Acute venous disease: Venous thrombosis and venous trauma

Evaluating thromboprophylaxis in the sickle cell disease population: Navigating the evidence gap

Sickle cell disease (SCD) arises from beta-globin gene mutations, with global estimates indicating around 500 000 affected neonates in 2021. In the United States, it is considered rare, impacting fewer than 200 000 individuals. The key pathogenic flaw lies in mutant haemoglobin S, prone to polymerization under low oxygen conditions, causing erythrocytes to adopt a sickled shape. This leads to complications like vascular occlusion, haemolytic anaemia, inflammation and organ damage. Beyond erythrocyte abnormalities however, there is a body of literature highlighting the hypercoagulable state that is likely a contributor to many of the complications we see in SCD. The persistent activation of the coagulation cascade results in thromboembolic events, notably venous thromboembolism (VTE) which is independently associated with increased mortality in both adults and children with SCD. While the increased risk of VTE in the SCD population seems well established, there is a lack of guidelines for thromboprophylaxis in this population. This Wider Perspective will describe the hypercoagulable state and increased thrombosis risk in the SCD population, as well as advocate for the development of evidence-based guidelines to aid in the prevention of VTE in SCD.

Obesity-Related Traits Mediate the Effects of Educational Attainment on the Risk of Varicose Veins, Venous Thromboembolism, and Phlebitis

BACKGROUND

 The extent to which educational attainment (EA) influences the risk of varicose veins (VVs), venous thromboembolism (VTE), and phlebitis occurrence, whether this pathway is mediated by obesity-related traits, and the proportion of their mediation is unknown.

METHODS

 A Mendelian randomization (MR) design was used to genetically investigate the causal effects of EA on the risk of VV, VTE, and phlebitis and to assess the mediating effect of obesity-related traits. Causal effects were estimated using primarily the multiplicative random-effects inverse variance-weighted method. This was supplemented by Cochran's Q-statistic, MR-Egger regression, MR funnel plots, and leave-one-out test to evaluate the reliability of the results. For the individual mediation effect, the coefficient product method was mainly utilized to estimate.

RESULTS

 An increase in genetically predicted EA was associated with a lower risk of VV, VTE, and phlebitis, as well as lower body mass index, basal metabolic rate, hip circumference, and waist circumference. As genetically predicted body mass index, basal metabolic rate, hip circumference, and waist circumference increased, the risk of developing VV, VTE, and phlebitis increased, respectively. Body mass index, basal metabolic rate, hip circumference, and waist circumference were identified as mediators of the protective effects of EA on VV, VTE, and phlebitis.

CONCLUSION

 The findings support a causal relationship between higher EA and lower risk of VV, VTE, and phlebitis. Obesity-related traits play a significant mediating role in these pathways, and there are interactions between them, with hip circumference mediating these pathways relatively independently from the other three.

Penetrating injury of the common femoral vein followed by local deep vein thrombosis: A case report

This case report discusses a unique scenario in which a 19-year-old patient with a penetrating wound in the common femoral vein developed deep vein thrombosis in response to life-threatening bleeding. The report highlights our thoughts on managing an isolated truncal venous injury leading to deep vein thrombosis, emphasizing the significance of surgical exploration in vascular trauma and the feasibility of employing non-invasive imaging diagnosis in preoperative planning.

Risk factors for venous thromboembolism in a single pediatric intensive care unit in China

BACKGROUND

Analyses of extensive, nationally representative databases indicate a rising prevalence of venous thromboembolism (VTE) among critically ill children. However, the majority of studies on childhood VTE have primarily concentrated on Caucasian populations in the United States and European countries. There is a lack of epidemiological studies on VTE in Chinese children.

METHODS

We conducted a retrospective cohort study of data from the Pediatric Intensive Care (PIC) database. Data were obtained and extracted by using Structured Query Language (SQL) and the administrative platform pgAdmin4 for PostgreSQL. Bivariate analyses were conducted in which categorical variables were analyzed by a chi-square test and continuous variables were analyzed by a Student's t-test. Separate multivariable logistic regressions were employed to investigate the associations between VTE and sociodemographic factors as well as clinical factors.

RESULTS

Our study included 12,881 pediatric patients from the PIC database, spanning the years 2010 to 2018. The incidence rate of pediatric VTE was 0.19% (24/12,881). The venous thrombotic locations were deep venous thrombosis extremities (n = 18), superior vena cava (n = 1), cerebral sinovenous (n = 1), and other deep venous thrombosis (n = 4). Univariate analysis showed that age, weight, shock, sepsis, cancer and vasopressor receipt were statistically significant risk factors for pediatric VTE (all p ≤ 0.05). After multivariable logistic regression analysis, only shock (aOR: 6.77, 95%CI: 1.33-34.73, p = 0.019) and admission for sepsis (aOR: 6.09, 95%CI: 1.76-21.09, p = 0.004) were statistically significant associated with pediatric VTE.

CONCLUSIONS

In conclusion, data obtained from the Pediatric Intensive Care (PIC) database revealed a prevalence of VTE in pediatric patients of 0.19%. The most common location for venous thrombi was deep venous thrombosis (DVT) in the extremities. We identified that shock and sepsis were statistically significant factors associated with pediatric VTE.

Superficial Venous Thrombosis: A Comprehensive Review

Superficial venous thrombosis (SVT), an inflammatory-thrombotic process of a superficial vein, is a relatively common event that may have several different underlying causes. This phenomenon has been generally considered benign, and its prevalence has been historically underestimated; the estimated incidence ranges from about 0.3 to 1.5 event per 1000 person-years, while the prevalence is approximately 3 to 11%, with different reports depending on the population studied. However, such pathology is not free of complications; indeed, it could extend to the deep circulation and embolize to pulmonary circulation. For this reason, an ultrasound examination is recommended to evaluate the extension of SVT and to exclude the involvement of deep circulation. Also, SVT may be costly, especially in the case of recurrence. Therefore, accurate management is necessary to prevent sequelae and costs related to the disease. This review aims to analyse the epidemiology of SVT, its complications, optimal medical treatment, and open questions with future perspectives.

In Vivo Porcine Model of Acute Iliocaval Deep Vein Thrombosis

CLINICAL IMPACT

The study establishes a rapid, technically straightforward, and reproducible porcine large animal model for acute iliocaval deep vein thrombosis (DVT). The procedure can be performed with basic endovascular skillsets. With its procedural efficiency and consistency, the platform is promising for comparative in vivo testing of venous thrombectomy devices in a living host, and for future verification and validation studies to determine efficacy of novel thrombectomy devices relative to predicates.

Diagnosis and treatment of venous thromboembolism and clinical application of inferior vena cava filter in China

OBJECTIVE

This study investigated the trend of venous thromboembolism (VTE) in China during the past 10 years and assessed the clinical application of inferior vena cava filters (IVCFs).

METHODS

A survey designed to investigate the diagnosis and management of VTE, specifically the application of IVCFs, was distributed nationally from January 2009 to December 2019. The respondents were mainly designated medical professionals and were asked to complete 4 major and 61 minor items in the survey.

RESULTS

A total of 53 medical centers, including 27 radiologic and 26 vascular surgery centers, from 21 provinces in China participated in the study. These centers had diagnosed and treated 171,310 patients with VTE; 83,969 were inpatients (49%). During a 10-year period, an increasing trend of VTE diagnosis and inpatient management, 3.8-fold and 4.8-fold, respectively, was observed. The characteristics of the inpatients were as follows: 15% bilateral lower extremity deep vein thrombosis (DVT), 27% right lower extremity DVT, and 58% left lower extremity DVT. Anticoagulation therapy included unfractionated heparin with vitamin K antagonists (8%), low-molecular-weight heparin (LMWH) with vitamin K antagonists (21%), LMWH with transition to rivaroxaban (34.2%), LMWH with transition to dabigatran (2.4%), rivaroxaban alone (33.4%), and dabigatran alone (1.0%). The percentage of patients continuing anticoagulation therapy at 3, 6, 12, 24, and >24 months was 36%, 35%, 18%, 6.0%, and 5%, respectively. The in-hospital mortality for the patients with VTE was 3.2%, with DVT and pulmonary embolism responsible for 5.2% and DVT alone for 2.7%. Thrombolytic therapy was initiated for 39,046 of 83,969 patients (46.5%), including catheter-directed thrombolysis for 33,189 of the 39,046 patients (85%) and evaluation of the iliac vein using ultrasound and/or venography for 63,816 patients (76%). Urokinase was the main thrombolytic drug used (98%), followed by recombinant tissue-type plasminogen activator. Complete and partial thrombolysis was achieved in 70% and 30% of the patients, respectively. Bleeding complications were observed in 3.5% of patients, and 20% of the patients with bleeding complications required intervention. Between 2009 and 2019, 40,478 IVCFs (76% retrievable) were implanted in hospitalized VTE patients. During the enrollment period, the total number of IVCFs implanted increased by 3.8-fold, with a 4.8-fold increase in retrievable IVCFs and 7.5-fold decline in permanent IVCFs. The removal rate for the retrievable IVCFs was 72%. After IVCF implantation, 94.8% of patients received anticoagulation therapy for an average of 9.1 ± 8.6 months. The overall complication rate associated with IVCF placement was 15.5% (n = 6274 of 40,478 IVCFs), including tilting (54%), vena cava thrombosis (26.1%), caval penetration (12.6%), and migration (7.3%). No IVCF placement-related mortality occurred.

CONCLUSIONS

A significant increase occurred in VTE diagnosis in China during the past decade. Anticoagulation therapy was the mainstay treatment, and catheter-directed thrombolysis was widely used. Most IVCFs placed were retrievable, and the use of permanent IVCFs has largely been discarded.

A nomogram model based on the combination of the systemic immune-inflammation index, body mass index, and neutrophil/lymphocyte ratio to predict the risk of preoperative deep venous thrombosis in elderly patients with intertrochanteric femoral fracture: a retrospective cohort study

OBJECTIVES

Deep vein thrombosis (DVT) has been considered as a frequent and serious consequence of intertrochanteric femoral fractures in the elderly. Several negative repercussions of DVT can be considerably mitigated by its timely recognition and treatment. The current work was aimed at exploring the factors independently predicting DVT among cases suffering from intertrochanteric femoral fractures and validate their predictive usefulness in diagnosing DVT.

METHODS

Between April 2017 and July 2022, clinical information from 209 cases showing preoperative DVT for femoral intertrochanteric fractures were retrospectively evaluated. In patients with femoral intertrochanteric fractures, logistic regression analysis with a backward stepwise method was adopted for detecting independent predictors for the diagnosis of preoperative DVT. Using multivariate logistic regression, a nomogram prediction model was developed and verified with the testing group.

RESULTS

According to multivariate logistic regression model, body mass index (BMI) (OR 0.79, 95% CI 0.63-0.99, P = 0.042), neutrophil/lymphocyte ratio (NLR) (OR 7.29, 95% CI 1.53, 34.64, P = 0.0012), and systemic immune-inflammation index (SII) (OR 6.61, 95% CI 2.35, 18.59, P = 0.001) were independent predictors for DVT before surgery among cases developing intertrochanteric femoral fracture. AUC values were 0.862 and 0.767 for training and testing groups, separately, while their mean errors in the calibration curve were 0.027 and 0.038 separately. Decision curve analysis (DCA) curve revealed a high value of clinical application for both groups.

CONCLUSION

Upon admission, BMI, NLR, and SII are independent predictors of DVT before surgery among cases developing intertrochanteric femoral fractures. Additionally, the nomogram based on the BMI, NLR, and SII can assist clinicians in determining if preventive and symptomatic therapies are required to improve DVT prognosis and reduce its associated mortality.

Back To Basics: Theory of Thrombus Formation and Potential Implications for Therapies?

Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), is a common and potentially fatal condition. Despite existing treatments, recurrence rates and complications remain high. Understanding the pathophysiology of thrombus formation is crucial for developing effective therapies. This narrative review provides an overview of the critical elements of acute and chronic DVT, presents a theoretical framework for understanding thrombus formation, and discusses potential implications for therapeutic interventions. In addition, a hypothesis of thrombus formation is formulated, encompassing all elements described in this work.

Varicose veins as a risk factor for venous thromboembolism in arthroplasty patients: Meta-analysis

OBJECTIVE

A meta-analysis to determine if patients with varicose veins are at an increased risk of venous thromboembolism (VTE) when undergoing major lower limb arthroplasty.

METHODS

Medline, Embase, and Cochrane Library databases were searched using appropriate terms for studies that reported post-operative VTE in patients who had lower limb arthroplasty with any history of varicose veins. Methodological quality of included studies was quantified using the Risk of Bias (ROB) assessment tools. Findings were reported using the meta-analysis of observational studies in epidemiology (MOOSE) checklist.

RESULTS

A total of 129 studies were identified with 11 observational studies being eligible for inclusion. This consisted of 265,194 patients who underwent lower limb arthroplasty, 2188 of which had pre-existing varicose veins. Overall, VTE occurred in 1845 patients, and 122 cases had varicose veins present at time of arthroplasty. Meta-analysis indicates that patients undergoing lower limb arthroplasty with varicose veins are at increased risk of having a VTE, OR 2.37, 95% CI 1.54-3.63, (p < 0.001). One study evaluated if previous varicose veins surgery influenced the risk of VTE in arthroplasty patients, OR 0.96 (95% CI 0.7-1.28), p = 0.429.

CONCLUSIONS

Varicose veins and lower limb arthroplasty are known independent risk factors for VTE. There is a paucity of data regarding the risk of VTE in patients undergoing lower limb arthroplasty who have co-existing varicose veins. This meta-analysis shows that patients with varicose veins are at an increased risk of VTE when undergoing major lower limb arthroplasty. Further studies are required in order to determine if such patients should undergo varicose vein surgery before undertaking major lower limb joint replacement.

Appearance and Frequency of Deep Venous Thrombosis After Total Hip Arthroplasty

Objectives

Postoperative venous thromboembolism is an important peri-operative complication associated with total hip arthroplasty (THA). In particular, early detection of deep venous thrombosis (DVT) is important for the prevention of pulmonary embolism (PE). However, the methods and timing of examinations for DVT detection differ among the facilities. This study aimed to clarify the time, site, and frequency of DVT after THA.

Materials and Methods

Background characteristics including age, sex, body mass index, diagnosis, operation type, operation time, and anesthesia type were investigated in 348 patients who underwent THA at our hospital between April 2017 and April 2019. Blood tests were performed preoperatively and on postoperative days (POD) 0, 1, 3, 7, 14, and 21. Simultaneously, vascular ultrasonography was performed to investigate the time and site of thrombus occurrence before and after the surgery.

Results

DVT was observed in 27.2% of the patients on POD 21. The DVT-positive ratio was 9.4% (6/64) in males and 31.3% (89/284) in females. There was a significant difference between the groups (p = 0.0002). Patients in the DVT-positive group were significantly older than those in the DVT-negative group (73.0 ± 7.9 years vs. 63.3 ± 11.2 years, p = 0.0041). DVT mainly occurred in the soleal vein (74.7%). However, there was no significant difference between the operated and non-operated sides. In the DVT-positive group, thrombus occurred in 13.3% of preoperative cases, 20.0% on POD 0, 46.7% on POD 1, 13.3% on POD 3, 6.7% on POD 7, and 0% on POD 14 and 21.

Conclusions

Vascular ultrasonography showed that thrombus occurred most frequently in the soleal vein. Thrombus occurred in 66.6% of DVT-positive patients by POD 1, indicating that thrombus appeared very early after surgery. All thrombus cases were formed by POD 7.

Analysis of high-risk factors for preoperative DVT in elderly patients with simple hip fractures and construction of a nomogram prediction model

BACKGROUND

Hip fractures are anatomically classified in relation to femoral neck, intertrochanteric or subtrochanteric fractures. Simple hip fractures discussed in this study are femoral neck fractures or intertrochanteric fractures, which are the most common types of hip fractures. Controversy remains regarding the value of biochemical indices of thrombosis in elderly patients with fractures. A retrospective study was conducted to investigate the index admission data in blood draws of elderly patients with hip fractures and their high-risk factors for deep venous thrombosis (DVT). A nomogram prediction model for DVT was established to facilitate a rapid, accurate, and effective prediction based on the results.

METHODS

The data were based on 562 elderly patients undergoing hip fracture surgery, from whom 274 patients were selected for enrollment. The 274 patients were divided into two groups using preoperative vascular color Doppler ultrasonography. Chi-square tests, t-tests, and U tests were conducted, and logistic regression analysis was conducted showing different factors between the two groups. Independent risk factors with statistical significance (P < 0.05) were obtained, and the logistic regression equation and the new variable prediction probability_1 (PRE_1) were constructed. The receiver operating characteristic (ROC) curve of risk factors and PRE_1 was drawn to obtain the area under the curve (AUC) and truncation value of each risk factor. Finally, a nomogram prediction model was constructed using the R programming language to calculate the concordance index (C-index).

RESULTS

Time from injury to hospitalization, platelet (PLT) count, D-dimer level, fibrinogen (FIB) level, and systemic immune-inflammatory index (SII) score were independent risk factors for preoperative DVT in elderly patients with hip fractures. The logistic regression equation and PRE_1 were constructed by combining the above factors. ROC analysis showed that the area under the curve for PRE_1 (AUC = 0.808) was greater than that of the other factors. The sensitivity of PRE_1 (sensitivity = 0.756) was also higher than that of the other factors, and the specificity of PRE_1 (specificity = 0.756) was higher than that of two other factors. Moreover, a predictive nomogram was established, and the results showed a high consistency between the actual probability and the predicted probability (C-index = 0.808), indicating a high predictive value in fractures accompanied by DVT.

CONCLUSIONS

This study confirmed that SII score could be used as a risk factor in the prediction of DVT occurrence. A nomogram prediction model was constructed by combining 5 independent risk factors: time from injury to admission, PLT count, D-dimer level, FIB level, and SII score, which had high predictive values for fractures accompanied by DVT. This model use is limited to simple hip fracture.

Large-scale correlation analysis of deep venous thrombosis and gut microbiota

Objective

Although previous studies have shown that gut microbiota may be involved in the occurrence of deep venous thrombosis (DVT), the specific link between the two remains unclear. The present study aimed to explore this question from a genetic perspective.

Materials and methods

Genome-wide association study (GWAS) summary data of DVT were obtained from the UK Biobank (N = 9,059). GWAS summary data of the gut microbiota were obtained from the Flemish Gut Flora Project (N = 2,223) and two German cohorts (FoCus, N = 950; PopGen, N = 717). All the participants were of European ancestry. Linkage disequilibrium score (LDSC) regression has great potential for analyzing the heritability of disease or character traits. LDSC regression was used to analyze the genetic correlation between DVT and the gut microbiota based on the GWAS summary data obtained from previous studies. Mendelian randomization (MR) was used to analyze the genetic causal relationship between DVT and the gut microbiota. We used the random effects inverse variance weighted, MR Egger, weighted median, simple mode, and weighted mode to perform MR analysis. We performed a sensitivity analysis of the MR analysis results by examining heterogeneity and horizontal pleiotropy.

Results

Linkage disequilibrium score analysis showed that Streptococcaceae (correlation coefficient = -0.542, SE = 0.237, P = 0.022), Dialister (correlation coefficient = -0.623, SE = 0.316, P = 0.049), Streptococcus (correlation coefficient = -0.576, SE = 0.264, P = 0.029), and Lactobacillales (correlation coefficient = -0.484, SE = 0.237, P = 0.042) had suggestive genetic correlation with DVT. In addition, the MR analysis showed that Streptococcaceae had a positive genetic causal relationship with DVT (P = 0.027, OR = 1.005). There was no heterogeneity or horizontal pleiotropy in the MR analysis (P > 0.05).

Conclusion

In this study, four gut microbes (Streptococcaceae, Dialister Streptococcus, Lactobacillales) had suggestive genetic correlations with DVT, and Streptococcaceae had a positive causal relationship with DVT. Our findings provide a new research direction for the further study of and prevention of DVT.

Oberflächliche Venenthrombose der Beinvenen – Eine systematische Übersicht – Teil 1: Definition, Ätiologie, Diagnostik

Einleitung Die oberflächliche Venenthrombose (OVT) der Beinvenen ist mit einer Inzidenz von 0,5–1/1000 Einwohner/Jahr ein häufiges und mit einer Frequenz assoziierter thromboembolischer Ereignisse in bis zu 25 % der Fälle ein ernst zu nehmendes Krankheitsbild. In der vorliegenden Übersichtsarbeit sollen alle relevanten Aspekte der OVT basierend auf der aktuellen wissenschaftlichen Literatur behandelt werden.

Methoden Die systematische Übersicht umfasst das Wissen über die OVT basierend auf dem gesamten, systemisch recherchierten Erkenntnismaterial in den Datenbanken PubMed und Google Scholar. Eine Literaturrecherche in PubMed von Publikationen (1968–2018) mit den Suchbegriffen „Superficial vein thrombosis; thrombophlebitis“ ergab 102 aussagekräftige Arbeiten, die nach Vorlage der Originalarbeit ausgewertet wurden. Teil 1 der Arbeit behandelt Aspekte zur Definition, Klassifikation, Ätiologie und Diagnostik.

Ergebnisse Die OVT manifestiert sich klinisch neben den typischen Entzündungszeichen als strangförmige Induration, die Ausdruck eines thrombotischen Verschlusses epifaszialer Venen ist. Ätiologisch bedeutsam ist das Vorhandensein von Varikose (68 % der Fälle), Adipositas (23 %), Gerinnungsstörungen (18 %) und Tumorleiden (8 %). Das Durchschnittsalter der Betroffenen beträgt 62 Jahre, in 60 % der Fälle sind Frauen betroffen. Zunehmendes Lebensalter ist ein relevanter Risikofaktor. Diagnostisch ist es wichtig, das genaue Ausmaß der OVT zu beschreiben, insbesondere die Thrombuslänge und die Entfernung zum tiefen Venensystem. Dies, einschließlich der Beurteilung des tiefen Beinvenensystems, sollte bei jedem Patienten mit möglicher OVT zeitnah mittels Ultraschalldiagnostik erfolgen. Eine hier vorgeschlagene Klassifikation von 4 Ausprägungsgraden der OVT kann die Zuordnung zur aktuell empfohlenen Therapie erleichtern.

Schlussfolgerung Aufgrund der Häufigkeit und des Risikos potenziell lebensbedrohender Komplikationen sollte der OVT der Beinvenen eine größere Beachtung zukommen, insbesondere mit Blick auf eine spezialisierte Diagnostik durch Phlebologen.

Anatomical consideration of deep calf veins: application to catheter-directed thrombolysis

Purpose

An antegrade approach is frequently used in catheter-directed thrombolysis to remove deep-vein thrombosis. However, the antegrade approach is difficult when accessing veins with small diameters; therefore, understanding the variation of deep calf vein is important.

Methods

This study measured the diameters and surface areas of the proximal and distal posterior tibial vein, peroneal vein, and anterior tibial vein to determine which are preferable for venous access. This study dissected 132 legs from Korean and Thai cadavers. The proximal and distal posterior tibial vein, peroneal vein, and anterior tibial vein were scanned and measured.

Results

The mean diameter and surface area were largest for the proximal tibial vein, at 6.34 mm and 0.312 cm², respectively, followed by the anterior tibial vein (5.22 mm and 0.213 cm²), distal posterior tibial vein (3.29 mm and 0.091 cm²), and peroneal vein (3.43 mm and 0.081 cm²). The proximal posterior tibial vein and anterior tibial vein have large diameters and surface areas, which make them ideal for applying an antegrade approach in catheter-directed thrombolysis.

Conclusions

The distal posterior tibial vein and peroneal vein are not recommended due to their smaller surface areas and also the anatomical variations therein.

Understanding Chronic Venous Disease: A Critical Overview of Its Pathophysiology and Medical Management

Chronic venous disease (CVD) is a multifactorial condition affecting an important percentage of the global population. It ranges from mild clinical signs, such as telangiectasias or reticular veins, to severe manifestations, such as venous ulcerations. However, varicose veins (VVs) are the most common manifestation of CVD. The explicit mechanisms of the disease are not well-understood. It seems that genetics and a plethora of environmental agents play an important role in the development and progression of CVD. The exposure to these factors leads to altered hemodynamics of the venous system, described as ambulatory venous hypertension, therefore promoting microcirculatory changes, inflammatory responses, hypoxia, venous wall remodeling, and epigenetic variations, even with important systemic implications. Thus, a proper clinical management of patients with CVD is essential to prevent potential harms of the disease, which also entails a significant loss of the quality of life in these individuals. Hence, the aim of the present review is to collect the current knowledge of CVD, including its epidemiology, etiology, and risk factors, but emphasizing the pathophysiology and medical care of these patients, including clinical manifestations, diagnosis, and treatments. Furthermore, future directions will also be covered in this work in order to provide potential fields to explore in the context of CVD.

Acquired antithrombin deficiency is a risk factor for venous thromboembolism after major trauma

BACKGROUND

Up to 30% of severely injured patients on prophylactic anticoagulation experience venous thromboembolism (VTE). Our previous work shows that acquired antithrombin (AT) deficiency [AT<80%] occurs in approximately 20% of trauma patients upon admission and drives poor responsiveness to enoxaparin. However, changes in AT over time and its association with VTE remain unknown. The aim of this study was to determine the relationship between acquired AT deficiency and VTE in severely injured patients.

METHODS

A secondary analysis of the Pragmatic, Randomized Optimal Platelet and Plasma Ratios (PROPPR) clinical trial was performed. Patients who died within 24 h of hemorrhage were excluded from analysis. Demographics, mechanism and severity of injury, transfusions volumes, and outcomes were compared between patients who did and did not develop VTE. Non-parametric statistical tests were used to compare patients with and without VTE. Logistic regression analyses were performed to identify predictors of VTE risk, controlling for AT deficiency (over first 72 h), age, gender, race, body mass index, study site, randomization group and injury severity. A Cox proportional hazards model was used to assess the contribution of AT deficiency to the risk of VTE, while censoring for early deaths.

RESULTS

Of the 680 patients enrolled in PROPPR, 101 died of hemorrhage. Of the remaining 579 patients, 86 (14.9%) developed VTE. The median time to VTE was 6 days (IQR 3, 13). No differences in demographics, injuries, or transfusion volumes were identified between VTE cases and controls. AT deficiency at 72 h post-admission was independently associated with VTE. Patients who experienced AT deficiency at 72 h had a 3.3 fold increased risk of VTE [p < 0.01; 95% CI 1.56, 6.98]. Lastly, patients who developed VTE had worse outcomes as displayed by significantly fewer hospital-free days compared to non-VTE patients [0 (0, 8) vs. 4 (0, 18), p < 0.01, respectively].

CONCLUSIONS

Acquired AT deficiency (AT<80%) is an important risk factor for VTE in severely injured patients. These data indicate that intervening, perhaps through AT supplementation, in the first three days after injury could mitigate the risk of VTE and improve patient outcomes.

Targeting Contrast Agents With Peak Near-Infrared-II (NIR-II) Fluorescence Emission for Non-invasive Real-Time Direct Visualization of Thrombosis

Thrombosis within the vasculature arises when pathological factors compromise normal hemostasis. On doing so, arterial thrombosis (AT) and venous thrombosis (VT) can lead to life-threatening cardio-cerebrovascular complications. Unfortunately, the therapeutic window following the onset of AT and VT is insufficient for effective treatment. As such, acute AT is the leading cause of heart attacks and constitutes ∼80% of stroke incidences, while acute VT can lead to fatal therapy complications. Early lesion detection, their accurate identification, and the subsequent appropriate treatment of thrombi can reduce the risk of thrombosis as well as its sequelae. As the success rate of therapy of fresh thrombi is higher than that of old thrombi, detection of the former and accurate identification of lesions as thrombi are of paramount importance. Magnetic resonance imaging, x-ray computed tomography (CT), and ultrasound (US) are the conventional non-invasive imaging modalities used for the detection and identification of AT and VT, but these modalities have the drawback of providing only image-delayed indirect visualization of only late stages of thrombi development. To overcome such limitations, near-infrared (NIR, ca. 700-1,700 nm) fluorescence (NIRF) imaging has been implemented due to its capability of providing non-invasive real-time direct visualization of biological structures and processes. Contrast agents designed for providing real-time direct or indirect visualization of thrombi using NIRF imaging primarily provide peak NIR-I fluorescence emission (ca. 700-1,000 nm), which affords limited tissue penetration depth and suboptimal spatiotemporal resolution. To facilitate the enhancement of the visualization of thrombosis via providing detection of smaller, fresh, and/or deep-seated thrombi in real time, the development of contrast agents with peak NIR-II fluorescence emission (ca. 1000-1,700 nm) has been recently underway. Currently, however, most contrast agents that provide peak NIR-II fluorescence emissions that are purportedly capable of providing direct visualization of thrombi or their resultant occlusions actually afford only the indirect visualization of such because they only provide for the (i) measuring of the surrounding vascular blood flow and/or (ii) simple tracing of the vasculature. These contrast agents do not target thrombi or occlusions. As such, this mini review summarizes the extremely limited number of targeting contrast agents with peak NIR-II fluorescence emission developed for non-invasive real-time direct visualization of thrombosis that have been recently reported.

A systematic review and meta-analysis of the treatment of obstructive chronic deep venous disease using dedicated venous stents

OBJECTIVES

This review aims to summarise the efficacy and safety of dedicated venous stenting for the treatment of obstructive chronic deep venous disease. The approaches to stenting and post-procedural management of different vascular units are also highlighted.

METHODS

MEDLINE and Embase were searched to identify relevant literature on dedicated venous stents published from January, 2010 to May, 2020. The patient population and study characteristics; procedural characteristics; and outcomes related to post-stenting symptoms, health-related quality of life, patency and complications were analysed.

RESULTS

Sixteen single-arm observational studies were included from 2,366 studies identified from key-word searches. In total, 1,688 patients were included, of which 70.5% had post-thrombotic syndrome and the remainder had non-thrombotic iliac vein lesions. Nine studies (n = 848), stated whether lesions were stenotic (36.6%) or occlusive (63.4%). Seven studies did not report the lesion characteristics (n = 840). Eight different dedicated venous stent brands were employed. 73.4% of ulcers healed at last follow-up. The remaining symptomatic changes were described narratively; sustained improvements in pain, venous claudication and oedema following stenting were observed. Significant post-stenting improvements in health-related quality of life were noted, as measured by the Chronic Venous Insufficiency Questionnaire-20 instrument. Overall, the most frequently reported complications were in-stent occlusion (n = 204), in-stent stenosis (n = 149) and minor bleeding (n = 77). At 12 months, the primary patency ranged from 59% to 94%, whilst the secondary patency ranged 87% to 100%. The pooled-primary and secondary stent patency rates at 12 months were 74.0% and 90.4%, respectively. The incidence of major and minor bleeding was 1.9% and 4.7%, respectively; bleeding complications were more common in patients undergoing hybrid intervention.

CONCLUSION

Deep venous stenting using dedicated venous stents is a safe technique to treat obstructive chronic deep venous disease and within the limitations of this study, is associated with good patency outcomes and symptomatic improvement.

Is variation in posterior tibial veins a risk factor for deep-vein thrombosis?

INTRODUCTION

This study proposes variations in the posterior tibial vein as one of the risk factors for deep-vein thrombosis. Understanding the anatomical classification of the posterior tibial vein would guide the antegrade approach of catheter-directed thrombolysis.

MATERIALS AND METHODS

One hundred thirty-four legs from Korean and Thai cadavers were dissected. The posterior tibial veins were classified into four types according to the number of proximal and distal veins.

RESULTS

The most common type was type Ia (64/134), followed by type IIa (28/134), type Ib (24/134), and type IIb (16/134).

CONCLUSIONS

The anterior tibial and fibular veins had exactly two paired veins; however, the posterior tibial vein had many variations. We assume that patients with type IIb and IIa have a higher risk of thrombosis and hidden symptoms due to collateral formation. Additionally, the classification of the posterior tibial vein and dividing into proximal and distal posterior tibial vein would help practitioners predict the course and guide the application of catheter-directed thrombolysis.

Imaging primer for CT angiography in peripheral vascular trauma

The use of computed tomography angiography (CTA) for the evaluation of peripheral vascular trauma has become increasingly prevalent in the past decade with the development of multidetector CT (MDCT) and multiple studies subsequently demonstrating high sensitivity, specificity, and diagnostic accuracy when compared with conventional angiography. Additional benefits of MDCT include the ability to rapidly acquire the images, perform multiplanar and 3D reconstructions, and assess the adjacent soft tissues and bones. Rapid intravenous injection of iodinated contrast material is required for optimal arterial enhancement. CTA manifestations of an arterial injury may be direct, and include active contrast extravasation, pseudoaneurysm, arteriovenous fistula (AVF), intimal injury, dissection, or occlusion. There are also indirect signs which have a high association with vascular injury, and should raise suspicion, when present. Pitfalls related to image acquisition or patient factors can be mitigated with appropriate planning and post-processing techniques.

Coagulation factor XIII-A and activated FXIII-A decrease in some deep vein thrombosis patients following catheter-directed thrombolysis

: The objective of the study was to assess the effect of tissue plasminogen activator administered during catheter-directed thrombolysis (CDT) on coagulation factor XIII (FXIII). Thrombolytic therapy carries significant risks, such as life-threatening bleeds. The mechanisms responsible for major bleeds and intracerebral hemorrhages during thrombolysis are not fully understood. Activated FXIII (FXIII-A) lies at the intersection of coagulation and fibrinolysis. Using purified proteins and blood collected from nine deep vein thrombosis patients undergoing CDT, the stability of FXIII-A and FXIII were measured immediately before, immediately after and 1-day post thrombolysis. We found that purified tissue plasminogen activator directly degraded FXIII-A. During CDT, FXIII levels were decreased by more than 40% in five of nine patients and FXIII-A levels were decreased by more than 85% in two patients when it was activated. FXIII-A and FXIII-A can decrease during CDT in some patients, warranting further research into the role of FXIII-A in bleeding from thrombolysis.

Aspiration thrombectomy for acute iliofemoral or central deep venous thrombosis

OBJECTIVE

The use of catheter-directed thrombolysis (CDT) may provide clinical benefit in patients with acute deep venous thrombosis (DVT), but significant doubt remains about its indications and risks. We assessed technical success in resolution of acute iliofemoral or central DVT after single-session treatment with a novel mechanical aspiration thrombectomy device as an alternative to initiation of CDT.

METHODS

This was a single-center retrospective review of patients with acute iliofemoral or central DVT treated with the Indigo continuous aspiration mechanical thrombectomy 8 system (Penumbra, Inc, Alameda, Calif) from 2016 to 2017. The primary outcome was technical success, defined as resolution of >70% of thrombus without need for postaspiration CDT, as an initial or adjunctive treatment. Secondary end points included DVT recurrence and treatment complications.

RESULTS

There were 10 patients (50% male) with a median age of 44 years (range, 19-68 years). Indication for treatment was DVT (n = 4), recurrent DVT (n = 1), stent thrombosis (n = 3), high-grade extrinsic narrowing of the inferior vena cava (IVC) due to immunoglobulin G4-related disease (n = 1), and IVC obstruction from liver tumor invasion (n = 1). Five patients had underlying May-Thurner syndrome. Five patients had iliofemoral involvement, two iliocaval, and one iliac vein alone. Two patients had central DVT, one of them involving the IVC and one involving the superior vena cava with brachiocephalic extension. Aspiration thrombectomy was technically successful in a total of six patients. Success was achieved in five of eight patients as the initial or main treatment modality and as an adjunctive treatment in one of two patients. Of the four patients in whom aspiration thrombectomy was not successful, three underwent successful further treatment with CDT. Recurrence after successful aspiration was seen in two patients. One patient developed pulmonary embolism that required no additional treatment. One patient experienced severe headaches treated with oral analgesics.

CONCLUSIONS

We observed a technical success of 60% for acute iliofemoral and central DVT with an aspiration thrombectomy system that allowed definitive treatment in one setting. As a novel therapy, this avoided the need for thrombolysis in the majority of selected cases with no bleeding complications and is a promising technique for acute DVT management.

The Role of Inflammation in Venous Thromboembolism

Venous thromboembolism (VTE), comprising deep vein thrombosis (DVT), and pulmonary embolism (PE), is becoming increasingly recognized as a cause of morbidity and mortality in pediatrics, particularly among hospitalized children. Furthermore, evidence is accumulating that suggests the inflammatory response may be a cause, as well as consequence, of VTE, but current anticoagulation treatment regimens are not designed to inhibit inflammation. In fact, many established clinical VTE risk factors such as surgery, obesity, cystic fibrosis, sepsis, systemic infection, cancer, inflammatory bowel disease, and lupus likely modulate thrombosis through inflammatory mediators. Unlike other traumatic mechanisms of thrombosis involving vascular transection and subsequent exposure of subendothelial collagen and other procoagulant extracellular matrix materials, inflammation of the vessel wall may initiate thrombosis on an intact vein. Activation of endothelial cells, platelets, and leukocytes with subsequent formation of microparticles can trigger the coagulation system through the induction of tissue factor (TF). Identification of biomarkers to evaluate VTE risk could be of great use to the clinician caring for a patient with inflammatory disease to guide decisions regarding the risk:benefit ratio of various types of potential thromboprophylaxis strategies, or suggest a role for anti-inflammatory therapy. Unfortunately, no such validated inflammatory scoring system yet exists, though research in this area is ongoing. Elevation of C-reactive protein, IL-6, IL-8, and TNF-alpha during a response to systemic inflammation have been associated with increased VTE risk. Consequent platelet activation enhances the prothrombotic state, leading to VTE development, particularly in patients with other risk factors, most notably central venous catheters.

Safety and Efficacy of Catheter Direct Thrombolysis in Management of Acute Iliofemoral Deep Vein Thrombosis: A Systematic Review

Purpose

Catheter direct thrombolysis (CDT) has been shown to be an effective treatment for deep venous thrombosis. The objective of the review is to improve safety and efficacy of the CDT by using ward based protocol, better able to predict complications and treatment outcome through monitoring of haemostatic parameters and clinical observation during thrombolysis procedure.

Materials and Methods

MEDLINE, EMBASE, CENTRAL and Web of Science were searched for all articles on deep venous thrombosis, thrombolysis and correlations of clinical events (bleeding, successful thrombolysis) during thrombolysis with hemostatic parameters to March 2016. The risk of bias in included studies was assessed by Cochrane Collaboration’s tool and Cochrane Risk of Bias Assessment Tool: for Non-Randomized Studies of Interventions.

Results

Twenty-four studies were included in the review and we found that improving safety and efficacy of CDT by using ward based protocol depending on eight factors; strict patient selection criteria, types of fibrinolytic drugs, mode of fibrinolytic drug injection, biochemical markers monitoring (fibrinogen, D-dimer, activated partial thromboplastin time, plasminogen activator inhibitor-1), timing of intervention, usage of intermittent pneumatic calf, ward monitoring and thrombolysis imaging assessment (intravascular ultrasound). These factors may help to improve safety and efficacy by reducing total thrombolytic drug dosage and at the same time ensure successful lysis. There is a marked lack of randomized controlled trials discussing the safety and efficacy of catheter direct thrombolysis.

Conclusion

CDT can be performed safely and efficiently in clinical ward, providing that careful nursing, biochemical monitoring, proper selection and mode of infusion of fibrinolytic drugs, usage of Intermittent pneumatic calf and adequate thrombolysis imaging assessment are ensured.

Thrombectomy Combined with Indwelling-catheter Thrombolysis is more Effective than Pure Thrombectomy for the Treatment of Lower Extremity Deep Venous Thrombosis

This study was a retrospective analysis of the efficacy of thrombectomy plus local catheter-directed thrombolysis (CDT) for the treatment of lower extremity deep venous thrombosis (LDVT).

The experimental group underwent thrombectomy plus LCDT, whereas the control group underwent thrombectomy plus systemic thrombolysis via the dorsalis pedis vein. Venography and vascular color Doppler ultrasound were performed 7 days after surgery and at follow-up. The differences in the thigh and calf circumferences of normal and affected limbs were compared between groups. The venous patency score and venous patency rate were used for outcome evaluation. Compared with the control group, the experimental group showed a lower venous patency score and higher venous patency rate after treatment (P<0.05). Thirty patients were followed for 3 to 6 months, and according to the last evaluation, the differences in thigh and calf circumference between the normal and affected limbs remained lower in the experimental group than in the control group (P<0.05). Moreover, the venous patency score was lower, and the venous patency rate was higher in the experimental group than in the control group (P<0.05).

[Posttraumatic thromboembolic complications: Incidence, risk factors, pathophysiology and prevention]

Venous thromboembolism (VTE) remains a major challenge in critically ill patients. Subjects admitted in intensive care unit (ICU), in particular trauma patients, are at high-risk for both deep vein thrombosis (DVT) and pulmonary embolism (PE). The rate of symptomatic PE in injured patients has been reported previously ranging from 1 to 6%. The high incidence of posttraumatic venous thromboembolic events is well known. In fact, major trauma is a hypercoagulable state. Several factors placing the individual patient at a higher risk for the development of DVT and PE have been suggested: high ISS score, meningeal hemorrhage and spinal cord injuries have frequently been reported as a significant risk factor for VTEs after trauma. Posttraumatic pulmonary embolism traditionally occurs after a period of at least 5 days from trauma. The prevention can reduce the incidence and mortality associated with the pulmonary embolism if it is effective. There is no consensus is now available about the prevention of venous thromboembolism in trauma patients.

Epidemiology and Risk Assessment of Pediatric Venous Thromboembolism

The incidence of diagnosed venous thromboembolism (VTE) has been increasing concurrent with advances in technology and medical care that enhance our ability to treat pediatric patients with critical illness or complex multiorgan system dysfunction. Although the overall incidence of VTE is estimated at 0.07-0.49 per 10,000 children, higher rates are observed in specific populations including hospitalized children, those with central venous catheters (CVCs) or patients convalescing from a major surgery. While the absolute number of pediatric VTE events may seem trivial compared to adults, the increasing incidence, associated with increased mortality and morbidity, the availability of novel therapies, and the impact on the cost of care have made investigation of VTE risk factors and prevention strategies a high priority. Many putative risk factors for pediatric VTE have been reported, primarily from single-institution, retrospective studies which lack appropriate methods for verifying independent risk factors. In addition, some risk factors have inconsistent definitions, which vex meta-analyses. CVCs are the most prevalent risk factors but have not consistently been assigned the highest level of risk as defined by odds ratios from retrospective, case-control studies. Few risk-assessment models for hospital-acquired pediatric VTE have been published. Some models focus exclusively on hospitalized pediatric patients, while others target specific populations such as patients with cancer or severe trauma. Multicenter, prospective studies are needed to identify and confirm risk factors in order to create a pediatric risk-assessment tool and optimize preventive measures and reduce unintended harm.

Evaluation of venous return in lower limb by passive ankle exercise performed by PHARAD

This paper presents evaluation of venous return, i.e., blood flow volume of vein (BF), in the lower limb after passive exercise performed by our developed "parallel link type human ankle rehabilitation assistive device (PHARAD)". The PHARAD can perform complex passive exercises (plantar flexion/dorsiflexion, inversion/eversion, adduction/abduction, and combination of these motions) by reproducing input motions of a foot plate that is attached to a sole of foot. The passive exercise can be performed for not only rehabilitation but also prevention of deep vein thrombosis (DVT). In this study, we measured the concentration of Total hemoglobin (Total-Hb) using multi-channel near infra-red spectroscopy (NIRS)-based tissue oximeters and calculated a gradient of Total-Hb during a venous occlusion. We defined the gradient as BF and evaluated BF after 3 min passive exercise performed by the PHARAD comparing to BF of resting. Seven healthy young adult people were recruited for the experiment and we assessed passive exercise, active exercise, and walking. Experimental results show that BF after the passive exercises significantly increases compare to BF of resting and this indicates that passive exercises performed by the PHARAD increases BF and has a potential to prevent DVT.

The post thrombotic syndrome: Ignore it and it will come back to bite you

Post thrombotic syndrome (PTS) is a very common chronic complication of deep venous thrombosis (DVT), as three out of ten patients with lower extremity DVT will develop PTS. The possibility to identify patients at risk is limited. Diagnosis is challenging, because there is no gold standard diagnostic method. Progress in diagnostic options may therefore change future diagnostic strategies. The better understanding of pathophysiologic processes that underlie PTS may stimulate the development of treatment modalities and improve and diversify management options. The quest for adequate preventive strategies and treatment is important because PTS has a detrimental effect on patients' quality of life and is associated with increased healthcare as well as societal costs. The problem of PTS prevention is therefore clearly relevant to patients, doctors as well as policy makers.

Inflammation in venous thromboembolism: Cause or consequence?

Venous thromboembolism (VTE) which includes deep vein thrombosis (DVT) and pulmonary thromboembolism (PTE) is a moderately common disease especially in elderly population with high rate of recurrence and complications. Evidence is accumulating that VTE is not restricted to coagulation system and immune system appears to be involved in formation and resolution of thrombus. The present study was aimed at reviewing current evidences on immune system abnormalities such as alterations in cytokines, chemokines and immune cells. Also, current evidences suggest that; a, inflammation in general functions as a double-edged sword, b, inflammation can be both a cause and a consequence of VTE, and c, current anti-coagulation therapies are not well-equipped with the capacity to selectively inhibit inflammatory cells and pathways. Applying such inferences for selective pharmacological targeting of immune mediators in VTE and thereby for adoption of higher effective anti-thromboinflammatory strategies, either therapeutic or prophylactic, is henceforth to be considered as the line of research for future.

Compartment Syndrome following Open Femoral Fracture with an Isolated Femoral Vein Injury Treated with Acute Repair

Acute compartment syndrome is a surgical emergency and its diagnosis is more difficult in obtunded or insensate patients. We present the case of a 34-year-old woman who sustained a Gustilo-Anderson grade III open midshaft femur fracture with an isolated femoral vein injury treated with direct repair. She developed lower leg compartment syndrome at 48 hours postoperatively, necessitating fasciotomies. She was subsequently found to have a DVT in her femoral vein at the level of the repair and was started on therapeutic anticoagulation. This case highlights the importance of recognition of isolated venous injuries in a trauma setting as a risk factor for developing compartment syndrome.

Catheter-Directed Thrombolysis Along with Mechanical Thromboaspiration versus Anticoagulation Alone in the Management of Lower Limb Deep Venous Thrombosis-A Comparative Study

Catheter-directed thrombolysis (CDT) with assisted mechanical thrombolysis is now considered as the standard of medical care for deep vein thrombosis (DVT). The study was conducted to describe the immediate and long-term (6 months) safety and effectiveness of CDT in patient with lower limb DVT compared with the routine anticoagulation alone. All 12 to 85 years old patients with recent (0-8 weeks) DVT were included. In CDT group, thrombus was aspirated mechanically and streptokinase (STK) was given along with unfractionated heparin (UFH). After 6 months, deep venous patency and postthrombotic syndrome (PTS) was assessed by using duplex ultrasound and Villalta scale, respectively. Among 51 patients with completed data, 25 patients were allocated additional CDT given for a mean duration of 108 ± 32 hours and 26 patients were allocated standard treatment alone. Grade III (complete) lysis was achieved in 37% patients and grade II (50-90%) lysis in 63% of patients. Patients with partial lysis underwent percutaneous transluminal angioplasty and/or venous stenting. After 6 months, iliofemoral patency was found in 20 (80%) in the CDT group versus 7 (23%) in anticoagulation alone group (p < 0.01). PTS was seen in 5 (20%) in the CDT group versus 19 (77%) in anticoagulation alone group (p < 0.01). We conclude that CDT and conventional manual aspiration thrombectomy are an effective treatment for lower extremity DVT. STK infusion can be safely given up to 6 days. As addition of UFH can cause thrombocytopenia, so daily monitoring of complete blood counts is needed during CDT.

Variability in the Management of Superficial Venous Thrombophlebitis across Practitioners Based in North America and the Global Community

Introduction. This study aimed to compare management patterns of patients with SVT among healthcare practitioners based in North America versus those in the global community. Methods. A 17-question, multiple choice survey with questions regarding SVT diagnosis and management strategies was provided to practitioners who attended the American Venous Forum (AVF) meeting in 2011. Results. There were 487 practitioners surveyed with 365 classified as North American (US or Canada) and 122 (56 Europe, 25 Asia, 11 South America, and 7 Africa) representing the global community. The key difference seen between the groups was in the initial imaging study used in patients presenting with SVT (P = 0.046) and physicians in the US ordered fewer bilateral duplex ultrasounds and more unilateral duplex ultrasounds (49.6% versus 58.2%, 39.7% versus 34.4%). In the US cohort, phlebologists and vascular surgeons constituted 82% (n = 300) of the specialties surveyed. In the global community, SVT was managed by phlebologists or vascular surgeons 44% (n = 54) of the time. Surgical management was highly variable between groups. Conclusion. There is currently no consensus between or among practitioners in North America or globally as to the surgical management of SVT, duration of follow-up, and anticoagulation parameters.

Biomarkers for post thrombotic syndrome: a case-control study

INTRODUCTION

There is limited knowledge on the etiology of post thrombotic syndrome (PTS), although several mechanisms have been proposed. The objectives are to explore the role of different pathogenic mechanisms for PTS, through measurement of an elaborate panel of biomarkers in patients with and without PTS.

MATERIALS AND METHODS

Patients with a history of deep vein thrombosis (DVT) with PTS (cases) and without PTS after minimal 2years follow-up (controls), were selected from the outpatient clinic of two Dutch hospitals. As a reference to the normal population healthy individuals (HI) without a history of venous thromboembolism were invited to participate. The population consisted of: 26 cases, 27 controls, and 26 HI. A panel of predefined biomarkers was measured in venous blood.

RESULTS

D-dimer showed a decreasing trend from cases to controls to HI; p=0.010. Thrombin/antithrombin complex levels were significantly higher in cases than in controls; p=0.032, and HI; p=0.017. APC-ratio was significantly lower in cases compared to controls; p=0.032, and HI; p=0.011. A significant trend of increasing proTAFI from cases, to controls, and HI; p=0.002 was found. There were no differences in inflammatory markers (CRP, Interleukin-6, Interleukin-8). Thrombomodulin, tissue-plasminogen activator, and von Willebrand factor were higher in patients compared to HI. There was a significant trend of decreasing sVCAM, from cases, to controls, and HI; p=0.029.

CONCLUSIONS

Patients with PTS displayed increased coagulation activity, an altered pattern of fibrinolytic marker expression, and increased endothelial activation. We found no evidence of systemic inflammation in patients with PTS at 63months since the last DVT.

Endovascular management of proximal lower limb deep venous thrombosis - A prospective study with six-month follow-up

BACKGROUND

Catheter-directed thrombolysis with assisted mechanical thrombolysis is the standard of medical care for proximal deep vein thrombosis. We studied the immediate and intermediate (six months) safety and effectiveness of catheter-directed thrombolysis in patients with proximal lower limb deep vein thrombosis.

METHODOLOGY

Thirty consecutive patients aged between 20 and 70 years with proximal lower limb deep vein thrombosis formed the study group. Catheter-directed thrombolysis was done with streptokinase infuse through a catheter kept in the ipsilateral popliteal vein. Unfractionated heparin was given along with streptokinase. Mechanical thromboaspiration using guiding catheter was performed in addition to thrombolytic therapy. After six months, post-thrombotic syndrome and deep venous patency were assessed by using Villalta scale and duplex ultrasound, respectively.

RESULTS

Thirty patients with proximal lower limb deep vein thrombosis were treated with catheter-directed thrombolysis. Mean age of the study patients was 41.7 ± 15 years. Mean duration of illness was 13.3 ± 12 days. The mean duration of thrombolysis was 4.5 ± 1.3 days. Grade III (complete) lysis was achieved in 10 (33%) and Grade II (50-90%) lysis in 20 (67%) of patients. Patients with significant residual lesion in Grade II lysis following catheter-directed thrombolysis underwent percutaneous transluminal angioplasty alone (12/20) or venous stenting (8/20). All patients improved clinically following catheter-directed thrombolysis or assisted catheter-directed thrombolysis. Four patients (13%) developed pulmonary embolism during course of hospital stay and among them two (6.5%) patients died. Eleven patients (37%) had minor bleeding or hematoma at local site, and seven (23%) developed anemia requiring blood transfusion and four (13%) patients had thrombocytopenia. After six months, iliofemoral patency was found in 20 (72%) and post-thrombotic syndrome was seen in six (21%) patients. Two (6.5%) patients died during follow-up due to nephrotic syndrome and carcinoma breast.

CONCLUSION

Catheter-directed thrombolysis and conventional manual aspiration thrombectomy are an effective treatment for proximal lower extremity deep vein thrombosis with good short and intermediate outcome.

Interpretation of peripheral venous duplex testing

Venous duplex ultrasound and plethysmography are used to evaluate patients for suspected deep venous thrombosis (DVT) or venous insufficiency symptoms. Testing can provide clinicians with detailed information on location, extent, and severity of venous conditions before and after treatment. Duplex ultrasound can image the venous system from the vena cava to the peripheral veins, including veins of the calf musculature, and is the recommended technique to diagnose DVT. Accurate interpretation of venous testing requires an understanding of venous hemodynamics, including normal flow phasicity with cardiac and respiratory motion and the changes produced by acute DVT. Duplex scanning provides a roadmap of vein anatomy similar to contrast venography and essential hemodynamic information about the presence of proximal obstruction, vein valve function, and perforator vein reflux. Indications for testing include the diagnosis of acute/chronic DVT and evaluation of patients with venous insufficiency manifested as edema, varicose veins, or ambulatory venous hypertension. Venous plethysmography, an indirect physiologic test, can be used to estimate severity of obstructive or reflux venous pathophysiology and document improvement in venous hemodynamics after intervention. Using criteria based on ultrasound imaging and physiologic testing, venous conditions producing a swollen or painful limb can be accurately determined and aid in appropriate treatment selection.

Deep vein thrombosis in patients with severe motor and intellectual disabilities

Most patients with severe motor and intellectual disabilities (SMID) have restricted mobility capability and have been bedridden for long periods because of paralysis of the extremities caused by abnormal muscular tonicity due to cerebral palsy and developmental disabilities, and such patients are associated with a high risk for the complications of deep vein thrombosis (DVT). Here, we report 8 patients (34.8%) with DVT among 23 patients with SMID during prolonged bed rest. However, we did not detect thrombosis in the soleal veins, finding it mostly in the superficial femoral and common femoral veins. Regarding laboratory data for the coagulation system, there were no cases with D-dimer above 5 µg/ml. Concerning sudden death in patients with SMID, we have to be very careful of the possibility of pulmonary thromboembolism due to DVT. Therefore, we should consider the particularities of an underdeveloped vascular system from underlying diseases for the evaluation of DVT in patients with SMID. A detailed study of DVT as a vascular complication is very important for smooth medical care of SMID and compression Doppler ultrasonography of the lower extremities, as noninvasive examination, is very helpful. (English translation of Jpn J Phlebol 2012; 23: 17-24).

Popliteal venous aneurysm with deep venous thrombosis in the contralateral calf: report of a case

Although a popliteal venous aneurysm is a rare entity, it is an important cause of pulmonary embolism (PE), which is occasionally life-threatening. We herein report a case of a popliteal venous aneurysm with deep venous thrombosis (DVT) in the contralateral calf. A 65-year-old male, who presented with sudden onset palpitation and dyspnea, was transferred to our hospital. Enhanced computed tomography revealed PE and a venous aneurysm of the left popliteal vein. The popliteal venous aneurysm was saccular and had an intramural thrombus. Furthermore, duplex scanning detected DVT in the contralateral calf. The patient underwent a tangential aneurysmectomy with lateral venorraphy. The surgery and postoperative course were uneventful. The PE and calf DVT disappeared with perioperative anticoagulant therapy. It is recommended that, in the treatment of popliteal venous aneurysms, special attention should be given to the condition of the venous vessels of the contralateral leg, because this can influence the therapeutic strategy.

Does previous varicose vein surgery alter deep vein thrombosis risk after lower limb arthroplasty?

OBJECTIVE

To determine the rates of deep vein thrombosis (DVT) and pulmonary embolism (PE) after total knee arthroplasty (TKA) and total hip arthroplasty (THA) in patients who have had previous varicose vein (VV) surgery.

METHODS

Data on 57,364 patients who had undergone THAs and 51,859 patients who had undergone TKAs were obtained from the Scottish Arthroplasty Project and cross-referenced with patients for whom DVT/PE events had been recorded (Scottish Morbidity Database).

RESULTS

The THA DVT rate in patients who had previously undergone VV surgery was 0.8% (27/3478), and in those with no previous VV diagnosis or surgery was 0.8% (428/53,659). In patients with a previous VV diagnosis but no VV surgery, the THA DVT rate was 3.1% (7/227) (Pearson χ2 test, χ2 = 14.8, degrees of freedom = 2, P = 0.001). No significant difference was found for the corresponding data in the TKA cohort. The THA PE rate in patients who had previously undergone VV surgery was 0.7% (26/3478), and in those with no previous VV diagnosis or surgery 0.7% (376/53,659). No correlation was found between prior VV interventions and PE rates.

CONCLUSION

Untreated VVs are associated with an increased risk of DVT after THA. Therefore, patients with VVs should consider having them treated prior to undergoing orthopedic interventions.

Nomograms to predict risk of in-hospital and post-discharge venous thromboembolism after abdominal and thoracic surgery: an American College of Surgeons National Surgical Quality Improvement Program analysis

BACKGROUND

Postoperative venous thromboembolism (VTE) is increasingly viewed as a quality of care metric, although risk-adjusted incident rates of postoperative VTE and VTE after hospital discharge (VTEDC) are not available. We sought to characterize the predictors of VTE and VTEDC to develop nomograms to estimate individual risk of VTE and VTEDC.

METHODS

Using the American College of Surgeons National Surgical Quality Improvement Program database, we identified 471,867 patients who underwent inpatient abdominal or thoracic operations between 2005 and 2010. We excluded primary vascular and spine operations. We built logistic regression models using stepwise model selection and constructed nomograms for VTE and VTEDC with statistically significant covariates.

RESULTS

The overall, unadjusted, 30-d incidence of VTE and VTEDC was 1.5% and 0.5%, respectively. Annual incidence rates remained unchanged over the study period. On multivariate analysis, age, body mass index, presence of preoperative infection, operation for cancer, procedure type (spleen highest), multivisceral resection, and non-bariatric laparoscopic surgery were significant predictors for VTE and VTEDC. Other significant predictors for VTE, but not VTEDC, included a history of chronic obstructive pulmonary disease, disseminated cancer, and emergent operation. We constructed and validated nomograms by bootstrapping. The concordance indices for VTE and VTEDC were 0.77 and 0.67, respectively.

CONCLUSIONS

Substantial variation exists in the incidence of VTE and VTEDC, depending on patient and procedural factors. We constructed nomograms to predict individual risk of 30-d VTE and VTEDC. These may allow more targeted quality improvement interventions to reduce VTE and VTEDC in high-risk general and thoracic surgery patients.

Management of traumatic popliteal vein injuries

PURPOSE

The aim of this study was to evaluate different repair methods of popliteal vein injuries, and to assess the relationship between early patency and surgical outcome.

METHODS

Thirty patients with popliteal vein injuries underwent surgical repair procedure at our hospital from March 2000 to April 2010. Patients who were haemodynamically unstable and those with massive bleeding from limb wounds were taken directly to the operating room. Stable patients underwent preoperative colour-flow duplex ultrasonography (CFDU).

RESULTS

Our study group consisted of 26 males and 4 females, ranging in age from 17 to 60 years with a mean age of 25.3 ± 5.9 years. The mechanism of trauma was penetrating in 27 patients and blunt in the remaining 3 patients. Treatment included primary venous repair in 11 cases, end-to-end anastomosis in 8, interposition vein graft in 10, and interposition polytetrafluoroethylene (PTFE) graft in 1. There were 26 patients with associated arterial injury, of which 4 cases had primary repair, 9 had end-to-end anastomosis, 11 had saphenous vein graft interposition, and 2 had PTFE graft interposition. Associated bone fracture was seen in 6 patients. There were no deaths. One patient required a below-knee amputation. Postoperative CFDU revealed thrombosed venous repair in 7 cases without any sequelae.

CONCLUSION

Popliteal venous injuries can be repaired with minimal downside and a good early patency rate. Additionally, transient venous patency allows for establishment of venous and lymphatic collateralisation. Alternatively, venous ligation should be considered only in unstable patients who refuse blood transfusion (Jehovah's witnesses). In these victims, adjuvant management may be required such as the use of fasciotomy and anticoagulation treatment.

Aspectos clínicos, ultra-sonográficos e venográficos da tromboflebite jugular experimental em equinos

A tromboflebite jugular ocorre frequentemente em equinos, decorrendo geralmente de processos mórbidos associados à iatrogenia, podendo levar a perda de função, edema cefálico, diminuição do desempenho atlético e ainda causar o óbito. Esta enfermidade nos equinos apesar de frequente é pouco conhecida quanto à sua evolução e tratamentos. O objetivo deste trabalho foi avaliar a evolução da tromboflebite jugular experimental em equinos, quanto às alterações clínicas e estruturais envolvidas na enfermidade, observando-se os aspectos clínicos, ultra-sonográficos e venográficos no contexto do trombo e do vaso, quanto à possibilidade de recanalização do trombo produzido e da vascularização compensatória. A tromboflebite da veia jugular foi induzida, unilateralmente, em 05 equinos nos quais previamente à indução da tromboflebite e diariamente após foram observadas manifestações clínicas e realizados exames ultra-sonográficos. Venografias foram feitas nos momentos pré-indução, na indução e a cada seis dias após a indução da tromboflebite, verificando-se a recanalização do trombo oclusivo e a presença de vasos na drenagem sanguínea compensatória. Observou-se a ocorrência de edema moderado das regiões parotídea, massetérica e supra-orbitária e discreto edema submandibular que reduziram até o 6º dia, permanecendo apenas discreto aumento parotídeo. O ingurgitamento da jugular cranial a região da indução permaneceu durante todo o período de avaliação. A porção caudal à tromboflebite mostrou ingurgitamento frente ao garrote na entrada do tórax desde o primeiro dia após a indução. Os exames ultra-sonográficos mostraram formação de trombo oclusivo total durante todo o período de observação em 3 animais e o restabelecimento parcial do fluxo na jugular em 2 animais e a presença de vasos colaterais conduzindo o sangue da porção cranial para a porção caudal à obstrução. As venografias revelaram fluxo sanguíneo "linear" normal no momento pré-operatório, constatando nos momentos pós-operatórios a presença oclusiva do trombo, com o contraste preenchendo os vasos tributários compensatórios direcionados à porção caudal à oclusão da veia ou ainda estagnado cranialmente ao trombo. Conclui-se que a trombose oclusiva na tromboflebite jugular experimental e unilateral sofre recanalização e compensação vascular por vasos tributários de drenagem, com redução gradativa dos sinais decorrentes da estase sanguínea de retorno, especificamente as regiões cefálicas com edema. Estudos envolvendo a tromboflebite jugular nos equinos devem evoluir nos aspectos experimental e clínico.