Clinical and Procedural Outcomes with or without Balloon Guide Catheters during Endovascular Thrombectomy in Acute Ischemic Stroke: A Systematic Review and Meta-analysis with First-line Technique Subgroup Analysis.

BACKGROUND: Balloon guide catheters are increasingly used to improve clot retrieval by temporarily stopping proximal blood flow during endovascular thrombectomy. PURPOSE: Our aim was to provide a summary of the literature comparing the procedural and clinical outcomes of endovascular thrombectomy with or without balloon guide catheters, depending on the first-line technique used. DATA SOURCES: We used PubMed/MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews. STUDY SELECTION: We chose studies that compared using balloon guide catheters with not using them. DATA ANALYSIS: Random effects meta-analysis was performed to compare the procedural outcomes measured as the first-pass effect, successful reperfusion, number of passes, procedural duration, arterial puncture to reperfusion time, distal emboli, and clinical outcomes. DATA SYNTHESIS: Overall, a meta-analysis of 16 studies (5507 patients, 50.8% treated with balloon guide catheters and 49.2% without them) shows that the use of balloon guide catheters increases the odds of achieving a first-pass effect (OR = 1.92; 95% CI, 1.34-2.76; P < .001), successful reperfusion (OR = 1.85; 95% CI, 1.42-2.40; P < .001), and good functional outcome (OR =1.48; 95% CI, 1.27-1.73; P < .001). Balloon guide catheters reduce the number of passes (mean difference = -0.35; 95% CI, -0.65 to -0.04; P = .02), procedural time (mean difference = -19.73; 95% CI, -34.63 to -4.83; P = .009), incidence of distal or new territory emboli (OR = 0.5; 95% CI, 0.26-0.98; P = .04), and mortality (OR = 0.72; 95% CI, 0.62-0.85; P < .001). Similar benefits of balloon guide catheters are observed when the first-line technique was a stent retriever or contact aspiration, but not for a combined approach. LIMITATIONS: The analysis was based on nonrandomized trials with a moderate risk of bias. CONCLUSIONS: Current literature suggests improved clinical and procedural outcomes associated with the use of balloon guide catheters during endovascular thrombectomy, especially when using the first-line stent retriever.

Impact of COVID-19 on radiology training: Royal College of Radiologists Junior Radiologists Forum national survey.

AIM: To obtain a national snapshot of radiology trainees' experience during the first wave of the pandemic. MATERIALS AND METHODS: A 25-item questionnaire was disseminated to representatives from all training regions across the UK in July 2020. Each representative collated the collective experiences of trainees in their training programme in key domains, including redeployment, shielding, training, and teaching. RESULTS: Ninety-five percent (38 of 40) of representatives completed the questionnaire. Trainees in up to 76% of training programmes were redeployed to wards and some trainees were shielding in 81% of programmes. Only 27% of programmes enabled remote reporting for isolating or shielding trainees. Sixty-two percent of respondents felt their well-being needs were supported. There was an overall increase in the attendance, volume, and quality of teaching and training nationally due to improved accessibility via remote-learning methods. Significant challenges were described with reporting, interventional procedures, and multidisciplinary team meeting attendance, although 62% of programmes noted an increase in service provision. Less in-person feedback was reported with in-person training still deemed necessary for practical skills. The Royal College of Radiologists Junior Radiologists Forum webinars were well received by all trainees with continuation of the series recommended. CONCLUSION: The COVID-19 pandemic has had a clear impact on many areas of radiology training in the UK. Early strategies have been adopted to mitigate the challenges faced by trainees and opportunities for future improvement are highlighted.

Regional Mechanical Thrombectomy Imaging Protocol in Patients Presenting with Acute Ischemic Stroke during the COVID-19 Pandemic.

BACKGROUND AND PURPOSE: Chest CT is a rapid, useful additional screening tool for coronavirus disease 2019 (COVID-19) in emergent procedures. We describe the feasibility and interim outcome of implementing a modified imaging algorithm for COVID-19 risk stratification across a regional network of primary stroke centers in the work-up of acute ischemic stroke referrals for time-critical mechanical thrombectomy. MATERIALS AND METHODS: We undertook a retrospective review of 49 patients referred to the regional neuroscience unit for consideration of mechanical thrombectomy between April 14, 2020, and May 21, 2020. During this time, all referring units followed a standard imaging protocol that included a chest CT in addition to a head CT and CT angiogram to identify Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) infective pulmonary changes. RESULTS: Overall, 2 patients had typical COVID-19 radiologic features and tested positive, while 7 patients had indeterminate imaging findings and tested negative. The others had normal or atypical changes and were not diagnosed with or suspected of having COVID-19. There was an overall sensitivity of 100%, specificity of 74.1%, negative predictive value of 100%, and positive predictive value of 22.2% when using chest CT to diagnose COVID-19 in comparison with the real-time reverse transcriptase-polymerase chain reaction test. The mean additional time and radiation dose incurred for the chest CT were 184 ± 65.5 seconds and 2.47 ± 1.03 mSv. Multiple cardiovascular and pulmonary incidental findings of clinical relevance were identified in our patient population. CONCLUSIONS: Chest CT provides a pragmatic, rapid additional tool for COVID-19 risk stratification among patients referred for mechanical thrombectomy. Its inclusion in a standardized regional stroke imaging protocol has enabled efficient use of hospital resources with minimal compromise or delay to the overall patient treatment schedule.

Mapping of pain circuitry in early post-natal development using manganese-enhanced MRI in rats.

Premature or ill full-term infants are subject to a number of noxious procedures as part of their necessary medical care. Although we know that human infants show neural changes in response to such procedures, we know little of the sensory or affective brain circuitry activated by pain. In rodent models, the focus has been on spinal cord and, more recently, midbrain and medulla. The present study assesses activation of brain circuits using manganese-enhanced magnetic resonance imaging (MEMRI). Uptake of manganese, a paramagnetic contrast agent that is transported across active synapses and along axons, was measured in response to a hindpaw injection of dilute formalin in 12-day-old rat pups, the age at which rats begin to show aversion learning and which is roughly the equivalent of full-term human infants. Formalin induced the oft-reported biphasic response at this age and induced a conditioned aversion to cues associated with its injection, thus demonstrating the aversiveness of the stimulation. Morphometric analyses, structural equation modeling and co-expression analysis showed that limbic and sensory paths were activated, the most prominent of which were the prefrontal and anterior cingulate cortices, nucleus accumbens, amygdala, hypothalamus, several brainstem structures, and the cerebellum. Therefore, both sensory and affective circuits, which are activated by pain in the adult, can also be activated by noxious stimulation in 12-day-old rat pups.

Traumatic plastic deformation of the tibia: case report and literature review.

Plastic deformation refers to the deformation of a bone, without fracture of its cortices, that persists once the deforming force has been removed. It is not a common condition but is seen more frequently in children than in adults. Of the cases published, there have been only three previous reports of tibial involvement, with the forearm being the most commonly affected site. We describe the case of a 10-year-old girl who, after falling down a slope, came to a sudden stop when her right foot hit a rock. This resulted in a fracture of the fibula and bowing of the tibia. We discuss the dilemmas faced in treatment and recommend regular follow up until the patient reaches skeletal maturity.

Clinical percutaneous imaging of coronary anatomy using an over-the-wire ultrasound catheter system.

This manuscript describes initial applications of a unique new intravascular ultrasound imaging catheter. This 5.5F catheter uses an over-the-wire design and incorporates a phased array transducer at its tip. There are no moving parts. A 360 degree image is produced perpendicular to the catheter axis using a 20 MHz center frequency. A dedicated minicomputer is used for initial image processing, as well as enhancement and analysis. Initial studies using phantoms demonstrated excellent accuracy for linear dimensions (r = 0.99, range 3.0 to 7.6 mm, image = 1.0 phantom + 0.1). Serial imaging of the same arterial segment in vitro showed good reproducibility (coefficients of variance 2.5-5.2%). Likewise, intra- and inter-observer variability in image analysis was minimal (r = 0.92-0.99). Initial in vivo studies were performed in dogs. The catheter was easily passed over a wire into mesenteric, cerebral and coronary vessels without evidence of significant vessel trauma. Subsequently, 20 patients had percutaneous coronary imaging performed during cardiac catheterization. Cardiac motion was rarely a problem and acceptable images were obtained in all but two patients. Areas of calcification, mild stenoses, branching vessels and graft atherosclerosis could be identified. We conclude that intracoronary ultrasound imaging will be useful for assessing vascular pathology, for studying both rapid change in vessel size as well as chronic progression or regression of atherosclerosis, and for assisting with new therapeutic interventions.