Presence and degree of residual venous obstruction on serial duplex imaging is associated with increased risk of recurrence and progression of infrainguinal lower extremity deep venous thrombosis

Role of platelet count in a murine stasis model of deep vein thrombosis

Platelets are core components of thrombi but their effect on thrombus burden during deep vein thrombosis (DVT) has not been fully characterized. We examined the role of thrombopoietin-altered platelet count on thrombus burden in a murine stasis model of DVT. To modulate platelet count compared to baseline, CD1 mice were pretreated with thrombopoietin antisense oligonucleotide (THPO-ASO, 56% decrease), thrombopoietin mimetic (TPO-mimetic, 36% increase), or saline (within 1%). Thrombi and vein walls were examined on postoperative days (POD) 3 and 7. Thrombus weights on POD 3 were not different between treatment groups (p = .84). The mean thrombus weights on POD 7 were significantly increased in the TPO-mimetic cohort compared to the THPO-ASO (p = .005) and the saline (p = .012) cohorts. Histological grading at POD 3 revealed a significantly increased smooth muscle cell presence in the thrombi and CD31 positive channeling in the vein wall of the TPO-mimetic cohort compared to the saline and THPO-ASO cohorts (p < .05). No differences were observed in histology on POD 7. Thrombopoietin-induced increased platelet count increased thrombus weight on POD 7 indicating platelet count may regulate thrombus burden during early resolution of venous thrombi in this murine stasis model of DVT.

The impact of COVID-19 on the prognosis of deep vein thrombosis following anticoagulation treatment: a two-year single-center retrospective cohort study

BACKGROUND

Coronavirus disease 2019 (COVID-19) has been proved as a significant risk factor for deep vein thrombosis (DVT) after several waves of pandemic. This study aims to further investigate impact of COVID-19 on prognosis of DVT following anticoagulation treatment.

METHODS

A total of 197 patients with initially detected DVT and meanwhile accomplishing at least 3 months anticoagulation treatment were identified from our hospital between January 2021 and December 2022. DVT characteristics, clinical data, and exposure to COVID-19 were recorded for multivariable logistic regression analysis to identify DVT aggravation related risk factors. Propensity score matching (PSM) was used to balance baseline covariates. Kaplan-Meier curves and Log-Rank test were performed to exhibit distribution of DVT aggravation among different subgroups.

RESULTS

In 2022, patients exhibited higher incidence rates of DVT aggravation compared to those in 2021 (HR:2.311, P = 0.0018). The exposure to COVID-19, increased red blood cell count, increased D-dimer level and reduced prothrombin time were found to be associated with DVT aggravation (P < 0.0001, P = 0.014, P < 0.001, P = 0.024), with only exposure to COVID-19 showing a significant difference between two years (2022:59/102, 57.84%, 2021:7/88, 7.37%, P < 0.001). In PSM-matched cohorts, the risk for DVT aggravation was 3.182 times higher in COVID-19 group compared to the control group (P < 0.0001). Exposure to COVID-19 increased the risk of DVT aggravation among patients who completed three months anticoagulant therapy (HR: 5.667, P < 0.0001), but did not increase incidence rate among patients who completed more than three months anticoagulant therapy (HR:1.198, P = 0.683). For patients with distal DVT, COVID-19 was associated with a significant increased risk of DVT recurrence (HR:4.203, P < 0.0001). Regarding principal diagnoses, incidence rate of DVT aggravation was significantly higher in COVID-19 group compared to the control group (Advanced lung cancer: P = 0.011, surgical history: P = 0.0365, benign lung diseases: P = 0.0418).

CONCLUSIONS

Our study reveals an increased risk of DVT aggravation following COVID-19 during anticoagulation treatment, particularly among patients with distal DVT or those who have completed only three months anticoagulant therapy. Adverse effects of COVID-19 on DVT prognosis were observed across various benign and malignant respiratory diseases. Additionally, extended-term anticoagulant therapy was identified as an effective approach to enhance DVT control among patients with COVID-19.

Mechanical Thrombectomy vs. Pharmacomechanical Catheter Directed Thrombolysis for the Treatment of Iliofemoral Deep Vein Thrombosis: A Propensity Score Matched Exploratory Analysis of 12 Month Clinical Outcomes

OBJECTIVE

To compare thrombus removal and residual venous symptoms and signs of disease following interventional treatment of iliofemoral deep vein thrombosis (DVT) with mechanical thrombectomy (MT) and pharmacomechanical catheter directed thrombolysis (PCDT).

METHODS

Retrospective cohort analysis of propensity score matched subgroups from the multicentre prospective MT ClotTriever Outcomes registry and the PCDT arm of the randomised Acute Venous Thrombosis: Thrombus Removal with Adjunctive Catheter Directed Thrombolysis trial. Patients with bilateral DVT, symptom duration greater than four weeks, isolated femoral-popliteal disease, or incomplete case data were excluded. Patients with iliofemoral DVT were propensity score matched (1:1) on 10 baseline covariables, including race, sex, age, body mass index, leg treated, prior thromboembolism, Marder score, symptom duration, provoked deep vein thrombosis status, and Villalta score. Reduction in post-procedure thrombus burden (i.e., Marder scores), assessment of venous symptoms and signs (i.e., Villalta scores) at 12 months, and healthcare resource utilisation were compared between subgroups.

RESULTS

Propensity score matching resulted in 130 patient pairs with no significant differences in baseline characteristics between the MT and PCDT groups. MT was associated with a greater reduction in Marder scores (91.0% vs. 67.7%, p < .001), and a greater proportion of patients at 12 months with no post-thrombotic syndrome (83.1% vs. 63.6%, p = .007) compared with matched patients receiving PCDT. No differences in rates of adjunctive stenting or venoplasty were identified (p = .27). Higher rates of single session treatment were seen with MT (97.7% vs. 26.9%, p < .001), which also showed shorter mean post-procedure hospital stays (1.81 vs. 3.46 overnights, p < .001), and less post-procedure intensive care unit utilisation (2.3% vs. 52.8%, p < .001).

CONCLUSION

Compared with PCDT, MT was associated with greater peri-procedural thrombus reduction, more efficient post-procedure care, and improved symptoms and signs of iliofemoral vein disease at 12 months.

Single-center experience with the ClotTriever BOLD catheter for deep vein thrombosis percutaneous mechanical thrombectomy of the lower extremity

Background

The ClotTriever System is a percutaneous mechanical thrombectomy system used to treat deep vein thrombosis (DVT). The BOLD catheter is a newer compatible component with a modified coring element for which reported outcomes are limited. This retrospective study aims to assess the preliminary procedural safety and success data for patients treated with the BOLD catheter.

Methods

All consecutive patients with symptomatic lower extremity DVT who underwent thrombectomy with the BOLD catheter between 23 November 2021 and 26 June 2022 at a single center were included. Baseline and procedural characteristics were reported. The primary outcome, intraprocedural safety, was assessed by a chart review of recorded intraprocedural adverse events (AEs) or device malfunction. The secondary outcome, procedural success, was defined as ≥75% reduction in the total occlusion across treated venous segments. This was assessed by an interventionalist review of pre- and postprocedural venograms. Additional outcomes included length of postprocedural hospital stay and assessment of AEs at discharge and a 30-day follow-up visit.

Results

Eleven patient cases were reviewed. The median patient age was 65 years, the majority were women, and all were treated unilaterally. All procedures were completed in a single session without intraprocedural AEs or device malfunction. The median procedural blood loss was 50 ml. A review of pre- and postprocedural venograms showed that 35 venous segments were treated, including the femoral (n = 9), common femoral (n = 9), external iliac (n = 10), and common iliac (n = 7) veins. Procedural success was achieved in 10 patients (90.9%), and the median reduction rate in venous occlusion was 100%. The median length of postprocedural hospital stay was 1 day, and no AEs were noted at discharge (N = 11). One adverse event occurred among the eight patients who completed their follow-up visit. A patient with advanced-stage cancer and medication failure had a recurrent DVT 13 days postprocedure, which was not related to the device or procedure.

Conclusions

No safety concerns concerning the BOLD catheter were raised during the review of the cases included in this analysis, and the device was successful in reducing venous occlusion in patients with symptomatic proximal lower extremity DVT.

Six-Month Outcomes of Mechanical Thrombectomy for Treating Deep Vein Thrombosis: Analysis from the 500-Patient CLOUT Registry

PURPOSE

Mechanical thrombectomy for the treatment of deep vein thrombosis (DVT) is being increasingly utilized to reduce symptoms and prevent postthrombotic syndrome (PTS), but more data on clinical outcomes are needed. Mechanical thrombectomy was studied in the ClotTriever Outcomes (CLOUT) registry with 6-month full analysis outcomes reported herein.

MATERIALS AND METHODS

The CLOUT registry is a prospective, all-comer study that enrolled 500 lower extremity DVT patients across 43 US sites treated with mechanical thrombectomy using the ClotTriever System. Core-lab assessed Marder scores and physician-assessed venous patency by duplex ultrasound, PTS assessment using Villalta score, venous symptom severity, pain, and quality of life scores through 6 months were analyzed. Adverse events were identified and independently adjudicated.

RESULTS

All-cause mortality at 30 days was 0.9%, and 8.6% of subjects experienced a serious adverse event (SAE) within the first 30 days, 1 of which (0.2%) was device related. SAE rethrombosis/residual thrombus incidence was 4.8% at 30 days and 8.0% at 6 months. Between baseline and 6 months, venous flow increased from 27.2% to 92.5% of limbs (P < 0.0001), and venous compressibility improved from 28.0% to 91.8% (P < 0.0001), while median Villalta scores improved from 9.0 at baseline to 1.0 at 6 months (P < 0.0001). Significant improvements in venous symptom severity, pain, and quality of life were also demonstrated. Outcomes from iliofemoral and isolated femoral-popliteal segments showed similar improvements.

CONCLUSION

Outcomes from the CLOUT study, a large prospective registry for DVT, indicate that mechanical thrombectomy is safe and demonstrates significant improvement in symptoms and health status through 6 months. Level of Evidence 3: Non-randomized controlled cohort/follow-up study.

Influence of the 4G/5G polymorphism of plasminogen activator inhibitor-1 gene in acute unprovoked deep vein thrombosis and residual vein thrombosis

BACKGROUND

Plasminogen activator inhibitor-1 (PAI-1) is an important inhibitor of plasminogen activator, but the role of the PAI-1 4G/5G polymorphism in deep vein thrombosis (DVT) has been contradictory. In this study, we investigated the distribution of the PAI-1 4G/5G genotype in Chinese patients with DVT compared with healthy controls and the association between the PAI-1 4G/5G genotype and the persistence of residual venous occlusion (RVO) after different treatments.

METHODS

The PAI-1 4G/5G genotype was determined by fluorescence in situ hybridization in 108 patients with unprovoked DVT and 108 healthy controls. The patients with DVT were treated with catheter-based therapy or anticoagulation only. RVO was assessed by duplex sonography during the follow-up.

RESULTS

Thirty-two patients (29.6%) were homozygous for 4G (4G/4G), 62 patients (57.4%) were heterozygous for 4G/5G, and 14 patients (13%) were homozygous for 5G (5G/5G). No significant difference in genotype frequency was found between patients with DVT and controls. A total of 86 patients completed follow-up of ultrasound examination with a mean follow-up of 13.4 ±7.2 months. The results of patients with RVO were significantly different between homozygous 4G carriers (76.9%), heterozygous 4G/5G (58.3%), and homozygous carriers of 5G (33.3%) (P <.05) at the end of follow-up. Catheter-based therapy showed a better result in patients who were noncarriers of 4G (P = .045).

CONCLUSIONS

The PAI-1 4G/5G genotype was not a relevant predictor for DVT in Chinese patients, but is a risk factor for persistent RVO after idiopathic DVT.

Six-Month Deep Vein Thrombosis Outcomes by Chronicity: Analysis of the Real-World ClotTriever Outcomes Registry

PURPOSE

To analyze the first 250 patients from the prospective, multicenter, industry-sponsored ClotTriever Outcomes (CLOUT) registry, assessing the safety and effectiveness of mechanical thrombectomy for acute, subacute, and chronic deep vein thrombosis (DVT).

MATERIALS AND METHODS

Real-world patients with lower extremity DVT were treated with the ClotTriever System (Inari Medical, Irvine, California). Adjuvant venoplasty, stent placement, or both were performed at the physician's discretion. Thrombus chronicity was determined by visual inspection of removed thrombus, categorizing patients into acute, subacute, and chronic subgroups. Serious adverse events (SAEs) were assessed through 30 days. Clinical and quality-of-life (QoL) outcomes are reported through 6 months.

RESULTS

Thrombus chronicity was designated for 244 of the 250 patients (acute, 32.8%; subacute, 34.8%; chronic, 32.4%) encompassing 254 treated limbs. Complete or near-complete (≥75%) thrombus removal was achieved in 90.8%, 81.9%, and 83.8% of the limbs with acute, subacute, and chronic thrombus, respectively. No fibrinolytics were administered, and 243 (99.6%) procedures were single sessions. One (0.4%) patient in the subacute group experienced a device-related SAE, a fatal pulmonary embolism. On comparing baseline and 6-month data, improvements were demonstrated in median Villalta scores (acute, from 10 to 1; subacute, from 9 to 1; chronic, from 10 to 3; for all, P < .0001) and mean EuroQol group 5-dimension (EQ-5D) self-report questionnaire scores (acute, 0.58 to 0.89; subacute, 0.65 to 0.87; chronic, 0.58 to 0.88; for all, P < .0001). There were no significant differences in outcomes across the subgroups.

CONCLUSIONS

Mechanical thrombectomy using the ClotTriever System with adjunctive venoplasty and stent placement is safe and similarly effective for acute, subacute, and chronic DVT.

Recurrent deep vein thrombosis following brown recluse spider bite complicated by medication noncompliance and residual scar tissue: A rare case report

Clinicians should be aware of the occurrence of deep vein thrombosis following brown recluse spider bite.

Safety and Effectiveness of Mechanical Thrombectomy From the Fully Enrolled Multicenter, Prospective CLOUT Registry

Background

We report in-hospital outcomes from the multicenter, prospective, single-arm ClotTriever Outcomes (CLOUT) registry, which enrolled up to 500 patients with proximal lower extremity deep vein thrombosis (DVT) treated with percutaneous mechanical thrombectomy using the ClotTriever System (Inari Medical).

Methods

The CLOUT registry enrolled all-comer patients with DVT, irrespective of symptom duration, thrombus age, prior treatment of the current DVT, or bilateral thrombus. The primary effectiveness end point was defined as complete or near complete (≥75%) reduction in Marder score. Thrombus burden was assessed by an independent core laboratory. Mortality and serious adverse events, including device-relatedness, were adjudicated by an independent medical monitor. Here, safety and outcomes are evaluated through discharge.

Results

The median age was 61.9 years (IQR, 48.0-70.8), 50.5% were women, 24.9% had a history of DVT, and 23.2% had previously failed treatment of the current DVT. Nearly all procedures (99.4%) were performed in a single session with negligible procedural blood loss (median 40.0 mL; IQR, 20.0-50.0), and most patients (97.8%) required no subsequent intensive care unit monitoring. The primary effectiveness end point was achieved in 91.2% of limbs. Through discharge, 1 device-related serious adverse event (0.2%) occurred. Health status, as assessed by self-reported pain and circumferential measurements of limb edema, were significantly improved at discharge.

Conclusions

Thrombectomy with the ClotTriever System is a safe and effective treatment for proximal lower extremity DVT, while also avoiding the need of intensive care. Early patient improvements are demonstrated, and follow-up is ongoing to 2 years.

The incidence, risk factors, characteristics, and prognosis of recurrent deep venous thrombosis in the contralateral lower extremity

BACKGROUND

Recurrent events after a first symptomatic deep venous thrombosis (DVT) are relatively frequent, but little is known about contralateral recurrent DVT (RDVT).

METHODS

We retrospectively reviewed the medical records of patients with a first symptomatic lower extremity DVT between January 2017 and April 2021. The incidence, demographics, risk factors, and prognosis of RDVT were analyzed, with differences compared between patients with contralateral RDVT and those with ipsilateral RDVT.

RESULTS

In 570 consecutive patients with DVT, 28 patients (4.91%) developed contralateral RDVT, and 49 patients (8.60%) developed ipsilateral RDVT during a mean follow-up of 27.62 ± 14.84 months. Contralateral RDVT was more frequently found in the right lower extremity, whereas ipsilateral RDVT had more left lower extremity involvement. The median follow-up was 12 months until ipsilateral RDVT and 26.5 months until contralateral RDVT. In multivariate Cox analysis, inherited thrombophilia, stent extension with 50% to 100% coverage, autoimmune disease and anticoagulation noncompliance were identified as risk factors for contralateral RDVT. During follow-up, 5 patients (17.86%) with contralateral RDVT and 10 patients (20.41%) with ipsilateral RDVT died (P > .05), with 12 of 15 dying of an underlying malignancy.

CONCLUSIONS

The incidence of contralateral RDVT after a first symptomatic DVT is relatively low, and contralateral DVT is strongly associated with stent extension with 50% to 100% coverage, autoimmune disease, anticoagulation noncompliance, and inherited thrombophilia. Compared with ipsilateral RDVT, contralateral RDVT occurs later and is more often in the right lower extremity. Survival following contralateral RDVT is similar to survival following ipsilateral RDVT, with underlying malignancy being the leading cause of death.

The Importance of Early Thrombus Removal

Historically, anticoagulation has been the primary treatment for acute lower extremity deep venous thrombosis (DVT) with or without thrombolysis. Despite large amounts of clinical research data supporting an ‘open vein hypothesis’, which favours early thrombus removal, clinicians have been hesitant to take this option due to a historically high risk of major bleeding and a few notable studies that failed to show any meaningful benefit. The ATTRACT trial failed to show the benefit of using pharmacomechanical catheter-directed thrombolysis (PCDT) for iliofemoral and femoropopliteal DVT but did result in more bleeding. However, the CaVent study before it revealed a significant reduction in post-thrombotic syndrome (PTS) for patients with iliofemoral and femoral DVT after long-term follow-up past 24 months that grew over time. Since these trials, there have been significant advancements in magnetic resonance and CT venography, intravascular ultrasound (IVUS), venous stenting and thrombectomy catheters meaning there is little to no need for adjunct thrombolytics. Results from ongoing research such as CLEAR-DVT reflect the advances in modern technology.

Histologic assessment of lower extremity deep vein thrombus from patients undergoing percutaneous mechanical thrombectomy

BACKGROUND

Histologic analyses of deep vein thrombi (DVTs) have used autopsy samples and animal models. To the best of our knowledge, no previous study has reported on thrombus composition after percutaneous mechanical extraction. Because elements of chronicity and organization render thrombus resistant to anticoagulation and thrombolysis, a better understanding of clot evolution could inform therapy.

METHODS

We performed a histologic evaluation of DVTs from consecutive patients who had undergone mechanical thrombectomy for extensive iliofemoral DVTs using the Clottriever/Flowtriever device (Inari Medical, Irvine, Calif). The DVTs were scored using a semiquantitative method according to the degree of fibrosis (collagen deposition on trichrome staining) and organization (endothelial growth with capillaries and fibroblastic penetration).

RESULTS

Twenty-three specimens were available for analysis, with 20 presenting as acute DVT (≤14 days from symptom onset). Of the 23 patients, 11 (48%) had had >5% fibrosis (ie, collagen deposition) and 14 (61%) had had >5% organization (ie, endothelial growth, capillaries, fibroblasts). Four patients with acute DVT had had ≥25% organized thrombus and two had had ≥25% collagen deposition. Of the 20 patients with acute DVT, 40% had had >5% fibrosis and 55% had had >5% organization. The acuity of DVT did not correlate with the amount of fibrosis or organizing scores.

CONCLUSIONS

A large proportion of patients with acute DVT will have histologic elements of chronicity and fibrosis. A better understanding of the relationship between such elements and the response to anticoagulant agents and fibrinolytic drugs could inform our approach to therapy.

Direct Oral Anticoagulants in Patients With Inherited Thrombophilia and Venous Thromboembolism: A Prospective Cohort Study

Background

In this prospective cohort study, we aimed to evaluate the efficacy and safety of direct oral anticoagulants (DOACs) versus heparin/vitamin K antagonists for the treatment of venous thromboembolism (VTE) in patients with inherited thrombophilia.

Methods and Results

We enrolled consecutive patients with acute VTE and inherited thrombophilia treated with DOACs (cases) or heparin/vitamin K antagonists (controls), matched for age, sex, ethnicity, and thrombophilia type. End points were VTE recurrence and bleeding complications; residual vein thrombosis and post‐thrombotic syndrome; VTE recurrence after anticoagulant discontinuation. Two hundred fifty‐five cases (age 52.4±17.3 years, Female 44.3%, severe thrombophilia 33.1%) and 322 controls (age 49.7±18.1 years, Female 50.3%, severe thrombophilia 35.1%) were included. The cumulative incidence of VTE recurrence during anticoagulation was 1.09% in cases versus 1.83%, adjusted hazard ratio (HR) 0.67 (95% CI, 0.16–2.77). The cumulative incidence of bleeding was 10.2% in cases versus 4.97%, HR 2.24 (95% CI 1.10–4.58). No major bleedings occurred in cases (versus 3 in controls). No significant differences regarding residual vein thrombosis and post‐thrombotic syndrome. After anticoagulant discontinuation, DOACs yielded a significantly lower 2‐year VTE recurrence risk versus traditional anticoagulants (HR, 0.61 [95% CI, 0.47–0.82]).

Conclusions

DOACs and heparin/vitamin K antagonists showed a similar efficacy in treating VTE in patients with thrombophilia. Although major bleeding episodes were recorded solely with heparin/vitamin K antagonists, we noted an overall increased bleeding rate with DOACs. The use of DOACs was associated with a lower 2‐year risk of VTE recurrence after anticoagulant discontinuation.

[Additional possibilities in conservative treatment of patients with post-thrombotic disease of lower limbs]

AIM

This study was undertaken to evaluate efficacy of Actovegin in the composition of comprehensive therapy in patients presenting with post-thrombotic disease of lower extremities free from trophic disorders.

PATIENTS AND METHODS

The study included a total of 60 patients (28 men and 32 women) diagnosed as having post-thrombotic disease of lower limbs without trophic disorders (C1-C3 according to the CEAP classification), induced by previously endured iliofemoral phlebothrombosis. The duration of the disease varied from 1 year to 10 years. All patients for 10 days received Actovegin intravenously in drips at a dose of 1200 mg (30 ml of the drug reconstituted in 400 ml of normal saline) followed by continuing taking the drug orally in a daily dose of 1200 mg for 30 days. During the whole follow up period the patients wore class 2 compression stockings (RAL standard). The results of the carried out treatment in relation to the subjective complaints (pain, feeling of heaviness, convulsions, pruritus and paresthesias) were assessed by the visual analogue scale and based on the CIVIQ-20 questionnaire, with additionally measuring the malleolar circumference.

RESULTS

On the background of the carried out therapy the patients demonstrated a significant decrease in the oedematous syndrome in the area of the ankles. This parameter decreased form 26.88±0.39 cm to 25.02±0.35 cm (p<0.05). The patients' complaints of tingling decreased form 5.73±0.79 to 2.32±0.68 points (p<0.05), the incidence and intensity of convulsions fell from 6.51±1.39 to 3.2±0.98 points (p<0.05). The intensity of the oedematous syndrome (swelling) decreased significantly from 8.11±1.75 to 4.33±1.20 points (p<0.05), the pain syndrome fell from 7.92±1.88 to 3.12±1.45 points (p<0.05), the feeling of heaviness in the lower limbs decreased from 8.52±1.73 to 3.91±1.48 points (p<0.05). Also, improvement of the general quality of life of patients was observed (the integral parameter decreased from 63.27±1.8 to 44.33±1.19 points, p<0.05).

Challenging Management of a Patient With Severe Bilateral Deep Vein Thrombosis

Among patients with proximal iliofemoral deep vein thrombosis (DVT) and an elevated Villalta score, anticoagulation therapy alone may not be a sufficient management strategy in select cases. In this article, we report a case of severe bilateral iliofemoral DVT that resisted the standard treatment for DVT, requiring catheter-directed thrombolysis and subsequent mechanical thrombectomy.