Complex dental extractions in a patient with severe haemophilia A and inhibitors treated with activated prothrombin complex concentrate.

Abstract

Inhibitors that neutralise the function of clotting factor VIII occur in up to 30% of patients with severe haemophilia A1. The development of these allo-antibodies is one of the most serious complications of haemophilia and bleeding episodes become refractory to standard treatment. Among patients whose inhibitor titre is greater than 5 Bethesda units (BU), factor VIII (FVIII) replacement, even at very high doses, is generally ineffective at stopping the bleeding. Consequently, alternative therapeutic approaches are necessary: these consist primarily of using inhibitor bypassing agents. Two bypassing products are currently available on the market: factor eight inhibitor bypassing activity (FEIBA; Baxter Healthcare Corporation, Vienna, Austria), which is an activated prothrombin complex concentrate (aPCC), and recombinant activated factor VII (rFVIIa; Novoseven Novo Nordisk A/S Bagsvaerd, Denmark). The two bypassing agents achieve haemostasis through different mechanisms, bypassing the FVIII-dependent step in the coagulation cascade and promoting haemostasis by enhancing the generation of thrombin. Both products are used for controlling bleeding during surgery in haemophilic patients with inhibitors, though their efficacy may differ. As each bleeding episode is unique to each patient, each surgical operation and site of bleeding, clear guidelines on the treatment of patients are lacking and indications come from suggestions of experts in the field2. With reference to dental surgery in haemophilic patients with high inhibitor titre treated with FEIBA, few case reports have been published in the literature3,4. We proposed a treatment protocol consisting in anaesthesia without vasoconstriction, sutures associated with local haemostatic measures, such as oxidised cellulose sponges and tranexamic acid, and administration of factor replacement, which proved extremely effective in non-haemophiliac patients undergoing tooth extractions5. The same protocol, modified by the use of a bypassing agent instead of FVIII replacement therapy, was applied in the patient described below.