Prevention and treatment of the post-thrombotic syndrome

Diagnosis and treatment of deep vein thrombosis of the lower and upper limbs. 2024 recommendations of the venous thromboembolism group of the Spanish Society of Internal Medicine

Deep vein thrombosis (DVT) of the limbs is a common disease and causes significant morbidity and mortality. It is frequently the prelude to pulmonary embolism (PE), it can recur in 30% of patients and in 25-40% of cases they can develop post-thrombotic syndrome (PTS), with a significant impact in functional status and quality of life. This document contains the recommendations on the diagnosis and treatment of acute DVT from the Thromboembolic Disease group of the Spanish Society of Internal Medicine (SEMI). PE and thrombosis of unusual venous territories (cerebral, renal, mesenteric, superficial, etc.) are outside its scope, as well as thrombosis associated with catheter and thrombosis associated with cancer, which due to their peculiarities will be the subject of other positioning documents of the Thromboembolic Disease group of the Spanish Society of Internal Medicine (SEMI).

Stent deformations in the common iliac and iliofemoral veins as a result of hip flexion and extension

OBJECTIVE

In the present study, we characterized deformations of venous stents implanted into common iliac veins for nonthrombotic iliac vein lesions and iliofemoral veins for deep vein thrombosis due to hip movements commensurate with everyday activities such as walking, sitting, and stair climbing.

METHODS

Patients treated with iliofemoral venous stents were recruited from three centers and underwent imaging with two orthogonal two-dimensional projection radiographs. Stents in the common iliac veins and iliofemoral veins crossing the hip joint were imaged with the hip in 0°, 30°, 90° and -15°, 0°, and 30° positions, respectively. Using the radiographs, the three-dimensional geometries of the stents were constructed for each hip position, and the diametric and bending deformations between those positions were quantified.

RESULTS

Twelve patients were included, and the findings showed that the common iliac vein stents experienced approximately twofold more local diametric compression with 90° hip flexion compared with 30° flexion. Also, iliofemoral vein stents crossing the hip joint experienced significant bending with hip hyperextension (-15°) but not with hip flexion. In both anatomic locations, maximum local diametric and bending deformations were in proximity with each other.

CONCLUSIONS

Stents implanted in the common iliac and iliofemoral veins exhibit greater deformation during high hip flexion and hyperextension, respectively, and iliofemoral venous stents interact with the superior ramus of the pubis during hyperextension. These findings suggest that device fatigue could be influenced by the type and level of patient physical activity, in addition to anatomic positioning, opening up the potential benefit of activity modification and the use of a careful implantation strategy. The proximity of maximum diametric and bending deformations means that simultaneous multimodal deformations should be considered for device design and evaluation.

Clinical Observation of Uninterrupted Thrombolytic Therapy via Indwelling Catheter for Lower Limb Deep Vein Thrombosis

Purpose

Observe uninterrupted thrombolytic therapy via indwelling catheter for lower limb deep vein thrombosis.

Methods

We retrospectively studied data from 32 patients with lower extremity deep vein thrombosis who received comprehensive treatment, consisting of general treatment, inferior vena cava filter implantation, interventional thrombolysis, angioplasty, stenting, and post-operative monitoring.

Results

The efficacy and safety of the comprehensive treatment were observed for a follow-up period of 6-12 months. The treatment was 100% effective; patient results indicated no serious bleeding, acute pulmonary embolism, or death after surgery.

Conclusion

The combination of intravenous and healthy side femoral vein puncture and directed thrombolysis to treat acute lower limb deep vein thrombosis is safe, effective, and minimally invasive while still achieving a good therapeutic effect.

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.

Machine learning-based prediction of the post-thrombotic syndrome: Model development and validation study

Background

Prevention is highly involved in reducing the incidence of post-thrombotic syndrome (PTS). We aimed to develop accurate models with machine learning (ML) algorithms to predict whether PTS would occur within 24 months.

Materials and methods

The clinical data used for model building were obtained from the Acute Venous Thrombosis: Thrombus Removal with Adjunctive Catheter-Directed Thrombolysis study and the external validation cohort was acquired from the Sun Yat-sen Memorial Hospital in China. The main outcome was defined as the occurrence of PTS events (Villalta score ≥5). Twenty-three clinical variables were included, and four ML algorithms were applied to build the models. For discrimination and calibration, F scores were used to evaluate the prediction ability of the models. The external validation cohort was divided into ten groups based on the risk estimate deciles to identify the hazard threshold.

Results

In total, 555 patients with deep vein thrombosis (DVT) were included to build models using ML algorithms, and the models were further validated in a Chinese cohort comprising 117 patients. When predicting PTS within 2 years after acute DVT, logistic regression based on gradient descent and L1 regularization got the highest area under the curve (AUC) of 0.83 (95% CI:0.76–0.89) in external validation. When considering model performance in both the derivation and external validation cohorts, the eXtreme gradient boosting and gradient boosting decision tree models had similar results and presented better stability and generalization. The external validation cohort was divided into low, intermediate, and high-risk groups with the prediction probability of 0.3 and 0.4 as critical points.

Conclusion

Machine learning models built for PTS had accurate prediction ability and stable generalization, which can further facilitate clinical decision-making, with potentially important implications for selecting patients who will benefit from endovascular surgery.

Analysis of Related Influencing Factors of Deep Vein Thrombosis after Lumbar Internal Fixation and Treatment Strategy

Lumbar internal fixation is a traditional surgical method for the treatment of degenerative diseases of the lumbar spine. However, due to its large surgical trauma, it easily causes complications such as deep venous thrombosis (DVT) after the operation. DVT refers to the abnormal coagulation of blood in deep veins, blocking the lumen, causing venous blood return disorder, causing venous blood return disorder to cause swelling and pain, which affects the recovery of the patient's lumbar spine function. In severe cases, even complicated pulmonary embolism endangers the life and health of the patient. Therefore, it is extremely important to explore the related influencing factors and effective treatment of DVT. The purpose of this study was to investigate the influencing factors and effective treatment of DVT after lumbar internal fixation. Univariate analysis and multivariate a logistic regression model were used to analyze the related factors affecting DVT after lumbar internal fixation. Conventional treatments such as anticoagulation, promotion of venous blood return, and improvement of limb circulation were given to patients with DVT, and functional exercise was guided to compare the hypercoagulability and hyperviscosity of blood in patients with DVT before and after treatment. The results showed that the incidence of DVT after lumbar internal fixation was related to age, BMI, and bed time. Getting out of bed for functional exercise in time after surgery can effectively prevent the formation of DVT. Preoperative grading examination, intraoperative intervention, postoperative physical exercise, and other preventive guidance can be carried out according to different individuals during the perioperative period to prevent the formation of postoperative DVT.

Venous Thromboembolism for the Practicing Cardiologist

Venous thromboembolism (VTE), encompassing pulmonary embolism (PE) and deep vein thrombosis (DVT), is encountered commonly. Acute PE may present as a high-risk cardiovascular emergency, and acute DVT can cause acute and chronic vascular complications. The goal of this review is to ensure that cardiologists are comfortable managing VTE-including risk stratification, anticoagulation therapy, and familiarity with primary reperfusion therapy. Clinical assessment and determination of degree of right ventricular dysfunction are critical in initial risk stratification of PE and determination of parenteral versus oral anticoagulation therapy. Direct oral anticoagulants have emerged as preferred first-line oral anticoagulation strategy in VTE scenarios.

Clinical efficacy of one-stage thrombus removal via contralateral femoral and ipsilateral tibial venous access for pharmacomechanical thrombectomy in entire-limb acute deep vein thrombosis

OBJECTIVE

In the present study, we compared the early results between different approaches for pharmacomechanical thrombectomy (PMT) in the treatment of entire-limb acute deep vein thrombosis (DVT).

METHODS

The present retrospective cohort study included patients with entire-limb acute DVT who had undergone PMT from January 2016 to March 2019 at two independent vascular centers. At the first center (Renji Hospital), the vascular surgeons used contralateral femoral venous access or ipsilateral tibial venous access (CFVA/ITVA). All consecutive patients with entire-limb acute DVT had undergone PMT through CFVA/ITVA at the first center. At the second center (Affiliated Hangzhou First People's Hospital), the vascular surgeons had conducted PMT using the traditional approach via ipsilateral popliteal venous access (IPVA). All consecutive patients had undergone PMT through IPVA at the second center. The primary endpoint was the incidence of post-thrombotic syndrome (PTS). The secondary endpoints included thrombus removal grade, venous primary patency rate, and the incidence of moderate-to-severe PTS.

RESULTS

A total of 73 patients were enrolled in the present study, including 37 patients with CFVA/ITVA at the first center and 36 patients with IPVA at the second center. No significant difference was detected between the two groups in age, gender, onset time, affected limb, or risk factors. The proportion of patients who had undergone catheter-directed thrombolysis was significantly lower in the CFVA/ITVA group than in the IPVA group (P = .010). Thrombus removal grade III was achieved more often in the CFVA/ITVA group than in the IPVA group (P = .007). The PTS incidence was significantly lower in the CFVA/ITVA group than in the IPVA group (P = .043). The thrombus removal grade and access type were independent factors associated with the development of PTS. Patients with complete thrombus removal (grade III) and CFVA/ITVA had a significantly lower incidence of PTS.

CONCLUSIONS

PMT can increase the thrombus clearance rate, reduce the requirement for subsequent catheter-directed thrombolysis, and, potentially, decrease the incidence of PTS using CFVA/ITVA instead of traditional IPVA in the treatment of entire-limb acute DVT.

Venous Biomechanics of Angioplasty and Stent Placement: Implications of the Poisson Effect

PURPOSE

To characterize the Poisson effect in response to angioplasty and stent placement in veins and identify potential implications for guiding future venous-specific device design.

MATERIALS AND METHODS

In vivo angioplasty and stent placement were performed in 3 adult swine by using an established venous stenosis model. Iron particle endothelium labeling was performed for real-time fluoroscopic tracking of the vessel wall during intervention. A finite-element computational model of a vessel was created with ADINA software (version 9.5) with arterial and venous biomechanical properties obtained from the literature to compare the response to radial expansion.

RESULTS

In vivo angioplasty and stent placement in a venous stenosis animal model with iron particle endothelium labeling demonstrated longitudinal foreshortening that correlated with distance from the center of the balloon (R² = 0.87) as well as adjacent segment narrowing that correlated with the increase in diameter of the treated stenotic segment (R² = 0.89). Finite-element computational analysis demonstrated increased Poisson effect in veins relative to arteries (linear regression coefficient slope comparison, arterial slope 0.033, R² = 0.9789; venous slope 0.204, R² = 0.9975; P < .0001) as a result of greater longitudinal Young modulus in veins compared with arteries.

CONCLUSIONS

Clinically observed adjacent segment narrowing during venous angioplasty and stent placement is a result of the Poisson effect, with redistribution of radially applied force to the longitudinal direction. The Poisson effect is increased in veins relative to arteries as a result of unique venous biomechanical properties, which may be relevant to consider in the design of future venous interventional devices.

Catheter-Based Therapies and Other Management Strategies for Deep Vein Thrombosis and Post-Thrombotic Syndrome

Acute deep vein thrombosis (DVT) causes substantial short-term and long-term patient morbidity. Medical, lifestyle, and compressive therapies have been investigated for the prevention of pulmonary embolism (PE) and recurrence of venous thromboembolism (VTE). However, patient-centered outcomes such as resolution of presenting DVT symptoms and late occurrence of post-thrombotic syndrome (PTS) have not been prioritized to the same degree. Imaging-guided, catheter-based endovascular therapy has been used in selected patients to alleviate these sequelae, but important questions remain about their optimal use. In this article, we review the available evidence and summarize the rationale for use of catheter-based therapy in specific patient groups.

Prevention and Management of the Post-Thrombotic Syndrome

The post-thrombotic syndrome (PTS) is a form of chronic venous insufficiency secondary to prior deep vein thrombosis (DVT). It affects up to 50% of patients after proximal DVT. There is no effective treatment of established PTS and its management lies in its prevention after DVT. Optimal anticoagulation is key for PTS prevention. Among anticoagulants, low-molecular-weight heparins have anti-inflammatory properties, and have a particularly attractive profile. Elastic compression stockings (ECS) may be helpful for treating acute DVT symptoms but their benefits for PTS prevention are debated. Catheter-directed techniques reduce acute DVT symptoms and might reduce the risk of moderate-severe PTS in the long term in patients with ilio-femoral DVT at low risk of bleeding. Statins may decrease the risk of PTS, but current evidence is lacking. Treatment of PTS is based on the use of ECS and lifestyle measures such as leg elevation, weight loss and exercise. Venoactive medications may be helpful and research is ongoing. Interventional techniques to treat PTS should be reserved for highly selected patients with chronic iliac obstruction or greater saphenous vein reflux, but have not yet been assessed by robust clinical trials.

Increased inflammation and endothelial markers in patients with late severe post-thrombotic syndrome

Introduction

Post-thrombotic syndrome (PTS) is a limiting long-term complication present in 20–50% of patients with deep venous thrombosis (DVT) of the lower limbs. A panel of biomarkers with potential relevance to enhance knowledge on the pathophysiology of PTS was investigated.

Methods

This case-control study included 93 patients with DVT in the lower limbs, 31 with severe PTS (cases) and 62 with mild/no PTS (controls), over 24 months after an acute episode. Thirty-one healthy individuals (HI) with no history of DVT were included as a reference to the population. FVIII activity, D-dimer, inflammatory cytokines, endothelial dysfunction markers, matrix metalloproteinases, and their inhibitors, tissue remodeling and growth factor levels were evaluated. The classification of PTS was, by the Villalta scale.

Results

Patients with severe PTS showed elevated levels of CRP, sICAM-1, sE-selectin, and decreased MMP-9 and MCP-1 levels when compared to patients with mild/no PTS. Moreover, DVT patients presented higher levels of FVIII and D-dimer when compared to HI.

Conclusions

DVT patients present an inflammatory status, endothelial dysfunction and altered proteolysis MMPs activity, even a long time after the acute thrombotic episode, which is more significant in severe PTS. These results suggest a possible role of these mediators in the maintenance and worsening of PTS severity.

Compression therapy for treating post-thrombotic syndrome

BACKGROUND

Post-thrombotic syndrome (PTS) is a long-term complication of deep vein thrombosis (DVT) characterised by chronic complaints such as oedema and skin changes including; venous ectasia, varicose veins, redness, eczema, hyperpigmentation, and in severe cases fibrosis of the subcutaneous adipose in the affected limb. These chronic complaints are the effects of venous outflow restriction that can cause symptoms such as heaviness, itching, pain, cramps, and paraesthesia. Twenty to fifty percent of people with DVT develop post-thrombotic complications. Several non-pharmaceutical measures are used for prevention of PTS during the acute phase of DVT. These include elevation of the legs and compression therapy. There have been limited studies regarding the effectiveness of compression therapy for prevention or treatment of PTS. As a result, clinicians and guidelines differ in their assessment of compression therapy during treatment of DVT and in the treatment of PTS. This is an update of a review first published in 2003.

OBJECTIVES

To assess the effectiveness of compression therapy for treatment of post-thrombotic syndrome, including elastic compression stockings and mechanical devices compared with no intervention, placebo and with each other.

SEARCH METHODS

For this update, the Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase and CINAHL databases and World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registries on 2 July 2018.

SELECTION CRITERIA

We included trials that evaluated compression therapy for the treatment of PTS. The primary outcomes were severity of PTS and adverse effects. There were no restrictions on date or language. Two review authors (SA, DNK) independently assessed whether potentially relevant studies met the inclusion criteria.

DATA COLLECTION AND ANALYSIS

One review author extracted and summarised data and one review author (DNK) verified them. We resolved disagreements by discussion. We assessed methodological study quality with the Cochrane 'Risk of bias' tool. We used GRADE to assess the overall certainty of the evidence supporting the outcomes assessed in this review.

MAIN RESULTS

We identified four trials, with 116 participants, investigating the effectiveness of compression therapy for treatment of PTS. The methodology used by each trial was too heterogeneous to perform a meta-analysis, so we reported our findings narratively.Two trials studied the effect of graduated elastic compression stockings (GECS) on improvement of PTS symptoms. One study reported beneficial haemodynamic effects, while the other found no benefits on PTS severity compared to placebo (very low-certainty evidence). There was very limited evidence available for adverse effects and quality of life (QoL). The two studies did not report on compliance rates during the study period.Two trials studied the effects of intermittent mechanical compression devices. Both reported improvement in PTS severity (low-certainty evidence). Improvement of the severity of PTS was defined by treatment 'success' or 'failure'. Only one study comparing compression devices evaluated adverse effects and QoL. Although 9% of the participants experienced adverse effects such as leg swelling, irritation, superficial bleeding, and skin itching (moderate-certainty evidence), QoL was improved (moderate-certainty evidence). Studies did not assess compliance using intermittent mechanical compression devices.None of the studies evaluated patient satisfaction.

AUTHORS' CONCLUSIONS

There is very low-certainty evidence regarding the use of GECS for treatment of PTS as assessed by two small studies of short duration. One study reported beneficial haemodynamic effects, while one found no benefits on PTS severity compared to control/placebo stockings. There is very limited evidence for adverse effects, patient satisfaction, QoL, and compliance rates. There is low-certainty evidence favouring use of intermittent pneumatic compression devices compared to a control device for the treatment of severity owing to different measurements used by the studies reporting on this outcome and small studies of short duration. There is moderate-certainty evidence of improved QoL but possible increased adverse effects related to compression device use owing to small studies of short duration. High-certainty evidence to support the use of compression therapy in prevention of PTS is lacking and any conclusions drawn from current evidence should be interpreted with care. Further research is needed to assess whether compression can result in long-term reduction and relief of the symptoms caused by PTS, or prevent deterioration and leg ulceration.

Iliac Vein Stent Placement: Acute Venographic Changes and Relevance to Venous Biomechanics

PURPOSE

To describe acute venographic changes of external iliac vein (EIV) after ipsilateral common iliac vein (CIV) stent placement.

MATERIALS AND METHODS

Retrospective review was performed of 17 cases with placement of a single CIV stent. Central CIV stent diameter and minimal ipsilateral EIV diameter were measured on venogram; vein diameter was measured at the same 2 anatomic locations on venogram obtained before intervention. Relative CIV diameter increase was defined as the ratio of change in central CIV diameter after stent placement to CIV diameter before intervention. Relative EIV diameter reduction was defined as the ratio of change in diameter of EIV after stent deployment in CIV to EIV diameter before intervention. Diameters before and after intervention were compared using a 2-tailed, paired sample t test. Pearson coefficient was calculated for correlations.

RESULTS

There was a significant reduction of EIV diameter after ipsilateral CIV stent placement compared with before stent placement (mean 9.3 mm ± 3.1 vs 11.9 mm ± 3.8; P < .01); mean decrease in EIV diameter was 21.7% ± 15.8. There was a correlation between relative CIV diameter increase and relative EIV diameter reduction (r = .8917).

CONCLUSIONS

Significant venographic narrowing of the EIV occurs after placement of an adjacent CIV stent, and the degree of narrowing is associated with the relative increase in CIV diameter. These findings may be explained by the inherent anisotropic elasticity of veins. Further study is warranted to guide future venous interventions.