[Post-thrombotic syndrome - Prophylaxis, diagnostics and complication management]. / Postthrombotisches Syndrom.

The post-thrombotic syndrome PTS occurs when a relevant residual thrombus load remains after a deep vein thrombosis and/or the function of the venous valves is disturbed. The knowledge of the different types of PTS generates individualized therapeutic and secondary prophylactic approaches. Immediate compression, movement in compression garments and an effective anticoagulation are crucial for both the prevention and the outcome of post thrombotic syndromes.

Risk of developing post thrombotic syndrome after deep vein thrombosis with different anticoagulant regimens: A systematic review and pooled analysis.

BACKGROUND: Post-thrombotic syndrome (PTS) is common in patients with deep vein thrombosis (DVT). It is unclear if different types of anticoagulant therapies (e.g. vitamin K antagonists (VKA), direct oral anticoagulants (DOACs) or low molecular weight heparin (LMWH)) are associated with different risks of PTS. We sought to assess the incidence rates of PTS development following a proximal DVT of the lower extremity managed with different types of anticoagulation regimens. METHODS: A systematic search of MEDLINE, EMBASE and PubMed, from inception to June 2023 was performed. The primary outcome was development of PTS. The secondary outcomes included severe PTS, venous ulcers, and major bleeding. Incidence rates were pooled using the random effects model and expressed as event per 100 patient-years with its associated 95 % confidence intervals (CI) using R software. RESULTS: A total of 21 (4342 patients) articles were included in the analysis. The adjusted pooled incidence of PTS was 15.1 (95 % CI: 8.7 to 26.1), 18.2 (95 % CI: 9.4 to 35.1) and 24.6 (95 % CI: 9.2 to 65.5) per 100 patient-years patients managed with VKA, DOAC and LMWH, respectively. The adjusted pooled incidence of severe PTS was 5.1 (95 % CI: 2.6 to 10.0) and 0.2 (95 % CI: 0.01 to 2.7) per 100 patient-years for VKAs and DOACs, respectively. CONCLUSIONS: The development of PTS is common in patients with proximal lower extremity DVT. The incidence rates of PTS seem to be similar across the different anticoagulation regimens, but severe PTS may be lower among patients receiving a DOAC.

Risk factors of moderate to severe post-thrombotic syndrome within 2 years in patients with subacute thrombosis: A case-control study.

OBJECTIVE: The aim of this study was to study the risk factors influencing the occurrence of moderate to severe post-thrombotic syndrome (PTS) within 2 years in patients with subacute lower extremity deep vein thrombosis (DVT). METHODS: Seventy patients who developed moderate to severe PTS within 2 years after subacute lower extremity DVT from June 2018 to June 2022 were retrospectively selected as the case group. They were matched 1:1 by sex and age (±5 years) with 70 patients who did not develop moderate to severe PTS during the same follow-up period as the control group. Multiple logistic regression, stratified analysis, and interaction analyses were used to explore the risk factors for moderate to severe PTS. RESULTS: The multiple logistic regression model showed that patients with iliofemoral vein thrombosis had a significantly increased risk of developing moderate to severe PTS within 2 years. Patients who underwent intraluminal intervention treatment during hospitalization had a significantly reduced risk. The odds ratios were 4.000 (95% confidence interval, 1.597-10.016) for the femoral-popliteal vein thrombosis and 0.262 (95% confidence interval, 0.106-0.647) for the anticoagulation treatment group. The stratified analysis showed that intraluminal intervention treatment was a protective factor against moderate to severe PTS within 2 years across different strata of hypertension, thrombus type, body mass index, duration of anticoagulation, and wearing compression stockings. Additionally, there was an interaction between thrombus type and treatment method, with intraluminal intervention treatment having a more pronounced effect on preventing moderate to severe PTS in patients with iliofemoral vein thrombosis. CONCLUSIONS: Iliofemoral vein thrombosis is a risk factor for the development of moderate to severe PTS within 2 years in patients with subacute lower extremity DVT. Intraluminal intervention treatment can reduce the risk of moderate to severe PTS, especially in patients with iliofemoral vein thrombosis.

Fibrinogen levels and clot properties identify patients who benefit from catheter-directed thrombolysis after DVT.

ABSTRACT: Ultrasound-accelerated catheter-directed thrombolysis (UA-CDT) to improve patency after deep vein thrombosis (DVT) has not conclusively been shown to prevent postthrombotic syndrome (PTS) but might benefit patients who are unlikely to obtain patency with standard treatment. We hypothesized that these patients could be selected based on their fibrin clot properties. To study this, patients with acute iliofemoral DVT from the CAVA (Ultrasound-Accelerated Catheter-Directed Thrombolysis Versus Anticoagulation for the Prevention of Post-thrombotic Syndrome) trial had blood samples taken at inclusion. Fibrin clot properties in plasma were determined by turbidimetric clotting (lag time and maximal turbidity) and lysis assays (time to 50% lysis and lysis rate), permeation assay, and confocal microscopy (fiber density), as well as levels of fibrin clot modifiers fibrinogen and C-reactive protein (CRP). Patency was defined as >90% iliofemoral vein compressibility at 12-month ultrasound. PTS was defined as ≥5 Villalta score at 6 or 12 months. In total, 91 of 152 patients were included, including 43 with additional UA-CDT and 48 with standard treatment. Patients with additional UA-CDT more often obtained patency (55.8 vs 27.1%) Patients who obtained patency had longer lag times and lower maximal turbidity, fibrinogen, and CRP; only maximal turbidity and fibrinogen remained associated when adjusting for treatment, thrombus load, and body mass index. Fibrinogen levels had an optimal cutoff at 4.85 g/L. Low fibrinogen levels best predicted patency. Additional UA-CDT decreased the risk of PTS only in patients with high fibrinogen. Therefore, additional UA-CDT might prevent PTS in selected patients based on routinely measured fibrinogen levels. This study was registered at www.ClinicalTrials.gov as #NCT00970619.

Effectiveness, reach, uptake and feasibility of digital health interventions for adults with venous thromboembolism: protocol of a systematic review and meta-analysis.

INTRODUCTION: Prevention of recurrence after an episode of venous thromboembolism (VTE), and also the post-thrombotic syndrome (PTS), is still a recognised challenge. In this meta-analysis, we will summarise existing evidence to compare intelligent system follow-up and routine follow-up for patients with VTE. METHODS AND ANALYSIS: Relevant randomised controlled trials (RCTs) and cohort studies will be included from the following databases: MEDLINE/PubMed, Web of Science and the Cochrane Library. The last search time will be 31 March 2024. Two reviewers will independently identify RCTs and cohort studies according to eligibility and exclusion criteria. The risk of bias of included cohort studies will be assessed with the Newcastle-Ottawa Scale, Methodological Index of Non-Randomised Studies, and the risk of bias of RCTs will be assessed with and Cochrane Collaboration's tool. The primary outcomes include overall survival rate and PTS incidence rate. The Grades of Recommendations, Assessment, Development and Evaluation tool will be used to assess the level of evidence for outcome from RCTs. RevMan V.5.4 software will be used to pool outcomes. ETHICS AND DISSEMINATION: Ethical approval was obtained from Shanghai Ninth People's Hospital, Shanghai JiaoTong University School of Medicine Science Research Ethics Committee (SH9H-2023-T466-1). The findings will be disseminated to the public through conference presentations and publication in peer-reviewed scientific journals. PROSPERO REGISTRATION NUMBER: CRD42023410644.

Compression Therapy in Acute Deep Venous Thrombosis of the Lower Limb and for the Prevention of Post-Thrombotic Syndrome.

BACKGROUND: After an acute deep venous thrombosis (DVT) of the lower limb, 20% to 63% of patients develop post-thrombotic syndrome (PTS). In this review, we address the efficacy of compression therapy in the treatment of acute DVT of the lower limb, and for the prevention of PTS. METHODS: 12 randomized controlled trials (RCTs) and one meta-analysis, with a total of 3751 patients, were identified in a structured literature search. RESULTS: Two RCTs showed that adding compression therapy to drug treatment in the first 9 days of the acute phase of lower limb DVT led to more rapid pain relief (p<0.050) and less swelling (remaining difference in circumference, 1 cm versus 3 cm, p<0.050). As for the prevention of PTS, four RCTs showed a short-term benefit or no benefit of compression therapy. In three further RCTs, medical compression stockings (MCS) brought about a 16% to 27% absolute reduction of the frequency and severity of PTS (47% vs. 20 %, p<0.001; 40% vs. 21% (95% confidence intervals [29.9; 50.1] and [12.7; 29.5], respectively; and 58% vs. 42%, relative risk [RR] 0.73 [0,55; 0.96]). The benefit of MCS was also confirmed in a recent meta-analysis (RR 0.66 [0.44; 0.99], I2 = 88%). Thigh-length MCS were not superior to knee-length MCS for the prevention of PTS (33% vs. 36%, hazard ratio [HR] 0.93 [0.62; 1.41]). Individual, symptomoriented tailoring of the duration of treatment was not inferior to a fixed treatment duration of 24 months (29% vs. 28%; odds ratio [OR] 1.06 [0.78;1.44]). CONCLUSION: Compression therapy relieves symptoms in acute DVT and lessens the frequency and severity of PTS. It is therefore recommended as standard treatment.

Principles of Optimal Antithrombotic Therapy for Iliac VEnous Stenting (POATIVES): A national expert-based Delphi consensus study.

OBJECTIVE: Management of antithrombotic therapy in patients undergoing venous stents has not yet reached consensus, and there are not any recommendations from published guidelines. We undertook a Delphi consensus from Chinese experts to develop recommendations regarding the preferred antithrombotic therapy in patients following venous stenting. METHODS: The phase 1 questionnaire was comprised of three clinical scenarios of venous stenting for non-thrombotic iliac vein lesions (NIVL), acute deep vein thrombosis (DVT), and post-thrombotic syndrome (PTS) and was sent to venous practitioners across China. In phase 2, the results of phase 1 were distributed to a panel of experts for evaluation along with a questionnaire encompassing a series of statements produced during phase 1. A modified Delphi method was used to reach consensus on recommendations through two rounds of surveys. RESULTS: The phase 1 questionnaire was completed by 283 respondents. In phase 2, an expert panel consisting of 28 vascular surgeons and interventional radiologists was assembled and voted 17 statements relating to antithrombotic management after venous stenting for NIVL (4 statements), DVT (6 statements), and PTS (7 statements). The majority of the statements about the antithrombotic agent selection received a high consensus strength. CONCLUSIONS: Based on the national Delphi consensus of Chinese experts regarding antithrombotic therapy following iliac venous stenting in three common scenarios, most of the statements could be used to guide antithrombotic management following venous stenting. Further studies are required to clarify controversial issues including the dose and duration of anticoagulants, the role of antiplatelet agents, especially in patients with NIVL.

Graduated elastic compression stockings in the prevention of post-thrombotic syndrome: A systematic review and meta-analysis.

BACKGROUND: The effect of graduated elastic compression stockings (ECS) in the prevention of post-thrombotic syndrome (PTS) has been questioned since a large randomized trial found no prophylactic effect of ECS. OBJECTIVE: To assess the effect of the wearing time of ECS on the incidence of post-thrombotic syndrome (PTS) after proximal deep venous thrombosis, we performed a meta-analysis of the incidence of PTS across randomized and observational studies. METHOD: PubMed, Embase and Cochrane databases were searched until 12 June 2023 for studies on the effect of ECS on PTS. References of eligible studies were also screened in order to identify other potential studies that might have been missed during the search. RESULTS: Four studies comprising a total of 1467 patients met our inclusion criteria for early initiation and consistent use of ECS in patients with acute proximal DVT. ECS significantly reduced the incidence of mild-moderate PTS (OR: 0.48; 95% CI: 0.36-0.63) as well as severe PTS (OR: 0.44; 95% CI: 0.28-0.58).

TILE pilot trial study protocol: Tinzaparin Lead-in to Prevent the Post-Thrombotic syndrome study protocol.

INTRODUCTION: The post-thrombotic syndrome (PTS) is a form of chronic venous insufficiency due to a prior ipsilateral deep venous thrombosis (DVT). This is a frequent complication that develops in 20%-50% of patients after a proximal DVT and is associated with significant healthcare, economic and societal consequences. In the absence of effective and well-tolerated treatment options for established PTS, effective preventative measures are needed. Anticoagulation itself reduces the risk of PTS, and low-molecular-weight heparin may reduce this further through anti-inflammatory properties targeting the initial acute inflammatory phase of DVT. METHODS AND ANALYSIS: The Tinzaparin Lead-In to Prevent the Post-Thrombotic syndrome pilot trial is an investigator-initiated, multicentre, open-label assessor-blinded trial that will randomise patients with first acute symptomatic common femoral or iliac DVT to receive either a 3-week lead-in course of tinzaparin, followed by rivaroxaban (experimental arm) or rivaroxaban alone (control arm). Its primary objectives are to assess: (1) proportion of PTS at 6 months using the Villalta scale and (2) study feasibility, which consists of (a) the proportion of screened patients eligible for the study, (2) the proportion of eligible patients recruited and (c) the proportion of recruited patients adherent to treatment (defined as at least 80% of drug taken). This study will determine the feasibility of a subsequent larger definitive trial. Secondary outcomes include change of quality of life scores, PTS severity, global improvement, patient satisfaction, bleeding, recurrent venous thromboembolism, leg pain, death and lost to follow-up. Target recruitment will be a total of 60 participants, recruited at 5-6 centres. ETHICS AND DISSEMINATION: Primary ethics approval was received from the Sunnybrook Health Sciences Center Research Ethics Board (approval ID 3315). Results of the study will be disseminated via peer-reviewed presentation at scientific conferences and open access publication. TRIAL REGISTRATION NUMBER: NCT04794569.

Coagulation-monitored, dose-adjusted catheter-directed thrombolysis or pharmaco-mechanical thrombus removal in deep vein thrombosis.

Background: Pharmaco-mechanical thrombectomy (PMT) and catheter-directed thrombolysis (CDT) are therapeutic options for selected patients with acute deep vein thrombosis (DVT) to prevent post-thrombotic syndrome (PTS). Patients and methods: We aimed to describe the clinical characteristics and outcomes of 159 patients with symptomatic iliofemoral DVT undergoing PMT alone, CDT alone, or CDT followed by PMT (bail-out) in the Swiss Venous Stent Registry. The primary outcome was the incidence of peri-interventional major and minor bleeding complications (ISTH criteria). Secondary outcomes included the incidence of PTS and stent patency after 3 years. Results: Mean age was 49±20 years and 58% were women. DVT involved the iliac veins in 99% of patients, whereas 53% had an underlying iliac vein compression. PMT alone was used in 40 patients, CDT alone in 77, and 42 received initial CDT followed by bail-out PMT due to insufficient thrombus clearance. Single-session PMT was the preferred approach in patients with iliac vein compression, patent popliteal vein, and absence of IVC thrombus. Patients treated with PMT alone received a lower r-tPA dose (median 10 mg, IQR 10-10) vs. those treated with CDT (20 mg, IQR 10-30). The rate of peri-interventional major bleeding was 0%, 1%, and 2%, whereas that of minor bleeding was 0%, 1%, and 12%, respectively, all occurring during CDT. After 3 years, PTS occurred in 6%, 9%, and 7% of patients, respectively. The primary stent patency rate was 95%, 88%, and 83%, respectively. Conclusions: The use of PMT and CDT for iliofemoral DVT was overall safe and resulted in high long-term patency and treatment success. Given the less severe presentation of DVT, single-session PMT appeared to be characterized by numerically better primary patency and lower perioperative bleeding event rates than CDT.

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.

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

BACKGROUND: Post thrombotic syndrome (PTS) is a serious complication of deep venous thrombosis (DVT). There were always debates on the efficacy of elastic compression stockings (ECS) in prevention for post thrombotic syndrome. OBJECTIVE: To assess effects of elastic compression stockings and ECS's wearing time on post thrombotic syndrome after diagnosis of deep venous thrombosis. METHODS: PubMed, Cochrane Library, Embase, Web of Science were last searched on 23 November 2022 for studies assessing effects of elastic compression stockings or theirs wearing time on post thrombotic syndrome after diagnosis of deep venous thrombosis. RESULTS: 9 randomized controlled trials were included. Wearing elastic compression stockings was associated with a statistically reduction in the overall post thrombotic syndrome rate (RR 0.73, 95 % CI 0.53 to 1.00; P = 0.05; I2 = 82 %). No significant difference in severe post thrombotic syndrome rate, recurrent deep venous thrombosis rate, and death rate was seen whether wearing elastic compression stockings or not. The pooled effect of studies comparing different wearing time of elastic compression stockings showed no significant difference in post thrombotic syndrome rate, severe and moderate post thrombotic syndrome rate, recurrent deep venous thrombosis syndrome rate and death rate. CONCLUSIONS: Wearing ECS can reduce the risk of developing PTS after DVT and a wearing time of less than or equal to 1 year is comparable to 2 years wearing. The results support ECS's role as a foundation therapy for preventing PTS.

Meta-analysis of lytic catheter-based intervention for acute proximal deep vein thrombosis in the reduction of post-thrombotic syndrome.

OBJECTIVE: Post-thrombotic syndrome (PTS) is a common complication of deep vein thrombosis (DVT) that can result in significant morbidity for the patient with detrimental impact on their quality of life. Evidence supporting lytic catheter-based interventions (LCBI) undertaken for early thrombus reduction in acute proximal DVT for the prevention of PTS is conflicting. Despite this, rates of LCBIs are increasing. To summaries the existing evidence and pool treatment effects, a meta-analysis of randomized controlled trials assessing the efficacy of LCBIs in proximal acute DVT for the prevention of PTS was undertaken. METHODS: This meta-analysis was undertaken aligning with PRISMA guidelines following a protocol pre-registered on PROSPERO. Online searches of Medline and Embase databases, as well as the gray literature, were performed up to December 2022. Included articles were randomized controlled trials that studied the use of LCBIs with additional anticoagulation vs anticoagulation alone and had determined follow-up periods. Outcomes of interest were PTS development, moderate to severe PTS, major bleeding episodes, and quality-of-life measures. Subgroup analyses were performed for DVTs involving the iliac vein and/r common femoral vein. Meta-analysis was performed using a fixed effects model. Quality assessment was performed using the Cochrane Risk of Bias and GRADE assessment tools. RESULTS: Three trials were included in the final meta-analysis, the Post-thrombotic Syndrome after Catheter-directed Thrombolysis for Deep Vein Thrombosis (CaVenT), Acute Venous Thrombosis: Thrombus Removal with Adjunctive Catheter-Directed Thrombolysis (ATTRACT), and Ultrasound-accelerated Catheter-directed Thrombolysis Versus Anticoagulation for the Prevention of Post-thrombotic Syndrome (CAVA) trials, comprising 987 patients. Patients undergoing LCBIs had a reduced risk of PTS (relative risk [RR], 0.84; 95% confidence interval [CI], 0.74-0.95; P = .006) and a lower risk of developing moderate to severe PTS (RR, 0.75; 95% CI, 0.58-0.97; P = .03). LBCIs increased the risk of having a major bleed (RR, 2.03; 95% CI, 1.08-3.82; P = .03). In the iliofemoral DVT subgroup analysis, there was a trend toward decreasing the risk of developing PTS and moderate to severe PTS (P = .12 and P = .05, respectively). There was no significant difference in quality-of-life score (as measured by the Venous Insufficiency Epidemiological and Economic Study - Quality of Life/Symptoms) between the two groups (P = .51). CONCLUSIONS: Pooling of current best evidence suggests that LCBIs in acute proximal DVT decreases the rate of PTS and moderate to severe PTS with a number needed to treat of 12 and 18, respectively. However, this is complicated by a significantly higher rate of major bleeding with a number needed to treat of 37. This evidence supports the use of LCBIs in selected patients, including those who are at low risk of major bleeding.

Successful Secondary Endovascular Intervention in Pediatric Patients with Venous Thromboembolic Events.

BACKGROUND: In the past, pediatric patients with venous thromboembolic events (VTE) were treated with low-molecular-weight heparin (LMWH) which was successful in around 70% of the cases. However, anticoagulation alone might not restore patency in all patients, and advanced therapeutic options to prevent postthrombotic syndrome are needed. During recent years, endovascular interventions have become a treatment option for pediatric patients with persistent thrombotic occlusion, not only in life- or limb-threatening VTE. METHODS: We evaluated 12 consecutive patients (11-17 years) with newly diagnosed VTE being treated at our department during the last 4 years (2017-2020). In case follow-up examination showed persistent venoocclusion under anticoagulation, patients received secondary interventional therapy like recanalization, percutaneous transluminal angioplasty with or without catheter-directed thrombolysis, and stenting. Patients with no clinical signs of venoocclusion or regredient thrombosis in imaging examination received anticoagulation alone. RESULTS: Six of 12 (50%) patients underwent catheter intervention. Median time from diagnosis to intervention was 4 months (0-12 months). Reintervention was necessary in one (8%) case and complete recanalization failed in one (8%) case. There were no major bleeding events or other major postinterventional complications, no acute or late local recurrence, and all patients reported clinical improvement after the procedure. CONCLUSION: If endovascular intervention is used in teenage patients with persistent symptomatic VTE, reduction of postthrombotic symptoms is possible, even if intervention is performed secondary to failure of anticoagulation. Multidisciplinary treatment decisions can be based on the clinical course and follow-up imaging.

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

OBJECTIVE: To identify the rate of post-thrombotic syndrome (PTS) after isolated distal deep venous thrombosis (IDDVT) by performing a meta-analysis of the rate of PTS across randomised and observational studies. DATA SOURCES: MEDLINE, Embase, the Cochrane Controlled Trials Register, Clinicaltrials.gov, European Union Clinical Trials, International Standard Randomised Controlled Trial Number, and the Australian and New-Zealand Trials Registries. REVIEW METHODS: This review followed PRISMA guidelines using a registered protocol (CRD42021282136). Databases were searched up to December 2021 and prospective studies reporting the development of post-thrombotic syndrome were included; these were pooled with the meta-analysis. RESULTS: The results showed a post-thrombotic rate of 17% (95% CI 11 - 26%) (seven studies, 217 cases, 1 105 participants). Heterogeneity was high (I2 = 89%). On meta-regression, the rate of post-thrombotic syndrome was not correlated with the length of follow up (p = .71). Three studies (302 participants) reported the severity of post-thrombotic syndrome: 78% were mild (Villalta score 5 - 9); 11% were moderate (Villalta score 10 - 14), and 11% were severe (Villalta score ≥ 15). CONCLUSION: The risk of post-thrombotic syndrome after IDDVT was one in five and the risk of severe clinical manifestations, including ulceration, was one in 50. There was significant clinical, methodological, and statistical heterogeneity between studies and a substantial risk of bias from pooled studies. Randomised trials to support interventions for prevention of post-thrombotic syndrome are urgently needed.

Restoring Venous Patency with the ClotTriever Following Deep Vein Thrombosis.

BACKGROUND: Although randomized data remain inconclusive, invasive endovenous therapy is increasingly favored in patients with extensive iliocaval or iliofemoral deep vein thrombosis (DVT) to reduce the rates of postthrombotic syndrome. Previously, pharmacomechanical thrombectomy was the therapy of choice, but the Inari ClotTriever device is an appealing, purely mechanical, alternative. It may reduce bleeding risk, intensive care unit admission, and the need for multiple procedures when compared with traditional thrombolysis. We present a series of 18 patients treated with the ClotTriever for extensive iliocaval or iliofemoral DVT. METHODS: The Inari ClotTriever is a percutaneous mechanical thrombectomy system consisting of an expandable nitinol collection bag that is dragged along the vein wall, separating and capturing thrombus for collection into the retrieval sheath. We retrospectively reviewed all patients undergoing ClotTriever thrombectomy since the device became available at our quaternary referral center in June 2019. The review of these patients' records was determined to be exempt by our institutional review board. RESULTS: Eighteen patients underwent ClotTriever thrombectomy between June 2019 and November 2021. Most patients (N = 16, 89%) presented within 2 weeks of symptom onset, and identifiable provoking factors were present in all patients. The most common provoking factor was anatomy, with May-Thurner syndrome present in 8 patients. All patients had restoration of unimpeded venous flow in the treated segments, although 3 had some residual nonflow limiting thrombus. There were no bleeding events or repeat venous procedures. The median postprocedure length of stay of 2 days. Postoperative venous imaging was performed in 15 patients and showed patency of the treated segment in 14 patients. Revised Clinical Venous Severity Scores were available in 14 patients during the course of follow-up. Of these, 9 patients' highest scores were 0, 2 patients' highest scores were 2, 2 patients' highest scores were 4, and 1 patient had a high score of 8. CONCLUSIONS: Venous flow was re-established in all 18 patients treated with the ClotTriever in this series, with no bleeding complications, and median postprocedure length of stay of 2 days. All patients with available follow-up, except 1, retained patency of the treated venous segments, and most had mild postthrombotic syndrome or none at all. These findings suggest that the ClotTriever is a safe and effective way to treat extensive iliocaval/femoral DVT.

Criteria to predict midterm outcome after stenting of chronic iliac vein obstructions (PROMISE trial).

BACKGROUND: Endovenous stent placement has become a first-line approach to prevent post-thrombotic syndrome in patients with chronic post-thrombotic obstruction (PTO) or nonthrombotic iliac vein lesions if conservative management fails. This study aims to identify factors associated with loss of patency to facilitate patient selection for endovenous stenting. METHODS: We retrospectively analyzed 108 consecutive patients after successful endovenous stenting for chronic vein obstruction performed at a single institution from January 2008 to July 2020. Using multivariable logistic regression, we explored potential predictive factors for loss of stent patency, including baseline demographics, post-thrombotic changes, and peak flow velocities measured in the common femoral vein (CFV), deep femoral vein, and femoral vein (FV) using duplex ultrasound examination. RESULTS: The mean follow-up duration was 41 ± 26 months, and participants had a mean age of 47.4 ± 15.4 years with 46.3% women. Ninety (83.3%) patients had PTO and 18 (16.7%) had nonthrombotic iliac vein lesions, predominantly due to May-Thurner syndrome. Loss of patency occurred in 20 (18.5%) patients, all treated for PTO. Comorbidities, side of intervention, and sex did not differ between patients with occluded and patent stents. Stent occlusion was more common with increasing number of stents implanted (P < .001) and with distal stent extension into and beyond the CFV (P < .001). Preinterventional predictive factors for stent occlusion were lower duplex ultrasound peak velocity in the CFV (odds ratio [OR]: 7.52, 95% confidence interval [CI]: 2.54-22.28; P < .001) and FV (OR: 10.75, 95% CI: 2.07-55.82; P < .005), and post-thrombotic changes in the deep femoral vein (OR: 4.51, 95% CI: 1.53-13.25; P = .006) and FV (OR: 3.62: 95% CI: 1.11-11.84; P = .033). Peak velocities of ≤7 cm/s (interquartile range: 0-20 cm/s) in the CVF and ≤8 cm/s (interquartile range: 5-10 cm/s) in the FV were significantly associated with loss of patency. CONCLUSIONS: Insufficient venous inflow as assessed by low peak velocities in the CFV and FV as well as post-thrombotic findings represent reliable risk predictors for stent occlusions, warranting their inclusion into the decision-making process for invasive treatment of PTO.

25 mm Hg versus 35 mm Hg elastic compression stockings to prevent post-thrombotic syndrome after deep vein thrombosis (CELEST): a randomised, double-blind, non-inferiority trial.

BACKGROUND: The optimal strength of compression needed to prevent post-thrombotic syndrome (PTS) after a proximal deep vein thrombosis (DVT) is debated. We aimed to assess whether 25 mm Hg elastic compression stockings (ECS) are non-inferior to 35 mm Hg ECS in preventing PTS after a DVT. METHODS: In this multicentre, double-blind, non-inferiority, randomised controlled trial, we enrolled adults (≥18 years) with a first ipsilateral proximal DVT attending 46 French vascular medicine hospital departments or private practices. Participants were randomly allocated (1:1, stratified by centre, age, and sex; with varying block sizes of two and four) to wear 25 mm Hg or 35 mm Hg ECS for 2 years. The primary outcome was the cumulative rate of PTS 2 years after inclusion, defined by a Villalta scale (≥5). Efficacy was assessed by intention-to-treat and in eligible participants who had complete primary outcome data. A per-protocol analysis was also conducted among compliant patients as a secondary outcome measure. Safety was assessed in all participants who used ECS at least once, and for which we have at least some tolerance information during follow-up. The margin for non-inferiority was 12·5%. This study is registered with ClinicalTrials.gov, NCT01578122, and has been completed. FINDINGS: Between June 28, 2012, and July 21, 2017, we enrolled 341 eligible participants who consented to randomisation. 233 (68%) were men and median age was 59 years (IQR 45-70). Collection of ethnicity and race as a routine research variable is not authorised in France. Median follow-up was 735 days (IQR 721-760). 249 (73%) had complete data at 2 years. For the primary analysis, 40 (31%) of 129 participants with complete data in the 25 mm Hg ECS group and 40 (33%) of 120 in the 35 mm Hg group had PTS (absolute difference -2·3% [90% CI -12·1 to 7·4], pnon-inferiority=0·0062; relative risk 0·93, 95% CI 0·65 to 1·33). Results remained similar after imputation of missing data in patients we were authorised to do so: the cumulative proportion of PTS was 45 (29%) of 154 in the 25 mm Hg ECS group versus 52 (35%) of 148 in the 35 mm Hg ECS group (relative risk 0·83, 95% CI 0·60 to 1·16). Absolute difference was -5·9%, (90% CI -14·7 to 2·9), p=0·0003 for non-inferiority. Adherence was optimal (>80% and modified GIRERD score of 0-2) for 75 (51%) of 146 patients assigned to 25 mm Hg ECS and for 56 (42%) of 134 patients assigned to 35 mm Hg ECS (p=0·11). Regarding major adverse events related to ECS, there were no between-group differences in rates of deep vein thrombosis (0 vs 1 [0·6%]), ipsilateral leg ulcer (0 vs 1 [0·6%]), infection (0 vs 0), or death (0 vs 0) between the 169 patients evaluated in the 25 mm Hg ECS group and the 159 patients in the 35 mm Hg ECS group. Two (1%) of 328 patients who ever wore ESC developed ECS-related serious adverse events, one distal DVT and one leg ulcer (both in the 35 mm Hg ECS group). In the 25 mm Hg group, 6 patients died, 14 had a venous thromboembolic recurrence (proximal DVT or pulmonary embolism), and 7 had a major bleed. In the 35 mm Hg group, 5 patients died, 10 had a venous thromboembolic recurrence (proximal DVT or pulmonary embolism), and 6 had a major bleed. INTERPRETATION: Although we did not reach the prespecified sample size, our results suggest that 25 mm Hg ECS are non-inferior to 35 mm Hg ECS in preventing PTS. Larger more powerful studies are needed. FUNDING: Laboratoires Innothera, France.