Efficacy and safety of venous thromboembolism prophylaxis with apixaban in major orthopedic surgery.

Over the last 15 years, low-molecular-weight heparins (LMWHs) have been accepted as the "gold standard" for pharmaceutical thromboprophylaxis in patients at high risk of venous thromboembolism (VTE) in most countries around the world. Patients undergoing major orthopedic surgery (MOS) represent a population with high risk of VTE, which may remain asymptomatic or become symptomatic as deep vein thrombosis or pulmonary embolism. Numerous trials have investigated LMWH thromboprophylaxis in this population and demonstrated high efficacy and safety of these substances. However, LMWHs have a number of disadvantages, which limit the acceptance of patients and physicians, especially in prolonged prophylaxis up to 35 days after MOS. Consequently, new oral anticoagulants (NOACs) were developed that are of synthetic origin and act as direct and very specific inhibitors of different factors in the coagulation cascade. The most developed NOACs are dabigatran, rivaroxaban, and apixaban, all of which are approved for thromboprophylaxis in MOS in a number of countries around the world. This review is focused on the pharmacological characteristics of apixaban in comparison with other NOACs, on the impact of NOAC on VTE prophylaxis in daily care, and on the management of specific situations such as bleeding complications during NOAC therapy.

Therapy of isolated calf muscle vein thrombosis: a randomized, controlled study.

BACKGROUND: Treatment of isolated calf muscle vein thrombosis (ICMVT) is controversial. There are no data from prospective, controlled studies. Objective of this article was to compare the efficacy and safety of a short-term course of anticoagulation with compression therapy alone. METHODS: We prospectively randomized patients with symptomatic, sonographically proven ICMVT in the soleal and/or gastrocnemial muscle veins in two treatment arms. The first received low-molecular-weight heparin for 10 days at therapeutic dosage (nadroparin 180 anti-activated factor X units once daily) and compression therapy for three months, and the second received compression therapy alone. Primary efficacy endpoint of the study was sonographically proven progression of ICMVT into the deep veins and clinical pulmonary embolism (PE) as confirmed by objective testing. Secondary efficacy and primary safety endpoints were major bleeding, death not due to PE, and complete sonographically proven recanalization of the muscle vein. We assessed transient and permanent risk factors for venous thromboembolism. RESULTS: One-hundred seven patients were finally ruled eligible for evaluation: 89% outpatients, 11% hospitalized patients. In the heparin group (n=54) progression to deep vein thrombosis (DVT) occurred in two patients (3.7%), in the group compression therapy alone (n=53) progression to DVT occurred in two patients (n.s.). No clinical PE and no death occurred. Thrombus recanalization after 3 months was not statistically significant different between the two study groups. No major bleeding occurred. CONCLUSION: The data do not show superiority of a short-term regimen of low-molecular-weight heparin and compression therapy in comparison with compression therapy alone in patients with ICMVT in a rather low-risk population.

Cancer in males and risk of venous thromboembolism.

Venous thromboembolism (VTE) is a common complication associated with increased mortality in cancer patients. Adequate treatment of thrombotic complications increases survival in these patients although additional complications such as thrombus progression with pulmonary embolism and bleeding events are common. The incidence of types of cancer as well as malignancy-associated VTE varies between genders. This article focuses on cancers more common in male patients and reviews the risk of VTE with special regard to types of cancer and anticancer therapy.

Venous thrombosis after long-haul flights.

BACKGROUND: The risk for venous thromboembolism after long-haul flights represents a controversial issue. The aim of our study was to assess the incidence of venous thrombosis associated with long-haul flights in a prospective, controlled cohort study. METHODS: We included 964 passengers returning from long-haul flights (flight duration, > or =8 hours) and 1213 nontraveling control subjects. We excluded participants who were being treated with anticoagulant drugs or who used compression stockings. Main outcome measures were the incidence of ultrasonographically diagnosed thrombosis in the calf muscle and deep veins, symptomatic pulmonary embolism, and death. RESULTS: We diagnosed venous thrombotic events in 27 passengers (2.8%) and 12 controls (1.0%) (risk ratio [RR], 2.83; 95% confidence interval [CI], 1.46-5.49). Of these, 20 passengers (2.1%) and 10 controls (0.8%) presented with isolated calf muscle venous thrombosis (RR, 2.52; 95% CI, 1.20-5.26), whereas 7 passengers (0.7%) and 2 controls (0.2%) presented with deep venous thrombosis (RR, 4.40; 95% CI, 1.04-18.62). Symptomatic pulmonary embolism was diagnosed in 1 passenger with deep venous thrombosis (P =.44). All of these individuals had normal findings at baseline ultrasonography. Passengers with isolated calf muscle venous thrombosis or deep venous thrombosis had at least 1 risk factor for venous thrombosis (>45 years of age or elevated body mass index in 21 of 27 passengers). The follow-up after 4 weeks revealed no further venous thromboembolic event. CONCLUSIONS: Long-haul flights of 8 hours and longer double the risk for isolated calf muscle venous thrombosis. This translates into an increased risk for deep venous thrombosis as well. In our study, flight-associated thrombosis occurred exclusively in passengers with well-established risk factors for venous thrombosis.

Complete compression ultrasonography of the leg veins as a single test for the diagnosis of deep vein thrombosis.

Noninvasive diagnosis of deep vein thrombosis (DVT) is based on ultrasound examination of the leg veins, usually restricted to only compression of the proximal veins (CUS). Patients with negative CUS findings require a second examination or a combination with other tests, which impairs clinical efficiency. In this prospective outcome study, 1646 consecutive patients with clinically suspected DVT were examined once by a standardized protocol of complete compression ultrasound comprising all proximal and distal veins (CCUS) as the only diagnostic test. The examination was equivocal in 15 patients (1% technical failure rate). Another 366 patients (22%) were tested positive for proximal DVT, distal DVT, muscle vein thrombosis, or phlebitis. Of 1265 patients in whom CCUS findings were negative, 242 met exclusion criteria for follow-up (age <18, life expectancy <3 months, other reasons for anticoagulation, postthrombotic lesions of the leg veins, or lack of informed consent). During the 3 months of follow-up, three of 1023 patients with negative CCUS findings experienced a symptomatic venous thromboembolic event (0.3% [95% CI 0.1%-0.8%]). We conclude that the CCUS protocol has a low technical failure rate and is safe with respect to excluding DVT, thereby reducing the diagnostic workup of patients with suspected DVT to a single ultrasound examination.