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Biomedical subjects

Y Dargaud

Publications and source records attributed to Y Dargaud.

7 recordsLinked to original sources
PubMed2006

Basic aspects of bypassing agents.

Bypassing agents consist of activated prothrombin complex concentrates (aPCC) and recombinant factor VIIa (rFVIIa). Their main utilization is for prevention and treatment of bleeding complications, which may occur in inhibitor-developing haemophiliacs, although new indications for rFVIIa (e.g. trauma-related and cerebral bleeds) are now under evaluation in clinical trials. The mechanisms of action for these agents are still not fully understood. The relative complexity of the composition of aPCC suggests the possibility of multiple modes of action for achieving haemostasis. Among those possibilities, the contributions of activated factor X and prothrombin have been demonstrated in recent years both in vitro and in animal models for the only aPCC which remains on the market. rFVIIa also exhibits a complex mode of action, improving coagulation through both tissue factor-dependent and -independent pathways. The various mechanisms that occur at the cellular surfaces, particularly on the outer leaflet of the platelet membrane, primarily contribute to Xase complex formation and thrombin generation. The ways in which these agents affect the complex kinetics of fibrin formation at the site of vascular damage need further clarification, although significant progress has been achieved in the last 10 years. In addition, the ex vivo monitoring that would reflect achievement of haemostasis in vivo is still not standardized, although several attempts using thromboelastography, thrombin generation and the kinetics of fibrin formation have been initiated.

Blood Coagulation↗
PubMed2005

Management of pregnant women with increased risk of venous thrombosis.

OBJECTIVE: To evaluate the usefulness of score based management of pregnancies with high risk of venous thromboembolism (VTE). METHOD: 116 consecutive pregnancies in 109 women with confirmed thrombophilia and/or history of VTE were studied. Patients were managed in accordance with international recommendations. Recently, a VTE risk prediction score was established. An independent group assessed retrospectively and in a blinded way the usefulness of this score. RESULTS: Of the 116 pregnancies, an antithrombotic prophylaxis by low molecular weight heparin was prescribed in 61 cases (52.6%). All patients with a positive score (n=57, 49.1%) have been treated with an antenatal thromboprophylaxis. In the population where the score was negative (n=55 cases), none of the patients received antenatal prophylaxis. But, despite a negative score, four patients were treated by their general practitioner. During the study period, there was only one episode of VTE. CONCLUSION: Implementing this scoring system has resulted in favorable outcomes and a low risk of recurrent thrombosis in this limited series of women with increased risk of VTE.

Adult↗
PubMed2005

Major surgery in a severe haemophilia A patient with high titre inhibitor: use of the thrombin generation test in the therapeutic decision.

Summary. In haemophilia patients with inhibitor, elective orthopaedic surgery is usually performed under recombinant activated factor VII (rFVIIa). We report here the case of a severe haemophilia A patient with a high inhibitor who needed a bilateral total knee arthroplasty. Recombinant FVIIa was previously shown to be ineffective for the treatment of muscle and joint bleedings, and he had a history of excessive postoperative bleeding under activated prothrombin complex concentrate (APCC). Thrombin generation test (TGT) was used to assess the efficacy of Factor Eight Inhibitor Bypassing Activity (FEIBA). Insufficient correction of thrombin-generating capacity was observed after administration of 75 U kg(-1) FEIBA. In a multidisciplinary environment, a bilateral total knee arthroplasty was performed using a protocol combining immunoadsorption of inhibitors preoperatively associated with FVIII replacement during a first phase followed by FEIBA when the inhibitor reappeared. To our knowledge this is the first direct application of TGT in the management of haemophilia patients with inhibitor, which indicated that a sequential use of immunoadsorption, FVIII and FEIBA was the most appropriate treatment to perform this major elective surgery. This case demonstrates that this combined protocol can be safely used to cover major surgery in inhibitor patients. In addition, it also suggests that TGT may have a major contribution in the decision-making process of the most adapted therapy for the treatment of such high-risk patients.

Adult↗
PubMed2004

Haemophilia and thrombophilia: an unexpected association!

In patients with haemophilia, a close correlation is usually observed between the clinical expression of the disease and plasmatic factor VIII/factor IX clotting activity. However, some patients experience milder bleeding phenotypes than others, although they exhibit a similar biological profile. The high prevalence of some inherited thrombophilia risk factors offers the possibility of a co-inheritance in haemophilic patients which could influence the phenotypic expression of the disease. Rare thrombotic complications occurring in haemophiliacs could also be facilitated by the co-inheritance of modifier genes. The majority of thrombotic events occurring in haemophiliacs are in relation to clotting factor infusions or central venous catheters. Concerning surgical situations, in the absence of therapeutic recommendations, postoperative thromboprophylaxis is not systematically performed in haemophiliacs. However, substitutive treatment more or less completely corrects the coagulation defect and makes the venous thrombosis risk closer to the control population. It should be emphasized that haemophilia does not fully protect against venous thromboembolic disease. Patients with haemophilia very infrequently experience thrombotic events. Thus, the management of thrombotic complications occurring in haemophilic patients should be discussed in each case according to the precipitating risk factors, the clinical context and the thrombo-haemorrhagic balance of the patient with respect to a particular clinical situation.

Catheterization↗
PubMed2004

Multiple arterial thromboses in a patient with primary antiphospholipid syndrome receiving a bromocriptine therapy.

We report a patient with a previously known primary antiphospholipid syndrome who had life threatening multiple arterial thromboses. The patient experienced a myocardial infarction with intraventricular thrombi under bromocriptine therapy in the puerperium, despite prophylactic low molecular weight heparin therapy. In this patient, no microvascular involvement was identified, thus eliminating the diagnosis of catastrophic antiphospholipid syndrome. Arterial thromboses may be explained by peripheral emboli originating from the intraventricular thrombi. This case emphasizes the necessity of a careful evaluation of the risk-benefit balance of bromocriptine therapy in patients with arterial risk factors. It also emphasizes the need for a correct diagnosis of catastrophic antiphospholipid syndrome allowing to limit the prescription of aggressive therapies.

Adult↗
PubMed2002

Study of the relationship between the suprascapular artery and the brachial plexus.

The literature concerning the relationship of the suprascapular artery with the brachial plexus is quite limited. The aims of this study were to investigate the different types of relationships between the suprascapular artery and the brachial plexus trunks and to try to clarify their prevalence in the European population. Our study involved the dissection of 100 upper extremities from adults, all of European origin (55 women, 45 men). In the classic description, the suprascapular artery passes in front of the brachial plexus (group A) in the majority of cases, then behind the omohyoid before reaching the superior border of the scapula. There are two other types of relationship with the brachial plexus: the suprascapular artery can pass between the trunks of the brachial plexus (group B) or the artery can pass behind the brachial plexus (group C). To our knowledge there has been only one study on the subject, carried out by Kosugi et al. Our results show a not inconsiderable number of variations in the relationships between the suprascapular artery and the brachial plexus (29%). Although no differences were noted between the sexes, a significant number of individual variations were revealed by the comparative study of dissections performed on both upper extremities of the same individual. Our results suggest that new studies are required to complete these initial anatomical results observed on a small sample of subjects of European origin. The French version of this article is available in the form of electronic supplementary material and can be obtained by using the Springer LINK server located at http://dx.doi.org/10.1007/s00276-002-0026-5.

Arteries↗