John Thornton

Analysis of Workflow and Time to Treatment on Thrombectomy Outcome in the Endovascular Treatment for Small Core and Proximal Occlusion Ischemic Stroke (ESCAPE) Randomized, Controlled Trial

Background— The Endovascular Treatment for Small Core and Proximal Occlusion Ischemic Stroke (ESCAPE) trial used innovative imaging and aggressive target time metrics to demonstrate the benefit of endovascular treatment in patients with acute ischemic stroke. We analyze the impact of time on clinical outcome and the effect of patient, hospital, and health system characteristics on workflow within the trial. Methods and Results— Relationship between outcome (modified Rankin Scale) and interval times was modeled by using logistic regression. Association between time intervals (stroke onset to arrival in endovascular-capable hospital, to qualifying computed tomography, to groin puncture, and to reperfusion) and patient, hospital, and health system characteristics were modeled by using negative binomial regression. Every 30-minute increase in computed tomography-to-reperfusion time reduced the probability of achieving a functionally independent outcome (90-day modified Rankin Scale 0–2) by 8.3% (P=0.006). Symptom onset-to-imaging time was not associated with outcome (P>0.05). Onset-to-endovascular hospital arrival time was 42% (34 minutes) longer among patients receiving intravenous alteplase at the referring hospital (drip and ship) versus direct transfer (mothership). Computed tomography-to-groin puncture time was 15% (8 minutes) shorter among patients presenting during work hours versus off hours, 41% (24 minutes) shorter in drip-ship patients versus mothership, and 43% (22 minutes) longer when general anesthesia was administered. The use of a balloon guide catheter during endovascular procedures shortened puncture-to-reperfusion time by 21% (8 minutes). Conclusions— Imaging-to-reperfusion time is a significant predictor of outcome in the ESCAPE trial. Inefficiencies in triaging, off-hour presentation, intravenous alteplase administration, use of general anesthesia, and endovascular techniques offer major opportunities for improvement in workflow. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT01778335.

Safety and Efficacy of Solitaire Stent Thrombectomy Individual Patient Data Meta-Analysis of Randomized Trials

Background and Purpose— Recent positive randomized trials of endovascular therapy for ischemic stroke used predominantly stent retrievers. We pooled data to investigate the efficacy and safety of stent thrombectomy using the Solitaire device in anterior circulation ischemic stroke. Methods— Patient-level data were pooled from trials in which the Solitaire was the only or the predominant device used in a prespecified meta-analysis (SEER Collaboration): Solitaire FR With the Intention for Thrombectomy as Primary Endovascular Treatment (SWIFT PRIME), Endovascular Treatment for Small Core and Anterior Circulation Proximal Occlusion With Emphasis on Minimizing CT to Recanalization Times (ESCAPE), Extending the Time for Thrombolysis in Emergency Neurological Deficits—Intra-Arterial (EXTEND-IA), and Randomized Trial of Revascularization With Solitaire FR Device Versus Best Medical Therapy in the Treatment of Acute Stroke Due to Anterior Circulation Large Vessel Occlusion Presenting Within Eight Hours of Symptom Onset (REVASCAT). The primary outcome was ordinal analysis of modified Rankin Score at 90 days. The primary analysis included all patients in the 4 trials with 2 sensitivity analyses: (1) excluding patients in whom Solitaire was not the first device used and (2) including the 3 Solitaire-only trials (excluding ESCAPE). Secondary outcomes included functional independence (modified Rankin Score 0–2), symptomatic intracerebral hemorrhage, and mortality. Results— The primary analysis included 787 patients: 401 randomized to endovascular thrombectomy and 386 to standard care, and 82.6% received intravenous thrombolysis. The common odds ratio for modified Rankin Score improvement was 2.7 (2.0–3.5) with no heterogeneity in effect by age, sex, baseline stroke severity, extent of computed tomography changes, site of occlusion, or pretreatment with alteplase. The number needed to treat to reduce disability was 2.5 and for an extra patient to achieve independent outcome was 4.25 (3.29–5.99). Successful revascularization occurred in 77% treated with Solitaire device. The rate of symptomatic intracerebral hemorrhage and overall mortality did not differ between treatment groups. Conclusions— Solitaire thrombectomy for large vessel ischemic stroke was safe and highly effective with substantially reduced disability. Benefits were consistent in all prespecified subgroups.

Retrieval of a Migrated Coil Using an X6 MERCI Device

Coil migration is a recognised but rare complication of endovascular coiling. Many techniques are available commercially for coil retrieval. We report the case of an acute subarachnoid hemorrhage in a 54-year-old woman in which a migrated coil was successfully retrieved using an X6 MERCI device.

Diastolic Filling Parameters Derived from Myocardial Perfusion Imaging Can Predict Left Ventricular End-Diastolic Pressure at Subsequent Cardiac Catheterization

Morbidity and mortality increase when diastolic dysfunction accompanies coronary artery disease (CAD). An elevated stress 201Tl lung-to-heart ratio (LHR) is a traditional marker of elevated left ventricular end-diastolic pressure (LVEDP), which adds prognostic value in CAD. Since the introduction of 99mTc-labeled agents, this valuable marker has been lost. Hence, there is only a limited ability to assess diastolic dysfunction by myocardial perfusion imaging (MPI). Methods: Fifty-two consecutive patients with an ejection fraction of ≥45% underwent MPI and cardiac catheterization within 15 d. Peak filling rate (PFR), time to PFR (TPFR), and filling rate during the first third of diastole (1/3FR) were obtained from MPI with SPECT software. Resting 201Tl LHR was calculated manually, and LVEDP was obtained at catheterization. Results: PFR, TPFR, and 1/3FR correlated significantly with LVEDP (r = −0.53, 0.45, and −0.45, respectively; P = 0.00005, 0.0009, and 0.0009, respectively), whereas resting 201Tl LHR did not (r = 0.10, P = 0.49). Receiver-operating-characteristic curve analysis of PFR, TPFR, and 1/3FR for detecting LVEDPs of ≥18 mm Hg showed areas under the curve of 0.83, 0.75, and 0.80, respectively. The combination of PFR and 1/3FR showed a negative predictive value of 84%, a positive predictive value of 86%, and a specificity of 94%. Conclusion: Diastolic filling variables obtained with the SPECT software showed a significant correlation with LVEDP. PFR, TPFR, and 1/3FR were superior to resting 201Tl LHR and showed good sensitivity, specificity, and predictive power for detecting LVEDPs of ≥18 mm Hg. Hence, combining data on the presence of perfusion defects with data on diastolic impairments can be achieved by adding these variables to MPI results.

Coil Migration through a Neuroform 3 Stent during Endovascular Coiling: A Case Report

A 43-year-old woman attended for stent assisted coiling. A Neuroform 30 × 4.5 mm stent had been successfully placed over the left periophthalmic aneurysm. During the coiling the first coil migrated through the crowns in the stent, lodging at the MCA bifurcation. We believe that the coil herniated through the overlying stent due to the carotid siphon curvature and the open cell design. Furthermore the distal markers of the stent impeded coil extraction with a MERCI device.

Outcome Prediction in Acute Stroke Patients Considered for Endovascular Treatment: a Novel Tool

Functional outcome following emergent intra-arterial thrombectomy is variable and likely reflects the heterogeneous characteristics of acute stroke patients. The aims of our study were (1) to study which pre-treatment variables correlate with functional outcome and (2) to devise a tool which would reliably predict outcome. Prospective data of patients treated with intra-arterial mechanical thrombectomy in our institution between 2010 and 2012 were collected. A preliminary univariate analysis of baseline variables was performed and data outliers were identified by constructing scatter and box plots. Systematic bivariate analysis was then carried out using a linear regression model and the individual contributing weights of the variables to outcome calculated. The B and constant values from the regression were used to construct a predictive formula. Fifty-seven patients, 35 males (61.4%) and 22 females (38.6%) with a mean age of 62.3 years (range 26–87) were included in the cohort. Statistical correlations of baseline variables and functional outcome showed that age, National Institutes of Health Stroke Scale at presentation and CT leptomeningeal collaterals were strongly correlated (p<0.01), and were later included in the linear regression model. A tool was devised from the regression formula combining weighted inputs of the three variables. Regression statistics and residual analysis were then performed to assess the accuracy and reliability of the proposed tool. The proposed tool is easy to use and reliably predicts functional outcome prior to endovascular therapy. It may help clinical decision-making in the acute setting and offers ‘tailor-made’ outcome expectations.

Imaging of Adult Ocular and Orbital Pathology - a Pictorial Review

Orbital pathology often presents a diagnostic challenge to the reporting radiologist. The aetiology is protean, and clinical input is therefore often necessary to narrow the differential diagnosis. With this manuscript, we provide a pictorial review of adult ocular and orbital pathology.

Defining the Role of the Stroke Physician During Endovascular Therapy of Acute Ischemic Stroke

Six recent trials and a patient-level meta-analysis have demonstrated the superiority of endovascular therapy (EVT) compared with standard care (including intravenous alteplase) among patients with large-artery anterior circulation strokes.1–7 The absolute benefit of EVT was substantial in these trials, and EVT now requires careful implementation and optimization in real-world settings to provide all eligible patients with this new standard of care. Parallel rather than serial workflow, with team members having well-defined roles, is a crucial element in providing rapid and effective delivery of acute stroke care.8nnThere is little or no literature on the division of labor or the expected role for each individual in this setting, and existing stroke guidelines do not elaborate on this issue. Although each system may require customization, it is clear is that there must be physician leadership outside of the angiography suite, a physician in addition to the neurointerventionalist (who is most commonly a radiologist, but who may be a neurosurgeon or neurologist) in the angiography suite, and a physician to coordinate care between the other stroke team members throughout the periprocedural period. We suggest that it is necessary to designate a physician to fulfill these roles during the EVT process, and we have termed herein the individual fulfilling this role the stroke physician.nnThe stroke physician must work in close collaboration with the neurointerventionalist to optimize the speed, efficiency, and safety of EVT, elements which are critical to enhancing patient outcomes. A proposed division of physician roles is shown in Table, with emphasis on parallel rather than serial workflow. The administration of intravenous alteplase is ideally performed under the guidance of a stroke physician with specialized training in stroke care. This is most often a neurologist but may also be an emergency physician, geriatrician, internist, or family physician, …

Drip and ship versus direct to endovascular thrombectomy: The impact of treatment times on transport decision-making:

Introduction In ischaemic stroke care, fast reperfusion is essential for disability free survival. It is unknown if bypassing thrombolysis centres in favour of endovascular thrombectomy (mothership) outweighs transport to the nearest thrombolysis centre for alteplase and then transfer for endovascular thrombectomy (drip-and-ship). We use conditional probability modelling to determine the impact of treatment times on transport decision-making for acute ischaemic stroke. Materials and methods Probability of good outcome was modelled using a previously published framework, data from the Irish National Stroke Register, and an endovascular thrombectomy registry at a tertiary referral centre in Ireland. Ireland was divided into 139 regions, transport times between each region and hospital were estimated using Google’s Distance Matrix Application Program Interface. Results were mapped using ArcGIS 10.3. Results Using current treatment times, drip-and-ship rarely predicts best outcomes. However, if door to needle times are reduced to 30 min, drip-and-ship becomes more favourable; even more so if turnaround time (time from thrombolysis to departure for the endovascular thrombectomy centre) is also reduced. Reducing door to groin puncture times predicts better outcomes with the mothership model. Discussion This is the first case study modelling pre-hospital transport for ischaemic stroke utilising real treatment times in a defined geographic area. A moderate improvement in treatment times results in significant predicted changes to the optimisation of a national acute stroke patient transport strategy. Conclusions Modelling patient transport for system-level planning is sensitive to treatment times at both thrombolysis and thrombectomy centres and has important implications for the future planning of thrombectomy services.

Unruptured Basilar Tip Aneurysm with Internal Septation: Coiling Implications?

An internal septum within a basilar artery aneurysm is an infrequent anomaly and is very rarely reported in the literature. We report a 62-year-old lady that was incidentally diagnosed with basilar tip aneurysm. Further imaging with magnetic resonance imaging (MRI) revealed internal septation within this aneurysm which was later confirmed with digital subtraction angiography (DSA). She underwent coil embolisation, which involved technical manipulation of the microcatheter and the balloon to enable coiling of each separate aneurysm compartment. We present this case to illustrate the effect of this anatomical variation on the selection of endovascular treatment strategy.