterial segment. Doppler angle measurements were calculated and compiled for each vessel segment. Doppler angles were smallest for the middle cerebral artery M1 segment (median 24.6°) and ophthalmic artery (median 25.0°), and largest for the anterior cerebral artery A2 segment (median 76.4°) and posterior cerebral artery P2 segment (median 75.8°). The ophthalmic artery had the highest proportion of Doppler angles that were less than 60° (99%) while the anterior cerebral artery A2 segment had the lowest proportion of Doppler angles that were less than 60° (10%). These angle measurements indicate the expected deviation between measured and true velocities in the cerebral arteries, highlighting specific segments that may be prone to underestimation of velocity.

StentRetriever- aspiration (SRa) vs direct aspiration (DA) in the treatment of acute M2 segment occlusion of middle cerebral artery: A single center randomized prospective study

Decision making and patient selection for isolated occlusion of the M2 segment of the middle cerebral artery is challenging, with the efficacy of treatment for such distal occlusions still controversial in recent studies, as occlusion in such small and thin vessels tends to manifest with less severe symptoms initially and hold higher surgical risks. It is even less clear which endovascular technique is more effective for this type of occlusion, with the choice usually left to the radiologist's preference. We conducted a controlled prospective study of consecutive patients presenting to Novara Hospital with an acute M2 occlusion diagnosed at the AngioCt and, following a predetermined randomization, we divided them into two treatment arms with either stent retriever aspiration (SRa) or direct aspiration (DA). All patients were examined on admission, at discharge and after 3 months, and clinical data as well as mRS and NIHSS scale scores were recorded. Our primary aim was to evaluate the difference in recanalization rate in the two groups by comparing the angiographic eTICI obtained with the two techniques. We then investigated whether there were differences in clinical outcomes and complications. Our data confirm a good recanalization rate with an eTICI ≥ 2b in 76.19% of patients in the cohort. An overall good outcome was achieved in 57% of patients as ∆NIHSS and in 50.79% of patients considering mRS. We found no statistically significant difference in recanalization rate nor higher complication rate in either the SRa or DA group. Both techniques are safe, effective and can be considered equally.

Morphology and variations of middle cerebral artery: systematic review and meta-analysis.

To review morphometry, morphology, branching patterns and anomalies of middle cerebral artery (MCA). The databases of PubMed, Google Scholar and Scopus were searched with different keywords. The review comprised of 45 studies. Meta-analysis was done for dimensions of MCA, shapes, patterns and MCA anomalies. Newcastle-Ottawa Scale was used for assessment of literature. Statistical analysis was done using R software using meta package. Thirteen research were combined to determine the proportion of MCA length and pooled proportion was 16.53 cm (15.33 to 17.72 cm); I2=98%; P-value<0.01. Nine studies were combined to determine proportion of MCA diameter and pooled proportion was 2.85 cm (2.52 to 3.17 cm); I2=100%; P-value<0.05. M1 segment mean length is more on left side as compared to right side. Mean length in males (16.57±1.40 cm) is more than females (15.9±1.32 cm). Mean diameter of M1 segment is similar on both sides. Mean diameter in males (3.20±0.09 cm) is higher than females (3.14±0.18 cm). Different branching patterns observed were single trunk, early bifurcation, bifurcation, trifurcation, quadrifurcation and multiple trunks. The most typical MCA branching pattern is bifurcation. The shapes of MCA like straight shaped, U shaped, C shaped, inverted U shaped and S-shaped of M1 segment have been described. Straight MCA is the most common shape. The MCA measurements and branching pattern will assist surgeons in limiting errors in the treatment of cerebral aneurysms and infarcts and providing the best possible result for the patients. An understanding of MCA shape will aid surgeons and physicians in effective endovascular recanalization.

FreeClimb 88 catheter with Tenzing 8 delivery for contact aspiration mechanical thrombectomy of anterior circulation large vessel occlusions.

Contact aspiration mechanical thrombectomy (CAMT) with 0.088-inch catheters may improve first-pass success rates, but delivery of such catheters can be challenging and limit effectiveness. This study examines the initial multicenter experience using the FreeClimb 88 catheter paired with the Tenzing 8 delivery catheter. Retrospective analysis was performed of consecutive patients with large vessel occlusion (LVO) of the internal carotid artery (ICA) or M1 segment of the middle cerebral artery treated with off-label CAMT using the FreeClimb 88 and Tenzing 8 at eight sites participating in the early limited release for these devices. Demographic and procedural variables were collected and analyzed with descriptive statistics and multivariable analysis. Fifty-three consecutive patients were treated. Large vessel occlusion was located in the ICA in 19/53 (35.8%) patients; 34/53 (64.2%) were in the M1 segment. FreeClimb 88 was successfully delivered to the site of occlusion in 50/53 (94.3%) of patients. First-pass TICI 2c or 3 was achieved with FreeClimb 88 delivered by Tenzing 8 in 36 (67.9%) cases. Among cases with successful FreeClimb 88 delivery 9/50 (18.0%) required additional smaller devices to perform thrombectomy of distal occlusions after recanalization of the initial LVO. No complications or symptomatic hemorrhages occurred following thrombectomy. Contact aspiration mechanical thrombectomy performed for ICA or M1 LVOs using FreeClimb 88 delivered with Tenzing 8 was safe, effective, and efficient in this early experience, with first-pass TICI 2c or 3 was achieved in 68% of patients without procedural complications occurring in any cases.

Improved technical outcomes with converting thrombectomy techniques after failed first pass recanalization

BackgroundA higher number of recanalization attempts reduces the efficacy of endovascular thrombectomy (EVT) for acute ischemic stroke secondary to large vessel occlusion (LVO). We assessed the impact of switching EVT...