The background and role of catheter-directed thrombolysis evolving procedures for acute iliofemoral deep venous thrombosis

Minimal invasive treatment such as early endovenous thrombus removal for iliofemoral deep venous thrombosis (DVT) emerged in the end of last century. The principle is catheter-directed thrombolysis (CDT) using either plasminogen activating agents alone, as ultrasound-assisted CDT, or in combination with mechanical devices as pharmaco-mechanical CDT. The interest for this treatment modality is the high rate of post-thrombotic syndrome (PTS) with anticoagulation (AC) alone, especially after iliofemoral DVT. Recently published randomized controlled trials (RCTs) comparing early thrombus removal with AC alone, as well as non-randomized studies, have demonstrated favorable rates, or at least a decrease of moderate and severe PTS, in favor of these procedures. This article will summarize the background and evolution of the procedures in the last three decades and discuss fundamental criteria for inclusion and exclusion, focusing on the procedures regarding thrombus age and location, technical issues, complications and results including different outcome measures for PTS, for which iliac DVT involvement is a massive risk factor to be prevented.

Hyperendogenous Heparinization Suggests a Guideline for the Management of Massive Wasp Stings in Two Victims

Bees and wasps (order Hymenoptera) are commonly encountered worldwide and often deliver defensive stings when in contact with humans. Massive envenomation resulting from >50 stings causes a toxic reaction and life-threatening complications that typically result in rhabdomyolysis and disseminated intravascular coagulation. Two male patients who were stung over 80 times by wasps experienced severe coagulation abnormality. Consecutive examination by thromboelastography (TEG) guided by heparinase treatment during their hospitalization evidenced heparin-like coagulation dysfunction despite no clinical use of heparin-like substances. Numerous tests were also conducted to confirm whether the coagulation abnormalities could be attributed to hyperendogenous heparinization and allergic reaction, rhabdomyolysis, and vascular endothelial cell injury without apparent disseminated intravascular coagulation, which might all be affected by the production of endogenous heparin. The reduced coagulation potential caused by hyperendogenous heparinization was associated with the binding of antithrombin and the activation of fibrinolysis. In addition, TEG-identified coagulopathy was moderated using protamine for heparin neutralization. The massively envenomed patients survived and were discharged after completion of medical care. We also review clinical manifestations from other published case reports, including topical treatment. Our study provides clinical evidence and guidance for diagnosis via TEG and appropriate intervention with protamine for patients with massive wasp envenomation.

Diosmin 600 in adjunction to rivaroxaban reduces the risk of post-thrombotic syndrome after femoropopliteal deep vein thrombosis: results of the RIDILOTT DVT study

BACKGROUND

To assess the efficacy and safety of long-term diosmin 600 therapy added to rivaroxaban and elastic compression stockings (ECS) in patients with femoropopliteal deep vein thrombosis (DVT).

METHODS

This single-center, open-label randomized clinical trial RIDILOTT DVT enrolled patients with their first femoropopliteal DVT confirmed by duplex ultrasound scan (DUS). Participants were randomly allocated to the control group (standard treatment with rivaroxaban for six months and ECS for 12 months) or the experimental group (standard treatment with the additional use of diosmin 600 mg once daily for 12 months). Patients were followed for 12 months. The primary outcome was post-thrombotic syndrome (PTS), according to the Villalta Score (≥5). The secondary outcomes were deep vein recanalization, chronic venous disease (CVD) progression, the severity of PTS (Villalta), and CVD (VCSS), quality of life (CIVIQ-20), venous thromboembolism recurrence, and adverse event (AE).

RESULTS

Ninety patients were randomized (45 per group). There were 56 men and 34 women with a mean age of 57.8±13.4 years, and 69% had clinically unprovoked DVT. PTS frequency at 12 months was significantly lower (8.9% vs. 48.9%) in the experimental group compared with control one (relative risk, 0.14; 95% confidential interval, 0.04-0.43, P<0.001). Adding diosmin 600 was associated with quicker and complete vein recanalization, lower CVD progression rate, and lower Villalta, VCSS, and CIVIQ-20 scores. There was no difference in recurrent DVT or AE.

CONCLUSIONS

Adjunctive use of diosmin 600 to rivaroxaban and ECS in patients with femoropopliteal DVT can improve the clinical and ultrasound outcomes after 12 months of treatment.

Utilization of the Caprini score in conjunction with thrombodynamic testing reduces the number of unpredicted postoperative venous thromboembolism events in patients with colorectal cancer

BACKGROUND

The thrombodynamic test (TD) is a novel global test of hemostasis that allows to study the spatial-temporal characteristics of a clot formation in real time under conditions close to natural ones and demonstrates high sensitivity to detect the state of hypercoagulation. The main paraments of the test are the velocity of clot growth, clot's size, and clot density. The objective of this study was to compare the classic Caprini 2005 score and its modified version in association with the results of TD. The goal is to predict postoperative venous thromboembolism (VTE) in surgical patients undergoing surgery for colorectal cancer.

METHODS

This was a prospective observational clinical study involving 80 patients (33 men and 47 women; mean age, 73.9 ± 7.2 years) who underwent major (79 cases) or minor (1 case) surgery for colorectal cancer. Patients were at high risk for postoperative VTE (ie, a mean Caprini score of 9.9 ± 2.0) and received combined prophylaxis (ie, antiembolic compression stockings and enoxaparin 40 mg once daily) until discharge. Enoxaparin was administered at a fixed time of blood sampling for the TD test. Duplex ultrasound scan was performed to detect postoperative vein thrombosis before and 5 to 7 days after surgery.

RESULTS

Postoperative vein thrombosis was found in 21 of 80 patients (26.3%; 95% confidence interval, 17.9%-36.8%). Regression analysis and receiver operating characteristic (ROC) curve showed that Caprini scores significantly predicted VTE (P < .0001; area under the curve [AUC] = 0.839 ± 0.045). Analysis of ROC curve coordinates showed that a cutoff point of 11 scores had a sensitivity of 76.2% and a specificity of 74.6%. The results of the TD test showed significant hypercoagulation despite enoxaparin administration in patients with VTE. Regression analysis and ROC curves demonstrated that the following TD parameters had the greatest predictability for postoperative DVT: initial velocity of clot growth (Vin) and clot size (CS) measured at 12 hours after enoxaparin administration (AUC, 0.697 ± 0.063 and AUC, 0.790 ± 0.059, respectively), as well as Vin and CS measured 24 hours after the enoxaparin injection (S = 0.847 ± 0.059 and S = 0.803 ± 0.069, respectively). The cutoff points for VTE prediction at 12 and 24 hours seemed to be a Vin of greater than 62.5 and greater than 64.5 μm/minute (normal range, 35-56 μm/minute) as well as a CS of greater than 1351.5 and greater than 1333.5 μm (normal range, 800-1200 μm), respectively. Identified thresholds for TD parameters have been integrated into Caprini scores under the item "other congenital or acquired thrombophilia." The total Caprini scores were recalculated in patients where one or all TD parameters had exceeded the cutoff followed by reanalysis of the ROC curves. The best predictability was found for Caprini scores considering the elevation of all four TD parameters (AUC, 0.924 ± 0.029) with increased cutoff to a score of 12 with a sensitivity of 85.7% and a specificity of 81.4%. The use of cutoffs for the original and modified scores could be used to calculate the number of patients that were under cutoff but developed with VTE: 10.2% and 5.9%, respectively.

CONCLUSIONS

Integrating TD parameters into the Caprini score increases the ability to predict postoperative VTE.

Use of Micronized Purified Flavonoid Fraction Together with Rivaroxaban Improves Clinical and Ultrasound Outcomes in Femoropopliteal Venous Thrombosis: Results of a Pilot Clinical Trial

INTRODUCTION

The aim of this study was to assess the impact of adding long-term micronized purified flavonoid fraction (MPFF) to standard treatment of femoropopliteal deep vein thrombosis (DVT).

METHODS

This pilot, comparative, open-label study with blinded outcome assessor enrolled patients with a first episode of femoropopliteal DVT confirmed by duplex ultrasound scanning (DUS). All participants were randomly allocated to one of two treatment groups: (1) control that received a standard treatment with oral rivaroxaban, and (2) experimental that involved additional treatment with MPFF 1000 mg/day. Both drugs were used for 6 months. Patients were followed for the whole treatment period and underwent DUS every 2 months to determine the degree of recanalization by popliteal (PV), femoral vein (FV), and common femoral vein (CFV) compressibility. Thrombi extension were assessed by the modified Marder score. At the end of the follow-up period, patients were assessed with Villalta and venous clinical severity scales (VCSS). Patients with a Villalta score ≥ 5 were diagnosed with post-thrombotic syndrome (PTS).

RESULTS

Sixty patients were randomized to the control or MPFF groups (n = 30 in each group). There were 40 men and 20 women with a mean age ± SD of 56.3 ± 13.4 years. Clinically unprovoked DVT was recognized in 65% of cases and left side localization in 45%. The mean baseline Marder score was 15.0 ± 4.8 and 11.1 ± 4.3 in the experimental and control groups, respectively (p = 0.002). At 6 months, the mean Villalta score in the MPFF group was significantly lower compared with control (2.9 ± 2.7 versus 5.8 ± 3.0; p < 0.0001). PTS was diagnosed in six patients (20%) and 17 patients (57%) in the experimental and control groups respectively (p = 0.007). A significant difference between the groups was also observed for the VCSS value (2.3 ± 1.9 versus 4.9 ± 1.9; p < 0001). After 6 months of treatment the Marder score decreased to 0.8 ± 1.6 and 2.8 ± 3.5 in the experimental and control groups, respectively (p = 0.006). In the MPFF group, there was a greater reduction in the Marder score (p < 0.0001) and more rapid rate of recanalization for the FV (p < 0.0001), with a non-significant trend for the CFV (p = 0.130) and PV (p = 0.204) compared with the control group. Full recanalization of the PV at 6 months was observed in 24 patients (80%) who had received MPFF, and only 17 patients (57%) in the control group (p = 0.095).

CONCLUSION

The addition of MPFF to standard therapy for DVT in the form of oral rivaroxaban can reduce the incidence of PTS at 6 months in patients with proximal DVT and increase the speed of deep vein recanalization.

FUNDING

Les Laboratoires Servier funded the article processing fees, editorial assistance, and open access fee for this manuscript.