Highlights from the I international symposium of thrombosis and anticoagulation in internal medicine, October 23-25, 2008, Sao Paulo, Brazil

The importance of thrombosis and anticoagulation in clinical practice is rooted firmly in several fundamental constructs that can be applied both broadly and globally. Awareness and the appropriate use of anticoagulant therapy remain the keys to prevention and treatment. However, to assure maximal efficacy and safety, the clinician must, according to the available evidence, choose the right drug, at the right dose, for the right patient, under the right indication, and for the right duration of time. The first International Symposium of Thrombosis and Anticoagulation in Internal Medicine was a scientific program developed by clinicians for clinicians. The primary objective of the meeting was to educate, motivate and inspire internists, cardiologists and hematologists by convening national and international visionaries, thought-leaders and dedicated clinician-scientists in Sao Paulo, Brazil. This article is a focused summary of the symposium proceedings. © Springer Science+Business Media, LLC 2009.

Deep venous thrombosis prophylaxis in oral and maxillofacial surgery: a Brazilian survey

Background : Deep venous thrombosis (DVP) is a frequent disease. Prophylaxis is the best means to reduce its incidence, for lowering morbidity and mortality rates and treatment costs caused by its complications. Objective : To evaluate the knowledge and use of any kind of DVT prophylaxis by Brazilian Oral and Maxillofacial surgeons. Materials and Methods : A questionnaire was sent to all Oral and Maxillofacial surgeons associated to the Brazilian College of Oral and Maxillofacial Surgeons that have a valid e-mail address. The data retrieved was evaluated and tabulated. Results : Of the 1100 questionnaires sent, only 4% were retrieved. The 42 retrieved were included in the study. Twenty six of the surgeons do not use any kind of deep venous thrombosis (DVT) prophylaxis, 11 use mechanical means as elastic compressive stockings or pneumatic compressive devices for prophylaxis, and 5 uses low-molecular weight heparins (LMWH) as the choice for prophylaxis. Conclusion : The data collected, despite the low rate of participation (4%) by the surgeons, shows that this subject still does not receive proper attention. Whereas other medical specialties make routine use of prophylactic means maybe the maxillofacial surgeons lack concern on that matter.

Avaliação da qualidade de vida em pacientes portadores de câncer de esôfago submetidos à inserção de stent esofágico auto-expansível

Pós-graduação em Bases Gerais da Cirurgia - FMB

Increased risk of venous thrombosis by AB alleles of the ABO blood group and Factor V Leiden in a Brazilian population

Most cases of a predisposition to venous thrombosis are caused by resistance to activated protein C, associated in 95% of cases with the Factor V Leiden allele (FVL or R506Q). Several recent studies report a further increased risk of thrombosis by an association between the AB alleles of the ABO blood group and Factor V Leiden. The present study investigated this association with deep vein thrombosis (DVT) in individuals treated at the Hemocentro de Pernambuco in northeastern Brazil. A case-control comparison showed a significant risk of thrombosis in the presence of Factor V Leiden (OR = 10.1), which was approximately doubled when the AB alleles of the ABO blood group were present as well (OR = 22.3). These results confirm that the increased risk of deep vein thrombosis in the combined presence of AB alleles and Factor V Leiden is also applicable to the Brazilian population suggesting that ABO blood group typing should be routinely added to FVL in studies involving thrombosis.

Recanalization after acute deep vein thrombosis

O processo de recanalização das veias dos membros inferiores, após um episódio de trombose venosa profunda aguda em pacientes anticoagulados com heparina e inibidores da vitamina K, faz parte da evolução natural da remodelagem do trombo venoso. Esse complexo processo de remodelagem envolve a adesão do trombo à parede da veia, à resposta inflamatória da parede do vaso, levando à organização e subsequente contração do trombo, à neovascularização e à lise espontânea de áreas no interior do trombo. A presença de fluxo arterial espontâneo em veias com trombose recanalizada tem sido descrita como secundária à neovascularização e se caracteriza pelo desenvolvimento de fluxo com padrão de fístulas arteriovenosas, identificadas por meio de mapeamento dúplex colorido. Nesta revisão, são discutidos alguns aspectos controversos da história natural da trombose venosa profunda, para uma melhor compreensão da sua evolução e do seu impacto sobre a doença venosa.

Long-term clinical and ultrasonographic evaluation of thrombophilic patients with deep venous thrombosis

OBJECTIVE:The purpose of this study was to evaluate the long term clinical and ultrasonographic outcomes of thrombophilic patients with deep venous thrombosis (DVT).METHOD:Cohort study, retrospective case-control with cross-sectional analysis. Thirty-nine thrombophilic patients and 25 non-thrombophilic patients were assessed 76.3 ± 45.8 months after diagnosis. Demographic and family data were collected, as well as data from clinical and therapeutic progress, and physical and ultrasound examinations of the limbs were performed. Groups were matched for age and gender and the variables studied were compared across groups.RESULTS:Deep venous thrombosis was more frequent in women. The most common thrombophilias were antiphospholipid syndrome and factor V Leiden mutation. There was no difference between groups in terms of the number of pregnancies or miscarriages and the majority of women did not become pregnant after DVT. Non-spontaneous DVT prevailed. Proximal DVT and DVT of the left lower limb were more frequent, and the main risk factor was use of oral contraceptives. All patients were treated with anticoagulation. There was a higher frequency of pulmonary embolism in non-thrombophilic patients. Most patients considered themselves to have a normal life after DVT and reported wearing elastic stockings over at least 2 years. Seventy-one percent of patients had CEAP > 3, with no difference between groups. Deep venous reflux was more frequent in thrombophilic patients.CONCLUSION:There were no significant differences between groups with respect to most of the variables studied, except for a higher frequency of pulmonary embolism in non-thrombophilic patients and greater frequency of deep venous reflux in thrombophilic patients.

The Kallikrein Inhibitor from Bauhinia bauhinioides (BbKI) shows antithrombotic properties in venous and arterial thrombosis models

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A Reproducible Venous Thrombosis Model in Horses Induced by the Combination of an Endothelial Lesion and Blood Flow Stasis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Recanalization Rates after Acute Deep Vein Thrombosis: A Single-center Experience Using a Newly Proposed Vein Diameter Variation Index

Background: Duplex ultrasound scanning (DUS) is the method of choice for diagnosis of deep vein thrombosis (DVT). However, only a few studies have performed prospective serial DUS after an acute episode of DVT to assess its evolution. This study aimed to report our experience using DUS combined with a thrombosis score (TS) and a newly proposed vein diameter variation index (VDVI) to evaluate the rate of resolution of DVT by assessing and quantifying the early stages of vein recanalization in proximal vein segments within 6 months after an episode of acute lower extremity DVT.Methods: Twelve patients with first episode of acute lower extremity DVT confirmed by DUS as occurring in <= 10 days after the onset of venous thrombosis symptoms were followed up prospectively for 6 months. TS and VDVI were calculated at 1, 3, and 6 months to assess vein recanalization. Intra-thrombus arteriovenous fistula formation was also investigated and related to the recanalization process.Results: Seven (58%) women were included, with a total cohort median age of 53.5 +/- 19 years. The left lower extremity was affected in 7 (58%) patients. DVT was diagnosed in 55 proximal vein segments. All patients had proximal DVT, with involvement of the external iliac, femoral, and popliteal veins. After 6 months, there was a significant decrease in TS and increase in VDVI (P < 0.001) in all proximal vein segments assessed, indicating thrombus regression. The more distal the DVT was, the faster was the VDVI increase, with most popliteal veins being recanalized at 3 months (P < 0.001). Intra-thrombus arteriovenous fistula was identified in 50% of patients at 1 month while on anticoagulation.Conclusions: The combined use of two different DUS-based assessment tools, TS and the proposed VDVI, provided an effective method to prospectively assess vein recanalization rates after an episode of acute lower extremity DVT in this series of patients and may allow a correct evaluation of DVT and its resolution or progression.

PREDICTABLE INTERPROXIMAL TISSUE REMOVAL WITH A SURGICAL STENT

The correction of diastemas in the anterior region with composite resin is considered to be practical and conservative. Harmony between the restorative material and the periodontium is necessary to achieve satisfactory functional and esthetic results. Whenever excessive gingiva occurs in the interproximal region, removal is necessary to avoid excessively contoured restorations. A predictable technique is described to conservatively remove interproximal tissue in situations in which crown lengthening is required to treat bilateral diastemas. A surgical template based on the diagnostically waxed cast was produced to serve as a reference during periodontal surgery.

Embolization of splenorenal shunt associated to portal vein thrombosis and hepatic encephalopathy

Hepatic encephalopathy (HE) is a cognitive disturbance characterized by neuropsychiatric alterations. It occurs in acute and chronic hepatic disease and also in patients with portosystemic shunts. The presence of these portosystemic shunts allows the passage of nitrogenous substances from the intestines through systemic veins without liver depuration. Therefore, the embolization of these shunts has been performed to control HE manifestations, but the presence of portal vein thrombosis is considered a contraindication. In this presentation we show a cirrhotic patient with severe HE and portal vein thrombosis who was submitted to embolization of a large portosystemic shunt. Case report: a 57 years-old cirrhotic patient who had been hospitalized many times for persistent HE and hepatic coma, even without precipitant factors. She had a wide portosystemic shunt and also portal vein thrombosis. The abdominal angiography confirmed the splenorenal shunt and showed other shunts. The larger shunt was embolized through placement of microcoils, and the patient had no recurrence of overt HE. There was a little increase of esophageal and gastric varices, but no endoscopic treatment was needed. Since portosystemic shunts are frequent causes of recurrent HE in cirrhotic patients, portal vein thrombosis should be considered a relative contraindication to perform a shunt embolization. However, in particular cases with many shunts and severe HE, we found that one of these shunts can be safely embolized and this procedure can be sufficient to obtain a good HE recovery. In conclusion, we reported a case of persistent HE due to a wide portosystemic shunt associated with portal vein thrombosis. As the patient had other shunts, she was successfully treated by embolization of the larger shunt. (C) 2014 Baishideng Publishing Group Inc. All rights reserved.

Do anticoagulant and antiplatelet agents prevent acute graft thrombosis in renal transplantation? A meta-analysis of case series studies

Introduction & Objectives: Thrombosis of the renal allograft is expected to occur in 1–6% of kidney transplants, and graft loss is expected in almost all cases. Anticoagulant and anti-platelet agents could serve as an adjunctive preventive measure, but sound evidence of benefits are still lacking, in this setting. We therefore assessed the efficacy and safety of anticoagulant and anti-platelet agents, in reducing the rate of renal allograft thrombosis. Methods: A review of the literature was carried out in major databases (MEDLINE, EMBASE and LILACS), with a comprehensive search strategy, to locate all available case series studies of anticoagulant and/or anti-platelet prophylaxis of thrombosis in renal transplantation. The date of the last search was 11 August 2014. We pooled all case series in a proportional meta-analysis. Statistical significance was achieved if the 95% confidence intervals obtained for each intervention did not overlap. Results: Our search strategy retrieved 7160 titles, from which 21 case series were chosen for analysis. A total of 3246 patients were identified (1718 treated with antiplatelet and/or anticoagulant agents, and 1528 non-treated control subjects). Allograft thrombosis occurred in 7.24% (95% CI 3.45 to 12.27%) of the patients receiving no intervention, compared to 3.38% (95% CI 1.45 to 6.1%), 1.2% (95% CI 0.6 to 2.1%) and 0.47% (95% CI 0.001 to 1.79%), in the anticoagulant, aspirin, and aspirin + anticoagulant groups, respectively. Bleeding complication rates were 28.0% (95% CI 15.4 to 42.7%) for anticoagulants, compared to 12.13% (95% CI 0.8 to 33.93%) for aspirin + anticoagulant, 0.31% (95% CI 0.0001 to 1.32%) for aspirin, and 6.1% (95% CI 2.2 to 11.7%) for the control group. Conclusions: Aspirin is more effective in reducing allograft thrombosis, after kidney transplantation, whether alone or in association with an anticoagulant, when compared to no drug prophylaxis, and without higher haemorrhagic complication rates. Anticoagulants, when used alone, do not show a beneficial effect on thrombosis rates, additionally yielding higher bleeding rates.

Lufaxin, a Novel Factor Xa Inhibitor From the Salivary Gland of the Sand Fly Lutzomyia longipalpis Blocks Protease-Activated Receptor 2 Activation and Inhibits Inflammation and Thrombosis In Vivo

Objective-Blood-sucking arthropods' salivary glands contain a remarkable diversity of antihemostatics. The aim of the present study was to identify the unique salivary anticoagulant of the sand fly Lutzomyia longipalpis, which remained elusive for decades. Methods and Results-Several L. longipalpis salivary proteins were expressed in human embryonic kidney 293 cells and screened for inhibition of blood coagulation. A novel 32.4-kDa molecule, named Lufaxin, was identified as a slow, tight, noncompetitive, and reversible inhibitor of factor Xa (FXa). Notably, Lufaxin's primary sequence does not share similarity to any physiological or salivary inhibitors of coagulation reported to date. Lufaxin is specific for FXa and does not interact with FX, Dansyl-Glu-Gly-Arg-FXa, or 15 other enzymes. In addition, Lufaxin blocks prothrombinase and increases both prothrombin time and activated partial thromboplastin time. Surface plasmon resonance experiments revealed that FXa binds Lufaxin with an equilibrium constant approximate to 3 nM, and isothermal titration calorimetry determined a stoichiometry of 1:1. Lufaxin also prevents protease-activated receptor 2 activation by FXa in the MDA-MB-231 cell line and abrogates edema formation triggered by injection of FXa in the paw of mice. Moreover, Lufaxin prevents FeCl3-induced carotid artery thrombus formation and prolongs activated partial thromboplastin time ex vivo, implying that it works as an anticoagulant in vivo. Finally, salivary gland of sand flies was found to inhibit FXa and to interact with the enzyme. Conclusion-Lufaxin belongs to a novel family of slow-tight FXa inhibitors, which display antithrombotic and anti-inflammatory activities. It is a useful tool to understand FXa structural features and its role in prohemostatic and proinflammatory events. (Arterioscler Thromb Vasc Biol. 2012;32:2185-2196.)