Definition of post-thrombotic syndrome of the leg for use in clinical investigations: a recommendation for standardization

Post-thrombotic syndrome: prevention is better than cure

Post-thrombotic syndrome (PTS) can be debilitating to patients and have a major economic impact on health-care services. It arises after deep venous thrombosis (DVT) due to residual venous obstruction or valvular reflux, leading to increased venous pressure in the microcirculation. While the inflammatory process at the time of DVT may aid thrombus resolution, it may also promote destruction of venous valves. The diagnosis of PTS is principally clinical and patients typically complain of leg heaviness, swelling, pain, itching, cramps, ulcer and signs of lipodermatosclerosis. Several clinical scales or classifications have been used but it is recommended that Villalta scale is the most suitable. Risk factors for PTS include a proximal DVT and recurrent thrombosis as well as obesity and prior varicose veins. Poor quality of anticoagulation control may also be a factor. Established PTS is usually managed along the same lines as chronic venous hypertension with compression therapy and leg elevation. Surgery has only a limited role but may benefit some patients. Further trials are desperately needed to define the role of acute thrombolysis and mechanical thrombectomy, which seem to be promising treatments in the studies to date. For patients who have had a DVT more attention should be given to prescribing and using compression hosiery.

Postthrombotic vein wall remodeling: preliminary observations

BACKGROUND

Postthrombotic syndrome is characterized by a fibrotic vein injury following deep vein thrombosis (DVT). We sought to quantify the change in vein wall thickness in patients who fail to resolve DVT by 6 months and whether there were differences in blood or plasma levels of inflammatory proteins associated with venous remodeling.

METHODS

Patients presenting with confirmed lower extremity DVT were prospectively recruited for this study. Duplex imaging of the lower extremity venous system was performed, and blood was collected at entrance and repeat evaluation with blood draw and ultrasound imaging at 1 and 6 months. DVT resolution and thickness of the vein wall was quantified by ultrasound imaging in each segment affected by thrombus, and a contralateral, unaffected vein wall served as a control. Gene and protein expression of inflammatory markers were examined from leukocytes and serum, respectively. Analysis of variance or Student t-tests were used, and a P < .05 was significant. N = 10 to 12 for all analyses.

RESULTS

Thirty-two patients (12 patients with DVT resolution at 6 months, 10 patients with persistent thrombus at 6 months, and 10 healthy controls) were compared. Both resolving and nonresolving DVT were associated with a 1.5- to 1.8-fold increased vein wall thickness at 6 months (P = .008) as compared with nonaffected vein wall segments. However, the thickness of the affected segments was 1.4-fold greater in patients who had total resolution of the DVT by 6 months than in patients who had persistent chronic thrombus 6 months after presentation (P = .01). There was a four- to five-fold increased level of matrix metalloproteinase-9 (MMP-9) antigen in thrombosed patients compared with nonthrombosed patient controls (P < .05), while Toll-like receptor-9 (TLR-9) gene expression was three-fold less than controls (P < .05) at enrollment. D-dimer and P-selectin were higher in thrombosed as compared to controls at diagnosis but not at 6 months. Both TLR-4 (marker of inflammation) and P-selectin gene expression were higher in leukocytes from patients with chronic DVT compared with those who resolved at 1 month after diagnosis (P < .05).

CONCLUSIONS

This preliminary study suggests ongoing vein wall remodeling after DVT, measurable by ultrasound and associated with certain biomarkers. At 6 months, the vein wall is markedly thickened and directly correlates with resolution. This suggests that the vein wall response is initiated early following thrombus formation and persists even in the presence of total resolution.

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.

An update on etiology, prevention, and therapy of postthrombotic syndrome

Postthrombotic syndrome is a common sequelae resulting from deep venous thrombosis. The primary interventions are prevention and treatment, both of which many vascular specialists may not always recognize. We review the definition, epidemiology, the basic pathophysiology, and preventative management for postthrombotic syndrome. The current primary medical and interventional treatment modalities to decrease the occurrence of postthrombotic syndrome are also highlighted. Many of these treatments are currently available and simply need to be adhered to, whereas others are a shift in the paradigm, focusing on active thrombus removal.

Predictors of the post-thrombotic syndrome with non-invasive venous examinations in patients 6 weeks after a first episode of deep vein thrombosis

BACKGROUND

Post-thrombotic syndrome (PTS) is a chronic complication of deep vein thrombosis (DVT) affecting a large number of patients. Because of its potential debilitating effects, identification of patients at high risk for the development of this syndrome is relevant, and only a few predictors are known.

OBJECTIVES

To assess the incidence and potential predictors of PTS.

METHODS

We prospectively followed 111 consecutive patients for 2 years after a first episode of objectively documented DVT of the leg. With non-invasive venous examinations, residual thrombosis, valvular reflux, calf muscle pump function and venous outflow resistance were assessed at 6 weeks, 3 months, 6 months, 1 year, and 2 years. The Clinical, Etiologic, Anatomic, and Pathophysiologi classification was used to record the occurrence and severity of PTS. Regression analysis with area under the receiver operating characteristic (ROC) curve was performed to identify potential predictors.

RESULTS

The cumulative incidence of PTS was 46% after 3 months, and the incidence and severity did not increase further. Men appeared to be at increased risk as compared with women (risk ratio [RR] 1.4, 95% confidence interval [CI] 0.9-2.2), as were patients over 50 years as compared with younger patients (RR 1.4%, 95% CI 0.9-2.1). Patients with thrombosis localized in the proximal veins at diagnosis had an increased risk of PTS as compared with patients with distal thrombosis (RR 2.3%, 95% CI 1.0-5.6). PTS developed in 32 of 52 patients (62%) with residual thrombosis in the proximal veins 6 weeks after diagnosis, as compared with 17 of 45 patients (38%) without residual proximal thrombosis, leading to a 1.6-fold increased risk (95% CI 1.0-2.5). The presence of valvular reflux in the superficial veins was also a predictor at 6 weeks, with a 1.6-fold increased risk as compared with patients without superficial reflux (95% CI 1.1-2.3). A multivariate analysis of these predictors yielded an area under the ROC curve of 0.72 (95% CI 0.62-0.82).

CONCLUSIONS

PTS develops in half of all patients within 3 months, with no further increase being seen up to 2 years of follow-up. Male sex, age over 50 years, proximal localization of the thrombus at entry, residual proximal thrombosis and superficial valvular reflux at 6 weeks seem to be the most important predictors of PTS in patients with a first episode of DVT. Duplex scanning 6 weeks after diagnosis appears to be clinically useful for the identification of patients at risk of PTS.

The feasibility of catheter-directed thrombolysis for acute deep vein thrombosis: a regional perspective

Background

Deep vein thromboses (DVTs) are a significant cause of morbidity and mortality. Valvular destruction leads to the spectrum of disease called the post-thrombotic syndrome (PTS) with the sequelae of chronic venous ulceration and a reduced quality of life. Catheter-directed thrombolysis (CDT) may reduce the incidence of PTS following an acute proximal DVT and increases quality of life thereafter, but it is uncertain what proportion of patients diagnosed with a DVT would be suitable for CDT.

Methods

This study quantified the proportion of patients investigated for DVT that would have been suitable for CDT. A retrospective review was performed of all upper and lower limb duplex ultrasound scans for suspected DVTs in a contemporary one-year period in a major regional vascular institute. All positive scans for acute proximal lower limb DVTs were compared against strict inclusion and exclusion criteria for CDT, based on national guidelines and international randomized trials.

Results

A total of 2368 duplex ultrasound venous investigations were performed in a one-year period and 252 scans demonstrated DVT. Of these, 158 were acute proximal lower limb DVTs. Application of the inclusion and exclusion criteria for CDT suggested that 47/158 (30%) were potentially suitable for CDT using current criteria. The median age of the 158 patients was 58 years, meaning that more than half were of working age and 54% were men.

Conclusion

Using current eligibility criteria, only about 30% of patients with DVT appear to be suitable for CDT.

Six-month exercise training program to treat post-thrombotic syndrome: a randomized controlled two-centre trial

BACKGROUND

Exercise training may have the potential to improve post-thrombotic syndrome, a frequent, chronic complication of deep venous thrombosis. We conducted a randomized controlled two-centre pilot trial to assess the feasibility of a multicentre-based evaluation of a six-month exercise training program to treat post-thrombotic syndrome and to obtain preliminary data on the effectiveness of such a program.

METHODS

Patients were randomized to receive exercise training (a six-month trainer-supervised program) or control treatment (an education session with monthly phone follow-ups). Levels of eligibility, consent, adherence and retention were used as indicators of study feasibility. Primary outcomes were change from baseline to six months in venous disease-specific quality of life (as measured using the Venous Insufficiency Epidemiological and Economic Study Quality of Life [VEINES-QOL] questionnaire) and severity of post-thrombotic syndrome (as measured by scores on the Villalta scale) in the exercise training group versus the control group, assessed by t tests. Secondary outcomes were change in generic quality of life (as measured using the Short-Form Health Survey-36 [SF-36] questionnaire), category of severity of post-thrombotic syndrome, leg strength, leg flexibility and time on treadmill.

RESULTS

Of 95 patients with post-thrombotic syndrome, 69 were eligible, 43 consented and were randomized, and 39 completed the study. Exercise training was associated with improvement in VEINES-QOL scores (exercise training mean change 6.0, standard deviation [SD] 5.1 v. control mean change 1.4, SD 7.2; difference 4.6, 95% CI 0.54 to 8.7; p = 0.027) and improvement in scores on the Villalta scale (exercise training mean change -3.6, SD 3.7 v. control mean change -1.6, SD 4.3; difference -2.0, 95% CI -4.6 to 0.6; p = 0.14). Most secondary outcomes also showed greater improvement in the exercise training group.

INTERPRETATION

Exercise training may improve post-thrombotic syndrome. It would be feasible to definitively evaluate exercise training as a treatment for post-thrombotic syndrome in a large multicentre trial.

Venous compression for prevention of postthrombotic syndrome: a meta-analysis

PURPOSE

To determine the effectiveness of venous compression stockings or compression bandages on the reduction of postthrombotic syndrome in patients with deep venous thrombosis.

METHODS

We attempted to identify all published trials in all languages identified by PubMed through June 2009. Meta-analysis was performed.

RESULTS

Based on 5 randomized trials of patients with deep venous thrombosis comparing treatment with venous compression to controls, mild-to-moderate postthrombotic syndrome occurred in 64 of 296 (22%) treated with venous compression, compared with 106 of 284 (37%) in controls (relative risk=0.52). Severe postthrombotic syndrome occurred in 14 of 296 (5%) treated, compared with 33 of 284 (12%) controls (relative risk=0.38). Any postthrombotic syndrome occurred in 89 of 338 (26%) treated, compared with 150 of 324 (46%) controls (relative risk=0.54).

CONCLUSION

Venous compression reduced the incidence of postthrombotic syndrome, particularly severe postthrombotic syndrome. Venous compression in patients with deep venous thrombosis would seem to be indicated for this purpose. There was, however, wide variation in the type of stockings used, time interval from diagnosis to application of stockings, and duration of treatment. Further investigation, therefore, is needed.

Post-thrombotic syndrome after central venous catheter removal in childhood cancer survivors is associated with a history of obstruction

BACKGROUND

A potential long-term complication of central venous catheter (CVC)-related deep vein thrombosis (DVT), both symptomatic and asymptomatic, is development of post-thrombotic syndrome (PTS) characterized by persistent pain, swelling, and skin changes. Signs and symptoms of PTS were reported after CVC removal. The aim of this study was to assess the risk factors for development of PTS in childhood cancer survivors.

PROCEDURE

Children followed at the after cancer follow-up clinic were enrolled. The patients were screened for PTS using Kuhle's PTS pediatric score. Patient's records were retrospectively reviewed for clinical and CVC-related data.

RESULTS

Fifty-one children were enrolled at a median of 2.3 (range 0.33-7.5) years after removal of their CVC. The median age of the children the time of treatment was 6.5 (range 0.25-18) years. Mild PTS was present in 20 children (39%, 95% CI 26-54%). Pain symptoms were reported in five children (9.5%, 95% CI 3.3-21.4%). Higher rate of PTS was found in children with history of CVC occlusion. The odd ratio (95% CI) for PTS in children with history of occlusion was 3.7 (95% CI 1.1-12.5%) (P = 0.029). The occurrence of PTS was not associated with age at the time of treatment, time from CVC removal, duration of CVC, and history of infection.

CONCLUSIONS

Screening cancer survivors for PTS after CVC removal should be integrated to the after cancer follow-up clinic. Obstruction of CVC may indicate for asymptomatic DVT. Whether thromboprophylaxis and/or prevention of CVC occlusion can decrease the rate of PTS needs to be studied.

The postthrombotic syndrome

Following deep vein thrombosis (DVT), one of every two patients will develop postthrombotic syndrome (PTS), which causes remarkable consequences on the socioeconomic level. Residual thrombosis is an important predictor of PTS, and severe early symptoms, old age, obesity, improper anticoagulation, recurrent thrombosis and varicose veins are major risk factors. Diagnosis of PTS is mainly based on the clinical findings for patients with a history of DVT, while in those without it, instrumental diagnosis might help in detecting a previous DVT. Prompt administration of adequate compression elastic stockings (ECS) in patients with symptomatic DVT reduces the frequency of PTS by half. Usually, the management of an established PTS is demanding, and often discouraging. However, when carefully supervised and instructed to wear proper ECS, more than 50% of patients either remain quiescent or improve during long-term follow-up.

Indications for catheter-directed thrombolysis in the management of acute proximal deep venous thrombosis

Deep vein thromboses (DVTs) cause significant morbidity and mortality in the general population. Oral anticoagulation therapy may reduce thrombus propagation but does not cause clot lysis and therefore does not prevent postthrombotic syndrome (PTS). Catheter-directed thrombolysis (CDT) can be used to treat DVTs as an adjunct to medical therapy, but there is no consensus defining exact indications. Current evidence suggests that CDT can reduce clot burden and DVT recurrence and consequently prevents the formation of PTS compared with systemic anticoagulation. Appropriate indications include younger individuals with acute proximal thromboses, a long life expectancy, and relatively few comorbidities. Limb-threatening thromboses may also be treated with CDT, although the subsequent mortality remains high. A number of randomized controlled trials are currently under way comparing the longer-term outcomes of CDT compared with anticoagulation alone. Initial reports suggest that venous patency and valvular function are better maintained after CDT. The effectiveness of combined pharmacomechanical thrombectomy and the role of vena cava filters need to be investigated further before strong recommendations can be made. The reported short-term outcomes following catheter-based intervention for DVT are encouraging in selected patients. Further evidence is required to establish long-term benefits and cost-effectiveness.

Individually tailored duration of elastic compression therapy in relation to incidence of the postthrombotic syndrome

OBJECTIVE

We assessed whether individualized shortened duration of elastic compression stocking (ECS) therapy after acute deep venous thrombosis (DVT) is feasible without increasing the incidence of postthrombotic syndrome (PTS).

METHODS

At the outpatient clinic of the Maastricht University Medical Centre, 125 consecutive patients with confirmed proximal DVT were followed for 2 years. Villalta scores were assessed on four consecutive visits; 3, 6, 12, and 24 months after the acute event. Reflux was assessed once by duplex testing. After 6 months, patients with scores <or=4 on the Villalta clinical score and in the absence of reflux were allowed to discontinue ECS therapy. If reflux was present, two consecutive scores <or=4 were needed to discontinue ECS therapy.

RESULTS

ECS therapy was discontinued in 17% of patients at 6 months, in 48% at 12 months, and in 50% at 24 months. Reflux on duplex testing was present in 74/101 (73.3%) tested patients and was not associated with the onset of PTS. At the 6-month visit, the cumulative incidence of PTS was 13.3%, at 12 months 17.0%, and at 24 months 21.1%. Varicosities/venous insufficiency (present at baseline) was significantly associated with PTS; hazard ratio 3.2 (1.2-9.1).

CONCLUSIONS

Patients with a low probability for developing PTS can be identified as early as 6 months after the thrombotic event, and individualized shortened duration of ECS therapy based on Villalta clinical scores may be a safe management option. These findings need to be confirmed in a randomized clinical trial.

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.

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.

Contemporary issues in the prevention and management of postthrombotic syndrome

OBJECTIVE

To provide an evidence-based review and clinical summary of postthrombotic syndrome (PTS).

DATA SOURCES

A literature review was performed via MEDLINE (1950-July 1, 2009) and International Pharmaceutical Abstracts (1970-June 2009) searches using the terms post-thrombotic syndrome, post-phlebitic syndrome, deep vein thrombosis, and compression stockings.

DATA SYNTHESIS

PTS is best characterized as a chronic syndrome of clinical signs and symptoms including pain, swelling, parasthesias, and ulceration in the affected limb following deep vein thrombosis (DVT). It occurs in up to half of patients with symptomatic DVT, usually within the first 2 years. Although the pathophysiology of PTS is not well understood, a thrombus may cause venous hypertension and valvular incompetence resulting in edema, tissue hypoxia, and in severe cases, ulceration. Risk factors for PTS include recurrent ipsilateral DVT, obesity, and poor quality of anticoagulant therapy. PTS diagnosis is based on the presence of typical signs and symptoms and may be made using one of several clinical scoring systems. Prevention of PTS should focus on DVT prevention and the use of elastic compression stockings following DVT, while fibrinolysis remains under investigation as an effective method for PTS prevention. The treatment of PTS may include either pharmacologic or mechanical modalities, although none of these regimens has been rigorously tested. Pharmacists have the opportunity to provide more comprehensive antithrombotic management by educating patients and providers on PTS, recommending appropriate preventive therapy, assisting patients in obtaining and adhering to this therapy, and assisting providers with the management of PTS.

CONCLUSIONS

Providers should be proactive in preventing PTS, with pharmacists taking an active role in optimal DVT prevention, identifying patients at risk for PTS, and counseling and directing preventive therapies.

Measurement properties of the Villalta scale to define and classify the severity of the post-thrombotic syndrome

SUMMARY

The post-thrombotic syndrome (PTS) is a frequent and important complication of deep venous thrombosis (DVT). The diagnosis of PTS is based primarily on the presence of typical symptoms and clinical signs. In the 1990s, a clinical scale known as the Villalta scale was proposed as a measure that could be used to diagnose and classify the severity of PTS. The objective of the present paper was to review the published evidence on the measurement properties of the Villalta scale. Results of the review demonstrate that the Villalta scale is a reliable and valid measure of PTS in patients with previous, objectively confirmed DVT. The scale is acceptable to research subjects and research personnel, and shows responsiveness to clinical change in PTS. Aspects of the Villalta scale that merit further evaluation include test-retest reliability, more detailed assessment of ulcer severity and assessment of responsiveness across the full range of PTS severity. Research aimed at improving the measurement of PTS will also help to improve the overall validity of findings generated by clinical studies of PTS.