Learning Curve Effect of Combined Technique Thrombectomy as First-Line Attempt for Acute Ischemic Stroke: A Single-Center Retrospective Study.

OBJECTIVES: We retrospectively examined the initial experience and learning curve after the introduction of thrombectomy with the combined technique using an aspiration catheter and a stent retriever as first-line attempt for acute ischemic stroke. METHODS: Consecutive patients undergoing thrombectomy for acute ischemic stroke at our institution between January 2020 and December 2022 were divided into 3 groups according to the year of thrombectomy. Patient characteristics and procedural, safety, and clinical outcomes were compared between the three year periods to determine predictors of favorable clinical outcome. RESULTS: In 2020, 2021, and 2022, the numbers of patients were 74, 70, and 90, respectively, with similar patient characteristics across the three years; successful recanalization rates were 79.7%, 97.1%, and 93.3%, respectively (P < 0.01 for the first 2 years); median procedure times were 67, 43, and 32 minutes, respectively (P < 0.01 for the first 2 years and P = 0.018 for the last 2 years); first pass effect rates were 20.3%, 41.4%, and 44.4%, respectively (P < 0.01 for the first 2 years); symptomatic intracranial hemorrhage rates were 14.9%, 2.9%, and 1.1%, respectively (P = 0.018 for the first 2 years); and percentages of modified Rankin Scale score 0-2 at 90 days were 24.3%, 42.9%, and 41.1%, respectively (P = 0.022 for the first 2 years). Procedure time (P = 0.038) and successful recanalization (P = 0.041) were independent predictors of favorable clinical outcome. CONCLUSIONS: The learning curve effect of the combined technique may be associated with better clinical outcome due to increased successful recanalization rates, shortened procedure time, and reduced symptomatic intracranial hemorrhage.

Aortogenic calcified cerebral embolism diagnosed with an embolus retrieved by thrombectomy: illustrative case.

BACKGROUND: Calcified cerebral embolism has been reported as a cause of acute cerebral infarction, but an aortogenic origin has rarely been identified as the embolic source. The authors describe a case of aortogenic calcified cerebral embolism in a patient with other embolic sources. OBSERVATIONS: In a patient with cerebral infarction and atrial fibrillation, a white hard embolus was retrieved by mechanical thrombectomy. Pathological analysis of the embolus revealed that it was mostly calcified, with some foam cells and giant cells. The macroscopic and pathological findings allowed the authors to finally diagnose an aortogenic calcified cerebral embolism. LESSONS: Even in patients with cardiogenic embolic sources, it is possible to identify a complex aortic atheroma with calcification as the embolic source, based on the macroscopic and pathological findings of the embolus retrieved by mechanical thrombectomy.

Basilar artery occlusion due to vertebral artery injury treated with thrombectomy and distal vertebral artery embolization through the unaffected side.

Background: There is no established opinion regarding embolization of asymptomatic traumatic vertebral artery injuries that do not require cervical spine repair and fixation. Case Description: A 78-year-old man fell backward from a height of about 1 m and was rushed to his previous hospital. He had a fracture of the left transverse process of the 6th cervical vertebra. Six hours after the trauma, he became unconscious; magnetic resonance angiography showed occlusion of the left vertebral and basilar arteries, and he was transferred to our hospital. The basilar artery was completely recanalized 430 min after the onset of unconsciousness. Due to the presence of thrombi in the distal vertebral artery at the level of the 6th cervical vertebra and collateral blood flow from the deep cervical artery, the distal vertebral artery was occluded to prevent embolism. Postoperative diffusion-weighted imaging showed extensive infarction in the posterior circulation, and the patient died two days after surgery. Conclusion: In the case of vertebral artery injury, preparation for early occlusion of the basilar artery is necessary. If a thrombus and collateral blood flow are present distal to the vertebral artery injury, distal vertebral artery embolization may be necessary to prevent embolism.

De novo expansion formation in the outer curvature of the internal carotid artery after flow diverter deployment for an infectious cavernous carotid aneurysm: illustrative case.

BACKGROUND: Infectious aneurysms very rarely occur in the cavernous carotid artery. Recently, treatment by flow diverter implantation with preservation of the parent artery has been the treatment of choice. OBSERVATIONS: A 64-year-old woman presented with stenosis at the C5 segment of the left internal carotid artery (ICA), followed by ocular symptoms within 2 weeks, with a de novo aneurysm in the left cavernous carotid artery and wall irregularity with stenosis from the C2 to C5 segments of the left ICA. Antimicrobial therapy was given for 6 weeks, and a Pipeline Flex Shield was implanted. Angiography 6 months after treatment showed complete obliteration of the infectious aneurysm and improvement of the stenosis. However, de novo expansions were formed in the outer curvature of C3 and C4 segments of the ICA where the Pipeline device had been deployed. LESSONS: Aneurysms that develop rapidly and show shape changes over time, accompanied by fever and inflammation, may be associated with an infection. Because of the fragility in the irregular wall of the parent vessel associated with infectious aneurysms, de novo expansion may form in the outer curvature of the parent vessel after flow diverter placement; thus, careful follow-up is necessary.

Aneurysm Perforation Due to Advancement of the Coil Delivery Wire During Stent-Assisted Embolization.

We report a case of intraprocedural aneurysm rupture during coil embolization caused by a coil delivery wire. A 68-year-old woman underwent stent-assisted coil embolization for an unruptured aneurysm in the internal carotid artery (ICA). A low profile visible intraluminal support device was deployed at the aneurysm neck. Coil embolization was performed with a jailing technique. After deflection of the jailed microcatheter was released, a coil was placed in the aneurysm against resistance to coil insertion. The movement of the microcatheter tip was restricted with the stent. A coil delivery wire that was advanced after coil detachment perforated the aneurysm. Hemostasis was achieved, and coil embolization was finished with a slight neck remnant. Complete occlusion of the aneurysm was confirmed on angiography six months later. Advancement of a coil alignment marker after coil detachment may cause aneurysm perforation due to coil delivery wire advancement. In stent-assisted coil embolization, when the movement of the microcatheter tip in the aneurysm is restricted by the stent and there is resistance to coil insertion, the risk of perforation due to the coil delivery wire after coil detachment should be noted.

Gradual dilatation of an occluded transverse sinus associated with dural arteriovenous fistula after balloon angioplasty with sinus packing: A case report.

BACKGROUND: There is no consensus as to whether balloon angioplasty alone or stent placement is effective for sinus occlusion associated with dural arteriovenous fistula (DAVF). Herein, we first report a case of transverse sinus occlusion associated with DAVF in which gradual sinus dilatation was observed after balloon angioplasty with embolization of the affected sinus with shunt flow. CASE PRESENTATION: A 69-year-old man presented with executive dysfunction. Magnetic resonance imaging revealed left transverse sinus-sigmoid sinus DAVF with occlusion of the left jugular vein and right transverse sinus. Before endovascular treatment, the patient had symptomatic epilepsy and subarachnoid hemorrhage. Retrograde leptomeningeal venous drainage disappeared with packing of the left transverse sinus-sigmoid sinus. Subsequently, balloon angioplasty of the right occluded transverse sinus was performed to maintain the normal venous drainage and remaining shunt outflow. Dilatation of the right transverse sinus was poor immediately after surgery. However, angiography after 10 days and 6 months revealed gradual dilatation of the right transverse sinus. CONCLUSION: Sinus occlusion, which is thought to be caused by sinus hypertension associated with DAVF rather than chronic organized thrombosis or thrombophilia, may dilate over time after balloon angioplasty and shunt flow reduction if occluded sinus is necessary for facilitating normal venous drainage.

Four-dimensional map of the human early visual system.

OBJECTIVE: We generated a large-scale, four-dimensional map of neuronal modulations elicited by full-field flash stimulation. METHODS: We analyzed electrocorticography (ECoG) recordings from 63 patients with focal epilepsy, and delineated the spatial-temporal dynamics of visually-elicited high-gamma70-110 Hz amplitudes on a standard brain template. We then clarified the neuronal events underlying visual evoked potential (VEP) components, by correlating with high-gamma amplitude measures. RESULTS: The medial-occipital cortex initially revealed rapid neural activation followed by prolonged suppression, reflected by augmentation of high-gamma activity lasting up to 100 ms followed by attenuation lasting up to 1000 ms, respectively. With a number of covariate factors incorporated into a prediction model, the eccentricity representation independently predicted the magnitude of post-activation suppression, which was more intense in regions representing more parafoveal visual fields compared to those of more peripheral fields. The initial negative component on VEP was sharply contoured and co-occurred with early high-gamma augmentation, whose offset then co-occurred with a large positive VEP peak. A delayed negative VEP peak was blunt and co-occurred with prolonged high-gamma attenuation. CONCLUSIONS: Eccentricity-dependent gradient in neural suppression in the medial-occipital region may explain the functional difference between peripheral and parafoveal/central vision. Early negative and positive VEP components may reflect neural activation, whereas a delayed negative VEP peak reflecting neural suppression. SIGNIFICANCE: Our observation provides the mechanistic rationale for transient scotoma or mild flash-blindness, characterized by physiological afterimage preferentially formed in central vision following intense but non-injurious light exposure.