CT and MRI appear to be accurate for DVT diagnosis (sensitivity and specificity >90%), but are rarely used because CT requires radiographic contrast and is associated with high radiation exposure, and both CT and MRI are costly.1,35,36Â CT and MRI are valuable options if US examination of the pelvic veins, inferior or superior vena cava, or innominate veins is inadequate. It’s prevalence is one patient per thousand people per year and out of 100,000 hospital admissions, 239 are from VTE [2-4]. 12 Key messages. However, over 50% of patients with suspected PE have an abnormal perfusion scan that is nondiagnostic and, therefore, requires further testing. is supported by an investigator award from the Heart and Stroke Foundation of Canada, as well as the Jack Hirsh Professorship in Thromboembolism. likely/unlikely. The most convincing finding is a new noncompressible popliteal or common femoral segment. Ascending phlebography is still considered the diagnostic standard for diagnosing DVT but it is invasive, costly, and not devoid of risk. The NICE guideline on the management of venous thromboembolism (VTE) does not currently recommend the use of PERC in the diagnostic pathway. This question is for testing whether or not you are a human visitor and to prevent automated spam submissions. Some VTE diagnostic tests can identify an alternative diagnosis (eg, CT pulmonary angiography [CTPA] or leg US), whereas others do not (eg, D-dimer testing or perfusion scanning). 2. Venous US is very accurate for the diagnosis of a first proximal DVT, with a sensitivity and specificity approaching 95%.1,6Â An unequivocally positive test is diagnostic for DVT. The overall incidence of venous thromboembolism (VTE) --including both deep vein thrombosis (DVT) and pulmonary embolism (PE) — is one case per 1000 patient years. This can exclude isolated distal DVT (ie, all DVT), and avoid the need for a repeat US examination after 7 days.1,30Â However, examination of the distal veins has the disadvantage of diagnosing â¼50% to 100% more DVT and, compared with serial proximal venous US (initial and 7 days), does not reduce the risk of VTE during follow up (â¼1% over 3 months in both groups). A non-specific increase in D-dimer concentration is seen in many situations, precluding its use for diagnosing venous thromboembolism (VTE). Although the clinical diagnosis of VTE may be improved with the use of the Wells’ clinical probability model and D-dimer measurements, there is considerable disagreement about the order in which these strategies should be used to exclude the diagnosis of DVT and PE, and to reduce the number of serial ultrasound studies. Of the cases with DVT, â¼90% involve the legs, 5% involve the arms (or more central veins), and 5% involve unusual deep venous sites (eg, visceral or cerebral veins). 8 Chronic treatment and prevention of recurrence. The first is to withhold treatment and repeat the proximal venous US after 7 days to detect the small number of isolated distal DVT that subsequently extend into the proximal veins (â¼3%). If the D-dimer test is negative, it means that the patient probably does not have a blood clot. Ascending venography was the reference standard for the diagnosis of DVT (proximal, distal, and upper extremity). However, a low D-dimer concentration is thought to rule out the presence of circulating fibrin and therefore VTE. For patients with suspected DVT, this includes: (1) a low CPTP; or (2) negative proximal US (Table 3). It continues to be used in difficult to diagnose cases of upper-extremity DVT. Low. This is a clinical prediction model that aims to improve the accuracy of pre-test screening for pulmonary embolism and to decrease incidence of unnecessary clinical imagery.There are 7 parameters that are taken into account, all referring to risk factors for venous thromboembolism events: A score of â¥2 has been termed âDVT likely.â This group makes up â¼40% of patients and has a prevalence of DVT of â¼33%. The ability of diagnostic tests to correctly identify or exclude VTE is influenced by VTE prevalence and test accuracy characteristics. However, a negative D-dimer appears to retain its high negative predictive value (Table 4).29Â, Results that ârule-inâ or ârule-outâ upper-extremity DVT. If a previous test is not available for comparison, the positive predictive value of ultrasound is low in patients with previous DVT. In patients with suspected recurrent DVT, venography distinguishes new thrombus (intraluminal filling defect) from old (no intraluminal filling defect), but may be nondiagnostic if there is extensive nonfilling of the deep veins due to old disease. DVT Modified Wells Criteria Probability of VTE increases from 3 to 75 % as wells score increases. Ventilation imaging improves the specificity of perfusion scanning, with an 85% or higher prevalence of PE in patients with 2 or more large (>75% of a segment) perfusion defects that are normally ventilated (âhigh-probability scanâ). However, D-dimer still has a high negative predictive value for recurrent VTE. A systematic review and meta-analysis, D-dimer threshold increase with pretest probability unlikely for pulmonary embolism to decrease unnecessary computerized tomographic pulmonary angiography, Variable D-dimer thresholds for diagnosis of clinically suspected acute pulmonary embolism, Selective D-dimer testing for diagnosis of a first suspected episode of deep venous thrombosis: a randomized trial, Diagnostic accuracy of conventional or age adjusted D-dimer cut-off values in older patients with suspected venous thromboembolism: systematic review and meta-analysis, Potential of an age adjusted D-dimer cut-off value to improve the exclusion of pulmonary embolism in older patients: a retrospective analysis of three large cohorts, Performance of age-adjusted D-dimer cut-off to rule out pulmonary embolism, The combination of four different clinical decision rules and an age-adjusted D-dimer cut-off increases the number of patients in whom acute pulmonary embolism can safely be excluded, Age-adjusted D-dimer cutoff levels to rule out pulmonary embolism: the ADJUST-PE study, Safety and feasibility of a diagnostic algorithm combining clinical probability, D-dimer testing, and ultrasonography for suspected upper extremity deep venous thrombosis: a prospective management study, Risk of deep vein thrombosis following a single negative whole-leg compression ultrasound: a systematic review and meta-analysis, Antithrombotic therapy for VTE disease: CHEST Guideline and Expert Panel Report, Interobserver agreement on ultrasound measurements of residual vein diameter, thrombus echogenicity and Doppler venous flow in patients with previous venous thrombosis, Accuracy of diagnostic tests for clinically suspected upper extremity deep vein thrombosis: a systematic review, Whole-arm ultrasound to rule out suspected upper-extremity deep venous thrombosis in outpatients, The accuracy of MRI in diagnosis of suspected deep vein thrombosis: systematic review and meta-analysis, Diagnostic value of CT for deep vein thrombosis: results of a systematic review and meta-analysis, Magnetic resonance direct thrombus imaging differentiates acute recurrent ipsilateral deep vein thrombosis from residual thrombosis, Subsegmental pulmonary embolism diagnosed by computed tomography: incidence and clinical implications. Similarly, not all detected VTE need to be treated. Combinations of test results that rule-in and rule-out DVT or PE are summarized in Tables 3-5. D-dimer testing. With whole-leg venous US, the examination is extended to include the distal (ie, calf) veins. D-dimer is also less well evaluated in patients with suspected upper-extremity DVT. CTPA, which outlines thrombi in the pulmonary arteries and often identifies alternative diagnoses, has become the imaging test of choice for PE.3,18,38,39Â The accuracy of CTPA varies with the extent of PE and CPTP. The American College of Physicians guidelines for the treatment of VTE suggests criteria for making this decision.31Â. doi: 10.5482/HAMO-13-06-0029. In chronic DVT, the affected vein is noncompressible and small. D-dimer tests vary in terms of the measurement method and the D-dimer level that is used to categorize a test as positive or negative. Antiphospholipid syndrome is thought to be associated with a high risk for both recurrent venous thromboembolism and arterial thrombosis.67 The presence of persistently elevated antiphospholipid antibodies with a first venous thromboembolism is an acceptable indication for indefinite duration of anticoagulation.16 67 A diagnosis of antiphospholipid syndrome is made on the … When ventilation-perfusion (V/Q) scanning was the primary diagnostic test for PE, a posttest probability of â¥85% was considered diagnostic and grounds for long-term anticoagulant therapy (ie, corresponding to a âhigh probabilityâ scan). Elevated RBC mass > 25% above mean normal predicted value or hemoglobin > 18.5 gm/dL (male) or 16.5 gm/dL (female) 2. In the linked systematic review and meta-analysis (doi:10.1136/bmj.b2990), Geersing and colleagues analysed the diagnostic performances of several qualitative and quantitative D-dimer tests used at the point of care.1 They found that quantitative tests perform better than qualitative ones, but …. Copyright ©2020 by American Society of Hematology, What posttest probability ârules-inâ or ârules-outâ DVT or PE, Clinical pretest probability (CPTP) for DVT and PE, Venography for leg and upper-extremity DVT, CT and magnetic resonance imaging (MRI) venography for DVT, Sequence of testing for DVT and PE, and results that are diagnostic, https://doi.org/10.1182/asheducation-2016.1.397, deep venous thrombosis of upper extremity, Active cancer (treatment ongoing or within previous 6 mo or palliative)Â, Paralysis, paresis, or recent plaster immobilization of the lower extremitiesÂ, Recently bedridden >3 d or major surgery within 4 wksÂ, Localized tenderness along the distribution of the deep venous systemÂ, Calf swelling 3 cm greater than on asymptomatic side (measured 10 cm below tibial tuberosity)Â, Pitting edema confined to the symptomatic legÂ, Alternative diagnosis as likely or greater than that of DVTÂ, Alternative diagnosis is less likely than PEÂ, Immobilization or surgery in previous 4-wk periodÂ, Malignancy or treatment of it in previous 6-mo periodÂ, âNoncompressibility of proximal veins (calf vein trifurcation included)Â, âNoncompressibility of distal veins, when findings are extensiveÂ, âIntraluminal defect (unequivocal) with associated absence of flow in the iliac veins or inferior vena cava, when compressibility cannot be assessedÂ, âIntraluminal filling defect in proximal or distal deep veinsÂ, âNegative very sensitive test (eg, D-dimer <500 Î¼g/L) AND low or moderate CPTPÂ, âNegative moderately sensitive test (including D-dimer <1000 Î¼g/L) AND low CPTPÂ, âFully compressible proximal veins AND low CPTPÂ, âFully compressible proximal veins AND moderately or very sensitive D-dimer testÂ, âFully compressible proximal and distal veins (whole-leg US)Â, âFully compressible proximal veins AND normal repeat proximal US after 7 dÂ, âAll deep veins seen and no intraluminal filling defectsÂ, âA new, noncompressible proximal vein segmentÂ, âA 4-mm increase in diameter of the common femoral or popliteal vein compared with a previous testÂ, âA unequivocal extension of thrombosis (eg, additional 10 cm) within the femoral veinÂ, âIntraluminal filling defect in proximal or distal deep veins (new, or >3 mo after last event)Â, ââ¤1 mm increase in diameter of the common femoral, and femoral and popliteal veins compared with a previous test AND remains unchanged on repeat testing after 2 d and 7 dÂ, âNoncompressibility of the axillary, brachial veins, or jugular veinÂ, âIntraluminal defect (unequivocal) with associated absence of flow in the subclavian veinÂ, âIntraluminal filling defect within brachial vein to superior vena cavaÂ, âNo DVT within brachial to subclavian veins AND not suspected of having a more central DVTÂ, âNo DVT on US AND normal repeat US after 7 dÂ, âNegative very sensitive test (eg, D-dimer <500 Î¼g/L) AND low or unlikely CPTPÂ, âNo intraluminal filling defect within brachial vein to superior vena cavaÂ, âIntraluminal filling defect in a lobar or main pulmonary arteryÂ, âIntraluminal filling defect in a segmental pulmonary artery AND moderate or high CPTPÂ, âHigh-probability scan AND moderate or high CPTPÂ, Positive diagnostic test for DVT (with a nondiagnostic V/Q scan or CTPA, or scan not done)Â, Perfusion scan (usually part of V/Q scan)Â, âNegative moderately sensitive test AND low CPTPÂ, âIn patients over 50 y, D-dimer level <10 times the patient's age AND a low or moderate CPTPÂ, Nondiagnostic V/Q scan or CTPA AND normal proximal venous US AND one of:Â, âNegative moderately or very sensitive D-dimer testÂ, âNormal repeat proximal US after 7 d and 14 dÂ, May identify a suspected alternative to PE (eg, progressive malignancy; aortic dissection)Â, May identify a suspected alternative to DVT (eg, ruptured Baker cyst; hematoma)Â, Favors whole-leg US over serial proximal USÂ, D-dimer will be high even if no DVT or PE (eg, postoperative; inpatient; sepsis)Â, Younger, particularly if females and pregnantÂ, Lung disease or abnormal chest radiographÂ.
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