Prospective evaluation of the clinical deterioration in post-thrombotic limbs

Interventional treatment for post-thrombotic chronic venous obstruction: Progress and challenges

Chronic venous obstruction, including nonthrombotic iliac vein lesions and post-thrombotic syndrome, presents a significant burden on patients' quality of life and health care systems. Venous recanalization and stenting have emerged as promising minimally invasive approaches, yet challenges in patient selection, procedural techniques, and long-term outcomes persist. This review synthesizes current knowledge on the interventional treatment of post-thrombotic syndrome, focusing on the evolution of endovascular techniques and stenting. Patient selection criteria, procedural details, and the characteristics of dedicated venous stents are discussed. Particular emphasis is given to the role of inflow and other anatomical considerations, along with postoperative management protocols for an optimal long-term outcome.

Chronic Venous Insufficiency in A Selected Nurse Population: A Cross-Sectional Study

Chronic venous insufficiency (CVI) causes severe symptoms and complications in the general population, but the prevalence, related risk factors, and treatment of CVI are unknown among nurses. The demographics and occupational factors of nurses from a university hospital were collected by questionnaires, and the presentation of CVI was confirmed by the specialist vascular surgeons. A total of 1606 participants were enrolled, and the prevalence of CVI was 7.5%. After multivariate adjustment, CVI was positively related to deep venous thrombosis history (OR 6.44, 95% CI 2.73-15.22), increased standing time (OR 2.21, 95% CI 1.20-4.10), and increased time in night shift rotation (OR 2.01, 95% CI 1.29-3.14). CVI was negatively related to oral contraceptives (OR .43, 95% CI .21-.87). Of the participants, 72.5% with CVI received compression therapy. For them, wearing compression stockings with a pressure of >20 mmHg or for >4 h/day significantly increased the rate of symptom relief, while the length of compression stockings made no difference. Thus, it was beneficial for nurses to spend less time standing and shorten their time in night shift rotation. Wearing compression stockings with sufficient pressure and for enough time was recommended for CVI symptom relief.

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.

microRNA-301a-3p is a potential biomarker in venous ulcers vein and gets involved in endothelial cell dysfunction

Venous ulcer is a common contributor to chronic venous insufficiency (CVI) of lower limbs, which seriously affects the life quality of patients. In this study, we researched the expression characteristics of microRNA-301a-3p (miR-301a-3p) in patients with CVI and investigated the impact of miR-301a-3p on the dysfunction of human umbilical vein endothelial cells (HUVECs). The plasma level of miR-301a-3p in normal controls, patients with varicose great saphenous vein, and patients with the venous ulcer of lower limbs were measured. We adopted Interleukin-1β (IL-1β), H2O2, and oxygen and glucose deprivation (OGD) to induce endothelial cell injury in vitro. In this way, we evaluated the influence of miR-301a-3p on HUVEC viability, apoptosis, inflammatory response, and oxidative stress. Our data showed that miR-301a-3p was substantially overexpressed in patients with lower limb venous ulcers. The viability of HUVECs decreased, and miR-301a-3p was up-regulated after IL-1β, H2O2, and OGD treatment. miR-301a-3p inhibition greatly ameliorated the dysfunction and cell damage of HUVECs, promoted IGF1/PI3K/Akt/PPARγ, and down-regulated NF-κB/MMPs. The phosphatidylinositol 3-kinase (PI3K) inhibitor (LY294002) or the peroxisome proliferator-activated receptor-γ (PPARγ) inhibitor (GW9661) reversed the anti-inflammatory, antioxidant, and anti-apoptotic effects mediated by miR-301a-3p down-regulation. The nuclear factor-κB (NF-κB) inhibitor lessened cell injury mediated by miR-301a-3p overexpression. In terms of the mechanism, miR-301a-3p targeted the 3'UTR of Insulin-like growth factor-1 (IGF1) and repressed the profile of IGF1. Thus, miR-301a-3p mediates venous endothelial cell damage by targeting IGF1 and regulating the IGF1/PI3K/Akt/PPARγ/NF-κB/MMPs pathway.

Why Venous Leg Ulcers Have Difficulty Healing: Overview on Pathophysiology, Clinical Consequences, and Treatment

Venous leg ulcers (VLUs) are one of the most common ulcers of the lower extremity. VLU affects many individuals worldwide, could pose a significant socioeconomic burden to the healthcare system, and has major psychological and physical impacts on the affected individual. VLU often occurs in association with post-thrombotic syndrome, advanced chronic venous disease, varicose veins, and venous hypertension. Several demographic, genetic, and environmental factors could trigger chronic venous disease with venous dilation, incompetent valves, venous reflux, and venous hypertension. Endothelial cell injury and changes in the glycocalyx, venous shear-stress, and adhesion molecules could be initiating events in VLU. Increased endothelial cell permeability and leukocyte infiltration, and increases in inflammatory cytokines, matrix metalloproteinases (MMPs), reactive oxygen and nitrogen species, iron deposition, and tissue metabolites also contribute to the pathogenesis of VLU. Treatment of VLU includes compression therapy and endovenous ablation to occlude the axial reflux. Other interventional approaches such as subfascial endoscopic perforator surgery and iliac venous stent have shown mixed results. With good wound care and compression therapy, VLU usually heals within 6 months. VLU healing involves orchestrated processes including hemostasis, inflammation, proliferation, and remodeling and the contribution of different cells including leukocytes, platelets, fibroblasts, vascular smooth muscle cells, endothelial cells, and keratinocytes as well as the release of various biomolecules including transforming growth factor-β, cytokines, chemokines, MMPs, tissue inhibitors of MMPs (TIMPs), elastase, urokinase plasminogen activator, fibrin, collagen, and albumin. Alterations in any of these physiological wound closure processes could delay VLU healing. Also, these histological and soluble biomarkers can be used for VLU diagnosis and assessment of its progression, responsiveness to healing, and prognosis. If not treated adequately, VLU could progress to non-healed or granulating VLU, causing physical immobility, reduced quality of life, cellulitis, severe infections, osteomyelitis, and neoplastic transformation. Recalcitrant VLU shows prolonged healing time with advanced age, obesity, nutritional deficiencies, colder temperature, preexisting venous disease, deep venous thrombosis, and larger wound area. VLU also has a high, 50-70% recurrence rate, likely due to noncompliance with compression therapy, failure of surgical procedures, incorrect ulcer diagnosis, progression of venous disease, and poorly understood pathophysiology. Understanding the molecular pathways underlying VLU has led to new lines of therapy with significant promise including biologics such as bilayer living skin construct, fibroblast derivatives, and extracellular matrices and non-biologic products such as poly-N-acetyl glucosamine, human placental membranes amnion/chorion allografts, ACT1 peptide inhibitor of connexin 43, sulodexide, growth factors, silver dressings, MMP inhibitors, and modulators of reactive oxygen and nitrogen species, the immune response and tissue metabolites. Preventive measures including compression therapy and venotonics could also reduce the risk of progression to chronic venous insufficiency and VLU in susceptible individuals.

Long-term outcome after nonsurgical management of Paget-Schroetter syndrome

OBJECTIVE

Paget-Schroetter syndrome (PSS) is an uncommon disease with potentially debilitating long-term effects. The optimal therapy for PSS is unclear, and the role of surgical decompression of the thoracic outlet is still being questioned. In this study, we present long-term results of patients treated with catheter-directed thrombolysis (CDT) and anticoagulation without surgical management.

METHODS

This is a retrospective case series of all patients who previously underwent treatment of PSS in our institution between the years 2007 and 2019. Patients were evaluated for clinical signs of post-thrombotic syndrome (PTS) using a modified Villalta scoring scale, including measurements of the circumference of the treated and untreated arms. Duplex ultrasound examination of the treated vein was performed, and quality of life was evaluated using the shortened Disabilities of the Arm, Shoulder, and Hand questionnaire.

RESULTS

Eighteen consecutive patients previously treated for PSS with CDT and anticoagulation compose the cohort of this study. None underwent surgical thoracic outlet decompression. All were contacted and invited for clinical and ultrasound evaluation. Follow-up was available for all patients. Mean age at diagnosis was 29 years (range, 16-46 years), and 15 (79%) were male. Mean time from the index event to the follow-up clinic visit was 109 months (range, 37-176 months). Patients were treated with anticoagulation for a mean period of 26 months (range, 6-120 months). Seventeen patients (94%) had a Villalta score of 0 to 3, consistent with nonexistence of PTS. Fourteen patients (78%) were completely asymptomatic. Seven patients (39%) had no difference in arm circumference. A difference in arm circumference between the treated arm and the healthy arm of 1 cm and 2 cm was seen in nine (50%) and two (11%) patients, respectively. Based on the shortened Disabilities of the Arm, Shoulder, and Hand score, none of the patients suffered from impaired quality of life. Duplex ultrasound scanning of the affected veins was performed on 16 of the 18 patients (89%). The vein appeared patent in all examined patients. In three patients, the wall of the examined vein was thickened and irregular.

CONCLUSIONS

This study suggests that PSS patients can be treated with anticoagulation and CDT alone, without the need for surgical thoracic outlet decompression. This is based on long-term follow-up of these patients objectively evaluated by means of valid scoring systems. These findings suggest that symptoms or signs of PTS rarely develop, the patients do not suffer from impaired quality of life, and patency of the diseased vein is commonly maintained.

Report of the Society for Vascular Surgery and the American Venous Forum on the July 20, 2016 meeting of the Medicare Evidence Development and Coverage Advisory Committee panel on lower extremity chronic venous disease

On July 20, 2016, a Medicare Evidence Development and Coverage Advisory Committee panel assessed the benefits and risks of currently used lower extremity chronic venous disease (CVD) treatments and their effects on health outcome of the American adult population. The main purpose of the meeting was to advise the Centers for Medicare & Medicaid Services on coverage determination for interventions used for treatment of CVD. A systematic review of the Agency for Healthcare Research and Quality was presented, followed by lectures of invited experts and a public hearing of representatives of professional societies and the industry. After discussing critical issues, the panel voted for key questions. This report summarizes the presented evidence to support recommendations of the Society for Vascular Surgery/American Venous Forum coalition and the presentations on selected discussion topics. These included important venous disease evidence gaps that have not been sufficiently addressed, venous disease treatment disparities and how they may affect the health outcomes of Medicare beneficiaries, and mechanisms that might be supported by the Centers for Medicare & Medicaid Services to improve the evidence base to optimize the care of patients with lower extremity CVD.

Does Catheter-Directed Thrombolysis Prevent Postthrombotic Syndrome?

Purpose

The aim of this study is to identify risk factors of postthrombotic syndrome (PTS) and evaluate the efficacy of catheter-directed thrombolysis (CDT) for preventing the development of PTS in patients with lower extremity deep vein thrombosis (DVT).

Materials and Methods

From 2005 January to 2013 December, 139 limbs of 126 patients were included in this study who had the first episode of proximal DVT at the affected limb and who had visited our out-patient clinic. CDT was performed on 55 limbs (39.6%). We achieved complete recanalization in 39 limbs (70.9%) and partial recanalization (residual thrombus <50.0%) in 16 limbs (29.1%). We retrospectively reviewed medical records for possible predictors of PTS.

Results

Median follow-up duration was 83 months (range, 30–136 months). No differences were found between the CDT and non-CDT group in age, gender, duration of symptom, use of anticoagulation and recurrence of DVT. A significantly higher thrombotic burden was observed in the CDT group (P=0.009). In a binary logistic regression model, patients with PTS had significantly higher body mass index (BMI) (odds ratio [OR], 1.303; 95% confidence interval [CI], 1.079–1.574; P=0.006) and longer thrombotic burden involved in ilio-femoro-popliteal DVT (OR, 3.666; 95% CI, 1.093–12.296; P=0.035). CDT did not influence the risk of PTS (P>0.05).

Conclusion

We suggest that CDT is not effective in preventing PTS, while higher BMI and longer thrombotic burden are associated with the development of PTS in patients with DVT.

Venous stent placement ameliorates cutaneous microvascular function in iliocaval venous obstruction

BACKGROUND

The role of cutaneous microvascular dysfunction is well known in the development of chronic venous disease. However, the effects of venous obstruction on microcirculation have not been well investigated. The aim of this study was to assess cutaneous microvascular function in patients with iliocaval venous obstruction (ICVO) before and after venous stent placement.

METHODS

Endothelium-dependent and endothelium-independent vasodilator responses to iontophoretic administration of incremental doses of acetylcholine (ACh) and sodium nitroprusside (SNP) were evaluated using a laser Doppler scanner in the perimalleolar region in the supine and sitting positions in patients with ICVO (n = 11) and in healthy control subjects (n = 15). Cutaneous microvascular function, the Venous Clinical Severity Score (VCSS), and the Clinical, Etiology, Anatomy, and Pathophysiology (CEAP) clinical class were re-evaluated 3 months after stent placement in patients with ICVO.

RESULTS

The vasodilatory responses to ACh and SNP in the cutaneous microcirculation were lower in patients with ICVO than in healthy subjects in the sitting position (P < .05). Recanalization and stent placement were successful in all patients in the evaluation of VCSS and clinical class, and a significant decrease was determined in the signs and symptoms of the venous disease (P < .01). Stent placement resulted in a significant increase in vasodilation response to both ACh and SNP in the supine position and no improvement in the sitting position in patients with ICVO.

CONCLUSIONS

ICVO impairs endothelium-dependent and endothelium-independent vasodilation in the perimalleolar region. Iliocaval venous stent placement may recover microvascular dysfunction at different levels.

Time taken to the maximum increase in the oxygenated hemoglobin level in calf muscle as a predictor of mild and moderate post-thrombotic syndrome

BACKGROUND

Near-infrared spectroscopy (NIRS) allows continuous noninvasive monitoring of changes in the tissue levels of oxygenated hemoglobin (O2Hb) and deoxygenated hemoglobin (HHb) and can identify the severity of chronic venous diseases. Here we investigated the predictors of post-thrombotic syndrome (PTS) using NIRS in patients with a first episode of deep venous thrombosis (DVT).

METHODS

The study enrolled 129 patients with DVT. Risk factors in each patient were assessed at presentation. Venous abnormalities confirmed by ultrasound and parameters derived from NIRS were evaluated at 6 months after DVT. On standing, increases in O2Hb and HHb (ΔO2Hbst and ΔHHbst) and the times taken for each concentration to become maximal (TO2Hbst, and THHbst) were measured. During 10 tiptoe movements, O2Hb showed a continuous decrease (ΔO2Hbex), whereas venous expulsion (ΔHHbEex) and subsequent retention (ΔHHbRex) were observed. The oxygenation index (HbD; HbD = O2Hb - HHb) was also calculated at the end of standing and at the end of 10 tiptoe movements (ΔHbDst and ΔHbDex). Final clinical manifestations were evaluated at 6 years, and PTS was considered to be present if the Villalta score was ≥5.

RESULTS

Thirteen patients were excluded and 116 patients were finally included. Of these, 19 (16%) developed PTS. Among various NIRS-derived parameters, TO2Hbst had the highest area under the curve (0.88; 95% confidence interval [CI], 0.80-0.93; P < .01) with the best cutoff value (TO2Hbst ≤48 seconds). On univariate analysis, variables associated with greater risk for development of PTS were stroke (odds ratio [OR], 5.59; 95% CI, 0.74-42.41; P = .06), idiopathic DVT (OR, 4.13; 95% CI, 1.36-12.55; P < .01) and iliofemoral DVT (OR, 4.31; 95% CI, 1.48-12.60; P < .01) at initial presentation, venous occlusion combined with reflux (OR, 4.24; 95% CI, 1.50-12.00; P < .01), and NIRS-derived TO2Hbst ≤48 seconds (OR, 43.03; 95% CI, 9.04-204.81; P < .01) at 6 months. Multivariate logistic regression analysis finally revealed venous occlusion combined with reflux (OR, 4.80; 95% CI, 1.03-22.36; P < .05) and NIRS-derived TO2Hbst ≤48 seconds (OR, 53.73; 95% CI, 8.43-342.41; P < .01) to be independently associated with PTS progression.

CONCLUSIONS

NIRS-derived TO2Hbst ≤48 seconds is a promising time-course predictor of PTS progression.

Analysis of 1,338 Patients with Acute Lower Limb Deep Venous Thrombosis (DVT) Supports the Inadequacy of the Term "Proximal DVT"

OBJECTIVE/BACKGROUND

For decades acute lower limb deep venous thrombosis (DVT) has been subdivided into distal DVT (isolated to the calf veins) and proximal DVT (extending above calf vein level). The aim of this study was to analyse the anatomical site and extent of thrombus in a large cohort of patients with acute DVT.

METHODS

A retrospective analysis of all patients aged >18 years, presenting with unilateral DVT according to duplex ultrasound investigation was performed at the University Hospital of Antwerp, Belgium (1994-2012). The anatomical site and extent of thrombus was registered and subdivided into five segments: calf veins (segment 1), popliteal vein (segment 2), femoral vein (segment 3), common femoral vein (segment 4), and iliac veins, with or without inferior vena cava (segment 5).

RESULTS

The median age of the 1,338 patients (50% male) included was 62 years (range 18-98 years). Left sided DVT was predominant (57%). DVT was limited to one segment in 443 patients, of whom 370 had DVT isolated to the calf veins (28% of total cohort). In 968 patients with what was previously called "proximal DVT", the median number of affected segments was three (range 1-5 segments). In this group iliofemoral DVT (at least involving segment four and/or five) was present in 506 patients (38% of total cohort), whereas the remaining patients had femoropopliteal DVT (at least in segment two and/or three but not in four or five). Iliofemoral DVT without thrombus in segments one and two was present in 160 patients (12% of total cohort).

CONCLUSION

This study illustrates the large diversity of thrombus distribution in patients previously described as having "proximal DVT". Therefore, this term should be abandoned and replaced with iliofemoral and femoropopliteal DVT. Patients with iliofemoral DVT (38%) could be considered for early clot removal; 12% of all patients with DVT would be ideal candidates for such intervention.

Pathogenesis of venous ulcer

The underlying pathophysiology of venous ulceration is venous hypertension, which initiates a complex cascade of cellular humeral events that are then magnified by genetic factors. Hemodynamic abnormalities are features of primary and secondary chronic venous diseases that lead to disease progression. Through a sequence of events, some patients develop venous leg ulcers, if the process is not interrupted. The exact science of the pathophysiology of the progression of chronic venous disease to venous leg ulcers is still in its infancy, but the framework for future study has been established.

Thrombus age is ideally measured by history or MRV prior to thrombus removal

Many factors are known to be important in order to achieve optimal results after thrombus removal for iliofemoral DVT. Not much is published in the literature about timing the treatment, though many guidelines recommend treatment within 14 days. This time span lies within the phrase of acute DVT according to the definition given in many reporting standards. This article will highlight the value of information acquired from patients directly regarding onset of symptoms versus information acquired from imaging with the purpose of a more precise selection of patients for catheter-directed thrombolysis for iliofemoral DVT. What is the value of clinical information acquired from patients and does the information from imaging have additional value?

Re-modelling of venous thrombosis

Venous thromboembolism is one of the most common causes of morbidity and mortality in modern societies. The entirety of events involved in venous thrombus formation and resolution remains to be elucidated. Temporal relation between the initial cellular insult, thrombus formation and resolution is critical for instituting a prompt treatment. This paper analyses the current basic knowledge and the events involved in venous re-modelling after an episode of venous thrombosis.

Our early experience with iliofemoral vein stenting in patients with post-thrombotic syndrome

Introduction:

Venous balloon dilation and stent therapy have been proposed as effective treatments for chronic iliofemoral thrombosis. In this study, we report our experience and describe the one-year outcome and efficacy of balloon angioplasty and stenting for the treatment of post-thrombotic syndrome (PTS) in iliofemoral vein segments.

Methods:

From June 2011 to June 2012, 52 consecutive patients with chronic PTS (59 limbs; 75% women; median age 58 years; range: 23–76 years) referred to our unit for interventional assessment were included in the study. Treatment effects were assessed using Villalta scale, Venous Clinical Severity Score (VCSS) and Chronic Venous Insufficiency Questionnaire (CIVIQ)-20 for PTS, CEAP (clinical, aetiological, anatomical and pathological elements) grading and measurement of leg circumference, before and after intervention.

Results:

Stenting was successfully accomplished in all patients. Coagulation abnormality was identified in 21 subjects (40.3%). CEAP grades were as follows: C3 in 19 patients, C4 in 24 patients, C5 in one patient and C6 in eight patients. According to Villalta scores, three patients were mild, seven patients were moderate and 42 patients were severe PTS. VCSS, Villalta scale and CIVTQ-20 showed a significant decrease in the severity of PTS signs and symptoms ( P < 0.001). The calf and middle thigh circumferences decreased significantly on both sides ( P < 0.001).

Conclusion:

Treatment of iliac venous obstruction with balloon angioplasty and stenting appears to be a minimally invasive and safe therapeutic approach in patients with PTS offering quick symptomatic relief, good patency and minimal morbidity.

Postthrombotic syndrome and quality of life in patients with iliofemoral venous thrombosis treated with catheter-directed thrombolysis

BACKGROUND

Postthrombotic syndrome (PTS) is a common complication after iliofemoral venous thrombosis, often resulting in poor quality of life (QOL) among the affected patients. This study assessed development of PTS and its effect on QOL among patients treated for iliofemoral venous thrombosis by catheter-directed thrombolysis.

METHODS

Patients admitted with an iliofemoral venous thrombosis and treated with catheter-directed thrombolysis at Gentofte University Hospital from 1999 to 2008 were invited to participate. Duplex ultrasound imaging was used to assess venous patency and valve function. Each patient completed the generic Short-Form 36-item (SF-36) health survey assessment, producing physical component (PCS) and mental component summary (MCS) scores, and the disease-specific Venous Insufficiency Epidemiological and Economic Study (VEINES)-Quality of Life (QOL)/Symptoms (Sym), questionnaires to assess QOL. PTS was assessed using the Villalta scale.

RESULTS

The study included 109 patients. Median follow-up was 71 months. PTS developed in 18 patients (16.5%) and of those, initial thrombolysis was successful in 13. Patients with PTS had significantly worse mean ± standard deviation scores than patients without PTS on VEINES-QOL (34.2 ± 9.6 vs 53.1 ± 6.6; P < .0001), VEINES-Sym (34.0 ± 8.8 vs 53.2 ± 6.6; P < .0001), SF-36 MCS (44.2 ± 15.5 vs 52.3 ± 11.0; P = .005), and SF-36 PCS (42.3 ± 9.1 vs 53.5 ± 7.8; P < .0001) subscales. Patients with reflux or chronic occlusions, or both, had significantly lower mean ± SD scores than patients with patent veins without reflux on VEINES-QOL (43.5 ± 14.3 vs 51.0 ± 8.8; P = .044) and SF-36 PCS (47.2 ± 10.9 vs 52.4 ± 8.5; P = .049) scales.

CONCLUSION

PTS was associated with worse QOL, although only a few patients developed PTS after catheter-directed thrombolysis of iliofemoral venous thrombosis. Patients with patent veins and sufficient valves have higher QOL scores than patients with reflux and occluded veins.

Postthrombotic vein wall remodeling: preliminary observations

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Factors predicting development of post-thrombotic syndrome in patients with a first episode of deep vein thrombosis: preliminary report

OBJECTIVE

To investigate the indicative parameters reflecting the progression of post-thrombotic syndrome (PTS) in patients with a first episode of deep vein thrombosis (DVT).

DESIGN AND METHODS

The patients' initial risk factors were assessed at presentation. Venous occlusion, and reflux and reflux parameters were evaluated at 6 months using venous duplex scanning. Near-infrared spectroscopy (NIRS) was also used to measure calf muscle deoxygenated haemoglobin levels at 6 months. Clinical manifestations were categorised using the clinical, etiologic, anatomic and pathophysiologic (CEAP) classification for chronic venous insufficiency (CVI), and the patients were divided into those having no PTS (C(0-3S),E(s),A(s,d,p),P(r,o)) and those having PTS (C(4-6S),E(s),A(s,d,p),P(r,o)).

RESULTS

Of the 121 patients evaluated, 25 (21%) developed PTS with a mean follow-up period of 66 months. At initial presentation, ilio-femoral DVT (odds ratio (OR) 3.4, 95% confidence interval (CI) 1.4-8.6) was associated with development of PTS. At 6 months, venous occlusion combined with reflux (OR 4.4, 95% CI 2.9-20.7), peak reflux velocity >29.7 cm s(-1) (OR 13.7, 95% CI 4.1-45.7) and mean reflux velocity >8.6 cm s(-1) (OR 4.4, 95% CI 1.5-12.9) in the popliteal vein detected by duplex scanning were strong predictors of PTS. NIRS-derived retention index >3.5 was the strongest predictor of PTS at 6 months (OR 67.4, 95% CI 14.3-318.1).

CONCLUSIONS

Ilio-femoral DVT is associated with the development of PTS at initial presentation. By contrast, occlusion and reflux, high reflux velocity in the popliteal vein and increased NIRS-derived retention index are important time-course predictors of PTS progression.

Clinical significance of recurrent venous thromboembolism

Recurrent venous thromboembolism is a significant problem leading to increased morbidity and mortality. It has a high impact on patients' quality of life and imposes a great financial burden on society. Cumulative recurrence has been reported as 40% at 10 years, while the chance of developing postthrombotic signs and symptoms in the lower extremities almost quadruples when ipsilateral. There is also a higher chance of developing pulmonary hypertension. Important factors for recurrence are unprovoked episodes of deep vein thrombosis, malignancy and older age. The evidence for other factors is controversial. Accurate diagnosis and treatment tailored to the patients' history, thrombotic events and risk factors are necessary to optimize management and prevent recurrence.

Impact and clinical significance of recurrent venous thromboembolism

Background

The purpose of this review was to analyse current knowledge and controversies associated with the diagnosis, treatment and prevention of recurrent venous thromboembolism (VTE).

Methods

MEDLINE and manual searches were performed to select prospective papers on the diagnosis, treatment and prevention of recurrent VTE for their relevance and quality.

Results

The cumulative incidence of recurrent VTE increases from 11 per cent at 1 year to 40 per cent at 10 years. The incidence of recurrence is higher in unprovoked thrombosis compared with provoked VTE. Patients with unprovoked deep vein thrombosis also have a greater number of multiple recurrences. Ultrasonography or D-dimer monitoring may have an impact on the duration of anticoagulation but further refinements are needed. The incidence of skin damage is higher in ipsilateral recurrence compared with contralateral or no recurrence. Legs with ipsilateral recurrence more often have both reflux and obstruction.

Conclusion

The role and weight of the predictive factors for recurrent VTE and its sequelae, and the type and optimal duration of anticoagulation have not been studied adequately. Fatality associated with pulmonary embolism and rates of recurrent VTE remain unacceptably high.