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.

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.

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.

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.

Mechanical thrombectomy in medium vessel occlusions using the novel aspiration Q catheters: an international multicenter experience

BACKGROUND

Medium vessel occlusions (MeVOs) comprise a large proportion of all stroke events. We performed a multicenter study of MIVI Q catheters, a novel design that optimizes suction forces without an increase in lumen diameter, for the treatment of MeVOs, aiming to evaluate its efficacy and safety.

METHODS

Databases of two US and two UK centers were retrospectively reviewed for MeVO patients (M2-M3, anterior cerebral artery (ACA), or posterior cerebral artery (PCA)) treated with Q catheters. Outcomes were assessed as successful recanalization (modified Thrombolysis in Cerebral Infarction (mTICI) score ≥2b), first pass effect (FPE), and modified FPE (mFPE) as single pass achieving mTICI ≥2c and mTICI≥2b, respectively, and 90 day modified Rankin Scale (mRS) score.

RESULTS

69 patients were included (median age 71 years, IQR 56-82.5; 52.2% men). Median National Institutes of Health Stroke Scale (NIHSS) score at admission was 14, and Alberta Stroke Program Early CT Score (ASPECTS) was 9. Primary (without large vessel occlusion (LVO)) and secondary (with LVO) MeVOs represented 47.8% and 52.2% of cases, respectively. Q catheters used were Q3 (47.8%), Q4 (33.3%), Q5 (10.1%), and Q6 (8.7%). mTICI≥2b was achieved in 92.8% of patients, with FPE in 47.8%, and mFPE in 68.1%. Two (2.9%) intraprocedural complications (symptomatic intracranial hemorrhage) occurred. 50% (27/54) achieved an mRS score of ≤2 at the 90 day follow-up. The median NIHSS at admission was significantly higher in secondary than in primary MeVOs (19.5 vs 12, P=0.009). The rate of mRS ≤2 at 90 days was significantly higher in primary than in secondary MeVOs (77.3% vs 31.3%, P=0.002).

CONCLUSIONS

Treatment of MeVO patients with Q catheters resulted in optimal angiographic and clinical outcomes. Although angiographic results were similar between primary and secondary MeVOs, the former had less severe presenting NIHSS and better outcomes at 90 days than the latter.

Effect of proximal blood flow arrest during endovascular thrombectomy (ProFATE): Study protocol for a multicentre randomised controlled trial

BACKGROUND

Observational studies have demonstrated improved outcomes with the adjunctive use of balloon guide catheters (BGC) during endovascular thrombectomy (EVT) for anterior circulation acute ischaemic stroke (AIS). However, the lack of high-level evidence and global practice heterogeneity justifies a randomised controlled trial (RCT) to investigate the effect of transient proximal blood flow arrest on the procedural and clinical outcomes of patients with AIS following EVT.

HYPOTHESIS

Proximal blood flow arrest in the cervical internal carotid artery during EVT for proximal large vessel occlusion is superior to no flow arrest in achieving complete vessel recanalisation.

METHODS

ProFATE is an investigator-initiated, pragmatic, multicentre RCT with blinding of participants and outcome assessment. An estimated 124 participants with an anterior circulation AIS due to large vessel occlusion, an NIHSS of ⩾2, ASPECTS ⩾ 5 and eligible for EVT using a first-line combined technique (contact aspiration and stent retriever) or contact aspiration only will be randomised (1:1) to receive BGC balloon inflation or no inflation during EVT.

OUTCOMES

The primary outcome is the proportion of patients achieving near-complete/complete vessel recanalisation (eTICI 2c-3) at the end of the EVT procedure. Secondary outcomes include the functional outcome (modified Rankin Scale at 90 days), new or distal vascular territory clot embolisation rate, near-complete/complete recanalisation after the first pass, symptomatic intracranial haemorrhage, procedure-related complications and death at 90 days.

DISCUSSION

This is the first RCT to investigate the effect of proximal blood flow arrest during EVT using a BGC on the procedural and clinical outcomes of patients with AIS due to large vessel occlusion.

Antiplatelet Therapy in Neurointervention

The aim of this review is to provide an overview of the use of antiplatelet medication in neurointervention, with a focus on the clinical indications for antiplatelet use in both preventing and reducing platelet aggregation. This review will cover current antiplatelet medications, pharmacokinetics, and pharmacodynamics. We will provide an overview of different endovascular devices and discuss the antiplatelet regimes in neurointervention, highlighting gaps in evidence and scope for future studies.Two randomized controlled trials have evaluated antiplatelet use in the setting of acute large vessel occlusion stroke, with neither demonstrating benefit in their overall cohorts. Evidence on antiplatelet medication for both acute and elective stenting for acute stroke and treatment of cerebral aneurysms is currently based on large case series, and practice in neurointervention has increasingly utilized dual antiplatelet regimes with clopidogrel and second-line agents like prasugrel and ticagrelor. Clopidogrel function testing has an increasing role in neurointerventional procedures, particularly for high metal surface area stents such as the braided flow diverter type stents. Intravenous glycoprotein IIB/IIIA inhibitors have been utilized for both acute bridging and rescue therapy.Antiplatelet decision making is complex, and there are few randomized control trials to guide clinical practice. Comparative trials to guide decision making remain important in both the acute and elective settings. Standardised protocols incorporating platelet function testing may play a role in assisting decision making until more robust clinical evidence is available, particularly in the context of acute neurointerventional stenting for stroke and ruptured cerebral aneurysms.

Association between time to treatment and clinical outcomes in endovascular thrombectomy beyond 6 hours without advanced imaging selection

BACKGROUND

The effectiveness and safety of endovascular thrombectomy (EVT) in the late window (6-24 hours) for acute ischemic stroke (AIS) patients selected without advanced imaging is undetermined. We aimed to assess clinical outcomes and the relationship with time-to-EVT treatment beyond 6 hours of stroke onset without advanced neuroimaging.

METHODS

Patients who underwent EVT selected with non-contrast CT/CT angiography (without CT perfusion or MR imaging), between October 2015 and March 2020, were included from a national stroke registry. Functional and safety outcomes were assessed in both early (<6 hours) and late windows with time analyzed as a continuous variable.

RESULTS

Among 3278 patients, 2610 (79.6%) and 668 (20.4%) patients were included in the early and late windows, respectively. In the late window, for every hour delay, there was no significant association with shift towards poorer functional outcome (modified Rankin Scale (mRS)) at discharge (adjusted common OR 0.98, 95% CI 0.94 to 1.01, p=0.27) or change in predicted functional independence (mRS ≤2) (24.5% to 23.3% from 6 to 24 hours; aOR 0.99, 95% CI0.94 to 1.04, p=0.85). In contrast, predicted functional independence was time sensitive in the early window: 5.2% reduction per-hour delay (49.4% to 23.5% from 1 to 6 hours, p=0.0001). There were similar rates of symptomatic intracranial hemorrhage (sICH) (3.4% vs 4.6%, p=0.54) and in-hospital mortality (12.9% vs 14.6%, p=0.33) in the early and late windows, respectively, without a significant association with time.

CONCLUSION

In this real-world study, there was minimal change in functional disability, sICH and in-hospital mortality within and across the late window. While confirmatory randomized trials are needed, these findings suggest that EVT remains feasible and safe when performed in AIS patients selected without advanced neuroimaging between 6-24 hours from stroke onset.

Incidence and predictors of poor functional outcome despite complete recanalisation following endovascular thrombectomy for acute ischaemic stroke

BACKGROUND

Numerous ischaemic stroke patients experience poor functional outcome despite successful recanalisation following endovascular thrombectomy (EVT). We aimed to identify the incidence and predictors of futile complete recanalisation (FCR) in a national stroke registry.

METHODS

Patients who achieved complete recanalisation (mTICI 3) following EVT, between October 2015 and March 2020, were included from a United Kingdom national stroke registry. Modified Rankin Scale of 4-6 at discharge was defined as a 'poor/futile outcome'. Backward stepwise multivariable logistic regression analysis was performed with FCR as the dependent variable, incorporating all baseline characteristics, procedural time metrics and post-procedural events.

RESULTS

We included 2132 of 4383 patients (48.8%) with complete recanalisation post-EVT, of which 948 patients (44.4%) developed FCR. Following multivariable regression analysis adjusted for potential confounders, patients with FCR were associated with multiple baseline patient, imaging and procedural factors: age (p=0.0001), admission NIHSS scores (p=0.0001), pre-stroke disability (p=0.007), onset-to-puncture (p=0.0001) and procedural times (p=0.0001), presence of diabetes (p=0.005), and use of general anaesthesia (p=0.0001). Although not predictive of outcome, post-procedural events including development of any intracranial haemorrhage (ICH) (p=0.0001), symptomatic ICH (sICH) (p=0.0001) and early neurological deterioration (END) (p=0.007) were associated with FCR.

CONCLUSION

Nearly half of patients in this national registry experienced FCR following EVT. Significant predictors of FCR included increasing age, admission NIHSS scores, pre-stroke disability, onset-to-puncture and procedural times, presence of diabetes, atrial fibrillation, and use of general anaesthesia. Post procedural development of any ICH, sICH, and END were associated with FCR.

Perfusion imaging in acute ischaemic stroke - the beginning of the end?

Endovascular thrombectomy (EVT) for large vessel occlusion in acute ischaemic stroke is the standard of care when initiated within 6 hours of stroke onset, and is performed between 6-24 hours using advanced neuroimaging (CT perfusion or MR imaging) for patients who meet the strict imaging selection criteria. However, adherence to the restrictive imaging criteria recommended by current guidelines is impeded in many parts of the world, including the UK, by resource constraints and limited access to advanced neuroimaging in the emergency setting. Furthermore, recent randomised and non-randomised studies have demonstrated that patients selected without advanced neuroimaging (with non-contrast CT and CT angiography only) using less restrictive imaging criteria for EVT eligibility beyond 6 hours from onset still benefited from EVT treatment, thereby increasing the proportion of patients eligible for EVT and widening the potential treatment impact at a population level. Hence, current guidelines should be updated expeditiously to reflect the level I evidence in support of more liberal imaging selection criteria for patients presenting with acute ischaemic stroke due to a large vessel occlusion.

Endovascular thrombectomy beyond 24 hours from ischemic stroke onset: a propensity score matched cohort study

BACKGROUND

The safety and functional outcome of endovascular thrombectomy (EVT) in the very late (VL; >24 hours) time window from ischemic stroke onset remains undetermined.

METHODS

Using data from a national stroke registry, we used propensity score matched (PSM) individual level data of patients who underwent EVT, selected with CT perfusion or non-contrast CT/CT angiography, between October 2015 and March 2020. Functional and safety outcomes were assessed in both late (6-24 hours) and VL time windows. Subgroup analysis was performed of imaging selection modality in the VL time window.

RESULTS

We included 1150 patients (late window: 1046 (208 after PSM); VL window: 104 (104 after PSM)). Compared with EVT treatment initiation between 6 and 24 hours, patients treated in the VL window had similar modified Rankin Scale (mRS) scores at discharge (ordinal shift; common OR=1.08, 95% CI 0.69 to 1.47, p=0.70). No significant differences in achieving good functional outcome (mRS ≤2 at discharge; 28.8% (VL) vs 29.3% (late), OR=0.97, 95% CI 0.58 to 1.64, p=0.93), successful reperfusion (modified Thrombolysis in Cerebral Infarction score of 2b-3) (p=0.77), or safety outcomes of symptomatic intracranial hemorrhage (p=0.43) and inhospital mortality (p=0.23) were demonstrated. In the VL window, there was no significant difference in functional outcome among patients selected with perfusion versus those selected without perfusion imaging (common OR=1.38, 95% CI 0.81 to 1.76, p=0.18).

CONCLUSION

In this real world study, EVT beyond 24 hours from stroke onset or last known well appeared to be feasible, with comparable safety and functional outcomes to EVT initiation between 6 and 24 hours. Randomized trials assessing the efficacy of EVT in the VL window are warranted, but may only be feasible with a large international collaborative approach.

Perfusion Imaging for Endovascular Thrombectomy in Acute Ischemic Stroke Is Associated With Improved Functional Outcomes in the Early and Late Time Windows

The impact on clinical outcomes of patient selection using perfusion imaging for endovascular thrombectomy (EVT) in patients with acute ischemic stroke presenting beyond 6 hours from onset remains undetermined in routine clinical practice.

Association between anesthesia modality and clinical outcomes following endovascular stroke treatment in the extended time window

BACKGROUND

There is a paucity of data on anesthesia-related outcomes for endovascular treatment (EVT) in the extended window (>6 hours from ischemic stroke onset). We compared functional and safety outcomes between local anesthesia (LA) without sedation, conscious sedation (CS) and general anesthesia (GA).

METHODS

Patients who underwent EVT in the early (<6 hours) and extended time windows using LA, CS, or GA between October 2015 and March 2020 were included from a UK national stroke registry. Multivariable analyses were performed, adjusted for age, sex, baseline stroke severity, pre-stroke disability, EVT technique, center, procedural time and IV thrombolysis.

RESULTS

A total of 4337 patients were included, 3193 in the early window (1135 LA, 446 CS, 1612 GA) and 1144 in the extended window (357 LA, 134 CS, 653 GA). Compared with GA, patients treated under LA alone had increased odds of an improved modified Rankin Scale (mRS) score at discharge (early: adjusted common (ac) OR=1.50, 95% CI 1.29 to 1.74, p=0.001; extended: acOR=1.29, 95% CI 1.01 to 1.66, p=0.043). Similar mRS scores at discharge were found in the LA and CS cohorts in the early and extended windows (p=0.21). Compared with CS, use of GA was associated with a worse mRS score at discharge in the early window (acOR=0.73, 95% CI 0.45 to 0.96, p=0.017) but not in the extended window (p=0.55). There were no significant differences in the rates of symptomatic intracranial hemorrhage or in-hospital mortality across the anesthesia modalities in the extended window.

CONCLUSION

LA without sedation during EVT was associated with improved functional outcomes compared with GA, but not CS, within and beyond 6 hours from stroke onset. Prospective studies assessing anesthesia-related outcomes in the extended time window are warranted.

Pressor therapy in acute ischaemic stroke: an updated systematic review

Background

Low blood pressure (BP) in acute ischaemic stroke (AIS) is associated with poor functional outcome, death, or severe disability. Increasing BP might benefit patients with post-stroke hypotension including those with potentially salvageable ischaemic penumbra. This updated systematic review considers the present evidence regarding the use of vasopressors in AIS.

Methods

We searched the Cochrane Database of Systematic Reviews, MEDLINE, EMBASE and trial databases using a structured search strategy. We examined reference lists of relevant publications for additional studies examining BP elevation in AIS.

Results

We included 27 studies involving 1886 patients. Nine studies assessed increasing BP during acute reperfusion therapy (intravenous thrombolysis, mechanical thrombectomy, intra-arterial thrombolysis or combined). Eighteen studies tested BP elevation alone. Phenylephrine was the most commonly used agent to increase BP (n = 16 studies), followed by norepinephrine (n = 6), epinephrine (n = 3) and dopamine (n = 2). Because of small patient numbers and study heterogeneity, a meta-analysis was not possible. Overall, BP elevation was feasible in patients with fluctuating or worsening neurological symptoms, large vessel occlusion with labile BP, sustained post-stroke hypotension and ineligible for intravenous thrombolysis or after acute reperfusion therapy. The effects on functional outcomes were largely unknown and close monitoring is advised if such intervention is undertaken.

Conclusion

Although theoretical arguments support increasing BP to improve cerebral blood flow and sustain the ischaemic penumbra in selected AIS patients, the data are limited and results largely inconclusive. Large, randomised controlled trials are needed to identify the optimal BP target, agent, duration of treatment and effects on clinical outcomes.

Isolated clival subdural haemorrhage from a dolicoectactic vertebrobasilar aneurysm: Case report and overview of endovascular treatment strategies

Posterior fossa aneurysms presenting with isolated subdural haemorrhage (SDH) have scarcely been described with no cases attributed to a vertebrobasilar (VB) location. Non-saccular VB aneurysms are a distinct sub-group and in this report we also discuss the pathophysiology and treatment options for these difficult-to-manage lesions. We present a case of a 49 year-old man who presented with a 7-day history of severe headaches who was found to have an isolated acute clival SDH. Vascular imaging revealed a VB dolicoectatic segment with superimposed fusiform dilatations that contacted the dura adjacent to the SDH. A staged treatment was performed with initial parental vessel occlusion of the ruptured vertebral artery segment and subsequent insertion of a braided stent (LEO) with flow diverting properties into the progressively dilating basilar artery. A third procedure was performed to occlude a recurrent pouch at the lower basilar dilatation. Complete angiographic occlusion was achieved and the patient is under continued surveillance. To our knowledge, this is the first case of a ruptured non-saccular VB aneurysm presenting with radiologically isolated clival SDH. Clinical history will often inform the need for vascular imaging in such atypical presentations. Managing these lesions remains an endovascular challenge and requires a specialist multi-disciplinary approach.

Left Atrial Enlargement on Non-Gated CT Is Associated with Large Vessel Occlusion in Acute Ischaemic Stroke

Background

Recent reports have suggested that atrial fibrillation (AF) is more prevalent in the large vessel occlusion (LVO) subgroup of acute ischaemic stroke patients. Given the association between left atrial enlargement (LAE) and AF, we sought to evaluate the feasibility of assessing LAE on non-gated CT and its association with LVO in the hyperacute stroke setting.

Methods

We analysed our prospectively collected database that included all stroke patients referred for consideration of endovascular treatment between April 14, 2020, and May 21, 2020. During this period, a CT chest was included in our regional stroke protocol to aid triage of patients suspected for COVID-19 from which cardiac measurements were obtained. Patients were dichotomized into LVO and no-LVO groups, and LA measurements were trichotomized into normal, borderline, and enlarged. Univariate analyses were performed between groups.

Results

Of the included 38 patients, 21 were categorized as LVO and 17 as no LVO. There was a statistically significant association between LAE and LVO (p = 0.028). No significant difference was demonstrated between groups for the baseline AF and other clinical characteristics, except for baseline NIHSS (p = 0.0005). There was excellent inter- and intra-rater reliability (ICC = 0.969) for LA measurements.

Conclusion

Our study provides preliminary data to suggest LAE is more prevalent in the LVO stroke subgroup at presentation and can be reliably assessed on non-gated CT in the hyperacute setting. These findings have potential implications for stratifying secondary management and may prompt a more rigorous pursuit of occult AF or other cardiac causes of stroke.

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.

Direct mechanical thrombectomy without intravenous thrombolysis versus bridging therapy for acute ischemic stroke: A meta-analysis of randomized controlled trials

BACKGROUND

Direct mechanical thrombectomy may result in similar outcomes compared to a bridging approach with intravenous thrombolysis (IVT + MT) in acute ischemic stroke. Recent randomized controlled trials have varied in their design and noninferiority margin.

AIM

We sought to meta-analyze accumulated trial data to assess the difference and non-inferiority in clinical and procedural outcomes between direct mechanical thrombectomy and bridging therapy.

SUMMARY OF REVIEW

We conducted a systematic review of electronic databases following the preferred reporting items for systematic reviews and meta-analyses guidelines. Random effects meta-analyses were conducted for the pooled data. The primary outcome was good functional outcome at 90 days (modified Rankin scale (mRS) ≤ 2). Secondary outcomes included excellent functional outcome (mRS ≤ 1), mortality, any intracranial hemorrhage, symptomatic intracranial hemorrhage, successful reperfusion (thrombolysis in cerebral infarction ≥ 2 b), and procedure-related complications. Four randomized controlled trials comprising 1633 patients (817 direct mechanical thrombectomy, 816 bridging therapy) were included. There were no statistical differences for the 90-day good functional outcome (OR = 1.02, 95% CI 0.84-1.25, p = 0.54, I²= 0%), and the absolute risk difference was 1% (95% CI: -4% to 5%). The lower 95% CI falls within the strictest noninferiority margin of -10% among included randomized control trials. Direct mechanical thrombectomy reduced the odds of successful reperfusion (OR = 0.76, 95% CI: 0.60-0.97, p = 0.03, I²= 0%) and any intracranial hemorrhage (OR = 0.65, 95% CI: 0.49-0.86, p = 0.003, I²= 38%). There was no difference in the remaining secondary outcomes. The risk of bias for all studies was low.

CONCLUSION

The combined trial data assessing direct mechanical thrombectomy versus bridging therapy showed no difference in improving good functional outcome. The wide noninferiority thresholds set by individual trials are in contrast with the clinical consensus on minimally important differences. However, our pooled analysis indicates noninferiority of direct mechanical thrombectomy with a 4% margin of confidence. The application of these findings is limited to patients presenting directly to mechanical thrombectomy-capable centers and real-world workflow times may differ against those achieved in a trial setting.

Use of 8Fr angio-seal for closure of femoral arteriotomy following use of 8Fr and 9Fr sheaths in patients undergoing mechanical thrombectomy for acute ischaemic stroke

BACKGROUND

Little is known about the safety of off-label use of an 8Fr Angio-Seal VIP for large-bore arteriotomies in patients treated with mechanical thrombectomy (MT) and intravenous thrombolysis (IVT) for acute ischaemic stroke (AIS). We aimed to identify differences in the groin complication rate using an 8Fr Angio-Seal VIP for common femoral arteriotomy closures following the use of 8Fr and 9Fr sheaths.

METHODS

All AIS patients who underwent MT at our tertiary neuroscience unit between January 2018 and March 2020 were retrospectively reviewed.

RESULTS

161 patients were included in the study, of whom 56 and 105 patients underwent an arteriotomy using an 8Fr sheath (36 of them receiving IVT) and a 9Fr sheath (57 of them receiving IVT). Overall, 17 groin complications were identified (10.5%) in 5 patients (8.9%) who had had 8Fr sheaths inserted and 12 patients (11.4%) who had had 9Fr sheaths inserted. Major complications were identified in only 2 patients (1.2%), one patient in each of the 8Fr and 9Fr cohorts suffering a pseudoaneurysm requiring intervention. No retroperitoneal haematoma, infection, acute limb ischaemia or ipsilateral DVT was identified. No significant difference in groin complications was observed between the 8Fr and 9Fr femoral arteriotomy cohorts or between the MT patients that did or did not receive adjunctive IVT.

CONCLUSION

In the setting of MT with IVT, off-label use of an 8Fr Angio-Seal VIP for closure of a femoral arteriotomy following use of a 9Fr sheath has a similar safety profile to the licensed use of an 8Fr Angio-Seal VIP for closure of a femoral arteriotomy following use of an 8Fr sheath or smaller.

Local anesthesia as a distinct comparator versus conscious sedation and general anesthesia in endovascular stroke treatment: a systematic review and meta-analysis

BACKGROUND

The optimal anesthetic modality for endovascular treatment (EVT) in acute ischemic stroke (AIS) is undetermined. Comparisons of general anesthesia (GA) with composite non-GA cohorts of conscious sedation (CS) and local anesthesia (LA) without sedation have provided conflicting results. There has been emerging interest in assessing whether LA alone may be associated with improved outcomes. We conducted a systematic review and meta-analysis to evaluate clinical and procedural outcomes comparing LA with CS and GA.

METHODS

We reviewed the literature for studies reporting outcome variables in LA versus CS and LA versus GA comparisons. The primary outcome was 90 day good functional outcome (modified Rankin Scale (mRS) score of ≤2). Secondary outcomes included mortality, symptomatic intracerebral hemorrhage, excellent functional outcome (mRS score ≤1), successful reperfusion (Thrombolysis in Cerebral Infarction (TICI) >2b), procedural time metrics, and procedural complications. Random effects meta-analysis was performed on unadjusted and adjusted data.

RESULTS

Eight non-randomized studies of 7797 patients (2797 LA, 2218 CS, and 2782 GA) were identified. In the LA versus GA comparison, no statistically significant differences were found in unadjusted analyses for 90 day good functional outcome or mortality (OR=1.22, 95% CI 0.84 to 1.76, p=0.3 and OR=0.83, 95% CI 0.64 to 1.07, p=0.15, respectively) or in the LA versus CS comparison (OR=1.14, 95% CI 0.76 to 1.71, p=0.53 and OR=0.88, 95% CI 0.62 to 1.24, p=0.47, respectively). There was a tendency towards achieving excellent functional outcome (mRS ≤1) in the LA group versus the GA group (OR=1.44, 95% CI 1.00 to 2.08, p=0.05, I²=70%). Analysis of adjusted data demonstrated a tendency towards higher odds of death at 90 days in the GA versus the LA group (OR=1.24, 95% CI 1.00 to 1.54, p=0.05, I²=0%).

CONCLUSION

LA without sedation was not significantly superior to CS or GA in improving outcomes when performing EVT for AIS. However, the quality of the included studies impaired interpretation, and inclusion of an LA arm in future well designed multicenter, randomized controlled trials is warranted.

Flow-related posterior cerebral artery aneurysms with internal carotid artery occlusions: An institutional series

BACKGROUND

Aneurysm formation after internal carotid artery (ICA) occlusion has been described in animal models and human case series with alteration of cerebral blood flow dynamics considered an aetiological risk factor. Such de novo aneurysms have seldom been described in the posterior cerebral artery (PCA) with the majority observed in the anterior circulation collateral pathways.

METHODS

We retrospectively reviewed our institutional database of posterior circulation aneurysms in patients with iatrogenic, atherosclerotic or congenital ICA occlusions. A comprehensive review of the online literature using the PubMed and Medline databases was performed to identify previous cases of PCA aneurysms that were considered 'flow-related'.

RESULTS

We present five patients with symptomatic or ruptured PCA aneurysms with ICA occlusions. Age at presentation ranged from 21-58 and aneurysm size from 3-12 mm. All cases had angiographic evidence of posterior-anterior flow via the ipsilateral posterior communicating artery (PComA). The clinical presentation, diagnostic imaging and management strategies are further discussed. A literature review identified only two previous reported cases.

CONCLUSION

To our knowledge this is the first single centre series of posterior circulation aneurysms in patients with ICA occlusions that are considered to be 'flow-related.' The natural history of these rare lesions is unclear and the best management and surveillance strategy requires a patient-tailored approach by an experienced neurovascular team.

Neurological Disorders Associated With COVID-19 Hospital Admissions: Experience of a Single Tertiary Healthcare Center

Background: Early reports have detailed a range of neurological symptoms in patients with the SARS-CoV-2 infection. However, there is a lack of detailed description and incidence of the neurological disorders amongst hospitalized COVID-19 patients. We describe a range of neurological disorders (other than non-specific neurological symptoms), including their clinical, radiological, and laboratory findings, encountered in our cohort of COVID-19 patients admitted to a large tertiary institution.

Methods: We reviewed our prospectively collated database of all adult Neurology referrals, Neurology and Stroke admissions and Neurological multi-disciplinary team meetings for all hospitalized patients with suspected or proven COVID-19 from 17 March 2020 to 31 August 2020.

Results: Twenty-nine of 1,243 COVID-19 inpatients (2.3%) presented with COVID-19-related neurological disorders. The mean age was 68.9 ± 13.5(SD) years, age range of 34–97 years, and there were 16 males. Twenty two patients had confirmed, five were probable and two had suspected COVID-19 infection according to the WHO case classification. Eight patients (27%) required critical care admission. Neurological symptoms at presentation included acute confusion and delirium, seizures, and new focal neurological deficits. Based on the pre-defined neurological phenotype, COVID-19 patients were grouped into four main categories. Sixteen patients had cerebrovascular events (13 with acute ischemic stroke and three had hemorrhagic features), seven patients were found to have inflammatory, non-inflammatory and autoimmune encephalopathy (including two with known Multiple Sclerosis), whilst disorders of movement and peripheral nervous system were diagnosed in three patients each.

Conclusion: Although the exact prevalence and etiology remain unclear, new onset of neurological disorders, in addition to anosmia, is non-sporadic during the acute COVID-19-infection. Longitudinal follow-up of these patients is required to determine the clinical and functional outcome, treatment response and long-term effects of the SARS-CoV-2 infection.

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.

Trans-arterial embolisation (TAE) in haemorrhagic pelvic injury: review of management and mid-term outcome of a major trauma centre

BACKGROUND

Management of pelvic fracture associated haemorrhage is often complex with high morbidity and mortality rates. Different treatment options are used to control bleeding with an on-going discussion in the trauma community regarding the best management algorithm.

MAIN BODY

Recent studies have shown trans-arterial embolisation (TAE) to be a safe and effective technique to control pelvic fracture associated haemorrhage. Computed tomography (CT) evidence of active bleeding, haemodynamic instability, and pelvic fracture patterns are amongst important indicators for TAE.

CONCLUSION

Herein, we aim to provide a comprehensive literature review of the effectiveness of TAE in controlling haemorrhage secondary to pelvic fracture according to the indications, technique and embolic agents, and outcomes, whilst incorporating our Level 1 major trauma centre's (MTC) results between 2014-2017.

Incidental extravascular findings in CT angiograms in patients post endovascular abdominal aortic aneurysm repair: clinical relevance and frequency

Background

To evaluate the incidence and clinical relevance of extravascular incidental findings (EVIF), particularly malignancies, in planning and follow-up CT angiograms (CTA) of the abdominal aorta in patients who underwent endovascular aneurysm repair (EVAR) of abdominal aortic aneurysm. Retrospective study of 2203 planning and follow-up CTAs of 418 patients who underwent EVAR in a single tertiary centre between 2006 and 2015. CTA reports were scrutinized for EVIFs, which were classified according to clinical relevance, into (I) immediate, (II) potential and (III) no clinical relevance. Clinical follow-up and management were reviewed for significant findings. Follow-up CTAs of patients with incidental malignancies were re-reviewed by two consultant radiologists to evaluate if early missed malignant findings on previous CTAs were present.

Results

In total, 950 EVIFs were noted in 418 patients [31 females (7.4%), 387 males (92.6%); age range 63–93, mean age 79.0 years]. The number of patients with findings in each category were; Category I (115), Category II (165), Category III (304). Incidental malignant findings were reported in 51 patients (12.2%), of which 27 were noted on the initial CTA (6.5%) and 24 on follow-up CTAs (5.7%). Of the 24 patients with malignancies on follow-up CTAs, 13 had early malignant findings missed or misinterpreted on previous CTAs, while 11 had no significant abnormality even on retrospective review.

Conclusion

A high number of significant EVIFs, particularly incidental malignancies, can be identified in follow-up CTAs of patients who undergo EVAR. Specific ‘review areas’ when reporting surveillance CTAs can be recommended based on the findings of our study.

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.

Ophthalmic manifestations postlightning strike

Various ophthalmic complications affecting the anterior and posterior segments have been identified due to lightning strike. We report the first case of an indirect lightning-induced full thickness macular hole formation in the UK as evidenced by slit lamp examination and optical coherence tomography (OCT) scan in a 77-year-old woman presenting with sudden visual loss in her right eye and thermal skin injury affecting her scalp. Her best corrected visual acuities were LogMAR 0.46 and 0.12 in the right and left eyes, respectively. There were no other ocular manifestations observed in either eye. She was initially managed conservatively with non-steroidal anti-inflammatory drug eye drops but surgery was later advised due to minimal changes in the visual acuity and macular hole on follow-up. OCT scanning is important in diagnosing macular holes, which usually warrant surgical intervention.

Characterization of corneal stromal stem cells with the potential for epithelial transdifferentiation

INTRODUCTION

The corneal stroma is being increasingly recognized as a repository for stem cells. Like the limbal and endothelial niches, stromal stem cells often reside in the peripheral cornea and limbus. These peripheral and limbal corneal stromal cells (PLCSCs) are known to produce mesenchymal stem cells in vitro. Recently, a common corneal stromal and epithelial progenitor was hinted at. This study aims to examine the stem cell potential of corneal stromal cells and to investigate their epithelial transdifferentiation ability.

METHODS

PLCSCs were grown in traditional Dulbecco modified Eagle medium (DMEM)-based keratocyte culture medium and an M199-based medium and analyzed for a profile of cell-surface markers by using flow cytometry and differentiated into mesenchymal phenotypes analyzed with quantitative polymerase chain reaction (qPCR) and histologic staining. PLCSCs in M199 were subsequently divided into subpopulations based on CD34 and CD105 expression by using fluorescence- activated cell sorting (FACS). Subpopulations were characterized by marker profile and mesenchymal differentiation ability. Both whole PLCSCs and subpopulations were also cultured for epithelial transdifferentiation.

RESULTS

Cells cultured in M199 demonstrated a more stem-like cell-surface marker profile, and the keratocyte marker CD34 was retained for several passages but absent in cells cultured in DMEM. Cells cultured in M199 also exhibited a greater mesenchymal differentiation potential, compared with DMEM. PLCSCs could be divided into CD34(+)CD105(+), CD34-CD105(+), and CD34-CD105- subpopulations, of which CD34(+)CD105(+) cells were the most stemlike with regard to marker expression and mesenchymal differentiation potential. Subpopulations of PLCSCs exhibited differing abilities to transdifferentiate into epithelial phenotypes. Cells that were initially CD34(+)CD105(+) showed the greatest differentiation potential, producing CK3(+) and CK19(+) cells, and expressed a range of both epithelial progenitor (HES1, FRZB1, DCT, SOD2, ABCG2, CDH1, KRT19) and terminally differentiated (DSG3, KRT3, KRT12, KRT24) genes.

CONCLUSIONS

Culture medium has a significant effect on the phenotype and differentiation capacity of PLCSCs. The stroma contains a heterogeneous cell population in which we have identified CD34(+) cells as a stem cell population with a capacity for mesenchymal and epithelial differentiation.

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.