ABSTRACT
OBJECTIVE: The highly intricate nature of the cervical spinal cord can cause arteriovenous shunts in these segments that may be associated with heightened clinical risks and treatment complexities. In this article, the authors aimed to provide a comprehensive analysis of the detailed natural course, treatment, and clinical outcomes of cervical spinal cord arteriovenous shunts (SCAVSs) based on the largest cohort to date. METHODS: Two hundred forty consecutive patients were included. Data on clinical presentation, angioarchitecture, treatment, and follow-up were retrospectively reviewed. RESULTS: The cohort demonstrated a greater prevalence of acute onset (63.3% vs 36.7%). Spontaneous recovery was observed in 63.7% of patients after onset, with a significantly elevated recovery rate observed among patients experiencing acute onset (72.4% vs 48.9%, p < 0.001). The risks of acute and gradual clinical deterioration after onset was 11.9%/year and 13.4%/year, respectively. Microsurgery was performed in 39.6% of patients, while the remaining 60.4% exclusively underwent embolization. The complete obliteration rate was 65.3% after microsurgery and 21.4% after embolization. The rate of treatment-related deterioration was 14.7% after microsurgery and 6.2% after embolization. After partial treatment, the acute and gradual deterioration rates were 4.1%/year and 6.6%/year, respectively. Lack of spontaneous recovery after onset was an independent predictor of embolization-related deterioration (OR 17.905, p = 0.007) and long-term gradual deterioration after partial treatment (HR 2.325, p = 0.021). After a median follow-up period of 32.55 months, prognosis was unfavorable in 16.7% of patients, with the sole independent risk factor being the absence of spontaneous recovery after onset (OR 2.476, p = 0.018). CONCLUSIONS: The outcomes of patients with cervical SCAVS were generally favorable, even in patients with only partial obliteration of the lesions. However, patients who did not show a trend toward spontaneous recovery after onset had a significantly elevated risk of unfavorable prognosis, highlighting the need for prompt clinical intervention.
ABSTRACT
Incorporating ultralow loading of nanoparticles into polymers has realized increases in dielectric constant and breakdown strength for excellent energy storage. However, there are still a series of tough issues to be dealt with, such as organic solvent uses, which face enormous challenges in scalable preparation. Here, a new strategy of dual in situ synthesis is proposed, namely polymerization of polyethylene terephthalate (PET) synchronizes with growth of calcium borate nanoparticles, making polyester nanocomposites from monomers directly. Importantly, this route is free of organic solvents and surface modification of nanoparticles, which is readily accessible to scalable synthesis of polyester nanocomposites. Meanwhile, uniform dispersion of as ultralow as 0.1 wt% nanoparticles and intense bonding at interfaces have been observed. Furthermore, the PET-based nanocomposite displays obvious increases in both dielectric constant and breakdown strength as compared to the neat PET. Its maximum discharged energy density reaches 15 J cm-3 at 690 MV m-1 and power density attains 218 MW cm-3 under 150 Ω resistance at 300 MV m-1, which is far superior to the current dielectric polymers that can be produced at large scales. This work presents a scalable, safe, low-cost, and environment-friendly route toward polymer nanocomposites with superior capacitive performance.
ABSTRACT
OBJECTIVE: Isolated spinal aneurysms (ISAs) are rare causes of subarachnoid hemorrhage (SAH), which encompass a highly heterogeneous group of clinical entities with multifarious pathogeneses, clinical characteristics, and treatment strategies. Therefore, knowledge about the ISAs remains inadequate. In this study, the authors present a comprehensive analysis of clinical data associated with ISAs at their institutions to enhance the understanding of this disease. METHODS: Patients with ISAs confirmed by spinal angiography or surgery at the authors' institutions between 2015 and 2022 were included. Data regarding clinical presentation, lesion location, aneurysm morphology, comorbidities, treatment results, and clinical outcomes were reviewed. RESULTS: Seven patients with ISAs were included in the study. Among them, 4 patients (57.1%) experienced severe headache, and 3 patients (42.9%) reported sudden-onset back pain. Additionally, lower-extremity weakness and urinary retention were observed in 2 of these patients (28.6%). Four of the aneurysms exhibited fusiform morphology, whereas the remaining were saccular. All saccular aneurysms in this series were attributed to hemodynamic factors. Conservative treatment was administered to 3 patients, 2 of whom underwent follow-up digital subtraction angiography, which showed spontaneous occlusion of both aneurysms. Four patients ultimately underwent invasive treatments, including 2 who underwent microsurgery and 2 who received endovascular embolization. One patient died of recurrent SAH, while the remaining 6 patients had a favorable prognosis at the latest follow-up assessment. CONCLUSIONS: The morphology of aneurysms may be associated with their etiology. Saccular ISAs are usually caused by pressure due to abnormally increased blood flow, whereas fusiform lesions may be more likely to be secondary to vessel wall damage. The authors found that a saccular spinal aneurysm in young patients with a significant dilated parent artery may be a vestige of spinal cord arteriovenous shunts. ISAs can be managed by surgical, endovascular, or conservative procedures, and the clinical outcome is generally favorable. However, the heterogeneous nature of the disease necessitates personalized treatment decision-making based on specific clinical features of each patient.