Venous valvular reflux in veins not involved at the time of acute deep vein thrombosis

Diagnosis of post-thrombotic syndrome: International union of phlebology (UIP) survey of medical specialists

OBJECTIVE

To review the current approaches to the diagnosis of Post-Thrombotic Syndrome (PTS) and to evaluate the potential need for a diagnostic tool.

METHOD

Medical specialists were invited to participate in an online survey of their current approaches to the diagnosis and management of PTS, including the use of scoring systems, diagnostic imaging techniques and the extent the practitioner reviews the patient's venous history.

RESULTS

502 participants completed the survey. Over 80% obtained imaging reports to confirm a history of deep vein thrombosis (DVT). 72% of participants always obtained an up-to-date duplex ultrasound for PTS diagnosis. Over 50% did not use a scoring system for either PTS diagnosis or management. 65% of the participants agreed that a new system for PTS diagnosis should be devised.

CONCLUSION

Heterogeneity was observed in methods of diagnosing PTS by medical practitioners with frequent use of medical imaging studies and moderate use of scoring systems. Development of a new diagnostic tool for PTS should be considered for future studies.

Deep Venous Thrombosis and Ulcers of Lower Limbs: Ultrasound Findings in 156 Patients

Venous ulcers (VUs) of lower limbs affect 1% of Western population. In most cases, ultrasounds show only superficial venous insufficiency (SVI), but a deep venous insufficiency (DVI) may also be present without a history of deep vein thrombosis (DVT). To assess SVI and DVI in DVT-positive and DVT-negative patients with VU, a retrospective cohort of 123 patients entered the study (50 male and 73 female, minimum age 29 years and maximum age 90 years, and mean 70.6 years). In 56 patients (45.5%), ulcer was on the right leg, in 52 (42.3%) on the left leg, and in 15 patients (12.2%), ulcer was bilateral, resulting in a total number of 138 limbs in the study. Sixty-six patients suffered DVT, while in 72 anamnesis was negative. Color duplex ultrasound was performed on both limbs, which revealed insufficiencies of superficial and/or deep veins in 18 limbs which had not been affected by an ulcer or a previous DVT. So the study was on 156 limbs. SVI were substantially overlapping in two groups ( p -value = 0.593), while combined SVI and DVI was 72.5% in DVT positive limbs ( p -value = 0.001). In 70% of cases with a femoral vein insufficiency ( p -value = 0.036) or popliteal vein insufficiency (PVI) ( p -value 0,003), a DVT history was present. Of 18 limbs, although not affected by ulcer or previous DVT, eight were positive for DVI (two femoral veins and six popliteal veins). In the patient with VU, the history of DVT is a strong predictor of DVI insufficiency. In DVT-positive patients with ulcer, the number of "combined superficial and deep insufficiencies" appears to be particularly significant and surgical treatment must take this into account. A previous DVT has a low impact on great and small saphenous insufficiencies in ulcer patients; these were substantially overlapping in DVT-positive and DVT-negative patients. The 18 limbs with DVI and SVI without ulcer and DVT history were unexpected result. We think these patients must have a close follow-up to avoid the onset of a VU.

A narrative review on the epidemiology, prevention, and treatment of venous thromboembolic events in the context of chronic venous disease

OBJECTIVE

Chronic venous disease (CVD) describes a spectrum of conditions associated with venous hypertension. The association between various CVD etiologies and the subsequent risk of venous thromboembolism (VTE), such as deep vein thrombosis or pulmonary embolism, is a topic of considerable clinical interest. The aims of the present review were to characterize the risk of VTE according to the CVD etiology and to determine the optimal anticoagulation strategy for the treatment or prevention of VTE in patients with CVD.

METHODS

An extensive search of the available surgical and medical data was conducted in PubMed and Google Scholar. We searched for the following terms and other related terms to identify relevant studies: CVD, chronic venous insufficiency, varicose veins, post-thrombotic syndrome (PTS), anticoagulation, venous thromboembolism, and venous disease scoring systems (eg, CEAP [clinical, etiology, anatomic, pathophysiology], Villalta, Ginsberg, venous clinical severity score). The identified studies included randomized control trials, retrospective and prospective observational studies, narrative and systematic reviews, case reports, and case series that contributed to the proposed aims. The ClinicalTrials.gov database was also queried to identify any relevant ongoing clinical trials.

RESULTS

Congenital CVD carries a heightened risk of VTE, although few higher level studies are available to inform on this topic or on the appropriate anticoagulation strategies for these patients. Noncongenital CVD seems to carry a heightened risk of VTE, although few studies have adequately differentiated between primary and secondary etiologies. Varicose veins are a risk factor for primary VTE but might not be associated with an increased risk of recurrent VTE. In the hospital setting, patients with varicosities should be provided thromboprophylaxis. In the setting of varicose vein intervention, high-risk patients should be identified using risk assessment models and receive thromboprophylaxis. The risk of recurrent VTE in the setting of PTS is unclear but indefinite anticoagulation is not currently indicated. For patients with PTS, residual vein thrombosis might be an indicator of when anticoagulation can be safely stopped, although practical limitations to its application exist.

CONCLUSIONS

CVD is associated with an increased risk of VTE. Few studies have differentiated between classes of CVD using a standardized method and have assessed the efficacy of anticoagulation prophylaxis against or treatment of VTE. Additional studies are needed to determine the optimal therapy for preventing and treating VTE in patients with active concurrent CVD.

Post-thrombotic Syndrome: Preventative and Risk Reduction Strategies Following Deep Vein Thrombosis

Venous disease is common in the general population, with chronic venous disorders affecting 50–85% of the western population and consuming 2–3% of healthcare funding. It, therefore, represents a significant socioeconomic, physical and psychological burden. Acute deep vein thrombosis, although a well-recognised cause of death through pulmonary embolism, can more commonly lead to post-thrombotic syndrome (PTS). This article summarises the pathophysiology and risk factor profile of PTS, and highlights various strategies that may reduce the risk of PTS, and the endovenous management of iliofemoral deep vein thrombosis. The authors summarise the advances in PTS risk reduction strategies and present the latest evidence for discussion.

How I use catheter-directed interventional therapy to treat patients with venous thromboembolism

Patients who present with severe manifestations of acute venous thromboembolism (VTE) are at higher risk for premature death and long-term disability. In recent years, catheter-based interventional procedures have shown strong potential to improve clinical outcomes in selected VTE patients. However, physicians continue to be routinely faced with challenging decisions that pertain to the utilization of these risky and costly treatment strategies, and there is a relative paucity of published clinical trials with sufficient rigor and directness to inform clinical practice. In this article, using 3 distinct clinical scenario presentations, we draw from the available published literature describing the natural history, pathophysiology, treatments, and outcomes of VTE to illustrate the key factors that should influence clinical decision making for patients with severe manifestations of deep vein thrombosis and pulmonary embolism. The results of a recently completed pivotal multicenter randomized trial are also discussed.

Catheter-directed thrombolysis to avoid late consequences of acute deep vein thrombosis

The application of catheter-based methods to treat acute deep vein thrombosis (DVT) has increased in recent years. Catheter-directed thrombolysis (CDT), introduced during the early 1990s, has shown the ability to rapidly eliminate thrombus and is used in many centers as a salvage therapy for DVT patients who exhibit a poor initial response to anticoagulant therapy. However, CDT has disadvantages in terms of safety and resource use. Although CDT methods have evolved substantially to try to address these issues, for most of the last 25years there was little high-quality data on CDT outcomes upon which to base patient care decisions. The paucity of evidence was particularly problematic for long-term outcomes such as recurrent venous thromboembolism (VTE) and the post-thrombotic syndrome (PTS). Fortunately, rigorous studies of CDT are now being completed. Accordingly, the purpose of this article is to: 1) state the known and unknown factors influencing risk and benefit with use of CDT and related methods to treat acute DVT; 2) summarize emerging evidence showing the patient outcomes that occur when CDT is used for first-line management of DVT; and 3) suggest clinical parameters for CDT utilization in light of the available evidence.

Development of Postthrombotic Syndrome After Acute Unilateral Iliofemoral Thrombosis: Clinical Dynamics and Hemodynamic Changes

Four hundred thirty-six patients with acute unilateral thrombosis in the iliofemoral venous segment were followed up to establish the relationship between changes in the veins and clinical dynamics of postthrombotic syndrome. Physical examination and ascending phlebography were performed at the time of admission and 1 month later. Follow-up visits (physical examination and venous ultrasound study) were performed annually during 10 years. Cumulative rate of class 0 extremities decreased from 89% at the first year to 59% after 10 years. Progressive dynamics was seen in 41% of cases; 17% of these extremities had occlusions, and 83% had proximal reflux; 59% of the extremities demonstrated stable-type clinical dynamics. Occlusions were found in 41% and reflux in 59% of these cases. Recanalization and valvular incompetence at the site of the initial deep vein thrombosis are more likely to lead to progressive type of the disease. Valvular incompetence in the distal veins does not correlate with severity of the disease.

Venous Imaging for Reflux Using Duplex Ultrasonography

Refinements in pulsed wave and color flow Doppler in conjunction with gray scale ultrasound have made duplex ultrasonography the optimal diagnostic modality for assessment of lower extremity venous reflux. This safe, non-invasive, and cost-effective modality can accurately determine reflux in the deep, perforating and superficial venous systems of the lower extremity. However, proper technique and uniform testing using duplex ultrasonography and rapid cuff deflation are essential. In this article, the authors provide an overview of the technical and interpretive aspects of duplex ultrasound imaging for reflux in the veins of the lower extremity.

Chronic Venous Obstruction: Diagnostic Considerations and Therapeutic Role of Percutaneous Iliac Stenting

Iliac venous outflow obstruction has an important role in the expression of symptomatic chronic venous insufficiency. This anatomic obstruction is frequently overlooked, owing in part to diagnostic difficulty. The combination of venous obstruction and reflux leads to more severe clinical disease. Current diagnostic modalities do not allow an definitive assessment of hemodynamically critical venous obstruction. No single invasive or noninvasive study can accurately detect borderline obstruction of potential hemodynamic significance. A high index of suspicion is critical in the initial recognition of chronic venous obstruction. The diagnosis relies on clinical signs and symptoms and radiologic assessment of morphologic venous outflow obstruction. Treatment strategy should be based on the results of morphologic investigations such as transfemoral phlebography or, preferably, intravascular ultrasonography. Percutaneous iliac venous stenting offers a safe and efficient method to correct pelvic venous obstruction. Percutaneous iliac stenting does not preclude subsequent venous bypass or corrective superficial and deep reflux surgery. This article reviews the etiologic factors and diagnostic modalities of iliac venous obstruction. The therapeutic role of percutaneous iliac stenting in the management of venous obstruction is also discussed.

Primary venous insufficiency increases risk of deep vein thrombosis

BACKGROUND

Varicose veins have been recognized as a risk factor for deep vein thrombosis (DVT). However, venous reflux has not carried the same correlation. This study evaluated the association between primary valvular reflux and DVT.

METHODS

We performed a nested case-control study with enrollment of outpatients presenting to the vascular laboratory with signs and symptoms of DVT. All patients had a complete bilateral venous duplex examination evaluating for DVT and superficial and deep venous valvular reflux. Eighty-seven patients with confirmed DVT on venous duplex were selected for the study group. The control group was randomly selected from the same cohort in a 4:1 ratio matched by age and gender (n = 348). Groups were compared for the prevalence of deep and superficial reflux.

RESULTS

DVT outpatients were 4.7-times more likely to have primary valvular reflux than symptomatic controls (65.5% vs 29.0%; 95% confidence interval [CI], 2.8-7.7; P < .000001). Deep reflux was 2.1-times more prevalent (36.8% vs 21.6%; odds ratio, 2.12; 95% CI, 1.28-3.51; P = .005) and superficial reflux was 4.6-times more prevalent (43.7% vs 14.4%; odds ratio, 4.62; 95% CI, 2.75-7.77; P < .0000001) in DVT patients than in controls. DVT patients were also 2.1-times more likely to have combined deep and superficial reflux than non-DVT patients (13.8% vs 6.6%, 95% CI, 1.08-4.75; P = .044).

CONCLUSIONS

The prevalence of primary valvular reflux in patients with DVT is significantly higher than expected. Reflux may be considered as a novel risk factor for DVT. Two-thirds of patients with DVT have pre-existent primary chronic venous disease, which is likely to contribute to post-thrombotic morbidity.

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.

Interventional therapy for venous thromboembolism

Advances in image-guided, catheter-based interventions have shown great potential to improve outcomes in patients with venous thromboembolism. Catheter-directed thrombolysis has been shown in one randomized controlled trial to reduce the risk of post-thrombotic syndrome in patients with acute lower extremity deep vein thrombosis; data from a larger national institute of health trial are expected in early 2017. The use of catheter-directed thrombolysis is also being increasingly considered for patients with submassive or massive pulmonary embolism. Preliminary studies suggest that endovascular stent placement and ablative therapies may be used to reduce symptoms and improve quality of life in severely affected patients with established post-thrombotic syndrome. In this article, we summarize the risks and benefits of endovascular venous thromboembolism therapies as currently understood, highlight clinical situations where their benefit may outweigh risks, and describe ongoing and upcoming pivotal research initiatives with multidisciplinary participation.

Multifaceted management of the postthrombotic syndrome

The postthrombotic syndrome (PTS) is a frequent cause of chronic pain, swelling, ulceration, and disability in patients with lower extremity deep vein thrombosis (DVT). As interventional radiologists are consulted on more patients with chronic DVT and PTS, their management strategies must be informed by a balanced understanding of the different facets of chronic DVT care and the available treatment options. This article provides an overview of the important elements of a multifaceted approach to the management of patients with PTS that includes pharmacological, physiological, and endovascular aspects of care.

Interventional approaches to deep vein thrombosis

The last decade has seen increased use of aggressive, catheter-based methods of treating deep vein thrombosis (DVT). In this article, we outline the risks, benefits, and uncertainties surrounding endovascular DVT therapies, describe clinical situations in which endovascular treatment options should reasonably be considered, and update the reader on new outcome data that pertains to catheter-based DVT interventions. Endovascular thrombolytic therapy is reasonable to perform for selected patients with DVT causing acute limb-threatening circulatory compromise, acute inferior vena cava occlusion, or acute iliofemoral DVT for the purposes of limb salvage and relief of presenting DVT symptoms, and appears likely to prevent post-thrombotic syndrome (PTS) in patients with proximal DVT. A multicenter randomized trial, the ATTRACT Study, is currently underway in the United States to determine whether pharmacomechanical catheter-directed thrombolysis (PCDT) is sufficiently safe and effective to be recommended for routine use in proximal DVT patients. Selected patients with established moderate-to-severe PTS in association with an occluded iliac vein or a refluxing saphenous vein may also be amenable to endovascular intervention to reduce venous hypertension, alleviate symptoms, and improve limb function and quality of life. Pending the results of further studies, an individualized approach to patient selection for interventional DVT therapies is recommended.

Rationale and Indications for Aggressive Early Thrombus Removal

Randomized clinical trials have defined anticoagulation with unfractionated or low-molecular-weight heparin followed by warfarin as a standard therapy for acute deep venous thrombosis (DVT). Such treatment is highly effective in preventing recurrent venous thromboembolism with a low risk of bleeding, but provides imperfect protection against development of the post-thrombotic syndrome. Several strategies of early thrombus removal, including surgical venous thrombectomy, catheter-directed thrombolysis and pharmacomechanical thrombectomy have been developed with the goal of reducing the incidence of the post-thrombotic syndrome by restoring venous patency and preserving valvular function. Although clinical judgement and a consideration of the individual patient's medical condition and values are required, early thrombus removal strategies should be considered in selected patients with phlegmasia cerulea dolens and those with a first episode of acute iliofemoral thrombosis of less than 14 days duration.

Evaluating the Role of Compression Stockings in Preventing Post thrombotic Syndrome: A Review of the Literature

Background. Postthrombotic syndrome (PTS) is a burdensome and costly complication of deep vein thrombosis (DVT). Up to 50% of patients with DVT will develop the disease within two years following the diagnosis of acute DVT. Various risk factors for developing PTS have been identified and different modalities have been used to prevent its development. Compression stockings have been studied for the prevention of PTS in patients diagnosed with proximal DVT. Methods. MEDLINE and EMBASE databases were searched to identify relevant original articles. Results. Several trials including two metaanalyses have examined the role of compression stockings for the prevention of PTS. Although most trials showed significant reduction in the development of PTS with the use of compression stockings, limitations in study design prevent the generalizability of the data. Two studies supported an individualized tailored duration especially in patients at low risk for developing the syndrome. A randomized double-blind placebo-controlled trial involving 800 patients is currently ongoing and may confirm the results of older studies. Conclusions. Clinical trials support the use of compression stockings in patients diagnosed with proximal DVT for the prevention of PTS.

Endovascular Procedures in the Management of DVT

The post-thrombotic syndrome (PTS) develops in 25%-50% of patients with proximal lower extremity deep vein thrombosis (DVT) despite the use of standard anticoagulant therapy and elastic compression stockings. PTS is a major cause of quality of life impairment in DVT patients and often leads to limiting venous claudication, work disability, and venous ulcers. Endovascular thrombolytic procedures that eliminate venous thrombus, restore venous flow, and show strong potential to prevent PTS are now under study in multicenter randomized clinical trials. In addition, endovascular procedures can be used to treat valvular reflux and venous obstruction and thereby provide symptom improvement to patients with chronic established PTS.

Pathophysiology of Post-Thrombotic Syndrome: The Effect of Recurrent Venous Thrombosis and Inherited Thrombophilia

Post-thrombotic syndrome is an important chronic complication of deep vein thrombosis. This syndrome can be debilitating to patients and has a major economic impact on health care services. The pathophysiology of post-thrombotic syndrome is currently incompletely understood. Because therapeutic options for post-thrombotic syndrome are extremely limited and results are often disappointing, recognizing of the pathophysiology and risk factors of this syndrome is essential to prevent the disabling consequences of this disease. The present paper focuses on risk determinants of post-thrombotic syndrome after deep vein thrombosis. The contribution of recurrent venous thrombosis and inherited thrombophilia to the pathogenesis of this syndrome is reviewed and discussed in details.

The role of thrombolysis in the clinical management of deep vein thrombosis

The cornerstones of current management of deep vein thrombosis (DVT) are the routine use of anticoagulant therapy, graduated elastic compression stockings, and early ambulation. Thrombolytic therapy was previously reserved only for patients with life-, limb-, or organ-threatening complications. However, the postthrombotic syndrome has been increasingly recognized as a frequent and serious long-term complication of DVT. In parallel, endovascular thrombolytic methods have evolved considerably in recent years, prompting discussion and controversy as to whether they should be more liberally used. In some centers, pharmacomechanical catheter-directed thrombolysis is now routinely used in the treatment of acute iliofemoral DVT. Randomized trials are currently under way to determine when the use of pharmacomechanical catheter-directed thrombolysis is appropriate in patients presenting with acute proximal DVT.

Early Outcomes and Risk Factors in Venous Thrombectomy: An Analysis of the American College of Surgeons NSQIP Dataset

Objectives: Thrombus removal has been shown to improve venous physiology in acute iliofemoral deep-venous thrombosis. Our study focuses on the contemporary application of venous thrombectomy based on data from the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP). Methods: Data submitted by over 200 hospitals to the ACS NSQIP participant use file was accessed for the years 2005-2008. The ACS NSQIP protocol provides clinically rigorous preoperative risk and 30-day outcomes for a prospective and systematic sample of vascular surgery patients. Patients were identified who had undergone venous thrombectomy through leg access (Primary procedure CPT 34421 or 34451). Demographic and clinical variables along with 30-day morbidity (1 or more of 21 defined complications) and mortality were evaluated. Secondary/concomitant procedures CPT codes were collected. Univariate analysis between groups was performed using χ 2 or T-tests with P ≤ .05 considered significant. Results: A total of 91 patients were identified who underwent primary venous thrombectomy. The mean age was 62.5 ± 15.8 y and 45 of 91 (49.5%) were female. Thirty-day mortality was 8.8% (8/91). Composite morbidity was 25.3% (23/91). Intraoperative transfusion was required in 18.7% of the patients, lower extremity fasciotomy was performed in 8.8% of the patients and an inferior vena cava (IVC) filter was placed in 2.2% of the patients. An arteriovenous anastomosis was created in only 1 patient; venous angioplasty was performed in 3.3% of the patients. Conclusions: Venous thrombectomy is associated with significant postoperative morbidity and mortality. This is at least partially due to the associated comorbidities of this patient population, approximately 1/5 in our study were ASA class 4. Most frequent causes of morbidity are pulmonary and wound infection complications. Only 2 patients had an IVC filter placed during the operation. Adjunctive procedures to assist vein patency such as arteriovenous fistula creation or venous angioplasty were infrequently performed.

The Post-Thrombotic Syndrome

The post-thrombotic syndrome (PTS) is an important chronic complication of deep vein thrombosis (DVT). The present review focuses on risk determinants of PTS after DVT and available means to prevent and treat PTS. More than one-third of patients with DVT will develop PTS, and 5% to 10% of patients develop severe PTS, which can manifest as venous ulcers. PTS has an adverse impact on quality of life as well as significant socioeconomic consequences. The main risk factors for PTS are persistent leg symptoms 1 month after acute DVT, anatomically extensive DVT, recurrent ipsilateral DVT, obesity, and older age. Subtherapeutic dosing of initial oral anticoagulation therapy for DVT treatment may also be linked to subsequent PTS. By preventing the initial DVT and DVT recurrence, primary and secondary prophylaxis of DVT will prevent cases of PTS. Daily use of elastic compression stockings for 2 years after proximal DVT appears to reduce the risk of PTS; however, uncertainty remains regarding optimal duration of use, optimal compression strength, and usefulness after distal DVT. The cornerstone of managing PTS is compression therapy, primarily using elastic compression stockings. Venoactive medications such as aescin and rutosides may provide short-term relief of PTS symptoms. Further studies to elucidate the pathophysiology of PTS, to identify clinical and biological risk factors, and to test new preventive and therapeutic approaches to PTS are needed.

A follow-up study of the fate of small asymptomatic deep venous thromboses

Background

Postoperative asymptomatic deep venous thromboses (ADVT) can give rise to posttthrombotic syndrome (PTS), but there are still many unresolved issues in this context. For example, there is a lack of knowledge regarding the fate of small ADVT following minor orthopedic surgery. This follow-up study evaluates postthrombotic changes and clinical manifestations of PTS in a group of patients with asymptomatic calf vein DVT after surgery for Achilles tendon rupture.

Methods

Forty-six consecutive patients with distal ADVT were contacted and enrolled in a follow-up consisting of a single visit at the hospital at a mean time of 5 years postoperatively, including clinical examination and scoring, ultrasonography and venous plethysmography. All patients had participated in DVT-screening with colour duplex ultrasound (CDU) 3 and 6 weeks postoperatively and 80% of them were treated with anticoagulation.

Results

With CDU postthrombotic changes and deep venous reflux were detected at follow-up in more than 50% of the patients, more commonly in somewhat larger calf DVT:s initially affecting more than one vessel. However, only about 10% of the patients had significant venous reflux according to venous plethysmography. No patient had plethysmographic evidence of remaining outflow obstruction, but presence of postthrombotic changes shown with CDU negatively influenced venous outflow capacity measured with plethysmography. A clinical entity of PTS was rarely found and occurred only in two patients (4%) and then classified by Villalta scoring as of mild degree with few clinical signs of disease. Distal ADVT:s detected in the early postoperative period (3 weeks) showed DVT-progression in 75% of the limbs that were still immobilized and without anticoagulation.

Conclusions

Asymptomatic postoperative distal DVT:s following surgery for Achilles tendon rupture have a good prognosis and a favourable clinical outcome. In our material of 46 patients the general appearance of the clinical entity of PTS at 5 years follow-up was low (<5%). Morphological and functional abnormalities were mainly seen in those patients that initially had somewhat larger distal DVT:s involving more than one deep calf vein segment.

Deep venous thrombosis: the opportunity at hand

OBJECTIVE

The use of imaging-guided treatments for deep venous thrombosis (DVT) is accelerating. Increased appreciation of the impact of postthrombotic syndrome on DVT patients' quality of life and advances in thrombolytic methods have together sparked an unprecedented degree of interdisciplinary collaboration in developing contemporary DVT treatment guidelines and a pivotal clinical trial to establish the risk-benefit ratio of interventional DVT therapy.

CONCLUSION

Radiologists should improve their DVT education, support ongoing clinical trials, and collaborate with DVT-focused nonradiologists in their institutions.

How I treat postthrombotic syndrome

Postthrombotic syndrome (PTS) is a chronic complication of deep venous thrombosis (DVT) that reduces quality of life and has important socioeconomic consequences. More than one-third of patients with DVT will develop PTS, and 5% to 10% of patients will develop severe PTS, which may manifest as venous ulceration. The principal risk factors for PTS are persistent leg symptoms 1 month after the acute episode of DVT, extensive DVT, recurrent ipsilateral DVT, obesity, and older age. Daily use of elastic compression stockings (ECSs) for 2 years after proximal DVT appears to reduce the risk of PTS; however, there is uncertainty about optimal duration of use and compression strength of ECSs and the magnitude of their effect. The cornerstone of managing PTS is compression therapy, primarily using ECSs. Venoactive medications such as aescin and rutoside may provide short-term relief of PTS symptoms. The likelihood of developing PTS after DVT should be discussed with patients, and symptoms and signs of PTS should be monitored during clinical follow-up. Further studies to elucidate the pathophysiology of PTS, to identify clinical and biologic risk factors, and to test new preventive and therapeutic approaches to PTS are needed to ultimately improve the long-term prognosis of patients with DVT.

Valvular dysfunction and venous obstruction in the post-thrombotic syndrome

Medical thrombosis physicians have tended to view deep vein thrombosis (DVT) as essentially a problem of biology and hematology. This "field condition" concept holds that in susceptible individuals, DVT risk factors lead to a global hypercoagulable state which results in venous thrombosis. However, less attention has been paid to the key problems of venous anatomy and physiology that lead to the post-thrombotic syndrome (PTS) and its major health consequences. The primary objectives of this article are: (1) to review the macroscopic pathophysiology of PTS; (2) to discuss the roles of valvular reflux and venous obstruction in the development of PTS; and (3) to explore new endovascular PTS prevention and treatment strategies that feature the prevention or elimination of valvular reflux and late venous obstruction to improve DVT patient outcomes.

[New results in the research of the biomechanics of the venous system]

The upright posture of man had been a major evolutional challenge. The mechanisms responsible for orthostatic tolerance mostly affect the venous system. In this paper, we discuss new results regarding the biomechanics of the venous system highlighting a rather neglected field, the biomechanical properties of the vein wall. These properties change according to localization of veins, age, gender and body mass. The anti-gravitational adaptation of veins is a complex process involving all three layers of the venous wall. Local myogenic and humoral mechanisms as well as systemic hormonal and nervous influences control the adaptive processes in the veins. Long term adaptation involves structural and functional remodeling of the venous wall. Disorders of the veins mostly cause pathological remodeling. Hemodynamic factors (pressure and flow) together with inflammatory processes may lead to pathological alterations, changing the biomechanical properties of the vein wall, which further contribute to the reservation and progression of venous dysfunction. Appropriate testing of venous function can reveal biomechanical disorders even in clinically asymptomatic patients. Thus, biomechanical investigation of veins not only helps to understand the underlying pathomechanism but it also can contribute to early diagnosis and follow-up of venous disorders. When recognized in time, pathological remodeling can be prevented or treated. In this way, the incidence of venous disorder could be cut back reducing both human suffering and material loss.

Superficial venous interventions: assessing the risk of DVT

Objectives

Understand the potential consequences of deep vein thrombosis (DVT) in patients undergoing superficial venous interventions, the proper way to assess DVT risk in patients with superficial venous disease and the appropriate management of patients stratified by risk level.

Methods

Review of published literature

Results

Because DVT can have major long-term consequences, DVT risk should be assessed as a routine part of the preprocedure evaluation of venous disease. Chronic venous disease may have multiple contributing factors amenable to treatment in both the superficial and deep venous systems.

Conclusion

Superficial venous interventions should be deferred in patients at particularly high risk for DVT, but may be performed with appropriate countermeasures for DVT prophylaxis in patients at moderate risk.

Five-year outcome study of deep vein thrombosis in the lower limbs

OBJECTIVE

Venous disease was evaluated in relation to post-thrombotic syndrome 5 years after deep venous thrombosis (DVT) in patients treated with a regimen of low-molecular-weight heparin (LMWH) and warfarin in a Hospital-in-the-Home program.

METHODS

The presence of flow, reflux and compressibility in 51 patients (102 limbs, 54 with DVT and 48 without DVT) was assessed by duplex ultrasound scanning. Blood tests were carried out for prothrombotic screening. Venous disease was related to pathologic severity of post-thrombotic syndrome, characterized by the CEAP (clinical, etiologic, anatomic, pathophysiologic) classification on a scale of 0 to 6.

RESULTS

In the 102 limbs studied, 30 patients (59%) had an underlying thrombophilic disorder. The most common cause of DVT was postoperation and prolonged immobilization not related to postoperation. The most common thrombophilic abnormalities were anticardiolipin antibody and a deficiency of protein C or S, or both. Twenty-six limbs (48%) had proximal involvement (proximal and proximal plus distal DVT); resolution (recanalization or normal vein) in these limbs was seen in 85% at 6 months and 96% at 5 years. After 5 years, 25 of these proximal DVT limbs (96%) developed reflux and there were 4 limbs in CEAP class 0, 8 in classes 1 to 3, and 14 in classes 4 to 6. All of the 28 limbs (52%) with distal DVT showed DVT resolution by 6 months. After 5 years, 10 limbs (36%) developed reflux, and 13 limbs were in class 0, 12 in classes 1 to 3, and 3 limbs in classes 4 to 6. No DVT was detected in the 48 contralateral limbs, but reflux was detected in 25 limbs (52%), predominately in the superficial veins (16 limbs, 64%).

CONCLUSIONS

The resolution of thrombus was more rapid and complete in patients with distal DVT than in those with proximal DVT. Patients with proximal DVT developed a more severe form of post-thrombotic syndrome that was likely related to the development of deep venous reflux. An important finding of this study was an unexpectedly high incidence of venous reflux in the apparently unaffected limb. Although these non-DVT limbs were not investigated at presentation, our data is consistent with the hypothesis that DVT may result in a more systemic disorder of venous function.

Natural history of venous thromboembolism

Most deep vein thromboses (DVTs) start in the calf, and most probably resolve spontaneously. Thrombi that remain confined to the calf rarely cause leg symptoms or symptomatic pulmonary embolism (PE). The probability that calf DVT will extend to involve the proximal veins and subsequently cause PE increases with the severity of the initiating prothrombotic stimulus. Although acute venous thromboembolism (VTE) usually presents with either leg or pulmonary symptoms, most patients have thrombosis at both sites at the time of diagnosis. Proximal DVTs resolve slowly during treatment with anticoagulants, and thrombi remain detectable in half of the patients after a year. Resolution of DVT is less likely in patients with a large initial thrombus or cancer. About 10% of patients with symptomatic DVTs develop severe post-thrombotic syndrome within 5 years, and recurrent ipsilateral DVT increases this risk. About 10% of PEs are rapidly fatal, and an additional 5% cause death later, despite diagnosis and treatment. About 50% of diagnosed PEs are associated with right ventricular dysfunction, which is associated with a approximately 5-fold greater in-hospital mortality. There is approximately 50% resolution of PE after 1 month of treatment, and perfusion eventually returns to normal in two thirds of patients. About 5% of treated patients with PE develop pulmonary hypertension as a result of poor resolution. After a course of treatment, the risk of recurrent thrombosis is higher (ie, approximately 10% per patient-year) in patients without reversible risk factors, in those with cancer, and in those with prothrombotic biochemical abnormalities such as antiphospholipid antibodies and homozygous factor V Leiden.

Early thrombus remodelling of isolated calf deep vein thrombosis

OBJECTIVE

this prospective study was designed to evaluate the evolution of thrombus propagation and lysis in relation to patterns and distribution of isolated calf DVT.

METHODS

fifty-two limbs in 48 patients mean age 59+/-15, range 24-78 years, with isolated calf DVT that had at least one exam within 10 days of DVT detection were included in the study. Patients with a documented episode of prior DVT or evidence of post-thrombotic changes during the initial ultrasound exam were excluded. The initial thrombus length, patterns and location of the thrombi were recorded. On follow-up the propagation and lysis patterns of the clot were studied.

RESULTS

remodelling of the thrombus, excluding echotexture and vein diameter changes on ultrasound, occurred in 23 limbs, (44%). Ascending propagation only was seen in seven limbs (13%) descending propagation only in two (4%) and in both directions in five (10%). Propagation at least to popliteal vein was detected in seven limbs (13%). Thrombus developed or extended to initially uninvolved veins in six limbs (12%). Pulmonary embolism developed only in one patient (2%; 95% CI: 0-11%). The site and the size of thrombus or the number of veins involved in the baseline exam did not correlate with the remodeling of thrombus. Soleal and gastrocnemial veins were comparable with the posterior tibial and peroneal veins in terms of thrombus propagation and lysis.

CONCLUSIONS

early thrombus remodelling occurs in 44% of limbs with isolated calf DVT. This includes ascending and descending thrombus propagation and lysis. Thrombus development or propagation to initially uninvolved calf veins is found in 12%. Thrombus remodelling does not appear to be related to size, site and patterns of thrombosis.

A 16-year haemodynamic follow-up of women with pregnancy-related medically treated iliofemoral deep venous thrombosis

OBJECTIVES

to evaluate clinical and functional long-term outcomes following pregnancy-related medically treated iliofemoral deep venous thrombosis (DVT).

DESIGN

retrospective follow-up of patients identified through a registry search.

MATERIAL AND METHODS

twenty-five women underwent clinical examination, colour duplex ultrasound and computerised strain-gauge plethysmography on two occasions a mean of nine and 16 years after DVT.

RESULTS

40% of the patients were completely asymptomatic and 52% had no clinical signs of venous disease after a mean follow-up of 16 years. The clinical signs were in general mild, and none of the 25 patients had skin changes or ulcers. Deep venous reflux was found in 36% of the patients; the same percentage at nine- and 16-years follow-up, and 24% had normal ultrasonographic appearance of all deep veins. None of the patients had plethysmographic evidence of outflow obstruction. There was a significant relationship between measures of venous reflux and the presence of leg swelling, but there was no clear relation between functional abnormalities and the extent of the initial DVT.

CONCLUSION

even after 16 years there are relatively mild symptoms and signs of venous disease in women with medically treated pregnancy-related iliofemoral DVT. Our results do not support earlier stated opinions that these patients represent a particular risk group for developing post-thrombotic syndrome.

Deep venous thrombosis and superficial venous reflux

OBJECTIVE

Although superficial venous reflux is an important determinant of post-thrombotic skin changes, the origin of this reflux is unknown. The purpose of this study was to evaluate the frequency and etiologic mechanisms of superficial venous reflux after acute deep venous thrombosis (DVT).

METHODS

Patients with a documented acute lower extremity DVT were asked to return for serial venous duplex ultrasound examinations at 1 day, 1 week, 1 month, every 3 months for the first year, and every year thereafter. Reflux in the greater saphenous vein (GSV) and lesser saphenous vein (LSV) was assessed by standing distal pneumatic cuff deflation.

RESULTS

Sixty-six patients with a DVT in 69 lower extremities were followed up for a mean of 48 (SD +/- 32) months. Initial thrombosis of the GSV was noted in 15 limbs (21.7%). At 8 years, the cumulative incidence of GSV reflux was 77.1% (SE +/- 0.11) in DVT limbs with GSV involvement, 28.9% (+/- 0.09%) in DVT limbs without GSV thrombosis, and 14.8% (+/- 0.05) in uninvolved contralateral limbs (P <.0001). For LSV reflux, the cumulative incidence in DVT limbs was 23.1% (+/- 0.06%) in comparison with 10% (+/- 0.06%) in uninvolved limbs (P =.06). In comparison with uninvolved contralateral limbs, the relative risk of GSV reflux for DVT limbs with and without GSV thrombosis was 8.7 (P <.001) and 1.4 (P =.5), respectively. The relative risk of LSV reflux in thrombosed extremities compared with uninvolved extremities was 3.2 (P =.07). Despite these observations, the fraction of observed GSV reflux that could be attributable to superficial thrombosis was only 49%.

CONCLUSIONS

Superficial venous thrombosis frequently accompanies DVT and is associated with development of superficial reflux in most limbs. However, a substantial proportion of observed reflux is not directly associated with thrombosis and develops at a rate equivalent to that in uninvolved limbs.

Thrombolysis for experimental deep venous thrombosis maintains valvular competence and vasoreactivity

PURPOSE

Thrombolysis protects the structural and functional integrity of vein wall in an experimental model of acute deep venous thrombosis (DVT) immediately after treatment, but late sequelae have not been studied. We designed experiments to compare the effects of thrombolysis and surgical thrombectomy at 4 weeks after the treatment of DVT.

METHODS

DVT was produced bilaterally in male mongrel dogs by proximal and distal femoral vein ligation. Five dogs underwent sham operation. After 48 hours, the ligatures were removed, and the thrombosis was treated with either Fogarty balloon catheter thrombectomy (shear force, 60 g; n = 6) or catheter-directed urokinase infusion (4000 U/min for 90 minutes; n = 6). At 4 weeks, patency and valvular competence were determined by duplex ultrasound scanning. Thrombogenicity was studied by the measurement of radiolabeled fibrin and platelet deposition. Veins were explanted and prepared for histologic examination, scanning electron microscopy, and functional studies in organ chambers.

RESULTS

All veins were patent at 1 month. Recanalized thrombus was observed histologically in four (66%) thrombectomized veins, one (17%) thrombolyzed vein, and none of the sham-operated veins (P =.04). Scanning electron microscopy demonstrated similar luminal endothelial cell loss (11%-25%) in all three groups. Platelet and fibrin depositions were not different among groups. Valvular incompetence (reflux duration, >0.5 sec) did not differ significantly in the groups (thrombectomized veins, 2 of 12 (17%); thrombolyzed veins, 0 of 12 (0%); P = NS). In organ chamber studies, endothelium-dependent relaxations to calcium ionophore, but not adenosine diphosphate, were inhibited by an antagonist of nitric oxide production after thrombectomy (P <.05, thrombectomy vs sham- and thrombolysis-treated veins). All veins relaxed to exogenous nitric oxide.

CONCLUSION

Both thrombectomy and thrombolysis restored patency and achieved similar valvular competence. Surgical thrombectomy, however, resulted in more residual thrombus and contributed to changes in endothelium-mediated relaxations at 4 weeks. Thrombolysis maintained both structural integrity and endothelial function.

Indications for surgical treatment of iliofemoral vein thrombosis

The goals of treatment of acute iliofemoral DVT should be prevention of fatal PE, reduction of pain and swelling of the involved leg, trying to stop the development of phlegmasia cerulea dolens and venous gangrene, prevention of disabling PTS by early removal of the blood clot, avoiding proximal venous obstruction, preserving normal, functioning valves in the leg veins, and preventing reflux. The authors recommend an aggressive approach with rapid removal of the occluding thrombus in the leg veins extending up into the iliac veins in active patients with a short history of symptomatic DVT, usually less than 7 days. This approach is not justified in chronically ill, bedridden, high-risk, or aged patients, or those with serious intercurrent disease or limited life expectancy. In these patients, such interventions can only be indicated for limb salvage in phlegmasia cerulea dolens when conservative treatment does not prevent the development of an acute compartment syndrome with venous gangrene. The preferred means of accomplishing early and quick removal of the thrombus is CDITT. Most of the authors' positive experience with thrombolysis is based on the use of urokinase. The Food and Drug Administration (FDA) has put this drug on temporary hold for almost 1 year. The alternative drugs (e.g., tissue plasminogen activator [tPA]) have not been tested for CDITT of DVT, and tPA is not FDA-approved for this indication. When there are contraindications or failure of thrombolysis, TE with a temporary AVF is a valid alternative.

Results of valvuloplasty in patients presenting deep venous insufficiency and recurring ulceration

The purpose of this retrospective study was to assess mid-term results of valvuloplasty in patients presenting chronic recurring venous stasis ulceration. From 1988 to 1993, valvuloplasty was performed in the superficial femoral vein of 33 lower extremities in 28 patients presenting recurring ulceration. In 23 cases, previous surgery in the superficial venous system or perforating vein had failed. Preoperative work-up demonstrated primary deep venous insufficiency (PDVI) in 22 extremities (group I), proximal PDVI in association with distal postthrombotic syndrome (PTS) in 10 (group II), and Klippel-Trenaunay syndrome in 1. Hemodynamic assessment with tourniquet placement demonstrated a mean venous return time of 9 sec (+10, -8). Descending femoral phlebography showed Kistner grade 4 in 30 cases. Outcome was evaluated by clinical examination and Dupplex scan with photophlethysmography at follow-up times ranging from 2 to 7.6 years (mean: 51 months). Correlation between outcome of valvuloplasty and clinical findings was excellent. The incidence of poor clinical and hemodynamic results was higher for patients with PTS. Valve repair in association with surgery for superficial vein insufficiency and ligation of perforators gives good results in patients with isolated PDVI.

Understanding and preventing deep vein thrombosis and pulmonary embolism

Deep vein thrombosis and its complications, including pulmonary embolism, are major health problems in the United States, resulting in more than 260,000 hospital admissions and 100,000 deaths each year. Thirty percent of patients diagnosed with deep vein thrombosis will experience at least one recurrence of symptoms. To minimize patient morbidity and mortality and to contain health care costs, prevention, early diagnosis, and treatment of these conditions are essential. In this article the incidence pathophysiology risk factors, and clinical course of deep vein thrombosis and pulmonary embolism are discussed, as well as the clinician's role in prevention and treatment.

Late clinical and hemodynamic sequelae of isolated calf vein thrombosis

PURPOSE

Despite the frequent occurrence of isolated calf vein thrombosis (ICVT), little is known about the long-term clinical and hemodynamic sequelae of this condition. This study was conducted to determine late clinical symptoms and vascular laboratory abnormalities in patients after ICVT.

METHODS

Of 146 patients in whom ICVT was documented by color flow duplex scanning between 1989 and 1994, 37 were reexamined. Data included history, physical examination, venous recovery time (VRT), and duplex valve closure time (DVCT). A control group with no history of venous disease also underwent identical clinical and hemodynamic testing.

RESULTS

Thirty-seven patients (18 male and 19 female) with a median age of 56 years (range, 22 to 76 years) were examined at a mean follow-up of 3.4 years (range, 2.2 to 5.8 years) after the diagnosis of ICVT in 39 extremities. Seventeen subjects (34 extremities) were recruited as normal controls. Presenting symptoms at the time of ICVT included calf pain in 17 patients, calf swelling in seven, pain and swelling in seven, pulmonary symptoms in four, pulmonary symptoms and calf pain in one, and no symptoms in one. In the patients with ICVT, VRT was abnormal in 23% of extremities with ICVT and in 9% of extremities without ICVT. None of the extremities in the control group had an abnormal VRT (p < 0.05). DVCT was abnormal in one or more venous segments in 26% of extremities diagnosed with ICVT and in 6% of control extremities (p < 0.05). Follow-up clinical examination in patients with ICVT revealed 13 (35%) with reticular veins, 10 (27%) with varicose veins, two (5.4%) with edema, one (2.7%) with pigmentation and ulcer (contralateral extremity to ICVT with a previous history of proximal deep venous thrombosis), 13 (35%) with mild discomfort, and one (2.7%) with severe pain. All symptoms attributable to ICVT were mild in nature except in one patient who had severe pain and no physical or hemodynamic vascular laboratory abnormalities at follow-up.

CONCLUSION

At an average of 3.4 years after ICVT, approximately one third of patients showed evidence of mild to moderate venous valvular insufficiency, but mostly in segments not involved with ICVT, and few had significant clinical symptoms attributable to venous disease.