Safety and efficacy of antithrombotics in outpatients with symptomatic COVID-19: A systematic review and meta-analysis

BACKGROUND

Coronavirus disease (COVID-19) is a global health emergency, with well over six hundred million infections and over six million deaths to date. Besides other ramifications, it is also associated with inflammation and an augmented risk of thromboembolic complications. Despite this, the risks and benefits of antithrombotic drugs in patients with mild to moderate COVID-19 have not been well-established and remain controversial.

OBJECTIVES

To evaluate the safety and efficacy of antithrombotic drugs on mild to moderate symptomatic COVID-19 patients by performing an updated systematic review and meta-analysis.

METHODS

We queried electronic databases (PubMed, Cochrane Central, Scopus, and Embase) from their inception up to September 2022 for randomized controlled trials comparing antithrombotic drugs against placebo. The outcomes of interest were the need for hospital care, mortality, and thromboembolic events in the enrolled participants. Dichotomous outcomes were presented as risk ratio (RR) with 95 % confidence intervals (CIs) and were consolidated using random-effects model.

MAIN RESULTS

Five eligible studies (Rivaroxaban/Apixaban, two; enoxaparin, two; Sulodexide, one), consisting of 2,005 participants with mild to moderate COVID-19, were included. Pooled results show that antithrombotics, when compared to placebo, do not significantly reduce all-cause mortality (RR 0.51, 95 % CI 0.15-1.68; P = 0.27; I2 = 0), thromboembolic events (RR 0.78, 95 % CI 0.17-3.51; P = 0.74; I2 = 0), need for hospitalization (RR 0.73, 95 % CI 0.51-1.03; P = 0.08; I2 = 0), nor significantly increase clinically relevant non-major bleeding events (RR 2.36, 95 % CI 0.56-9.89; P = 0.24; I2 = 0). However, when Sulodexide was compared independently to other antithrombotics, it significantly reduced the need for hospitalization (RR 0.60, 95 % CI 0.37-0.95; P = 0.03).

CONCLUSIONS

Our pooled analysis was not able to establish statistically significant benefits or risks of using antithrombotic drugs in mild to moderate COVID-19 patients. To further improve our understanding of the efficacy, safety and risk profile of such a therapy, large sample randomized clinical trials are required on a wide scale.

Efficacy of Allopurinol in Improving Endothelial Dysfunction: A Systematic Review and Meta-Analysis

INTRODUCTION

Endothelial dysfunction has been implicated in various cardiovascular disorders as the initial pathology. Allopurinol has been shown to improve endothelial dysfunction in patients with gout, but its effect on cardiovascular patients is unclear.

AIMS

We aim to assess allopurinol efficacy in improving endothelial dysfunction overall and in different disease states including but not limited to heart failure, chronic kidney disease, ischemic heart disease METHODS: We conducted a literature search of PubMed, Cochrane's Central Library, and Scopus until December 2022, including randomized controlled trials and double-arm observational studies. The primary outcome measure was endothelial function assessed by change in flow mediated dilation (FMD) RESULTS: Our meta-analysis included 22 studies with a total of 1472 patients. Our pooled analysis shows that allopurinol significantly improved FMD (WMD = 1.46%, 95% CI [0.70, 2.22], p < 0.01) compared to control. However, there was no significant difference between allopurinol and control for endothelial-independent vasodilation measured by forearm blood flow (WMD = 0.10%, 95% CI [- 0.89, 0.69], p = 0.80). Subgroup analysis indicated that the effect of allopurinol on FMD was more significant in diabetic and congestive heart failure patients.

CONCLUSION

While allopurinol may improve endothelial function in various patient populations, further high-quality randomized controlled trials are needed to determine its efficacy in preventing cardiovascular disease exacerbation.

Effectiveness of Emergency versus Nonemergent Coronary Angiography After Out-of-Hospital Cardiac Arrest without ST-Segment Elevation: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

The optimal timing of coronary angiography (CAG) in patients after out-of-hospital cardiac arrest (OHCA) without ST-segment elevation remains controversial. Therefore, we conducted a meta-analysis of randomized control trials to investigate the effectiveness of emergency CAG versus delayed CAG in OHCA patients with a non-ST-segment elevated rhythm. PubMed, Scopus, CINAHL, Cochrane CENTRAL, and JBI databases were searched from inception to September 7, 2022. Our primary end point was survival with a good neurological outcome, whereas the secondary outcomes included short-term survival, mid-term survival, recurrent arrhythmias, myocardial infarction after hospitalization, major bleeding, acute kidney injury, and left ventricular ejection fraction. Nine randomized control trials involving 2,569 patients were included in this analysis. Our meta-analysis showed no significant difference in the improvement of neurological outcome (RR 0.96, 95% Confidence Interval [CI] [0.87, 1.06]), short-term survival (risk ratio [RR] 0.98, 95% CI [0.89, 1.08]), mid-term survival (RR 0.98, 95% CI [0.87, 1.10]), recurrent arrhythmias (RR 1.02, 95% CI [0.50, 2.06]), myocardial infarction (RR 0.66, 95% CI [0.13, 3.30]), major bleeding (RR 0.96, 95% CI [0.55, 1.69]), acute kidney injury (RR 1.20, 95% CI [0.32, 4.49]) and left ventricular ejection fraction (RR 0.89, 95% CI [0.69, 1.15]) in patients who underwent emergency CAG compared with delayed CAG patients. In conclusion, our analysis revealed that emergency CAG had no prognostic superiority over delayed CAG in patients with OHCA without ST-segment elevation.

Folfirinox vs. Gemcitabine + Nab-Paclitaxel as the First-Line Treatment for Pancreatic Cancer: A Systematic Review and Meta-Analysis

Background

The efficacy and safety of Folfirinox (FFX) or gemcitabine + nab-paclitaxel (GnP) to be used as the first-line drugs for pancreatic cancer (PC) is yet to be established. We conducted an analysis of retrospective studies to assess the efficacy and safety of these two regimens by comparing their survival and safety outcomes in patients with PC.

Methods

We conducted an extensive review of two electronic databases from inception till February 2023 to include all the relevant studies that compared FFX with GnP published and unpublished work. Retrospective studies were only included. Overall survival (OS) and progression-free survival (PFS) were pooled using hazard ratios (HRs), while objective response rate (ORR) and safety outcomes were pooled using odds ratios (ORs) with 95% confidence interval (CI) using the random effects model.

Results

A total of 7,030 patients were identified in a total of 21 articles that were shortlisted. Pooled results concluded that neither FFX nor GnP was associated to increase the OS time (HR: 0.93, 95% CI: 0.83 - 1.04; P = 0.0001); however, FFX was more likely associated with increased PFS when compared to GnP (HR: 0.88, 95% CI: 0.81 - 0.97; P < 0.0001). ORR proved to be non-significant between the two regimens (OR: 0.90, 95% CI: 0.64 - 1.27; P = 0.15). Safety outcomes included neutropenia, anemia, thrombocytopenia and diarrhea. GnP was more associated with diarrhea (OR: 1.96, 95% CI: 1.22 - 3.15; P = 0.001), while FFX was seen to cause anemia (OR: 0.70, 95% CI: 0.51 - 0.98; P = 0.10) in PC patients. Neutropenia and thrombocytopenia were in-significant in the two drug regimens (OR: 1.10, 95% CI: 0.92 - 1.31; P = 0.33 and OR: 0.83, 95% CI: 0.60 - 1.13; P = 0.23, respectively).

Conclusion

FFX and GnP showed a significant difference in increasing the PFS, while no difference was observed while measuring OS. Safety outcomes showed that FFX and GnP shared similar safety profiles as FFX was associated with hematological outcomes, while GnP was more associated with non-hematological outcomes.

An Individual Patient-Level Meta-Analysis of Ischemic Versus Nonischemic Cardiomyopathy and Trajectory of Decongestion in Patients With Acute Decompensated Heart Failure

Data are limited regarding the impact of ischemic cardiomyopathy (ICM) or non-ICM (NICM) on the trajectory of in-hospital decongestion among patients with acute decompensated heart failure (ADHF). Therefore, we aimed to assess the course of decongestion among patients admitted for ADHF by history of ICM and NICM. Patients included in the DOSE (Diuretic strategies in patients with acute decompensated heart failure), ROSE (ROSE acute heart failure randomized trial), and Ultrafiltration in decompensated heart failure with cardiorenal syndrome (CARRESS-HF) trials of patients with ADHF were categorized into ICM and NICM based on history. Among 762 patients included in our meta-analysis, 433 (56.8%) had a history of ICM. Patients with ICM were older (70.8 vs 63.9 years; p ≤0.001) and had higher rates of co-morbidities. After covariate adjustment, there was no significant differences between NICM and ICM regarding net fluid loss (4,952 vs 4,384 ml, p = 0.81) or mean change in serum N-terminal pro-brain natriuretic peptide (-2,162 vs -1,809 pg/ml, p = 0.092). Mean change in weight showed modest improvement in favor of patients with NICM, but this did not meet statistical significance (-8.24 vs -7.70 pounds, p = 0.068). After adjustment, there was no significant difference in the risk of 60-day composite all-cause mortality or hospitalization for HF among those with ICM versus NICM. Among patients with left ventricular ejection fraction <40%, NICM was associated with higher scoring on global sense of well-being (global visual analog scale; +25.5 vs +19.1, p = 0.023) and improvement in serum creatinine (-0.031 mg/100 ml vs +0.042 mg/100 ml, p = 0.009) at 72 hours. Among patients with left ventricular ejection fraction >40%, NICM was associated with decreased scoring on global visual analog scale at 72 hours (+15.7 vs +21.2, p = 0.049). In conclusion, more than half of the patients admitted for ADHF had ICM. History of ICM was not independently associated with a difference in course of decongestion, self-assessment of well-being and dyspnea, or short-term clinical outcomes.

A Systematic Review and Meta-Analysis on Effectiveness of Mineralocorticoid Receptor Antagonists in Reducing the Risk of Atrial Fibrillation

Mineralocorticoid receptor antagonists (MRAs) are known to improve clinical outcomes in heart failure, particularly heart failure with reduced ejection fraction. However, the effect of MRAs on the incidence of and recurrence of atrial fibrillation (AF) is not well established. Therefore, databases, such as PubMed, EMBASE, and Cochrane Central, were searched from inception to September 2021 for randomized controlled trials of MRAs with AF as an outcome. Risk ratios (RRs) with 95% confidence interval (CIs) were combined using the random-effects model. A total of 10 randomized controlled trials (n = 11,356) were included. Our pooled analysis demonstrates that MRAs reduce the risk of AF occurrence by 23% compared with the control therapy (RR 0.77, 95% CI 0.65 to 0.91, p = 0.003, I2 = 40%). Subgroup analysis demonstrated that MRAs reduced the risk of both new-onset AF (RR 0.84, 95% CI 0.61 to 1.16, p = 0.28, I2 = 43%) and recurrent AF (RR 0.73, 95% CI 0.59 to 0.90, p = 0.004, I2 = 26%) similarly; p interaction = 0.48. Our meta-analysis concludes that MRAs reduce the risk of development of AF overall, with consistent effects in new-onset and recurrent AF.

Duet of Death: Biventricular Thrombus in a Methamphetamine User

We present the case of a 60-year-old male who developed an ischemic stroke due to left ventricular (LV) thrombus emboli as a complication of methamphetamine-induced cardiomyopathy. The patient had a history of methamphetamine abuse, hypertension, and ischemic stroke with no residual deficits presented with new onset slurred speech, left-sided weakness, and numbness for two hours. Computed tomography (CT) of the head showed no acute changes, and a tissue plasminogen activator was given in the emergency department within 30 minutes of arrival. Urine drug screen (UDS) was positive for methamphetamine, and magnetic resonance imaging (MRI) of the brain showed acute cortical infarcts in the right frontal lobe and parietal lobe and chronic infarct in the left occipital lobe. Transthoracic echocardiography showed bilateral ventricular thrombus and severely reduced ejection fraction of 20-25%. The patient had no evidence of thrombophilia and was started on a heparin drip for thrombus and goal-directed medical therapy for heart failure with reduced ejection fraction (HFrEF). Upon discharge, the patient was prescribed the oral anticoagulant rivaroxaban. The LV thrombus emboli were attributed to causing ischemic stroke. This case highlights the potential risk of ischemic stroke due to LV thrombus emboli in patients with methamphetamine-induced cardiomyopathy.

Fat Pulmonary Embolism With Crazy-Paving Pattern Opacities and Pneumothorax: A Rare Complication of Liposuction

Fat embolism syndrome (FES) is a rare multiorgan disease caused by microvascular obstruction by fat globules and free fatty acid-mediated endothelial injury leading to pro-inflammatory cytokine release. We present a rare case of a 54-year-old woman who underwent elective aesthetic liposuction and developed FES and pneumothorax within 12 hours of the procedure.

The Role of Vitamin D Supplementation Before Coronary Artery Bypass Grafting in Preventing Postoperative Atrial Fibrillation in Patients With Vitamin D Deficiency or Insufficiency: A Systematic Review and Meta-Analysis

This study aims to evaluate the role of preoperative vitamin D supplementation before coronary artery bypass grafting (CABG) surgery in preventing postoperative atrial fibrillation (POAF) in vitamin D deficient or insufficient patients. Three randomized controlled trials (RCTs) comprising 448 subjects were selected after a detailed search was conducted on PubMed, Cochrane CENTRAL, Scopus, and Embase in December 2022. Analysis was run using RevMan (version 5.4.1; Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, 2014). The analysis collected risk ratio (RR) and 95% confidence interval (CI) data from the relevant studies, which were then pooled using a random effects model. A significance level of less than 0.05 (p<0.05) was considered significant. Our analysis showed that compared with the standard of care, preoperative vitamin D supplementation in vitamin D deficient and insufficient patients effectively reduced POAF after CABG surgery (RR=0.6, 95% CI=0.4-0.9, P=0.01). There was no significant difference in the duration of hospitalization between the vitamin D supplementation group compared with the control following CABG (mean difference -0.85, 95% CI -2.13 to 0.43, P = 0.19). This meta-analysis shows that preoperative vitamin D supplementation in vitamin D deficient and insufficient patients undergoing CABG can reduce the rate of POAF. As POAF is associated with many complications, providing vitamin D supplementation to individuals with a vitamin D deficiency undergoing CABG can improve long-term cardiovascular outcomes following surgery.

The Safety and Efficacy of GLP-1 Receptor Agonists in Heart Failure Patients: A Systematic Review and Meta-Analysis

Evaluation of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) usage in heart failure (HF) patients with or without type 2 diabetes mellitus (T2DM) could be proven to be a critical breakthrough in treatment options available for these patients. Our study focuses on understanding the safety and efficacy of GLP-1 RAs in this patient population by pooling the data from 9 randomized controlled trials (RCTs) comprising 871 subjects. As compared with the placebo, GLP-1 RAs did not improve major adverse cardiovascular events (MACE) which include cardiovascular (CV) mortality and heart failure (HF) hospitalizations, our primary outcome. CV mortality (RR = 1.03, 95% CI = 0.56-1.88, P = 0.92) and HF hospitalizations (RR = 1.18, 95%CI = 0.93-1.51, P = 0.18). Similarly, GLP-1 RAs did not improve our secondary findings of left ventricular ejection fraction (LVEF) and 6-minute walk test (6MWT). LVEF (RR = 1.96, 95%CI = -0.16-4.07, P = 0.07) or 6 MWT (RR = 8.43, 95% CI = -2.69-19.56, P = 0.14). This meta-analysis shows that GLP-1 RAs do not improve cardiovascular outcomes in HF patients with or without T2DM.

Correlation of Call Burden and Sleep Deprivation with Physician Burnout, Driving Crashes, and Medical Errors among US Neurointerventionalists

BACKGROUND AND PURPOSE

High call frequency can lead to inadequate sleep, fatigue, and burnout, resulting in detrimental effects on physicians and patients. We aimed to assess the correlation between the frequency and burden of neurointerventional surgery calls and sleep deprivation with physician burnout, physical and driving safety, and fatigue-related medical errors.

MATERIALS AND METHODS

We sent an online questionnaire to the members of the 2 neurointerventional surgery societies comprising 50 questions and spanning 3 main topics: 1) overnight/weekend call burden, 2) sleeping patterns, and 3) Copenhagen Burnout Inventory.

RESULTS

One hundred sixty-four surveys were completed. Most (54%) neurointerventional surgeons reported burnout. Call burden of ≥1 every 3 days and being in practice >10 years were independent predictors of burnout. Thirty-nine percent reported falling asleep at the wheel, 23% reported a motor vehicle crash/near-crash, and 34% reported medical errors they considered related to call/work fatigue. On multivariate logistic regression, high call burden (called-in >3 times/week) was an independent predictor of sleeping at the wheel and motor vehicle crashes. Reporting <4 hours of uninterrupted sleep was an independent predictor of motor vehicle crashes and medical errors. Most neurointerventional surgeons recommended a maximum call frequency of once every 3 days.

CONCLUSIONS

Call frequency and burden, number of years in practice, and sleep deprivation are associated with burnout of neurointerventional surgeons, sleeping at the wheel, motor vehicle crashes, and fatigue-related medical errors. These findings contribute to the increasing literature on physician burnout and may guide future societal recommendations related to call burden in neurointerventional surgery.

COVID-19 and Bradyarrhythmias: A Case Report With Literature Review

We report a case of a 51-year-old male with no past medical history who was admitted for acute hypoxic respiratory failure secondary to COVID-19. During his hospitalization, the patient developed sinus bradycardia and frequent sinus pauses were observed on telemetry. No other cause of his bradyarrhythmia was identified except for his COVID-19 infection. There has been numerous case reports and case series describing different arrhythmias seen in patients infected with COVID-19. We present a case of sinus arrest in a patient with COVID-19 and a review of other case reports describing bradyarrhythmia in COVID-19 patients.

Post-Paracentesis Hemoperitoneum From a Bleeding Mesenteric Varix: A Case Report on a Rare Presentation

We report a case of a 53-year-old male with decompensated liver cirrhosis secondary to alcohol abuse and hepatitis C infection who was admitted for hemorrhagic shock secondary to upper GI bleed. He underwent a therapeutic paracentesis 17 days after admission with the removal of 6 L of ascitic fluid. The patient became hemodynamically unstable after paracentesis and an acute drop in his hemoglobin was noted. On imaging, he was found to have massive hemoperitoneum secondary to a bleeding mesenteric varix. This is a very rare complication of paracentesis in patients with advanced cirrhosis and should be recognized early in the post-procedure period to initiate prompt life-saving measures to minimize morbidity and mortality.

1082 Are Trauma and Orthopaedics Consultant Posts Decreasing in Frequency and Increasing in Subspecialisation?

Aim

Changes to the configuration of the NHS Trauma Services in T&O and the level of subspecialisation are changing and could impact training and the number of consultant posts available at CCT. The aim of this study was to review the number of T&O Consultant posts and determine the frequency of the subspecialist requirements of these posts from 2011 to 2020, to assess the perceived reduction in advertised numbers and the increasing sub specialisation as a whole.

Method

451 volumes of the BMJ were reviewed over Jan 2011 - April 2020. The total number of jobs advertised were recorded. Additionally, for each post, sub-specialism, regional analysis and substansive or locum tenure were recorded.

Results

1141 jobs were advertised during this period. There has been a decreasing trend in the total number of advertised posts of 13% per annum. Proportion of specialty jobs remain constant yearly. However, jobs listing Trauma clearly decreased after 2012, when trauma centres were initiated. Clear decreases were present in North-west and Scotland in number of jobs. There has also been an increasing trend of advertisement of substantive posts, with locum posts forming less than 13% of total advertisements.

Conclusions

We found no significant increase in job specialism contradicting previous research. Overall, the total number of Consultant jobs in Trauma and Orthopaedics is decreasing, especially in the north-west and Scotland, two of the biggest employers. Questions must be asked for the future of training in T&O to meet service needs.

Flow Diversion of Posterior Circulation Aneurysms: Systematic Review of Disaggregated Individual Patient Data

BACKGROUND

Experience with endoluminal flow diversion for the treatment of posterior circulation aneurysms is limited.

PURPOSE

We sought to investigate factors associated with the safety and efficacy of this treatment by collecting disaggregated patient-level data from the literature.

DATA SOURCES

PubMed, EMBASE, and Ovid were searched up through 2019 for articles reporting flow diversion of posterior circulation aneurysms.

STUDY SELECTION

Eighty-four studies reported disaggregated data for 301 separate posterior circulation aneurysms.

DATA ANALYSIS

Patient, aneurysm, and treatment factors were collected for each patient. Outcomes included the occurrence of major complications, angiographic occlusion, and functional outcomes based on the mRS.

DATA SYNTHESIS

Significant differences in aneurysm and treatment characteristics were seen among different locations. Major complications occurred in 22%, angiographic occlusion was reported in 65% (11.3 months of mean follow-up), and good functional outcomes (mRS 0-2) were achieved in 67% (13.3 months of mean follow-up). Multivariate analysis identified age, number of flow diverters used, size, and prior treatment to be associated with outcome measures. Meta-analysis combining the current study with prior large nondisaggregated series of posterior circulation aneurysms treated with flow diversion found a pooled incidence of 20% (n = 712 patients) major complications and 75% (n = 581 patients) angiographic occlusions.

LIMITATIONS

This study design is susceptible to publication bias. Use of antiplatelet therapy was not uniformly reported.

CONCLUSIONS

Endoluminal flow diversion is an important tool in the treatment of posterior circulation aneurysms. Patient age, aneurysm size, prior treatment, and the number of flow diverters used are important factors associated with complications and outcomes.

Bis-(1,2,4-triazin-3-yl) ligand structure driven selectivity reversal between Am3+ and Cm3+: solvent extraction and DFT studies

Selectivity between Am3+ and Cm3+ was investigated after their aqueous complexation with three structurally tailored hydrophilic bis-(1,2,4-triazin-3-yl) ligands followed by their extraction with N,N,N'N'-tetraoctyl diglycolamide (TODGA) dissolved in an ionic liquid (C4mim·Tf2N). The three hydrophilic ligands used were SO3PhBTP, SO3PhBTBP, and SO3PhBTPhen. It was evident from the solvent extraction studies that SO3PhBTP formed a stronger complex with Cm3+ than with Am3+, but SO3PhBTPhen showed better complexation ability for Am3+ than for Cm3+, and SO3PhBTBP showed no selectivity for the two actinide ions. DFT calculations indicated that the coordinating 'N' atoms in BTP were more co-planar in the complex and this co-planarity was higher in the Cm3+ complex as compared to that in Am3+. In the case of BTBP and BTPhen ligands, on the other hand, the co-planarity was more pronounced in the Am3+ complexes. Mayer's bond order calculations of M-N bonds in the complexes also indicated a reversal of the complexation ability of the BTP and BTPhen ligands for Am3+ and Cm3+. Calculations of the complexation energies further supported the higher selectivity of the BTP ligand for Am3+ by -52.0 kJ mol-1, and better selectivity of the BTPhen ligand for Cm3+ by -24.7 kJ mol-1.

258 Increase in Cycling Injuries During COVID-19: Unintended Consequences of Lockdown Restrictions in The United Kingdom

Introduction

Higher number of cycling injuries were observed during the COVID-19 period in the United Kingdom at our institution. Many were serious injuries requiring hospitalisation and some requiring surgery. We investigated whether the lockdown led to a legitimate increase in incidence of cycling related injuries, resulting in a higher number of aerosol generating procedures (AGPs). This would assess whether the guidance on exercise during lockdown was appropriate, shaping future regulation in the case of cyclical lockdowns.

Method

Records were screened retrospectively for cycling related injuries between April 1st and May 12th (lockdown) 2020 and for same period in 2019 as a control group. Injury severity, distribution and number of surgical procedures resulting from these were assessed.

Results

The proportion of injuries due to cycling rose threefold (n = 55) during the COVID-19 lockdown. Injuries included fractures, soft tissue injuries and mixed injuries. An increase in the number of operative procedures (n = 13) and AGPs was also noted.

Conclusions

Vague guidance and allowance of one form of outdoor exercise per day may have unintentionally contributed to rise in cycling injuries as many took to cycling for recreation. To make the guidance appropriate, usual forms of exercise should be encouraged, risk taking behaviours discouraged and safe cycling practices endorsed.

Refractory Stroke Thrombectomy: Prevalence, Etiology, and Adjunctive Treatment in a North American Cohort

BACKGROUND AND PURPOSE

Acute stroke intervention refractory to mechanical thrombectomy may be due to underlying vessel wall pathology including intracranial atherosclerotic disease and intracranial arterial dissection or recalcitrant emboli. We studied the prevalence and etiology of refractory thrombectomy, the safety and efficacy of adjunctive interventions in a North American-based cohort.

MATERIALS AND METHODS

We performed a multicenter, retrospective study of refractory thrombectomy, defined as unsuccessful recanalization, vessel reocclusion in <72 hours, or required adjunctive antiplatelet glycoprotein IIb/IIIa inhibitors, intracranial angioplasty and/or stenting to achieve and maintain reperfusion. Clinical and imaging criteria differentiated etiologies for refractory thrombectomy. Baseline demographics, cerebrovascular risk factors, technical/clinical outcomes, and procedural safety/complications were compared between refractory and standard thrombectomy groups. Multivariable logistic regression analysis was performed to determine independent predictors of refractory thrombectomy.

RESULTS

Refractory thrombectomy was identified in 25/302 cases (8.3%), correlated with diabetes (44% versus 22%, P = .02) as an independent predictor with OR = 2.72 (95% CI, 1.05-7.09; P = .04) and inversely correlated with atrial fibrillation (16% versus 45.7%, P = .005). Refractory etiologies were secondary to recalcitrant emboli (20%), intracranial atherosclerotic disease (60%), and/or intracranial arterial dissection (44%). Four (16%) patients were diagnosed with early vessel reocclusion, and 21 patients underwent adjunctive salvage interventions with glycoprotein IIb/IIIa inhibitor infusion alone (32%) or intracranial angioplasty and/or stenting (52%). There were no significant differences in TICI 2b/3 reperfusion efficacy (85.7% versus 90.9%, P = .48), symptomatic intracranial hemorrhage rates (0% versus 9%, P = .24), favorable clinical outcomes (39.1% versus 48.3%, P = .51), or mortality (13% versus 28.3%, P = .14) versus standard thrombectomy.

CONCLUSIONS

Refractory stroke thrombectomy is encountered in <10% of cases, independently associated with diabetes, and related to underlying vessel wall pathology (intracranial atherosclerotic disease and/or intracranial arterial dissection) or, less commonly, recalcitrant emboli. Emergent salvage interventions with glycoprotein IIb/IIIa inhibitors or intracranial angioplasty and/or stenting are safe and effective adjunctive treatments.

Carotid Stenting without Embolic Protection Increases Major Adverse Events: Analysis of the National Surgical Quality Improvement Program

BACKGROUND AND PURPOSE

Published data regarding embolic protection device efficacy is mixed, and its use during carotid artery stent placement remains variable. We, therefore, examined the frequency of embolic protection device use and its association with outcomes after carotid artery stent placement using a national quality improvement data base.

MATERIALS AND METHODS

Patients undergoing carotid artery stent placement with or without embolic protection devices were identified in the American College of Surgeons National Surgical Quality Improvement Program data base. The primary outcome was the incidence of major adverse cardiovascular events (defined as death, stroke, or myocardial infarction/arrhythmia) within 30 days. Propensity scoring was used to create 2 matching cohorts of patients using demographic and baseline variables.

RESULTS

Between 2011 and 2018, among 1200 adult patients undergoing carotid artery stent placement, 23.8% did not have embolic protection devices. There was no trend toward increased embolic protection device use with time. Patients without embolic protection device use received preoperative antiplatelets less frequently (90.6% versus 94.6%, P = .02), underwent more emergent carotid artery stent placement (7.2% versus 3.6%, P = .01), and had a higher incidence of major adverse cardiovascular events (OR = 1.81; 95% CI, 1.11-2.94) and stroke (OR = 3.31; 95% CI, 1.71-6.39). After compensating for baseline imbalances using propensity-matched cohorts (n = 261 for both), carotid artery stent placement without an embolic protection device remained associated with increased major adverse cardiovascular events (9.2% versus 4.2%; OR = 2.30; 95% CI, 1.10-4.80) and stroke (6.5% versus 1.5%; OR = 4.48; 95% CI, 1.49-13.49).

CONCLUSIONS

Lack of embolic protection device use during carotid artery stent placement is associated with a 4-fold increase in the likelihood of perioperative stroke. Nevertheless, nearly one-quarter of patients in the American College of Surgeons National Surgical Quality Improvement Program underwent unprotected carotid artery stent placement. Efforts targeting improved embolic protection device use during carotid artery stent placement are warranted.

Selective permeation of 90Y from a mixture of 90Y/90Sr through diglycolamide impregnated supported liquid membranes

An attempt was made in this work to evaluate a simple flat sheet supported liquid membrane technique for the separation of carrier free ⁹⁰Y from ⁹⁰Sr using two diglycolamide carrier ligands, (i) N,N,N',N'-tetra-n-octyl-diglycolamide (TODGA), and (ii) N,N,N',N'-tetra-(2-ethylhexyl)-diglycolamide (TEHDGA). Various experimental parameters were optimized to get selective transport of ⁹⁰Y over ⁹⁰Sr. At 6 M HNO₃ feed acidity, >95% ⁹⁰Y could be recovered selectively in just 4 h with both the ligands. Under identical experimental conditions, about 0.1% transport of Sr was also recorded which could be completely removed by passing through a Sr selective column to get medical grade ⁹⁰Y pure product. A mathematical model equation was also derived and experimentally validated for predicting the transport of ⁹⁰Y through membrane.

Sternoclavicular Joint Septic Arthritis and Anterior Mediastinal Mass in a Young Athlete: Possible Immune-modulatory Effect of Growth Hormone

Septic arthritis of sternoclavicular joint (SCJ) is a rare disease, however, not uncommon in patients who abuse intravenous drugs. It can present with a wide range of manifestations that can pose diagnostic challenges, which can result in a delay in diagnosis and treatment. Over the last few decades, there is a surge in the use of nonprescription recombinant human growth hormone (rhGH) by the young healthy population and athletes for its purported ergogenic effects. Furthermore, we lack quantitative information about the adverse effects of the chronic use of rhGH in a healthy population due to the scarcity of epidemiological data. We are reporting a case of a young male athlete who was chronically using the subcutaneous rhGH formulation to build lean body mass, and presented with septic arthritis of right SCJ due to methicillin-sensitive Staphylococcus aureus (MSSA) complicated by a necrotic inflammatory response involving the mediastinum which infiltrated the apical lung parenchyma. The clinical presentation masqueraded as the mediastinal mass raising the suspicion of mediastinal malignancy. Histological analysis of the tissue of SCJ and mediastinal area revealed no malignant cells but a lymphocyte-predominant inflammatory response with germinal centers was observed, which was an atypical response to MSSA bacterial infection. We have reviewed the literature to elucidate the immune-modulatory effect of rhGH, as the chronic use of rhGH by our patient probably has contributed to an atypical immune response to MSSA. The patient was treated with an extended duration of parenteral antibiotics and multiple incision and debridements to achieve complete resolution of infection over the next six months. This is a unique case of septic arthritis of right SCJ in a patient on chronic subcutaneous rhGH which masqueraded as a mediastinal mass raising concern of malignancy; moreover, it highlights the probable immune-modulatory role of rhGH which instigated an atypical immune response to MSSA infection.

Development of Central Nervous System Vasculitis in a Patient with Waldenstrom Macroglobulinemia: A Rare Presentation with Poor Prognosis

Waldenstrom macroglobulinemia (WM) is a rare lymphoproliferative disorder characterized by the presence of monoclonal immunoglobulin M in serum. WM may present with neurologic complications involving the peripheral and central nervous systems (CNS) though CNS complications associated with WM are rare. We present a case of a 72-year-old male with an 18-month history of WM who experienced neurologic and constitutional symptoms indicative of WM progression over a three-week period while on rituximab maintenance therapy. The patient’s symptoms were initially attributed to rituximab-induced asthenia though his clinical condition did not improve with rituximab discontinuation. Due to progressively worsening neurologic symptoms, the patient was re-evaluated and found to have multiple cerebral infarcts and increased serum cryoglobulin levels indicative of cryoglobulinema. The patient was promptly initiated on a combination regimen of high dose steroids, intravenous immunoglobulin (IVIG), and plasmapheresis but had a poor response. Brain biopsy revealed necrotizing vasculitis with dense intra- and peri-vascular CD3 positive T-cell infiltrates with mural necrosis. This is a unique case of WM complicated by type 1 cryoglobulinemia associated with CNS vasculitis that was unresponsive to active rituximab therapy; this case illustrates a poor prognosis of patients with CNS involvement in WM.

GUide sheath Advancement and aspiRation in the Distal petrocavernous internal carotid artery (GUARD) Technique during Thrombectomy Improves Reperfusion and Clinical Outcomes

BACKGROUND AND PURPOSE

Adjunctive techniques to stent retriever thrombectomy include balloon-guide catheters and/or distal access catheters for aspiration. We describe a novel technique using a flexible, 6 French 088 distal guide sheath advanced past the skull base to augment mechanical thrombectomy. We studied the relative safety and efficacy of this technique in the setting of a combined stent retriever-distal access catheter aspiration thrombectomy protocol.

MATERIALS AND METHODS

We performed a retrospective case-control study of intracranial internal carotid artery or M1-M2 middle cerebral artery occlusions requiring mechanical thrombectomy. Patients were divided into 2 groups based on thrombectomy techniques: conventional stent retriever with distal access catheter aspiration without (standard) and with adjunctive GUide sheath Advancement and aspiRation in the Distal petrocavernous internal carotid artery (GUARD). Using propensity score matching, we compared procedural safety, reperfusion efficacy using the modified Thrombolysis in Cerebral Infarction scale and clinical outcomes with the modified Rankin Scale.

RESULTS

In comparing the GUARD (45 patients) versus standard (45 matched case controls) groups, there were no significant differences in demographics, NIHSS presentations, IV rtPA use, median onset-to-groin puncture times, procedural complications, symptomatic intracranial hemorrhage, or mortality. The GUARD group demonstrated significantly higher successful mTICI ≥2b reperfusion rates (98% versus 80%, P = .015) and improved functional mRS ≤2 outcomes (67% versus 43%, P = .04), with independent effects of the GUARD technique confirmed in a multivariable logistic regression model.

CONCLUSIONS

The GUARD technique during mechanical thrombectomy with combined stent retrieval-distal access catheter aspiration is safe and effective in improving reperfusion and clinical outcomes.

Diagnostic Accuracy of High-Resolution Black-Blood MRI in the Evaluation of Intracranial Large-Vessel Arterial Occlusions

BACKGROUND AND PURPOSE

3D high-resolution black-blood MRI or MR vessel wall imaging allows evaluation of the intracranial arterial wall and extraluminal pathology. We investigated the diagnostic accuracy and reliability of black-blood MRI for the intraluminal detection of large-vessel arterial occlusions.

MATERIALS AND METHODS

We retrospectively identified patients with intracranial arterial occlusions, confirmed by CTA or DSA, who also underwent 3D black-blood MRI with nonenhanced and contrast-enhanced T1 sampling perfection with application-optimized contrasts by using different flip angle evolution (T1 SPACE) sequences. Black-blood MRI findings were evaluated by 2 independent and blinded neuroradiologists. Large-vessel intracranial arterial segments were graded on a 3-point scale (grades 0-2) for intraluminal baseline T1 hyperintensity and contrast enhancement. Vessel segments were considered positive for arterial occlusion if focal weak (grade 1) or strong (grade 2) T1-hyperintense signal and/or enhancement replaced the normal intraluminal black-blood signal.

RESULTS

Thirty-one patients with 38 intracranial arterial occlusions were studied. The median time interval between black-blood MRI and CTA/DSA reference standard studies was 2 days (range, 0-20 days). Interobserver agreement was good for T1 hyperintensity (κ = 0.63) and excellent for contrast enhancement (κ = 0.89). High sensitivity (100%) and specificity (99.8%) for intracranial arterial occlusion diagnosis was observed with either intraluminal T1 hyperintensity or contrast-enhancement imaging criteria on black-blood MRI. Strong grade 2 intraluminal enhancement was maintained in >80% of occlusions irrespective of location or chronicity. Relatively increased strong grade 2 intraluminal T1 hyperintensity was noted in chronic/incidental versus acute/subacute occlusions (45.5% versus 12.5%, P = .04).

CONCLUSIONS

Black-blood MRI with or without contrast has high diagnostic accuracy and reliability in evaluating intracranial large-vessel arterial occlusions with near-equivalency to DSA and CTA.

Adjunctive Efficacy of Intra-Arterial Conebeam CT Angiography Relative to DSA in the Diagnosis and Surgical Planning of Micro-Arteriovenous Malformations

BACKGROUND AND PURPOSE

Micro-arteriovenous malformations are an underrecognized etiology of intracranial hemorrhage. Our study aimed to assess the adjunctive efficacy of intra-arterial conebeam CTA relative to DSA in the diagnosis and surgical planning of intracranial micro-AVMs.

MATERIALS AND METHODS

We performed a retrospective study of all micro-AVMs (≤1-cm nidus) at our institution. Blinded neuroradiologists qualitatively graded DSA and intra-arterial conebeam CTA images for the detection of specific micro-AVM anatomic parameters (arterial feeder, micronidus, and venous drainer) and defined an overall diagnostic value. Statistical and absolute differences in the overall diagnostic values defined the relative intra-arterial conebeam CTA diagnostic values, respectively. Blinded neurosurgeons reported their treatment approach after DSA and graded the adjunctive value of intra-arterial conebeam CTA to improve or modify treatment. Intra-arterial conebeam CTA efficacy was defined as interobserver agreement in the relative intra-arterial conebeam CTA diagnostic and/or treatment-planning value scores.

RESULTS

Ten patients with micro-AVMs presented with neurologic deficits and/or intracranial hemorrhages. Both neuroradiologists assigned a higher overall intra-arterial conebeam CTA diagnostic value (P < .05), secondary to improved evaluation of both arterial feeders and the micronidus, with good interobserver agreement (τ = 0.66, P = .018) in the relative intra-arterial conebeam CTA diagnostic value. Both neurosurgeons reported that integrating the intra-arterial conebeam CTA data into their treatment plan would allow more confident localization for surgical/radiation treatment (8/10; altering the treatment plan in 1 patient), with good interobserver agreement in the relative intra-arterial conebeam CTA treatment planning value (τ = 0.73, P = .025).

CONCLUSIONS

Adjunctive intra-arterial conebeam CTA techniques are more effective in the diagnostic identification and anatomic delineation of micro-AVMs, relative to DSA alone, with the potential to improve microsurgical or radiosurgery treatment planning.

Characterization of friction and moisture of porcine lingual tissue in vitro in response to artificial saliva and mouthwash solutions

BACKGROUND

The purpose of this research is to characterize the effects of mouthwash solutions on oral friction and moisture using a quantitative in vitro approach.

MATERIALS AND METHODS

The frictional coefficient of in vitro porcine tongue samples was measured using a magnetic levitation haptic device equipped with a custom tactor designed to mimic human skin. A commercially available moisture meter was used to measure moisture content of the samples. Tongue samples were first tested before treatment, then after application of saliva (either human or artificial), and again after application of 1 of 11 different mouthwash solutions.

RESULTS

The data indicate that the samples treated with artificial saliva vs real saliva have comparable friction coefficient and moisture content. Furthermore, the moisture and friction coefficient remain relatively constant for up to 60 minutes after exposure to ambient conditions. Samples treated with artificial saliva have an average friction coefficient in the range of 0.70-0.80. Application of mouthwash solutions produced an average friction coefficient of 0.39-0.49 but retained the high moisture content of the artificial salivary layer. Several mouthwash solutions resulted in statistically significant differences in the friction coefficient relative to each other.

CONCLUSION

The results of this study demonstrate that a magnetic levitation device can be an effective tool for in vitro oral tribology and that artificial saliva is an effective substitute for real saliva in extended in vitro experiments. The application of mouthwash generally reduces the coefficient of friction of the tongue samples while preserving a relatively high moisture level, and some mouthwashes reduce friction significantly more than others.

In Vivo Assessment of the Impact of Regional Intracranial Atherosclerotic Lesions on Brain Arterial 3D Hemodynamics

BACKGROUND AND PURPOSE

Intracranial atherosclerosis induces hemodynamic disturbance, which is not well-characterized, particularly in cerebral flow redistribution. We aimed to characterize the impact of regional stenotic lesions on intracranial hemodynamics by using 4D flow MR imaging.

MATERIALS AND METHODS

4D flow MR imaging was performed in 22 symptomatic patients (mean age, 68.4 ± 14.2 years) with intracranial stenosis (ICA, n = 7; MCA, n = 9; basilar artery, n = 6) and 10 age-appropriate healthy volunteers (mean age, 60.7 ± 8.1 years). 3D blood flow patterns were visualized by using time-integrated pathlines. Blood flow and peak velocity asymmetry indices were compared between patients and healthy volunteers in 4 prespecified arteries: ICAs, MCAs, and anterior/posterior cerebral arteries.

RESULTS

3D blood flow pathlines demonstrated flow redistribution across cerebral arteries in patients with unilateral intracranial stenosis. For patients with ICA stenosis compared with healthy volunteers, significantly lower flow and peak velocities were identified in the ipsilateral ICA (P = .001 and P = .001) and MCA (P < .001 and P = .001), but higher flow, in the ipsilateral PCA (P < .001). For patients with MCA stenosis, significantly lower flow and peak velocities were observed in the ipsilateral ICA (P = .009 and P = .045) and MCA (P < .001 and P = .005), but significantly higher flow was found in the ipsilateral posterior cerebral artery (P = .014) and anterior cerebral artery (P = .006). The asymmetry indices were not significantly different between patients with basilar artery stenosis and the healthy volunteers.

CONCLUSIONS

Regional intracranial atherosclerotic lesions not only alter distal arterial flow but also significantly affect ipsilateral collateral arterial hemodynamics.

Effect of discrete (individual) and mixed (bulk) genomic DNA on genetic diversity estimates and population structure in Teak (Tectona grandis L. f.)

Teak (Tectona grandis L.f.), a paragon timber tree of tropical deciduous forests of Central and Peninsular India, is highly prized for its wood colour, decorative grains, durability and lightness. An experiment was carried out to compare the genetic variation detected and genetic relationships inferred in five teak populations via 10 genomic DNA samples per population each of either single seed or bulk of 3- or 5- seeds with the help of ISSR markers. The genomic DNA of single seed exhibited higher number of polymorphic loci, per cent polymorphism, nei’s genetic diversity and shannon Information Index than the bulk genomic DNA of 3- or 5- seeds. The bulking of genomic DNA of 3- and 5- seeds using Nei’s genetic distance coefficient revealed similar genetic relationships, which were at variance with those in single seed treatment. Mantel’s correlation test among the genetic distance matrices of single seed sampling, 3-seed bulk and 5-seed bulk sampling also confirmed the trend. Since the bulking of genomic DNA did not generate compatible estimates of diversity parameters and genetic relationship of five populations from its single seed sampling, we recommend strict guarding of identities of genotypes within the collected samples for obtaining precise estimates and drawing accurate conclusions about the genetic diversity and clustering of populations.

Impact of Pial Collaterals on Infarct Growth Rate in Experimental Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Cerebral infarction evolves at different rates depending on available blood flow suggesting that treatment time windows vary depending on the degree of pial collateral recruitment. This work sought to mathematically model infarct growth and determine whether infarct volume growth can be predicted by angiographic assessment of pial collateral recruitment in an experimental MCA occlusion animal model.

MATERIALS AND METHODS

Pial collateral recruitment was quantified by using DSA, acquired 15 minutes following permanent MCA occlusion in 6 canines based on a scoring system (average pial collateral score) and arterial arrival time. MR imaging-based infarct volumes were measured 60, 90, 120, 180, 240 and 1440 minutes following MCA occlusion and were parameterized in terms of the growth rate index and final infarct volume (V_Final) as V(t) = V_Final [1 - e^{(-G × t)}] (t = time). Correlations of the growth rate index and final infarct volume to the average pial collateral score and arterial arrival time were assessed by linear bivariate analysis. Correlations were used to generate asymptotic models of infarct growth for average pial collateral score or arterial arrival time values. Average pial collateral score- and arterial arrival time-based models were assessed by F tests and residual errors.

RESULTS

Evaluation of pial collateral recruitment at 15 minutes postocclusion was strongly correlated with 24-hour infarct volumes (average pial collateral score: r² = 0.96, P < .003; arterial arrival time: r² = 0.86, P < .008). Infarct growth and the growth rate index had strong and moderate linear relationships to the average pial collateral score (r² = 0.89; P < .0033) and arterial arrival time (r² = 0.69; P < .0419), respectively. Final infarct volume and the growth rate index were algebraically replaced by angiographically based collateral assessments to model infarct growth. The F test demonstrated no statistical advantage to using the average pial collateral score- over arterial arrival time-based predictive models, despite lower residual errors in the average pial collateral score-based model (P < .03).

CONCLUSIONS

In an experimental permanent MCA occlusion model, assessment of pial collaterals correlates with the infarct growth rate index and has the potential to predict asymptotic infarct volume growth.

Quantifying Intracranial Plaque Permeability with Dynamic Contrast-Enhanced MRI: A Pilot Study

BACKGROUND AND PURPOSE

Intracranial atherosclerotic disease plaque hyperintensity and/or gadolinium contrast enhancement have been studied as imaging biomarkers of acutely symptomatic ischemic presentations using single static MR imaging measurements. However, the value in modeling the dynamics of intracranial plaque permeability has yet to be evaluated. The purpose of this study was to use dynamic contrast-enhanced MR imaging to quantify the contrast permeability of intracranial atherosclerotic disease plaques in symptomatic patients and to compare these parameters against existing markers of plaque volatility using black-blood MR imaging pulse sequences.

MATERIALS AND METHODS

We performed a prospective study of contrast uptake dynamics in the major intracranial vessels proximal and immediately distal to the circle of Willis using dynamic contrast-enhanced MR imaging, specifically in patients with symptomatic intracranial atherosclerotic disease. Using the Modified Tofts model, we extracted the volume transfer constant (K^trans) and fractional plasma volume (V_p) parameters from plaque-enhancement curves. Using regression analyses, we compared these parameters against time from symptom onset as well as intraplaque hyperintensity and postcontrast enhancement derived from T1 SPACE, a black-blood MR vessel wall imaging sequence.

RESULTS

We completed analysis in 10 patients presenting with symptomatic intracranial atherosclerotic disease. K^trans and V_p measurements were higher in plaques versus healthy white matter and similar or less than values in the choroid plexus. Only K^trans correlated significantly with time from symptom onset (P = .02). Dynamic contrast-enhanced MR imaging parameters were not found to correlate significantly with intraplaque enhancement or intraplaque hyperintensity (P = .4 and P = .17, respectively).

CONCLUSIONS

Elevated K^trans and V_p values found in intracranial atherosclerotic disease plaques versus healthy white matter suggest that dynamic contrast-enhanced MR imaging is a feasible technique for studying vessel wall and plaque characteristics in the proximal intracranial vasculature. Significant correlations between K^trans and symptom onset, which were not observed on T1 SPACE-derived metrics, suggest that K^trans may be an independent imaging biomarker of acute and symptom-associated pathologic changes in intracranial atherosclerotic disease plaques.

Emergent Endovascular Management of Long-Segment and Flow-Limiting Carotid Artery Dissections in Acute Ischemic Stroke Intervention with Multiple Tandem Stents

BACKGROUND AND PURPOSE

Although most cervical dissections are managed medically, emergent endovascular treatment may become necessary in the presence of intracranial large-vessel occlusions, flow-limiting and long-segment dissections with impending occlusion, and/or hypoperfusion-related ischemia at risk of infarction. We investigated the role of emergent endovascular stenting of long-segment carotid dissections in the acute ischemic stroke setting.

MATERIALS AND METHODS

We retrospectively studied long-segment carotid dissections requiring stent reconstruction with multiple tandem stents (≥3 stents) and presenting with acute (<12 hours) ischemic stroke symptoms (NIHSS score, ≥4). We analyzed patient demographics, vascular risk factors, clinical presentations, imaging/angiographic findings, technical procedures/complications, and clinical outcomes.

RESULTS

Fifteen patients (mean age, 51.5 years) with acute ischemic stroke (mean NIHSS score, 15) underwent endovascular stent reconstruction for vessel and/or ischemic tissue salvage. All carotid dissections presented with >70% flow limiting stenosis and involved the distal cervical ICA with a minimum length of 3.5 cm. Carotid stent reconstruction was successful in all patients with no residual stenosis or flow limitation. Nine patients (60%) harbored intracranial occlusions, and 6 patients (40%) required intra-arterial thrombolysis/thrombectomy, achieving 100% TICI 2b-3 reperfusion. Two procedural complications were limited to thromboembolic infarcts from in-stent thrombus and asymptomatic hemorrhagic infarct transformation (7% morbidity, 0% mortality). Angiographic and ultrasound follow-up confirmed normal carotid caliber and stent patency, with 2 cases of <20% in-stent stenosis. Early clinical improvement resulted in a mean discharge NIHSS score of 6, and 9/15 (60%) patients achieved a 90-day mRS of ≤2.

CONCLUSIONS

Emergent stent reconstruction of long-segment and flow-limiting carotid dissections in acute ischemic stroke intervention is safe and effective, with favorable clinical outcomes, allowing successful thrombectomy, vessel salvage, restoration of cerebral perfusion, and/or prevention of recurrent thromboembolic stroke.

Intracranial Vessel Wall MRI: Principles and Expert Consensus Recommendations of the American Society of Neuroradiology

Intracranial vessel wall MR imaging is an adjunct to conventional angiographic imaging with CTA, MRA, or DSA. The technique has multiple potential uses in the context of ischemic stroke and intracranial hemorrhage. There remain gaps in our understanding of intracranial vessel wall MR imaging findings and research is ongoing, but the technique is already used on a clinical basis at many centers. This article, on behalf of the Vessel Wall Imaging Study Group of the American Society of Neuroradiology, provides expert consensus recommendations for current clinical practice.

Neurointerventional management of carotid webs associated with recurrent and acute cerebral ischemic syndromes

BACKGROUND

A carotid web can be defined as an endoluminal shelf-like projection often noted at the origin of the internal carotid artery (ICA) just beyond the bifurcation. Diagnosis of a carotid web as an underlying cause of recurrent ischemic stroke is infrequent and easily misdiagnosed as an atheromatous plaque. Surgery has traditionally been used to resect symptomatic lesions while there is no enough evidence supporting medical therapy as the sole management. To our knowledge there is only one report about carotid artery stenting (CAS) as a definite management of carotid web and no previous reports of acute large-vessel occlusions undergoing mechanical thrombectomy in the setting of carotid web as the etiology.

CASE REPORT

We report two cases: The first presented with recurrent ischemic stroke in the same arterial territory and the other with an emergent left middle cerebral artery (MCA) occlusion that underwent endovascular mechanical thrombectomy in which initial computed tomographic angiograms (CTA) suggested carotid web etiologies. Following confirmation with digital subtraction angiography (DSA), both patients ultimately underwent endovascular carotid stenting instead of surgical resection for definitive carotid web treatment.

CONCLUSIONS

Carotid webs are a rare cause of ischemic stroke in young and middle-aged adults that can readily be identified by CTA. Endovascular management may include emergent mechanical thrombectomy for large-vessel thromboembolic complications, and for definitive treatment with carotid stenting across the carotid web as an alternative to surgical resection and medical management for secondary stroke prevention.

Autosomal Dominant Polycystic Kidney Disease and Intracranial Aneurysms: Is There an Increased Risk of Treatment?

BACKGROUND AND PURPOSE

Autosomal dominant polycystic kidney disease is associated with an increased risk of intracranial aneurysms. Our purpose was to assess whether there is an increased risk during aneurysm coiling and clipping.

MATERIALS AND METHODS

Data were obtained from the National Inpatient Sample (2000-2011). All subjects had an unruptured aneurysm clipped or coiled and were divided into polycystic kidney (n = 189) and control (n = 3555) groups. Primary end points included in-hospital mortality, length of stay, and total hospital charges. Secondary end points included the International Classification of Diseases, Ninth Revision codes for iatrogenic hemorrhage or infarction; intracranial hemorrhage; embolic infarction; and carotid and vertebral artery dissections.

RESULTS

There was a significantly greater incidence of iatrogenic hemorrhage or infarction, embolic infarction, and carotid artery dissection in the patients with polycystic kidney disease compared with the control group after endovascular coiling. There was also a significantly greater incidence of iatrogenic hemorrhage or infarction in the polycystic kidney group after surgical clipping. However, the hospital stay was not longer in the polycystic kidney group, and the total hospital charges were not higher. Additional analysis within the polycystic kidney group revealed a significantly shorter length of stay but similar in-hospital costs when subjects underwent coiling versus clipping.

CONCLUSIONS

Patients with polycystic kidney disease face an increased risk during intracranial aneurysm treatment, whether by coiling or clipping. This risk, however, does not translate into longer hospital stays or increased hospital costs. Despite the additional catheterization-related risks of dissection and embolization, coiling results in shorter hospital stays and similar mortality compared with clipping.

Evaluation of 4D vascular flow and tissue perfusion in cerebral arteriovenous malformations: influence of Spetzler-Martin grade, clinical presentation, and AVM risk factors

BACKGROUND AND PURPOSE

The role of intracranial hemodynamics in the pathophysiology and risk stratification of brain AVMs remains poorly understood. The purpose of this study was to assess the influence of Spetzler-Martin grade, clinical history, and risk factors on vascular flow and tissue perfusion in cerebral AVMs.

MATERIALS AND METHODS

4D flow and perfusion MR imaging was performed in 17 patients with AVMs. Peak velocity and blood flow were quantified in AVM feeding and contralateral arteries, draining veins, and the straight sinus. Regional perfusion ratios (CBF, CBV, and MTT) were calculated between affected and nonaffected hemispheres.

RESULTS

Regarding flow parameters, high-grade AVMs (Spetzler-Martin grade of >2) demonstrated significantly increased peak velocity and blood flow in the major feeding arteries (P < .001 and P = .004) and straight sinus (P = .003 and P = .012) and increased venous draining flow (P = .001). The Spetzler-Martin grade significantly correlated with cumulative feeding artery flow (r = 0.85, P < .001) and draining vein flow (r = 0.80, P < .001). Regarding perfusion parameters, perinidal CBF and CBV ratios were significantly lower (P < .001) compared with the remote ratios and correlated negatively with cumulative feeding artery flow (r = -0.60, P = .014 and r = -0.55, P = .026) and draining vein flow (r = -0.60, P = .013 and r = -0.56, P = .025). Multiple regression analysis revealed no significant association of AVM flow or perfusion parameters with clinical presentation (rupture and seizure history) and AVM risk factors.

CONCLUSIONS

Macrovascular flow was significantly associated with increasing Spetzler-Martin grade and correlated with perinidal microvascular perfusion in cerebral AVMs. Future longitudinal studies are needed to evaluate the potential of comprehensive cerebral flow and perfusion MR imaging for AVM risk stratification.

Quantifying Intracranial Aneurysm Wall Permeability for Risk Assessment Using Dynamic Contrast-Enhanced MRI: A Pilot Study

BACKGROUND AND PURPOSE

Pathological changes in the intracranial aneurysm wall may lead to increases in its permeability; however the clinical significance of such changes has not been explored. The purpose of this pilot study was to quantify intracranial aneurysm wall permeability (K(trans), VL) to contrast agent as a measure of aneurysm rupture risk and compare these parameters against other established measures of rupture risk. We hypothesized K(trans) would be associated with intracranial aneurysm rupture risk as defined by various anatomic, imaging, and clinical risk factors.

MATERIALS AND METHODS

Twenty-seven unruptured intracranial aneurysms in 23 patients were imaged with dynamic contrast-enhanced MR imaging, and wall permeability parameters (K(trans), VL) were measured in regions adjacent to the aneurysm wall and along the paired control MCA by 2 blinded observers. K(trans) and VL were evaluated as markers of rupture risk by comparing them against established clinical (symptomatic lesions) and anatomic (size, location, morphology, multiplicity) risk metrics.

RESULTS

Interobserver agreement was strong as shown in regression analysis (R(2) > 0.84) and intraclass correlation (intraclass correlation coefficient >0.92), indicating that the K(trans) can be reliably assessed clinically. All intracranial aneurysms had a pronounced increase in wall permeability compared with the paired healthy MCA (P < .001). Regression analysis demonstrated a significant trend toward an increased K(trans) with increasing aneurysm size (P < .001). Logistic regression showed that K(trans) also predicted risk in anatomic (P = .02) and combined anatomic/clinical (P = .03) groups independent of size.

CONCLUSIONS

We report the first evidence of dynamic contrast-enhanced MR imaging-modeled contrast permeability in intracranial aneurysms. We found that contrast agent permeability across the aneurysm wall correlated significantly with both aneurysm size and size-independent anatomic risk factors. In addition, K(trans) was a significant and size-independent predictor of morphologically and clinically defined high-risk aneurysms.

Perfusion-based selection for endovascular reperfusion therapy in anterior circulation acute ischemic stroke

BACKGROUND AND PURPOSE

Controversy exists about the role of perfusion imaging in patient selection for endovascular reperfusion therapy in acute ischemic stroke. We hypothesized that perfusion imaging versus noncontrast CT- based selection would be associated with improved functional outcomes at 3 months.

MATERIALS AND METHODS

We reviewed consecutive patients with anterior circulation strokes treated with endovascular reperfusion therapy within 8 hours and with baseline NIHSS score of ≥8. Baseline clinical data, selection mode (perfusion versus NCCT), angiographic data, complications, and modified Rankin Scale score at 3 months were collected. Using multivariable logistic regression, we assessed whether the mode of selection for endovascular reperfusion therapy (perfusion-based versus NCCT-based) was independently associated with good outcome.

RESULTS

Two-hundred fourteen patients (mean age, 67.2 years; median NIHSS score, 18; MCA occlusion 74% and ICA occlusion 26%) were included. Perfusion imaging was used in 76 (35.5%) patients (39 CT and 37 MR imaging). Perfusion imaging-selected patients were more likely to have good outcomes compared with NCCT-selected patients (55.3 versus 33.3%, P = .002); perfusion selection by CT was associated with similar outcomes as that by MR imaging (CTP, 56.; MR perfusion, 54.1%; P = .836). In multivariable analysis, CT or MR perfusion imaging selection remained strongly associated with good outcome (adjusted OR, 2.34; 95% CI, 1.22-4.47), independent of baseline severity and reperfusion.

CONCLUSIONS

In this multicenter study, patients with acute ischemic stroke who underwent perfusion imaging were more than 2-fold more likely to have good outcomes following endovascular reperfusion therapy. Randomized studies should compare perfusion imaging with NCCT imaging for patient selection for endovascular reperfusion therapy.

T1 gadolinium enhancement of intracranial atherosclerotic plaques associated with symptomatic ischemic presentations

BACKGROUND AND PURPOSE

Contrast enhancement of intracranial atherosclerotic plaques has recently been investigated using high field and high resolution MR imaging as a risk factor in the development of ischemic stroke. We studied the reliability of conventional MR imaging at 1.5T in evaluating intraplaque enhancement and its relationship with acute cerebrovascular ischemic presentations in patients with severe intracranial atherosclerotic disease.

MATERIALS AND METHODS

We retrospectively identified and analyzed 19 patients with 22 high-grade intracranial atherosclerotic disease plaques (>70% stenosis) in vessels cross-sectionally visualized by neuroanatomic MR imaging. Atherosclerotic plaques were classified as asymptomatic or symptomatic. Two blinded neuroradiologists independently ranked each lesion for the presence of intraplaque enhancement by use of a 5-point scale (1-5). Furthermore, plaque enhancement was quantified as the relative change in T1WI spin-echo signal intensity (postcontrast/precontrast) in the vessel wall at the site of each intracranial atherosclerotic disease lesion.

RESULTS

Intraplaque enhancement was observed in 7 of 10 (70%) symptomatic plaques, in contrast to 1 of 12 (8%) asymptomatic plaques. Interobserver reliability correlated well for intraplaque enhancement (κ = 0.82). The degree of relative plaque enhancement in symptomatic versus asymptomatic lesions (63% versus 23%) was statistically significant (P = .001, t test).

CONCLUSIONS

In this pilot study, we determined that intraplaque enhancement could be reliably evaluated with the use of cross-sectional imaging and analysis of vessels/plaques by use of conventional neuroanatomic MR imaging protocols. In addition, we observed a strong association between intraplaque enhancement in severe intracranial atherosclerotic disease lesions and ischemic events with the use of conventional MR imaging. Our preliminary study suggests that T1 gadolinium-enhancing plaques may be an indicator of progressing or symptomatic intracranial atherosclerotic disease.

Endovascular management of pediatric high-flow vertebro-vertebral fistula with reversed basilar artery flow. A case report and review of the literature

Vertebral artery arteriovenous fistula (VAVF) is mostly known as a post-traumatic and/or iatrogenic arteriovenous complication. However, spontaneous high-flow VAVF associated with flow reversal in the basilar artery has not been reported in children. We describe a unique asymptomatic presentation of a spontaneous high-flow VAVF associated with flow reversal in the basilar artery in a pediatric patient. The literature for classification, pathophysiology, treatment strategies, and post-procedural complications is also reviewed.

Intracranial 4D flow MRI: toward individualized assessment of arteriovenous malformation hemodynamics and treatment-induced changes

BACKGROUND AND PURPOSE

Arteriovenous malformations are an important etiology of hemorrhagic stroke. However, current imaging modalities and risk do not provide insights into individual AVM hemodynamics and its role in pathophysiology. The aims of this study are to determine whether intracranial 4D flow MR imaging can provide insights into arteriovenous malformation hemodynamics independent of the Spetzler-Martin grade and to report the changes in flow observed during staged embolization.

MATERIALS AND METHODS

Intracranial 3D blood flow was assessed in 20 patients with AVM (age = 39 ± 15 years, Spetzler-Martin grade ranging from 1-4) with the use of 4D flow MR imaging (temporal resolution = 45 ms, spatial resolution = [1.2-1.6mm](3)). AVM hemodynamics were visualized by means of time-integrated 3D pathlines depicting the AVM arterial feeding and venous draining patterns over the cardiac cycle. Analysis included the grading of feeding and draining velocities on a 3-point scale (0 = low <25 cm/s, 1 = medium <50 cm/s, 2 = high >50 cm/s). For 4 of 20 patients undergoing 4D flow MR imaging follow-up after staged embolization, peak velocities were quantified in arterial feeders, draining veins, the sagittal sinus, and contralateral arteries.

RESULTS

In 50% of the cases with Spetzler-Martin grade >2, heterogeneous flow (velocity grade differences >1) was found across arteries and veins. Velocities in draining veins increased from Spetzler-Martin grade = 1 (grading = 0.5 ± 0.6) to Spetzler-Martin grade ≥3 (1.1 ± 0.6), whereas arterial velocities were similar (1.7 ± 0.6 versus 1.5 ± 0.6). In the postembolization subgroup of 4 patients, 4D flow MR imaging demonstrated successively more compact AVM and redistribution of velocities. Changes in arterial and venous velocities during treatment were highly different among individuals.

CONCLUSIONS

Spetzler-Martin grade does not reflect differences in 3D AVM arterial and venous hemodynamics, and an individual assessment of AVM hemodynamics may be needed for improved lesion characterization. Four-dimensional flow MR imaging may have the potential to monitor and guide embolization treatment planning.

Should patients with autosomal dominant polycystic kidney disease be screened for cerebral aneurysms?

Autosomal dominant polycystic kidney disease is a genetic disorder affecting 1 in 1000 people worldwide and is associated with an increased risk of intracranial aneurysms. It remains unclear whether there is sufficient net benefit to screening this patient population for IA, considering recent developments in imaging and treatment and our evolving understanding of the natural history of unruptured aneurysms. There is currently no standardized screening protocol for IA in patients with ADPCKD. Our review of the literature focused on the above issues and presents our appraisal of the estimated value of screening for IA in the setting of ADPCKD.

Juvenile pilocytic astrocytoma in association with arteriovenous malformation

Pilocytic astrocytomas are highly vascular, relatively common primary brain tumors in the pediatric population, but their association with a true arteriovenous malformation (AVM) is extremely rare. We describe an eight-year-old girl with a right supratentorial juvenile pilocytic astrocytoma (WHO grade I) with an angiographically documented AVM entangled in the tumor mass who presented with intracranial hemorrhage due to a ruptured anterior choroidal artery pseudoaneurysm encased in the lesion. The AVM nidus as well as the hemorrhage site was embolized with Onyx. A literature review revealed only one previous report of a true intermixture of these two lesions. We hypothesize whether the association of vascular malformations and primary brain tumors are merely coincidental or if they point to the existence of a distinct entity and/or a common etiologic factor.

Spontaneous post-partum cervical carotid artery dissection in a patient with reversible cerebral vasoconstriction syndrome

Post-partum cervicocephalic artery dissection (pp-CAD) is a rare and poorly understood condition. To our knowledge, only 21 cases have been reported. Reversible cerebral segmental vasoconstriction (RCSV) was first described by Call and Fleming in 1988, and its association with pp-CAD has only been reported in three cases. However, in those cases it is unclear whether the pp-CAD may have been caused by straining during labor and therefore merely coincidental to the intracranial arteriopathy. We describe a 41-year-old right-handed African-American woman who developed the syndrome of pp-CAD (headaches, trace subarachnoid hemorrhage and diffuse cerebral arteriopathy on angiogram) two weeks after delivery. In this unique case, the patient had fortuitously undergone an MR study twice over a four day period which included the carotid bifurcations. During that time the patient was an inpatient, on bed rest and subject to continuous cardiac monitoring. The interval studies documented a true spontaneous right internal carotid artery dissection occurring without obvious cause. The patient had noted moderate right neck pain developing between the two MR studies but experienced no neurological deficits. Subsequent conventional angiography confirmed the presence of postpartum cerebral arteriopathy and the cervical dissection. The patient was managed conservatively with antiplatelet medication and had an otherwise uneventful course. We hypothesize whether transient arterial wall abnormalities, postpartum hormonal changes or subtle connective tissue aberrations play a similar role in the pathogenesis of these two associated conditions.

Acute life-threatening hemorrhage in patients with head and neck cancer presenting with carotid blowout syndrome: follow-up results after initial hemostasis with covered-stent placement

BACKGROUND AND PURPOSE

CSP in patients with HNC presenting with CBS can provide immediate hemostasis to prevent exsanguination. We evaluated the safety and efficacy of CSP to control acute life-threatening hemorrhage in patients with HNC presenting with CBS.

MATERIALS AND METHODS

We retrospectively reviewed 10 patients (7 men, 3 women; mean age, 59 years) with HNC presenting with acute life-threatening hemorrhage from CBS that was treated with CSP. We studied patient demographics, presentations, procedures, initial and delayed complications, and technical and clinical outcomes on follow-up.

RESULTS

All patients achieved immediate hemostasis following CSP. Periprocedural complications consisted of groin hematomas (n=2), acute limb ischemia requiring thrombectomy, and an asymptomatic temporal lobe hemorrhage. Imaging and clinical follow-up were available for a mean of 17.7 months (range, 1-60 months). Two patients remained asymptomatic with a patent stent and no evidence of rebleeding at 17 and 21 months, respectively. Recurrent hemorrhages requiring retreatment were encountered in 3 patients secondary to stent infections (30%) at mean duration of 8 months. Neurologic morbidity resulted from stent thrombosis and stroke at 8 months in a single patient. Mortality was unrelated to CSP but was a result of palliative hospice care (n=3) at a mean of 2 months or natural disease progression (n=1) with documented patency of the stent at 6 months.

CONCLUSIONS

Acute life-threatening hemorrhage from CBS related to advanced HNC can be safely and effectively treated with CSP. However, potential delayed ischemic or infectious complications are common in the exposed or infected neck.

Usefulness of percutaneously injected ethylene-vinyl alcohol copolymer in conjunction with standard endovascular embolization techniques for preoperative devascularization of hypervascular head and neck tumors: technique, initial experience, and correlation with surgical observations

BACKGROUND AND PURPOSE

Few reports have described the embolization of head and neck lesions by using direct percutaneous techniques. We report our preliminary experience in the direct percutaneous embolization of hypervascular head and neck tumors by using Onyx in conjunction with standard endovascular embolization techniques. We describe the technical aspects of the procedure and its efficacy in reducing intraoperative blood loss.

MATERIALS AND METHODS

We retrospectively studied 14 patients (3 females and 11 males; mean age, 33.4 years; range, 11-56 years) with 15 hypervascular tumors of the head and neck that underwent direct percutaneous embolization with Onyx in conjunction with particulate embolization. Nine paragangliomas and 6 JNAs underwent treatment. Documented blood loss was obtained from operative reports in these 15 patients with surgical resection performed 24-48 hours after the embolization.

RESULTS

Intratumoral penetration with progressive blood flow stasis was achieved during each injection. A mean of 3.1 needles (20-gauge, 3.5-inch spinal needle) were placed percutaneously into the lesion (range, 1-6). The mean intraoperative blood loss was 780 mL (range, <50-2200 mL). Near total angiographic devascularization was achieved in 13 of 15 tumors. There were no local complications or neurologic deficits from the percutaneous access or embolization of these hypervascular tumors.

CONCLUSIONS

In this study, the use of percutaneous injected Onyx in conjunction with standard endovascular embolization techniques in patients with hypervascular head and neck tumors seemed to enhance the ability to devascularize these tumors before operative removal.

Interaction of Eu3+ with N,N,N',N'-tetraoctyl diglycolamide: a time resolved luminescence spectroscopy study

N,N,N',N'-tetraoctyl diglycolamide (TODGA) has been identified as one of the promising extractants for the partitioning of minor actinides from high-level nuclear waste solutions. Solvent extraction studies have shown that stoichiometry of the extracted species of Eu(3+) with TODGA depend on the nature of diluent. Time resolved luminescence spectroscopy (TRLS) has been employed to investigate the complexation of Eu(3+) with TODGA under different experimental conditions. The effects of different experimental parameters such as aqueous phase acidity, nature of diluent, and TODGA concentration on the luminescence lifetime of Eu(3+) ions have been investigated. The lifetime measurements of the complexed fraction of Eu(3+) with TODGA suggested the absence of water molecules in the inner coordination sphere of the metal ion in different solvents. In ethanol-water (60/40%) mixture, the complexation of Eu(3+) with TODGA under varying ligand-to-metal ratios suggested the formation of 1:1, 1:2, and 1:3 species, viz., Eu(TODGA)(3+), Eu(TODGA)(2)(3+), and Eu(TODGA)(3)(3+), respectively. The conditional stability constants logbeta(1), logbeta(2), and logbeta(3) were calculated as 6.1+/-0.5, 10.8+/-0.7, and 14.3+/-0.6, respectively. The nature of diluent did not influence the luminescence spectra of Eu(3+) in the presence of TODGA.