De novo dural arteriovenous fistula after mechanical thrombectomy for cerebral venous thrombosis: A case report.

Background: Although the relationship between dural arteriovenous fistula (dAVF) and cerebral venous thrombosis (CVT) has been reported, the etiology has not been clarified. Here, we report a case of de novo dAVF after mechanical thrombectomy for CVT and discuss the underlying mechanism. Case Description: A 61-year-old woman presented with a gradually worsening headache and was diagnosed with severe CVT. Mechanical thrombectomy was performed for the CVT because of progressive neurological deterioration despite anticoagulation therapy. Two years after the initial treatment, angiography revealed a de novo dAVF with a direct shunt of the left convexity cortical vein. Transarterial embolization with Onyx was performed and the shunt was completely obliterated. Conclusion: In this report, we describe a case of de novo dAVF with CVT that was treated with mechanical thrombectomy. Even if CVT improves with mechanical thrombectomy, we must be aware of the occurrence of de novo dAVF.

Histopathological Composition of Thrombus in Acute Ischemic Stroke May Vary Even Within the Same Patient: A Preliminary Study Examining Clots According to Their Area of Retrieval.

Objective: Mechanical thrombectomy enables histopathological examination of clots in patients who have suffered acute ischemic strokes. Many studies have described about the relationship between the histopathological compositions of retrieved thrombi and imaging findings, clinical outcomes, and stroke etiology without consensus. In this study, we examined the histological composition of thrombi according to their retrieval site and methods. Methods: We divided retrieved clots into three parts (those retrieved from the proximal and distal parts of the stent retriever, and those aspirated through the guiding catheter) and then histopathologically analyzed their compositions by measuring the area occupied by red blood cells (RBCs), fibrin/platelets (F/Ps), and white blood cells (WBCs). Results: Each specimen showed various composition even within the same patient. For example, the area occupied by RBCs was 20.9% ± 12.1%, 30.5% ± 13.5%, and 41.3% ± 16.1% in the clot retrieved from the proximal and distal parts of the stent retriever, and those aspirated through the guiding catheter, respectively. Conclusion: Histopathological clot composition may vary even within the patient. Further research is needed to investigate more objective methods of histopathological analysis and their clinical significance.

A Case of Acute Embolism of the Accessory Middle Cerebral Artery Treated Using ADAPT Thrombectomy without Lesion Passing.

An accessory middle cerebral artery (AMCA) is a variant vessel that branches from the anterior cerebral artery (ACA) and runs through the Sylvian fissure along the middle cerebral artery (MCA). We report a case of acute embolic occlusion of the AMCA that was treated with thrombectomy using direct aspiration first pass technique (ADAPT). An 88-year-old woman with a history of atrial fibrillation, loss of consciousness, and right hemiparesis was referred to our hospital. Diffusion-weighted magnetic resonance imaging (MRI) showed high signal intensity in the left frontal lobe, insular cortex, and deep white matter, and magnetic resonance angiography (MRA) demonstrated left internal carotid artery (ICA) occlusion. Mechanical thrombectomy using the ADAPT technique was performed with complete recanalization. Final angiography revealed left ACA and AMCA because of the thrombus located at the origin of the left ACA and AMCA. In the case of an acute ischemic stroke associated with AMCA, it is difficult to understand and recognize the anatomy of the vessel before thrombectomy. Therefore, the ADAPT technique, which can treat acute embolic occlusion without lesion passing, is recommended due to its safety. If there is a mismatch between the perfusion area of the occluded artery and the ischemic area or the neurological findings before thrombectomy, it is extremely important to keep in mind the presence of vessel variation in the MCA.

The Histopathological Findings of Two Nonbranching Saccular Cerebral Aneurysms.

Cerebral aneurysms arising from nonbranching sites are different from ordinary branching aneurysms in clinical course and histology. We pathologically examined two cases of saccular aneurysm occurring at nonbranching sites. One was a pseudoaneurysm arising at a branch of the right pericallosal artery. The other had an entirely hyalinized and thickened aneurysmal wall. Despite similar angiographical findings, our two cases had different pathological features as described above. Based on the pathological findings obtained from these cases, we believe that aneurysms in nonbranching sites are caused by injury to the internal elastic lamina. A ruptured aneurysm may be discovered as a blood blister-like aneurysm, whereas an unruptured one may develop into a "nonbranching true aneurysm."

Sub-2 nm Thick Fluoroalkylsilane Self-Assembled Monolayer-Coated High Voltage Spinel Crystals as Promising Cathode Materials for Lithium Ion Batteries.

We demonstrate herein that an ultra-thin fluoroalkylsilane self-assembled monolayer coating can be used as a modifying agent at LiNi0.5Mn1.5O4-δcathode/electrolyte interfaces in 5V-class lithium-ion batteries. Bare LiNi0.5Mn1.5O4-δ cathode showed substantial capacity fading, with capacity dropping to 79% of the original capacity after 100 cycles at a rate of 1C, which was entirely due to dissolution of Mn(3+) from the spinel lattice via oxidative decomposition of the organic electrolyte. Capacity retention was improved to 97% on coating ultra-thin FAS17-SAM onto the LiNi0.5Mn1.5O4 cathode surface. Such surface protection with highly ordered fluoroalkyl chains insulated the cathode from direct contact with the organic electrolyte and led to increased tolerance to HF.