Endovascular treatment of brain arteriovenous malformations: clinical outcomes of patients included in the registry of a pragmatic randomized trial.

OBJECTIVE: The role of endovascular treatment in the management of patients with brain arteriovenous malformations (AVMs) remains uncertain. AVM embolization can be offered as stand-alone curative therapy or prior to surgery or stereotactic radiosurgery (SRS) (pre-embolization). The Treatment of Brain AVMs Study (TOBAS) is an all-inclusive pragmatic study that comprises two randomized trials and multiple registries. METHODS: Results from the TOBAS curative and pre-embolization registries are reported. The primary outcome for this report is death or dependency (modified Rankin Scale [mRS] score > 2) at last follow-up. Secondary outcomes include angiographic results, perioperative serious adverse events (SAEs), and permanent treatment-related complications leading to an mRS score > 2. RESULTS: From June 2014 to May 2021, 1010 patients were recruited in TOBAS. Embolization was chosen as the primary curative treatment for 116 patients and pre-embolization prior to surgery or SRS for 92 patients. Clinical and angiographic outcomes were available in 106 (91%) of 116 and 77 (84%) of 92 patients, respectively. In the curative embolization registry, 70% of AVMs were ruptured, and 62% were low-grade AVMs (Spetzler-Martin grade I or II), while the pre-embolization registry had 70% ruptured AVMs and 58% low-grade AVMs. The primary outcome of death or disability (mRS score > 2) occurred in 15 (14%, 95% CI 8%-22%) of the 106 patients in the curative embolization registry (4 [12%, 95% CI 5%-28%] of 32 unruptured AVMs and 11 [15%, 95% CI 8%-25%] of 74 ruptured AVMs) and 9 (12%, 95% CI 6%-21%) of the 77 patients in the pre-embolization registry (4 [17%, 95% CI 7%-37%] of 23 unruptured AVMs and 5 [9%, 95% CI 4%-20%] of 54 ruptured AVMs) at 2 years. Embolization alone was confirmed to occlude the AVM in 32 (30%, 95% CI 21%-40%) of the 106 curative attempts and in 9 (12%, 95% CI 6%-21%) of 77 patients in the pre-embolization registry. SAEs occurred in 28 of the 106 attempted curative patients (26%, 95% CI 18%-35%, including 21 new symptomatic hemorrhages [20%, 95% CI 13%-29%]). Five of the new hemorrhages were in previously unruptured AVMs (n = 32; 16%, 95% CI 5%-33%). Of the 77 pre-embolization patients, 18 had SAEs (23%, 95% CI 15%-34%), including 12 new symptomatic hemorrhages [16%, 95% CI 9%-26%]). Three of the hemorrhages were in previously unruptured AVMs (3/23; 13%, 95% CI 3%-34%). CONCLUSIONS: Embolization as a curative treatment for brain AVMs was often incomplete. Hemorrhagic complications were frequent, even when the specified intent was pre-embolization before surgery or SRS. Because the role of endovascular treatment remains uncertain, it should preferably, when possible, be offered in the context of a randomized trial.

Patient Selection in a Pragmatic Study on the Management of Patients with Brain Arteriovenous Malformations.

BACKGROUND: The Treatment of Brain Arteriovenous Malformations Study (TOBAS) is an all-inclusive pragmatic study comprising 2 randomized clinical trials (RCTs). Patients excluded from the RCTs are followed in parallel treatment and observation registries, allowing a comparison between RCT and registry patients. METHODS: The first randomized clinical trial (RCT-1) offers 1:1 randomized allocation of intervention versus conservative management for patients with arteriovenous malformation (AVM). The second randomized clinical trial (RCT-2) allocates 1:1 pre-embolization or no pre-embolization to surgery or radiosurgery patients judged treatable with or without embolization. Characteristics of RCT patients are reported and compared to registry patients. RESULTS: From June 2014 to May 2021, 1010 patients with AVM were recruited; 498 patients were observed and 373 were included in the treatment registries. Randomized allocation in RCT-1 was applied to 139 (26%) of the 512 patients (including 127 of 222 [57%] with unruptured AVMs) considered for curative treatment. RCT-1 AVM patients differed (in rupture status, Spetzler-Martin grade and baseline modified Rankin Score) from those in the observation or treatment registries (P < 0.001). Most patients had small (<3 cm; 71%) low-grade (Spetzler-Martin I-II; 64%) unruptured (91%) AVMs. The allocated management was conservative (n = 71) or curative (n = 68), using surgery (n = 39), embolization (n = 16), or stereotactic radiosurgery (n = 13). Pre-embolization was considered for 179/309 (58%) patients allocated/assigned to surgery or stereotactic radiosurgery; 87/179 (49%) were included in RCT-2. RCT-2 patient AVMs differed in size, eloquence and grade from patients of the pre-embolization registry (P < 0.01). Most had small (<3 cm in 82%) low-grade (83%) AVMs in non-eloquent brain (64%). CONCLUSIONS: Patients included in the RCTs differ significantly from registry patients. Meaningful results can be obtained if multiple centers actively participate in the TOBAS RCTs.

Comparison of three antithrombotic strategies for emergent carotid stenting during stroke thrombectomy: a multicenter study.

BACKGROUND: Periprocedural antithrombotic treatment is a key determinant for the risk-benefit balance of emergent carotid artery stenting (eCAS) during stroke thrombectomy. We aimed to assess the safety and efficacy of three types of antithrombotic treatment. METHODS: Retrospective review of prospectively collected endovascular databases in four comprehensive stroke centers, including consecutive cases of eCAS for tandem lesion strokes between January 2019 and July 2021. During this period, each center prospectively applied one of three periprocedural protocols: (a) two centers administered aspirin (250 mg IV); (b) one center administered aspirin and heparin (bolus+24 hours infusion); and (c) one center applied an aggressive antiplatelet strategy consisting of aspirin and clopidogrel (loading doses), with added intravenous tirofiban if in-stent thrombosis was observed during thrombectomy. Dichotomized comparisons of outcomes were performed between aggressive versus non-aggressive strategy (aspirin±heparin) and aspirin+heparin versus aspirin-alone groups. RESULTS: Among 161 included patients, 62 received aspirin monotherapy, 38 aspirin+heparin, and 61 an aggressive treatment. Aggressive antiplatelet treatment was associated with an increased rate of excellent (modified Thrombolysis in Cerebral Infarction (mTICI) 2c-3) recanalization and reduced carotid stent thrombosis at day 1 (3.5% vs 16.3%), compared with non-aggressive strategy. There were no significant differences in hemorrhagic transformation or 90-day mortality. There was a tendency towards better clinical outcome with aggressive treatment, without reaching statistical significance. Addition of heparin to aspirin was not associated with an increased rate of carotid stent patency. CONCLUSIONS: Aggressive antiplatelet treatment was associated with improved intracranial recanalization and carotid stent patency, without safety concerns. These findings have implications for randomized trials and may be of utility for clinicians when making antithrombotic treatment choices.

Conservative versus aggressive antiplatelet strategy for emergent carotid stenting during stroke thrombectomy.

BACKGROUND: There is no consensus regarding optimal antiplatelet regimen for emergent carotid stenting during stroke thrombectomy. We aimed to assess the safety and efficacy of an aggressive periprocedural antiplatelet strategy focused on preserving stent patency, in comparison with conservative antiplatelet strategy consisting of aspirin monotherapy. MATERIALS AND METHODS: Retrospective review of a prospectively collected database in a comprehensive stroke center, including all cases of emergent carotid stenting for tandem lesions stroke between 01.03.2012-01.06.2021. Aggressive antiplatelet strategy consisted of dual antiplatelet therapy (DAPT) with aspirin and clopidogrel loading doses, with added intravenous (IV) tirofiban if in-stent thrombosis was observed during thrombectomy. Clinical and radiological outcomes were compared between conservative and aggressive antiplatelet treatment groups using inverse probability of treatment weighting (IPTW) analysis based on propensity scores. RESULTS: We included 132 cases (76.5% atheroma, 22.7% dissection, 0.7% carotid web). Forty-five patients (34%) cases received conservative antiplatelet therapy. The remaining 87 (65.9%) received aggressive antiplatelet therapy: 66 (75.8%) treated with DAPT, 21 (24.1%) with DAPT and tirofiban. Periprocedural heparin was avoided in all cases. In adjusted analysis of the weighted samples, aggressive antiplatelet strategy was associated with improved carotid stent patency (aOR 0.23, 95% CI 0.07-0.80, p = 0.021), higher proportion of moderate clinical outcome (mRS ≤ 3, aOR 2.72, 95% CI 1.01-7.30, p = 0.04), with no significant differences in mortality and hemorrhagic transformation (HT) rates. CONCLUSIONS: In this retrospective study, aggressive periprocedural antiplatelet strategy led to improved stent patency and clinical outcomes, without increased HT. Further prospective randomized research is warranted to identify the optimal combination of antiplatelet agents for emergent carotid stenting in the setting of acute stroke.

Surgical treatment of brain arteriovenous malformations: clinical outcomes of patients included in the registry of a pragmatic randomized trial.

OBJECTIVE: The Treatment of Brain Arteriovenous Malformations Study (TOBAS) is a pragmatic study that includes 2 randomized trials and registries of treated or conservatively managed patients. The authors report the results of the surgical registry. METHODS: TOBAS patients are managed according to an algorithm that combines clinical judgment and randomized allocation. For patients considered for curative treatment, clinicians selected from surgery, endovascular therapy, or radiation therapy as the primary curative method, and whether observation was a reasonable alternative. When surgery was selected and observation was deemed unreasonable, the patient was not included in the randomized controlled trial but placed in the surgical registry. The primary outcome of the trial was mRS score > 2 at 10 years (at last follow-up for the current report). Secondary outcomes include angiographic results, perioperative serious adverse events, and permanent treatment-related complications leading to mRS score > 2. RESULTS: From June 2014 to May 2021, 1010 patients were recruited at 30 TOBAS centers. Surgery was selected for 229/512 patients (44%) considered for curative treatment; 77 (34%) were included in the surgery versus observation randomized trial and 152 (66%) were placed in the surgical registry. Surgical registry patients had 124/152 (82%) ruptured and 28/152 (18%) unruptured arteriovenous malformations (AVMs), with the majority categorized as low-grade Spetzler-Martin grade I-II AVM (118/152 [78%]). Thirteen patients were excluded, leaving 139 patients for analysis. Embolization was performed prior to surgery in 78/139 (56%) patients. Surgical angiographic cure was obtained in 123/139 all-grade (89%, 95% CI 82%-93%) and 105/110 low-grade (95%, 95% CI 90%-98%) AVM patients. At the mean follow-up of 18.1 months, 16 patients (12%, 95% CI 7%-18%) had reached the primary safety outcome of mRS score > 2, including 11/16 who had a baseline mRS score ≥ 3 due to previous AVM rupture. Serious adverse events occurred in 29 patients (21%, 95% CI 15%-28%). Permanent treatment-related complications leading to mRS score > 2 occurred in 6/139 patients (4%, 95% CI 2%-9%), 5 (83%) of whom had complications due to preoperative embolization. CONCLUSIONS: The surgical treatment of brain AVMs in the TOBAS registry was curative in 88% of patients. The participation of more patients, surgeons, and centers in randomized trials is needed to definitively establish the role of surgery in the treatment of unruptured brain AVMs. Clinical trial registration no.: NCT02098252 (ClinicalTrials.gov).

Safety and Angiographic Efficacy of Intra-Arterial Fibrinolytics as Adjunct to Mechanical Thrombectomy: Results from the INFINITY Registry.

BACKGROUND AND PURPOSE: Data on safety and efficacy of intra-arterial (IA) fibrinolytics as adjunct to mechanical thrombectomy (MT) are sparse. METHODS: INtra-arterial FIbriNolytics In ThrombectomY (INFINITY) is a retrospective multi-center observational registry of consecutive patients with anterior circulation large-vessel occlusion ischemic stroke treated with MT and adjunctive administration of IA fibrinolytics (alteplase [tissue plasminogen activator, tPA] or urokinase [UK]) at 10 European centers. Primary outcome was the occurrence of symptomatic intracranial hemorrhage (sICH) according to the European Cooperative Acute Stroke Study II definition. Secondary outcomes were mortality and modified Rankin Scale (mRS) scores at 3 months. RESULTS: Of 5,612 patients screened, 311 (median age, 74 years; 44.1% female) received additional IA after or during MT (194 MT+IA tPA, 117 MT+IA UK). IA fibrinolytics were mostly administered for rescue of thrombolysis in cerebral infarction (TICI) 0-2b after MT (80.4%, 250/311). sICH occurred in 27 of 308 patients (8.8%), with an increased risk in patients with initial TICI0/1 (adjusted odds ratio [aOR], 2.3; 95% confidence interval [CI], 1.1 to 5.0 per TICI grade decrease) or in those with intracranial internal carotid artery occlusions (aOR, 3.7; 95% CI, 1.2 to 12.5). In patients with attempted rescue of TICI0-2b and available angiographic follow-up, 116 of 228 patients (50.9%) showed any angiographic reperfusion improvement after IA fibrinolytics, which was associated with mRS ≤2 (aOR, 3.1; 95% CI, 1.4 to 6.9). CONCLUSIONS: Administration of IA fibrinolytics as adjunct to MT is performed rarely, but can improve reperfusion, which is associated with better outcomes. Despite a selection bias, an increased risk of sICH seems possible, which underlines the importance of careful patient selection.

Local anesthesia versus general anesthesia during endovascular therapy for acute stroke: a propensity score analysis.

BACKGROUND: To date, the choice of optimal anesthetic management during endovascular therapy (EVT) of acute ischemic stroke patients remains subject to debate. We aimed to compare functional outcomes and complication rates of EVT according to the first-line anesthetic management in two comprehensive stroke centers: local anesthesia (LA) versus general anesthesia (GA). METHODS: Retrospective analysis of prospectively collected databases, identifying all consecutive EVT for strokes in the anterior circulation performed between January 1, 2018 and December 31, 2018 in two EVT-capable stroke centers. One center performed EVT under LA in the first intention, while the other center systematically used GA. Using propensity score analysis, the two groups underwent 1:1 matching, then procedural metrics, complications, and clinical outcomes were compared. Good outcome was defined as 90 days modified Rankin Scale (mRS) ≤2, and successful recanalization as modified Thrombolysis In Cerebral Ischemia (mTICI) 2b-3. RESULTS: During the study period, 219 patients were treated in the LA center and 142 in the GA center. Using the propensity score, 97 patients from each center were matched 1:1 according to the baseline characteristics. Local anesthesia was associated with a significantly lower proportion of good outcome (36.1% vs 52.0%, OR 0.53, 95% CI 0.33 to 0.87; p=0.039), lower rate of successful recanalization (70.1% vs 95.8%, OR 0.13, 95% CI 0.04 to 0.39; p<0.001), and more procedural complications (14.4% vs 3.0%, OR 3.44, 95% CI 1.09 to 14.28; p=0.018). There were no significant differences in 90-day mortality or symptomatic hemorrhagic transformation rates. CONCLUSIONS: In this study, systematic use of GA for stroke EVT was associated with better clinical outcomes, higher recanalization rates, and fewer procedural complications compared with patients treated under LA as the primary anesthetic approach.

Treatment with flow diverter stent during pregnancy.

Intracranial aneurysms are rarely diagnosed during pregnancy. If treatment is necessary, surgery was traditionally preferred over embolization in case of ongoing pregnancy, due to concerns regarding foetal radiation exposure. We present a case of 21 mm unruptured carotid-ophthalmic aneurysm diagnosed during pregnancy and treated with flow diversion. Foetal radiation dose was estimated between 1 and 5 mGy, well below recommended limits. Double antiplatelet therapy with prasugrel and aspirin was administered between week 17 and week 37, followed by uneventful vaginal delivery at 39 weeks. The new-born infant did not present any clinical abnormalities. Post-natal angiography showed complete aneurysm occlusion. To our knowledge, this is the first report of flow diverter stent placement during ongoing pregnancy. Although a good outcome was observed in this case, this result should be interpreted with caution. Further studies are needed in order to better define the safety profiles of intracranial stents and double antiplatelet therapies during pregnancy.

Endovascular versus surgical treatment for improvement of oculomotor nerve palsy caused by unruptured posterior communicating artery aneurysms.

BACKGROUND: There is no consensus regarding the best treatment option for unruptured aneurysms of the posterior communicating artery (PCom) presenting with oculomotor nerve palsy (ONP). We aimed to assess predictors of ONP recovery in a multicenter series of consecutive patients. MATERIALS AND METHODS: A retrospective review of prospective databases in three tertiary neurosurgical centers was carried out, selecting patients with ONP caused by unruptured PCom aneurysms, treated by surgical clipping or embolization, between January 2006 and December 2013. Patient files and imaging studies were used to extract ophthalmological assessments, treatment outcomes, and follow-up data. Predictors of ONP recovery during follow-up were explored using univariate and multivariate analyses. RESULTS: We identified 55 patients with a median ONP duration before treatment of 11 days (IQR 4.5-18); the deficit was complete in 27 (49.1%) and incomplete in 28 (50.9%) cases. Median aneurysm size was 7 mm (IQR 5-9). Twenty-four (43.6%) patients underwent surgical clipping and 31 (56.4%) embolization as the primary treatment. Overall, ONP improved in 40 (72.7%) patients and persisted/recurred in 15 (27.3 %). Surgery, interval to complete treatment <4 weeks, aneurysm recurrence during follow-up, and retreatment during follow-up were significantly correlated with ONP outcome in the univariate analysis. In the multivariate analysis, independent predictors of ONP improvement were interval to complete treatment <4 weeks (OR 5.15, 95% CI 1.37 to 23.71, p=0.015) and aneurysm recurrence during follow-up (OR 0.1, 95% CI 0.02 to 0.47, p=0.003). CONCLUSION: There was no significant difference in ONP recovery between surgical clipping and embolization. The best predictor for ONP recovery was timely, complete, and durable aneurysm exclusion.

Balloon-assisted coiling of intracranial aneurysms using the Eclipse 2L double lumen balloon.

BACKGROUND: Eclipse 2L is a new double lumen balloon microcatheter for neurovascular use, with several design features that separate it from previous generation devices. We aimed to report our initial experience of balloon-assisted coiling of intracranial aneurysms using the Eclipse 2L balloon. MATERIALS AND METHODS: Retrospective single-center review of patients who underwent balloon-assisted coiling with the Eclipse 2L balloon, for ruptured or unruptured intracranial aneurysms between 1 June 2016 and 31 December 2018. Cases with adjunctive use of stents and recurrences of previously embolized aneurysms were excluded. Patient files were used to extract aneurysm characteristics, complications, immediate and long-term results. RESULTS: We identified 120 patients with 126 aneurysms, of which 83 (65.8%) unruptured. Average aneurysm size was 5.9 mm (standard deviation 3.2 mm), with a dome-to neck-ratio of 1.7 (SD 0.6). Most aneurysms (79.3%) were wide necked. Immediate angiographic exclusion (Raymond-Roy grade I-II) was obtained in 95.1% of cases (81.7% grade I and 13.4% grade II). Procedural morbidity was 3.2% with no procedural mortality. Follow-up imaging was available for 115 aneurysms (91.2%). After an average follow-up period of 8.9 months (SD 7.3 months), 96.5% of aneurysms presented class I-II occlusion. Two aneurysms (1.7%) were retreated during follow-up. CONCLUSION: Balloon-assisted coiling using the Eclipse 2L double lumen balloon is feasible for aneurysms in a wide range of locations in the anterior and posterior circulation. The angiographic results and complication rates compare favorably with previously published studies.

Embolization of very small (≤3 mm) unruptured intracranial aneurysms: A large single-center experience on treatment of unruptured versus ruptured cases.

OBJECTIVE: In selected cases, embolization can be indicated for very small unruptured intracranial aneurysms. Previous studies reported high intraprocedural rupture rates. Recent improvements of endovascular devices and availability of small, soft platinum coils may lead to improved safety and efficacy profiles. METHODS: Retrospective review of embolizations for unruptured and ruptured intracranial aneurysms with maximal diameter ≤3 mm between January 1, 2009, and January 15, 2018. Infectious aneurysms were excluded. Patient files were used to extract aneurysm characteristics, complications, and immediate and long-term results. RESULTS: We identified 99 embolizations for 97 patients with 100 aneurysms, of which 70 aneurysms were unruptured. Initial success rate was 92.9%. We observed 1 asymptomatic intraprocedural perforation of an unruptured aneurysm, accounting for 1.4% of unruptured cases (1% of all embolizations). Neurological morbidity was 2.8% for unruptured aneurysms and 3.3% for ruptured aneurysms (P = 0.89). There was no procedural mortality. Follow-up was available for 85 (93.4%) patients. After 28.2 months (2-77), there was no aneurysmal bleeding; 2 (2.2%) aneurysms needed retreatment. Long-term results (30.5 months [3-77]) were available for all unruptured aneurysms. Among 64 successfully embolized unruptured aneurysms, 5 (7.8%) had residual neck filling and 1 (1.5%) needed retreatment. There were no significant differences in patient characteristics or complications between ruptured and unruptured aneurysms. CONCLUSIONS: In the context of technical evolution of endovascular devices, we observed a procedural perforation rate lower than previously reported, low morbidity and no mortality. Further prospective studies are warranted to update our knowledge about safety of embolization for very small intracranial aneurysms.

Gastrointestinal Hormones Manipulation to Counteract Metabolic Syndrome Using Duodenal Targeted Embolization.

PURPOSE: Targeted embolization of gastrointestinal (GI) arteries can modify hormonal production. We aimed to evaluate the impact of the embolization of the gastroduodenal artery (GDA) on the activity of foregut mucosa. METHODS: The GDA's duodenal branch was embolized in 12 Yucatan pigs using 100-300 µm (group A; n = 4) or 300-500 µm (group B; n = 4) microspheres, followed by coiling of the branch. In 4 animals (sham), only saline was injected. The levels of GI hormones (ghrelin, glucose-dependent insulinotropic peptide [GIP], glucagon-like peptide-1 [GLP-1], insulin, peptide YY [PYY], leptin) and the gene expression of sodium-glucose-linked transporter-1 (SGLT-1) and glucose transporter-2 (GLUT-2) were assessed before (T0), 1 hour (T1), 1 month (T2), 3 months (T3), and 6 months (T4) after embolization. RESULTS: In group A, a segmental duodenal stenosis occurred in all cases, which required balloon dilatation. There was a significant drop in the baseline glycemia in group A at T1 and T4 versus sham. Ghrelin was reduced in group A versus baseline and versus group B at T2 and T3 and versus sham at T1 and T3. Insulin was significantly lower in group A versus B at T1 and at T4 but not versus sham. SGLT-1 expression increased in B and sham at T4, while it remained stable in group A. GLUT-2 expression increased in sham at T4 but not in A or B. CONCLUSIONS: GDA embolization induced a decrease in ghrelin production and influenced expression of glucose carriers in the foregut mucosa.

Beam hardening artifacts of liquid embolic agents: comparison between Squid and Onyx.

BACKGROUND: Initial clinical experience with Squid shows subjectively reduced artifacts on post-embolization CT scans compared with Onyx. To further investigate these observations, we aimed to perform a comparison of artifacts between Squid and Onyx in a controlled in vitro model. MATERIALS AND METHODS: Onyx 18 and all four variants of Squid (Squid 18, Squid 18 low density (LD), Squid 12, Squid 12 LD) were each injected in dimethylsulfoxide (DMSO) compatible test tubes. The tubes containing precipitated embolic material were inserted in a CT phantom for conventional and flat panel CT acquisitions. Beam hardening artifacts were quantified using objective and subjective measurements. RESULTS: Objective evaluation of artifacts within regions of interest (ROIs) placed around the embolic material on CT and flat panel CT images demonstrated significantly lower noise and Hounsfield unit (HU) range values for all four Squid products compared with Onyx 18. On both CT and flat panel CT, LD variants of Squid 18 and Squid 12 had significantly lower noise and HU range values than their normal density counterparts on longitudinal ROIs. When using subjective measures for diagnostic value within ROIs placed around the embolic material on both CT and flat panel CT images, the number of non-diagnostic ROIs was significantly higher for Onyx 18 than for all four Squid variants. CONCLUSION: All four variants of Squid induced fewer beam hardening artifacts than Onyx 18 on CT and flat panel CT acquisitions. LD variants of Squid induced fewer artifacts than their normal density counterparts.

A Systematic Review of the Complex Effects of Cannabinoids on Cerebral and Peripheral Circulation in Animal Models.

While cannabis is perceived as a relatively safe drug by the public, accumulating clinical data suggest detrimental cardiovascular effects of cannabinoids. Cannabis has been legalized in several countries and jurisdictions recently. Experimental studies specifically targeting cannabinoids' effects on the cerebral vasculature are rare. There is evidence for transient vasoconstrictive effects of cannabinoids in the peripheral and cerebral vasculature in a complex interplay of vasodilation and vasoconstriction. Vasoreactivity to cannabinoids is dependent on the specific molecules, their metabolites and dose, baseline vascular tone, and vessel characteristics as well as experimental conditions and animal species. We systematically review the currently available literature of experimental results in in vivo and in vitro animal studies, examining cannabinoids' effects on circulation and reactive vasodilation or vasoconstriction, with a particular focus on the cerebral vascular bed.

Mechanical thrombectomy for repeated cerebral tumor embolism from a thoracic sarcomatoid carcinoma.

Cerebral embolism originating from intracardiac tumors represents a rare cause of stroke and has been documented in both adult and pediatric populations. We present a patient recently diagnosed with a right pulmonary hilum tumor, invading the pulmonary veins and the left atrium. Two consecutive episodes of large cerebral vessel occlusion in separate vascular territories occurred in the same day and were treated by mechanical thrombectomy. Embolic material retrieved on both occasions contained tumor fragments with peripheral endothelialization. To our knowledge, this is the first report with histological confirmation of cerebral embolism from an invasive extracardiac tumor.

Mechanical thrombectomy for repeated cerebral tumor embolism from a thoracic sarcomatoid carcinoma.

Cerebral embolism originating from intracardiac tumors represents a rare cause of stroke and has been documented in both adult and pediatric populations. We present a patient recently diagnosed with a right pulmonary hilum tumor, invading the pulmonary veins and the left atrium. Two consecutive episodes of large cerebral vessel occlusion in separate vascular territories occurred in the same day and were treated by mechanical thrombectomy. Embolic material retrieved on both occasions contained tumor fragments with peripheral endothelialization. To our knowledge, this is the first report with histological confirmation of cerebral embolism from an invasive extracardiac tumor.

Aneurysmal wall imaging in a case of cortical superficial siderosis and multiple unruptured aneurysms.

We report a case of interhemispheric and bifrontal cortical superficial siderosis in association with two intracranial aneurysms. The patient had no clinical history suggestive of aneurysm rupture, no feature of amyloid angiopathy or other apparent etiology for cortical siderosis. We performed high resolution brain MRI with dark blood T1 sequences before and after IV contrast injection. An anterior communicating aneurysm showed partial wall enhancement on the posterior wall whereas a left posterior communicating aneurysm did not. In the light of recent reports of the association of wall enhancement with unstable aneurysms, we considered wall enhancement to be a marker of inflammation and remodeling of the aneurysm wall, resulting in chronic hemorrhagic suffusion in the subarachnoid spaces. To our knowledge, this is the first report offering proof for a possible link between apparently unruptured aneurysms and cortical siderosis.