Ultra-Long Transfers for Endovascular Thrombectomy-Mission Impossible?: The Australia-New Zealand Experience.

BACKGROUND: Endovascular thrombectomy (EVT) access in remote areas is limited. Preliminary data suggest that long distance transfers for EVT may be beneficial; however, the magnitude and best imaging strategy at the referring center remains uncertain. We hypothesized that patients transferred >300 miles would benefit from EVT, achieving rates of functional independence (modified Rankin Scale [mRS] score of 0-2) at 3 months similar to those patients treated at the comprehensive stroke center in the randomized EVT extended window trials and that the selection of patients with computed tomography perfusion (CTP) at the referring site would be associated with ordinal shift toward better outcomes on the mRS. METHODS: This is a retrospective analysis of patients transferred from 31 referring hospitals >300 miles (measured by the most direct road distance) to 9 comprehensive stroke centers in Australia and New Zealand for EVT consideration (April 2016 through May 2021). RESULTS: There were 131 patients; the median age was 64 [53-74] years and the median baseline National Institutes of Health Stroke Scale score was 16 [12-22]. At baseline, 79 patients (60.3%) had noncontrast CT+CT angiography, 52 (39.7%) also had CTP. At the comprehensive stroke center, 114 (87%) patients underwent cerebral angiography, and 96 (73.3%) proceeded to EVT. At 3 months, 62 patients (48.4%) had an mRS score of 0 to 2 and 81 (63.3%) mRS score of 0 to 3. CTP selection at the referring site was not associated with better ordinal scores on the mRS at 3 months (mRS median of 2 [1-3] versus 3 [1-6] in the patients selected with noncontrast CT+CT angiography, P=0.1). Nevertheless, patients selected with CTP were less likely to have an mRS score of 5 to 6 (odds ratio 0.03 [0.01-0.19]; P<0.01). CONCLUSIONS: In selected patients transferred >300 miles, there was a benefit for EVT, with outcomes similar to those treated in the comprehensive stroke center in the EVT extended window trials. Remote hospital CTP selection was not associated with ordinal mRS improvement, but was associated with fewer very poor 3-month outcomes.

Endovascular thrombectomy versus standard bridging thrombolytic with endovascular thrombectomy within 4·5 h of stroke onset: an open-label, blinded-endpoint, randomised non-inferiority trial.

BACKGROUND: The benefit of combined treatment with intravenous thrombolysis before endovascular thrombectomy in patients with acute ischaemic stroke caused by large vessel occlusion remains unclear. We hypothesised that the clinical outcomes of patients with stroke with large vessel occlusion treated with direct endovascular thrombectomy within 4·5 h would be non-inferior compared with the outcomes of those treated with standard bridging therapy (intravenous thrombolysis before endovascular thrombectomy). METHODS: DIRECT-SAFE was an international, multicentre, prospective, randomised, open-label, blinded-endpoint trial. Adult patients with stroke and large vessel occlusion in the intracranial internal carotid artery, middle cerebral artery (M1 or M2), or basilar artery, confirmed by non-contrast CT and vascular imaging, and who presented within 4·5 h of stroke onset were recruited from 25 acute-care hospitals in Australia, New Zealand, China, and Vietnam. Eligible patients were randomly assigned (1:1) via a web-based, computer-generated randomisation procedure stratified by site of baseline arterial occlusion and by geographic region to direct endovascular thrombectomy or bridging therapy. Patients assigned to bridging therapy received intravenous thrombolytic (alteplase or tenecteplase) as per standard care at each site; endovascular thrombectomy was also per standard of care, using the Trevo device (Stryker Neurovascular, Fremont, CA, USA) as first-line intervention. Personnel assessing outcomes were masked to group allocation; patients and treating physicians were not. The primary efficacy endpoint was functional independence defined as modified Rankin Scale score 0-2 or return to baseline at 90 days, with a non-inferiority margin of -0·1, analysed by intention to treat (including all randomly assigned and consenting patients) and per protocol. The intention-to-treat population was included in the safety analyses. The trial is registered with ClinicalTrials.gov, NCT03494920, and is closed to new participants. FINDINGS: Between June 2, 2018, and July 8, 2021, 295 patients were randomly assigned to direct endovascular thrombectomy (n=148) or bridging therapy (n=147). Functional independence occurred in 80 (55%) of 146 patients in the direct thrombectomy group and 89 (61%) of 147 patients in the bridging therapy group (intention-to-treat risk difference -0·051, two-sided 95% CI -0·160 to 0·059; per-protocol risk difference -0·062, two-sided 95% CI -0·173 to 0·049). Safety outcomes were similar between groups, with symptomatic intracerebral haemorrhage occurring in two (1%) of 146 patients in the direct group and one (1%) of 147 patients in the bridging group (adjusted odds ratio 1·70, 95% CI 0·22-13·04) and death in 22 (15%) of 146 patients in the direct group and 24 (16%) of 147 patients in the bridging group (adjusted odds ratio 0·92, 95% CI 0·46-1·84). INTERPRETATION: We did not show non-inferiority of direct endovascular thrombectomy compared with bridging therapy. The additional information from our study should inform guidelines to recommend bridging therapy as standard treatment. FUNDING: Australian National Health and Medical Research Council and Stryker USA.

Robotic Interventional Neuroradiology: Progress, Challenges, and Future Prospects.

Advances in robotic technology have improved standard techniques in numerous surgical and endovascular specialties, offering more precision, control, and better patient outcomes. Robotic-assisted interventional neuroradiology is an emerging field at the intersection of interventional neuroradiology and biomedical robotics. Endovascular robotics can automate maneuvers to reduce procedure times and increase its safety, reduce occupational hazards associated with ionizing radiations, and expand networks of care to reduce gaps in geographic access to neurointerventions. To date, many robotic neurointerventional procedures have been successfully performed, including cerebral angiography, intracranial aneurysm embolization, carotid stenting, and epistaxis embolization. This review aims to provide a survey of the state of the art in robotic-assisted interventional neuroradiology, consider their technical and adoption limitations, and explore future developments critical for the widespread adoption of robotic-assisted neurointerventions.

Determinants of last lap speed in paced and maximal 1500-m time trials.

PURPOSE: The present study identified the physiological and performance characteristics that are deterministic during a maximal 1500-m time trial and in paced 1500-m time trials, with an all-out last lap. METHODS: Thirty-two trained middle-distance runners (n = 21 male, VO2peak: 72.1 ± 3.2; n = 11, female, VO2peak: 61.2 ± 3.7 mL kg-1 min-1) completed a 1500-m time trial in the fastest time possible (1500FAST) as well as a 1500MOD and 1500SLOW trial whereby mean speed was reduced during the 0-1100 m by 5% and 10%, respectively. Anaerobic speed reserve (ASR), running economy (RE), the velocity corresponding with VO2peak (VVO2peak), maximal sprint speed (MSS) and maximal accumulated oxygen deficit (MAOD) were determined during additional testing. Carnosine content was quantified by proton magnetic resonance spectroscopy in the gastrocnemius and expressed as a Z-score to estimate muscle fibre typology. RESULTS: 1500FAST time was best explained by RE and VVO2peak in female runners (adjusted r2 = 0.80, P < 0.001), in addition to the 0-1100-m speed relative to VVO2peak in male runners (adjusted r2 = 0.72, P < 0.001). Runners with a higher gastrocnemius carnosine Z-score (i.e., higher estimated percentage of type II fibres) and greater MAOD, reduced their last lap time to a greater extent in the paced 1500-m trials. Neither ASR nor MSS was associated with last lap time in the paced trials. CONCLUSION: These findings suggest that VVO2 peak and RE are key determinants of 1500-m running performance with a sustained pace from the start, while a higher carnosine Z-score and MAOD are more important for last lap speed in tactical 1500-m races.

Vanguard Study: Initial experience with the new fourth generation Pipeline Vantage Flow Diverter (PVFD): 6-month results, technical and clinical considerations.

BACKGROUND: The Pipeline Embolization Device has proven to be a safe and effective device for the treatment of intracranial aneurysms. The Pipeline Vantage Flow Diverter (PVFD) with Shield Technology is the new fourth generation of this implant, with modifications made compared to previous iterations. We aimed to evaluate the mechanical properties and clinical safety and efficacy of this device. METHODS: Vanguard is a single arm, single center, prospective study. Between April 2021 and April 2023, all consecutive patients with an unruptured aneurysm treated with Pipeline Vantage flow-diverting stents were included. There were no aneurysm size or location exclusion criteria. Safety (neurological serious adverse events) and efficacy (device deployment and aneurysm occlusion) were independently reviewed. Imaging follow-up data, and immediate, early (<30 days), and delayed (>30 days) neurological serious adverse events were independently assessed. RESULTS: 101 consecutive patients with a total of 115 aneurysms were included. The aneurysms were situated in the anterior (90.4%) or posterior (9.6%) circulations. A total of 124 devices were implanted. The deployment success rate was 100%. In four (4.0%) cases post-deployment angioplasty was required to optimize device wall apposition. Occlusion rates at 1 month were 54.7%, at 3 months 72.1%, and at 6 months 81.7%. Morbidity and mortality were 4.9% and 0%, respectively, at 6 months. Eight cases (6.9%) demonstrated in-stent stenosis, four of which had 'fish mouth' deformity. CONCLUSION: Initial results of the new generation PVFD for unruptured intracranial aneurysm treatment demonstrate overall satisfactory device performance, safety profile, and effectiveness.

Health budget implications of mechanical thrombectomy for acute ischaemic stroke in Australia.

INTRODUCTION: This research evaluates the budget impact of treating acute ischaemic stroke (AIS) using a combination of mechanical thrombectomy (MT) with stent retrievers (SR) and intravenous tissue-plasminogen activator (IV-tPA) in Australia. METHODS: This study examined the economic impact over five years for a patient cohort based on the number of patients treated with MT+ IV-tPA in Australia 2021, versus treatment with IV-tPA alone. A budget impact (BI) model was developed to project direct medical costs (economic impact) of IV-tPA+ MT with SR vs. Intravenous tissue-plasminogen activator alone over a five-year period (2021-2025 inclusive) from a healthcare perspective. The model is composed of a short-run decision tree model based on a 3-month post-treatment modified Rankin Scale (mRS) from the EXTEND-IA study and a published long-run Markov state transition model. Acute, mid-term and long-term care costs were projected based on anticipated mRS scores from the EXTEND-IA trial. Estimated yearly and cumulative budget impact were reported to indicate the economic impact of the two treatment strategies for AIS in the Australian healthcare system. RESULTS: MT+IV-tPA had a greater budgetary impact than IV-tPA alone, with annual savings starting at Year 1 and continuing through to Year 5. Cost savings of 21% or approximately $36 million can be achieved over five years for the patient cohort treated in Australia in 2021. Each MT procedure performed delivers approximately $3280 in annual health system savings per patient. CONCLUSION: Treatment of AIS with a combination of MT+IV-tPA generates significant savings in the Australian healthcare system compared with IV-tPA alone.

Transradial versus transfemoral access for diagnostic cerebral angiography: frequency of acute MRI findings in 500 consecutive patients at a single center.

BACKGROUND: The frequency of clinically symptomatic and asymptomatic diffusion-weighted imaging (DWI) hyperintense lesions and their correlation with the transradial artery (TRA) approach is unclear. OBJECTIVE: To assess the frequency of abnormal diffusion restriction foci on DWI following cerebral angiography (digital subtraction angiography (DSA)) with the TRA or transfemoral artery (TFA) approach and identify predictors of DWI restriction foci. METHODS: We analysed data from consecutive diagnostic cerebral angiograms obtained between January 2021 and October 2023 at a single tertiary center. MRI DWI was performed 2 hours after DSA. Patients underwent neurological assessment periprocedurally, as well as prior to discharge. RESULTS: 500 patients were analysed; 277 (55%) procedures were performed via TRA and 223 (45%) via TFA. Overall, 74 (14.8%) patients had abnormal findings in the postprocedure MRI DWI. A higher incidence of positive DWI findings was noted in the TRA group, with 46 (16.6%) patients, compared with 28 (12.6%) in the TFA group (P=0.21). Symptomatic events occurred in seven (2.5%) of the TRA group and in two (0.9%) of the TFA cohort (P=0.31). At 60 days, the neurological deficit rate was one (0.4%) for the TRA group and one (0.4%) for the TFA group. Procedure time was the only significant predictor of DWI restriction (OR=1.04 per minute; P=0.0001). CONCLUSION: Although there were more symptomatic or asymptomatic embolic events with TRA than with the TFA approach following elective cerebral angiography, this was not significantly different. We recommend the choice of vascular access based on patient anatomy and characteristics, aimed at improving care through enhanced safety.

Evaluation of flow diverters for cerebral aneurysm therapy: recommendations for imaging analyses in clinical studies, endorsed by ESMINT, ESNR, OCIN, SILAN, SNIS, and WFITN.

BACKGROUND: Multiple studies and meta-analyses have described the technical and clinical outcomes in large cohorts of aneurysm patients treated with flow diverters (FDs). Variations in evaluation methodology complicate making comparisons among studies, hinder understanding of the device behavior, and pose an obstacle in the assessment of further advances in FD therapy. METHODS: A multidisciplinary panel of neurointerventionalists, imaging experts, and neuroradiologists convened with the goal of establishing consensus recommendations for the standardization of image analyses in FD studies. RESULTS: A standardized methodology is proposed for evaluating and reporting radiological outcomes of FD treatment of intracranial aneurysms. The recommendations include general imaging considerations for clinical studies and evaluations of longitudinal changes, such as neointimal lining and stenosis. They cover standards for classification of aneurysm location, morphology, measurements, as well as the assessment of aneurysm occlusion, wall apposition, and neck coverage. These reporting standards further define four specific braid deformation patterns: foreshortening, fish-mouthing, braid bump deformation, and braid collapse, collectively termed 'F2B2'. CONCLUSIONS: When widely applied, standardization of methods of measuring and reporting outcomes will help to harmonize the assessment of treatment outcomes in clinical studies, help facilitate communication of results among specialists, and help enable research and development to focus on specific aspects of FD techniques and technology.

Evaluation of effectiveness and safety of the CorPath GRX robotic system in endovascular embolization procedures of cerebral aneurysms.

BACKGROUND: Robotic-assisted neurointervention was recently introduced, with implications that it could be used to treat neurovascular diseases. OBJECTIVE: To evaluate the effectiveness and safety of the robotic-assisted platform CorPath GRX for treating cerebral aneurysms. METHODS: This prospective, international, multicenter study enrolled patients with brain aneurysms that required endovascular coiling and/or stent-assisted coiling. The primary effectiveness endpoint was defined as successful completion of the robotic-assisted endovascular procedure without any unplanned conversion to manual treatment with guidewire or microcatheter navigation, embolization coil(s) or intracranial stent(s) deployment, or an inability to navigate vessel anatomy. The primary safety endpoint included intraprocedural and periprocedural events. RESULTS: The study enrolled 117 patients (74.4% female) with mean age of 56.6 years from 10 international sites,. Headache was the most common presenting symptom in 40/117 (34.2%) subjects. Internal carotid artery was the most common location (34/122, 27.9%), and the mean aneurysm height and neck width were 5.7±2.6 mm and 3.5±1.4 mm, respectively. The overall procedure time was 117.3±47.3 min with 59.4±32.6 min robotic procedure time. Primary effectiveness was achieved in 110/117 (94%) subjects with seven subjects requiring conversion to manual for procedure completion. Only four primary safety events were recorded with two intraprocedural aneurysm ruptures and two strokes. A Raymond-Roy Classification Scale score of 1 was achieved in 71/110 (64.5%) subjects, and all subjects were discharged with a modified Rankin Scale score of ≤2. CONCLUSIONS: This first-of-its-kind robotic-assisted neurovascular trial demonstrates the effectiveness and safety of the CorPath GRX System for endovascular embolization of cerebral aneurysm procedures. TRIAL REGISTRATION NUMBER: NCT04236856.

Safety and efficacy of adjunctive intra-arterial antithrombotic therapy during endovascular thrombectomy for acute ischemic stroke: a systematic review and meta-analysis.

BACKGROUND: Half of patients who achieve successful recanalization following endovascular thrombectomy (EVT) for acute ischemic stroke experience poor functional outcome. We aim to investigate whether the use of adjunctive intra-arterial antithrombotic therapy (AAT) during EVT is safe and efficacious compared with standard therapy (ST) of EVT with or without prior intravenous thrombolysis. METHODS: Electronic databases were searched (PubMed/MEDLINE, Embase, Cochrane Library) from 2010 until October 2023. Data were pooled using a random-effects model and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Risk of bias was assessed using ROBINS-I and ROB-2. The primary outcome was functional independence (modified Rankin Scale (mRS) 0-2) at 3 months. Secondary outcomes were successful recanalization (modified Thrombolysis In Cerebral Infarction (TICI) 2b-3), symptomatic intracranial hemorrhage (sICH), and 90-day mortality. RESULTS: 41 randomized and non-randomized studies met the eligibility criteria. Overall, 15 316 patients were included; 3296 patients were treated with AAT during EVT and 12 020 were treated with ST alone. Compared with ST, patients treated with AAT demonstrated higher odds of functional independence (46.5% AAT vs 42.6% ST; OR 1.22, 95% CI 1.07 to 1.40, P=0.004, I2=48%) and a lower likelihood of 90-day mortality (OR 0.71, 95% CI 0.61 to 0.83, P<0.0001, I2=20%). The rates of sICH (OR 1.00, 95% CI 0.82 to 1.22,P=0.97, I2=13%) and successful recanalization (OR 1.09, 95% CI 0.84 to 1.42, P=0.52, I2=76%) were not significantly different. CONCLUSION: The use of AAT during EVT may improve functional outcomes and reduce mortality rates compared with ST alone, without an increased risk of sICH. These findings should be interpreted with caution pending the results from ongoing phase III trials to establish the efficacy and safety of AAT during EVT.

Transradial versus transfemoral arterial approach for cerebral angiography and the frequency of embolic events on diffusion weighted MRI.

BACKGROUND: The radial artery approach has become popular as a 'radial first' strategy for arterial access in neuroangiography and neurointerventions. Recent studies have shown that transradial arterial access (TRA) for cerebral angiography has been associated with reduced access site complication rates and improved patient satisfaction compared with transfemoral access (TFA). The goal of this study was to evaluate the presence of abnormal MRI diffusion weighted imaging (DWI) foci following DSA and correlate their frequency with TRA or TFA. METHODS: We prospective analyzed 200 consecutive adult DSAs performed from January 2021 to January 2022, at a single tertiary center. RESULTS: Of the 200 consecutive diagnostic cerebral angiograms, 51% were performed via TRA and 49% were performed via TFA. Of the TRA cerebral angiograms, 17.5% demonstrated at least one hyperintense focus on MRI DWI. Of the TFA procedures, 5.2% were considered positive. One patient (0.5%) in the TRA group experienced a minor neurologic deficit postoperatively that had not completely resolved at 90 days after the procedure and no neurologic deficits occurred in the TFA group. CONCLUSIONS: Despite the proven benefit of TRA over TFA in neurointervention, the number of MRI DWI restriction foci were significantly more frequent during cerebral angiography when TRA was selected. Although the number of clinically symptomatic events were minimal, the widespread use of the technique may become clinically relevant. Further studies contrasting the TRA and TFA techniques will be beneficial for cerebral angiography.

The Aristotle 18 and 24 microwires in neuroIntervention: Early experience at a single centre.

BACKGROUND: Current neurointerventional procedures are expanding the use of large bore microcatheters, of up to 0.033" inner diameters, to accommodate intrasaccular flow disruptors or neck-bridging devices, including flow diverters. The use of large bore microwires may mitigate the ledge gap between wire and catheter, facilitate navigation and offer support in distal tortuous anatomy. We aim to report our early experience using the novel Aristotle (Scientia Vascular, West Valley City, UT) 18 and 24 microwires in neurovascular interventions. METHODS: We analysed neurointerventional procedures in which the Aristotle 18 and 24 microwires were used at a single centre. Prospectively collected data, from March 2022 to February 2023, including patient's clinical outcome (successful target vessel, aneurysm catheterisation, peri-procedural complications (thromboembolic, haemorrhagic, vessel dissection or perforation) were analysed. RESULTS: Overall, the use of Aristotle 18 and 24 microwires was recorded in 84 neurointerventional procedures during the study period, including endovascular aneurysm treatment (n = 30), endovascular thrombectomy (n = 46), dural venous sinus manometry/stent placement (n = 7), and extracranial carotid artery stent placement (n = 1). The Aristotle 18 microwire was used in conjunction with 0.021" microcatheters and the Aristotle 24 microwire with the 0.027 or 0.033" microcatheters. In all cases (100%), the target vessel or aneurysm was reached with the microwire, allowing seamless advancement of the selected microcatheters. No procedure related complications were recorded. CONCLUSIONS: The use of the Aristotle 18 and 24 microwires in neurointerventional procedures is feasible and safe. The microwires provide reduced ledge gap, improved torquability, support and safety over standard 0.014" microwires.

Braid stability after flow diverter treatment of intracranial aneurysms: a systematic review and meta-analysis.

BACKGROUND: The aim of this study was to evaluate the overall rates of braid changes associated with flow diverter (FD) treatment for intracranial aneurysms (IAs). Additionally, we sought to provide an overview of the currently reported definitions related to these complications. METHODS: A systematic search was conducted from the inception of relevant literature up to April 2023, encompassing six databases. The included studies focused on patients with IAs treated with FDs. We considered four main outcome measures as FD braid changes: (1) fish-mouthing, (2) device braid narrowing, (3) device braid collapsing, and (4) device braid deformation. The data from these studies were pooled using a random-effects model. RESULTS: A total of 48 studies involving 3572 patients were included in the analysis. Among them, 14 studies (39%) provided definitions for fish-mouthing. However, none of the included studies offered specific definitions for device braid narrowing, collapsing, or deformation, despite reporting rates for these complications in six, five, and three studies, respectively. The pooled rates for braid changes were as follows: 3% (95% CI 2% to 4%, I2=27%) for fish-mouthing, 7% (95% CI 2% to 20%, I2=85%) for narrowing, 1% (95% CI 0% to 3%, I2=0%) for collapsing, and 1% (95% CI 1% to 4%, I2=0%) for deformation. CONCLUSION: The findings of this study suggest that FD treatment for IAs generally exhibits low rates of fish-mouthing, device braid narrowing, collapsing, and deformation. However, the lack of standardized definitions hinders the ability to compare device outcomes objectively, emphasizing the need for uniform definitions for FD braid changes in future prospective studies on FD.

The Muscle Typology of Elite and World-Class Swimmers.

PURPOSE: To examine whether the muscle typology of elite and world-class swimmers could discriminate between their best distance event, swimming stroke style, or performance level. METHODOLOGY: The muscle carnosine content of 43 male (860 [76] FINA [Fédération Internationale de Natation] points) and 30 female (881 [63] FINA points) swimmers was measured in the soleus and gastrocnemius by proton magnetic resonance spectroscopy and expressed as a carnosine aggregate Z score (CAZ score) to estimate muscle typology. A higher CAZ score is associated with a higher estimated proportion of type II fibers. Swimmers were categorized by their best stroke, distance category (sprinters, 50-100 m; middle distance, 200-400 m; or long distance, 800 m-open water), and performance level (world-class, world top 10, or elite and world top 100 swimmers outside of the world top 10). RESULTS: There was no significant difference in the CAZ score of sprint- (-0.08 [0.55]), middle- (-0.17 [0.70]), or long-distance swimmers (-0.30 [0.75], P = .693). World-class sprint swimmers (all strokes included) had a significantly higher CAZ score (0.37 [0.70]) when compared to elite sprint swimmers (-0.25 [0.61], P = .024, d = 0.94). Breaststroke swimmers (0.69 [0.73]) had a significantly higher CAZ score compared to freestyle (-0.24 [0.54], P < .001, d = 1.46), backstroke (-0.16 [0.47], P = .006, d = 1.42), and butterfly swimmers (-0.39 [0.53], P < .001, d = 1.70). Furthermore, within the cohort of breaststroke swimmers, there was a significant positive correlation between FINA points and CAZ score (r = .728, P = .011); however, this association was not evident in other strokes. CONCLUSION: While there was no clear association between muscle typology and event distance specialization, world-class sprint swimmers possess a greater estimated proportion of type II fibers compared to elite sprint swimmers, as well as breaststroke swimmers compared to freestyle, backstroke, and butterfly swimmers.

Single Centre Initial Experience with the Scepter Mini Balloon Microcatheter.

BACKGROUND: The use of balloon microcatheters in interventional neuroradiology is well documented. However, their use is sometimes limited by the small diameter and excessive tortuosity of the vasculature. The Scepter Mini dual-lumen balloon microcatheter (SMBM) (Microvention, Aliso Viejo, CA) has been designed to address these challenges by decreasing the distal catheter profile, allowing distal access to the target vessel. METHODS: This is a single-centre retrospective analysis of the initial cases performed using the Scepter Mini balloon microcatheter. The targeted conditions were vascular malformations. Patient clinical data, angiographic features of the vascular abnormalities and operation reports were reviewed and the procedural parameters, radiation doses, occlusion rates and complications were assessed. RESULTS: A total of 15 SMBM were used in 11 cases. In all cases the procedure performed was balloon inflation and antegrade delivery of precipitating hydrophobic injectable liquid (PHIL) (Microvention, Aliso Viejo, CA) for embolisation of a targeted feeding vessel and cranial and spinal vascular malformations. Successful feeding vessel distal access and antegrade liquid embolisation was achieved in 100% of the cases. One of the 11 cases was an emergency procedure. One procedural target vessel rupture, likely due to overinflation, and three minor post-procedure complications were observed. CONCLUSION: The SMBM represents a significant advance in the treatment of cerebrospinal vascular malformations, allowing balloon catheter access into tortuous and small calibre vessels.

Aspiration technique for percutaneous endovascular retrieval of contraceptive device embolized to the pulmonary vasculature.

Contraceptive implant migration into the pulmonary circulation is an uncommon, but potentially serious complication. We describe an "aspiration" technique for percutaneous retrieval of a contraceptive implant from a subsegmental pulmonary artery, using a Penumbra Neuron MAX 088 guiding catheter and a Merit Medical VacLok Vacuum Pressure Syringe, as an alternative to the previously described snare technique. Our patient had an uneventful recovery and was discharged home on the same day.

Determinants of Performance in Paced and Maximal 800-m Running Time Trials.

PURPOSE: We aimed to identify the underpinning physiological and speed/mechanical determinants of different types of 800-m running time trials (i.e., with a positive or negative pacing strategy) and key components within each 800-m time trial (i.e., first and final 200 m). METHODS: Twenty trained male 800-m runners (800-m personal best time (min:s): 1:55.10 ± 0:04.44) completed a maximal 800-m time trial (800MAX) and one pacing trial, whereby runners were paced for the first lap, and speed was reduced by 7.5% (800PACE) relative to 800MAX, whereas the last lap was completed in the fastest time possible. Anaerobic speed reserve, running economy, the velocity corresponding with V˙O2peak (VV˙O2peak), maximal sprint speed (MAXSS), maximal accumulated oxygen deficit, and sprint force-velocity-power profiles were derived from laboratory and field testing. Carnosine content was quantified by proton magnetic resonance spectroscopy in the gastrocnemius and soleus and expressed as a carnosine aggregate Z (CAZ) score to estimate muscle typology. Data were analyzed using multiple stepwise regression analysis. RESULTS: MAXSS and vV˙O2peak largely explained the variation in 800MAX time (r2 = 0.570; P = 0.020), whereas MAXSS was the best explanatory variable for the first 200-m time in 800MAX (adjusted r2 = 0.661, P < 0.001). Runners with a higher CAZ score (i.e., higher estimated percentage of type II fibers) reduced their last lap time to a greater extent in 800PACE relative to 800MAX (adjusted r2 = 0.413, P < 0.001), whereas better maintenance of mechanical effectiveness during sprinting, a higher CAZ score and vV˙O2peak was associated with a faster final 200-m time during 800PACE (adjusted r2 = 0.761, P = 0.001). CONCLUSIONS: These findings highlight that diversity in the physiological and speed/mechanical characteristics of male middle-distance runners may be associated with their suitability for different 800-m racing strategies to have the best chance of winning.

Muscle Fiber Typology and Its Association With Start and Turn Performance in Elite Swimmers.

PURPOSE: To determine the association between estimated muscle fiber typology and the start and turn phases of elite swimmers during competition. METHODS: International and national competition racing performance was analyzed from 21 female (FINA points = 894 ± 39: 104.5 ± 1.8% world record ratio [WRR]) and 25 male (FINA points = 885 ± 54: 104.8 ± 2.1% WRR) elite swimmers. The start, turn, and turn out times were determined from each of the swimmers' career best performance times (FINA points = 889 ± 48: 104.7 ± 2.0% WRR). Muscle carnosine concentration was quantified by proton magnetic resonance spectroscopy in the gastrocnemius and soleus and was expressed as a carnosine aggregate z score relative to an age- and gender-matched nonathlete control group to estimate muscle fiber typology. Linear mixed models were employed to determine the association between muscle fiber typology and the start and turn times. RESULTS: While there was no significant influence of carnosine aggregate z score on the start and turn times when all strokes and distance events were entered into the model, the swimmers with a higher carnosine aggregate z score (ie, faster muscle typology) had a significantly faster start time in 100-m events compared with the swimmers with a lower carnosine aggregate z score (P = .02, F = 5.825). The start and turn times were significantly faster in the male compared with the female swimmers in the 100-m events compared with other distances, and between the 4 different swimming strokes (P < .001). CONCLUSION: This study suggests that start times in sprint events are partly determined (and limited) by muscle fiber typology, which is highly relevant when ∼12% of the overall performance time is determined from the start time.

The Influence of Muscle Fiber Typology on the Pacing Strategy of 200-m Freestyle Swimmers.

PURPOSE: To determine the influence of muscle fiber typology (MFT) on the pacing strategy of elite swimmers competing in the 200-m freestyle event. METHOD: The top 3 career-best performances from 25 elite 200-m freestyle swimmers were analyzed-12 women (1:58.0 [0:01.3] min:s) and 13 men (1:48.4 [0:02.5]). Muscle carnosine concentration was quantified by proton magnetic resonance spectroscopy in the gastrocnemius and soleus muscles and expressed as a carnosine aggregate z score (CAZ score) relative to an age- and gender-matched nonathlete control group to estimate MFT. Linear regression models were employed to examine the influence of MFT on the percentage of overall race time spent in each 50-m lap. RESULTS: Swimmers with a higher CAZ score spent a greater percentage of race time in lap 3 compared with swimmers with a lower CAZ score (0.1%, 0.0% to 0.2%; mean, 90% confidence interval, P = .02). For every 1% increase in the percentage of race time spent in lap 1, the percentage of race time spent in lap 3 decreased by 0.4% for swimmers with a higher CAZ score (0.2% to -0.5%, P = .00, r = -.51), but not for swimmers with a lower CAZ score (-0.1%, -0.3% to 0.1%, P = .28, r = -.18). The percentage of race time spent in lap 4 decreased by 0.8% for higher-CAZ-score swimmers (-0.5% to -1.0%, P = .00, r = -.66) and by 0.9% for lower-CAZ-score swimmers (-0.6% to -1.3%, P = .00, r = -.65) when lap 1 percentage increased by 1%. CONCLUSION: MFT may influence the pacing strategy of swimmers in the 200-m freestyle event, which provides an avenue for maximizing individualized pacing strategies of elite swimmers.

Relationships between Lower Limb Muscle Characteristics and Force-Velocity Profiles Derived during Sprinting and Jumping.

PURPOSE: This study aimed to identify the relationships between lower limb muscle characteristics and mechanical variables derived from the vertical (jumping) and horizontal (sprinting) force-velocity-power (FVP) profiles. METHODS: Nineteen subelite male rugby league players performed a series of squat jumps and linear 30-m sprints to derive the vertical and horizontal FVP profiles, respectively. The theoretical maximal force (F0), velocity (V0), and power (Pmax) were derived from both the vertical (i.e., vF0, vV0, and vPmax) and the horizontal (i.e., hF0, hV0, and hPmax) FVP profiles. Vastus lateralis (VL), biceps femoris long head, and gastrocnemius medialis (GM) and lateralis muscle fascicle length, pennation angle, and thickness were measured using B-mode ultrasonography. Magnetic resonance imaging was used to calculate volumes of major lower limb muscles, whereas proton magnetic resonance spectroscopy was used to quantify the carnosine content of the GM to estimate muscle fiber typology. RESULTS: Variation in vPmax was best explained by GM muscle fiber typology (i.e., greater estimated proportion of Type II fibers) and VL volume (adjusted r2 = 0.440, P = 0.006), whereas adductor and vastus medialis volume and GM muscle fiber typology explained the most variation in hPmax (adjusted r2 = 0.634, P = 0.032). Rectus femoris and VL volume explained variation in vF0 (r2 = 0.430, P = 0.008), whereas adductor and vastus medialis volume explained variation in hF0 (r2 = 0.432, P = 0.007). Variations in vV0 and hV0 were best explained by GM muscle fiber typology (adjusted r2 = 0.580, P < 0.001) and GM muscle fiber typology and biceps femoris short head volume (adjusted r2 = 0.590, P < 0.001), respectively. CONCLUSION: Muscle fiber typology and muscle volume are strong determinants of maximal muscle power in jumping and sprinting by influencing the velocity- and force-oriented mechanical variables.