Blake Yarascavitch
University of Texas Southwestern Medical Center
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Featured researches published by Blake Yarascavitch.
JAMA | 2015
Jetan H. Badhiwala; Farshad Nassiri; Waleed Alhazzani; Magdy Selim; Forough Farrokhyar; Julian Spears; Abhaya V. Kulkarni; Sheila K. Singh; Abdulrahman Alqahtani; Bram Rochwerg; Mohammad Alshahrani; Naresh Murty; Adel Alhazzani; Blake Yarascavitch; Kesava Reddy; Osama O. Zaidat; Saleh A. Almenawer
IMPORTANCE Endovascular intervention for acute ischemic stroke improves revascularization. But trials examining endovascular therapy yielded variable functional outcomes, and the effect of endovascular intervention among subgroups needs better definition. OBJECTIVE To examine the association between endovascular mechanical thrombectomy and clinical outcomes among patients with acute ischemic stroke. DATA SOURCES We systematically searched MEDLINE, EMBASE, CINAHL, Google Scholar, and the Cochrane Library without language restriction through August 2015. STUDY SELECTION Eligible studies were randomized clinical trials of endovascular therapy with mechanical thrombectomy vs standard medical care, which includes the use of intravenous tissue plasminogen activator (tPA). DATA EXTRACTION AND SYNTHESIS Independent reviewers evaluated the quality of studies and abstracted the data. We calculated odds ratios (ORs) and 95% CIs for all outcomes using random-effects meta-analyses and performed subgroup and sensitivity analyses to examine whether certain imaging, patient, treatment, or study characteristics were associated with improved functional outcome. The strength of the evidence was examined for all outcomes using the GRADE method. MAIN OUTCOMES AND MEASURES Ordinal improvement across modified Rankin scale (mRS) scores at 90 days, functional independence (mRS score, 0-2), angiographic revascularization at 24 hours, symptomatic intracranial hemorrhage within 90 days, and all-cause mortality at 90 days. RESULTS Data were included from 8 trials involving 2423 patients (mean [SD] age, 67.4 [14.4] years; 1131 [46.7%] women), including 1313 who underwent endovascular thrombectomy and 1110 who received standard medical care with tPA. In a meta-analysis of these trials, endovascular therapy was associated with a significant proportional treatment benefit across mRS scores (OR, 1.56; 95% CI, 1.14-2.13; P = .005). Functional independence at 90 days (mRS score, 0-2) occurred among 557 of 1293 patients (44.6%; 95% CI, 36.6%-52.8%) in the endovascular therapy group vs 351 of 1094 patients (31.8%; 95% CI, 24.6%-40.0%) in the standard medical care group (risk difference, 12%; 95% CI, 3.8%-20.3%; OR, 1.71; 95% CI, 1.18-2.49; P = .005). Compared with standard medical care, endovascular thrombectomy was associated with significantly higher rates of angiographic revascularization at 24 hours (75.8% vs 34.1%; OR, 6.49; 95% CI, 4.79-8.79; P < .001) but no significant difference in rates of symptomatic intracranial hemorrhage within 90 days (70 events [5.7%] vs 53 events [5.1%]; OR, 1.12; 95% CI, 0.77-1.63; P = .56) or all-cause mortality at 90 days (218 deaths [15.8%] vs 201 deaths [17.8%]; OR, 0.87; 95% CI, 0.68-1.12; P = .27). CONCLUSIONS AND RELEVANCE Among patients with acute ischemic stroke, endovascular therapy with mechanical thrombectomy vs standard medical care with tPA was associated with improved functional outcomes and higher rates of angiographic revascularization, but no significant difference in symptomatic intracranial hemorrhage or all-cause mortality at 90 days.
Annals of Surgery | 2014
Saleh A. Almenawer; Forough Farrokhyar; Chris J. Hong; Waleed Alhazzani; Branavan Manoranjan; Blake Yarascavitch; Parnian Arjmand; Benedicto Baronia; Kesava Reddy; Naresh Murty; Sheila K. Singh
Objective:To compare the efficacy and safety of multiple treatment modalities for the management of chronic subdural hematoma (CSDH) patients. Background:Current management strategies of CSDHs remain widely controversial. Treatment options vary from medical therapy and bedside procedures to major operative techniques. Methods:We searched MEDLINE (PubMed and Ovid), EMBASE, CINAHL, Google scholar, and the Cochrane library from January 1970 through February 2013 for randomized and observational studies reporting one or more outcome following the management of symptomatic patients with CSDH. Independent reviewers evaluated the quality of studies and abstracted the data on the safety and efficacy of percutaneous bedside twist-drill drainage, single or multiple operating room burr holes, craniotomy, corticosteroids as a main or adjuvant therapy, use of drains, irrigation of the hematoma cavity, bed rest, and treatment of recurrences following CSDH management. Mortality, morbidity, cure, and recurrence rates were examined for each management option. Randomized, prospective, retrospective, and overall observational studies were analyzed separately. Pooled estimates, confidence intervals (CIs), and relative risks (RRs) were calculated for all outcomes using a random-effects model. Results:A total of 34,829 patients from 250 studies met our eligibility criteria. Sixteen trials were randomized, and the remaining 234 were observational. We included our unpublished single center series of 834 patients. When comparing percutaneous bedside drainage to operating room burr hole evacuation, there was no significant difference in mortality (RR, 0.69; 95% CI, 0.46–1.05; P = 0.09), morbidity (RR, 0.45; 95% CI, 0.2–1.01; P = 0.05), cure (RR, 1.05; 95% CI, 0.98–1.11; P = 0.15), and recurrence rates (RR, 1; 95% CI, 0.66–1.52; P = 0.99). Higher morbidity was associated with the adjuvant use of corticosteroids (RR, 1.97; 95% CI, 1.54–2.45; P = 0.005), with no significant improvement in recurrence and cure rates. The use of drains following CSDH drainage resulted in a significant decrease in recurrences (RR, 0.46; 95% CI, 0.27–0.76; P = 0.002). Craniotomy was associated with higher complication rates if considered initially (RR, 1.39; 95% CI, 1.04–1.74; P = 0.01); however, craniotomy was superior to minimally invasive procedures in the management of recurrences (RR, 0.22; 95% CI, 0.05–0.85; P = 0.003). Conclusions:Percutaneous bedside twist-drill drainage is a relatively safe and effective first-line management option. These findings may result in potential health cost savings and eliminate perioperative risks related to general anesthetic.
Neuro-oncology | 2015
Saleh A. Almenawer; Jetan H. Badhiwala; Waleed Alhazzani; Jeffrey N. Greenspoon; Forough Farrokhyar; Blake Yarascavitch; Almunder Algird; Edward Kachur; Aleksa Cenic; Waseem Sharieff; Paula Klurfan; Thorsteinn Gunnarsson; Olufemi Ajani; Kesava Reddy; Sheila K. Singh; Naresh Murty
BACKGROUND Optimal extent of surgical resection (EOR) of high-grade gliomas (HGGs) remains uncertain in the elderly given the unclear benefits and potentially higher rates of mortality and morbidity associated with more extensive degrees of resection. METHODS We undertook a meta-analysis according to a predefined protocol and systematically searched literature databases for reports about HGG EOR. Elderly patients (≥60 y) undergoing biopsy, subtotal resection (STR), and gross total resection (GTR) were compared for the outcome measures of overall survival (OS), postoperative karnofsky performance status (KPS), progression-free survival (PFS), mortality, and morbidity. Treatment effects as pooled estimates, mean differences (MDs), or risk ratios (RRs) with corresponding 95% confidence intervals (CIs) were determined using random effects modeling. RESULTS A total of 12 607 participants from 34 studies met eligibility criteria, including our current cohort of 211 patients. When comparing overall resection (of any extent) with biopsy, in favor of the resection group were OS (MD 3.88 mo, 95% CI: 2.14-5.62, P < .001), postoperative KPS (MD 10.4, 95% CI: 6.58-14.22, P < .001), PFS (MD 2.44 mo, 95% CI: 1.45-3.43, P < .001), mortality (RR = 0.27, 95% CI: 0.12-0.61, P = .002), and morbidity (RR = 0.82, 95% CI: 0.46-1.46, P = .514) . GTR was significantly superior to STR in terms of OS (MD 3.77 mo, 95% CI: 2.26-5.29, P < .001), postoperative KPS (MD 4.91, 95% CI: 0.91-8.92, P = .016), and PFS (MD 2.21 mo, 95% CI: 1.13-3.3, P < .001) with no difference in mortality (RR = 0.53, 95% CI: 0.05-5.71, P = .600) or morbidity (RR = 0.52, 95% CI: 0.18-1.49, P = .223). CONCLUSIONS Our findings suggest an upward improvement in survival time, functional recovery, and tumor recurrence rate associated with increasing extents of safe resection. These benefits did not result in higher rates of mortality or morbidity if considered in conjunction with known established safety measures when managing elderly patients harboring HGGs.
Neurosurgery | 2012
Blake Yarascavitch; Jennifer Chuback; Saleh A. Almenawer; Kesava Reddy; Mohit Bhandari
BACKGROUND The importance of evidence-based medicine has been well documented and supported across various surgical subspecialties. OBJECTIVE To quantify the levels of evidence across publications in the neurosurgical literature, to assess the change in evidence over time, and to indicate predictive factors of higher-level evidence. METHODS We reviewed the levels of evidence across published clinical studies in 3 neurosurgical journals from 2009 to 2010. Randomized trials were evaluated by use of the Detsky quality of reporting scale. Levels-of-evidence data for the same journals in 1999 were obtained from the literature, and regression analysis was performed to identify predictive factors for higher-level evidence. RESULTS Of 660 eligible articles, 14 (2.1%) were Level I, 54 (8.2%) were level II, 73 (11.1%) were Level III, 287 (43.5%) were level IV, and 232 (35.2%) were level V. The number of level I studies decreased significantly between 1999 and 2010 (3.4% vs. 2.1%, respectively; P = .01). Seven randomized clinical trials were identified, and 1 trial had significant methodological limitations (mean Detsky index = 16.3; SD = 1.8). Publications with larger sample size were significantly associated with higher levels of evidence (levels I and II; odds ratio, 1.7; 95% confidence interval, 1.45-2.05; P = .001). The ratio of higher levels of evidence to lower levels was 0.11. CONCLUSION Higher levels of evidence (levels I and II) represent only 1 in 10 neurosurgical clinical papers in the top neurosurgical journals. Increased awareness of the need for better evidence in the field through education and adoption of the levels of evidence may improve the conduct and publication of prospective studies.
Annals of Internal Medicine | 2015
Jetan H. Badhiwala; Chung K. Lai; Waleed Alhazzani; Forough Farrokhyar; Farshad Nassiri; Maureen O. Meade; Alireza Mansouri; Niv Sne; Mohammed Aref; Naresh Murty; Christopher D. Witiw; Sheila K. Singh; Blake Yarascavitch; Kesava Reddy; Saleh A. Almenawer
Cervical spine trauma is a major public health problem and a common reason for admission to trauma wards and intensive care units. The cervical spine is injured in 2.3% to 4.3% (14) of blunt traumas. Resultant neurologic impairment is encountered in 33% to 54% (57) of patients with cervical spine trauma. In fact, more than 50% of all acute spinal cord injuries affect the cervical spine (8, 9). Unfortunately, these injuries have poor functional outcomes. Mortality after traumatic cervical spinal cord injury may exceed 20% (1013), and survivors often face lifelong physical disability, along with the associated emotional, psychological, and social burdens (6, 8, 14, 15). The economic costs of spinal cord injury are enormous. In the United States, the total annual direct cost of spinal cord injuries approaches
Burns | 2015
Jennifer Chuback; Blake Yarascavitch; Alec Yarascavitch; Manraj Nirmal Kaur; Stuart Martin; Achilleas Thoma
8 billion (16). These factors make diligent and efficient cervical spine clearance protocols a critical priority. The exclusion of cervical spine injury in obtunded patients with trauma poses a significant challenge given the lack of a reliable clinical examination. Common practices at many trauma centers include routine acquisition of cervical spine magnetic resonance imaging (MRI), dynamic radiography (flexion and extension), or continued cervical immobilization until patients are awake and asymptomatic after a negative computed tomography (CT) scan (17, 18). These protocols may increase health care costs unduly, place critically ill patients at risk for deterioration during transportation, and prolong cervical collar immobilization and its associated illnesses. On the other hand, the consequences of missing an injury can be devastating and may include loss of functional ability, independence, and possibly life (1921). The primary aim of this study was to elucidate the role for further routine imaging or prolonged cervical immobilization in excluding significant cervical spine injury after negative CT results in obtunded patients who had blunt traumatic injury. Methods This systematic review was done according to a predefined protocol (Supplement) in accordance with MOOSE (Meta-analysis Of Observational Studies in Epidemiology) guidelines (22) and the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) Statement (23). Supplement. Study Protocol Search Strategy We searched MEDLINE (PubMed and Ovid), EMBASE, CINAHL, Google Scholar, and the Cochrane Library from January 2000 through November 2014 for studies on the role of CT followed by a validating test in evaluating the cervical spine of obtunded trauma patients. We used, in various combinations, keywords and Medical Subject Headings terms pertinent to the patient population (altered, comatose, intensive care, intubated, mental status, obtunded, unconscious, unevaluable, unexaminable, unreliable, or unresponsive), medical condition (fracture, injury, instability, or trauma), anatomical site of interest (cervical-spine or cervical), and relevant radiological imaging methods (clearance, computed tomography, CT, dynamic, extension, flexion, fluoroscopy, imaging, magnetic resonance, MDCT, MR, MRI, plain film, radiograph, or X-ray). We also manually searched the references of relevant studies to identify additional studies for consideration. Selection Criteria Three investigators independently evaluated the studies for eligibility. Selection criteria included a study of any design (randomized, controlled trial; prospective cohort study; or retrospective cohort study). Studies were eligible if the diagnostic protocol of interest included a negative finding on a helical CT scan of the entire cervical spine followed by a confirmatory test. We included only the population of obtunded patients with blunt trauma (Glasgow Coma Scale [GCS] score 14, unreliable clinical examination, or intubation). Only English-language studies documenting the outcome measures of missed cervical spine injury or intervention after a negative CT result and additional findings of a validating test were included. We excluded studies with a sample size of fewer than 10 patients and studies in which partial cervical spine CT scans were used. For studies reporting data on overlapping cohorts from the same institution, we included only the study with the most inclusive cohort to prevent duplication. Studies evaluating only the pediatric population were excluded. Studies that examined awake and obtunded patients were included only if the outcomes of unreliable patients were analyzed separately. Abstracts from meeting proceedings were excluded if the data were not published in full-text articles in a peer-reviewed journal. Disagreements among the 3 reviewers about the decision to include or exclude a study were resolved by consensus and, if necessary, consultation with a fourth reviewer. Data Extraction and Quality Assessment Data from eligible studies were independently extracted by the 3 primary reviewers and verified for accuracy by the fourth reviewer. Discrepancies were resolved by discussion and consensus. We used data collection forms that included the following fields: title, author, year and country of publication, study design, sample size, patient demographic characteristics, Injury Severity Score, GCS score, definition of obtunded, mechanism of injury, CT specifications, further imaging or follow-up of patients with negative CT scans, image interpreter, missed acute cervical spine injuries, and changes in management. The 3 primary reviewers performed quality assessment independently. We used the QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies-2) tool (24) and examined patient selection, the index test and reference standard used, and flow and timing to determine whether the risk of bias and concerns about applicability to the review question were low, unclear, or high among eligible studies. Definition of Variables Our primary outcome of interest was clinically significant cervical spine injury missed by CT and detected by the confirmatory test. A clinically significant injury was defined as one resulting in mechanical instability or requiring intervention or change in management. We excluded soft tissue signal changes that did not affect spine stability. The definition of cervical spine instability varied among included studies and was assessed by using many classification systems. Most eligible studies defined instability in accordance with the work of White and Panjabi (25) on biomechanics of the spine. Previous studies defined unstable and purely ligamentous injuries as those involving all 3 columns (26). We adopted and documented cervical spine instability outcomes as reported by the authors of included studies, regardless of the classification used. Changes in management after negative CT results and positive findings on a validating test included prolonged external immobilization or operative stabilization. An obtunded patient was defined as someone who was not fully awake and had an altered level of consciousness (GCS 14). These patients lacked a reliable neurologic examination that could aid in the diagnosis of spinal injury. High-quality CT scans were defined as those protocolled with narrow slice width (1 to 3 mm) and reconstruction in multiple planes. A well-interpreted CT study was defined as an image read by a health professional with special training and expertise in reading such images (that is, a consultant radiologist) rather than an on-call physician or radiology resident. Data Synthesis and Analysis Studies were grouped on the basis of how further evaluation of obtunded trauma patients with negative results from cervical spine CT was handled. The first group included studies that routinely performed MRI after a CT scan that was interpreted as normal. The second group comprised studies in which patients were routinely evaluated with dynamic radiography after negative CT results. The third group included studies in which patients were followed with serial physical examination after a normal CT result, with further imaging obtained as guided by clinical indications (for example, neurologic deficit). For each group, we examined mechanical cervical spine instability, need for operative stabilization, and collar use after negative CT results and additional findings on the confirmatory test. We examined high-quality studies separately. These reports fulfilled 4 criteria: prospective study design, low risk of bias and low concerns about applicability in all domains on the QUADAS-2 tool, well-interpreted CT images, and use of high-quality CT specifications. Given the small number of events (if any), formal meta-analysis was not possible. Data from individual studies are displayed in forest plots with 95% CIs. Exact binominal 1-sided 95% CIs were calculated for each proportion obtained from eligible studies (27). We used R, version 3.1.2 (R Foundation for Statistical Computing), to generate all forest plots. Role of the Funding Source This study received no funding. Results Characteristics of Included Studies Our search yielded 2112 results, of which 1959 were excluded after title and abstract screening. Another 125 were excluded after full-text review (Appendix Figure). The remaining 28 studies (2855) were included, and they reported on a total of 3627 obtunded blunt trauma patients with negative results from cervical spine CT and a validating test. Twenty studies (28, 29, 32, 34, 35, 37, 4044, 46, 4855) were retrospective cohort studies, and 8 (30, 31, 33, 36, 38, 39, 45, 47) were prospective cohort studies. Descriptions of eligible studies are provided in Appendix Tables 1 and 2. Details of methodological assessment of included studies with the QUADAS-2 tool are presented in Appendix Table 3. Appendix Figure. Summary of evidence search and selection. CT = computed tomography. Appendix Table 1. Characteristics of Included Studies Appendix Table 2. Outcomes of Eligible Studies Appendix Table 3. Quality Assessment of Eligible Studies Wit
Journal of Neurosurgery | 2014
Jetan H. Badhiwala; Forough Farrokhyar; Waleed Alhazzani; Blake Yarascavitch; Mohammed Aref; Almunder Algird; Naresh Murty; Edward Kachur; Aleksa Cenic; Kesava Reddy; Saleh A. Almenawer
PURPOSE In an otherwise healthy patient with severe facial disfigurement secondary to burns, composite tissue allotransplantation (CTA) results in life-long immunosuppressive therapy and its associated risk. In this study, we assess the net gain of CTA of face (in terms of utilities) from the perspectives of patient, general public and medical expert, in comparison to the risks. METHODS Using the standard gamble (SG) and time-trade off (TTO) techniques, utilities were obtained from members of general public, patients with facial burns, and medical experts (n=25 for each group). The gain (or loss) in utility and quality adjusted life years (QALY) were estimated using face-to-face interviews. A sensitivity analysis using variable life expectancy was conducted. RESULTS From the patient perspective, severe facial burn was associated with a health utility value of 0.53, and 27.1 QALYs as calculated by SG, and a health utility value of 0.57, and 28.9 QALYs as calculated by TTO. In comparison, CTA of the face was associated with a health utility value of 0.64, and 32.3 QALYs (or 18.2 QALYs years per sensitivity analysis) as calculated by SG, and a health utility value of 0.67, and 34.1 QALYs (or 19.2QALYs per sensitivity analysis) as calculated by TTO. However, a loss of 8.9 QALYs (by SG method) to 9.5 QALYs (by TTO method) was observed when the life expectancy was decreased in the sensitivity analysis. Similar results were obtained from the general population and medical experts perspectives. CONCLUSION We found that severe facial disfigurement is associated with a significant reduction in the health-related quality of life, and CTA has the potential to improve this. Further, we found that a trade-off exists between the life expectancy and gain in the QALYs, i.e. if life expectancy following CTA of face is reduced, the gain in QALY is also diminished. This trade-off needs to be validated in future studies.
Archive | 2015
Jetan H. Badhiwala; Farshad Nassiri; Waleed Alhazzani; Magdy Selim; Forough Farrokhyar; Julian Spears; Abhaya V. Kulkarni; Sheila K. Singh; Abdulrahman Alqahtani; Bram Rochwerg; Mohammad Alshahrani; Naresh Murty; Adel Alhazzani; Blake Yarascavitch; Kesava Reddy; Osama O. Zaidat; Saleh A. Almenawer
Cancer Research | 2018
Sheila K. Singh; Branavan Manoranjan; Anna Dvorkin-Gheva; Chitra Venugopal; Steven Moreira; Michelle Kameda-Smith; Minomi Subapanditha; Ashley Adile; David Bakhshinyan; Neil Savage; Blake Yarascavitch; Olufemi Ajani; Adam Fleming; Bradley W. Doble
Neuro-oncology | 2017
Michelle Kameda-Smith; Branavan Manoranjan; Olufemi Ajani; Blake Yarascavitch; Tina Petrelli; Sheila K. Singh; Adam Fleming