Primary conus medullaris arteriovenous shunt and secondary lumbo-sacral epidural arteriovenous fistula: One malformation can hide another.

We report an anatomical-based association between conus medullaris pial arteriovenous shunt that drain caudally towards the lumbosacral area with very delayed onset of an acquired lumbar epidural shunt, draining secondarily towards intradural veins and responsible for a venous congestive myelopathy with identical clinical symptoms. These patients require close clinical and imaging follow-ups in order to propose adequate treatments before onset of irreversible neurological deficits. MRA should include the lumbo-sacral area in its field of view.

Acute ischemic stroke treated with mechanical thrombectomy and fungal endocarditis: A case report and systematic review of the literature.

Fungal endocarditis is a rare clinical form of infective endocarditis. The main etiology of FE is Candida albicans but also Candida parapsilosis and the overall mortality is high. We report a case of an acute ischemic stroke treated by mechanical thrombectomy, with the histopathological analysis of the retrieved clot followed by the confirmation of fungal endocarditis. An extensive review of the literature has been proposed and three key points concerning the fungal endocarditis predisposing factors, the relation between thrombolysis and hemorrhagic risk and, finally, the importance of clot analysis have been discussed.

Aberrant trans-osseous venous drainage of the superficial middle cerebral vein: case report.

The superficial middle cerebral veins (SMCVs) are large veins to drain the brain and therefore anatomical knowledge of them is important for neurosurgeons and neuroradiologists. In a patient with a ruptured blister aneurysm, we incidentally found during angiography an aberrant drainage of the SMCVs, which penetrated the lateral part of the greater sphenoid wing and directly connected the SMCVs with the deep facial vein. Neurosurgeons usually need to remove that part of the greater sphenoid wing during the fronto-temporal approach. The existence of a well-developed current channel could be a contraindication for this type of procedure.

Thrombectomy for M1-Middle Cerebral Artery Occlusion: Angiographic Aspect of the Arterial Occlusion and Recanalization: A Preliminary Observation.

BACKGROUND AND PURPOSE: Despite the recent technical evolution of the endovascular treatment of acute ischemic stroke, late and incomplete recanalization can be achieved after several maneuvers but with a potentially higher risk of futile reperfusion and complications, such as clot fragmentation. The aim of this article is to investigate the impact of the angiographic phenotype of M1-middle cerebral artery occlusions, classified as regular and irregular in aspect, on the results of treatment by stent retrievers (SRs) or contact aspiration (CA). METHODS: From January to April 2016, 84 consecutive patients, admitted for acute ischemic stroke with a middle cerebral artery occlusion, were treated by endovascular therapy. Among them, 60 patients (26M, 34F, median age, 70.5; interquartile range, 58.5-80.0) were treated by SR (25/60, 41.7%) or CA (35/60, 58.3%) as a first-line approach in 2 experienced centers. Patients' characteristics, timing, and procedural data were prospectively recorded and compared between the 2 study subgroups (regular and irregular phenotype). RESULTS: A regular phenotype at the occlusion site was observed in 24 patients (40%). Among these, successful recanalization after the first-line strategy (Thrombolysis in Cerebral Infarction 2b-3) was achieved in 100% of patients treated by CA and in only 33.3% of patients treated by SR (P=0.001). For irregular phenotypes, SR achieved Thrombolysis in Cerebral Infarction 2b-3 in 73.9% and CA, in 38.5% (P=0.036) of cases. Among regular phenotype patients, the average number of maneuvers was 1.3 (median, 1; range 1-3) with first-line CA and 2.7 (median, 3; range 1-5) with first-line SR (P=0.008). CONCLUSIONS: The angiographic phenotype of the occlusion site may be associated with a different response to SR and CA in this preliminary experience.

Fenestration of the supraclinoid segment of the ICA and associated aneurysms: a case report with literature review.

The supraclinoid ICA fenestration (SIF) is considered an extremely rare congenital anomaly. However, most of the reported cases of SIF are associated with intracranial aneurysms either ruptured or unruptured. We report the case of a 55-year-old patient with a right SIF and an unruptured, large, wide-necked aneurysm located on the larger limb of the fenestration and a second small aneurysm distal to the SIF. The aneurysms were treated with a Pipeline flow-diverter stent, achieving the complete reconstruction of the anatomy of the carotid siphon. The literature concerning these peculiar anatomic conditions has been reviewed, allowing discussion about treatment of such associated lesions.

Successful Reperfusion With Mechanical Thrombectomy Is Associated With Reduced Disability and Mortality in Patients With Pretreatment Diffusion-Weighted Imaging-Alberta Stroke Program Early Computed Tomography Score ≤6.

BACKGROUND AND PURPOSE: In acute ischemic stroke patients, diffusion-weighted imaging (DWI)-Alberta Stroke Program Early Computed Tomography Score (ASPECTS) is correlated with infarct volume and is an independent factor of functional outcome. Patients with pretreatment DWI-ASPECTS ≤6 were excluded or under-represented in the recent randomized mechanical thrombectomy trials. Our aim was to assess the impact of reperfusion in pretreatment DWI-ASPECTS ≤6 patients treated with mechanical thrombectomy. METHODS: We analyzed data collected between January 2012 and August 2015 in a bicentric prospective clinical registry of consecutive acute ischemic stroke patients treated with mechanical thrombectomy. Every patient with a documented internal carotid artery or middle cerebral artery occlusion with pretreatment DWI-ASPECTS ≤6 was eligible for this study. The primary end point was a favorable outcome defined by a modified Rankin Scale score ≤2 at 90 days. RESULTS: Two hundred and eighteen patients with a DWI-ASPECTS ≤6 were included. Among them, 145 (66%) patients had successful reperfusion at the end of mechanical thrombectomy. Reperfused patients had an increased rate of favorable outcome (38.7% versus 17.4%; P=0.002) and a decreased rate of mortality at 3 months (22.5% versus 39.1%; P=0.013) compared with nonreperfused patients. The symptomatic intracranial hemorrhage rate was not different between the 2 groups (13.0% versus 14.1%; P=0.83). However, in patients with DWI-ASPECTS <5, favorable outcome was low (13.0% versus 9.5%; P=0.68) with a high mortality rate (45.7% versus 57.1%; P=0.38) with or without successful reperfusion. CONCLUSIONS: Successful reperfusion is associated with reduced mortality and disability in patients with a pretreatment DWI-ASPECTS ≤6. Further data from randomized studies are needed, particularly in patients with DWI-ASPECTS <5.

Mechanical Thrombectomy for Minor and Mild Stroke Patients Harboring Large Vessel Occlusion in the Anterior Circulation: A Multicenter Cohort Study.

BACKGROUND AND PURPOSE: Proximal large vessel occlusion (LVO) is present in up to 30% of minor strokes. The effectiveness of mechanical thrombectomy (MT) in the subgroup of minor stroke with LVO in the anterior circulation is still open to debate. Data about MT in this subgroup of patients are sparse, and their optimal management has not yet been defined. The purpose of this multicenter cohort study was to evaluate the effectiveness of MT in patients experiencing acute ischemic stroke (AIS) because of LVO in the anterior circulation, presenting with minor-to-mild stroke symptoms (National Institutes of Health Stroke Scale score of <8). METHODS: Multicenter cohort study involving 4 comprehensive stroke centers having 2 therapeutic approaches (urgent thrombectomy associated with best medical treatment [BMT] versus BMT first and MT if worsening occurs) about management of patients with minor and mild acute ischemic stroke harboring LVO in the anterior circulation. An intention-to-treat analysis was conducted. The primary end point was the rate of excellent outcome defined as the achievement of a modified Rankin Scale score of 0 to 1 at 3 months. RESULTS: Three hundred one patients were included, 170 with urgent MT associated with BMT, and 131 with BMT alone as first-line treatment. Patients treated with MT were younger, more often received intravenous thrombolysis, and had shorter time to imaging. Twenty-four patients (18.0%) in the medical group had rescue MT because of neurological worsening. Overall, excellent outcome was achieved in 64.5% of patients, with no difference between the 2 groups. Stratified analysis according to key subgroups did not find heterogeneity in the treatment effect size. CONCLUSIONS: Minor-to-mild stroke patients with LVO achieved excellent and favorable functional outcomes at 3 months in similar proportions between urgent MT versus delayed MT associated with BMT. There is thus an urgent need for randomized trials to define the effectiveness of MT in this patient subgroup.

Is Reperfusion Useful in Ischaemic Stroke Patients Presenting with a Low National Institutes of Health Stroke Scale and a Proximal Large Vessel Occlusion of the Anterior Circulation?

BACKGROUND: In population-based studies, patients presenting with minor or mild stroke symptoms represent about two-thirds of stroke patients, and almost one-third of these patients are unable to ambulate independently at the time of discharge. Although mechanical thrombectomy (MT) has become the standard of care for acute ischaemic stroke with proximal large vessel occlusion (LVO) in the anterior circulation, the management of patients harbouring proximal occlusion and minor-to-mild stroke symptoms has not yet been determined by recent trials. The purpose of this study was to evaluate the impact of reperfusion on clinical outcome in low National Institutes of Health Stroke Scale (NIHSS) patients treated with MT. METHODS: We analysed 138 consecutive patients with acute LVO of the anterior circulation (middle cerebral artery M1 or M2 segment, internal carotid artery or tandem occlusion) with NIHSS <8, having undergone MT in 3 different centres. Reperfusion was graded using the modified thrombolysis in cerebral infarction (TICI) score and 3 grades were defined, ranging from failed or poor reperfusion (TICI 0, 1, 2A) to complete reperfusion (TICI 3). The primary clinical endpoint was an excellent outcome defined as a modified Rankin score (mRs) 0-1 at 3-months. The impact of reperfusion grade was assessed in univariate and multivariate analyses. The secondary endpoints included favourable functional outcome (90-day mRS 0-2), death and safety concerns. RESULTS: Successful reperfusion was achieved in 81.2% of patients (TICI 2B, n = 47; TICI 3, n = 65). Excellent outcome (mRs 0-1) was achieved in 69 patients (65.0%) and favourable outcome (mRs ≤2) in 108 (78.3%). Death occurred in 7 (5.1%). Excellent outcome increased with reperfusion grades, with a rate of 34.6% in patients with failed/poor reperfusion, 61.7% in patients with TICI 2B reperfusion, and 78.5% in patients with TICI 3 reperfusion (p < 0.001). In multivariate analysis adjusted for patient characteristics associated with excellent outcome, the reperfusion grade remained significantly associated with an increase in excellent outcome; the OR (95% CI) was 3.09 (1.06-9.03) for TICI 2B and 6.66 (2.27-19.48) for TICI 3, using the failed/poor reperfusion grade as reference. Similar results were found regarding favourable outcome (90-day mRs 0-2) or overall mRS distribution (shift analysis). CONCLUSION: Successful reperfusion is strongly associated with better functional outcome among patients with proximal LVO in the anterior circulation and minor-to-mild stroke symptoms. Randomized controlled studies are mandatory to assess the benefit of MT compared with optimal medical management in this subset of patients.

Prior IV Thrombolysis Facilitates Mechanical Thrombectomy in Acute Ischemic Stroke.

BACKGROUND: In acute ischemic stroke (AIS), bridging therapy, including intravenous thrombolysis (IVT) and mechanical thrombectomy (MET), appears to be very promising. However, data on the impact of IVT before the endovascular procedure are limited. METHODS: To examine the impact of IVT on the MET procedure, we compared the duration of this procedure, number of passes, recanalization rate, safety issues, and outcome in consecutively recruited patients either eligible for MET alone (intravenous fibrinolysis contraindication) or receiving MET preceded by IVT for proximal middle cerebral artery (MCA) occlusion within 6 hours of stroke onset. RESULTS: From January 2011 to June 2013, 68 cases with proximal MCA occlusion were available for analysis (MET alone, 40; IVT + MET, 28). The 2 groups did not differ significantly in baseline characteristics. The median National Institutes of Health Stroke Scale score at admission was 15 (10-20) for MET and 18 (13-19) for IVT + MET groups, respectively (P = .39). The median duration of the endovascular procedure (from groin puncture to recanalization) was significantly shorter in the IVT + MET group compared with that in MET alone (35 minutes [21-60] versus 60 minutes [25-91]; P = .043). The number of passes of the thrombectomy device per patient tended to be lower in the IVT + MET group than those in the MET group (P = .080). The IVT + MET group also had a higher rate of complete recanalization and a better outcome at 3 months. CONCLUSIONS: Prior IVT may facilitate the MET procedure. Further studies on MET in AIS should assess the direct impact of IVT on the endovascular procedure.

MRI and MRA of spinal cord arteriovenous shunts.

The purpose of this review is to describe the diagnostic criteria for spinal cord arteriovenous shunts (SCAVSs) when using magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA), and to discuss the extent to which the different MRI and MRA sequences and technical parameters provide the information that is required to diagnose these lesions properly. SCAVSs are divided into four groups according to location (paraspinal, epidural, dural, or intradural) and type (fistula or nidus); each type of lesion is described. SCAVSs are responsible for neurological symptoms due to spinal cord or nerve root involvement. MRI is usually the first examination performed when a spinal cord lesion is suspected. Recognition of the image characteristics of vascular lesions is mandatory if useful sequences are to be performed-especially MRA sequences. Because the treatment of SCAVSs relies mainly on endovascular therapies, MRI and MRA help with the planning of the angiographic procedure. We explain the choice of MRA sequences and parameters, the advantages and pitfalls to be aware of in order to obtain the best visualization, and the analysis of each lesion.

Angiographic collateral venous phase: a novel landmark for leptomeningeal collaterals evaluation in acute ischemic stroke.

BACKGROUND: Although recanalization rates constantly increase (>80%), a favorable clinical outcome is achieved in only 45-55% of patients undergoing mechanical thrombectomy (MT) for anterior circulation stroke. Collateral circulation seems to play a major role in determining this discrepancy. The aim of the study was to investigate a novel angiographic landmark assessing the collateral venous phase (CVP) compared with the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) score, based on the arterial collateral assessment. METHODS: Two hundred patients with anterior circulation stroke treated by MT between 2016 and 2021 were included. The ASITN/SIR score and the presence of CVP were blindly evaluated by expert neuroradiologists. Three subanalyses were performed comparing patients with good versus poor collaterals, CVP presence versus absence, and a composite analysis including both ASITN/SIR and CVP grading results. RESULTS: Good collateral circulation (ASITN >2) was observed in 113 patients (56.5%) whereas CVP was present in 90 patients (45%) and mostly in patients with good collaterals. Favorable clinical and neuroradiological outcomes were more likely observed in patients with both good collaterals and the presence of CVP than in those with good collaterals and absence of CVP (modified Rankin Scale score 0-2: 77.3% vs 7.9%, p<0.0001; mortality: 9.3% vs 26.3%, p=0.02; 24-hour Alberta Stroke Program Early CT Score: 8 vs 6, p<0.0001), while ASITN/SIR score alone was not significantly associated with clinical outcomes. CONCLUSIONS: The presence of CVP improves the angiographic assessment of collateral circulation. CVP could be proposed as a new imaging landmark to better understand the functionality of collaterals.

Reconstruction of the sphenoid sinus erosion or dehiscence after treatment of unruptured intracavernous aneurysms with flow diverter stents.

BACKGROUND: Intracavernous carotid aneurysms (ICCAs) are rare, frequently asymptomatic, with a low rupture risk, which, however, can lead to life-threatening epistaxis. The aim of this study was to assess the effect of the treatment of asymptomatic ICCAs with flow diverters (FD) on sphenoid bone erosion or dehiscence in a selected cohort of patients. METHODS: We retrospectively reviewed all asymptomatic ICCAs with sphenoid bone erosion or dehiscence detected on cone beam CT (CBCT) and treated with FD between December 2018 and December 2022. Patients were followed-up with CBCT and bone reconstruction was blindly evaluated by two interventional neuroradiologists and classified as unchanged, partial, or complete. RESULTS: A total of 10 patients (women: 90%, mean age 58 years) treated with an FD for an asymptomatic ICCA with associated sphenoid bone erosion or dehiscence were included in this cohort. Sphenoid bone erosion was present in seven patients and dehiscence was observed in the remaining three. After treatment with FD, complete reconstruction of the sphenoid sinus wall occurred in seven cases, and partial reconstruction in two cases. Sphenoid bone erosion remained unchanged after treatment in only one patient. CONCLUSIONS: The decision to treat asymptomatic and unruptured ICCAs remains challenging due to their benign natural history and low hemorrhagic risk. The presence of sphenoid sinus erosion or dehiscence should not be overlooked since it could be considered as an indication for prophylactic treatment of life-threatening epistaxis. The mechanisms of bone erosion by the aneurysm and of reconstruction after treatment are still to be fully elucidated.

Unfavorable clinical outcomes in patients with good collateral scores following endovascular treatment for acute ischemic stroke of the anterior circulation: The UNCLOSE study.

BACKGROUND: Patients with acute ischemic stroke secondary to large vessel occlusions and good collaterals are frequently associated with favorable outcomes after mechanical thrombectomy, although poor outcomes are observed also in this subgroup. We aimed to investigate the factors associated with unfavorable outcomes (modified Rankin Scale3-6) in this specific subgroup of patients. METHODS: In total, 219 patients (117 females) with anterior circulation stroke and good collaterals (American Society for Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology grades 3-4), treated by mechanical thrombectomy between 2016 and 2021 at our institution were included in this study. Clinical files and neuroimaging were retrospectively reviewed. Univariate and multivariate analyses were performed to identify the predictors of unfavorable outcomes in the overall population (primary endpoint). Secondary endpoints focused on the analysis of the predictors of unfavorable outcomes in the subgroup of successfully recanalized patients, mortality, and symptomatic intracerebral hemorrhages in the overall population. RESULTS: Poor outcome was observed in 47% of the patients despite the presence of good collaterals. Older age (p < 0.001), higher baseline National Institute of Health stroke scale (p < 0.001), no intravenous thrombolysis administration (p = 0.004), > 3 passes (p = 0.01), and secondary transfers (p < 0.001) were associated with the primary endpoint. The multivariate analysis showed a predictive effect of modified treatment in cerebral infarction 2b-3 and of first pass effect on symptomatic intracerebral hemorrhage. CONCLUSIONS: Despite good collaterals, defined through the American Society for Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology scale, poor outcomes occurred in almost half of the patients. Patients with good collaterals not receiving intravenous thrombolysis were significantly associated with unfavorable outcomes, whereas first pass effect was not significantly correlated with clinical outcome in this specific cohort of patients. Different methods to assess collaterals should also be investigated.

Rupture of a detachable-tip microcatheter away from the detachment zone during Onyx 18 embolization of an arteriovenous malformation and management of the complication.

Leakage of liquid embolic material is a rare but dreaded complication during embolization of an arteriovenous malformation (AVM). We describe the rupture of a microcatheter away from the detachment site and the successful removal of the cast of Onyx 18 in the carotid artery by aspiration. A young adult patient diagnosed with a right temporal unruptured AVM underwent endovascular embolization using Onyx 18. The AVM was approached using an Apollo microcatheter. After 4 min of Onyx 18 injection, leakage of Onyx 18 in the petrous segment of the internal carotid artery was noticed while the distal tip of the microcatheter remained patent. The plug of Onyx was successfully removed using an aspiration technique via the Envoy DA catheter. Analysis of the microcatheter confirmed that the rupture occurred away from the detachment site. However, no definite cause for the rupture has been identified.

White thrombus as a possible feature of atypical stroke etiology: Coxiella burnetii as the primary cause of acute ischemic stroke.

Acute ischemic stroke (AIS) is the most common neurologic complication of infective endocarditis. We describe a singular case report of a 62- year-old male with AIS related to the occlusion of the left middle cerebral artery. Thrombus-aspiration allowed retrieving a 6 millimeters white thrombus. The real-time polymerase chain reaction performed on the thrombus detected Coxiella Burnetii allowed the diagnosis of infective endocarditis (IE) and the identification of the specific pathogen. Coxiella Burnetii is an endemic, small, intracellular, gram-negative coccobacillus and it is a rare cause of IE. The management of AIS caused by IE remains controversial, although in the cases of major occlusion mechanical thrombectomy is associated with better clinical outcomes. IE patients could not present symptoms and signs related to the infection, therefore we underline the importance of the microbiological analysis of the retrieved thrombi especially when atypical etiology is suspected.

Mechanical Thrombectomy in Distal Residual Occlusions of the Middle Cerebral Artery after Large Vessel Recanalization in Acute Stroke: 2b or not 2b? A Pragmatic Approach in Real-Life Scenarios.

BACKGROUND /OBJECTIVE: Recent studies have suggested that a recanalization grade of modified Thrombolysis in Cerebral Infarction (mTICI) score ≥2c is strongly related with good clinical outcome rather than the current therapeutic angiography target ≥2b. To achieve better recanalization, additional further maneuvers on distal residual vessel occlusion (RVO) may be required. The aim of this study was to evaluate the safety and efficacy of rescue treatment in RVOs after recanalization of large vessel occlusions in the anterior circulation. METHODS: A single-center retrospective review of a prospectively maintained stroke databank was performed. Patients presenting with RVOs after mechanical thrombectomy on the M1/internal carotid artery terminus were included and further divided into treated and untreated groups: the former underwent additional maneuvers on RVOs, whereas the latter did not. Baseline and posttreatment clinical, radiologic, and angiographic data were compared between the 2 groups. End points included good functional outcome (modified Rankin Scale [mRS] score ≤2) rates of hemorrhagic transformations, neurologic deterioration and mortality. RESULTS: RVOs were observed in 183/488 patients (37.5%). 74/183 (40.4%) underwent rescue treatment, showing a better outcome in terms of median 24 hours National Institutes of Health Stroke Scale score (13 vs. 18; P < 0001), 24 hours Alberta Stroke Programme Early CT Score (6 vs. 5; P < 0.001) and 3 months mRS score 0-2 (47.3% vs. 33.1%; P = 0.06). Recanalization of the superior (frontal) branch of the middle cerebral artery was particularly critical in terms of outcome. Hemorrhagic transformation was higher in the untreated group (53.6% vs. 66.6%; P = 0.1) as well as symptomatic intracranial hemorrhage (13.1% vs. 29.4%; P = 0.01). Neurologic deterioration occurred more often among untreated patients (16.2% vs. 25.7%; P = 0.1). Three complications (1.3%) occurred during rescue treatment. CONCLUSIONS: When feasible, improving mTICI score 2a-2b recanalization to mTICI 2c/3 is safe and associated with a better clinical outcome, particularly for residual occlusions involving the superior branch of bifurcation.

Intradural spinal cord arteriovenous shunts in a personal series of 210 patients: novel classification with emphasis on anatomical disposition and angioarchitectonic distribution, related to spinal cord histogenetic units.

OBJECTIVE: Few classifications of intradural spinal arteriovenous shunts (ID-SAVSs) have considered their anatomical localization in relation to their phenotype and angioarchitectonics. The authors propose another vision of ID-SAVSs allowing a reappraised classification based on analysis of the anatomical disposition, angioarchitecture, and histogenetic location of these vascular malformations. METHODS: The radiological and clinical records of 210 patients with ID-SAVSs were retrospectively reviewed, considering their localization, vascular architectonics, and correlation with the 5 histogenetic units of the spinal cord. Among these, 183 files with complete data allowed precise analysis of the ID-SAVSs. RESULTS: Among these 183 files (162 and 21 cases with single and multiple lesions, respectively), different entities were identified: 13 pial macro arteriovenous fistulas (MAVFs), 92 pial micro arteriovenous fistulas (mAVFs), 33 superficial pial niduses, and 69 intramedullary niduses. Thirteen sulcal shunts (either fistulas or niduses) were considered subtypes of pial lesions. Among the 21 multiple cases, 11 were monomyelomeric while 10 were multimyelomeric. Pial lesions, either fistulas or niduses, were dominantly vascularized by pial arteries (anterior or posterior depending on the localization of the shunt) and occasionally (except for MAVFs) by transmedullary arteries. Pial niduses occasionally extended into the funiculus by recruiting intrinsic veins or by extension of the nidus itself inside the white matter. Intramedullary niduses were always vascularized by both centrifugal and centripetal feeders, respectively, from sulcal arteries (SAs) and pial arteries. Sulcal lesions are pial lesions located within the ventral median sulcus and vascularized by SAs and veins. Single or multiple ID-SAVSs can be part of various syndromes such as hereditary hemorrhagic telangiectasia, Parkes-Weber, RASA1, CLOVES, and spinal arteriovenous metameric syndromes. Histogenetic analyses revealed a specific distribution of each ID-SAVS in the 5 histogenetic units of the spinal cord: intramedullary niduses were found almost equally from cervical to thoracic units, while MAVFs and mAVFs were mostly found from thoracic to postcrural ones. Pial niduses showed intermediate features between intramedullary and fistulous lesions and were mostly distributed from brachial to crural segments. CONCLUSIONS: Precise analysis of the anatomical disposition of ID-SAVSs in relation to functional histogenetic units allows a better understanding of these lesions and improved therapeutic management.

Thrombectomy by Direct Cervical Access in Case of Common Carotid Occlusion with Collateral Supply to Internal Carotid Artery: Uncommon Anatomic Variant.

BACKGROUND: Mechanical thrombectomy for acute ischemic stroke recently proved its superiority to standard medical management alone. With the increasing number of procedures, practitioners are exposed to unexpected situations that may lead to failure of access and significantly worse clinical outcome. Being able to plan the procedure and use alternative techniques may be useful in case of peculiar anatomy. CASE DESCRIPTION: We report here the case of a 60-year-old man referred to our institution for an acute ischemic stroke. The patient had an initial National Institutes of Health Stroke Scale score of 19. The patient's medical history revealed an unspecified cervical treatment at the level of C5-C6 20 years previously. Magnetic resonance imaging showed a left M1 occlusion and the absence of ipsilateral common carotid. The digital subtraction angiography revealed an anastomosis through the left inferior and superior thyroid artery. Mechanical thrombectomy was performed through direct cervical access with a TICI 3 recanalization score. CONCLUSIONS: Absence of viable access to perform mechanical thrombectomy during acute ischemic stroke is a rare but pejorative event. Direct common carotid puncture, even in its distal segment, when necessary is a feasible technique to perform internal carotid catheterization.

Intravenous Thrombolysis Prior to Mechanical Thrombectomy in Acute Ischemic Stroke: Silver Bullet or Useless Bystander?

BACKGROUND AND PURPOSE: Recent single-center series and meta-analyses suggest that mechanical thrombectomy (MT) without prior intravenous thrombolysis (IVT) might be equally effective to bridging therapy. We analyzed, within the Endovascular Treatment in Ischemic Stroke (ETIS) prospective observational registry, the angiographic and clinical outcomes after IVT+MT versus MT alone. METHODS: From December 2012 to December 2016, a total of 1,507 consecutive patients with a proximal arterial occlusion of the anterior circulation were treated by MT. Of these, 975 (64.7%) received prior IVT. Immediate angiographic and clinical outcomes at 90 days (modified Rankin Scale [mRS]) were compared between the two groups while checking for propensity score, matched-propensity score and by inverse probability of treatment weighting (IPTW) propensity score method. RESULTS: Favorable outcome (mRS 0 to 2) was more frequently achieved after IVT+MT (n=523, 53.6%) than after MT alone (n=222, 41.8%) with an unadjusted odds ratio (OR) for bridging therapy of 1.61 (95% confidence interval [CI], 1. 29 to 2.01). This difference remained not significant in matched-propensity score cohort (OR, 1.21; 95% CI, 0.90 to 1.63) although it remained according to adjusted propensity score (OR, 1.31; 95% CI, 1.02 to 1.68) and IPTW (OR, 1.37; 95% CI, 1.09 to 1.73) analyses. A significant difference was found in terms of excellent outcome (mRS 0 to 1) (adjusted OR, 1.63; 95% CI, 1.25 to 2.11) and successful reperfusion (adjusted OR, 1.58; 95% CI, 1.33 to 2.15). No differences in intracerebral hemorrhage or in allcause mortality within 90 days were found between groups. CONCLUSION: s IVT prior to MT is associated with increased excellent outcome and successful reperfusion rates. These findings support the use of bridging therapy.

Concomitant conus medullaris arteriovenous shunts and sacral dural arteriovenous fistulas: pathophysiological links related to the venous drainage of the lesions in a series of five cases.

BACKGROUND: Spinal cord arteriovenous shunts (scAVSs) are a group of lesions located in the spinal cord itself or in the surrounding structures. The most common scAVSs are spinal dural arteriovenous fistulas (sDAVFs), which are acquired lesions. The pathogenesis of sDAVFs involves thrombosis and venous hypertension as trigger factors. Intradural scAVSs such as spinal cord arteriovenous nidus type malformations (AVMs) and pial arteriovenous fistulas are less common than sDAVFs and are considered to have a so-called 'congenital' origin. The association between different concomitant scAVSs is very rare and the association of sDAVFs with intradural scAVSs has been described in only a few case reports. METHODS: We describe a case series of five patients presenting with a conus medullaris AVS associated with a lower lumbar or sacral DAVF. RESULTS: Three of our patients were <30 years old at presentation. In four of these five cases the intradural scAVS drained caudally, engorging the epidural plexus in the same location as the sDAVF. In only one case, who presented with thrombosis of the drainage of the main compartment of a conus medullaris pial AVF, was the location of the DAVF opposite to the location of the residual drainage. CONCLUSION: We discuss the pathophysiological link between scAVS and sDAVF on the basis of the rarity of the DAVF, the uncommon association between scAVS and sDAVF, the presence of sDAVF in young patients, and the venous hypertension created by the venous drainage towards the sacral area responsible for angiogenesis creating the dural shunt.