The incidence of deep vein thrombosis in women undergoing cesarean delivery

Introduction

Venous thromboembolism (VTE) is one of the leading causes of maternal mortality in the United States. Cesarean delivery is a known risk factor. This study was to determine the incidence of deep vein thrombosis (DVT) post cesarean delivery.

Materials and Methods

This was a prospective cohort study where two patients having undergone cesarean delivery each day were randomly selected. A lower extremity compression ultrasound was performed prior to hospital discharge. If no DVT was detected, participants were asked to return for a second ultrasound two weeks postpartum. Participants were also telephone-interviewed at three months for reported VTE.

Results

Of the 194 patients who consented to study participation, only one participant developed DVT after cesarean delivery, giving an overall incidence of 0.5% (95% CI, 0.1 to 2.8%). There were no DVT identified on the second ultrasound nor VTE reported 3 months postpartum.

Conclusions

We found the DVT rate after cesarean delivery to be 0.5%.     

Outpatient management of acute deep vein thrombosis: results from the OTIS-DVT registry

Objectives

We aimed to investigate clinical practice patterns for the outpatient management of acute deep vein thrombosis (DVT).

Methods

In the prospective Outpatient Treatment of Deep Vein Thrombosis in Switzerland (OTIS-DVT) registry, 534 consecutive outpatients with acute DVT (49% proximal, 24% recurrent, and 12% cancer-associated) were enrolled: 41% patients were managed in private angiology practice, 34% in an outpatient hospital department, and 25% in private general or internal medicine practice.

Results

For diagnosis, ultrasound was used in 95% and D-dimer testing in 53%. Low-molecular-weight heparin (LMWH) was prescribed for a median (IQR) duration of 7 (5-12) days in 83% of patients, and vitamin K-antagonists for 163 (92-183) days in 81%. Mechanical measures to prevent post-thrombotic syndrome were prescribed in 83%; compression stockings or bandages for a median (IQR) duration of 364 (101-730) days from hospital physicians, and 92 (45-183) days from private practice physicians (p < 0.001). Among patients with symptomatic proximal DVT, mechanical measures were prescribed for at least 2 years in 24% patients; 55% in hospital, and 6% in private practice (p < 0.001). Among patients with cancer-associated DVT, the median (IQR) duration of LMWH therapy was 16 (8-45) days, and 35% received LMWH for less than 90 days.

Conclusions

The OTIS-DVT registry provides representative information on clinical practice patterns for outpatients with acute DVT managed by hospital or private practice physicians. The use of mechanical measures in patients with symptomatic proximal DVT and the administration of LMWH for a long-term therapy of cancer-associated DVT require improvement to comply with current guidelines.     

Thrombolysis and fibrinolytic parameters during heparin treatment of deep vein thrombosis

Thirty-nine patients with symptomatic, venographically verified deep vein thrombosis (DVT) were studied during treatment with heparin in order to investigate the correlation between the venographic changes and parameters of heparin therapy or fibrinolytic components. Venograms were scored with a 40-grade scale, and after one week a significant improvement with an average reduction of the thrombi of 17% was observed. No statistically significant correlation was found between reduction of thrombus size and duration of heparin treatment, total amount of heparin administered, mean levels of APTT, plasmin-α₂-antiplasmin complex (PAP), tissue plasminogen activator (t-PA) antigen or t-PA-inhibitor. Only a short history of the thrombus was significantly correlated to thrombolysis. The concentrations of PAP and t-PA-inhibitor were not influenced, while that of t-PA antigen showed a significant increase during heparin infusion. Even if statistically significant correlations were not obtained, the patients with pronounced thrombolytic effect had high PAP-levels. Furthermore, patients with high t-PA-inhibitor levels had no lysis. The results suggest, that also other factors than plasminogen dependent fibrinolysis are of importance for the thrombolytic effect.     

Exclusion of venous thromboembolism: evaluation of D-Dimer PLUS for the quantitative determination of D-dimer

The objective of this study was to evaluate if D-Dimer PLUS (Dade Behring, USA), a rapid fully automated assay, could be used as an initial screening test in the diagnosis of venous thromboembolism (VTE). Samples from 274 consecutive symptomatic patients with suspected pulmonary embolism (n=229; 79% outpatients, 21% inpatients), deep venous thrombosis (n=37; 84% outpatients, 16% inpatients) or suspected for both complications (n=8) were tested with this D-dimer assay with a Sysmex CA-1500 Coagulation Analyzer. Clinical probability for pulmonary embolism (PE) or deep venous thrombosis (DVT) was staged according to a pretest risk score proposed by Wells. Final diagnosis of PE and/or DVT was established by spiral-computed tomography of the pulmonary arteries or compression ultrasonography, respectively. PE was diagnosed in 13.5% of the patients, whereas DVT was confirmed in 17.7% of the patients. The optimal cut-off value for exclusion of venous thromboembolism was 130 mug/l, and sensitivity, specificity and negative predictive value (NPV) were 95.0% (95% CI: 92.4-97.6), 30.4% (95% CI: 25.0-35.8) and 97.2% (95% CI: 95.2-99.2), respectively. In fact, two patient with PE were missed using D-Dimer PLUS; both cases were outpatients. In conclusion, this assay appears to be safe when implemented in an algorithm based on clinical assessment, D-dimer concentration, and radiological diagnostic techniques to stratify the risk for PE or DVT. However, higher sensitivities and negative predictive values were claimed in the scarce published reports for the D-Dimer PLUS assay than found in this study.     

颅脑损伤患者深静脉血栓形成的危险因素分析及预防方法

目的探讨颅脑损伤患者深静脉血栓(DVT)形成的高危因素及预防方法。方法对3 6 2例颅脑损伤患者伤后每间隔1 0 d检查一次下肢血管彩超,发现DVT后给予及时治疗。对发生DVT与未发生DVT的患者进行年龄、疾病、卧床时间、性别等各因素的患病率进行对照分析。结果 3 6 2例患者发现DVT 4 8例,DVT患肢6 3侧,DVT患病率高血压者为1 7.5 0%(2 8/1 6 0),无高血压者9.9 0%(2 0/2 0 2),年龄<6 0岁者1 0.7 1%(3 3/3 0 8),>6 0岁者2 7.7 8%(1 5/5 4),糖尿病者2 5.3 0%(2 1/8 3),无糖尿病者9.6 8%(2 7/2 7 9);瘫痪肢体2 2.9 2%(4 4/1 9 2),未瘫痪肢体3.5 7%(1 9/5 3 2),卧床≤1 0 d时DVT患病率2.2 1%(8/3 6 2),≤2 0 d时7.4 6%(1 7/2 2 8),≤3 0 d时1 2.1 2%(2 4/1 9 8),≤4 0 d时2 4.4 3%(3 2/1 3 1),≤5 0 d时3 9.8 1%(4 3/1 0 8)。结论颅脑损伤患者DVT的发生与年龄、血压、血糖、肢体活动度、卧床时间等密切相关,与性别关系不大。高龄、高血压史、糖尿病史、瘫痪肢体、卧床时间>1 0 d等均是形成DVT的高危因素,而且卧床时间越长,形成DVT的风险越大。     

创伤性深静脉血栓形成大鼠模型Wnt信号通路的作用*☆

背景：创伤后深静脉血栓形成具有潜在的临床危害性,可并发肺栓塞、脑栓塞。Wnt信号途径调节控制多种疾病过程,可能影响深静脉血栓的形成。 目的：探讨Wnt信号通路在创伤性深静脉血栓形成中的作用。 方法：将30只SD大鼠随机分为正常对照组和模型组。模型组根据造模后的不同生物学状态再分为高峰期血栓形成组和高峰期血栓不形成组,造模后5d无创切取股静脉血管组织,随后抽取各组大鼠总RNA,用Genechip Rat Genome 230 2.0芯片测定股静脉RNA表达,并分析Wnt信号通路基因表达变化情况。 结果与结论：与正常对照组比较,血栓形成组发现1 906个基因出现表达差异,无血栓形成组差异表达基因数目合计1 568个;与无血栓形成组比较,血栓形成组有437个出现表达差异,其中Wnt信号通路卷曲相关蛋基因、膜联结合蛋白基因、酪蛋白激酶Ⅱ基因、p53基因、蛋白磷酶2A 基因、环腺苷酸依赖性激酶同功酶基因、连接素β基因、原癌基因、fos相关抗原基因、Rac基因、钙调素依赖型蛋白激酶Ⅱ基因、钙调神经磷酸酶基因等均上调;卷曲蛋白基因、磷脂酶C基因等下调。提示Wnt信号通路可能是调控血栓的生物学状态的重要信号通路之一。     

重型颅脑损伤患者深静脉血栓的预防及治疗进展

重型颅脑损伤患者多指格拉斯哥评分小于8分者,由于意识障碍、卧床、制动、凝血机制紊乱等因素,是发生深静脉血栓(deep vein thrombosis,DVT)的高危人群,如不进行干预,DVT发生率超过50％[1],更有报道显示重症监护室中头部外伤患者72h内发生DVT高达11％[2].但由于DVT缺乏特异性症状,且重型脑外伤患者多处于昏迷状态,缺乏下肢自觉主诉,故无法早期发现及干预治疗,一旦发生,则增加肺栓塞(pulmonary embolism,PE)等风险[3],严重时危及生命,已成为住院患者死亡的常见原因之一[4].本文现综述近年重型颅脑外伤患者发生DVT的预防及治疗措施研究进展,为制定更规范合理的预防和治疗提供依据.     

创伤后深静脉血栓形成中的黏着斑激酶信号通路*☆

背景：创伤后深静脉血栓形成的分子机制复杂,黏着斑激酶信号通路在深静脉血栓形成过程中的作用尚未阐明。 目的：探讨黏着斑激酶信号通路在创伤性深静脉血栓形成中的作用。 方法：取20只SD大鼠制备股骨骨折模型。造模后5 d,根据血栓形成情况将模型大鼠分为2组：血栓形成组和无血栓形成组,每组10只。另取10只正常大鼠作为对照组。无创切取大鼠股静脉血管组织,抽取总RNA,Genechip Rat Genome 430 2.0芯片测定股静脉RNA的表达,并分析黏着斑激酶信号通路基因表达的变化。 结果与结论：与无血栓形成组比较,血栓形成组中黏着斑激酶信号通路细胞外基质、蛋白激酶C、Fyn、辅肌动蛋白、Vav等关键基因均上调;下调的有整联蛋白α、肌球蛋白轻链磷酸酶、c-Jun基因。结果提示黏着斑激酶信号通路可能是调控血栓生物学状态的重要信号通路。     

Metabolic syndrome as a risk factor for deep vein thrombosis after acute cardiac conditions

The metabolic syndrome (MS), a cluster of cardiovascular risk factors known to be associated with type II diabetes and arterial disease, has been recently reported to be associated with venous thromboembolism (VTE). In this case-control study MS was tested as a potential risk factor for deep vein thrombosis (DVT) after acute coronary syndromes (ACS) and acute heart failure (AHF).Globally, 86 patients with objectively diagnosed DVT during cardiac rehabilitation after ACS and AHF were compared with a sex and age-matched population of cardiac patients without objectively confirmed DVT. MS was significantly associated to the presence of DVT (OR 2.38; 95% CI 1.64, 3.12), independent from type of cardiac event, prolonged hospitalization, and obesity. Among single determinants of MS, only hypertriglyceridemia was significantly associated with VTE.The presence of MS could increase the risk of VTE after acute cardiac events, thus affecting morbidity and mortality in this patient population.     

高血压性脑出血患者并发下肢静脉血栓的危险因素及对策

目的探讨高血压性脑出血后下肢静脉血栓形成的危险因素和防治措施。方法回顾分析9例高血压性脑出血患者发生下肢静脉血栓的临床资料。确诊后均给予抬高患肢、抗血小板、溶栓及抗凝治疗。结果 9例患者中痊愈6例,好转2例,死亡1例。患者肢体瘫痪、高凝状态、下肢血液回流缓慢、静脉壁损伤及血管内异物为下肢静脉血栓形成的高危因素。结论一旦发生下肢深静脉血栓,积极给予抗血小板、溶栓及抗凝等治疗措施,并采取抬高患肢、减少活动是防止血栓脱落发生致死性肺动脉栓塞的关键。     

Abdominal obesity and the risk of recurrent deep vein thrombosis

BACKGROUND: Abdominal obesity has been found to be associated with an increased risk of deep vein thrombosis (DVT). Whether patients with abdominal obesity have an increased risk of recurrence is currently unknown. METHODS: Patients with objective diagnosis of DVT and a life expectancy of greater than 6 months underwent measurement of the circumference of the waist. A waist circumference of greater than 102 cm for men and greater than 88 cm for women defined abdominal obesity. Information on age, gender, and on the presence of risk factors for DVT was collected. At follow-up, all patients underwent serial compression ultrasound of the lower limbs and were clinically evaluated every 6 months. RESULTS: One hundred patients were enrolled, 58 with abdominal obesity and 42 without. Mean age was 64.5 and 57.3 years, respectively (p<0.05). Percentage of male patients was 32.8% and 81.0% (p<0.01). Unprovoked DVT and transient risk factors rates were similar in both groups. Overall, recurrent DVT was documented in 29 patients, 16 in patients with abdominal obesity (27.6%) and 13 in patients without (31.0%). At the multivariate regression analysis HR for VTE recurrence in abdominal obese patients was 1.26 (95% confidence interval=0.47-3.4). CONCLUSIONS: Abdominal obesity does not seem to modify the risk of recurrent DVT.     

Problems with measuring compression device performance in preventing deep vein thrombosis

The purpose of this article is to discuss issues related to the use and performance of mechanical compression devices in preventing deep vein thrombosis (DVT), such as graduated compression stockings (GCSs) and pneumatic compression devices (PCDs). While various studies have shown mechanical compression to be effective against DVT, the adequacy of the performance of these devices has not been conclusively determined. One reason for this inconclusiveness is small sample bias in which the results of many studies are open to a considerable chance of error. Another problem is that the studies may not be appropriate designed to measure device effectiveness and be free of bias. In addition, new methods of DVT prophylaxis are forcing a reexamination of what it means for a device to be “effective.” Finally, the prevention of DVT is not likely to occur if the patient declines to comply with a prescribed treatment. Compliance is particularly bad with GCSs and some compliance comparisons on PCDs have suffered from failing to control for potentially confounding factors. As such, more and better studies need to be performed on these devices.     

Performance of two relatively new quantitative D-dimer assays (Innovance D-dimer and AxSYM D-dimer) for the exclusion of deep vein thrombosis

Introduction

D-dimer assays are now widely used as the first-line test in the diagnostic algorithm of suspected deep vein thrombosis (DVT). The aim of this study was to evaluate the performance of two relatively new quantitative D-Dimer assays (Innovance™ and AxSYM®) by comparison with a clinical gold standard.

Patients and methods

311 samples from outpatients with clinical suspicion of DVT, included in a prospective management study, was analysed (prevalence of DVT 23%). The diagnostic workup included estimation of pre-test probability, D-dimer determination, objective imaging as well as 3 month clinical follow up of negative patients.

Results

No significant differences were seen in sensitivity and negative predictive values between Innovance, AxSYM and the reference assays. The area under the ROC curve was slightly lower for the AxSYM assay and the correlation to the reference assays was only moderate (r < 0.8) whereas the agreement with the Vidas assay was near excellent (κ = 0.8). The Innovance assay reached the highest AUC, showed a strong correlation with the reference assays (r ≥ 0.9) and a good agreement with the Vidas assay (κ = 0.76). In combination with a low pre-test probability score the Innovance assay reached a NPV of 100% (95% CI, 92-100) and the AxSYM assay 98% (95% CI, 87-100).

Conclusion

The Innovance and AxSYM assays show an overall good and comparable performance for the exclusion of DVT when compared to the established assays. Our results for the AxSYM assay indicate that the optimal cut-off value needs to be further evaluated.     

Diagnostic efficacy of the D-Dimer assay in disseminated intravascular coagulation (DIC)

The D-Dimer (D-D) assay for measuring cross-linked fibrin degradation products is now available for the clinical laboratory. We combined this assay with other tests to assess patients with diagnosed or suspected DIC. Also, a small group of patients (20) with deep venous thrombosis (DVT) were studied. The D-D test, antithrombin-III assay, FDP titer, fibrinopeptide-A level, protamine sulfate test, fibrinogen, prothrombin time, and activated partial thromboplastin time were used. The D-D test was abnormal in 93.7%, the AT-III level was abnormal in 87.5%, the fibrinopeptide-A level was abnormal in 89.5%, and the FDP titer was elevated in 83.7% of patients with DIC. When assessing patients found not to have confirmed DIC the D-D assay was abnormal in 20%, the AT-III level was abnormal in 6%, and the fibrinopeptide-A level was elevated in 13%. We conclude the D-Dimer assay to be a useful molecular marker of hemostasis in diagnosing DIC and this test will often discriminate between those patients with or without DIC, especially when used with the AT-III and fibrinopeptide-A assays. Of the battery of tests used in this study, the most useful, in descending order of efficacy, appear to be the D-dimer assay (93.7% abnormal), the fibrinopeptide-A titer (89.5% abnormal), the AT-III level (87.5% abnormal), and the FDP titer (83.7% abnormal).     

Microparticle-associated tissue factor activity in patients with acute unprovoked deep vein thrombosis and during the course of one year

Background

Tissue factor (TF) is the main in-vivo initiator of blood coagulation. Microparticles (MPs) are small procoagulant membrane vesicles. Elevated TF-bearing MPs have been found in different prothrombotic conditions and MP-associated TF activity may contribute to the pathogenesis of unprovoked deep vein thrombosis (DVT).

Objective

To determine MP-TF activity levels at diagnosis of DVT and at four additional time points during the course of one year in a well-defined group of patients with unprovoked DVT of the lower limb.

Patients/Methods

In this study, 41 patients with acute unilateral symptomatic and unprovoked DVT of the lower limb were included and followed for 1 year. Venous blood samples for determination of MP-TF activity were drawn at diagnosis of acute DVT, and 1-, 3-, 6-, and 12 months later. In addition, 10 young and healthy control subjects were included.

Results

The median MP-TF activity was 0.06 pg/mL (25th-75th percentile: 0.0-0.53) in patients with acute DVT and 0.18 pg/mL (0.07-0.33) in healthy controls, and did not differ significantly (p = 0.35). No significant changes in MP-TF activity were found in the follow-up measurements. MP-TF activity did also not differ significantly between patients with proximal- or distal DVT and between those with- or without residual DVT after 6 months.

Conclusions

MP-TF activity is low at the acute event in patients with unprovoked DVT of the lower limb and remains unchanged during the course of the disease. Our data do not support the hypothesis that TF-bearing MPs play a determining role in the pathogenesis of unprovoked DVT.     

The role of fibrin monomers in optimizing the diagnostic work-up of deep vein thrombosis

Despite the use of a clinical score and D-dimers to exclude deep vein thrombosis (DVT), the majority of patients still need repeated ultrasound (US). The aim of the study was to investigate whether fibrin monomers (FMs), as markers of thrombin generation, have additional value in the diagnosis of DVT. This is a posthoc analysis of 464 outpatients, participants in a management study using D-dimers (Tina-Quant and a clinical score in the exclusion of DVT. Two new FM assays (Auto LIA-FM and IATRO SF, Japan) were performed. Overall sensitivity, negative predictive value (NPV) and specificity of the D-dimer test were 98%, 98% and 42%. The optimal cut-off point for the Auto LIA-FM test was 相似文献   

Results of a new rapid d-dimer assay (cardiac d-dimer) in the diagnosis of deep vein thrombosis.

The objective was to evaluate the accuracy of a new full blood rapid D-dimer assay in the diagnosis of suspected deep vein thrombosis (DVT). In 100 consecutive patients with suspected DVT, clinical probability was staged according to a pretest score proposed by Wells. For the determination of plasma D-dimer, heparin and citrate blood samples were drawn, and Cardiac D-dimer, STA-LIA, and Tina-quant tests were performed. Final diagnosis was confirmed either by duplex sonography or ascending venography. DVT was diagnosed in 37%, thrombophlebitis in 10%, and no venous thromboembolism was diagnosed in 52%. In 2% pulmonary embolism was detected and one patient was dismissed before final diagnosis. Cardiac D-dimer assay from citrate tubes showed a sensitivity of 88.6%, a specificity of 54%, a positive predictive value of 57.4%, and a negative predictive value of 87.1%. Nearly identical results were observed with heparin tubes. Corresponding results were 88.6%, 48%, 52.5%, and 85.7% for STA-LIA and 88.6%, 46%, 53.4%, and 85.2% for Tina-quant, respectively. In conclusion, we can say that Cardiac D-dimer is a rapid, whole blood assay with a great potential for clinical use. It can help in diagnosing DVT from citrate as well as heparin tubes with comparable sensitivity, specificity, positive and negative predictive values as STA-LIA and Tina-quant tests.     

A rapid and quantitative D-Dimer assay in whole blood and plasma on the point-of-care PATHFAST analyzer

The objective of this study was to evaluate the accuracy indices of the new rapid and quantitative PATHFAST D-Dimer assay in patients with clinically suspected deep-vein thrombosis (DVT). Eighty two consecutive patients (34% DVT, 66% non-DVT) with suspected DVT of a lower limb were tested with the D-Dimer assay with a PATHFAST analyzer. The diagnostic value of the PATHFAST D-Dimer assay (which is based on the principle of a chemiluminescent enzyme immunoassay) for DVT was evaluated with pre-test clinical probability, compression ultrasonography (CUS). Furthermore, each patient underwent contrast venography and computed tomography, if necessary. The sensitivity and specificity of the D-Dimer assay using 0.570 mug/mL FEU as a clinical cut-off value was found to be 100% and 63.2%, respectively, for the diagnosis of DVT, with a positive predictive value (PPV) and negative predictive value (NPV) of 66.7% and 100%, respectively. The correlation between the results of PATHFAST D-Dimer and VIDAS D-Dimer was acceptable (y=1.134x+0.003, r=0.902). The test reproducibility was good (CV%: from 4.0% to 5.0% for plasma and from 7.1% to 7.5% for whole blood) and the total imprecision was very good (CV%: 3.6-5.7%). Whole blood as well as plasma can be used as samples in this assay (y=1.013x-0.010, r=0.971 for heparinized specimens; y=1.068x+0.003, r=0.989 for citrated specimens). Because of its high sensitivity and NPV PATHFAST D-Dimer assay can be useful for the rapid rule out of DVT in patients admitted with suspected thrombosis.