Compression stockings to prevent post-thrombotic syndrome: a randomised placebo-controlled trial

Revisiting the Open Vein Hypothesis to Reduce the Postthrombotic Syndrome: Implications for Multidisciplinary Care and Research: A Scientific Statement From the American Heart Association

The "open vein hypothesis" postulates that early thrombus clearance and restoration of venous blood flow may prevent postthrombotic syndrome after proximal deep vein thrombosis. Since its proposal several decades ago, new insights from basic and clinical studies have motivated a re-evaluation and refinement of this hypothesis. According to data from these studies, susceptibility to postthrombotic syndrome occurs as a result of differences in genetic composition, thrombophilic conditions, predilection to inflammation and fibrosis, endogenous fibrinolytic capability, timing of s ymptom presentation and treatment initiation, and efficacy of antithrombotic therapy. Although initial restoration of an open vein appears to be beneficial for selected patient groups, freedom from postthrombotic syndrome is more likely in the setting of long-term venous patency, reduced recurrent thrombotic episodes, and reduced perithrombotic (eg, vein wall and valve) inflammation. These underlying biological mechanisms need further elucidation, with a long-term goal of personalizing treatment by mapping the individuals' clinical presentation with their underlying risk factors and assessing time-dependent biological processes that occur as a clinical venous thrombosis resolves. This scientific statement (1) highlights historical fundamentals of the open vein hypothesis and then showcases new research insights into the pathophysiological factors driving postthrombotic syndrome; (2) discusses advantages and disadvantages of imaging modalities for deep vein thrombosis used in clinical practice, including the potential to depict thrombus chronicity and status of vein wall injury; (3) proposes measures to develop integrated multidisciplinary care for deep vein thrombosis focused on the reduction of postthrombotic syndrome; and (4) identifies priority areas and questions for further research.

Chronic Venous Insufficiency and Management

Chronic venous insufficiency is common and is associated with progressive leg discomfort, heaviness, edema, discoloration and ulceration, and venous obstruction, reflux, or both. Venous insufficiency and varicose veins are widespread and are common in Western countries. Risk factors include age, female gender, positive family history, pregnancy and parity, obesity, prolonged standing, and history of deep vein thrombosis. Chronic venous disease is the leading etiology of leg ulcers, which are associated with poor quality of life. Compression, pharmacologic therapy, and catheter-based techniques have shown promise for deep vein recanalization, closure of incompetent superficial veins, and elimination of varicose veins.

Iliofemoral Acute Deep Venous Thrombosis, Chronic Deep Venous Thrombosis, and May-Thurner Syndrome

Acute iliofemoral deep vein thrombosis (DVT) is associated with higher rates of severe chronic symptoms and complications, and in rare cases with acute limb ischemia. Early detection is a key to provide prompt treatment, including endovascular intervention, in selected patients. When iliofemoral DVT is related to external compression of the left iliac vein by the right common iliac artery is termed May-Thurner syndrome. Approximately, 20% to 50% of patients with chronic DVT will develop post-thrombotic syndrome, a collection of symptoms including lower extremity edema, skin changes, vein dilation, pain, fatigue, and ulcer formation.

Syringe-assisted test-aspiration with mechanical aspiration thrombectomy results in good safety and short-term outcomes in the treatment of patients with deep venous thrombosis

ObjectiveTo evaluate the short-term outcomes and safety of syringe-assisted test-aspiration with mechanical aspiration thrombectomy in the treatment of deep venous thrombosis.MethodsThis was a single-center, retrospective study of hospitalized patients with iliofemoral and/or inferior vena caval deep venous thrombosis, excluding those with pulmonary embolism. We collected the following patient data from the electronic medical records: age, sex, provoked/unprovoked deep venous thrombosis, symptom duration, thrombosed segments, and the presence of a tumor, thrombophilia, diabetes, and/or iliac vein compression syndrome. Venography and computed tomographic venography were performed in all patients before the procedure. All patients underwent syringe-assisted test-aspiration with mechanical aspiration thrombectomy under local anesthesia and sedation, and all received low-molecular-weight heparin peri-operatively. All patients underwent implantation of an inferior vena caval filter. Rivaroxaban was administered post-procedure, instead of heparin, for 3-6 months, with lower extremity compression.ResultsOverall, 29 patients with deep venous thrombosis underwent syringe-assisted test-aspiration with mechanical aspiration thrombectomy from January 2022 to October 2022 in our institution. Technical success (>70% thrombus resolution) was achieved in all patients, and using a single procedure in 25/29 patients (86%). Concomitant stenting was performed in 18/29 (62%) of the patients, and 21/29 (69%) underwent angioplasty. The median (interquartile range) procedure time was 110 min (100-122), the median intra-operative bleeding volume was 150 mL (120-180), and the median decrease in the hemoglobin concentration from pre- to post-operative was 7 g/L (4-14). The median follow-up duration was 7 months (5-9). All patients obtained symptomatic relief, and 27/29 achieved near-remission or full remission (combined total). No patients experienced peri-operative bleeding complications, or symptom recurrence or post-thrombectomy syndrome during follow-up.ConclusionThe short-term outcomes following syringe-assisted test-aspiration with mechanical aspiration thrombectomy in the treatment of deep venous thrombosis were excellent, and the procedure was safe.

Risk acceptance for deep venous interventions of the lower limb

Objectives: To discover the maximum risk acceptable to patients and clinicians for complications typical to endovascular interventions in the setting of proximal deep vein thrombosis (DVT) and post-thrombotic syndrome (PTS).Design: This was an observational study comparing patient/clinician risk acceptances in interviews using validated Standard Gamble methodology.Methods: 30 patients with previous DVT and 30 vascular clinicians were given a scenario describing a hypothetical case of a patient being managed with acute iliofemoral DVT and another with PTS. Subjects were asked to provide the maximum risk they would accept for individual complications to cure the condition. To interpret variability, the Venous Clinical Severity Score, SF-36 domains and VEINES-QoL for each patient were plotted against their risk acceptance for major bleeding in the DVT scenario.Results: For the DVT scenario, patients accepted high median risks compared to clinicians for major bleeding (40% vs 5%, p < .001), bleeding at other sites (50% vs 5%, p < .001), damage to blood vessels (60% vs 5%, p < .001), further procedures (80% vs 20%, p < .001), and treatment failure (75-80% vs 10-20%, p < .001). However, the gap was lower for intracranial bleeding (5% vs 1%, p = .004), pulmonary embolism (5 vs 5%, p = .39) or death (1% vs 0.75%, p = .77). For the PTS scenario, there were similar results again with a lower difference for pulmonary embolism (10% vs 5%, p = .02) and death (0.5% vs 1%, p = .72). Importantly, patient risk acceptance for major bleeding was negatively correlated to the emotional wellbeing (Rho = -0.43, p = .018) and social functioning (Rho = -0.38, p = .042) SF-36 domains.Conclusion: Overall, patients accepted a greater chance of most adverse events compared with clinicians. Patients prepared to accept greater risk were those with poorer emotional wellbeing and social functioning. It is important to take these issues into account when making shared decisions with patients about the management of their DVT/PTS.

The Postthrombotic syndrome, where are we now?

Post thrombotic syndrome (PTS) is a frequent complication occurring in patients with deep venous thrombosis (DVT). This chronic condition is associated with a negative impact on quality of life and substantial economic costs. Despite current treatment with anticoagulants and compression therapy, a significant proportion of DVT patients develop PTS. Optimising the diagnosis and identification of high-risk patients is important to provide more appropriate individualised treatment. In addition, a better understanding of the pathogenesis is leading to the necessary improvement of both current treatment strategies and the development of new treatment modalities. Treatments aimed at prevention as well as those aimed at reducing the symptoms of already manifested PTS should be further investigated. Research is currently taking place on promising therapeutical targets including pharmacological (anti-inflammatory and venoactive drugs), and interventional approaches (e.g. mechanical thrombectomy) in patients at different stages of PTS. Progress in all these areas is needed to solve the complex problem of PTS.

Incidence and risk factors for postthrombotic syndrome in neonates and children in a single-center cohort study

BACKGROUND

Postthrombotic syndrome (PTS) is a chronic condition following deep vein thrombosis (DVT) and is associated with pain, swelling, and restricted use of the affected limb. In pediatric age groups, its incidence and risk factors are not well-known.

METHODS

This observational cohort study of all consecutive children (≤18 years) with DVT treated at the Emma Children's Hospital Amsterdam between January 2001 and January 2021 was conducted to identify incidence and risk factors for PTS in neonates aged ≤2 months and children aged >2 months. PTS was diagnosed using the modified Villalta scale.

RESULTS

In total, 315 patients were included. The 20-year incidence of PTS was 20.0% in neonates and 40.0% in children. In neonates, involvement of ≥3 vessels (odds ratio [OR], 6.6; 95% CI, 1.6-26.4) and incomplete thrombus resolution (OR, 3.0; 95% CI, 1.1-8.0) were risk factors for PTS. In children, involvement of ≥3 vessels (OR, 6.2; 95% CI, 2.2-17.8), recurrent DVT (OR, 3.7; 95% CI, 1.3-10.3), and incomplete thrombus resolution (OR, 5.2; 95% CI, 1.6-17.0) were associated with PTS. Exercise ≥3 times/wk (OR, 0.4; 95% CI, 0.2-0.9), central venous catheter-related DVT (OR, 0.2; 95% CI, 0.1-0.5), and provoked DVT (OR, 0.4; 95% CI, 0.1-0.97) were protective factors for PTS.

CONCLUSION

This study demonstrated a high incidence of pediatric PTS. Additionally, risk factors for PTS differed between neonates and children. These findings provide a basis for better prevention and management of PTS that may differ between neonates and children.

Standard- versus extended-duration anticoagulation for primary venous thromboembolism prophylaxis in acutely ill medical patients

BACKGROUND

Venous thromboembolism (VTE) includes two interrelated conditions, deep vein thrombosis (DVT) and pulmonary embolism (PE). Risk factors include dehydration, prolonged immobilization, acute medical illness, trauma, clotting disorders, previous thrombosis, varicose veins with superficial vein thrombosis, exogenous hormones, malignancy, chemotherapy, infection, inflammation, pregnancy, obesity, smoking, and advancing age. It is estimated that hospitalized patients are 100 times more likely to develop VTE and, compared with surgical patients, medical patients often have more severe forms of VTE. VTE carries a significant risk of morbidity and mortality. Prophylactic strategies, including mechanical and pharmacological methods, are recommended for patients at risk of VTE. Pharmacological prophylaxis is considered the standard practice for acutely ill medical patients at risk of developing VTE in the absence of contraindications. For hospitalized patients, the risk of VTE extends beyond hospital stay and up to 90 days, with most events occurring within 45 days of discharge. Despite that, it remains unclear whether extended-duration anticoagulation for primary VTE prophylaxis would provide benefits without added risks or harm.

OBJECTIVES

To assess the benefits and risks of standard- versus extended-duration anticoagulation for primary VTE prophylaxis in acutely ill medical patients.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialized Register, CENTRAL, MEDLINE, Embase, CINAHL and Web of Science databases, as well as the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers up to 27 March 2023. We also searched reference lists of all included studies for additional references and searched the last five years of the American Society of Hematology conference proceedings.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) comparing standard-duration versus extended-duration anticoagulation for primary VTE prophylaxis in acutely ill medical patients (adults being treated in a medical inpatient setting).

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures set by Cochrane. At least two authors independently screened titles and abstracts for inclusion and performed data extraction. Two authors independently assessed the risk of bias (RoB) using the Cochrane RoB 2 tool. We analyzed outcomes data using the risk ratio (RR) with 95% confidence intervals (CIs). We used the GRADE approach to assess the certainty of evidence for each outcome. Our outcomes of interest were assessed in the short term (during the treatment period and within 45 days of hospitalization) and long term (assessed beyond 45 days of hospitalization). Primary outcomes were symptomatic VTE, major bleeding, and all-cause mortality. Secondary outcomes were total VTE, a composite of fatal and irreversible vascular events (including myocardial infarction, non-fatal PE, cardiopulmonary death, stroke), fatal bleeding, and VTE-related mortality.

MAIN RESULTS

A total of seven RCTs fulfilled our inclusion criteria, comprising 40,846 participants. All studies contributing data to our outcomes were at low risk of bias in all domains. Most studies reported the outcomes in the short term. Extended-duration anticoagulation, compared with standard-duration anticoagulation, for primary VTE prophylaxis in acutely ill medical patients reduced the risk of short-term symptomatic VTE (RR 0.60, 95% CI 0.46 to 0.78; standard-duration 12 per 1000, extended-duration 7 per 1000, 95% CI 6 to 10; number needed to treat for an additional beneficial outcome [NNTB] 204, 95% CI 136 to 409; 4 studies, 24,773 participants; high-certainty evidence). This benefit, however, was offset by an increased risk of short-term major bleeding (RR 2.05, 95% CI 1.51 to 2.79; standard-duration 3 per 1000, extended duration 6 per 1000, 95% CI 5 to 8; number needed to treat for an additional harmful outcome [NNTH] 314, 95% CI 538 to 222; 7 studies, 40,374 participants; high-certainty evidence). Extended-duration anticoagulation, compared with standard-duration, results in little to no difference in short-term all-cause mortality (RR 0.97, 95% CI 0.87 to 1.08; standard-duration 34 per 1000, extended-duration 33 per 1000, 95% CI 30 to 37; 5 studies, 38,080 participants; high-certainty evidence), reduced short-term total VTE (RR 0.75, 95% CI 0.67 to 0.85; standard-duration 37 per 1000, extended duration 28 per 1000, 95% CI 25 to 32; NNTB 107, 95% CI 76 to 178; 5 studies, 33,819 participants; high-certainty evidence), and short-term composite of fatal and irreversible vascular events (RR 0.71, 95% CI 0.56 to 0.91; standard-duration 41 per 1000, extended-duration 29 per 1000, 95% CI 23 to 37; NNTB 85, 95% CI 50 to 288; 1 study, 7513 participants; high-certainty evidence). Extended-duration anticoagulation may result in little to no difference in short-term fatal bleeding (RR 2.28, 95% CI 0.84 to 6.22; standard-duration 0 per 1000, extended-duration 0 per 1000, 95% CI 0 to 1; 7 studies, 40,374 participants; low-certainty evidence), and likely results in little to no difference in short-term VTE-related mortality (RR 0.78, 95% CI 0.58 to 1.05; standard-duration 5 per 1000, extended-duration 4 per 1000 95% CI 3 to 6; 6 studies, 36,170 participants; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

In the short term, extended- versus standard-duration anticoagulation for primary VTE prophylaxis in acutely ill medical patients reduced the risk of symptomatic VTE at the expense of an increased risk of major bleeding. Extended-duration anticoagulation resulted in little to no difference in all-cause mortality. Extended-duration anticoagulation reduced the risk of total VTE and the composite of fatal and irreversible vascular events, but may show little to no difference in fatal bleeding and VTE-related mortality. Further data, with longer follow-up, are needed to determine the optimal agent and duration for primary VTE prophylaxis in acutely ill medical patients.

Early Thrombus Removal for Acute Lower Extremity Deep Vein Thrombosis: Update on Inclusion, Technical Aspects, and Postprocedural Management

Acute lower extremity deep vein thrombosis (DVT) is a common disorder with significant associated morbidity, including pain and swelling, as well as the risk of pulmonary embolism (PE), recurrent venous thromboembolism (VTE) and chronic debilitating post-thrombotic syndrome (PTS). Anticoagulation is standard of care for DVT treatment. It assists in reducing thrombus progression and the occurrence of PE, but incomplete DVT resolution increases the risk of recurrent VTE, valvular insufficiency, and PTS. Endovascular DVT interventions, such as catheter-directed thrombolysis, pharmacomechanical thrombectomy, and large-bore mechanical thrombectomy offer an alternative therapeutic strategy for DVT management. This paper will discuss technical factors and current issues when performing lower extremity DVT interventions including patient selection, anticoagulation, choice of device for endovascular thrombus removal, adjunctive techniques, and venous stent management.Level of Evidence: No level of evidence for: review articles, basic science, laboratory investigations, and experimental study articles.

Impact of self-reported race on Villalta Scale postthrombotic syndrome scores and correlation with venous disease-specific quality of life: an exploratory analysis of the Acute Venous Thrombosis: Thrombus Removal with Adjunctive Catheter-Directed Thrombolysis Trial

Background

The Villalta Scale (VS) to diagnose postthrombotic syndrome (PTS) consists of 5 patient-reported leg symptoms and 6 clinician-rated leg signs. It is unknown how the scale performs across racial groups.

Objectives

Our study explored if there were differences in VS scores, particularly clinician-rated signs components, according to self-reported race.

Methods

Exploratory analysis of the ATTRACT trial, a randomized controlled trial conducted at 56 US sites that investigated pharmacomechanical catheter-directed thrombolysis to prevent PTS after proximal deep vein thrombosis (DVT). At the 6-month visit after randomization, we compared self-reported Black (n = 123) and White (n = 541) participants for mean total VS score, VS symptoms score, VS signs score, individual signs scores, and correlation coefficients between VS signs and VS symptoms scores and between VS signs and Venous Insufficiency Epidemiological and Economic Study Quality of Life (VEINES-QOL) scores (a self-reported venous disease-specific quality of life measure).

Results

Mean total VS score (4.67 vs. 4.12, P = .54),VS signs score (1.66 vs. 2.00, P = .07), and VS symptoms score (2.83 vs. 2.04, P = .10) were similar between Black and White participants. The mean score for one individual VS sign, venous ectasia, was lower in Black vs. White participants (0.24 vs. 0.63, P< .01). There was similar, modest correlation in Black and White participants between VS signs and VS symptoms scores (r black = 0.19; r white = 0.23) and between VS signs and VEINES-QOL scores (r black = -0.32; r white = -0.30). Results were adjusted for ATTRACT trial treatment group, age, sex, body mass index, DVT extent, hypertension, diabetes, dyslipidemia, and congestive heart failure.

Conclusion

The findings suggest that some differences in VS scores exist according to self-reported race. It is unclear whether these reflect clinicians' underrating of some VS signs and/or differences in PTS severity. Further work is needed to understand how the VS performs across racial groups.

Very long-term risk of moderate-to-severe postthrombotic syndrome after deep vein thrombosis

BACKGROUND

Postthrombotic syndrome (PTS) refers to manifestations of chronic venous insufficiency after a deep vein thrombosis (DVT). The risk of developing moderate-to-severe PTS in the very long term is largely unknown and particularly in case of distal DVT. Furthermore, the impact of DVT vs other causes of chronic venous insufficiency on long-term manifestations of PTS is also unknown.

OBJECTIVES

To assess the very long-term risk of moderate-to-severe PTS after DVT and the role that DVT plays in PTS symptoms.

METHODS

Patients with lower-limb DVT enrolled in the multicenter Optimisation de l'interrogatoire dans l'evaluation du risque thromboembolique veineux (OPTIMEV) study underwent a very long-term telephone follow-up. We assessed i) the proportion of moderate-to-severe PTS (assessed with the patient-reported Villalta score) according to DVT extent and ii) the population attributable fraction that DVT plays in patients' moderate-to-severe PTS manifestations.

RESULTS

Fourteen years after DVT, moderate-to-severe PTS developed in 35 of 185 patients with distal DVT (18.9%; 95% CI, 13.5%-25.3%), 11 of 47 patients with popliteal DVT (23.4%; 95% CI, 12.3%-38.0%), and 27 of 74 patients with iliofemoral DVT (36.5%; 95% CI, 25.6%-48.5%). The population attributable fraction of DVT in moderate-to-severe symptoms of PTS was 25.7% (-18.1% to 53.3%) in patients with distal DVT, 27.3% (-63.7% to 67.7%) in patients with popliteal DVT, and 43.1% (+0.7%-67.4%) in patients with iliofemoral DVT.

CONCLUSION

In the very long term after DVT, a quarter of patients have moderate-to-severe PTS manifestations. However, the impact of the DVT on these manifestations appears nonpredominant and varies according to DVT extent. Distal DVT does not significantly increase the risk of developing moderate-to-severe PTS.

Pulmonary Embolism Management Audit and Machine Learning Analysis of Delayed Anticoagulation in a Swiss Teaching Hospital

Background/Objectives: Diagnosing acute pulmonary embolism (PE) is challenging due to its wide range of symptoms and numerous differential diagnoses. Medical professionals must balance performing all essential examinations and avoiding unnecessary testing. This study aimed to retrospectively audit the diagnosis and treatment of acute PE at a Swiss public teaching hospital to determine the adherence to current guidelines and to identify the factors associated with the delayed initiation of anticoagulation in PE patients. Methods: In this retrospective observational cohort study, we included all adult patients hospitalized with PE at the Cantonal Hospital Baselland (KSBL) between November 2018 and October 2020, where the diagnosis was made within the first twelve hours of their arrival to the emergency department (ED). LASSO regression was employed to identify clinical characteristics associated with delayed anticoagulation initiation. Results: A total of 197 patients were included (mean age: 70 years, 54% female). The audit revealed that diagnostic workup was conducted according to guidelines in 57% of cases. Often, D-dimer levels were measured although not strictly necessary (70%). Pretest probability was assessed and documented using the Wells or Geneva score in only 3% of patients, and risk assessment via the Pulmonary Embolism Severity Index (PESI) score was documented in 21% of patients. The median time from ED arrival to CT scan was 120 min (IQR 89.5-210.5), and the median time to anticoagulation initiation was 193 min (IQR 145-277). Factors identified by LASSO associated with delayed anticoagulation included prolonged time from ED arrival to CT scan, the presence of distended jugular veins on examination, ED arrival in the morning, and presenting symptoms of weakness or tiredness. Complementary leg ultrasound was performed in 57% of patients, with 38% of these cases lacking prior clinical examination for deep vein thrombosis. The duration of the anticoagulation treatment was not specified in the discharge report for 17% of patients. A medical follow-up after discharge was recommended in 75% of the patients. Conclusions: In conclusion, while the management of PE at the KSBL generally adheres to high standards, there are areas for improvement, particularly in the morning performance, the use of a pretest probability assessment, D-dimer measurement, risk assessment via the PESI score, the performance of complementary leg ultrasounds, clarification of the anticoagulation duration, and follow-up management.

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.

Percutaneous transluminal angioplasty of femoropopliteal veins for treatment of post-thrombotic syndrome

Background: Controversy persists concerning the endovascular treatment of the post-thrombotic syndrome (PTS), particularly if femoropopliteal veins are involved. Methods: We screened consecutive patients with PTS who underwent percutaneous transluminal angioplasty (PTA) of femoropopliteal veins using posterior tibial or popliteal vein access who had at least 3-month follow-up. Our assessment included the evaluation of primary and secondary patency of the treated segments by Doppler ultrasound (DUS) and clinical outcomes measured by the change in Villalta score as well as ulcer healing. Results: Among 29 patients, 8 (27.7%) were women and the mean (SD) age was 53.3 (13.6) years. Posterior tibial vein and popliteal access were used in 26 (89.7%) and 3 patients (10.3%), respectively. 13 (44.8%) patients had prior (n = 11, 37.9%) or concomitant (n = 9, 31.0%) endovascular treatment of the iliac or common femoral veins. At a median follow-up of 395 days (Q1: 205-Q3: 756 days), primary patency of femoropopliteal veins was 79.3% (95% CI 64.6-94.1%) and secondary patency was 82.8% (95% CI, 69.0-96.5%). The percentage of patients with moderate or severe PTS according to the Villalta score decreased from baseline to last follow-up from 34.5% to 18.5% and from 31% to 14.8%, respectively (p<0.003). Overall, the mean (SD) Villalta score decreased from 11.5 (1.7) to 8.0 (1.7) (p<0.0001). Postprocedural complete ulcer healing occurred in 4 out of 5 (80%) patients. Two (6.9%) patients developed new ulcers. No major bleeding, pulmonary embolism, stroke, or death occurred. Conclusion: PTA of femoropopliteal veins via posterior tibial or popliteal vein access appears to improve the severity of PTS with acceptable patency rates.

Anticoagulation and compression therapy for proximal acute deep vein thrombosis

The treatment of proximal deep vein thrombosis (DVT) of the lower limbs includes an initial management phase, covering the first 1 to 3 weeks, a primary treatment phase, lasting a minimum of 3 months, and a secondary treatment phase for those patients requiring continuing anticoagulation beyond the first 3 to 6 months. During the initial phase most patients with DVT can be managed as outpatients. Exclusion criteria for home treatment include high risk of bleeding, limb threatening DVT or other conditions requiring hospitalisation. Anticoagulant drugs represent the mainstay of treatment and include parenteral drugs such as unfractionated heparin or low molecular weight heparin, and oral drugs such as the vitamin K antagonists and the direct oral anticoagulants (DOACs). DOACs are currently recommended as the first line of treatment for proximal DVT of the lower limbs, with no preference for one DOAC over another. Factors to consider when choosing the anticoagulant strategy include, among others, renal and liver function, underlying diseases such as cancer or the antiphospholipid syndrome, and patient preferences. Indefinite duration of anticoagulation beyond the first 3 to 6 months is recommended for patients with unprovoked DVT and patients with permanent, chronic risk factors. Two DOACs, namely apixaban and rivaroxaban, can be administered at low doses for the secondary prevention of DVT. Elastic compression stockings (ECS) have been used for decades in patients with proximal DVT with the aim of counteracting the venous hypertension generated by the vascular disorder and reducing leg edema and to prevent the post-thrombotic syndrome.

Ferumoxytol-enhanced MRI assessment of venous Thrombus resolution and macrophage content in a murine deep vein thrombosis model

BACKGROUND

Imaging evaluation of acute deep vein thrombosis (DVT) or post-thrombotic syndrome (PTS) in animal or clinical models is limited to anatomical assessment of the location and extent of thrombi. We hypothesize that Fe-MRI, used to evaluate macrophage content in other inflammatory diseases, can be useful to evaluate the thromboinflammatory features after DVT over time.

METHODS

Nineteen wild-type CD-1 mice underwent surgical IVC ligation to induce DVT. Mice received either saline or 5 mg/kg of 14E11, a Factor XI inhibitor, before the procedure. Fe-MRI was performed on days 6-7 after ligation to evaluate thrombus volume, perfusion, and macrophage content via T2-weighted images. Mice were euthanized at days 3-15 after surgery. The thrombi and adjacent vein walls were excised, weighed, formalin-fixed, and paraffin-embedded for immunohistological analysis. Specimens were stained with specific antibodies to evaluate macrophage content, collagen deposition, neovascularization, and recanalization. Significance was determined using the Mann-Whitney U or Student's t-test.

RESULTS

After IVC-ligation in control mice, thrombus weights decreased by 59 % from day 3 to 15. Thrombus volumes peaked on day 5 before decreasing by 85 % by day 13. FXI inhibition led to reduced macrophage content in both thrombi (p = .008) and vein walls (p = .01), decreased thrombus volume (p = .03), and decreased thrombus mass (p = .01) compared to control mice. CCR2+ staining corroborated these findings, showing significantly reduced macrophage presence in the thrombi (p = .002) and vein wall (p = .002).

CONCLUSIONS

Fe-MRI T2 relaxation times can be used to characterize and quantify post-thrombotic changes of perfusion, macrophage content, and thrombus volume over time in a surgical mouse model of venous thrombosis. This approach could lead to better quantification of in vivo inflammation correlating monocyte and macrophage content within resolving thrombi and veins and may serve as a useful tool for research and clinically in the evaluation of the post-thrombotic environment.

A Retrospective Study Comparing Pharmacomechanical Thrombectomy with Catheter-Directed Thrombolysis for Acute Deep Venous Thrombosis

BACKGROUND

This study aims to conduct a comparative analysis of the clinical efficacy and safety between pharmacomechanical thrombectomy (PMT) and catheter-directed thrombolysis (CDT) in the context of acute lower-extremity deep venous thrombosis (LEDVT).

METHODS

A retrospective review of our institution's patient database spanning from February 2011 to December 2019 was performed to identify cases of acute LEDVT. The patients were categorized into 2 distinct groups based on the thrombolytic interventions administered: the PMT group, specifically denoting PMT with AngioJet in our investigation, and the CDT group. Comprehensive data sets encompassing patient demographics, risk factors, procedural specifics, thrombolysis grading, and complications were collected. Subsequent follow-up evaluations at the 2-year mark posttreatment included assessments of postthrombotic syndrome (PTS) and the quality of life.

RESULTS

Among the 348 patients identified (mean age: 50.12 ± 15.87 years; 194 females), 200 underwent CDT during the early stage (2011 to 2017), while 148 received PMT between 2017 and 2019. Baseline data between the 2 groups exhibited no statistically significant differences. Thrombus scores significantly decreased in both cohorts posttherapy (each P < 0.001).Patients subjected to PMT demonstrated higher thrombolysis rates (77.35 ± 9.44% vs. 50.85 ± 6.72%), reduced administration of the thrombolytic agent urokinase [20 (20€20) vs. 350 (263€416), P < 0.001], larger limb circumference differences (above the knee: 6.03 ± 1.76 cm vs. 4.51 ± 1.82 cm, P < 0.001; below the knee: 2.90 ± 1.16 cm vs. 2.51 ± 0.90 cm, P < 0.001), and shorter lengths of stay (7.19 ± 3.11 days vs. 12.33 ± 4.77 days, P < 0.001). However, the PMT group exhibited a higher decline in hemoglobin levels (13.41 ± 10.59 g/L vs. 10.88 ± 11.41 g/L, P = 0.038) and an increase in creatinine levels [9.58 (2.32€15.82) umol/L vs. 4.53 (2.87€6.08) umol/L, P < 0.001] compared to the CDT group. No statistically significant differences were observed in the numbers of balloon angioplasty, stent implantation (each P > 0.050), and minor and major complications between the 2 groups. At the 1-year follow-up, PTS occurred in 13.51% of the PMT group compared to 26% of the CDT group (P = 0.025), with a higher incidence of moderate-severe PTS in the CDT group (8% vs. 2.7%, P = 0.036). At the 2-year follow-up, PTS was observed in 16.2% of the PMT group and 31.5% in the CDT group, P = 0.004. Preoperative and postoperative D-values of 36-Item Short Form Health Survey (SF-36) Physical Component Summary and SF-36 Mental Component Summary showed no statistically significant between-group differences.

CONCLUSIONS

In our institutional experience, both PMT and CDT have proven to be effective and safe therapeutic approaches for managing acute LEDVT. PMT, in particular, demonstrated superior efficacy in achieving thrombosis resolution and mitigating the risk of PTS, affirming its role as a favorable intervention in this clinical context.

Acute phase determinant of post-thrombotic syndrome: A review of the literature

BACKGROUND

Post-thrombotic syndrome (PTS) is the main long-term complication of deep vein thrombosis (DVT). Several therapies are being evaluated to prevent or to treat PTS. Identifying the patients most likely to benefit from these therapies presents a significant challenge.

OBJECTIVES

The objective of this review was to identify risk factors for PTS during the acute phase of DVT.

ELIGIBILITY CRITERIA

We searched the PubMed and Cochrane databases for studies published between January 2000 and January 2021, including randomized clinical trials, meta-analyses, systematic reviews and observational studies.

RESULTS

Risk factors for PTS such as proximal location of DVT, obesity, chronic venous disease, history of DVT are associated with higher risk of PTS. On the initial ultrasound-Doppler, a high thrombotic burden appears to be a predictor of PTS. Among the evaluated biomarkers, some inflammatory markers such as ICAM-1, MMP-1 and MMP-8 appear to be associated with a higher risk of developing PTS. Coagulation disorders are not associated with risk of developing PTS. Role of endothelial biomarkers in predicting PTS has been poorly explored. Lastly, vitamin K antagonist was associated with a higher risk of developing PTS when compared to direct oral anticoagulants and low molecular weight heparin.

CONCLUSIONS

Several risk factors during the acute phase of VTE are associated with an increased risk of developing PTS. There is a high-unmet medical need to identify potential biomarkers for early detection of patients at risk of developing PTS after VTE. Inflammatory and endothelial biomarkers should be explored in larger prospective studies to identify populations that could benefit from new therapies.

Overall haemostatic potential assay for prediction of outcomes in venous and arterial thrombosis and thrombo-inflammatory diseases

Thromboembolic diseases including arterial and venous thrombosis are common causes of morbidity and mortality globally. Thrombosis frequently recurs and can also complicate many inflammatory conditions through the process of 'thrombo-inflammation,' as evidenced during the COVID-19 pandemic. Current candidate biomarkers for thrombosis prediction, such as D-dimer, have poor predictive efficacy. This limits our capacity to tailor anticoagulation duration individually and may expose lower risk individuals to undue bleeding risk. Global coagulation assays, such as the Overall Haemostatic Potential (OHP) assay, that investigate fibrin generation and fibrinolysis, may provide a more accurate and functional assessment of hypercoagulability. We present a review of fibrin's critical role as a central modulator of thrombotic risk. The results of our studies demonstrating the OHP assay as a predictive biomarker in venous thromboembolism, chronic renal disease, diabetes mellitus, post-thrombotic syndrome, and COVID-19 are discussed. As a comprehensive and global measurement of fibrin generation and fibrinolytic capacity, the OHP assay may be a valuable addition to future multi-modal predictive tools in thrombosis.

Valitrack study: Objective evaluation of medical compression wearing time and patient activity with the Accutrack® by Sigvaris Group sensor

INTRODUCTION

Objective measurement of compliance is mandatory to evaluate therapeutic effects and clinical benefits of medical compression stockings. This Valitrack study evaluates the Accutrack sensor equipped with an accelerometer. The evaluation is done under controlled and free conditions and during washing.

RESULTS

Global accordance results are excellent: Sensitivity (98.6%) and specificity (95.2%) and 92% of patients are not disturbed by the sensors when putting on the stockings.

DISCUSSION

Thanks to its specificities one sensor per patient is sufficient. Its sensitivity distinguishes still and active positions. Only hand washing remains a false positive. The Accutrack sensor objectively measures compliance and will not be a bias because 96% of patients forget it.

CONCLUSIONS

Objective compliance measurement with Accutrack allows us to evaluate the efficacity of compression, the reasons of non-compliance, and the patient's actual physical activity according to its accelerometer time-stamped.

Compression Therapy in Acute Deep Venous Thrombosis of the Lower Limb and for the Prevention of Post-Thrombotic Syndrome—a Review Based on a Structured Literature Search

BACKGROUND

After an acute deep venous thrombosis (DVT) of the lower limb, 20% to 63% of patients develop post-thrombotic syndrome (PTS). In this review, we address the efficacy of compression therapy in the treatment of acute DVT of the lower limb, and for the prevention of PTS.

METHODS

12 randomized controlled trials (RCTs) and one meta-analysis, with a total of 3751 patients, were identified in a structured literature search.

RESULTS

Two RCTs showed that adding compression therapy to drug treatment in the first 9 days of the acute phase of lower limb DVT led to more rapid pain relief (p<0.050) and less swelling (remaining difference in circumference, 1 cm versus 3 cm, p<0.050). As for the prevention of PTS, four RCTs showed a short-term benefit or no benefit of compression therapy. In three further RCTs, medical compression stockings (MCS) brought about a 16% to 27% absolute reduction of the frequency and severity of PTS (47% vs. 20 %, p<0.001; 40% vs. 21% (95% confidence intervals [29.9; 50.1] and [12.7; 29.5], respectively; and 58% vs. 42%, relative risk [RR] 0.73 [0,55; 0.96]). The benefit of MCS was also confirmed in a recent meta-analysis (RR 0.66 [0.44; 0.99], I2 = 88%). Thigh-length MCS were not superior to knee-length MCS for the prevention of PTS (33% vs. 36%, hazard ratio [HR] 0.93 [0.62; 1.41]). Individual, symptomoriented tailoring of the duration of treatment was not inferior to a fixed treatment duration of 24 months (29% vs. 28%; odds ratio [OR] 1.06 [0.78;1.44]).

CONCLUSION

Compression therapy relieves symptoms in acute DVT and lessens the frequency and severity of PTS. It is therefore recommended as standard treatment.

Black holes in compression therapy: A quest for data

OBJECTIVE

Although compression therapy (CT) is considered a crucial conservative treatment in chronic venous disease, strong evidence is missing for many clinical indications. This literature review aims to point out what strong evidence we have for CT and all the clinical scenarios where strong evidence still needs to be included.

METHODS

The research was conducted on MEDLINE with PubMed, Scopus and Web of Science. The time range was set between January 1980 and October 2022. Only articles in English were included.

RESULTS

The main problem with CT is the low scientific quality of many studies on compression. Consequently, we have robust data on the effectiveness of CT only for advanced venous insufficiency (C3-C6), deep vein thrombosis and lymphedema. We have data on the efficacy of compression for venous symptoms control and in sports recovery, but the low quality of studies cannot result in a strong recommendation. For compression in postvenous procedures, superficial venous thrombosis, thromboprophylaxis, post-thrombotic syndrome prevention and treatment, and sports performance, we have either no data or very debated data not allowing any recommendation.

CONCLUSIONS

We need high-level scientific studies to assess if CT can be effective or definitely ineffective in the clinical indications where we still have a paucity of or contrasting data.

Evaluating pharmacological THRomboprophylaxis in Individuals undergoing superficial endoVEnous treatment across NHS and private clinics in the UK: a multi-centre, assessor-blind, randomised controlled trial-THRIVE trial

INTRODUCTION

Endovenous therapy is the first choice management for symptomatic varicose veins in NICE guidelines, with 56-70 000 procedures performed annually in the UK. Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), is a known complication of endovenous therapy, occurring at a rate of up to 3.4%. Despite 73% of UK practitioners administering pharmacological thromboprophylaxis to reduce VTE, no high-quality evidence supporting this practice exists. Pharmacological thromboprophylaxis may have clinical and cost benefit in preventing VTE; however, further evidence is needed. This study aims to establish whether when endovenous therapy is undertaken: a single dose or course of pharmacological thromboprophylaxis alters the risk of VTE; pharmacological thromboprophylaxis is associated with an increased rate of bleeding events; pharmacological prophylaxis is cost effective.

METHODS AND ANALYSIS

A multi-centre, assessor-blind, randomised controlled trial (RCT) will recruit 6660 participants from 40 NHS and private sites across the UK. Participants will be randomised to intervention (single dose or extended course of pharmacological thromboprophylaxis plus compression) or control (compression alone). Participants will undergo a lower limb venous duplex ultrasound scan at 21-28 days post-procedure to identify asymptomatic DVT. The duplex scan will be conducted locally by blinded assessors. Participants will be contacted remotely for follow-up at 7 days and 90 days post-procedure. The primary outcome is imaging-confirmed lower limb DVT with or without symptoms or PE with symptoms within 90 days of treatment. The main analysis will be according to the intention-to-treat principle and will compare the rates of VTE at 90 days, using a repeated measures analysis of variance, adjusting for any pre-specified strongly prognostic baseline covariates using a mixed effects logistic regression.

ETHICS AND DISSEMINATION

Ethical approval was granted by Brent Research Ethics Committee (22/LO/0261). Results will be disseminated in a peer-reviewed journal and presented at national and international conferences.

TRIAL REGISTRATION NUMBER

ISRCTN18501431.

Incidence and predictors of post-thrombotic syndrome in patients with proximal DVT in a real-world setting: findings from the GARFIELD-VTE registry

Although substantial progress has been made in the pathophysiology and management of the post-thrombotic syndrome (PTS), several aspects still need clarification. Among them, the incidence and severity of PTS in the real world, the risk factors for its development, the value of patient's self-evaluation, and the ability to identify patients at risk for severe PTS. Eligible participants (n = 1107) with proximal deep-vein thrombosis (DVT) from the global GARFIELD-VTE registry underwent conventional physician's evaluation for PTS 36 months after diagnosis of their DVT using the Villalta score. In addition, 856 patients completed a Villalta questionnaire at 24 months. Variable selection was performed using stepwise algorithm, and predictors of severe PTS were incorporated into a multivariable risk model. The optimistic adjusted c-index was calculated using bootstrapping techniques. Over 36-months, 27.8% of patients developed incident PTS (mild in 18.7%, moderate in 5.7%, severe in 3.4%). Patients with incident PTS were older, had a lower prevalence of transient risk factors of DVT and a higher prevalence of persistent risk factors of DVT. Self-assessment of overall PTS at 24 months showed an agreement of 63.4% with respect to physician's evaluations at 36 months. The severe PTS multivariable model provided an optimistic adjusted c-index of 0.68 (95% CI 0.59-0.77). Approximately a quarter of DVT patients experienced PTS over 36 months after VTE diagnosis. Patient's self-assessment after 24 months provided added value for estimating incident PTS over 36 months. Multivariable risk analysis allowed good discrimination for severe PTS.

Prognosis and Factors 4 to 10 Years After Deep Vein Thrombosis: A Long-Term Follow-up Cohort Study

Post-thrombotic syndrome (PTS) is one of the most common long-term complications of lower extremity deep vein thrombosis (DVT). In order to study the long-term adverse prognosis of patients with DVT, explore the influencing factors for the prognosis of DVT, and provide a reliable reference for future research in the field of venous thrombosis, we collected and summarized information about the incidence of PTS, the PTS score and grading, the associated symptoms and drug-related adverse reactions in 501 patients with DVT. In our study, 54.1% of patients with DVT (271 of 501) experienced indications and manifestations of PTS, the male to female ratio was approximately 1:1. During the long-term follow up, the most common symptoms of PTS were anterior tibial edema and pain. By statistical analysis, we found that the outcome of thrombosis was the influencing factor of PTS score (1-4 points, P<.05). The grading of PTS was primarily influenced by the history of varicose veins and DVT in the lower extremities. The duration of taking antithrombotic drugs affected the outcome of thrombosis (P<.05), especially among the female patients. In addition, varied factors, such as lower extremity DVT complicated with pulmonary embolism and the duration of antithrombotic drug use were found to increase the chances of experiencing drug-related adverse reactions (odds ratio [OR]=2.798, 95% confidence interval [CI]: 1.413-5.541 / OR=2.778, 95% CI: 1.231-6.269). The above 2 factors were significant only among female patients with DVT (OR=4.03, 95% CI: 1.608-10.103 / OR=3.918, 95% CI: 1.123-13.669).

Comparative outcomes of catheter-directed thrombolysis versus AngioJet pharmacomechanical catheter-directed thrombolysis for treatment of acute iliofemoral deep vein thrombosis

OBJECTIVE

The objective of this study was to compare the outcomes of pharmacomechanical thrombolysis and thrombectomy (PCDT) plus catheter-directed thrombolysis (CDT) vs CDT alone for the treatment of acute iliofemoral deep vein thrombosis (DVT) and summarize the clinical experience, safety outcomes, and short- and long-term efficacy.

METHODS

We performed a 4-year retrospective, case-control study. A total of 95 consecutive patients with acute symptomatic iliofemoral deep vein thrombosis (DVT) with a symptom duration of ≤7 days involving the iliac and/or common femoral veins underwent endovascular interventions. The patients were divided into two groups according to their clinical indications: PCDT plus CDT vs CDT alone. Statistical analyses were used to compare the clinical characteristics and outcomes between the two groups. Additionally, the patients were followed up for 3 to 36 months after treatment, and the proportions of post-thrombotic syndrome (PTS) and moderate to severe PTS were analyzed using the Kaplan-Meier survival method.

RESULTS

A total of 95 consecutive patients were analyzed in this retrospective study, of whom, 51 underwent CDT alone and 44 underwent PCDT plus CDT. Between the two groups, in terms of immediate-term efficacy and safety, significant differences were found in the catheter retention time (60.64 ± 12.04 hours vs 19.42 ± 4.04 hours; P < .001), dosages of urokinase required (5.82 ± 0.81 million units vs 1.80 ± 0.64 million units; P < .001), the detumescence rate at 24 hours postoperatively (48.46% ± 8.62% vs 76.79% ± 7.98%; P = .026), the descent velocity of D-dimer per day (2266.28 ± 1358.26 μg/L/D vs 3842.34 ± 2048.02 μg/L/D; P = .018), total hospitalization stay (6.2 ± 1.40 days vs 3.8 ± 0.70 days; P = .024), number of postoperative angiograms (2.4 ± 0.80 vs 1.2 ± 0.30; P = .042), and grade III venous patency (>95% lysis: 54.5% vs 68.6%; P = .047). Furthermore, during the follow-up period, significant differences were found in the incidence of PTS (Villalta scale ≥5 or a venous ulcer: 47.0% vs 27.7%; P = .037), and the incidence proportion of moderate to severe PTS at 12 months (15.7% vs 4.5%; P = .024) and 24 months (35.3% vs 11.4%; P = .016).

CONCLUSIONS

Compared with CDT alone, in the iliofemoral DVT subgroup with a symptom duration of ≤7 days, PCDT plus CDT could significantly relieve early leg symptoms, shorten the hospitalization stay, reduce bleeding complications, promote long-term venous patency, and decrease the occurrence of PTS and the incidence proportion of moderate to severe PTS. Thus, the short- and long-term outcomes both support the superiority of PCDT plus CDT vs CDT in this subgroup.

Acute and chronic venous occlusion

This review article provides an overview of acute and chronic venous occlusion, a condition that can cause significant morbidity and mortality if not diagnosed and treated promptly. The article begins with an introduction to the anatomy of the venous system, followed by a discussion of the causes and clinical features of venous occlusion. The diagnostic tools available for the assessment of venous occlusion, including imaging modalities such as ultrasound, CT, and MRI, are then discussed, along with their respective advantages and limitations. The article also covers the treatment options for acute and chronic venous occlusion, including anticoagulant therapy and endovascular interventions. This review aims to provide radiologists with an updated understanding of the pathophysiology, diagnosis, and management of acute and chronic venous occlusion.

Current challenges in the prevention and management of post-thrombotic syndrome-towards improved prevention

Post-thrombotic syndrome (PTS) is a common and potentially debilitating complication of deep vein thrombosis (DVT), affecting up to 50% of DVT patients. The consequence of this chronic condition includes reduced quality of life, increased use of the healthcare system and decreased productivity. The societal impact of this condition is projected to increase, given our ageing population and increased burden of thrombotic diseases. Despite significant recent advances in our understanding of PTS, many unanswered questions remain. Currently, there are few effective and proven options for established PTS; hence, the emphasis should be on instituting effective prevention to reduce the progression to PTS. Effective anticoagulation lowers the risk of PTS, with direct oral anticoagulants appearing to outperform vitamin-K antagonists. However, the evidence for elastic compression stockings and endovascular thrombolysis or thrombectomy techniques remains unclear. Accurate identification of individuals at high risk of developing PTS may also improve the targeting of preventative interventions. This review will examine the current body of evidence regarding PTS, with a focus on preventative strategies as well as novel biomarkers.

Biomarkers and the post-thrombotic syndrome: A systematic review of biomarkers associated with the occurrence of the post-thrombotic syndrome after lower extremity deep venous thrombosis

INTRODUCTION

Post-thrombotic syndrome (PTS) is a frequent chronic complication of deep venous thrombosis (DVT). Biomarkers are potentially valuable clinical tools for handling PTS. The purpose of this review was to examine which biomarkers are associated with the development of PTS in adults with lower extremity DVT.

METHODS

We performed a systematic review of all English language prospective studies of biomarkers and PTS published in PubMed and EMBASE. Studies were included if diagnosing DVT by diagnostic imaging and assessing PTS by clinical scales, for example, the Villalta scale. Biomarkers of thrombophilia and pathological clot properties were not assessed. Data was reported qualitatively.

RESULTS

15 prospective studies were included. Studies varied widely in study design and methods of data analysis. Forty-six different biomarkers were examined, with seven being measured in two or more studies. The most frequently studied biomarkers were D-dimer, CRP, and IL-6. Associations between PTS and D-dimer were predominantly significant, while results on CRP and IL-6 were inconsistent. ICAM-1 was consistently associated with PTS in all studies and at all timepoints. IL-10 was significantly related to PTS development in the largest study and at all time points. Adiponectin, tPA, HRG and TAFI, MMP-1 and -8, and TIMP-1 and -2 were significantly associated with PTS in single studies.

CONCLUSION

(1) Further research on biomarkers and PTS is clearly warranted. (2) Significant differences in study designs made it difficult to draw reliable conclusions regarding individual biomarkers. We suggest the implementation of a standardized framework for the study of biomarkers and PTS, to make comparison of future studies more feasible. (3) D-dimer, ICAM-1, IL-10, MMP-1 and 8, TIMP-1, TIMP-2, and adiponectin are clinical biomarkers of particular interest to include in future studies of PTS. Large scale systemic quantitative proteomic analyses of DVT patients could help identify novel biomarkers of interest in PTS-patients.

Epidemiology and Diagnosis of Post-Thrombotic Syndrome: Qualitative Synthesis with a Systematic Review

Background: Post-thrombotic syndrome (PTS) is a common and debilitating sequela of lower limb deep vein thrombosis (DVT). There is significant heterogeneity in reported PTS incidence due to lack of standardised diagnostic criteria. This review aimed to develop diagnostic criteria for PTS and subsequently refine the reported incidence and severity. Methods: PRISMA principles were followed; however, the review was not registered. The Cochrane CENTRAL database, MEDLINE, Embase, the NHS NICE Healthcare Databases Advanced Search interface, and trial registers including isrctn.com and clinicaltrials.gov were searched for studies addressing areas of interest (PTS definition, epidemiology, assessment). An experienced Clinical Librarian undertook the systematic searches, and two independent reviewers agreed on the relevance of the papers. Conflicts were resolved through panel review. Evidence quality was assessed using a modified Coleman scoring system and weighted according to their relevance to the aforementioned areas of interest. Results: A total of 339 abstracts were retrieved. A total of 33 full-text papers were included in this review. Following qualitative analysis, four criteria were proposed to define PTS: (1) a proven thrombotic event on radiological assessment; (2) a minimum 24-month follow-up period after an index DVT; (3) assessment with a validated score; and (4) evidence of progression of venous insufficiency from baseline. Four papers conformed to our PTS definition criteria, and the incidence of mild to moderate PTS ranged from 7 to 36%. On reviewing the studies which utilised the recommended Villalta scale, PTS incidence narrowed further to 23-36%. Incidence and severity reached a plateau at 24 months. Conclusions: Four diagnostic criteria were developed from qualitative synthesis. When these criteria were applied to the literature, the range of reported PTS incidence narrowed. These four criteria may standardise PTS diagnosis in future studies, facilitating the pooling of data for meta-analysis and synthesis of higher levels of evidence.

Prophylactic anticoagulants for non-hospitalised people with COVID-19

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic has impacted healthcare systems worldwide. Multiple reports on thromboembolic complications related to COVID-19 have been published, and researchers have described that people with COVID-19 are at high risk for developing venous thromboembolism (VTE). Anticoagulants have been used as pharmacological interventions to prevent arterial and venous thrombosis, and their use in the outpatient setting could potentially reduce the prevalence of vascular thrombosis and associated mortality in people with COVID-19. However, even lower doses used for a prophylactic purpose may result in adverse events such as bleeding. It is important to consider the evidence for anticoagulant use in non-hospitalised people with COVID-19.

OBJECTIVES

To evaluate the benefits and harms of prophylactic anticoagulants versus active comparators, placebo or no intervention, or non-pharmacological interventions in non-hospitalised people with COVID-19.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 18 April 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing prophylactic anticoagulants with placebo or no treatment, another active comparator, or non-pharmacological interventions in non-hospitalised people with COVID-19. We included studies that compared anticoagulants with a different dose of the same anticoagulant. We excluded studies with a duration of under two weeks.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. Our primary outcomes were all-cause mortality, VTE (deep vein thrombosis (DVT) or pulmonary embolism (PE)), and major bleeding. Our secondary outcomes were DVT, PE, need for hospitalisation, minor bleeding, adverse events, and quality of life. We used GRADE to assess the certainty of the evidence.

MAIN RESULTS

We included five RCTs with up to 90 days of follow-up (short term). Data were available for meta-analysis from 1777 participants. Anticoagulant compared to placebo or no treatment Five studies compared anticoagulants with placebo or no treatment and provided data for three of our outcomes of interest (all-cause mortality, major bleeding, and adverse events). The evidence suggests that prophylactic anticoagulants may lead to little or no difference in all-cause mortality (risk ratio (RR) 0.36, 95% confidence interval (CI) 0.04 to 3.61; 5 studies; 1777 participants; low-certainty evidence) and probably reduce VTE from 3% in the placebo group to 1% in the anticoagulant group (RR 0.36, 95% CI 0.16 to 0.85; 4 studies; 1259 participants; number needed to treat for an additional beneficial outcome (NNTB) = 50; moderate-certainty evidence). There may be little to no difference in major bleeding (RR 0.36, 95% CI 0.01 to 8.78; 5 studies; 1777 participants; low-certainty evidence). Anticoagulants probably result in little or no difference in DVT (RR 1.02, 95% CI 0.30 to 3.46; 3 studies; 1009 participants; moderate-certainty evidence), but probably reduce the risk of PE from 2.7% in the placebo group to 0.7% in the anticoagulant group (RR 0.25, 95% CI 0.08 to 0.79; 3 studies; 1009 participants; NNTB 50; moderate-certainty evidence). Anticoagulants probably lead to little or no difference in reducing hospitalisation (RR 1.01, 95% CI 0.59 to 1.75; 4 studies; 1459 participants; moderate-certainty evidence) and may lead to little or no difference in adverse events (minor bleeding, RR 2.46, 95% CI 0.90 to 6.72; 5 studies, 1777 participants; low-certainty evidence). Anticoagulant compared to a different dose of the same anticoagulant One study compared anticoagulant (higher-dose apixaban) with a different (standard) dose of the same anticoagulant and reported five relevant outcomes. No cases of all-cause mortality, VTE, or major bleeding occurred in either group during the 45-day follow-up (moderate-certainty evidence). Higher-dose apixaban compared to standard-dose apixaban may lead to little or no difference in reducing the need for hospitalisation (RR 1.89, 95% CI 0.17 to 20.58; 1 study; 278 participants; low-certainty evidence) or in the number of adverse events (minor bleeding, RR 0.47, 95% CI 0.09 to 2.54; 1 study; 278 participants; low-certainty evidence). Anticoagulant compared to antiplatelet agent One study compared anticoagulant (apixaban) with antiplatelet agent (aspirin) and reported five relevant outcomes. No cases of all-cause mortality or major bleeding occurred during the 45-day follow-up (moderate-certainty evidence). Apixaban may lead to little or no difference in VTE (RR 0.36, 95% CI 0.01 to 8.65; 1 study; 279 participants; low-certainty evidence), need for hospitalisation (RR 3.20, 95% CI 0.13 to 77.85; 1 study; 279 participants; low-certainty evidence), or adverse events (minor bleeding, RR 2.13, 95% CI 0.40 to 11.46; 1 study; 279 participants; low-certainty evidence). No included studies reported on quality of life or investigated anticoagulants compared to a different anticoagulant, or anticoagulants compared to non-pharmacological interventions.

AUTHORS' CONCLUSIONS

We found low- to moderate-certainty evidence from five RCTs that prophylactic anticoagulants result in little or no difference in major bleeding, DVT, need for hospitalisation, or adverse events when compared with placebo or no treatment in non-hospitalised people with COVID-19. Low-certainty evidence indicates that prophylactic anticoagulants may result in little or no difference in all-cause mortality when compared with placebo or no treatment, but moderate-certainty evidence indicates that prophylactic anticoagulants probably reduce the incidence of VTE and PE. Low-certainty evidence suggests that comparing different doses of the same prophylactic anticoagulant may result in little or no difference in need for hospitalisation or adverse events. Prophylactic anticoagulants may result in little or no difference in risk of VTE, hospitalisation, or adverse events when compared with antiplatelet agents (low-certainty evidence). Given that there were only short-term data from one study, these results should be interpreted with caution. Additional trials of sufficient duration are needed to clearly determine any effect on clinical outcomes.

Post-thrombotic syndrome and chronic thromboembolic pulmonary hypertension: diagnosis and management

Post-thrombotic syndrome and chronic thromboembolic pulmonary hypertension are two distinct clinical syndromes associated with adverse patient outcomes following a venous thromboembolism. Clinical manifestations of post-thrombotic syndrome include persistent pain, swelling and ultimately venous ulceration following a deep venous thrombosis. Patients experiencing chronic thromboembolic pulmonary hypertension may have symptoms ranging from exertional dyspnoea to overt right heart failure. From a physician's perspective, the most effective preventative strategy is good quality anticoagulation for prophylaxis of primary and secondary venous thromboembolism. The treatment of post-thrombotic syndrome mainly involves lifestyle modifications alongside the use of elastic compression stockings while patients with chronic thromboembolic pulmonary hypertension should be offered targeted surgical and medical treatment options available at expert centres. Further research is warranted for both conditions to determine the role of direct oral anticoagulants when used with a preventive or therapeutic intent.

Lessons Learned With Venous Stenting: In-flow, Outflow, and Beyond

Venous stents are being used with increasing frequency, with a multitude of dedicated venous stents now well established or emerging onto the market. This review explores the multifaceted aspects of venous stenting. We discuss the history of venous stents, indications for their use, the imaging required before, during and after stenting, as well as some technical tips and tricks which we have found to be helpful in our own daily practice with a particular focus on iliofemoral venous stenting. Ultimately, this article seeks to enhance the understanding of venous stenting, offering insights into what we feel are best practices, challenges, and prospects for improved patient outcomes.

Is it necessary to wear compression stockings and how long should they be worn for preventing post thrombotic syndrome? A meta-analysis of randomized controlled trials

BACKGROUND

Post thrombotic syndrome (PTS) is a serious complication of deep venous thrombosis (DVT). There were always debates on the efficacy of elastic compression stockings (ECS) in prevention for post thrombotic syndrome.

OBJECTIVE

To assess effects of elastic compression stockings and ECS's wearing time on post thrombotic syndrome after diagnosis of deep venous thrombosis.

METHODS

PubMed, Cochrane Library, Embase, Web of Science were last searched on 23 November 2022 for studies assessing effects of elastic compression stockings or theirs wearing time on post thrombotic syndrome after diagnosis of deep venous thrombosis.

RESULTS

9 randomized controlled trials were included. Wearing elastic compression stockings was associated with a statistically reduction in the overall post thrombotic syndrome rate (RR 0.73, 95 % CI 0.53 to 1.00; P = 0.05; I2 = 82 %). No significant difference in severe post thrombotic syndrome rate, recurrent deep venous thrombosis rate, and death rate was seen whether wearing elastic compression stockings or not. The pooled effect of studies comparing different wearing time of elastic compression stockings showed no significant difference in post thrombotic syndrome rate, severe and moderate post thrombotic syndrome rate, recurrent deep venous thrombosis syndrome rate and death rate.

CONCLUSIONS

Wearing ECS can reduce the risk of developing PTS after DVT and a wearing time of less than or equal to 1 year is comparable to 2 years wearing. The results support ECS's role as a foundation therapy for preventing PTS.

Oral direct thrombin inhibitors or oral factor Xa inhibitors versus conventional anticoagulants for the treatment of deep vein thrombosis

BACKGROUND

Deep vein thrombosis (DVT) is a condition in which a clot forms in the deep veins, most commonly of the leg. It occurs in approximately one in 1000 people. If left untreated, the clot can travel up to the lungs and cause a potentially life-threatening pulmonary embolism (PE). Previously, a DVT was treated with the anticoagulants heparin and vitamin K antagonists. However, two forms of direct oral anticoagulants (DOACs) have been developed: oral direct thrombin inhibitors (DTIs) and oral factor Xa inhibitors, which have characteristics that may be favourable compared to conventional treatment, including oral administration, a predictable effect, lack of frequent monitoring or dose adjustment and few known drug interactions. DOACs are now commonly being used for treating DVT: recent guidelines recommended DOACs over conventional anticoagulants for both DVT and PE treatment. This Cochrane Review was first published in 2015. It was the first systematic review to measure the effectiveness and safety of these drugs in the treatment of DVT. This is an update of the 2015 review.  OBJECTIVES: To assess the effectiveness and safety of oral DTIs and oral factor Xa inhibitors versus conventional anticoagulants for the long-term treatment of DVT.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase and CINAHL databases and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 1 March 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) in which people with a DVT, confirmed by standard imaging techniques, were allocated to receive an oral DTI or an oral factor Xa inhibitor compared with conventional anticoagulation or compared with each other for the treatment of DVT.  DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were recurrent venous thromboembolism (VTE), recurrent DVT and PE. Secondary outcomes included all-cause mortality, major bleeding, post-thrombotic syndrome (PTS) and quality of life (QoL). We used GRADE to assess the certainty of evidence for each outcome.

MAIN RESULTS

We identified 10 new studies with 2950 participants for this update. In total, we included 21 RCTs involving 30,895 participants. Three studies investigated oral DTIs (two dabigatran and one ximelagatran), 17 investigated oral factor Xa inhibitors (eight rivaroxaban, five apixaban and four edoxaban) and one three-arm trial investigated both a DTI (dabigatran) and factor Xa inhibitor (rivaroxaban). Overall, the studies were of good methodological quality. Meta-analysis comparing DTIs to conventional anticoagulation showed no clear difference in the rate of recurrent VTE (odds ratio (OR) 1.17, 95% confidence interval (CI) 0.83 to 1.65; 3 studies, 5994 participants; moderate-certainty evidence), recurrent DVT (OR 1.11, 95% CI 0.74 to 1.66; 3 studies, 5994 participants; moderate-certainty evidence), fatal PE (OR 1.32, 95% CI 0.29 to 6.02; 3 studies, 5994 participants; moderate-certainty evidence), non-fatal PE (OR 1.29, 95% CI 0.64 to 2.59; 3 studies, 5994 participants; moderate-certainty evidence) or all-cause mortality (OR 0.66, 95% CI 0.41 to 1.08; 1 study, 2489 participants; moderate-certainty evidence). DTIs reduced the rate of major bleeding (OR 0.58, 95% CI 0.38 to 0.89; 3 studies, 5994 participants; high-certainty evidence).   For oral factor Xa inhibitors compared with conventional anticoagulation, meta-analysis demonstrated no clear difference in recurrent VTE (OR 0.85, 95% CI 0.71 to 1.01; 13 studies, 17,505 participants; moderate-certainty evidence), recurrent DVT (OR 0.70, 95% CI 0.49 to 1.01; 9 studies, 16,439 participants; moderate-certainty evidence), fatal PE (OR 1.18, 95% CI 0.69 to 2.02; 6 studies, 15,082 participants; moderate-certainty evidence), non-fatal PE (OR 0.93, 95% CI 0.68 to 1.27; 7 studies, 15,166 participants; moderate-certainty evidence) or all-cause mortality (OR 0.87, 95% CI 0.67 to 1.14; 9 studies, 10,770 participants; moderate-certainty evidence). Meta-analysis showed a reduced rate of major bleeding with oral factor Xa inhibitors compared with conventional anticoagulation (OR 0.63, 95% CI 0.45 to 0.89; 17 studies, 18,066 participants; high-certainty evidence).  AUTHORS' CONCLUSIONS: The current review suggests that DOACs may be superior to conventional therapy in terms of safety (major bleeding), and are probably equivalent in terms of efficacy. There is probably little or no difference between DOACs and conventional anticoagulation in the prevention of recurrent VTE, recurrent DVT, pulmonary embolism and all-cause mortality. DOACs reduced the rate of major bleeding compared to conventional anticoagulation. The certainty of evidence was moderate or high.

The risk for post-thrombotic syndrome of subjects with deep vein thrombosis in an Indonesian referral hospital: a retrospective cohort study

BACKGROUND

Post-thrombotic syndrome (PTS) is a complication of deep vein thrombosis (DVT) and affects 20-40% of DVT subjects. The risk factor of PTS after DVT is difficult to determine. We aimed to evaluate the incidence of PTS after 3 months of DVT diagnosis and to determine the risk of PTS.

METHODS

A retrospective cohort study of subjects who developed DVT confirmed by Doppler ultrasound in Cipto Mangunkusumo Hospital from April 2014 until June 2015. The presence of PTS was assessed after 3 months of completed DVT treatment using the Villalta score. Risk factors for PTS were evaluated from medical records.

RESULTS

There were 91 subjects with DVT with mean age of 58 years. 56% were female. It was dominated by subjects aged ≥ 60 years (45.1%). Hypertension (30.8%) and diabetes mellitus (26.4%) were the major comorbidities in this study. Deep vein thrombosis occurred commonly in unilateral side (79.1%), proximal localization (87.9%), and unprovoked DVT (47.3%). The cumulative incidence of PTS after DVT was 53.8%, 69% of subjects had mild PTS. Heaviness of the leg (63.2%) and edema (77.5%) were the most common symptoms.

RESULTS

There were 91 subjects with DVT with mean age of 58 years. 56% were female. It was dominated by subjects aged ≥ 60 years (45.1%). Hypertension (30.8%) and diabetes mellitus (26.4%) were the major comorbidities in this study. Deep vein thrombosis occurred commonly in unilateral side (79.1%), proximal localization (87.9%), and unprovoked DVT (47.3%). The cumulative incidence of PTS after DVT was 53.8%, 69% of subjects had mild PTS. Heaviness of the leg (63.2%) and edema (77.5%) were the most common symptoms. Significant risk factors for PTS were unprovoked DVT (adjusted RR 1.67; 95%CI: 1.17-2.04; p = 0.01) and female gender (adjusted RR 1.55; 95%CI: 1.03-1.94; p = 0.04). Age, body mass index, thrombus location, immobilization, malignancy and surgery was not associated with PTS.

CONCLUSION

We conclude that 53.8% of subjects suffered PTS after 3 months of DVT. Unprovoked DVT and female gender were significant risk factors for PTS.

Systematic Review and Meta-Analysis of the Pooled Rate of Post-Thrombotic Syndrome After Isolated Distal Deep Venous Thrombosis

OBJECTIVE

To identify the rate of post-thrombotic syndrome (PTS) after isolated distal deep venous thrombosis (IDDVT) by performing a meta-analysis of the rate of PTS across randomised and observational studies.

DATA SOURCES

MEDLINE, Embase, the Cochrane Controlled Trials Register, Clinicaltrials.gov, European Union Clinical Trials, International Standard Randomised Controlled Trial Number, and the Australian and New-Zealand Trials Registries.

REVIEW METHODS

This review followed PRISMA guidelines using a registered protocol (CRD42021282136). Databases were searched up to December 2021 and prospective studies reporting the development of post-thrombotic syndrome were included; these were pooled with the meta-analysis.

RESULTS

The results showed a post-thrombotic rate of 17% (95% CI 11 - 26%) (seven studies, 217 cases, 1 105 participants). Heterogeneity was high (I2 = 89%). On meta-regression, the rate of post-thrombotic syndrome was not correlated with the length of follow up (p = .71). Three studies (302 participants) reported the severity of post-thrombotic syndrome: 78% were mild (Villalta score 5 - 9); 11% were moderate (Villalta score 10 - 14), and 11% were severe (Villalta score ≥ 15).

CONCLUSION

The risk of post-thrombotic syndrome after IDDVT was one in five and the risk of severe clinical manifestations, including ulceration, was one in 50. There was significant clinical, methodological, and statistical heterogeneity between studies and a substantial risk of bias from pooled studies. Randomised trials to support interventions for prevention of post-thrombotic syndrome are urgently needed.

Resistance exercise promotes the resolution and recanalization of deep venous thrombosis in a mouse model via SIRT1 upregulation

BACKGROUND

Early exercise for acute deep venous thrombosis (DVT) improves the patient's symptoms and does not increase the risk of pulmonary embolism. However, information about its effect on thrombus resolution is limited. The aim of this study was to investigate the role of resistance exercise (RE) in thrombus resolution and recanalization and determine its underlying mechanisms.  METHODS: Ninety-six C57BL/6 J mice were randomly divided into four groups: Control group (C, n = 24); DVT group (D, n = 24); RE + DVT group (ED, n = 24); and inhibitor + RE + DVT group (IED, n = 24). A DVT model was induced by stenosis of the inferior vena cava (IVC). After undergoing IVC ultrasound within 24 h post-operation to confirm DVT formation, mice without thrombosis were excluded. Other mice were sacrificed and specimens were obtained 14 or 28 days after operation. Thrombus-containing IVC was weighed, and the thrombus area and recanalization rate were calculated using HE staining. Masson's trichrome staining was used to analyze the collagen content. RT-PCR and ELISA were performed to examine IL-6, TNF-α, IL-10, and VEGF expression levels. SIRT1 expression was assessed using immunohistochemistry staining and RT-PCR. VEGF-A protein expression and CD-31-positive microvascular density (MVD) in the thrombus were observed using immunohistochemistry.  RESULTS: RE did not increase the incidence of pulmonary embolism. It reduced the weight and size of the thrombus and the collagen content. Conversely, it increased the recanalization rate. It also decreased the levels of the pro-inflammatory factors IL-6 and TNF-α and increased the expression levels of the anti-inflammatory factor IL-10. RE enhanced VEGF and SIRT1 expression levels and increased the MVD in the thrombosis area. After EX527 (SIRT1 inhibitor) was applied, the positive effects of exercise were suppressed.

CONCLUSIONS

RE can inhibit inflammatory responses, reduce collagen deposition, and increase angiogenesis in DVT mice, thereby promoting thrombus resolution and recanalization. Its underlying mechanism may be associated with the upregulation of SIRT1 expression.

Oncovascular surgery for advanced pelvic malignancy

BACKGROUND

The number of units with experience in extended radical resections for advanced pelvic tumours has grown substantially in recent years. The use of complex vascular resections and reconstructive techniques in these units is expected to increase with experience. This review aimed to provide a cutting-edge overview of this evolving surgical approach to complex pelvic tumours with vascular involvement.

METHODS

This was a narrative review of published data on major vascular resection and reconstruction for advanced pelvic tumours, including preoperative evaluation, techniques used, and outcomes. Advice for treatment decisions is provided, and based on current literature and the personal experience of the authors. Current controversies and future directions are discussed.

RESULTS

Major vascular resection and reconstruction during surgery for advanced pelvic tumours is associated with prolonged operating time (510-678 min) and significant blood loss (median 2-5 l). R0 resection can be achieved in 58-82 per cent at contemporary specialist units. The risk of major complications is similar to that of extended pelvic resection without vascular involvement (30-40 per cent) and perioperative mortality is acceptable (0-4 per cent). Long-term survival is achievable in approximately 50 per cent of patients.

CONCLUSION

En bloc resection of the common or external iliac vessels during exenterative pelvic surgery is a feasible strategy for patients with advanced tumours which infiltrate major pelvic vascular structures. Oncological, morbidity, and survival outcomes appear comparable to more central pelvic tumours. These encouraging outcomes, combined with an increasing interest in extended pelvic resections globally, will likely lead to more exenteration units developing oncovascular experience.

Chronic Venous Disease of the Lower Extremities: A State-of-the Art Review

Chronic venous disease is a common disease, the prevalence of which increases with age, and can cause debilitating symptoms that adversely affect the quality of life. The risk factors include family history, female sex, obesity, pregnancy, parity, and history of deep vein thrombosis. Moreover, it is associated with venous obstruction, reflux, or both, which, in turn, leads to ambulatory venous hypertension. Chronic venous disease is the leading cause of leg ulcers, which place a significant cost burden on the health care system. Compression therapy remains the cornerstone of treatment, particularly for more advanced disease. Superficial saphenous vein reflux can be associated with significant symptoms. Catheter techniques, both thermal and nonthermal, have demonstrated efficacy and safety in successful closure and symptom improvement. Deep vein obstruction can be broadly divided into thrombotic and nonthrombotic and can lead to symptomatic chronic venous disease. Recanalization using balloons and stents has been increasingly used and studied in such patients. It is critical to develop training opportunities and guidelines to improve evidence-based and appropriate care for cardiologists treating chronic venous disease.

Exploring the Villalta scale to capture postthrombotic syndrome using alternative approaches: A subanalysis of the ATTRACT trial

Background

Clinical trials that evaluated interventions to prevent postthrombotic syndrome (PTS) used the Villalta scale (VS) to define PTS, but there is a lack of consistency in its use.

Objectives

This study aimed to improve the ability to identify patients with clinically meaningful PTS after DVT in participants of the ATTRACT trial.

Methods

We conducted a post hoc exploratory analysis of 691 patients from the ATTRACT study, a randomized trial evaluating the effectiveness of pharmacomechanical thrombolysis to prevent PTS in proximal deep vein thrombosis. We compared 8 VS approaches to classify patients with or without PTS in terms of their ability to discriminate between those with poorer vs better venous disease-specific quality of life (Venous Insufficiency Epidemiological and Economic Study Quality of Life [VEINES-QOL]) between 6- and 24-months follow-up. The difference in the average area under the fitted curve of VEINES-QOL scores between PTS and no PTS ( Δ A U C ¯ ) were compared among approaches.

Results

For any PTS (a single VS score ≥5), approaches 1 to 3 had similar Δ A U C ¯ (-21.2, -23.7, -22.0, respectively). Adjusting the VS for contralateral chronic venous insufficiency (CVI) or restricting to patients without baseline CVI (approaches 7 and 8) did not improve Δ A U C ¯ (-13.6, -19.9, respectively; P >.01). For moderate-to-severe PTS (a single VS score ≥10), approaches 5 and 6 requiring 2 positive assessments had greater but not statistically significant Δ A U C ¯ than approach 4, using one single positive assessment (-31.7, -31.0, -25.5, respectively; P >.01).

Conclusion

A single VS score of ≥ 5 reliably distinguishes patients with clinically meaningful PTS as assessed by impact on QOL and is preferred because of greater convenience (only one assessment needed). Alternative methods to define PTS (ie, adjusting for CVI) do not improve the scale's ability to identify clinically meaningful PTS.

Developing and optimizing a machine learning predictive model for post-thrombotic syndrome in a longitudinal cohort of patients with proximal deep venous thrombosis

BACKGROUND

Post-thrombotic syndrome (PTS) is the most common chronic complication of deep venous thrombosis (DVT). Risk measurement and stratification of PTS are crucial for patients with DVT. This study aimed to develop predictive models of PTS using machine learning for patients with proximal DVT.

METHODS

Herein, hospital inpatients from a DVT registry electronic health record database were randomly divided into a derivation and a validation set, and four predictive models were constructed using logistic regression, simple decision tree, eXtreme Gradient Boosting (XGBoost), and random forest (RF) algorithms. The presence of PTS was defined according to the Villalta scale. The areas under the receiver operating characteristic curves, decision-curve analysis, and calibration curves were applied to evaluate the performance of these models. The Shapley Additive exPlanations analysis was performed to explain the predictive models.

RESULTS

Among the 300 patients, 126 developed a PTS at 6 months after DVT. The RF model exhibited the best performance among the four models, with an area under the receiver operating characteristic curves of 0.891. The RF model demonstrated that Villalta score at admission, age, body mass index, and pain on calf compression were significant predictors for PTS, with accurate prediction at the individual level. The Shapley Additive exPlanations analysis suggested a nonlinear correlation between age and PTS, with two peak ages of onset at 50 and 70 years.

CONCLUSIONS

The current predictive model identified significant predictors and accurately predicted PTS for patients with proximal DVT. Moreover, the model demonstrated a nonlinear correlation between age and PTS, which might be valuable in risk measurement and stratification of PTS in patients with proximal DVT.

On-treatment Comparative Effectiveness of Vitamin K Antagonists and Direct Oral Anticoagulants in GARFIELD-VTE, and Focus on Cancer and Renal Disease

Background Direct oral anticoagulants (DOACs) provide a safe, effective alternative to vitamin K antagonists (VKAs) for venous thromboembolism (VTE) treatment, as shown via intention-to-treat comparative effectiveness analysis. However, on-treatment analysis is imperative in observational studies because anticoagulation choice and duration are at investigators' discretion.

Objectives The aim of the study is to compare the effectiveness of DOACs and VKAs on 12-month outcomes in VTE patients using on-treatment analysis.

Methods The Global Anticoagulant Registry in the FIELD - VTE (GARFIELD-VTE) is a world-wide, prospective, non-interventional study observing treatment of VTE in routine clinical practice.

Results In total, 8,034 patients received VKAs (n = 3,043, 37.9%) or DOACs (n = 4,991, 62.1%). After adjustment for baseline characteristics and follow-up bleeding events, and accounting for possible time-varying confounding, all-cause mortality was significantly lower with DOACs than VKAs (hazard ratio: 0.58 [95% confidence interval 0.42–0.79]). Furthermore, patients receiving VKAs were more likely to die of VTE complications (4.9 vs. 2.2%) or bleeding (4.9 vs. 0.0%). There was no significant difference in rates of recurrent VTE (hazard ratio: 0.74 [0.55–1.01]), major bleeding (hazard ratio: 0.76 [0.47–1.24]), or overall bleeding (hazard ratio: 0.87 [0.72–1.05]) with DOACs or VKAs. Unadjusted analyses suggested that VKA patients with active cancer or renal insufficiency were more likely to die than patients treated with DOAC (52.51 [37.33–73.86] vs. 26.52 [19.37–36.29] and 9.97 [7.51–13.23] vs. 4.70 [3.25–6.81] per 100 person-years, respectively).

Conclusion DOACs and VKAs had similar rates of recurrent VTE and major bleeding. However, DOACs were associated with reduced all-cause mortality and a lower likelihood of death from VTE or bleeding compared with VKAs.

Deep Venous Thrombosis

Venous thromboembolism (VTE) is the third most common cardiovascular disorder, affecting up to 5% of the population. VTE commonly manifests as lower-extremity deep venous thrombosis (DVT) or pulmonary embolism. Half of these events are associated with a transient risk factor and may be preventable with prophylaxis. Direct oral anticoagulants are effective and safe and carry a lower risk for bleeding than vitamin K antagonists. Many patients with VTE will have a chronic disease requiring long-term anticoagulation. Postthrombotic syndrome affects 25% to 40% of patients with DVT and significantly impacts function and quality of life.

Outcomes from a tertiary care center using a catheter thrombectomy system for managing acute iliofemoral deep vein thrombosis

OBJECTIVE

The aim of the present study was to report a large, single-center experience using the ClotTriever thrombectomy system (Inari Medical, Irvine, CA) for the management of acute iliofemoral (IF) deep vein thrombosis (DVT). One limitation of all endovascular devices for the treatment of acute IF-DVT has been the inability to completely remove all acute thrombus and the need for adjunctive thrombolysis with its attendant risk of bleeding complications.

METHODS

A single-center retrospective review of consecutive patients with acute IF-DVT treated with the ClotTriever thrombectomy system (Inari Medical) is reported. Procedural efficacy was evaluated by an independent core imaging laboratory (Syntactx, New York, NY). Both procedural and in-hospital safety were assessed during the index hospitalization. The treated vein patency was assessed using duplex ultrasound at 30 days after the procedure.

RESULTS

A total of 96 patients were included in the present retrospective review, 40 of whom (40%) had contraindications to thrombolytic therapy. In terms of efficacy, 93 patients (97%) had ≥75% thrombus removal. During the index hospitalization, two patients (2%) had experienced a symptomatic pulmonary embolus. However, no mortality, major bleeding, or device-related complications had occurred in the study population. Of the 96 patients, 64 had undergone duplex ultrasound at 30 days after the procedure. Of the 64 patients, 62 had normal flow (97%), 53 (83%) had normal compressibility, and 11 (17%) had partial compressibility.

CONCLUSIONS

The ClotTriever thrombectomy catheter was both safe and effective in our cohort of patients with acute IF-DVT outside a randomized clinical trial.

A realist evaluation to identify targets to improve the organization of compression therapy for deep venous thrombosis- and chronic venous disease patients

Background

Although compression therapy is well established for patients with deep venous thrombosis (DVT) and chronic venous disease (CVD), considerable variation exists in its organization in clinical practice which may impact patient outcomes. The current study aims to deepen our understanding of the main drivers of the complex care organization for compression therapy and to identify targets for improvement.

Methods

This realist evaluation includes a mixed-method design consisting of semi-structured interviews with patients and health care professionals involved in compression therapy (n = 30), stakeholder meetings (n = 2) and surveys (n = 114). Data were collected to create the content of context-mechanism-outcome-configurations (CMOcs) important in compression therapy. Based on these CMOcs, targets for improvement to optimize the organization of compression care were identified.

Results

We identified overarching context factors and mechanisms targeting four optimal outcomes for the organization of compression therapy: selecting initial compression therapy types that support patient’s self-reliance (1), evidence based selection of elastic compression stocking type and class (2), patient-based selection of assistive devices (3), individualizing treatment duration for DVT patients (4a) and providing follow-up for CVD patients (4b). We found that increasing health care professionals’ knowledge of compression therapy, the availability of unambiguous protocols and guidelines, increasing patient involvement (and if applicable their informal care giver) in the decision making process, the accessible availability of resources, and increasing interdisciplinary consultation enhanced desirable outcomes. These targets triggered mechanisms such as increased health care professionals’ willingness, confidence and motivation to provide patient-based care and increased patients’ self-confidence and self-efficacy.

Conclusions

This study provides a detailed insight into what needs to be in place to optimize compression care and identified five main targets for improvement.

Role of Physical Therapists in the Management of Individuals at Risk for or Diagnosed With Venous Thromboembolism: Evidence-Based Clinical Practice Guideline 2022

No matter the practice setting, physical therapists work with patients who are at risk for or who have a history of venous thromboembolism (VTE). In 2016, the first clinical practice guideline (CPG) addressing the physical therapist management of VTE was published with support by the American Physical Therapy Association's Academy of Cardiovascular and Pulmonary Physical Therapy and Academy of Acute Care, with a primary focus on lower extremity deep vein thrombosis (DVT). This CPG is an update of the 2016 CPG and contains the most current evidence available for the management of patients with lower extremity DVT and new key action statements (KAS), including guidance on upper extremity DVT, pulmonary embolism, and special populations. This document will guide physical therapist practice in the prevention of and screening for VTE and in the management of patients who are at risk for or who have been diagnosed with VTE. Through a systematic review of published studies and a structured appraisal process, KAS were written to guide the physical therapist. The evidence supporting each action was rated, and the strength of statement was determined. Clinical practice algorithms based on the KAS were developed that can assist with clinical decision-making. Physical therapists, along with other members of the health care team, should implement these KAS to decrease the incidence of VTE, improve the diagnosis and acute management of VTE, and reduce the long-term complications of VTE.