ABSTRACT
BACKGROUND AND OBJECTIVES: Postclipping cerebral infarction (PCI) remains a major concern after treatment for unruptured intracranial aneurysms (UIAs). However, studies of microsurgical clipping based on diffusion-weighted imaging are limited. We aimed to present the incidence, risk factors, and types of PCI and its radiological and clinical characteristics. METHODS: This was a retrospective single-center study in which patients were scheduled to undergo microsurgical clipping for anterior circulation UIAs. The overall incidence and risk factors were calculated. Based on the operation and relevant artery, we categorized PCI on diffusion-weighted imaging into 4 types and presented their radiological and clinical characteristics. RESULTS: We reviewed the radiological and clinical data of 605 patients. The overall incidence of PCI was 16.7% (101/605), of which asymptomatic infarction was 14.9% (90/605) and symptomatic infarction was 1.8% (11/605). Hypertension (adjusted odds ratio [aOR], 2.258; 95% confidence interval [CI]: 1.330-3.833), temporary clipping (aOR, 1.690; 95% CI: 1.034-2.760), multiple aneurysm locations (aOR, 1.832; 95% CI: 1.084-3.095), and aneurysm dome size (aOR, 1.094; 95% CI: 1.006-1.190) were independent risk factors for PCI. Type II (perianeurysmal perforator) infarction was the most common type of PCI (48.6%) and the most common cause of symptomatic infarction (72.7%). Types II and III (distal embolic) infarctions correlated with atherosclerotic changes in the aneurysm wall and temporary clipping (62.4% and 70.6%, respectively). The type IV (unrelated) infarction group had a higher incidence of systemic atherosclerosis (55%). CONCLUSION: Microsurgical clipping is a safe and viable option for the treatment of anterior circulation UIAs. However, modification of the surgical technique, preoperative radiological assessment, and patient selection are required to reduce the incidence of PCI.
ABSTRACT
The Alpha stent is an intracranial closed-cell stent with a unique mesh design to enhance wall apposition. It recently underwent structural modifications to facilitate easier stent deployment. This study aimed to evaluate the safety and efficacy of stent-assisted coil embolization for unruptured intracranial aneurysms using the Alpha stent. Between January 2021 and November 2021, 35 adult patients with 35 unruptured intracranial aneurysms in the distal internal carotid artery were prospectively enrolled. For efficacy outcomes, magnetic resonance angiography at the 6-month follow-up was evaluated using the Raymond-Roy occlusion classification (RROC). The safety outcome evaluated the occurrence of symptomatic procedure-related neurological complications up to 6 months postoperatively. Technical success was achieved in 34/35 (97.1%). Six months postoperatively, aneurysm occlusion showed RROC I in 32/35 (91.4%) and RROC II in 3/35 (8.6%) patients. Procedure-related neurologic complications occurred in one patient (2.9%) who experienced hemiparesis due to acute lacunar infarction, which resulted in a 6-month mRS score of 1. The Alpha stent demonstrated excellent efficacy and safety outcomes in stent-assisted coil embolization of unruptured distal ICA aneurysms. The recent structural modifications allowed for easier stent delivery and deployment.Clinical trial registration number: KCT0005841; registration date: 28/01/2021.
Subject(s)
Embolization, Therapeutic , Intracranial Aneurysm , Adult , Humans , Intracranial Aneurysm/diagnostic imaging , Intracranial Aneurysm/surgery , Treatment Outcome , Embolization, Therapeutic/adverse effects , Embolization, Therapeutic/methods , Stents/adverse effects , Blood Vessel Prosthesis , Cerebral Angiography/methods , Retrospective StudiesABSTRACT
Computational fluid dynamics (CFD) has been utilized to calculate hemodynamic parameters in anterior communicating artery aneurysm (AComA), which is located at a junction between left and right A1 and A2 segments. However, complete or half circle of Willis (CoW) models are used indiscriminately. This study aims to suggest recommendations for determining suitable CoW model. Five patient-specific CoW models with AComA were used, and each model was divided into complete, left-half, and right-half models. After validating the CFD using a flow experiment, the hemodynamic parameters and flow patterns in five AComAs were compared. In four out of five cases, inflow from one A1 side had a dominant influence on the AComA, while both left and right A1 sides affected the AComA in the remaining case. Also, the average difference in time-averaged wall shear stress between the complete and half models for four cases was 4.6%, but it was 62% in the other case. The differences in the vascular resistances of left and right A1 and A2 segments greatly influenced the flow patterns in the AComA. These results may help to enhance clinicians' understanding of blood flow in the brain, leading to improvements in diagnosis and treatment of cerebral aneurysms.
Subject(s)
Intracranial Aneurysm , Humans , Circle of Willis , Hemodynamics/physiology , Cerebrovascular Circulation/physiology , BrainABSTRACT
Eye movement analysis is critical to studying human brain phenomena such as perception, cognition, and behavior. However, under uncontrolled real-world settings, the recorded gaze coordinates (commonly used to track eye movements) are typically noisy and make it difficult to track change in the state of each phenomenon precisely, primarily because the expected change is usually a slower transient process. This paper proposes an approach, Improved Naive Segmented linear regression (INSLR), which approximates the gaze coordinates with a piecewise linear function (PLF) referred to as a hypothesis. INSLR improves the existing NSLR approach by employing a hypotheses clustering algorithm, which redefines the final hypothesis estimation in two steps: (1) At each time-stamp, measure the likelihood of each hypothesis in the candidate list of hypotheses by using the least square fit score and its distance from the k-means of the hypotheses in the list. (2) Filter hypothesis based on a pre-defined threshold. We demonstrate the significance of the INSLR method in addressing the challenges of uncontrolled real-world settings such as gaze denoising and minimizing gaze prediction errors from cost-effective devices like webcams. Experiment results show INSLR consistently outperforms the baseline NSLR in denoising noisy signals from three eye movement datasets and minimizes the error in gaze prediction from a low precision device for 71.1% samples. Furthermore, this improvement in denoising quality is further validated by the improved accuracy of the oculomotor event classifier called NSLR-HMM and enhanced sensitivity in detecting variations in attention induced by distractor during online lecture.
Subject(s)
Eye Movements , Humans , Eye Movements/physiology , Linear Models , Algorithms , Eye-Tracking TechnologyABSTRACT
BACKGROUND: Surpass Evolve Flow Diverter (SE-FD; Stryker Neurovascular, Kalamazoo, MI, USA) was launched in 2019 as a new generation FD of Surpass Streamline. The aim of this study was to report the effectiveness and safety of SE-FD insertion for unruptured intracranial aneurysm at one-year follow-up. METHODS: Between November 2019 and October 2021, a total of 106 patients with 108 aneurysms were treated with FD in single institution. Of these, SE-FD insertion was performed in 40 patients with 41 aneurysms. At one-year follow-up, clinical and angiographic outcomes were retrospectively evaluated from electronic medical record and aneurysm database. RESULTS: There were 12 male and 28 female patients (mean age 59.1 years, 95% CI: 55.3-62.9). Fusiform aneurysm dissection was 46.3% (19/41). Mean maximum aneurysm diameter was 13.2 mm (SD 5.53), and 34.1% (14/41) of aneurysms were 15 mm or bigger. Among 41 aneurysms, complex aneurysm (recurred, thrombosed, or branch artery-incorporated) was accounted for 41.5% (17/41). All procedures were successfully conducted with 7.3% (3/41) of procedure-related complications. At one-year follow-up (N.=40), neurologic morbidity was noted in 2 cases (5.0%; both with modified Rankin Scale [mRS] 1) without any mortality. At one-year follow-up (N.=41), radiologic outcomes were adequate occlusion in 33 (80.5%) and complete occlusion in 29 (70.7%). There was no retreatment in our cohort. CONCLUSIONS: Surpass Evolve Flow Diverter seemed to be safe and effective for the treatment of dissecting/fusiform or complex aneurysms at one-year follow-up. However, further study is needed to evaluate long term results.