3358 INTRODUCTION: Non-neoplastic chronic portal vein thrombosis (PVT) is a frecuent diagnosis in the course of liver cirrhosis, with reported prevalences of 0.6% to 15,8%. PVT can motivate life-threatening complications due to worsening portal hypertension, so anticoagulation therapy is challenging in these patients. OBJECTIVE: To analyze the response to antithrombotic therapy and changes in liver function tests in 28 patients with chronic PVT associated with cirrhosis. PATIENTS AND METHODS: 28 consecutive patients with liver cirrhosis and chronic PVT were treated with antithrombotic therapy from 2004 to 2009. Hepatocellular carcinoma and known thrombophilic risks were ruled out. Therapy consisted in 15 days of therapeutic doses of low molecular weight heparin (LMWH) (enoxaparin) adjusted according to baseline coagulability (Table 1), followed by either prophylactic doses (40mg/day) of LMWH or acenocoumarol (target INR 2–3), during 6 months. Response was evaluated after 6 months. If recanalization was complete, therapy was suspended. If recanalization was partial or no recanalization was observed, therapy was continued until response. RESULTS: From the 28 patients studied, 19 (68%) were males with a median age of 53 years (range 35–77). Cirrhosis was due to alcoholism (25%), virus (54%), mixed in 1 patient and other causes in 3 patients. PVT involved the portal trunk and/or branches in 19/28 (68%) patients, mesenteric vein in 2 patients and portal trunk and/or branches, mesenteric and/or splenic vein thrombosis coexisted in 7 patients. 19/28 (68%) of the patients had moderate or moderate-severe hypocoagulability range. Complete and partial thrombosis was seen in 18 and 10 patients at diagnosis, respectively. From the 28 patients, 18 (64%) responded to antithrombotic therapy after 6 months, with a complete recanalization in 13 patients 13/18 (72%) and partial in 5/18 patients (28%). None of the 28 patients presented hemorrhagic complications and none showed platelets counts below baseline values. 17 from the 18 patients who responded, showed altered liver function tests before therapy. After 6 months, 8/17 (47%) improved liver function (only one patient had received antiviral therapy). After a median follow up of 42 months (range 7–67), 15/18 (83%) patients continued showing complete or partial response while 3 patients progressed. Of note, 3 patients of this group could proceed to further liver transplantation. CONCLUSIONS: Antithrombotic therapy in chronic PVT in cirrhotic patients resulted in a high response rate (64%) in our study, with a complete recanalization in 72% of the cases. Adjusted dose scheme according to level of hypocoagulability seems to be effective and safe, since 63% of the subgroups of moderate and moderate-severe hypocoagulability responded with no haemorrhagic complications. Disclosures: No relevant conflicts of interest to declare.

Inherited antithrombin deficiency is associated with an increased risk of venous thromboembolism. There is no consensus about pregnancy management in antithrombin deficiency patients because there are very few cases published in the literature. We report a successful pregnancy in a 32-year-old female carrier of a homozygous type II (L99F) antithrombin deficiency who developed a spontaneous deep vein thrombosis at the age of 27 years.

4676 INTRODUCTION: Bernard Soulier Syndrome (BSS) is a rare qualitative and quantitative autosomal recessive platelet disorder molecularly characterized by defective GPIb-IX-V membrane glycoprotein that is related to platelet adhesion and interaction with both Von Willebrand factor and endothelium. It is usually expressed by an enlarged bleeding time and decreased yet giant sized platelets, and can cause severe hemorrhagic complications during pregnancy. CASE REPORT: We present two successful pregnancies and labour management on a 33-year-old woman diagnosed in her childhood with BSS. Ristocetin induced platelet agglutination test and membrane glycoprotein study were performed to get the diagnosis. Furthermore, in the last year we have completed the diagnosis with platelet receptor expression flow citometry analysis, finding out depleted antiGPIbα and antiGPIX antibodies. Changes which prevent GPIbα for correct expression and processing were observed. Also integrin αIIbβ3 levels were risen due to the big sized platelets. A PCR product was obtained from genomic DNA using the GPIbα oligonucleotide pair; sense and antisense, and direct DNA sequencing of the amplification was performed in a model ABIprism 377 DNA sequencer (Perkin-Elmer Cetus). The direct sequencing of the sense strand of the 5x fragment shows in the patient the simultaneous presence of G and C nucleotids in 688 position, and the T and A nucleotids in 715 position. These punctual mutations give Ala200Pro substitutions and Cys209Ser in heterozygosis in mature peptide, respectively, Figure 1. The Ala200Pro mutation has not been reported in others cases of Bernard-Soullier, previously. The Cys209Ser has been described in other two Spanish patients: one in homozygosis and the other in heterozygosis associated to the mutation. Our patient presented hemorrhagic symptoms from 18 month old with an average of 40×103/μ l platelet count and increased platelet volume who required multiple platelet transfusions during her childhood. In the menarche main hemorrhagic manifestations consisted on methrorragia and epistaxis which were controlled with tranexamic acid. At the age of 26 a spontaneous ovarian cyst rupture required urgent hospital admission and two platelet pool transfusion. On December 2007 she consulted for epistaxis, and on September 2008 cesarean delivery was planned at 38th week of pregnancy; platelet count was 40×103/μ l, antiplatelet antibodies were negative for membrane glycoproteins and antiHLA-1 was positive against 98% donors tested. As a result, an HLA-compatible donor was searched, and two platelet apheresis were transfused one hour before surgery and every 12 hours after the procedure. The next 4 days one apheresis every 48 hours were transfused with no hemorrhagic symptoms. On January 2010, she presented with her second pregnancy; the patient had severe anemia, with high transfusion requirements; neither hemorrhage or hemolysis was detected, and even the possibility of a Munchausen syndrome was questioned. Unplanned caesarean was performed at 32th week because of the clinical instability of the patient, and this time we could not find on time an HLA-compatible donor, so two random platelet pools were transfused one hour before surgery and one platelet apheresis every day during 4 days after caesarean deliver, without any hemorrhagic complication. The newborn was asymptomatic with normal platelet count. The patientxs haemoglobin level returned to normal after five days of delivery. CONCLUSIONS: We present the successful labour management of two consecutive pregnancies on a young woman diagnosed with BSS. The low prevalence of this syndrome (less than one case per million population) explains the absence of well-established protocols for the management of pregnancy in this disease. Up to date there are only twelve reported cases of pregnancy and delivery in BSS patients, most of them presenting with severe hemorrhagic complications. Correct platelet transfusion is the mainstay of treatment, and screening for anti-platelet antibodies study is mandatory due to its high prevalence in these patients. Disclosures: No relevant conflicts of interest to declare.

4397 OBJECTIVES Thrombotic events have been reported as a major cause of morbidity after the Fontan procedure. There is no consensus about the type and duration of postoperative anticoagulation prophylaxis, due to the high risk of bleeding complications, the difficulties in monitoring and the questionable therapeutic compliance in children. In spite of the lack of long term prospective studies in this situation, the ACCP has recommended in their guidelines OAT following Fontan or Glenn operation for at least 6 months. This has also been our practice in our institution during the period of study. AIM OF THE STUDY To analyze the efficacy and complications of OAT in our pediatric patients after undergoing the Fontan operation. METHODS Retrospective chart review of all the children treated with OAT in our institution between 1995 and 2009. All patients were treated initially with acenocumarol 0,2 mg/kg, except the Fontan patients, who received 0,1 mg/kg. Target INR was 2–3 for all patients. The Mann-Whitney test was used to compare the rate of complications, and the percentage of visits out of target INR between the Fontan patients and the rest of the cohort. RESULTS There were 61 children (26 female/35 males) aged between 1 month and 17 years, who received OAT with a range of follow up between 4 months and 14 years: 27 after Fontan operation (Group A), an 34 for other reasons (Group B: n=13 non prothetic valve cardiopathy, n=21 treatment of thromboembolic disease). The average follow-up was similar in both groups (median of 6.5 months in group A vs.7.5 months in group B). There were few complications: 1 mild epistaxis and 1 thrombotic event in group B, and none in group A. There were no differences in the proportion of controls in normal range between both groups; there was a moderate proportion of controls outside the target range of INR, with higher distribution below the range than above the range. The median dose used to achieve the target INR was 0.3 mg/kg/d in Group A and 0.4 mg/kg/d in Group B. CONCLUSIONS Oral Anticoagulant therapy is safe and effective in pediatric patients,with very low rates of thrombotic or hemorragic complications including those undergoing the Fontan surgery. There were not any differences between both groups in any of the analizyed parameters. Disclosures: No relevant conflicts of interest to declare.

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