Basic mechanisms and pathogenesis of venous thrombosis

A Review of Venous Thromboembolism Risk Assessment and Prophylaxis in Plastic Surgery

BACKGROUND

Venous thromboembolism is a significant cause of postoperative death and morbidity. While prophylactic and treatment regimens exist, they usually come with some risk of clinically relevant bleeding and, thus, must be considered carefully for each individual patient.

METHODS

This special topic article represents a review of current evidence regarding venous thromboembolism risk, biology, and prevention in plastic surgery patients. The specific types and duration of available prophylaxis are also reviewed. The balance of venous thromboembolism risk must be weighed against the risk of hemorrhage.

RESULTS

Though alternatives exist, the most validated risk assessment tool is the 2005 modification of the Caprini Risk Assessment Model. Controversies remain regarding recommendations for outpatient and low risk cosmetic patients. The authors additionally make recommendations for high-risk patients regarding the use of tranexamic acid, estrogen therapy, anesthesia, and prophylaxis regimens.

CONCLUSION

Our profession has made great strides in understanding the science behind venous thromboembolism, risk stratification for patients, and prophylactic regimens; yet, continued studies and definitive data are needed.

Differential Presentations of Arterial Thromboembolic Events Between Venous Thromboembolism and Atrial Fibrillation Patients

Objective: Atrial fibrillation (AF) and venous thromboembolism (VTE) share several risk factors related to arterial thromboembolism. No study has reported the differential contribution to arterial thromboembolic events and mortality between these two conditions in the same population. We therefore assessed the differential arterial thromboembolic events between AF and VTE.

Methods: We included AF and VTE national cohorts derived from Taiwan National Health Insurance Research Database between 2001 and 2013. The eligible population was 314,861 patients in the AF cohort and 41,102 patients in the VTE cohort. The primary outcome was arterial thromboembolic events, including ischemic stroke, extracranial arterial thromboembolism (ECATE) and myocardial infarction (MI). Secondary outcomes were all-cause mortality and cardiovascular death.

Results: After a 1:1 propensity matching, 32,688 patients in either group were analyzed. The risk of arterial thromboembolic events was lower in the VTE cohort than that in the AF cohort (subdistribution hazard ratio [SHR], 0.60; 95% confidence interval [CI], 0.57–0.62). The risk of ischemic stroke (SHR, 0.44; 95% CI, 0.42–0.46) and MI (SHR, 0.80; 95% CI, 0.72–0.89) were lower in the VTE cohort, while the risk of ECATE (SHR, 1.23; 95% CI, 1.14–1.33; particularly lower extremities) was higher in the VTE cohort. All-cause mortality rate was higher in the VTE cohort (HR, 1.18; 95% CI, 1.15–1.21) while the risk of cardiovascular death was lower in the VTE cohort (HR, 0.96; 95% CI, 0.93–0.995).

Conclusions: Patients with AF had higher risks of arterial thromboembolic events compared to patients with VTE, despite having risk factors in common. The VTE cohort had higher risks of all-cause mortality and ECATE, particularly lower extremity events, compared to AF patients. The differential manifestations of thromboembolism sequelae and mortality between AF and VTE patients merit further investigation.

Textile Electrodes: Influence of Electrode Construction and Pressure on Stimulation Performance in Neuromuscular Electrical Stimulation (NMES)

The major reason for preventable hospital death is venous thromboembolism (VTE). Non-pharmacological treatment options include electrical stimulation or compression therapy to improve blood flow in the extremities. Textile electrodes offer potential to replace bulky devices commonly used in this field, thereby improving the user compliance. In this work, the performance of dry and wet knitted electrodes in combination with pressure application to the electrode was evaluated in neuromuscular electrical stimulation (NMES). A motor point stimulation on the calf was performed on nine healthy subjects to induce a plantarflexion and the required stimulation intensity as well as the perceived pain were assessed. The performance of the different electrode constructions was compared and the influence of the pressure application was analysed. The results show that wet textile electrodes (0.9 % saline solution) perform significantly better than dry electrodes. However, opportunities were found for improving the performance of dry textile electrodes by using an uneven surface topography in combination with an intermediate to high pressure application to the electrode (> 20 mmHg), e.g. by using a compression stocking. Moreover, the smaller of the two tested electrode areas (16 cm²; 32 cm²) appears to be favourable in terms of stimulation comfort and efficiency.

Applicability of Narrow Groove Theory in Designing Washout Features for Rotary Blood Pumps. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2021;2021:5419-5424. [PMID: 34892352 DOI: 10.1109/embc46164.2021.9630426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

High and low shear regions in rotary blood pumps require sufficient washout flow to minimize blood residence time, thereby preventing hemolysis or regions of stasis that can lead to pump thrombosis. Spiral groove bearings (SGBs) both enhance pump washout and reduce erythrocyte exposure to high shear. Narrow groove theory (NGT) has been used as an analytical tool to estimate the flow performance of a flat SGB during the design stage. However, NGT cannot accurately predict the performance of a conical SGB. In this study, we formulated an analytical model from the established NGT by adding an inertia correction term to incorporate variations in centrifugal force, which improved washout prediction in a conical SGB. The modified NGT model was then validated by comparison with experimental results. The results show that the modified NFT analytical model can reasonably predict washout rate when the spiral groove geometry favors creep flow conditions. The conical half angle of the SGB had the most significant impact on washout, with a decrease in half angle leading to large increases in wash-out flow. Small half angles also maintained viscous pumping at larger Reynolds numbers. In summary, the modified NGT can be a useful tool for designing conical SGBs for rotary blood pump washout within the creep flow regime.

Bioactive Natural Compounds with Antiplatelet and Anticoagulant Activity and Their Potential Role in the Treatment of Thrombotic Disorders

Natural anticoagulant drugs can be obtained from plants, rich in secondary bioactive metabolites which, in addition to being effective antioxidants, also possess anticoagulant and antiplatelet properties and, for this reason, can be excellent candidates for the treatment of thrombotic diseases. This review reports an overview of the hemostatic process and thrombotic disorders together with data on plants, more and less common from around the world, containing bioactive compounds characterized by antiplatelet and anticoagulant activity. The reported literature was obtained from Medline, PubMed, Elsevier, Web of Science, Google Scholar considering only articles in the English language, published in peer-reviewed journals. The number of citations of the articles and the impact factor of the journals were other parameters used to select the scientific papers to be included in the review. The analysis of the literature data selected demonstrates that many plants’ bioactive compounds show antiplatelet and anticoagulant activity that make them potential candidates to be used as new natural compounds able to interfere with both primary and secondary hemostasis. Moreover, they could be used together with anticoagulants currently administered in clinical practice to increase their efficacy and to reduce complications in the treatment of thrombotic disorders.

Evaluating post-operative venous thromboembolism risk in urology patients using a validated risk assessment model

Background

Venous thromboembolism (VTE) is an important cause of post-surgical morbidity and mortality. This study aimed to apply a validated risk assessment model to evaluate the risk of post-operative VTE in urology patients.

Methods

This prospective descriptive observational study used the Caprini risk assessment model to evaluate VTE risk in patients planned for elective urology surgery at a tertiary Johannesburg hospital from January to June 2020.

Results

Two hundred and twenty-six patients with a mean age of 52 years were evaluated for post-operative VTE risk. The population was generally overweight, with a mean BMI of 26.3 kg/m2. The mean Caprini score was 4.42, reflecting a population at high risk for post-operative VTE. There was no statistically significant difference between males and females in this regard. On average, participants had three risk factors for post-operative VTE. Fifteen per cent of all patients were at low risk for VTE, while 40.3% of participants were categorised as moderate risk. The category with the highest percentage of participants (44.7%) was the high-risk category (Caprini score ≥ 5). High-risk patients undergoing oncology surgery comprised 16.8% of the population, and these patients may require extended duration pharmacological thromboprophylaxis to prevent VTE. The most clinically significant risk factors for post-operative VTE included age, obesity, malignancy and HIV infection.

Conclusion

Venous thromboembolism may be difficult to diagnose, and clinicians may underestimate the risk for it to develop. Risk assessment models, such as the Caprini score, are objective and a practical tool to guide the application of thromboprophylaxis. The application of the Caprini RAM in the elective urological surgery population at Chris Hani Baragwanath Academic Hospital yields similar results to studies performed elsewhere on similar surgical populations. Further research is required to evaluate whether the actual incidence of VTE correlates with the risk assessment in this population. Clinician compliance with the use of RAMs as well as the corresponding recommendations for prophylaxis may need to be evaluated. A validated risk assessment model which accounts for procedure-specific risks in urology may be useful.

High fibrinogen γ' levels in patient plasma increase clot formation at arterial and venous shear

Fibrinogen γ' accounts for 3% to 40% of plasma fibrinogen. Earlier studies indicated that fibrinogen γ' forms altered fibrin clots under static conditions, whereas clinically, altered plasma γ' levels are associated with arterial and venous thrombosis. However, the effects of static vs flow conditions on the role of γ' throughout the pathophysiological range is unknown. This study explores the effects of γ' levels on clot formation and structure in static and flow conditions. Coagulation of plasma samples with low (n = 41; 3%), normal (n = 45; 10%), or high (n = 33; 30%) γ' levels were compared with that of purified fibrinogen mixtures with increasing ratios of γ' (3%, 10%, 30%). Clots were analyzed by confocal microscopy, permeation, turbidity, and lysis techniques. In a novel 2-step flow-perfusion model, fibrinogen-deficient plasma repleted with increasing ratios of γ' (3%, 10%, 30%) or plasmas with low (n = 5, 3%) or high (n = 5, 30%) γ' were flowed over preformed platelet aggregates at arterial (500 s-1) and venous (150 s-1) shear rates. Increasing γ' percentages within the pathophysiological range (3%-30%) did not result in any change in clot-formation rates; however, it led to significantly higher clot density, thinner fibers, and slower lysis in static conditions. Under flow at arterial shear, high γ' (30%) led to faster (+44.1%-75.3%) and increased (+104%-123%) fibrin deposition, with clots exhibiting a larger volume (+253%-655%) and height (+130%-146%). These trends were magnified at venous shear. Overall, our findings demonstrate the significant impact of pathophysiological fibrinogen γ' levels on clot structure and provide new flow-dependent mechanisms to explain how γ' increases thrombosis risk.

Structural and Binding Effects of Chemical Modifications on Thrombin Binding Aptamer (TBA)

The thrombin binding aptamer (TBA) is a promising nucleic acid-based anticoagulant. We studied the effects of chemical modifications, such as dendrimer Trebler and NHS carboxy group, on TBA with respect to its structures and thrombin binding affinity. The two dendrimer modifications were incorporated into the TBA at the 5' end and the NHS carboxy group was added into the thymine residues in the thrombin binding site of the TBA G-quadruplex (at T4, T13 and both T4/T13) using solid phase oligonucleotide synthesis. Circular dichroism (CD) spectroscopy confirmed that all of these modified TBA variants fold into a stable G-quadruplex. The binding affinity of TBA variants with thrombin was measured by surface plasmon resonance (SPR). The binding patterns and equilibrium dissociation constants (K_D) of the modified TBAs are very similar to that of the native TBA. Molecular dynamics simulations studies indicate that the additional interactions or stability enhancement introduced by the modifications are minimized either by the disruption of TBA-thrombin interactions or destabilization elsewhere in the aptamer, providing a rational explanation for our experimental data. Overall, this study identifies potential positions on the TBA that can be modified without adversely affecting its structure and thrombin binding preference, which could be useful in the design and development of more functional TBA analogues.

Armored Droplets as Soft Nanocarriers for Encapsulation and Release under Flow Conditions

Technical challenges in precision medicine and environmental remediation create an increasing demand for smart materials that can select and deliver a probe load to targets with high precision. In this context, soft nanomaterials have attracted considerable attention due to their ability to simultaneously adapt their morphology and functionality to complex ambients. Two major challenges are to precisely control this adaptability under dynamic conditions and provide predesigned functionalities that can be manipulated by external stimuli. Here, we report on the computational design of a distinctive class of soft nanocarriers, built from armored nanodroplets, able to selectively encapsulate or release a probe load under specific flow conditions. First, we describe in detail the mechanisms at play in the formation of pocket-like structures in armored nanodroplets and their stability under external flow. Then we use that knowledge to test the capacity of these pockets to yield flow-assisted encapsulation or expulsion of a probe load. Finally, the rheological properties of these nanocarriers are put into perspective with those of delivery systems employed in pharmaceutical and cosmetic technology.

In situ Pulmonary Artery Thrombosis: A Previously Overlooked Disease

Pulmonary thromboembolism (PTE) is the third leading cause of death in cardiovascular diseases. PTE is believed to be caused by thrombi detached from deep veins of lower extremities. The thrombi travel with systemic circulation to the lung and block pulmonary arteries, leading to sudden disruption of hemodynamics and blood gas exchange. However, this concept has recently been challenged by accumulating evidence demonstrating that de novo thrombosis may be formed in pulmonary arteries without deep venous thrombosis. On the other hand, chronic thromboembolic pulmonary hypertension (CTEPH), a subtype of pulmonary hypertension, could have different pathogenesis than traditional PTE. Therefore, this article summarized and compared the risk factors, the common and specific pathogenic mechanisms underlying PTE, in situ pulmonary artery thrombosis, and CTEPH at molecular and cellular levels, and suggested the therapeutic strategies to these diseases, aiming to facilitate understanding of pathogenesis, differential diagnosis, and precision therapeutics of the three pulmonary artery thrombotic diseases.

Vaccine-induced immune thrombotic thrombocytopenia after vaccination against Covid-19: A clinical dilemma for clinicians and patients

The coronavirus disease 2019 (Covid-19) pandemic has had devastating effects on public health worldwide, but the deployment of vaccines for Covid-19 protection has helped control the spread of SARS Coronavirus 2 (SARS-CoV-2) infection where they are available. The common side effects reported following Covid-19 vaccination were mostly self-restricted local reactions that resolved quickly. Nevertheless, rare vaccine-induced immune thrombotic thrombocytopenia (VITT) cases have been reported in some people being vaccinated against Covid-19. This review summarizes the thromboembolic events after Covid-19 vaccination and discusses its molecular mechanism, incidence rate, clinical manifestations and differential diagnosis. Then, a step-by-step algorithm for diagnosing such events, along with a management plan, are presented. In conclusion, considering the likeliness of acquiring severe SARS-CoV-2 infection and its subsequent morbidity and mortality, the benefits of vaccination outweigh its risks. Hence, if not already initiated, all governments should begin an effective and fast public vaccination plan to overcome this pandemic.

Numerical Simulations of Red-Blood Cells in Fluid Flow: A Discrete Multiphysics Study

In this paper, we present a methodological study of modelling red blood cells (RBCs) in shear-induced flows based on the discrete multiphysics (DMP) approach. The DMP is an alternative approach from traditional multiphysics based on meshless particle-based methods. The proposed technique has been successful in modelling multiphysics and multi-phase problems with large interfacial deformations such as those in biological systems. In this study, we present the proposed method and introduce an accurate geometrical representation of the RBC. The results were validated against available data in the literature. We further illustrate that the proposed method is capable of modelling the rupture of the RBC membrane with minimum computational difficulty.

Robotic-assisted hiatal hernia repair and pulmonary embolism: an institution-based retrospective cohort study

Hiatal hernia (HH) is an abnormal protrusion of components of the abdominal viscera through the esophageal hiatus. The laparoscopic approach is the gold standard for repair with the robotic technique now gaining wide acceptance. Pulmonary embolism (PE) is a well-known post-operative complication but its incidence following robotically assisted HH repairs is not well known. This study provides a descriptive analysis of three patients who developed PE after robotic repairs of their HHs. The incidence of PE in the studied cohort was 2.7% (3 of 112) with a male preponderance (66.7%). The mean age of the patients was 55.3 years with a mean BMI of 32.2 kg/m². The average duration of surgery was 4.2 h with sizes of the diaphragmatic defects ranging from 3 to 6 cm. Confirmatory PE diagnosis was made with a chest CT angiogram and the mean length of hospital stay was 4 days. PE although rare, is a preventable cause of in-patient mortality and morbidity with implications on healthcare costs and hospital resource use. The Caprini model provides a guide to pre-operative patient risk stratification and PE prevention, and the patients in this study were in the moderate to high-risk groups. Risk factors common to all patients were: age > 40 years, BMI > 30 kg/m² and duration of surgery > 2 h with one of the patients having a previous history of PE. There are no established PE chemoprophylaxis guidelines for robotic HH repairs and in this cohort, heparin was commenced 6-8 h post-operatively. Thus, there is a need for a consensus chemoprophylaxis guideline in this subset of surgical patients. PE following robotic HH repair is associated with prolonged hospital stay and increased healthcare costs. Guidelines for effective pre-operative chemoprophylaxis for these repairs are needed to optimize patient outcomes.

Role of combining anticoagulant and antiplatelet agents in COVID-19 treatment: a rapid review

Although primarily affecting the respiratory system, COVID-19 causes multiple organ damage. One of its grave consequences is a prothrombotic state that manifests as thrombotic, microthrombotic and thromboembolic events. Therefore, understanding the effect of antiplatelet and anticoagulation therapy in the context of COVID-19 treatment is important. The aim of this rapid review was to highlight the role of thrombosis in COVID-19 and to provide new insights on the use of antithrombotic therapy in its management. A rapid systematic review was performed using preferred reporting items for systematic reviews. Papers published in English on antithrombotic agent use and COVID-19 complications were eligible. Results showed that the use of anticoagulants increased survival and reduced thromboembolic events in patients. However, despite the use of anticoagulants, patients still suffered thrombotic events likely due to heparin resistance. Data on antiplatelet use in combination with anticoagulants in the setting of COVID-19 are quite scarce. Current side effects of anticoagulation therapy emphasise the need to update treatment guidelines. In this rapid review, we address a possible modulatory role of antiplatelet and anticoagulant combination against COVID-19 pathogenesis. This combination may be an effective form of adjuvant therapy against COVID-19 infection. However, further studies are needed to elucidate potential risks and benefits associated with this combination.

Recent Advances of Cell Membrane Coated Nanoparticles in Treating Cardiovascular Disorders

Cardiovascular diseases (CVDs) are the leading cause of death worldwide, causing approximately 17.9 million deaths annually, an estimated 31% of all deaths, according to the WHO. CVDs are essentially rooted in atherosclerosis and are clinically classified into coronary heart disease, stroke and peripheral vascular disorders. Current clinical interventions include early diagnosis, the insertion of stents, and long-term preventive therapy. However, clinical diagnostic and therapeutic tools are subject to a number of limitations including, but not limited to, potential toxicity induced by contrast agents and unexpected bleeding caused by anti-platelet drugs. Nanomedicine has achieved great advancements in biomedical area. Among them, cell membrane coated nanoparticles, denoted as CMCNPs, have acquired enormous expectations due to their biomimetic properties. Such membrane coating technology not only helps avoid immune clearance, but also endows nanoparticles with diverse cellular and functional mimicry. In this review, we will describe the superiorities of CMCNPs in treating cardiovascular diseases and their potentials in optimizing current clinical managements.

Hyper-viscoelastic damage modeling of whole blood clot under large deformation

Blood clots play a diametric role in our bodies as they are both vital as a wound sealant, as well as the source for many devastating diseases. In blood clots' physiological and pathological roles, their mechanics play a critical part. These mechanics are non-trivial owing to blood clots' complex nonlinear, viscoelastic behavior. Casting this behavior into mathematical form is a fundamental step toward a better basic scientific understanding of blood clots, as well as toward diagnostic and prognostic computational models. Here, we identify a hyper-viscoelastic damage model that we fit to original data on the nonlinear, viscoelastic behavior of blood clots. Our model combines the classic Ogden hyperelastic constitutive law, a finite viscoelastic model for large deformations, and a non-local, gradient-enhanced damage formulation. By fitting our model to cyclic tensile test data and extension-to-failure data, we inform the model's nine unknown material parameters. We demonstrate the predictability of our model by validating it against unseen cyclic tensile test and stress-relaxation data. Our original data, model formulation, and the identified constitutive parameters of this model are openly available for others to use, which will aid in developing accurate, quantitative simulations of blood clot mechanics.

Targeted next-generation sequencing reveals novel and known variants of thrombophilia associated genes in Saudi patients with venous thromboembolism

BACKGROUND

Thrombophilia is a substantial source of indisposition and mortality in several countries, including Arab populations. Deep venous thrombosis (DVT) with or without pulmonary embolism (PE) is the prevalent clinical manifestation of thrombophilia. While many genetic risk factors for DVT are known, almost all associated with hemostasis, many genetic factors remain unexplained. Nowadays, Next Generation Sequencing (NGS) offers a potential solution that allows several candidate genes to be analyzed simultaneously at a reasonable expense.

METHODS

We performed variant screening in the thrombophilia associated genes in Factor V Leiden (FVL) mutation-negative patients using Ion Torrent Next-generation sequencing (NGS). Ion AmpliSeq panel for 18 genes was designed. Twenty-nine unrelated patients with idiopathic VTE were recruited for NGS.

RESULTS

We were able to identify 19 variants (1 novel and 18 previously reported) in 10 out of 18 targeted genes. Pathogenic variants were identified in 22 patients demonstrating mutation detection rates of 76%. Previously reported variants in the F5, MTHFR, PROS1, PROC, F8, F9, SERPINA10, SERPIND1, and HRG genes were recognized in 21 patients. More than one variant in the targeted genes was detected in some of the patients with VTE. We identified SERPINA10 recurrent variant p.(R88*) in seven patients representing 32% of VTE cases. Additionally, we report one novel variant c.356G > T, p.(G119V) in the F7 gene, considered to be pathogenic in this study.

CONCLUSIONS

Our studies finding illustrates the ability of targeted next-generation sequencing to uncover uncommon/unknown genetic variants that may predispose to thrombophilia. The finding of the novel variant in the F7 gene extends the spectrum of variants affecting thrombosis. While a comparatively small number of subjects have been included in our cohort, the findings summarize the possible genetic features of thrombophilia.

Evaluation of the Efficacy of Enoxaparin in the Neonatal Intensive Care Unit

OBJECTIVE

This article evaluates the efficacy of enoxaparin when targeting anti-factor Xa levels of 0.5 to 1 units per milliliter in the neonatal intensive care unit.

STUDY DESIGN

This is a retrospective chart review of 45 neonates receiving enoxaparin for the treatment of venous thromboembolism. Enoxaparin dosing and corresponding anti-factor Xa levels were collected. Time to resolution of clot was confirmed by imaging and compared between clots in various locations.

RESULTS

The median time to clot resolution was 76 days (interquartile range 40-91 days). Clot location, postnatal age, and sex at the clot onset were significantly associated with time to clot resolution in a multivariable Cox model (p-value: 0.03, 0.03, and < 0.01, respectively). Of the 54 patients analyzed for safety, 5 patients (9.3%) experienced bleeding events resulting in the discontinuation of enoxaparin.

CONCLUSION

Based on our findings, 50% of all patients evaluated, regardless of thrombus location, achieved resolution within the first 76 days of therapy. Clots located in the extremities tended to resolve sooner, hence earlier reimaging should be considered.

Clinical characteristics and outcomes of venous thromboembolism in patients hospitalized for COVID-19: Systematic review and meta-analysis

Venous thromboembolism is prevalent in hospitalized COVID-19 patients. Through systematic review and meta-analysis, we have investigated the differences in clinical characteristics and outcome of hospitalized COVID-19 patients with (+) and without (-) venous thromboembolism (VTE). 45 studies with a total of 8859 patients were included in the qualitative synthesis. Subsequently, 38 studies with a total of 7847 patients, were quantitatively analyzed. There was no mortality difference between the VTE (-) and VTE (+) hospitalized COVID-19 patients (RR1.32 (0.97, 1.79); 0.07; I2 64%, p ​< ​0.001). Patients with VTE (+) were more likely to get admitted to the intensive care unit (RR1.77 (1.26, 2.50); p ​< ​0.001; I2 63%, p ​= ​0.03) and mechanically ventilated (RR 2.35 (1.22, 4.53); p ​= ​0.01; I2 88%, p ​< ​0.001). Moreover, male gender (RR 1.19 (1.14,1.24), p ​< ​0.001; I2 0%, p ​= ​0.68), increased the risk of VTE. Regarding patients lab values', VTE (+) was significantly associated with higher white blood cell, neutrophil count, D-Dimer, alanine aminotransferase (ALT), lactate dehydrogenase (LDH), and C-reactive protein (CRP), along with prolonged prothrombin time. On the contrary, VTE (+) was associated with lower albumin and neutrophil-lymphocyte ratio (NLR). This findings provide the initial framework for risk stratification of hospitalized COVID-19 patients with VTE.

Trauma magnitude of the meta-epyphyseal cancellous affects the incidence of deep vein thrombosis. A prospective cohort study on the dynamic of Collagen I, Collagen IV, Tissue factor, P-Selectin and Nitric Oxide in the thrombus formation following hip and knee surgeries

INTRODUCTION

The purpose of this study was to analyze the traumatization degree of meta-epiphyseal cancellous of hip and knee joints in major orthopedic surgery that affects the incident of deep vein thrombosis (DVT) event through the dynamics expression of pro-thrombogenic biomarkers (Collagen I, Collagen IV, Tissue Factor, P-selectin) and anti-thrombogenic (Nitric Oxide).

METHODS

In this cohort prospective study, there were sixty-nine (69) subjects that were divided into three (3) groups, with twenty-three (23) subjects that were treated with total arthroplasty (TA), twenty-two (22) subjects were treated with hemiarthroplasty (HA), twenty-four (24) subjects were treated with open reduction internal fixation (ORIF). Subjects from May 2010 to September 2011 who met the inclusion criteria were included in this study. All patients were treated without thromboprophylaxis. Blood samples were taken in three different periods, before surgery, 72 h, and 144 h after surgery, for examination of pro-thrombogenic biomarkers (Collagen I, Collagen IV, Tissue Factor, P-selectin) and anti-thrombogenic (Nitric Oxide), which are the components involved in the hemostasis.

RESULTS

DVTs were proven by venography (or Doppler ultrasound in 8 cases) done at 144 h after the surgeries. Eighteen (18) subjects had DVT (26.1%), with ten (10) subjects from the TA group (43.5%), five (5) subjects from the HA group (22.7%), and three (3) subjects from ORIF groups (12.5) %). The risk for experiencing DVT on TA is 3.5 times more than the ORIF group, while in HA group is 2.1 times more than ORIF group. The role of biomarker levels on DVT incidence was found in Col I (p < 0.1) and NO (p < 0.05) at 72 h after surgery.

CONCLUSION

This research confirms that trauma magnitude of the meta-epiphyseal cancellous of hip and knee joints in major orthopedic surgery influences the incidence of DVTs, through the elevation of Col I and NO. An estimated 72 h after surgery is a useful period to examine these biomarkers to help predict the diagnose of DVT. The involvement of the other biomarkers studied (Col IV, TF, and Ps) could not be proven. Future studies are needed to evaluate other biomarkers in the complex process of hemostasis to establish the diagnose of DVT.

Is There Value in Venous Thromboembolism Chemoprophylaxis After Pediatric Scoliosis Surgery? A 28-Year Single Center Study

BACKGROUND

With a recognized increase in the incidence of venous thromboembolism (VTE) in children, especially in those with complex, chronic conditions, it is important for patient safety and risk management to identify subgroups that would benefit from prophylactic treatment. The aim of our study was to assess whether scoliosis surgery in children was associated with an increased incidence of VTE, including deep venous thrombosis (DVT) and pulmonary embolism, and if chemoprophylaxis is warranted.

METHODS

We reviewed our institution's Pediatric Orthopaedic Spine Database (1992-2019) to identify patients who had a symptomatic VTE postoperatively.

RESULTS

There were 1471 patients (1035 female, 436 male) with a mean age at surgery of 12.1±3.2 years (range, 1 to 18 y) underwent posterior spinal fusion and instrumentation (2131 procedures). No patients were given pharmacological VTE prophylaxis, and no routine screening for VTE was performed. Two patients had a lower extremity DVT (0.13%) within 6 months following surgery, (range, 55 to 161 d). Neither patient had a subsequent pulmonary embolism. They were 9 and 17 years of age with a diagnosis of neuromuscular scoliosis (1 each postpolio and myelodysplasia). One affected patient had a central venous line inserted perioperatively, a known risk factor for thromboembolism. All DVTs were treated with appropriately dosed anticoagulants. None had a family history of hypercoagulation.

CONCLUSIONS

The risk of symptomatic VTE is extraordinarily low after pediatric spinal deformity surgery. Mechanical prophylaxis is sufficient in most cases. Further multi-center studies may help identify patient specific risk factors.

Impact of Music Therapy on Preoperative Anxiety and Degree of Cooperation With Anesthesia Induction in Children With Simple Congenital Heart Disease

PURPOSE

To evaluate the impact of music therapy (MT) on preoperative anxiety and degree of cooperation with anesthesia induction in children with simple congenital heart disease (CHD).

DESIGN

A randomized controlled clinical study.

METHODS

Ninety children were randomly assigned to the MT and control groups. The MT groups underwent a preoperative 30-minute session of MT, whereas the control group did not listen to any music and had the same amount of quiet time. The modified Yale Preoperative Anxiety Scale-Short Form (mYPAS-SF) was used to evaluate the patients' preoperative anxiety on entering the anesthesia waiting area (T1), 10 minutes after entering the waiting area (T2), and during the initiation of anesthesia induction (T3); the degree of cooperation with anesthesia induction was assessed using the Induction Compliance Checklist. The mean arterial blood pressure (MAP) and heart rate (HR) at T1, T2, T3, and T4 (the time of successful anesthesia) were also recorded.

FINDINGS

One child was excluded from the MT group, and one was excluded from the control group. No difference was found in the mYPAS-SF score, MAP, or HR between the two groups at T1. The mYPAS-SF scores of the MT group were significantly lower than those of the control group at T2 and T3. At T2, T3, and T4, the MAP and HR of the MT group were lower than those of the control group. A statistically significant difference was found in the Induction Compliance Checklist score between the two groups.

CONCLUSIONS

MT can reduce preoperative anxiety and improve the degree of cooperation with anesthesia induction.

Rare and Underestimated Association of Pulmonary Embolism and Olanzapine Therapy; Report of Two Cases

Venous thromboembolic disease (VTD) is a very common and severe pathological condition in which there are many predisposing factors. Olanzapine is a drug frequently used in psychiatric practises; it is thought to increase the risk of VTD. Here, we report two cases, a young man and a woman, with a medical history of schizophrenia treated by olanzapine who developed pulmonary embolism and we did not find any aetiologies of VTD in them. Due to the link between olanzapine and pulmonary embolism, which has been previously described, olanzapine is considered responsible for this problem. Two mechanisms have been reported in the literature in this regard; significant weight gain and lethargy, which are very common side effects of olanzapine. So far, no direct effect of olanzapine on platelet aggregation or coagulation has been found. In patients developing VTD while being treated with olanzapine, discontinuation of olanzapine as a treatment option must be done with an adjustment of antipsychotic treatment and regular monitoring of psychic symptoms. Since the diagnosis of pulmonary embolism is not easy to make in a schizophrenic patient, clinicians should take that in consideration when prescribing these drugs and when facing clinical situations where VTD is suspected.

The Role of Oxidative Stress in Cardiovascular Aging and Cardiovascular Diseases

Aging can be seen as process characterized by accumulation of oxidative stress induced damage. Oxidative stress derives from different endogenous and exogenous processes, all of which ultimately lead to progressive loss in tissue and organ structure and functions. The oxidative stress theory of aging expresses itself in age-related diseases. Aging is in fact a primary risk factor for many diseases and in particular for cardiovascular diseases and its derived morbidity and mortality. Here we highlight the role of oxidative stress in age-related cardiovascular aging and diseases. We take into consideration the molecular mechanisms, the structural and functional alterations, and the diseases accompanied to the cardiovascular aging process.

Revisiting One of the Dreaded Outcomes of the Current Pandemic: Pulmonary Embolism in COVID-19

Pulmonary embolism (PE) is a commonly encountered clinical entity in patients with coronavirus disease 2019 (COVID-19). Up to 1/3 of patients have been found to have PE in the setting of COVID-19. Given the novelty of the virus causing this pandemic, it has not been easy to address diagnostic and management issues in PE. Ongoing research and publications of the scientific literature have helped in dealing with COVID-19 lately and this applies to PE as well. In this article, we attempt to succinctly yet comprehensively discuss PE in patients with COVID-19 with a review of the prevailing literature.

Nonlinear, dissipative phenomena in whole blood clot mechanics

When a thrombus breaks off and embolizes it can occlude vital vessels such as those of the heart, lung, or brain. These thromboembolic conditions are responsible for 1 in 4 deaths worldwide. Thrombus resistance to embolization is driven by its intrinsic fracture toughness as well as other, non-surface-creating dissipative mechanisms. In our current work, we identify and quantify these latter mechanisms toward future studies that aim to delineate fracture from other forms of dissipation. To this end, we use an in vitro thrombus mimic system to produce whole blood clots and explore their dissipative mechanics under simple uniaxial extension, cyclic loading, and stress-relaxation. We found that whole blood clots exhibit Mullins-like effect, hysteresis, permanent set, strain-rate dependence, and nonlinear stress-relaxation. Interestingly, we found that performing these tests under dry or submerged conditions did not change our results. However, performing these tests under room temperature or body temperature conditions yielded differences. Importantly, because we use venous blood our work is most closely related to venous in vivo blood clots. Overall, we have demonstrated that whole blood clots show several dissipative phenomena - similarly to hydrogels - that will be critical to our understanding of thrombus embolization.

Factors Affecting the Formation and Treatment of Thrombosis by Natural and Synthetic Compounds

Venous thromboembolism (VTE) refers to deep vein thrombosis (DVT), whose consequence may be a pulmonary embolism (PE). Thrombosis is associated with significant morbidity and mortality and is the third most common cardiovascular disease after myocardial infarction and stroke. DVT is associated with the formation of a blood clot in a deep vein in the body. Thrombosis promotes slowed blood flow, hypoxia, cell activation, and the associated release of many active substances involved in blood clot formation. All thrombi which adhere to endothelium consist of fibrin, platelets, and trapped red and white blood cells. In this review, we summarise the impact of various factors affecting haemostatic disorders leading to blood clot formation. The paper discusses the causes of thrombosis, the mechanism of blood clot formation, and factors such as hypoxia, the involvement of endothelial cells (ECs), and the activation of platelets and neutrophils along with the effects of bacteria and reactive oxygen species (ROS). Mechanisms related to the action of anticoagulants affecting coagulation factors including antiplatelet drugs have also been discussed. However, many aspects related to the pathogenesis of thrombosis still need to be clarified. A review of the drugs used to treat and prevent thrombosis and natural anticoagulants that occur in the plant world and are traditionally used in Far Eastern medicine has also been carried out.

Post-traumatic pulmonary embolism: incidence, physiopathology, risk factors of early occurrence, and impact outcome. A narrative review

BACKGROUND

Venous thromboembolism (VTE) is a well-established complication of trauma. So far, the factors that are related to early post-traumatic pulmonary embolism (PE) occurrence have been given little attention.

AIMS

We have conducted this literature review in order to analyze the incidence and the physiopathology of post-traumatic PE among intensive care unit (ICU) trauma patients, analyze the incidence of early post-traumatic PE, and elucidate risk factors associated with post-traumatic PE. Moreover, we aim to study the impact/outcome of post-traumatic PE in the ICU.

METHODS

We used the PubMed and EMBASE databases and entered the following key words in MeSH research: Deep vein thrombosis (DVT), Post-traumatic Pulmonary embolism, Early pulmonary-embolism, risk factors, and Prognosis.

RESULTS

The incidence of PE among trauma patients varies considerably, ranging from 0.35% to 24%. The incidence of early post-traumatic PE varies widely from 10 to 42%. After a traumatic injury, many factors have been found to be responsible for the formation of DVT and PE. In addition to the risk factors of hypercoagulability described by Virchow in his original triad, inflammation acting via endothelial damage may be considered as a fourth factor. The literature review showed that lower limb fractures and age are the most frequent factors associated with PE (particularly in early PE). The heterogeneity among studies limits reliable conclusions regarding the true risk factors for the timing of the occurrence of post-traumatic PE. Fatality from pulmonary embolism (PE) is close to 50% in some series. Moreover, high mortality rates, a high rate of nosocomial infections, and a prolonged stay in an ICU and/or in a hospital were found to be associated with the development of PE.

CONCLUSION

Post-traumatic PE is frequent in ICUs. Inflammation acting via endothelial damage may be considered as a fourth factor in addition to the Virchow's triad of risk factors for venous thrombosis. Fractures of the lower extremities, obesity, and age happen to be the most frequent factors associated with PE (in particular early PE). PE development was associated with high rates of mortality, nosocomial infections, and a prolonged stay in an ICU and/or in a hospital. Therefore, prevention is warranted.

Recent advances in understanding, diagnosing and treating venous thrombosis

Focusing on the current state of the art, this article (a) describes recent advances in the understanding of the pathogenesis of venous thromboembolism (VTE), (b) discusses current approaches for the prevention, diagnosis and treatment of VTE, (c) outlines the role of aspirin for VTE prevention and treatment, and (d) highlights the unmet needs in VTE management and describes novel approaches to address them.

Aspirin with or without statin in the treatment of endotheliitis, thrombosis, and ischemia in coronavirus disease

INTRODUCTION

In the genesis of coronavirus disease (COVID-19), there is a process of endotheliitis associated with thrombotic changes, no studies have reported the use of acetylsalicylic acid (ASA) as a possible therapeutic approach. Statins could potentiate the ASA therapy.

METHODS

This is a series of 14 cases with a laboratory-confirmed diagnosis of COVID-19. All patients underwent the ASA therapy. Those who had risk factors for vascular disease also underwent the high-potency statin therapy. When symptoms were totally or practically resolved, patients were discharged and advised to continue medications for a complementary time, according to the clinical evolution of each patient.

RESULTS

The mean age of monitored patients was 48.6 years. A total of 78.6% patients presented with at least one comorbidity, which could have contributed as a risk factor for a poor prognosis in the evolution of COVID-19. Four patients had secondary bacterial infections; three patients needed hospitalization. None of the cases progress to stage III, and all patients had remission of symptoms, with 100% survival.

CONCLUSIONS

the process of endothelial dysfunction in COVID-19 involves disseminated thrombosis, initially microvascular and later expansion into larger vessels. ASA could act as a secondary prophylaxis and prevent thrombosis from developing and reaching stage III of the disease. As this was a case series, we cannot provide definitive conclusions; however, this study allows us to formulate hypotheses and support clinical trials to evaluate benefits of the ASA therapy in the treatment of COVID-19.

The role of bone marrow-derived cells in venous thromboembolism

Venous thrombosis is a life-threatening condition with high morbidity and mortality. Abnormal functioning of different cells in the blood is an integral part of its pathogenesis. In this review, we describe the contribution of bone marrow-derived cells to the development of this debilitating disease. We present both epidemiological and clinical data demonstrating involvement of various cell types in venous thrombosis, and discuss potential mechanisms underlying these effects. Modern concepts including recently discovered new paradigms in thrombosis, such as neutrophil extracellular traps, mast cells, and polyphosphate, are summarized.

The role of valve stiffness in the insurgence of deep vein thrombosis

Deep vein thrombosis is a life-threatening development of blood clots in deep veins. Immobility and blood flow stagnancy are typical risk factors indicating that fluid dynamics play an important role in the initiation of venous clots. However, the roles of physical parameters of the valves and flow conditions in deep vein thrombosis initiation have not been fully understood. Here, we describe a microfluidics in vitro method that enabled us to explore the role of valve elasticity using in situ fabrication and characterisation. In our experimental model the stiffness of each valve leaflet can be controlled independently, and various flow conditions were tested. The resulting complex flow patterns were detected using ghost particle velocimetry and linked to localised thrombus formation using whole blood and an aqueous suspension of polystyrene particles. In particular, valves with leaflets of similar stiffness had clot formation on the valve tips whereas valves with leaflets of different stiffness had clot formation in the valve pocket.

[Recommendations on antithrombotic treatment during the COVID-19 pandemic. Position statement of the Working Group on Cardiovascular Thrombosis of the Spanish Society of Cardiology]

The new coronavirus SARS-CoV-2, which gives rise to the highly contagious COVID-19 disease, has caused a pandemic that is overwhelming health care systems worldwide. Affected patients have been reported to have a heightened inflammatory state that increases their thrombotic risk. However, there is very scarce information on the management of thrombotic risk, coagulation disorders, and anticoagulant therapy. In addition, the situation has also greatly influenced usual care in patients not infected with COVID-19. This article by the Working Group on Cardiovascular Thrombosis of the Spanish Society of Cardiology aims to summarize the available information and to provide a practical approach to the management of antithrombotic therapy.

Recommendations on antithrombotic treatment during the COVID-19 pandemic. Position statement of the Working Group on Cardiovascular Thrombosis of the Spanish Society of Cardiology

The new coronavirus SARS-CoV-2, which gives rise to the highly contagious COVID-19 disease, has caused a pandemic that is overwhelming health care systems worldwide. Affected patients have been reported to have a heightened inflammatory state that increases their thrombotic risk. However, there is very scarce information on the management of thrombotic risk, coagulation disorders, and anticoagulant therapy. In addition, the situation has also greatly influenced usual care in patients not infected with COVID-19. This article by the Working Group on Cardiovascular Thrombosis of the Spanish Society of Cardiology aims to summarize the available information and to provide a practical approach to the management of antithrombotic therapy.

Worth looking! venous thromboembolism in patients who undergo preperitoneal pelvic packing warrants screening duplex

BACKGROUND

Venous thromboembolism (VTE) in patients with major pelvic fractures who undergo preperitoneal pelvic packing (PPP) has not been investigated. We hypothesized that patients who undergo PPP are at high risk for VTE, thus early prophylactic anticoagulation and screening duplex are warranted.

STUDY DESIGN

All patients requiring PPP from 2015 to 2019 were reviewed. Management and outcomes were analyzed.

RESULTS

During the study period, 79 patients underwent PPP. Excluding the early deaths, 17 patients had deep venous thrombosis (DVT) and 6 had pulmonary emboli (PE); 4 patients had both DVT/PE. Overall mortality was 15%. Thirty-two patients underwent screening duplex within 72 h of admission and 10 were positive for DVT.

CONCLUSION

Patients with complex pelvic trauma undergoing PPP have a 23% incidence of DVT and an additional 8% incidence of PE. 31% of screening ultrasounds are positive. The overall mortality was 15%. With a high incidence of VTE in this patient population, we recommend screening duplex ultrasounds.

Characteristics and risk factors of deep vein thrombosis in hemiplegic, healthy and bilateral limbs of hemiplegic patients: a 10-year retrospective study

Deep vein thrombosis (DVT) in hemiplegic patients mainly affects hemiplegic limbs, DVT can also occur only in healthy limbs, and some hemiplegic patients have DVT in both limbs. Characteristics and risk factors of DVT in hemiplegic, healthy, and bilateral limbs are unknown. To describe the proportion, risk factors, extent, and timing of DVT in hemiplegic, healthy and bilateral limbs. A 10-year retrospective review of consecutive patients was performed. DVT affected hemiplegic limbs in 34 (62%), healthy limbs in 11 (20%), and was bilateral in 10 (18%). DVT was more likely to develop in healthy limbs of hemiplegic patients without surgery (odds ratio (OR) 0.022; 95% confidence interval (CI) 0.001-0.922), and without diabetes (OR 0.023, 95% CI 0.001-0.853). Among the veins at the level of which DVT occurred, intermuscular veins represented 20 (45%) in hemiplegic, 5 (37%) in healthy, and 6 (74%) in bilateral limbs. The median time that DVT occurred after hemiplegia onset was 18 days (interquartile range [IQR] 9-79) in hemiplegic, 17 days (IQR 10-56) in healthy, and 21 days (IQR 8-27) in bilateral limbs. Early and effective prevention of DVT after surgery and optimal management of diabetes may reduce the risk of DVT in bilateral limbs. It's important to prevent proximal extension of calf vein DVT. DVT prophylaxis should be started early and continued for at least 3 weeks after hemiplegia onset.

Blood Clot Phenotyping by Rheometry: Platelets and Fibrinogen Chemistry Affect Stress-Softening and -Stiffening at Large Oscillation Amplitude

(1) Background: Together with treatment protocols, viscoelastic tests are widely used for patient care. Measuring at broader ranges of deformation than currently done will add information on a clot’s mechanical phenotype because fibrin networks follow different stretching regimes, and blood flow compels clots into a dynamic non-linear response. (2) Methods: To characterize the influence of platelets on the network level, a stress amplitude sweep test (LAOStress) was applied to clots from native plasma with five platelet concentrations. Five species were used to validate the protocol (human, cow, pig, rat, horse). By Lissajous plots the oscillation cycle for each stress level was analyzed. (3) Results: Cyclic stress loading generates a characteristic strain response that scales with the platelet quantity at low stress, and that is independent from the platelet count at high shear stress. This general behavior is valid in the animal models except cow. Here, the specific fibrinogen chemistry induces a stiffer network and a variant high stress response. (4) Conclusions: The protocol provides several thresholds to connect the softening and stiffening behavior of clots with the applied shear stress. This points to the reversible part of deformation, and thus opens a new route to describe a blood clot’s phenotype.

Chronic Obstructive Pulmonary Disease Is Associated With Higher Rates of Venous Thromboemboli Following Primary Total Knee Arthroplasty

BACKGROUND

There is discordance in the literature regarding the presence of chronic obstructive pulmonary disease (COPD) and the development of venous thromboemboli (VTEs). Therefore, the purpose of this study is to determine whether COPD patients undergoing primary total knee arthroplasty (TKA) have higher rates of (1) in-hospital lengths of stay (LOS); (2) readmissions; (3) VTEs; and (4) costs of care.

METHODS

COPD patients undergoing primary TKA were identified and matched to controls in a 1:5 ratio by age, gender, and medical comorbidities. Patients with a history of VTEs or hypercoagulable states were excluded. The query yielded 211,378 patients in the study (n = 35,230) and control (n = 176,148) cohorts. Outcomes analyzed included in-hospital LOS, readmission rates, VTEs, and costs of care. A P-value less than .01 was considered statistically significant.

RESULTS

COPD patients were found to have significantly longer in-hospital LOS (4 vs 3 days, P < .0001). Study group patients were also found to have significantly higher incidence and odds ratio (OR) of readmission rates (20.9% vs 16.3%; OR 1.36, P < .0001) and VTEs (1.75 vs .93; OR 1.18, P < .0001). Additionally, the study demonstrated that COPD patients incurred higher 90-day episode-of-care costs ($15,626.85 vs $14,471.29, P < .0001).

CONCLUSION

After adjusting for confounding variables, our study found an association between COPD and higher rates of developing VTEs following primary TKA. The study can be used by orthopedic surgeons to adequately counsel and educate these patients of the potential complications which may arise following their TKA.

Head, Neck, and Abdominopelvic Septic Thrombophlebitis: Current Evidence and Challenges in Diagnosis and Treatment

Septic thrombophlebitis (STP) is a complex, cross-disciplinary clinical condition that combines a localized infection with a neighboring venous thrombosis. STP can occur at several possible anatomic sites, such as dural sinuses, jugular vein (Lemierre syndrome), portal vein (pylephlebitis), and pelvic veins. Its high mortality in the preantibiotic era improved considerably with the introduction of modern antibiotics. However, little evidence exists to date to guide its clinical management. The incidence of STP or its risk factors may be increasing, and its mortality may still be considerable. These trends would have far-reaching implications, especially in the setting of increasing resistance to antimicrobial agents. No clinical assessment tools exist to support patient screening or guide treatment in STP. Few interventional studies exist on the efficacy and safety of anticoagulation. Recommendations on its indications, duration, and the agents of choice are mostly based on evidence derived from small observational studies. While all forms of STP pose similar challenges, future research may benefit from the distinction between bacteria-associated, virus-associated, and mycosis-associated thrombophlebitis. Addressing these gaps in evidence would enhance our ability to diagnose this condition and treat patients effectively.

Thrombin-responsive engineered nanoexcavator with full-thickness infiltration capability for pharmaceutical-free deep venous thrombosis theranostics

Although nanotechnology has shown great promise for treating multiple vascular diseases in recent years, simultaneous noninvasive detection and efficient dissolution of deep venous thrombosis (DVT) still remains challenging. In particular, long blockage areas and large thrombus thicknesses in DVT cause enormous difficulties for site-specific deep-seated thrombus theranostics. Therefore, based on the unique components of DVT, the novel concept of a thrombin-responsive full-thickness infiltration nonpharmaceutical nanoplatform for DVT theranostics is proposed here. The penetration depth is innovatively enhanced with efficient targeting and accumulation in the whole thrombi. Herein, we report a thrombin-responsive phase-transition liposome incorporating a liquid perfluoropentane (PFP) core and modified with two binding peptides, activatable cell-penetrating peptide (ACPP) and fibrin-binding ligand (FTP), which contribute to efficient liposome targeting and accumulation within the thrombi. This targeted nanoplatform is constructed to dig out the thrombus with the assistance of low-intensity focused ultrasound (LIFU), performing the destructive function of an excavator via an acoustic droplet vaporization effect (acting as a "nanoexcavator" system), which can activate and vaporize into microbubbles to enhance LIFU efficacy. The resulting microbubbles enable real-time monitoring of the therapeutic process with ultrasound imaging and high performance photoacoustic imaging after loading DIR. This non-invasive nonpharmaceutical thrombolytic strategy is an improvement over existing clinical methods without systemic side effects.

Conservative surgery for ovarian torsion in young women: perioperative complications and national trends

OBJECTIVE

To analyse populational trends and perioperative complications following conservative surgery versus oophorectomy in women <50 years of age with ovarian torsion.

DESIGN

Population-based retrospective observational study.

SETTING

Nationwide Inpatient Sample in the USA (2001-2015).

POPULATION

In all, 89 177 ovarian torsions including 20 597 (23.1%) conservative surgeries and 68 580 (76.9%) oophorectomies.

METHODS

(1) Trend analysis to assess utilisation of conservative surgery over time, (2) multivariable binary logistic regression to identify independent factors associated with conservative surgery and (3) inverse probability of treatment weighting with a generalised estimating equation to analyze perioperative complications.

MAIN OUTCOME MEASURES

Trends, characteristics and complications related to conservative surgery.

RESULTS

Performance of conservative surgery increased from 18.9 to 25.1% between 2001 and 2015 (32.8% relative increase, P = 0.001) but decreased steadily after age 15, and sharply declined after age 35 (P < 0.001). On multivariable analysis, younger age exhibited the largest effect size for conservative surgery among the independent factors (adjusted odds ratios 3.39-7.96, P < 0.001). In the weighted model, conservative surgery was associated with an approximately 30% decreased risk of perioperative complications overall (10.0% versus 13.6%, odds ratio 0.73, 95% confidence interval 0.62-0.85, P < 0.001) and was not associated with venous thromboembolism (0.2 versus 0.3%, P = 0.457) or sepsis (0.4 versus 0.3%, P = 0.638).

CONCLUSION

There has been an increasing utilisation of conservative surgery for ovarian torsion in the USA in recent years. Our study suggests that conservative surgery for ovarian torsion may not be associated with increased perioperative complications.

TWEETABLE ABSTRACT

Conservative surgery for ovarian torsion may not be associated with increased perioperative complications.

Biological Activities of Rhamnan Sulfate Extract from the Green Algae Monostroma nitidum (Hitoegusa)

Monostroma nitidum is a green single-cell layered algae that grows on the southwest coast of Japan. It is often used for salad ingredients, boiled tsukudani, soups, etc., due to its health benefits. M. nitidum is composed of many cell aggregates, and the various substances that fill the intercellular space are dietary fibers, vitamins, and minerals. Rhamnan sulfate (RS), a sulfated polysaccharide, is main the component of the fiber extracted from M. nitidum. Recently, some biological properties of RS have been demonstrated by in vitro and in vivo studies that probably protect human subjects from viruses and ameliorate vascular dysfunction caused by metabolic disorders, especially lifestyle-related diseases. In this review, we focus on the antithrombotic effects of RS and introduce its antiviral and other biological activities.

The Endothelium as a Driver of Liver Fibrosis and Regeneration

Liver fibrosis is a common feature of sustained liver injury and represents a major public health problem worldwide. Fibrosis is an active research field and discoveries in the last years have contributed to the development of new antifibrotic drugs, although none of them have been approved yet. Liver sinusoidal endothelial cells (LSEC) are highly specialized endothelial cells localized at the interface between the blood and other liver cell types. They lack a basement membrane and display open channels (fenestrae), making them exceptionally permeable. LSEC are the first cells affected by any kind of liver injury orchestrating the liver response to damage. LSEC govern the regenerative process initiation, but aberrant LSEC activation in chronic liver injury induces fibrosis. LSEC are also main players in fibrosis resolution. They maintain liver homeostasis and keep hepatic stellate cell and Kupffer cell quiescence. After sustained hepatic injury, they lose their phenotype and protective properties, promoting angiogenesis and vasoconstriction and contributing to inflammation and fibrosis. Therefore, improving LSEC phenotype is a promising strategy to prevent liver injury progression and complications. This review focuses on changes occurring in LSEC after liver injury and their consequences on fibrosis progression, liver regeneration, and resolution. Finally, a synopsis of the available strategies for LSEC-specific targeting is provided.

Circulating and tissue microRNAs as a potential diagnostic biomarker in patients with thrombotic events

Venous and arterial thrombosis are conditions that have a considerable burden if left untreated. The hypoxia-induced by the occluded vessel can disrupt the circulation of any organ, the cornerstone of treating thrombosis is rapid diagnosis and appropriate treatment. Diagnosis of thrombosis may be made by using laboratory tests or imaging techniques in individuals who have clinical manifestations of a thrombotic event. The use of serum micro ribonucleic acids (RNAs) has recently been applied to the diagnosis of thrombosis. These small RNA molecules are emerging as new diagnostic markers but have had very limited applications in vascular disease. Most of the articles provided various microRNAs with different levels of accuracy. However, there remains a lack of an appropriate panel of the most specific microRNA in the literature. The purpose of the present review was to summarize the existing data on the use of microRNAs as a diagnostic biomarker for venous thrombosis.

Understanding Inflammatory Responses in the Manifestation of Prothrombotic Phenotypes

Inflammasome complex is a multimeric protein comprising of upstream sensor protein of nucleotide-binding oligomerization domain (NOD)-like receptor family. It has an adaptor protein apoptosis-associated speck-like protein and downstream effector cysteine protease procaspase-1. Activation of inflammasome complex is body’s innate response to pathogen attack but its abnormal activation results in many inflammatory and cardiovascular disorders including thrombosis. It has displayed a prominent role in the clot formation advocating an interplay between inflammation and coagulation cascades. Therefore, elucidation of inflammasome and its molecular mechanisms in the manifestation of prothrombotic phenotypes becomes pertinent. Thrombosis is the formation and propagation of blood clot in the arterial or venous system due to several interactions of vascular and immune factors. It is a prevalent pathology underlying disorders like venous thromboembolism, stroke and acute coronary syndrome; thus, making thrombosis, a major contributor to the global disease burden. Recently studies have established a strong connection of inflammatory processes with this blood coagulation disorder. The hemostatic balance in thrombosis gets altered by the inflammatory mechanisms resulting in endothelial and platelet activation that subsequently increases secretion of several prothrombotic and antifibrinolytic factors. The upregulation of these factors is the critical event in the pathogenesis of thrombosis. Among various inflammasome, nucleotide-binding domain, leucine-rich-containing family, pyrin domain containing 3 (NLRP3) is one of the best-studied sterile inflammasome strengthening a link between inflammation and coagulation in thrombosis. NLRP3 activation results in the catalytic conversion of procaspase-1 to active caspase-1, which facilitate the maturation of interleukin-1β (IL-1β) and interleukin-18. These cytokines are responsible for immune cells activation critical for immune responses. These responses further results in endothelial and platelet activation and aggregation. However, the exact molecular mechanism related to the pathogenesis of thrombosis is still elusive. There have been several reports that demonstrate Tissue factor (TF)-mediated signaling in the production of pro-inflammatory cytokines enhancing inflammation by activating protease-activated receptors on various cells, which lead to additional cytokine expression. Therefore, it would be illuminating to interpret the inflammasomes regulation in coagulation and inflammation. This review, thus, tries to comprehensively compile emerging regulatory roles of the inflammasomes in thrombosis and discusses their molecular pathways in the manifestation of thrombotic phenotypes.

The risk of lower-limb superficial vein thrombosis relative to lower-limb venous thrombotic events is not increased in winter months

OBJECTIVES

Ambient temperature (that impacts differently venous flow in superficial and deep veins) could have a different effect on the risk of superficial and deep venous thrombosis. We searched for a trimestral variation of the risk of superficial venous thrombosis among all lower-limb thrombotic events (lower-limb thrombotic events = superficial venous thrombosis + deep venous thrombosis).

METHODS

We retrospectively analyzed the results of venous ultrasound investigations performed among 11,739 patients (aged 67 ± 19 years old, 56.1% males) referred for suspected lower-limb thrombotic events over a 12-year period. Chi-square test was used to compare the superficial venous thrombosis/lower-limb thrombotic events ratio observed by trimesters to a homogeneous distribution.

RESULTS

The proportion of lower-limb thrombotic events were 30.7%, 28.8%, 31.1%, and 31.4% (Chi²: 0.133; p = 0.987) of total investigations, while that of superficial venous thrombosis among all lower-limb venous thrombotic events were 27.2%, 30.0%, 31.4%, and 31.0%, for the first, second, third, and fourth trimesters respectively (Chi²: 0.357; p: 0.949).

CONCLUSION

No trimestral variation of the superficial venous thrombosis/lower-limb venous thrombotic events ratio was observed.