Deep Venous Thrombosis and Pulmonary Embolism

To review noninvasive methods for diagnosis of first and recurrent deep venous thrombosis and provide evidence-based recommendations for the diagnosis of deep venous thrombosis in symptomatic, asymptomatic, and pregnant patients. Accuracy (comparison with contrast venography) and management (safety of withholding anticoagulants when results were normal) studies that evaluated tests for diagnosis of deep venous thrombosis were identified from a MEDLINE search, personal files, and bibliographies of reviews and original studies. Prospective cohort studies (accuracy and management studies) and randomized comparisons (management studies) that satisfied predefined methodologic criteria were included. Sensitivity, specificity, and positive and negative predictive values were determined for accuracy studies. Rates of venous thromboembolism during long-term follow-up of patients with normal results were determined for management studies. Data from individual studies were combined under a random-effects model. The accuracy of noninvasive tests was compared, with emphasis on within-study comparisons. Recommendations for diagnosis of deep venous thrombosis were developed by a multidisciplinary group and graded according to the strength of the supporting evidence. Venous ultrasonography is the most accurate noninvasive test for the diagnosis of a first symptomatic proximal deep venous thrombosis. However, neither ultrasonography nor impedance plethysmography is accurate in asymptomatic postoperative patients. Venous ultrasonography is less accurate for symptomatic isolated distal (calf) deep venous thrombosis than for proximal deep venous thrombosis, and the clinical utility of venous ultrasonography of the distal veins is uncertain. Withholding anticoagulant therapy in symptomatic patients with suspected deep venous thrombosis who have normal results on serial venous ultrasonography or impedance plethysmography is safe. Diagnosis of recurrent deep venous thrombosis requires evidence of new thrombus formation, such as a new noncompressible venous segment detected by venous ultrasonography, conversion of a normal result on impedance plethysmography to abnormal, or presence of an intraluminal filling defect on venography. Suspected deep venous thrombosis in pregnant patients can usually be managed with serial venous ultrasonography or impedance plethysmography. In symptomatic patients with a suspected first episode of deep venous thrombosis, clinical assessment and D-dimer testing are complementary to testing with venous ultrasonography and impedance plethysmography. Patients with suspected deep venous thrombosis can usually be managed with noninvasive testing. However, if the results of this testing are nondiagnostic or are discordant with the clinical assessment, venography should be considered.

Trauma patients are at exceedingly high risk for the development of deep venous thrombosis and pulmo nary embolism. The incidence, pathophysiology, diag nosis, prophylaxis, and therapy of deep venous throm bosis and pulmonary embolism in the trauma patient are reviewed. The type of injury, systemic pertubations, and enforced immobility are important factors in pathogenesis. Patients with lower extremity injuries and spine fractures with paraplegia appear to be at highest risk. Orthopedic devices used to treat these injuries of ten preclude the conventional noninvasive diagnostic modalities. Further, hemorrhagic risk often impacts the judgment regarding the use of prophylactic measures as well as the therapy once deep venous thrombosis is diagnosed. Better data regarding the incidence of ve nous thromboembolism and the applicability of existing diagnostic, prophylactic, and treatment approaches in this population are needed. Accidents are responsible for over 140,000 deaths and approximately 70 million nonfatal injuries an nually in the United States [1]. Most of the fatalities occur within hours of injury as a result of exsangui nation or a lethal head injury, but approximately 20% survive for days or weeks [2], usually in the intensive care unit. The primary causes of late death are sepsis and multiple-organ failure [2]. Increasing evidence, however, suggests that pulmonary embo lism (PE) is now becoming a leading cause of late death, especially in some high-risk groups [3-5]. The increase in the incidence of PE is due in part to improvements in trauma care, which have lowered the early mortality rate [6-8], leaving more patients at risk for late death. In addition, autopsy examina tions, used more frequently to audit trauma care systems [6,9], have documented an increase in clini cally unsuspected deep venous thrombosis (DVT) and PE. This review was prompted because of the appar ent increase in DVT and PE in the trauma popula tion, and because the trauma patient presents very difficult and unique problems compared with the nontrauma patient with regard to the diagnosis, prophylaxis, and treatment of these disorders. In this review, we address the incidence, pathophys iology, diagnosis, treatment, and prophylaxis of DVT and PE in the trauma patient. We do not con sider the entities of fat embolism or pulmonary microemboli as a cause of late pulmonary failure.

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.

Association between inflammation biomarkers, anatomic extent of deep venous thrombosis, and venous symptoms after deep venous thrombosis.

Period Prevalence of Iliofemoral Venous Occlusive Disease by Doppler Ultrasound Imaging and Corresponding Treatment in a Tertiary Care Facility

Current noninvasive imaging techniques for diagnosis of deep venous thrombosis (DVT) of extremities are limited in their ability to demonstrate central vein involvement and to distinguish acute from chronic changes. The utility of spin-echo magnetic resonance (MR) imaging for DVT was evaluated in 100 patients suspected of having either upper- (n = 25) or lower-extremity (n = 75) DVT. Ninety-seven patients were imaged successfully. In a subset of 36 patients, prospective comparison of MR imaging with contrast venography revealed a sensitivity of 90%, specificity of 100%, and Kappa level of agreement of .752 (P less than .0001). MR imaging showed more central extent of thrombus than did venography in all five patients with upper-extremity DVT and in 13 of 25 patients (52%) with lower-extremity DVT. Although all patients in the study were evaluated for acute symptoms, 13 of 59 (22%) MR imaging studies positive for DVT demonstrated chronic disease. MR images demonstrated ancillary abnormalities in 18 of 41 (44%) patients who did not have DVT. Thus, MR imaging has a role as the definitive examination when the results of initial screening studies are unsatisfactory, or as a first-line examination if (a) there is suspicion of upper-extremity or pelvic vein thrombosis, (b) there is a history of prior DVT that necessitates distinction of acute from chronic changes, or (c) other tests are unavailable.

A clinical case of a 71-year old patient with stomach cancer and concomitant lower extremity deep venous thrombosis diagnosed before the surgical treatment is presented. The patient was administered anticoagulants, and despite the treatment, a diagnosis of deep venous thrombosis with high risk for thromboembolism was set up. Considering high risk for pulmonary embolism, an inferior vena cava filter was implanted in infrarenal part of inferior vena cava at the first stage. On the second day after the cancer surgery (subtotal stomach resection with lymphadenectomy), clot detachment and its dislocation from the left common femoral vein to the area where the cava filter was implanted with further fixation were diagnosed. Accurate diagnosis of lower extremity deep venous thrombosis with high risk for thromboembolism set up by ultrasonography and timely inferior vena cava filter implantation saved the patient with cancer from developing pulmonary embolism.

Optimal medical therapy for acute lower extremity deep venous thrombosis (DVT) remains an enigma. While clinical trials demonstrate non-inferiority with an oral anti-Xa inhibitor, or direct oral anticoagulant (DOAC), versus combined low-molecular weight heparin (LMWH) and oral vitamin K antagonist (VKA), the most effective regimen remains to be determined. This study is a single-center retrospective cohort study from October 2014 to December 2015 of patients with a diagnosis of acute DVT and subsequent serial lower extremity venous duplex. Demographics, medical history, medications, serial ultrasound findings, as well as the primary anticoagulant used for treatment were collected and analyzed by two independent data extractors. Treatment failure was defined as any new DVT or progression of an existing DVT within 3months of diagnosis of the index clot. Risk factors for treatment failure were assessed using standard odds ratios and Fischer's exact test. Among 496 patients with an acute lower extremity DVT, 54% (n = 266) were men, mean age was 61years, 35% (n = 174) involved the popliteal or more proximal segments, and 442 had documentation of the primary treatment for DVT: 20% (n = 90) received nothing; 20% (n = 92) received an oral VKA; 34% (n = 149) received a DOAC; 20% (n = 90) received LMWH; and 5% (n = 21) received another class of anticoagulant. Within 3months, 21% (n=89 out of 427) had treatment failure defined as any new DVT or progression of prior DVT. Patients treated with a DOAC were less likely to experience treatment failure when compared with any other treatment (odds ratio 0.43; 95% confidence intervals [0.23, 0.79]; p = 0.0069) and when compared with traditional oral VKA (OR 0.44; 95% CI [0.21, 0.92]; p = 0.029). None of prior history of DVT, pulmonary embolism, thrombophilia, renal insufficiency, hepatic insufficiency, cancer, or antiplatelet therapy correlated with treatment failure. Treatment outcome did not correlate with being on any anticoagulation versus none (p = 0.74), nor did it correlate with the duration of treatment (<3months versus ≥3months) (p = 0.42). Proximal and distal DVTs showed no difference in treatment failure (19% versus 22%, respectively; p = 0.43). In summary, the use of a DOAC for acute lower extremity DVT yielded better overall outcomes and fewer treatment failures at 3months as compared to traditional oral VKA therapy based on serial duplex imaging.

The risk of venous thromboembolism is increased during pregnancy. Although the absolute overall risk of deep venous thrombosis (DVT) or pulmonary embolism (PE) in pregnancy is low, clinicians are highly vigilant to the development of this disease in pregnancy because of the severe consequences to both mother and child if this condition is not diagnosed, treated and prevented. Although prompt recognition and diagnosis of DVT or PE is critical to reduce maternal morbidity, diagnosis of both DVT and PE currently relies on data from studies in nonpregnant patients. However, there are some recent studies offering new insights in this area. The development of venous thromboembolism during pregnancy is influenced by inherent patient risk factors, pregnancy-associated risk factors, and the mode and type of delivery. The degree of risk increase from these factors individually and in combination, to warrant routine thromboprophylaxis, weighed against bleeding risks, is not yet defined. With increased use of assisted reproductive techniques to achieve pregnancy, clinicians must also be vigilant to the development of venous thrombosis in early pregnancy, occurring in unusual sites such as the upper extremities.

To analyze postoperative risk factors in deep venous thrombosis of lower extremities. Methods: A retrospective analysis was made on the postoperative data of 834 patients who received Color Doppler Flow Imaging (CDFI) for their veins of lower extremities at a 3 first-class ternary hospital from Oct., 2011 to Jun., 2013, then the χ test and multivariate Logistic regression analysis were performed on the possible risk factors contributed to thrombosis. Results: The results of χ test and multivariate Logistic regression analysis showed: age> 50 years (OR = 3.541), prolonged procedure time (OR = 3.409), postoperative heart failure (OR = 2.906), postoperative anxiety (OR = 2.508), postoperative fever (OR = 2.619), smoking (OR = 2.185), prolonged bed rest (OR = 2.995) were important risk factors; while postoperative moderate drinking (OR = 0.462), wearing elastic stockings (OR = 0.374) were protective factors. Conclusion: CDFI is an ideal examination method in the diagnosis of deep venous thrombosis of lower extremities, and the postoperative care should be strengthened to reduce this thrombosis <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[1]</sup> .

One hundred twenty-four patients, with 133 involved extremities having the clinical diagnosis of deep venous thrombosis of the lower extremity, were studied by phleborheography and phlebography. Seventy-two limbs were proved to have deep venous thrombosis and 61 to have no evidence of thrombi in the deep veins. Classic symptoms of muscle pain and muscle tenderness, swelling, and the presence of a positive Homans sign obtained by dorsiflexion of the foot were found to occur with approximately equal frequency in those limbs with and without deep venous thrombosis.

One hundred twenty-six patients with clinically suspected acute deep venous thrombosis of the lower extremity (DVT) were examined comparatively with ultrasound and venography. In total, 174 lower extremity venograms were obtained. Ultrasonic examinations were performed on patients in the supine position. The venous segments were evaluated almost exclusively with transversal scanning. In the thigh, the only criterion for DVT was the reduced or absent compressibility of the venous lumen when gently compressed with the transducer. In the calf, normal unobstructed veins can usually not be viewed in the supine patient, whereas thrombotic veins appear as sonolucent, incompressible channels. Eight-three of the 174 lower extremity venograms were positive for DVT. In the majority of cases (53 of 83) the thrombotic process had involved two or more segments in combination. The sites of involvement of the different venous segments were distributed as follows: 24 occlusions of the common femoral vein, 52 of the superficial femoral vein, 56 of the popliteal vein, and 71 of the calf veins. Ultrasound had a sensitivity of 100% for thrombosis of the common femoral vein, 96% for the superficial femoral veins, 98% for the popliteal vein, and 93% for the calf veins. For the entire lower extremity, in regard to the diagnosis of thrombosis, the overall sensitivity was 95%. In 90% the extension of the occlusion was foreseen correctly. In no cases were false-positive results reported. Thus the overall specificity was 100%. The authors conclude that real-time ultrasound is a highly accurate method for the diagnosis of DVT of the lower extremity. It is the only indirect method capable of evaluating the venous system of the thigh, as well as that of the calf, with high accuracy. It should be the first choice of diagnostic imaging method in the diagnosis of deep venous thrombosis of the lower extremity.

With its highly variable clinical presentation, the diagnosis of cerebral venous sinus thrombosis (SVT), and especially of deep venous thrombosis (DVT), as rare but important causes of stroke is challenging. Because noncontrast cranial CT (NCCT) is still the imaging technique of choice in most emergency departments, we aimed to investigate its value in the diagnosis of SVT and DVT. Screening our patient data base, we identified 8 patients with DVT and 25 patients with SVT. We also included a control group of 36 patients who had presented with clinical signs of DVT or SVT but in whom thrombosis was subsequently excluded. MR imaging, multidetector row CT angiography (MDCTA), and/or digital subtraction angiography (DSA) were used as the reference standard. Three independent readers assessed the NCCTs for the presence of direct and indirect signs of DVT or SVT. Direct signs included the presence of hyperattenuated sinuses (ie, cord sign) or veins (ie, attenuated vein sign), whereas parenchymal edema and hemorrhage were indirect signs. The sensitivity and specificity of the attenuated vein sign for the diagnosis of DVT were 100%, and 99.4%, respectively, whereas the sensitivity and specificity of the cord sign for SVT were 64.6% and 97.2%, respectively. The sensitivity and specificity values of NCCT were 93.7% and 98% for intracerebral edema and 94.8% and 98.7% for intracerebral hemorrhages, respectively. Although NCCT is insufficient to exclude a SVT, its value in the emergency diagnosis of DVT seems to be very high.

Diagnosis of deep venous thrombosis and alternative diseases in symptomatic outpatients

Fibrinolytic activity in patients with idiopathic and secondary deep venous thrombosis