Search

Aim To present a technical note on intra-sinusal bone ring concomitant with Le Fort 1 osteotomy. Material and method A 57-year-old man was referred to our Department for full-mouth rehabilitation. Oral examination identified: uncompensated multiple tooth loss and a class 3 skeletal malocclusion. The treatment plan consisted in a Le Fort 1 osteotomy and short-arch dental implant rehabilitation. Intra-sinusal bone ring technique associated with Le Fort 1 osteotomy were carried out under general anaesthesia. Result High primary retention was clinically observed of both the implant and the bone graft. Radiographic follow-up demonstrated satisfactory healing of the graft and implant osseointegration. Conclusion Bone ring technique concomitant with Le Fort 1 osteotomy seems to be appropriate to correct jaw discrepancy associated to a single tooth loss of the upper molar region with residual bone height of at least 3 mm to ensure implant primary stability.

L’hématome intracrânien spontané a un pronostic clinique sévère. Le devenir des patients dépend de l’efficacité de la prise en charge initiale. L’importance du saignement, le volume de l’hématome et son évolution sont les facteurs principaux qui contrôlent mortalité et morbidité. Les traitements anticoagulants oraux, antivitamines K (AVK) et anticoagulants oraux directs (AOD), favorisent l’expansion de l’hématome. La correction rapide de l’hémostase permet le contrôle partiel de l’hématome. Alors que la réversion des AVK par les concentrés de complexe prothrombinique (CCP) a fait l’objet de recommandations bien diffusées, l’attitude thérapeutique reste peu codifiée avec les AOD, alliant l’utilisation de l’idarucizumab pour le dabigatran et des CCP pour les anti-Xa qui n’ont, pour l’instant, pas d’antidote.

Patient blood management (PBM) is the timely application of evidence-informed medical and surgical concepts designed to maintain haemoglobin concentration, optimise haemostasis and minimise blood loss in an effort to improve patient outcomes. The aim of this consensus statement is to provide recommendations on the management of anaemia and haematinic deficiencies in pregnancy and in the post-partum period as part of PBM in obstetrics. A multidisciplinary panel of physicians with expertise in obstetrics, anaesthesia, haematology, policymaking and epidemiology was convened by the Network for the Advancement of Patient Blood Management, Haemostasis and Thrombosis (NATA) in collaboration with the International Federation of Gynaecology and Obstetrics (FIGO) and the European Board and College of Obstetrics and Gynaecology (EBCOG). Members of the task force assessed the quantity, quality and consistency of the published evidence and formulated recommendations using the system developed by the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) working group. The recommendations in this consensus statement are intended for use by clinical practitioners managing the perinatal care of women in all settings and by policymakers in charge of decision making for the update of clinical practice in health-care establishments. They need to be tailored for application in individual patients or any population after consideration of the values and preferences of both health-care providers and patients, as well as equity issues; explicit assessment of harms and benefits of each recommendation; feasibility including resources, capacity and equipment; and implementability.

Les nouvelles recommandations 2018 de l’ESA vont changer le paysage de la thromboprophylaxie. Realisees avec le concours de (et endossees par) deux societes europeennes d’orthopedie (EHS et EKS), la Societe europeenne d’urologie (EAU), une Societe de chirurgie digestive (EDS), la Societe europeenne de gyneco-obstetrique (EPCOG), l’ESICM, l’ISTH et NATA, elles apportent un nouvel eclairage comparativement aux recommandations de 2008 et 2012 de l’ACCP. Elles viennent d’etre endossees egalement par la SFAR. Elles reprennent en detail neuf sujets cliniques et trois controverses qui n’avaient pas ete traites par les precedentes recommandations nord-americaines. Longtemps absente des recommandations nord-americaines, l’aspirine a fait un grand retour en 2012 avec les 9e recommandations de l’ACCP qui la placait au meme niveau que les heparines de bas poids moleculaire, les anticoagulants oraux directs, ou les antivitamines K, avec un grade 1B pour la prevention apres une chirurgie de la prothese totale de hanche ou de genou. Son utilisation est d’ailleurs de pratique courante aux Etats-Unis. Les recommandations europeennes reprennent ce niveau de recommandation (1B) en y adjoignant la chirurgie pour la fracture du femur. La recommandation est degradee en 2 C quand il est suggere de preferer l’aspirine pour les chirurgies a haut risque hemorragique, a faible risque thrombotique, ou pour les programmes de rehabilitation rapide apres chirurgie. Aucune dose n’est proposee meme si l’on peut imaginer donner une dose de charge de 160 a 325 mg un jour, suivie d’une dose d’entretien de 75 mg quotidienne. La duree doit rester celle qui etait proposee avec les anticoagulants, soit un mois. Attention, seules ces trois indications chirurgicales sont concernees. Pas d’aspirine ailleurs. L’ensemble des recommandations peut etre retrouve dans l’Executive Summary publie par l’European Journal of Anesthesiology: Afshari A, Ageno W, Ahmed A, Duranteau J, Faraoni D, Kozek-Langenecker S, et al. European Guidelines on perioperative venous thromboembolism prophylaxis: Executive summary. Eur J Anaesthesiol. 2018;35:77–83.

En la profilaxis de la enfermedad tromboembolica venosa en los pacientes hospitalizados por una afeccion aguda grave se ha utilizado, con exito pero sin modificacion de la mortalidad, esencialmente, una heparina de bajo peso molecular (HBPM) o el pentasacarido fondaparinux. La estrategia sugerida actualmente por las sociedades cientificas se basa en el uso de un sistema de clasificacion por puntos del riesgo tromboembolico asociado a un sistema de clasificacion por puntos de prediccion del riesgo hemorragico. Un pequeno numero de situaciones clinicas (cancer, trombofilia, accidente cerebrovascular, viajes largos, hospitalizacion en unidades de cuidados intensivos, etc.) son objeto de una propuesta de enfoque preventivo en funcion del nivel de riesgo. Finalmente, a pesar de progresos importantes, no se ha llegado a un consenso sobre la tromboprofilaxis en los pacientes hospitalizados en un entorno medico no quirurgico. Existe una tendencia a reducir la duracion del tratamiento en comparacion con las estrategias mas antiguas. No debe utilizarse sistematicamente, sino que debe decidirse en funcion de los sistemas de clasificacion por puntos validados prospectivamente.

La profilassi della malattia tromboembolica venosa nei pazienti ricoverati per una patologia acuta grave ha utilizzato, con successo ma senza modificazione della mortalita, essenzialmente un’eparina di basso peso molecolare (EBPM) o il pentasaccaride (fondaparinux). La strategia attualmente consigliata dalle societa scientifiche si basa sull’utilizzo di un punteggio di rischio tromboembolico associato a un punteggio di predizione del rischio emorragico. Un piccolo numero di situazioni cliniche (cancro, trombofilia, accidente vascolare cerebrale, lunghi viaggi, ricovero in un’unita di terapia intensiva, ecc.) e oggetto di una proposta di atteggiamento preventivo in funzione del livello di rischio. Complessivamente, malgrado importanti progressi, la tromboprofilassi nei pazienti ricoverati in ambiente medico non giunge a un consenso. Vi e la tendenza a ridurre la durata del trattamento rispetto alle strategie piu antiche. La tromboprofilassi non deve essere utilizzata sistematicamente, ma deve essere decisa in funzione dei punteggi validati prospetticamente.

Click to hear Dr Baglin's perspective on the role of the laboratory in treatment with new oral anticoagulants SUMMARY: One of the key benefits of the direct oral anticoagulants (DOACs) is that they do not require routine laboratory monitoring. Nevertheless, assessment of DOAC exposure and anticoagulant effects may become useful in various clinical scenarios. The five approved DOACs (apixaban, betrixaban, dabigatran etexilate, edoxaban and rivaroxaban) have different characteristics impacting assay selection and the interpretation of results. This article provides an updated overview on (i) which test to use (and their advantages and limitations), (ii) when to assay DOAC levels, (iii) how to interpret the results relating to bleeding risk, emergency situations and perioperative management, and (iv) what is the impact of DOACs on routine and specialized coagulation assays. Assays for anti-Xa or anti-IIa activity are the preferred methods when quantitative information is useful, although the situations in which to test for DOAC levels are still debated. Different reagent sensitivities and variabilities in laboratory calibrations impact assay results. International calibration standards for all specific tests for each DOAC are needed to reduce the inter-laboratory variability and allow inter-study comparisons. The impact of the DOACs on hemostasis testing may cause false-positive or false-negative results; however, these can be minimized by using specific assays and collecting blood samples at trough concentrations. Finally, prospective clinical trials are needed to validate the safety and efficacy of proposed laboratory thresholds in relation to clinical decisions. We offer recommendations on the tests to use for measuring DOACs and practical guidance on laboratory testing to help patient management and avoid diagnostic errors. ispartof: Journal of Thrombosis and Haemostasis vol:16 issue:2 pages:209-219 ispartof: location:England status: published

I farmaci derivati dal plasma (FDP) sono delle proteine terapeutiche indicate come trattamento sostitutivo di deficit quantitativi o qualitativi, costituzionali o acquisiti in proteine essenziali. Questi prodotti sono preparati industrialmente a partire dal plasma umano secondo un procedimento di alta tecnologia, il frazionamento plasmatico, garantendo la loro efficacia e una sicurezza massimale nei confronti del rischio infettivo. Lo status di «farmaco» impone il rispetto di un protocollo rigido e regolamentato. Noi trattiamo i FDP usati a scopo antiemorragico e antitrombotico, nel quadro di patologie spesso gravi, a volte rare, in situazioni croniche o in urgenza, in situazioni che minacciano la prognosi vitale. La loro frequenza di utilizzo e molto variabile. I fattori VIII, IX e di von Willebrand sono i piu prescritti, in profilassi o nel trattamento delle complicanze emorragiche. Dal momento che i deficit costituzionali in fattori XI, XIII, antitrombina e proteina C sono molto rari, l’utilizzo dei concentrati di fattori corrispondenti e aneddotico. Viceversa, i concentrati di complesso protrombinico non attivato e attivato e i concentrati di fibrinogeno occupano un ruolo crescente nell’arsenale terapeutico come agenti emostatici nella gestione delle emorragie massive associate a deficit acquisiti.

Los medicamentos derivados del plasma (MDP) son proteinas terapeuticas que se prescriben como tratamiento sustitutivo de deficits cuantitativos o cualitativos, constitucionales o adquiridos, de proteinas esenciales. Estos productos se preparan industrialmente a partir del plasma humano con un procedimiento de alta tecnologia, denominado fraccionamiento plasmatico, que garantiza su eficacia y una seguridad maxima respecto al riesgo infeccioso. El estatus de «medicamento» supone ajustarse a un protocolo estricto y reglamentado. Aqui se han de considerar los MDP que se usan con objetivo antihemorragico y antitrombotico en el contexto de patologias a menudo graves, a veces infrecuentes, en situacion cronica o de urgencia, y en casos que amenazan el pronostico vital. La frecuencia con la que se usan es muy variable. Los factores VIII, IX y de Von Willebrand son los que mas se prescriben, ya sea como profilaxis o tratamiento de las complicaciones hemorragicas. Dado que los deficits constitucionales de factores XI, XIII, antitrombina y proteina C son muy infrecuentes, el uso de los concentrados de factores correspondientes es excepcional. En cambio, los concentrados de complejo protrombinico no activado y activado, asi como los concentrados de fibrinogeno, ocupan un lugar creciente en el arsenal terapeutico como agentes hemostaticos en el manejo de las hemorragias masivas vinculadas a deficits adquiridos.

Heparins and vitamin K antagonists (VKA) used commonly are the standard treatment of venous and arterial thromboses. They are very efficient and safe, but have some limitations: iatrogenicity, laboratory monitoring, parenteral use for heparins and fondaparinux. Nowadays, four new inhibitors of factor Xa are used orally (rivaroxaban, apixaban, edoxaban, betrixaban), and they are at least as efficient as heparins and vitamin K antagonists. The objective is to substitute these indirect inhibitors of factor Xa (heparins, low molecular weight heparins and fondaparinux) in the prevention of venous and arterial thromboembolic episodes. The new direct inhibitors do not require routine laboratory monitoring of blood coagulation. They inhibit the extrinsic and the intrinsic pathways of blood coagulation. Rivaroxaban and apixaban are efficacious and safe in the prevention of cerebral infarcts in patients with non-valvular fibrillation. Apixaban is another direct inhibitor of factor Xa used orally which is developed in the same indications as rivaroxaban. Edoxaban and betrixaban are also in development. The objective of this work is to study the pharmacodynamic, pharmacokinetic, the efficacy and safety of these four oral direct factor Xa inhibitors.

La chirurgie a change grâce aux progres extraordinaires des techniques chirurgicales et anesthesiques, mais egalement grâce a la pression justifiee des patients et des autorites de Sante. Les procedures de recuperation rapide, de meme que la chirurgie ambulatoire, ont enormement progresse ces dernieres annees. Elles modifient egalement le paysage. Le risque thromboembolique veineux s’en trouve affecte favorablement. Il est desormais bien montre qu’une intervention plus courte que la moyenne comporte un risque thromboembolique veineux moins important. De meme, une hospitalisation raccourcie ne peut pas induire le meme risque qu’une hospitalisation prolongee. Ainsi quand il fallait 15 jours d’hospitalisation apres une colectomie pour cancer il y a une quinzaine d’annees, le risque thromboembolique etait evidemment plus important que de nos jours, ou les deux tiers des patients seront sortis au troisieme jour. Les resultats de la RRAC (Recuperation Rapide Apres Chirurgie) sont encore plus spectaculaires en chirurgie de la prothese totale de hanche et de la prothese totale du genou. Toutefois, le probleme pose par la maladie thromboembolique veineuse en postoperatoire est loin d‘etre regle. En particulier, meme si les durees d’hospitalisation diminuent, les procedures de RRAC ne sont pas encore dominantes en chirurgie tumorale abdomino-pelvienne ou en orthopedie pour la chirurgie du rachis. Les traitements prophylactiques restent ceux recommandes par les recommandations de la SFAR 2011 et de l’ACCP 2012, et il en va de meme pour les durees de traitement. Ainsi, jusqu’a preuve du contraire toute chirurgie majeure abdominale doit recevoir la prophylaxie preventive usuelle d’heparine de bas poids moleculaire (4000 U d’enoxaparine SC, 5000 UI de dalteparine SC) durant un mois. De la meme maniere les debats qui enflamment la chirurgie bariatrique sont loin d’etre termines : une ou deux injections, quelles doses, combien de temps ? Enfin, il faut bien reconnaitre que l’evaluation du risque thromboembolique est differente selon qu’on se situe de part ou d’autre de l’Atlantique, en Anesthesie-Reanimation ou en Chirurgie.

Resume L’objectif a ete d’evaluer, a partir de donnees de la litterature, le risque d’hemorragies fatales qu’ajouterait un eventuel traitement anticoagulant curatif des thromboses veineuses asymptomatiques depistees par un echo-doppler systematique apres protheses totales de hanche/genou, et de fractures de hanche. Materiel et methodes L’incidence des evenements thromboemboliques et hemorragiques avec la prophylaxie recommandee et celle des hemorragies majeures iatrogenes liees au traitement anticoagulant curatif, ont ete extraites d’essais cliniques randomises, d’analyses des codages de pathologies en sortie d’hospitalisation, de registres et enquetes observationnelles. L’incidence des evenements mortels a ete calculee pour l’embolie pulmonaire, les hemorragies sous prophylaxie, et les hemorragies iatrogenes sous anticoagulation curative, en multipliant le taux moyen de l’evenement symptomatique par son coefficient de mortalite. Les taux d’evenements mortels ont ete evalues pour un ensemble theorique de 10 000 protheses totales de hanche/genou, et de 10 000 fractures de hanche. Resultats Sur 10 000 patients apres protheses de hanche/genou, cinq embolies pulmonaires fatales et deux hemorragies fatales sont attendues malgre la prophylaxie recommandee. L’anticoagulation curative des thromboses asymptomatiques sous-jacentes ajouterait neuf hemorragies fatales dont huit liees au traitement des seules thromboses distales. Sur 10 000 fractures de hanche soumises a une prophylaxie prolongee, six embolies pulmonaires fatales et 23 hemorragies fatales sont attendues. L’anticoagulation curative des thromboses asymptomatiques ajouterait 16 hemorragies fatales dont 14 liees au traitement des seules thromboses distales. Conclusion L’anticoagulation curative des thromboses veineuses asymptomatiques, en particulier distales, conduirait a davantage de deces par hemorragie qu’elle ne pourrait en eviter par embolie pulmonaire, ce qui renforce la recommandation de ne pas les depister.

B-cell lymphoblastic lymphoma (B-LBL) rarely occurs in the oral cavity (3.5% of all intra-oral malignant tumors). Few cases of B-LBL mandibular bone involvement have been reported.We report the case of a 30-year-old female patient presenting with a single swelling of the left mandibular region, having grown for several weeks. Maxillo-facial CT and MRI showed inflammation of soft tissues and muscles without initial signs of osteitis, thus noncontributive to the diagnosis. A biopsy allowed diagnosing an intra-oral bone lymphoblastic lymphoma. The patient was referred to the hematooncology unit for treatment.Jaw localization of non Hodgkin's lymphoma is rare. Clinical symptomatology and radiological signs are poorly contributive. The diagnosis relies on a histopathological analysis.

The vascular endothelium has been characterized in every organ system, and is described as a selective permeable barrier and as a dynamic and disseminated organ with endocrine function. These activities have been shown to result from the interactions of ligands with membrane-bound receptors as well as through specific junctional proteins and receptors that govern cell-cell interactions. The endothelial cells' movement (e.g., angiogenesis) has been hypothesized to occur following the release of stimuli that could promote the formation of new blood vessels. Angiogenesis has also been reported to be the continued expansion of the vascular tree in avascular regions, as a result of the sprouting of endothelial cells from existing vessels. Most commonly, angiogenesis has been characterized during wound healing and tumour growth. Herein we summarize and discuss the latest results from fundamental laboratory research aimed at proving a link between the proliferation of cancer and angiogenesis, as well as the new rationale around novel pro- and anti-angiogenic molecules.

Resume Introduction Les necroses cutanees sont des complications rares des traitements anticoagulants oraux par anti-vitamine K (AVK). Elles se manifestent par des necroses hemorragiques et surviennent habituellement a l’instauration du traitement. Nous decrivons un cas atypique de necroses cutanees apparues apres deux ans de traitement par fluindione, revelant un deficit genetique en proteine C. Observation Une femme de 70 ans, aux antecedents de maladie veineuse thromboembolique et d’obesite, consultait en urgence pour une vaste zone de necrose cutanee hemorragique de la paroi abdominale. Elle etait traitee depuis deux ans par fluindione. Le diagnostic de necrose cutanee induite par le traitement AVK etait retenu, permettant de mettre en evidence un deficit genetique en proteine C. Une recidive a la reprise d’un traitement du meme type, malgre une administration concomitante d’heparine de bas poids moleculaire, ne permettait pas la poursuite de l’anticoagulation orale par AVK. Discussion L’originalite de cette observation reside dans la survenue tardive de la necrose cutanee. Cet evenement indesirable a ete decrit a l’instauration des AVK, notamment entre le troisieme et le sixieme jours, en raison d’un etat d’hypercoagulabilite transitoire chez les patients deficitaires en proteine C ou, plus rarement, en proteine S. La survenue tardive d’une necrose cutanee, plusieurs annees apres le debut du traitement par AVK, peut s’expliquer par une aggravation brutale du deficit preexistant en proteine C sous l’influence de facteurs infectieux et iatrogenes.

Direct oral anticoagulants (DOAs), inhibitors of factor IIa or Xa, are expected to replace vitamin K antagonists in most of their indications. It is likely that patients on long-term treatment with DOAs will be exposed to elective or emergency surgery or invasive procedures. Due to the present lack of experience in such conditions, we cannot make recommendations, but only propose perioperative management for optimal safety as regards the risk of bleeding and thrombosis. DOAs may increase surgical bleeding, they have no validated antagonists, they cannot be monitored by simple, standardised laboratory assays, and their pharmacokinetics vary significantly from patient to patient. Although DOAs differ in many respects, the proposals in the perioperative setting need not be specific to each. For procedures with low risk of haemorrhage, a therapeutic window of 48 h (last administration 24h before surgery, restart 24h after) is proposed. For procedures with medium or high haemorrhagic risk, we suggest stopping DOAs 5 days before surgery to ensure complete elimination of the drug in all patients. The treatment should be resumed only when the risk of bleeding has been controlled. In patients with a high risk of thrombosis (e.g. those in atrial fibrillation with an antecedent of stroke), bridging with heparin (low molecular weight, or unfractionated if the former is contraindicated) is proposed. In emergency, the procedure should be postponed for as long as possible (minimum 1-2 half-lives) and non-specific anti-haemorrhagic agents, such as recombinant human activated factor VIIa, or prothrombin concentrates, should not be given for prophylactic reversal, due to their uncertain benefit-risk.

Les antagonistes de la vitamine K (AVK) et les heparines sont les therapeutiques de reference de la prevention des accidents thromboemboliques veineux et arteriels. Ils ont de nombreux avantages et un petit nombre d’inconvenients: iatrogenicite et necessite d’une surveillance biologique pour les AVK, activite limitee a la voie parenterale pour les heparines.

Assisted reproductive techniques (ART) concern procedures designed to increase fertility of couples: artificial insemination, in vitro fertilization (IVF), either classical or after intracytoplasmic sperm injection (ICSI), transfer of frozen embryos, or gamete intrafallopian transfer. Their use has greatly increased these last years. They may be associated with severe ovarian hyperstimulation syndrome and one possible major complication is venous or arterial thrombosis. Thromboses are rare but potentially serious with important sequellae. They are mostly observed in unusual sites such as head and neck vessels and the mechanism is still unknown although hypotheses have been proposed. This review is an update of our knowledge and an attempt to consider guidelines for the prevention and treatment of ART-associated thromboses, which frequently occur when the woman is pregnant. Prevention of severe ovarian hyperstimulation by appropriate stimulation procedures, detection of women at risk of hyperstimulation and of women at high risk of thrombosis should allow reduction of the risk of thrombosis, possibly by administration of a thromboprophylaxis at a timing and dose which can be only determined by extrapolation.

There are strong demands for innovative anti-thrombogenic materials, such as carbon, because of their necessity in fabricating artificial organs and progressive surgical vascular prostheses. Serial platelet deposition, surface topography, and patency were evaluated in control standard (N 45) and carbon-lined (N 45), small diameter (4 mm inner diameter) polytetrafluoroethylene grafts implanted in the abdominal aortic replacement in rabbits. A pilot study of 80 animals—40 carbon-lined (CL) and 40 standard (ST) grafts were used to develop microsurgical techniques. The 2-hour graft patency (Doppler and angiographic studies) showed better patency rate in the CL group (93% vs 80%). In 10 animals (5 ST and 5 CL grafts) the platelet deposition on each prostheses was quantitated by means of Indium 111 labeled platelets in a dual, isotope-platelet imaging technique. Platelet deposition on ST grafts 2 hours after insertion was significantly higher than on the CL grafts (6.60±1.98×103 platelets/mm2 vs 0.82±0.25×103 platelets/mm2;p

Resume Les traitements par les deux principaux inhibiteurs de l’agregation plaquettaire, l’aspirine et le clopidogrel, sont utilises regulierement au long cours par plus d’un million de francais, et le plus souvent, dans la prevention secondaire des accidents thrombotiques arteriels tels que l’infarctus du myocarde, les accidents vasculaires cerebraux ou les complications ischemiques de l’arteriopathie des membres inferieurs. Le terme de « resistance » souvent utilise est source de confusion. Il doit etre explicite et il semble plus judicieux de parler de « variabilite de reponse », terme plus generalement accepte par les specialistes et les chercheurs. Il est preferable d’utiliser le terme de variabilite de reponse plaquettaire car les veritables resistances pharmacologiques sont rares et ce distinguo peut avoir une importance clinique en terme pronostic. De nombreux travaux tant biologiques que cliniques et une abondante litterature ont ameliore la comprehension de ce sujet. Divers examens d’exploration des fonctions plaquettaires peuvent etre utilises pour evaluer l’impact biologique du traitement. Ils devraient dans un proche avenir contribuer a la mise en place de recommandations ou de suggestions pour l’optimisation des modalites therapeutiques. Les resultats attendus de larges etudes prospectives en cours devront au prealable confirmer l’interet potentiel et la pertinence clinique de ces tests avant leur utilisation en routine.

In a previous work, we have compared two automated techniques for platelet-rich plasma using a thrombocounter or whole blood with the continuous flow instrument Auto-analyzer (AA). More recently, we have tested two instruments using whole blood: the first one, fully automated: Coulter S+; and the other one, semi-automated: Clay-Adams. In the present work, these 4 methods are compared to the phase contrast microscope technique, used as reference. The coefficients of variation ranged betweeen 2 and 13 per cent. The coefficients of correlation between the different methods were between 0.92 and 0.96. Platelet distribution curves for platelet volumes obtained in parallel with platelet-rich plasma and with whole blood in 30 controls, show that platelet population are not significantly different. These instruments count particles and, therefore, necessitate a calibration made by means of platelet standards. Different platelet standards have been studied: those containing latex particles seem to give better results than suspensions of human or animal platelets.

The overall thromboembolic risk is the resultant of patient-related risk and surgical risk. The surgical risk is decreasing, especially with the introduction of new procedures (fast-track surgery). The value of prophylaxis has been firmly established. Mechanical prophylaxis is to be used as first-line prophylaxis when there is a risk of bleeding. Combining this with drugs increases the antithrombotic efficacy. However, the effectiveness of prophylaxis on pulmonary embolism and mortality has not been demonstrated. Renal function needs to be evaluated when low molecular weight heparins, fondaparinux, rivaroxaban or dabigatran are prescribed. An age of over 75 years and low body weight (

Acute venous thromboembolism (VTE) is a serious and potentially fatal disorder, which often complicates the course of hospitalized medical patients. This is particularly true for carriers of malignant diseases. While the introduction of thromboprophylactic measures has probably affected the occurrence of postoperative VTE, there is an increasing awareness of the importance of medical conditions in determining thromboembolic events. Simple and clinically relevant risk assessment models are available to facilitate VTE risk assessment in hospitalized medical patients. Their validation in prospective studies is in progress. Randomized controlled clinical trials have consistently documented the efficacy of heparins and fondaparinux for prevention of VTE in hospitalized medical patients with a minimal haemorrhagic risk. Recognition of the incidence and clinical importance of thrombosis will probably encourage more widespread use of antithrombotic prophylaxis in medical patients and especially in some particular types of malignancies.

La trombosis venosa profunda es el resultado de un fenomeno fisiologico que se desarrolla en un lugar no deseado de la red venosa. Se produce por razones que pocas veces estan relacionadas con trastornos de la coagulacion (trombofilia), sino sobre todo con la estasis venosa y con lesiones endoteliales. Estos tres elementos constituyen la clasica triada de Virchow. Es probable que el factor tisular sea un mediador determinante de la enfermedad tromboembolica, cuyas consecuencias locales pueden producir molestias funcionales en la pierna y ser potencialmente catastroficas si da lugar a una embolia pulmonar. La cirugia ortopedica y traumatologica es causa destacada de enfermedad venosa tromboembolica, sobre todo las protesis totales de cadera y de rodilla, asi como las fracturas del extremo superior del femur, que aparecen en una poblacion a menudo envejecida, con una movilidad reducida, con sobrepeso y con factores frecuentes de comorbilidad. La profilaxis farmacologica ha experimentado progresos considerables en las ultimas decadas, hasta el punto de que la embolia pulmonar mortal se ha convertido en excepcional, por fortuna. En cambio, no esta desprovista de riesgos y, en la actualidad, el carne de identidad de un antitrombotico debe incluir un estudio preciso de dos aspectos: el beneficio profilactico y el riesgo hemorragico. Los estudios se realizan en poblaciones escogidas y se basan en las pruebas complementarias, que son mas sensibles que los fenomenos clinicos gracias a la frecuente positividad. Deben completarse mediante cohortes de pacientes de la «vida real». La flebografia ya no se emplea mas que en los estudios. La eco-Doppler es la exploracion de rutina en la practica clinica. La farmacopea aumenta con regularidad gracias a nuevas moleculas, procedentes en la mayoria de los casos de la fragmentacion de la heparina, que bloquean la formacion de trombina mediante el factor X activado o directamente la propia trombina. La eficacia de los medicamentos ha creado un autentico apasionamiento por su utilizacion, y la tendencia actual deberia ser mas selectiva para adaptar a cada paciente concreto la molecula, su posologia, la hora de la primera inyeccion, asi como su ritmo de prescripcion, pasando de la epoca del tratamiento «listo para administrar» a la del tratamiento «sobre medida».