Extensive splanchnic vein thrombosis after SARS-CoV-2 vaccination: A Vascular Liver Disease Group (VALDIG) initiative.

BACKGROUND AND AIMS: Since the introduction of SARS-CoV-2 vaccines, several cases of vaccine-induced immune thrombocytopenia and thrombosis (VITT) have been described, especially cerebral vein thrombosis. We aimed to retrospectively collect all new cases of acute onset first or recurrent splanchnic vein thrombosis (SVT) following a recent SARS-CoV-2 vaccination within the Vascular Liver Disease Group network. APPROACH AND RESULTS: New cases of SVT were identified from April 2021 to April 2022; follow-up was completed on December 31, 2022. Criteria to define VITT were derived from previous studies. Data from a pre-COVID cohort of patients with SVT (N=436) were used for comparison of clinical presentation, etiology, and outcome. Twenty-nine patients were identified with SVT occurring with a median of 11 days (range 2-76) after the first (48%), second (41%), or third (10%) vaccination (ChAdOx1 nCov-19 (n=12) or BNT162b2 (n=14), other (n=3) Only 2 patients(7%) fulfilled criteria for definite VITT. Twenty (69%) had SVT at multiple sites, including 4 (14%) with concomitant extra-abdominal thrombosis. Only 28% had an underlying prothrombotic condition, compared to 52% in the pre-COVID SVT cohort ( p =0.01). Five patients (17%) underwent bowel resection for mesenteric ischemia, compared with 3% in pre-COVID SVT ( p <0.001). Two patients died shortly after diagnosis (7%). CONCLUSIONS: Although definite VITT was rare, in 72% of cases, no other cause for SVT could be identified following SARS-CoV-2 vaccination. These cases were different from patients with nonvaccine-related SVT, with lower incidence of prothrombotic conditions, higher rates of bowel ischemia, and poorer outcome. Although SVT after SARS-CoV-2 vaccination is rare in absolute terms, these data remain relevant considering ongoing revaccination programs.

A Case of Complete Resolution of Cauda Equina Syndrome Caused by Extensive Iliocaval Thrombosis: The Role of Thrombolysis and Venous Stents.

PURPOSE: The cauda equina syndrome (CES) is a rare condition affecting less than 1 in 100,000 patients annually. Diagnosing CES is challenging because of its rare incidence, potentially subtle presentation, and various underlying etiologies. Vascular causes, such as inferior vena cava (IVC) thrombosis, are uncommon but should be considered, since timely recognition and treatment of deep vein thrombosis (DVT) as a cause of CES can avoid irreversible neurological damage. CASE REPORT: A 30-year-old male presented with partial CES caused by nerve root compression due to venous congestion from an extensive iliocaval DVT. He completely recovered after thrombolysis and stenting of the IVC. His iliocaval tract remained patent until the last date of follow-up at 1 year without signs of post-thrombotic syndrome. Broad molecular, infectious, and hematological laboratory tests did not reveal any underlying disease for the thrombotic event, particularly no hereditary or acquired thrombophilia. CONCLUSION: Timely recognition of venous thrombosis as a cause of CES is essential. This is the first case report of CES caused by an extensive iliocaval DVT successfully treated with thrombolysis and venous stenting with good resolution of DVT and CES. CLINICAL IMPACT: This case-report describes a patient with cauda equina syndrome resulting from an extensive iliocaval deep vein thrombosis due to an underlying stenosis of the inferior vena cava. Thrombolysis and venous stenting succesfully restored venous patency and thereby relieved symptoms and signs of cauda equina syndrome, in addition to (long-term) therapeutic dose anticoagulation. It is important to timely recognize deep vein thrombosis as a cause of cauda equina syndrome and to consider endovenous treatment in a specialized center.

TropicALL study: Thromboprophylaxis in Children treated for Acute Lymphoblastic Leukemia with Low-molecular-weight heparin: a multicenter randomized controlled trial.

BACKGROUND: Venous thromboembolism (VTE) is a common and severe complication during treatment of acute lymphoblastic leukemia (ALL). An important cause is the intensive use of asparaginase. Prospective cohort studies in which prophylactic low-molecular-weight heparin (LMWH) was used to prevent VTE showed lower VTE risk than in historic control cohorts, with a negligible bleeding risk. However, the efficacy of thromboprophylaxis with LMWH during ALL treatment has never been investigated in a randomized design. Here, we present the protocol of a randomized controlled trial in which the efficacy and safety of thromboprophylaxis with high prophylactic dose LMWH versus no thromboprophylaxis will be assessed in children treated for primary ALL with asparaginase. METHODS/DESIGN: Thromboprophylaxis in Children treated for Acute Lymphoblastic Leukemia with Low-molecular-weight heparin (TropicALL) is a multicenter, randomized controlled open-label trial conducted in the Netherlands. Patients between 1 and 19 years of age with primary ALL, who are treated within the Dutch Childhood Oncology Group (DCOG) ALL-11 or 12 study will be randomized to thromboprophylaxis with LMWH once daily, (dose of 85 IU/kg (intervention arm A)), or to no thromboprophylaxis (arm B, standard of care) during asparaginase courses of ALL treatment. Primary efficacy endpoint is symptomatic objectified VTE during ALL treatment; secondary efficacy endpoints are overall survival and the composite of symptomatic and asymptomatic objectified VTE. Primary safety endpoints are major bleeding, clinically relevant non-major bleeding and minor bleeding. A total of 324 patients will be included to obtain a relative risk reduction of 75% with a power of 80%, using a two-sided test with significance level α = 0.05. DISCUSSION: This trial will be the first to assess efficacy and safety of thromboprophylaxis with LMWH during asparaginase treatment for ALL in children in a randomized design. TRAIL REGISTRATION: Nederlands Trial Register NTR4707 . Registered 30 July 2014.

Role of phenotypic and genetic testing in managing clopidogrel therapy.

The P2Y12 inhibitors, clopidogrel, prasugrel, and ticagrelor, are administered in fixed doses without laboratory monitoring. Randomized trials in acute coronary syndrome have shown that prasugrel and ticagrelor are more effective than standard-dose clopidogrel. Nonetheless, standard-dose clopidogrel remains widely used because it causes less bleeding and is less expensive. Patients treated with standard-dose clopidogrel have substantial variability in platelet inhibition, which is partly explained by genetic polymorphisms encoding CYP2C19, the hepatic enzyme involved in biotransformation of clopidogrel to its active metabolite. Some advocate tailoring P2Y12 inhibitor therapy according to the results of routine laboratory testing. Although there is good evidence for analytic, biological, and clinical validity of several phenotypic and genotypic biomarkers, the benefit of a management strategy that incorporates routine biomarker testing over standard of care without such testing remains unproven. Appropriately designed, adequately powered trials are needed but face the challenges of feasibility, cost, and the progressive switch from clopidogrel to prasugrel or ticagrelor.

Risk of ischaemic stroke according to pattern of atrial fibrillation: analysis of 6563 aspirin-treated patients in ACTIVE-A and AVERROES.

AIMS: The pattern of atrial fibrillation (AF) occurrence-paroxysmal, persistent, or permanent-is associated with progressive stages of atrial dysfunction and structural changes and may therefore be associated with progressively higher stroke risk. However, previous studies have not consistently shown AF pattern to predict stroke but have been hampered by methodological shortcomings of low power, variable event ascertainment, and variable anticoagulant use. METHODS AND RESULTS: We analysed the rates of stroke and systemic embolism in 6563 aspirin-treated patients with AF from the ACTIVE-A/AVERROES databases. There was thorough searching for events and adjudication. Multivariable analyses were performed with the adjustment for known risk factors for stroke. Mean age of patients with paroxysmal, persistent, and permanent AF was 69.0 ± 9.9, 68.6 ± 10.2, and 71.9 ± 9.8 years (P < 0.001). The CHA2DS2-VASc score was similar in patients with paroxysmal and persistent AF (3.1 ± 1.4), but was higher in patients with permanent AF (3.6 ± 1.5, P < 0.001). Yearly ischaemic stroke rates were 2.1, 3.0, and 4.2% for paroxysmal, persistent, and permanent AF, respectively, with adjusted hazard ratio of 1.83 (P < 0.001) for permanent vs. paroxysmal and 1.44 (P = 0.02) for persistent vs. paroxysmal. Multivariable analysis identified age ≥ 75 year, sex, history of stroke or TIA, and AF pattern as independent predictors of stroke, with AF pattern being the second strongest predictor after prior stroke or TIA. CONCLUSION: In a large population of non-anticoagulated AF patients, pattern of AF was a strong independent predictor of stroke risk and may be helpful to assess the risk/benefit for anticoagulant therapy, especially in lower risk patients.

A systematic review of contemporary trials of anticoagulants in orthopaedic thromboprophylaxis: suggestions for a radical reappraisal.

In the last decade, major advances in venous thromboembolism (VTE) prophylaxis in orthopaedic surgery have included the development of new anticoagulants that are poised to replace low molecular weight heparins (LMWHs) and improvements in operative and perioperative care that have likely led to a decline in the rates of symptomatic VTE and mortality independent of anticoagulant use. A systematic review of the literature was performed to identify phase III randomized controlled trials of VTE prevention that compared new anticoagulants (fondaparinux, rivaroxaban, dabigatran, apixaban) with LMWH (enoxaparin) in major elective orthopaedic surgery. Our aims were to obtain best estimates of the rates of patient important events (symptomatic VTE, mortality, and bleeding) in contemporary trials of VTE prevention, and to consider the implications of these contemporary rates for clinical practice and future research. Fourteen studies, which enrolled 40,285 patients, were included in the analyses. The combined median rates (ranges) for all five anticoagulants for symptomatic VTE and mortality to the end of follow-up were 0.99 % (0.15-2.58 %) and 0.26 % (0-0.92 %) respectively, whereas the median rate (range) of clinically important bleeding was 3.44 % (2.25-7.74 %). In contemporary trials of anticoagulants, the rates of symptomatic VTE and mortality are low, but the rates of clinically important post-operative bleeding remain relatively high. Based on these results, we propose that approaches that minimize bleeding without substantially reducing efficacy merit investigation, particularly if improvement in surgical and perioperative care have also resulted in falling baseline patient important VTE rates independent of anticoagulant use.

Clinical Course of Cerebral Venous Thrombosis in Adult Acute Lymphoblastic Leukemia.

BACKGROUND: Venous thromboembolism (VTE) is a frequent complication in patients with acute lymphoblastic leukemia (ALL). A significant proportion of patients develop cerebral venous thrombosis (CVT). METHODS: To investigate risk factors for and the clinical course of CVT in ALL patients, we describe all cases of CVT which occurred in a well-defined cohort of 240 adults, treated for newly diagnosed ALL in the HOVON (Dutch-Belgian Hemato-Oncology Cooperative Group)-37 study. We conducted a nested case-control study to explore the relevance of early symptoms and risk factors for CVT in ALL patients. RESULTS: Nine of 240 patients developed CVT (4%). CVT occurred during or shortly after L-asparaginase therapy (in 8 cases) and shortly after intrathecal methotrexate injections (in all cases) during cycle I of remission induction treatment. CVT was associated with prior headache and seizures. In 5 of 9 patients with CVT, headache before the diagnosis of CVT occurred within 3 days after lumbar puncture and initially had a postural character. CONCLUSIONS: CVT is relatively common in adult ALL patients. Our data suggest that CVT in adult ALL patients results from the additive effects of multiple risk factors, with a particular role for asparaginase and the effects of lumbar punctures for intrathecal therapy.

Circulating nucleosomes and neutrophil activation as risk factors for deep vein thrombosis.

OBJECTIVE: The formation of neutrophil extracellular traps and the exposure of nucleosomes on these neutrophil extracellular traps contribute to coagulation activation and the propagation of deep vein thrombosis (DVT) in animal models. However, no data are available on the role of neutrophil extracellular traps or nucleosomes in patients with thrombosis. METHODS AND RESULTS: We conducted a case-control study, in which levels of circulating nucleosomes and neutrophil elastase-α1-antitrypsin complexes were assessed in plasma from 150 patients with objectified symptomatic DVT (cases) and compared with 195 patients with a clinical suspicion of DVT but in whom DVT was excluded (controls). We explored the association between both nucleosomes and elastase-α1-antitrypsin complexes, and the presence of DVT by calculating the odds ratio with corresponding 95% CIs. Elevated levels of both circulating nucleosomes and elastase-α1-antitrypsin complexes were associated with a 3-fold risk of DVT, and the associations remained similar after adjustment for potential confounders (malignancy, smoking, recent immobilization, recent hospitalization). The risk increased with higher nucleosome and elastase-α1-antitrypsin complex levels, suggesting a dose-dependent relationship among circulating nucleosomes, activated neutrophils, and DVT. CONCLUSIONS: Our study suggests an association among circulating nucleosomes, activated neutrophils, and presence of DVT in humans, which might have implications for treatment and prevention.

A meta-analysis to assess the risk of bleeding and thrombosis following chimeric antigen receptor T-cell therapy: Communication from the ISTH SSC Subcommittee on Hemostasis and Malignancy.

BACKGROUND: Chimeric antigen receptor T-cell (CAR T-cell) therapy is increasingly utilized for treatment of hematologic malignancies. Hematologic toxicities including thrombosis and bleeding complications have been reported. Accurate estimates for thrombotic and bleeding outcomes are lacking. OBJECTIVES: We performed a systematic review and meta-analysis in patients who received CAR T-cell therapy for an underlying hematologic malignancy with the objective to: a) assess the thrombosis and bleeding risk associated with CAR T-cell therapy, b) assess the impact of CRS and ICANS on the risks of thrombosis and bleeding, and c) assess the safety of anticoagulant or antiplatelet use in the period following treatment with CAR T-cell therapy. METHODS: We searched MEDLINE, EMBASE, and Cochrane CENTRAL up to February 2022 for studies reporting thrombotic or bleeding outcomes in patients receiving CAR T-cell therapy. Pooled event rates were calculated using a random-effects model. We performed subgroup analyses stratified by follow-up duration, CAR T-cell target antigen, and underlying hematologic malignancy. RESULTS: We included 47 studies with a total of 7040 patients. High heterogeneity between studies precluded reporting of overall pooled rates of thrombotic and bleeding events. In studies with follow-up duration of ≤6 months, the pooled incidence of venous thrombotic events was 2.4% (95% CI, 1.4%-3.4%; I2 = 0%) per patient-month, whereas the rate was 0.1% (95% CI, 0%-0.1%; I2 = 0%) per patient-month for studies with longer follow-up periods (>6 months). The pooled incidences of any bleeding events per patient-month in studies with follow-up duration of ≤6 months and >6 months were 1.9% (95% CI, 0.6%-3.1%; I2 = 78%) and 0.3% (95% CI: 0%-0.8%, I2 = 40%), respectively. Secondary analyses by CAR T-cell target antigen, underlying malignancy, and primary outcome of the studies did not reveal significant differences in the rates of thromboembolism, any bleeding events, or major bleeding events. CONCLUSION: The risk of both thrombosis and bleeding following CAR T-cell therapy appears to be highest in the initial months following infusion.

Anticoagulation for splanchnic vein thrombosis in myeloproliferative neoplasms: a systematic review and meta-analysis.

BACKGROUND: Optimal anticoagulation management in patients with myeloproliferative neoplasms (MPN) experiencing splanchnic vein thrombosis (SpVT) requires balancing risks of bleeding and recurrent thrombosis. OBJECTIVES: We conducted a systematic review and meta-analysis to assess the incidence of bleeding and thrombosis recurrence in patients with MPN-SpVT. METHODS: We included retrospective or prospective studies in English with ≥10 adult patients with MPN-SpVT. Outcomes included recurrent venous thrombosis (SpVT and non-SpVT), arterial thrombosis, and major bleeding. Pooled rates per 100 patient years with 95% CIs were calculated by DerSimonian-Laird method using random-effects model. RESULTS: Out of 4624 studies screened, 9 studies with a total of 443 patients were included in the meta-analysis with median follow-up of 3.5 years. In the 364 patients with MPN-SpVT treated with anticoagulation, pooled event rate for major bleeding was 2.8 (95% CI, 1.5-5.1; I2 = 95%), for recurrent venous thrombosis was 1.4 (95% CI, 0.8-2.2; I2 = 72%), and for arterial thrombosis was 1.4 (95% CI, 0.6-3.3; I2 = 92%) per 100 patient years. Among 79 patients (n = 4 studies) who did not receive anticoagulation, pooled event rate for major bleeding was 3.2 (95% CI, 0.7-12.7; I2 = 97%), for recurrent venous thrombosis 3.5 (95% CI, 1.8-6.4; I2 = 88%), and for arterial thrombosis rate 1.6 (95% CI, 0.4-6.6; I2 = 95%) per 100 patient years. CONCLUSION: Patients with MPN-SpVT treated with anticoagulation have significant risks for both major bleeding and thrombosis recurrence. Further studies are necessary to determine the optimal anticoagulation approach in patients with MPN-SpVT.

Cerebral venous thrombosis and thrombophilia: a systematic review and meta-analysis.

Cerebral venous thrombosis (CVT) is a rare manifestation of venous thromboembolism (VTE) and stroke. The aim of our systematic review was to provide an updated summary of the strength of association between CVT and thrombophilia and to explore the relevance of thrombophilia for recurrence of CVT or other VTE, or other outcome variables. MEDLINE (via PubMed), EMBASE (via Ovid), and CENTRAL were systematically searched, including references of retrieved articles. Cohort studies of ≥ 40 patients and case-control studies comparing the prevalence of thrombophilia in patients with CVT and unrelated controls were eligible. Two reviewers independently selected studies, assessed quality, and extracted data. A meta-analysis was performed for high quality case-control studies with unselected cases and healthy controls. Odds ratios with 95% confidence intervals were calculated and pooled. We included 23 cohort studies and 33 case-control studies. A significant association was demonstrated between CVT and all inherited thrombophilic factors, as well as increased levels of homocysteine. Inconclusive results were found on the relevance of thrombophilia for recurrent CVT or other VTE. Although there is a strong association between CVT and thrombophilia, the clinical relevance of thrombophilia testing in patients with CVT seems limited, similarly to other forms of VTE.

Cancer and venous thrombosis: current comprehensions and future perspectives.

Venous thromboembolism (VTE) is a common complication in all types of cancer and adversely impacts cancer prognosis. Randomized controlled trials with primary thromboprophylaxis in cancer patients generally show effective VTE relative risk reductions of up to 60%. However, absolute risks of VTE were fairly low. Thromboprophylaxis should therefore only be recommended to cancer patients at highest risk of VTE, who may benefit most from prophylaxis. Predictive risk models to identify patients at a high risk of VTE are promising, however additional validation is required. An increasing proportion of cancer-associated VTE is formed by incidental VTE, with similar risk factors and clinical consequences. Randomized trials are not yet available, but it seems reasonable to treat incidental VTE similarly to symptomatic VTE. In a substantial proportion of patients with unprovoked VTE without known cancer at the time of VTE diagnosis, concomitant or occult cancer is identified. Studies have investigated the value of extensive screening over routine examinations alone for occult cancer. Although extensive screening may be able to identify more occult cancers, its clinical benefit over routine screening has not been demonstrated.

Relevance of the JAK2V617F mutation in patients with deep vein thrombosis of the leg.

Venous thromboembolism (VTE) can be the first presenting symptom in myeloproliferative neoplasms (MPN). Studies have demonstrated a high prevalence of the JAK2V617F mutation in patients with splanchnic vein thrombosis. Fewer studies have been done in patients with thrombosis outside the splanchnic area, showing a lower prevalence although the clinical relevance of the mutation in these patients, e.g., progression to overt MPN, remains unknown. The objective of this study was to determine the effect size of JAK2V617F in prospectively collected DNA samples of patients objectively diagnosed with deep vein thrombosis (DVT) of the leg and controls without DVT, with follow-up on JAK2V617F-positive patients to assess clinical relevance. Presence of JAK2V617F was determined in DNA samples from 187 patients with DVT and 201 controls, using quantitative RT-PCR. Hematological parameters were also analyzed. All initially JAK2V617F-positive patients were reassessed. Of 187 patients with DVT, 178 were analyzed for JAK2V617F, and in four (2.3%; 95% CI 0.1-4.4), JAK2V617F was present. Of 201 controls, 198 were analyzed; one was JAK2V617F positive (0.5%; 95% CI -0.5-1.5, OR 4.5; 95% CI 0.5-40.9). None had MPN features, nor upon reassessment after a median follow-up of 68.5 months. Four JAK2V617F-positive patients with DVT and one control without DVT did not develop overt MPN after a median follow-up of nearly 6 years. Thus, in patients with non-splanchnic venous thrombosis, JAK2V617F appears not to be clinically relevant.

Stroke and Thromboembolism in Patients with Heart Failure and Sinus Rhythm: A Matter of Risk Stratification?

Patients with heart failure (HF) in sinus rhythm (SR) experience an increased incidence of thromboembolic events including stroke. Among patients with HF, high-quality evidence supports the use of oral anticoagulation when atrial fibrillation is present, but the benefit of anticoagulation in SR in the absence of other known indications for anticoagulation is unclear. In four randomized controlled trials (RCTs), warfarin did not improve a composite of clinical outcomes compared with aspirin or placebo in patients with HF with reduced ejection fraction (HFrEF) and SR. A recent RCT assessed the efficacy of the direct oral anticoagulant rivaroxaban versus placebo in patients with HFrEF (including mildly reduced ejection fraction), SR, and coronary artery disease. While rivaroxaban had a neutral effect on the primary composite outcome of myocardial infarction, stroke, or all-cause mortality, exploratory analyses revealed a significant reduction in strokes. It is thus possible that a subgroup of patients with HFrEF who are at high risk of stroke may benefit from anticoagulation. The challenge is to adequately identify this subgroup and to balance the potential benefit of anticoagulation with the risk of major bleeding. There is also an unmet need for evidence around anticoagulation in HF with preserved ejection fraction and SR. This review explores the current evidence around anticoagulation in patients with HF and SR, identifies challenges regarding outcome definitions and patient selection, and offers suggestions for future research.

A systematic review of antithrombotic treatment of venous thromboembolism in patients with myeloproliferative neoplasms.

Patients with myeloproliferative neoplasms (MPNs), polycythemia vera, essential thrombocythemia, and primary myelofibrosis, have an increased risk of thrombosis. Risk of recurrent thrombosis can be reduced with antithrombotic therapy and/or cytoreduction, but the optimal long-term management in patients with MPN with a history of venous thromboembolism (VTE) is unknown, and clinical practice is heterogeneous. We performed a systematic review and meta-analysis of randomized trials and observational studies evaluating anticoagulant and/or antiplatelet therapy, with or without cytoreduction, in MPN patients with a history of VTE. A total of 5675 unique citations were screened for eligibility. No randomized trials were identified. Ten observational studies involving 1295 patients with MPN were included in the analysis. Overall, 23% had an arterial or recurrent venous thrombotic event on follow-up. The recurrence risk was lowest for patients on oral anticoagulation plus cytoreduction (16%); 55 of 313 (18%) with vitamin K antagonists (VKA) and 5 of 63 (8%) with direct oral anticoagulants (DOACs). In 746 analyzed patients, the risk of recurrent VTE ranged up to 33% (median 13%) and was low in 63 DOAC plus cytoreduction-treated patients (3.2%). All types of antithrombotic treatments were associated with a lower risk of recurrent VTE when combined with cytoreduction. Most studies had a high risk of bias, whereas clinical and statistical heterogeneity led to inconsistent and imprecise findings. In summary, evidence on the optimal antithrombotic treatment of VTE in patients with MPN is based on observational studies only with low certainty for all strategies. Our data suggest that a combination of anticoagulation and cytoreduction may provide the lowest recurrence risk.

The prevention and management of asparaginase-related venous thromboembolism in adults: Guidance from the SSC on Hemostasis and Malignancy of the ISTH.

Venous thromboembolism is a common complication of asparaginase-based chemotherapy regimens for the treatment of acute lymphoblastic leukemia. Thrombosis associated with asparaginase administration poses a number of specific and often clinically challenging management decisions. This review provides guidance on the prevention and treatment of thrombosis associated with asparaginase in adults including discussions on antithrombin repletion, pharmacologic thromboprophylaxis, cerebral venous thrombosis, and therapeutic anticoagulation.

Magnetic Resonance Thrombus Imaging to Differentiate Acute from Chronic Portal Vein Thrombosis.

Introduction Timely diagnosis and treatment of portal vein thrombosis (PVT) is crucial to prevent morbidity and mortality. However, current imaging tests cannot always accurately differentiate acute from chronic (nonocclusive) PVT. Magnetic resonance noncontrast thrombus imaging (MR-NCTI) has been shown to accurately differentiate acute from chronic venous thrombosis at other locations and may also be of value in the diagnostic management of PVT. This study describes the first phase of the Rhea study (NTR 7061). Our aim was to select and optimize MR-NCTI sequences that would be accurate for differentiation of acute from chronic PVT. Study Design The literature was searched for different MRI sequences for portal vein and acute thrombosis imaging. The most promising sequences were tested in a healthy volunteer followed by one patient with acute PVT and two patients with chronic PVT, all diagnosed on (repetitive) contrast-enhanced computed tomography (CT) venography to optimize the MR-NCTI sequences. All images were evaluated by an expert panel. Results Several MR-NCTI sequences were identified and tested. Differentiation of acute from chronic PVT was achieved with 3D T1 TFE (three-dimensional T1 turbo field echo) and 3D T1 Dixon FFE (three-dimensional T1 fast field echo) sequences with best image quality. The expert panel was able to confirm the diagnosis of acute PVT on the combined two MR-NCTI sequences and to exclude acute PVT in the two patients with chronic PVT. Conclusion Using 3D T1 TFE and 3D T1 Dixon FFE sequences, we were able to distinguish acute from chronic PVT. This clinical relevant finding will be elucidated in clinical studies to establish their test performance.

Venous thromboembolism in a large cohort of children with acute lymphoblastic leukemia: Risk factors and effect on prognosis.

BACKGROUND: Venous thromboembolism (VTE) is relatively common in children with acute lymphoblastic leukemia (ALL). Thrombotic risk factors in ALL are asparaginase and steroids. However, within the ALL populations treated on the same regimen, it is less clear which other risk factors play a role. Furthermore, few data are available on the effect of VTE on ALL outcomes. METHODS: In 778 children (1-18 years) with newly diagnosed precursor-B-lineage or T-lineage ALL, treated in the Dutch Childhood Oncology Group (DCOG) ALL-10 protocol in the Netherlands (October 2004 to April 2013), we conducted a nested case control study with 59 VTE cases and 118 controls to identify risk factors for VTE. RESULTS: Fifty-nine of 778 ALL patients developed VTE (7.6%), with cerebral venous sinus thrombosis (CVST) in 26 of 59 patients (44.1%). VTE occurred during induction treatment in 59.3% (n = 35) and in 40.7% (n = 24) during medium risk intensification. Conditional multivariable logistic regression analysis showed that age and ALL subtype were significantly associated with VTE (age ≥7 years: OR 2.72, 95% CI 1.33-5.57; ALL subtype T-ALL: OR 2.95, 95% CI 1.02-8.57). A multivariable Cox model showed no association between the occurrence of VTE and event free survival. In CVST patients, permanent disability was present in 34.6%. CONCLUSION: Within this large pediatric ALL cohort, we demonstrated a high morbidity in CVST patients. Age ≥7 years at diagnosis and T-ALL subtype were the main risk factors for VTE, and should be considered in preventive strategies.

Individualised versus standard duration of elastic compression therapy for prevention of post-thrombotic syndrome (IDEAL DVT): a multicentre, randomised, single-blind, allocation-concealed, non-inferiority trial.

BACKGROUND: Therapy with elastic compression stockings has been the cornerstone for prevention of post-thrombotic syndrome for decades in patients after acute deep venous thrombosis. It is uncertain who benefits most from therapy, and what the optimum duration of therapy should be. We therefore aimed to assess the safety and efficacy of individualised duration of compression therapy versus the standard duration of 24 months following an initial treatment period of 6 months. METHODS: We did a multicentre, randomised, single-blind, allocation-concealed, non-inferiority trial at 12 hospitals in the Netherlands and two in Italy. We randomly assigned patients (1:1) with acute proximal deep vein thrombosis of the leg and without pre-existent venous insufficiency (Clinical Etiological Anatomical and Pathophysiological score