Predicting deep venous thrombosis in pregnancy: external validation of the LEFT clinical prediction rule.

The assessment of clinical probability represents an important step in the diagnostic strategy of patients with suspected deep vein thrombosis. The recently derived LEFt clinical prediction rule for pregnant women combines three variables: symptoms in the left leg (L), calf circumference difference of 2 centimeters or over (E for edema) and first trimester presentation (Ft) but is lacking an external validation. The LEFt rule was computed among pregnant women with suspected deep vein thrombosis who were included in a multicenter prospective diagnostic management outcome study. We calculated the proportion of women and the prevalence of deep vein thrombosis in each probability group, along with the diagnostic performances of the LEFt rule. All variables needed to compute the rule could be retrieved in 157 of the 167 pregnant women with suspected deep vein thrombosis. The prevalence of confirmed deep vein thrombosis was 13 of 157 (8.3%). The LEFt rule was negative in 46 (29%) women. A deep vein thrombosis was diagnosed in 13 of 111 (11.7%, 95% Confidence Interval (CI): 8.3-20.9%) of women with at least one of the LEFt criteria, as compared with none of 46 (0.0%, 95%CI: 0.0-7.9%) of women with none of the LEFt criteria. These results suggest that a negative LEFt rule accurately identifies pregnant women in whom the proportion of confirmed deep vein thrombosis appears to be very low. The rule should not be used as stand-alone test for excluding DVT during pregnancy, but might rather be implemented in a diagnostic strategy in association with D-dimer measurement and compression ultrasonography.

Bilateral thenar hammer syndrome.

BACKGROUND: Thenar hammer syndrome is a very rare condition that mimics rheumatic diseases such as carpal syndrome tunnel, Raynaud's phenomenon, and hand synovitis. OBJECTIVE: To describe the sonographic presentation of thenar hammer syndrome in a typical patient. METHODS: Grey-scale sonography and colour Doppler imaging of the hands with an iU22 scanner (Philips) were performed. RESULTS: In B mode, the lesion was seen as a large, rounded, heterogeneous area combining hypoechoic and echogenic components. Pseudoaneurysm was diagnosed based on presence of a cystic saccular formation arising directly from the adjacent artery and exhibiting an irregular thick wall with turbulent blood flow in the lumen. Colour Doppler showed blood flow in part of the lumen, the rest of which was filled with a thrombus seen as echogenic tissue. CONCLUSION: Sonography can help to diagnose thenar hammer syndrome. Angiography may be unnecessary in patients with normal colour Doppler findings.

Computer-assisted venous thrombosis volume quantification.

Venous thrombosis (VT) volume assessment, by verifying its risk of progression when anticoagulant or thrombolytic therapies are prescribed, is often necessary to screen life-threatening complications. Commonly, VT volume estimation is done by manual delineation of few contours in the ultrasound (US) image sequence, assuming that the VT has a regular shape and constant radius, thus producing significant errors. This paper presents and evaluates a comprehensive functional approach based on the combination of robust anisotropic diffusion and deformable contours to calculate VT volume in a more accurate manner when applied to freehand 2-D US image sequences. Robust anisotropic filtering reduces image speckle noise without generating incoherent edge discontinuities. Prior knowledge of the VT shape allows initializing the deformable contour, which is then guided by the noise-filtering outcome. Segmented contours are subsequently used to calculate VT volume. The proposed approach is integrated into a system prototype compatible with existing clinical US machines that additionally tracks the acquired images 3-D position and provides a dense Delaunay triangulation required for volume calculation. A predefined robust anisotropic diffusion and deformable contour parameter set enhances the system usability. Experimental results pertinence is assessed by comparison with manual and tetrahedron-based volume computations, using images acquired by two medical experts of eight plastic phantoms and eight in vitro VTs, whose independently measured volume is the reference ground truth. Results show a mean difference between 16 and 35 mm(3) for volumes that vary from 655 to 2826 mm(3). Two in vivo VT volumes are also calculated to illustrate how this approach could be applied in clinical conditions when the real value is unknown. Comparative results for the two experts differ from 1.2% to 10.08% of the smallest estimated value when the image acquisition cadences are similar.

Ascribing leg symptoms to chronic venous disorders: the construction of a diagnostic score.

OBJECTIVES: The goal was to create a simple diagnostic scoring system able to differentiate leg symptoms related to chronic venous disorders (CVD) from those produced by other causes. METHODS: A prospective observational study was done of ambulatory or hospitalized patients from 13 private and five institutional vascular centers. Two groups of patients with leg symptoms were investigated. The CVD-positive (CVD+) patients had clinically documented CVD and significant venous reflux at duplex ultrasound examination, but no arterial, rheumatologic, or neurologic disorders. The CVD-negative (CVD-) patients had disorders of an arterial, rheumatic, or neurologic origin but no clinical or duplex ultrasound signs of CVD. Patients completed a 54-item questionnaire characterizing their symptoms. Items of the diagnostic score were selected as those associated with the highest likelihood ratio (LR) for CVD in a first series of patients. They were combined into a few criteria, the number of which, when validated in a patient, would produce the value of the score for this patient. Selection of the most relevant score was performed through the comparison of the surface area under receiver operating characteristic curves. The construct validity of this score was evaluated through a factor analysis. The diagnostic performance of the scoring system was evaluated in a second series of patients similar to the first series. RESULTS: In the construction phase, 123 CVD+ patients and 94 CVD- patients were enrolled. The validation series consisted of 92 patients (67 venous and 25 nonvenous). The most efficient scoring system was composed of four combined criteria: sensation of heavy or swollen legs (sensitivity, 0.82; specificity, 0.55; LR, 1.84); associated with itching, impatient legs, or phlebalgia (sensitivity, 0.55; specificity, 0.92; LR, 6.41); worsened by a hot environment or improved by a cold environment (sensitivity, 0.78; specificity, 0.71; LR, 2.72); not worsened by walking (sensitivity, 0.89; specificity, 0.62; LR, 2.33). The score was calculated as the number (0 to 4) of the above criteria validated by the patient, with a threshold level of >3, it was shown to have a high specificity (0.95) and a fair sensitivity (0.75) for CVD. Factor analysis showed the construct validity of the score, and consistent results were found in the validation series. CONCLUSION: The clinical relevance of this scoring system remains to be evaluated prospectively in standard clinical conditions. However, these results already document that venous symptoms can be differentiated from leg symptoms of other origins.

Ultrasound assessment of salivary glands in patients with primary Sjögren's syndrome treated with rituximab: Quantitative and Doppler waveform analysis.

OBJECTIVES: Noninvasive objective tests are needed to diagnose primary Sjogren's syndrome (pSS) and to evaluate treatment responses. Ultrasound imaging of the salivary glands is rapid and noninvasive. Recent open-label studies suggested that anti-CD20 (rituximab) may be effective in pSS. The purpose of this study was to look for ultrasound evidence of the effects of rituximab in pSS. METHODS: We compared 16 patients fulfilling the new American-European consensus group criteria for pSS to 9 controls, using B-mode ultrasound features (parenchymal homogeneity and gland size) and Doppler waveform analysis of the transverse facial artery of parotid glands. We compared the same parameters in the patients before and after 12 weeks of intravenous rituximab therapy. RESULTS: Compared to controls, untreated patients had significant abnormalities in salivary gland structure (p < 0.0001) and parotid size (2.05 +/- 0.33 cm versus 1.70 +/- 0.28 cm; p = 0.001). Doppler waveform analysis showed significant differences before, but not after, lemon stimulation between untreated patients and controls. After rituximab treatment, significant size reductions were noted in the parotids (2.05 +/- 0.3 cm at baseline and 1.86 +/- 0.27 cm at week 12; p = 0.002) and submandibular glands (2.02 +/- 0.54 cm at baseline and 1.66 +/- 0.34 cm at week 12; p = 0.001). Doppler resistive indices after lemon stimulation were significantly increased after rituximab treatment. CONCLUSION: Salivary gland measurements and blood inflow responses to salivary stimulation as assessed by ultrasound hold promise as objective noninvasive tools for evaluating rituximab effects in patients with pSS.

Diagnostic value of a negative single complete compression ultrasound of the lower limbs to exclude the diagnosis of deep venous thrombosis in pregnant or postpartum women: a retrospective hospital-based study.

OBJECTIVE: We aimed at determining whether a negative single complete compression ultrasonography (CUS) of the lower limbs veins is a safe and accurate diagnostic method to rule out the diagnosis of deep venous thrombosis in pregnant and early postpartum women. DESIGN: Hospital-based retrospective study. SETTING: The gynaecology and vascular ultrasound units of three general hospitals in western France. PATIENTS: We identified from the hospitals databases all pregnant or up to three months postpartum women who underwent CUS for a suspicion of deep venous thrombosis between January 2002 and December 2004. METHODS: Questionnaires were sent to all women with a negative CUS. Their medical records were also checked. MAIN OUTCOME MEASURES: We assessed the three-month thromboembolic risk and its 95% percent confidence interval in women left untreated on the basis of a negative single complete CUS of the lower limbs. RESULTS: During the study period, 162 pregnant or postpartum women underwent CUS for a suspicion of deep venous thrombosis. It was positive in 44 (27%). The 118 women who had a negative CUS were sent the questionnaire. Information about the three-month follow-up was found for 107 patients (91%). None of them experienced a thromboembolic event during follow-up: 0.0% (95% CI: 0.0-3.6). CONCLUSIONS: Single complete CUS of lower limbs veins appears to be a safe method to rule out the diagnosis of deep venous thrombosis in pregnant or early postpartum women. This has to be confirmed by a prospective management study with a formal follow-up.

Concordance rate differences of 3 noninvasive imaging techniques to measure carotid stenosis in clinical routine practice: results of the CARMEDAS multicenter study.

BACKGROUND AND PURPOSE: To replace digital subtraction angiography (DSA) in carotid stenosis evaluation, noninvasive imaging techniques have to reach a high concordance rate. Our purpose is to compare the concordance rates of contrast-enhanced MR angiography (CEMRA) and CT angiography (CTA) with Doppler ultrasound (DUS) in clinical routine practice. METHODS: We evaluated prospectively with DUS, CEMRA, and CTA 150 patients suspected of carotid stenosis. The overall concordance rates of the 3 techniques were calculated for symptomatic stenosis > or =50% and > or =70%, for asymptomatic stenosis > or =60%, and for occlusion. For the carotid arteries treated by surgery (n=97), the results of each method and combined techniques were recorded, and misclassification rates were evaluated from surgical reports. RESULTS: The overall concordance rates of DUS-CEMRA, DUS-CTA, and CEMRA-CTA were not statistically different. However, the concordance rate of DUS-CEMRA (92.53%) was significantly higher than that for DUS-CTA (79.10%) in the surgical asymptomatic stenosis group (P=0.0258). CTA considered alone would misclassify the stenosis in a significant number of cases (11 of 64) in the surgical asymptomatic group compared with CEMRA (3 of 67) and DUS (1 of 66) (P=0.0186 versus MRA, P=0.0020 versus DUS). CONCLUSIONS: With the techniques as utilized in our study, the overall concordance rates of combined noninvasive methods are similar for measuring carotid stenosis in clinical routine practice, but in asymptomatic carotid stenosis, the decision making for surgery is significantly altered if DUS and CTA are considered in place of DUS and CEMRA.

High prevalence of asymptomatic deep vein thrombosis on admission in a medical unit among elderly patients.

The prevention of venous thromboembolism in medical patients remains questioned. All consecutive outpatients admitted in our medical unit were considered for inclusion in this study which aimed to estimate the prevalence of asymptomatic venous thrombosis on admission and the incidence during hospital stay. Exclusion criteria were: age <18 years, suspicion of venous thromboembolism, stay <4 days, ongoing anticoagulant therapy. Venous compression ultrasonography of the lower limbs was performed within 48 h. 234 patients were included. The prevalence of asymptomatic deep vein thrombosis on admission and the incidence during hospital follow-up were respectively 5.5% (95% confidence interval, 3.1 to 9.5%) and 2.6 per 1,000 person-days (95% confidence interval, 0.0 to 5.2). The prevalence and the incidence reached respectively 17.8% (95% confidence interval, 8.5 to 32.6%) and 6.0 per 1,000 person-days (95% confidence interval, 0.0 to 12.7) among patients over 80 years. A high prevalence of asymptomatic deep vein thrombosis on admission was suggested particularly among elderly medical patients.