Ultrasonography For Deep Venous Thrombosis Research Articles

D-Dimer and Ultrasonography as the Early-Diagnostic Tools for Lower-Limb Trauma Patients with Deep Vein Thrombosis: A Literature Review

Introduction. The mortality of venous thromboembolism increased among trauma patients. Both the D-dimer test and ultrasonography are selected to diagnose venous thromboembolism due to non-traumatic causes but are rarely utilized in emergency trauma settings. Objectives. This literature review comprehensively explains the accuracy of the D-dimer test and ultrasonography for deep vein thrombosis (DVT) diagnosis. This study finding might broaden the diagnostic recommendation for traumatic patients with deep vein thrombosis. Method. This study used articles from four distinct journal databases. Only eight of the 480 articles found during searching proceeded with the screening process. Thus, five articles were included in the review after matching the eligibility criteria. Results. Three articles compared the accuracy of using the D-dimer test and ultrasonography, while others compared the accuracy of conventional ultrasonography to venography or colour duplex ultrasonography. Using three mg/L as the cut-off point, the D-dimer test's pooled sensitivity and specificity were 88,37% and 96,96%. Meanwhile, ultrasonography for DVT resulted in a pooled sensitivity of 59% and specificity of 95%. Conclusion. Using both tools in trauma cases with DVT would give a more accurate diagnosis. A systematic review of this issue would be preferred to support this argument.

Surveillance or no surveillance ultrasonography for deep vein thrombosis and outcomes of critically ill patients: a pre-planned sub-study of the PREVENT trial

We examined the association between surveillance for deep vein thrombosis (DVT) among medical-surgical critically ill patients by twice-weekly ultrasonography and 90-day all-cause mortality. This was a pre-planned sub-study of the Pneumatic Compression for Preventing Venous Thromboembolism (PREVENT) trial (Clinicaltrials.gov: NCT02040103) that compared addition of intermittent pneumatic compression (IPC) to pharmacologic prophylaxis versus pharmacologic prophylaxis alone. The surveillance group included enrolled patients in the trial, while the non-surveillance group included eligible non-enrolled patients. Using logistic regression and Cox proportional hazards models, we examined the association of surveillance with the primary outcome of 90-day mortality. Secondary outcomes were DVT and pulmonary embolism (PE). The surveillance group consisted of 1682 patients and the non-surveillance group included 383 patients. Using Cox proportional hazards model with bootstrapping, surveillance was associated with a decrease in 90-day mortality (adjusted HR 0.75; 95% CI 0.57, 0.98). Surveillance was associated with earlier diagnosis of DVT [(median 4days (IQR 2, 10) vs. 20days (IQR 16, 22)] and PE [median 4days (IQR 2.5, 5) vs. 7.5days (IQR 6.1, 28.9)]. There was an increase in diagnosis of DVT (adjusted HR 5.49; 95% CI 2.92, 13.02) with no change in frequency in diagnosis of PE (adjusted HR 0.56; 95% CI 0.19, 1.91). Twice-weekly surveillance ultrasonography was associated with an increase in DVT detection, reduction in diagnostic testing for non-lower limb DVT and PE, earlier diagnosis of DVT and PE, and lower 90-day mortality. The PREVENT trial is registered at ClinicalTrials.gov, ID: NCT02040103. Registered on 3 November 2013; Current controlled trials, ID: ISRCTN44653506. Registered on 30 October 2013.

Diagnosis and treatment of incidental venous thromboembolism in cancer patients: guidance from the SSC of the ISTH

Modern computer tomography (CT) with its higher sensitivity and resolution has increased the detection of incidental venous thromboembolism (VTE) in the venous and pulmonary vasculature during routine imaging for cancer staging and response assessment [1]. As a result, up to half of all VTEs diagnosed in oncology centers are incidental [1-5]. Although widely accepted, the diagnosis of incidental VTE is made without using the standard imaging studies required for confirming the presence of symptomatic VTE (i.e. compression ultrasonography for deep vein thrombosis [DVT] and CT pulmonary angiography [CTPA] or ventilation/perfusion lung scan for pulmonary embolism [PE]). The accuracy and reliability of staging imaging in making a diagnosis of DVT or PE have not been established. This article is protected by copyright. All rights reserved

Risk factors for venous thromboembolism after spine surgery.

The efficacy and safety of chemical prophylaxis to prevent the development of deep venous thrombosis (DVT) or pulmonary embolism (PE) following spine surgery are controversial because of the possibility of epidural hematoma formation. Postoperative venous thromboembolism (VTE) after spine surgery occurs at a frequency similar to that seen after joint operations, so it is important to identify the risk factors for VTE formation following spine surgery. We therefore retrospectively studied data from patients who had undergone spinal surgery and developed postoperative VTE to identify those risk factors. We conducted a retrospective clinical study with logistic regression analysis of a group of 80 patients who had undergone spine surgery at our institution from June 2012 to August 2013. All patients had been screened by ultrasonography for DVT in the lower extremities. Parameters of the patients with VTE were compared with those without VTE using the Mann-Whitney U-test and Fisher exact probability test. Logistic regression analysis was used to analyze the risk factors associated with VTE. A value of P < 0.05 was used to denote statistical significance. The prevalence of VTE was 25.0% (20/80 patients). One patient had sensed some incongruity in the chest area, but the vital signs of all patients were stable. VTEs had developed in the pulmonary artery in one patient, in the superficial femoral vein in one patient, in the popliteal vein in two patients, and in the soleal vein in 18 patients. The Mann-Whitney U-test and Fisher exact probability test showed that, except for preoperative walking disability, none of the parameters showed a significant difference between patients with and without VTE. Risk factors identified in the multivariate logistic regression analysis were preoperative walking disability and age. The prevalence of VTE after spine surgery was relatively high. The most important risk factor for developing postoperative VTE was preoperative walking disability. Gait training during the early postoperative period is required to prevent VTE.

Analysis of risk factors for deep vein thrombosis of the lower extremity for patients with bone metastases

To analyze the risk factors for deep vein thrombosis (DVT) of the lower extremity in patients with bone metastases. Ninety patients with bone metastases were admitted to our hospital From January 2010 to December 2011, and their clinical data were retrospectively analyzed. There were 57 males and 33 females with a mean age of 61 years (range, 27 to 78 years). On admission, all cases were detected by color Doppler ultrasonography for DVT of bilateral lower extremities. Univariate and multivariate analyses were performed to determine the probable risk factors including gender, age, body weight, tumor location, bed confinement and etc. Among the 90 patients, DVT was found in 24 patients on admission and the DVT incidence was 26.7% (24/90). The univariate analysis showed that bed confinement, multiple metastasis, pathological fracture, primary lesion detected, blood group, fibrinogen and hematocrit were significantly related to the incidence of DVT (P < 0.05). The logistic multivariate regression analysis showed that bed confinement, pathological fracture and fibrinogen were independent risk factors for the incidence of DVT. Bed confinement, pathological fracture and fibrinogen are independent risk factors for the incidence of DVT for patients with bone metastases. Patients with bed confinement >3 days, pathological fracture or fibrinogen >4 g/L should be routinely screened for lower extremity DVT on admission. Once identified, the DVT patients should be treated as early as possible.

How can we improve the diagnosis of deep vein thrombosis and pulmonary embolism at the primary level?

c i n e ltd Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), is not uncommon in primary care, with a reported incidence of almost one case per 1000 person-years [1]. VTE is highly feared for its associated mortality, since the risk of PE-related early mortality may be higher than 15%, as well as its associated morbidity, since patients with VTE may also develop long-term complications such as chronic thromboembolic pulmonary hypertension or postphlebitic syndrome [2]. On the other hand, anticoagulation is an effective treatment for VTE, but carries a non-negligible rate of major bleeding events, ranging from 2% in clinical trials to 7.4% in population cohort studies [3]. When VTE is suspected, it is therefore mandatory to quickly achieve the correct diagnosis. Nonetheless, this process is particularly difficult in primary care, because of the limited number of available diagnostic tools and the nonspecific clinical presentations of DVT and PE. Therefore, the ultimate aim is to determine in which patients DVT or PE can be safely ruled out and which patients should be referred for additional diagnostic workup in secondary care. The current diagnostic approach to VTE is based on the combination of three tools: diagnostic clinical prediction rules (CPRs) for assessing the pretest probability; d-dimer measurement; and imaging tests (i.e., venous ultrasono graphy for DVT and computed tomo graphy pulmonary angiography [CTPA] or ventilation-perfusion lung scan for PE). In patients who present with suspected DVT, the CPR developed by Wells and colleagues is currently the most used worldwide [4]. The Wells CPR includes information from patients’ medical history (active cancer, recent immobilization of the lower extremities, recent bedridden or major surgery), physical examination (tenderness along the deep venous system, entire leg swollen or calf difference greater than 3 cm, pitting edema and collateral superficial veins) and a subjective variable (i.e., an alternative diagnosis for patients’ symptoms) [4]. As the Wells CPR has been developed for secondary care outpatients, its applicability to primary care is still uncertain. A prospective validation study showed that the Wells CPR, in combination with a negative quantitative d-dimer test, did not adequately rule out DVT in the primary care setting [5]. This result could be partly due to different population characteristics, since secondary care patients are often selected by primary care physicians, and partly to the subjectively estimated probability of an alternative diagnosis, which might be assessed differently by general practitioners and by specialists. Oudega and colleagues have developed a specific primary care CPR for suspected DVT that included eight simple diagnostic indicators (male gender, oral contraceptive use, presence of malignancy, recent surgery, absence of leg trauma, vein Nicoletta Riva Research Center on Thromboembolic Disorders & Antithrombotic Therapies, Department of Clinical & Experimental Medicine, University of Insubria, Varese, Italy

The impact of risk assessment on the implementation of venous thromboembolism prophylaxis in foot and ankle surgery.

The purpose of this prospective study was to determine whether the more frequently quoted procedure and patient specific risk factors have any impact in the implementation of venous thromboembolism (VTE) prophylaxis following foot and ankle surgery. Two hundred and sixteen patients were included in the study. A variety of operative procedures was carried out with the common denominator being a below knee cast for at least 4 weeks and nonweightbearing for an average of 6 weeks in 130 patients. The remainder of the patients (88) had hallux surgery not requiring a cast and were allowed to weightbear. No patient received any form of thromboprophylaxis postoperatively. All patients were subjected to compression ultrasonography for deep vein thrombosis (DVT) between 2 and 6 weeks postoperatively. There was a 5.09% incidence of VTE (0.9% pulmonary embolism) overall. As no VTE (neither DVT nor pulmonary embolus) developed in the hallux subgroup, i.e. patients not requiring immobilization and were allowed to weightbear, the incidence of VTE in the cast/nonweightbearing group was 8.46%. The results are descriptive and only statistically analyzed where possible, as the sample size of the VTE group was small. There was no significant difference in number of risk factors and no association between gender in the VTE and non VTE groups. 90.9% of patients in the VTE group had a total risk factor score of 5 or more and 73.7% of patients in the non VTE group had a total risk factor score of 5 or more. The average timing to the diagnosis of VTE in this current study was 33.1 days. In view of the unacceptable incidence of VTE and the average total risk factor score of 5 or more (for which thromboprophylaxis is recommended) in the majority of the patients, the authors feel that the routine use of thromboprophylaxis in foot and ankle surgery requiring nonweightbearing in combination with short leg cast immobilization, is warranted. This prophylaxis should continue until the patient regains adequate mobility either by weightbearing (in or out of the cast) or removal of cast immobilization (weightbearing or nonweightbearing), usually between 28 and 42 days.

Compression Ultrasonography of the Lower Extremity With Portable Vascular Ultrasonography Can Accurately Detect Deep Venous Thrombosis in the Emergency Department

Compression ultrasonography of the lower extremity is an established method of detecting proximal lower extremity deep venous thrombosis when performed by a certified operator in a vascular laboratory. Our objective is to determine the sensitivity and specificity of bedside 2-point compression ultrasonography performed in the emergency department (ED) with portable vascular ultrasonography for the detection of proximal lower extremity deep venous thrombosis. We did this by directly comparing emergency physician-performed ultrasonography to lower extremity duplex ultrasonography performed by the Department of Radiology. This was a prospective, cross-sectional study and diagnostic test assessment of a convenience sample of ED patients with a suspected lower extremity deep venous thrombosis, conducted at a single-center, urban, academic ED. All physicians had a 10-minute training session before enrolling patients. ED compression ultrasonography occurred before Department of Radiology ultrasonography and involved identification of 2 specific points: the common femoral and popliteal vessels, with subsequent compression of the common femoral and popliteal veins. The study result was considered positive for proximal lower extremity deep venous thrombosis if either vein was incompressible or a thrombus was visualized. Sensitivity and specificity were calculated with the final radiologist interpretation of the Department of Radiology ultrasonography as the criterion standard. A total of 47 physicians performed 199 2-point compression ultrasonographic examinations in the ED. Median number of examinations per physician was 2 (range 1 to 29 examinations; interquartile range 1 to 5 examinations). There were 45 proximal lower extremity deep venous thromboses observed on Department of Radiology evaluation, all correctly identified by ED 2-point compression ultrasonography. The 153 patients without proximal lower extremity deep venous thrombosis all had a negative ED compression ultrasonographic result. One patient with a negative Department of Radiology ultrasonographic result was found to have decreased compression of the popliteal vein on ED compression ultrasonography, giving a single false-positive result, yet repeated ultrasonography by the Department of Radiology 1 week later showed a popliteal deep venous thrombosis. The sensitivity and specificity of ED 2-point compression ultrasonography for deep venous thrombosis were 100% (95% confidence interval 92% to 100%) and 99% (95% confidence interval 96% to 100%), respectively. Emergency physician-performed 2-point compression ultrasonography of the lower extremity with a portable vascular ultrasonographic machine, conducted in the ED by this physician group and in this patient sample, accurately identified the presence and absence of proximal lower extremity deep venous thrombosis.

Prevalence of venous thromboembolism in neurosurgical patients

This study was conducted to clarify the prevalence of venous thromboembolism (VTE) in neurosurgical patients. Prospective study for venous thromboembolism screening after neurosurgery was conducted. Thirty-seven patients were screened by ultrasonography for deep vein thrombosis in the lower extremities at an average of 12 days postoperatively. All patients received standard thromboprophylaxis using graded compression stocking with/without intermittent pneumatic compression following the VTE prevention guidelines. Definitive diagnosis of venous thromboembolism was made by contrast-enhanced whole-body computed tomography. Prevalence of deep vein thrombosis of the lower legs was 13.5% (5/37). Incidence of pulmonary embolism was 60% (3/5) in patients having deep vein thrombosis. All patients having venous thromboembolism were asymptomatic. In high-risk patients, VTE prevalence after neurosurgery was high even under mechanical prophylaxis. Additional pharmacological prophylaxis should be considered for patients with high risk of VTE.

Emergency Clinician–Performed Compression Ultrasonography for Deep Venous Thrombosis of the Lower Extremity

Emergency clinician-performed ultrasonography holds promise as a rapid and accurate method to diagnose and exclude deep venous thrombosis. However, the diagnostic accuracy of emergency clinician-performed ultrasonography performed by a heterogenous group of clinicians remains undefined. Prospective, single-center study conducted at an urban, academic emergency department (ED). Clinician participants included ED faculty, supervised residents, and midlevel providers who completed a training course for above-calf, 3-point-compression, venous ultrasonography. Patient participants had suspected leg deep venous thrombosis and greater than or equal to 1 predefined sign or symptom. Before any imaging, clinicians classified patients as low (<15%), moderate (15% to 40%), or high (>40%) pretest probability of deep venous thrombosis, followed by emergency clinician-performed ultrasonography. A whole-leg reference venous ultrasonography was then performed and interpreted separately in the radiology department. Patients were followed for 30 days. The criterion standard for deep venous thrombosis(+), required thrombosis of any leg vein on a reference ultrasonograph and clinical plan to treat. We enrolled 183 patients, and 27 (15%) had deep venous thrombosis(+). The sensitivity and specificity emergency clinician-performed ultrasonography was 70% (95% confidence interval [CI] 60% to 80%) and 89% (95% CI 83% to 94%), respectively, with overall diagnostic accuracy of 85% (95% CI 79% to 90%). The posterior probability of deep venous thrombosis(+) among the 88 low-risk patients with a negative emergency clinician-performed ultrasonographic result was 1 of 88, or 1.1% (95% CI 0% to 6%), and the posterior probability of deep venous thrombosis(+) among 14 high-risk patients with a positive emergency clinician-performed ultrasonographic result was 11 of 14, or 79% (95% CI 49% to 95%). The overall diagnostic accuracy of single-visit emergency clinician-performed ultrasonography performed by a heterogeneous group of ED clinicians is intermediate but may be improved by pretest probability assessment.

Ultrasonography for DVT – how useful is single point augmentation?

Aims: It is unclear whether the absence of normal augmentation of spectral Doppler flow at a single point is an accurate predictor of lower limb acute deep vein thrombosis (DVT) or whether its presence reliably excludes DVT. Our main objective was to assess the role of single point augmentation of spectral Doppler flow in the diagnosis of acute DVT. Secondary objectives included identifying the augmentation response in non-DVT diagnoses. Methods: Patients attending the ultrasound department of two hospitals during an eight-month period for investigation of suspected acute DVT were eligible. Spectral Doppler assessment of the superficial femoral vein was recorded during valsalva manoeuvre and calf compression in the asymptomatic and symptomatic legs. The Doppler waveform was characterised as 'Normal' or 'Abnormal'. Standard compression ultrasonography of the symptomatic leg was then performed with the presence of DVT or an alternative diagnosis documented. Results: 167 patients underwent ultrasound examination using the study methodology. 9 patients were subsequently excluded due to bilateral DVT or inability to tolerate calf compression. The remaining 158 patients demonstrated a mean age of 65.4 years with 28 DVTs identified (17.7% of patients). Calf compression elicited a normal response in 118/130 non DVT examinations (specificity=90.8%) and was abnormal in 18/28 DVT examinations (sensitivity=64.3%). Diminished or absent augmentation was identified in alternative diagnoses that included haematoma and Baker's cyst. Conclusions: This study demonstrates that single point augmentation of venous flow has a high specificity and negative predictive value in the assessment of suspected acute DVT. However, the sensitivity is low with 35.4% of DVTs associated with normal Doppler spectra on calf compression (the majority of these missed DVTs are isolated to the calf veins). Conversely, an abnormal augmentation response may be seen in non DVT diagnoses.

Enoxaparin and heparin comparison of deep vein thrombosis prophylaxis in total hip replacement patients

We compared the efficacy and safety of standard heparin to that of low molecular weight heparin (Enoxaparin) in 100 hip replacement patients. A total of 100 patients who underwent total hip replacement surgery were randomised to receive a study medication. Enoxaparin was administered to 50 patients (prophylaxis with subcutaneous injection of 40 mg of Enoxaparin daily was initiated 12 h preoperatively), and heparin (subcutaneous standard heparin initiated 8 h preoperatively on a dose of 5,000 IU and continued to 15,000 IU per day in three equal dosages every 8 h) was given to 50 patients. Each treatment was continued until the patients were discharged from the hospital. They were made to undergo lower extremity duplex ultrasonography for deep vein thrombosis before discharge and discontinued from medication if no pathology was found. The primary parameter to determine the efficacy was the prevalence of venous thromboembolic disease. The primary parameter to determine safety was the prevalence of major bleeding. Two patients in the heparin group developed DVT, which was detected by routine duplex ultrasonography at the end of hospitalisation, and two patients in the exoparine group were detected with late DVT during the postoperative period of 6 weeks. Seven patients had minor and major bleeding in both the groups. Six patients in the heparin group discontinued from medication because of hepatic, renal dysfunctions, and serious discharges from the wound. Enoxaparin is as safe and as effective as standard heparin in total hip replacement surgery.

Systematic review and meta-analysis of the diagnostic accuracy of ultrasonography for deep vein thrombosis.

BackgroundUltrasound (US) has largely replaced contrast venography as the definitive diagnostic test for deep vein thrombosis (DVT). We aimed to derive a definitive estimate of the diagnostic accuracy of US for clinically suspected DVT and identify study-level factors that might predict accuracy.MethodsWe undertook a systematic review, meta-analysis and meta-regression of diagnostic cohort studies that compared US to contrast venography in patients with suspected DVT. We searched Medline, EMBASE, CINAHL, Web of Science, Cochrane Database of Systematic Reviews, Cochrane Controlled Trials Register, Database of Reviews of Effectiveness, the ACP Journal Club, and citation lists (1966 to April 2004). Random effects meta-analysis was used to derive pooled estimates of sensitivity and specificity. Random effects meta-regression was used to identify study-level covariates that predicted diagnostic performance.ResultsWe identified 100 cohorts comparing US to venography in patients with suspected DVT. Overall sensitivity for proximal DVT (95% confidence interval) was 94.2% (93.2 to 95.0), for distal DVT was 63.5% (59.8 to 67.0), and specificity was 93.8% (93.1 to 94.4). Duplex US had pooled sensitivity of 96.5% (95.1 to 97.6) for proximal DVT, 71.2% (64.6 to 77.2) for distal DVT and specificity of 94.0% (92.8 to 95.1). Triplex US had pooled sensitivity of 96.4% (94.4 to 97.1%) for proximal DVT, 75.2% (67.7 to 81.6) for distal DVT and specificity of 94.3% (92.5 to 95.8). Compression US alone had pooled sensitivity of 93.8 % (92.0 to 95.3%) for proximal DVT, 56.8% (49.0 to 66.4) for distal DVT and specificity of 97.8% (97.0 to 98.4). Sensitivity was higher in more recently published studies and in cohorts with higher prevalence of DVT and more proximal DVT, and was lower in cohorts that reported interpretation by a radiologist. Specificity was higher in cohorts that excluded patients with previous DVT. No studies were identified that compared repeat US to venography in all patients. Repeat US appears to have a positive yield of 1.3%, with 89% of these being confirmed by venography.ConclusionCombined colour-doppler US techniques have optimal sensitivity, while compression US has optimal specificity for DVT. However, all estimates are subject to substantial unexplained heterogeneity. The role of repeat scanning is very uncertain and based upon limited data.

Resident-Performed evaluation for deep venous thrombosis reduces time to diagnoses “After-Hours”

Study objectives: The vascular laboratory may not be available 24 hours a day to evaluate patients with suspected lower extremity deep venous thrombosis (DVT). We assess the impact of resident-performed compression ultrasonography on the time to diagnosis for patients treated “after hours” with suspected DVT. Methods: This was a prospective study of patients treated after hours with suspected DVT during a 6-month period in an urban, academic emergency department (ED). Patients were enrolled only when a study physician was available in the ED. Informed consent and compression ultrasonography without color Doppler were done by 1 of 8 participating resident sonographers not responsible for the care of the patient. Treating clinicians were blinded to the results of this examination and determined treatment course with private physicians when available. Results: Forty-eight patients were enrolled with suspected DVT and underwent resident-performed compression ultrasonography for DVT before evaluation by the vascular laboratory. There were 23 true positives, 1 equivocal examination considered a “false positive” for the sake of analysis, 24 true negatives, and no false negatives, corresponding to a sensitivity of 100% (95% confidence interval [CI] 82% to 100%) and specificity of 96% (95% CI 78% to 100%) for lower extremity DVT. Eleven patients were admitted, presumptively anticoagulated, and had inpatient evaluation by the vascular laboratory an average of 23 hours (95% CI 14.2 to 32) after compression ultrasonography in the ED. Thirty-seven patients were held overnight in the ED and underwent vascular laboratory evaluation an average of 7.7 hours (95% CI 5.3 to 10.2) after compression ultrasonography in the ED. Discussion: Our only equivocal examination occurred in a patient with tender lymphadenopathy caused by unilateral cellulitis, preventing the resident from performing adequate compression pressure for an adequate examination. Conclusion: Resident-performed compression ultrasonography for DVT was accurate and associated with a decrease in time to diagnosis for patients treated after hours.

The value of ultrasonography for deep vein thrombosis after arthroplasty of hip or knee

The value of ultrasonography for deep vein thrombosis after arthroplasty of hip or knee

Optimal management strategy for use of compression US for deep venous thrombosis in symptomatic patients: A cost-effectiveness analysis

The authors' purpose was to identify the optimal strategy for using compression ultrasonography (US) in patients suspected of having deep venous thrombosis (DVT). The authors developed a decision-analytic model representing the natural history of DVT and the benefits and risks of anticoagulation therapy. They evaluated six initial imaging strategies: (a) unilateral examination of the common femoral and popliteal veins; (b) unilateral examination of the common femoral, popliteal, and femoral veins; (c) bilateral examination of the common femoral and popliteal veins; (d) bilateral examination of the common femoral, popliteal, and femoral veins; (e) complete unilateral examination of the symptomatic leg (including calf veins); and (f) complete bilateral examination of both legs. For 65-year-old men with unilateral symptoms of DVT, the most effective strategy was bilateral examination of the common femoral and popliteal veins with anticoagulation therapy in patients with proximal DVT and follow-up bilateral examination of the common femoral and popliteal veins in patients without an initial diagnosis of DVT with an incremental cost-effectiveness ratio of $39,000 per quality-adjusted life year gained. These results suggest that bilateral examination limited to the common femoral and popliteal veins, with follow-up bilateral examination limited to the common femoral and popliteal veins, was as cost-effective as other well-accepted medical interventions. The results were sensitive to the distribution of clot, diagnostic accuracy of compression US, and probability of bleeding with long-term morbidity.

Diagnostic utility of ultrasonography of leg veins in patients suspected of having pulmonary embolism.

The standard diagnostic approach in patients suspected of having pulmonary embolism starts with perfusion-ventilation lung scanning. If the resulting scan is not diagnostic, pulmonary angiography should be done. The use of tests for deep venous thrombosis has been advocated as an adjunct to establishing the diagnosis of pulmonary embolism, but no prospective studies have provided adequate information about the value of these tests. To determine the accuracy and potential clinical utility of compression ultrasonography in the diagnosis of pulmonary embolism. Prospective cohort study with blinded assessment of ultrasonographic results. Teaching hospital. 397 consecutive inpatients and outpatients in whom pulmonary embolism was clinically suspected. Sensitivity and specificity of compression ultrasonography. Perfusion-ventilation scanning and angiography were the conjoint gold standard for determining the presence or absence of pulmonary embolism. Also calculated were the number of angiograms and lung scans avoided and the number of patients unnecessarily treated when compression ultrasonography was included in the diagnostic strategy. The overall sensitivity of compression ultrasonography for deep venous thrombosis in patients with pulmonary embolism was 29% (95% CI 22% to 37%); the specificity was 97% (CI, 94% to 99%). Adding ultrasonography to the diagnostic approach before lung scanning would avoid approximately 14% of lung scans and 9% of angiograms but would lead to unnecessary treatment of 13% of patients who have an abnormal ultrasonographic result (2% to 4% of all those receiving anticoagulation). When compression ultrasonography is done only in patients with a nondiagnostic lung scan, 9% of angiographies are prevented at the cost of unnecessarily treating 26% of patients who have an abnormal ultrasonographic result (2% of all patients receiving anticoagulation). The diagnostic value of compression ultrasonography for the detection of deep venous thrombosis in patients suspected of having pulmonary embolism is limited; the gain in diagnostic efficiency obtained through the use of ultrasonography may be offset by a loss in diagnostic accuracy.