Explore the vast range of titles available.

Abstract BACKGROUND Thin-walled regions (TWRs) of aneurysm surfaces observed in microscopic surgery are thought to be vulnerable areas for growth and rupture of unruptured intracranial aneurysms (UIAs). OBJECTIVE To identify hemodynamic features of TWRs of aneurysms by using computational fluid dynamics (CFD) analyses of unruptured middle cerebral artery bifurcation (MCAB) aneurysms. METHODS Nine patients with 11 MCAB aneurysms were enrolled, and their TWRs were identified. CFD analysis was performed using 3 parameters: pressure, wall shear stress (WSS), and WSS divergence (WSSD). Each parameter was evaluated for its correspondence with TWR. RESULTS Among 11 aneurysms, 15 TWRs were identified. Corresponding matches with CFD parameters (pressure, WSS, and WSSD) were 73.33, 46.67, and 86.67%, respectively. CONCLUSION WSSD, a hemodynamic parameter that accounts for both magnitude and directionality of WSS, showed the highest correspondence. High WSSD might correspond with TWR of intracranial aneurysms, which are likely high-risk areas for rupture.

BackgroundAlthough cranioplasty (CP) is a frequently performed and simple procedure, complications are common, particularly bone flap resorption and infection. The timing of surgery is as an important contributory factor, but the optimal timing has not been clearly determined.ObjectiveWe retrospectively investigated bone flap resorption and surgical site infection after CP to determine the optimal timing of surgery for reduction of complications.MethodsThe study enrolled 126 patients who underwent decompressive craniectomy (DC) and subsequent CP. Patients with bone flap resorption or surgical site infection were analyzed as the “complication” group. Receiver operating characteristic curve analysis was performed and the Youden index was used to dichotomize “early CP” and “late CP” groups. Univariate and multivariate survival analyses were performed.ResultsThe complication group included 42 patients. The Youden index was used to identify a cutoff value for the DC-CP interval of > 44 days, and this was used to define early (< 45 days) and late (≥ 45 days) CP. Late CP was a significant risk factor in univariate and multivariate Cox regression analyses.ConclusionThis study showed that early CP before 45 days after DC is associated with a lower rate of bone flap resorption and surgical site infection than late CP.

PurposeThe Woven EndoBridge (WEB) device is an intrasaccular flow disruptor designed for the treatment of wide-neck intracranial bifurcation aneurysms. The purpose of this study was to evaluate various factors associated with clinical and angiographic outcomes following WEB treatment.MethodsThis multicenter, retrospective study analyzed 405 patients with 412 aneurysms treated with the WEB device across 22 neurovascular centers. Clinical and radiologic data were reviewed to identify factors influencing patients’ clinical outcome and target aneurysmal occlusion at short-term (within 6 months) and long-term (beyond 1 year) follow-up. Occlusion status of target aneurysms was analyzed in relation to the various clinical and morphological factors. Outcomes were also compared based on institutional treatment volume.ResultsCenters with higher WEB treatment volumes (more than 30 cases) demonstrated lower thromboembolic events with sequelae (0.8% vs. 5.9%, p = 0.003). The rate of aneurysmal adequate occlusion, defined by Raymond-Roy occlusion class 1 and 2, increased from 70.2% at short-term (mean, 133 ± 42 days) to 83.2% at long-term (mean, 499 ± 134 days) follow-up (p = 0.003). Aneurysm diameter was inversely correlated with complete occlusion, with a 6-mm cutoff identified. Wide-neck aneurysms exhibited lower occlusion rates at short-term period, but this effect was not observed at later periods. Aneurysms at the basilar apex and internal carotid artery terminus demonstrated higher rates of complete occlusion (p = 0.046). Smoking acted as an inhibitor of long-term occlusion of target aneurysms.ConclusionInstitutional experience appeared to play a role in reducing procedure-related thromboembolic complications. Aneurysmal diameter, neck width, location and patients’ smoking status influenced angiographic outcomes.

raumatic brain injury (TBI) is a significant global health concern, particularly affecting young individuals, and is a leading cause of mortality and morbidity worldwide. Despite improvements in treatment infrastructure, many TBI patients choose discharge against medical advice (DAMA), often declining necessary surgical interventions. We aimed to investigate the factors that can be associated with DAMA in TBI patients that were recommended to have surgical treatment. This study was conducted at single tertiary university center (2008–2018), by retrospectively reviewing 1510 TBI patients whom visited the emergency room. We analyzed 219 TBI surgical candidates, including 50 declining surgery (refused group) and the others whom agreed and underwent decompressive surgery. Retrospective analysis covered demographic characteristics, medical history, insurance types, laboratory results, CT scan findings, and GCS scores. Statistical analyses identified factors influencing DAMA. Among surgical candidates, 169 underwent surgery, while 50 declined. Age (60.8 ± 17.5 vs. 70.5 ± 13.8 years; p  < 0.001), use of anticoagulating medication ( p  = 0.015), and initial GCS scores (9.0 ± 4.3 vs. 5.3 ± 3.2; p  < 0.001) appeared to be associated with refusal of decompressive surgery. Based on our analysis, factors influencing DAMA for decompressive surgery included age, anticoagulant use, and initial GCS scores. Contrary to general expectations and some previous studies, our analysis revealed that the patients’ medical conditions had a larger impact than socioeconomic status under the Korean insurance system, which fully covers treatment for TBI. This finding provides new insights into the factors affecting DAMA and could be valuable for future administrative plans involving national insurance.

Purpose Spontaneous vertebrobasilar dissecting aneurysm (VBD) is a very challenging disease with an unpredictable clinical course and controversies on treatment strategy. The present study reports radiological and clinical outcomes of stent-alone treatment (SAT) for VBD. Methods Twenty-four VBDs treated with SAT are included in the present study. Clinical and angiographic data were reviewed retrospectively. Results A total of 24 lesions in 22 patients with a mean follow-up period of 16.21 months were included. Of the 24 individual lesions, 23 were intracranial vertebral artery lesions and 1 lesion was located in the basilar artery. There were six cases of ruptured dissections with the other cases having various symptoms. The immediate post-SAT angiographic outcomes included 5 lesions with good remodeling over 90% recovery and 19 poorly remodeled lesions. The latest angiographic outcomes included 17 cases of good remodeling (remodeling rate over 90%), 6 cases of poor remodeling (remodeling rate below 70%), and 1 case with morphological aggravation. The overlapping stent technique was used in seven cases and it was significantly associated with good angiographic results. None of the rupture cases underwent re-rupture post SAT. There was one case of a symptomatic complication of a femoral arteriovenous fistula. Conclusions The SAT could be a feasible alternative for the treatment of VBD. The overlapping technique was significantly associated with good angiographic outcome. We expect that technological development of the intracranial stent will allow better procedural outcomes of SAT.

Abstract BACKGROUND Many physicians consider aneurysmal wall enhancement (AWE) on high resolution-vessel wall imaging (HR-VWI) as an imaging biomarker of unstable unruptured intracranial aneurysms (UIAs). OBJECTIVE To evaluate the clinical value of different AWE signal intensities (SIs) by assessing the correlation between the AWE SIs and surgical findings and rupture risk assessment tools. METHODS Twenty-six patients with 34 aneurysms who underwent surgical clipping were included. The corrected AWE SI was calculated by comparing T1-weighted images with post-gadolinium enhanced T1-weighted images. The correlation of AWE with the population, hypertension, age, size of aneurysm, earlier subarachnoid hemorrhage from another aneurysm, site of aneurysm (PHASES) and earlier subarachnoid hemorrhage, location of the aneurysm, age >60 years, population, size of the aneurysm, shape of the aneurysm (ELAPSS) scores was evaluated using correlation and linear regression analysis. To quantify the surgical findings, the average color value of the aneurysms expressed in the CIELCh system was measured. Δh, color difference from yellow, was used for statistical analysis. RESULTS The mean age of the patients and aneurysm size were 64.08 yr and 6.95 mm, respectively. The mean AWE SI, PHASES and ELAPSS scores, and Δh were 22.30, 8.41, 20.32, and 41.36, respectively. The coefficients of correlation of AWE SI with the PHASES and ELAPSS scores and Δh were 0.526, 0.563, and –0.431. We found that the AWE SI affected the PHASES (β = 0.430) and ELAPSS scores (β = 0.514) and Δh (β = –0.427) in simple linear regression analysis. CONCLUSION The AWE on HR-VWI was correlated with the PHASES and ELAPSS scores and the color. The stronger the AWE, the higher were the PHASES and ELAPSS scores and the more abnormal was the color. The AWE might indicate the degree of inflammation.

Intracranial endovascular procedures are less invasive and relatively safe; however, these procedures do carry a risk of complications, such as thromboembolization, arterial injury, and vessel occlusion. We present a case of carotid-cavernous fistula development secondary to injury of the cavernous segment of the internal carotid artery (ICA) during stent angioplasty and its treatment by transarterial coil embolization. Probable causes of this complication and its treatment method are discussed. To the best of our knowledge, this is the first report of such a case.

The purpose of this study was to systematically review studies in the literature to assess the superiority between microsurgery and radiosurgery regarding the efficacy in improving petroclival meningioma (PCM)-related trigeminal neuralgia (TN). PubMed, Embase, Web of Science, and Cochrane clinical trial databases were systematically searched from the inception until December 08, 2022. The overall proportion of patients with improved TN after treatment in all six included studies was 56% (95% confidence interval [CI], 35–76.9%). Higgins I 2 statistics showed significant heterogeneity ( I 2  = 90%). Subgroup analysis showed that the proportion of improved TN was higher in the microsurgery group than that in the radiosurgery group (89%; 95% CI, 81–96.5% vs. 37%, 95% CI, 22–52.7%, respectively, p  < 0.01). Subgroup analysis (for studies that documented the number of posttreatment Barrow Neurological Institute scores 1 and 2) revealed that the proportion of pain-free without medication after treatment was higher in the microsurgery group than that in the radiosurgery group (90.7%; 95% CI, 81–99.7% vs. 34.5%, 95% CI, 21.3–47.7.7%, respectively, p  < 0.01). Based on the results of this meta-analysis, we concluded that microsurgery is superior to radiosurgery in controlling PCM-related TN.

Silicon platelet corrugated feedhorn arrays for cosmic microwave background (CMB) measurements at millimeter wavelengths (130 GHz to 170 GHz) have been developed for deployment for the polarization-sensitive upgrade to both the Atacama Cosmology Telescope (ACTpol) and the South Pole Telescope (SPTpol). We present fabrication developments and the first results of a prototype monolithic feedhorn array consisting of 84 horns. Measurements at room temperature show good beam quality across the needed bandwidth, return loss of <−20 dB, an insertion loss of <−0.4 dB, and cross polarization of <−23 dB. The 32 platelets were aligned to a 1 σ variation of 8 μm.

A piezoelectric-based hydraulic actuator is a type of piston-cylinder device which is operated by internal flow energy. Recently, an artificial muscle and a micro actuator have been developed using a new smart material and internal flow control. Thus, the actuating velocity of the fabricated integrated hybrid system was investigated using the pumping frequency and load weight. The actuating velocity was then calculated using a developed program, and the numerical result was compared with the experimental result to validate the numerical program. Also, the internal flow rate was measured to analyze the pump efficiency experimentally. The flow rate inside the integrated hybrid actuator calculated using a CFD program for various pumping frequencies was then compared with the experimental results. The maximum outlet velocity was obtained at the pumping frequency of 35 Hz and the velocity decreased from that point due to flow loss.