Suspected Deep Vein Thrombosis Research Articles

Correlation of Wells Score, Prothrombin Time, Activated Partial Thromboplastin Time, Fibrinogen and D-Dimer Levels with Doppler Ultrasonography in Suspected Deep Vein Thrombosis Patients

BACKGROUND/AIM: Venous thromboembolism (VTE) occur from formation of blood clots in the veins, which are mostly composed of fibrin and red blood cells with a small component of leukocytes and platelets. Most VTE manifests as deep vein thrombosis (DVT) and pulmonary embolism (PE). The lack of availability of Doppler ultrasound in health facilities especially in remote areas, makes the diagnosis of DVT challenging. There for, history taking, physical examination and laboratory findings are very important in diagnosing DVT especially in those area where Doppler ultrasound unavailable. Based on this we study the correlation Wells scores, Prothrombin Time (PT), Activated Partial Thromboplastin Time (APTT), Fibrinogen, and D-Dimer levels with the findings on Doppler ultrasound in patients with suspected DVT in Wahidin Sudirohusodo Hospital Makassar. 
 
 METHOD: The study was conducted in Department of Internal Medicine, Wahidin Sudirohusodo Hospital Makassar from 2018 to 2019. Subjects were inpatients in Department of Internal Medicine with DVT suspicion. Wells scores, PT, APTT, Fibrinogen, D-Dimer levels and Doppler ultrasound results of all subjects were recorded and then analyzed. The patient is DVT positive if confirmed by Doppler Ultrasonography. Statistical analysis was performed by descriptive statistical calculations and frequency distribution as well as the Independent-t statistical test, Chi Square test and Fisher Exact test.
 
 RESULTS: Among 38 subject, 24 were men (63.2%) and 14 were women (36.8%). We found higher Wells score, shortened PT and APTT, increased fibrinogen in subject with positive Doppler ultrasound, without a significant correlation. A significant correlation was found between increased D-Dimer levels positive Doppler ultrasound results (79.4%, p = 0.048). When Wells score is added with analysis a significant correlation was also found (80.6%, p = 0.044). 
 
 CONCLUSION: A significant correlation was found between increased D-Dimer levels positive Doppler ultrasound results (79.4%, p = 0.048). When Wells score is added with analysis a significant correlation was also found (80.6%, p = 0.044).

Role of D-Dimer Assay in Early Detection of Suspected Deep Vein Thrombosis in Obese Individuals

Role of D-Dimer Assay in Early Detection of Suspected Deep Vein Thrombosis in Obese Individuals

Biomarkers and Clinical Prediction Rules in the Diagnosis of Suspected Deep Vein Thrombosis: A Comparison of Cancer and Non-Cancer Patients

Introduction: Despite efforts toward prevention, thousands of patients suffer from venous thromboembolic disease (VTE), consisting of deep vein thrombosis (DVT) and pulmonary embolism (PE), each year; this results in significant morbidity and mortality. Clinical prediction rules, such as the Wells score, in conjunction with biomarkers like the D-dimer, are suggested by national guidelines to aide in evaluating for DVT. Substantial interest exists in developing improved diagnostic testing strategies and algorithms to limit the need for more costly, time consuming, and/or invasive testing. Novel biomarkers, like the soluble P selectin (sP-Sel), a cell adhesion molecule that functions to mediate thrombus formation and amplification, have shown promise in this area.While cancer patients suffer from a high burden of VTE, the D-dimer and Wells score are less helpful in this group. This is due to non-specific D-dimer elevations in these patients, and cancer being part of the Wells risk stratification schema. We sought to identify a more specific combination of biomarkers and Wells score, for the diagnosis of DVT that would apply to cancer patients as well.Methods: We previously performed a prospective cohort study of adults presenting with symptoms of DVT afflicting the upper or lower extremities (Vandy et al. J Vasc Surg Venous Lymphat Disord., 2013). Patients were enrolled from December 2008 to July 2013. Those with isolated calf DVT, superficial venous thrombosis, pregnant or breastfeeding, on therapeutic anticoagulation, or with symptoms of simultaneous upper and lower DVT were excluded. After informed consent was obtained, clinical characteristics and biomarkers (D-dimer, C-reactive protein (CRP), Von Willebrand Factor activity (VWF), and sP-Sel) were collected, and duplex ultrasonography was performed to determine if DVT was present. In this subset analysis, cancer patients were compared to non-cancer patients with regards to thrombotic risk factors, biomarker values, and to assess the test characteristics of various combinations of biomarkers and Wells score.Results: A total of 373 patients were enrolled, 151 (40%) in the cancer group, compared to 222 (60%) in the non-cancer group. Cancer patients were more likely to have a DVT on confirmatory testing (58.9% vs. 43.2%). Cancer patients tended to be older, male, have a lower BMI, more recent acute illness, and more central lines, relative to the non-cancer group. Non-cancer patients were more likely to have other potential risk factors for thrombosis, i.e. recent surgery, oral contraceptive use, and a family history of thrombosis. Biomarker values for CRP and sP-Sel were similar, however VWF and D-dimer values were significantly higher in the cancer patients (see table).D-Dimer > 500 with Wells score ≥ 2 was less specific for the diagnosis of DVT among cancer patients compared to non-cancer patients (p=0.003). However, D-Dimer ≥ 500 with sP-Sel ≥ 90 showed not only high specificity, but that specificity was not different between the cancer and non-cancer populations (p=0.88). sP-Sel ≥ 90 and Wells ≥ 2 had similar performance characteristics in both groups as well (p=0.54 for specificity, p=0.14 for positive predictive value (PPV)).Conclusion: Co-morbid risk factors for thrombosis among cancer patients included an older age, male gender, and an increased use of central lines. This group was less likely to have other potential thrombotic risk factors like family history or recent surgery.Our results concur with the finding that the D-dimer, combined with a clinical prediction rule, is not as helpful for DVT in cancer patients. Moreover, this study further supports sP-Sel as a specific test for DVT, that can be combined with clinical information (Wells score) or other laboratory data (D-dimer) to reflect the presence of DVT and potentially rule in clot; the test seems equally useful for both cancer and non-cancer populations. This could potentially be used to guide initial patient management in scenarios where imaging or further testing is not immediately available, such as in an outpatient clinic or rural area. Further exploration of the optimal strategy for utilizing biomarkers and clinical prediction rules in the diagnosis of DVT in cancer is needed. [Display omitted] DisclosuresSood:Bayer: Research Funding.

Clinical and Ultrasound Sequelae of Nonvisualized Calf Veins on Duplex Ultrasound for Suspected Deep Vein Thrombosis

Objectives Calf veins are not visualized in up to 40% of lower extremity venous duplex ultrasounds (DUS). Little is known about the clinical implications of nonvisualized calf veins. We sought to investigate the incidence of nonvisualized calf veins, rate of subsequent venous thromboembolism (VTE), and factors influencing successful visualization on subsequent DUS. Methods We reviewed all patients who had DUS in 2012 at our institution who had nonvisualized calf veins, no deep vein thrombosis (DVT), and available follow-up. Demographics, Well's score, body mass index (BMI), indication for DUS, activity level, reason for nonvisualization, initial and subsequent DUS results, and subsequent occurrence of VTE were collected. Results A total of 8,237 DUS were performed in 2012. Of these, 891 (10.8%) DUS in 717 patients had at least one nonvisualized calf vein. Seven hundred twenty-eight limbs (484 patients) had no DVT and had available follow-up and comprised the study population. The most common reasons for nonvisualization were edema (35.5%) and body habitus (31.8%). Twenty-two (4.5%) patients were subsequently identified to have VTE; 9 limbs had only pulmonary emboli, 12 had only DVT, and 1 had both. Only length of stay in the hospital correlated with the development of VTE. One hundred forty-eight of the 484 patients had subsequent DUS at a median of 2.43 months; 45.3% of subsequent DUS successfully imaged the previously nonvisualized veins. Whole lower extremity swelling, single vein nonvisualization, and single limb nonvisualization at initial DUS were associated with successful visualization on subsequent DUS. Thirteen (8.8%) new DVT were seen on subsequent DUS, six were seen in calf veins that previously were not visualized, and seven were seen in either femoropopliteal veins or calf veins that previously were visualized and did not have thrombus. Conclusions Non-visualized calf veins are common in DUS. Almost half of patients with nonvisualized veins on initial DUS had successful visualization on subsequent DUS. Whole lower extremity swelling, single vein nonvisualization, and single limb nonvisualization at initial DUS were associated with successful visualization on subsequent DUS. In all, 4.1% of patients with nonvisualized veins on initial DUS go on to develop VTE and 8.8% of patients who have subsequent DUS are found to have DVT. When initial DUS is unable to visualize calf veins, selective repeat DUS may be useful to identify either new or initially unseen DVT.

Imaging Tests for Suspected Deep Vein Thrombosis.

Imaging Tests for Suspected Deep Vein Thrombosis.

Imaging Tests for Suspected Deep Vein Thrombosis-Reply.

Imaging Tests for Suspected Deep Vein Thrombosis-Reply.

Can patients with pulmonary embolism be managed as an outpatient?

Suspected deep vein thrombosis (DVT) and pulmonary embolism (PE) are two of the commonest presentations to hospitals. Increasingly, physicians are comfortable in managing DVT as an outpatient especially with the arrival of non-vitamin K based anticoagulants which have facilitated this approach. However, most patients who are confirmed to have a PE are still managed as an inpatient. Is there a possibility that at least some of these patients can be managed for their thrombotic condition out of hospital? First, it would be useful to ascertain whether outpatient management of PE is necessary. The diagnosis of PE is increasing due to several reasons. This is primarily due to an increased awareness of this condition, especially in high-risk population including those who recently had surgery or prolonged periods of immobility and those with chronic medical conditions. Second, there are an increased number of requests for computerized tomography (CT) of the thorax; for staging of newly diagnosed malignancy and to exclude pathology for non-specific symptoms for the fear of medico-legal consequences.1 These scans are picking up two types of PE—‘incidental’ PE defined as evidence of thrombosis detected on imaging studies performed for other indications such as cancer staging (1–2% of all CT thorax) and ‘sub-segmental’ PE which are clots restricted to the smaller segments of the pulmonary artery which may be of clinical consequence.2,3 Sub-segmental PE is the consequence of more sensitive CT imaging technique which has resulted in the incidence of emboli confined to sub-segmental arteries increasing from …

Clinical and Ultrasound Sequelae of Nonvisualized Calf Veins on Duplex Ultrasonography for Suspected Deep Vein Thrombosis

Clinical and Ultrasound Sequelae of Nonvisualized Calf Veins on Duplex Ultrasonography for Suspected Deep Vein Thrombosis

C0454: Accuracy of Nurse-Performed Compression Ultrasonography in the Diagnosis of Proximal Symptomatic Deep Vein Thrombosis: A Prospective Cohort Study

Summary. Background: Compression ultrasonography(CUS) has been recognized as the diagnostic procedure ofchoice for the investigation of patients with suspecteddeep vein thrombosis (DVT); the aim of this study was toassess the diagnostic accuracy of nurse-performed CUSfor symptomatic proximal DVT of the lower limb. Mate-rial and Methods: We prospectively evaluated all consecu-tive outpatients referred for suspected DVT from January2011 to December 2012. All patients underwent bilateralproximal lower limb CUS, first by trained nurses andthen by physicians expert in vascular ultrasonography,with every group blinded with respect to each other. Thistest was repeated after 5–7 days in all negative or unclearexaminations. Interobserver agreement and accuracy ofnurse-performed CUS were calculated, considering thephysician’s final diagnosis as the reference test. Results:Six hundred ninety-seven patients were included in thestudy. DVT was diagnosed in 122 patients by expertultrasound physicians with an overall prevalence of17.5% (95% confidence interval [CI] 15.8%–20.6%).Nurse agreement with the physician in DVT diagnosiswas excellent (Cohen’s j 0.82, 95% CI 0.79–0.85). Nurse-performed CUS had a sensitivity of 84.4% (95% CI81.7%–87.1%) and a specificity of 97.0% (95% CI95.8%–98.3%) with a diagnostic accuracy of 94.8% (95%CI 93.2%–96.5%). Conclusion: Our results suggest thatnurse-performed CUS may be a potential useful alterna-tive to physician performed CUS with a good accuracy.However, sensibility of nurse-performed CUS appearedsuboptimal and future studies should incorporate in theevaluation of this technique other pretest tools that mayincrease its accuracy.Keywords: diagnostic tests; Doppler ultrasonography;nurses; vascular diseases; venous thrombosis.IntroductionPrompt diagnosis of deep vein thrombosis (DVT) isessential to decrease the risk of potentially fatal pulmo-nary embolism and postthrombotic syndrome inuntreated patients [1,2]. Diagnostic strategies in DVTshould be accurate, simple to apply, and cost effective.Currently, compression ultrasonography (CUS) is consid-ered the method of choice for the diagnosis of DVT insymptomatic patients, and its use has been validated inseveral prospective studies [2–4]. The potential advantagesof this technique are the ease of performance by manyoperators and the availability in many hospitals with vir-tually all ultrasound scanners, regardless of generation,model, and even probe frequency [5].Although CUS has shown good accuracy for the diag-nosis of symptomatic proximal DVT, its specificity andsensitivity for calf vein thrombi are much lower [2,4]. Forthis reason, CUS may be limited to the proximal veinsand repeated within 1 week when negative (serial proxi-mal CUS) or extended to both proximal and distal veinsand performed on a single occasion with color-Dopplersupport (whole-leg ultrasonography) [2,5]; both strategiesare reliable diagnostic options for the management ofthese patients [2,5].

Validation d’un score de probabilité clinique de thrombose veineuse profonde des membres inférieurs spécifique à la médecine générale

Suspected deep vein thrombosis (DVT) of lower limbs (LL) may require different tools to rule out or confirm the diagnosis. Clinical probability provides help to select useful tests, interpret their results, and decide to treat the patient meanwhile. Clinical prediction rules that risk stratify patients with suspected DVT can be established from inpatients, but no prediction rule not requiring laboratory tests has been established from primary care patients. We previously derived and internally validated such a prediction rule. The aim of this study is to externally validate this score.The score was applied to Optimev outpatients with suspected LL-DVT, and without suspected pulmonary embolism. Sensitivity and specificity were calculated for proximal and distal DVT, according to each score. The area under the ROC curve was calculated for each kind of DVT, in order to assess the validity of the score on predicting the presence or absence of DVT.Among 3523 outpatients prospectively included in the Optimev study for suspected LL DVT, overall prevalence of DVT was 29.7% (n=1046), ranging from 21.7% in the non-high score probability, to 61.4% in the high score probability. The area under the ROC curve was 0.79 [CI 95%, 0.77-0.80]. With subgroup analysis, the area under curve was 0.83 [CI 95%, 0.82-0.85] for proximal DVT, and 0.75 [CI 95%, 0.73-0.77] for distal DVT.This score reliably identifies primary care patients with LL DVT, whether proximal or distal.

Venous Duplex Scanning for Suspected Deep Vein Thrombosis: Results Before and After Elimination of After-Hours Studies

A 24-hour venous duplex ultrasound (VDU) for suspected deep vein thrombosis (DVT) imposes significant resource burdens on a hospital. We hypothesize that termination of after-hours services increases empiric therapy without affecting clinical outcomes. A retrospective review of patients evaluated by the emergency department (ED) for suspected DVT in 2005 and 2007. Demographics, empiric treatment, and complications were compared using propensity scores and multivariate regression models. In 2005 and 2007, 318 and 365 patients, respectively, had VDU after referral by the ED. In all, 49 (16%) tests during 2005 were after-hours, with 31 and 25 acute DVTs in 2005 and 2007, respectively. More patients received empiric treatment in 2007: 51 (14%) vs 26 ([8%]; P = .019) and tended to be more likely to have acute DVT: 7 (28%) vs 3 ([10%]; P = .08). We detected no complications from empiric anticoagulation and no difference in outcome. Estimated annual savings were $11 864. Elimination of around-the-clock VDU can render substantial savings to hospitals without adverse consequence in the management of acute DVT.

Safety of Excluding Suspected Deep Vein Thrombosis with a Single Whole-Leg Compression Ultrasound: Systematic Review and Meta-Analysis.

Abstract 243 Background:In patients with suspected lower extremity deep vein thrombosis (DVT), compression ultrasonography (CUS) is typically used as the initial test to confirm or exclude DVT. Patients with a negative CUS and either a moderate-to-high probability and/or a positive D-dimer usually require repeat CUS testing after 5–7 days to exclude proximal propagation of distal DVT, reducing diagnostic efficiency. Whole-leg compression ultrasound may safely exclude proximal and distal DVT in a single evaluation. Purpose:To assess the safety of withholding anticoagulation in patients presenting with suspected lower extremity DVT following a single negative whole-leg CUS. Methods:MEDLINE, EMBASE, CINAHL, LILACS, Cochrane, Health Technology Assessments databases were searched from January 1970 to April 2009 without language restrictions. This search was supplemented by reviewing Google, Google Scholar, clinicaltrials.gov, meeting abstracts, conference proceedings, reference lists, and by contacting content experts. Study Selection and Data Extraction:Randomized controlled trials and prospective cohort studies of patients with suspected DVT with a negative whole-leg CUS, not treated with anticoagulation, and followed at least 90 days for occurrence of venous thromboembolism (VTE). Studies required objective confirmation of VTE events during follow-up. Two authors independently reviewed articles and extracted data. Results:Six studies were included totaling 4,229 patients with negative whole-leg CUS exams and not receiving anticoagulation. VTE or suspected VTE-related death occurred within the follow-up period in 24 (0.6%) patients. Of these 24 events, 9 (37.5%) were distal DVT, 7 (29.2%) were proximal DVT, 6 (25.0%) were non-fatal pulmonary embolism, and 2 (8.3%) were deaths, possibly related to VTE. Combined VTE event rate at 3 months was 0.46% (95% CI 0.22, 0.70). Limitations:Pretest probability assessment was not available for all analyzed patients. Conclusions:Withholding anticoagulation in patients with suspected DVT based on a single whole-leg CUS is associated with a low risk of VTE (0.46%) during 3 months of follow-up. This strategy represents a safe and efficient alternative to serial CUS testing in patients with suspected DVT. Disclosures:No relevant conflicts of interest to declare.

Effectiveness of Management of Suspected Deep Vein Thrombosis in General Practice Based on a Clinical Decision Rule Including a Point of Care D-dimer Test.

Prior studies have evaluated the safety and effectiveness of a diagnostic work up based on combined use of a clinical decision rule and a D-dimer laboratory test in patients with suspected deep vein thrombosis in secondary care facilities. The overall outcome of these studies show that approximately 30% of additional objective evaluation can be avoided without compromising the safety, resulting in failure rates of less than 1%. The objective of our study was to assess the effectiveness of a modified algorithm using a dichotomized clinical decision rule including a point of care D-dimer test in patients suspected of deep vein thrombosis in primary care. The AMUSE study is a prospective cohort study of consecutive patients with clinically suspected acute deep vein thrombosis conducted in 400 general practices coordinated by 3 university affiliated centers in the Netherlands from March 2004 through January 2007. The study population of 1029 patients included 63% women. Patients were categorized as “deep vein thrombosis unlikely” or “deep vein thrombosis likely” using a dichotomized version of a for general practice adapted clinical decision rule based on the Wells rule. Patients classified as unlikely were excluded from further testing. All other patients underwent ultrasonography. Anticoagulants were withheld from patients classified as unlikely. All patients were followed up for 3 months. The main outcome measure was symptomatic or fatal venous thromboembolism (VTE) during 3 months follow-up. Deep vein thrombosis was classified as unlikely in 500 patients (48.6%), all of whom were not treated with anticoagulants; subsequent non fatal VTE occurred in 8 patients (1.6% [95 CI 0.7–3.1%]). In 500 patients categorized as likely, deep vein thrombosis was confirmed in 124 patients (24.8%), 3 patients did not receive objective testing (0.6%) and 373 patients were tested negative (74.6%). Two out of 4 patients not receiving objective testing had confirmed deep vein thrombosis in the 3 month follow-up period. In patients that tested negative 4 non fatal events occurred during the 3 month follow-up (1.1%). The algorithm was completed and allowed a management decision in 97.2% of patients. We conclude that this management strategy is both safe and highly effective in patients with suspected deep vein thrombosis in general practice. Its use is associated with low risk for subsequent fatal and nonfatal VTE and a further increase in the yield of objective diagnostic tests.

Duplex Ultrasound in the Emergency Department for the Diagnostic Management of Clinically Suspected Deep Vein Thrombosis

To evaluate the accuracy and safety of an emergency duplex ultrasound (EDUS) evaluation performed by emergency physicians in the emergency department. Consecutive adult patients suspected of having their first episode of deep vein thrombosis (DVT) presenting to the emergency department were included in the study. All examinations were performed by emergency physicians trained with a 30-hour ultrasound course. Based on EDUS findings, patients were classified into one of three groups: normal, abnormal, and uncertain. Patients with abnormal and uncertain findings were initially treated as having a DVT. Patients with normal EDUS findings were discharged from the emergency department without anticoagulant therapy. A formal duplex ultrasound evaluation was repeated by a radiologist in all patients within 24-48 hours. Patients with normal findings on duplex ultrasound evaluation were followed up for symptomatic venous thromboembolism for up to one month. A total of 399 patients were studied. The EDUS findings were normal in 301 (75%), abnormal in 90 (23%), and uncertain in eight (2%). All abnormal test results were confirmed by the formal duplex ultrasound evaluation, and three patients (0.8%) with uncertain findings on EDUS examination were subsequently diagnosed as having a distal DVT (positive predictive value, 95% [95% confidence interval, 92% to 95%]; negative predictive value, 100% [95% confidence interval = 99% to 100%]). No patients with normal findings on EDUS examination died or experienced venous thromboembolism at the one-month follow-up. EDUS examination yielded a high negative predictive value and good positive predictive value, allowing rapid discharge and avoiding improper anticoagulant treatment.

Duplex Ultrasound in the Emergency Department for the Diagnostic Management of Clinically Suspected Deep Vein Thrombosis

Duplex Ultrasound in the Emergency Department for the Diagnostic Management of Clinically Suspected Deep Vein Thrombosis

Evaluation of D-Dimer in the Diagnosis of Suspected Deep-Vein Thrombosis

Evaluation of D-Dimer in the Diagnosis of Suspected Deep-Vein Thrombosis

Screening for Deep Vein Thrombosis and Pulmonary Embolism in Outpatients with Suspected DVT or PE by the Sequential Use of Clinical Score: A Sensitive Quantitative D-Dimer Test and Noninvasive Diagnostic Tools

The requirement for a safe diagnostic strategy should be based on an overall posttest incidence of venous thromboembolism (VTE) of less than 1% during 3-month follow-up. The negative predictive value (NPV) during 3 months of follow-up is 98.1 to 99% after a normal venogram, 97 to 98% after a normal compression ultrasonography (CUS), and > 99% after serial CUS testing. Serial CUS testing is safe but 100 CUS must be repeated to find one or two CUS positive for deep vein thrombosis (DVT), which is not cost-effective and indicates the need to improve the diagnostic workup of DVT by the use of clinical score assessment and D-dimer testing. The NPV varies from 97.6 to 99.4% for low clinical score followed by a negative SimpiRED test, indicating the need for a first CUS. The NPV is 98.4 to 99.3% for a normal rapid enzyme-linked immunosorbent assay (ELISA) VIDAS D-dimer test result (< 500 ng/mL) irrespective of clinical score. The NPV is more than 99% for a negative CUS followed by either a negative SimpiRED test or an ELISA VIDAS test result of < 1000 ng/mL without the need to repeat a second CUS within 1 week. The sequential use of a sensitive, rapid ELISA D-dimer and clinical score assessment will safely reduce the need for CUS testing by 40 to 60%. Large prospective outcome studies demonstrate that with one negative examination with complete duplex color ultrasonography (CCUS) of the proximal and distal veins of the affected leg with suspected DVT, it is safe to withhold anticoagulant treatment, with a negative predictive value of 99.5%. This may indicates that CCUS is equal to serial CUS or the combined use of clinical score, D-dimer testing, and CUS. Pulmonary angiography is the gold standard for segmental pulmonary embolism (PE) but not for subsegmental PE. A normal perfusion lung scan and a normal rapid ELISA VIDAS D-dimer test safely excludes PE. Helical spiral computed tomography (CT) detects all clinically relevant PE and a large number of alternative diagnoses in symptomatic patients with suspected PE and can replace both the ventilation perfusion scan and pulmonary angiography to safely rule in PE and to rule out PE with an NPV of > 99%. The combination of clinical assessment, a rapid ELISA VIDAS D-dimer, followed by CUS will reduce the need for helical spiral CT by 40 to 50%.

A Prospective Cohort Study of the Epidemiology of Symptomatic Venous Thromboembolism (VTE) after Isolated Leg Fractures Distal to the Knee without Thromboprophylaxis.

We report final results from the first, large, multicenter, prospective cohort study designed to define the incidence of symptomatic venous thromboembolism (VTE) in patients with isolated leg fractures below the knee, and determine if routine thromboprophylaxis will be cost-effective. The reported incidence of deep vein thrombosis (DVT) using screening venography in such patients is as high as 40%. This has lead to the use of routine anticoagulant prophylaxis for several weeks in many such patients. However the vast majority of venographically-detected DVTs are asymptomatic, distal thrombi, whose clinical relevance is uncertain. Therefore venography may not be the best outcome measure to assess the clinical burden of clinically-important VTE, or as an endpoint for trials of thromboprophylaxis.Methods: From August 2002 to June 2005, 2446 consecutive patients with fractures of the patella, fibula and foot (treated operatively or conservatively) and tibial fractures (treated non operatively) were assessed at 5 hospitals in Ontario, Canada. Patients were enrolled after informed consent within 96 hours of the injury. Patients with major trauma, active cancer, and previous VTE were excluded. Thromboprophylaxis was not allowed. Patients were followed prospectively for 3 months, with telephone calls at 14 days, 6 weeks and 3 months. Education regarding symptoms of DVT and pulmonary embolism (PE) was provided at study entry and patients were asked about VTE symptoms at follow up. Suspected DVT and PE were investigated in a standardized manner.Results: 1200 patients have been enrolled and 1174 have completed 3-month follow up at this time. The last patient will complete follow up by the end of September 2005. The mean age of this cohort was 45 years (range 16 to 93) and 60% were female. Most injuries were caused by falls (56 %), followed by vehicular accidents (25 %), sports injuries (16 %), and occupational injuries (3 %). 18 % of patients had other minor injuries. 99 % of these fractures were unilateral. Fractures of the fibula were the commonest (39 %), followed by metatarsal (30 %), phalanges (12 %), calcaneus, talus or tarsal (10 %), tibia (10 %) and patella (5 %). 7 % of fractures were surgically treated. 82% of patients received a cast or splint for a mean duration of 42 ± 35 days. Six patients (0.5%) received anticoagulant prophylaxis (outside study protocol) at some time within the study period. Complete follow up was available for 98 % of this cohort. 21 patients either withdrew consent for follow up, or could not be contacted despite numerous attempts. By 3 months, only 7 of 1174 patients had sustained a symptomatic, objectively-confirmed VTE (2 proximal DVT, 3 calf DVT, 2 PE) with no fatal PE - an incidence of 0.6 % (95% C.I. 0.2 to 1.2).Conclusions: Based on a large prospective cohort of patients with leg fractures below the knee with no prophylaxis use, and 98% follow-up, we observed no fatal PE, and only 0.6% symptomatic VTE, confirming that routine thromboprophylaxis is not warranted, and not likely to be cost-effective in these patients. Furthermore symptomatic VTE is so uncommon, that it is unlikely that any high-risk subgroups can be identified for targeted prophylaxis. This study also highlights the significant discrepancy in the incidence of VTE between studies using venography and those utilizing clinical endpoints.

Alternative to Repeat Ultrasonography for Suspected DVT

For patients with suspected deep-vein thrombosis (DVT) but normal results on proximal-vein ultrasonography, repeat ultrasonography after 1 week can

Deep vein thrombosis assessment clinic: Evaluation of a new working practice

Suspected deep vein thrombosis (DVT) is a common reason for medical referral to hospital. We evaluated our new approach to assessment of DVT using combined automated strain gauge plethysmography and pretest probability score in comparison with venous ultrasonography in 100 consecutive patients with suspected DVT referred to the nurse-led clinic. The combined plethysmography and pretest probability score produced a negative predictive value of 99%, positive predictive value 53%, sensitivity 94% and specificity 83% for detection of a DVT. We conclude that our new working practice for DVT assessment is both safe and cost effective and can lead to a reduction in venous ultrasonography of approximately 70%.