Lower Extremity Venous Duplex Scans Research Articles

Тромбоз вен нижних конечностей и его последствия в восстановительном периоде инсульта

Post-stroke lower extremity vein thrombosis can be the reason behind complications of embolic nature and death. This study aimed to investigate the influence of provoking factors, frequency and localization of acute thrombosis, post-thrombotic changes in the lower extremity veins during stroke recovery period. The study involved 1315 patients, 885 (67.3%) male and 430 (32.7%) female, ages 18–94 years, mean age 59.23 ± 13.7 years. All participants underwent lower extremity venous duplex scanning in the early and late stages of stroke recovery period. We found no evidence of interconnections between presence of signs of thrombosis and/or its consequences and the pathogenetic variant of stroke the patient had. Acute deep vein thrombosis was diagnosed significantly more often (p < 0.05) in the early stage of stroke recovery period. The frequency of acute lower extremity vein thrombosis was 7.8%, post-thrombotic changes — 5.6%. Isolated lesion of the lower leg veins was the most common complication associated with deep veins (49.6%). We have discovered a significant relationship between the side of lower extremity paresis (plegia) of and the side of deep vein thrombosis (p < 0.001). No relationship was found between lower extremity superficial and deep vein thrombosis and use of anticoagulants and antiplatelet agents (p > 0.05). Excess body weight was associated with damage to the lower extremity proximal veins (p < 0.05). Women had lower extremity vein thrombosis significantly more often (p < 0.05). Repeated lower extremity venous duplex scanning upon admission to the rehabilitation hospital allowed reducing the risk of venous thromboembolic complications that may develop during the stroke recovery period.

Prevalence of deep vein thrombosis in heparin prophylaxis patients in general surgery department

Introduction: One of the complications of surgery operation is deep vein thrombosis. Because of its dangerous side effects, it is important to prevent it. The purpose of this study was to determine the incidence of deep venous thrombosis in patients with DVT-associated risk factors Methods: This cross-sectionalstudy was performed on 100 patients at high risk for probability of DVT incidence in accordance with the known risk factors of the attached checklist over one-year interval in the General Surgery Department of Imam Reza hospital. All patients underwent lower extremity bandages during operation and prophylaxis with 5,000 units of subcutaneous heparin every 8 hours after surgery. At day-3 after the operation, the Color Doppler Ultrasound of the lower extremity and the evaluation of Iliac and Femoral and Popliteal venous system in two sides (bilateral) were performed.Descriptive statistics were reported in this study. Results: Incidence of DVT after surgery was evaluated in one hundred high-risk patients underwent heparin prophylaxis for one year. Both sides of lower extremity venous Duplex Scan was performed on the third day after surgery operation. Only one case with partial subclinical thrombosis of the right femoral vein was found. Meanwhile, heparin did not have any complications. Conclusions: Although the study seems to require a larger sample size for more accurate evaluations, given the fact that all patients were considered to be at high risk for DVT, the final result for one-percent of DVT incidence in this statistic community can be extended to larger communities with further studies.

Modification of Step Ladder with Handrail for The Lower Extremity Venous Duplex Scanning

Modification of Step Ladder with Handrail for The Lower Extremity Venous Duplex Scanning

The Impact of Epidural Analgesia on the Rate of Thromboembolism without Chemical Thromboprophylaxis in Major Oncologic Surgery

Patients with abdominopelvic cancers are at increased risk of venous thromboembolism (VTE) due to their malignancy. We evaluated outcomes and the rate of VTE in patients undergoing abdominopelvic surgery for malignancy with preoperative epidural analgesia without postoperative chemical VTE prophylaxis. A retrospective review between 2009 and 2015 identified 285 patients with malignancy who underwent abdominopelvic surgery by a single surgeon (AWS). Lower extremity venous duplex scans (VDS) were performed preoperatively and before discharge. Demographics, procedures, and VTE outcomes were reviewed. The median age was 66 years. The average operative time was 315 minutes. All patients ambulated on postoperative day (POD) one or two. Epidural catheters (ECs) were removed on postoperative day four or five. No patient received VTE prophylaxis while an epidural catheter was in place. Preoperative lower extremity VDS revealed above-knee deep vein thrombosis (DVT) in seven patients (2.5%). Postoperative lower extremity VDS revealed acute DVT in 24 patients (8.4%): nine (3.2%) above-knee and 15 (5.2%) below-knee. The nine patients with above-knee DVT were anticoagulated after epidural removal. No patient developed a pulmonary embolism. Our data suggest that patients undergoing major open operations with epidural analgesia have low rates of DVT and may obviate the need for chemical prophylaxis. However, larger studies are required to determine the overall effects of epidural analgesia on the development of DVTs postoperatively.

Mycotic Aneurysm Detected by the Axiom: Scan Where the Pain Is

The lower extremity venous duplex scan is one of the most frequently ordered examinations in the vascular laboratory. Many laboratories will use the protocol format on the ultrasound machine to decrease time spent on examinations and increase productivity. The sonographer needs to be sure to obtain a thorough examination and not simply be led by the images to be acquired in the protocol setting. In addition, with more and more emphasis on sonographer productivity, it is tempting to do the test requested, move on to the next test, and let other professionals deal with the patient's symptoms. A recent interesting case in the vascular laboratory is used as an example of deviating from a strictly protocol-driven test to listening to the patient's complaints and scanning the symptomatic area.

A TWO-YEAR FOLLOW-UP OF A FEMALE PATIENT WITH RECURRENT PULMONARY THROMBOEMBOLISM AFTER SUCCESSFUL COMBINED TREATMENT

Objective: to describe a clinical case of recurrent pulmonary thromboembolism (PTE) with developed chronic thromboembolic pulmonary hypertension (CTEPH) and successful stenting of the pulmonary artery branch after ineffective thrombolysis. Patient Ch. born in 1978 was admitted to a cardiology unit with suspected PTE. The patient complained of obvious resting dyspnea increasing with minimal physical exercise. Blood test revealed leukocytosis, D-dimer just above the normal value. Electrocardiography showed sinus rhythm, right axis deviation, and complete right bundle-branch block. EchoCG indicated right hearth dilatation with an increase in systolic pressure gradient across the tricuspid valve up to 60 mm Hg. Lower extremity venous duplex scanning revealed a muscle vein dilated up to 14 mm with echogenic parietal deposits in the muscle thickness at the middle third of the right leg; compression was virtually complete; the valves were incompetent and a muscle vein irregularly dilated up to 7 mm in the middle third of the left leg; the walls were uneven; compression was complete. Angiopulmonography detected occlusion of the lower and middle lobe branches of the right pulmonary artery and the lower lobe branch of the left pulmonary artery. Results. It was decided to perform local thrombolysis in terms of the patient»s young age, obvious clinical symptoms (New-York Heart Association Functional Class (FC) III–IV dyspnea) and the data of earlier studies on the benefit from thrombolysis in intermediate-risk persons and a council of a vascular surgeon, a cardiologist, and an X-ray endovascular diagnosis and treatment physician, and an invasive specialist. The patient underwent local thrombolysis with purolase 6,000,000 IU. Control angiopulmonography revealed no positive changes in the branches of the pulmonary artery. Because of ineffective thrombolysis and the persistence of significant pulmonary hypertension and FC III–IV dyspnea, the patient underwent conduction recanalization of the area of left lower lobe pulmonary artery occlusion, percutaneous transluminal balloon angioplasty, and endoprosthesis replacement with an 8.0–29-mm holometallic peripheral stent. Control angiopulmonography showed that the arterial lumen was completely restored and blood flow was not distally embolized. Conclusion. This clinical case is an example of the delayed diagnosis of recurrent PTE, which was a reason for ineffective thrombolytic therapy that had been performed 11 days after the onset of an episode. In this situation, percutaneous transluminal balloon angioplasty and pulmonary artery branch stenting can improve the status of a patient and reduce the risk of CTEPH in the future. In spite of its apparent ease, angioplasty can cause problems: impossibility and hazard of enhanced contrasting of the pulmonary artery; extensive injury of its branches; arterial cicatricial process associated with multiple episodes of PTE. After angioplasty, patients may develop reperfusion pulmonary edema, the causes of which are fully unclear. However, the successful intervention makes it possible to lower pulmonary artery pressure, pulmonary vascular resistance, and blood NT-proBNP levels and to increase exercise tolerance. At the present time, a number of centers are performing such procedures in patients with CTEPH. This requires 2–3 balloon inflations per session. Holometallic stent placement can decrease the number of necessary inflations and reinterventions in the future. This clinical case demonstrates that pulmonary artery stenting is successful in the patient with recurrent PTE after ineffective thrombolysis.

Isolated calf muscular vein thrombosis is associated with pulmonary embolism and a high incidence of additional ipsilateral and contralateral deep venous thrombosis.

Little is known about the natural history of isolated gastrocnemial and soleal vein thrombosis (IGSVT), and recommendations for treatment and follow-up are therefore anecdotal. This study sought to determine the rates of venous thromboembolism (VTE) progression and resolution and theeffect of antithrombotic therapy in patients with IGSVT. A vascular laboratory database was queried from January 2002 to December 2006 to identify patients with duplex-diagnosed IGSVT and follow-up duplex scan studies. Duplex scan examinations were reviewed to determine rates ofresolution and development of new ipsilateral and contralateral VTE. Records were reviewed for comorbid conditions, VTE risk factors, anticoagulation therapy, the effect of anticoagulation on resolution of IGSVT, and diagnosis of pulmonary embolism (PE) confirmed by computed tomographic angiography. Patients with at least one follow-up duplex scan studywere included in our analysis. Sixty-five limbs with isolated IGSVT were identified in 57 patients with follow-up duplex scans (mean, 2.75 studies per patient; mean follow-up, 113days). Twenty patients (35%) received therapeutic anticoagulation after the IGSVT diagnosis. There were sevenPEs, two on the same day as initial IGSVT diagnosis, and two within 1 week of diagnosis. IGSVT resolution rates by Kaplan-Meier analysis at 1 and 3 months were 20% and 41%, respectively. Eleven patients (19%) developed additional ipsilateral deep venous thrombosis (DVT; three axial calf vein thromboses and five proximal DVT) or contralateral DVT (oneaxialcalf vein thrombosis [CVT], one IGSVT, and one proximal DVT) during follow-up. Of the eight patients who developed additional ipsilateral DVT, five also developed concurrent contralateral DVT. Overall, 14% of patients developed contralateral DVT. Median time to development of additional DVT was 10 days. Therapeutic anticoagulation was associated with DVT resolution. However, VTE recurrence was not significantly affected by age, gender, anticoagulation, oral contraceptives, known hypercoagulable states, or comorbidities (smoking, cancer, trauma, postsurgical status, renal failure, hyperlipidemia, diabetes, or cardiopulmonary abnormalities; P> .05). Isolated calf muscular vein thrombosis is associated with PE and a significant incidence of VTE progression. Therapeutic anticoagulation is associated with DVT resolution, but its effect on VTE recurrence was not demonstrated. Untreated patients with IGSVT should receive follow-up bilateral lower extremity venous duplex scans within 10 days of diagnosis.

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Introduction: Fondaparinux (FP, Arixtra®) is a preferred drug for venous thromboembolism (VTE) prophylaxis in critically ill patients. However, it is contraindicated in renal failure due to concerns of drug accumulation and increased bleeding risk. We sought to prospectively study FP for VTE prophylaxis in critically ill patients with renal failure at an extended dosing interval of 2.5 mg every 48 hours (q48h), instead of the usual q24h. Hypothesis: FP, dosed at an extended interval regimen of 2.5 mg q48h in critically ill patients with renal failure, results in satisfactory peak (Pk) and trough (Tr) plasma FP levels. Methods: ICU patients with renal failure (acute or chronic, creatinine clearance < 30 ml/min, +/- dialytic therapy) were prospectively studied while receiving FP, dosed at 2.5 mg q48h. FP Pk and Tr plasma levels were obtained around doses 1-5. FP levels (µg/ml) are expressed as mean±SD for each dose and as % within 2 SD of reported levels in patients with normal renal function (Pk=0.47 ± 0.2 and Tr=0.18 ± 0.1). Clinical efficacy was assessed with lower extremity venous duplex scans at study entry and completion. Major and minor bleeding events were recorded. Results: Twenty one patients were studied to date, 13 on dialytic therapy. Patients received an average of 5 doses of FP. Mean of FP Pk and Tr levels for doses 1-5 were 0.34 ± 0.1 (n=60) and 0.15 ± 0.1 (n=47), respectively. For doses 1, 3, and 5, Pk levels were 0.23 ± 0.1 (n=20), 0.37 ± 0.1 (n=9), and 0.42 ± 0.1 (n=6), and Tr levels were 0.11 ± 0.1 (n=18), 0.20 ± 0.1 (n=10), and 0.18 ± 0.1 (n=4). There was a significant increase in Pk levels from dose 1 to dose 3 and 5, (p<0.005 by ANOVA and post-hoc). No significant difference was present after dose 3 for Pk or Tr levels. Overall, 98% of Pk and 95% of Tr levels were within the acceptable prophylaxis range. No VTE events were noted. There were no major and 3 minor bleeding events through dose 5. Conclusions: FP dosed at an extended interval regimen of 2.5 mg q48h for VTE prophylaxis in ICU patients with renal failure results in satisfactory Pk and Tr levels. This dosing regimen appears pharmacologically sound, effective and safe in this patient population.

Pulmonary Embolism Without Deep Venous Thrombosis

To identify patients with pulmonary embolism (PE) without deep venous thrombosis (DVT), and to compare them with those with an identifiable source on upper (UED) and lower-extremity venous duplex scans (LED). We performed a retrospective review of 2700 computed tomography angiograms of the chest between January 2008 and September 2010 and identified 230 patients with PE. We then evaluated the results of UED and LED and divided the patients into four groups based on the results of their duplex studies. We compared patients with PE and DVT with those with PE and no DVT in terms of age, gender, size and location of PE, critical illness, malignancy, and in-hospital mortality. We identified 152 women and 78 men (mean age, 68 years) with PE. One hundred thirty-one patients had a documented source of PE (group 1). Fifty-three patients had negative LED results, but did not undergo UED (group 2). Thirty-one patients did not undergo either LED or UED (group 3). Seven men and eight women had no documented source of PE on UED and LED (group 4). Ten of 15 patients in group 4 had a documented malignancy listed as one of their diagnoses. Because patients in groups 2 and 3 did not undergo complete duplex studies, we excluded them from our analysis. We then reviewed the discharge summaries of patients in groups 1 and 4. There was no statistically significant difference in age and gender distribution, size and location of PE, critical illness, smoking status, cardiovascular disease, trauma, and in-hospital mortality between patients in group 1 and 4. Patients in group 4 had a statistically significant increased prevalence of malignancy (67% vs. 40%, P = 0.046). Patients in group 4 also had a higher percentage of active cancer than those in group 1 (47% vs. 24%, P = 0.084), although not statistically significant. We defined active cancer as either a metastatic disease or a malignancy diagnosed shortly before or after the diagnosis of PE. Patients who were undergoing treatment for cancer at the time of diagnosis of PE were also considered to have active cancer. We demonstrated a statistically significant increased prevalence of malignancy in patients with PE without DVT. However, pathophysiology and clinical significance are the aspects that remain to be understood after accrual of more patients and further research. Possibilities such as de novo thrombosis of pulmonary arteries, complete dislodgement of thrombi from peripheral veins, or false-negative venous duplex need to be explored.

Infra-popliteal deep venous thrombi and the risk of symptomatic pulmonary embolism in hospitalized patients

Infra-popliteal veins include the tibial and peroneal veins, as well as the soleal and gastrocnemial veins collectively known as the calf muscle veins (CMVs). Acute infra-popliteal deep venous thrombi (DVTs) are often considered insignificant with regard to the risk of pulmonary embolism (PE). A retrospective review of 4035 consecutive lower extremity venous duplex scans were made in 3146 hospital patients at our Intersocietal Commission for the Accreditation of Vascular Laboratories (ICAVL)-accredited vascular lab. Seven hundred sixteen (17.7%) duplex scans were positive for acute DVTs, and 112 (2.8%) were associated with PEs. The breakdown of positive duplexes for acute DVTs was as follows: 202 (28.2%) isolated femoral-popliteal DVTs with PE in 23 (11.4%), 304 (42.5%) isolated infra-popliteal DVTs with PE in 24 (7.9%) and 210 (29.3%) multilevel DVTs involving both vein segments (femoral-popliteal and infra-popliteal) with PE in 38 (18.1%). Of the 304 isolated acute infra-popliteal DVTs, 207 (68.1%) were isolated CMV DVTs with evidence of PE in 12 (5.8%). No statistically significant difference (P = 0.27) in the risk of PE between isolated femoral-popliteal and isolated infra-popliteal DVTs was noted. A significant number of patients (5.8%) with isolated CMV DVTs developed PE. Lower limb venous scans for DVTs should evaluate the infra-popliteal veins. Hospitalized patients with infra-popliteal DVTs should receive anticoagulation.

Value of venous color flow duplex scan as initial screening test for geriatric inpatients with clinically suspected pulmonary embolism

AimThe contribution of lower extremity venous duplex scan to the diagnostic strategy for pulmonary embolism has been demonstrated by many authors. However, the positive diagnostic value of this noninvasive test in clinically suspected pulmonary embolism is not very high (10%–18%). Since thromboembolic risks increase considerably in hospitalized patients with advanced age, this study aims to determine the importance of lower extremity venous color flow duplex scan in this particular subgroup of patients with clinically suspected pulmonary embolism. The effects of clinical presentation and risk factors on the results of duplex scan have been also studied.MethodsBetween July 2007 and January 2010, 95 consecutive Lebanese geriatric (≥60 years of age) inpatients with clinically suspected pulmonary embolism assessed in an academic tertiary-care center for complete lower extremity venous color flow duplex scan were retrospectively reviewed. Age varied between 60 and 96 years (mean, 79.9 years). Forty patients were males and 55 females. Absence of compressibility was the most important criteria for detecting acute venous thrombosis.ResultsOut of 95 patients, 33 patients (34.7%) were diagnosed with recent deep venous thrombosis of lower extremities (14 proximal and 19 distal) using complete venous ultrasound. Nine of these 33 patients (27.2%) had a history of venous thromboembolism and eleven (33.3%) presented with edema of lower extremities. A total of 28 patients (84.8%) with positive duplex scan had associated risk factors for venous thromboembolism.ConclusionLower extremity venous color flow duplex scan appears to be a reasonable initial screening test in the diagnostic algorithm of pulmonary embolism in geriatric inpatients with clinically suspected pulmonary embolism. This is particularly true in patients with a history of venous thromboembolism, in patients with a clinical presentation suggesting venous thrombosis, in uremic patients and in patients with altered general and mental status who are not candidates for chest computed tomography.

The Current State of Practice in the Diagnosis of Venous Thromboembolism at an Academic Medical Center

Evidence-based guidelines for the diagnosis of venous thromboembolism (VTE) have been recommended, yet the adoption of such guidelines into daily practice is unknown. The purpose of this study was to describe the current practices in the diagnosis of VTE. Medical records of 1161 adult patients who underwent lower extremity venous duplex scans (VDS), chest computerized tomographic (CT) angiography, or ventilation and perfusion (V/Q) scans during a 6-month period were retrospectively reviewed in an academic medical center. Patients who were first diagnosed by CT or V/Q scan still underwent a VDS. Nine patients at high risk had incomplete CT scans, yet no further tests were performed. Five pregnant patients had CT scans as the initial test instead of being screened with VDS or V/Q scanning. Inappropriate use of imaging tests was documented. The recommended guidelines of using clinical probability and D-dimer as the initial screening tests for VTE diagnosis were underused.

Case Study: Cystic Adventitial Disease of the Popliteal Artery

Introduction —Adventitial cystic disease is an unusual cause of lower-extremity ischemia. It affects large arteries, typically where the artery is near a joint space, and the popliteal artery is most commonly involved. Methods —A 60-year-old man with venous insufficiency and prior deep vein thrombosis was referred for a lower-extremity venous evaluation. He had chronic degenerative joint disease, with bilateral knee osteoarthritis, but a history of exertional right calf pain was elicited. His right femoral and popliteal pulses were normal, but the posterior tibial pulse was diminished and the dorsal pedal artery pulse was absent. A lower-extremity duplex ultrasound examination was performed, including conventional and panoramic B-mode imaging, color Doppler and power Doppler imaging, and pulsed flow assessment. Results —Chronic deep and superficial venous thrombosis was identified in the right lower extremity. During the examination, the right popliteal artery was noted to be abnormal. Imaging showed the flow lumen in the popliteal artery to be visibly narrowed by more than 50%. Peak systolic velocities (PSV) in the proximal popliteal artery were 82 cm/sec, with a normal triphasic waveform, but the PSV increased to 221 cm/sec through the stenotic segment. The luminal narrowing was limited to an approximately 3 cm segment of the popliteal artery. There was no visible plaque or evidence of vascular calcification. The lumen appeared compressed by hypoechoic, septated cystic material. There was no flow within the well-visualized cystic structure. The findings were subsequently correlated with arteriography. Adventitial cystic disease of the popliteal artery was diagnosed. The patient underwent successful right popliteal artery cystectomy. Intra-operative and post-operative duplex evaluations demonstrated normal findings. Conclusion —Cystic adventitial disease is a rare disorder that can compromise arterial perfusion to the leg and it is one nonatherosclerotic cause of intermittent claudication. In some cases, the popliteal artery may occlude. Incidental arterial disease may be encountered frequently with lower extremity venous duplex scanning. With a careful examination by a thorough technologist, rare and interesting pathology, such as cystic adventitial disease, is possible.

Enoxaparin treatment in high-risk trauma patients limits the utility of surveillance venous duplex scanning

Objective: The value of surveillance venous duplex scanning for detecting unsuspected deep venous thrombosis (DVT) in trauma patients who are receiving enoxaparin prophylaxis is open to question. This study was undertaken to determine whether enoxaparin reduced the clinical utility of surveillance scanning and whether management of these patients was altered by findings of the scans. Methods: The medical records of trauma patients who met defined criteria for high DVT risk, admitted during 30 consecutive months, were reviewed. These patients received enoxaparin 30 mg every 12 hours for the duration of their admissions. Per protocol, surveillance lower extremity venous duplex scans were performed within 72 hours of enoxaparin administration and then weekly until patients were discharged from the hospital. The records were reviewed for thromboembolic events (DVT or pulmonary embolism [PE]), patient location and ambulatory status, therapeutic interventions (systemic anticoagulation, vena cava filter), and complications of enoxaparin therapy. Results: A total 241 patients underwent 513 venous duplex examinations (1-13 per patient). Eight patients had DVT on the initial scan; seven of these patients were asymptomatic. Five were treated with anticoagulation and/or vena cava filter placement. Of the 233 patients with initially negative duplex scan results, five patients (2%) developed clinically unsuspected lower extremity DVT while hospitalized. All of these five patients were in an intensive care unit. Three of the five patients had no change in treatment. Two of the five underwent anticoagulation, and one vena cava filter was placed. PE occurred in two hospitalized patients, one of whom was ambulatory, with negative duplex scan results. After hospital discharge, six other patients had symptomatic DVT or PE despite in-hospital scans with negative results. Complications associated with enoxaparin included hemorrhage (2) and thrombocytopenia (8). Conclusions: After initial negative scan results, repeat surveillance duplex scanning during hospitalization detected a low incidence (2%) of DVT in high-risk patients. Furthermore, the detection of unsuspected DVT altered the clinical management of less than 1% of the patients tested. Thus, after a venous duplex scan with negative results and initiation of enoxaparin prophylaxis, subsequent surveillance duplex examinations are not warranted in asymptomatic trauma patients. (J Vasc Surg 2001;34:447-52.)

Prospective screening for postoperative deep venous thrombosis in patients undergoing infrainguinal revascularization

Purpose: The incidence of deep venous thrombosis (DVT) in patients undergoing infrainguinal bypass graft procedures has not been well documented, and the need for routine prophylaxis remains controversial. The purpose of this study was to prospectively evaluate the risk of postoperative DVT complicating infrainguinal revascularization. Methods: Seventy-four patients undergoing infrainguinal bypass graft procedures during a 12-month period were prospectively screened for DVT. Bilateral lower extremity venous duplex scan imaging was performed preoperatively and within 1 week and 6 weeks, postoperatively. Routine DVT prophylaxis was not used, with anticoagulation reserved for specific indications. Results: Of the 74 patients screened, three patients (4.1%) had DVT identified on preoperative venous duplex scan imaging and were excluded from the study. Of the remaining 71 patients enrolled, only two patients (2.8%) had postoperative DVT. Postoperative DVT was ipsilateral to the bypass graft extremity in both patients, with involvement of the peroneal vein in one patient and the femoral vein in the other. Although routine prophylaxis was not used, 18 of these patients (25%) were anticoagulated for other indications, with DVT occurring in one patient (5.6%). Of the remaining 53 patients who did not receive postoperative anticoagulation, only one patient (1.8%) had DVT. Conclusions: According to this prospective study, the risk of postoperative DVT in patients undergoing infrainguinal revascularization is low. Routine prophylaxis is not recommended, with postoperative anticoagulation reserved for specific indications. (J Vasc Surg 2000;32:669-75.)

Do Patients with Acute Deep Vein Thrombosis Have Fever?

The purpose of this study was to determine whether those with lower extremity acute venous thrombosis have fever. During a recent 14.5-month period, 1847 patients undergoing lower extremity venous duplex scanning also had their oral temperature measured using a digital thermometer at the time of duplex examination. Patients were 57.8 +/- 17.3 years of age (range, 14 to 99). Temperature was 98.5 +/- 1.1 degrees F. Twenty-three patients had acute inferior vena cava thrombosis, 60 had acute iliac vein thrombosis, 138 had acute femoral venous thrombosis, and 131 had acute popliteal venous thrombosis. Calf vein thromboses were present in 102 patients, and 43 patients had superficial venous thrombosis. A total of 228 patients had acute lower extremity venous thrombosis in one or more of these venous segments. Temperature with acute lower extremity venous thrombosis was 98.7 +/- 1.05 degrees F versus 98.5 +/- 1.10 degrees F in those with no acute thrombosis. Although small, this temperature difference was statistically significant (P < 0.02). Acute deep venous thrombosis (DVT) was defined as acute popliteal or more proximal femoral, iliac, or vena cava thrombosis. The temperature for the 175 patients with acute DVT was 98.7 +/- 1.10 degrees F versus 98.5 +/- 1.10 degrees F for those without DVT (P < or = 0.035). There was no temperature that served to accurately differentiate those who did from those who did not have DVT. The frequency that patients with DVT had fever, defined as a temperature > or = 100 degrees F, was 9.1 per cent (16 of 175) with DVT versus 7.5 per cent (126 of 1678) without DVT (not significant). In the subgroup with a temperature > or = 101 degrees F, 4.6 per cent (8 of 175) with DVT had such a fever versus 3.4 per cent (57 of 1672) without DVT (not significant). Those undergoing venous duplex who were found to have acute lower extremity venous thrombosis, including acute DVT, had statistically higher temperatures, but such temperature differences were minimal. The incidence of fever, defined as a temperature > or = 100 degrees F or > or = 101 degrees F, was not different between those with and those without acute DVT. It appears that the presence of fever may not be a sensitive or specific indicator for the presence of underlying acute DVT.

Contralateral duplex scanning for deep venous thrombosis is unnecessary in patients with symptoms

Bilateral lower extremity venous duplex scanning for acute deep venous thrombosis (DVT) has been advocated because of the high incidence of occult contralateral leg involvement. We investigated the clinical necessity of such a policy. The results from 2996 venous duplex studies performed during the past 2 years were retrospectively reviewed. A total of 1694 of these scans were performed on patients with symptoms, of whom 248 (15%) were found to have an acute DVT. Symptoms were limited to one side in 198 patients, whereas bilateral complaints were noted in 50 patients. Among the patients with symptoms of acute DVT, 72 (29%) had bilateral involvement. Bilaterality was more likely in patients with bilateral symptoms than in those with only unilateral symptoms (56% vs 22%; p < 0.005). Of the patients with unilateral symptoms and bilateral DVT, all of them had either acute (80%) or acute and chronic (20%) thrombosis in the symptomatic leg. The contralateral asymptomatic limb had fewer acute and more chronic DVT (41% and 55%, respectively). No patient from the entire group admitted with symptoms had an acute DVT in the asymptomatic limb without a concomitant acute DVT in the symptomatic leg. Unilateral scanning would decrease the examination time by 21% and potentially increase total reimbursement for symptomatic venous scans by 9% compared with routine bilateral duplex scanning. Although bilateral involvement is frequent in patients with symptoms of acute DVT, treatment in these patients is not altered by this finding. We conclude that contralateral venous scanning in patients with unilateral symptoms is not clinically indicated and that unilateral scanning would result in improved cost-efficiency for vascular laboratories.

Asymptomatic deep venous thrombosis in the trauma patient: is an aggressive screening protocol justified?

The incidence and sequelae of deep venous thrombosis (DVT) in trauma patients are unclear because the majority of patients who develop DVT are asymptomatic. This study evaluated the incidence, risk factors, and efficacy of prophylaxis for DVT in trauma patients over a 5-year period. Trauma patients at high risk for DVT were evaluated biweekly with lower extremity venous duplex scans. The DVT prophylaxis was instituted on admission with low-dose heparin therapy and pneumatic compression. The incidence of asymptomatic DVT identified by duplex screening was 10% (45 of 458); one pulmonary embolus occurred. Five variables were significant from bivariate and multiple logistic regression analysis: age (p = 0.005), Injury Severity Score (p = 0.005), length of stay (p = 0.004), Trauma and Injury Severity Score (p = 0.01), and spinal injury (p = 0.014). This analysis documents that trauma patients with these risk factors are at increased risk for the development of asymptomatic DVT, despite prophylaxis, and warrant surveillance with venous duplex sonography.

Bilateral Popliteal Vein Aneurysms

An 82-year-old man was admitted with a left hip fracture sustained in a fall. The fracture was surgically repaired. Ipsilateral leg swelling developed over the following 2 weeks. A lower extremity venous duplex scan demonstrated isolated dilatation of the popliteal veins in both lower extremities. Chronic thrombosis was noted in both popliteal veins at the level of this dilatation. Initial duplex scanning also revealed acute thrombus in the left popliteal, posterior tibial, and peroneal veins. A repeat scan 1 week later identified propagation of thrombus into the superficial femoral vein. Popliteal vein aneurysms, although rare, can cause significant morbidity and mortality. The literature is also reviewed.

Pitfalls in lower extremity venous duplex scanning

Results of scans performed on 1074 patients over an 18-month period were evaluated to define the limitations of lower extremity venous duplex scanning. Eighty-four patients had confirmatory phlebography performed within 24 hours of their venous duplex scanning. In 71 patients scans were considered diagnostic (sensitivity 91%, specificity 95%). Eighteen studies (13 equivocal, 5 misinterpretations) were scrutinized to determine the limitations of venous duplex scanning compared to phlebography and are the focus of this analysis. Seven patients had phlebograms documenting only infrapopliteal thrombus, seven had normal phlebographic findings, and four had findings consistent with chronic thrombosis. In the seven patients with infrapopliteal thrombus, four had normal imaging outcomes but abnormal Doppler flow patterns, whereas three had both normal imaging results and flow patterns. All four patients with chronic thrombosis had identifiable thrombus and abnormal flow patterns by venous duplex scanning, but in each case thrombus age was indeterminate. Of the seven patients with normal phlebographic results, five had incompressible segments of the superficial femoral vein on imaging, one had abnormal Doppler flow without visualized thrombus and without apparent reason, one had venous duplex scanning visualized thrombus with a normal outcome on phlebography. These data suggest that the diagnostic yield of lower extremity venous duplex scanning may be improved by (1) meticulous infrapopliteal vein examination, (2) better estimation of the age of the thrombotic process, and (3) recognizing segmental incompressibility of the superficial femoral vein within the adductor canal as a normal finding especially in the absence of abnormal Doppler flow or imaged thrombus.