Search

Introduction Contrast venography is the standard method for the diagnosis of deep vein thrombosis, but its widespread use is hampered mainly due to the invasive nature of the test, limited [...]

Background: Despite advances in primary prophylaxis, venous thromboembolism still occurs in a considerable number of high-risk surgical patients. Screening with conventional ultrasound imaging to detect asymptomatic deep vein thrombosis (DVT) has been suggested as a strategy to improve management of such patients, but it is insufficiently sensitive. We evaluated the ability of color Doppler ultrasound to improve the sensitivity of compression ultrasound in the detection of asymptomatic DVT in high-risk orthopedic patients. Methods: We prospectively evaluated bilateral compression and color Doppler ultrasound measurements of the entire leg in 204 consecutive patients who underwent elective hip or knee replacement surgery, using contrast venography as the reference test. The sensitivity, specificity, and positive predictive value of the ultrasonography tests were determined. Results: The sensitivity, specificity, and positive predictive value (with 95% confidence intervals [CIs]) of compression ultrasound for the detection of proximal DVT were 60% (39%-81%), 96% (92%-99%), and 71% (48%-89%), respectively. The sensitivity, specificity, and positive predictive value (with 95% CIs) of compression ultrasound for the detection of calf vein thrombosis were 33% (18%-52%), 91% (83%-96%), and 58% (34%-80%), respectively. Color Doppler ultrasonography did not identify any additional proximal or calf vein thrombi to those detected by compression ultrasound alone. The sensitivity for all thrombi was, 47% (95% CI, 34%-61%) with a positive predictive value of 65% (95% CI, 48%-79%). Conclusions: Color Doppler ultrasonography has a moderate to low accuracy for the detection of DVT in patients who have had hip and knee replacement surgery. Color Doppler ultrasonography does not increase the detection rate for asymptomatic DVT over compression ultrasound and thus cannot be recommended as a screening test in this setting.

Background: Little is known about the clinical, diagnostic, and prognostic aspects of upper-extremity deep vein thrombosis (UEDVT). Objectives: To identify the clinical and laboratory parameters associated with this disease, to assess the diagnostic accuracy of ultrasonographic methods for its detection, and to establish the frequency of both early and late complications. Patients and Methods: After a careful history was taken, 58 consecutive patients with signs and symptoms that were clinically suggestive of UEDVT underwent the determination of antithrombin III and protein C and S levels and resistance to activated protein C and lupuslike anticoagulants. Compression ultrasonography, color flow Doppler imaging, and Doppler ultrasonography were performed prior to venography. Patients with confirmed UEDVT underwent objective tests to detect a pulmonary embolism and were followed up prospectively, to record recurrent thromboembolic events and postthrombotic sequelae. Results: Findings from venography confirmed UEDVT in 27 patients (47%). Central venous catheters, thrombophilic states, and a previous leg vein thrombosis were statistically significantly associated with UEDVT. Sensitivity and specificity of compression ultrasonography (96% and 93.5%, respectively) and color flow Doppler imaging (100% and 93%, respectively) were comparable and better than those of Doppler ultrasonography (81% and 77%, respectively). Objective findings suggestive of a pulmonary embolism were recorded in 36% of the patients with UEDVT. After a mean follow-up of 2 years, 2 patients with UEDVT experienced recurrent thromboembolic events, and 4 had postthrombotic sequelae. Conclusions: Symptomatic UEDVT is associated with central venous catheters, thrombophilic states, and a previous leg vein thrombosis. Both compression ultrasonography and color flow Doppler imaging are accurate methods for its detection. A pulmonary embolism is a common complication of the disease. Finally, this disorder may recur and may be followed by postthrombotic sequelae. Arch Intern Med. 1997;157:57-62

Background: in patients who have symptomatic deep venous thrombosis, the long-term risk for recurrent venous thromboembolism and the incidence and severity of post-thrombotic sequelae have not been well documented. Objective: To determine the clinical course of patients during the 8 years after their first episode of symptomatic deep venous thrombosis. Design: Prospective cohort study. Setting: University outpatient thrombosis clinic. Patients: 355 consecutive patients with a first episode of symptomatic deep venous thrombosis. Measurements: Recurrent venous thromboembolism, the post-thrombotic syndrome, and death. Potential risk factors for these outcomes were also evaluated. Results: The cumulative incidence of recurrent venous thromboembolism was 17.5% after 2 years of follow-up (95% CI, 13.6% to 22.2%),24.6% after 5 years CI, 19.6% to 29.7%), and 30.3% after 8 years (CI, 23.6% to 37.0%). The presence of cancer and of impaired coagulation inhibition increased the risk for recurrent venous thromboembolism (hazard ratios, 1.72 [CI, 1.31 to 2.25] and 1.44 [CI, 1.02 to 2.01 ], respectively). In contrast, surgery and recent trauma or fracture were associated with a decreased risk for recurrent venous thromboembolism (hazard ratios, 0.36 [CI, 0.21 to 0.62] and 0.51 [CI, 0.32 to 0.87], respectively). The cumulative incidence of the post-thrombotic syndrome was 22.8% after 2 years (CI, 18.0% to 27.5%), 28.0% after 5 years (CI, 22.7% to 33.3%), and 29.1% after 8 years (CI, 23.4% to 34.7%). The development of ipsilateral recurrent deep venous thrombosis was strongly associated with the risk for the post-thrombotic syndrome (hazard ratio, 6.4; CI, 3.1 to 13.3). Survival after 8 years was 70.2% (CI, 64.7% to 75.6%). The presence of cancer increased the risk for death (hazard ratio, 8.1; CI, 3.6 to 18.1). Conclusion: Patients with symptomatic deep venous thrombosis, especially those without transient risk factors for deep venous thrombosis, have a high risk for recurrent venous thromboembolism that persists for many years. The post-thrombotic syndrome occurs in almost one third of these patients and is strongly related to ipsilateral recurrent deep venous thrombosis. These findings challenge the widely adopted use of short-course anticoagulation therapy in patients with symptomatic deep venous thrombosis., Patients who have experienced deep venous clots appear likely to experience recurrent clots or other symptoms of blocked circulation over the long term. Of 355 patients experiencing a deep venous clot in a leg, 30% experienced another leg vein clot and 30% experienced venous ulceration, severe pain, or intractable swelling within a follow-up period of eight years. Having cancer or a disease that increased the risk of blood clots increased the risk of having recurrent clots or other venous symptoms and experiencing the first clot as a result of surgery or other injury reduced the risk.

Background: Epidemiologic studies on deep-vein thrombosis (DVT) have been mainly confined to the inpatient population. The aim of this study was to investigate the association between DVT and acquired risk factors in a large cohort of outpatients with clinically suspected DVT. Methods: Consecutive outpatients with clinically suspected DVT were enrolled in the study. Before objective testing, all patients were interviewed by a trained physician for the presence of risk factors for DVT development. Subsequently, the presence or absence of DVT was assessed with venography. Results: Approximately 50% of cases of DVT were considered to be secondary to a major risk factor (immobilization, trauma, and/or recent surgery). Among additional risk factors, only increased age (over 60 years), male gender, malignant neoplasm, heart failure, systemic lupus erythematosus, and arteriopathy were independently associated with the risk of acute DVT. Conclusion: Major risk factors for venous thromboembolism are a common cause of DVT among symptomatic outpatients; therefore, the usefulness of extending DVT prophylaxis in the outpatient setting should be tested. The role of additional risk factors in the development of DVT needs to be established by properly designed studies.

* Background.--Serial testing with impedance plethysmography or compression ultrasonography has been demonstrated to be feasible and accurate for the detection of deep vein thrombosis (DVT) in symptomatic outpatients, and these techniques are replacing contrast venography in this patient category. Limited data, however, are available on the clinical utility of these noninvasive tests in symptomatic hospitalized patients. The objectives of our study were to determine the feasibility of ascending contrast venography and to evaluate the accuracy of these two noninvasive methods for the detection of DVT in symptomatic hospitalized patients. Methods.--A prospective, 'blind' comparison of impedance plethysmography and compression ultrasonography with ascending contrast venography was performed in consecutive hospitalized patients with clinically suspected DVT of the leg. Results.--Of the 127 potentially eligible patients, 44 had to be excluded; 25 of these could not undergo venography (feasibility of venography, 80.3%). The sensitivity, specificity, and positive and negative predictive values of impedance plethysmography for proximal DVT were 96%, 83%, 82%, and 97%, respectively. For compression ultrasonography, these measures for proximal DVT were 97%, 86%, 87%, and 97%, respectively. The overall prevalence of DVT was 53%, of which 85% was located proximally. Conclusions.--Contrast venography cannot be performed in about 20% of consecutive symptomatic patients. Both impedance plethysmography and compression ultrasonography are feasible and valid alternatives to contrast venography in the diagnostic treatment of these patients. (Arch Intern Med. 1992;152:1901-1903)

Deep-vein thrombosis (DVT) of the legs occurs when blood clots form in the veins of the legs. Preoperative diagnosis is required to locate and characterize these clots. This is usually done using venography, a technique for X-raying veins. Venography requires the injection of a contrast material to help visualize the clot. These contrast materials can cause side effects, including the development of blood clots in the veins. There are two main types of contrast materials, high-osmolar and low-osmolar. Studies have shown that the high-osmolar materials are more likely to cause side effects. This study examined the use of the low-osmolar, nonionic material, iohexol, to evaluate its effectiveness and to determine the amount and kinds of side effects it produced. Venography using iohexol was performed on 463 patients. They were subsequently examined for side effects. Eighty-three patients reported minor side effects including pain in the foot, nausea, dizziness, edema (accumulation of fluids in tissues), and itching. Two patients suffered serious side effects (bronchospasm, a spasm of the airways). A subset of 41 patients were examined for fibrinogen uptake as an indicator of blood clot formation. Although 10 of these patients tested positive, further examination showed that only one patient had formed new clots. The results reported here were comparable to those of previous studies showing a low incidence of blood clot formation when low-osmolar materials were used, and the incidence of new blood clots was much lower than has been reported with high-osmolar contrast agents. Iohexol was associated with less discomfort than many of the other materials used. These results indicate that iohexol is a safe and effective contrast material for use in venography. (Consumer Summary produced by Reliance Medical Information, Inc.)

The development of engineered tissues represents a new therapeutic possibility in the treatment of chronic ulcers of the lower limbs in a diabetic patient. In our experience this tissue consists [...]