Long-term outcome after additional catheter-directed thrombolysis versus standard treatment for acute iliofemoral deep vein thrombosis (the CaVenT study): a randomised controlled trial

Sonografisch assistierte venöse Thrombektomie im ersten Trimenon – ein Fallbericht

Es wird der Fall einer Patientin in der 12. Schwangerschaftswoche (SSW) mit einer deszendierenden 4-Etagen-Thrombose, welche unter konservativen stationären Maßnahmen einen Progress des Befundes erlitten hat, vorgestellt und diskutiert. Die Patientin und ihr Ehemann hatten sich trotz erhöhten Risikos für den Fötus für eine operative Rekanalisation entschieden. Die venöse Thrombektomie wurde sonografisch assistiert, ohne Anlage einer AV-Fistel, durchgeführt. Die bei Schwangeren eingeschränkten diagnostischen Möglichkeiten und Einflussfaktoren für eine Risikoevaluation für Mutter und Kind werden dargestellt.

Efficacy of Shear Wave Elastography in the Differentiation of Acute and Subacute Deep Venous Thrombosis

ABSTRACT

It is important to know the age of clot formation to determine an appropriate treatment for deep vein thrombosis (DVT). The present study aims to differentiate between acute and subacute DVT using the shear wave elastography (SWE) technique. Patients with complaints no longer than 4 weeks and who were found to have early-stage (acute-subacute) thrombus on ultrasound (US) between January 2020 and May 2020 were included in the study. All of the patients underwent SWE using a Philips Healthcare EPIQ 5 Ultrasound System Inc. device with a high-resolution linear US probe (eL18-4, 22-2 MHz). Included in the study were 50 patients, including 23 with acute DVT and 27 with subacute DVT. Of the patients, 22 were women and 28 were men, and the mean age was 46.32 ± 11.33 years (range: 24-74 years). The mean SWE value was 2.63± 0.16 (2.39-2.96) in patients with acute DVT and 3.34± 0.31 (2.65-3.88) in patients with subacute DVT. The findings were statistically significant in the comparison of the 2 groups using an independent samples t test (P < 0.001). In the receiver operating characteristic analysis, the area under the curve was found to be 97.6%. When the cutoff value was taken as 2.85 according to the area under the curve, sensitivity was found to be 96.3%, and specificity was 91.3%. Thrombus stage plays a critical role in treatment decisions in DVT in the lower extremities. The present study reveals that the shear wave US elastography technique can be used to discriminate between acute and subacute DVT.

CAVA (Ultrasound-Accelerated Catheter-Directed Thrombolysis on Preventing Post-Thrombotic Syndrome) Trial: Long-Term Follow-Up Results

Background

The CAVA (Ultrasound‐Accelerated Catheter‐Directed Thrombolysis Versus Anticoagulation for the Prevention of Post‐Thrombotic Syndrome) trial did not show a reduction of post‐thrombotic syndrome (PTS) after additional ultrasound‐accelerated catheter‐directed thrombolysis in patients with acute iliofemoral deep vein thrombosis at 1‐year follow‐up. This prespecified analysis of the CAVA trial aimed to determine the impact of additional thrombolysis on outcomes of PTS at long‐term follow‐up.

Methods and Results

Patients aged 18 to 85 years with a first‐time acute iliofemoral deep vein thrombosis were included and randomly assigned (1:1) to either standard treatment plus ultrasound‐accelerated catheter‐directed thrombolysis or standard treatment alone. The primary outcome was the proportion of PTS (Villalta score ≥5 on 2 occasions ≥3 months apart or venous ulceration) at the final follow‐up visit. Additionally, PTS according to the International Society on Thrombosis and Haemostasis (ISTH) consensus definition was assessed to allow external comparability. Major bleedings were the main safety outcome. At a median follow‐up of 39.0 months (interquartile range, 23.3–63.8), 120 patients (79.8%) participated in the final follow‐up visit: 62 from the intervention group and 58 from the standard treatment group. PTS developed in 19 (30.6%) versus 26 (44.8%) patients, respectively (odds ratio [OR], 0.54; 95% CI, 0.26 to 1.15 [P=0.11]), with an absolute difference between groups of −14.2% (95% CI, −32.0% to 4.8%). Using the ISTH consensus definition, a significant reduction in PTS was observed (29 [46.8%] versus 40 [69.0%]) (OR, 0.40; 95% CI, 0.19–0.84 [P=0.01]) with an absolute difference between groups of −22.2% (95% CI, −39.8% to −2.8%). No new major bleedings occurred following the 12‐month follow‐up.

Conclusions

The impact of additional ultrasound‐accelerated catheter‐directed thrombolysis on the prevention of PTS was found to increase with time. Although this study was limited by its sample size, the overall findings indicate a reduction of mild PTS without impact on quality of life.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT00970619.

Thrombolytics for venous thromboembolic events: a systematic review with meta-analysis

Thrombolytic therapy might reduce venous thromboembolism-related mortality and morbidity, but it could also increase the risk of major bleeding. We systematically reviewed the literature to evaluate the effectiveness and safety of thrombolytics in patients with pulmonary embolism (PE) and/or deep venous thrombosis (DVT). We searched Medline, Embase, and Cochrane databases for relevant randomized controlled trials up to February 2019. Multiple investigators independently screened and collected data. We included 45 studies (4740 participants). Pooled estimates of PE studies indicate probable reduction in mortality with thrombolysis (risk ratio [RR], 0.61; 95% confidence interval [CI], 0.40-0.94) (moderate certainty) and possible reduction in nonfatal PE recurrence (RR, 0.56; 95% CI, 0.35-0.89) (low certainty). Pooled estimates of DVT studies indicate the possible absence of effects on mortality (RR, 0.77; 95% CI, 0.26-2.28) (low certainty) and recurrent DVT (RR, 0.99; 95% CI, 0.56-1.76) (low certainty), but possible reduction in postthrombotic syndrome (PTS) with thrombolytics (RR, 0.70; 95% CI, 0.59-0.83) (low certainty). Pooled estimates of the complete body of evidence indicate increases in major bleeding (RR, 1.89; 95% CI, 1.46-2.46) (high certainty) and a probable increase in intracranial bleeding (RR, 3.17; 95% CI 1.19-8.41) (moderate certainty) with thrombolytics. Our findings indicate that thrombolytics probably reduce mortality in patients with submassive- or intermediate-risk PE and may reduce PTS in patients with proximal DVT at the expense of a significant increase in major bleeding. Because the balance between benefits and harms is profoundly influenced by the baseline risks of critical outcomes, stakeholders involved in decision making would need to weigh these effects to define which clinical scenarios merit the use of thrombolytics.

Interventionelle Therapie der akuten iliofemoralen Thrombose

Der Goldstandard in der Behandlung der Phlebothrombose ist die konservative Therapie mittels Antikoagulation und Kompression. Bei akuten proximalen iliofemoralen Thrombosen mit Beteiligung der Beckenvene muss jedoch hierbei mit einer Inzidenz für das Entstehen eines postthrombotischen Syndroms im Langzeitverlauf von bis zu 70 % gerechnet werden. Zur Prävention eines solchen Folgeschadens rückt neben der selten durchgeführten operativen venösen Thrombektomie in den letzten Jahren zunehmend die interventionelle rekanalisierende Therapie in den Fokus der Behandlungsstrategie. In dieser Übersicht werden die verschiedenen Techniken und aktuellen Entwicklungen dieser Therapie dargestellt und einer kritischen Wertung vor dem Hintergrund der bestehenden Evidenz unterzogen.

A case report of successful intravascular shockwave lithotripsy and ad hoc directional venous atherectomy of extensive chronic femoral deep venous thrombosis

Background

Conventional treatment for chronic deep venous thrombosis (DVT) is anticoagulation. However, limited interventional endovascular options exist for patients with non-healing venous ulcers secondary to chronic DVT.

Case summary

We present a case of 67-year-old man with severely symptomatic post-thrombotic syndrome (PTS) with persistent high-grade femoral DVT despite prior compressive therapy and chronic oral anticoagulation. It has been successfully treated with intravascular shockwave lithotripsy and ad hoc directional venous atherectomy facilitating subsequent mechanical thrombectomy and venoplasty. The procedure was without complication and resulted in significant clinical improvement.

Discussion

We believe our novel endovascular interventional approach represents a unique modality of intervention for patients with chronic DVT and PTS resistant to conventional venoplasty.

Pediatric May-Thurner Syndrome-Systematic review and individual patient data meta-analysis

BACKGROUND

The outcomes of deep vein thrombosis (DVT) in children with May-Thurner Syndrome (MTS) remain unclear.

OBJECTIVES

This systematic review and patient-level meta-analysis aims to describe the outcomes of children with MTS presenting with DVT.

METHODS

A systematic review of the published literature was performed. Data related to patients <18 years diagnosed with MTS and DVT was extracted. Risk of bias was assessed using the Murad criteria. Outcomes included vessel patency post-treatment, DVT recurrence, and post-thrombotic syndrome (PTS). Predictive and explanatory models were developed for these outcomes.

RESULTS

In total, 109 cases were identified (age range 4-17 years; 77 females) in 28 studies; 75% of patients had ≥1 additional risk factor for DVT. PTS was seen in 61% of patients, DVT recurrence in 38%, and complete vessel patency post-treatment in 65%. The models developed to predict and explain PTS performed poorly overall. Recurrent thrombosis (adjusted for age and patency) predicted PTS (odds ratio [OR] 3.36, 95% confidence interval [CI] 1.28-8.82). DVT management strategies (adjusted for age and DVT characteristics) predicted vessel patency (OR 2.10, 95% CI 1.43-3.08). Lack of complete vessel patency (adjusted for age and thrombophilia) predicted recurrent DVT (OR 2.70, 95% CI 1.09-6.67). Sensitivity analyses showed the same direction of effects for all outcomes.

CONCLUSIONS

PTS and DVT recurrence occur frequently in pediatric MTS. PTS prediction is complex and it was not possible to identify early predictors to guide clinical practice. Use of imaging-guided therapy and thrombus burden predicted venous patency, and lack of patency predicted DVT recurrence.

Antithrombotics and new interventions for venous thromboembolism: Exploring possibilities beyond factor IIa and factor Xa inhibition

Direct oral anti-activated factor X and antithrombin agents have largely replaced vitamin K antagonists as the standard of care in treatment of venous thromboembolism. However, gaps in efficacy and safety persist, notably in end-stage renal disease, implantable heart valves or assist devices, extracorporeal support of the circulation, and antiphospholipid syndrome. Inhibition of coagulation factor XI (FXI) emerges as a promising new therapeutic target. Antisense oligonucleotides offer potential advantages as a prophylactic or therapeutic modality, with one dose-finding trial in orthopedic surgery already published. In addition, monoclonal antibodies blocking activation and/or activity of activated factor XI are investigated, as are small-molecule inhibitors with rapid offset of action. Further potential targets include upstream components of the contact pathway such as factor XII, polyphosphates, or kallikrein. Finally, catheter-directed, pharmacomechanical antithrombotic strategies have been developed for high- and intermediate-risk pulmonary embolism, and large randomized trials aiming to validate their efficacy, safety, and prognostic impact are about to start.

Catheter-directed thrombolysis and mechanical intervention in deep venous thrombosis: what is the status after the ATTRACT trial?

Deep venous thrombosis (DVT) is a major cause of acute and chronic morbidity, mortality, and increased healthcare costs. Endovascular methods for thrombus removal and reestablishing venous patency are increasing in both scope and usage. The most commonly used method for endovascular thrombectomy is catheter-directed thrombolysis (CDT). Several studies have shown promise for CDT in alleviating acute symptomatology in acute lower extremity DVT as well as mitigating potential long-term consequences of DVT, such as post-thrombotic syndrome (PTS). The Acute Venous Thrombosis: Thrombus Removal with Adjunctive Catheter-Directed Thrombolysis (ATTRACT) trial is the largest and most comprehensive randomized-controlled trial to date evaluating CDT compared to anticoagulation alone for the treatment of acute symptomatic proximal lower extremity DVT. This review discusses the current status of CDT and adjunctive endovascular interventions for DVT, particularly in the context of the ATTRACT trial.

Comparison of ultrasound-accelerated versus conventional catheter-directed thrombolysis for deep vein thrombosis: A systematic review and meta-analysis

BACKGROUND

Recent in vitro and clinical studies have shown that ultrasound-accelerated catheter-directed thrombolysis (USACDT) can accelerate thrombolysis. Therefore, in this meta-analysis, we aimed to compare the efficacy and safety of USACDT with conventional catheter-directed thrombolysis in patients with deep vein thrombosis.

METHODS

A systematic search of the following electronic databases was performed from their dates of inception to 20 June 2020: MEDLINE, Scopus, Google Scholar, CINAHL, Cochrane Library, and EMBASE. All randomized controlled trials that directly compared the complications and efficacy of USACDT and conventional catheter-directed thrombolysis in patients with deep vein thrombosis were identified. The statistical analysis was performed using comprehensive meta-analysis software.

RESULTS

Finally, 18 studies with a total of 597 participants were included in our meta-analysis according to the eligibility criteria. Pooled proportion of USACDT success in patients with deep vein thrombosis was 87.8% (18 studies; 95% CI: 83.1-91.3). Success rate was significantly higher in USACDT treatment than in conventional catheter-directed thrombolysis treatment (seven studies; OR: 2.96; 95% CI: 1.69-5.16; P < 0.01)). Although the mean infusion time was higher in catheter-directed thrombolysis treatment compared to USACDT treatment, this difference was not statistically significant (three studies; MD: -1.46; 95% CI: -3.25-0.32; P = 0.10). Moreover, pooled rate of complications was lower in USACDT than catheter-directed thrombolysis which was not statistically significant (seven studies; OR: 0.49; 95% CI: 0.13-1.76; P = 0.27).

CONCLUSION

This meta-analysis revealed that USACDT significantly increased the success rate of thrombolysis compared to conventional catheter-directed thrombolysis. Furthermore, USACDT was associated with lower rate of complication and infusion time. Taken together, these findings confirm the superiority of this novel intervention over conventional catheter-directed thrombolysis in treatment of patients with deep vein thrombosis.

Comparison of Pharmacomechanical Catheter-Directed Thrombolysis versus Catheter-Directed Thrombolysis for the Treatment of Acute Iliofemoral Deep Vein Thrombosis: Measures of Long-Term Clinical Outcome and Quality of Life

BACKGROUND

We studied the occurrence of post-thrombotic syndrome (PTS) in patients with either Pharmacomechanical Catheter-Directed Thrombolysis (hereafter "pharmacomechanical thrombolysis"; PT) or Catheter-Directed Thrombolysis (CDT) for the treatment of acute iliofemoral deep vein thrombosis (DVT).

METHODS

This retrospective study of data archived between September 2013 and September 2015 was surveyed. Two separate patient populations were identified and analyzed: patients were separated into PT group or CDT group. For up to 5 years post-treatment, the incidence, severity of PTS, and chronic venous insufficiency questionnaire (CIVIQ) score difference were compared.

RESULTS

The study identified 131 patients divided into PT group (65) and CDT group (66). Within the 5-year follow-up period, there was no significant difference in the incidence of PTS (45.0% PT vs. 57.6% CDT; odds ratio (OR) = 0.602; 95% confidence interval (CI), 0.291-1.242; P = 0.201), but there was reduced severe PTS in the PT group (Villalta scale ≥15 or ulcer:11.7% PT vs. 27.1% CDT; OR 0.355; 95%CI 0.134-0.941, P = 0.039; and Venous Clinical Severity Score (VCSS) ≥8: 13.3%PT vs. 28.8% CDT; OR 0.380; 95% CI 0.149-0.967, P = 0.045). There was also a larger improvement of venous disease-specific quality of life (QOL) in the PT group at 5 years [(62.89 ± 14.19) vs (56.39 ±15.62), P = 0.036] compared to the CDT group.

CONCLUSION

In patients with acute iliofemoral DVT treated with PT, PT significantly reduced PTS severity scores, and resulted in greater improvement in venous disease-specific QOL. However, the incidence of was not significantly different from that measured in the CDT.

A risk score for iliofemoral patients with deep vein thrombosis

OBJECTIVE

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

E-selectin inhibitor is superior to low-molecular-weight heparin for the treatment of experimental venous thrombosis

BACKGROUND

This study evaluated E-selectin inhibition with GMI-1271 (Uproleselan [GMI]) alone and in combination with the standard of care low-molecular-weight heparin (LMWH) to improve vein recanalization, decrease vein wall inflammation and protect against adverse bleeding in a primate model. We sought to examine this novel treatment of venous thrombosis.

METHODS

Using a well-documented primate animal model, iliac vein thrombosis was induced by balloon occlusion of the iliac vein for 6 hours. Starting on day 2 after thrombosis, animals began treatment in two phases. In phase one, nontreated controls received no treatment (n = 5) vs animals treated with the E-selectin inhibitor GMI, 25 mg/kg, subcutaneous (SC), once daily (n = 4) for 21 days (previously published data). In phase two, animals were treated with GMI plus a combination of LMWH 1.5 mg/kg or 40 mg (GMI + LMWHc) SC once daily (n = 8) for 19 days; and animals treated with LMWH 1.5 mg/kg or 40 mg (LMWHc) SC once daily (n = 6) for 19 days. Animals were evaluated by magnetic resonance venography for vein recanalization and inflammation by gadolinium extravasation, duplex ultrasound, coagulation tests (thromboelastography, bleeding time, prothrombin time, activated partial thromboplastin time, fibrinogen) and complete blood count at baseline, days 2, 7, 14, and 21 at euthanasia. Statistical analysis included using unpaired t test with Welch's correction for direct comparisons and one-way analysis of variance for comparison between the groups.

RESULTS

Percent vein recanalization by magnetic resonance venography was highest in the GMI alone group followed by GMI + LMWHc, both significantly different from control. On ultrasound examination, animals treated with GMI alone had no decrease in open vein lumen by day 21, whereas decreases were observed in groups GMI + LMWHc (-26%), LMWHc (-27%), and controls (-80%). Vein wall inflammation decreased significantly in all treated groups. Intimal fibrosis and intimal thickness was best preserved in the GMI alone group. An analysis of total vein wall collagen revealed a trend in all treatment groups of decreasing vein wall collagen. No clinically significant bleeding events were noted in any group. The LMWH groups trended to have prolonged coagulation test values, whereas E-selectin inhibition with GMI did not cause clinically significant changes in coagulation measures.

CONCLUSIONS

Treatment with E-selectin inhibition results in improved vein recanalization, a decrease in vein wall inflammation and vein wall intimal thickness and fibrosis, with no changes in markers of coagulation. E-selectin inhibition with GMI alone is superior to E-selectin inhibition combined with LMWH, LMWH alone, and no treatment in this deep vein thrombosis model of iliac vein thrombosis.

A predictive model for postthrombotic syndrome in proximal deep vein thrombosis patients

Background

Postthrombotic syndrome (PTS) is the most common long-term complication of deep vein thrombosis (DVT). Predictive models for PTS after hospitalized DVT patients, especially those with proximal DVT for whom preventative intervention decisions need to be made, are rare. We aimed to develop and externally validate a clinical predictive model for PTS in patients with proximal DVT.

Methods

This study was a retrospective, single-center, case-control study. The data used in our model were retrospectively collected from a prospective registry database in which 210 (derivation) and 90 (validation) consecutive patients were first diagnosed with proximal DVT. We developed a nomogram using the multivariate logistic regression model. External validation of our predictive model and previous predictive models in our validation set was assessed by discrimination, calibration, and clinical utility.

Results

Of the 30 candidate predictors, 5 were significantly associated with PTS in our final multivariable model, including the number of signs and symptoms (OR 1.33, 95% CI: 1.17 to 1.53, P<0.001), male sex (OR 1.79, 95% CI: 1.07 to 3.06, P=0.028), varicose vein history (OR 3.02, 95% CI: 1.04 to 7.60, P<0.001), BMI (OR 1.06, 95% CI: 1.00 to 1.12, P=0.052), and chronic DVT (OR 2.66, 95% CI: 1.49 to 4.79, P<0.001). The area under the curve was 0.724 in our predictive model, indicating suitable external performance.

Conclusions

A simple-to-use nomogram effectively predicts the risk of PTS in patients with proximal DVT. This predictive model may be considered for use in clinical care.

Does ATTRACT change our DVT management practice?

In 2017, the long awaited results of the ATTRACT trial were published in the New England Journal of Medicine leaving the scientific community with disappointment as the study did not show the expected results. Producing not the expected outcome is not uncommon in science - furthermore, it is important to disapprove common beliefs. But has the ATTRACT trial really the power to change our practice? Are the results correct in terms of evidence based on the methods used?

Time-Restricted Salutary Effects of Blood Flow Restoration on Venous Thrombosis and Vein Wall Injury in Mouse and Human Subjects

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Imaging Predicts Vein Wall Scarring and Statin Benefit in Murine Venous Thrombosis

BACKGROUND

The postthrombotic syndrome is a common, often morbid sequela of venous thrombosis (VT) that arises from thrombus persistence and inflammatory scarring of juxtaposed vein walls and valves. Noninvasive ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) imaging can measure neutrophil inflammation in VT. Here, we hypothesized (1) early fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) VT inflammation can predict subsequent vein wall scarring (VWS) and (2) statin therapy can reduce FDG-PET VT inflammation and subsequent VWS.

METHODS

C57BL/6J mice (n=75) underwent induction of stasis-induced VT of the inferior vena cava or jugular vein. Inferior vena cava VT mice (n=44) were randomized to daily oral rosuvastatin 5 mg/kg or saline starting at day -1. Subgroups of mice then underwent FDG-PET/CT 2 days after VT induction. On day 14, a subset of mice was euthanized, and VWS was assessed via histology. In vitro studies were further performed on bone marrow-derived neutrophils.

RESULTS

Statin therapy reduced early day 2 FDG-PET VT inflammation, thrombus neutrophil influx, and plasma IL (interleukin)-6 levels. At day 14, statin therapy reduced VWS but did not affect day 2 thrombus mass, cholesterol, or white blood counts, nor reduce day 2 glucose transporter 1 or myeloperoxidase expression in thrombus or in isolated neutrophils. In survival studies, the day 2 FDG-PET VT inflammation signal as measured by mean and maximum standardized uptake values predicted the extent of day 14 VWS (area under the receiver operating characteristic curve =0.82) with a strong correlation coefficient (r) of r=0.73 and r=0.74, respectively. Mediation analyses revealed that 40% of the statin-induced VWS reduction was mediated by reductions in VT inflammation as quantified by FDG-PET.

CONCLUSIONS

Early noninvasive FDG-PET/CT imaging of VT inflammation predicts the magnitude of subsequent VWS and may provide a new translatable approach to identify individuals at risk for postthrombotic syndrome and to assess anti-inflammatory postthrombotic syndrome therapies, such as statins.

A Case Series of Catheter-Directed Thrombolysis With Mechanical Thrombectomy for Treating Severe Deep Vein Thrombosis

Two cases of extensive symptomatic deep vein thrombosis without phlegmasia cerulea dolens were successfully treated with an endovascular technique that combines catheter-directed thrombolysis and mechanical thrombectomy.

Post-thrombotic syndrome

Post-thrombotic syndrome (PTS) is a chronic venous insufficiency manifestation following an episode of deep-vein thrombosis (DVT). It is an important and frequent long-term adverse event of proximal DVT affecting 20-50% of patients. This position paper integrates data guiding clinicians in deciding PTS diagnosis, treatment and follow-up.

Single-Session Thrombolysis-Free Treatment of Deep Vein Thrombosis With a Novel Mechanical Thrombectomy Device

Catheter-directed thrombolysis of iliofemoral deep vein thrombosis (DVT) carries an increased risk of major bleeding and may fail to rapidly remove thrombus or prevent post-thrombotic syndrome. We describe an alternative, thrombolysis-free, advanced DVT treatment strategy with rapid single-session percutaneous mechanical thrombectomy using the ClotTriever system. (Level of Difficulty: Intermediate.).

Postinterventional antithrombotic management after venous stenting of the iliofemoral tract in acute and chronic thrombosis: A systematic review

Venous stenting has become a common treatment option for central deep venous outflow obstructions and postthrombotic syndrome. Following successful recanalization and stenting, stent patency is endangered by in-stent thrombosis and recurrent venous thromboembolism. Antithrombotic therapy might reduce patency loss. This systematic review summarizes the literature on antithrombotic therapy following (post)thrombotic venous stenting. A systematic PubMed, MEDLINE, EMBASE, and Cochrane search was performed for studies addressing antithrombotic therapy prescribed following venous stenting of the iliofemoral tract indicated by acute or chronic thrombotic pathology. A total of 277 articles was identified of which 64 (56 original studies) were selected. Overall, a mean primary patency rate of 82.3% was seen 1 year after the intervention, which decreased to 73.3% after 2 years. In the majority (43 of 56 studies, 77%), treatment was based on use of vitamin K antagonists, either with (18%) or without (59%) use of antiplatelet drugs. Only two studies (4%) directly assessed the effect of antithrombotic therapy on treatment outcomes. The impact of postinterventional antithrombotic therapy on stent patency remains unknown because of limited and insufficient data available in current literature. Further clinical research should more clearly address the role of antithrombotic therapy for preservation of long-term patency following venous stenting.

Advances in the Management of Acute Venous Thromboembolism and New Therapeutic Agents

Important advances in the understanding and management of venous thromboembolism (VTE) have enhanced our ability to diagnose, prevent, and treat VTE. In this narrative review, we discuss how recent advances in the understanding and management of VTE are changing practice, highlight ongoing unmet needs in VTE management, and outline how novel therapeutic targets with little or no influence on hemostasis may help address these unmet needs.

Diagnostic and Technical Challenges in the Care of a Complex Patient With Post-Thrombotic Syndrome

Iliofemoral deep vein thrombosis can lead to post-thrombotic syndrome, a costly and morbid condition. Endovascular treatment is increasingly used for symptomatic relief, but clinical success depends on accurate patient evaluation and selection. This case describes the diagnostic and technical challenges in the care of a complex patient with post-thrombotic syndrome following stroke and extensive deep vein thrombosis. It highlights the multi-disciplinary work-up for a patient with post-thrombotic syndrome presenting with confounding symptoms, as well as the importance of considering alternative access for successful lower extremity venous recanalization.

Defining the human and health care costs of chronic venous insufficiency

Chronic venous insufficiency (CVI) affects more than 25 million adults in the United States alone, and more 6 million with advanced stages of venous disease. The high incidence of CVI and the increasing costs of care, place a heavy financial burden on the US health care system. Recent studies estimate the total cost of care at more than $3 billion per year. These staggering numbers highlight the importance of timely diagnosis, treatment, and prevention of CVI. In this article, we review the epidemiology and prevalence of CVI, and its financial impact on national health care budget. Racial disparities in CVI and the impact of socioeconomic status on access to care are also discussed. Finally, we discuss CVI-related screening programs and the importance of preventative measures in venous disease.

Endovascular Treatment for Lower Extremity Deep Vein Thrombosis: An Overview

Lower extremity deep vein thrombosis (DVT) is a serious medical condition that can result in local pain and gait disturbance. DVT progression can also lead to death or major disability as a result of pulmonary embolism, postthrombotic syndrome, or limb amputation. However, early thrombus removal can rapidly relieve symptoms and prevent disease progression. Various endovascular procedures have been developed in the recent years to treat DVT, and endovascular treatment has been established as one of the major therapeutic methods to treat lower extremity DVT. However, the treatment of lower extremity DVT varies according to the disease duration, location of affected vessels, and the presence of symptoms. This article reviews and discusses effective endovascular treatment methods for lower extremity DVT.

Histopathologic analysis of extracted thrombi from deep venous thrombosis and pulmonary embolism: Mechanisms and timing

BACKGROUND

Mechanical thrombectomy is increasingly being used as an alternative to pharmacologic therapies for the treatment of patients with acute deep venous thrombosis (DVT) and pulmonary embolism (PE) and allows direct histopathologic comparison of thrombi extracted from living patients. We performed histopathologic analysis to thrombi extracted from cases of DVT and PE to gain insights into their relative cellular compositions.

METHODS

Thrombus retrieved using a catheter-based thrombectomy system (ClotTriever for lower extremity DVT and FlowTriever for PE) from the 17 patients (7 DVT cases and 10 PE cases) were histologically evaluated. Histological features were used to estimate their age and pathological characteristics.

RESULTS

The thrombus in all cases were composed of fibrin, platelets, red blood cells, and acute inflammatory cells. The weights of thrombus obtained from DVT versus PE cases were heavier (DVT 7.2 g (g) (5.6-10.2) vs. PE 4.8 g (3.6-6.8), p = .01). Overall thrombus healing (i.e., thrombus composed of smooth muscle cells, endothelial cells, and proteoglycans) was different between DVT and PE cases. 6/7 (86%) with features of late stage healing were from DVT cases while only three of ten (30%) were from PE cases while PE contained more acute thrombi with 7/10 (70%) stage 2 as compared 1/7 (14%) for DVT (p = .0498).

CONCLUSION

This study is the first to directly compare the histology of extracted thrombus in DVT versus PE cases from patients with clinical events. Overall PE cases demonstrated significantly earlier stage thrombus with a larger component of red blood cells.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Feasibility of anticoagulation using low molecular-weight heparin during catheter-directed thrombolysis for lower extremity deep venous thrombosis

Background

The optimal anticoagulant scheme during catheter-directed thrombolysis (CDT) for deep venous thrombosis (DVT) remains unknown. This study was performed to evaluate the feasibility of anticoagulation therapy using low molecular-weight heparin (LMWH) during CDT for DVT.

Methods

The clinical data of DVT patients who underwent CDT during the past six years was retrospectively collected and reviewed. Patients were divided into therapeutic-dose anticoagulation (TPDA) and sub therapeutic-dose anticoagulation (sub-TPDA) groups according to LMWH dosage.

Results

A total of 61 patients involving 61 limbs were comprised. Acute and subacute DVT were identified in 39 (63.9%) and 22 (36.1%) patients, respectively. Thrombosis involving the iliac vein was identified in 34 (55.7%) patients. Inferior vena cava filter placement was performed in 38 (62.3%) patients. Intraoperatively, adjunctive balloons, stents, and thrombectomy were provided for nine (14.8%), four (6.6%), and one (1.6%) patients, respectively. Twenty (32.8%) patients accepted TPDA therapy, while 41 (67.2%) patients were administrated with sub-TPDA therapy. Median urokinase infusion rate was 2.5 (0.83 to 5) × 10⁴ U/h. Median infusion duration time was 4 (2 to 14) days, and median urokinase dose infused was 2.4 (0.6 to 10.80) × 10⁶ U. During CDT, five (8.2%) cases of minor bleeding were observed, and blood transfusion was not required. No major bleeding, symptomatic pulmonary embolisms, or death occurred. Complete (> 90%) and partial thrombolysis (50 ~ 90%) were achieved in 56 (91.8%) patients. In comparison with sub-TPDA group, TPDA group exhibited no significant differences in baseline characteristics, clinical improvement, thrombolysis results, and complications.

Conclusions

Anticoagulation therapy using low molecular-weight heparin during CDT with low infusion rate for DVT is likely to be feasible and safe. Sub-therapeutic-dose anticoagulation and therapeutic-dose could be used for CDT with similar clinical outcome and bleeding complications.

Surgical and non-surgical approaches in the management of lower limb post-thrombotic syndrome

Introduction: Post-thrombotic syndrome (PTS) is a common lifelong condition affecting up to 50% of those suffering from deep vein thrombosis (DVT). PTS compromises function and quality of life with subsequent venous ulceration in up to 29% of those affected.Areas covered: A literature review of surgical and non-surgical approaches in the prevention and treatment of PTS was undertaken. Notable areas include the use of percutaneous endovenous interventions and the use of graduated compression stockings (GCS) after acute proximal DVT.Expert opinion: In patients with acute iliofemoral DVT, we think it is important to have a frank conversation with the patient about catheter-directed thrombolysis, aiming to reduce the severity of PTS experienced. We advocate ultrasound-accelerated thrombolysis with adjunctive procedures, such as deep venous stenting for proximal iliofemoral DVT. For patients with isolated femoral DVT, we believe that anticoagulation and GCS should be recommended. In patients with established PTS, we recommend GCS for symptomatic relief. We recommend that patients engage in regular exercise where possible with the prospect of gaining symptomatic relief. For those with severe PTS that has a significant effect on quality of life, we discuss the patient's case at a multi-disciplinary team meeting to plan for endovenous intervention.

A Retrospective Comparison of Catheter-Directed Thrombolysis versus Pharmacomechanical Thrombolysis for Treatment of Acute Lower Extremity Deep Venous Thrombosis

BACKGROUND

Pharmacomechanical thrombolysis (PMT) and catheter-directed thrombolysis (CDT) are frequently employed for treating deep venous thrombosis (DVT). However, there have been relatively few studies comparing PMT outcomes to those associated with CDT. The present study was thus designed to compare short- and mid-term PMT and CDT patient outcomes following the treatment of DVT of the lower extremities.

METHODS

This study was a retrospective analysis of 98 patients treated at the 3rd Affiliated Hospital of Shenzhen University (Shenzhen, China) and Beijing Chao Yang Hospital (Beijing, China). All patients had undergone treatment for symptomatic DVT of the lower legs via either CDT or PMT. Clinical records and outcome data between the patients in these 2 treatment groups were compared.

RESULTS

Of the 98 patients analyzed in this retrospective study, 50 had been treated via CDT while 48 had undergone PMT. These PMT and CDT operations were associated with mean treatment durations of 0.97 ± 0.20 hr and 32.48 ± 7.46 hr, respectively (P < 0.0001). Complete lysis was achieved in 78 patients (42 and 36 in the PMT and CDT groups, respectively P = 0.057), while effective lysis was achieved in 96 patients (48 and 48 in the PMT and CDT groups, respectively P = 0.162), with lysis being ineffective in the 2 remaining patients. PMT was associated with a significantly decreased length of hospital stay, usage of UK dose, and treatment duration relative to CDT(P < 0.0001). No major complications or MACE incidence were noted in either group, although 18 patients in the PMT group suffered from bradyarrhythmia (P = 0.007). Clinical efficacy was achieved in 96 patients (48 in each treatment group) at time of discharge (P = 0.162). A Kaplan-Meier analysis revealed that 2-year primary patency rates did not differ significantly between these 2 groups (P = 0.442).

CONCLUSION

PMT is an effective treatment modality in patients with symptomatic DVT. Relative to CDT it is associated with high treatment success rates, reduced treatment duration, and reduced hospitalization duration, although it is also associated with higher rates of systemic complications.

Thrombolytic strategies versus standard anticoagulation for acute deep vein thrombosis of the lower limb

BACKGROUND

Standard treatment for deep vein thrombosis (DVT) aims to reduce immediate complications. Use of thrombolytic clot removal strategies (i.e. thrombolysis (clot dissolving drugs), with or without additional endovascular techniques), could reduce the long-term complications of post-thrombotic syndrome (PTS) including pain, swelling, skin discolouration, or venous ulceration in the affected leg. This is the fourth update of a Cochrane Review first published in 2004.

OBJECTIVES

To assess the effects of thrombolytic clot removal strategies and anticoagulation compared to anticoagulation alone for the management of people with acute deep vein thrombosis (DVT) of the lower limb.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL and AMED and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registries to 21 April 2020. We also checked the references of relevant articles to identify additional studies.

SELECTION CRITERIA

We considered randomised controlled trials (RCTs) examining thrombolysis (with or without adjunctive clot removal strategies) and anticoagulation versus anticoagulation alone for acute DVT.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as recommended by Cochrane. We assessed the risk of bias in included trials with the Cochrane 'Risk of bias' tool. Certainty of the evidence was evaluated using GRADE. For dichotomous outcomes, we calculated the risk ratio (RR) with the corresponding 95% confidence interval (CI). We pooled data using a fixed-effect model, unless we identified heterogeneity, in which case we used a random-effects model. The primary outcomes of interest were clot lysis, bleeding and post thrombotic syndrome.

MAIN RESULTS

Two new studies were added for this update. Therefore, the review now includes a total of 19 RCTs, with 1943 participants. These studies differed with respect to the thrombolytic agent, the doses of the agent and the techniques used to deliver the agent. Systemic, loco-regional and catheter-directed thrombolysis (CDT) strategies were all included. For this update, CDT interventions also included those involving pharmacomechanical thrombolysis. Three of the 19 included studies reported one or more domain at high risk of bias. We combined the results as any (all) thrombolysis interventions compared to standard anticoagulation. Complete clot lysis occurred more frequently in the thrombolysis group at early follow-up (RR 4.75; 95% CI 1.83 to 12.33; 592 participants; eight studies) and at intermediate follow-up (RR 2.42; 95% CI 1.42 to 4.12; 654 participants; seven studies; moderate-certainty evidence). Two studies reported on clot lysis at late follow-up with no clear benefit from thrombolysis seen at this time point (RR 3.25, 95% CI 0.17 to 62.63; two studies). No differences between strategies (e.g. systemic, loco-regional and CDT) were detected by subgroup analysis at any of these time points (tests for subgroup differences: P = 0.41, P = 0.37 and P = 0.06 respectively). Those receiving thrombolysis had increased bleeding complications (6.7% versus 2.2%) (RR 2.45, 95% CI 1.58 to 3.78; 1943 participants, 19 studies; moderate-certainty evidence). No differences between strategies were detected by subgroup analysis (P = 0.25). Up to five years after treatment, slightly fewer cases of PTS occurred in those receiving thrombolysis; 50% compared with 53% in the standard anticoagulation (RR 0.78, 95% CI 0.66 to 0.93; 1393 participants, six studies; moderate-certainty evidence). This was still observed at late follow-up (beyond five years) in two studies (RR 0.56, 95% CI 0.43 to 0.73; 211 participants; moderate-certainty evidence). We used subgroup analysis to investigate if the level of DVT (iliofemoral, femoropopliteal or non-specified) had an effect on the incidence of PTS. No benefit of thrombolysis was seen for either iliofemoral or femoropopliteal DVT (six studies; test for subgroup differences: P = 0.29). Systemic thrombolysis and CDT had similar levels of effectiveness. Studies of CDT included four trials in femoral and iliofemoral DVT, and results from these are consistent with those from trials of systemic thrombolysis in DVT at other levels of occlusion.

AUTHORS' CONCLUSIONS

Complete clot lysis occurred more frequently after thrombolysis (with or without additional clot removal strategies) and PTS incidence was slightly reduced. Bleeding complications also increased with thrombolysis, but this risk has decreased over time with the use of stricter exclusion criteria of studies. Evidence suggests that systemic administration of thrombolytics and CDT have similar effectiveness. Using GRADE, we judged the evidence to be of moderate-certainty, due to many trials having small numbers of participants or events, or both. Future studies are needed to investigate treatment regimes in terms of agent, dose and adjunctive clot removal methods; prioritising patient-important outcomes, including PTS and quality of life, to aid clinical decision making.

Can we predict and prevent the postthrombotic syndrome?

Postthrombotic syndrome (PTS) remains one of the major late complications of deep vein thrombosis (DVT) with a reported prevalence from 10 to 50%. Many factors were found to be related with the development and severity of PTS such as ipsilateral recurrent DVT, advanced age, obesity, ilio-femoral DVT and primary chronic venous disease presence. Some PTS prediction models have been proposed based on risk factor weight. However, it is still difficult to predict which patient with DVT will develop PTS and thus, the clinical application of these models remains limited. Among the identified problems the heterogeneity of the DVT patient population together with the variety of PTS clinical presentations and difficulties concerning PTS severity assessment should be mentioned. Difficulties on the implementation of the specific and objective PTS identification method have also the significant influence on the research focusing on PTS prevention modalities including risk factor modification, compression treatment, anticoagulation and invasive DVT treatment. In this review, the current approach and knowledge on PTS prediction and prevention are presented, including the conservative and invasive DVT treatment possibilities.

Referral patterns for catheter-directed thrombolysis for iliofemoral deep venous thrombosis

OBJECTIVES

Post thrombotic syndrome (PTS) is a serious complication of deep venous thromboses (DVTs). PTS occurs more frequently and severely following iliofemoral DVT compared to distal DVTs. Catheter directed thrombolysis (CDT) of iliofemoral DVTs may reduce PTS incidence and severity.We aimed to determine the rate of iliofemoral DVT within our institution, their subsequent management, and compliance with NICE guidelines.

METHODS

Retrospective review of all DVTs diagnosed over a 3-year period was conducted. Cases of iliofemoral DVT were identified using ICD-10 codes from patient notes, and radiology reports of Duplex scans. Further details were retrieved, such as patient demographics and referrals to vascular services. NICE guidance was applied to determine if patients would have been suitable for CDT. A survey was sent to clinicians within medicine to identify awareness of CDT and local guidelines for iliofemoral DVT management.

RESULTS

225 patients with lower limb DVTs were identified. Of these, 96 were radiographically confirmed as iliofemoral DVTs. The median age was 77. 67.7% of iliofemoral DVTs affected the left leg. Right leg DVTs made up 30.2% and 2.1% were bilateral DVTs. Of the 96 iliofemoral DVTs, 21 were deemed eligible for CDT. Only 3 patients (14.3%) were referred to vascular services, and 3 received thrombolysis.From our survey, 95.5% of respondents suggested anticoagulation alone as management for iliofemoral DVT. Only one respondent recommended referral to vascular services. There was a knowledge deficiency regarding venous anatomy, including superficial versus deep veins.

CONCLUSIONS

CDT and other mechanochemical procedures have been shown to improve outcomes of patients post-iliofemoral DVT, however a lack of awareness regarding CDT as a management option results in under-referral to vascular services. We suggest closer relations between vascular services and their "tributary" DVT clinics, development of guidelines and robust care pathways in the management of iliofemoral DVT.

Prevention, diagnosis, and management of venous thromboembolism in the critically ill surgical and trauma patient

PURPOSE OF REVIEW

Venous thromboembolism (VTE), which encompasses deep vein thrombosis and pulmonary embolism, is common among trauma patients and critically ill surgical patients admitted to the ICU. Critical care surgical patients are at an extremely high risk for VTE and the related morbidity and mortality associated with it. The present review aims to provide an overview of the importance of identifying risk factors, prescribing effective prohylaxis, accurate diagnosis, and timely appropriate treatment for trauma and critically ill surgical patients with VTE in the ICU.

RECENT FINDINGS

VTE is a healthcare burden among critically ill surgical patients that is mostly preventable through adherence to prophylactic protocols that aim to recognize VTE risk factors while simultaneously providing guidance to appropriate timing and administration prophylaxis regimens. Newer pharmacologic therapies for prophylaxis and treatment, diagnostic modalities, and indications for therapy of VTE have continued to evolve.

SUMMARY

Critical care surgical and trauma patients represent a population that are at a heightened risk for VTE and associated complications. Appropriate screening, prevention strategies, accurate diagnosis, and timely administration of appropriate treatment must be utilized to reduce morbidity and mortality.

Predictors of long-term post-thrombotic syndrome following high proximal deep vein thrombosis: a cross-sectional study

Background

Post-thrombotic syndrome (PTS) is a frequent chronic complication of proximal deep vein thrombosis (DVT) of the lower limb, but predictors of PTS are not well established. We aimed to examine predictors of PTS in patients with long-term PTS following proximal DVT.

Methods

During 2006–09, 209 patients with a first time acute upper femoral or iliofemoral DVT were randomized to receive either additional catheter-directed thrombolysis or conventional therapy alone. In 2017, the 170 still-living participants were invited to participate in a cross-sectional follow-up study. In the absence of a gold standard diagnostic test, PTS was defined in line with clinical practice by four mandatory, predefined clinical criteria: 1. An objectively verified DVT; 2. Chronic complaints (> 1 month) in the DVT leg; 3. Complaints appeared after the DVT; and 4. An alternative diagnosis was unlikely. Possible predictors of PTS were identified with multivariate logistic regression.

Results

Eighty-eight patients (52%) were included 8–10 years following the index DVT, and 44 patients (50%) were diagnosed with PTS by the predefined clinical criteria. Younger age and higher baseline Villalta score were found to be independent predictors of PTS, i.e., OR 0.96 (95% CI, 0.93–0.99), and 1.23 (95% CI, 1.02–1.49), respectively. Lack of iliofemoral patency at six months follow-up was significant in the bivariate analysis, but did not prove to be significant after the multivariate adjustments.

Conclusions

In long-term follow up after high proximal DVT, younger age and higher Villalta score at DVT diagnosis were independent predictors of PTS.

Comparing Safety and Efficacy of Rivaroxaban with Warfarin for Patients after Successful Stent Placement for Chronic Iliofemoral Occlusion: A Retrospective Single Institution Study

OBJECTIVE

The aim was to compare the safety and effectiveness of rivaroxaban and warfarin as anticoagulants for treating patients with post-thrombotic syndrome (PTS) with chronic iliofemoral venous occlusion undergoing iliofemoral venous stenting.

METHODS

This single institution retrospective study analysed patients with PTS with chronic iliofemoral venous occlusion who were prescribed rivaroxaban or warfarin for one year after successfully undergoing iliofemoral venous stenting. The primary safety and efficacy endpoints were bleeding complication rate and primary patency rate at one year. Secondary outcomes included Villalta score, symptom recurrence rate, ulcer healing rate, and clinically driven target lesion revascularisation (CD-TLR) rate during follow up.

RESULTS

From January 2016 to December 2017, 154 legs from 154 patients were included in this study (69 in rivaroxaban group and 85 in warfarin group). The groups were well matched for patient demographics, clinical characteristics, and procedural details. There was no significant difference between the rivaroxaban group and warfarin group in bleeding complication rate (10% vs. 16%, p = .23, hazard ratio [HR] 0.58, 95% confidence interval [CI] 0.25 - 1.37) at one year, as well as major bleeding complication rate (0% vs. 2%, p = .20, HR 0.16, 95% CI 0.01 - 2.61) and minor bleeding complication rate (10% vs. 14%, p = .40, HR 0.67, 95% CI 0.27 - 1.66). The primary patency rate was higher in the rivaroxaban group at one year (84% vs. 71%, p = .049, HR 0.50, 95% CI 0.26 - 0.96) and at two years (79% vs. 63%, p = .037, HR 0.52, 95% CI 0.29 - 0.93). At a mean follow up of 24 months (range 1 - 42 months), the rivaroxaban group had a significantly lower post-operative Villalta score (4.87 ± 3.51 vs. 6.88 ± 5.85, p = .010, t = 2.64, 95% CI 0.50 - 3.52), lower rate of symptom recurrence (4% vs. 32%, p < .001), lower CD-TLR rates (3% vs. 13%, p = .039), and higher ulcer healing rate (90% vs. 59%, p = .004) than the warfarin group.

CONCLUSION

For PTS patients with chronic iliofemoral venous occlusion undergoing iliofemoral venous stenting, rivaroxaban probably exhibited similar safety but superior efficacy to warfarin. However, further prospective control studies with large sample size are necessary to confirm the results.

Diagnosis and treatment of iliac vein stenosis

Stenosis of the iliac veins is common in patients with chronic venous insufficiency. The article describes the methods for the diagnosis and treatment of iliac vein stenosis. The causes of iliac vein stenosis include extravasal compression or the consequences of ileofemoral thrombosis. Stenosis of the iliac veins exists in 1/4 of the entire adult population, but clinical manifestations do not occur in all patients. Stenosis of the iliac veins should be considered in case of an unknown edema, more often in the left lower extremity, since venous duplex ultrasound of lower extremities is not sensitive and specific enough when examining the veins above the inguinal ligament. The most accurate diagnostic method is intravascular ultrasound (IVUS) but the appeared computed tomography angiography (CTA) and magnetic resonance angiography (MRA) with high-quality images have become a good replacement for IVUS. The main method of treatment of iliac vein stenosis, besides stenting, isindispensable drug therapy consisting of antithrombotic and phlebotonic drugs.

Post-thrombotic Syndrome: Preventative and Risk Reduction Strategies Following Deep Vein Thrombosis

Venous disease is common in the general population, with chronic venous disorders affecting 50–85% of the western population and consuming 2–3% of healthcare funding. It, therefore, represents a significant socioeconomic, physical and psychological burden. Acute deep vein thrombosis, although a well-recognised cause of death through pulmonary embolism, can more commonly lead to post-thrombotic syndrome (PTS). This article summarises the pathophysiology and risk factor profile of PTS, and highlights various strategies that may reduce the risk of PTS, and the endovenous management of iliofemoral deep vein thrombosis. The authors summarise the advances in PTS risk reduction strategies and present the latest evidence for discussion.

Medicine and Phlebolymphology: Time to Change?

Biomedical science is undergoing a reappraisal of its scientific advancement process and of the related healthcare management. Progress in medicine should combine improvements of knowledge, efficacy, and safety of diagnostic/therapeutic procedures, with adequate cost-effectiveness profiles. This narrative review is aimed at assessing in medicine, more specifically in phlebology and lymphology: (a) scientific literature possible biases, (b) the level of evidence, comprehensiveness, and cost-effectiveness of the main therapeutic options, and (c) the possible contribution of integrative and translational medicine. Current medical research may have cognitive biases, or industry-tied influences, which impacts clinical practice. Some reductionism, with an increasing use of drugs and technology, often neglecting the understanding and care of the root causative pathways of the diseases, is affecting biomedical science as well. Aging brings a relevant burden of chronic degenerative diseases and disabilities, with relevant socio-economic repercussions; thus, a major attention to cost-effectiveness and appropriateness of healthcare is warranted. In this scenario, costly and innovative but relatively validated therapies may tend to be adopted in venous and lymphatic diseases, such as varicose veins, leg venous ulcer, post-thrombotic syndrome, pelvic congestion syndrome, and lymphedema. Conversely, a more comprehensive approach to the basic pathophysiology of chronic venous and lymphatic insufficiency and the inclusion of pharmacoeconomics analyses would benefit overall patients' management. Erroneous lifestyle and nutrition, together with chronic stress-induced syndromes, significantly influence chronic degenerative phlebo-lymphatic diseases. The main active epigenetic socio-biologic factors are obesity, dysfunctions of musculo-respiratory-vascular pumps, pro-inflammatory nutrition, hyperactivation of stress axis, and sedentarism. An overall critical view of the scientific evidence and innovations in phebolymphology could be of help to improve efficacy, safety, and sustainability of current practice. Translational and integrative medicine may contribute to a patient-centered approach. Conversely, reductionism, eminence/reimbursement-based decisional processes, patients' lack of education, industry-influenced science, and physician's improvable awareness, may compromise efficacy, safety, appropriateness, and cost-effectiveness of future diagnostic and therapeutic patterns of phlebology and lymphology.

Percutaneous thrombectomy using a novel single session device for acute iliofemoral deep vein thrombosis

A 74-year-old woman presented with acute symptomatic left thigh and calf swelling; imaging demonstrated evidence of occlusive thrombosis from the upper left common iliac vein to the mid-thigh. Single session zero-thrombolysis venous thrombectomy was performed using the ReVene^TM Thrombectomy Catheter.

Thrombolytic therapy in acute venous thromboembolism

Although anticoagulation remains the mainstay of treatment of acute venous thromboembolism (VTE), the use of thrombolytic agents or thrombectomy is required to immediately restore blood flow to thrombosed vessels. Nevertheless, systemic thrombolysis has not clearly been shown to improve outcomes in patients with large clot burdens in the lung or legs as compared with anticoagulation alone; this is in part due to the occurrence of intracranial hemorrhage in a small percentage of patients to whom therapeutic doses of a thrombolytic drug are administered. Algorithms have been developed to identify patients at high risk for poor outcomes resulting from large clot burdens and at low risk for major bleeding in an effort to improve outcomes in those receiving thrombolytic therapy. In acute pulmonary embolism (PE), hemodynamic instability is the key determinant of short-term survival and should prompt consideration of immediate thrombolysis. In hemodynamically stable PE, systemic thrombolysis is not recommended and should be used as rescue therapy if clinical deterioration occurs. Evidence is accumulating regarding the efficacy of administering reduced doses of thrombolytic agents systemically or via catheters directly into thrombi in an effort to lower bleed rates. In acute deep venous thrombosis, catheter-directed thrombolysis with thrombectomy can be used in severe or limb-threatening thrombosis but has not been shown to prevent postthrombotic syndrome. Because the management of acute VTE can be complex, having a rapid-response team (ie, PE response team) composed of physicians from different specialties may aid in the management of severely affected patients.

Ten-year trends in iliofemoral deep vein thrombosis treatment and referral pathways

OBJECTIVES

Iliofemoral deep venous thrombosis is associated with an increased risk of developing post-thrombotic syndrome resulting in reduced quality of life. As there is debate about best management practices, this study aimed to examine the referral and treatment pathways for patients presenting with iliofemoral deep venous thrombosis over an 11-year period at our institution.

METHODS

We conducted a retrospective review of patients diagnosed with lower limb deep vein thrombosis between 2010 and 2020. Ultrasound report findings were reviewed for the presence of iliofemoral deep venous thrombosis with acute, occlusive, or proximal clot. Multiple factors were extracted, including patient demographics, risk factors, diagnostic methods, interventions, referrals, and details of follow-up. The CaVenT and ATTRACT trials studied the benefit of thrombolysis in the early phase of iliofemoral deep venous thrombosis management as compared to anticoagulation alone. An analysis was conducted of patients requiring thrombolysis to determine whether these trials impacted physician practice patterns for thrombolysis. Data were organized and examined by year for trends in treatment and referral pathways.

RESULTS

The review yielded 2792 patients assessed for lower limb deep venous thrombosis by ultrasound. Four hundred and sixty-seven (16.7%) patients were confirmed to have an occlusive iliofemoral deep venous thrombosis. The average age was 62.7 years (18-101 years). Half (50.4%) of the patients were male. The most common etiology for clot was malignancy-induced hypercoagulable state (39.0%). There was no difference in incidence of iliofemoral deep venous thrombosis diagnosed by ultrasound per year, with an average of 42.5 per year and a peak of 61. There was a trend towards increased rates of computed tomography imaging, ranging between 9.1% and 52.9%. The rate thrombolysis per year ranged between 1.8% and 8.9%, with a range of 4.3% (n = 20) to 8.9% (n = 5) in 2018. The use of pharmacomechanical thrombolysis increased, from 25% (n = 1) in 2010-2012 to 87.5% (n = 7) in 2018-2020. The rate of inferior vena cava filter insertion alone decreased from 18.2% in 2010 (n = 4) to 5.9% (n = 1) in 2020. The length of thrombolysis treatment also decreased, from 100% of patients (n = 4) receiving treatment duration greater than 24 h in 2010-2012 to 0% (n = 0) in 2018-2020. About 45% of patients receiving thrombolysis (n = 9) had venous stenting. No difference in treatment outcomes were observed, with greater than 87.5% of patients reaching intermediate to full resolution of clot burden. No patients experienced intracranial hemorrhage.

CONCLUSIONS

The results of this analysis highlight the change in practice in our institution over time. The low rate of intervention likely reflects the current lack of consensus in published guidelines. It is important for future work to elicit the most appropriate management pathways for patients with iliofemoral deep venous thrombosis.

Accuracy of contralateral Villalta score to assess for pre-existing chronic venous insufficiency in patients with unilateral deep vein thrombosis

BACKGROUND

International guidelines recommend using the Villalta score (VS) to diagnose the postthrombotic syndrome (PTS). However, a high proportion of PTS detected with VS could just reflect the presence of preexisting primary venous insufficiency (PVI). Furthermore, it is unclear whether the contralateral VS (cl-VS) can be used to assess for preexisting PVI.

OBJECTIVES

To estimate whether cl-VS can be used to assess for preexisting PVI, and to assess the proportion of PTS that could be attributable to preexisting PVI.

METHODS

Subanalysis of the SOX multicenter randomized trial focusing on patients with a first unilateral proximal deep vein thrombosis (DVT) followed for up to 2 years. PVI was defined as a baseline cl-VS > 4, and PTS as VS > 4 in the leg ipsilateral to DVT starting 6 months after DVT.

RESULTS

Among 680 patients, mean cl-VS remained stable over time: 1.23 (standard deviation [SD] ±2.49) at baseline and 1.17 (±2.20), 1.59 (±2.81), 1.54 (±2.50), 1.65 (±2.82), and 1.55 (±2.63) at the 1-, 6-, 12-, 18-, and 24-month visits, respectively. Baseline cl-VS and ipsilateral VS measured during follow-up were mildly correlated (Pearson correlation = 0.13-0.25). This association disappeared after subtracting the cl-VS measured at the same visit from the ipsilateral VS. Overall, 48.8% of patients developed PTS of whom 12.8% had baseline cl-VS > 4.

CONCLUSION

In our study of patients with a first unilateral proximal DVT, the proportion of patients with PTS who had a cl-VS > 4 is modest. However, cl-VS appears to be stable over time. Its assessment could constitute a simple way of documenting preexisting PVI and help to classify patients as having PTS.

Endovascular management of the deep venous thrombosis: A new challenging role for the endovascular specialist in 2020

Over the last years, the endovascular approach to the management of the acute and chronic deep vein thrombosis (DVT) has gained more and more attention from the scientific community. DVT is the third most common cardiovascular disease after coronary heart disease and stroke, with classic treatment based on anticoagulation. Recent evidences have highlighted the risk of postthrombotic syndrome as high as 30%-50% in proximal ilio-femoral lesions, with irreversible clinical symptoms and impact on the quality of life of the population. Since 2000s, the new concept of thrombus removal in the acute phase has been supported by the introduction of different techniques based on the endovascular ablation of the clot by in-situ fibrinolysis and, more recently, fragmentation and aspiration. In the chronic phase, recanalization of the thrombosed segment is recommended by stent placement to remove the obstruction and eventually reduce the congestion. Immediate technical success of these procedures is widely satisfying, whereas the long-term clinical benefits are still debated. This paper presents an overview of the modern management of the DVT by endovascular approach with regard to the clinical contexts, interventional strategies and clinical outcomes. Endovascular specialist needs to be aware of this incoming challenge, as local expertise is demanded for the modern management of these patients in multidisciplinary theaters.

Risk factors for acute kidney injury after pharmacomechanical thrombolysis for acute deep vein thrombosis

BACKGROUND

Pharmacomechanical thrombolysis (PMT) is an established treatment for selected patients with acute deep vein thrombosis (DVT). Despite significant clinical success, hemolysis can lead to acute kidney injury (AKI) with unknown longer term implications. Our aim was to characterize the rate of AKI after PMT and identify those patients at the greatest risk.

METHODS

A retrospective medical record review of patients with acute DVT who had undergone PMT in our institution from 2007 to 2018 was performed. The baseline demographics, comorbidities, preoperative clinical characteristics, procedural details, postoperative hospital course, and follow-up data were reviewed. The primary outcome was postoperative AKI (≥1.5 times preoperative creatinine), and longer term renal impairment. Logistic regression modeling was used to identify associated factors.

RESULTS

A total of 137 patients (mean age, 47 ± 16.6 years; 49.6% male) who had undergone PMT for treatment of acute DVT were identified (85.4% AngioJet system; Boston Scientific Corp, Marlborough, Mass). Of the 137 patients, 30 (21.9%) had developed AKI in the periprocedural period, 1 of whom had required hemodialysis in the perioperative period. The patients who had developed AKI had had significantly greater rates of preoperative coronary artery disease (23.1% vs 4.7%; P = .002), diabetes mellitus (19.2% vs 6.6%; P = .045), dyslipidemia (42.3% vs 17.9%; P = .008), and hypertension (53.6% vs 29.3%; P = .018). No significant difference was found in preoperative creatinine (0.99 vs 0.92 mg/dL; P = .65) or glomerular filtration rate (GFR; 96.9 vs 91.8 mL/min; P = .52) between the two groups. Multivariate analysis demonstrated bilateral DVT (odds ratio [OR], 4.35; 95% confidence interval [CI], 1.47-12.86; P = .008), single-session PMT (OR, 3.05; 95% CI, 1.02-9.11; P = .046), and female sex (OR, 2.85; 95% CI, 1.01-8.04; P = .048) were significant predictors of AKI. Of the 30 patients, 10 had had normal renal function at discharge and 15 and 25 patients had had normal renal function at the first and subsequent clinical follow-up visits, respectively. The remaining five patients (3.6%) had progressed to moderate (GFR, <60 mL/min) or severe (GFR, <30 mL/min) renal insufficiency, with one requiring long-term hemodialysis.

CONCLUSIONS

The use of PMT for treatment of acute DVT conferred a risk of AKI that will progress to chronic renal failure in a small fraction of affected patients. Patients with bilateral extensive DVTs have a greater risk of AKI; thus, longer priming with a thrombolytic drip before PMT should be preferred for this population.