Bioengineering Studies of Periodic External Compression as Prophylaxis Against Deep Vein Thrombosis—Part II: Experimental Studies on a Simulated Leg

1982 ◽  
Vol 104 (2) ◽  
pp. 96-104 ◽  
Author(s):  
D. A. Olson ◽  
R. D. Kamm ◽  
A. H. Shapiro
Keyword(s):  
Deep Vein Thrombosis ◽  
Fluid Velocity ◽  
Experimental Studies ◽  
Companion Paper ◽  
Uniform Compression ◽  
External Compression ◽  
Vein Thrombosis ◽  
Sequential Mode ◽  
Deep Vein

In this companion paper to “Part I: Numerical Simulations,” we report in vitro experimental studies performed on a simple model leg consisting of a “vein” of thin-walled latex tubing surrounded by “tissue” of open-pore foam rubber. Three modes of periodic external compression were investigated: i) uniform compression; (ii) graded compression, decreasing from ankle to knee; and (iii) sequential compression, progressing from ankle to knee. The modes are compared on the basis of three hemodynamic criteria: degree of vessel collapse, level of fluid velocity, and level of shear stress. In uniform compression these measures of merit are distributed very nonuniformly along the length of the leg: they are high near the proximal end of the cuff but low elsewhere, a result due to the formation proximally of a partially occlusive throat. The latter does not form in either graded or sequential compression, with the consequence that favorable values of the three measures of merit occur more uniformly along the length of the pressurized region. It is concluded that either the graded or sequential mode of compression, or perhaps a combination of the two, would be more effective than uniform compression as a prophylaxis against deep vein thrombosis.

Bioengineering Studies of Periodic External Compression as Prophylaxis Against Deep Vein Thrombosis—Part I: Numerical Studies

1982 ◽  
Vol 104 (2) ◽  
pp. 87-95 ◽  
Author(s):  
R. D. Kamm
Keyword(s):  
Deep Vein Thrombosis ◽  
Numerical Study ◽  
Volume Flow Rate ◽  
Lower Leg ◽  
Uniform Compression ◽  
Total Blood ◽  
External Compression ◽  
Simultaneous Application ◽  
Vein Thrombosis ◽  
Deep Vein

This paper presents the results of a numerical study of the technique of periodic external compression for the prevention of deep vein thrombosis. In the model the veins of the lower leg are portrayed as a continuous system rather than as discrete elements as in previous models. Consequently, we are able to explore the detailed effects of different modes of compression including (i) uniform compression, the simultaneous application of uniform pressure over the entire lower leg, (ii) graded compression, the application of nonuniform pressure, maximum at the ankle and minimum at the knee, and (iii) wavelike compression, a wave of compression proceeding from the ankle toward the knee. These numerical results indicate that the effectiveness of uniform compression is severely compromised by the formation of a flow-limiting throat at the proximal end of the compression cuff that reduces both the rate at which blood is discharged from the lower leg and the total blood volume removed. Both of these detrimental effects can be avoided by the use of either wavelike or graded compression. Both alternate methods are shown to produce more uniform augmentation of volume flow rate, flow velocity, and shear stress, throughout the entire lower leg. In the companion paper, Part II [18] (see following article), these same compression modes are tested using a simple hydraulic model consisting of a single latex tube inside a foam cylinder as a highly simplified representation of a human leg.

Management of Acute Iliofemoral Deep Vein Thrombosis

2018 ◽  
Author(s):  
Albeir Y Mousa
Keyword(s):  
Pulmonary Embolism ◽  
Deep Vein Thrombosis ◽  
Venous Thrombosis ◽  
Deep Venous Thrombosis ◽  
Inferior Vena ◽  
Vena Cava ◽  
External Compression ◽  
Vein Thrombosis ◽  
Surgical Thrombectomy ◽  
Deep Vein

Acute deep venous thrombosis (DVT) of iliofemoral segment is one of the most dreaded presentations of venous thromboembolism, as it can not only compromise the function of the extremity but may also result in pulmonary embolism and even death. There are many causes for acute iliofemoral DVT, including underdiagnosed May-Thurner syndrome, hypercoagulable syndrome, and external compression on iliocaval segment. The available treatment depends on the acuity of the symptoms. Acute iliofemoral DVT can be treated with medical anticoagulation, pharmacomechanical therapy, including thrombolysis or surgical thrombectomy. Chronic iliofemoral occlusion may be treated with recanalization of the occluded segments with angioplasty stenting. This review contains 4 Figures, 4 Tables and 63 references Key Words: acute, angioplasty, deep venous thrombosis, iliofemoral, inferior vena cava, pharmacomechanical therapy, occlusion, stent

Microrna-342-3p Loaded by Human Umbilical Cord Mesenchymal Stem Cells-derived Exosomes Attenuates Deep Vein Thrombosis by Downregulating EDNRA

2021 ◽  
Author(s):  
Zhiyu Pan ◽  
Qian Chen ◽  
Hongjian Ding ◽  
Huaqing Li
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Deep Vein Thrombosis ◽  
Umbilical Cord ◽  
Umbilical Vein ◽  
Dynamic Balance ◽  
Human Umbilical Cord ◽  
Vein Thrombosis ◽  
Deep Vein

Abstract Objectivexosomes (exos) exert biological functions to maintain the dynamic balance of cells and tissues by transferring biological cargo to recipient cells. Thus, this study explored human umbilical cord mesenchymal stem cells (hucMSCs)-derived exo transfer of microRNA (miR)-342-3p in deep vein thrombosis (DVT).MethodsHucMSCs were isolated and transfected with miR-342-3p antagomir/agomir. Then, hucMSCs-exos were extracted and injected into rats with DVT to observe inflammation and pathological damage in thrombotic vein. HucMSCs-exos were co-cultured with human umbilical vein endothelial cells (HUVECs) in vitro to observe angiogenesis. miR-342-3p and endothelin A receptor (EDNRA) expression in rats with DVT, as well as their interaction was analyzed.ResultsmiR-342-3p was downregulated and EDNRA was upregulated in rats with DVT. HucMSCs-exos induced the repair of venous thrombosis and suppressed inflammation and pathological injury in rats with DVT, as well as promoted angiogenesis of HUVECs. Upregulated miR-342-3p delivery by hucMSCs-exos alleviated DVT in rats and improved angiogenesis of HUVECs, while downregulated miR-342-3p performed oppositely. miR-342-3p targeted EDNRA, and the effect of hucMSCs-exos transfer of upregulated miR-342-3p was rescued by overexpressing EDNRA.ConclusionBriefly, miR-342-3p loaded by hucMSCs-exos attenuates DVT by downregulating EDNRA, offering a novel direction to treat DVT.

Management of Acute Iliofemoral Deep Vein Thrombosis

2018 ◽  
Author(s):  
Albeir Y Mousa
Keyword(s):  
Pulmonary Embolism ◽  
Deep Vein Thrombosis ◽  
Venous Thrombosis ◽  
Deep Venous Thrombosis ◽  
Inferior Vena ◽  
Vena Cava ◽  
External Compression ◽  
Vein Thrombosis ◽  
Surgical Thrombectomy ◽  
Deep Vein

Acute deep venous thrombosis (DVT) of iliofemoral segment is one of the most dreaded presentations of venous thromboembolism, as it can not only compromise the function of the extremity but may also result in pulmonary embolism and even death. There are many causes for acute iliofemoral DVT, including underdiagnosed May-Thurner syndrome, hypercoagulable syndrome, and external compression on iliocaval segment. The available treatment depends on the acuity of the symptoms. Acute iliofemoral DVT can be treated with medical anticoagulation, pharmacomechanical therapy, including thrombolysis or surgical thrombectomy. Chronic iliofemoral occlusion may be treated with recanalization of the occluded segments with angioplasty stenting. This review contains 4 Figures, 4 Tables and 63 references Key Words: acute, angioplasty, deep venous thrombosis, iliofemoral, inferior vena cava, pharmacomechanical therapy, occlusion, stent

Inhibition of Prothrombinase and Not Soluble Factor Xa (fXa) Predicts Efficacy of fXa Inhibitors in an In Vivo Model of Deep Vein Thrombosis.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 902-902
Author(s):  
Suzanne Delaney ◽  
Ann Arfsten ◽  
Sherin Halfon ◽  
Gail Siu ◽  
John Malinowski ◽  
...  
Keyword(s):  
Deep Vein Thrombosis ◽  
Plasma Concentration ◽  
Plasma Concentrations ◽  
Factor Xa ◽  
Vein Thrombosis ◽  
Prothrombinase Complex ◽  
Antithrombotic Efficacy ◽  
Deep Vein

Abstract Factor Xa (fXa) inhibitors are being tested in the clinic for the prevention and treatment of deep vein thrombosis (DVT) following orthopedic surgery. The antithrombotic efficacy of these drug candidates has traditionally been established in animal models as it is not known whether fXa amidolytic activity, activated partial thromboplastin time (aPTT) or prothrombin time (PT) predict efficacious doses. The present study was designed to test the hypothesis that the potency of fXa inhibitors against fXa incorporated into the prothrombinase complex would predict in vivo antithrombotic efficacy. Eight fXa inhibitors from four structurally distinct chemical series with a range of activities against fXa were tested for their ability to inhibit the prothrombinase complex in human plasma. Thrombin generation and subsequent cleavage of a specific thrombin substrate was used as a measure of prothrombinase activity, inhibitory activity being defined by the concentration of inhibitor required to produce a 2-fold extension in the time to maximal thrombin production (2x lag). In vitro rabbit PTs were also determined. Inhibition in the rabbit DVT model was assessed as previously described (Thromb Haemost1994; 71:357) and related to plasma concentrations of drug. Agent fXa IC50 (nM) Prothrombinase 2x lag (μM) Plasma concentration in DVT (μM) Thrombosis inhibition (%) Rabbit PT 2x change (μM) PRT50034 0.5 0.18 0.06 94 7.0 PRT54681 1.3 0.22 1.14 37 2.7 PRT54676 0.7 0.24 1.65 47 1.7 PRT54004 0.4 0.25 1.04 47 1.0 PRT54456 0.8 0.34 3.39 41 1.5 PRT56848 4.4 0.92 5.2 11 4.7 PRT54955 3.5 1.35 4.6 19 8.8 PRT57106 8.2 1.66 9.2 0 64 All compounds inhibited soluble fXa by 50 % at concentrations less than 10 nM. However, the rank order of potencies for inhibition of soluble fXa differed from that required to inhibit the prothrombinase complex. There was also poor correlation between the 2x lag value for prothrombinase inhibition and the concentration required to achieve a 2x change in rabbit PT (r2 = 0.57). Neither the activities of fXa inhibition nor the change in rabbit PT predicted activity in the DVT model. In contrast, compounds could be broadly divided into 3 levels of efficacy for inhibition of in vivo thrombus growth depending on their potency in the in vitro prothrombinase assay. PRT50034 had the lowest 2x lag value of 0.18 μM and was the most potent inhibitor of in vivo thrombosis with 94 % inhibition at a plasma concentration of 65 nM. The second group of compounds, with 2x lag values in the prothrombinase assay ranging from 0.22 to 0.34 μM, inhibited in vivo thrombus formation by 37 to 47 % at plasma concentrations ranging from 1.04 to 3.39 μM. Compounds in the third category were the least potent prothrombinase inhibitors (2x lag values greater than 0.92 μM) and were unable to significantly inhibit in vivo thrombosis even at plasma concentrations of 9.2 μM. These data show that the 2x lag value obtained in the prothrombinase assay, and not inhibition of soluble fXa or extension of rabbit PT, is capable of predicting fXa inhibitor efficacy in the in vivo rabbit DVT model.

scholarly journals Concentrated and Diluted Heparin-Prophylaxis of Postoperative Deep Vein Thrombosis

1977 ◽  
Author(s):  
S. Törngren ◽  
K. Forsberg
Keyword(s):  
Deep Vein Thrombosis ◽  
In Vitro Study ◽  
Standard Dosage ◽  
Vitro Experiment ◽  
In Vitro Experiment ◽  
Vein Thrombosis ◽  
Calcium Heparin ◽  
The Mean ◽  
Deep Vein

Two calcium heparin solutions (Vitrum AB) have been evaluated in a controlled blind study with standard dosage of 5000 IE subcutaneously. The injections were given 2 hours before operation and 12-hourly for 6-8 days after operation. 175 patients undergoing abdominal surgery were included and randomized into 3 groups. 75% of the patients had malignant disease. 66 patients recieved heparin 500 IE/ml (1 ml), 47 patients recieved heparin 25000 IE/ml (0.2 ml) and 62 patients recieved 5% glueos. Deep vein thrombosis (DVT) was diagnosed with the 125I-fibrinogen method. Finally the heparin solutions with different viscocity were compared in an in vitro experiment. The nurses who injected the patients gave injections into weighed bottles with the usual technique.DVT was diagnosed in 32% of the control patients, 15% of those on heparin 5000 IE/ml and 21% of those on heparin 25000 IE/ml. The difference between controls and heparin 5000 IE/ml is statistically significant (p<0.05). In the in vitro experiment the mean dosage of heparin 5000 IE/ml was 5100 IE and the mean dosage of heparin 25000 IE/ml was 4415 IE. The dosage of heparin 25000 IE/ml was significantly less than 5000 IE (p<0.0l).We conclude that the frequency of DVT is reduced with calcium heparin 5000 IE/ml (1 ml) 12-hourly for 6-8 days after operation. The concentrated heparin 25000 IE/ml (0.2 ml) does not significantly reduce postoperative DVT, which probably can be explained from our results in the in vitro study.

Enhanced Thrombolysis by Ultrasound-Assisted Catheter-Directed Thrombolysis and Microbubbles in an In Vitro Model of Iliofemoral Deep Vein Thrombosis

2019 ◽  
Vol 119 (07) ◽  
pp. 1094-1101 ◽  
Author(s):  
Rolf P. Engelberger ◽  
Verena Schroeder ◽  
Michael Nagler ◽  
Raja Prince ◽  
Daniel Périard ◽  
...  
Keyword(s):  
Deep Vein Thrombosis ◽  
Weight Reduction ◽  
Negative Control ◽  
Human Whole Blood ◽  
Vein Thrombosis ◽  
Catheter Directed Thrombolysis ◽  
Ultrasound Assisted ◽  
Deep Vein ◽  
D Dimer

There is a need to improve the efficacy and safety of catheter-directed thrombolysis (CDT) for thrombo-occlusive diseases, and ultrasound-assisted CDT (USAT) is a promising approach. We tested if thrombolysis efficacy of USAT can be improved by adding gaseous microbubbles (MB). We developed an in vitro dynamic overflow model for iliofemoral deep vein thrombosis, and added MB to an USAT system with ultrasound energy and dose of tissue plasminogen activator according to clinical practice. A total of 64 clots (mean baseline weight of 8.23 ± 1.12 g, generated from citrated human whole blood from 7 healthy male volunteers) were randomly assigned to 1 of 4 study protocols of 30 minutes' duration: negative control, CDT, USAT, and USAT + MB.Thrombolysis efficacy was assessed by measuring the change in D-dimer levels in the overflow liquid and the percentage of clot weight reduction. Compared to negative control, change in D-dimer increased by 62% (p = 0.017), 128% (p = 0.002), and 177% (p < 0.001) in the CDT, USAT, and USAT + MB groups, respectively. D-dimer increase was greater in the USAT than in the CDT group (p = 0.014), and greater in the USAT + MB than in the USAT group (p = 0.033). Compared to negative control, percentage of clot weight reduction increased by 123% (p = 0.016), 154% (p = 0.002), and 233% (p < 0.001) in the CDT, USAT, and USAT + MB groups, respectively. Percentage of clot weight reduction was greatest in the USAT + MB group (p < 0.05 compared with all other groups). In conclusion, our in vitro study suggests that the thrombolytic efficacy of USAT in human whole blood clots can be improved by local administration of MB.

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

Vascular ◽  
2021 ◽  
pp. 170853812110105
Author(s):  
Mehrdad Farrokhi ◽  
Maria Khurshid ◽  
Sassan Mohammadi ◽  
Bardia Yarmohammadi ◽  
Yaser Bahramvand ◽  
...  
Keyword(s):  
Deep Vein Thrombosis ◽  
Success Rate ◽  
Meta Analysis ◽  
Cochrane Library ◽  
Infusion Time ◽  
Eligibility Criteria ◽  
Vein Thrombosis ◽  
Catheter Directed Thrombolysis ◽  
Deep Vein

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.

Does Acute Urinary Retention after Total Joint Replacement Predispose to Deep Vein Thrombosis?

1995 ◽  
Vol 5 (2) ◽  
pp. 69-71
Author(s):  
D.W. Murray ◽  
C.L.M.H. Gibbons ◽  
S.J. Gregg-Smith
Keyword(s):  
Deep Vein Thrombosis ◽  
Urinary Retention ◽  
Joint Replacement ◽  
Hip Replacement ◽  
Acute Urinary Retention ◽  
Total Joint Replacement ◽  
Experimental Studies ◽  
Venous Outflow ◽  
Vein Thrombosis ◽  
Deep Vein

Deep vein thrombosis (DVT) and acute urinary retention are both common complications of total hip replacement. Previous experimental studies have demonstrated that bladder distension obstructs the iliac veins causing a decrease in venous outflow from the legs, and that after hip replacement a decrease in venous outflow is associated with the development of DVT. This suggests that acute urinary retention after joint replacement predisposes to DVT and that routine catheterisation would reduce the risk of DVT. The aim of the study was to determine, using strain gauge venous plethysmography, whether acute urinary retention after joint replacement causes a decrease in venous outflow from the legs. It was found that acute retention did not significantly alter the venous outflow. We therefore conclude that acute urinary retention after joint replacement does not predispose to DVT.

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