Proven Deep Venous Thrombosis Research Articles

Clinical Study of Deep Vein Thrombosis of Lower Limbs

Understanding the natural history of venous thrombosis is important for optimal management of this condition. Once risk factors are recognized it is possible to avoid these risk factors or to use active prophylaxis to reduce the morbidity and mortality. This study is targeted at identifying the risk factors of deep vein thrombosis in our set up, the role of Heparin in prophylaxis and to do a comparative study of low molecular weight Heparin with unfractionated Heparin in treatment of deep vein thrombosis of lower limb in Guru Gobind Singh Government hospital, Jamnagar. Material and Methods: Study population consisted of 50 consecutive patients with deep vein thrombosis, admitted to Guru Gobind Singh hospital, Jamnagar. We have studied 50 patients above 18 years of age with proven deep venous thrombosis by Doppler ultrasound. A complete clinical history was taken to assess risk factors, level of immobility if present and thorough physical examination was done. Routine investigations such as hemogram, haematocrit, blood indices, and liver and renal function tests were done. Diagnosis of deep vein thrombosis was detected by radiographic imaging like Doppler ultrasonography. Results: In our study, most of patients presented with complaints of swelling (70%) and pain (48%) of the affected lower limb. Few patients (4%) had symptoms of breathlessness (SOB), chest pain and orthopnea suggestive of pulmonary embolism. 34 patients in our study were having reasonably good level of haemoglobin while rests of all were having anaemia of different degree4 patients had haemoglobin below 8gm/dl and that needed separate treatment also. Leukocytosis was present in 16 patients. 16 patients had smoking as associated risk factor along with other acquired risk factors and 5 patients had obesity along with other risk factors. The most common complication of DVT is pulmonary embolism which occurs due to dislodgement of thrombus. Conclusion: Even though it is grievous, DVT can be prevented and treatable. Better and regular availability of drugs like LMWH and safer oral anticoagulants in the smallest possible region of the country can do wonders to save lives. Larger studies focusing more on coagulation cascade, molecular biology and genetics will be even bigger help to mankind.

Vena Cava Filters are not Superior to Low Molecular Weight Heparin in Venous Thromboembolism Prophylaxis: A Study on Long-Term Immobilized Neurosurgical Patients.

Deep venous thrombosis (DVT) and pulmonary embolism (PE) are the most frequent surgical problems and associated with high morbidity and mortality. Neurosurgical patients constitute a unique group where prophylaxis with anticoagulant and antiaggregant agents are relatively contraindicated due to the natural course of vascular problems such as aneurysms, hemorrhagic tumors or hematomas or increased vulnerability to complex spinal surgeries and trauma. We included 67 patients predicted to be immobilized for 2 or more months in this retrospective analysis. A vena cava filter was inserted between the first and seventh postoperative day in 40 patients in a prophylactic manner whereas 27 patients received low dose heparin for the same purpose. The patients were evaluated for symptomatic DVT or PE. Percutaneous insertion was performed for all filters without any complication. DVT occurred in two patients of the filter group and 1 patient of the heparin group. There was no PE recorded in any patient of either group. Patients were followed up for 22 months in the filter and 16 months in the heparin group. We conclude that prophylactic filter use in high risk neurosurgical patients is not beneficial and not superior to low-molecular-weight heparin use. Nevertheless, it is reasonable to prevent PE in patients with proven DVT who have no contraindication for anticoagulant drugs.

Prognostic Implications of Imaging-Based Bone Marrow Assessment in Lymphoma: 18F-FDG PET, MR Imaging, or 18F-FDG PET/MR Imaging?

2017 Objectives To evaluate FDG-PET/CT as a potential molecular imaging modality for venous thromboembolism (VTE) in a prospective, observational proof-of-concept pilot study. Methods Patients with proven deep venous thrombosis or pulmonary embolism (DVT+/PE+) or disproven DVT or PE (DVT-/PE-) were eligible. Exclusion criteria (non-inclusion) were: Age Results Eleven patients were included: Two women and nine men with a mean age of 65 years (range 50-78 years); seven DVT+, four DVT-, four PE+, and no PE- (four patients were both DVT+ and PE+). The duration of symptoms prior to inclusion was 2-7 days for the DVT+ patients, and 2 weeks-5 months for the PE+ patients. All seven DVT+ patients showed abnormal FDG uptake in the corresponding leg, while none of the DVT- patients or the PE+ patients showed abnormal FDG uptake in the venous vasculature. Conclusions Our results substantiate the potential role of FDG-PET/CT in VTE, especially for DVT with all DVT+ being positive and all DVT- being negative. The results from lung scan positive patients are likely due to non-specificity of the latter modality in determining the age of the clots. Therefore, the results from FDG-PET/CT images could actually represent the true nature of older and inactive PE. Although further studies are warranted for definite clarification, FDG-PET/CT may give rise to a paradigm shift in both diagnostic and therapeutic strategies for the management of VTE by screening the entire body for VTE and underlying occult malignancies, and by differentiating acute from chronic VTE.

Clinical presentation and outcome of venous thromboembolism in COPD

Chronic obstructive pulmonary disease (COPD) is a moderate risk factor for venous thromboembolism (VTE), but neither the clinical presentation nor the outcome of VTE in COPD patients is well known. The clinical presentation of VTE, namely pulmonary embolism (PE) or deep venous thrombosis (DVT), and the outcome at 3 months (death, recurrent VTE or bleeding) were compared between 2,984 COPD patients and 25,936 non-COPD patients included in the RIETE (Registro Informatizado de la Enfermedad TromboEmbólica) registry. This ongoing international, multi-centre registry includes patients with proven symptomatic PE or DVT. PE was the more frequent VTE presentation in COPD patients (n = 1,761, 59%). PE presentation was more significantly associated with COPD patients than non-COPD patients (OR 1.64, 95% CI 1.49-1.80). During the 3-month follow-up, mortality (10.8% versus 7.6%), minor bleeding (4.5% versus 2.3%) or first VTE recurrences as PE (1.5% versus 1.1%) were significantly higher in COPD patients than in non-COPD patients. PE was the most common cause of death. COPD patients presented more frequently with PE than DVT. It may explain the worse prognosis of COPD patients, with a higher risk of death, bleeding or VTE recurrences as PE compared with non-COPD patients. Further therapeutic options are needed.

Gadofosveset enhanced MR phlebography for detecting pelvic and deep vein leg thrombosis

Deep venous thrombosis is mainly diagnosed by ultrasound today. In some instances diagnosis is challenging and magnetic resonance angiography could be an attractive alternative. Gadofosveset is a blood pool contrast agent with some favourable properties for this purpose. We investigated eight patients with proven deep venous thrombosis by Gadofosveset enhanced MR phlebography. We performed a 3D gradient-echo sequence with an overall measurement time of 9 minutes and 6 seconds. One minute after injection of Gadofosveset in a concentration of 0.12 ml/kg body weight images were acquired. Thrombi were visualised by their lack of luminal contrast filling. Thrombi were visualised in all patients. In one patient with extended thrombosis a previously undiagnosed ovarian adenocarcinoma was detected additionally. Deep venous thromboses in lower extremities can be visualised reliably by performing MR phlebography with blood pool contrast agent Gadofosveset. Visualisation of the complete venous system is feasible. This investigation method may be performed in patients difficult to investigate with ultrasound or may be used for planning interventional procedures.

The Feasibility and Safety of Anticoagulation during Chemotherapy Associated Thrombocytopenia for Thrombotic Complications of Malignancy.

The optimal management of patients with hematological malignancies who require therapeutic anticoagulation for thromboembolic disease or prosthetic cardiac valves while receiving myelosuppressive chemotherapy has not been established. In particular, the role of anticoagulation during chemotherapy-induced thombocytopenia, with its attendant increased risk of bleeding, is undefined. We describe the feasibility and safety of a dynamic dosing strategy for continuous anticoagulation during chemotherapy-induced thrombocytopenia. Sixty patients with haematological malignancies who required anti-coagulation for venous thromboembolism or prosthetic cardiac valves while receiving chemotherapy were assessed. All were receiving myelosuppressive chemotherapy for a haematological malignancy (27 Acute myeloid or promyelocytic leukaemia; 18 non-Hodgkin lymphoma; 9 plasma cell myeloma; 6 Acute lymphoblastic leukaemia), and required anticoagulation for either proven deep venous thrombosis (catheter-related thrombosis in 32 patients; non-catheter associated deep venous thrombosis in 18) or pulmonary embolus (9) or prosthetic cardiac valves (1). Three patients underwent allogeneic stem cell transplantation and 7 autologous stem cell transplantation. Median time from diagnosis of the thromboembolic disease to commencement chemotherapy was 10 days (range 0–40). Patients were anticoagulated with subcutaneous enoxaparin 1mg/kg body weight twice daily while the platelet count was ≥50×109/L and 0.5mg/kg once daily to maximum of 40mg while it was <50×109/L; platelets were transfused to maintain a count ≥20×109/L. Patients were clinically assessed daily for clinical evidence of bleeding or thrombosis, and underwent regular radiological screening for thrombotic complications. Plasma anti-Xa levels were assayed regularly only in patients with elevated serum creatinine (4 patients) or body mass index (1 patient). Median number of days of chemotherapy-induced thrombocytopenia <150×109/L was 20 (range 1--84); <50×109/L 12 (0–41), and <20×109/L was 2 (0–30). Enoxaparin was delivered at full dose on 31% of thrombocytopenic days (median per patient 12 days, range 5–23), at reduced dose on 63% of days (median per patient 20 days, range 0–68), and withheld on 6% of days (median per patient 1 day, range 0–8). Of days where enoxaparin was withheld, 45% were for procedures; 20% bleeding; and 35% other reasons, including refractory thrombocytopenia <20×109/L. Serious bleeding complications during anticoagulation were uncommon. Three patients (5%) experienced major bleeding episodes: two developed gastrointestinal bleeding requiring endoscopic intervention and transfusion while receiving reduced dose anticoagulation with platelet counts of 20–50 ×109/L; one developed bleeding requiring surgical intervention at an existing wound site when the platelet count was 19 ×109/L, but had not received enoxaprin that day. Minor bleeding, including bruising at the sites of injections and menorrhagia was common. No further thromboembolic complications were identified in any patient. This study suggests that dynamically dosed anticoagulation is safe and feasible during thrombocytopenia following chemotherapy, including conditioning for stem cell transplantation, in patients who are carefully selected and closely monitored. This strategy was not associated with excessive bleeding and appeared effective in preventing further thromboembolic complications.

Floating thrombi on the Eustachian valve as a complication of venous thromboembolic disease

Floating right heart thrombi can occur in 4–18% of patients with pulmonary embolism. Usually, the diagnosis is done by echocardiography and carries an important prognostic significance as thrombi can embolize at any moment and severe pulmonary embolism is the most frequent way of floating right heart thrombi presentation (mortality rate >40%). We present a case report of floating right thrombi in a patient with proven deep venous thrombosis complicated with nonmassive pulmonary embolism that was successfully treated with thrombolysis.

Blood rheology in deep venous thrombosis—relation to persistent and transient risk factors

Introduction: The risk of recurrence in patients with symptomatic deep venous thrombosis (DVT) is higher in patients with persistent risk factors than in patients with transient risk factors. The purpose of this prospective study was to investigate the course of rheological variables in patients with DVT up to 1 year after the acute event in relation to risk factors. Patients and methods: In 37 patients with proven DVT plasma fibrinogen, plasma viscosity, red cell aggregation, whole blood viscosity, hematocrit and platelet aggregation were studied in the acute phase, at 6 weeks and at 12 months. Results: In the acute phase, patients had higher fibrinogen (medians and ranges; 450 [270–611] vs. 247 [170–340] mg/dl, p<0.01), plasma viscosity (1.67 [1.48–1.96] vs. 1.60 [1.50–1.70] mPa s, p<0.01), red cell aggregation (9.76 [5.87–12.66] vs. 5.66 [3.67–8.46] arbitrary units; p<0.01) and whole blood viscosity (5.78 [5.61–5.87] vs. 5.59 [5.27–5.9] mPa s, p<0.01), but lower hematocrit (40 [32–46] vs. 45 [38–50]%, p<0.01) and platelet aggregation (by epinephrine: 41 [13–85] vs. 79 [29–91]%, ( p<0.01) than controls. During the 1-year follow-up, fibrinogen, plasma viscosity, red cell aggregation and whole blood viscosity constantly decreased, whereas hematocrit and platelet aggregation increased in the total of patients (all p<0.01). Subgroup analysis according to risk factors showed that at 12 months patients with persistent risk factors ( N=21) had higher plasma fibrinogen (357 [235–450] vs. 247 [214–335] mg/dl, p<0.01), plasma viscosity (1.65 [1.50–1.80] vs. 1.59 [1.42–1.77] mPa s, p<0.05) and red cell aggregation (7.82 [6.0–11.3] vs. 6.3 [5.2–7.1] arb. units, p<0.01) than patients with transient risk factors ( N=16). Compared with controls, these variables were increased in patients with persistent risk factors (all p<0.01), but not in patients with transient risk factors (all n.s.). Conclusion: In patients with persistent risk factors rheological changes are still present 1 year after acute DVT, whereas in patients with transient risk factors blood rheology returns to normal. Further studies are needed to clarify whether blood rheology might be helpful to identify patients at high risk of recurrence.

Radiolabeled peptides in the detection of deep venous thrombosis

Venous thrombosis and pulmonary embolism are major clinical problems that result in significant morbidity and mortality. It is estimated that 600,000 cases of pulmonary embolism occur each year in the United States, resulting in the death of approximately 100,000 patients. Most of these pulmonary emboli arise from deep venous thrombosis (DVT). The clinical diagnosis of DVT is unreliable. Only a third of patients with a clinical suspicion of DVT have objective evidence of the disease, and half of patients with proven DVT do not have any clinical symptoms. Although ascending contrast venography is the present standard for the diagnosis of DVT, duplex ultrasonography, which is increasingly used in combination with color Doppler flow imaging, is accepted as a useful clinical afternative to contrast venography. Both contrast venography and ultrasonography are imaging procedures that detect changes in venous anatomy that are caused by the presence of an intraluminal thrombus that is sufficiently formed either to reduce vascular filling with contrast medium or to resist compression. However, these imaging procedures do not reflect the metabolic activity of the clot, and therefore, they may overestimate the presence of active clots. The sensitivity of ultrasonography is also limited by various disease-related and technical factors. An alternative approach to the diagnosis of acute DVT is to detect a molecular marker of acute DVT that is not present in old, organized DVT. Recent advances in biotechnology permit the use of highly specific synthetic peptide or small molecular markers, which are involved in the acute stages of DVT formation and can be labeled efficiently with 99mTc. 99mTc-apcitide, a glycoprotein (GP IIb/IIIa) receptor antagonist previously known as 99mTc-P280, has been approved recently by the Food and Drug Administration for the clinical detection of acute DVT. Two other agents are currently under clinical investigation: 99mTc-DMP 444, which is another GP IIb/IIIa receptor antagonist, and 99mTc-Fibrin-Binding Domain (FBD), a radio-labeled fibrin-binding domain of fibronectin. Different clinical studies have shown a high diagnostic accuracy with these synthetic 99mTc-labeled peptides in the detection of acute DVT. Although further studies are needed to fully appreciate all of the diagnostic potential of these radiopharmaceuticals, the clinical introduction of 99mTcapcitide scintigraphy will certainly be helpful in expanding the use of nuclear medicine in a specific field in which it used to play a relatively marginal role.

Diagnostic Value of a New Sensitive Membrane Based Technique for Instantaneous D-Dimer Evaluation in Patients with Clinically Suspected Deep Venous Thrombosis

Plasma D-Dimer analysis, using ELISA assays, has demonstrated in previous studies a high sensitivity, suggesting its utility in excluding deep venous thrombosis (DVT). To assess the performance of a new rapid plasma D-Dimer ELISA measurement in suspected DVT patients with recent clinical signs, not exceeding one week. A prospective study of patients admitted for a suspected recent DVT. Contrast venography or compression ultrasonography were performed within 24 h of admission. A new membrane based ELISA technique, which uses an immunofiltration and two complementary monoclonal antibodies was tested. Results were expressed as positive or negative. A standard plasma D-Dimer ELISA measurement was also performed. D-Dimer performances were assessed at the end of the study. 265/448 patients had a proven DVT (72 distal, 193 proximal). The sensitivity of the instantaneous method in the diagnosis of overall DVT is 92 +/- 3.4% (95% CI), and specificity is 36.6 +/- 6.9%. Positive predictive value is 67.7 +/- 4.8% and negative predictive value is 76.1 +/- 8.9%. Sensitivity and negative predictive values reach 97.9 and 94.3% in the diagnosis of proximal DVT, but only 76.3 and 79.7% in the diagnosis of distal DVT. Similar results are observed with the standard ELISA method. This new rapid plasma D-Dimer measurement appears highly sensitive, and could substitute the older ELISA methods. Both methods provide lower sensitivity in the case of a distal DVT location.

Contrast venography: from gold standard to ‘golden backup’ in clinically suspected deep vein thrombosis

In a series of 180 patients, clinically suspected of having deep venous thrombosis (DVT), contrast venography was compared with radionuclide phlebography, duplex ultrasonography and strain gauge plethysmography. In most patients lung scintigraphy was also performed to detect pulmonary embolism (PE). Venography was performed on a routine basis. All venograms were read by at least two observers (radiologists or radiologist/resident) and an inter-observer agreement was reached of 96% with a kappa value of 0.935. In six patients venography was technically impossible or inadequate. 58% of the patients actually had DVT and 26% developed pulmonary embolism (PE). Of the patients with proven DVT, 43% developed PE. Of the three other methods duplex scanning scored the best for the detection of proximal thrombosis, with 92%, 90% and 9.2, and strain gauge plethysmography the worst, with values of 72%, 78% and 3.2 for, respectively, sensitivity, specificity and positive likelihood ratio's. On the basis of the presented material and the current literature it is concluded that the choice for a screening test for proximal thrombosis could best be made on the basis of (local) availability, cost-effectiveness and patient comfort. Duplex ultrasonography is tipped as the most promising method, accepting that distal thrombosis (calf veins) does not play an important role in PE. Contrast venography should be used as a ‘golden backup’ in any case of doubt.

Occult pulmonary embolism: a common occurrence in deep venous thrombosis.

Ventilation-perfusion scans were used in a prospective study to determine the prevalence of occult pulmonary embolus in proven deep venous thrombosis. Fifty-eight patients without symptoms of pulmonary embolism, but with venographically proven deep venous thrombosis, were subjected to chest radiographs, 99mTc macroaggregated-albumin perfusion scans, and 133Xe ventilation scans. Of the 49 patients with deep venous thrombosis proximal to the calf veins, 17 (35%) had high-probability scans. Of all 58 patients, only 12 (21%) had normal scans. When the study population was compared with a group of 430 patients described in reports of pulmonary perfusion in asymptomatic persons, a significantly higher percentage of high-probability scans was found in the study population with deep venous thrombosis. Baseline ventilation-perfusion lung scanning is valuable for patients with proven above-knee deep venous thrombosis.