Background: As of 8 April 2021, a total of 2.9 million people have died with or from the coronavirus infection causing COVID-19 (Corona Virus Disease 2019). On 29 January 2021, the European Medicines Agency (EMA) approved a COVID-19 vaccine developed by Oxford University and AstraZeneca (AZD1222, ChAdOx1 nCoV-19, COVID-19 vaccine AstraZeneca, Vaxzevria, Covishield). While the vaccine prevents severe course of and death from COVID-19, the observation of pulmonary, abdominal, and intracranial venous thromboembolic events has raised concerns. Objective: To describe the clinical manifestations and the concerning management of patients with cranial venous sinus thrombosis following first exposure to the “COVID-19 vaccine AstraZeneca”. Methods: Patient files, laboratory findings, and diagnostic imaging results, and endovascular interventions of three concerning patients were evaluated in retrospect. Results: Three women with intracranial venous sinus thrombosis after their first vaccination with “COVID-19 vaccine AstraZeneca” were encountered. Patient #1 was 22 years old and developed headaches four days after the vaccination. On day 7, she experienced a generalized epileptic seizure. Patient #2 was 46 years old. She presented with severe headaches, hemianopia to the right, and mild aphasia 13 days after the vaccination. MRI showed a left occipital intracerebral hemorrhage. Patient #3 was 36 years old and presented 17 days after the vaccination with acute somnolence and right-hand hemiparesis. The three patients were diagnosed with extensive venous sinus thrombosis. They were managed by heparinization and endovascular recanalization of their venous sinuses. They shared similar findings: elevated levels of D-dimers, platelet factor 4 antiplatelet antibodies, corona spike protein antibodies, combined with thrombocytopenia. Under treatment with low-molecular-weight heparin, platelet counts normalized within several days. Conclusion: Early observations insinuate that the exposure to the “COVID-19 vaccine AstraZeneca” might trigger the expression of antiplatelet antibodies, resulting in a condition with thrombocytopenia and venous thrombotic events (e.g., intracranial venous sinus thrombosis). These patients’ treatment should address the thrombo-embolic manifestations, the coagulation disorder, and the underlying immunological phenomena.

Although mechanical thrombectomy (MT) has been shown in numerous trials to be a successful treatment option for patients with large vessel occlusion (LVO), there is limited information on the safety and effectiveness of the technique in cases of recurrent LVO. To this end, we performed a retrospective review of our prospectively maintained database to identify all patients that had undergone more than one MT procedure January 2008 and January 2018. The data collected on these patients included baseline demographics and any history of diabetes mellitus, hypercholesterolaemia, hypertension, atrial fibrillation or smoking. We also recorded when the symptoms had started, the patient's NIHSS and ASPECT scores, the number of passes taken, the patient's final TICI score, any complications which arose and the patient's mRS at 90 days. Our dataset encompassed 25 patients (of which 17 (68%) were female) who had undergone a total number of 52 MT's. Average age at 1st presentation was 70 ± 12.8 years. The median time between one stroke and the next was 71 days (range 1-1059, IQR 183 days). The majority of the strokes were deemed cardioembolic (86.5%) in origin. There was no significant difference in the procedure times, number of passes or TICI scores. There was a significant difference in the mRS after the 1st and 2nd events (p = 0.014) but no significant difference if the 2nd event occurred contralateral to the 1st event (p = 0.66) (n = 22). It is therefore concluded that recurrent thrombectomy can be safely performed with no significant difference in the technical aspects of the procedure.

BackgroundThe use of flow diversion to treat intracranial aneurysms has increased in recent years.ObjectiveTo assess the safety and angiographic efficacy of the p64 flow modulation device.MethodsDiversion-p64 is an international, prospective, multicenter, single-arm, study conducted at 26 centers. The p64 flow modulation device was used to treat anterior circulation aneurysms between December 2015 and January 2019. The primary safety endpoint was the incidence of major stroke or neurologic death at 3–6 months, with the primary efficacy endpoint being complete aneurysm occlusion (Raymond-Roy Occlusion Classification 1) on follow-up angiography.ResultsA total of 420 patients met the eligibility criteria and underwent treatment with the p64 flow modulation device (mean age 55±12.0 years, 86.2% female). Mean aneurysm dome width was 6.99±5.28 mm and neck width 4.47±2.28 mm. Mean number of devices implanted per patient was 1.06±0.47, with adjunctive coiling performed in 14.0% of the cases. At the second angiographic follow-up (mean 375±73 days), available for 343 patients (81.7%), complete aneurysm occlusion was seen in 287 (83.7%) patients. Safety data were available for 413 patients (98.3%) at the first follow-up (mean 145±43 days) with a composite morbidity/mortality rate of 2.42% (n=10).ConclusionsDiversion-p64 is the largest prospective study using the p64 flow modulation device. The results of this study demonstrate that the device has a high efficacy and carries a low rate of mortality and permanent morbidity.

BackgroundCoil occlusion has become the standard treatment for many ruptured aneurysms. However, specific aneurysm structures pose technical difficulties and may require the use of adjunctive neck-bridging devices, which necessitate the use of dual antiplatelet therapy. The hydrophilic polymer coating (pHPC, phenox) is a surface modification that inhibits platelet adhesion.ObjectiveTo present initial experience with the pCONUS HPC device as an adjunct to coil embolization for ruptured aneurysms using single antiplatelet therapy (SAPT).MethodsAll patients who were treated with the pCONUS HPC for ruptured aneurysms using SAPT were retrospectively identified. The occurrence of thromboembolic and hemorrhagic complications was recorded together with the angiographic and clinical follow-up details.ResultsFifteen patients were identified (nine female) with a median age of 54 years (range 27–81). Six aneurysms were located at the anterior communicating artery, five at the middle cerebral artery bifurcation, two at the basilar artery bifurcation, one at the posterior communicating artery, and one involving the intradural internal carotid artery. Ten patients (66.6%) achieved modified Raymond–Roy classification I or II at post-treatment angiography, with 45.5% of patients having adequate occlusion (defined as complete occlusion or neck remnant) at follow-up. All patients received acetylsalicylic acid (ASA) as SAPT before and after the procedure. Intraprocedural thrombus formation was seen in three patients (20%), resolving in two patients after a bolus dose of eptifibatide, and one treated with mechanical aspiration. No clinical or radiological consequences were seen. There were no recurrent aneurysm ruptures. One patient died owing to cerebral vasospasm.ConclusionThis initial clinical experience highlights the possibility and limitations of using the pCONUS HPC device in the treatment of complex ruptured aneurysm with ASA as SAPT. Randomized trials with longer follow-up in larger cohorts are underway.

Background: Cerebral venous sinus or vein thromboses (SVT) are treated with heparin followed by oral anticoagulation. Even after receiving the best medical treatment, numerous patients experience neurological deterioration, intracerebral hemorrhage or brain edema. Debate regarding whether endovascular treatment (EVT) is beneficial in such severe cases remains ongoing. This systematic review summarizes the current evidence supporting the use of EVT for SVT on the basis of case presentations, with a focus on patient selection, treatment strategies and the effects of the COVID-19 pandemic. Methods: This systemic literature review included randomized controlled trials (RCTs) and retrospective observational data analyzing five or more patients. Follow-up information (modified Rankin scale (mRS)) was required to be provided (individual patient data). Results: 21 records (n = 405 patients; 1 RCT, 20 observational studies) were identified. EVT was found to be feasible and safe in a highly selected patient cohort but was not associated with an increase in good functional outcomes (mRS 0–2) in RCT data. In observational data, good functional outcomes were frequently observed despite an anticipated poor prognosis. Conclusion: The current evidence does not support the routine incorporation of EVT in SVT treatment. However, in a patient cohort prone to poor prognosis, EVT might be a reasonable therapeutic option. Further studies determining the patients at risk, choice of methods and devices, and timing of treatment initiation are warranted.

Objective: Endovascular embolization using non-adhesive agents (e.g., ethylene vinyl alcohol copolymer with suspended micronized tantalum dissolved in dimethyl sulfoxide; Squid, Balt Extrusion) is an established treatment of brain arteriovenous malformations, dural arteriovenous fistulas, and hypervascular neoplasms. Middle meningeal artery (MMA) embolization is a relatively new concept for treating chronic subdural hematomas (CSDH). This study aimed to evaluate the safety and effectiveness of the use of Squid in the endovascular treatment of CSDH. Methods: Embolization was offered to patients with CSDH with minimal or moderate neurological deficits and patients who had previously undergone open surgery to evacuate their CSDH without a significant effect. Distal catheterization of the MMA was followed by embolization of the hematoma capsule with Squid 12 or Squid 18. Safety endpoints were ischemic or hemorrhagic stroke and any other adverse event of the endovascular procedure. Efficacy endpoints were the feasibility of the intended procedure and a ≥ 50% reduction of the maximum depth of the CSDH confirmed by follow-up computed tomography (CT) after >3 months. Results: Between November 2019 and July 2021, 10 patients (3 female and 7 male, age range 42–89 years) were enrolled. Five patients had bilateral hematomas, and five patients had previously been operated on with no significant effect and recurrent hematoma formation. The attempted embolization was technically possible in all patients. No technical or clinical complication was encountered. During a post-procedural follow-up (median 90 days), 10 patients improved clinically. A complete resolution of the CSDH was observed in 10 patients. The clinical condition of all enrolled patients during the so-far last contact was rated mRS 0 or 1. Conclusion: A distal catheterization of the MMA for the endovascular embolization of CSDH with Squid allowed for the devascularization of the MMA and the dependent vessels of the hematoma capsule. This procedure resulted in a partial or complete resolution of the CSDH. Procedural complications were not encountered.

Mechanical thrombectomy in selected patients with wake-up stroke allows a good functional outcome comparable with that of controls. Outcome after mechanical thrombectomy in daytime-unwitnessed stroke seems to be inferior compared with that in controls. Advanced imaging modalities may increase the frequency of good functional outcome in both patients with wake-up stroke and daytime-unwitnessed stroke.

The Woven Endobridge (WEB; Microvention, Aliso Viejo, California, USA) is a relatively new device which has been shown to be safe and effective for the treatment of wide necked bifurcation aneurysms in multiple prospective Good Clinical Practice studies. However, the vast majority of aneurysms included in these studies have been unruptured. The aim of this review is to summarise the current evidence available on the treatment of ruptured aneurysms with the WEB.