Association between inherited thrombophilic abnormalities and central venous catheter thrombosis in patients with cancer: a meta-analysis

Upper extremity venous thrombosis in hospitalized patients: A prospective epidemiological study

BACKGROUND

The frequency of upper extremities vein thrombosis (UEVT) is rising with the increasing use of endovenous devices. These thromboses are particularly common among hospitalized patients. The epidemiology and risk factors for UEVT are poorly understood in a hospitalized population.

OBJECTIVE

To assess the prevalence of UEVT in hospitalized patients and study thrombosis risk factors according to their location.

METHODS

Prospective evaluation of patients hospitalized in a university hospital with clinical and Doppler ultrasound (DUS) assessment of the upper extremities.

RESULTS

Of the 400 patients included, 91(22.8 %) had UEVT including 8 (8.8 %) proximal thrombosis, 32 (35.2 %) arm venous thrombosis and 51 (56.0 %) forearm venous thrombosis; 7 (7.7 %) patients with UEVT had a concomitant symptomatic pulmonary embolism. In this population of hospitalized patients, 40 (10 %) had proximal or arm thrombosis and 51 (12.8 %) forearm thrombosis. All patients with UEVT had a venous catheter and 63 (69.2 %) of UEVT patients had therapeutic or prophylactic anticoagulation at the time of DUS evaluation. In multivariate analysis, peripheral intravenous catheter (PIVC) OR 3.71 [1.90; 7.91] (p < 0.001); MID line OR 3.58 [1.46; 8.91] (p = 0.005) and infection disease OR 2.21 [1.26; 4386] (p = 0.005) were associated with UEVT. Central venous catheter OR 66.24 [12.64; 587.03] was associated with proximal UEVT and MID line OR 12.61 [4.64; 35.77] (p < 0.001) with arm UEVT. Forearm UEVT were associated with PIVCOR 10.71[3.14; 67.37] (p = 0.001); infectious disease OR 2.87 [1.48; 5.60] (p = 0.002), iron infusion OR 3.11 [1.23; 7.47] and hospitalization for postpartum OR 4.37 [0.97; 18.06] (p = 0.04).

CONCLUSION

One in 5 hospitalized patients suffers from UEVT. Proximal venous thrombosis is uncommon. The presence of a catheter and hospitalization for infection are the factors most frequently associated with UEVT.

Venous Thromboembolism and Cancer: A Comprehensive Review from Pathophysiology to Novel Treatment

Acute thrombotic events can unveil occult cancer, as they are its first manifestation in about 20 to 30% of all cases. Malignancy interacts in an intricate way with the hemostatic system, promoting both thrombosis and bleeding. The main pathway involved in these reactions involves the activation of tumor-associated procoagulant factors, which eventually results in clot formation. The clinical manifestation of cancer-related thrombotic events mainly involves the venous side, and manifests in a broad spectrum of conditions, including unusual sites of venous thrombosis. The selection of patients who have a balanced risk–benefit profile for management of anticoagulation is complex, given individual patient goals and preferences, different prognosis of specific cancers, common comorbidities, potential drug–drug interactions, underweight states, and the competing risks of morbidity and mortality. Anticoagulant treatment in cancer settings is broadly debated, considering the potential application of direct oral anticoagulants in both thromboprophylaxis and secondary prevention, having demonstrated its efficacy and safety compared to conventional treatment. This review aims to provide a brief overview of the pathophysiology and management of cancer-related thrombosis, summarizing the results obtained in recent clinical trials.

Central catheter-associated deep vein thrombosis in cancer: clinical course, prophylaxis, treatment

The adequate handling of central venous catheters is a key element in the management of patients with cancer. Catheter-associated deep vein thrombosis is frequently observed in patients with malignant diseases; however, despite being a common complication among these patients, objective information concerning its epidemiology, clinical course, prophylaxis and treatment strategies is very limited. The reported incidence of catheter-related thrombosis (CRT) is highly variable, depending on symptomatic events, or if patients are screened for asymptomatic thrombosis. Several factors have been identified as potential predisposing factors for CRT, both technical and pathological aspects. The anticoagulant of choice is still unclear; while low-molecular-weight heparin is most commonly used, recent studies assessing the role of direct oral anticoagulants in the treatment of CRT show promise as an alternative, but the evidence remains insufficient and the decision must be made on a case-by-case basis.

Management of upper extremity deep vein thrombosis: an updated review of the literature

Upper extremity deep vein thrombosis (UEDVT) represents about 5-10% of all cases of deep vein thrombosis (DVT) with a steadily increasing incidence mostly due to the high prevalence of cancer and frequent use of intravascular devices such as central venous catheters and pacemaker. In primary UEDVT, the venous outflow obstruction and subsequent thrombosis are related to congenital or acquired anatomical abnormalities, whereas secondary UEDVT is often associated with malignancy or indwelling lines. A considerable proportion of patients with UEDVT develops serious complications such as recurrent thrombosis, post-thrombotic syndrome, and pulmonary embolism, therefore timely diagnosis and adequate treatment are of crucial importance. Despite sharing many similarities with lower extremity DVT, UEDVT has distinctive features requiring specific diagnostic and therapeutic approaches. The present review discusses the latest evidence on the epidemiology, diagnosis, and treatment of UEDVT, and provides management indications which may help guide clinical decision making.

Hereditary thrombophilia and thrombosis of tunneled hemodialysis catheters: A single center study

Introduction: Vascular access thrombosis increases the risk of mortality and morbidity in end-stage renal disease (ESRD) patients on hemodialysis (HD). This study aimed to evaluate hereditary thrombophilia factors in HD patients and its association with tunneled cuffed catheters’ thrombosis.

Methods: In this cross-sectional study, 60 consecutive patients with ESRD on HD with tunneled cuffed catheters were selected. Inherited thrombophilia factors (Anti-thrombin III, Protein C, Protein S, and Factor V Leiden) were measured and the patients were followed for 3 months to evaluate the incidence of catheter-related thrombosis. The association between these factors and catheter thrombosis was assessed.

Results: The mean age of patients was 60.30 ± 8.69 years. Forty-seven patients (78.30%) were female and thirteen patients (21.70%) were male. The most common cause of ESRD was diabetes mellitus (41.67%). The most catheter site was the right internal jugular vein (55%). There were 22 (36.67%) and 8 (13.33%) cases of thrombosis and mortality, respectively. The association between hereditary thrombophilia factors and catheter thrombosis was not statistically significant (P > 0.05).

Conclusion: In this small group of our patients, the frequency of hereditary thrombophilia was not significantly different between those with and without thrombosis of tunneled HD catheter.

Diagnostic and Therapeutic Management of Upper Extremity Deep Vein Thrombosis

Upper extremity deep vein thrombosis (UEDVT) accounts for 5% of all deep vein thromboses (DVTs). UEDVT may be complicated by post thrombotic syndrome and pulmonary embolism, and early recognition and prompt start of anticoagulant treatment are key. Primary UEDVT, also known as Paget-von Schrötter syndrome, is associated with repeated or sudden physical activity of the upper arm and venous outflow obstruction due to anatomical variations. Secondary UEDVT is often associated with malignancy or use of intravenous devices, such as central venous catheters or pacemaker leads. Although the diagnosis and treatment of UEDVT have many similarities with DVT of the lower extremities, knowledge of specific aspects regarding UEDVT is important to guide optimal management. In this review, we will discuss the epidemiology, diagnosis, and treatment of UEDVT based on the current literature.

Jugular venous catheter-associated thrombosis and fatal pulmonary embolism: A case report

INTRODUCTION

Central venous catheters related thrombosis (CRT) insertion has been shown to increase the risk of venous thromboembolism, particularly pulmonary embolism (PE). Nevertheless, deaths cased due to PE have been rarely reported.

PATIENT CONCERNS

A central venous catheter was introduced through the right jugular vein during the operation due to severe septic shock from a 57-year-old male patient. Two days after surgery, the hemodynamics was stable. On the 7th day, and low molecular weight heparin calcium (4100 units, once a day) was added for anticoagulation to prevent venous thromboembolism. On the 15th day, during the process of central venous catheter removal, the patient suddenly lost consciousness, suffered cardiac arrest, and received emergency cardiopulmonary resuscitation.

DIAGNOSIS

Jugular venous catheter-associated thrombosis and fatal PE. An acute bedside ultrasound showed a thrombus drifting with the blood stream in the right jugular vein. The lower section of the xiphoid process by echocardiography showed decreased systolic amplitude of the right atrium and right ventricle, widened and fixed inferior vena cava, and no variation with respiration. Para-sternal left ventricular long axis section showed that the right ventricular outflow tract was significantly extended, and the contraction amplitude of the anterior and posterior walls of the left ventricle decreased. Left ventricular short axis section indicated a right ventricle enlargement and ventricular septum deviation of left ventricle, showing "D" sign. Apical 4-chamber view showed that the right ventricular ratio increased and the contractile capacity decreased.

INTERVENTIONS

One and a half million units of urokinase were immediately given trough intravenous drip.

OUTCOMES

Twenty minutes after thrombolysis, the patient's autonomic heart rhythm was recovered, but continued to suffer from hypotension and coma, followed by multiple organ failure, and died 50 hours later.

CONCLUSION

Recent clinical practice guidelines recommend against the routine use of any anticoagulant thromboprophylaxis in patients with central venous catheters, but for patients at particularly high risk for CRT, consideration can be given to using higher doses of anticoagulant as prophylaxis, although there are virtually no data to support this approach.

Thrombophilia, risk factors and prevention

INTRODUCTION

Fifty-three years after the first description of an inherited prothrombotic condition (antithrombin deficiency), our knowledge on hereditary and acquired causes of hypercoagulability that can predispose carriers to venous thromboembolism (VTE) has greatly improved. Areas covered: Main causes of hereditary thrombophilia are summarized alongside new prothrombotic mutations recently discovered. The main causes of acquired thrombophilia, and namely, antiphospholipid antibody syndrome and hyperhomocysteinemia, are also discussed together with other common acquired prothrombotic states characterized by an increase of procoagulant factors and/or a decrease of natural anticoagulants. Finally, suggestions for thromboprophylaxis in carriers of hereditary thrombophilia according to current guidelines/evidence are made for the most challenging high-risk situations (i.e. surgery, pregnancy, contraception, cancer, economy class syndrome) as well as for the prevention of post-thrombotic syndrome. Expert opinion: A carrier of inherited thrombophilia should be evaluated in the framework of other (genetic and/or acquired) coexisting risk factors for first or recurrent VTE when assessing the need and duration of prevention (primary prophylaxis). Prevention strategies should be tailored to each patient and every situational risk factor. The knowledge of the carriership status of severe thrombophilia in the proband can be important to provide asymptomatic relatives with adequate counseling on thrombophilia screening or primary thromboprophylaxis.

Pathophysiology 1. Mechanisms of Thrombosis in Cancer Patients

Thrombosis is a major cause of morbidity and mortality in cancer patients. The pathogenesis of blood coagulation activation in oncological patients is complex and involves both clinical and biological factors. Abnormalities in one or more coagulation test are common in cancer patients, even without thrombotic manifestations, indicating an ongoing hypercoagulable condition. Moreover, venous thromboembolism (VTE) can be the first symptom of an occult malignancy in an otherwise healthy individual. The levels of laboratory markers of activation of blood coagulation parallel the development of malignancy, being the coagulant mechanisms important for both thrombogenesis and tumor progression. Besides general clinical risk factors for VTE, also disease-specific clinical factors, i.e., type and stage of the tumor, and anticancer therapies increase the thrombotic risk in these patients. Furthermore, biological factors, including the cancer cell-specific prothrombotic properties together with the host cell inflammatory response to the tumor, are relevant as well as unique players in the pathogenesis of the cancer-associated hypercoagulability. Cancer cells produce and release procoagulant and fibrinolytic proteins, inflammatory cytokines, and procoagulant microparticles. They also express adhesion molecules binding to the receptors of host vascular cells (i.e., endothelial cells, platelets, and leukocytes), thereby stimulating the prothrombotic properties of these normal cells, including the shed of cell-specific microparticles and neutrophil extracellular traps. Of interest, several genes responsible for the cellular neoplastic transformation drive the programs of hemostatic properties expressed by cancer tissues. A better understanding of such mechanisms will help the development of novel strategies to prevent and treat the Trousseau's syndrome (i.e., cancer-associated thrombosis).

Etiology and Management of Upper-Extremity Catheter-Related Thrombosis in Cancer Patients

Central venous access devices are a critical instrument in the treatment and supportive care delivery for oncology patients. Catheter-related thrombosis (CRT) is a common complication of central venous access devices in oncology patients. Risk factors for CRT include patient-, device-, and treatment-related risk factors. Treatment of CRT is indicated to reduce symptoms, prevent catheter malfunction, prevent recurrent DVT or thromboembolic pulmonary embolism, and minimize the risk of post-thrombotic syndrome. Minimal prospective data exist on the prevention and treatment of catheter-related thromboses in cancer patients. As such recommendations largely are derived from data in the lower-extremity DVT and PE studies in cancer and non-cancer patients. Based on the available literature, primary pharmacologic prophylaxis against CRT is not recommended in cancer patients. Treatment options for CRT include catheter removal, anticoagulation, catheter-directed thrombolysis, or surgical thrombectomy. Current evidence-based guidelines recommend LMWH as the anticoagulant of choice. However, recent data showing efficacy and safety of DOACs in cancer-related VTE may be extrapolated to treatment of CRT in cancer patients. In patients with CRT, catheter removal should be pursued if continued vascular access is no longer needed, the catheter is dysfunctional, a catheter-associated infection is present, or if CRT symptoms do not resolve with anticoagulation alone. Catheter-directed thrombolysis is reserved for rare severe cases of CRT. Herein we discuss the pathophysiology, clinical presentation, diagnosis, and general management of CRT in cancer patients.

How I diagnose and treat venous thromboembolism in sickle cell disease

The incidence of venous thromboembolism (VTE) in adult patients with sickle cell disease (SCD) is high. However, overlapping features between the clinical presentation of VTE and SCD complications and a low index of suspicion for thrombosis can influence patient management decisions. VTE in SCD can therefore present management challenges to the clinical hematologist. Herein, we present 3 distinct clinical vignettes that are representative of our clinical practice with SCD patients. These vignettes are discussed with specific reference to the hypercoagulable state in SCD patients, recent VTE diagnosis and anticoagulant therapy guidelines from the general population, and evaluation of the risk of bleeding as a result of long-term exposure to anticoagulant therapy. We examine current diagnostic and treatment options, highlight limitations of the existing clinical prognostic models that offer personalized guidance regarding the duration of anticoagulation, and propose a clinical approach to guide the decision to extend anticoagulation beyond 3 months.

ABO blood group related venous thrombosis risk in patients with peripherally inserted central catheters

OBJECTIVE

To investigate the association between ABO blood group and upper limb venous thrombosis (VT) risk in patients with peripherally inserted central catheters (PICC).

METHODS

Single centre retrospective cohort study. A cohort of patients who underwent PICC insertion from September 2010 to August 2014 were followed up for symptomatic VT presentations diagnosed by ultrasound. Blood group status was identified from hospital information systems.

RESULTS

2270 participants had 3020 PICCs inserted. There were 124 cases of symptomatic VT, an incident rate of 4% [95% confidence interval, CI (3-5%)]. Univariate analysis adjusting for the clustered sample showed that having chemotherapy, two or more previous PICCs, a larger catheter size, a diagnosis of cancer and having a blood group B were all associated with an increased risk of a VT. In the multivariate analysis, PICC diameter, cancer diagnosis and blood group B were all independently associated with increased risk of VT.

CONCLUSION

Patients undergoing PICC insertion with a blood group B appear to have a higher risk of VT, independent of risks attached to the PICC procedure and cancer diagnosis. Without any existing guidelines for PICC-related VT, this investigation creates a platform for further research to be conducted in order to establish guidelines. Advances in knowledge: Previous studies investigating VT risk associated with blood group status related to large heterogeneous populations. In this article, we look at patients specifically with PICC, which reduces the heterogeneity in the cohort. In addition, due to the substantial number of patients enrolled, we had a chance to perform multivariate analyses with statistical significance.

How I treat central venous access device-related upper extremity deep vein thrombosis

Central venous access device (CVAD)-related thrombosis (CRT) is a common complication among patients requiring central venous access as part of their medical care. Complications of CRT include pulmonary embolism, recurrent deep venous thrombosis, loss of central venous access, and postthrombotic syndrome. Patient-, device-, and treatment-related factors can influence the risk of CRT. Despite numerous randomized controlled trials, the clinical benefit of pharmacologic thromboprophylaxis for the prevention of CRT remains to be established. Therefore, minimizing patient exposure to known risk factors is the best available approach to prevent CRT. Venous duplex is recommended for the diagnosis of CRT. Anticoagulation for at least 3 months or the duration of the indwelling CVAD is recommended for treatment of CRT. Thrombolysis should be considered for patients at low risk for bleeding who have limb-threatening thrombosis or whose symptoms fail to resolve with adequate anticoagulation. CVAD removal should be consider for patients with bacteremia, persistent symptoms despite anticoagulation, and if the CVAD is no longer needed. Superior vena cava filters should be avoided. Prospective studies are needed to define the optimal management of patients with or at risk for CRT.

Diagnosis and management of factor V Leiden

INTRODUCTION

The discovery of the factor V Leiden (FVL) missense mutation (Arg506Gln) causing factor V resistance to the anticoagulant action of activated protein C was a landmark that allowed a better understanding of the basis of inherited thrombotic risk. FVL mutation is currently the most common known hereditary defect predisposing to venous thrombosis. Areas covered: Novel data-driven FVL diagnosis and therapeutic approaches in the management of FVL carriers in various clinical settings. Brief conclusions on topics of direct clinical relevance including currently available indications for primary and secondary prophylaxis, the management of female, pediatric carriers and asymptomatic relatives. Latest evidence on the association between FVL and cancer, as well as the possible use of direct oral anticoagulant therapy. Expert commentary: Although FVL diagnosis nowadays is highly accurate, many doubts remain regarding the best management and therapeutic protocols. The main role of clinicians is to tailor therapeutic strategies to carriers and their relatives. High familial penetrance, distinctive aspects of the first thrombotic event (provoked/unprovoked, age, etc.) and laboratory biomarkers can guide the optimal management of secondary antithrombotic prophylaxis, primary prophylaxis in asymptomatic individuals, and whether to screen relatives.

Characteristics and Risk Factors of Cancer Associated Venous Thromboembolism

INTRODUCTION

The objective of this study was to examine the differences in commonly associated characteristics and risk factors of venous thromboembolism (VTE) between patients with and without cancer in a VTE population.

MATERIALS AND METHODS

Uniform data were collected for patients with a diagnosis of VTE obtaining care at CDC funded Thrombosis Network Centers. Patient characteristics and risk factors were compared in VTE patients with and without cancer. Logistic regression was used to calculate the unadjusted and adjusted odds ratios (ORs) and 95% confidence intervals (CIs) to assess patient characteristics and thrombotic risk factors more frequently identified among VTE patients with cancer compared to those without cancer.

RESULTS

Between August 2003 and April 2011, 3,115 adult patients with a diagnosis of VTE including 189 (6.1%) patients with active cancer participated in the multi-site thrombosis registry. VTE patients with cancer had a higher prevalence of PE and DVT in unusual sites compared to those without cancer. Thrombophilia was more common among VTE patients without cancer than those with cancer (25.1% vs 10.6%, p<0.001). In adjusted analysis, age group≥45years (OR =5.20, 95% CI, 3.30, 8.18), surgery (OR =1.86, 95% CI, 1.19, 2.91), and hypertension (OR =1.66, 95% CI, 1.15, 2.40) were the VTE risk factors more commonly found among VTE patients with cancer.

CONCLUSION

The study identified several thrombotic risk factors more likely to be found with cancer associated VTE, which may help to characterize at risk cancer patients and to develop prevention and management strategies in this population.

Central venous catheter-related thrombosis

Thrombotic complications associated with the use of central venous catheters (CVCs) are common and lead to distressing patient symptoms, catheter dysfunction, increased risk of infections, long-term central venous stenosis, and considerable costs of care. Risk factors for catheter-related thrombosis include use of larger, multilumen, and peripherally inserted catheters in patients with cancer receiving chemotherapy. Symptomatic catheter-related thrombosis is treated with anticoagulation, generally without removing the catheter. The intensity and duration of anticoagulation depend on the extent of thrombosis, risk of bleeding, and need for continued use of a CVC. To date, the clinical benefit of prophylactic doses of anticoagulant has been disappointing and these agents are not used routinely for this purpose. This chapter focuses on recent evidence, remaining controversies, and practical approaches to reducing the burden of thrombosis associated with CVCs.

Clinical guidelines on central venous catheterisation. Swedish Society of Anaesthesiology and Intensive Care Medicine

Safe and reliable venous access is mandatory in modern health care, but central venous catheters (CVCs) are associated with significant morbidity and mortality, This paper describes current Swedish guidelines for clinical management of CVCs The guidelines supply updated recommendations that may be useful in other countries as well. Literature retrieval in the Cochrane and Pubmed databases, of papers written in English or Swedish and pertaining to CVC management, was done by members of a task force of the Swedish Society of Anaesthesiology and Intensive Care Medicine. Consensus meetings were held throughout the review process to allow all parts of the guidelines to be embraced by all contributors. All of the content was carefully scored according to criteria by the Oxford Centre for Evidence-Based Medicine. We aimed at producing useful and reliable guidelines on bleeding diathesis, vascular approach, ultrasonic guidance, catheter tip positioning, prevention and management of associated trauma and infection, and specific training and follow-up. A structured patient history focused on bleeding should be taken prior to insertion of a CVCs. The right internal jugular vein should primarily be chosen for insertion of a wide-bore CVC. Catheter tip positioning in the right atrium or lower third of the superior caval vein should be verified for long-term use. Ultrasonic guidance should be used for catheterisation by the internal jugular or femoral veins and may also be used for insertion via the subclavian veins or the veins of the upper limb. The operator inserting a CVC should wear cap, mask, and sterile gown and gloves. For long-term intravenous access, tunnelled CVC or subcutaneous venous ports are preferred. Intravenous position of the catheter tip should be verified by clinical or radiological methods after insertion and before each use. Simulator-assisted training of CVC insertion should precede bedside training in patients. Units inserting and managing CVC should have quality assertion programmes for implementation and follow-up of routines, teaching, training and clinical outcome. Clinical guidelines on a wide range of relevant topics have been introduced, based on extensive literature retrieval, to facilitate effective and safe management of CVCs.

Incidence and risk factors for central venous catheter-related thrombosis in hematological patients

Catheter-related thrombosis (CRT) is a serious complication in hematological patients, but the risk factors for its occurrence are not well established. The study objectives were to estimate the incidence of CRT and to identify the risk factors for developing CRT in hematological patients. In a prospective setting, 104 consecutive patients with 200 insertions of central venous catheters were enrolled into the study. The patients were screened for CRT by compression Doppler ultrasound every 10–14 days. Additionally, ultrasonography was performed in the case of clinical symptoms suggesting CRT. Over the course of 6,098 catheter days of follow-up, the incidence of CRT was 13.5 %. In 18/27 cases (66.6 %), radiological evidence of CRT was preceded by clinical symptoms. However, in 9/27 (33.3 %), CRT was clinically asymptomatic. The median times to symptomatic and asymptomatic CRT were 17 (range 1–49) and 8 (range 1–16) catheter days, respectively. In univariate analysis, the risk factors for CRT were exit-site infection (ESI) (P < 0.001), two or more prior chemotherapy lines (P = 0.015), catheter-related blood stream infection (P < 0.001), and Coagulase-negative staphylococci infection (P = 0.002). In multivariate analysis, ESI (OR 5.0; 95 % CI 1.6–6.3; P = 0.006) and two or more prior chemotherapy lines (OR 3.57; 95 % CI 1.27–10.11; P = 0.015) remained significantly associated with the risk of CRT. The results of our study provide information regarding the characteristic features of the patients who are at high risk of thrombosis, for whom Doppler ultrasound screening should be considered.

Assessing the risk and prognosis of thrombotic complications in cancer patients

CONTEXT

Cancer is characterized by the development of a prothrombotic state. Approximately 15% to 20% and 1.5% to 3.1% of cancer patients develop venous and arterial thrombosis, respectively, whereas 18% to 20% of idiopathic venous events are caused by an occult neoplasia. The highest risk is observed in hematologic, gastrointestinal, and lung malignancies, as well as in patients with active disease, especially in the first 3 months after cancer diagnosis. Hospitalization, surgical interventions, and implanted venous devices increase the thrombotic risk. Patients with metastatic disease, febrile neutropenia, infections, and severe comorbidities experience more frequently a thrombotic event. A contemporary prechemotherapy predictive model incorporates both clinical and biologic parameters, such as the primary cancer site, platelet count, white blood cell count, hemoglobin, use of erythropoietic agents, and body mass index. Several studies aim to clarify the prognostic value of tissue factor, P-selectin, thrombin generation, microparticles, and D-dimers.

OBJECTIVES

To summarize current views on epidemiology, risk factors, and predictive variables, discussing the future perspectives and existing limitations in clinical practice.

DATA SOURCES

Review of published literature, including review papers, epidemiologic studies, and clinical trials, in online medical databases.

CONCLUSIONS

The thrombogenic properties of tumor cells affect the prognosis and quality of life for the cancer population. Despite the improved awareness and prompt use of thromboprophylaxis, recent studies reported increased rates of thrombotic events, whereas the annual risks for thrombosis recurrence and bleeding are 21% and 12%, respectively. The clinical use of risk factors and prognostic parameters could allow for patient risk stratification and individualization of anticoagulant treatment.

Epidemiology of cancer-associated venous thrombosis

Cancer-associated venous thrombosis is a common condition, although the reported incidence varies widely between studies depending on patient population, start and duration of follow-up, and the method of detecting and reporting thrombotic events. Furthermore, as cancer is a heterogeneous disease, the risk of venous thrombosis depends on cancer types and stages, treatment measures, and patient-related factors. In general, cancer patients with venous thrombosis do not fare well and have an increased mortality compared with cancer patients without. This may be explained by the more aggressive type of malignancies associated with this condition. It is hypothesized that thromboprophylaxis in cancer patients might improve prognosis and quality of life by preventing thrombotic events. However, anticoagulant treatment leads to increased bleeding, particularly in this patient group, so in case of proven benefit of thromboprophylaxis, only patients with a high risk of venous thrombosis should be considered. This review describes the literature on incidence of and risk factors for cancer-associated venous thrombosis, with the aim to provide a basis for identification of high-risk patients and for further development and refinement of prediction models. Furthermore, knowledge on risk factors for cancer-related venous thrombosis may enhance the understanding of the pathophysiology of thrombosis in these patients.

Catheter-related thrombosis in cancer patients

Central venous catheters are commonly used in haematology departments for the administration of chemotherapy, blood products and parenteral nutrition in patients with haematological malignancy. Thrombosis is a recognized complication of such devices especially in oncology patients. Catheter-related thrombi (CRT) may lead to pulmonary embolism and infection, as well as catheter failure and potential delays in treatment. The vast majority of CRT are asymptomatic, thus a high index of suspicion is required in making the diagnosis. Doppler ultrasound or venography may be employed to identify CRT. Once confirmed, the initiation of treatment is a balance between the risks of anticoagulation against potential complications of CRT. A number of risk factors for CRT are discussed along with an overview of catheter types, their appropriate choice and intravascular positioning.

Testing for inherited thrombophilia and consequences for antithrombotic prophylaxis in patients with venous thromboembolism and their relatives. A review of the Guidelines from Scientific Societies and Working Groups

The clinical penetrance of venous thromboembolism (VTE) susceptibility genes is variable, being lower in heterozygous carriers of factor V Leiden and prothrombin 20210A (mild thrombophilia), and higher in the rare carriers of deficiencies of antithrombin, protein C or S, and those with multiple or homozygous abnormalities (high-risk thrombophilia). The absolute risk of VTE is low, and the utility of laboratory investigation for inherited thrombophilia in patients with VTE and their asymptomatic relatives has been largely debated, leading to the production of several Guidelines from Scientific Societies and Working Groups. The risk for VTE largely depends on the family history of VTE. Therefore, indiscriminate search for carriers is of no utility, and targeted screening is potentially more fruitful. In patients with VTE inherited thrombophilia is not scored as a determinant of recurrence, playing a minor role in the decision of prolonging anticoagulation; indeed, a few guidelines consider testing worthwhile to identify carriers of high-risk thrombophilia, particularly those with a family history of VTE. The identification of the asymptomatic carrier relatives of the probands with VTE and thrombophilia could reduce cases of provoked VTE, offering them primary antithrombotic prophylaxis during risk situations. In most guidelines, this is considered justified only for relatives of probands with a deficiency of natural anticoagulants or multiple abnormalities. Counselling the asymptomatic female relatives of individuals with VTE and/or thrombophilia before pregnancy or the prescription of hormonal treatments should be administered with consideration of the risk driven by the type of thrombophilia and the family history of VTE.

Central venous catheter care for the patient with cancer: American Society of Clinical Oncology clinical practice guideline

PURPOSE

To develop an evidence-based guideline on central venous catheter (CVC) care for patients with cancer that addresses catheter type, insertion site, and placement as well as prophylaxis and management of both catheter-related infection and thrombosis.

METHODS

A systematic search of MEDLINE and the Cochrane Library (1980 to July 2012) identified relevant articles published in English.

RESULTS

The overall quality of the randomized controlled trial evidence was rated as good. There is consistency among meta-analyses and guidelines compiled by other groups as well.

RECOMMENDATIONS

There is insufficient evidence to recommend one CVC type or insertion site; femoral catheterization should be avoided. CVC should be placed by well-trained providers, and the use of a CVC clinical care bundle is recommended. The use of antimicrobial/antiseptic-impregnated and/or heparin-impregnated CVCs is recommended to decrease the risk of catheter-related infections for short-term CVCs, particularly in high-risk groups; more research is needed. The prophylactic use of systemic antibiotics is not recommended before insertion. Data are not sufficient to recommend for or against routine use of antibiotic flush/lock therapy; more research is needed. Before starting antibiotic therapy, cultures should be obtained. Some life-threatening infections require immediate catheter removal, but most can be treated with antimicrobial therapy while the CVC remains in place. Routine flushing with saline is recommended. Prophylactic use of warfarin or low-molecular weight heparin is not recommended, although a tissue plasminogen activator (t-PA) is recommended to restore patency to occluded catheters. CVC removal is recommended when the catheter is no longer needed or if there is a radiologically confirmed thrombosis that worsens despite anticoagulation therapy.

Extra-abdominal venous thromboses at unusual sites

Venous thrombosis typically involves the lower extremities. Rarely, it can occur in cerebral, splanchnic, or renal veins, with a frightening clinical impact. Other rare manifestations are upper-extremity deep vein thrombosis, that can complicate with pulmonary embolism and post-thrombotic syndrome, and retinal vein occlusion, significantly affecting the quality of life. This review is focused on venous thromboses at unusual extra-abdominal sites. Local infections or cancer are frequent in cerebral sinus-venous thrombosis. Upper-extremity deep vein thrombosis is mostly due to catheters or effort-related factors. Common risk factors are inherited thrombophilia and oral contraceptive use. Acute treatment is based on heparin; in cerebral sinus-venous thrombosis, local or systemic fibrinolysis should be considered in case of clinical deterioration. Vitamin-K antagonists are recommended for 3-6 months; indefinite anticoagulation is suggested for recurrent thrombosis or unprovoked thrombosis and permanent risk factors. However, such recommendations mainly derive from observational studies; there are no data about long-term treatment of retinal vein occlusion.

Epidemiology and prevention of catheter-related thrombosis in patients with cancer

Central venous catheters are extensively used in patients with cancer to secure delivery of chemotherapy and facilitate phlebotomy. Unfortunately, considerable morbidity can result from early complications or late sequelae, ranging from arterial puncture, pneumothorax and bloodstream infections to catheter-related thrombosis (CRT). Contemporary studies have shown that the incidence of symptomatic CRT is ∼5%, whereas the incidence of asymptomatic CRT is higher, at 14-18%. The significance and mechanisms of catheter design, material, insertion location and technique, position of the catheter tip and other risk factors in contributing to the development of CRT are not well understood. Efforts to reduce thrombotic complications, involving flushing the catheter with heparinized solutions, the use of heparin-bonded catheters, and systemic anticoagulant prophylaxis, have been largely ineffective. More studies are needed to understand the pathophysiology of thrombotic complications, to help identify effective interventions to reduce this adverse outcome.

Factor V Leiden thrombophilia

Factor V Leiden is a genetic disorder characterized by a poor anticoagulant response to activated Protein C and an increased risk for venous thromboembolism. Deep venous thrombosis and pulmonary embolism are the most common manifestations, but thrombosis in unusual locations also occurs. The current evidence suggests that the mutation has at most a modest effect on recurrence risk after initial treatment of a first venous thromboembolism. Factor V Leiden is also associated with a 2- to 3-fold increased relative risk for pregnancy loss and possibly other obstetric complications, although the probability of a successful pregnancy outcome is high. The clinical expression of Factor V Leiden is influenced by the number of Factor V Leiden alleles, coexisting genetic and acquired thrombophilic disorders, and circumstantial risk factors. Diagnosis requires the activated Protein C resistance assay (a coagulation screening test) or DNA analysis of the F5 gene, which encodes the Factor V protein. The first acute thrombosis is treated according to standard guidelines. Decisions regarding the optimal duration of anticoagulation are based on an individualized assessment of the risks for venous thromboembolism recurrence and anticoagulant-related bleeding. In the absence of a history of thrombosis, long-term anticoagulation is not routinely recommended for asymptomatic Factor V Leiden heterozygotes, although prophylactic anticoagulation may be considered in high-risk clinical settings. In the absence of evidence that early diagnosis reduces morbidity or mortality, decisions regarding testing at-risk family members should be made on an individual basis.

[Activated protein C resistance and factor V Leiden: clinical interest]

Activated protein C resistance (APCR) is a coagulation abnormality often linked to FV Leiden mutation, a single nucleotide G1691A substitution resulting in arginine 506→glutamine missense factor V mutation. FV Leiden has a frequency of 20 to 30% in groups of patients with venous thrombosis while it is of 4 to 10% in normal subjects. FV Leiden is considered as a weak risk factor of thrombosis except in homozygote. FV Leiden is implicated in deep venous thrombosis occurrence. Duration of oral anticoagulant treatment is six months in patients developing a first venous thrombosis except in patients with combined defects or a clinical context suggesting a high risk of severe relapse. Detection of APCR by coagulation methods is often used in first intention with a high specificity if plasmas tested are diluted in factor V deficient plasma. Genotyping study is essential to establish the heterozygote or homozygote statute and certain teams perform it directly. Nevertheless, APCR not related to FV Leiden could be an independent thrombosis risk factor. APCR and FV Leiden are included in laboratory investigations of thrombophilic markers in patients less than 50 years with venous thrombosis. In arterial thrombosis, FV Leiden implication is weak or absent. FV Leiden increases the risk of thrombosis in other situations as in patients with cancer. An association with recurrent miscarriages and other vasculoplacental complications is also reported in many studies but the data concerning the efficacy of antithrombotic treatment to prevent recurrence are currently insufficient.

Childhood outcomes of neonates diagnosed with portal vein thrombosis

AIM

The study aims to determine childhood outcomes of neonates diagnosed with portal vein thrombosis (PVT).

METHODS

A retrospective chart review of neonates diagnosed with PVT who had documented follow up (physical examination, laboratory tests or ultrasonographic examination) at the age of 2 years or beyond was conducted.

RESULTS

Data were available for 70 children (71% of eligible neonates) at a median age of 5 years (range 2-8 years). Physical examination was unremarkable in all who were examined (n= 68). Twenty-five children had liver functions assessed and only mild abnormalities were detected in nine children. Six of 25 patients tested for thrombophilia showed abnormalities. Thirty-seven children had ultrasonographic follow up. Left lobar atrophy (LLA) was noted in 20 children (16 had isolated LLA, two had LLA and splenomegaly, and two had LLA and portal hypertension). Five children who had normal ultrasound examinations at discharge had splenomegaly (two with additional finding of LLA) at follow up. Two children with portal hypertension diagnosed during neonatal period needed porta-caval shunting.

CONCLUSION

Our results show that among patients, who had PVT as neonates, 28% still had asymptomatic LLA in childhood, 7% had slowly progressive splenomegaly and 3% required shunting because of progression of portal hypertension. Ultrasonographic follow up was the most sensitive method in detecting progression associated with neonatal PVT. Until more data are available, periodic long-term ultrasonographic follow up should be considered for neonates diagnosed with PVT.

Validation of a predictive model for identifying an increased risk for thromboembolism in children with acute lymphoblastic leukemia: results of a multicenter cohort study

Among risk factors for developing thromboembolism (VTE) in children with acute lymphoblastic leukemia were Escherichia coli asparaginase, concomitant steroid use, presence of central venous lines, and thrombophilic abnormalities. Developing a predictive model for determining children at increased risk would be beneficial in targeting interventional studies to high-risk groups (HRGs). Predictive variables were incorporated into a risk assessment model, which was evaluated in 456 children and then validated in 339 patients. VTE risk by score was no greater than 2.5 for low-risk group (LRG) and greater than 2.5 for HRG. VTE rates at 3.5 months (validation cohorts) were 2.5% in LRG and 64.7% in HRG. In multivariate analysis adjusted for age, duration of asparaginase administration, enoxaparin prophylaxis, and T-immunophenotype, the HRG was significantly associated with VTE compared with the LRG (hazard/95% confidence interval [CI], 8.22/1.85-36.53). Model specificity was 96.2% and sensitivity was 63.2%. As secondary objective we investigated the use of enoxaparin for VTE prophylaxis in the HRG. HRG patients without enoxaparin prophylaxis showed a significantly reduced thrombosis-free survival compared with children on low-molecular-weight heparin (LMWH). On the basis of the high specificity, the model may identify children with leukemia at risk of VTE. LMWH may help prevent VTE in the HRG; this warrants assessment in larger cooperative clinical trials.

Assessing risk of venous thromboembolism in the patient with cancer

PURPOSE

Patients with cancer are increasingly at risk for venous thromboembolism (VTE). Rates of VTE, however, vary markedly among patients with cancer.

DESIGN

This review focuses on recent data derived from population-based, hospital-based, and outpatient cohort studies of patients with cancer that have identified multiple clinical risk factors as well as candidate laboratory biomarkers predictive of VTE.

RESULTS

Clinical risk factors for cancer-associated VTE include primary tumor site, stage, initial period after diagnosis, presence and number of comorbidities, and treatment modalities including systemic chemotherapy, antiangiogenic therapy, and hospitalization. Candidate predictive biomarkers include elevated platelet or leukocyte counts, tissue factor, soluble P-selectin, and D-dimer. A recently validated risk model, incorporating some of these factors, can help differentiate patients at high or low risk for developing VTE while receiving chemotherapy.

CONCLUSION

Identifying patients with cancer who are most at risk for VTE is essential to better target thromboprophylaxis, with the eventual goal of reducing the burden as well as the consequences of VTE for patients with cancer.

Thrombosis in childhood acute lymphoblastic leukaemia: epidemiology, aetiology, diagnosis, prevention and treatment

Acute lymphoblastic leukaemia (ALL) is the most common malignancy associated with venous thromboembolism (VTE) in children. The prevalence of symptomatic VTE ranges from 0% to 36%, and the variation can be explained, at least in part, by differences in chemotherapeutic protocols. The mechanism for increased risk of VTE is associated with alterations in the haemostatic system by use of L-asparaginase (ASP) alone or in combination with vincristine or prednisone, presence of central venous lines (CVLs) and/or inherited thrombophilia. The children at greatest risk are generally those receiving Escherichia coli ASP concomitant with prednisone. The majority of symptomatic VTEs occur in the central nervous system or in the upper venous system. In the majority of cases, asymptomatic VTEs are associated with CVLs. External CVLs are affected more often than internal CVLs. Evidence-based guidelines on prevention and treatment guidelines for ALL-related VTE are lacking, and carefully designed clinical trials are needed urgently.

[Venous thromboembolism associated with long-term use of central venous catheters in cancer patients]

Increased incidence of cancers and the development of totally implanted venous access devices that contain their own port to deliver chemotherapy will lead to a greater than before numbers of central venous catheter-related thrombosis (CVCT). Medical consequences include catheter dysfunction and pulmonary embolism. Vessel injury caused by the procedure of CVC insertion is the most important risk factor for development of CVCT. This event could cause the formation of a fresh thrombus, which is reversible in the large majority of patients. In some cases, thrombus formation is not related to catheter insertion. The incidence of CVC-related DVT assessed by venography has been reported to vary from 30 to 60% but catheter-related DVT in adult patients is symptomatic in only 5% of cases. The majority of patients with CVC-related DVT is asymptomatic or has nonspecific symptoms: arm or neck swelling or pain, distal paresthesias, headache, congestion of subcutaneous collateral veins. In the case of clinical suspicion of CVC-related deep venous thrombosis (DVT), compressive ultrasonography (US), especially with doppler and color imaging, currently is first used to confirm the diagnosis. Consequently, contrast venography is reserved for clinical trials and difficult diagnostic situations. There is no consensus on the optimal management of patients with CVC-related DVT. Treatment of CVC-related VTE requires a five- to seven-day course of adjusted-dose unfractionated heparin or low molecular weight heparin (LMWH) followed by oral anticoagulants. Long-term LMWH that has been shown to be more effective than oral anticoagulant in cancer patients with lower limb DVT, could be used in these patients. The efficacy and safety of pharmacologic prophylaxis for CVC related thrombosis is not established and the last recommendations suggest that clinicians not routinely use prophylaxis to try to prevent thrombosis related to long-term indwelling CVCs in cancer patients. Additional studies performed in high risk populations with appropriate dosage and timing will help to define which patients could benefit from prophylaxis.