SoHyun Boo

Bio: SoHyun Boo is an academic researcher from West Virginia University. The author has contributed to research in topics: Aneurysm & Stroke. The author has an hindex of 6, co-authored 29 publications receiving 374 citations.

A population-based incidence of acute large vessel occlusions and thrombectomy eligible patients indicates significant potential for growth of endovascular stroke therapy in the USA.

Abstract: Background Data on large vessel strokes are important for resource allocation and infrastructure development. Objective To determine an annual incidence of large vessel occlusions (LVOs) and a thrombectomy eligible patient population. Methods All patients with acute ischemic stroke discharged over 3 years from a tertiary-level hospital serving a large geographic area were evaluated for an LVO (M1, internal carotid artery terminus, basilar artery). The incidence of LVO was determined for the hospital9s 4-county primary service area (PSA, population 210 000) based on each county9s discharges and extrapolated to the US population. ‘Thrombectomy eligibility’ for anterior circulation LVOs was based on time (onset Results 1157 patients were discharged from the hospital9s PSA, of whom 129 (11.1%, 95% CI 9.5% to 13.1%) had an LVO. This translated into an LVO incidence of 24 per 100 000 people per year (95% CI 20 to 28). 20 per 100 000 people per year had anterior circulation LVOs (95% CI 19 to 22), of whom 10/100 000/year (95% CI 8 to 11) were ‘thrombectomy eligible’. An additional 5/100 000/year (95% CI 3 to 6) presented with favorable ASPECTS after 6 hours of symptom onset. Basilar occlusion incidence was estimated at 4/100 000/year (95% CI 2 to 5). These rates yield 77 569 (95% CI 65 835 to 91 091) new LVOs per year in the USA. An estimated 10 284 mechanical thrombectomy procedures were performed in 2015. Conclusions This study estimates an LVO incidence of 24 per 100 000 person-years (95% CI 20 to 28). A current estimated annual thrombectomy rate of three procedures per 100 000 people indicates significant potential increase in the volume of endovascular procedures and the need to develop systems of care.

Intravenous thrombolysis before endovascular therapy for large vessel strokes can lead to significantly higher hospital costs without improving outcomes.

Abstract: Background Limited efficacy of IV recombinant tissue plasminogen activator (rt-PA) for large vessel occlusions (LVO) raises doubts about its utility prior to endovascular therapy. Purpose To compare outcomes and hospital costs for anterior circulation LVOs (middle cerebral artery, internal carotid artery terminus (ICA-T)) treated with either primary endovascular therapy alone (EV-Only) or bridging therapy (IV+EV)). Methods A single-center retrospective analysis was performed. Clinical and demographic data were collected prospectively and relevant cost data were obtained for each patient in the study. Results 90 consecutive patients were divided into EV-Only (n=52) and IV+EV (n=38) groups. There was no difference in demographics, stroke severity, or clot distribution. The mean (SD) time to presentation was 5:19 (4:30) hours in the EV-Only group and 1:46 (0:52) hours in the IV+EV group (p Conclusions IV rt-PA did not improve recanalization, thrombectomy efficacy, functional outcomes, or length of stay. Combined therapy was associated with significantly higher total and direct hospital costs than endovascular therapy alone.

A population-based incidence of M2 strokes indicates potential expansion of large vessel occlusions amenable to endovascular therapy

Abstract: Background M2 occlusions may result in poor outcomes and potentially benefit from endovascular therapy. Data on the rate of M2 strokes is lacking. Methodology Patients with acute ischemic stroke discharged over a period of 3 years from a tertiary level hospital in the ‘stroke belt’ were evaluated for M2 occlusions on baseline vascular imaging. Regional and national incidence was calculated from discharge and multicounty data. Results There were 2739 ICD-9 based AIS discharges. M2 occlusions in 116 (4%, 95% CI 3.5% to 5%) patients constituted the second most common occlusion site. The median National Institute of Health Stroke Scale (NIHSS) score was 12 (IQR 5–18). Good outcomes were observed in 43% (95% CI 34% to 53%), poor outcomes in 57% (95% CI 47% to 66%), and death occurred in 27% (95% CI 19% to 37%) of patients. Receiver operating characteristics curves showed the NIHSS to be predictive of outcomes (area under the curve 0.829, 95% CI 0.745 to 0.913, p 3 for NIHSS score ≥9 versus 30 (±34)cm 3 for NIHSS score Conclusion M2 occlusions can present with serious neurological deficits and cause significant morbidity and mortality. Patients with M2 occlusions and higher baseline deficits (NIHSS score ≥9) may benefit from endovascular therapy, thus potentially expanding the category of acute ischemic strokes amenable to intervention.

The ‘pit-crew’ model for improving door-to-needle times in endovascular stroke therapy: a Six-Sigma project

Abstract: Background Delays in delivering endovascular stroke therapy adversely affect outcomes. Time-sensitive treatments such as stroke interventions benefit from methodically developed protocols. Clearly defined roles in these protocols allow for parallel processing of tasks, resulting in consistent delivery of care. Objective To present the outcomes of a quality-improvement (QI) process directed at reducing stroke treatment times in a tertiary level academic medical center. Methods A Six-Sigma-based QI process was developed over a 3-month period. After an initial analysis, procedures were implemented and fine-tuned to identify and address rate-limiting steps in the endovascular care pathway. Prospectively recorded treatment times were then compared in two groups of patients who were treated ‘before’ (n=64) or ‘after’ (n=30) the QI process. Three time intervals were measured: emergency room (ER) to arrival for CT scan (ER–CT), CT scan to interventional laboratory arrival (CT–Lab), and interventional laboratory arrival to groin puncture (Lab–puncture). Results The ER–CT time was 40 (±29) min in the ‘before’ and 26 (±15) min in the ‘after’ group (p=0.008). The CT–Lab time was 87 (±47) min in the ‘before’ and 51 (±33) min in the ‘after’ group (p=0.0002). The Lab–puncture time was 24 (±11) min in the ‘before’ and 15 (±4) min in the ‘after’ group (p Conclusions A protocol-driven process can significantly improve efficiency of care in time-sensitive stroke interventions.

Anatomical differences in patients with lumbosacral transitional vertebrae and implications for minimally invasive spine surgery.

Abstract: OBJECTIVE The objective of this study was to investigate the neurovascular and anatomical differences in patients with lumbosacral transitional vertebrae (LSTV) and the associated risk of neurovascular injury in minimally invasive spine surgery. METHODS The authors performed a retrospective study of CT and MR images of the lumbar spine obtained at their institution between 2010 and 2014. The following characteristics were evaluated: level of the iliac crest in relation to the L4–5 disc space, union level of the iliac veins and arteries in relation to the L4–5 disc space, distribution of the iliac veins and inferior vena cava according to the different Moro zones (A, I, II, III, IV, P) at the L4–5 disc space, and the location of the psoas muscle at the L4–5 disc space. The findings were compared with findings on images obtained in 28 age- and sex-matched patients without LSTV who underwent imaging studies during the same time period. RESULTS Twenty-eight patients (12 male, 16 female) with LSTV and the requ...

Guidelines for the Early Management of Patients With Acute Ischemic Stroke: 2019 Update to the 2018 Guidelines for the Early Management of Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association.

Abstract: Background and Purpose- The purpose of these guidelines is to provide an up-to-date comprehensive set of recommendations in a single document for clinicians caring for adult patients with acute arterial ischemic stroke. The intended audiences are prehospital care providers, physicians, allied health professionals, and hospital administrators. These guidelines supersede the 2013 Acute Ischemic Stroke (AIS) Guidelines and are an update of the 2018 AIS Guidelines. Methods- Members of the writing group were appointed by the American Heart Association (AHA) Stroke Council's Scientific Statements Oversight Committee, representing various areas of medical expertise. Members were not allowed to participate in discussions or to vote on topics relevant to their relations with industry. An update of the 2013 AIS Guidelines was originally published in January 2018. This guideline was approved by the AHA Science Advisory and Coordinating Committee and the AHA Executive Committee. In April 2018, a revision to these guidelines, deleting some recommendations, was published online by the AHA. The writing group was asked review the original document and revise if appropriate. In June 2018, the writing group submitted a document with minor changes and with inclusion of important newly published randomized controlled trials with >100 participants and clinical outcomes at least 90 days after AIS. The document was sent to 14 peer reviewers. The writing group evaluated the peer reviewers' comments and revised when appropriate. The current final document was approved by all members of the writing group except when relationships with industry precluded members from voting and by the governing bodies of the AHA. These guidelines use the American College of Cardiology/AHA 2015 Class of Recommendations and Level of Evidence and the new AHA guidelines format. Results- These guidelines detail prehospital care, urgent and emergency evaluation and treatment with intravenous and intra-arterial therapies, and in-hospital management, including secondary prevention measures that are appropriately instituted within the first 2 weeks. The guidelines support the overarching concept of stroke systems of care in both the prehospital and hospital settings. Conclusions- These guidelines provide general recommendations based on the currently available evidence to guide clinicians caring for adult patients with acute arterial ischemic stroke. In many instances, however, only limited data exist demonstrating the urgent need for continued research on treatment of acute ischemic stroke.

Thrombectomy 6 to 24 Hours after Stroke with a Mismatch between Deficit and Infarct.

Abstract: BackgroundThe effect of endovascular thrombectomy that is performed more than 6 hours after the onset of ischemic stroke is uncertain. Patients with a clinical deficit that is disproportionately severe relative to the infarct volume may benefit from late thrombectomy. MethodsWe enrolled patients with occlusion of the intracranial internal carotid artery or proximal middle cerebral artery who had last been known to be well 6 to 24 hours earlier and who had a mismatch between the severity of the clinical deficit and the infarct volume, with mismatch criteria defined according to age (<80 years or ≥80 years). Patients were randomly assigned to thrombectomy plus standard care (the thrombectomy group) or to standard care alone (the control group). The coprimary end points were the mean score for disability on the utility-weighted modified Rankin scale (which ranges from 0 [death] to 10 [no symptoms or disability]) and the rate of functional independence (a score of 0, 1, or 2 on the modified Rankin scale, whic...

Thrombectomy 6 to 24 Hours after Stroke with a Mismatch between Deficit and Infarct

Abstract: Copyright © 2017 Massachusetts Medical Society. BACKGROUND The effect of endovascular thrombectomy that is performed more than 6 hours after the onset of ischemic stroke is uncertain. Patients with a clinical deficit that is disproportionately severe relative to the infarct volume may benefit from late thrombectomy. METHODS We enrolled patients with occlusion of the intracranial internal carotid artery or proximal middle cerebral artery who had last been known to be well 6 to 24 hours earlier and who had a mismatch between the severity of the clinical deficit and the infarct volume, with mismatch criteria defined according to age (<80 years or ≥80 years). Patients were randomly assigned to thrombectomy plus standard care (the thrombectomy group) or to standard care alone (the control group). The coprimary end points were the mean score for disability on the utility-weighted modified Rankin scale (which ranges from 0 [death] to 10 [no symptoms or disability]) and the rate of functional independence (a score of 0, 1, or 2 on the modified Rankin scale, which ranges from 0 to 6, with higher scores indicating more severe disability) at 90 days. RESULTS A total of 206 patients were enrolled; 107 were assigned to the thrombectomy group and 99 to the control group. At 31 months, enrollment in the trial was stopped because of the results of a prespecified interim analysis. The mean score on the utility-weighted modified Rankin scale at 90 days was 5.5 in the thrombectomy group as compared with 3.4 in the control group (adjusted difference [Bayesian analysis], 2.0 points; 95% credible interval, 1.1 to 3.0; posterior probability of superiority, >0.999), and the rate of functional independence at 90 days was 49% in the thrombectomy group as compared with 13% in the control group (adjusted difference, 33 percentage points; 95% credible interval, 24 to 44; posterior probability of superiority, >0.999). The rate of symptomatic intracranial hemorrhage did not differ significantly between the two groups (6% in the thrombectomy group and 3% in the control group, P = 0.50), nor did 90-day mortality (19% and 18%, respectively; P = 1.00). CONCLUSIONS Among patients with acute stroke who had last been known to be well 6 to 24 hours earlier and who had a mismatch between clinical deficit and infarct, outcomes for disability at 90 days were better with thrombectomy plus standard care than with standard care alone. (Funded by Stryker Neurovascular; DAWN ClinicalTrials.gov number, NCT02142283.) A BS TR AC T Thrombectomy 6 to 24 Hours after Stroke with a Mismatch between Deficit and Infarct

Endovascular Thrombectomy with or without Intravenous Alteplase in Acute Stroke

Abstract: Background In acute ischemic stroke, there is uncertainty regarding the benefit and risk of administering intravenous alteplase before endovascular thrombectomy. Methods We conducted a tri...