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.

Background and Objectives: Acute limb ischemia (ALI) is a life-threatening vascular emergency that requires immediate intervention to restore perfusion and prevent limb loss or mortality. Management strategies primarily include thrombolysis and surgical revascularization, each with distinct risks and benefits. This review evaluates and compares the outcomes of thrombolysis and surgical revascularization in ALI management, emphasizing their efficacy, safety, and patient selection criteria. Materials and Methods: A systematic review was conducted in adherence to PRISMA guidelines, analyzing data from 15 studies, including randomized controlled trials and large retrospective analyses, encompassing over 3500 patients with varying demographics and clinical presentations. Study quality was assessed using the Cochrane risk of bias tool and the Newcastle-Ottawa Scale. Results: Thrombolysis, utilizing agents such as urokinase or recombinant tissue plasminogen activator (rt-PA), demonstrated limb salvage rates up to 90% in acute cases, with 30-day mortality rates of 4-6%. It was particularly effective in patients with embolic occlusions or short symptom durations. However, bleeding complications associated with thrombolysis were reported in up to 47% of cases. Conversely, surgical revascularization remains crucial for those with advanced ischemia or contraindications to thrombolysis, offering reliable perfusion restoration but with higher perioperative morbidity, especially in older patients with significant comorbidities. Recent advancements, including hybrid approaches combining catheter-directed thrombolysis with percutaneous mechanical thrombectomy, have shown promise in improving outcomes by reducing procedure times and enhancing clot resolution. Conclusions: While thrombolysis and surgical revascularization are effective, optimizing patient selection remains a key challenge. Future research should focus on refining treatment algorithms, investigating novel thrombolytic agents, and expanding the role of minimally invasive techniques to improve long-term outcomes while mitigating complications such as bleeding and reperfusion injuries.

Acute lower extremity deep vein thrombosis (DVT), specifically proximal iliofemoral DVT, is a relatively common disorder that can result in a chronic debilitating post-thrombotic syndrome (PTS), with a significant effect on a patient's quality of life. Anticoagulation is first-line therapy; however, percutaneous interventions have emerged as treatment options for patients where there is concern that anticoagulation alone will not resolve the DVT as well as prevent PTS. This paper will discuss the existing data on these interventions and review current endovascular techniques, including catheter-directed thrombolysis, pharmacomechanical thrombectomy, and large-bore mechanical thrombectomy in the management of DVT.

The purpose of the research is to explore post-thrombotic syndrome (PTS) after catheter-directed thrombolysis (CDT) treatment for acute lower extremity deep vein thrombosis (DVT) risk factors.

We retrospectively selected 171 patients with acute lower extremity DVT undergoing CDT treatment, collected clinical data of the patients, grouped them according to the follow-up results of 1 year after treatment, and included patients with PTS into the concurrent group and patients who did not develop PTS assigned to the unconcurrent group. Univariate analysis and Logistic regression were applied to analyze the risk factors of PTS after catheterization and thrombolytic therapy for acute lower extremity DVT. We applied R4.2.3 software to build three hybrid machine-learning models, including a nomogram, decision tree, and random forest with independent influencing factors as predictive variables.

The incidence of PTS after CDT in acute lower extremity DVT was 36.84 %. BMI >24.33 kg/m2, disease time >7 d, mixed DVT, varicose vein history, stress treatment time>6.5 months, and filter category were independent risk factors for PTS after CDT treatment for acute lower extremity DVT. The AUC value predicted by the random forest model was higher than that of the nomogram model (Z = -2.337, P = 0.019) and the decision tree model (Z = -2.995, P = 0.003).

The occurrence of PTS after CDT treatment of acute lower extremity DVT is closely related to many factors, and the established random forest model had the best effect in predicting PTS complicated with PTS.

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).

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.

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.

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.

To compare the comparative effects of treatment with contemporary mechanical thrombectomy (MT) or anticoagulation (AC) on Villalta scores and post-thrombotic syndrome (PTS) incidence through 12 months in iliofemoral deep vein thrombosis (DVT).

Patients with DVT in the Acute Venous Thrombosis: Thrombus Removal with Adjunctive Catheter-Directed Thrombolysis (ATTRACT) randomized trial and the ClotTriever Outcomes (CLOUT) registry were included in this analysis. Both studies evaluated the effects of thrombus removal on the incidence of PTS. Patients with bilateral DVT, isolated femoral-popliteal DVT, symptom duration of >4 weeks, or incomplete case data for matching covariates were excluded. Propensity scores were used to match patients 1:1 who received AC (from ATTRACT) with those treated with mechanical thrombectomy (from CLOUT) using nearest neighbor matching on nine baseline covariates, including age, body mass index, leg treated, provoked DVT, prior venous thromboembolism, race, sex, Villalta score, and symptom duration. Clinical outcomes, including Villalta score and PTS, were assessed. Logistic regression was used to estimate the likelihood of developing PTS at 12 months.

A total of 164 pairs were matched, with no significant differences in baseline characteristics after matching. There were fewer patients with any PTS at 6 months (19% vs 46%; P < .001) and 12 months (17% vs 38%; P < .001) in the MT treatment group. Modeling revealed that, after adjusting for baseline Villalta scores, patients treated with AC had significantly higher odds of developing any PTS (odds ratio, 3.1; 95% confidence interval, 1.5-6.2; P = .002) or moderate to severe PTS (odds ratio, 3.1; 95% confidence interval, 1.1-8.4; P = .027) at 12 months compared with those treated with MT. Mean Villalta scores were lower through 12 months among those receiving MT vs AC (3.3 vs 6.3 at 30 days, 2.5 vs 5.5 at 6 months, and 2.6 vs 4.9 at 12 months; P < .001 for all).

MT treatment of iliofemoral DVT was associated with significantly lower Villalta scores and a lower incidence of PTS through 12 months compared with treatment using AC. Results from currently enrolling clinical trials will further clarify the role of these therapies in the prevention of PTS after an acute DVT event.

This study was designed to assess the optimal access route for the endovascular treatment of acute lower extremity deep vein thrombosis. This was a retrospective analysis of patients with acute lower extremity deep venous thrombosis who underwent endovascular treatment from February 2009 to December 2020. Patients underwent non-direct calf deep vein puncture (NDCDVP) from February 2009 to December 2011 and direct calf deep vein puncture (DCDVP) from January 2012 to December 2020. Catheter directed thrombolysis (CDT) was used to treat all patients in the NDCDVP group, whereas patients in the DCDVP group were treated with CDT or the AngioJet rhyolitic thrombectomy system. In patients exhibiting iliac vein compression syndrome, the iliac vein was dilated and implanted with a stent. Technical success rates and perioperative complication rates were compared between these two treatment groups. The NDCDVP group included 83 patients (40 males, 43 females) with a mean age of 55 ± 16 years, while the DCDVP group included 487 patients (231 males. 256 females) with a mean age of 56 ± 15 years. No significant differences were observed between these groups with respect to any analyzed clinical characteristics. The technical success rates in the NDCDVP and DCDVP groups were 96.4 and 98.2%, respectively (P > 0.05). In the NDCDVP group, the small saphenous vein (SSV)or great saphenous vein (GSV)were the most common access routes (77.1%, 64/83), whereas the anterior tibial vein (ATV) was the most common access route in the DCDVP group (78.0%, 380/487), followed by the posterior tibial vein (PTV) and peroneal vein (PV)(15.6% and 6.4%, respectively). Relative to the NDCDVP group, more patients in the DCDVP group underwent the removal of deep vein clots below the knee (7.2% [6/83] vs. 24.2% [118/487], P < 0.001). Moreover, relative to the NDCDVP group, significantly lower complication rates were evident in the DCDVP group (local infection: 10.8% vs. 0.4%, P < 0.001; local hematoma: 15.7% vs. 1.0%, P < 0.001). The position change rate was also significantly lower in the DCDVP group relative to the NDCDVP group (0% [0/487] vs. 60.2% [50/83], P < 0.001). The calf deep veins (CDVs) represent a feasible and safe access route for the endovascular treatment of lower extremity deep vein thrombosis.

Deep venous thrombosis (DVT) is a medical condition with significant post-event morbidity and mortality coupled with limited treatment options. Treatment strategy and efficacy are highly dependent on the structural composition of the thrombus, which evolves over time from initial formation and is currently unevaluable with standard clinical testing. Here, we investigate the use of intravascular polarization-sensitive optical coherence tomography (PS-OCT) to assess thrombus morphology and composition in a rat DVT model in-vivo, including changes that occur over the thrombus aging process. PS-OCT measures tissue birefringence, which provides contrast for collagen and smooth muscle cells that are present in older, chronic clots. Thrombi in the inferior vena cava of two cohorts of rats were imaged in-vivo with intravascular PS-OCT at 24 hours (acute, nrats = 3, 73 cross-sections) or 28 days (chronic, nrats = 4, 41 cross-sections) after thrombus formation. Co-registered histology was labelled by an independent pathologist to establish ground-truth clot composition. Automated analysis of OCT cross-sectional images differentiated acute and chronic thrombi with 97.6% sensitivity and 98.6% specificity using a linear discriminant model comprised of both polarization and conventional OCT metrics. These results support PS-OCT as a highly sensitive imaging modality for the assessment of DVT composition to differentiate acute and chronic thrombi. Intravascular PS-OCT imaging could be integrated with advanced catheter-based treatment strategies and serve to guide therapeutic decision-making and deployment, by offering an accurate assessment of DVT patients in real time.

Venous thromboembolism (VTE), notably deep venous thrombosis (DVT), represents a significant cardiovascular disease with high morbidity from post-thrombotic syndrome (PTS). Recent advancements in early thrombus removal technologies have prompted randomized controlled trials (RCT) to assess their efficacy and safety, particularly for iliofemoral DVT (IF-DVT), which carries the greatest risk of developing PTS. This narrative review summarizes these trials and introduces upcoming innovations to evaluate acute intervention for IF-DVT. Specific technologies discussed include catheter-directed thrombolysis, pharmacomechanical catheter-directed thrombolysis, ultrasound-accelerated catheter-directed thrombolysis, and non-lytic mechanical thrombectomy. This review underscores the importance of patient selection, with those presenting with extensive, symptomatic IF-DVT likely to benefit most.

The present study aimed to compare the effects of medical therapy (MT), systemic thrombolysis (ST), and pharmacomechanical thrombolysis (PMT) methods used in our clinic for the treatment of deep venous thrombosis (DVT) on symptom reduction, the incidence of post-thrombotic syndrome (PTS) development, and quality of life.

Data from160 patients diagnosed with acute DVT between January 2012 and May 2021 and treated and followed up in our clinic were retrospectively analyzed. The patients were divided into three groups according to treatment method. The patients who received MT treatment were defined as Group 1, anticoagulant treatment after ST as Group 2, and anticoagulant treatment after PMT as Group 3. The patients were called to the outpatient clinic, informed consent was obtained, EuroQol-5D-3 L (EQ-5D-3 L) scoring and Villalta scoring were performed, and anamnesis was taken.

A total of 160 patients were included, with 71 (44.4%) patients in Group 1, 45 (28.1%) in Group 2, and 44 (27.5%) in Group 3. The mean age was 48.9 ± 14.9 years for Group 1, 42.2 ± 10.8 for Group 2, and 29.0 ± 7.2 for Group 3. When the time to return to normal life and the EQ-5D-3 L score index were compared, the differences between Groups 1 and 2 and between Groups 1 and 3 were statistically significant (P = .000 and P = .000, respectively). However, the differences between Groups 2 and 3 were statistically insignificant (P = .213 andp = .074, respectively). When Villalta scores and EQ Visual Analogue Scale (EQ-VAS) scores were compared between groups, the difference between all groups was statistically significant (P = .000).

The medical treatment alone was observed to be insufficient in terms of symptomatic improvement, development of PTS, quality of life, and long-term complications. When the ST and PMT groups were compared, it was determined that PMT treatment was more advantageous in terms of EQ-VAS score and PTS development, although there was no statistical difference regarding complications, such as return to normal life and long-term quality of life, the incidence of recurrent DVT development, and pulmonary thromboembolism incidence.

This study aimed to evaluate the safety and efficacy of pharmacomechanical catheter-directed thrombolysis (PCDT) and stenting for treating acute iliofemoral deep venous thrombosis (DVT) combined with iliac vein compression syndrome (IVCS), and to identify the predictors of stent restenosis. Patients with acute proximal DVT combined with IVCS underwent PCDT and stenting from January 2017 to December 2022 were enrolled. Primary and secondary patency were assessed by duplex ultrasound (DUS). The morbidity of postthrombotic syndrome (PTS) was assessed by the Villalta score. Risk factors for stent restenosis were assessed using univariate and multivariate Cox regression models. Total of 254 patients were included. The mean follow-up time was 36.06 ± 17.66 months. The primary patency rates at 1 year, 3 years, and 5 years were 92.5%±1.7%, 85.4%±2.4%, and 82.4%±2.9%, respectively. The incidence of stent restenosis was 14.2%. Discontinuation of anticoagulants within one year [hazard ratio (HR) = 5.03; P = .048] was the factor associated with acute in-stent thrombosis. Previous DVT history (HR =2.29; P = .037) and stent placement across the inguinal ligament (HR =6.70; P < .001) were identified as independent risk factors significantly associated with stent restenosis. The overall PTS rate was 19.3%. PCDT with stenting is safe and effective for patients with iliofemoral DVT secondary to IVCS, leading to low rates of PTS. Previous DVT history and stents placed across the inguinal ligament may be predictors of stent restenosis. Furthermore, stent restenosis typically occurs within one year and is mainly caused by acute thrombosis due to discontinuation of anticoagulants.

Acute deep vein thrombosis (DVT) affects >350,000 patients each year in the United States. Contemporary rehospitalization rates and predictors of acute DVT have not been well-characterized. We aimed to evaluate the all-cause 30-day readmission rate and its association with catheter-directed thrombolysis and vena cava filters in patients with proximal and caval DVT.

Patients with an index hospitalization for acute proximal lower extremity DVT were evaluated for unplanned readmission rates at 30 days using the Nationwide Readmission Database from 2016 to 2017. We used Cox proportional hazard model to determine the predictors of 30-day readmissions and their association with inferior vena cava (IVC) filter and CDT use.

We identified 58,306 adult patients with an index hospitalization for acute proximal DVT. The unplanned 30-day rehospitalization rate was 14.7% (95% confidence interval [CI], 14.5-15.0%). There were 4995 patients (10.0%) who underwent CDT and 6085 (12.2%) who underwent IVC filter placement. In multivariable analysis, only CDT was associated with a lower hazard for rehospitalization (hazard ratio [HR], 0.77; 95% CI, 0.71-0.84; P < .001), whereas IVC filter placement (HR, 1.26; 95% CI, 1.19-1.34; P < .001), Charlson Comorbidity Index of >3 (HR, 1.47; 95% CI, 1.38-1.56; P < .001), malignancy (HR, 1.45; 95% CI, 1.34-1.57; P < .001), and length of stay >5 days (HR, 1.39; 95% CI, 1.33-1.46; P < .001), and acute kidney injury (HR, 1.18; 95% CI, 1.11-1.25; P < .001) were associated with higher readmission rates.

The 30-day unplanned rehospitalization rate continues to be high in patients with acute proximal DVT. CDT was associated with lower rehospitalization rates, whereas IVC filter placement was associated with increased rehospitalization rates.

Venous thromboembolism (VTE) affects >1.2 million Americans annually. Although the clinical outcomes and economic burdens of VTE have been well described, the impact of VTE on patients' health status has yet to be summarized. This systematic review summarizes how patient-reported outcome measures (PROMs) have been used in VTE to date.

PubMed/MEDLINE was queried for literature published through March 2023 using PROMs in a population of patients with VTE. Studies were excluded if the reference was an editorial, review, or case report, or if the study included patients with conditions other than VTE. Qualitative analyses were performed. After screening and exclusion, 136 references were identified; 5 described PROM development, 20 focused on PROM validation, and 111 used PROMs in outcomes research. The most used generic PROMs were the 36-item Short-Form Health Survey and EuroQol 5-dimensional questionnaire, and the most common disease-specific PROMs were the Venous Insufficiency Epidemiological and Economic Study-Quality of Life/Symptoms and the Pulmonary Embolism Quality of Life Questionnaire. PROMs were used to quantify the changes in health status after diagnosis, characterize the trajectory of subsequent improvement, and identify drivers of continued impairments in health status like postthrombotic syndrome and postpulmonary embolism syndrome. PROMs were also used to investigate the impact of novel treatment modalities on quality of life.

This review demonstrates the many benefits of PROM use, including quantifying changes in health status with treatment, capturing patients' experiences with the treatment itself, and identifying complications of VTE. Incorporating PROMs into VTE care will be an essential component of evaluating the effectiveness of novel therapies and should lead to improved shared decision-making for patients with VTE.

To evaluate the safety, feasibility and technical aspects of endovascular treatments for inferior vena cava (IVC) thrombosis secondary to deep venous thrombosis of the lower extremities.

A retrospective study of patients from two centres who received endovascular treatment for IVC thrombosis from January 2015 to December 2020. Under the protection of the IVC filter, all lesions were treated with manual aspiration thrombectomy (MAT) followed by catheter-directed thrombolysis (CDT). Technical aspects, complications, IVC patency, Venous Clinical Severity Score (VCSS) score and Villalta score were recorded during the follow-up observation.

Endovascular procedures including MAT and CDT were performed successfully in 36 patients (97.3%). The average duration of the endovascular procedure was 71 minutes (range: 35-152 min). To protect against fatal pulmonary artery embolism, 33 filters (91.7%) were deployed in the inferior renal IVC, while three patients (8.3%) received filter implantation in the retrohepatic IVC. No severe complications occurred during the procedure. In the follow-up observations, the cumulative primary and secondary patency rates in IVC were 95% and 100%, respectively. The patency rates for the iliac vein were as follows: a primary patency rate of 77% and a secondary patency rate of 85%. The average VCSS score was 5.9 ± 2.6, and the Villalta score was 3.9 ± 2.2. The rate of post thrombotic syndrome is 22% in our study as assessed by the villalta score (Villalta score>4).

Endovascular treatment for IVC thrombosis secondary to DVT of the lower extremities is feasible, safe, and effective. This strategy alleviates venous insufficiency and results in a high patency rate in IVC.

Acute iliofemoral deep vein thrombosis and chronic iliofemoral venous obstruction cause substantial patient harm and are increasingly managed with endovascular venous interventions, including percutaneous mechanical thrombectomy and stent placement. However, studies of these treatment elements have not been designed and reported with sufficient rigor to support confident conclusions about their clinical utility. In this project, the Trustworthy consensus-based statement approach was utilized to develop, via a structured process, consensus-based statements to guide future investigators of venous interventions. Thirty statements were drafted to encompass major topics relevant to venous study description and design, safety outcome assessment, efficacy outcome assessment, and topics specific to evaluating percutaneous venous thrombectomy and stent placement. Using modified Delphi techniques for consensus achievement, a panel of physician experts in vascular disease voted on the statements and succeeded in reaching the predefined threshold of >80% consensus (agreement or strong agreement) on all 30 statements. It is hoped that the guidance from these statements will improve standardization, objectivity, and patient-centered relevance in the reporting of clinical outcomes of endovascular interventions for acute iliofemoral deep venous thrombosis and chronic iliofemoral venous obstruction in clinical studies and thereby enhance venous patient care.

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).

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.

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.

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 purpose of this study was to determine the technical feasibility and safety of 3D rotational venography (3D-RV) in the diagnosis of non-thrombotic iliac vein lesions compared with traditional 2D-digital subtraction angiography (2-DSA).

The general epidemiological data (including age, gender), clinical manifestations (including major symptom, affected extremity, CEAP classification, comorbidity, stenosis rate), and intra-operative findings (iliac vein indentation position, collateral circulation, procedure time, X-rays dose, contrast agent dosage) of 61 NIVL patients who were assessed by 3D-RV and traditional 2-DSA between October 2018 to October 2022 were obtained and analyzed.

A total of 61 consecutive patients with symptomatic NIVL from our institution were enrolled in this study. With the aggravation of iliac vein stenosis, the proportion of indicators such as contralateral formation and iliac vein compression indentation reflecting the severity of compression under 3D-RV reconstruction increased significantly. Also, significant differences were observed between the 3D-RV and 2-DSA groups concerning procedure time (10.56 ± 0.09 s vs. 12.59 ± 0.37 s; p < 0.01), X-ray dose (41.25 ± 0.21 mGy vs. 81.59 ± 1.69 mGy; p < 0.01) and contrast agent dosage (21.48 ± 0.24 mL vs. 33.69 ± 0.72 mL; p < 0.01). Contralateral iliac vein imaging (p = 0.002), pelvic collateral vein imaging (p = 0.03), and external iliac vein indentation (p = 0.001) were found to influence the severity of iliac vein compression.

3D-RV can display dynamic stereo image information of NIVL, augmenting the information obtained from traditional 2-DSA. Contralateral iliac vein imaging, pelvic collateral vein imaging, and external iliac vein indentation can be used to evaluate the severity of iliac vein compression to some extent.

To establish the updated position of the Society of Interventional Radiology (SIR) on the endovascular management of acute iliofemoral deep vein thrombosis (DVT).

A multidisciplinary writing group with expertise in treating venous diseases was convened by SIR. A comprehensive literature search was conducted to identify studies on the topic of interest. Recommendations were drafted and graded according to the updated SIR evidence grading system. A modified Delphi technique was used to achieve consensus agreement on the recommendation statements.

A total of 84 studies, including randomized trials, systematic reviews and meta-analyses, prospective single-arm studies, and retrospective studies were identified and included in the review. The expert writing group developed 17 recommendations that pertain to the care of patients with acute iliofemoral DVT with the use of endovascular venous interventions.

SIR considers endovascular thrombus removal to be an acceptable treatment option in selected patients with acute iliofemoral DVT. Careful individualized risk assessment, high-quality general DVT care, and close monitoring during and after procedures should be provided.

A blockage to the blood vessels in the lower extremities may cause pain and discomfort. If left unmanaged, it may lead to amputation or chronic disability, such as in the form of post-thrombotic syndrome. We conducted a health technology assessment of mechanical thrombectomy (MT) devices, which are proposed to remove a blood clot, which may form in the arteries or veins of the lower legs. This evaluation considered blockages in the veins and arteries separately, and included an evaluation of effectiveness, safety, cost-effectiveness, the budget impact of publicly funding MT for lower limb blockages, patient preferences and values, and clinical and health system stakeholders' perspectives.

We performed a systematic literature search of the clinical evidence. We assessed the risk of bias of each included study using the Cochrane tool for randomized controlled trials or the risk of bias among non-randomized studies (RoBANS) tool for nonrandomized studies, and the quality of the body of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. We performed a systematic economic literature search. We did not conduct a primary economic evaluation since the clinical evidence is highly uncertain. We also analyzed the budget impact of publicly funding MT treatment for inpatients with arterial acute limb ischemia and acute deep vein thrombosis (DVT) in the lower limb in Ontario. To contextualize the potential value of MT, we spoke with people with acute DVT. To understand the barriers and facilitators of accessing MT, we surveyed clinical and health system stakeholders to gain their perspectives.

We included 40 studies (3 randomized controlled trials and 37 observational studies) in the clinical evidence review. For patients who experience arterial acute limb ischemia, compared with catheter-directed thrombolysis (CDT) alone, MT has greater technical success and patency and reduced hospital length of stay, but the evidence for these outcomes is uncertain (GRADE: Very low). Mechanical thrombectomy may reduce the volume of thrombolytic medication required and CDT infusion time (a determinant for intensive care unit [ICU] need) in patients experiencing acute DVT, but it is uncertain if this is to a meaningful degree (GRADE: Moderate to Very low). It may also reduce the proportion of people who experience post-thrombotic syndrome and overall hospital length of stay, but it is uncertain (GRADE: Very low).We estimated that publicly funding MT for people with arterial acute limb ischemia in Ontario would lead to an annual cost savings of $0.17 million in year 1 to $0.14 million in year 5, for a total savings of $0.83 million over 5 years. This cost savings was mainly attributed to reduced ICU stays among people who received MT, but the results had considerable uncertainty. For the population with acute DVT, publicly funding MT would lead to an additional cost of $0.77 million in year 1 to $1.44 million in year 5, for a total additional cost of $5.5 million over 5 years.The people with acute DVT with whom we spoke reported that MT was generally seen as a positive option, and those who had undergone the procedure reported positively on its value as a treatment to quickly remove a clot. Accessing treatment for DVT could be a barrier, especially in more remote areas of Ontario.Clinicians using the technology advised that facilitators to accessing the technology included perceived improvements in patient outcomes, resourcing requirements, addressing unmet needs, and avoidance of ICU stay. The main barrier identified was cost. Clinicians who were not using the technology advised that barriers were low case-use volume, along with costs for the equipment and for health human resources.

Mechanical thrombectomy may have greater technical success and patency and reduce hospital length of stay for patients experiencing an arterial acute limb ischemia and, for patients with an acute DVT, it may reduce CDT volume and infusion time, the proportion of people who experience post-thrombotic syndrome, and hospital length of stay. Mechanical thrombectomy may reduce the associated ICU costs, but it has higher equipment costs compared with usual care. Publicly funding MT in Ontario for populations with arterial acute limb ischemia may not lead to a substantial budget increase to the province. Publicly funding MT for acute DVT would lead to an additional cost of $5.5 million over 5 years. For people with acute DVT, MT was seen as a potential positive treatment option to remove the clot quickly. Overall, the majority of clinical stakeholders we engaged with (including both those with and without experience with MT) were supportive of the use of the technology.

Randomized trials have demonstrated the benefit of thrombus removal strategies in iliofemoral deep venous thrombosis (IFDVT) in providing early symptom relief and decreasing the incidence of post-thrombotic syndrome (PTS), especially severe PTS. However, the impact of quantum of residual thrombus burden (RTB) on PTS as determined by intravascular ultrasound examination and the role of venous stenting in the acute setting have not been evaluated and represent the focus of this study.

Sixty-nine limbs (65 patients) undergoing thrombus removal for acute symptomatic IFDVT between 2015 and 2021 formed the study cohort. The Venous Clinical Severity Score (VCSS) (range, 0-27) grade of swelling (GOS) (range, 0-4), and visual analog scale (VAS) pain scores (range, 0-10) were evaluated initially and at 6, 12, and 24 months after thrombus removal. Quality of life was appraised using the CIVIQ-20 instrument. The extent of initial and RTB after the intervention was estimated using intravascular ultrasound examination. Grading was done as less than 50% (1), 50% to 99% (2), or 100% (3) of luminal thrombus fill within each segment (common femoral vein, external iliac vein, and common iliac vein) by a blinded rater and then combined to generate a total score. The use of stenting, both concurrent (severe residual stenosis/persistent occlusion) and delayed (quality of life impairing residual or recurrent symptoms), was evaluated.

Of the 69 limbs, 53 underwent pharmacomechanical/mechanical thrombectomy (PMT), whereas 16 patients underwent PMT and catheter-directed thrombolysis with restoration of inline flow in all limbs. Post-intervention VCSS improved from 6 to 2 at 24 months (P < .0001). GOS improved from 4 to 0 at 24 months (P < .0001). The VAS pain score went from 5 to 0 at 6 months (P < .0001) and remained at 0 at 12 months (P < .0001), but increased to 3 at 24 months (P = .02). The CIVIQ-20 score improved from 38 to 22 (P = .001) over a median follow-up of 19 months. The median RTB total score improved from 9 to 4 (P < .0001). There was no impact of RTB total score (<3 vs >3) on VCSS (P = NS), GOS (P = NS), VAS pain score (P = NS) or CIVIQ-20 score (P = NS) at the various time points. Concurrent stenting was used in 23 limbs (33%) and delayed stenting was carried out in 10 limbs (14%). The median time to delayed stenting was 4 months after the initial thrombus removal intervention.

In patients undergoing PMT or PMT with catheter-directed thrombolysis for acute symptomatic IFDVT, the restoration of inline flow seems to be adequate to provide symptom relief and decrease the incidence of PTS. The extent of RTB does not seem to impact the VCSS, GOS, VAS pain score, or quality of life after such restoration. Stenting can be pursued selectively in the acute setting to help restore inline flow.

Background Recurrent pericarditis is characterized by painful flares and inflammation, which negatively impact health-related quality of life. RHAPSODY (rilonacept inhibition of interleukin-1 alpha and beta for recurrent pericarditis: a pivotal symptomatology and outcomes study) evaluated the efficacy and safety of rilonacept (IL-1α and -β cytokine trap) in recurrent pericarditis. A secondary analysis of these data evaluated the patient-reported outcome questionnaire score change during the trial. Methods and Results Participants completed 5 patient-reported outcome (PRO) questionnaires assessing pericarditis pain, health-related quality of life, general health status, sleep impact, and overall symptom severity. PRO score changes during the treatment run-in period (12 weeks) and the blinded randomized withdrawal period (up to 24 weeks) were evaluated using descriptive statistics and mixed model repeated measures analyses. Participants with PRO data from the run-in period (n=84) and the randomized withdrawal period (n=61; 30 rilonacept, 31 placebo) were included in analyses. Run-in baseline PRO scores indicated that pericarditis symptoms during pericarditis recurrence impacted health-related quality of life. All PRO scores significantly improved (P<0.001) on rilonacept treatment during the run-in period. For the randomized withdrawal period, PRO scores were maintained for participants receiving rilonacept. For those receiving placebo and who experienced a recurrence, PRO scores deteriorated at the time of recurrence and then improved following rilonacept bailout. At randomized withdrawal Week 24/End of Study, scores of participants who received bailout rilonacept were similar to those of participants who had continued rilonacept. Conclusions These results demonstrate the burden of pericarditis recurrences and the improved physical and emotional health of patients with recurrent pericarditis while on rilonacept treatment. These findings extend prior rilonacept efficacy results, demonstrating improvements in patient-reported health-related quality of life, sleep, pain, and global symptom severity while on treatment. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT03737110.

To identify the baseline patient characteristics that predict who will benefit from pharmacomechanical catheter-directed thrombolysis (PCDT) of acute iliofemoral deep vein thrombosis (DVT).

In the Acute Venous Thrombosis: Thrombus Removal with Adjunctive Catheter-Directed Thrombolysis (ATTRACT) multicenter randomized trial, 381 patients with acute iliofemoral DVT underwent PCDT and anticoagulation or anticoagulation alone. The correlations between baseline factors and venous clinical outcomes were evaluated over 24 months using post hoc regression analyses. Interaction terms were examined to evaluate for differential effects by treatment arm.

Patients with clinically severe DVT (higher baseline Villalta score) experienced greater effects of PCDT in improving 24-month venous outcomes, including moderate or severe postthrombotic syndrome (PTS) (odds ratios [ORs] and 95% confidence intervals [CIs] per unit increase in the baseline Villalta scores were as follows: for PCDT, OR, 1.08 [95% CI, 1.01-1.15]; for control, OR, 1.20 [95% CI, 1.12-1.29]; Pinteraction = .03), PTS severity (between-arm differences in the Villalta [Pinteraction = .004] and Venous Clinical Severity Scale [VCSS] [Pinteraction = .002)] scores), and quality of life (between-arm difference in the Venous Insufficiency Epidemiological and Economic Study Quality of Life score; Pinteraction = .025). Patients with previous DVT had greater effects of PCDT on 24-month PTS severity than those in patients without previous DVT (mean [95% CI] between-arm difference in the Villalta score, 4.2 [1.56-6.84] vs 0.9 [-0.44 to 2.26], Pinteraction = .03; mean [95% CI] between-arm difference in the VCSS score, 2.6 [0.94-4.21] vs 0.3 [-0.58 to 1.14], Pinteraction = .02). The effects of PCDT on some but not all outcomes were greater in patients presenting with left-sided DVT (Villalta PTS severity, Pinteraction = .04; venous ulcer, Pinteraction = .0499) or a noncompressible popliteal vein (PTS, Pinteraction = .02). The effects of PCDT did not vary by sex, race, ethnicity, body mass index, symptom duration, hypertension, diabetes, or hypercholesterolemia.

In patients with acute iliofemoral DVT, greater presenting clinical severity (higher baseline Villalta score) and a history of previous DVT predict enhanced benefits from PCDT.

Lower extremity deep vein thrombosis (DVT) is frequently encountered in clinical practice. Postthrombotic syndrome (PTS) is a common sequela of DVT and encompasses a wide variety of symptoms, including severe pain, edema, and ulceration, all of which may contribute to a negative impact on quality of life. Studies have demonstrated that acute thrombosis of the iliofemoral venous segment is correlated with high rates of PTS, increased severity of symptoms, and high rates of thrombus recurrence, despite patients receiving treatment with standard-of-care anticoagulation therapy. Endovascular interventions, including catheter-directed thrombolysis, pharmacomechanical thrombectomy, and mechanical thrombectomy, have generated significant interest as a method for reduction of short-term symptom severity and potential reduction of downstream PTS severity. While there is high-quality evidence evaluating the role of catheter-directed and pharmacomechanical thrombectomy for acute iliofemoral DVT, newer mechanical-only devices that utilize thrombectomy without fibrinolytic medication are less studied. Currently, there are limited data evaluating the efficacy and safety of these treatment modalities, although investigations are ongoing.

The objective of the study was to describe the quality of life (QoL) status and investigate the influencing factors of QoL among patients with deep vein thrombosis (DVT).

A retrospective analysis at a single center was performed, and the clinical data of 161 patients with DVT admitted to West China Hospital of Sichuan University from June 2019 to June 2020 were collected with the Villalta scale, Hospital Anxiety and Depression Scale (HADS), and Chronic Venous Insufficiency Questionnaire (CIVIQ). The relationship between QoL and influencing factors, including characteristics, course of DVT, postthrombotic syndrome (PTS), psychological status, and behaviors, was analyzed by Student's t-test, analysis of variance and multiple linear regression.

A total of 161 patients who completed all the questionnaires between 2019 and 2020 were included, and 110 patients (68%) were male. The mean QoL score acquired by the CIVIQ scale was 74.18±8.44, and the results showed significant differences between patients of different ages, genders, behaviors and psychological statuses (P < 0.05). Multiple regression analysis showed that age (P = 0.024), negative mood (P < 0.001), CCI index (P < 0.001), PTS (P < 0.001) and regular exercise (P = 0.002) influenced the CIVIQ scale evaluation model, in which exercise regularly was a protective factor for QoL, and age, negative mood, CCI index and PTS were risk factors for QoL.

The QoL of DVT patients was impaired and associated with age, mood, CCI index and PTS. Regular exercise is beneficial for improving the quality of life of DVT patients.

The optimal medical management of patients following endovascular deep venous interventions remains ill-defined. As such, the Society of Interventional Radiology Foundation (SIRF) convened a multidisciplinary group of experts in a virtual Research Consensus Panel (RCP) to develop a prioritized research agenda regarding antithrombotic therapy following deep venous interventions. The panelists presented the gaps in knowledge followed by discussion and ranking of research priorities based on clinical relevance, overall impact, and technical feasibility. The following research topics were identified as high priority: 1) characterization of biological processes leading to in-stent stenosis/rethrombosis; 2) identification and validation of methods to assess venous flow dynamics and their effect on stent failure; 3) elucidation of the role of inflammation and anti-inflammatory therapies; and 4) clinical studies to compare antithrombotic strategies and improve venous outcome assessment. Collaborative, multicenter research is necessary to answer these questions and thereby enhance the care of patients with venous disease.

The annual occurrence of venous thromboembolism (VTE) is 300,000-600,000 cases in the United States and 700,000 in Europe. VTE includes deep venous thrombosis (DVT) of upper or lower extremities, superior and inferior vena cava thrombosis, and pulmonary embolism (PE) as well. The primary treatment of DVT includes oral anticoagulation to prevent the progression of the thrombus and decrease the risk of pulmonary embolism. Depending on the symptoms, more invasive treatments can be applied to target the iliofemoral thrombus and its removal. However, less emphasis is given to acute symptomatology, early recovery of function, quality of life improvement, and the individualized likelihood of developing post-thrombotic syndrome. While invasive therapy has been used to enhance the acute management of iliofemoral DVT, our knowledge about the overall outcomes associated with the invasive treatment of VTE is still limited. In this review, we illustrate the available data on pharmacological and endovascular management of iliofemoral VTE, including therapies such as catheter-directed thrombolysis (CDT), mechanical thrombectomy (PMT), and pharmacomechanical catheter-directed thrombolysis (PCDT).

Lower extremity deep venous thrombosis (LEDVT) of lower extremities is one of the common clinical diseases. Lack of a timely treatment in the acute stage easily causes pulmonary embolism, thus seriously threatening patients' life. Low-molecular-weight heparin (LMWH), as a new generation of heparin-based anticoagulant and antithrombotic drug, is now commonly used in the clinical treatment of acute lower extremity deep venous thrombosis (ALEDVT). Relevant randomized controlled trials (RCTs) have reported the therapeutic efficacy and safety of Traditional Chinese medicine injection (TCMJ) combined with LMWH on ALDVT, although their conclusions remain controversial. In addition, the efficacy of various TCMJs has rarely been analyzed and compared. This study aims to evaluate the therapeutic efficacy and safety of TCMJ combined with LMWH on ALEDVT through a network meta-analysis.

RCTs reporting TCMJ combined with LMWH and LMWH along for the treatment of ALEDVT published before November 2021 will be searched in online databases, including the Cochrane Library, Embase, PubMed, Web of Science, Wanfang, Chongqing VIP Chinese Science and Technology Periodical Database, Chinese Biomedical Literature Database, and Chinese National Knowledge Infrastructure. Two investigators will be independently responsible for literature screening, data extraction, and quality evaluation according to Cochrane's risk of bias assessment tool. R software will be used to perform a network Meta-analysis.

The results of this meta-analysis will be submitted to a peer-reviewed journal for publication.

This study will provide high-quality, evidence-based medical evidence for comparing the therapeutic efficacy and safety of TCMJ combined with LMWH and LMWH alone on ALEDVT.

Venous thromboembolism (VTE), clinically presenting as deep-vein thrombosis (DVT) or pulmonary embolism (PE), constitutes a major global healthcare concern with severe complications, long-term morbidity and mortality. Although several clinical, genetic and acquired risk factors for VTE have been identified, the molecular pathophysiology and mechanisms of disease progression remain poorly understood. Anticoagulation has been the cornerstone of therapy for decades, but there still are uncertainties regarding primary and secondary VTE prevention, as well as optimal therapy duration. In this review we discuss the role of factor Xa in coagulation cascade and the different choices of anticoagulation therapy based on patients' predisposing risk factors and risk of event recurrence. Further, we compare newer agents to traditional anticoagulation treatment, based on most recent studies and guidelines.

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.

Catheter-directed thrombolysis (CDT) has been utilized as an adjunct to anticoagulant therapy in selected patients with deep vein thrombosis (DVT) for approximately 30 years. CDT used to be limited to patients with DVT causing acute limb threat and those exhibiting failure of initial anticoagulation, but has expanded over time. Randomized trials evaluating the first-line use of CDT for proximal DVT have demonstrated that CDT does not produce a major reduction in the occurrence of post-thrombotic syndrome (PTS) and that it is poorly suited for elderly patients and those with limited thrombus extent or major risk factors for bleeding. However, CDT does offer selected patients with acute iliofemoral DVT improvement in reducing early DVT symptoms, in achieving reduction in PTS severity, and in producing an improvement in health-related quality of life (QOL). Clinical practice guidelines from medical and surgical societies are now largely aligned with the randomized trial results. This review offers the reader an update on the results of recently completed clinical trials, and additional guidance on appropriate selection of patients with DVT for catheter-directed thrombolytic therapy.

Deep vein thrombosis (DVT) is a common disorder affecting approximately 900,000 new patients in the United States each year. Although the mainstay of treatment of DVT patients is therapeutic anticoagulation, some patients remain significantly symptomatic and therefore require more advanced interventions such as catheter-directed thrombolysis (CDT). We describe a case series of 13 patients with acute symptomatic inferior vena cava (IVC) and iliofemoral DVT that were treated with CDT using the Bashir Endovascular Catheter (BEC). We report the first-in-human use of BEC, which is a novel pharmacomechanical thrombolysis device. All the treated patients had complete and rapid resolution of their symptoms with excellent venous outflow. Despite initial promising results, larger studies using this catheter design will be needed to assess the role of BEC-directed therapy on rates of post-thrombotic syndrome and bleeding complications.

The aim of this systematic review was to investigate the long-term clinical impact of iliofemoral (IF) deep vein thrombosis (DVT) based on patient reported outcomes, physician administered test measures and compare medical to interventional treatment.

This study was conducted according to the Preferred Reporting Items for Systematic Reviews (PRISMA) guidelines. Criteria for inclusion were patients with thrombus involving the common femoral vein or more proximal veins, ≥5-year follow-up and physician assessment. Data quality was assessed using the Robins-I tool and Cochrane tool.

Eight studies that fulfilled our criteria were deemed eligible and provided data for 499 patients. There were 230 patients who received medical treatment and 269 interventional. Two studies were randomized controlled trials and six observational. Venous claudication, where reported, was found in 7.7% (1/13) of interventionally treated patients and 21% (13/62) of medically treated patients. Long term symptom resolution was reported in 58% (18/31) and 24% (12/50) of interventionally and medically treated patients, respectively. Venous ulcers were seen in 5.5% (7/126) of medically treated patients and 5% (5/100)of interventionally treated patients.

A wide range of signs and symptoms was reported at long-term. Interventional treatment appeared to be better than medical one but the evidence was weak. Given the significant lack of patient reported outcomes, objective testing and use of validated instruments, the results should be interpreted in context with these limitations. Data on long-term outcomes after IF DVT have been poorly reported and outcome criteria should be better defined in future studies.

Deep vein thrombosis (DVT) is a common condition with a high risk of post-thrombotic morbidity, especially in patients with a proximal thrombus. Successful iliofemoral clot removal has been shown to decrease the severity of post-thrombotic syndrome. It is assumed that earlier thrombus lysis is associated with a better outcome. Generally, the earlier IFDVT is confirmed, the earlier thrombus lysis could be performed. d-Dimer levels and Wells score are currently used to assess the preduplex probability for DVT; however, some studies indicate that the d-dimer value varies depending on the thrombus extent and localization. Using d-dimer and other risk factors might facilitate development of a model selecting those with an increased risk of IFDVT that might benefit from early referral for additional analysis and adjunctive iliofemoral thrombectomy.

All consecutive adult patients from a retrospective cohort of STAR diagnostic center (primary care) in Rotterdam suspected of having DVT between September 2004 and August 2016 were assessed for this retrospective study. The diagnostic workup for DVT including Wells score and d-dimer were performed as well as complete duplex ultrasound examination. Patients with objective evidence of DVT were categorized according to thrombus localization using the Lower Extremity Thrombolysis classification. Logistic regression analysis was done for a model predicting IFDVT. The cut-off value of the model was determined using a receiver operating characteristic curve.

A total of 3381 patients were eligible for study recruitment, of whom 489 (14.5%) had confirmed DVT. We developed a multivariate model (sensitivity of 77% and specificity of 82%; area under the curve, 0.90; 0.86-0.93) based on d-dimer, Wells score, age, and anticoagulation use, which is able to distinguish IFDVT patients from all patients suspected of DVT.

This multivariate model adequately distinguishes IFDVT among all suspected DVT patients. Practically, this model could give each patient a preduplex risk score, which could be used to prioritize suspected IFDVT patients for an immediate imaging test to confirm or exclude IFDVT. Further validation studies are needed to confirm potential of this prediction model for IFDVT.

Up to 50% of patients with proximal deep vein thrombosis (DVT) will develop the postthrombotic syndrome characterized by limb swelling and discomfort, hyperpigmentation, skin ulcers, and impaired quality of life. Although catheter-based interventions enabling the restoration of blood flow (RBF) have demonstrated little benefit on postthrombotic syndrome, the impact on the acuity of the thrombus and mechanisms underlying this finding remain obscure. In experimental and clinical studies, we examined whether RBF has a restricted time window for improving DVT resolution.

First, experimental stasis DVT was generated in C57/BL6 mice (n=291) by inferior vena cava ligation. To promote RBF, mice underwent mechanical deligation with or without intravenous recombinant tissue plasminogen activator administered 2 days after deligation. RBF was assessed over time by ultrasonography and intravital microscopy. Resected thrombosed inferior vena cava specimens underwent thrombus and vein wall histological and gene expression assays. Next, in a clinical study, we conducted a post hoc analysis of the ATTRACT (Acute Venous Thrombosis: Thrombus Removal with Adjunctive Catheter-Directed Thrombolysis) pharmacomechanical catheter-directed thrombolysis (PCDT) trial (NCT00790335) to assess the effects of PCDT on Venous Insufficiency Epidemiological and Economic Study quality-of-life and Villalta scores for specific symptom-onset-to-randomization timeframes.

Mice that developed RBF by day 4, but not later, exhibited reduced day 8 thrombus burden parameters and reduced day 8 vein wall fibrosis and inflammation, compared with controls. In mice without RBF, recombinant tissue plasminogen activator administered at day 4, but not later, reduced day 8 thrombus burden and vein wall fibrosis. It is notable that, in mice already exhibiting RBF by day 4, recombinant tissue plasminogen activator administration did not further reduce thrombus burden or vein wall fibrosis. In the ATTRACT trial, patients receiving PCDT in an intermediate symptom-onset-to-randomization timeframe of 4 to 8 days demonstrated maximal benefits in Venous Insufficiency Epidemiological and Economic Study quality-of-life and Villalta scores (between-group difference=8.41 and 1.68, respectively, P<0.001 versus patients not receiving PCDT). PCDT did not improve postthrombotic syndrome scores for patients having a symptom-onset-to-randomization time of <4 days or >8 days.

Taken together, these data illustrate that, within a restricted therapeutic window, RBF improves DVT resolution, and PCDT may improve clinical outcomes. Further studies are warranted to examine the value of time-restricted RBF strategies to reduce postthrombotic syndrome in patients with DVT.