Implementation of a Survey Spine Magnetic Resonance Imaging Protocol for Cord Compression in the Emergency Department: Experience at a Level-1 Trauma Center.

BACKGROUND AND PURPOSE: Imaging stewardship in the emergency department (ED) is vital in ensuring patients receive optimized care. While suspected cord compression (CC) is a frequent indication for total spine MRI in the ED, the incidence of CC is low. Recently, our level-I trauma center introduced a survey spine MRI protocol to evaluate for suspected CC while reducing exam time to avoid imaging overutilization. This study aims to evaluate the time savings, frequency of ordering patterns of the survey, and the symptoms and outcomes of patients undergoing the survey. MATERIALS AND METHODS: This retrospective study examined patients who received a survey spine MRI in the ED at our institution between 2018 and 2022. All exams were performed on a 1.5T GE scanner using our institutional CC survey protocol, which includes sagittal T2 and STIR sequences through the cervical, thoracic, and lumbar spine. Exams were read by a blinded, board-certified neuroradiologist. RESULTS: A total of 2,002 patients received a survey spine MRI protocol during the study period. Of these patients, 845 (42.2%, mean age 57 ± 19 years, 45% female) received survey spine MRI exams for the suspicion of CC, and 120 patients (14.2% positivity rate) had radiographic CC. The survey spine MRI averaged 5 minutes and 50 seconds (79% faster than routine MRI). On multivariate analysis, trauma, back pain, lower extremity weakness, urinary or bowel incontinence, numbness, ataxia, and hyperreflexia were each independently associated with CC. Of the 120 patients with CC, 71 underwent emergent surgery, 20 underwent non-emergent surgery, and 29 were managed medically. CONCLUSIONS: The survey spine protocol was positive for CC in 14% of patients in our cohort and acquired at a 79% faster rate compared to routine total spine. Understanding the positivity rate of CC, the clinical symptoms that are most associated with CC, and the subsequent care management for patients presenting with suspected cord compression who received the survey spine MRI may better inform the broad adoption and subsequent utilization of survey imaging protocols in emergency settings to increase throughput, improve allocation of resources, and provide efficient care for patients with suspected CC.ABBREVIATIONS: CC, cord compression; ED, emergency department; MRI, magnetic resonance imaging; T2; T2-weighted imaging sequence; STIR, short TI inversion recovery.

Trends in non-focal neurological chief complaints and CT angiography utilization among adults in the emergency department.

Prudent imaging use is essential for cost reduction and efficient patient triage. Recent efforts have focused on head and neck CTA in patients with emergent concerns for non-focal neurological complaints, but have failed to demonstrate whether increases in utilization have resulted in better care. The objective of this study was to examine trends in head and neck CTA ordering and determine whether a correlation exists between imaging utilization and positivity rates. This is a single-center retrospective observational study at a quaternary referral center. This study includes patients presenting with headache and/or dizziness to the emergency department between January 2017 and December 2021. Patients who received a head and neck CTA were compared to those who did not. The main outcomes included annual head and neck CTA utilization and positivity rates, defined as the percent of scans with attributable acute pathologies. Among 24,892 emergency department visits, 2264 (9.1%) underwent head and neck CTA imaging. The percentage of patients who received a scan over the study period increased from 7.89% (422/5351) in 2017 to 13.24% (662/5001) in 2021, representing a 67.4% increase from baseline (OR, 1.14; 95% CI 1.11-1.18; P < .001). The positivity rate, or the percentage of scans ordered that revealed attributable acute pathology, dropped from 16.8% (71/422) in 2017 to 10.4% (69/662) in 2021 (OR, 0.86; 95% CI 0.79-0.94; P = .001), a 38% reduction in positive examinations. Throughout the study period, there was a 67.4% increase in head and neck CTA ordering with a concomitant 38.1% decrease in positivity rate.

Orthopedic Surgery Volume Trends During the COVID-19 Pandemic and Postvaccination Era: Implications for Healthcare Planning.

BACKGROUND: The Coronavirus Disease 2019 (COVID-19) pandemic decreased surgical volumes, but prior studies have not investigated recovery through 2022, or analyzed specific procedures or cases of urgency within orthopedic surgery. The aims of this study were to (1) quantify the declines in orthopedic surgery volume during and after the pandemic peak, (2) characterize surgical volume recovery during the postvaccination period, and (3) characterize recovery in the 1-year postvaccine release period. METHODS: We conducted a retrospective cohort study of 27,476 orthopedic surgeries from January 2019 to December 2022 at one urban academic quaternary referral center. We reported trends over the following periods: baseline pre-COVID-19 period (1/6/2019 to 1/4/2020), COVID-19 peak (3/15/2020 to 5/16/2020), post-COVID-19 peak (5/17/2020 to 1/2/2021), postvaccine release (1/3/2021 to 1/1/2022), and 1-year postvaccine release (1/2/2022 to 12/30/2022). Comparisons were performed with 2 sample t-tests. RESULTS: Pre-COVID-19 surgical volume fell by 72% at the COVID-19 peak, especially impacting elective procedures (P < .001) and both hip and knee joint arthroplasty (P < .001) procedures. Nonurgent (P = .024) and urgent or emergency (P = .002) cases also significantly decreased. Postpeak recovery before the vaccine saw volumes rise to 92% of baseline, which further rose to 96% and 94% in 2021 and 2022, respectively. While elective procedures surpassed the baseline in 2022, nonurgent and urgent or emergency surgeries remained low. CONCLUSIONS: The COVID-19 pandemic substantially reduced orthopedic surgical volumes, which have still not fully recovered through 2022, particularly nonelective procedures. The differential recovery within an orthopedic surgery program may result in increased morbidity and can serve to inform department-level operational recovery.

Anatomic Utility of Single Branched Thoracic Endograft During Thoracic Endovascular Aortic Repair.

INTRODUCTION: Single branched thoracic endografts (SBTEs) have been designed for pathology requiring zone 2 seal during thoracic endovascular aortic repair (TEVAR). Numerous criteria must be met to allow for their implantation. Our aim was to analyze anatomic suitability for a next generation SBTE. METHODS: We reviewed 150 TEVAR procedures between 2015 and 2019. Proximal seal was: zone 0 in 21 (16%), zone 1 in 4 (3%), zone 2 in 52 (40%), zone 3 in 45 (35%), and zone 4 or distal in 7 (5%). We analyzed the Zone 2 patient's angiograms and CT angiograms using centerline software to measure arterial diameters and length in relation to the left common carotid artery (LCCA), left subclavian artery (LSA) and proximal extent of aortic disease to determine if patients met anatomic criteria of a novel SBTE. RESULTS: Zone 2 average age was 64.4 ± 16.3 years; 34 patients were male (65%). Indications for repair were aneurysm (N = 9, 17%), acute dissection (N = 14, 27%), chronic dissection with aneurysmal degeneration (N = 7, 13%), intramural hematoma (N = 9, 17%), penetrating aortic ulcer (N = 5, 10%), and blunt traumatic aortic injury (BTAI, N = 8, 15%). LSA revascularization occurred in 27 patients (52%). Overall, 20 (38.5%) of the zone 2 patients met anatomic criteria. Patients with dissection met anatomic criteria less frequently than aneurysm (33% [10 of 30] vs 64% [9 of 14]). Patients treated for BTAI rarely met the anatomic criteria (1 of 8, 13%). The main anatomic constraints were an inadequate distance from the LCCA to the LSA takeoff and from the LCCA to the start of the aortic disease process. CONCLUSION: Less than half of patients who require seal in zone 2 met criteria for this SBTE. Patients with aneurysms met anatomic criteria more often than those with dissection. The device would have little applicability in treating patients with BTAI.

Trends in coronary calcium score and coronary CT angiography imaging volume during the COVID-19 pandemic.

OBJECTIVES: The COVID-19 pandemic disrupted the delivery of preventative care and management of acute diseases. This study assesses the effect of the COVID-19 pandemic on coronary calcium score and coronary CT angiography imaging volume. MATERIALS AND METHODS: A single institution retrospective review of consecutive patients presenting for coronary calcium score or coronary CT angiography examinations between January 1, 2020 to January 4, 2022 was performed. The weekly volume of calcium score and coronary CT angiogram exams were compared. RESULTS: In total, 1,817 coronary calcium score CT and 5,895 coronary CT angiogram examinations were performed. The average weekly volume of coronary CTA and coronary calcium score CT exams decreased by up to 83% and 100%, respectively, during the COVID-19 peak period compared to baseline (P < 0.0001). The post-COVID recovery through 2020 saw weekly coronary CTA volumes rebound to 86% of baseline (P = 0.024), while coronary calcium score CT volumes remained muted at only a 53% recovery (P < 0.001). In 2021, coronary CTA imaging eclipsed pre-COVID rates (P = 0.012), however coronary calcium score CT volume only reached 67% of baseline (P < 0.001). CONCLUSIONS: A significant decrease in both coronary CTA and coronary calcium score CT volume occurred during the peak-COVID-19 period. In 2020 and 2021, coronary CTA imaging eventually superseded baseline rates, while coronary calcium score CT volumes only reached two thirds of baseline. These findings highlight the importance of resumption of screening exams and should prompt clinicians to be aware of potential undertreatment of patients with coronary artery disease.

Outcomes of great vessel debranching to facilitate thoracic endovascular aortic repair.

OBJECTIVE: With the expanding application of endovascular technology, the need to deploy into zone 0 has been encountered on occasion. In the present study, we evaluated the outcomes of great vessel debranching (GVD) as a method of extending the proximal landing zone to facilitate thoracic endovascular aortic repair (TEVAR). METHODS: We performed a single-center retrospective review of all patients who had undergone GVD followed by TEVAR between May 2013 and December 2020. The primary outcome was primary patency of all targeted vessels, with all-cause perioperative mortality as a secondary outcome. Kaplan-Meier analysis was used to account for censoring of mortality and primary patency. The extent of hybrid aortic repairs was characterized into type I (GVD plus TEVAR without ascending aorta or aortic arch reconstruction, type II (GVD plus TEVAR with ascending aorta reconstruction), and type III (GVD plus TEVAR with ascending aorta and aortic arch reconstruction with an elephant trunk (soft [surgical] or frozen [endovascular]]). RESULTS: A total of 42 patients (23 men [54.8%]; mean age, 62.2 ± 11.2 years) had undergone GVD, with 122 vessels revascularized (42 innominate, 42 left common carotid, and 38 left subclavian arteries). The indication for TEVAR was aneurysmal degeneration from aortic dissection in 32 patients (76.2%), a thoracic aneurysm in 9 patients (21.4%), and a perforated aortic ulcer in 1 patient (2.4%). The median duration between GVD and TEVAR was 82 days. The mean follow-up period was 25.7 ± 23.5 months. Type I repair was performed in 4, type II in 16, and type III in 22 patients. The perioperative mortality, stroke, and paraplegia rates were 9.5%, 7.1%, and 2.4%, respectively. Neither the extent of repair (P = .80) nor a history of aortic repair (P = .90) was associated with early mortality. Of the 38 patients who had survived the perioperative period, 6 had died >30 days postoperatively. At 36 months, the survival estimate was 68.6% (95% confidence interval, 45.7%-83.4%). The overall primary patency of the innominate artery, left common carotid artery, and left subclavian artery was 100%, 89.5%, and 94.1%, respectively. The primary-assisted patency rate was 100% for all the vessels. CONCLUSIONS: We found GVD to be a safe and effective method of extending the proximal landing zone into zone 0 with outstanding primary patency rates. Further studies are required to confirm the safety and longer term durability for these patients.

Computed tomography angiographic biomarkers help identify vulnerable carotid artery plaque.

OBJECTIVE: The current risk assessment for patients with carotid atherosclerosis relies primarily on measuring the degree of stenosis. More reliable risk stratification could improve patient selection for targeted treatment. We have developed and validated a model to predict for major adverse neurologic events (MANE; stroke, transient ischemic attack, amaurosis fugax) that incorporates a combination of plaque morphology, patient demographics, and patient clinical information. METHODS: We enrolled 221 patients with asymptomatic carotid stenosis of any severity who had undergone computed tomography angiography at baseline and ≥6 months later. The images were analyzed for carotid plaque morphology (plaque geometry and tissue composition). The data were partitioned into training and validation cohorts. Of the 221 patients, 190 had complete records available and were included in the present analysis. The training cohort was used to develop the best model for predicting MANE, incorporating the patient and plaque features. First, single-variable correlation and unsupervised clustering were performed. Next, several multivariable models were implemented for the response variable of MANE. The best model was selected by optimizing the area under the receiver operating characteristic curve (AUC) and Cohen's kappa statistic. The model was validated using the sequestered data to demonstrate generalizability. RESULTS: A total of 62 patients had experienced a MANE during follow-up. Unsupervised clustering of the patient and plaque features identified single-variable predictors of MANE. Multivariable predictive modeling showed that a combination of the plaque features at baseline (matrix, intraplaque hemorrhage [IPH], wall thickness, plaque burden) with the clinical features (age, body mass index, lipid levels) best predicted for MANE (AUC, 0.79), In contrast, the percent diameter stenosis performed the worst (AUC, 0.55). The strongest single variable for discriminating between patients with and without MANE was IPH, and the most predictive model was produced when IPH was considered with wall remodeling. The selected model also performed well for the validation dataset (AUC, 0.64) and maintained superiority compared with percent diameter stenosis (AUC, 0.49). CONCLUSIONS: A composite of plaque geometry, plaque tissue composition, patient demographics, and clinical information predicted for MANE better than did the traditionally used degree of stenosis alone for those with carotid atherosclerosis. Implementing this predictive model in the clinical setting could help identify patients at high risk of MANE.

Persistent disseminated intravascular coagulation despite correction of endoleaks after thoracoabdominal endovascular aneurysm repair.

Disseminated intravascular coagulation (DIC) is a rare complication of endovascular aortic repair, commonly associated with type I or type III endoleaks. DIC is also known as consumption coagulopathy because excessive thrombin formation and secondary fibrinolysis leads to consumption of coagulation factors with hyperfibrinolysis and activation of platelets, which can lead to excessive bleeding. We present the case of an 80-year-old woman who had undergone thoracic endovascular aortic repair for a type B aortic dissection that was complicated by a series of recurrent endoleak-induced DICs requiring multiple thoracic endovascular aortic repair extensions to cover the entire thoracoabdominal aorta. The DIC persisted despite the resolution of the endoleaks.

Elevated Neutrophil to Lymphocyte Ratio is Associated with Worse Outcomes after Carotid Endarterectomy in Asymptomatic Patients.

OBJECTIVE: Management of carotid artery stenosis (CAS) remains controversial and proper patient selection critical. Elevated neutrophil to lymphocyte ratio (NLR) has been associated with poor outcomes after vascular procedures. The effect of NLR on outcomes after carotid endarterectomy (CEA) in asymptomatic and symptomatic patients is assessed. MATERIALS AND METHODS: A retrospective review was conducted of all patients between 2010 and 2018 with carotid stenosis >70% as defined by CREST 2 criteria. A total of 922 patients were identified, of whom 806 were treated with CEA and 116 non-operatively with best medical therapy (BMT). Of patients undergoing CEA, 401 patients (290 asymptomatic [aCEA], 111 symptomatic [sCEA]) also had an available NLR calculated from a complete blood count with differential. All patients treated with BMT were asymptomatic and had a baseline NLR available. Kaplan-Meier analysis assessed composite ipsilateral stroke or death over 3 years. RESULTS: In sCEA group, the 3-year composite stroke/death rates did not differ between NLR < 3.0 (22.9%) vs NLR > 3.0 (38.1%) (P=.10). In aCEA group, patients with a baseline NLR >3.0 had an increased risk of 3-year stroke/death (42.6%) compared to both those with NLR <3.0 (9.3%, P<.0001) and those treated with BMT (23.6%, P=.003). In patients with NLR <3.0, aCEA showed a superior benefit over BMT with regard to stroke or death (9.3% vs. 26.2%, P=.02). However, in patients with NLR >3.0, there was no longer a benefit to prophylactic CEA compared to BMT (42.6% vs. 22.2%, P=.05). Multivariable analysis identified NLR >3.0 (HR, 3.23; 95% CI, 1.93-5.42; P<.001) and congestive heart failure (HR, 2.18; 95% CI, 1.33-3.58; P=.002) as independent risk factors for stroke/death in patients with asymptomatic carotid artery stenosis. CONCLUSIONS: NLR >3.0 is associated with an increased risk of late stroke/death after prophylactic CEA for asymptomatic carotid artery stenosis, with benefits not superior to BMT. NLR may be used to help with selecting asymptomatic patients for CEA. The effect of NLR and outcomes in symptomatic patients requires further study. Better understanding of the mechanism(s) for NLR elevation and medical intervention strategies are needed to modulate outcome risk in these patients.

Paclitaxel-coated peripheral arterial devices are associated with improved overall survival and limb salvage in patients with chronic limb-threatening ischemia.

OBJECTIVE: Paclitaxel (PTX)-coated peripheral arterial devices have been shown to decrease femoropopliteal artery restenosis and the need for reintervention compared with non-PTX-coated devices. The data regarding PTX efficacy and safety come from randomized controlled trials that almost exclusively enrolled patients with claudication. The outcomes of PTX treatment in patients who present with chronic limb-threatening ischemia (CLTI) are unknown. This study compares long-term outcomes in patients with CLTI treated with and without PTX. METHODS: We retrospectively reviewed 983 patients with CLTI treated with femoropopliteal artery angioplasty, atherectomy, stent, or combination between 2011 and 2019. Procedures were performed with additional proximal or distal tibial interventions as needed. Kaplan-Meier survival analysis and multivariable Cox-regression analysis compared overall survival (OS), amputation-free survival (AFS), freedom from major amputation (ff-MA), and freedom from target vessel revascularization (ff-TVR) between patients treated with and without PTX. RESULTS: Demographics, comorbidities, and Rutherford class were similar between 574 PTX (58.5%) and 409 non-PTX (41.6%) patients except that non-PTX patients were more likely to be male (56.2% vs 49.7%), dialysis dependent (19.6% vs 14.3%), and have higher average creatinine (2.3 vs 1.8 mg/dL). Through 4-year follow-up, the PTX group demonstrated a significant increase in OS (56.2% vs 43.9%, P = .013), AFS (52.6% vs 36.1%, P < .0001), ff-MA (87.4% vs 78.7%, P = .0007), and ff-TVR (77.6% vs 70.6%, P = .012). Multivariable Cox-regression analysis demonstrated that PTX treatment was associated with improved OS, AFS, ff-MA, and ff-TVR. CONCLUSIONS: In patients with CLTI, treatment with a PTX-coated device is associated with improved OS, AFS, ff-MA, and ff-TVR through 4-year follow-up. PTX-coated devices may be especially beneficial in patients who present with CLTI.

Elevated neutrophil to lymphocyte ratio is associated with decreased amputation-free survival after femoropopliteal percutaneous revascularization.

BACKGROUND: An elevated neutrophil-lymphocyte ratio (NLR) is a biomarker associated with adverse outcomes after cardiovascular surgery. This study evaluates the association of preoperative NLR with clinical outcomes after peripheral vascular intervention (PVI) of the femoropopliteal segments. METHODS: A retrospective review identified 488 patients who underwent percutaneous interventions of femoropopliteal arteries between 2011 and 2018 and had a pre-procedural complete blood count with differential with normal white blood cell count within 30 days prior to intervention. Amputation-free survival (AFS), survival, and freedom from major amputation were assessed using Kaplan-Meier methods. Cohorts of patients with NLR <3 (Low), 3-4 (Mid), and >4 (High) were compared using univariate and multivariable statistical models. In these analyses NLR was analyzed as a continuous variable to correlate with clinical outcomes. RESULTS: Mean age was 71.7±12.8 years and males constituted 55.5%. The majority of patients presented with chronic limb threatening ischemia (CLTI, 78.5%). Increasing NLR was correlated with increasing rates of comorbidities, except for smoking history. The 30-day mortality rates increased with increasing NLR: 1.4%, 4.3%, and 7.0% for low (<3), mid (3-4) and high (>4) NLR groups, respectively (P=0.005). Patients with a lower pre-operative NLR achieved significantly greater amputation-free survival at 4-year follow-up: low NLR, 65.5%; mid NLR, 37.5%; and high NLR, 17.6% (P<0.0001). By multivariable analysis, increasing NLR, advanced age, CLTI, and dialysis-dependent renal failure reduced AFS. CONCLUSIONS: Elevated NLR is an independent predictor of decreased AFS following percutaneous interventions of femoropopliteal segments. Further research on identification and modulation of risk factors for high NLR are warranted.

Kinetics of Magnetic Skyrmion Crystal Formation from the Conical Phase.

The particle-like magnetic skyrmion or skyrmion lattice (SkX) formation has promoted strong application and fundamental science interests. Despite extensive research, the kinetic of the SkX development is much less understood because of the ultrafast spin rotation and high sensitivity to external perturbations. Here, using in situ Lorentz transmission electron microscopy, we successfully measured the dynamics of SkX formation from the conical phase with precise control of both the temperature and the magnetic field. We discovered that the Avrami equation can accurately describe the transition process with an initial Avrami constant around 1, suggesting that the rate-limiting step for the quasiparticle lattice formation is one-dimensional heterogeneous nucleation of individual skyrmions. A modified Arrhenius rate law is established, with an energy barrier that has a square-root dependence on temperature and a quadratic dependence on the magnetic field. This study paves the way toward precise and predictable manipulation of topological spin structures.

A High Neutrophil-Lymphocyte Ratio Is Associated With Increased Morbidity and Mortality in Patients With Coronavirus Disease 2019.

OBJECTIVES: The neutrophil-lymphocyte ratio is an inexpensive and simple inflammatory marker. A higher ratio, indicative of an acute hyperinflammatory response or diminished overall physiologic health status, has been associated with poor prognoses. This study aimed to evaluate the prognostic potential of admission neutrophil-lymphocyte ratio in patients admitted to the medical ICU with coronavirus disease 2019. DESIGN: Retrospective review of prospectively collected data. SETTING: Medical ICU from a large medical center. PATIENTS: 2,071 consecutive patients admitted to the medical ICU with laboratory-confirmed severe acute respiratory syndrome coronavirus-2 between March 15, 2020, and December 30, 2020, were grouped by neutrophil-lymphocyte ratio above or below the median (7.45) at the time of hospital admission. INTERVENTIONS: Complete blood count with differential at the time of hospital admission. MEASUREMENTS AND MAIN RESULTS: A neutrophil-lymphocyte ratio above 7.45 at the time of hospital admission was associated with increased need for mechanical ventilation (45.8% vs 38.0%, p < 0.0001), vasopressor therapy (55.6% vs 48.2%, p = 0.001), and decreased survival through 180 days (54.8% vs 67.0%, p < 0.0001). Patients with a high neutrophil-lymphocyte ratio exhibited a 1.32 (95% CI, 1.14-1.54) times greater risk of mortality than those with a low neutrophil-lymphocyte ratio. CONCLUSIONS: The neutrophil-lymphocyte ratio at the time of hospital admission is an independent risk factor for morbidity and mortality. This prognostic indicator may assist clinicians appropriately identify patients at heightened risk for a severe disease course and tailor treatment accordingly.

Computer-based video training is effective in teaching basic surgical skills to novices without faculty involvement using a self-directed, sequential and incremental program.

INTRODUCTION: Computer-based video training (CBVT) of surgical skills overcomes limitations of 1:1 instruction. We hypothesized that a self-directed CBVT program could teach novices by dividing basic surgical skills into sequential, easily-mastered steps. METHODS: We developed a 12 video program teaching basic knot tying and suturing skills introduced in discrete, incremental steps. Students were evaluated pre- and post-course with a self-assessment, a written exam and a skill assessment. RESULTS: Students (n = 221) who completed the course demonstrated significant improvement. Their average pre-course product quality score and assessment of technique using standard Global Rating Scale (GRS) were <0.4 for 6 measured skills (scale 0-5) and increased post-course to ≥3.25 except for the skill tying on tension whose GRS = 2.51. Average speed increased for all skills. Students' self-ratings (scale 1-5) increased from an average of 1.4 ± 0.7 pre-elective to 3.9 ± 0.9 post-elective across all skills (P < 0.01). CONCLUSION: Self-directed, incremental and sequential video training is effective teaching basic surgical skills and may be a model to teach other skills or to play a larger role in remote learning.

Systematic review of hemostatic agents used in vascular surgery.

BACKGROUND: Hemostatic agents are routinely used in vascular surgery to complement proper suture techniques and decrease the risk of perioperative bleeding. A relative lack of comparative research studies have left surgeons with the option of choosing hemostatic agents based on their personal experience. The present review has highlighted the efficacy and safety of hemostatic agents and categorized them according to their primary mechanism of action and cost. METHODS: A systematic search strategy encompassing hemostatic agent products was deployed in the PubMed database. Single-center and multicenter, randomized, controlled trials with >10 patients were included in the present study. RESULTS: We reviewed 12 studies on the efficacy and safety of hemostatic agents compared with manual compression or other hemostatic agents. Using the time to hemostasis as the primary end point, all studies had found hemostatic agents to be significantly more efficient than manual compression. Likewise, adhesives (high pressure sealants) and dual agents (containing biologically active and absorbable components) were found to be more efficient, but costlier, than agents with either biologically active or absorbable components only. Agents with porcine or bovine constituents were found to trigger anaphylactic reactions in rare cases. Additionally, the absence of fibrin stabilizing factor XIII in a brand of fibrin sealant was speculated to reduce the affinity of the fibrin sealant for the expanded polytetrafluoroethylene graft. The cost of agents varied greatly depending on their active ingredient. CONCLUSIONS: Hemostatic agents appear to be highly effective at decreasing the risk of bleeding during surgical procedures. Although some hemostatic agents were demonstrated to achieve hemostasis faster than others, most are able to control bleeding within <10 minutes. Based on the limited data, the least expensive agents might suffice for limited suture lines used in routine procedures.

Paclitaxel-Coated Peripheral Arterial Devices are Associated with Reduced Mortality in Younger Patients.

BACKGROUND: Paclitaxel-coated devices have been shown to decrease restenosis when used in the femoropopliteal artery. Recent reports have suggested a possible risk of increased late mortality in patients treated with paclitaxel. It has been suggested that younger patients and those with limited comorbidities may be at higher risk. Our objective was to analyze long-term mortality based on patient age comparing treatment with paclitaxel to uncoated devices. METHODS: We performed a retrospective review of 1,170 consecutive patients who underwent femoropopliteal percutaneous intervention by angioplasty, atherectomy, stent placement, or combination between 2011 and 2018. Patients were grouped by age at the time of procedure: <60 years old (n = 244, 20.9%), 60-80 years old (n = 635, 54.3%), and >80 years old (n = 291, 24.9%). Within each group, patients were further divided by use of paclitaxel. The primary outcome measure was survival assessed by Kaplan-Meier analysis. Differences between the groups were analyzed with analysis of variance. Multivariable analysis was performed using Cox proportional hazard models. RESULTS: Of the 1,170 patients who underwent femoropopliteal percutaneous intervention, 654 (55.9%) received a paclitaxel-coated device during treatment and 516 (44.1%) did not. Mean age of the overall patient cohort was 70.4 ± 12.6 years and 663 (56.7%) were male. When comparing the groups by age we found an increase in age but a decrease in the proportion of patients who smoke. The use of paclitaxel-coated devices was similar across the groups (<60 years old, 56.2%; 60-80 years old, 57.0%; >80 years old, 52.6%; P = 0.45). Demographics and comorbidities were similar between the patients treated with and without paclitaxel within each age group except more males in the <60-year-old group treated without paclitaxel and more patients with chronic limb threatening ischemia in the >80-year-old group treated with paclitaxel. In patients <60 and 60-80 years old paclitaxel use was associated with increased survival at 4 years: <60 (80.7% vs. 64.4%; P = 0.04); 60-80 (63.2% vs. 55.1%; P = 0.04). Survival was similar in the >80-year-old group (46.6% vs. 32.8%; P = 0.65). CONCLUSIONS: Our data suggest that the use of paclitaxel-coated arterial devices is not associated with increased mortality. On the contrary, our data show that younger patients treated with paclitaxel show improved survival compared with those treated without paclitaxel. Paclitaxel-coated devices may be used with continued caution especially in patients at high risk for restenosis.

Treatment of Carotid Restenosis Using Transcarotid Revascularization.

OBJECTIVE: Transcarotid artery revascularization (TCAR) using the ENROUTE Neuroprotection System (Silk Road Medical) is a United States Food and Drug Administration-approved treatment modality for stroke risk reduction in the setting of carotid artery stenosis. The goal of this investigation was to define the real-world outcomes associated with the application of this technique to patients presenting with restenosis after previous carotid endarterectomy (CEA) or transfemoral carotid artery stenting (TF-CAS). METHODS: Retrospective review of prospectively maintained institutional databases capturing all nontrial TCARs performed between August 2013 and July 2018 using the ENROUTE Neuroprotection System was completed at 3 unaffiliated hospital systems and unified for descriptive outcomes analysis. RESULTS: During the study period, 237 combined TCARs were performed at our respective institutions. Of these procedures, 55 stents were implanted for the indication of restenosis after previous carotid revascularization (47 CEA, 8 TF-CAS). Within the 30-day perioperative period, we observed no ipsilateral strokes or deaths; one patient experienced perioperative myocardial infarction (MI; 1.8%). We noted a 4.8% incidence of postoperative hematoma, but none of these events were clinically significant as no reinterventions were performed in any of the 55 patients. Additionally, we did not observe any cases of stent thrombosis or pulmonary embolus. Mean length of stay was 2.2 ± 2.8 days. Our mean follow-up duration was 15.0 ± 9.2 months. Throughout the follow-up period, we did not observe any additional stroke or MI events. Additionally, there were no cases of in-stent restenosis, thrombosis, or reinterventions. CONCLUSION: Transcarotid artery revascularization can be performed in patients with restenotic carotid arteries with acceptable rates of ipsilateral stroke, MI, and death as demonstrated in this small multi-institutional series.

Mechanisms of Skyrmion and Skyrmion Crystal Formation from the Conical Phase.

Real-space topological magnetic structures such as skyrmions and merons are promising candidates for information storage and transport. However, the microscopic mechanisms that control their formation and evolution are still unclear. Here, using in situ Lorentz transmission electron microscopy, we demonstrate that skyrmion crystals (SkXs) can nucleate, grow, and evolve from the conical phase in the same ways that real nanocrystals form from vapors or solutions. More intriguingly, individual skyrmions can also "reproduce" by division in a mitosis-like process that allows them to annihilate SkX lattice imperfections, which is not available to crystals made of mass-conserving particles. Combined string method and micromagnetic calculations show that competition between repulsive and attractive interactions between skyrmions governs particle-like SkX growth, but nonconservative SkX growth appears to be defect mediated. Our results provide insights toward manipulating magnetic topological states by applying established crystal growth theory, adapted to account for the new process of skyrmion mitosis.

Anatomic criteria in the selection of treatment modality for atherosclerotic carotid artery disease.

OBJECTIVE: Three procedures are currently available to treat atherosclerotic carotid artery stenosis: carotid endarterectomy (CEA), transfemoral carotid artery stenting (TF-CAS), and transcarotid artery revascularization (TCAR). Although there is considerable debate evaluating each of these in a head-to-head comparison to determine superiority, little has been mentioned concerning the specific anatomic criteria that make one more appropriate. We conducted a study to define anatomic criteria in relation to inclusion and exclusion criteria and relative contraindications. METHODS: A retrospective review was conducted of 448 carotid arteries from 224 consecutive patients who underwent a neck and head computed tomography arteriography (CTA) scan before carotid intervention for significant carotid artery stenosis. Occlusion of the internal carotid artery (ICA) occurred in 15, yielding 433 arteries for analysis. Anatomic data were collected from CTA images and demographic and comorbidities from chart review. Eligibility for CEA, TF-CAS, and TCAR was defined on the basis of anatomy, not by comorbidity. RESULTS: CTA analysis revealed that 92 of 433 arteries (21%) were ineligible for CEA because of carotid lesions extending cephalad to the second cervical vertebra. Overall, 26 arteries (6.0%) were not eligible for any type of carotid artery stent because of small ICA diameter (n = 11), heavy circumferential calcium (n = 14), or combination (n = 1). An additional 126 arteries were ineligible for TF-CAS on the basis of a hostile aortic arch (n = 115) or severe distal ICA tortuosity (n = 11), yielding 281 arteries (64.9%) that were eligible. In addition to the 26 arteries ineligible for any carotid stent, TCAR was contraindicated in 39 because of a clavicle to bifurcation distance <5 cm (n = 17), common carotid artery diameter <6 mm (n = 3), or significant plaque at the TCAR sheath access site (n = 20), yielding 368 arteries (85.0%) that were eligible for TCAR. CONCLUSIONS: A significant proportion of patients who present with carotid artery stenosis have anatomy that makes one or more carotid interventions contraindicated or less desirable. Anatomic factors should play a key role in selecting the most appropriate procedure to treat carotid artery stenosis. Determination of superiority for one procedure over another should be tempered until anatomic criteria have been assessed to select the best procedural options for each patient.

Elevated neutrophil-lymphocyte ratio predicts mortality following elective endovascular aneurysm repair.

OBJECTIVE: The neutrophil-lymphocyte ratio (NLR) is an inexpensive and useful inflammatory marker that incorporates the balance of the innate (neutrophil) and adaptive (lymphocyte) immune responses. Data exist on the association between NLR and mortality in various coronary diseases and in cancer surgery, but there is a paucity of data on the impact of preoperative NLR on vascular surgical outcomes. The aim of this study was to evaluate the relationship between preoperative NLR and elective endovascular aortic aneurysm repair (EVAR) outcome. METHODS: A retrospective review of all patients who underwent elective EVAR at a single institution between 2010 and 2018 was conducted (n = 373). Only patients who had a preoperative complete blood count with differential within 30 days of their operation were included. The NLR was computed by dividing the absolute neutrophil count by the absolute lymphocyte count. A receiver operating characteristic curve was used to determine the optimal cutoff value of NLR with the strongest association with mortality. NLR was dichotomized so that patients with NLR above the threshold were at increased risk of mortality compared with those below it. Continuous variables were analyzed using Wilcoxon nonparametric signed-rank test and categorical variables with the Fisher exact test. A comparison of NLR and mortality was completed using Kaplan-Meier survival analysis. Cox regression analysis was used to evaluate factors associated with mortality through 5-year follow-up. RESULTS: Overall, 108 patients were included in this study. An NLR ≥ 4.0 was found to be associated with mortality (P < .0001). Thirty-two patients composed the High-NLR (NLR ≥ 4.0) group and the remaining 76 patients formed the Low-NLR (NLR < 4.0) group. Baseline characteristics were similar between groups, except that the High-NLR group was older (77.9 vs 74.4; P = .047). At a mean of 36.4 months follow-up, the overall mortality rate was 32.4%. Although there were no differences in the perioperative period, the Kaplan-Meier estimates of mortality were significantly greater in the High-NLR group at 1, 2, and 5 years postoperatively (P < .0001). The mean preoperative NLR of the deceased was higher (5.94 ± 5.20; median, 4.75; interquartile range, 3.17-7.83) than those who survived (2.87 ± 1.61; median, 2.53; interquartile range, 1.97-3.49) (P < .0001). Secondary interventions and sac enlargement rates were similar between groups. On univariable analysis, NLR (hazard ratio [HR], 1.17; 95% confidence interval [CI], 1.10-1.23; P < .0001), age (HR, 1.06; 95% CI, 1.02-1.11; P = .004), and aneurysm diameter (HR, 1.04; 95% CI, 1.01-1.07; P = .003) were associated with mortality. On multivariable analysis, NLR (HR, 1.19; 95% CI, 1.12-1.27; P < .0001), age (HR, 1.06; 95% CI, 1.01-1.11; P = .026), and aneurysm diameter (HR, 1.04; 95% CI, 1.02-1.07; P = .003) were associated with mortality. CONCLUSIONS: Patients with an elevated preoperative NLR, irrespective of other comorbidities, may represent a previously unrecognized subset of patients who are at heightened risk of mortality after elective EVAR. A complete blood count with differential is an inexpensive test that may be used as a prognostic indicator for outcome after EVAR. Further research is warranted to identify clinical, pathological, or anatomical factors associated with an elevated NLR and to determine modifiable factors, which may help improve long-term survival.