Diagnosis of acute lower limb deep venous thrombosis with ultrasound: trends and controversies

Evaluation of acute thrombus regression effect of edoxaban for deep vein thrombosis in patients with cancer: a single-center prospective observational study

BACKGROUND

Although there are reports on the recurrence prevention in the chronic phase using direct oral anticoagulants (DOACs) for deep vein thrombosis (DVT) in patients with cancer, acute thrombus regression effect using DOACs has not been assessed. This study aimed to assess the thrombus regression effect of initial treatment using edoxaban for acute lower-extremity DVT in patients with active cancer.

METHODS AND RESULTS

In this observational study, among the inpatients with cancer and lower-extremity DVT who underwent initial treatment with edoxaban at our hospital from November 2019 to December 2021, 34 consenting patients were recruited in this study. The quantitative ultrasound thrombus (QUT) score of thrombus volume was calculated at baseline (before administration) and 7-14 days after the start of edoxaban administration, using lower-extremity venous ultrasound to evaluate changes in thrombus volume. The primary and secondary endpoints were the acute thrombus regression effect of edoxaban and the impact of patients' clinical frailty on the thrombus regression effect, respectively. Anticoagulant therapy with edoxaban significantly reduced QUT score (p < 0.001). In addition, regardless of the Clinical Frailty Scale scores, QUT score decreased significantly.

CONCLUSION

Initial treatment with edoxaban was effective for lower-extremity DVT in patients with cancer. In addition, the effect was the same independent of the degree of frailty.

Do Patients with a Family or Personal History of Venous Thromboembolism have an Increased Risk of Recurrence?

BACKGROUND

 A family (FH) and personal history (PH) of venous thromboembolism (VTE) are commonly evaluated risk factors for recurrence. We examined the association between FH/PH of VTE and the risk of recurrence and whether a stronger history status (i.e., both FH/PH vs. no FH/PH) carries an increased recurrence risk.

METHODS

 We prospectively followed 813 patients aged ≥ 65 years with acute VTE from 9 Swiss hospitals. We classified patients into four groups: no FH/PH, FH only, PH only, and both FH/PH. The primary outcome was recurrent VTE during the full observation period. We examined the association between FH/PH status and the time to VTE recurrence using competing risk regression, adjusting for confounders and periods of anticoagulation.

RESULTS

 Of 813 patients with VTE, 59% had no FH/PH, 11% a FH only, 24% a PH only, and 7% had both a FH and PH of VTE. Overall, 105 patients had recurrent VTE during the full observation period. After adjustment, patients with a FH only (subhazard ratio [SHR] 0.8, 95% confidence interval [CI] 0.4-1.7), PH only (SHR 1.5, 95% CI 0.9-2.5), and both FH/PH (SHR 1.4, 95% CI 0.6-3.1) did not have an increased risk of recurrent VTE compared with those without FH/PH. When we considered the period after the completion of initial anticoagulation only, the results were similar.

CONCLUSION

 Our findings indicate that in patients with acute VTE, a FH and/or PH of VTE does not convey an increased risk of recurrent VTE. In particular, we did not find a "dose-effect" relationship between FH/PH status and VTE recurrence.

Non-contrast-enhanced magnetic resonance imaging technique diagnoses DVT and classifies thrombus

The accuracy of non-contrast MRI in diagnosing acute deep vein thrombosis (DVT) of the lower extremities is different. To explore the application of high-resolution non-contrast 3D CUBE T1-weighted MRI in the lower extremities DVT. We recruited 26 patients suspected DVT of the lower extremities from Hebei General Hospital in China. All patients underwent high-resolution non-contrast 3D CUBE T1-weighted MRI. We evaluated the sensitivity, specificity, positive predictive value, and negative predictive value of diagnosing thrombosis. And we divided thrombi into two parts: filling thrombus (FT) and non-filling thrombus (NFT), compared the agreement between MRI and Ultrasound (US) and analysed the locations of thrombi. Compared with US, MRI yielded a sensitivity of 79%, a specificity of 94.2% in mean value, a sensitivity of 85.7%, 97.4%, and 51.7% in iliac, femoral-popliteal, and calf segments respectively, a specificity of 97.6%, 88.3%, and 98.2% in iliac, femoral-popliteal, and in calf segments respectively. The accuracy of MRI in the diagnosis of lower extremity DVT was in very good agreement (κ = 0.711, 95% CI 0.627, 0.795). The FT was the most part in US and CUBE (68/56), CUBE can detect more NFT in femoral vein than US (22/4). 3D CUBE T1-weighted MRI can be used to accurately diagnose acute DVT and detect more NFT. It has the potential of follow-up at the end of treatment to establish a new baseline to stop anticoagulant drug.

Relationship Between the Incidence of Deep Vein Thrombosis During Hospitalization and the Energy of Injury in Tibial Plateau Fractures

This study aimed to investigate the relationship between the incidence of deep vein thrombosis (DVT) during hospitalization and the energy of injury in tibial plateau fractures (TPFs). One hundred and forty patients were enrolled between September 1, 2014, and October 1, 2017. According to Schatzker's classification, they were classified into the low-energy (type I-III) and high-energy (type IV-VI) groups. For DVT evaluation, duplex ultrasonography was performed in the lower extremities preoperatively and postoperatively. The location and changes of DVT were recorded. All patients underwent mechanical and chemical thromboprophylaxis. The incidence of DVT in TPFs was 36.43% and 46.43% preoperatively and postoperatively, respectively. The DVT incidence was 31.75% (20/63) in the low-energy group and 40.26% (31/77) in the high-energy group preoperatively, and 44.44% (28/63) in the low-energy group and 48.05% (37/77) in the high-energy group postoperatively. There was no significant difference between the 2 groups preoperatively (P = .298) and postoperatively (P = .785). The days between operation and discharge (P = .016), blood loss during surgery (P = .016), and preoperative d-dimer level (P = .02) showed differences between the 2 groups. Additionally, 29 new thrombi (14 [48.28%] in the high-energy group and 15 [51.72%] in the low-energy group) appeared and 16 preoperative thrombi disappeared postoperatively. Despite mechanical and chemical thromboprophylaxis, the DVT risk in patients with TPFs remains high. Although the DVT incidence is not significantly different between high-energy and low-energy injuries, the occurrence of DVT should be carefully monitored.

Deep Vein Thrombosis in the Uninjured Limb in Patients with Lower Extremity Fractures: A Retrospective Study

Objective

This study is aimed at investigating the incidence of deep vein thrombosis (DVT) in the uninjured limb during hospitalization and 1 month after surgery in patients with lower extremity fractures.

Methods

We collected the clinical data of patients with lower extremity fractures in Xi'an Honghui Hospital. Doppler ultrasonography was used to diagnose DVT. According to the results of ultrasonography, the patients were divided into two groups: uninjured limb with DVT group and uninjured limb without DVT group.

Results

A total of 494 patients who met all inclusion criteria were included in this study. The incidence rate of DVT in the uninjured limb was 19.84% and 18.83% during hospitalization and 1 month after surgery, respectively. Age (OR = 1.035, 95% CI: 1.013–1.059; P = 0.002) and D-dimer level 1 day after surgery (OR = 1.065, 95% CI: 1.030–1.102; P < 0.001) were independent risk factors for DVT during hospitalization. Similarly, age (OR = 1.045, 95% CI: 1.021–1.070; P < 0.001) and D-dimer level 1 day after surgery (OR = 1.048, 95% CI: 1.014–1.083; P = 0.006) were independent risk factors for DVT 1 month after surgery. During hospitalization and 1 month after surgery, 15.79% and 12.35% of patients had double lower limb thrombosis and 4.04% and 6.48% of patients had DVT in the uninjured limb only, respectively.

Conclusion

The actual incidence of DVT in the uninjured limb in patients with lower extremity fractures cannot be ignored despite the use of anticoagulants for prevention or treatment during hospitalization. We should also be aware of DVT in the uninjured limb while focusing on DVT in the injured limb.

The cumulative venous thromboembolism incidence and risk factors in intensive care patients receiving the guideline-recommended thromboprophylaxis

Few prospective studies have reported the cumulative incidence of venous thromboembolism (VTE) in the intensive care unit (ICU), especially for patients receiving guideline-recommended VTE prophylaxis. We aimed to design a prospective observational study to investigate the cumulative incidence and risk factors of ICU-acquired VTE for those populations.We prospectively studied 281 consecutively included patients in the ICU at a single center. All patients provided informed consent. Patients received ultrasound evaluation and were followed for VTE before ICU discharge or within 28 days of ICU stay. The type of VTE thromboprophylaxis was also recorded for all patients. Variables from univariate analyses that were associated with VTE were included in the binary logistic regression analysis to determine VTE predictors. The cumulative VTE incidence with 95% confidence interval (CI) was estimated using Kaplan-Meier methods.Patients had a median age of 60 years (range, 18-89) and an acute physiology and chronic health evaluation II score of 17 (range, 4-36). Despite all patients receiving guideline-recommended thromboprophylaxis, the cumulative incidence of VTE at 7, 14, 21, and 28 days was 4.45% (95% CI 2.55-7.71), 7.14% (95% CI 4.61-10.97), 7.53% (95% CI 4.92-11.43), and 9.55% (95% CI 6.55-13.81), respectively. Central venous catheter use (P = .002, odds ratio [OR] = 4.50), Caprini score (P = .012, OR = 1.20), and ICU length of stay (P = .006, OR = 1.08) were independent risk factors related to the incidence of VTE for patients admitted to the ICU.Our prospective observational study found that the 28-day cumulative incidence of VTE was relatively high for patients admitted to the ICU, despite the use of guideline-recommended thromboprophylaxis. Patients with femoral central venous catheter, prolonged ICU length of stay, or a high Caprini score may have an increased risk of developing VTE.

A high Gas6 level in plasma predicts venous thromboembolism recurrence, major bleeding and mortality in the elderly: a prospective multicenter cohort study

Essentials Predictive ability of pro-hemostatic Gas6 for recurrent venous thromboembolism (VTE) is unknown. We measured Gas6 levels in 864 patients with VTE over 3 years. High Gas6 (> 157%) at diagnosis is associated with VTE recurrence, major bleeding and mortality. Gas6 plasma levels measured 12 months after the index VTE are discriminatory for VTE recurrence. SUMMARY: Background Growth arrest-specific gene 6 (Gas6) is a prohemostatic protein with an unknown predictive ability for recurrent venous thromboembolism (VTE). In the elderly, VTE results in higher mortality but does not have a higher rate of recurrence than in younger patients. Consequently, anticoagulation management in the elderly is challenging. Objective To prospectively investigate the performance of Gas6 in predicting VTE recurrence, major bleeding and mortality in the elderly. Methods Consecutive patients aged ≥ 65 years with acute VTE were followed for a period of 3 years. Primary outcomes were symptomatic VTE recurrence, major bleeding, and mortality. Plasma Gas6 was measured with ELISA. Results Gas6 levels were measured in 864 patients at the time of the index VTE (T1) and, in 70% of them, also 12 months later (T2). The Gas6 level at T1 was discriminatory for VTE recurrence (C-statistic, 0.56; 95% confidence interval [CI] 0.51-0.62), major bleeding (0.60, 95% CI 0.55-0.65) and mortality (0.69, 95% CI 0.65-0.73) up to 36 months. VTE recurrence up to 24 months after T2 was discriminated by the Gas6 level at T2 (0.62, 95% CI 0.54-0.71). High Gas6 levels (> 157%) and continuous Gas6 levels at T1 were associated with VTE recurrence up to 6 months and 12 months, respectively. Conclusions In elderly patients, a high Gas6 level is associated with higher risks of VTE recurrence, major bleeding, and death. These findings support further studies to assess the performance of Gas6 in adjusting the length of anticoagulation.

Incidence and risk factors for venous thromboembolism in patients with pretreated advanced pancreatic carcinoma

Patients with pancreatic carcinoma are at an increased risk of venous thromboembolism (VTE), which is a major cause of morbidity and mortality in various types of cancer. The aim of this study was to determine the incidence and clinical significance of VTE in patients with pancreatic carcinoma, and to identify biomarkers for the detection of VTE in these patients. The eligibility criteria were chemo-naïve patients with primary pancreatic carcinoma, an Eastern Cooperative Oncology Group performance status of 0–2, and adequate organ function. All patients were screened for VTE using compression ultrasonography and dynamic computed tomography. The primary endpoint was the incidence of VTE, which we hypothesized would be between 10.0–20.0% for symptomatic and asymptomatic patients combined. Associations between clinical presentation and VTE were evaluated. VTE-associated markers were also investigated for their role in predicting prognosis. In total, 103 patients met the eligibility criteria. The overall cumulative incidence rate of VTE in patients with previously untreated pancreatic carcinoma was 16.5%. VTE occurrence was strongly associated with elevated serum D-dimer, fibrin degradation product, thrombin/antithrombin III complex, and prothrombin fragment 1 + 2 levels. The median overall survival time of VTE-positive and VTE-negative patients was 427 and 515 days, respectively. Approximately one-sixth of patients with advanced pancreatic carcinoma experienced VTE, although most were asymptomatic. Measurement of serum D-dimer, fibrin degradation product, thrombin/antithrombin III complex, and prothrombin fragment 1 + 2 levels may be useful for the early detection of VTE in patients with advanced pancreatic carcinoma.

Circulating extracellular DNA is an independent predictor of mortality in elderly patients with venous thromboembolism

BACKGROUND

Venous thromboembolism (VTE) is a major cause of morbidity and mortality in elderly patients. Extracellular DNA is a pro-inflammatory and pro-thrombotic mediator in vitro and in animal models. Levels of circulating extracellular DNA (ceDNA) are increased in VTE patients, but the association of ceDNA with VTE extent and clinical outcome is poorly understood.

OBJECTIVES

We analyzed the association of ceDNA with the extent of VTE, categorized as distal and proximal deep vein thrombosis and pulmonary embolism, and with the clinical outcomes VTE recurrence and mortality.

METHODS

We quantified ceDNA by a fluorescent probe, as well as circulating nucleosomes and neutrophil extracellular traps (NETs) by ELISA in plasma from 611 patients aged ≥ 65 years with acute VTE of a prospective cohort study (SWITCO65+).

RESULTS

Levels of ceDNA and nucleosomes, but not NETs, correlated with VTE extent. Infectious comorbidities independently increased ceDNA levels in VTE. CeDNA strongly correlated with C-reactive protein and leukocytosis, suggesting an association of ceDNA with inflammation in VTE patients. CeDNA furthermore predicted PE-related and all-cause mortality, but not VTE recurrence, during a 3-year follow-up.

CONCLUSIONS

Our study suggests that ceDNA levels in VTE patients reflect the degree of inflammation and may serve as a biomarker to stratify VTE patients at risk for mortality.

Short-Term Subcutaneous Fondaparinux and Oral Edoxaban for Acute Venous Thromboembolism

BACKGROUND

No studies have compared treatment efficacy between subcutaneous (SC) fondaparinux and oral edoxaban, which are categorized as factor Xa inhibitors, for venous thromboembolism (VTE) in the acute phase, and only a limited number of imaging-based quantitative studies have evaluated treatment.Methods and Results:In this open-label, randomized study, 50 patients with acute non-massive pulmonary embolism (PE) and/or deep-vein thrombosis (DVT) were assigned to fondaparinux or edoxaban groups. Lower-limb venous ultrasonography (US), and chest computed tomography (CT) were compared before and 7 days after treatment. Thrombus volume in DVT was calculated using quantitative ultrasound thrombosis (QUT) score on US. For evaluation of PE thrombus volume, lung perfused blood volume (PBV) on CT was calculated. The measurements before and after treatment, respectively, were as follows: QUT score: fondaparinux, 8.1±7.3 to 4.1±4.5; edoxaban, 7.7±6.3 to 4.4±4.3, both significant decreases (P=0.001, P<0.001, respectively); lung PBV: fondaparinux, 32.0±7.8 to 32.1±8.2 HU; edoxaban, 34.2±8.6 to 38.5±11.8 HU (P=0.732, P=0.426, respectively). On subjective CT-based evaluation, all pulmonary artery-related filling defects decreased/disappeared after treatment in both groups (P=NS).

CONCLUSIONS

Both SC fondaparinux and oral edoxaban are effective in acute VTE. Effects on thrombus regression on imaging-based quantitative measurement did not differ between the 2 drugs.

Predictors and Causes of Long-Term Mortality in Elderly Patients with Acute Venous Thromboembolism: A Prospective Cohort Study

BACKGROUND

Long-term predictors and causes of death are understudied in elderly patients with acute venous thromboembolism.

METHODS

We prospectively followed up 991 patients aged ≥65 years with acute venous thromboembolism in a multicenter Swiss cohort study. The primary outcome was overall mortality. We explored the association between patient baseline characteristics and mortality, adjusting for other baseline variables and periods of anticoagulation as a time-varying covariate. Causes of death over time were adjudicated by a blinded, independent committee.

RESULTS

The median age was 75 years. During a median follow-up period of 30 months, 206 patients (21%) died. Independent predictors of overall mortality were age (hazard ratio [HR], 1.32; 95% confidence interval [CI], 1.05-1.65, per decade), active cancer (HR, 5.80; 95% CI, 4.22-7.97), systolic blood pressure <100 mm Hg (HR, 2.77; 95% CI, 1.56-4.92), diabetes mellitus (HR, 1.50; 95% CI, 1.02-2.22), low physical activity level (HR, 1.92; 95% CI, 1.38-2.66), polypharmacy (HR, 1.41; 95% CI, 1.01-1.96), anemia (HR, 1.48; 95% CI, 1.07-2.05), high-sensitivity C-reactive protein >40 mg/L (HR, 1.88; 95% CI, 1.36-2.60), ultra-sensitive troponin >14 pg/mL (HR, 1.54; 95% CI, 1.06-2.25), and D-dimer >3000 ng/mL (HR, 1.45; 95% CI, 1.04-2.01). Cancer (34%), pulmonary embolism (18%), infection (17%), and bleeding (6%) were the most common causes of death.

CONCLUSIONS

Elderly patients with acute venous thromboembolism have a substantial long-term mortality, and several factors, including polypharmacy and a low physical activity level, are associated with long-term mortality. Cancer, pulmonary embolism, infections, and bleeding are the most common causes of death in the elderly with venous thromboembolism.

Black-blood thrombus imaging (BTI): a contrast-free cardiovascular magnetic resonance approach for the diagnosis of non-acute deep vein thrombosis

BACKGROUND

Deep vein thrombosis (DVT) is a common but elusive illness that can result in long-term disability or death. Accurate detection of thrombosis and assessment of its size and distribution are critical for treatment decision-making. In the present study, we sought to develop and evaluate a cardiovascular magnetic resonance (CMR) black-blood thrombus imaging (BTI) technique, based on delay alternating with nutation for tailored excitation black-blood preparation and variable flip angle turbo-spin-echo readout, for the diagnosis of non-acute DVT. METHODS: This prospective study was approved by institutional review board and informed consent obtained from all subjects. BTI was first conducted in 11 healthy subjects for parameter optimization and then conducted in 18 non-acute DVT patients to evaluate its diagnostic performance. Two clinically used CMR techniques, contrast-enhanced CMR venography (CE-MRV) and three dimensional magnetization prepared rapid acquisition gradient echo (MPRAGE), were also conducted in all patients for comparison. All images obtained from patients were analyzed on a per-segment basis. Using the consensus diagnosis of CE-MRV as the reference, the sensitivity (SE), specificity (SP), positive and negative predictive values (PPV and NPV), and accuracy (ACC) of BTI and MPRAGE as well as their diagnostic agreement with CE-MRV were calculated. Besides, diagnostic confidence and interreader diagnostic agreement were evaluated for all three techniques.

RESULTS

BTI with optimized parameters effectively nulled the venous blood flow signal and allowed directly visualizing the thrombus within the black-blood lumen. Higher SE (90.4% vs 67.6%), SP (99.0% vs. 97.4%), PPV (95.4% vs. 85.6%), NPV (97.8% vs 92.9%) and ACC (97.4% vs. 91.8%) were obtained by BTI in comparison with MPRAGE. Good diagnostic confidence and excellent diagnostic and interreader agreements were achieved by BTI, which were superior to MPRAGE on detecting the chronic thrombus.

CONCLUSION

BTI allows direct visualization of non-acute DVT within the dark venous lumen and has the potential to be a reliable diagnostic tool without the use of contrast medium.

Physical activity and risk of bleeding in elderly patients taking anticoagulants

BACKGROUND

Although the possibility of bleeding during anticoagulant treatment may limit patients from taking part in physical activity, the association between physical activity and anticoagulation-related bleeding is uncertain.

OBJECTIVES

To determine whether physical activity is associated with bleeding in elderly patients taking anticoagulants.

PATIENTS/METHODS

In a prospective multicenter cohort study of 988 patients aged ≥ 65 years receiving anticoagulants for venous thromboembolism, we assessed patients' self-reported physical activity level. The primary outcome was the time to a first major bleeding, defined as fatal bleeding, symptomatic bleeding in a critical site, or bleeding causing a fall in hemoglobin or leading to transfusions. The secondary outcome was the time to a first clinically relevant non-major bleeding. We examined the association between physical activity level and time to a first bleeding by using competing risk regression, accounting for death as a competing event. We adjusted for known bleeding risk factors and anticoagulation as a time-varying covariate.

RESULTS

During a mean follow-up of 22 months, patients with a low, moderate, and high physical activity level had an incidence of major bleeding of 11.6, 6.3, and 3.1 events per 100 patient-years and an incidence of clinically relevant non-major bleeding of 14.0, 10.3, and 7.7 events per 100 patient-years, respectively. A high physical activity level was significantly associated with a lower risk of major bleeding (adjusted sub-hazard ratio 0.40, 95% confidence interval 0.22-0.72). There was no association between physical activity and non-major bleeding.

CONCLUSIONS

A high level of physical activity is associated with a decreased risk of major bleeding in elderly patients receiving anticoagulant therapy.

The adherence to initial processes of care in elderly patients with acute venous thromboembolism

BACKGROUND

We aimed to assess whether elderly patients with acute venous thromboembolism (VTE) receive recommended initial processes of care and to identify predictors of process adherence.

METHODS

We prospectively studied in- and outpatients aged ≥65 years with acute symptomatic VTE in a multicenter cohort study from nine Swiss university- and non-university hospitals between September 2009 and March 2011. We systematically assessed whether initial processes of care, which are recommended by the 2008 American College of Chest Physicians guidelines, were performed in each patient. We used multivariable logistic models to identify patient factors independently associated with process adherence.

RESULTS

Our cohort comprised 950 patients (mean age 76 years). Of these, 86% (645/750) received parenteral anticoagulation for ≥5 days, 54% (405/750) had oral anticoagulation started on the first treatment day, and 37% (274/750) had an international normalized ratio (INR) ≥2 for ≥24 hours before parenteral anticoagulation was discontinued. Overall, 35% (53/153) of patients with cancer received low-molecular-weight heparin monotherapy and 72% (304/423) of patients with symptomatic deep vein thrombosis were prescribed compression stockings. In multivariate analyses, symptomatic pulmonary embolism, hospital-acquired VTE, and concomitant antiplatelet therapy were associated with a significantly lower anticoagulation-related process adherence.

CONCLUSIONS

Adherence to several recommended processes of care was suboptimal in elderly patients with VTE. Quality of care interventions should particularly focus on processes with low adherence, such as the prescription of continued low-molecular-weight heparin therapy in patients with cancer and the achievement of an INR ≥2 for ≥24 hours before parenteral anticoagulants are stopped.

The Swiss cohort of elderly patients with venous thromboembolism (SWITCO65+): rationale and methodology

Venous thromboembolism (VTE) is common and has a high impact on morbidity, mortality, and costs of care. Although most of the patients with VTE are aged ≥65 years, there is little data about the medical outcomes in the elderly with VTE. The Swiss Cohort of Elderly Patients with VTE (SWITCO65+) is a prospective multicenter cohort study of in- and outpatients aged ≥65 years with acute VTE from all five Swiss university and four high-volume non-university hospitals. The goal is to examine which clinical and biological factors and processes of care drive short- and long-term medical outcomes, health-related quality of life, and medical resource utilization in elderly patients with acute VTE. The cohort also includes a large biobank with biological material from each participant. From September 2009 to March 2012, 1,863 elderly patients with VTE were screened and 1003 (53.8%) were enrolled in the cohort. Overall, 51.7% of patients were aged ≥75 years and 52.7% were men. By October 16, 2012, after an average follow-up time of 512 days, 799 (79.7%) patients were still actively participating. SWITCO65+ is a unique opportunity to study short- and long-term outcomes in elderly patients with VTE. The Steering Committee encourages national and international collaborative research projects related to SWITCO65+, including sharing anonymized data and biological samples.

Prospective, multicenter validation of prediction scores for major bleeding in elderly patients with venous thromboembolism

BACKGROUND

The Outpatient Bleeding Risk Index (OBRI) and the Kuijer, RIETE and Kearon scores are clinical prognostic scores for bleeding in patients receiving oral anticoagulants for venous thromboembolism (VTE). We prospectively compared the performance of these scores in elderly patients with VTE.

METHODS

In a prospective multicenter Swiss cohort study, we studied 663 patients aged ≥ 65 years with acute VTE. The outcome was a first major bleeding at 90 days. We classified patients into three categories of bleeding risk (low, intermediate and high) according to each score and dichotomized patients as high vs. low or intermediate risk. We calculated the area under the receiver-operating characteristic (ROC) curve, positive predictive values and likelihood ratios for each score.

RESULTS

Overall, 28 out of 663 patients (4.2%, 95% confidence interval [CI] 2.8-6.0%) had a first major bleeding within 90 days. According to different scores, the rate of major bleeding varied from 1.9% to 2.1% in low-risk, from 4.2% to 5.0% in intermediate-risk and from 3.1% to 6.6% in high-risk patients. The discriminative power of the scores was poor to moderate, with areas under the ROC curve ranging from 0.49 to 0.60 (P = 0.21). The positive predictive values and positive likelihood ratios were low and varied from 3.1% to 6.6% and from 0.72 to 1.59, respectively.

CONCLUSION

In elderly patients with VTE, existing bleeding risk scores do not have sufficient accuracy and power to discriminate between patients with VTE who are at a high risk of short-term major bleeding and those who are not.

Interventional catheterisation of stenotic or occluded systemic veins in children with or without congenital heart diseases: early results and intermediate follow-up

AIMS

Limited data exists on midterm results concerning paediatric interventions on stenotic or occluded systemic veins following indwelling lines, cardiac surgery, or catheterisations. The purpose of this study was to report our acute and intermediate results concerning patients with (Group A) and without (Group B) congenital heart diseases (CHD) over a 10-year period.

METHODS AND RESULTS

From January 2000 to December 2010, 32 patients (23 in Group A and nine in Group B, respectively) underwent 39 interventional catheterisations aimed to dilate or recanalise occluded iliofemoral veins, inferior or superior venae cavae. Initial and follow-up catheterisation data were reviewed retrospectively. Midterm results were evaluated by means of echography, angiography, and CT scan in all 15 and 17 patients, respectively. Median age and weight of all patients at catheterisation were five years (range 0.1-18) and 15 kg (range 2-60), respectively. Fifty-two stents were implanted in 29 patients (32 vessels). In 25 patients 28 vessels were occluded and required recanalisation. There were no major complications. In all but three patients it was possible to treat the lesion. There were two procedural complications (5.1%): one acute stent occlusion and one local dissection. At a median follow-up of 2.5 years (range 1-10) we observed six complications of stenting (11.5%): two fractures, two occlusions and two restenoses.

CONCLUSIONS

Interventional catheterisation of stenotic or occluded systemic veins grants good immediate results at a low rate of complication. Stent dilatation or recanalisation may open the vessel for use during future procedures. However, long-term results are yet to be established.

Microfluidics based phantoms of superficial vascular network

Several new bio-photonic techniques aim to measure flow in the human vasculature non-destructively. Some of these tools, such as laser speckle imaging or Doppler optical coherence tomography, are now reaching the clinical stage. Therefore appropriate calibration and validation techniques dedicated to these particular measurements are therefore of paramount importance. In this paper we introduce a fast prototyping technique based on laser micromachining for the fabrication of dynamic flow phantoms. Micro-channels smaller than 20 µm in width can be formed in a variety of materials such as epoxies, plastics, and household tape. Vasculature geometries can be easily and quickly modified to accommodate a particular experimental scenario.

Contrast-enhanced sonographic diagnosis of unsuspected internal iliac vein thrombosis

We report a rare case of an isolated and unsuspected thrombosis in the right internal iliac vein. The presentation was atypical with regard to the clinical manifestations and the thrombus location. The patient was admitted for an acute abdominal pain in the right iliac fossa. The thrombosis was suspected on the basis of a portal-phase contrast-enhanced abdominal CT but the lack of a delayed phase did not allow confirmation. Contrast-enhanced ultrasound confirmed the diagnosis, by displaying a well-defined filling defect.

A meta-analysis of bed rest versus early ambulation in the management of pulmonary embolism, deep vein thrombosis, or both

BACKGROUND

Bed rest is often recommended as part of the management of deep vein thrombosis (DVT) and pulmonary embolism (PE), though this recommendation is not clearly evidence-based.

METHODS

Using the Cochrane Central Register of Controlled Trials, Medline, and Embase, this meta-analysis considered all randomized studies and prospective registries that compared the outcomes of patients with DVT, PE, or both, managed with bed rest versus early ambulation, in addition to anticoagulation. For each study, data regarding the incidence of new PE, new or progression of DVT, and death from all causes, were used to calculate relative risks (RR) and 95% confidence intervals (CI).

RESULTS

The 5 studies retained in this analysis included a total of 3048 patients. When compared to bed rest, early ambulation was not associated with a higher incidence of a new PE (RR 1.03; 95% CI 0.65-1.63; p=0.90). Furthermore, early ambulation was associated with a trend toward a lower incidence of new PE and new or progression of DVT than bed rest (RR 0.79; 95% CI 0.55-1.14; p=0.21) and lower incidence of new PE and overall mortality (RR 0.79; 95% CI 0.402-1.56; p=0.50).

CONCLUSIONS

Compared with bed rest, early ambulation of patients with DVT, PE or both, was not associated with a higher risk of progression of DVT, new PE or death. This meta-analysis does not support the systematic recommendation of bed rest as part of the early management of patients presenting with DVT, PE of both.

Edema in the lower limb of patients operated on for proximal femoral fractures

BACKGROUND

Patients with proximal femoral fracture (PFF) often develop postoperative edema in the operated limb. This may lead to reduced mobilization, increasing the length of hospitalization. It is therefore relevant to gain information about the extent and pathogenesis of this edema formation.

METHODS

Forty-one patients with PFF (30 women and 11 men) were studied pre- and postoperatively. Patients were grouped into pertrochanteric fractures and femoral cervical fractures, according to the AO/ASIF classification of PFF. Thigh and calf volumes were calculated in both fractured and contralateral limbs preoperatively and on postoperative days 3, 5, 7, and 30.

RESULTS

All patients with PFF developed edema in the operated limb. The greatest volume increase occurred on postoperative day 7 (p < 0.0005). The magnitude of edema in the thigh and the leg of patients with pertrochanteric fractures as compared with the nonoperative side was approximately twice as great as in those with femoral cervical fractures (p < 0.0001). There was a statistically significant daily increase in the volume of the operative limb as compared with the nonoperative side. Age and sex were not correlated with the extent of edema formation. Functionally significant deep venous thrombosis and local infection could be excluded as causative factors.

CONCLUSIONS

Postoperative edema in the thigh and leg of the operated limb was considerable. The magnitude of edema formation was related to the severity of primary trauma and the type of osteosynthesis. Therefore, the operation performed for PFF should be minimally traumatic.

Current approaches and controversial issues in the diagnosis of deep vein thrombosis via duplex Doppler ultrasound

Duplex and color Doppler sonography (DUS) is currently the technique of choice for the diagnosis of deep venous thrombosis (DVT) in symptomatic patients, because it has proven safe and cost-effective, with a very high sensitivity and specificity (96% and 98%, respectively) for the diagnosis of proximal DVT. Several issues regarding its method and clinical indications remain controversial, however. Although isolated calf vein thrombosis does not seem to have a significant adverse outcome in the short term, scanning the calf only in patients with localized symptoms or signs is cost-effective. Bilateral examination is indicated in high-risk patients or when screening asymptomatic patients. When negative, a complete DUS examination of the proximal and distal veins, at least down to the level of the popliteal trifurcation, allows withholding anticoagulant therapy without the risk of major complications. This examination may be repeated if signs or symptoms worsen. Some populations of asymptomatic patients at high risk of DVT may benefit from DUS screening. Bilateral DUS examination of lower limb veins should be performed as the initial examination in the workflow of pulmonary embolism only in patients with risk factors for DVT. Recurrent thrombosis is a challenging diagnosis for all imaging modalities. A diagnostic strategy combining clinical probability score and D-dimer test may refine the selection of patients. The pitfalls and limitations of venous DUS are related to vein anatomy, flow changes, technical issues, and operator expertise.

Ultrasonographic diagnosis of unusual portal vascular abnormalities in two cats

Two cases of ascites secondary to portal vascular abnormalities associated with portal hypertension are described. In the first case a five-month-old cat was presented with recurrent ascites and investigations showed that the underlying cause was a hepatic arteriovenous fistula. Ultrasonography showed direct communication of the coeliac artery and right branch of the portal vein. There was also hepatofugal flow in the main portal vein consistent with portal hypertension. The ultrasonographic features were similar to those seen in dogs with hepatic arteriovenous fistulae. In the second case, ascites, portal hypertension and an intraluminal mass in the main portal vein was diagnosed in a 16-year-old cat that had been presented with hyperthyroidism and hepatomegaly. Acquired portosystemic collaterals involving the left renal vein were present. Additional diagnostic investigations were not permitted. Ultrasonography was useful in both cases to document portal hypertension and the underlying cause.

Systematic review of thromboprophylaxis in colorectal surgery -- an update

OBJECTIVE

The incidence of thromboembolism after colorectal surgery is higher than after general surgery. The aim of this paper is to update a systematic review addressing thrombosis prophylaxis in connection with colorectal surgery.

METHODS

MEDLINE, EMBASE, LILACS, abstract books and reference lists from reviews were searched without language restrictions for randomized controlled trials or clinical controlled trials comparing prophylactic interventions and/or placebo up til August 2003. Five hundred and fifty-eight studies were identified of which 19 fulfilled the inclusion criteria. Data extraction was done by at least two of the authors. Outcome was deep venous thrombosis and/or pulmonary embolism diagnosed by various methods.

RESULTS

Any kind of heparin is better than no treatment or placebo (11 studies) with a Peto Odds ratio (POR) at 0.32 (95% CI 0.20-0.53). Unfractionated heparin and low molecular weight heparin (4 studies) were equally effective POR 1.01 (95% CI 0.67-1.52). The combination of graduated compression stockings and LMWH is better than LMWH alone (2 studies) with a POR at 4.17 (95% CI 1.37-12.70).

CONCLUSION

The optimal thromboprophylaxis in colorectal surgery is the combination of graduated compression stockings and low-dose unfractionated heparin or low molecular weight heparin.

Comparison of six D-dimer methods in patients suspected of deep vein thrombosis

We evaluated six D-dimer methods to determine their sensitivity, specificity, and negative predictive values (NPV) in symptomatic patients suspected of deep vein thrombosis (DVT). In patients suspected of DVT a whole blood D-dimer test (SimpliRED, Agen) was performed, and then tested using enzyme-linked immunosorbent assay (VIDAS D-Dimer, BioMerieux; Asserachrome D-Di, Stago International; Dimertest Gold, Agen) and automated immunoturbidometric methods (Advanced D-Dimer, Dade Behring; MiniQuant, Biopool). Each D-dimer method was independently compared with radiographic results to determine sensitivity and NPV. There were 151 patients enrolled in the study. Thirty-five (23.2%) patients had a positive Doppler ultrasound, with 26 proximal, eight distal, and one patient with both proximal and distal thrombus. Two patients (1.3%) had inconclusive studies and were excluded from the analyses. For all patients, the sensitivities for the rapid D-dimer methods were: SimpliRED, 82.3% [95% confidence interval (CI), 80.3-84.3%]; VIDAS D-Dimer, 91.4% (95% CI, 89.9-92.9%); MiniQuant D-Dimer, 96.3% (95% CI, 95.1-97.5%); and Advanced D-Dimer, 97.1% (95% CI, 96.3-97.9%). The sensitivity improved for SimpliRED (86.4%; 95% CI, 83.3-89.4%), VIDAS D-Dimer (95.5%; 95% CI, 85.0-100%), MiniQuant D-Dimer (100%; 95% CI, 96.9-100%) and Advanced D-Dimer (100%; 95% CI, 98.9-100%) in the inpatient population. The automated immunoturbidometric methods, the MiniQuant D-Dimer and Advanced D-Dimer, demonstrated comparable sensitivities and NPV with the VIDAS D-Dimer method in symptomatic patients suspected of DVT, which would suggest that these newer D-dimer methods could be used as part of the diagnostic algorithm for patients suspected of DVT.

Red blood cell methylfolate and plasma homocysteine as risk factors for venous thromboembolism: a matched case-control study

BACKGROUND

Moderate hyperhomocysteinaemia is a risk factor for venous thromboembolism. We do not know whether this risk depends on homocysteine itself or on components of the homocysteine remethylation pathway, such as methylfolate. We did a case-control study to analyse the relation between the major components of the homocysteine remethylation pathway and risk of venous thromboembolism.

METHODS

We measured concentrations of homocysteine, methionine, and folate in plasma, total folate and methylfolate in red-blood cells, and 5,10-methylenetetrahydrofolate reductase (MTHFR) C677T genotype and other known risk factors for venous thromboembolic disease in 243 patients with deep vein thrombosis or pulmonary embolism and controls matched for sex and age.

FINDINGS

Concentrations in plasma of homocysteine differed significantly between cases and controls. We noted a strong concentration-dependent association between concentrations of methylfolate in red-blood cells and risk of venous thromboembolism. The adjusted conditional odds ratio ranged from 1.0 for methylfolate 249 microg/L or greater to 7.1 (3.2-15.8) for methylfolate 141 microg/L or less. Methionine concentrations below the median were also independently associated with raised risk of venous thromboembolic disease, as were established risk factors such as high body-mass index, history of cancer, family history of thromboembolism, oral contraceptive use, and factor V Leiden mutation. Furthermore, the association between concentrations of methylfolate in red-blood cells and risk of thromboembolism varied according to MTHFR C677T genotype.

INTERPRETATION

Measurement of methylfolate concentrations in red-blood cells might help to identify people at risk of venous thromboembolism.

Heparins and mechanical methods for thromboprophylaxis in colorectal surgery

BACKGROUND

Colorectal surgery implies higher risk of postoperative thromboembolic complications as deep venous thrombosis (DVT) and pulmonary embolism (PE) than general surgery. The best prophylaxis in general surgery is heparin and graded compression stockings. No systematic review on combination prophylaxis or on thrombosis prophylaxis in colorectal surgery has been published.

OBJECTIVES

To compare the incidence of postoperative thromboembolism after colorectal surgery using prophylactic methods focussing on heparins and mechanical methods alone and in combinations.

SEARCH STRATEGY

Electronic searches was performed in MEDLINE, EMBASE back to 1970. Abstract books from major congresses were handsearched as were reference lists from previously performed reviews.

SELECTION CRITERIA

RCT or CCT comparing prophylactic interventions and/or placebo. Outcomes were ascending venography, 125 I-fibrinogen uptake test, ultrasound methods, pulmonary scintigraphy. Studies, using thermographic methods, other isotopic methods, plethysmographic methods, and purely clinical methods as the only diagnostic measure were excluded. 558 studies were identified - 477 were excluded. Only 3 of the identified studies focused exclusively on colorectal surgery. Studies of general surgery contain considerable numbers of colorectal patients. The authors of 66 studies in general and/or abdominal surgery were contacted for retrieving the results from the colorectal patients. Answers were received from very few. 19 studies entered this review.

DATA COLLECTION AND ANALYSIS

All studies and all data extraction were performed independently by at least two of the authors. Outcome was deep venous thrombosis and/or pulmonary embolism. Analysis of bleeding complications were unfeasible. 12 meaningful outcomes were analysed by means of the fixed effects model with Peto Odds Ratios.

MAIN RESULTS

Heparins versus no treatment: Any kind of heparincompared to no treatment or placebo (comparison 07.03, 11 studies). Heparin is better in preventing DVT and/or PE with a Peto Odds ratio at 0.32 (95% Confidence Interval 0.20-0.53) Unfractionated heparin versus low molecular weight heparin (comparison 08.03, 4 studies). The two treatments were found equally effective in preventing DVT and/or PE with a Peto Odds ratio 1.01 (95% Confidence Interval 0.67-1.52). Mechanical methods (comparison 10.3, 2 studies). The combination of graded compression stockings and LDH is better than LDH alone in preventing DVT and/or PE with a Peto Odds ratio at 4.17 (95% Confidence Interval 1.37-12.70).

REVIEWER'S CONCLUSIONS

The optimal prophylaxis in colorectal surgery is the combination of graduated compression stockings and low-dose unfractionated heparin. The unfractionated heparin can be replaced with low molecular weight heparin.

Oedema in the lower limb of patients with chronic critical limb ischaemia (CLI)

OBJECTIVE

approximately 70% of patients with chronic critical limb ischaemia (CLI) show clinical signs of oedema in the distal leg and foot. The primary aim of the present investigation was to quantify this oedema. In addition we investigated whether oedema formation could be due to deep venous thrombosis (DVT).

METHODS

fifteen patients with unilateral CLI and oedema were studied, four males and 11 females, with a mean age of 77+/-10.3 years. Water displacement volumetry (WDV) was used to measure limb volume. Colour duplex ultrasound (CDU) and venous occlusion plethysmography (VOP) were applied to exclude functionally significant DVT. Blood chemistry was analysed to screen for some causative factors of generalised oedema formation.

RESULTS

the mean volume of the limbs with CLI was 9% greater than the contralateral limbs (1279+/-325 ml vs. 1179+/-298 ml). None of the patients had functionally significant DVT. The mean plasma albumin concentration was reduced at 28.5+/-6.6 g/l.

CONCLUSION

a significantly reduced plasma albumin concentration cannot be regarded as a causative factor, since the oedema is unilateral. The aetiology of oedema formation is probably multifactorial, and further investigations are under progress to elucidate relevant pathogenetic factors.

Review of duplex and colour Doppler imaging of lower-limb arteries and veins

Ultrasonic imaging provides a non-invasive assessment of the arterial and venous circulation in the lower limb and is accepted as a valuable diagnostic technique. Grey-scale images identify plaque and thrombus, duplex assessment provides a measurement of blood velocity through a vessel, and colour Doppler imaging enables the rapid localization of arterial stenoses and occlusions and the identification of incompetent veins. This article outlines the principles of the different techniques and presents normal images. Procedures for investigating arterial stenoses, superficial venous incompetence and deep venous thrombosis are described, abnormal images presented and the limitations discussed. It is hoped to provide an insight into the strengths and limitations of ultrasonic vascular investigations for those involved in tissue viability and ulcer management.

Ultrasound screening for deep venous thrombosis after total knee arthroplasty. 2-year reassessment

The efficacy of ultrasound compared with ascending venography for the detection of deep venous thrombosis immediately after total knee arthroplasty was assessed after a 2-year interval. One hundred thirty-seven patients were eligible for the study; however, 31 patients received only one of the screening methods and a color Doppler examination was inconclusive in six patients. Therefore, 100 patients had a Doppler examination and a venogram. Overall, the sensitivity of ultrasound was 85%, the specificity 97%, the positive predictive value 85%, the negative predictive value 97%, and the accuracy 95%. The sensitivity in the calf was 83%, in the popliteal vein 86%, and in the femoral vein 100%. Two years ago, the initial assessment of ultrasound for the detection of deep venous thrombosis after surgery in patients who had total joint arthroplasty revealed a 75% sensitivity, 99% specificity, 91% positive predictive value, 97% negative predictive value, and 97% accuracy. The sensitivity in the calf was 83%; the sensitivity in the popliteal vein was 40%; and the sensitivity in the femoral vein was 50%. After 2 years of using this screening test with one technician and one radiologist, an improvement with this noninvasive technique was shown. However, it was found that Doppler imaging is not as sensitive as venography for detecting calf thrombi. Any imaging technique should be validated by each institution to determine the validity of the instrument and the learning curve of the technician administering the examination.