Anesthetic Course
One hour before entering the operating room, 1,500 units of Confact F® were transfused. In terms of transfusion volume, although we planned to carry out implant placement, it was determined that the amount of bleeding would not differ greatly from that of tooth extraction alone, so we used 25 IU/kg, basing our calculations on those published in the New England Journal of Medicine (Table 2).3 Immediately before surgery, we took another blood sample. We confirmed that VWF activity was 127% and that coagulation factor VIII had increased to 104%. We then proceeded with the surgery. Considering that fluctuations in hemodynamics during surgery promote bleeding, intravenous sedation was performed to stabilize circulation. Oxygen (2 l/min) was administered transnasally, and cefmetazole sodium (1 g) was administered preoperatively to prevent infection. During the operation, we used midazolam iv and propofol (1% Diprivan Injection kit®) target-controlled infusion for continuous intravenous sedation. Also, 2% Xylocaine Dental® with epinephrine 1:80,000 was used for local anesthesia. The operation time was 3 hours and 37 minutes, the anesthesia time was 4 hours and 16 minutes, and blood loss was 405 ml. Although it was a little difficult to stop bleeding during the operation, we completed the procedure with no major problems. No postoperative complications, such as bleeding were observed, and the prognosis was favorable. One week after the operation, evaluation of the coagulation factor VIII and VWF activity revealed that they had decreased to 48% and 23%, respectively, which were close to their preoperative values (Table 3).
Discussion
VWD is a congenital bleeding disorder inherited in an autosomal dominant manner. This condition consists of a quantitative or qualitative abnormality in the VWF, a hemostatic factor that causes a temporary hemostatic disorder. The VWF functions as an intrinsic coagulation factor that mediates platelet adhesion to subepithelial connective tissue and stabilizes binding to coagulation factor VIII.
A lack or decrease in these functions can cause bleeding. Under the disease classification proposed by the International Society on Thrombosis and Haemostasis, there are the following types of VWD: 1, 2A, 2B, 2M, 2N, and 3.4 Type 1 is the most common and features a quantitative deficiency of the VWF but no functional problems. It was previously reported that desmopressin (DDAVP) is effective for hemostasis management in mild to moderate hemophilia and VWD.5 Therefore, DDAVP was used in many cases considering side effects such as the risk of infection from hepatitis virus and AIDS. However, the increase in deficiency factor activity is uncertain. Although it is used for short-term hemostasis, it has limited application since it cannot be repeatedly or continuously used. The improved viral inactivation accuracy of Confact F®improves the purity and safety of the drug, and the risk of infection is said to be lower than before.6 Although in this case, we planned to perform tooth extraction and implant placement, it was determined that the amount of bleeding would not differ greatly from carrying out tooth extraction alone, so for the transfusion volume, we used 25 IU/kg, basing our calculations on those published in the New England Journal of Medicine (Table 2). Although no abnormal bleeding was observed during or after surgery, it was necessary to pay attention to bleeding when carrying out implant placement. Furthermore, stabilizing hemodynamics using appropriate analgesia and sedation is also considered extremely important for reducing the risk of bleeding.
Conclusion
In this case, we carried out safe perioperative management under intravenous sedation combined with local anesthesia after preoperatively supplementing with heat-treated factor VIII concentrate (Confact F®) when extracting teeth and placing implants for a Type 1 VWD patient. Stabilizing hemodynamics using appropriate analgesia and sedation is also considered important for reducing the risk of bleeding.