Kohei Chida

Cerebral hyperperfusion after reconstructive surgery can develop intracerebral hemorrhage. However, there is no previous report of cerebellar hyperperfusion after surgical treatment for dural arteriovenous fistula (DAVF). In this report, the authors describe a case of cerebellar hyperperfusion following endovascular obliteration of DAVF. A man in his 70s had a progressing cognitive disturbance. Preoperative angiography showed a high-grade DAVF at the right sigmoid sinus with occlusion of the ipsilateral internal jugular vein. Since the superior sagittal sinus (SSS) was also occluded and the left transverse sinus (TS) exhibited severe stenosis, the bilateral cerebellum exhibited severe venous congestion. Preoperative brain perfusion SPECT showed severely reduced cerebrovascular reactivity to acetazolamide in the bilateral cerebellum. Transvenous transluminal angioplasty of the left TS and SSS and coil embolization of the right sigmoid sinus were performed. While the patient did not develop new neurological deficits, postoperative brain perfusion SPECT showed increased cerebral blood flow in the bilateral cerebellum up to 210% compared to that before the endovascular treatment. Blood pressure was strictly controlled, and then cerebellar hyperperfusion recovered on postoperative day 7. Cerebellar hyperperfusion can develop after surgical treatment for DAVF. Therefore, careful evaluation of preoperative hemodynamics, even in the posterior fossa, may be important. https://thejns.org/doi/10.3171/CASE26342.

Neuroendovascular treatment for patients with large-volume residual false lumens in the dissected aorta is challenging. Here, the authors describe the "twining wire technique" as a bailout in cases with failed navigation of a guidewire into the true lumen due to a dissecting aorta. A man with a previous history of open surgical repair of the ascending aorta and aortic arch for type A dissection was transferred to the authors' hospital for recanalization of the occluded left middle cerebral artery (MCA). CT angiography showed a graft-repaired, deformed aortic arch with distally residual false lumen, narrowing the true lumen. During mechanical thrombectomy, a guidewire could not be navigated into the true lumen via transfemoral or transradial access due to the deformed aortic arch and distal residual false lumen. Another wire was therefore navigated transradially from the true lumen into the descending aorta by passing the narrowed segment of the aorta; the wire was used as a guide in the true lumen by twining both wires, achieving access to the true lumen via a transfemoral approach and recanalization of the occluded MCA. The twining wire technique was useful to achieve access to the true lumen in a dissected aorta with a residual false lumen. https://thejns.org/doi/10.3171/CASE25993.

BACKGROUND AND OBJECTIVES: The transradial approach (TRA) using balloon guide catheters (BGCs) has emerged as a neurointerventional option. However, the use of large-bore BGCs may be limited because of the small size of the radial arteries (RAs) and difficulty in navigating BGCs from the right RA to the left anterior circulation. To determine the feasibility and safety of the overtake technique for navigating 8Fr EmboGuard BGCs using the TRA. METHODS: We retrospectively reviewed consecutive patients primarily undergoing TRA using EmboGuard BGCs. The BGCs were placed using sheathless or sheath-based methods and navigated by overtaking long Simmons arm inner catheters hooked in the common carotid arteries under the guidance of a half-stiff wire. The minimum diameter of RAs was ≥2.8 mm in all patients. Patient demographics and procedural and clinical outcomes were evaluated at 90 d or later. RESULTS: Overall, 28 procedures were performed in 26 patients out of 364 procedures in 358 patients. Treatments were successfully completed with the 8Fr EmboGuard TRA in 27 procedures (96.4%) without conversion to the transfemoral approach. In one patient, exchanging the EmboGuard with another BGC was necessary due to herniation of the BGC into the aortic arch during navigation of the carotid stent system. RA occlusion occurred in 1 of 22 patients (3.8%) without ischemic complications. CONCLUSION: The overtake technique for navigating the 8Fr EmboGuard BGCs in patients having RAs ≥2.8 mm was feasible and safely performed regardless of the insertion methods.

Background and Purpose Plaque composition, but not stenosis degree, may play a key role in the development of recurrent ischemic events in patients with symptomatic, mild (Methods This study included 124 patients with cerebrovascular or retinal ischemic events ipsilateral to mild carotid stenosis. Best medical therapy (BMT) was administered to all participants. CEA or carotid artery stenting (CAS) was implemented at each institution’s discretion. Baseline and 6-, 12-, and 24-month follow-up data were collected. Primary endpoint was ipsilateral ischemic stroke. Secondary endpoints included any stroke, ipsilateral TIA, ipsilateral ocular symptoms, any death, and plaque progression requiring CEA/CAS. Multivariate Cox proportional hazard model was used to evaluate the predictors for each endpoint. Results Of 124 patients, 70 patients (56.5%) had the history of ipsilateral ischemic stroke and 51 (43.5%) had been treated with antiplatelet agents. Mean stenosis degree was 22.4±13.7%. Plaque composition was categorized into fibrous plaque in 22 patients, lipid-rich/necrotic core (LR/NC) in 25, and intraplaque hemorrhage (IPH) in 69. BMT was indicated for 59 patients, while CEA was performed in 63. The incidence of primary endpoint was significantly higher in BMT group than in CEA group (15.1% vs. 1.7%; HR, 0.18; 95%CI, 0.05–0.84; P=0.03). The predictors for ipsilateral ischemic stroke were CEA (HR, 0.18; 95%CI, 0.05–0.84; P=0.03) and IPH (HR, 1.92; 95%CI, 1.26–4.28; P=0.04). The results on secondary endpoints were very similar. Conclusion IPH may highly predict subsequent cerebrovascular events, whereas CEA may reduce these risk during a 2-year follow-up in patients with symptomatic, mild carotid stenosis. Registration This study has been registered in the University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR) (UMIN000023635). Contributors SK, KO, UM, and MS designed the study. DK wrote an original draft. All authors recruited patients. DK, KC, KY, KY, MM, SY, SM, KO, MU, MS, and SK analyzed the imaging data as the members of Central Judgement Committee and contributed to data analysis. SK takes final responsibility for the submitted publication.

Flow diverters (FDs) are utilized for a wide range of aneurysms, but show safety issues such as adverse interactions with static magnetic fields (displacement force and torque) and radiofrequency-induced heating during magnetic resonance imaging (MRI). The present study aimed to assess these adverse interactions in a 7-tesla (7T) static magnetic field and radiofrequency-induced heating during a 7T MRI for two types of FD. Displacement force and magnetically induced torque were assessed using the deflection angle method and low friction surface method, respectively. To assess heating, each FD was set in a phantom filled with gelled-saline mixed with polyacrylic acid and underwent a 7T MRI using a three-dimensional fast spin echo method. Displacement force and magnetically induced torque in the 7T static magnetic field were undetectable, and radiofrequency-induced heating during 7T MRI remained ≤ 0.6 °C for both types of FD, suggesting that magnetic field interactions and heating on FDs during a 7T MRI are acceptable from a safety perspective.

The coronavirus disease 2019 (COVID-19) pandemic continues to spread around the world, and widespread vaccination is considered the most effective way to end it. Although the efficacy of COVID-19 vaccines has been confirmed, their safety remains a concern. In this paper, we report two cases of ruptured vertebral artery dissecting aneurysm (VADA) immediately after messenger RNA (mRNA) anti-COVID-19 vaccination. In Case 1, a 60-year-old woman experienced sudden headache 3 weeks before her first dose of the Moderna mRNA-1273 COVID-19 vaccine. Magnetic resonance imaging showed dilatation of the right vertebral artery (VA) without intracranial hemorrhage. A day after the vaccination, she developed subarachnoid hemorrhage with pulmonary effusion due to a ruptured right VADA. She underwent endovascular internal trapping and parent artery occlusion under general anesthesia. In Case 2, a 72-year-old woman with a previous history of the left VA occlusion due to arterial dissection developed subarachnoid hemorrhage 7 days after the first dose of the Pfizer-BioNTech BNT162b2 COVID-19 mRNA vaccine due to a ruptured right VADA and underwent stent-assisted coil embolization under general anesthesia. The postoperative courses of these two cases were uneventful. The accumulation of more cases and further study are warranted to clarify the relationship between COVID-19 mRNA vaccination and ruptured intracranial dissecting aneurysms.