Angiographic Evolution of Brain Arteriovenous Malformation Angioarchitecture After Partial Endovascular Treatment.

BACKGROUND AND OBJECTIVES: Endovascular embolization of brain arteriovenous malformations (AVMs) is sometimes intentionally partial, in the case of staged treatment for instance. Residual AVMs may be prone to angioarchitectural modification during follow-up. The objective of this work is to evaluate the nature and extent of these modifications. METHODS: We performed a retrospective monocentric study on a cohort of adult patients treated by incomplete endovascular embolization for ruptured and unruptured AVMs with an available angiographic follow-up, without any intervening confounding event between the 2 angiographic examinations. AVM angioarchitectural modifications (arterial, nidal, and venous) were analyzed. Clinical and radiological data were tested in univariate analyses for association with the occurrence of AVM regression or progression. RESULTS: Eighty-two partial embolization sessions in 57 patients were included in the study. A 40% (33/82) rate of modification was found on follow-up, with 23/82 (28%) controls showing at least one angioarchitectural regression feature and 15/82 (18.3%) showing at least one angioarchitectural progression item. Nidal growth was the most frequent modification occurring after 12/82 (14.6%) embolizations. The only factor associated with nidal volume growth was a longer time interval between embolization and follow-up (median [IQR]: 190 [250] days vs 89.5[133] days in the subgroup without nidal growth; P = .02). Specific modifications of arterial supply, nidal anatomy, and venous drainage were identified and documented. CONCLUSION: Angioarchitectural modifications (both progression and regression) of brain AVMs are frequent findings after partial embolization. Nidal volume growth is associated with longer time intervals between embolization and follow-up.

Intracranial dural arteriovenous fistulas: association with cerebral venous thrombosis, baseline aggressiveness, and clinical outcomes. A retrospective multicenter study on 263 consecutive patients and literature review.

OBJECTIVE: The pathogenesis of intracranial dural arteriovenous fistulas (icDAVFs) is controversial. Cerebral vein thrombosis (CVT) and venous hypertension are recognized predisposing factors. This study aimed to evaluate the incidence of association between icDAVF and CVT and describe baseline aggressiveness and clinical outcomes for icDAVFs associated with CVT. The authors also performed a literature review of studies reporting icDAVF associated with CVT. METHODS: Two hundred sixty-three consecutive patients in two university hospitals with confirmed icDAVFs were included. A double-blind imaging review was performed to determine the presence or absence of CVT close or distant to the icDAVF. Location, type (using the Cognard classification), aggressiveness of the icDAVF, clinical presentation, treatment modality, and clinical and/or angiographic outcomes at 6 months were also collected. All prior brain imaging was analyzed to determine the natural history of onset of the icDAVF. RESULTS: Among the 263 included patients, 75 (28.5%) presented with a CVT concomitant to their icDAVF. For 18 (78.3%) of 23 patients with previous brain imaging available, CVT preceding the icDAVF was proven (6.8% of the overall population). Former/active smoking (OR 2.0, 95% CI 1.079-3.682, p = 0.022) and prothrombogenic status (active inflammation or cancer/coagulation trouble) were risk factors for CVT associated with icDAVF (OR 3.135, 95% CI 1.391-7.108, p = 0.003). One hundred eighty-seven patients (71.1%) had a baseline aggressive icDAVF, not linked to the presence of a CVT (p = 0.546). Of the overall population, 11 patients (4.2%) presented with spontaneous occlusion of their icDAVF at follow-up. Seven patients (2.7%) died during the follow-up period. Intracranial DAVF + CVT was not associated with a worse prognosis (modified Rankin Scale score at 3-6 months: 0 [interquartile range {IQR} 0-1] for icDAVF + CVT vs 0 [IQR 0-0] for icDAVF alone; p = 0.055). CONCLUSIONS: This was one of the largest studies focused on the incidence of CVT associated with icDAVF. For 6.8% of the patients, a natural history of CVT leading to icDAVF was proven, corresponding to 78.3% of patients with previous imaging available. This work offers further insights into icDAVF pathophysiology, aiding in identifying high-risk CVT patients for long-term follow-up imaging. Annual imaging follow-up using noninvasive vascular imaging (CT or MR angiography) for a minimum of 3 years after the diagnosis of CVT should be considered in high-risk patients, i.e., smokers and those with prothrombogenic status.

Comparison of rescue intracranial stenting versus best medical treatment alone in acute refractory large vessel occlusion: study protocol for the PISTAR multicenter randomized trial.

BACKGROUND: Mechanical thrombectomy (MT) has become a standard treatment for acute ischemic strokes (AIS). However, MT failure occurs in approximately 10-30% of cases, leading to severe repercussions (with mortality rates up to 40% according to observational data). Among the available rescue techniques, rescue intracranial stenting (RIS) appears as a promising option. OBJECTIVE: This trial is poised to demonstrate the superiority of RIS in addition to the best medical treatment (BMT) in comparison with BMT alone, in improving the functional outcomes at 3 months for patients experiencing an AIS due to a large vessel occlusion refractory to MT (rLVO). METHODS: Permanent Intracranial STenting for Acute Refractory large vessel occlusions (PISTAR) is a multicenter prospective randomized open, blinded endpoint trial conducted across 11 French University hospitals. Adult patients (≥18 years) with an acute intracranial occlusion refractory to standard MT techniques will be randomized 1:1 during the procedure to receive either RIS+BMT (intervention arm) or BMT alone (control arm). RESULTS: The primary outcome is the rate of good clinical outcome at 3 months defined as a modified Rankin Scale score ≤2 and evaluated by an independent assessor blinded to the randomization arm. Secondary outcomes include hemorrhagic complications, all adverse events, and death. The number of patients to be included is 346. Two interim analyses are planned with predefined stopping rules. CONCLUSION: The PISTAR trial is the first randomized controlled trial focusing on the benefit of RIS in rLVOs. If positive, this study will open new insights into the management of AIS. TRIAL REGISTRATION NUMBER: NCT06071091.

Evaluation of mechanical thrombectomy in acute ischemic stroke related to a distal arterial occlusion: A randomized controlled trial.

RATIONALE: Mechanical thrombectomy (MT) associated with the best medical treatment (BMT) has recently shown efficacy for the management of acute ischemic stroke (AIS) secondary to a large vessel occlusion. However, evidence is lacking regarding the benefit of MT for more distal occlusions. AIM: To evaluate the efficacy in terms of good clinical outcome at 3 months of MT associated with the BMT over the BMT alone in AIS related to a distal occlusion. METHODS: The DISCOUNT trial is a multicenter open-label randomized controlled trial involving French University hospitals. Adult patients (⩾18 years) with an AIS involving the anterior or posterior circulation secondary to a distal vessel occlusion within 6 h of symptom onset or within 24 h if no hyperintense signal on fluid attenuation inversion recovery acquisition will be randomized 1:1 to receive either MT associated with the BMT (experimental group) or BMT alone (control group). The number of patients to be included is 488. STUDY OUTCOMES: The primary outcome is the rate of good clinical outcome at 3 months defined as a modified Rankin scale (mRS) ⩽2 and evaluated by an independent assessor blinded to the intervention arm. Secondary outcomes include recanalization of the occluded vessel within 48 h, angiographic reperfusion in the experimental group, 3-month excellent clinical outcome (mRS ⩽ 1), all adverse events, and death. A cost utility analysis will estimate the incremental cost per quality-adjusted life year (QALY) gained. DISCUSSION: If positive, this study will open new insights in the management of AISs. TRIAL REGISTRATION: ClinicalTrials.gov: NCT05030142 registered on 1 September 2021.

Radial artery occlusion after aneurysm treatment using the rist guide catheter: Single center cohort study.

BACKGROUND AND PURPOSE: Delayed radial artery occlusion (dRAO) is a frequent complication after transradial access (TRA) for neurointervention when using standard large guide catheters. The RIST 079 guide catheter (RIST GC) is the first catheter designed for TRA in neurointervention. We aimed to assess the rate of dRAO after intracranial aneurysm (IA) treatment using the RIST GC. METHODS: Patients treated for an IA using TRA and the RIST GC between June 2021 and November 2022 were referred to a systematic US-doppler assessment of the radial artery patency at 3-month follow-up. Patients with and without dRAO were compared to identify risk factors. RESULTS: Twenty-two patients were included in the analysis. At 3-months follow up, 6 patients (27.3 %) presented with dRAO. Four patients were asymptomatic and 2 experienced post-operative radial hematoma and wrist pain. There was a tendency towards younger age, longer procedure duration and higher rate of forearm hematoma in patients with dRAO. Navigation using the RIST GC was successful in 90.9 % of cases. Intracranial access failures and navigation complications were all related to left internal carotid artery navigation. CONCLUSIONS: At 3-month follow up, 27.3 % of patients treated for IA using TRA with the RIST GC presented dRAO.

Longitudinal radiological follow-up of individual level non-ischemic cerebral enhancing lesions following endovascular aneurysm treatment.

BACKGROUND: Non-ischemic cerebral enhancing (NICE) lesions following aneurysm endovascular therapy are exceptionally rare, with unknown longitudinal evolution. OBJECTIVE: To evaluate the radiological behavior of individual NICE lesions over time. METHODS: Patients included in a retrospective national multicentric inception cohort were analyzed. NICE lesions were defined, using MRI, as delayed onset punctate, nodular, or annular foci enhancements with peri-lesion edema, distributed in the vascular territory of the aneurysm treatment, with no other confounding disease. Lesion burden and the longitudinal behavior of individual lesions were assessed. RESULTS: Twenty-two patients were included, with a median initial lesion burden of 36 (IQR 17-54) on the first MRI scan. Of the 22 patients with at least one follow-up MRI scan, 16 (73%) had new lesions occurring mainly within the first 200 weeks after the date of the procedure. The median number of new lesions per MRI was 6 (IQR 2-16). Among the same 22 patients, 7 (32%) had recurrent lesions. The median persistent enhancement of a NICE lesion was 13 weeks (IQR 6-30). No factor was predictive of early regression of enhancement activity with lesion regression kinetics mainly being patient-dependent. CONCLUSIONS: The behavior of individual NICE lesions was found to be highly variable with an overall patient-dependent regression velocity.

'Pressure cooker' and 'balloon pressure' techniques significantly increase 3-month complete occlusion rate after spinal arteriovenous fistula embolization as compared to glue: single center evaluation on 38 consecutive patients.

BACKGROUND: Spinal arteriovenous fistulas can be treated either by surgery or by endovascular means, using different strategies. The main drawback of embolization is the risk of recurrence. Our objective is to evaluate the angiographic occlusion rate and the predictive factors of angiographic cure of spinal arteriovenous fistulas at 3 months or more after embolization. METHODS: This is a retrospective single-center study including 38 consecutive patients with spinal arteriovenous fistulas treated by embolization as first-line treatment. We reviewed clinical and imaging data, complications, and the immediate angiographic occlusion rate of the fistulas, and at 3 months or more after the embolization. RESULTS: A total of 45 embolization procedures were performed: 30 procedures using glue, 15 using Onyx by 'pressure cooker' or 'balloon pressure' techniques. We observed no statistically significant difference between the two groups concerning the immediate angiographic occlusion rate (87% in both groups; P>0.9), as well as for periprocedural complication rates. The angiographic occlusion rate at 3 months or more was higher in the Onyx 'combined' techniques treated group (87% vs 40%, P=0.007). The use of Onyx 'combined' techniques was independently associated with angiographic cure at 3 months after embolization (P=0.029). No other factors were identified as predictive of angiographic cure and clinical recovery after embolization procedures, nor were any predictive factors identified for the occurrence of periprocedural complications. CONCLUSION: Embolization of spinal arteriovenous fistulas with Onyx using 'combined' techniques appears to be safe and associated with a higher rate of angiographic occlusion at 3 months than regular embolization with glue.

Nidus Compacity Determined by Semi-Automated Segmentation is a Strong Quantitative Predictor of Brain Arterio-Venous Malformation Cure.

BACKGROUND AND OBJECTIVE: A compact nidus is a well-known feature of good outcome after treatment in brain arteriovenous malformations (bAVM). This item, included in the "Supplementary AVM grading system" by Lawton, is subjectively evaluated on DSA. The present study aimed to assess whether quantitative nidus compacity along with other angio-architectural bAVM features were predictive of angiographic cure or the occurrence of procedure-related complications. MATERIALS AND METHODS: Retrospective analysis of 83 patients prospectively collected data base between 2003 to 2018 having underwent digital subtraction 3D rotation angiography (3D-RA) for pre-therapeutic assessment of bAVM. Angio-architectural features were analyzed. Nidus compacity was measured with a dedicated segmentation tool. Univariate and multivariate analyses were performed to test the association between these factors and complete obliteration or complication. RESULTS: Compacity was the only significant factor associated with complete obliteration in our predictive model using logistic multivariate regression; the area under the curve for compacity predicting complete obliteration was excellent (0.82; 95% CI 0.71-0.90; p < 0.0001). The threshold value maximizing the Youden index was a compacity > 23% (sensitivity 97%; specificity 52%; 95% CI 85.1-99.9; p = 0.055). No angio-architectural factor was associated with the occurrence of a complication. CONCLUSION: Nidus high compacity quantitatively measured on 3D-RA, using a dedicated segmentation tool is predictive of bAVM cure. Further investigation and prospective studies are warranted to confirm these preliminary results.

Endovascular treatment as first-line therapy in Spetzler-Martin grade III brain arteriovenous malformations: a multicenter retrospective study.

OBJECTIVE: The management of Spetzler-Martin grade (SMG) III brain arteriovenous malformations (bAVMs) may be challenging, whatever the exclusion treatment modality chosen. The purpose of this study was to evaluate the safety and effectiveness of endovascular treatment (EVT) as a first-line treatment of SMG III bAVMs. METHODS: The authors performed a retrospective, two-center, observational cohort study. Cases recorded in institutional databases between January 1998 and June 2021 were reviewed. Patients who were ≥ 18 years of age, had ruptured or unruptured SMG III bAVMs, and received EVT as first-line therapy were included. Baseline characteristics of patients and bAVMs, procedure-related complications, clinical outcome according to the modified Rankin Scale, and angiographic follow-up were assessed. The independent risk factors of procedure-related complications and poor clinical outcome were assessed using binary logistic regression. RESULTS: One hundred sixteen patients with 116 SMG III bAVMs were included. The mean age of the patients was 41.9 ± 14.0 years. The most common presentation was hemorrhage (66.4%). Forty-nine (42.2%) bAVMs were found to be completely obliterated by EVT alone at follow-up. Complications occurred in 39 patients (33.6%), including 5 (4.3%) major procedure-related complications. There was no independent predictor of procedure-related complication. Age > 40 years and poor preoperative modified Rankin Scale score were the independent predictors of poor clinical outcome. CONCLUSIONS: EVT of SMG III bAVMs provides encouraging results but needs further improvement. When the embolization procedure performed with intent to cure appears difficult and/or risky, a combined technique (with microsurgery or radiosurgery) may be a safer and more effective strategy. In terms of safety and effectiveness, the benefit of EVT (alone or included in a multimodal management strategy) for SMG III bAVMs needs to be confirmed by randomized controlled trials.

Superselective 3D digital subtraction angiography and magnetic resonance fusion imaging for the management of micro-arteriovenous malformations.

Cerebral micro-arteriovenous malformations (AVM) are defined by an infracentimetric nidus or a nidus solely visible on superselective digital subtraction angiography (DSA).12 While representing a minority of brain AVMs, intracerebral hemorrhage is a frequent manifestation in this subset of AMVs.2 Micro-AVMs are often occult lesions, with superselective DSA being instrumental for increasing diagnostic yield.13 While superselective three-dimensional DSA (3D-DSA)/MR fusion imaging has been employed to better delineate anatomical proximity in cerebral AVMs with a visible nidus on MRI,4 this fusion algorithm has not yet been used for describing the relationship of micro-AVMs nidus and afferent arteries with neighboring structures, in order to guide endovascular and microsurgical procedures. In this technical video (Video 1), we present 3 cases regarding micro-AVM embolization, in which superselective 3D-DSA/MR fusion imaging aided therapeutic decision, by defining the local anatomy and allowing a safer procedure.

'Balloon pressure technique' for endovascular treatment of spinal cord arteriovenous fistulas: preliminary results in 10 cases.

BACKGROUND: Spinal arteriovenous fistulas (SAVFs) are challenging lesions to treat by endovascular means. Our purpose was to report our early experience with dual lumen balloons (DLBs) for embolization of SAVFs using ethylene vinyl alcohol (EVOH) (the so-called 'balloon pressure technique' (BPT)). MATERIALS AND METHODS: During the inclusion period, 10 consecutive patients (nine men, mean age 61.6 years) underwent endovascular treatment of a SAVF (seven dural SAVFs and three epidural SAVFs) at a single institution using the BPT. DLBs were used in all cases. In seven cases (70%), a regular DLB was used, while in three cases (30%), low profile DLBs were used. EVOH was used as the liquid embolic agent in all cases. Technical and clinical complications were systematically recorded. Clinical and angiographic outcomes were systematically evaluated more than 3 months after the procedure. RESULTS: Complete cure of the SAVF by endovascular means alone was obtained in 80% of cases (8/10). For the two patients with incomplete SAVF occlusion, surgery was successfully performed secondarily. No recurrence was found at the 3 month follow-up in the eight patients for whom complete occlusion was obtained at the end of the embolization procedure. No permanent clinical complication was recorded using the BPT. Clinical improvement was observed in 6/10 (60%) cases. CONCLUSION: BPT was a feasible technique, with regular or low profile DLBs, for embolization of SAVFs. Our preliminary results suggest the safety and effectiveness of this technique.

Long-Term Middle Meningeal Artery Caliber Reduction Following Trisacryl Gelatine Microsphere Embolization for the Treatment of Chronic Subdural Hematoma.

PURPOSE: Middle meningeal artery (MMA) particle embolization is a promising treatment of chronic subdural hematomas (CSDH). The main purpose of this study is to measure MMA proximal caliber and assess the visibility of the two main MMA branches as a surrogate for long-term distal arterial patency following MMA CSDH embolization with trisacryl gelatine microspheres (TAGM). METHODS: This is a single-center retrospective study. All patients having undergone MMA TAGM only embolization for CSDH treatment between 15 March 2018 and 6 June 2020 with an interpretable follow-up magnetic resonance imaging (MRI) examination and no confounding factors were included. Patients were compared with controls matched for age, sex and MRI machine. Two independent readers analyzed the MRI images. RESULTS: In this study, 30 patients having undergone embolization procedures using TAGM of 36 MMAs were included. The follow-up MRI scans were performed after a mean delay of 14.8 ± 7.1 months (range 4.9-29.4 months). The mean diameter of TAGM embolized MMAs (1 mm; 95% confidence interval, CI 0.9-1.1) was significantly smaller than the mean diameter of paired control MMAs (1.3 mm; 95% CI 1.3-1.4) (p < 0.001). The mean proximal diameter of the embolized MMAs (0.9 mm; 95% CI 0.7-1.1) was significantly smaller than the mean diameter of the contralateral MMAs in the same patients (1.4 mm; 95% CI 1.3-1.6)(p < 0.001). CONCLUSION: Long-term follow-up MRI demonstrated a significant impact of TAGM embolization on MMA proximal caliber as well as on the visibility of the two main MMA branches. All comparisons indicated that there was a probable lasting impact of embolization on the patency of distal branches.

Incidence and risk factors of epilepsy following brain arteriovenous malformation rupture in adult patients.

BACKGROUND: Little is known about incidence, time of onset, clinical presentation, and risk factors of epileptic seizure following brain arteriovenous malformation (bAVM) rupture. METHODS: We performed a monocentric retrospective cohort study from January 2003 to March 2021. The main objective of this study was to determine the incidence of seizures after spontaneous bAVM rupture in nonepileptic adult patients and describe the corresponding clinical features. The secondary objective was to identify clinical, radiological, or biological predictors for the occurrence of de novo seizures after bAVM rupture. RESULTS: Of the 296 cases of bAVM rupture registered during the study period, 247 nonepileptic patients (male 53%, median age 40) were included in the study. Fifty-nine patients (23.9%) had at least one seizure after bAVM rupture. The use of preventive antiepileptic drugs (10.3 [1.5-74.1]; P = 0.02) and decompressive craniectomy (15.4 [2.0-125]; P < 0.009) were independently associated with the occurrence of epilepsy after the bAVM rupture. The factors independently associated with the absence of any seizure after the rupture were isolated intraventricular hemorrhage (0.3 [0.1-0.99]; P = 0.04) and infratentorial location of the bAVM (0.2 [0.1-0.5]; P = 0.09). The first seizure occurred within the first year or within 5 years in, respectively, 83.1% and 98.3% of the patients. CONCLUSIONS: Epilepsy affects nearly a quarter of patients after bAVM rupture. Decompressive craniectomy represents an independent risk factor significantly associated with the occurrence of epilepsy after bAVM rupture. The introduction of preventive AEDs after rupture could be considered in these most severe patients who have a decompressive craniectomy.

Conserved meningeal lymphatic drainage circuits in mice and humans.

Meningeal lymphatic vessels (MLVs) were identified in the dorsal and caudobasal regions of the dura mater, where they ensure waste product elimination and immune surveillance of brain tissues. Whether MLVs exist in the anterior part of the murine and human skull and how they connect with the glymphatic system and extracranial lymphatics remained unclear. Here, we used light-sheet fluorescence microscopy (LSFM) imaging of mouse whole-head preparations after OVA-A555 tracer injection into the cerebrospinal fluid (CSF) and performed real-time vessel-wall (VW) magnetic resonance imaging (VW-MRI) after systemic injection of gadobutrol in patients with neurological pathologies. We observed a conserved three-dimensional anatomy of MLVs in mice and humans that aligned with dural venous sinuses but not with nasal CSF outflow, and we discovered an extended anterior MLV network around the cavernous sinus, with exit routes through the foramina of emissary veins. VW-MRI may provide a diagnostic tool for patients with CSF drainage defects and neurological diseases.

Safety and Effectiveness of First-line Endovascular Management of Low-Grade Brain Arteriovenous Malformations : Single Center Experience in 145 Patients.

PURPOSE: Spetzler-Martin grade (SMG) I-II (low-grade) brain arteriovenous malformations (BAVMs) are often considered safe for microsurgical resection; however, the role of endovascular treatment (EVT) remains to be clarified in this indication, especially for unruptured BAVMs. The purpose of our study was to assess the safety and effectiveness of endovascular treatment as the first-line treatment for low-grade BAVMs. METHODS: From our local database, we retrospectively retrieved patients with low-grade BAVMs, either ruptured or unruptured, treated by embolization as first-line treatment in our department between January 2005 and January 2020. The primary endpoint was the total obliteration rate of BAVMs, and secondary endpoints were hemorrhagic complications and final clinical outcome, assessed through shift of the modified Rankin scale, and mortality rate secondary to BAVM embolization. RESULTS: A total of 145 patients meeting inclusion criteria and treated by EVT as first-line therapy were included in the study (82 ruptured and 63 unruptured BAVMs). Overall, complete exclusion of BAVMs was achieved in 110 patients (75.9%); 58 patients (70.7%) with ruptured and 52 (82.5%) unruptured BAVMs, including 37.9% BAVMs excluded by EVT alone (35.5% among ruptured and 44.4% among unruptured BAVMs) and 38% by combined treatment (EVT and surgery or EVT and SRS). There was no BAVM volume cut-off predictive for total obliteration by embolization alone. Early minor hemorrhagic complications were reported in 14 patients (9.6%) and early major hemorrhagic complications were reported in 5 patients (3.4%). No late hemorrhagic complications (0%) occurred; mortality rate was 0.7% (1/145 patients). Improved/unchanged mRS was reported in 137 patients (94.5%). CONCLUSION: Endovascular treatment alone or associated with others exclusion techniques, might be safe and effective for complete exclusion of low-grade brain arteriovenous malformations regardless of the volume.

Prohibitive Radial Artery Occlusion Rates Following Transradial Access Using a 6-French Neuron MAX Long Sheath for Intracranial Aneurysm Treatment.

OBJECTIVE: To evaluate the feasibility, safety, and rate of radial artery occlusion (RAO) after the treatment of intracranial aneurysms using a 6F Neuron MAX (Penumbra, Alameda, CA, USA) long sheath directly into the radial artery. METHODS: All consecutive patients treated for unruptured intracranial aneurysms with TRA using a 6F Neuron MAX catheter between September 2019 and May 2021 in a single tertiary center were screened. They were referred to a consultation and an ultrasound-Doppler assessment of the radial artery 3 months after treatment with the attending neuroradiologist. Patients with available assessment of the radial artery patency were included. RESULTS: A total of 17 patients (median age: 58 years, range 35-68 years; sex ratio F/M: 15/2) were treated for intracranial aneurysms using a 6F Neuron MAX directly into the right radial artery and included. Treatment was a technical success for 16/17 (94%) patients and 1 patient (6%) required a conversion to femoral access. The median radial artery diameter at the puncture site was 2.7 mm (range 1.8-2.9mm). No symptomatic RAO was noted during follow-up. Assessment at 3 months revealed 7/17 (41%) asymptomatic RAOs. CONCLUSION: Even if technically feasible, the use of a 6F Neuron Max long sheath for triaxial catheterization in intracranial interventions, especially flow diversion, may be responsible for a high radial artery occlusion rate (41%). Although being asymptomatic in all cases in our series, this high occlusion rate may be a concern for further interventions. The development of dedicated radial long sheaths for neurointerventions, with external hydrophilic coating, seems necessary.

Safety and effectiveness of mechanical thrombectomy for primary isolated distal vessel occlusions: A monocentric retrospective comparative study.

BACKGROUND: Distal vessel occlusions represent about 25-40% of acute ischemic stroke (AIS), either as primary occlusion or secondary occlusion complicating mechanical thrombectomy (MT) for large vessel occlusion. OBJECTIVE: Our aim was to evaluate safety and effectiveness of MT associated with the best medical treatment (BMT) in the management of AIS patients with distal vessel occlusion in comparison with the BMT alone. METHODS: Retrospective analysis was conducted on AIS patients treated by MT+BMT for primary distal vessel occlusion between 2015 and 2020, and were compared with a historic cohort managed by BMT alone between 2006 and 2015 selected based on the same inclusion criteria. A secondary analysis was conducted using propensity score matching (PSM) including the following: NIHSS, age and treatment with intravenous thrombolysis (IVT) as covariates. RESULTS: Of 650 patients screened, 44 patients with distal vessel occlusions treated by MT+BMT were selected and compared with 36 patients who received BMT alone. After PSM, 28 patients in each group were matched without significant difference. Good clinical outcome defined as mRS≤2 was achieved by 53.6% of the MT+BMT group and 57% of the BMT group (OR, 0.87; 95%CI, 0.3-2.4; p = 1.00). The mortality rate was comparable in both groups (7% vs. 10.7% in MT+BMT and BMT patients, respectively; OR=0.64; 95%CI, 0.1-4; p = 1.00). Symptomatic intracranial hemorrhage (ICH) was seen in only one patient treated by MT+BMT (3.6%). CONCLUSION: Mechanical thrombectomy seems to be comparable with the best medical treatment regarding the effectiveness and safety in the management of patients with distal vessel occlusions.

Benefit of mechanical thrombectomy in acute ischemic stroke related to calcified cerebral embolus.

PURPOSE: Mechanical thrombectomies (MT) in patients with large vessel occlusion (LVO) related to calcified cerebral embolus (CCE) have been reported, through small case series, being associated with low reperfusion rate and worse outcome, compared to regular MT. The purpose of the MASC (Mechanical Thrombectomy in Acute Ischemic Stroke Related to Calcified Cerebral Embolus) study was to evaluate the incidence of CCEs treated by MT and the effectiveness of MT in this indication. METHODS: The MASC study is a retrospective multicentric (n = 37) national study gathering the cases of adult patients who underwent MT for acute ischemic stroke with LVO related to a CCE in France from January 2015 to November 2019. Reperfusion rate (mTICI ≥ 2B), complication rate and 90-day mRS were systematically collected. We then conducted a systematic review by searching for articles in PubMed, Cochrane Library, Embase and Google Scholar from January 2015 to March 2020. A meta-analysis was performed to estimate clinical outcome at 90 days, reperfusion rate and complications. RESULTS: We gathered data from 35 patients. Reperfusion was obtained in 57% of the cases. Good clinical outcome was observed in 28% of the patients. The meta-analysis retrieved 136 patients. Reperfusion and good clinical outcome were obtained in 50% and 29% of the cases, respectively. CONCLUSION: The MASC study found worse angiographic and clinical outcomes compared to regular thrombectomies. Individual patient-based meta-analysis including the MASC findings shows a 50% reperfusion rate and a 29% of good clinical outcome.

Angiographic Anatomy of the Middle Meningeal Artery in Relation to Chronic Subdural Hematoma Embolization.

PURPOSE: Middle meningeal artery (MMA) embolization is emerging as a potential treatment of chronic subdural hematomas (CSDHs). The purpose of this study is to describe MMA angiographic anatomy in relation to CSDH embolization. METHODS: This retrospective monocentric study was performed on imaging data of MMA embolization procedures for CSDH treatment performed between March 15, 2018 and April 30, 2020. Imaging data, including digital subtraction angiography (DSA) were reviewed independently by two physicians. Discrepancies were resolved by consensus. The MMA bifurcation pattern was analyzed according to an extended Adachi classification. Relations of the MMA with the ophthalmic artery (OA) were also analyzed. RESULTS: In this study, 140 MMAs were analyzed. Dominance of the anterior branch (type I) was observed in only 57/140 (41%) MMAs with a moderate interobserver agreement for classifying MMA into type I against all other (κ = 0.53, 95% confidence interval, CI 0.39-0.67). The posterior branch presented a proximal origin (type A), at the point of emergence of the MMA from the foramen spinosum or its immediate vicinity, in 48/135 (36%) MMAs with a very good interobserver agreement for classifying MMAs into type A against all other (κ = 0.82, 95% CI 0.72-0.92). An angiographic relationship with the OA was observed in 26 MMAs (19%). CONCLUSION: In the majority of CSDH patients both anterior and posterior branches of the MMA should be targeted to achieve extensive convexity devascularization. Frequent anatomical variations of the MMA with respect to emergence of the posterior branch and MMA orbital branches are expected to impact CSDH embolization strategy.

Anterior interhemispheric approach for anterior fossa dural arteriovenous fistulas.

Anterior fossa dural arteriovenous fistulas (AF-DAVF) usually display a cortical venous drainage and are therefore at risk for rupture. Microsurgery is traditionally considered in many centers as the first-line treatment since endovascular treatment (EVT) entails a lower cure rate and significant ophthalmic risks. The anterior interhemispheric approach (AIA), originally described by Mayfrank in 1996, seems to offer the effectiveness of microsurgery while limiting the risks related to subfrontal craniotomy. The objective of this study was to analyze the surgical outcomes of patients who underwent this surgical approach for the treatment of AF-DAVF. We hereby describe our 10 years' experience of patients treated for an AF-DAVF with this technique in our institution and retrospectively analyzed our results. In addition, we describe our operative technique and its specificities. Eleven patients with AF-DAVF were included in our study. The definitive cure of the fistula was confirmed in all cases with postoperative cerebral angiography. All patients had a good neurological outcome and no major complication occurred. Brain retractors were never used during surgery, the frontal sinus was never opened neither, and anosmia was never observed after surgery. Anterior interhemispheric approach seems to be safe and effective to treat AF-DAVF with lower risks than other surgical approaches. This technique could be more widely considered when facing such midline vascular lesion.