Ultrasound Evaluation of the Lower Extremity Veins

Pulmonary embolism induces pneumonia-like lung injury beyond pulmonary infarction

Patients with pulmonary embolism (PE) commonly manifest concomitant "pneumonia," which is generally believed to be either a cause (infection) or a consequence (infarction) of PE. This study aimed to clarify the relationship between PE and "pneumonia-like" lesions beyond pulmonary infection and infarction. Chest computed tomography (CT) images of patients with PE and deep vein thrombosis (DVT) were retrospectively analyzed to compare the incidence of pneumonia lesions. The pathological damage and wet/dry ratio of lung tissues were observed in PE rats and PE plasma-injected rats. In total, 793 and 914 inpatients were enrolled in the PE and DVT groups, respectively. Pneumonia lesions were observed in 36.9% and 26.3% of patients in the PE and DVT groups, respectively (p < 0.0001). Among PE rats, 33.3% exhibited focal severe lung injury, which closely resembled the pathological damage of community-acquired pneumonia. The wet/dry ratio was significantly higher in the PE group than in the PE-control group (4.98 ± 0.08 vs. 4.39 ± 0.06, p < 0.0001). Among PE plasma-injected rats, individuals with focal proven lung injury were found at all experimental points, with an incidence of 27.6%. The lung wet/dry ratio was significantly higher in the PE plasma group than in the PE-control plasma group at 1 and 2 h postinjection (5.02 ± 0.12 vs. 4.61 ± 0.06 and 4.76 ± 0.16 vs. 4.34 ± 0.09, respectively; p < 0.05). In conclusion, the manifestation of pneumonia lesions in chest CT images was higher among PE patients than among DVT patients. Plasma of PE rats could induce focal pneumonia-like lung injury in healthy rats.

Development and validation of a newly developed nomogram for predicting the risk of deep vein thrombosis after surgery for lower limb fractures in elderly patients

Background

Prevention of deep vein thrombosis (DVT) is indispensable in the treatment of lower limb fractures during the perioperative period. This study aimed to develop and validate a novel model for predicting the risk of DVT in elderly patients after orthopedic surgeries for lower limb fractures.

Methods

This observational study included 576 elderly patients with lower limb fractures who were surgically treated from January 2016 to December 2018. Eleven items affecting DVT were optimized by least absolute shrinkage and selection operator regression analysis. Multivariable logistic regression analysis was performed to construct a predictive model incorporating the selected features. C-index was applied to evaluate the discrimination. Decision curve analysis was employed to determine the clinical effectiveness of this model and calibration plot was applied to evaluate the calibration of this nomogram. The internal validation of this model was assessed by bootstrapping validation.

Results

Predictive factors that affected the rate of DVT in this model included smoking, time from injury to surgery, operation time, blood transfusion, hip replacement arthroplasty, and D-dimer level after operation. The nomogram showed significant discrimination with a C-index of 0.919 (95% confidence interval: 0.893-0.946) and good calibration. Acceptable C-index value could still be reached in the interval validation. Decision curve analysis indicated that the DVT risk nomogram was useful within all possibility threshold.

Conclusion

This newly developed nomogram could be used to predict the risk of DVT in elderly patients with lower limb fractures during the perioperative period.

Incidence of lower limb deep vein thrombosis in patients with COVID-19 pneumonia through different waves of SARS-CoV-2 pandemic: A multicenter prospective study

OBJECTIVE

The aim of this study was to evaluate the incidence of deep vein thrombosis (DVT) of the lower limbs in patients hospitalized with COVID-19 pneumonia in a non-ICU setting according to the different waves of the SARS-CoV-2 pandemic.

METHODS

Multicenter, prospective study of patients with COVID-19 pneumonia admitted to Internal Medicine units in Italy during the first (March-May 2020) and subsequent waves (November 2020 -April 2021) of the pandemic using a serial compression ultrasound (CUS) surveillance to detect DVT of the lower limbs.

RESULTS

Three-hundred-sixty-three consecutive patients were enrolled. The pooled incidence of DVT was 8%: 13.5% in the first wave, and 4.2% in the subsequent waves (p = 0.002). The proportion of patients with early (< 4 days) detection of DVT was higher in patients during the first wave with respect to those of subsequent waves (8.1% vs 1.9%; p = 0.004). Patients enrolled in different waves had similar clinical characteristics, and thrombotic risk profile. Less patients during the first wave received intermediate/high dose anticoagulation with respect to those of the subsequent waves (40.5% vs 54.5%; p = 0.005); there was a significant difference in anticoagulant regimen and initiation of thromboprophylaxis at home (8.1% vs 25.1%; p<0.001).

CONCLUSIONS

In acutely ill patients with COVID-19 pneumonia, the incidence of DVT of the lower limbs showed a 3-fold decrease during the first with respect to the subsequent waves of the pandemic. A significant increase in thromboprophylaxis initiation prior to hospitalization, and the increase of the intensity of anticoagulation during hospitalization, likely, played a relevant role to explain this observation.

Assessment of venous Doppler ultrasound findings of acute unilateral lower limb swelling in a tertiary facility in central Ghana: a retrospective analytical study

Background

Unilateral lower limb swelling has wide differential diagnoses with varying treatment plans, requiring an early and accurate diagnosis. Doppler ultrasound offers an extensive examination of the vascular system providing a platform for diagnosis and avoidance of unnecessary invasive procedures. Thus, it becomes pertinent to ensure that all the sonographic information required for the accurate diagnosis of a swollen lower limb is documented and critically analyzed in our setting, hence this study.

Results

The records of a total of 151 patients with acute unilateral lower limb swelling were retrieved, females constituted the majority (51.7%). The overall mean age was 58.70 ± 16.71 years. Statistical significance was specified at p ≤ 0.05 for this study. The males were on the average 1.86 years younger than the female, but this difference was not statistically significant (p = 0.495). Patients older than 60 years constituted the majority 72 (47.7%) followed by the 40–60-year age category 61 (40.4%), and the left lower limb was affected more often 82 (54.3%). Multiple inguinal lymphadenopathy 82 (35.7%) and edema with thickened skin and subcutaneous layers 67 (29.1%) were the two most recurrent ultrasound features. There was no significant association between the sonographic features and the diagnoses made for acute unilateral lower limb swelling, except for the feature of edema with thickened skin and subcutaneous layers (p = 0.004) and the diagnosis of cellulitis (p = 0.047) that increased significantly with age.

Conclusion

Multiple inguinal lymphadenopathy and edema of the skin and subcutaneous layers were the most recurrent ultrasound features with cellulitis as the main diagnosis for acute unilateral lower limb swelling in our setting. Edema with thickened skin and subcutaneous layers and cellulitis both increased significantly with age. Sonographers, sonologists, and radiologists must be on the look-out for these in their practices.

Diagnosis and Treatment of Deep Vein Thrombosis in the Emergency Department: Results of an Italian Nominal Group Technique Study

Early diagnosis and treatment of deep vein thrombosis (DVT) is a main issue in the Emergency setting. With the aim of assisting clinicians in the diagnosis and the subsequent management of DVT in the Emergency Departments, a Nominal Group Technique (NGT) study was conducted. A panel of 5 Italian experts developed 21 consensus statements based on available evidence and their clinical experience. The agreed consensus statements may assist clinicians in applying the results of clinical studies and clinical experience to routine care settings, providing guidance on all aspects of the risk assessment, prophylaxis, early diagnosis and appropriate treatment of DVT in the EDs.

Construction and Validation of a Nomogram for Predicting the Risk of Deep Vein Thrombosis in Hepatocellular Carcinoma Patients After Laparoscopic Hepatectomy: A Retrospective Study

Background

The incidence of deep vein thrombosis (DVT) in hepatocellular carcinoma (HCC) patients after laparoscopic hepatectomy (LH) is unclear, and there is no effective method for DVT risk assessment in these patients.

Methods

The data from the total of 355 consecutive HCC patients who underwent LH were included. A DVT risk algorithm was developed using a training set (TS) of 243 patients, and its predictive performance was evaluated in both the TS and a validation set (VS) of 112 patients. The model was then used to develop a DVT risk nomogram (TRN).

Results

The incidence of DVT in the present study was 18.6%. Age, sex, body mass index (BMI), comorbidities and operative position were independent risk factors for DVT in the TS. The model based on these factors had a good predictive ability. In the TS, it had an area under the receiver operating characteristic (AUC) curve of 0.861, Hosmer-Lemeshow (H-L) goodness of fit p value of 0.626, sensitivity of 44.4%, specificity of 96.5%, positive predictive value (PPV) of 74.1%, negative predictive value (NPV) of 88.4%, and accuracy of 86.8%. In the VS, it had an AUC of 0.818, H-L p value of 0.259, sensitivity of 38.1%, specificity of 98.9%, PPV of 88.9%, NPV of 87.4%, and accuracy of 87.5%. The TRN performed well in both the internal and the external validation, indicating a good clinical application value. The TRN had a better predictive value of DVT than the Caprini score (p < 0.001).

Conclusion

The incidence of DVT after LH was high, and should not be neglected in HCC patients. The TRN provides an efficacious method for DVT risk evaluation and individualized pharmacological thromboprophylaxis.

Incidence of deep vein thrombosis through an ultrasound surveillance protocol in patients with COVID-19 pneumonia in non-ICU setting: A multicenter prospective study

Objective

The aim of this study was to assess the incidence of deep vein thrombosis (DVT) of the lower limbs, using serial compression ultrasound (CUS) surveillance, in acutely ill patients with COVID-19 pneumonia admitted to a non-ICU setting.

Methods

Multicenter, prospective study of patients with COVID-19 pneumonia admitted to Internal Medicine units. All patients were screened for DVT of the lower limbs with serial CUS. Anticoagulation was defined as: low dose (enoxaparin 20–40 mg/day or fondaparinux 1.5–2.5 mg/day); intermediate dose (enoxaparin 60–80 mg/day); high dose (enoxaparin 120–160 mg or fondaparinux 5–10 mg/day or oral anticoagulation). The primary end-point of the study was the diagnosis of DVT by CUS.

Results

Over a two-month period, 227 consecutive patients with moderate-severe COVID-19 pneumonia were enrolled. The incidence of DVT was 13.7% (6.2% proximal, 7.5% distal), mostly asymptomatic. All patients received anticoagulation (enoxaparin 95.6%) at the following doses: low 57.3%, intermediate 22.9%, high 19.8%. Patients with and without DVT had similar characteristics, and no difference in anticoagulant regimen was observed. DVT patients were older (mean 77±9.6 vs 71±13.1 years; p = 0.042) and had higher peak D-dimer levels (5403 vs 1723 ng/mL; p = 0.004). At ROC analysis peak D-dimer level >2000 ng/mL (AUC 0.703; 95% CI 0.572–0.834; p = 0.004) was the most accurate cut-off value able to predict DVT (RR 3.74; 95%CI 1.27–10, p = 0.016).

Conclusions

The incidence of DVT in acutely ill patients with COVID-19 pneumonia is relevant. A surveillance protocol by serial CUS of the lower limbs is useful to timely identify DVT that would go otherwise largely undetected.

Predictors for the risk and severity of post-thrombotic syndrome in vascular Behçet's disease

OBJECTIVE

Deep vein thrombosis (DVT) of the lower extremities is the most common form of vascular involvement in Behçet disease (BD), frequently leading to post-thrombotic syndrome (PTS) as a disabling complication. We have described the clinical characteristics and predictors of PTS presence among patients with BD and lower extremity DVT. We also used venous Doppler ultrasound (US) examinations in our assessment.

METHODS

Patients with BD (n = 205; 166 men, 39 women; age 39 ± 9.5 years) and a history of DVT were investigated. The Villalta scale was used to assess the presence and severity of PTS. Doppler US examinations were performed within 1 week of the clinical evaluation. The total number of vessels with reflux, thrombi, recanalization, and collateral vessels were calculated.

RESULTS

Of the 205 patients with BD, 62% had had PTS and 18% had had severe PTS. Patients with PTS had had greater reflux (P = .054) and thrombosis (P = .02) scores compared with patients without PTS. Treatment with anticoagulation (AC), immunosuppressive (IS) therapy, or AC combined with IS drugs did not affect the occurrence of PTS. However, patients treated with IS therapy, with or without AC drugs, had a decreased incidence of severe PTS compared with the AC-only group (P = .017). Patients treated with AC plus IS agents also had increased collateral scores compared with patients treated with only IS drugs. Interferon-α use seemed to provide better recanalization scores compared with azathioprine only (1.0 [range, 0-14] vs 2.5 [range, 0-10]; P = .010).

CONCLUSION

Patients with BD and DVT have a high risk of developing severe PTS. IS treatment decreases the development of severe PTS. AC therapy might influence the course of PTS by increasing the collateral scores, and the use of interferon-α also increased recanalization scores. Routine assessment with Doppler US examinations could be helpful in the prediction of severe PTS.

Evaluation of stability of deep venous thrombosis of the lower extremities using Doppler ultrasound

Objective

This study aimed to assess using Doppler ultrasound for analyzing stability of deep venous thrombosis (DVT) of the lower extremities.

Methods

Patients with DVT of the lower extremities who were treated from August 2017 to December 2019 were selected. The patients were divided into stable and unstable groups according to whether thrombus was collected in a filter. Related ultrasound and blood test results were analyzed and compared.

Results

A total of 126 patients with DVT of the lower extremities were included, of whom 74 were in the stable group and 52 were in the unstable group. There were significant differences in the prothrombin time (PT), and lipoprotein alpha, D-dimer, and triglyceride levels between the groups. D-dimer levels >2800 ug/L, smoking, history of venous thrombosis, PT >13.15 s, and body mass index >24.45 kg/m² were independent risk factors for stability of DVT of the lower extremities. The area under the curve with combined detection of DVT was significantly higher than that for body mass index, PT, and D-dimer alone.

Conclusion

Doppler ultrasound may be reliable for analyzing the stability of DVT of the lower extremities. Related strategies targeting risk factors are required for reducing DVT of the lower extremities.

40-MHz high-frequency vector Doppler imaging for superficial venous valve flow estimation

PURPOSE

Doppler ultrasound imaging has been used widely for diagnosing vascular diseases. Recently, vector Doppler imaging (VDI) has been proposed for visualizing the blood flow in all directions to yield more detailed information for estimating flow conditions. Increasing the resolution of VDI is important for the structural mapping of superficial vessels with microstructure. However, VDI that operates under a high-frequency ultrasound (HFUS; >30 MHz) is rare. In this study, a 40-MHz high-frequency VDI (HFVDI) based on ultrafast ultrasound imaging was developed to obtain the vector information of blood flow around the superficial venous valve.

METHODS

The use of HFUS imaging system causes an overload of data acquisition easily. In order to provide sufficient recording time, the frame rate should be reduced. Because the aliasing problem worsens due to a low frame rate when operating Doppler imaging, phase-unwrapping processing methods based on spatial and temporal continuities were applied. Flow phantom experiments were performed to validate the accuracy. In vivo experiments were performed on the valve of superficial veins of healthy volunteers.

RESULTS

The experimental results from the phantom study indicated that the error of velocity estimation was <10% in most cases. Dynamic changes of valve movements and flow conditions (including velocity profiles and vector) were observed. Because of the high resolution of HFVDI, the jet and vortex phenomena were observed between the leaflets and in the sinus pocket, respectively.

CONCLUSIONS

Flow velocities ranging from 2 to 15 mm/s were measured at different locations around the venous valve during the opening and closing phases. All the results indicated that HFVDI has the potential to be a useful tool for vessel duplex scanning.

Prevalence and associations of incidental nonvenous duplex findings discovered during lower extremity venous imaging

OBJECTIVE

Venous duplex imaging defines venous pathology (VP). Unexpected clinically relevant findings are also found but rarely mentioned in the literature. This study aims to define the prevalence of ancillary findings (nonvenous duplex) by study type and venous outcome and subgroup associations with primary study indication and risk factors.

METHODS

Our vascular laboratory database was queried for lower extremity venous duplex studies with comments regarding ancillary findings and associated patient demographics, primary study indication, associated conditions, and venous study outcome.

RESULTS

There were 52,215 venous studies performed, 48,425 to evaluate for venous occlusion (acute/chronic) and 3790 for venous reflux. Of these studies, 15,810 found VP and 36,405 found no venous disease. There were 875 studies with venous disease that had ancillary duplex findings (5.5%) noted as 559 (3.5%) with prominent lymph node(s) (LN), 179 (1.1%) Baker's cyst (BC), 44 (0.3%) hematoma/mass (HM), 31 (0.2%) arterial aneurysm, and 16 (0.1%) arterial occlusion. There were 3130 studies free of VP with ancillary findings (8.6%) noted as 2258 (6.2%) prominent LN(s), 626 (1.7%) BC, 156 (0.4%) HM, 37 (0.1%) arterial aneurysm, and 22 (0.06%) arterial occlusion. The overall prevalence of ancillary findings was 8.62%. Analysis demonstrated statistically more ancillary findings in venous occlusion (odds ratio [OR], 1.25) studies, which was the largest group at 13 to 1. Studies free of venous disease had more ancillary findings (P < .001) with an OR of 1.88 and similar results were noted for LN(s), BC, and hematoma. Studies with VP favored a finding of aneurysm (OR, 0.52). Subgroup analyses demonstrated that those with prominent LN(s) were statistically older and male and BC statistically older in those with coexistent venous disease. BC subgroup analysis showed that studies free of venous disease were 2.5 times more likely to report pain as the primary study indication (P < .0001). In general, within ancillary subgroups, leg symptoms were statistically more prominent on the side with ancillary pathology and free of venous disease.

CONCLUSIONS

Ancillary findings are not uncommon and are more common in studies found free of VP. The most common are LNs, BC and HM and, within subgroups, significant leg symptoms favors the presence of ancillary findings without coexisting venous disease. Ancillary findings should be an integral part of a quality report.

Not all deep vein thrombosis is created equal: Incidence of preexisting chronic deep vein thrombosis among high-risk traumatized patients

BACKGROUND

Traumatized patients are at risk of developing deep vein thrombosis (DVT) and DVT prophylaxis is the standard of care. The Centers for Medicare and Medicaid Services classifies DVT as a hospital-acquired condition and can deny payment for treatment of DVT and, in addition, place financial penalties on hospitals with higher than acceptable rates of DVT, unless the DVT was preexisting. We sought to determine the rate of preexisting chronic DVT among symptomatic traumatized inpatients at our ACS-verified Level 1 trauma center.

METHODS

Retrospective review of all traumatized patients admitted for >48 hours over a 7-year study period ending December 2016. Patients who had undergone lower extremity duplex ultrasound (LEDUS) were reviewed further to evaluate the results of these tests. Patients were classified as having either no DVT, acute DVT, or chronic (preexisting) DVT based on sonographic characteristics. Incidence, patient demographics, injury severity and outcomes were compared for patients with and without DVT and also for patients with acute and chronic DVT.

RESULTS

Five thousand five hundred forty-three patients met inclusion criteria. Of those, 391 (7.0%) had undergone at least one LEDUS for suspicion of DVT. Deep vein thrombosis was diagnosed in 64 (16%) of the patients undergoing LEDUS and thus 1.1% of the entire population had symptomatic DVT diagnosed during admission. Of the 64 patients with DVT, sonographic characteristics classified 56 (87.5%) as "acute." 6 (9%) as "chronic" (preexisting) and 2 (3.5%) as "indeterminate." Among the six patients found to have a preexisting DVT only three (50%) acknowledged a history of DVT.

CONCLUSION

In the absence of routine DVT surveillance almost 10% of traumatized patients diagnosed with DVT likely have chronic preexisting DVT that is unknown to the patient in 50% of cases. This has significant financial implications for hospitals.

LEVEL OF EVIDENCE

Epidemiologic/Prognostic, level III.

Respiratory variability of peak velocities in the common femoral vein estimated with vector flow imaging and Doppler ultrasound

Respiratory variability of peak velocities (RVPV) in the common femoral vein measured with ultrasound can reveal venous outflow obstruction. Pulse wave (PW) Doppler is the gold standard for venous velocity estimation of the lower extremities. PW Doppler measurements are angle dependent, whereas vector flow imaging (VFI) can yield angle-independent measures. The hypothesis of the present study was that VFI can provide RVPV estimations without the angle dependency of PW Doppler for an improved venous disease assessment. Sixty-seven patients with symptomatic chronic venous disease were included in the study. On average, VFI measured a lower RVPV than PW Doppler (VFI: 14.11 cm/s; PW: 17.32 cm/s, p = 0.002) with a non-significant improved precision compared with PW Doppler (VFI: 21.09%; PW: 26.49%, p = 0.08). In a flow phantom, VFI had improved accuracy (p < 0.01) and equal precision compared with PW Doppler. The study indicated that VFI can characterize the hemodynamic fluctuations in the common femoral vein.

Frequency and Significance of Perforating Venous Insufficiency in Patients with Chronic Venous Insufficiency of Lower Extremity

OBJECTIVE

The aim of this study was to reveal the frequency and impact of perforating venous insufficiency (PVI) in chronic venous insufficiency (CVI) of lower extremity (LE).

MATERIALS AND METHODS

Between 2012 and 2017, a total of 1154 patients [781 females (67.68%) and 373 males (32.32%), 228 (19.76%) unilateral and 926 (80.24%) bilateral LE] were examined using Doppler ultrasound (US). A total of 2080 venous systems of LEs [31.4% male (n=653) and 68.6% female (n=1427); 1056 left LEs (50.77%) and 1024 right LEs (49.23%)] were examined. All patients had symptoms of venous insufficiency (VI).

RESULTS

PVI was revealed in 27.5% (n=571) of LEs. Varicose veins (VVs) related with perforating vein (PV) were revealed in 44.7% of LEs (n=929). PVI was observed in 50.91% of patients with chronic deep venous thrombosis (DVT), 64.41% with deep venous insufficiency (DVI), 59.81% with great saphenous vein (GSV) insufficiency, 68.49% with small saphenous vein (SSV) insufficiency, 58.65% with accessory GSV insufficiency, and 58.77% with PV associated with VVs. There was a statistically significant relationship between PVI and chronic DVT, DVI, GSV, SSV, and accessory GSV insufficiency (p<0.001). A significant relationship was observed between the increase in PV diameter and the presence of PVI (p<0.001).

CONCLUSION

PVI is quite common in combined VI, and PV evaluation should be a part of LE venous system examination.

Experience of Using Shear Wave Elastography Imaging in Superficial Venous Insufficiency of the Lower Extremity

We investigated the effectiveness of shear wave elastography (SWE) in patients with lower extremity superficial venous insufficiency (VI). A total of 138 symptomatic patients, 51 asymptomatic volunteers, and a total of 359 lower extremities (257 symptomatic, 102 asymptomatic) were examined. All participants underwent Doppler ultrasound (US) evaluation to determine VI and SWE measurements performed by manually drawing vein wall and perivenous tissue with free region of interest at the great saphenous vein (GSV) and small saphenous vein (SSV). The GSV, SSV diameter, VI, and volume flow of reflux were compared with the SWE values. The SWE values of the symptomatic group for GSV and SSV were significantly higher than those of the asymptomatic control group regardless of whether VI was detected by Doppler US (P < 0.001). There was a statistically significant increase in SWE values for the symptomatic group who were diagnosed as having reflux in GSV and SSV (P < 0.001). A significant positive correlation between increased GSV, SSV diameter, and SWE values was seen (P < 0.001). Venous insufficiency can be diagnosed with a 84.7% sensitivity and 84.2% specificity when 2655 m/s was designated as cutoff value, and with a 85.4% sensitivity and 84.2% specificity when 22,350 kPa was designated as the cutoff value in GSV. Venous insufficiency can be diagnosed with a 84.3% sensitivity and 82.4% specificity when 2845 m/s was designated as cutoff value, and with a 85.7% sensitivity and 84.4% specificity when 27,100 kPa was designated as the cutoff value in SSV. Shear wave elastography may be used effectively in addition to conventional Doppler US examination in diagnosing and following VI.

The prevalence of chronic deep venous thrombosis in trauma: Implications for hospitals and patients

INTRODUCTION

Deep venous thrombosis (DVT) is considered a preventable complication in trauma patients. Hospitals risk financial penalties for DVT rates above accepted benchmarks. These penalties do not apply to chronic DVT, which develops before admission. Lower-extremity duplex ultrasound (LEDUS) can detect characteristics of thrombus chronicity, allowing differentiation of chronic from acute DVT. The objective of this study was to determine the prevalence of chronic DVT in hospitalized trauma patients.

METHODS

We performed a retrospective review of trauma patients admitted to our Level I trauma center between July 1, 2006 and October 31, 2016 who had a DVT on initial screening LEDUS. Our center utilizes screening and surveillance LEDUS for patients admitted more than 48 hours. Definitions for chronic and acute DVT were extracted from existing literature. Patients with DVT on initial LEDUS underwent review of that LEDUS to assess clot chronicity and were classified as having acute DVT, chronic DVT, or DVT of indeterminate age. Demographic data, medical history, and injury characteristics were collected. Patients with acute DVT and those with chronic DVT were compared.

RESULTS

The prevalence of chronic DVT among patients with a DVT on initial LEDUS was 29.9%. Chronic DVT occurred in patients who were older and less severely injured. An above-knee component was significantly more common in chronic DVT (65%). Only 34 (41%) of those with chronic DVT reported a history of DVT. Among the patients with chronic DVT, 44 (53%) had a subsequent LEDUS, of whom 4 (9%) showed thrombus progression and 6 (14%) formed a new DVT.

CONCLUSION

Lower-extremity duplex ultrasound can identify chronic DVT, which represents nearly 30% of all DVT found on initial screening LEDUS in trauma patients. Those with chronic DVT should receive pharmacologic and mechanical prophylaxis because of the incidence of progression and new acute DVT. They should also be counseled regarding the possibilities of recurrence and chronic venous insufficiency.

LEVEL OF EVIDENCE

Diagnostic study, level III.

Advanced imaging in acute and chronic deep vein thrombosis

Deep venous thrombosis (DVT) affecting the extremities is a common clinical problem. Prompt imaging aids in rapid diagnosis and adequate treatment. While ultrasound (US) remains the workhorse of detection of extremity venous thrombosis, CT and MRI are commonly used as the problem-solving tools either to visualize the thrombosis in central veins like superior or inferior vena cava (IVC) or to test for the presence of complications like pulmonary embolism (PE). The cross-sectional modalities also offer improved visualization of venous collaterals. The purpose of this article is to review the established modalities used for characterization and diagnosis of DVT, and further explore promising innovations and recent advances in this field.

Doppler ultrasound study and venous mapping in chronic venous insufficiency

Chronic venous insufficiency of the lower limbs is very prevalent. In recent decades, Doppler ultrasound has become the method of choice to study this condition, and it is considered essential when surgery is indicated. This article aims to establish a method for the examination, including venous mapping and preoperative marking. To this end, we review the venous anatomy of the lower limbs and the pathophysiology of chronic venous insufficiency and explain the basic hemodynamic concepts and the terminology required to elaborate a radiological report that will enable appropriate treatment planning and communication with other specialists. We briefly explain the CHIVA (the acronym for the French term "cure conservatrice et hémodynamique de l'insuffisance veineuse en ambulatoire"=conservative hemodynamic treatment for chronic venous insufficiency) strategy, a minimally invasive surgical strategy that aims to restore correct venous hemodynamics without resecting the saphenous vein.

Ultrasonographic findings of the various diseases presenting as calf pain

There are various causes of calf pain. The differential diagnoses affecting the lower leg include cystic lesions, trauma-related lesions, infection or inflammation, vascular lesions, neoplasms, and miscellaneous entities. Ultrasound (US) provide detailed anatomical information of the calf structures, and it offers the ability to confirm, other calf abnormalities, particularly when deep vein thrombosis (DVT) is ruled out. The purpose of this article is to review the causes of a painful calf presenting as DVT and incidental findings found as part of the work-up of DVT, and to provide a broad overview of US findings and clinical features of these pathologies.

Endovascular Interventions for Acute and Chronic Lower Extremity Deep Venous Disease: State of the Art

The societal and individual burden caused by acute and chronic lower extremity venous disease is considerable. In the past several decades, minimally invasive endovascular interventions have been developed to reduce thrombus burden in the setting of acute deep venous thrombosis to prevent both short- and long-term morbidity and to recanalize chronically occluded or stenosed postthrombotic or nonthrombotic veins in symptomatic patients. This state-of-the-art review provides an overview of the techniques and challenges, rationale, patient selection criteria, complications, postinterventional care, and outcomes data for endovascular intervention in the setting of acute and chronic lower extremity deep venous disease. Online supplemental material is available for this article.

Role of B-color and Resolution Sonography Presets for the Diagnosis of Lower Extremity Deep Vein Thrombosis

Sonography is an accurate and commonly used method of determining the presence, location, and acuity of deep vein thrombosis (DVT). A retrospective data analysis of 284 venous examinations was performed to determine if imaging presets increase the ability to detect an acute DVT. There were no significant differences between the outcomes of three modalities of sonographic imaging. If a patient had a prior DVT, the likelihood of observing another DVT using only two-dimensional imaging, resolution presets, or the B-color option was approximately nine times greater than for a patient who did not have a prior DVT. Sex, age, body mass index, ethnicity, and comorbidities of diabetes and/or hypertension were not significant predictors of observing a DVT. Using a resolution-enhancing preset that increases the overall frequency range to reduce artifacts and improve border definition and/or using the B-color preset to tint the overall image did not improve the likelihood of detecting an acute DVT during a lower extremity venous duplex sonogram.

Update on the lower extremity venous ultrasonography examination

Lower extremity venous ultrasonography is an accurate method to diagnose acute deep venous thrombosis (DVT). Recurrent DVT is often difficult diagnosis. The decision to order ultrasonography can be based on pretest risk assessment. If the ultrasonography study is negative, the report may recommend follow-up for patients whose clinical condition changes or for patients with specific risks. Lower extremity venous ultrasonography is the gold standard for diagnosis of DVT. It is accurate and objective, and because the clinical assessment of patients is limited and its potential complication, pulmonary embolism, is significant, the impact of a positive and negative test is high.

Evaluating the Use of a Negative D-Dimer and Modified Low Wells Score in Excluding above Knee Deep Venous Thrombosis in an Outpatient Population, Assessing Need for Diagnostic Ultrasound

Aims. Colour doppler ultrasonography (CDUS) is widely used in the diagnosis of deep venous thrombosis (DVT); however, the number of scans positive for above knee DVT is low. The present study evaluates the reliability of the D-dimer test combined with a clinical probability score (Wells score) in ruling out an above knee DVT and identifying patients who do not need a CDUS. Materials and Method. This study is a retrospective audit and reaudit of a total of 816 outpatients presenting with suspected lower limb DVT from March 2009 to March 2010 and from September 2011 to February 2012. Following the initial audit, a revised clinical diagnostic pathway was implemented. Results. In our initial audit, seven patients (4.9%) with a negative D-dimer and a low Wells score had a DVT. On review, all seven had a risk factor identified that was not included in the Wells score. No patient with negative D-dimer and low Wells score with no extra clinical risk factor had a DVT on CDUS (negative predictive value 100%). A reaudit confirmed adherence to our revised clinical diagnostic pathway. Conclusions. A negative D-dimer together with a low Wells score and no risk factors effectively excludes a lower limb DVT and an ultrasound is unnecessary in these patients.

Lack of spontaneous venous pulsation: possible risk indicator in normal tension glaucoma?

PURPOSE

Recently, the absence of spontaneous venous pulsation (SVP) has been suggested as a vascular risk factor for primary open-angle glaucoma (POAG). As the mechanism behind this phenomenon is still unknown, the authors have studied this vascular component using colour Doppler imaging (CDI).

METHODS

A total of 236 patients were divided into three diagnostic groups: healthy controls (81), POAG (86) and normal tension glaucoma (NTG; 69). All subjects were submitted to CDI studies of the retrobulbar circulation, intraocular pressure measurements and assessment of SVP existence. Mann-Whitney, chi-square contingency tables and Spearman correlations were used to explore differences and correlations between variables in the diagnostic groups.

RESULTS

Eighty-two percent of healthy controls had SVP (66/81), while a smaller numbers were registered in both glaucoma groups: POAG - 50% (43/86); NTG - 51% (35/69). In NTG patients, but not in POAG patients, the prevalence of the SVP phenomenon decreases with increased glaucoma damage (p = 0.04; p = 0.55, respectively). Overall glaucoma patients from both groups had lower central retinal vein (CRV) velocities than the healthy controls (p < 0.05). NTG patients with SVP had less severe visual field defects (mean defect -6.92 versus -11.1, p < 0.05), higher [correction added after online publication 21 September 2012; the word 'higher' has been inserted to replace the word 'lower'] peak systolic and mean flow velocities in the central retinal artery (p < 0.01; p < 0.05, respectively) as well as higher [correction added after online publication 21 September 2012; the word higher has been inserted to replace the word lower] maximal velocities and RI of the CRV (p < 0.02; p < 0.05, respectively).

CONCLUSIONS

Glaucoma patients have a decrease in CRV velocities. SVP is less prevalent in glaucoma patients than in healthy individuals. This phenomenon apparently reflects different hemodynamic patterns in the central retinal vessels. This variable may be of particular importance in NTG patients, where it may be associated with more advanced functional damage.

Venous thromboembolism in an industrial north american city: temporal distribution and association with particulate matter air pollution

BACKGROUND

Emerging evidence, mainly from Europe and Asia, indicates that venous thromboembolism (VTE) occurs most often in winter. Factors implicated in such seasonality are low temperature-mediated exacerbation of coagulation and high levels of particulate matter (PM) air pollution. However, in contrast to most European and Asian cities, particulate matter pollution peaks in the summer in many North American cities.

OBJECTIVES

We aimed to exploit this geographical difference and examine the temporal distribution of VTE in a cold-weather, North American city, Detroit, with a summer PM peak. Our goal was thereby to resolve the influence of temperature and PM levels on VTE.

METHODS

Our retrospective, analytical semi-ecological study used chart review to confirm 1,907 acute, ambulatory VTE cases, divided them by location (Detroit versus suburban), and plotted monthly VTE frequency distributions. We used Environmental Protection Agency data to determine the temporal distribution of PM pollution components in Detroit. Suburban PM air pollution is presumed negligible and therefore not monitored.

RESULTS

Acute VTE cases in Detroit (1,490) exhibited a summer peak (June 24(th)) and differed from both a uniform distribution (P<0.01) and also that of 1,123 no-VTE cases (P<0.02). Levels of 10 µm diameter PM and coarse particle (2.5 to 10 µm) PM also exhibited summer peaks versus a winter peak for 2.5 µm diameter PM. Contrary to their urban counterparts, suburban cases of acute VTE (417) showed no monthly variation.

CONCLUSIONS

The summer peak of acute VTE in Detroit indicates that low temperature is not a major factor in VTE pathogenesis. In contrast, concordance of the 10 µm diameter PM, coarse particle, and the Detroit VTE monthly distributions, combined with no monthly suburban VTE variation, is consistent with a role for PM pollution. Furthermore, divergence of the VTE and 2.5 µm PM distributions suggests that particle size may play a role.

Deep vein thrombosis in orthopedic surgery of the lower extremities

To prevent pulmonary embolism due to deep venous thrombosis (DVT), we have treated 611 patients undergoing orthopedic surgery of the lower extremities with our protocol including pre- and postoperative ultrasonic venous screening and anticoagulant therapy if necessary. A total of 118 patients (19.3%) developed DVT. Among demographic and clinical factors, the site of operation (knee joint surgery: odds ratio 5.17), age (>60: odds ratio 3.91), and operation time (>120 minutes: odds ratio 4.52) were identified as significant risk factors of development of DVT. One patient received an infusion of urokinase for DVT of femoral vein, but no patients developed serious postoperative bleeding or pulmonary thromboembolisms. (*English Translation of J Jpn Coll Angiol, 2010, 50: 95-100.).

ACR Appropriateness Criteria(®) on suspected lower extremity deep vein thrombosis

Lower extremity deep vein thrombosis (DVT) is a common clinical concern, with an incidence that increases with advanced age. DVT typically begins below the knee but may extend proximally and result in pulmonary embolism. Pulmonary embolism can occur in 50% to 60% of patients with untreated DVT and can be fatal. Although clinical examination and plasma d-dimer blood evaluation can often predict the presence of DVT, imaging remains critical for the diagnostic confirmation and treatment planning of DVT. Patients with above-the-knee or proximal DVT have a high risk for pulmonary embolism and are recommended to receive anticoagulation therapy. On the other hand, patients with below-the-knee or distal DVT rarely experience pulmonary embolism, and anticoagulation therapy in these patients remains controversial. However, one sixth of patients with distal DVT may experience extension of their thrombus above the knee and therefore are recommended to undergo serial imaging assessment at 1 week to exclude proximal DVT extension if anticoagulation therapy is not initiated. Ultrasound is the preferred imaging method for evaluation of patients with newly suspected lower extremity DVT. Magnetic resonance and CT venography can be especially helpful for the evaluation of suspected DVT in the pelvis and thigh. Contrast x-ray venography, the historic gold standard for DVT assessment, is now less commonly performed and primarily reserved for patients with more complex presentations such as those with suspected recurrent acute DVT.

Diagnosis and management of life-threatening pulmonary embolism

Pulmonary embolus (PE) is estimated to cause 200 000 to 300 000 deaths annually. Many deaths occur in hemodynamically unstable patients and the estimated mortality for inpatients with hemodynamic instability is between 15% and 25%. The diagnosis of PE in the critically ill is often challenging because the presentation is nonspecific. Computed tomographic pulmonary angiography appears to be the most useful study for diagnosis of PE in the critically ill. For patients with renal insufficiency and contrast allergy, the ventilation perfusion scan provides an alternative. For patients too unstable to travel, echocardiography (especially transesophageal echocardiography) is another option. A positive result on lower extremity Doppler ultrasound can also aid in the decision to treat. The choice of treatment in PE depends on the estimated risk of poor outcome. The presence of hypotension is the most significant predictor of poor outcome and defines those with massive PE. Normotensive patients with evidence of right ventricular (RV) dysfunction, as assessed by echocardiography, comprise the sub-massive category and are at intermediate risk of poor outcomes. Clinically, those with sub-massive PE are difficult to distinguish from those with low-risk PE. Cardiac troponin, brain natriuretic peptide, and computed tomographic pulmonary angiography can raise the suspicion that a patient has sub-massive PE, but the echocardiogram remains the primary means of identifying RV dysfunction. The initial therapy for patients with PE is anticoagulation. Use of vasopressors, inotropes, pulmonary artery (PA) vasodilators and mechanical ventilation can stabilize critically ill patients. The recommended definitive treatment for patients with massive PE is thrombolysis (in addition to anticoagulation). In massive PE, thrombolytics reduce the risk of recurrent PE, cause rapid improvement in hemodynamics, and probably reduce mortality compared with anticoagulation alone. For patients with a contraindication to anticoagulation and thrombolytic therapy, surgical embolectomy and catheter-based therapies are options. Thrombolytic therapy in sub-massive PE results in improved pulmonary perfusion, reduced PA pressures, and a less complicated hospital course. No survival benefit has been documented, however. If one is considering the use of thrombolytic therapy in sub-massive PE, the limited documented benefit must be weighed against the increased risk of life-threatening hemorrhage. The role of surgical embolectomy and catheter-based therapies in this population is unclear. Evidence suggests that sub-massive PE is a heterogeneous group with respect to risk. It is possible that those at highest risk may benefit from thrombolysis, but existing studies do not identify subgroups within the sub-massive category. The role of inferior vena cava (IVC) filters, catheter-based interventions, and surgical embolectomy in life-threatening PE has yet to be completely defined.

An adolescent with lower-extremity swelling

Lower-extremity swelling is an uncommon presentation in a pediatric emergency department. Deep venous thrombosis is one of the common differential diagnoses in a patient with an underlying predisposing factor. We report a case of a previously healthy adolescent without any risk factor for thromboembolism presented with deep venous thrombosis. The pertinent literature is reviewed.

Non-compressibility ratio of sonography in deep venous thrombosis

BACKGROUND

The risk of post-thrombotic syndrome and pulmonary embolism can be increased if there is failure to diagnose deep venous thrombosis (DVT) promptly. Emergency physicians (EPs) need a quick and readily available test to diagnose, treat and help them decide whether to discharge or admit DVT patients in a timely manner. The aim of this study was to investigate the value of the non-compressibility ratio of thrombosed veins in DVT patients, and give EPs an objective value to aid them in their decision-making with regard to DVT patients in the emergency department.

METHODS

We reviewed 34 adult patients with DVT diagnosed by sonography in an emergency department. Medical records including demographic data and sonography results were retrospectively reviewed and analyzed.

RESULTS

Mean age was 72.9 ± 16.5 years. Group I comprised 14 patients (41.2%) who had DVT in the popliteal and femoral veins. Group II comprised 8 patients (23.5%) who had DVT isolated to the popliteal vein and 12 patients (35.3%) who had DVT isolated to the femoral vein. Group I had a significantly higher non-compressibility ratio than Group II (93.4 ± 6.2% vs. 80.1 ± 19.2%, p < 0.05). The area under the receiver operating characteristic curve of the non-compressibility ratio between discriminating groups was 0.711 (95% confidence interval, 0.527-0.854; p < 0.05). The clinical prognostic score of Group I was significantly higher than that of Group II (6.2 ± 1.8 vs. 4.1 ± 2.6, p < 0.05). There was a significant positive correlation between the non-compressibility ratio of the thrombosed vein and the clinical prognostic score (p = 0.001).

CONCLUSION

The non-compressibility ratio of the thrombosed vein provides EPs with an objective test to evaluate the severity of DVT and to admit patients for consideration of adverse outcomes.

Clinically significant thromboembolic disease in orthopedic oncology: an analysis of 986 patients treated with low-molecular-weight heparin

BACKGROUND AND OBJECTIVES

Thromboembolic risk in orthopedic oncology is high due to several factors. The aim of this study was to assess clinically significant thromboembolic disease in 986 patients operated on with a prosthetic reconstruction of the lower limbs after the resection of bone tumors and prophylactically treated with low-molecular-weight heparin (LMWH).

METHODS

Between 1983 and 2006, 986 patients had uncemented megaprostheses after a resection of the lower limbs for bone tumors. Antithromboembolic prophylaxis was always administered with LMWH from the immediate postoperative time until the time of complete weight-bearing. Phlebographies and vascular ecodoppler were not performed postoperatively on a regular basis. Patients were followed in the clinic with imaging studies for several years (lower limb CT, MRI, CT of the chest for malignant tumors). The diagnosis of symptomatic venous thromboembolism (VTE) was established or excluded on clinical evidence and MRI study.

RESULTS

Among the 986 cases treated, only 11 patients (1.1%) showed a major thromboembolic event confirmed clinically and through imaging. One of these patients died with pulmonary embolism a few days after surgery. Two cases of thromboembolism occurred in patients with a vascular bypass.

CONCLUSIONS

Despite general oncologic and orthopedic factors favoring VTE, the clinical occurrence of this event was extremely low in this series, probably due to a consistent and careful prophylaxis, prolonged until the time of complete weight-bearing.

Ultrasound in evaluation of post-interventional femoral vein obstruction: a case report

Ultrasound is the preferred imaging modality in diagnosis of vascular complications following cardiac catheterization and intervention. In some cases, however, bleeding surrounding the femoral vessels, may severely distort the color Doppler images, making detection of venous complications especially difficult. This report refers to such a case where post-catheterization haematoma was suspected to cause an obstruction of the femoral vein. Spectral Doppler recordings of blood flow in the common femoral vein, up-stream, distal to the hemorrhagic area, confirmed the diagnosis of obstruction by demonstrating changes in the venous flow pattern in the common femoral vein, consistent with venous hypertension. Due to the poor quality of the ultrasound images, the exact cause of the obstruction had to be established by another imaging modality, not affected by haemorrhages. CT showed that the common femoral vein was compressed at the puncture site by surrounding haemorrhages. Thus, when bleeding due to cardiac catheterization is associated with possible venous obstruction and findings by color Doppler are equivocal due to degradation of the color-Doppler image, detection of venous hypertension by spectral Doppler, performed distal to the bleeding area, strongly supports the presence of venous obstruction where the exact cause may be established by CT.

The medical Doppler in hand surgery: its scientific basis, applications, and the history of its namesake, Christian Johann Doppler

The word Doppler is used synonymously in hand surgery for evaluating patency of vascular structures; however, the science and history behind the Doppler effect are not as well-known. We will present the theories behind the Doppler effect and the history of the person who made this discovery.