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

Current Ultrasound Technologies and Instrumentation in the Assessment and Monitoring of COVID-19 Positive Patients

Since the emergence of the COVID-19 pandemic in December of 2019, clinicians and scientists all over the world have faced overwhelming new challenges that not only threaten their own communities and countries but also the world at large. These challenges have been enormous and debilitating, as the infrastructure of many countries, including developing ones, had little or no resources to deal with the crisis. Even in developed countries, such as Italy, health systems have been so inundated by cases that health care facilities became oversaturated and could not accommodate the unexpected influx of patients to be tested. Initially, resources were focused on testing to identify those who were infected. When it became clear that the virus mainly attacks the lungs by causing parenchymal changes in the form of multifocal pneumonia of different levels of severity, imaging became paramount in the assessment of disease severity, progression, and even response to treatment. As a result, there was a need to establish protocols for imaging of the lungs in these patients. In North America, the focus was on chest X-ray and computed tomography (CT) as these are widely available and accessible at most health facilities. However, in Europe and China, this was not the case, and a cost-effective and relatively fast imaging modality was needed to scan a large number of sick patients promptly. Hence, ultrasound (US) found its way into the hands of Chinese and European physicians and has since become an important imaging modality in those locations. US is a highly versatile, portable, and inexpensive imaging modality that has application across a broad spectrum of conditions and, in this way, is ideally suited to assess the lungs of COVID-19 patients in the intensive care unit (ICU). This bedside test can be done with little to no movement of the patients from the unit that keeps them in their isolated rooms, thereby limiting further exposure to other health personnel. This article presents a basic introduction to COVID-19 and the use of the US for lung imaging. It further provides a high-level overview of the existing US technologies that are driving development in current and potential future US imaging systems for lung, with a specific emphasis on portable and 3-D systems.

Safety of a strategy combining D-dimer testing and whole-leg ultrasonography to rule out deep vein thrombosis

Guidelines for the diagnostic workup of deep vein thrombosis (DVT) recommend assessing the clinical pretest probability before proceeding to D-dimer testing and/or compression ultrasonography (CUS) if the patient has high pretest probability or positive D-dimer. Referring only patients with positive D-dimer for whole-leg CUS irrespective of pretest probability may simplify the workup of DVT. In this prospective management outcome study, we assessed the safety of such a strategy. We included consecutive outpatients referred to the Emergency Department at Østfold Hospital, Norway, with suspected DVT between February 2015 and November 2018. STA-Liatest D-Di Plus D-dimer was analyzed for all patients, and only patients with levels ≥0.5 µg/mL were referred for CUS. All patients with negative D-dimer or negative CUS were followed for 3 months to assess the venous thromboembolic rate. One thousand three hundred ninety-seven patients were included. Median age was 64 years (interquartile range, 52-73 years), and 770 patients (55%) were female. D-dimer was negative in 415 patients (29.7%) and positive in 982 patients (70.3%). DVT was diagnosed in 277 patients (19.8%). Six patients in whom DVT was ruled out at baseline were diagnosed with DVT within 3 months of follow-up for a thromboembolic rate of 0.5% (95% confidence interval, 0.2-1.2). A simple diagnostic approach with initial stand-alone D-dimer followed by a single whole-leg CUS in patients with positive D-dimer safely ruled out DVT. We consider this strategy to be a valuable alternative to the conventional workup of DVT in outpatients. This trial was registered at www.clinicaltrials.gov as #NCT02486445.

The prevalence of incidental uterine venous plexus thrombosis in women attending a gynecology clinic

BACKGROUND

The uterine venous plexus (UVP) is an unusual site for venous thrombosis (VT). Our aim was to determine the prevalence of UVP thrombosis (UVPT) and identify associated risk factors.

METHODS

We conducted a cross-sectional study on consecutive nonpregnant women attending our general gynecology clinic with a wide variety of presenting symptoms over a 16-month period. All women underwent a transvaginal ultrasound scan which involved detailed examination of the uterine venous plexus. Women diagnosed with incidental UVPT had thrombophilia screening, lower limb venous duplex imaging, and specialist hematological review. Logistic regression was used to examine associations between various risk factors and UVPT.

RESULTS

We screened 1383 women, 39 of whom had an incidental UVPT, giving a prevalence of 3.0% (95% confidence interval [CI], 2.1%-4.1%). Multivariate analysis showed positive associations between multiparity (odds ratio [OR] 5.75 [95% CI 2.10, 15.7]), recent surgery (OR 3.10 [95% CI 1.19, 8.07]), presence of leg varicose veins (OR 3.15 [95% CI 1.32, 7.49]), and a family history of venous thromboembolism (OR 8.74 [1.65, 46.4]) and negative associations between postmenopausal status (OR 0.36 [95% CI 0.13, 0.95]) and the development of UVPT. Thrombophilia was detected in 12.8% women diagnosed with UVPT.

CONCLUSIONS

The prevalence of incidental UVPT in a general gynecology population was 3.0%. Several demographic and clinical factors were found to be associated with UVPT. This could help to identify women at risk of this condition, and facilitate its early detection and development of evidence-based management strategies.

Molecular Ultrasound Imaging

In the last decade, molecular ultrasound imaging has been rapidly progressing. It has proven promising to diagnose angiogenesis, inflammation, and thrombosis, and many intravascular targets, such as VEGFR2, integrins, and selectins, have been successfully visualized in vivo. Furthermore, pre-clinical studies demonstrated that molecular ultrasound increased sensitivity and specificity in disease detection, classification, and therapy response monitoring compared to current clinically applied ultrasound technologies. Several techniques were developed to detect target-bound microbubbles comprising sensitive particle acoustic quantification (SPAQ), destruction-replenishment analysis, and dwelling time assessment. Moreover, some groups tried to assess microbubble binding by a change in their echogenicity after target binding. These techniques can be complemented by radiation force ultrasound improving target binding by pushing microbubbles to vessel walls. Two targeted microbubble formulations are already in clinical trials for tumor detection and liver lesion characterization, and further clinical scale targeted microbubbles are prepared for clinical translation. The recent enormous progress in the field of molecular ultrasound imaging is summarized in this review article by introducing the most relevant detection technologies, concepts for targeted nano- and micro-bubbles, as well as their applications to characterize various diseases. Finally, progress in clinical translation is highlighted, and roadblocks are discussed that currently slow the clinical translation.

Usefulness of computed tomography venography in gynecologic cancer patients with lower extremity edema

Lower extremity (LEx) edema is a common complication in gynecologic cancer patients. There are 2 main causes of edema in these patients such as deep vein thrombosis (DVT) and lymphedema. Early diagnosis and treatment of DVT are certainly important, but it is often difficult to evaluate proximal DVT by using ultrasound. The aim of this study is to demonstrate the usefulness of computed tomography venography of the lower extremity (CTV LEx) for the diagnosis of the DVT and investigate predictive factor of DVT in gynecologic cancer patients with LEx edema.The medical records of 415 gynecologic cancer patients who were referred to the department of rehabilitation medicine with LEx edema were retrospectively reviewed in this case-controlled study. We categorized CTV LEx findings as follows: DVT proximal to the inguinal ligament (inferior vena cava or iliac vein thrombosis) and DVT distal to the inguinal ligament (femoral, popliteal, or calf vein thrombosis). We also evaluated patient characteristics including D-dimer level. We analyzed the correlation of each factor with DVT frequency and used receiver operating characteristic curve analysis to determine the appropriate D-dimer threshold.Sixty-six patients were diagnosed with DVT; of them, 35 (53%) had DVT proximal to the inguinal ligament. Twenty-two patients were diagnosed with pulmonary embolism, of whom 15 had proximal DVT. Patients with proximal DVT tended to have pulmonary embolism (P < .001). Distal organ metastasis (odds ratio [OR], 2.88; P = .002) and a high D-dimer level (OR, 1.13; P = .001) were correlated with DVT.CTV LEx is a useful diagnostic tool for gynecologic cancer patients with LEx edema, particularly high-risk patients, that should be performed at the initial evaluation.

Effort Thrombosis in 2 Athletes Suspected of Musculoskeletal Injury

Objective

This case series describes the clinical presentation of effort thrombosis and the utility of sonography in its diagnosis.

Clinical Features

Two young male athletes presented to separate chiropractic clinics with suspected musculoskeletal shoulder injury. The first complained of dull shoulder pain after pitching in a baseball game and had no other signs or symptoms. The second presented after performing a weighted plank exercise and had prominent edema and discoloration of the affected extremity.

Intervention and Outcome

In the first patient, who had no physical signs to suggest thrombosis, a normal sonographic musculoskeletal shoulder exam prompted imaging in the abduction-external rotation position. This provided visualization of a thrombus in the axillosubclavian vein. Emergent referral followed, and treatment was initiated with thrombolysis and surgery, which resolved his condition. The second patient had physical signs consistent with effort thrombosis and was also referred to the emergency department, where sonography was performed and revealed thrombosis of the axillary and basilic veins. He responded to anticoagulants and thrombolysis and avoided surgery.

Conclusion

Effort thrombosis has a variable presentation that can mimic common musculoskeletal disorders and has a poorly defined diagnostic pathway. Acute shoulder pain in an athlete, especially with extremity edema after repetitive exertion, warrants urgent imaging such as sonography and emergent referral. Clinicians should understand the importance of a timely evaluation and diagnosis of effort thrombosis and that imaging may include sonography as a first-line imaging tool.

Calf deep vein thrombosis – clinical relevance, diagnostic approaches and therapeutic options

Summary. Isolated distal deep vein thromboses (IDDVT) represent up to 50 % of legs deep vein thromboses (DVT). However, since their natural history is to date unknown, the need to diagnose and treat them is a matter of debate. The diagnostic strategy based on the assessment of pre-test probability and D-dimer demonstrated a scarse efficiency for IDDVT. The choice between a proximal and a complete ultrasonographic approach should be guided by the clinical context, the local expertise and the patient characteristics. Randomized and observational studies have analyzed the need of therapy and compared different regimens of anticoagulation, with conflicting results. Systematic reviews and meta-analyses tend to support the usefulness of an anticoagulant treatment, even if the optimal dose and duration are not still defined. A careful stratification of the patient’s profile, taking into account risk factors for proximal extension, recurrence and bleeding should address the therapeutic approach, which must always be discussed with an adequately informed patient. Further studies aimed to clarify the natural history of IDDVT, and to assess safety and efficacy of lower intensity and shorter duration protocols are urgently needed.

Diagnosis of deep vein thrombosis

Deep vein thrombosis (DVT) is part of the clinical spectrum of venous thromboembolism disease (VTE), whose estimated annual incidence rate is 1-2 episodes per 1000 individuals and represents the third leading cause of cardiovascular mortality in developed countries. Establishing an accurate diagnosis of DVT is essential for preventing acute complications (such as pulmonary embolism) and chronic complications associated with post-thrombotic syndrome. Currently, there are well-established diagnostic algorithms for lower extremity DVT, which include clinical probability models that help establish the risk of experiencing the disease based on the patients' history, clinical findings, D dimer measurements, fibrin degradation product tests with a high negative predictive value and imaging tests to confirm the diagnosis. Venous compression ultrasonography is currently the technique of choice because it is a non-invasive, easy-to-administer test that can make serial evaluations. There is much accumulated evidence that DVT can be safely ruled out in patients with a low or intermediate clinical probability and a negative D dimer (<500 ng/mL) without performing additional examinations. The consensus is not as clear about the need for a proximal or complete examination of the entire extremity. Other techniques may also be employed, such as magnetic resonance venography and venous phase computed axial tomography, although these should not be a substitute for compression ultrasonography as the initial diagnostic test. There are other special circumstances in which the diagnosis is more problematic and there are no diagnostic algorithms as consolidated, such as DVT during pregnancy, diagnosing rethrombosis and DVT that affects the upper extremities.

Advances in the Diagnosis of Venous Thromboembolism: A Literature Review

The incidence of venous thromboembolism (VTE), including lower extremity deep vein thrombosis (DVT) and pulmonary embolism (PE) is increasing. The increase in suspicion for VTE has lowered the threshold for performing imaging studies to confirm diagnosis of VTE. However, only 20% of suspected cases have a confirmed diagnosis of VTE. Development of pulmonary embolism rule-out criteria (PERC) and update in pre-test probability have changed the paradigm of ruling-out patient with low index of suspicion. The D-dimer test in conjunction to the pre-test probability has been utilized in VTE diagnosis. The age appropriate D-dimer cutoff and inclusion of YEARS algorithm (signs of the DVT, hemoptysis and whether PE is the likely diagnosis) for the D-dimer cutoff have been recent updates in the evaluation of suspected PE. Multi-detector computed tomography pulmonary angiography (CTPA) and compression ultrasound (CUS) are the preferred imaging modality to diagnose PE and DVT respectively. The VTE diagnostic algorithm do differ in pregnant individuals. The prerequisite of avoiding excessive radiation has recruited planar ventilation-perfusion (V/Q) scan as preferred in pregnant patients to evaluate for PE. The modification of CUS protocol with addition of the Valsalva maneuver should be performed while evaluating DVT in pregnant individual.

Interventions for preventing venous thromboembolism in adults undergoing knee arthroscopy

BACKGROUND

Knee arthroscopy (KA) is a routine orthopedic procedure recommended to repair cruciate ligaments and meniscus injuries and in eligible patients, to assist the diagnosis of persistent knee pain. KA is associated with a small risk of thromboembolic events. This systematic review aims to assess if pharmacological or non-pharmacological interventions may reduce this risk. This review is the second update of the review first published in 2007.

OBJECTIVES

To assess the efficacy and safety of interventions, whether mechanical, pharmacological, or in combination, for thromboprophylaxis in adult patients undergoing KA.

SEARCH METHODS

For this update, the Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, the CENTRAL, MEDLINE, Embase and CINAHL databases, and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registries, on 14 August 2019.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and controlled clinical trials (CCTs), whether blinded or not, of all types of interventions used to prevent deep vein thrombosis (DVT) in males and females aged 18 years and older undergoing KA. There were no restrictions on language or publication status.

DATA COLLECTION AND ANALYSIS

Two authors independently selected studies for inclusion, assessed trial quality with the Cochrane 'Risk of bias' tool, and extracted data. A third author addressed discrepancies. We contacted study authors for additional information when required. We used GRADE to assess the certainty of the evidence.

MAIN RESULTS

This update adds four new studies, bringing the total of included studies to eight and involving 3818 adult participants with no history of thromboembolic disease undergoing KA. Studies compared daily subcutaneous (sc) low-molecular-weight heparin (LMWH) versus control (five studies); oral rivaroxaban 10 mg versus placebo (one study); daily sc LMWH versus graduated compression stockings (GCS) (one study); and aspirin versus control (one study). The incidence of pulmonary embolism (PE) in all trials combined was low, with seven cases in 3818 participants.There were no deaths in any of the intervention or control groups. LMWH versus control When compared with control, LMWH probably results in little to no difference in the incidence of PE in patients undergoing KA (risk ratio (RR) 1.81, 95% confidence interval (CI) 0.49 to 6.65; 1820 participants; 3 studies; moderate-certainty evidence). LMWH showed no reduction of the incidence of symptomatic DVT (RR 0.61, 95% CI 0.18 to 2.03; 1848 participants; 4 studies; moderate-certainty evidence). LMWH may reduce the risk of asymptomatic DVT but the evidence is very uncertain (RR 0.14, 95% CI 0.03 to 0.61; 369 participants; 2 studies; very low-certainty evidence). There was no evidence of an increased risk of all adverse events combined (RR 1.85, 95% CI 0.95 to 3.59; 1978 participants; 5 studies; moderate-certainty evidence). No evidence of a clear effect on major bleeding (RR 0.98, 95% CI 0.06 to 15.72; 1451 participants; 1 study; moderate-certainty evidence), or minor bleeding was observed (RR 1.79, 95% CI 0.84 to 3.84; 1978 participants; 5 studies; moderate-certainty evidence). Rivaroxaban versus placebo One study with 234 participants compared oral rivaroxaban 10 mg versus placebo. No evidence of a clear impact on the risk of PE (no events in either group), symptomatic DVT (RR 0.16, 95% CI 0.02 to 1.29; moderate-certainty evidence); or asymptomatic DVT (RR 0.95, 95% CI 0.06 to 15.01; very low-certainty evidence) was detected. Only bleeding adverse events were reported. No major bleeds occurred in either group and there was no evidence of differences in minor bleeding between the groups (RR 0.63, 95% CI 0.18 to 2.19; moderate-certainty evidence). Aspirin versus control One study compared aspirin with control. No PE, DVT or asymptomatic events were detected in either group. Adverse events including pain and swelling were reported but it was not clear what groups these were in. No bleeds were reported. LMWH versus GCS One study with 1317 participants compared the use of LMWH versus GCS. There was no clear difference in the risk of PE (RR 1.00, 95% CI 0.14 to 7.05; low-certainty evidence). LMWH use did reduce the risk of DVT compared to people using GCS (RR 0.17, 95% CI 0.04 to 0.75; low-certainty evidence). No clear difference in effects was seen between the groups for asymptomatic DVT (RR 0.47, 95% CI 0.21 to 1.09; very low-certainty evidence); major bleeding (RR 3.01, 95% CI 0.61 to 14.88; moderate-certainty evidence) or minor bleeding (RR 1.16, 95% CI 0.64 to 2.08; moderate-certainty evidence). Levels of thromboembolic events were higher in the GCS group than in any other group. We downgraded the certainty of the evidence for imprecision resulting from overall small event numbers; risk of bias due to concerns about lack of blinding, and indirectness as we were uncertain about the direct clinical relevance of asymptomatic DVT detection.

AUTHORS' CONCLUSIONS

There is a small risk that healthy adult patients undergoing KA will develop venous thromboembolism (PE or DVT). There is moderate- to low-certainty evidence of no benefit from the use of LMWH, aspirin or rivaroxaban in reducing this small risk of PE or symptomatic DVT. There is very low-certainty evidence that LMWH use may reduce the risk of asymptomatic DVT when compared to no treatment but it is uncertain how this directly relates to incidence of DVT or PE in healthy patients. No evidence of differences in adverse events (including major and minor bleeding) was seen, but data relating to this were limited due to low numbers of events in the studies reporting within the comparisons.

Diagnostic performance of lower extremity Doppler ultrasound in detecting iliocaval obstruction

OBJECTIVE

To retrospectively evaluate the performance of two commonly used Doppler ultrasound parameters, namely, venous flow phasicity and response to Valsalva maneuver, in detecting iliocaval obstruction.

METHODS

All imaging studies of patients seen by interventional radiology for lower extremity venous disease at a single institution from 1996 to 2018 were retrospectively identified. Lower extremity ultrasounds with a concurrent magnetic resonance, computed tomography, or conventional venogram performed within the next 7 days, which served as gold standard, were further identified (n = 192 examinations, including 313 limbs). Iliocaval obstruction were assessed by two ultrasound criteria: (1) nonphasic flow and/or (2) nonresponsive flow to Valsalva in the common femoral vein. The sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) for diagnosing iliocaval obstruction were calculated for each ultrasound criterion, and also for when the two criteria were assessed jointly.

RESULTS

Of the 313 limbs assessed for venous flow phasicity, 133 (42.5%) had an iliocaval obstruction confirmed on subsequent venography. Nonphasic flow demonstrated a sensitivity of 69.2%, specificity of 82.8%, NPV of 78.4%, and PPV of 74.8% for diagnosing iliocaval obstruction. Of the 212 limbs assessed for Valsalva response, 88 (41.5%) had a confirmed iliocaval obstruction. Nonresponsive flow to Valsalva demonstrated a sensitivity of 13.6%, specificity of 97.6%, NPV of 61.6%, and PPV of 80.0% for diagnosing iliocaval obstruction. Joint assessment using phasicity and Valsalva criteria demonstrated a sensitivity of 68.2%, specificity of 87.2%, NPV of 79.6%, and PPV of 78.9%.

CONCLUSIONS

In this tertiary care setting, Doppler ultrasound examination was not a reliable diagnostic tool for detecting iliocaval obstruction.

Fat-suppressed magnetic resonance volume interpolated examination for deep venous thrombosis compared with duplex sonography

The aim of the present study was to evaluate magnetic resonance venography (MRV) scanned by breath-hold volume interpolated body examination with spectral fat saturation (VIBE-fs), combined with Dixon fat-suppressed VIBE (VIBE-Dixon) by using a 1.5T MR scanner for detecting deep venous thrombosis (DVT) compared with duplex sonography. A total of 31 patients with DVT were identified using duplex sonography and were enrolled in the present study for MRV examination, from the inferior vena cava to the ankle level after injection of gadopentetate dimeglumine. Venous segment-to-segment comparison was assessed for DVT detection between MRV and duplex sonography. A total of two radiologists separately performed subjective image quality assessment using a 5-point scale. Cohen's κ coefficient, Wilcoxon rank sum test and intraclass correlation coefficient values were used for statistical analysis. Of the 303 evaluated vein segments, duplex sonography identified 119 (39.3%; 119/303) venous segments with thrombus, while MRV detected 170 (56.1%; 170/303) venous segments with thrombus. The diagnostic agreement rate of DVT between duplex sonography and MRV was poor in the deep femoral vein and anterior tibial veins, while it was excellent in the inferior vena cava (IVC), common iliac vein, external iliac vein, femoral vein, popliteal vein, posterior tibial veins and peroneal veins. In addition, poor reliability was detected in the deep femoral vein, anterior tibial veins and peroneal veins, but good to excellent reliability was observed in IVC, common iliac vein, external iliac vein, femoral vein, popliteal vein and posterior tibial veins. Furthermore, image quality scores of each venous segment between the two radiologists indicated no statistical difference. Therefore, MRV scanned using VIBE-fs for the suprainguinal and VIBE-Dixon for the infrainguinal region may be a useful method for detecting DVT compared with duplex sonography. The results of present study proved this MR protocol to be a beneficial alternative imaging modality for the detection of DVT when duplex sonography is inadequate or not able to be performed.

Characterization of intramuscular calf vein thrombosis on routine knee MRI

OBJECTIVE

Literature regarding intramuscular calf vein thrombosis (IMCVT) or infrapopliteal deep vein thrombosis (DVT) evaluation by magnetic resonance imaging (MRI) is limited, particularly with regard to routine unenhanced knee examinations. We attempt to correlate routine unenhanced MRI findings with ultrasound evaluations of the lower extremity deep venous system.

MATERIALS AND METHODS

The radiology information system was searched, yielding a total of 67 patients who had undergone both routine knee MRI and duplex ultrasound examinations within 14 days. The MRI examination findings recorded were the presence and pattern of edema, segmental vein dilation, intraluminal signal on fluid-sensitive sequences, and abnormal hyperintense signal on axial T1-weighted sequences. The presence and extent of thrombus more centrally (i.e., intramuscular calf vein thrombosis with or without extension into the popliteal vein) was reassessed on ultrasound.

RESULTS

When comparing patients with positive (n = 13) and negative (n = 54) ultrasound, there were significant differences in each of these parameters: perivascular edema, intramuscular edema, focal vein dilation, and abnormal fluid-sensitive signal. In the subset of patients with popliteal extension of the intramuscular calf vein thrombosis compared with those without any deep vein thrombosis, there was a statistically significant increase in peripopliteal edema, abnormal fluid-sensitive signal, and abnormal hyperintense T1 signal.

CONCLUSION

Imaging findings on routine unenhanced MRI have a high rate of concordance with duplex ultrasound performed through the calf in the detection of intramuscular calf vein thrombosis.

Vascular Tests for Dermatologists

Dermatologists encounter patients with a variety of lower extremity ulcers including those related to venous insufficiency and peripheral arterial disease. Vascular studies, including ankle brachial pressure index, toe pressure, toe brachial index, Doppler arterial waveform, Duplex ultrasonography, and angiography, play an essential role in the prevention, diagnosis, and management of vascular diseases. In fact, dermatologists are often the first medical providers to see patients with complex vascular conditions. Knowledge of the appropriate indications, interpretations, limitations, and advantages of the various vascular studies is critical to the successful and swift management of each patient presenting with a lower extremity ulcer. This study reviews the most commonly ordered arterial and venous studies and discusses the appropriate indications and interpretation of these studies.

Hospitalist-Operated Compression Ultrasonography: a Point-of-Care Ultrasound Study (HOCUS-POCUS)

BACKGROUND

Venous thromboembolism includes deep vein thrombosis (DVT) and pulmonary embolism. Compression ultrasonography is the most common way to evaluate DVT and is typically performed by sonographers and interpreted by radiologists. Yet there is evidence that ultrasound examinations can be safely and accurately performed by clinicians at the bedside.

OBJECTIVE

To measure the operating characteristics of hospital medicine providers performing point-of-care ultrasound (POCUS) for evaluation of DVT.

DESIGN

This is a prospective cohort study enrolling a convenience sample of patients. Hospital medicine providers performed POCUS for DVT and the results were compared with the corresponding formal vascular study (FVS) interpreted by radiologists.

PARTICIPANTS

Hospitalized non-ICU patients at four tertiary care hospitals for whom a DVT ultrasound was ordered.

MAIN MEASURES

The primary outcomes were the sensitivity, specificity, and predictive values of the POCUS compression ultrasound compared with a FVS. The secondary outcome was the elapsed time between order and the POCUS study compared with the time the FVS was ordered to when the formal radiology report was finalized.

KEY RESULTS

One hundred twenty-five limbs from 73 patients were scanned. The prevalence of DVT was 6.4% (8/125). The sensitivity of POCUS for DVT was 100% (95% CI 74-100%) and specificity was 95.8% (95% CI 91-98%) with a positive predictive value of 61.5% (95% CI 35-84%) and a negative predictive value of 100% (95% CI 98-100%). The median time from order to POCUS completion was 5.8 h versus 11.5 h median time from order until the radiology report was finalized (p = 0.001).

CONCLUSION

Hospital medicine providers can perform compression-only POCUS for DVT on inpatients with accuracy similar to other specialties and settings, with results available sooner than radiology. The observed prevalence of DVT was lower than expected. POCUS may be reliable in excluding DVT but further study is required to determine how to incorporate a positive POCUS DVT result into clinical practice.

Is the Oral Chemical Prophylaxis Necessary for the Prevention of Venous Thromboembolism after Joint Arthroplasty in a Korean Population?

Purpose

Venous thromboembolism (VTE) is a serious complication that may occur after a major orthopedic surgery. The aim of the present study was to determine the necessity of a chemical thromboprophylactic agent (rivaroxaban [RXB]) by analyzing the prevalence of VTE in Korean arthroplasty patients who received RXB for prophylaxis compared with those who did not receive RXB.

Materials and Methods

A total of 2,603 patients who underwent knee or hip arthroplasty between 1996 and 2017 were prospectively evaluated. Of these, 1,608 patients underwent surgery before January 2010 and were not administered any type of prophylaxis after surgery; the remaining 995 underwent surgery after 2010 and received oral RXB once daily for 5–13 days from the day after hemovac drain removal to postoperative day 14.

Results

The primary study outcome was the prevalence of VTE, pulmonary embolism or death during follow up. The overall incidence of VTE was 1.69% (n=44); of these, 12 occurred in the RXB group and 32 in the non-prophylactic group. The odds ratio of VTE in the RXB group was 0.61. However, the statistical power of the study was 0.313 due to the low incidence of VTE.

Conclusion

Treatment with oral chemical prophylaxis decreased the incidence of VTE after knee or hip arthroplasty in a Korean population. Furthermore, no serious complications occurred after administering oral RXB, which, coupled with its convenience, suggests oral RXB offers an attractive alternative to other agents. However, we recommend that further studies, including a multicenter study, be conducted to achieve adequate statistical power.

The rate of missed diagnosis of lower-limb DVT by ultrasound amounts to 50% or so in patients without symptoms of DVT: A meta-analysis

BACKGROUND

To assess whether the ultrasound (US) is a reliable approach in detecting lower-limb deep-vein thrombosis (DVT) in patients without symptoms of DVT.

METHODS

The research team performed a systematic search in PubMed, Ovid, Cochrane, and Web of Science without language or date restrictions. Full-text reports on prospective diagnostic studies involve the detection of lower-limb proximal and distal DVT in patients without symptoms of DVT using US and venography. A meta-analysis was performed using Meta-DiSc (version 1.4), providing the pooled sensitivity, specificity, positive (LR+) and negative (LR-) likelihood ratios of the detection accuracy of US. There were 4 different classes of subgroup analysis-the class of patients stratified by location of US exam (proximal, distal, whole leg), the class stratified by technique (color/doppler, compression, both modalities), the class stratified by kind of surgery (orthopedic, otherwise hospitalized) and the class stratified by era of publishing (1980s, 1990s, 2000s). The study quality and the risk of bias were evaluated using QUADAS-2, with heterogeneity was assessed and quantified by the Q score and I statistics, respectively.

RESULTS

The meta-analysis included 26 articles containing 41 individual studies with a total of 3951 patients without symptoms of DVT. Using venography as the gold standard, US for proximal DVT had a pooled sensitivity of 59% (95% confidence interval (CI) = 51%-66%) and a pooled specificity of 98% (95% CI = 97%-98%), US for distal DVT had a poor sensitivity of 43% (95% CI = 38%-48%) and a pooled specificity of 95% (95% CI = 94%-96%), US for whole-leg DVT had a pooled sensitivity of 59% (95% CI = 54%-64%) and a pooled specificity of 95% (95% CI = 94%-96%), US for post-major orthopedic surgery patients had a pooled sensitivity of 52% (95% CI = 49%-55%), and US for other types of patients had a pooled sensitivity of 58% (95% CI = 43%-72%). Pure compression technique for DVT had a poor sensitivity of 43% (95% CI = 39%-48%), pure color/doppler technique for DVT had a pooled sensitivity of 58% (95% CI = 53%-63%), compression and color/doppler technique for DVT had a pooled sensitivity of 61% (95% CI = 48%-74%).

CONCLUSION

US could be a useful tool for diagnosing DVT, but it has a lower positive rate and a higher false negative rate. The rate of missed diagnosis of lower-limb DVT by US amounts to 50% or so in the patients without symptoms of DVT. The negative results do not preclude the possibility of DVT and if appropriate heightened surveillance and continued monitoring or try a more accurate inspection method is warranted. The whole leg evaluation and color/doppler technique should be the preferred approach.

Overview of venous pathology related to repetitive vascular trauma in athletes

BACKGROUND

Athletes are generally young, high-functioning individuals. Pathology in this cohort is associated with a decrease in function and consequently has major implications on quality of life. Venous disorders can be attributed to a combination of vascular compression with a high burden of activity.

OBJECTIVE

This article promotes increased awareness of these uncommon conditions specific to the athlete by summarizing pathophysiology, clinical features, investigation, and treatment protocols for use in clinical practice. Prognostic outcomes of these management regimens are also discussed, allowing for clinicians to counsel these high-functioning individuals appropriately. With the aim of providing an overview of sport-related venous pathology, a literature review was undertaken identifying articles that were independently reviewed by the authors.

RESULTS

Lower limb venous thrombosis has been identified in young, high-functioning athletes attributed to both compression-related venous trauma, associated with repetitive movements resulting in intimal damage, and blunt trauma. The diagnosis and treatment follow the same protocols as for the general population. Of note, early ambulation is advocated, with an aim to return to premorbid (noncontact) function within 6 weeks. Athletes performing high-intensity repetitive upper limb movement, such as baseball players, are predisposed to upper limb deep venous thrombosis (DVT). Diagnosis follows the same protocols as for lower extremity DVT; however, the optimal treatment strategy remains debated. Current guidelines advocate the use of anticoagulation alone. A specific subset of primary upper limb DVT is effort thrombosis, where there is compression at the level of the thoracic outlet. Thrombolysis with first rib resection is indicated in the acute setting within 14 days. In cases of complete occlusion, surgical decompression with venous reconstruction may be required. Popliteal vein entrapment syndrome is also discussed. This entity has been identified as an overuse injury associated with popliteal vein compression. Duplex ultrasound examination is indicated as a first-line investigation, with conservative noninvasive options considered as an initial management strategy. Chronic venous insufficiency or persistent symptoms may require subsequent surgical decompression.

CONCLUSIONS

Key conditions including upper extremity and lower extremity venous thrombosis, venous aneurysms, Paget-Schroetter syndrome (effort thrombosis), and popliteal vein entrapment syndrome are discussed. Further studies evaluating long-term outcomes on morbidity for current treatment regimens in upper extremity DVT, effort thrombosis, venous thoracic outlet syndrome, and popliteal venous entrapment syndrome are required.

Analysis of recanalization of deep venous thrombosis: a comparative study of patients treated with warfarin vs. rivaroxaban

BACKGROUND

Deep venous thrombosis (DVT) strikes around ten million people worldwide every year and is associated with major complications including pulmonary embolism and post-thrombotic syndrome. Anticoagulation is the standard treatment, with administration of heparins, vitamin K antagonists, fondaparinux, or, more recently, direct oral anticoagulants (DOACs). Anticoagulants reduce thrombus progression and facilitate natural thrombolytic mechanisms, leading to a phenomenon known as recanalization, which can occur in varying degrees and over variable periods of time, under influence from many different factors, including the type of anticoagulation employed.

OBJECTIVES

To evaluate the degree of recanalization and the time taken, by analysis of color Doppler ultrasonography (CDU) reports from patients with DVT treated with DOACs or with heparin + warfarin.

METHODS

A retrospective analysis was conducted of demographic data and CDU reports from patients with DVT who had been treated from January 2009 to December 2016. These patients were classified into two groups, according to the treatment given: Group I (heparin + warfarin): 26 patients; or Group II (rivaroxaban): 51 patients. The primary outcomes assessed were degree of recanalization and time taken.

RESULTS

Recanalization rates at 30, 90, and 180 days were 10%, 52.5%, and 78.9%, respectively, in Group I, and 55.3%, 83.5%, and 92.4%, respectively, in Group II, with statistically significant difference (p = 0.041).

CONCLUSIONS

Both treatments led to recanalization. Recanalization occurred earlier among patients treated with rivaroxaban.

General practitioner use of D-dimer in suspected venous thromboembolism: historical cohort study in one geographical region in the Netherlands

OBJECTIVES

To investigate how many general practitioner (GP)-referred venous thromboembolic events (VTEs) are diagnosed during 1 year in one geographical region and to investigate the (urgent) referral pathway of VTE diagnoses, including the role of laboratory D-dimer testing.

DESIGN

Historical cohort study.

SETTING

GP patients of 47 general practices in a demarcated geographical region of 161 503 inhabitants in the Netherlands.

PARTICIPANTS

We analysed all 895 primary care patients in whom either the GP determined a D-dimer value or who had a diagnostic work-up for suspected VTE in a non-academic hospital during 2015.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcomes of this study were the total number of VTEs per year and the diagnostic pathways-including the role of GP determined D-dimer testing-of patients urgently referred to secondary care for suspected VTE. Additionally, we explored the use of an age-adjusted D-dimer cut-off.

RESULTS

The annual VTE incidence was 0.9 per 1000 inhabitants. GPs annually ordered 5.1 D-dimer tests per 1000 inhabitants. Of 470 urgently GP-referred patients, 31.3% had a VTE. Of those urgently referred based on clinical assessment only (without D-dimer testing), 73.8% (96/130) had a VTE; based on clinical assessment and laboratory D-dimer testing yielded 15.0% (51/340) VTE. Applying age-adjusted D-dimer cut-offs to all patients aged 50 years or older resulted in a reduction of positive D-dimer results from 97.9% to 79.4%, without missing any VTE.

CONCLUSIONS

Although D-dimer testing contributes to the diagnostic work-up of VTE, GPs have a high detection rate for VTE in patients who they urgently refer to secondary care based on clinical assessment only.

Venous Thromboembolism and Bleeding Adverse Events in Lower Leg, Ankle, and Foot Orthopaedic Surgery with and without Anticoagulants

BACKGROUND

Currently, there is insufficient knowledge about the benefits of anticoagulant use for primary prevention of venous thromboembolism (VTE) and its inherent risk of bleeding adverse events in patients undergoing surgery distal to the knee.

METHODS

The study included patients who had undergone an orthopaedic procedure distal to the tibial articular surface when they were 18 years of age or older. Using retrospective information from a tertiary care referral center, we compared patient demographics, clinical findings, diagnostic reports, procedures performed, and the rate of symptomatic VTE and bleeding adverse events between patients who had and those who had not received anticoagulant prophylaxis. Propensity score matching was used to minimize selection bias due to prophylactic treatment allocation.

RESULTS

A total of 5,286 patients who had received anticoagulant prophylaxis for below-the-knee surgery were successfully matched with 5,286 patients who had not received anticoagulant prophylaxis for such surgery. After propensity score matching, the standardized difference between the groups was <0.1 for all baseline characteristics, indicating a negligible difference between the groups. Patients who received anticoagulant prophylaxis had a significantly lower risk of developing a VTE compared with patients who did not (39 patients [0.7%] versus 99 patients [1.9%]), with an odds ratio (OR) of 0.38 (95% confidence interval [CI], 0.25 to 0.56; p < 0.001). In contradistinction, patients who received anticoagulant prophylaxis had a significantly higher risk of developing a bleeding adverse event than those who did not (115 [2.2%] versus 55 [1.0%]; OR, 2.18 [95% CI, 1.55 to 3.09]; p < 0.001).

CONCLUSIONS

Anticoagulant prophylaxis reduced the risk of VTE after surgery distal to the tibial articular surface by 3-fold but resulted in a concomitant 2-fold increase in the risk of a bleeding adverse event. Large-scale, prospective studies are necessary to better understand the true incidence of such events, associated patient-specific risk factors, efficacy of various thromboprophylactic regimens, and patient-reported implications of such events.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Highly Elevated Quantitative D-Dimer Assay Values Increase the Likelihood of Venous Thromboembolism

Objectives  In patients with suspected venous thromboembolism (VTE), the D-dimer assay is commonly utilized as part of the workup. The assay is primarily used to determine whether to proceed with radiographic imaging. We compared D-dimer levels in patients suspected of having VTE. We hypothesized that higher D-dimer values predict a higher likelihood of subsequent VTE diagnosis.

Methods  We conducted a secondary analysis of a multinational, prospective observational study of low- to intermediate-risk adult patients presenting to the emergency department with suspicion of VTE. Demographic and clinical data were collected in a structured manner. Advanced imaging including ultrasound, computed tomography (CT) pulmonary angiography, and ventilation/perfusion scanning was obtained at the discretion of the treating physicians. Imaging was evaluated by board-certified radiologists in real time. D-dimer values' bins were evaluated using a logistic regression model.

Results  We evaluated 1,752 patients for suspected deep vein thrombosis (DVT), with 191 (10.4%) DVT positive. We evaluated 1,834 patients for suspected pulmonary embolism (PE), with 108 (5.9%) PE positive. Higher D-dimer values in both groups were associated with higher likelihood of subsequent VTE diagnosis, with D-dimer values > 3,999 ng/mL in both groups having the highest incidence of VTE. More than 50% of those patients were VTE positive.

Conclusions  Increasing D-dimer values predict increased likelihood of being found VTE positive in this patient population. Among those in the highest D-dimer category, > 3,999 ng/mL, over half of patients were VTE positive. Further research could determine additional nuance in D-dimer as a tool to work up suspected VTE.

Ultrasound elastography is useful to distinguish acute and chronic deep vein thrombosis

Essentials Ultrasound elastography uses tissue deformation to assess the relative quantification of its elasticity. Compression and duplex ultrasonography may be unable to correctly determine the thrombus age. Ultrasound elastography may be useful to distinguish between acute and chronic deep vein thrombosis. The exact determination of the thrombus age could have both therapeutic and prognostic implications. BACKGROUND: Background Ultrasound elastography (UE) imaging is a novel sonographic technique that is commonly employed for relative quantification of tissue elasticity. Its applicability to venous thromboembolic events has not yet been fully established; in particular, it is unclear whether this technique may be useful in determining the age of deep vein thrombosis (DVT). Thus, the aim of this study was to assess the role of UE in distinguishing acute from chronic DVT. Methods Consecutive patients with a first unprovoked acute and chronic (3 months old) DVT of the lower limbs were analyzed. Patients with recurrent DVT or with a suspected recurrence were excluded. The mean elasticity index (EI) values of acute and chronic popliteal and femoral vein thrombosis were compared. The accuracy of the EI in distinguishing acute from chronic DVT was also assessed by measuring the sensitivity, specificity, positive and negative predictive values, and likelihood ratios. Results One-hundred and forty-nine patients (mean age 63.9 years, standard deviation 13.6; 73 males) with acute and chronic DVT were included. The mean EI of acute femoral DVT was higher than that of chronic femoral DVT (5.09 versus 2.46), and the mean EI of acute popliteal DVT was higher than that of chronic popliteal DVT (4.96 versus 2.48). An EI value of > 4 resulted in a sensitivity of 98.9% (95% confidence interval [CI] 93.3-99.9), a specificity of 99.1% (95% CI 94.8-99.9), a positive predictive value of 91.1% (95% CI 77.9-97.1), a negative predictive value of 98.6% (95% CI 91.3-99.9), a positive likelihood ratio of 13.23 (95% CI 93-653) and a negative likelihood ratio of 0.001 (95% CI 0.008-0.05) for acute DVT. Conclusions UE appears to be a promising technique for distinguishing between acute and chronic DVT. Larger prospective studies are warranted to confirm our preliminary findings.

Postoperative major surgery patients developing silent deep vein thrombosis: A prospective observational study

Surgical patients are at high risk for developing deep vein thrombosis (DVT). There are many reports concerning DVT, but little is known about silent deep vein thrombosis (sDVT). This study aimed to determine the incidence of sDVT. Secondary objective is to identify the associated factors for the use of DVT prophylaxis and Caprini risk scores among major surgery patients. This prospective observational study involved postoperative surgical patients who are at risk of developing sDVT. The Caprini risk-assessment scores were calculated, and each subject had a preoperative and postoperative compression ultrasound complemented by duplex venous ultrasonography of deep venous system. No patient from the study experienced sDVT. There were significant associations between Caprini risk score group (odds ratio, 8.16; 95% confidence interval [CI], 1.01-68.74; P = .016) and the use of central venous catheter (odds ratio, 6.34; 95% CI, 1.62-24.80; P = .008) with DVT prophylaxis. Interestingly, the use of central venous catheter resulted in more than four-point increment of Caprini risk scores (mean increment, 4.19; 95% CI, 3.16-5.21; P < .001). Besides that, age was also significantly associated with Caprini risk scores (β coefficient, 0.06; 95% CI, 0.02-0.11). Result from our study shows that the sDVT was nonexistent in this study setting. High-Caprini risk score group and the presence of central venous catheter were the significant predictor factors for the use of DVT prophylaxis. Significant predictor factors for Caprini risk scores were age and the presence of central venous catheter.

D-dimer monitoring combined with ultrasonography improves screening for asymptomatic venous thromboembolism in acute spinal cord injury

Objective: We compared screening methods for asymptomatic venous thromboembolism (VTE) in patients with acute spine and spinal cord injuries (SCI). Patients were screened by D-dimer monitoring alone (DS group) or by D-dimer monitoring combined with ultrasonography (DUS group).Design: Prospective cohort study.Setting: One department of a university hospital in Japan.Participants: 114 patients treated for acute SCI between 2011 and 2017.Interventions: N/A.Outcome Measures: D-dimers were measured upon admission and 1, 3, 5, 7, and 14 days thereafter. DUS-group patients also underwent an ultrasound 7 days after admission. If ultrasonography indicated deep venous thrombosis (DVT), or if D-dimer levels increased to ≥ 10 µg/mL, the patient was assessed for VTE, including DVT or pulmonary embolism (PE), by contrast venography. We analyzed the incidence of VTE detected in the DS and DUS groups.Results: In the DS group, D-dimers were elevated (≥ 10 µg/mL) in 15 of 70 patients (21.4%), and 9 of the 15 had asymptomatic VTE (12.9%, DVT 11.4%, PE 5.7%). In the DUS group, one patient developed VTE on day 4, and D-dimers were elevated in 13 of 43 patients (30.2%), ultrasonography indicated DVT in 12 patients (27.9%), and asymptomatic VTE was diagnosed in 12 patients (27.9%, DVT 27.9%, PE 4.7%). The DUS group had a higher incidence of DVT (P = 0.002) and VTE (P = 0.042) than the DS group.Conclusions: Combined D-dimer and ultrasound screening in patients with acute SCI improved the detection of VTE, including PE, compared with D-dimer screening alone.

Venous thromboembolism prophylaxis after hip preservation surgery: a review and presentation of institutional experience

Venous thromboembolism (VTE) is a serious complication after major orthopedic procedures. The best options for prevention of the VTE are still debated. The most popular evidence-based guidelines for prevention and treatment of VTE in orthopedic surgery addressed the total hip or knee arthroplasty and hip fractures as the major orthopedic surgeries. Majority of studies have evaluated the different modalities of the VTE prophylaxis in patients undergiong hip or knee arthroplasty. Hip preservation surgeries (HPS) including mini-open femoroacetabular osteoplasty, surgical dislocation of the hip, arthroscopic procedures, and periacetabular osteotomy (PAO) are gained popularity in recent two decades. The majority of these patients are young, healthy and active and may not be considered at high risk for VTE. The frequency of VTE in patients undergoing PAO seems to be low between 0 and 5%. There is a paucity of data regarding rates of VTE in young healthy patients undergoing HPS as well as the optimal prevention methods for VTE. Hence current VTE prevention guidelines do not cover HPS adequately. We aimed to review the available literature regarding VTE events and VTE prophylaxis options after HPS. We discussed the available and potential options for prophylaxis of VTE events in these procedures along with our experience in a large cohort of hip preservation surgery.

Cardiovascular magnetic resonance black-blood thrombus imaging for the diagnosis of acute deep vein thrombosis at 1.5 Tesla

BACKGROUND

The aim was to investigate the feasibility of a cardiovascular magnetic resonance (CMR) black-blood thrombus imaging (BBTI) technique, based on delay alternating with nutation for tailored excitation black-blood preparation and a variable flip angle turbo-spin-echo readout, for the diagnosis of acute deep vein thrombosis (DVT) at 1.5 T.

METHODS

BBTI was conducted in 15 healthy subjects and 30 acute DVT patients. Contrast-enhanced CMR venography (CE-CMRV) was conducted for comparison and only performed in the patients. Apparent contrast-to-noise ratios between the thrombus and the muscle/lumen were calculated to determine whether BBTI could provide an adequate thrombus signal for diagnosis. Two blinded readers assessed the randomized BBTI images from all participants and made independent decisions on the presence or absence of thrombus at the segment level. Images obtained by CE-CMRV were also randomized and assessed by the two readers. Using the consensus CE-CMRV as a reference, the sensitivity, specificity, positive and negative predictive values, and accuracy of BBTI, as well as its diagnostic agreement with CE-CMRV, were calculated. Additionally, diagnostic confidence and interobserver diagnostic agreement were evaluated.

RESULTS

The thrombi in the acute phase exhibited iso- or hyperintense signals on the BBTI images. All the healthy subjects were correctly identified from the participants based on the segment level. The diagnostic confidence of BBTI was comparable to that of CE-CMRV (3.69 ± 0.52 vs. 3.70 ± 0.47). High overall sensitivity (95.2%), SP (98.6%), positive predictive value (96.0%), negative predictive value (98.3%), and accuracy (97.7%), as well as excellent diagnostic and interobserver agreements, were achieved using BBTI.

CONCLUSION

BBTI is a reliable, contrast-free technique for the diagnosis of acute DVT at 1.5 T.

Imaging of acute pulmonary embolism: an update

Imaging plays an important role in the evaluation and management of acute pulmonary embolism (PE). Computed tomography (CT) pulmonary angiography (CTPA) is the current standard of care and provides accurate diagnosis with rapid turnaround time. CT also provides information on other potential causes of acute chest pain. With dual-energy CT, lung perfusion abnormalities can also be detected and quantified. Chest radiograph has limited utility, occasionally showing findings of PE or infarction, but is useful in evaluating other potential causes of chest pain. Ventilation-perfusion (VQ) scan demonstrates ventilation-perfusion mismatches in these patients, with several classification schemes, typically ranging from normal to high. Magnetic resonance imaging (MRI) also provides accurate diagnosis, but is available in only specialized centers and requires higher levels of expertise. Catheter pulmonary angiography is no longer used for diagnosis and is used only for interventional management. Echocardiography is used for risk stratification of these patients. In this article, we review the role of imaging in the evaluation of acute PE.

Sodium pentosan polysulfate efficacy as thromboprophylaxis agent in high-risk women following gynecological surgery

AIM

Sodium pentosan polysulfate (Na-PPS) is a plant-based agent that has similar action with low-molecular-weight heparin. It inhibits factor Xa, preventing blood clot formation. To date, its use in clinical practice as thromboprophylaxis agent is still limited. In addition, the efficacy and safety profile of this agent was not robustly reported globally, especially for countries with major Muslim population. We hypothesized that Na-PPS was equally effective as the standard thromboprophylaxis. We aim to compare the efficacy and safety of Na-PPS against standard agent (fondaparinux or enoxaparin).

METHODS

This was a randomized control, open-label trial. Women underwent major gynecological surgery were randomized to receive either subcutaneous 50 mg of Na-PPS twice daily or subcutaneous enoxaparin 40 mg once daily. Fondaparinux 2.5 mg once daily was given to Muslim women as an alternative to enoxaparin. The treatment was started 6 h postoperatively, for at least 3 days. All the patients received thromboembolic deterrent stockings. The primary efficacy outcome was venous thromboembolism up to 3 days postsurgery. The main safety outcomes were minor and major bleeding.

RESULTS

Among 109 participants, there was no incidence of venous thromboembolism. None of the women developed major bleeding. Minor bleeding was observed in 28.3% (15/53) and 5.4% (3/56) of Na-PPS and standard thromboprophylaxis group, respectively (P = 0.001).

CONCLUSION

Na-PPS was associated with increased risk of minor bleeding. There was insufficient data to conclude its efficacy as thromboprophylaxis. Further research is needed to evaluate Na-PPS safety as a standard thromboprophylactic agent.

Peripheral vascular disease assessment in the lower limb: a review of current and emerging non-invasive diagnostic methods

BACKGROUND

Worldwide, at least 200 million people are affected by peripheral vascular diseases (PVDs), including peripheral arterial disease (PAD), chronic venous insufficiency (CVI) and deep vein thrombosis (DVT). The high prevalence and serious consequences of PVDs have led to the development of several diagnostic tools and clinical guidelines to assist timely diagnosis and patient management. Given the increasing number of diagnostic methods available, a comprehensive review of available technologies is timely in order to understand their limitations and direct future development effort.

MAIN BODY

This paper reviews the available diagnostic methods for PAD, CVI, and DVT with a focus on non-invasive modalities. Each method is critically evaluated in terms of sensitivity, specificity, accuracy, ease of use, procedure time duration, and training requirements where applicable.

CONCLUSION

This review emphasizes the limitations of existing methods, highlighting a latent need for the development of new non-invasive, efficient diagnostic methods. Some newly emerging technologies are identified, in particular wearable sensors, which demonstrate considerable potential to address the need for simple, cost-effective, accurate and timely diagnosis of PVDs.

Ultrasound for Lower Extremity Deep Venous Thrombosis

Venous ultrasound is the standard imaging test for patients suspected of having acute deep venous thrombosis (DVT). There is variability and disagreement among authoritative groups regarding the necessary components of the test. Some protocols include scanning the entire lower extremity, whereas others recommend scans limited to the thigh and knee supplemented with serial testing. Some protocols use gray-scale ultrasound alone, whereas others include Doppler interrogation. Point-of-care ultrasound is recommended in some settings, and there is heterogeneity of these protocols as well. Heterogeneity of recommendations can lead to errors including incorrect application of guidelines, confusion among requesting physicians, and incorrect follow-up. In October 2016, the Society of Radiologists in Ultrasound convened a multidisciplinary panel of experts to evaluate the current evidence to develop recommendations regarding ultrasound protocols for DVT and the terminology used to communicate results to clinicians. Recommendations were made after open discussion and by unanimous consensus.

The panel recommends a comprehensive duplex ultrasound protocol from thigh to ankle with Doppler at selected sites rather than a limited or complete compression-only examination. This protocol is currently performed in many facilities and is achievable with standard ultrasound equipment and personnel. The use of these recommendations will increase the diagnosis of calf DVT and provide better data to explain the presenting symptoms. The panel recommends a single point-of-care protocol that minimizes underdiagnoses of proximal DVT.

The panel recommends the term chronic postthrombotic change to describe the residual material that persists after the acute presentation of DVT to avoid potential overtreatment of prior thrombus.

Adoption of a single standardized comprehensive duplex ultrasound and a single point-of-care examination will enhance patient safety and clinicians’ confidence.

Efficacy of Rivaroxaban for thromboprophylaxis after Knee Arthroscopy (ERIKA)

Without thromboprophylaxis, knee arthroscopy (KA) carries a low to moderate risk of venous thromboembolism. Over 5 million arthroscopies are performed worldwide yearly. It was our study objective to assess the efficacy and safety of rivaroxaban for thromboprophylaxis after therapeutic KA. Patients undergoing KA in nine Italian teaching or community hospitals were allocated to once-daily rivaroxaban (10 mg) or placebo for seven days in a phase II, multicentre, double-blind, placebo-controlled randomised trial. The primary efficacy outcome was a composite of all-cause death, symptomatic thromboembolism and asymptomatic proximal DVT at three months; major bleeding represented the primary safety outcome. All patients underwent whole-leg ultrasonography at day 7(+1), or earlier if symptomatic. A total of 241 patients were randomised (122 rivaroxaban, 119 placebo), and 234 completed the study. The primary efficacy outcome occurred in 1/120 of the rivaroxaban group and in 7/114 of the placebo group (0.8% vs 6.1%, respectively, p=0.03; absolute risk difference, −5.3%, 95% CI, −11.4 to −0.8; crude relative risk 0.14, 95% CI, 0.02 to 0.83; number-needed-to-treat=19). No major bleedings were observed. We found no association between different arthroscopic procedures and thrombotic events. Small sample size, high exclusion rate, and low number of anterior cruciate ligament reconstruction procedures are the main limitations of our study. In conclusion, a seven-day course of 10-mg rivaroxaban may be safely employed for thromboprophylaxis after KA. Whether prophylaxis after KA should be given to all patients, or to selected “high-risk” subjects, remains to be determined. A larger trial to verify our preliminary results is warranted.

Die chronische venöse Insuffizienz - Eine Zusammenfassung der Pathophysiologie, Diagnostik und Therapie

Die chronische Venenerkrankung ist eine weit verbreitete Krankheit, die in späteren Stadien mit einer Vielzahl an Symptomen, aber auch Komplikationen wie dem Ulcus cruris, einhergeht. Dies wiederum hat weitreichende Auswirkungen auf die Lebensqualität der Patienten wie auch auf das Gesundheitssystem. Für die Diagnostik der chronischen Venenerkrankungen steht eine Auswahl an Verfahren zur Verfügung, wobei sich die farbkodierte Duplexsonographie als Goldstandard etabliert hat. Im Bereich der Therapie kam es in den letzten Jahrzehnten zu großen Fortschritten, sodass heute auch Alternativen zum klassischen Stripping durch die endoluminalen Verfahren zur Verfügung stehen. Die Wahl der Therapieoption ist jedoch weiterhin stark abhängig von mehreren Faktoren, unter anderem von den anatomischen Gegebenheiten und dem Krankheitsstadium. Im folgenden Artikel werden die Anatomie und Pathophysiologie, sowie die aktuellen Standards der Diagnostik und Therapie zusammengefasst.

Chronic venous insufficiency - a review of pathophysiology, diagnosis, and treatment

Chronic venous disease is a common disorder associated with a variety of symptoms in later disease stages but also with complications such as venous leg ulcer. This, in turn, has substantial socioeconomic effects and significantly impacts patients' quality of life. While there are a number of diagnostic procedures available, color-flow duplex ultrasound has become the gold standard. As regards therapeutic options, major advances have been made in recent decades. Today, there are alternatives to saphenofemoral ligation and stripping of the great saphenous vein, including endovenous thermal ablation techniques. However, treatment selection continues to depend on many factors such as individual anatomical circumstances and disease stage. The following article provides an overview of the anatomy and pathophysiology as well as current diagnostic and therapeutic standards.

The diagnosis and treatment of venous thromboembolism in asian patients

Although the incidence of venous thromboembolism (VTE) in Asian populations is lower than in Western countries, the overall burden of VTE in Asia has been considerably underestimated. Factors that may explain the lower prevalence of VTE in Asian populations relative to Western populations include the limited availability of epidemiological data in Asia, ethnic differences in the genetic predisposition to VTE, underdiagnoses, low awareness toward thrombotic disease, and possibly less symptomatic VTE in Asian patients. The clinical assessment, diagnostic testing, and therapeutic considerations for VTE are, in general, the same in Asian populations as they are in Western populations. The management of VTE is based upon balancing the treatment benefits against the risk of bleeding. This is an especially important consideration for Asian populations because of increased risk of intracranial hemorrhage with vitamin K antagonists. Non-vitamin K antagonist oral anticoagulants have shown advantages over current treatment modalities with respect to bleeding outcomes in major phase 3 clinical trials, including in Asian populations. Although anticoagulant therapy has been shown to reduce the risk of postoperative VTE in Western populations, VTE prophylaxis is not administered routinely in Asian countries. Despite advances in the management of VTE, data in Asian populations on the incidence, prevalence, recurrence, risk factors, and management of bleeding complications are limited and there is need for increased awareness. To that end, this review summarizes the available data on the epidemiology, risk stratification, diagnosis, and treatment considerations in the management of VTE in Asia.

Direct oral anticoagulants in the treatment of pulmonary embolism

OBJECTIVE

The objective of this review is to examine the management strategies for pulmonary embolism (PE) with an emphasis of the role of direct oral anticoagulants (DOACs).

METHODS

PubMed was searched to identify relevant journal articles published through April 2017. Additional references were obtained from articles discovered during the database search.

RESULTS

Initial heparinization followed by long-term anticoagulation with vitamin K antagonists has been considered the mainstay for the treatment of PE. However, DOACs now offer comparably effective and potentially safer alternatives for both acute and long-term treatment of PE using a monotherapy approach without the need for initial heparinization for rivaroxaban or apixaban. Advantages to using DOACs include oral availability, rapid onset of action, minimal drug and food interactions, predictable pharmacokinetics, and lack of need for routine monitoring. Limitations of using these agents include a limited availability of assays to quickly and efficiently measure their anticoagulant effects and the lack of widely available reversal agents for the direct oral factor Xa inhibitors; although idarucizumab has recently been approved for the reversal of dabigatran's anticoagulant effects.

CONCLUSIONS

Advantages to using DOACs render them an attractive alternative to conventional therapy in PE treatment that may simplify acute and long-term treatment paradigms, improve patient outcomes, and increase patient compliance. However, questions remain pertaining to the use of DOACs in PE patients with high-risk features and in cancer patients and fragile populations. Clinical studies are under way to address many of these issues.

Doppler ultrasound and D-dimer

The diagnosis of venous thromboembolism has evolved considerably with the development of standardized diagnostic algorithms that include clinical probability assessment, D-dimer measurement and the use of non-invasive imaging modalities such as compression ultrasonography and computed tomography angiography. The implementation of these strategies aims to improve resource allocation and patient outcome. The judicious use of these diagnostic tools requires a thorough knowledge of the appropriate clinical setting in which every test and strategy is efficient and can be used safely. For this purpose, D-dimer measurement and compression ultrasonography are complementary: the former is mainly used to exclude VTE in selected patients, while the latter is used to confirm the presence of an underlying DVT.

This review provides an appraisal of the features and use of D-dimer and compression ultrasonography in the context of suspected venous thromboembolism.

Should we diagnose and treat distal deep vein thrombosis?

Ultrasound series report that isolated distal deep vein thrombosis (DVT), also known as calf DVT, represents up to 50% of all lower-limb DVTs and, therefore, is a frequent medical condition. Unlike proximal DVT and pulmonary embolism, which have been studied extensively and for which management is well standardized, much less is known about the optimal management of isolated calf DVT. Recent data arising from registries and nonrandomized studies have suggested that most distal DVTs do not extend to the proximal veins and have an uneventful follow-up when left untreated. These data had some impact on the international recommendations that recently stated that ultrasound surveillance instead of systematic therapeutic anticoagulation might be an option for selected low-risk patients. However, robust data from randomized studies are scarce. Only 5 randomized trials assessing the need for anticoagulation for calf DVT have been published. Many of these trials had an open-label design and were affected by methodological limitations. The only randomized placebo-controlled trial included low-risk patients (outpatients without cancer or previous venous thromboembolism [VTE]) and was hampered by limited statistical power. Nevertheless, data from this trial confirmed that the use of therapeutic anticoagulation in low-risk patients with symptomatic calf DVT is not superior to placebo in reducing VTE but is associated with a significantly higher risk of bleeding. Further randomized studies are needed to define the best therapy for high-risk patients (inpatients, patients with active cancer, or patients with previous VTE) and the optimal dose and duration of treatment.

Deep vein thrombosis: pathogenesis, diagnosis, and medical management

Deep vein thrombosis (DVT) is a major preventable cause of morbidity and mortality worldwide. Venous thromboembolism (VTE), which includes DVT and pulmonary embolism (PE), affects an estimated 1 per 1,000 people and contributes to 60,000-100,000 deaths annually. Normal blood physiology hinges on a delicate balance between pro- and anti-coagulant factors. Virchow's Triad distills the multitude of risk factors for DVT into three basic elements favoring thrombus formation: venous stasis, vascular injury, and hypercoagulability. Clinical, biochemical, and radiological tests are used to increase the sensitivity and specificity for diagnosing DVT. Anticoagulation therapy is essential for the treatment of DVT. With few exceptions, the standard therapy for DVT has been vitamin K-antagonists (VKAs) such as warfarin with heparin or fractionated heparin bridging. More recently, a number of large-scale clinical trials have validated the use of direct oral anticoagulants (DOACs) in place of warfarin in select cases. In this review, we summarize the pathogenesis, diagnosis, and medical management of DVT, with particular emphasis on anticoagulation therapy and the role of DOACs in the current treatment algorithm.

General Practitioner-Performed Compression Ultrasonography for Diagnosis of Deep Vein Thrombosis of the Leg: A Multicenter, Prospective Cohort Study

BACKGROUND

Patients with suspected deep vein thrombosis (DVT) of the lower limb represent a diagnostic dilemma for general practitioners. Compression ultrasonography (US) is universally recognized as the best test of choice. We assessed the diagnostic accuracy of compression US performed by general practitioners given short training in the management of symptomatic proximal DVT.

METHODS

From May 2014 to May 2016, we evaluated in a multicenter, prospective cohort study all consecutive outpatients with suspected DVT; bilateral proximal lower limb compression US was performed by general practitioners and by physicians expert in vascular US, each group blinded to the other's findings. In all examinations with a negative or nondiagnostic result, compression US was repeated by the same operator after 5 to 7 days. Inter-observer agreement and accuracy were calculated.

RESULTS

We enrolled a total of 1,107 patients. The expert physicians diagnosed DVT in 200 patients, corresponding to an overall prevalence of 18.1% (95% CI, 15.8%-20.3%). The agreement between the trained general practitioners and the experts was excellent (Cohen κ = 0.86; 95% CI, 0.84-0.88). Compression US performed by general practitioners had a sensitivity of 90.0% (95% CI, 88.2%-91.8%) and a specificity of 97.1% (95% CI, 96.2%-98.1%) with a diagnostic accuracy for DVT of 95.8% (95% CI, 94.7%-97.0%).

CONCLUSIONS

Our results suggest that, even in hands of physicians not expert in vascular US, compression US can be a reliable tool in the diagnosis of DVT. We found that the sensitivity achieved by general practitioners appeared suboptimal, however, so future studies should evaluate the implementation of proper training strategies to maximize skill.

Depiction of lower limb venous anatomy in patients undergoing interventional deep venous reconstruction-the role of balanced steady state free precession MRI

OBJECTIVES

This study evaluates the use of balanced steady-state free precession MRI (bSSFP-MRI) in the diagnostic work-up of patients undergoing interventional deep venous reconstruction (I-DVR). Intravenous digital subtraction angiography (IVDSA) was used as the gold-standard for comparison to assess disease extent and severity.

METHODS

A retrospective comparison of bSSFP-MRI to IVDSA was performed in all patients undergoing both examinations for treatment planning prior to I-DVR. The severity of disease in each venous segment was graded by two board-certified radiologists working independently, according to a predetermined classification system.

RESULTS

In total, 44 patients (225 venous segments) fulfilled the inclusion criteria. A total of 156 abnormal venous segments were diagnosed using bSSFP-MRI compared with 151 using IVDSA. The prevalence of disease was higher in the iliac and femoral segments (range, 79.6-88.6%). Overall sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and the diagnostic ratio for bSSFP-MRI were 99.3%, 91.9%, 12.3, 0.007 and 1700, respectively.

CONCLUSION

This study supports the use of non-contrast balanced SSFP-MRI in the assessment of the deep veins of the lower limb prior to I-DVR. The technique offers an accurate, fast and non-invasive alternative to IVDSA. Advances in Knowledge: Although balanced SSFP-MRI is commonly used in cardiac imaging, its use elsewhere is limited and its use in evaluating the deep veins prior to interventional reconstruction is not described. Our study demonstrates the usefulness of this technique in the work-up of patients awaiting interventional venous reconstruction compared with the current gold standard.