P1633: outcome of surgical interventions in patients with haemophilia a and b treated with extended half-life (ehl) factor concentrates in a single centre

Topic: 33. Bleeding disorders (congenital and acquired) Background: Haemophilia is a rare disorder with spontaneous bleeds, mainly into the joints and with a need for a treatment of intravenous replacement of the lacking clotting factor. EHL factor concentrates increased the effectiveness of prophylaxis and the management of bleeds for patients with haemophilia A and B with a lower burden of treatment. Real world evidence about surgical interventions with EHL factor concentrates is published for single products only. Due to the switch of haemophilia patients to EHL factor concentrates in the last years more data about the outcome in surgical interventions in a real world setting is available. Aims: The aim of this study was to assess the outcome of surgical interventions in patients with haemophilia A and B treated with EHL factor concentrates in a single haemophilia comprehensive care centre between 2016 and 2022. Methods: In a retrospective chart review all surgical interventions in our hospital in patients with haemophilia A and B were analysed. Patients with haemophilia A or B treated with EHL-FVIII or EHL-FIX concentrates undergoing surgical procedures between 2016 to 2022 in our hospital were included. Surgical procedures in patients with inhibitors against FVIII or FIX and outpatient invasive procedures were excluded. Results: In summary 87 surgical interventions (42 minor and 45 major surgeries) in 53 patients with haemophilia were performed. 67 surgeries in 42 patients with haemophilia A and 20 surgeries in 11 patients with haemophilia B. 44 surgeries were performed in patients with severe haemophilia A and 8 in patients in severe haemophilia B. The mean age of patients was 49.6 years with an age range from 1 year to 76 years. The replacement therapy during the surgeries was performed with four different EHL FVIII factor concentrates products: efmoroctocog alfa, rurioctocog alfa pegol, damactocog alfa pegol, turoctocog alfa pegol. and three different EHL FIX factor concetrates: albutrepenonacog alfa, nonacog beta pegol, eftrenonacog alfa. Bolus injections were performed directly before surgery and continued after surgery with variable intervals between 8 to 48 hours. The median dose before major surgery was 46.0 IU/kg FVIII and 50.0 IU/kg FIX and before minor surgery the median dose was 38.41 IU/kg FVIII and 40.57 IU/kg factor IX. Median duration in hospital after minor surgeries was 2.8 days and in major surgeries 6.0 days (range for all surgeries from 1 to 33 days). The median amount of EHL FVIII concentrate used was169 IU/kg in major surgeries and 75 IU/kg in minor surgeries. The median amount of EHL FIX concentrate used was 135 IU/kg in major surgeries and 65 IU/kg in minor surgeries. There were three bleeding complications during/after surgery. Medical prophylaxis against venous thrombosis with antithrombotic agents was not performed after surgery. No thromboembolic event and no inhibitor against FVIII or FIX were detected during follow-up. Summary/Conclusion: The replacement therapy with EHL factor concentrates in surgical interventions in patients with haemophilia A and B is safe and effective. Keywords: Factor VIII, Surgery, Hemophilia, Factor IX