Hybrid Surgery for symptomatic chronic internal carotid artery occlusion: a single-center experience.

BACKGROUND: Patients with symptomatic chronic internal carotid artery occlusion (ICAO) face a high risk of recurrent stroke despite receiving aggressive medical therapy. This study aimed to evaluate the effectiveness and safety of hybrid surgery in treating symptomatic chronic ICAO. METHODS: This retrospective case series was conducted at a single center. From January 2019 to December 2022, patients with symptomatic chronic ICAO who underwent hybrid surgery were included. We collected baseline data, lesion characteristics, revascularization rates, perioperative complications, and follow-up outcomes. RESULTS: The study enrolled 27 patients, comprising 22 males and 5 females, with symptomatic chronic ICAO. The hybrid surgery achieved a technical success rate of 100% for revascularization (n = 27), with a perioperative complication rate of 14.8% (n = 4). Following a median follow-up of 6.0 months (IQR, 4-10), 21 patients underwent a DSA or CT angiography reexamination, confirming a vascular patency rate of 90.5% (n = 19). One patient required surgery for severe in-stent restenosis, and another experienced asymptomatic occlusion. Clinical follow-ups were conducted for all 26 patients; no new strokes were reported in the qualifying artery territory, with 13 patients scoring 0, 12 scoring 1, and 1 scoring 2 on the mRS. CONCLUSION: Although hybrid surgery represent a promising option for treating chronic ICAO, they are also associated with a relatively high incidence of treatment-related complications. The application of composite surgery should be based on standardized technical guidelines and the careful selection of patients who are genuinely at high risk for recurrent strokes.

Remote work: Aircraft noise implications, prediction, and management in the built environment.

The COVID-19 pandemic has greatly changed workplace management. Most workplaces have adopted the work-from-home policy to minimize the risk of community spread. Consequently, housing estates remain largely occupied during office hours. Since some housing estates are situated in the vicinity of an airport, noise pollution resulted from the takeoff and landing of aircraft is now more noticed by residents, causing annoyance. This problem would be most acute for those located directly under the flight path. Before the pandemic, such aircraft operations had lower effect on the residents because most of them were not at home but at workplaces. Evidently, it is timely that more emphasis should now be placed during urban planning to predict and minimize aircraft noise in the built environment. This article first defines the aircraft noise metrics commonly used to assess environmental impact. Preceded by an overview of how aircraft noise affects the built environment, this article reviews how various aircraft noise prediction models have been used in urban planning. Lastly, this article reviews how aircraft noise can be managed for better acoustic comfort of the residents. Anticipating the adoption of hybrid work arrangement moving forward, this article aims to provide urban planning professionals with an avenue to understand how aircraft noise can negatively affect the built environment, which, in turn, justify why prediction and management of aircraft noise should be emphasized from the outset of urban planning.

The Feasibility of Remotely Piloted Aircrafts for VOR Flight Inspection.

This article analyzes the use of Remotely Piloted Aircrafts (RPA) in VOR (Very High Frequency Omnidirectional Range) flight inspection. Initially, tests were performed to check whether the Autopilot Positioning System (APS) met the regulatory requirements. The results of these tests indicated that the APS provided information within the standard regulations. A Hardware in the Loop (HIL) platform was implemented to perform flight tests following the waypoints generated by a mission automation routine. One test was performed without introducing disturbance into the proposed test platform. The other four tests were performed introducing errors in latitude and longitude in the APS into the platform. The errors introduced had the same characteristics as those measured in the initial tests, in order for the simulation tests to be as similar as possible to the real situation. The tests performed with positioning errors only did not lead to false misalignment detection. However, introducing positioning errors and a 4° VOR misalignment error, a misalignment of 3.99° was observed during the flight test. This is a value greater than the maximum one allowed by the regulations, and the system indicates the VOR misalignment. Five flight inspection tests were performed. In addition to the APS errors, tests with a modulation error were also conducted. Introducing a 4° VOR misalignment in conjunction with modulation error, a misalignment of 4.02° was observed, resulting in successful misalignment detection.

Direct carbon dioxide emissions from civil aircraft.

Global airlines consume over 5 million barrels of oil per day, and the resulting carbon dioxide (CO2) emitted by aircraft engines is of concern. This article provides a contemporary review of the literature associated with the measures available to the civil aviation industry for mitigating CO2 emissions from aircraft. The measures are addressed under two categories - policy and legal-related measures, and technological and operational measures. Results of the review are used to develop several insights into the challenges faced. The analysis shows that forecasts for strong growth in air-traffic will result in civil aviation becoming an increasingly significant contributor to anthropogenic CO2 emissions. Some mitigation-measures can be left to market-forces as the key-driver for implementation because they directly reduce airlines' fuel consumption, and their impact on reducing fuel-costs will be welcomed by the industry. Other mitigation-measures cannot be left to market-forces. Speed of implementation and stringency of these measures will not be satisfactorily resolved unattended, and the current global regulatory-framework does not provide the necessary strength of stewardship. A global regulator with 'teeth' needs to be established, but investing such a body with the appropriate level of authority requires securing an international agreement which history would suggest is going to be very difficult. If all mitigation-measures are successfully implemented, it is still likely that traffic growth-rates will continue to out-pace emissions reduction-rates. Therefore, to achieve an overall reduction in CO2 emissions, behaviour change will be necessary to reduce demand for air-travel. However, reducing demand will be strongly resisted by all stakeholders in the industry; and the ticket price-increases necessary to induce the required reduction in traffic growth-rates place a monetary-value on CO2 emissions of approximately 7-100 times greater than other common valuations. It is clear that, whilst aviation must remain one piece of the transport-jigsaw, environmentally a global regulator with 'teeth' is urgently required.

Organizational factors affecting the effectiveness of the educational process of training air traffic controllers.

The organizational aspects of the educational process of training air traffic controllers are analyzed. A critical assessment is given to the results of cooperation between education and aviation air traffic services. The data of a survey of students are presented, revealing the positive and negative aspects of the cooperation of the education system with civil aviation structures, in particular, the impact of the teacher's work experience on the quality of the educational process, as well as the rooted approach to the development of curricula. The dynamics of growth and decrease in the level of assimilation of educational material by students is shown, depending on the methodology of the teacher's current monitoring of progress.

Aeropolitics in a post-COVID-19 world.

We review selected aeropolitical issues that may impact the international aviation sector post-COVID-19. Consideration regarding ICAO's role in coordinating safety provisions using existing frameworks will be important. Issues relating to national airline bailouts and recapitalisation as well as international ownership are also explored. We offer several further, as yet unanswerable, questions about future aeropolitical issues, including how ICAO will continue to address the crisis, implications for air services capacity restrictions, the impact of deglobalisation and the question of state aid for national carriers and other parts of the aviation system.

Rationale for graft selection in patients with complex internal carotid artery aneurysms treated with extracranial to intracranial high-flow bypass and therapeutic internal carotid artery occlusion.

OBJECTIVE After internal carotid artery (ICA) sacrifice without revascularization for complex aneurysms, ischemic complications can occur. In addition, hemodynamic alterations in the circle of Willis create conditions conducive to the formation of de novo aneurysms or the enlargement of existing untreated aneurysms. Therefore, the revascularization technique remains indispensable. Because vessel sizes and the development of collateral circulation are different in each patient, the ideal graft size to prevent low flow-related ischemic complications (LRICs) in external carotid artery (ECA)-middle cerebral artery (MCA) bypass with therapeutic ICA occlusion (ICAO) has not been well established. Authors of this study hypothesized that the adequate graft size could be calculated from the size of the sacrificed ICA and the values of MCA pressure (MCAP) and undertook an investigation in patients with complex ICA aneurysms treated with ECA-graft-MCA bypass and therapeutic ICAO. METHODS In the period between July 2006 and January 2016, 80 patients with complex ICA aneurysms were treated with ECA-MCA bypass and therapeutic ICAO. Preoperative balloon test occlusion (BTO) was performed, and the BTO pressure ratio was defined as the mean stump pressure/mean preocclusion pressure. Low flow-related ischemic complications were defined as new postoperative neurological deficits and ipsilateral cerebral blood flow reduction. Initial MCAP (iMCAP), MCAP after clamping the ICA (cMCAP), and MCAP after releasing the graft (gMCAP) were intraoperatively monitored. The MCAP ratio was defined as gMCAP/iMCAP. Based on the Hagen-Poiseuille law, the expected MCAP ratio ([expected gMCAP]/iMCAP) was hypothesized as follows: (1 - cMCAP/iMCAP)(graft radius/ICA radius)2 + (cMCAP/iMCAP). Correlations between the BTO pressure ratio and cMCAP/iMCAP, and between the actual and expected MCAP ratios, were evaluated. Risk factors for LRICs were also evaluated. RESULTS The mean BTO pressure ratio was significantly correlated with the mean cMCAP/iMCAP (r = 0.68, p < 0.0001). The actual MCAP ratio correlated with the expected MCAP ratio (r = 0.43, p < 0.0001). If the expected MCAP ratio was set up using the BTO pressure ratio instead of cMCAP/iMCAP (BTO-expected MCAP ratio), the mean BTO-expected MCAP ratio significantly correlated with the expected MCAP ratio (r = 0.95, p < 0.0001). During a median follow-up period of 26.1 months, LRICs were observed in 9 patients (11%). An actual MCAP ratio < 0.80 (p = 0.003), expected MCAP ratio < 0.80 (p = 0.001), and (M2 radius/graft radius)2 < 0.49 (p = 0.002) were related to LRICs according to the Cox proportional-hazards model. CONCLUSIONS Data in the present study indicated that it was important to use an adequate graft to achieve a sufficient MCAP ratio in order to avoid LRICs and that the adequate graft size could be evaluated based on a formula in patients with complex ICA aneurysms treated with ICAO.

Sameerpannag Ras Mixture (SRM) improved neurobehavioral deficits following acute ischemic stroke by attenuating neuroinflammatory response.

ETHNOPHARMACOLOGICAL RELEVANCE: Cerebral ischemic stroke is one of the leading causes of death and long-term disability worldwide. Unfortunately, due to the failure of most of drugs in clinical trials recently, attentions have moved towards the traditional system of medicines including Ayurveda. In Ayurveda, Sameerpannag Ras (SR) is a mineral and metallic origin based formulation which has been used for the treatment of arthritis and chronic systematic inflammatory disorder. The current study was designed to investigate the neuroprotective effects of Sameerpannag Ras Mixture (SRM), on the neurobehavioral dysfunction and associated neuroinflammation, induced by transient Internal Carotid Artery Occlusion (ICAO) in mice model. MATERIALS AND METHODS: In the present study, mice were treated with Sameerpannag Ras Mixture (SRM) at the dose of 40mg/kg body weight by oral gavages for 3 and 7days respectively, twice a day, after the induction of ICAO for 90min followed by reperfusion. The efficacy of SRM was examined by scoring neurological behavioral deficit using the standard neurological deficit score (NDS), grip strength and rotarod performance tests at different time intervals of post-ICAO. RESULTS: Post-ischemic treatment with Sameerpannag Ras Mixture (SRM) at 40mg/kg significantly reduced Neurological Deficit Score and improved the motor coordination at different time intervals post-ICAO. The analysis of RT-qPCR data showed that transient cerebral ischemia could induce the inflammatory response genes in the affected striatal region of ICAO group, as compared to sham group, on day3 and day7 post-ICAO. Interestingly, SRM treatment showed marked improvement in the ischemia-induced neurobehavioral deficits by attenuating ischemia-induced neuroinflammatory response at both gene and protein level. CONCLUSION: The present study suggests that Sameerpannag Ras Mixture (SRM) treatment ameliorates behavioral outcomes after mild ischemia through the suppression of a number of inflammatory response genes involved in neuronal damage. This is the first report of the molecular mechanism underlying the significant neuroprotective action of the Ayurvedic drug, Sameerpannag Ras Mixture (SRM), using a mild stroke in mice model.