Detection of pelvic vein thrombosis by magnetic resonance angiography in patients with acute pulmonary embolism and normal lower limb compression ultrasonography

Negative Venous Leg Ultrasound in Acute Pulmonary Embolism: Prevalence, Clinical Characteristics, and Predictors

The purpose of this study was to investigate the prevalence, clinical characteristics, and predictors of negative venous leg ultrasound in acute pulmonary embolism (PE). We retrospectively analyzed a cohort of 168 patients with acute PE (median age 73 years, 44% women) evaluated with complete venous leg ultrasound. A multivariate logistic regression analysis was performed to identify the independent predictors of negative venous ultrasound in acute PE. Venous leg ultrasound was negative for deep venous thrombosis (DVT) in 78 patients (46.4%). Patients with negative venous ultrasound were less likely to have a history of DVT (7.7% vs. 20.0%, p = 0.0273) and had significantly lower D-dimer levels (median 2.5 vs. 6.2 mg/dL p < 0.0001). Negative venous ultrasound was more frequent in PE diagnosed with V/P-SPECT than in PE diagnosed with CT (66.2% vs. 34.0%, p < 0.0001). The prevalence of negative venous ultrasound increased with more peripherally located PE (29.5% for central/lobar, 43.1% for segmental, and 60.6% for subsegmental PE, p = 0.0049). For the multivariate analysis, a diagnosis of PE with V/P-SPECT rather than CT (OR 3.2, p = 0.0056) and lower D-dimer levels (OR 0.94, p = 0.0266) were independent predictors of negative venous ultrasound. In conclusion, venous leg ultrasound was negative for DVT in almost half of patients with acute PE. Negative venous ultrasound was more common in patients with no history of DVT, lower D-dimer levels, PE diagnosed with V/P-SPECT rather than CT, and more peripherally located PE.

Single-stage treatment with iliac vein stenting and stripping of great saphenous veins for patients with left iliac vein compression syndrome

BACKGROUND

We sought to evaluate the safety and feasibility of single-stage treatment with left iliac vein stenting and saphenous stripping in patients with left iliac vein compression (LIVC) and left great saphenous vein (GSV) incompetence.

METHOD

s: We conducted a prospective cohort study of 72 patients diagnosed with LIVC and left GSV incompetence between June 2012 to Oct 2018. We evaluated the periprocedural, 30-day, and 1-year outcomes of venous clinical severity score (VCSS), Chronic Venous Insufficiency Questionnaire 2 (CIVIQ2), the success rate of stent placement, duration of intervention, length of hospital stay, duplex recurrence, and clinically visible recurrence.

RESULTS

There were 43 patients in the two-staged group and 29 patients in the single-staged group. The clinical characteristics of the two groups were similar. There were no differences between the two groups in the technical success rate, perioperative mortality, and surgical morbidity. There was no significant difference in the duplex and clinically visible recurrence. The length of hospital stay was significantly lower in the single-staged group. The single-staged group was associated with a higher complication rate of ecchymosis. There was no death, pulmonary embolism, or contrast-induced nephropathy among the patients. The 1-year primary patency rate was similar.

CONCLUSIONS

Both treatment approaches were equally effective and had a high technical success rate. The single-staged group had a higher complication rate of ecchymosis due to heparin applying during the procedure.

Venous Thromboembolic Disease in Chronic Inflammatory Lung Diseases: Knowns and Unknowns

Persistent inflammation within the respiratory tract underlies the pathogenesis of numerous chronic pulmonary diseases. There is evidence supporting that chronic lung diseases are associated with a higher risk of venous thromboembolism (VTE). However, the relationship between lung diseases and/or lung function with VTE is unclear. Understanding the role of chronic lung inflammation as a predisposing factor for VTE may help determine the optimal management and aid in the development of future preventative strategies. We aimed to provide an overview of the relationship between the most common chronic inflammatory lung diseases and VTE. Asthma, chronic obstructive pulmonary disease, interstitial lung diseases, or tuberculosis increase the VTE risk, especially pulmonary embolism (PE), compared to the general population. However, high suspicion is needed to diagnose a thrombotic event early as the clinical presentation inevitably overlaps with respiratory disorders. PE risk increases with disease severity and exacerbations. Hence, hospitalized patients should be considered for thromboprophylaxis administration. Conversely, all VTE patients should be asked for lung comorbidities before determining anticoagulant therapy duration, as those patients are at increased risk of recurrent PE episodes rather than DVT. Further research is needed to understand the underlying pathophysiology of in-situ thrombosis in those patients.

Chronic CT features in PE patients with co-existing DVT

OBJECTIVE

Clinical features may be different in patients with PE without co-existing DVT compared to those with PE with co-existing DVT. This prospective study aims to investigate the different clinical features between patients with isolated pulmonary embolism (PE) and those with PE associated with deep venous thrombosis.

METHOD

This is a prospective study conducted in 107 consecutive patients diagnosed with acute PE in the emergency department or other departments of Kırıkkale University Hospital. The diagnosis of PE was confirmed by computed tomography pulmonary angiography (CTPA), which was ordered on the basis of symptoms and findings. Bilateral lower extremity compression ultrasound with standard 7.5 MHz linear array probe was applied to all patients. According to compression ultrasound results, the patients were divided into two classes as with and without deep venous thrombosis. Embolism in the main or lobar pulmonary arteries were classified as central, and those found only in segmental or subsegmental arteries were classified as peripheral. Laboratory parameters and Oxygen saturation were assessed on admission.

RESULTS

67 of 107 (62.6%) patients with PE were isolated pulmonary embolism, and 40 (37.4%) were PE + DVT. Patients with PE with co-existing DVT have wider pulmonary artery, higher d-dimer and pro BNP level, and lower saturation than those with isolated pulmonary embolism. Central pulmonary embolism is more common in patients with deep vein thrombus than those without it. (87.5% (35/40) vs 32.8% (22/67),p = 0.001). 38.6% of central pulmonary embolism occur without deep vein thrombosis of the lower extremities. Patients with PE with co-existing DVT have 42.5% mosaic perfusion pattern,70% chronic infarct appearance such as linear band, pleural nodüle, %15.0 thickened, small arteries and, %12.5 shrunken complete artery occlusion, suggesting the chronic background.

CONCLUSION

PE patients with co-existing DVT are clinically more serious than those who do not have a DVT. An acute picture may be present in the chronic background in a significant proportion of patients with PE with co-existing DVT. In the presence of deep vein thrombosis, pulmonary embolism is usually central, but more than one-third of central pulmonary emboli occur without lower extremity deep vein thrombosis.

Management and treatment of deep vein thrombosis in special populations

INTRODUCTION

Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), is the third most frequent cardiovascular disease besides myocardial infarction and stroke. Because DVT may cause life-threatening conditions, treatment should be started as soon as possible. This comprises certain challenges in special populations. Areas covered: In cancer-associated VTE, current treatment is different from non-cancer VTE due to disease-related interventions and higher bleeding risks. In the treatment of patients with extensive DVT, the role of catheter-directed thrombolysis has been investigated in two randomized trials, but results do not yield a recommendation for standard thrombolysis. The diagnosis of suspected recurrent DVT is especially challenging in case of ipsilateral DVT. Treatment strategies in recurrent DVT are dependent on the case and on particular risk factors. Also discussed is the therapy for DVT in pregnant women, which is more complex as a result of anticoagulants crossing the placenta. Expert commentary: DVT treatment in special populations poses special challenges due to high thrombotic and bleeding risk. This will be discussed in more detail in this review.

Accurate diagnosis of iliac vein thrombosis in pregnancy with magnetic resonance direct thrombus imaging (MRDTI)

A pregnant woman aged 29 years, G1P0 at 21 weeks of gestation of a dichorionic diamniotic twin, presented with suspected deep vein thrombosis (DVT) of the left leg. Repeated (compression) ultrasonography was not diagnostic for DVT but showed reduced flow over the left external iliac vein, common femoral vein and superficial femoral vein. In pursue of a definite diagnosis, magnetic resonance direct thrombus imaging was performed showing a clear high signal in the left common iliac vein which is diagnostic for acute thrombosis in this venous segment. Phase contrast venography supported this diagnosis, showing no flow in the left common iliac vein. Treatment with anticoagulants was started. 6 months after the diagnosis, the patient is doing well and does not report signs of post-thrombotic syndrome.

Three-Dimensional Gadolinium-Enhanced Magnetic Resonance Angiography Used as a “One-stop Shop” Imaging Procedure for Venous Thromboembolism: A Pilot Study

Pulmonary embolism and deep venous thrombosis are individual manifestations of a single entity, venous thromboembolic disease. This study aimed to assess the feasibility of 3-dimensional gadolinium-enhanced magnetic resonance angiography used as an “one-stop shop” imaging procedure visualizing both the pulmonary arteries and the deep lower venous system within a single investigation. The inclusion criterion was a proven or excluded venous thromboembolism. Diagnosis was based on an imaging work-up for pulmonary embolism including either perfusion lung scan or contrast-enhanced spiral computed tomography, or both, and an imaging work-up for deep venous thrombosis including either venous color-coded duplex sonography or ascending phlebography, or both. A gadolinium-enhanced “one-stop shop” magnetic resonance angiography was performed within 24 hours of completed diagnostic imaging work-up for pulmonary embolism and deep venous thrombosis in 20 patients. Results of pulmonary magnetic resonance angiography were concordant with perfusion lung scan and/or computed tomography in 90% of patients. Magnetic resonance angiography results of the deep lower venous system were concordant with venous duplex sonography and/or phlebography in 75% of patients and seemed to be more precise in 25% of patients. The “one-stop shop” imaging procedure using gadolinium-enhanced magnetic resonance angiography was feasible and proved to offer a reliable and rapid diagnostic approach in thromboembolic disease, sparing patients’ exposure to ionizing radiation and iodinated contrast media.

Endovascular treatment for symptomatic iliac vein compression syndrome: a prospective consecutive series of 48 patients

BACKGROUND

We sought to assess the prevalence of iliac vein compression syndrome (IVCS) in patients with unilateral left lower limb chronic venous disease and evaluate the feasibility and effectiveness of endovascular treatment for IVCS.

METHODS

We conducted a prospective cohort study of 48 consecutive patients diagnosed with IVCS between December 2008 and May 2012. We divided the patients into 2 groups: thrombotic IVCS (n = 12) and nonthrombotic IVCS (n = 36). We evaluated the perioperative, 30-day, and 1-year outcomes of endovascular treatment. We estimated the stent patency rate using the Kaplan-Meier method.

RESULTS

The prevalence of IVCS within our cohort was 14.8% (48/324). The technical success rate of the endovascular treatment was 95.8%. There was no death, pulmonary embolism, or contrast-induced nephropathy among the patients. The 1-year primary patency rate was 93.0%. There was no significant difference between the thrombotic and nonthrombotic IVCS groups (P = 0.156). Perioperative complications were minor and improved quickly. The median pain level recorded on a visual analogue scale declined from 4.5 to 1.2 (P < 0.05) in the thrombotic ICVS group and from 3.3 to 0.3 (P < 0.05) in the nonthrombotic ICVS group. The edema relief rates in the thrombotic and nonthrombotic ICVS groups were 81.8% and 58.5%, respectively. The cumulative recurrence free ulcer healing rate was 71.4% 12 months after treatment.

CONCLUSIONS

IVCS is more common than previously thought among patients with unilateral left lower limb chronic venous disease. Endovascular therapy, a minimally invasive approach to treating venous lesions, is a feasible and effective treatment for left-sided IVCS and has a high technical success rate and an acceptable complication profile.

Diagnosis of uterine vein thrombosis on transvaginal ultrasound

Deep venous thrombosis (DVT) is a potentially serious medical disorder, which may result in pulmonary embolism and death. Compression ultrasound is the investigation modality of choice for the diagnosis of DVT of the lower limb. Diagnosis of proximal thrombosis involving the pelvic veins is difficult and is usually made only after the thrombus extends into the veins of the lower limb. We present six cases of incidental uterine vein thrombosis diagnosed by transvaginal ultrasound. Our aim is to describe the technique of the examination of pelvic veins and criteria that could be used to diagnose uterine vein thrombosis. We also highlight difficulties in the management of women diagnosed with asymptomatic uterine vein thrombi as there is little evidence to guide clinicians in choosing between different treatment options.

Unusual deep vein thrombosis sites: magnetic resonance venography in patients with negative compression ultrasound and symptomatic pulmonary embolism

OBJECTIVES

To evaluate the clinical characteristics of patients with pulmonary embolism (PE), negative compression ultrasound (CUS) of the lower limbs and detection of unusual deep vein thrombosis (DVT) sites by means of magnetic resonance (MR) venography.

METHODS

A retrospective data analysis of PE patients hospitalized at our institution from April 2009 to 2011.

RESULTS

From April 2009 to 2011, a total of 762 PE patients were treated at our institution. In 169 of these patients CUS for DVT was negative. In these patients MR venography was performed for further evaluation. We found venous thrombosis at unusual sites in 12 of these patients. Due to free floating thrombus masses and fear of life-threatening PE progression we inserted an inferior vena cava filter in three of these 12 patients. The leading venous thromboembolism risk factor in our patients was immobilization (5 patients, 41.7%).

CONCLUSIONS

We conclude that especially in patients with PE and negative CUS of the lower limbs a thrombosis of the pelvic veins should be considered in case of symptoms for venous thrombosis in this area. Further diagnostic work-up with MR venography should be scheduled in these patients especially in patients with risk factor immobilization as therapeutic consequences might occur.

Finding the origin of pulmonary emboli with a total-body magnetic resonance direct thrombus imaging technique

Pulmonary embolism is considered to originate from embolization of a deep-vein thrombosis, resulting in two manifestations of one disease: venous thrombosis. However, in up to 50% of patients with pulmonary embolism no deep-vein thrombosis is found with ultrasonography. An explanation for this low proportion is currently lacking. Other imaging modalities may increase the yield of detection of deep-vein thrombosis in the calf or in the abdominal region. Alternatively, not all pulmonary emboli may originate from deep-vein thromboses in the extremities. We searched for the origin of pulmonary emboli, by performing total-body magnetic resonance imaging-scans to visualize thrombi. Ninety-nine patients with a first pulmonary embolism confirmed by computed tomography underwent a magnetic resonance direct thrombus imaging-scan, a validated technique using endogenous contrast. Additionally, acquired and genetic risk factors were assessed. No thrombus was found in 55 patients, whereas a thrombus was identified in 44 patients. The commonest thrombus location was the lower leg; 12 patients had isolated calf vein thrombosis and five had isolated superficial vein thrombosis. A peripheral thrombus was found by magnetic resonance imaging in less than half of patients with pulmonary embolism. We propose several hypotheses to explain the absence of thrombi, such as a cardiac thrombus origin or embolization of the whole deep-vein thrombus. The possibility that pulmonary embolism arises de novo in the lungs, due to local inflammation-driven coagulation, needs to be considered.

Diagnostic tests and strategies in venous thromboembolism

Venous thromboembolism (VTE) is a term including deep vein thrombosis (DVT) and pulmonary embolism (PE). Timely and accurate diagnosis of both is essential as delayed or missed diagnoses can result in death or longer term complications. Patients with suspected DVT should initially undergo a pretest probability Wells score. Depending on pretest probability Wells score they should then either proceed to two-point ultrasound scanning or D-dimer testing. Likewise, patients suspected of PE should undergo a two-level PE Wells score, and, if scored likely, a computed tomography pulmonary angiogram (CTPA), or, if there is a low pretest probability score, D-dimer testing. If positive, patients should undergo CTPA. Ventilation perfusion scanning (V/Q scan) or V/Q SPECT should be considered in place of CTPA if there is allergy to contrast media or renal impairment.

A Novel Scoring System for Lower-extremity Venous Pathology Analysed Using Magnetic Resonance Venography and Duplex Ultrasound

Objectives:

To present a novel scoring system for lower-extremity venous pathology (the LOVE score) and our experiences using it in our clinical practice to identify venous pathology with duplex ultrasound (DUS) and magnetic resonance venography (MRV).

Method:

A total of 40 patients, 30 suspected of chronic venous disease and 10 with acute deep vein thrombosis (DVT) were examined from the inferior vena cava (IVC) to the popliteal vein using DUS and MRV. The image findings were reported using the LOVE score.

Results

The majority of deep veins (368 out of 378 segments) were completely visualized by both our imaging techniques and could be analysed using the LOVE score. Both imaging techniques reported comparable findings with regard to the visualization of thrombus, obstruction, collaterals, trabeculations, anatomic variations and central venous compression (e.g. May–Thurner).

Conclusions:

The LOVE score can be used to expand and standardize the documentation of imaging the deep venous system beyond thrombosis, to help identify (optimal) treatment options in patients with venous disease, in both the clinical and research setting. This first assessment shows that both DUS and MRV are capable of systematically identifying a multitude of changes in the venous system.

Massive pulmonary embolism caused by internal iliac vein thrombosis with free-floating thrombus formation in the inferior vena cava

Nowadays, compression ultrasonography (CUS) is the gold standard for the routine diagnosis of deep venous thrombosis (DVT). The drawback of CUS is the low sensitivity concerning the diagnosis of isolated pelvic vein thrombosis, especially referring to isolated internal iliac vein and ovarian vein thromboses. Therefore, magnetic resonance (MR) venography has become a valuable alternative. We present the case of a 45-year-old female patient with a massive pulmonary embolism with the indication for thrombolytic therapy due to severe right ventricular overload. We were not able to detect a DVT in the lower limbs of this patient with CUS. However, further DVT workup by MR venography showed a free-floating thrombus formation originating from the right internal iliac veins into the inferior vena cava. Owing to the fact that this thrombus was free floating, surgical removal of the thrombus was scheduled and performed successfully. In some patients it might be important to look for so-called rare causes of pulmonary embolism, even when CUS of the lower limbs does not reveal any DVTs. The diagnostic procedure of choice for these patients seems to be MR phlebography, as iliac and pelvic veins can be evaluated without radiation exposure with this procedure.

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.

Utility of balanced steady-state free precession MR venography in the diagnosis of lower extremity deep venous thrombosis

OBJECTIVE

The purpose of this study was to determine the sensitivity and specificity of balanced steady-state free precession MR venography in the diagnosis of lower extremity deep venous thrombosis.

SUBJECTS AND METHODS

After undergoing lower extremity ultrasound because of suspicion of deep venous thrombosis, 64 patients were prospectively recruited to undergo balanced steady-state free precession MR venography with ultrasound as the reference standard. Ultrasound images were independently interpreted by two blinded ultrasound radiologists, and MR venograms were independently interpreted by two blinded MRI radiologists. The sensitivity, specificity, positive predictive value, and negative predictive value of MR venography were calculated for the diagnoses of all deep venous thrombosis, acute thrombi, and thrombosis of the popliteal, femoral, and common femoral veins individually. Proximal extent, thrombus age, ancillary findings, and interobserver agreement calculated with the Cohen kappa test were evaluated for ultrasound and MRI. The McNemar test was used to evaluate for statistical differences in diagnostic accuracy.

RESULTS

MR venography had a sensitivity of 94.7%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 97.7% for the diagnosis of all thrombi. For acute thrombi, the MR venography and ultrasound results were completely concordant. MR venography depicted greater proximal extent in five of 18 cases in which thrombosis was found. The MR venographic findings agreed completely with the ultrasound findings in determination of thrombus age. For both ultrasound and MR venography, interobserver agreement was 100% on a per-patient basis. No statistical difference was identified in the diagnostic performance of the two techniques.

CONCLUSION

Balanced steady-state free precession MR venography is highly accurate in the diagnosis of lower extremity deep venous thrombosis.

Vena caval thromboses

BACKGROUND

Patients with vena caval (VC) thrombosis have been reported with a variety of clinical presentations, which may create a diagnostic challenge for physicians.

OBJECTIVE

The objective of the study was to evaluate the clinical characteristics of patients with VC thrombosis.

PATIENTS AND METHODS

Files and all imaging methods of consecutive patients with superior or inferior VC thrombosis with or without pulmonary embolism (PE) between January 26, 2001, and May 12, 2006, were retrospectively studied in detail.

RESULTS

In our series, VC thromboses within the inferior and superior VC were detected in 28 patients, mostly by combined computed tomographic venography and spiral computed tomographic pulmonary angiography. Nine of these 28 patients (32.1%) had VC thromboses without PE (7 patients with isolated and 2 patients with nonisolated VC thrombosis). Key symptoms and findings in the 9 patients without PE were unexplained dyspnea and tachypnea, respectively.

CONCLUSIONS

Many patients with VC thrombosis do not have peripheral vein thrombosis. Moreover, nearly one third of patients with VC thrombosis have negative pulmonary angiograms but do have dyspnea and tachypnea.

Patent foramen ovale and cryptogenic stroke: a complex neuro-cardio-vascular problem

Patent foramen ovale has been suggested to be a risk factor for cryptogenic stroke by means of paradoxical embolism. The data, however, are complex, conflicting and largely unavailable. In this review, we attempt to summarize the existing data separately for the questions of whether patent foramen ovale is associated with cryptogenic stroke and whether it is a risk factor for a first ischemic stroke and for recurrent strokes. Treatment options will be discussed, and the different viewpoints from the two specialists mainly involved in the care of those complex patients (neurologists and cardiologists) will be provided.

The use of leg venous ultrasonography for the diagnosis of pulmonary embolism

The role of ultrasonography of the lower extremities for the evaluation of patients with suspected pulmonary embolism has become more clearly defined with time. Ultrasonography is a useful first-line test for pulmonary embolism in clinical circumstances in which radiographic imaging is contraindicated or not readily available (eg, pregnancy). Ultrasonography is likely not required for the evaluation of patients with suspected pulmonary embolism who have a negative computed tomography pulmonary angiography, particularly if there are no symptoms of deep vein thrombosis. Ultrasonography is helpful to exclude a diagnosis of deep vein thrombosis in patients who have nondiagnostic ventilation-perfusion scans. For patients with nondiagnostic ventilation-perfusion scans and negative ultrasonography who are considered clinically highly likely to have pulmonary embolism, it is recommended that computed tomography pulmonary angiography be performed.

Thromboembolic disease after combined anterior/posterior reconstruction for adult spinal deformity: a prospective cohort study using magnetic resonance venography

STUDY DESIGN

Thromboembolic disease (TED) after anterior/posterior spinal reconstructions was prospectively evaluated in 66 consecutive patients.

OBJECTIVE

Determine the incidence of TED after anterior/posterior spinal reconstruction.

SUMMARY OF BACKGROUND DATA

Few studies have examined the rate of TED after potentially high-risk combined anterior/posterior reconstructions. Magnetic resonance venography (MRV) is more effective at detecting pelvic deep venous thrombosis (DVT) than conventional screening, but has not been used in these patients.

METHODS

We undertook a prospective cohort study of 66 consecutive adult patients (mean, 52.7 +/- 9.6 years) undergoing combined anterior/posterior spinal reconstructions for spinal deformity. All patients received only mechanical DVT prophylaxis. After surgery, MRV and bilateral lower extremity Doppler ultrasounds were obtained to screen for DVT, and contrast-enhanced spiral computed tomography scans were obtained for clinical suspicion of pulmonary embolism (PE).

RESULTS

The total incidence of postoperative TED was 13.6% (9 patients). The overall rate of DVT was 9.1% (6 patients), one-third occurring in the pelvis. PE developed in 7.6% (5 patients). In 2 patients, PE developed less than 48 hours after positive dopplers. In 3 patients, PE developed despite negative screening studies. Right-sided thoracoabdominal approaches were associated with an increased risk of developing DVT (P = 0.03, Odds Ratio 9.8), PE (P = 0.01, Odds Ratio 20), and TED (P = 0.004, Odds Ratio 12).

CONCLUSION

We report a high rate of TED after extensive anterior/posterior spinal reconstructions, for which a right-sided thoracoabdominal approach is an independent risk factor and screening ineffective at preventing PE. These patients should be considered at high risk for postoperative TED.

Major vascular injury during anterior lumbar spinal surgery: incidence, risk factors, and management

STUDY DESIGN

Retrospective chart review.

OBJECTIVE

To examine the incidence of major vascular injury during anterior lumbar spinal surgery, attempt to identify predisposing risk factors, and to discuss management techniques.

SUMMARY OF BACKGROUND DATA

Major vascular injury can be a catastrophic complication of anterior lumbar spinal surgery.

METHODS

Current procedural terminology codes were used to identify the occurrence of major vascular injury, defined as injury to the iliac vessels, vena cava, and aorta. Once identified, the office record, hospital chart, operative note, and diagnostic test results were reviewed in detail.

RESULTS

Three hundred forty-five operations were performed on 338 patients. Incidence of major vascular complication was 2.9% (10 of 345). There were 9 injuries of the common iliac vein and a single aortic injury. Risk factors identified in patients with major vascular injury were current or previous osteomyelitis or discogenic infection (n = 3), previous anterior spinal surgery (n = 2), spondylolisthesis (n = 2; 1 isthmic Grade II, 1 iatrogenic Grade II), large anterior osteophyte (n = 2), transitional lumbosacral vertebra (n = 1), and anterior migration of interbody device (n = 1). Lateral venorrhaphy by suture (n = 6) and hemoclip application (n = 2) was augmented by topical agents, which constituted the sole method of repair on 1 occasion. Magnetic resonance venography demonstrated iliac vein thrombosis in 1 patient.

CONCLUSION

Current or previous osteomyelitis or discogenic infection, previous anterior spinal surgery, spondylolisthesis, osteophyte formation, transitional lumbosacral vertebra and anterior migration of interbody device point to an increased risk of vascular injury during anterior lumbar spinal surgery. Careful handling of the vascular structures and liberal use of topical hemostatic agents can lead to control of hemorrhage and preservation of vascular patency. Routine postoperative surveillance for proximal deep vein thrombosis, by magnetic resonance venography of the pelvic veins and inferior vena cava, should be performed after venorrhaphy.

Patent Foramen Ovale and Stroke: Prognosis and Treatment in Young Adults

A patent foramen ovale (PFO) is found with increased frequency in patients with stroke of undetermined origin but the significance and therapeutic implications of this observation remain unclear. Several lines of evidence suggest a role for the PFO in stroke pathophysiology for some cryptogenic stroke patients, such as those whose PFO is accompanied by a prothrombotic state, atrial septal aneurysm, or lower extremity/pelvic DVT. Diagnostic evaluation of the patient with cryptogenic stroke and PFO is directed at identifying these subgroups. Appropriate therapy for primary and secondary stroke prevention in a subject with a PFO remains unclear given current uncertainties as to the pathophysiological significance of PFO. Additional studies are needed, such as those focused on lower extremity veins or the cardiac interatrial septum, to guide therapy in specific stroke subpopulations.

Deep Venous Thrombosis in Patients With Acute Pulmonary Embolism

STUDY OBJECTIVES

To determine the prevalence of lower-limb deep venous thrombosis (DVT) that can be detected by compression ultrasonography (CUS) in patients with symptomatic pulmonary embolism (PE) diagnosed with spiral CT pulmonary angiography (CTPA); and to explore the risk factors for positive CUS results and the prognostic significance of such findings.

DESIGN

Post hoc analysis of data from a prospective multicenter outcome study of 1,041 patients with clinically suspected non-severe PE. All patients underwent CTPA and CUS within 24 h of enrollment and were followed up for 3 months.

PATIENTS

Among the 290 patients with positive CT findings, CUS was diagnostic in 281 patients who constitute the study population.

RESULTS

Mean age +/- SD was 64.3 +/- 17.7 years; 128 patients (44.8%) were men. DVT signs or symptoms were present in 90 patients (32%). CUS detected DVT in 169 patients (60.1%; 95% confidence interval [CI], 54.1 to 65.9%), including 127 patients (45.2%; 95% CI, 39.3 to 51.2%) with proximal DVT. Sensitivity and specificity of DVT symptoms for CUS-detectable DVT were 43% and 85%, respectively. Multivariate analysis showed that an age > or = 70 years (odds ratio [OR], 1.90; 95% CI, 1.14 to 3.17) and the presence of DVT signs or symptoms (OR, 4.12; 95% CI, 2.24 to 7.55) were independent risk factors for positive CUS results. DVT symptoms (OR, 4.78; 95% CI, 2.75 to 8.33) and a history of venous thromboembolism (OR, 2.59; 95% CI, 1.46 to 4.62) were independent risk factors for proximal DVT. The 3-month risk of recurrent thromboembolic event or death was not significantly different among patients with and without DVT (6.5% vs 2.7%, p = 0.15).

CONCLUSION

These results do not support screening for DVT in patients with CTPA-proven symptomatic PE; however, they suggest that CUS might prove especially efficient and safe as a frontline test in elderly patients with suspected PE. Further studies are needed before these conclusions can be translated into clinical recommendations.

Acute pulmonary embolism: an update on diagnosis and management

Pulmonary embolism (PE) is a common problem. Given the significant overlap of symptoms and signs between the presentation of PE and acute coronary syndromes, it becomes clear that cardiologists must be familiar with the diagnosis and treatment of PE. The critical issue is always to consider PE in the diagnosis of chest pain. It is then important to determine the likelihood of the diagnosis. For patients at moderate-to-high risk, helical CT provides a rapid and noninvasive diagnostic tool. Several other imaging studies are also available including ventilation/perfusion (V/Q) scan, magnetic resonance imaging, and pulmonary arteriography. Echocardiography can also provide valuable prognostic information. Several biomarkers including the d-dimers, troponins, and natriuretic peptides may provide additional information. The cornerstone of treatment includes anticoagulation. For patients with massive or submassive PE, thrombolysis and embolectomy should be considered. Finally, both primary and secondary prevention are critical to the long-term health of the patient.

Patent foramen ovale and its relationship to stroke

This article discusses the relationship between patent foramen ovale and stroke, particularly in reference to paradoxical embolism as a cause of cryptogenic stroke.

Computed tomography findings in 10 cases of iliac vein compression (May-Thurner) syndrome

OBJECTIVE

To present the computed tomography (CT) findings for the iliac veins of 10 patients who had left-sided lower extremity deep vein thrombosis due to iliac vein compression syndrome.

MATERIALS AND METHODS

The CT findings for 10 cases of left-sided acute or chronic deep vein thrombosis caused by iliac vein compression syndrome were retrospectively evaluated. The patients were five women and five men (mean age+/-S.D., 49.9+/-15.6 years). In each patient with iliac vein compression syndrome, the diagnosis of the compression was established by venography performed during endovascular treatment. Diameter of the left common iliac vein was also measured in 14 control subjects without any lower extremity venous disease for comparison.

RESULTS

In all 10 cases, CT images in the transverse plane demonstrated the left common iliac vein being compressed by the overlying right common iliac artery. The mean diameter at the origin of the left common iliac vein (3.5 mm) in patients group was much smaller than the mean diameter of the same vein (11.5 mm) in the control group (p<0.01). The mean percent stenosis of the left common iliac vein due to compression by the artery was 68%.

CONCLUSION

Pelvic CT images in the transverse plane are useful for detecting iliac vein compression by the overlying right common iliac artery in patients with left-sided deep vein thrombosis. Radiologists should be aware of this imaging finding of iliac vein compression by the artery where the inferior vena cava bifurcates into the common iliac veins.

Endovascular management of iliofemoral venous occlusive disease

New developments in the management of both acute and chronic iliac vein occlusive disease offer exciting options for the treatment of this often debilitating condition. Percutaneous clot removal using thrombolysis, mechanical thrombectomy, or a combination of the two is fast becoming the treatment of choice for patients presenting with acute iliofemoral deep vein thrombosis. Recanalization of chronic iliac vein occlusions with balloon angioplasty and stenting relieves symptoms of extremity swelling and pain in the majority of treated patients. Existing data provide convincing proof of the efficacy of endovascular recanalization procedures, and upcoming prospective, controlled trials will further clarify the role of these techniques in the therapeutic armamentarium.

Magnetic resonance angiography

MRA and MRI have become increasingly important diagnostic modalities in vascular surgery. The ability to obtain cross-sectional and angiographic images by these noninvasive and non-nephrotoxic modalities represents one of the most significant advances in vascular surgery over the past decade. We review the current status of MRI and MRA in vascular surgical practice.

Diagnosing pulmonary embolism

Objective testing for pulmonary embolism is necessary, because clinical assessment alone is unreliable and the consequences of misdiagnosis are serious. No single test has ideal properties (100% sensitivity and specificity, no risk, low cost). Pulmonary angiography is regarded as the final arbiter but is ill suited for diagnosing a disease present in only a third of patients in whom it is suspected. Some tests are good for confirmation and some for exclusion of embolism; others are able to do both but are often non-diagnostic. For optimal efficiency, choice of the initial test should be guided by clinical assessment of the likelihood of embolism and by patient characteristics that may influence test accuracy. Standardised clinical estimates can be used to give a pre-test probability to assess, after appropriate objective testing, the post-test probability of embolism. Multidetector computed tomography can replace both scintigraphy and angiography for the exclusion and diagnosis of this disease and should now be considered the central imaging investigation in suspected pulmonary embolism.

Increased Pelvic Vein Thrombi in Cryptogenic Stroke

BACKGROUND AND PURPOSE

Cryptogenic stroke is associated with an increased prevalence of patent foramen ovale. The Paradoxical Emboli From Large Veins in Ischemic Stroke (PELVIS) study hypothesized that patients with cryptogenic stroke have an increased prevalence of pelvic deep venous thrombosis (DVT).

METHODS

At 5 sites, patients 18 to 60 years of age received an MRI venogram (MRV) of the pelvis within 72 hours of new symptom onset. Clinical data were then determined. Radiologists blinded to clinical data later read the scans.

RESULTS

The 95 patients who met entry criteria were scanned. Their mean+/-SD age was 46+/-10 years, and time from stroke onset to pelvic MRV scan was 49+/-16 hours. Compared with those with stroke of determined origin (n=49), patients with cryptogenic stroke (n=46) were significantly younger, had a higher prevalence of patent foramen ovale (61% versus 19%), and had less atherosclerosis risk factors. Cryptogenic patients had more MRV scans with a high probability for pelvic DVT (20%) than patients with stroke of determined origin (4%, P<0.03), with most having an appearance of a chronic DVT.

CONCLUSIONS

In this study of young stroke patients evaluated early after stroke, patients with cryptogenic stroke showed differences in several clinical features compared with patients with stroke of determined origin, including increased prevalence of pelvic DVT. The results require confirmation but suggest that paradoxical embolus from the pelvic veins may be the cause of stroke in a subset of patients classified as having cryptogenic stroke.

CT for thromboembolic disease

Pulmonary embolism (PE) and deep venous thrombosis (DVT) constitute the two clinical manifestations of venous thromboembolic disease (VTE). The recent innovation of computed tomography venography (CTV) in conjunction with CT pulmonary arteriography (CTPA) provides a single noninvasive diagnostic test that can evaluate both components of VTE. PE is often an underestimated, underdiagnosed, and, consequently, undertreated disease entity. Herein, we review the epidemiology of thromboembolic disease, the diagnostic algorithm used in evaluation of patients with suspected VTE, and protocols for performing CTPA and CTV. Interpretation of these examinations is discussed in detail, because CTPA may pose new challenges to the practicing radiologist.