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.

Germline PTEN mutations are associated with a skewed peripheral immune repertoire in humans and mice.

Individuals with germline mutations in the gene encoding phosphatase and tensin homolog on chromosome ten (PTEN) are diagnosed with PTEN hamartoma tumor syndrome (PHTS) and are at high risk for developing breast, thyroid and other cancers and/or autoimmunity or neurodevelopmental issues including autism spectrum disorders. Although well recognized as a tumor suppressor, involvement of PTEN mutations in mediating such a diverse range of phenotypes indicates a more central involvement for PTEN in immunity than previously recognized. To address this, sequencing of the T-cell receptor variable-region ß-chain was performed on peripheral blood from PHTS patients. Based on patient findings, we performed mechanistic studies in two Pten knock-in murine models, distinct from each other in cell compartment-specific predominance of Pten. We found that PTEN mutations in humans and mice are associated with a skewed T- and B-cell gene repertoire, characterized by increased prevalence of high-frequency clones. Immunological characterization showed that Pten mutants have increased B-cell proliferation and a proclivity towards increased T-cell reactivity upon Toll-like-receptor stimulation. Furthermore, decreases in nuclear but not cytoplasmic Pten levels associated with a reduction in expression of the autoimmune regulator (Aire), a critical mediator of central immune tolerance. Mechanistically, we show that nuclear PTEN most likely regulates Aire expression via its emerging role in splicing regulation. We conclude that germline disruption of PTEN, both in human and mouse, results in compromised central immune tolerance processes that may significantly impact individual stress responses and therefore predisposition to autoimmunity and cancer.

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.

The changing trends of image-guided biopsy of small renal masses before intervention-an analysis of European multinational prospective EuRECA registry.

OBJECTIVES: To evaluate the use of pre-cryoablation biopsy for small renal masses (SRMs) and the effects of increasing uptake on histological results of treated SRMs. METHODS: From 2015 to 2019, patients with sporadic T1N0M0 SRMs undergoing percutaneous, laparoscopic, or open cryoablation from 14 European institutions within the European Registry for Renal Cryoablation (EuRECA) were included for the retrospective analysis. Univariate and multivariate logistic models were used to evaluate the trends, histological results, and the factors influencing use of pre-cryoablation biopsy. RESULTS: In total, 871 patients (median (IQR) age, 69 (14), 298 women) undergoing cryoablation were evaluated. The use of pre-cryoablation biopsy has significantly increased from 42% (65/156) in 2015 to 72% (88/122) in 2019 (p < 0.001). Patients treated for a benign histology are significantly more likely to have presented later in the trend, where pre-cryoablation biopsy is more prevalent (OR: 0.64, 95% CI 0.51-0.81, p < 0.001). Patients treated for undiagnosed histology are also significantly less likely to have presented in 2018 compared to 2016 (OR 0.31, 95% CI 0.10-0.97, p = 0.044). Patients aged 70+ are less likely to be biopsies pre-cryoablation (p < 0.05). R.E.N.A.L. nephrometry score of 10+ and a Charlson Comorbidity Index > 1 are factors associated with lower likelihood to not have received a pre-cryoablation biopsy (p < 0.05). CONCLUSION: An increased use of pre-cryoablation biopsy was observed and cryoablation patients treated with a benign histology are more likely to have presented in periods where pre-cryoablation biopsy is not as prevalent. Comparative studies are needed to draw definitive conclusions on the effect of pre-cryoablation biopsy on SRM treatments. KEY POINTS: • The use of biopsy pre-ablation session has increased significantly from 42% of all patients in 2015 to 74% in 2019. • Patients are less likely to be treated for a benign tumour if they presented later in the trend, where pre-cryoablation biopsy is more prevalent, compared to later in the trend (OR 0.64, 95% CI 0.51-0.81, p < 0.001). • Patients with comorbidities or a complex tumour (R.E.N.A.L. nephrometry score > 10) are less likely to not undergo biopsy as a separate session to cryoablation.

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.

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 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.

Optical Indistinguishability via Twinning Fields.

Here we introduce the concept of the twinning field-a driving electromagnetic pulse that induces an identical optical response from two distinct materials. We show that for a large class of pairs of generic many-body systems, a twinning field which renders the systems optically indistinguishable exists. The conditions under which this field exists are derived, and this analysis is supplemented by numerical calculations of twinning fields for both the 1D Fermi-Hubbard model, and tight-binding models of graphene and hexagonal boron nitride. The existence of twinning fields may lead to new research directions in nonlinear optics, materials science, and quantum technologies.

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.

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.

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.

Visitor presence and a changing soundscape, alongside environmental parameters, can predict enclosure usage in captive flamingos.

The sound environment of a zoo animal is a complex milieu of animal and human-generated sounds; coming from the species itself, other species, visitors, keepers and other zoo-users. Research determining how different components of the sound environment affect animal behaviour is surprisingly lacking but could have real-world impacts for animal welfare and zoo enclosure design. The current study investigated the effects of the sound environment on two flocks of flamingos housed in open-air enclosures at British zoos. Measures of how each flock used its enclosure (as a response variable) and environmental variables (Inband Power and Peak Frequency were recorded as characteristics of the sound environment, as well as temperature, humidity and cloud cover, and finally visitor presence-all as potential predictor variables) were made over a 2-month period. Assessment of space use by zoo animals is often used as a measure of the appropriateness of an exhibit and to understand welfare. Given that flamingo activity is influenced by weather and that the sound environment of the zoo is likely to be influenced by the number and the presence of visitors, it was assumed that these predictor variables would influence where the flamingos were located at different times of the day. As expected, there was a complicated relationship between enclosure use and Inband Power (average spectral density, a measure of sound energy) in both flocks; visitors generated salient sound but other visitor characteristics such as their physical presence may have impacted the movement of the birds around their enclosures. Results show a complex picture where environmental conditions influence flamingo enclosure usage as well as visitor presence and sounds around/in the enclosure. Findings are not consistent between the two flocks, with one flock demonstrating distinct temporal change to enclosure zone occupancy and the other responsive to humidity and cloud cover variation. We believe enclosure use can provide a valuable indication of how birds react to their soundscape; however, our findings suggest more work is needed to unpick the components of captive sound environments, and their relative effects on how animals use their space.

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.

Frequency of perigraft hygroma after open aortic reconstruction.

OBJECTIVE: The incidence of perigraft hygroma (PGH) development after aortic reconstruction remains poorly defined and its clinical relevance is questionable. This study was designed to establish the incidence of and determine the risk factors associated with PGH formation and its outcomes. METHODS: Patients who underwent open aortic reconstruction for either aneurysmal or occlusive disease with an expanded polytetrafluoroethylene (ePTFE) or polyester graft from 2004 to 2018 were retrospectively reviewed (n = 262). Only those who had follow-up imaging 3 or more months after repair were included. Patients with mixed graft types were excluded. PGH was defined as a perigraft fluid collection of 30 mm or greater in diameter with a radiodensity of 30 or fewer Hounsfield units on computed tomography at a minimum of 3 postoperative months. Analysis was conducted between patients with and without PGH. RESULTS: One hundred forty patients met the inclusion criteria: 88 were treated with ePTFE and 52 with polyester grafts. Twenty-three patients (16.4%) were found to have radiologic evidence of PGH. PGH developed more frequently in patients with ePTFE (21/88 [23.9%]) compared with those with polyester grafts (2/52 [3.8%]) (P = .002). Mean PGH size was 63.5 ± 36.4 mm (range, 33-153 mm) and the average time to PGH detection 27.7 months (range, 3-112 months). Baseline characteristics were similar between the groups. Patients who developed PGH had larger aneurysms, more often received ePTFE grafts, had larger graft diameters, and had bifurcated grafts. The overall mortality was 32.1% at a mean follow-up of 5.2 years. The 5-year mortality rates were similar between patients with and without PGH (26.1% vs 18.8%; P = .41). Of the 23 patients with PGH, 4 (all with ePTFE) presented with symptoms related to the PGH. The average size of symptomatic and asymptomatic PGH were 11.5 and 4.8 cm, respectively. Mortality rates overall were similar between those with and without symptoms (50.0% vs 36.8%; P = .99). CONCLUSIONS: Nearly one-quarter of aortic reconstructions with ePTFE are associated with PGH formation compared with 4% with polyester. Clinically significant PGH-related symptom development occurs in 20%. Patient education and close surveillance are warranted. Manufacturer's device modification is needed.

Duration of blood flow reversal during transcarotid artery revascularization does not affect outcome.

OBJECTIVE: Transcarotid artery revascularization (TCAR) has become an increasingly popular alternative for the treatment of carotid bifurcation stenosis. TCAR employs carotid blood flow reversal through an ex vivo common carotid artery to femoral vein shunt for neuroprotection during the placement and angioplasty of the carotid artery stent. There is a lack of data regarding an association between the duration of flow reversal and neurologic complications or other adverse events. We analyzed TCAR flow reversal time in relation to major adverse events. METHODS: There were 307 patients who underwent TCAR at four high-volume academic institutions. Patients were separated on the basis of the duration of carotid flow reversal as follows: group I, ≤8 minutes (n = 138); group II, 9-13 minutes (n = 105); group III, 14-20 minutes (n = 42); and group IV, >20 minutes (n = 22). Adverse events including stroke (assessed by a National Institute of Health Stroke Scale-certified examiner), myocardial infarction (MI), and death at discharge and 30 days were collected in all patients and were compared between groups using one-way analysis of variance and χ2 analysis. RESULTS: There were four strokes in the total cohort, yielding an overall stroke rate of 1.3%. All strokes were minor in nature; two were ipsilateral and two were contralateral. All patients demonstrated full recovery at 30 days. We found no significant difference in the stroke rate between any of the groups: I, 1.5% (2/138); II, 1.9% (2/105); III, 0% (0/42); and IV, 0% (0/22; P = .76). The four strokes occurred in patients with flow reversal time of 6, 7, 11, and 12 minutes. There was also no difference in the 30-day composite stroke/death or stroke/death/MI rates among the groups. CONCLUSIONS: The length of flow reversal during TCAR does not affect rates of stroke, MI, or death. These data suggest that operators should focus on the technical aspects of the procedure during flow reversal rather than on its duration.

Paclitaxel-coated peripheral artery devices are not associated with increased mortality.

OBJECTIVE: Long-term safety concerns have been raised that the use of paclitaxel-coated balloons and stents is linked to excess mortality. Our objective was to compare outcomes in patients treated with paclitaxel vs uncoated devices and to analyze long-term mortality. METHODS: We conducted a retrospective single-institution review of 1170 consecutive patients who underwent femoropopliteal percutaneous revascularization by angioplasty, atherectomy, stent placement, or combination between 2011 and 2018. The primary outcome measure was all-cause mortality. Groups were divided into patients who received paclitaxel (n = 652) and those who did not (n = 518). Categorical variables were assessed using χ2 analysis and continuous variables with the Wilcoxon signed rank test. A multivariable analysis was performed using multivariable logistic regression models. Mortality was compared using Kaplan-Meier survival analysis. RESULTS: Demographics, risk factors, and Rutherford class were similar between the groups, except that the paclitaxel group was more likely to have diabetes (60.9% vs 55.0%; P = .04), was less likely to be on dialysis (10.7% vs 14.9%; P = .04), and had lower average creatinine concentration (1.6 ± 1.8 mg/dL vs 2.0 ± 2.3 mg/dL; P = .003). There were no differences in all-cause mortality through 2 years between paclitaxel and no-paclitaxel cohorts (25.5% vs 30.3%; log-rank, P = .098). At 3 years and 3.5 years, mortality was significantly lower in the paclitaxel group: year 3, 32.1% vs 39.4% (log-rank, P = .041); year 3.5, 35.2% vs 43.9% (log-rank, P = .027). Survival rates were not significantly different in examining subgroups by diabetes, chronic kidney disease, presence of chronic limb-threatening ischemia, or paclitaxel-coated balloon manufacturer. Multivariable analysis demonstrated that age, dialysis, chronic limb-threatening ischemia, chronic kidney disease, and congestive heart failure were independent risk factors for mortality, whereas paclitaxel use was associated with lower mortality. CONCLUSIONS: The use of paclitaxel-coated balloons and stents does not increase mortality compared with uncoated devices out to 3.5 years. Paclitaxel-coated devices can be used with continued caution, especially in patients at increased risk of restenosis. Further long-term studies are needed to determine the risk of late mortality.

Network-based prediction of polygenic disease genes involved in cell motility.

BACKGROUND: Schizophrenia and autism are examples of polygenic diseases caused by a multitude of genetic variants, many of which are still poorly understood. Recently, both diseases have been associated with disrupted neuron motility and migration patterns, suggesting that aberrant cell motility is a phenotype for these neurological diseases. RESULTS: We formulate the POLYGENIC DISEASE PHENOTYPE Problem which seeks to identify candidate disease genes that may be associated with a phenotype such as cell motility. We present a machine learning approach to solve this problem for schizophrenia and autism genes within a brain-specific functional interaction network. Our method outperforms peer semi-supervised learning approaches, achieving better cross-validation accuracy across different sets of gold-standard positives. We identify top candidates for both schizophrenia and autism, and select six genes labeled as schizophrenia positives that are predicted to be associated with cell motility for follow-up experiments. CONCLUSIONS: Candidate genes predicted by our method suggest testable hypotheses about these genes’ role in cell motility regulation, offering a framework for generating predictions for experimental validation.

The learning curve of transcarotid artery revascularization.

BACKGROUND: In the pivotal U.S. Food and Drug Administration approval trial, ROADSTER, transcarotid artery revascularization (TCAR) using the ENROUTE Transcarotid Neuroprotection System (Silk Road Medical Inc, Sunnyvale, Calif) was shown to have one of the lowest reported complication rates, not only for carotid artery stent placement, but also for any carotid intervention, including endarterectomy. The number of cases required for a surgeon to gain the proficiency to realize these outcomes has not been studied. Our objective was to determine the learning curve for vascular surgeons performing the TCAR procedure. We examined the effect of surgeon procedural experience on intraoperative data and postoperative outcome. METHODS: This retrospective review analyzed data from a prospectively maintained database of 188 consecutive patients from three large academic centers who underwent TCAR. Procedures were ordered chronologically for each surgeon and grouped into bins of five. Operative times and flow reversal times were analyzed by analysis of variance. Results led to comparison of surgeons' early experience (cases 1-15) with their later experience (cases 16-50). The primary outcome was postoperative stroke and death. RESULTS: The mean procedural time for all cases was 75.0 ± 23.8 minutes. When the procedural time of cases 1 through 15 (mean, 79.0 ± 28.3 minutes) were compared with cases 16 through 50 (mean, 71.8 ± 19.0 minutes), a significant difference was noted (P = .02). The mean flow reversal time was 10.6 ± 6.8 minutes. When flow reversal times were compared using analysis of variance testing, cases 1 through 15 were statistically similar and cases 11 through 50 were also similar, but the two groups differed from each other (P < .001). For flow reversal, cases 1 through 15 had mean reversal times of 13.3 ± 8.8 minutes compared with 8.5 ± 3.5 minutes for cases 16 through 50 (P < .001). Postoperative stroke rates were similar in the 1 through 15 and 16 through 50 case groups (2.4% vs 1.0%; P = .59), as were death rates (0.0% vs 1.0%; P > .99). The combined stroke/death rates were also comparable at 2.4% in the early cohort vs 1.9% in the late cohort (P > .99). CONCLUSIONS: There seems to be a relatively short learning curve for the TCAR procedure. After 15 cases, surgeons are able to reduce procedural decrease by 10% (from 79.0 to 71.8 minutes), and flow reversal times by an average of 40% (from 13.3 to 8.5 minutes). More important, the rates of stroke and death do not differ between early and late experience with TCAR. The TCAR procedure may be quickly and safely adopted by vascular surgeons for carotid intervention.