Cervical arterial abnormalities and outcome after aneurysmal subarachnoid haemorrhage: A pilot cohort study.

BACKGROUND: Cervical arterial abnormalities are associated with intracranial aneurysm but their frequency and association with outcome in case of aneurysmal subarachnoid haemorrhage (aSAH) remains unknown. METHODS: Data were retrospectively extracted from a prospective database. Consecutive angiographies of aSAH patients on a 13-month period were reviewed as well as consecutive angiographies of SAH patients without evidence of aneurysm on a 20-month period. Occurrence of secondary neurological complications was collected with 3-month functional outcome (modified Rankin Scale ≥ 3 was considered as poor outcome). Cervical arterial abnormalities on angiographies were classified into two subcategories: trajectory and lumen vessel abnormalities. RESULTS: Forty-five patients displayed aneurysmal rupture (aSAH) while 39 patients had no evidence of aneurysm (non-aneurysmal SAH). Prevalence of cervical arterial abnormalities in aSAH and non-aneurysmal SAH patients were 82% (n = 37) and 64% (n = 25), respectively (p = 0.082). Lumen vessel abnormalities were significantly more frequent in case of aSAH (n = 31; 69%) than non-aneurysmal SAH: (n = 9; 23%; p < 0.001). Twenty-eight (62%) aSAH patients experienced poor outcome at 3 months. Lumen vessel abnormalities were significantly associated with 3-month poor outcome (74% (n = 23) versus 36% (n = 5); p = 0.021) without any significant increased occurrence of secondary complications such arterial vasospasm or delayed cerebral ischemia. CONCLUSION: Cervical arterial abnormalities are frequent in a cohort of aSAH patients. Lumen vessel abnormalities are associated with 3-month poor outcome.

Fibromuscular Dysplasia and Its Neurologic Manifestations: A Systematic Review.

Importance: Data on neurologic manifestations of fibromuscular dysplasia (FMD) are rare, and current knowledge remains limited. Objectives: To present a comprehensive review of the epidemiologic characteristics, management, and prognosis of the neurologic manifestations associated with cerebrovascular FMD (ie, involving cervical or intracranial arteries) and to guide future research priorities. Evidence Review: References were identified through searches of PubMed from inception to December 2017 using both the medical subject headings and text words. Additional sources were also identified by reviewing reference lists of relevant articles and through searches of the authors' personal files. Selected articles described at least 1 clinical or radiologic feature and/or outcome of cerebrovascular FMD. Isolated case reports could be included if they described interesting or noteworthy manifestations of FMD. Findings: A total of 84 relevant references were identified. Diagnosis of cerebrovascular FMD is based on the appearance of alternating arterial dilatation and constriction ("string of beads") or of focal narrowing, with no sign of atherosclerotic or inflammatory lesions. Although the diagnosis is easily apparent on results of radiographic imaging, making a diagnosis can be challenging in children or individuals with atypical phenotypes, such as purely intracranial FMD and arterial diaphragm. Involvement of multiple arteries is common, and there is increased incidence of cervical artery dissection and intracranial aneurysms. A variant in the PHACTR1 gene has been associated with FMD as well as cervical artery dissection and migraine, although less than 5% of cases of FMD are familial. Headaches, mainly of the migraine type, are observed in up to 70% of patients with FMD. Cerebrovascular FMD is mostly asymptomatic, but the most frequent neurologic manifestations include transient ischemic attack and ischemic stroke, notably in the presence of associated cervical artery dissection. Other conditions associated with FMD include subarachnoid hemorrhage and, rarely, intracranial hemorrhage. Management relies on observational data and expert opinion. Antiplatelet therapy is considered reasonable to prevent thromboembolic complications. Endovascular therapy is typically restricted to cases with symptomatic stenosis despite optimal medical therapy or in those with rupture of an intracranial aneurysm. Conclusions and Relevance: Longitudinal cohort studies of individuals of multiple ethnicities with biosampling are needed to better understand the risk factors, pathophysiological features, and outcomes of FMD. Patient advocacy groups could assist researchers in answering patient-centered questions regarding FMD.

Impact of the Thrombectomy Trials on the Management and Outcome of Large Vessel Stroke: Data From the Lyon Stroke Center.

Introduction: Randomized trials (RT) have recently validated the superiority of thrombectomy over standard medical care, including intravenous thrombolysis (IVT). However, data on their impact on routine clinical care remains scarce. Methods: Using a prospective observational registry, we assessed: (1) the clinical and radiological characteristics of all consecutive patients treated with thrombectomy; (2) the outcome of all patients with M1 occlusion (treated with thrombectomy or IVT alone). Two periods were compared: before (2013-2014) and after (2015-2016) the publication of RT. Results: Endovascular procedures significantly increased between the two periods (N = 82 vs. 314, p < 0.0001). In 2015-2016, patients were older (median [IQR]: 69 [57-80]; vs. 66 [53-74]; p = 0.008), had shorter door-to-clot times (69 [47-95]; vs. 110 [83-155]; p < 0.0001) resulting in a trend toward shorter delay from symptom onset to reperfusion (232 [185-300]; vs. 250 [200-339]; p = 0.1), with higher rates of reperfusion (71 vs. 48%; p = 0.0001). Conversely, no significant differences in baseline NIHSS scores, ASPECTS, delay to IVT or intracranial hemorrhage were found. In 2015-2016, patients with M1 occlusion were treated with thrombectomy more often than in 2013-2014 (87 vs. 32%, respectively; p < 0.0001), with a significant improvement in clinical outcome (shift analysis, lower modified Rankin scale scores: OR = 1.68; 95% CI: 1.10-2.57; p = 0.017). Conclusion: Following the publication of RT, thrombectomy was rapidly implemented with significant improvements in intrahospital delay and reperfusion rates. Treatment with thrombectomy increased with better clinical outcomes in patients with M1 occlusion.

Biomechanical Characterization of Intracranial Aneurysm Wall: A Multiscale Study.

OBJECTIVE: Aneurysm wall biomechanics are not yet an integral part of aneurysm rupture risk evaluation. We aimed to develop a new technique describing the biomechanical properties of aneurysm wall and correlating them to rupture status. METHODS: Aneurysm wall samples collected during surgery were submitted before and after freezing to tensile tests or as fresh samples to indentation tests. The lateral stiffness or the Young's modulus of the different samples was determined as a function of the mechanical test used. The impact of freezing on biomechanical properties was evaluated. The correlation of clinical and radiologic data with the biomechanical profile of the aneurysm samples was investigated. Two-photon microscopy was used to study collagen fiber organization. RESULTS: Sixteen aneurysm samples (11 unruptured and 5 ruptured) were included. Freezing decreased tissue stiffness. No significant difference was found between ruptured and unruptured aneurysm wall samples regarding demographic characteristics, ethnicity, smoking status, arterial hypertension, site, size and shape of the aneurysm, PHASES score, mechanical profile, or overall Young's modulus. Indentation tests found that the rupture occurred in a restricted area of increased elastic capacity and unruptured areas had increased stiffness. Two-photon microscopy found disruption of the collagen fiber network in rupture zones. CONCLUSIONS: The indentation test of fresh aneurysm wall samples described the heterogeneity of biomechanical properties of the tissue and found increased elastic capacity in the rupture zone and increased stiffness in the remainder of the aneurysm. This study could be a basis for further research aimed at building a biomechanical-based model of aneurysm rupture risk.

Transarterial Onyx Embolization of Intracranial Dural Fistulas: A Prospective Cohort, Systematic Review, and Meta-Analysis.

BACKGROUND: Onyx is important embolic material in the endovascular treatment of intracranial dural arteriovenous fistula (DAVF). However, its impact on DAVF occlusion rates, morbidity, mortality, and complication rates is not fully examined. OBJECTIVE: To improve understanding of safety and effectiveness profiles associated with transarterial endovascular treatment using Onyx for intracranial DAVF. METHODS: We analyzed data from our prospective clinical registry and conducted a systematic review of all previous transarterial embolization studies using Onyx published between January 2005 and December 2015 in MEDLINE and EMBASE. RESULTS: In the prospective study, 41 transarterial procedures were performed in 33 consecutive patients harboring 36 DAVFs. Complete initial exclusion was obtained in 32 of 36 (88.9%) fistulas; 31 fistulas were followed up showing 4 (12.9%) recurrences. Procedure-related morbidity and mortality were 3% and 0%, respectively. The literature review identified 19 studies involving a total of 425 patients with 463 DAVFs. Meta-analysis, including our registry data, showed an initial complete occlusion rate of 82% (95% confidence interval [CI]: 74%, 88%; I2, 70.6%), and recurrence rate at midterm of 2% (95% CI: 0%, 5%; I2, 21.5%). Pooled postoperative neurological deficit, procedure-related morbidity, and mortality rates were 4% (95% CI: 2%, 6%; I2, 0%), 3% (95% CI: 1%, 5%; I2, 0%), and 0%, respectively. CONCLUSION: This meta-analysis suggests that transarterial embolization with Onyx is a safe treatment modality for DAVFs. Although Onyx showed a low recurrence rate at midterm, the long-term risk is poorly addressed in our study and should warrant a longer follow-up.

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.

Mortality and Disability According to Baseline Blood Pressure in Acute Ischemic Stroke Patients Treated by Thrombectomy: A Collaborative Pooled Analysis.

BACKGROUND: High blood pressure (BP) is associated with worse clinical outcomes in the setting of acute ischemic stroke, but the optimal blood pressure target is still a matter of debate. We aimed to study the association between baseline BP and mortality in acute ischemic stroke patients treated by mechanical thrombectomy. METHODS AND RESULTS: A total of 1332 acute ischemic stroke patients treated by mechanical thrombectomy were enrolled (from January 2012 to June 2016) in the ETIS (Endovascular Treatment in Ischemic Stroke) registry. Linear and polynomial logistic regression models were used to assess the association between BP and mortality and functional outcome at 90 days. Highest mortality was found at lower and higher baseline systolic blood pressure (SBP) values following a J- or U-shaped relationship, with a nadir at 157 mm Hg (95% confidence interval 143-170). When SBP values were categorized in 10-mm Hg increments, the odds ratio for all-cause mortality was 3.78 (95% confidence interval 1.50-9.55) for SBP<110 mm Hg and 1.81 (95% confidence interval 1.01-3.36) for SBP≥180 mm Hg using SBP≥150 to 160 mm Hg as reference. The rate of favorable outcome was the highest at low SBP values and lowest at high SBP values, with a nonlinear relationship; in unplanned exploratory analysis, an optimal threshold SBP≥177 mm Hg was found to predict unfavorable outcome (adjusted odds ratio 0.47; 95% confidence interval 0.31-0.70). CONCLUSION: In acute ischemic stroke patients treated by mechanical thrombectomy, baseline SBP is associated with all-cause mortality and favorable outcome. In contrast to mortality, favorable outcome rate was the highest at low SBP values and lowest at high SBP values. Further studies are warranted to confirm these findings.

Vascular Tissue-Type Plasminogen Activator Promotes Intracranial Aneurysm Formation.

BACKGROUND AND PURPOSE: Although the mechanisms that contribute to intracranial aneurysm (IA) formation and rupture are not totally elucidated, inflammation and matrix remodeling are incriminated. Because tPA (tissue-type plasminogen activator) controls both inflammatory and matrix remodeling processes, we hypothesized that tPA could be involved in the pathophysiology of IA. METHODS: Immunofluorescence analyses of tPA and its main substrate within the aneurysmal wall of murine and human samples were performed. We then compared the formation and rupture of IAs in wild-type, tPA-deficient and type 1 plasminogen activator inhibitor-deficient mice subjected to a model of elastase-induced IA. The specific contribution of vascular versus global tPA was investigated by performing hepatic hydrodynamic transfection of a cDNA encoding for tPA in tPA-deficient mice. The formation and rupture of IAs were monitored by magnetic resonance imaging tracking for 28 days. RESULTS: Immunofluorescence revealed increased expression of tPA within the aneurysmal wall. The number of aneurysms and their symptomatic ruptures were significantly lower in tPA-deficient than in wild-type mice. Conversely, they were higher in plasminogen activator inhibitor-deficient mice. The wild-type phenotype could be restored in tPA-deficient mice by selectively increasing circulating levels of tPA via hepatic hydrodynamic transfection of a cDNA encoding for tPA. CONCLUSIONS: Altogether, this preclinical study demonstrates that the tPA present in the blood stream is a key player of the formation of IAs. Thus, tPA should be considered as a possible new target for the prevention of IAs formation and rupture.

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.

The pCONus Device for Treatment of Complex Wide-Neck Anterior Communicating Artery Aneurysms.

BACKGROUND AND PURPOSE: Anterior communicating artery (AcomA) aneurysms with a wide neck are often not feasible for endovascular coiling. Emerging devices for neck protection, such as the pCONus stent, are promising for endovascular treatment of challenging intracranial aneurysms. We report the preliminary results with pCONus in the treatment of wide-neck AcomA aneurysms. METHODS: All consecutive patients harboring AcomA aneurysms treated with pCONus in 3 European centers were retrospectively reviewed. RESULTS: Thirty-six patients (mean age, 61 years) harboring 36 saccular AcomA aneurysms (mean dome size, 7.3 mm; mean neck size, 5.4 mm) were included, of which 7 were treated in the setting of subarachnoid hemorrhage. A procedural angiographic complication was reported in 3 patients without clinical impact at 3 months. Five patients presented a postoperative neurological deficit without angiographic complication. Procedure-related permanent morbidity and mortality rates were 11% (3/33) and 0 at 3 months, respectively. Postoperative angiographic results showed a complete aneurysm occlusion in 56% (20/36), a neck remnant in 25% (9/36), and an aneurysm remnant in 19% (7/36) of cases. Four patients were retreated after early angiographic follow-up (mean, 3.2 months). Twenty-two patients were followed (mean, 12.9 months), and a complete aneurysm occlusion was observed in 59% of patients (13/22), and a neck remnant in 41% (9/22). There was no in-stent stenosis or jailed branch occlusion. Recanalization rate was 9%. CONCLUSIONS: The pCONus device allows endovascular coiling of wide-necked AcomA aneurysms.

Cervical artery tortuosity is associated with intracranial aneurysm.

Background Intracranial aneurysms may be associated with an underlying arteriopathy, leading to arterial wall fragility. Arterial tortuosity is a major characteristic of some connective tissue disease. Aim To determine whether intracranial aneurysm is associated with an underlying arteriopathy. Methods Using a case-control design, from May 2012 to May 2013, we selected intracranial aneurysm cases and controls from consecutive patients who had conventional cerebral angiography in our center. Cases were patients with newly diagnosed intracranial aneurysm. Controls were patients who had diagnostic cerebral angiography and free of aneurysm. The prevalence of tortuosity, retrospectively assessed according to standard definitions, was compared between cases and controls and, association between tortuosity and some aneurysm characteristics was examined, in cases only. Results About 659 arteries from 233 patients (112 cases and 121 controls) were examined. Tortuosity was found in 57 (51%) cases and 31 (26%) controls (adjusted OR = 2.71; 95%CI, 1.53-4.80). The same trend was found when looking at each tortuosity subtype (simple tortuosity, coil, kink) or at carotid or vertebral territory separately. In contrast, no association between tortuosity and rupture status, aneurysm number or neck size was found. Conclusions Cervical artery tortuosity is significantly associated with intracranial aneurysm, although not related to main aneurysm characteristics. Our results support the presence of an underlying diffuse arteriopathy in intracranial aneurysm patients.

PulseRider for Treatment of Wide-Neck Bifurcation Intracranial Aneurysms: 6-Month Results.

BACKGROUND/OBJECTIVE: PulseRider is a new endovascular stent dedicated to treat bifurcation intracranial aneurysms with a wide neck. Our purpose was to evaluate 6-month clinical and anatomic results of the device when used to facilitate endovascular coiling of wide-neck bifurcation aneurysms. METHODS: Unruptured intracranial aneurysms coiled with PulseRider, in 6 European centers and 1 U.S. center, were retrospectively reviewed from June 2014 to October 2015. Immediate and 6-month results were evaluated independently by using the Raymond classification scale. Recanalization was defined as worsening, and progressive thrombosis was defined as improvement on the Raymond scale. RESULTS: Nineteen patients (10 women, 9 men; mean age, 63 years) harboring 19 bifurcation aneurysms (mean dome size, 8.8 mm; mean neck size, 5.8 mm) were included. Immediate angiographic outcome showed 11 complete aneurysm occlusions, 6 neck remnants, and 2 residual aneurysms. Follow-up at 6 months, obtained in all patients, included 12 complete aneurysm occlusions (63.1%), 6 neck remnants (31.6%), and 1 residual aneurysm (5.3%). Adequate occlusion (defined as complete occlusion and neck remnant combined) was observed in 94.7%. Progressive thrombosis was observed in 2 cases (10.6%) and recanalization in 1 case (5.3%). There was no in-stent stenosis or jailed branch occlusion. No bleeding was observed during the follow-up period. Permanent morbidity rate was 5.3% (1/19), and the mortality rate was 0% at 6 months. CONCLUSIONS: The PulseRider allows endovascular treatment of wide-neck bifurcation intracranial aneurysms. Larger series are needed to confirm our preliminary results.

Stent-Retriever Thrombectomy for Acute Anterior Ischemic Stroke with Tandem Occlusion: A Systematic Review and Meta-Analysis.

OBJECTIVES: To assess the efficacy and safety profile of stent-retriever thrombectomy (SRT) in acute anterior ischemic stroke patients with tandem occlusion. MATERIALS AND METHODS: Using the MEDLINE database, we conducted a systematic review and meta-analysis of all studies that included patients with acute ischemic stroke attributable to tandem occlusion who received treatment with SRT between November 2010 and May 2015. RESULTS: The literature search identified 11 previous studies involving a total of 237 subjects out of whom 193 (81.4 %) were treated with acute stent placement for the extracranial internal carotid artery occlusion. Mean initial NIHSS score was 17, and median time from onset to recanalization was 283.5 min. Mean intravenous thrombolysis rate was 63.8 %. In the meta-analysis, the recanalization rate reached 81 % (95 % CI, 73-89). Meta-analysis of clinical outcomes showed a pooled estimate of 44 % (95 % CI, 33-55; 10 studies) for favourable outcome, 13 % (95 % CI, 8-20; 10 studies) for mortality, and 7 % (95 % CI, 2-13; eight studies) for symptomatic intracranial haemorrhage. CONCLUSION: SRT with emergency carotid stenting is associated with acceptable safety and efficacy in acute anterior stroke patients with tandem occlusion compared to natural history. However, the best modality to treat proximal stenosis is based on an individual case basis. KEY POINTS: • Stent retriever thrombectomy of tandem occlusion is efficient and safe. • Emergent carotid stenting during thrombectomy increase symptomatic intracranial haemorrhage without impact mortality. • Thrombectomy of tandem anterior circulation occlusion may be the first therapeutic option.

Early angiographic changes of intra-aneurysmal flow after flow-diverter stent treatment are not predictive of therapeutic success.

BACKGROUND AND PURPOSE: Flow-diverter stents (FDS) are new devices for the endovascular treatment of intracranial aneurysms (IAs) promoting progressive aneurysmal thrombosis. To date, the delay of aneurysmal exclusion remains unclear. We evaluated the correlation between angiographic changes in the first 24 hours and 12-month occlusion in aneurysms treated with FDS. METHODS: We retrospectively analyzed the intra-aneurysmal flow by evaluating the in-flow and out-flow delays on preoperative, immediate postoperative, 24-hour and 12-month follow-up angiography. Dichotomy of in-flow and out-flow within the aneurysm was considered as the time of contrast filling and time of contrast washing relatively to the parent artery. The delay times were compared and correlated with the therapeutic success of FDS at 12 months of follow-up. RESULTS: Out of 14 treated IAs, in 13 consecutive patients, n = 10 (71%) aneurysms showed complete occlusion at 12 months. Between immediate postoperative and 24-hour control, 10 aneurysms (71%) demonstrated in-flow modification, with eight increasing, two decreasing and four having no change. There were no statistical differences in therapeutic success in relation to the different flow-related profiles of intra-aneurysmal flux.Out-flow modifications were found in 11 aneurysms (79%) between immediate postoperative and 24-hour control, with five increasing, six decreasing and three having no change. Similar to the in-flow changes, there were no statistical differences in therapeutic success relative to the flow-related profiles. CONCLUSIONS: Early angiographic changes after FDS placement are very frequent, but are not correlated with the 12-month technical success of flow-diversion techniques.

Is systematic post-operative CT scan indicated after chronic subdural hematoma surgery? A case-control study.

BACKGROUND AND AIMS: The aim of the present study was to evaluate the interest of systematic post-operative CT scan after unilateral chronic subdural hematoma (CSDH) evacuation. To achieve this goal, we chose to evaluate the ability of post-operative CT scan to predict the most frequent complication of CSDH: hematoma recurrence. METHODS: We performed a retrospective case-control study. Cases were defined as patients who had CSDH recurrence; controls were those who did not. We first studied clinical data and pre-operative CT scan data. We then studied post-operative CT scan data: hematoma thickness and its decrease, persistence of midline shift, its value and its decrease, and presence of compressive pneumocephalus. RESULTS: Among 654 patients, 15 were defined as cases, and were matched with 30 non-recurrent patients defined as controls. Regarding systematic post-operative CT scan findings, unilateral CSDH recurrence was clearly associated with the persistence of midline shift induced by the presence of compressive pneumocephalus. CONCLUSIONS: Systematic post-operative CT scan after unilateral CSDH evacuation could predict hematoma recurrence. We therefore considered it as recommended, to adapt the clinical and radiological follow-up of CSDH patients.

Neurological involvement in hereditary hemorrhagic telangiectasia.

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disorder characterized by epistaxis, telangiectases, and multi-organ vascular dysplasia. Head and neck localizations of HHT are recurrent, frequent associated with serious complications. The aim of this study was to describe the clinical and imaging patterns of neurological involvement in HHT and to discuss the role of interventional radiology in the management of HHT patients. Based on a multidisciplinary experience of twenty years at our center, we report here the different aspects of neurological involvement of HHT. Depending on the genetic type of the disease, vascular abnormalities may affect different organs. The knowledge of neurological involvement according to specific localization of HHT makes detection easier. As cerebral or spinal arteriovenous fistula may be present in patients with epistaxis or pulmonary arteriovenous malformations (PAVMs), radiologists should be able to detect high-risk lesions and prevent related complications. Finally, we review indications and techniques of embolization for hemorrhagic lesions and emphasize that endovascular therapies are very effective and safe in experienced hands. Head and neck imaging is commonly used for the diagnosis of HHT. Imaging plays also a key role for patient evaluation before treatment as pluridisciplinary management is needed.

Carotid siphon morphology: Is it associated with posterior communicating aneurysms?

BACKGROUND AND PURPOSE: Posterior communicating artery (PComA) aneurysm seems to behave uniquely compared with other intracranial aneurysms at different locations. The association between the morphology of the carotid siphon and PComA aneurysms is not well known. This study aimed to investigate whether the anatomical characteristics of the carotid siphon are associated with the formation and rupture of PComA aneurysms. METHODS: One hundred and thirty-two patients were retrospectively reviewed in a monocentric case-control study. Sixty-seven consecutive patients with PComA aneurysms were included in the case group, and 65 patients with anterior circulation aneurysm situated in other intracranial locations were included in the control group, matched by age and sex. Morphological characteristics of the carotid siphon were analyzed using angiography images. A univariate analysis was used to investigate the association between the morphological characteristics and the formation of PComA aneurysms. Furthermore, a subgroup analysis within the case group compared ruptured and non-ruptured PComA aneurysms. RESULTS: Patients with PComA aneurysm had a significantly (1.31 ± 0.70 vs. 0.82 ± 0.46; P < 0.001) larger PComA. No association was observed between the morphological characteristics of the carotid siphon and the presence of a PComA aneurysm. Likewise, subgroup analysis showed no significant association between morphological characteristics of the carotid siphon and aneurysm rupture. CONCLUSIONS: This case-control study shows that the carotid siphon morphology seems not to be related to PComA aneurysm formation or rupture.

Spatiotemporal characterization of brain infarction by sequential multimodal MR imaging following transient focal ischemia in a Rat model of intra-arterial middle cerebral artery occlusion.

OBJECTIVES: To assess spatiotemporal brain infarction evolution by sequential multimodal magnetic resonance (MR) imaging in an endovascular model of acute stroke in rats. MATERIALS AND METHODS: A microwire was selectively placed in the middle cerebral artery (MCA) in 16 consecutives rats during 90 minutes occlusion. Longitudinal 7-T MR imaging, including angiography, diffusion, and perfusion was performed during ischemia, immediately after reperfusion, 3 h and 24 h after subsequent reperfusion. RESULTS: MCA occlusion was complete in 75 % and partial in 18.7 %. Hypoperfusion (mean ± SD) was observed in all animals during ischemia (-59 ± 18 % of contralateral hemisphere, area 31 ± 5 mm2). Infarction volume (mean ± SD) was 90 ± 64 mm3 during ischemia and 57 ± 67 mm3 at 24 h. Brain infarction was fronto-parietal cortical in five animals (31 %), striatal in four animals (25 %), and cortico-striatal in seven animals (44 %) at 24 h. All rats survived at 24 h. CONCLUSION: This model is suitable to neuroprotection studies because of possible acute and close characterization of spatiotemporal evolution of brain infarction by MR imaging techniques, and evidence of ischemic penumbra, the target of neuroprotection agents. However, optimization of the brain infarct reproducibility needs further technical and neurointerventional tools improvements. KEY POINTS: • Nitinol microwire is MRI compatible allowing spatiotemporal characterization of brain infarction in rats. • Microwire selective placement in middle cerebral artery allows complete artery occlusion in 75 %. • A diffusion/perfusion mismatch during arterial occlusion is observed in 77 % of rats.