The diagnosis of VWD is based on a history of bleeding diathesis, often with a family history of bleeding symptoms or diagnosed VWD, and confirmatory laboratory tests . VWD diagnosis and management remain challenging however, especially in children and adolescents with no history of bleeding diathesis. Such patients have usually not experienced significant hemostatic challenges and thus may lack any history of bleeding diathesis . Therefore, further examinations should be conducted when a pediatric patient exhibits abnormalities in preoperative laboratory tests even in the absence of any history of abnormal bleeding to investigate whether the patient has any coagulopathies.
In general, preoperative management in patients with VWD may include desmopressin, coagulation factor VIII concentrates containing VWF, cryoprecipitate, and topically applied hemostatic agents . Desmopressin has been shown to stimulate the release of VWF and coagulation factor VIII . Consequently, preoperative desmopressin administration may effectively reduce the risk of postoperative bleeding in pediatric patients with VWD undergoing adenotonsillectomy . However, its use is not without risk. Fluid and electrolyte management is required to prevent hyponatremia with possible seizures and fluid retention . There are also potential risks associated with factor concentrates and cryoprecipitate, including allergic reactions, thrombotic complications, and the transmission of blood-borne pathogens. Thus, to date, it remains unclear what preoperative management in patients with VWD is most appropriate for preventing postoperative bleeding.
In clinical practice, the preoperative management of patients with VWD currently depends on the type of VWD and the patient’s condition. The present patient was not definitely diagnosed with VWD, but type 1 VWD was suspected because VWF deficiency was mild and neither she nor her relatives had any history of episodes of bleeding diathesis. Consequently, the pediatrician did not recommend prophylactic administration of Confact F® or desmopressin before surgery, but advised us to prepare Confact F® and administer it immediately if hemostasis could not be achieved during surgery via conventional techniques. The National Heart, Lung, and Blood Institute (NHLBI) recommends that levels of VWF and coagulation factor VIII activities of at least 30%—and preferably over 50%—should be maintained for 1–5 days for minor surgery . Tonsillectomy is not a major surgery, but there is a high risk of bleeding during and after the procedure . Previous reports indicated that bleeding rates in children with known coagulopathies are between 2% and 17% [5,6,7,8]. Sun et al.  reported that the rate of delayed hemorrhage after tonsillectomy in children with VWD or hemophilia was much higher, especially in older children. Considering all the relevant factors including the patient’s condition, laboratory tests, the type of surgery, and the NHLBI recommendations , we followed the pediatrician’s instructions. In the current case, coagulation factor VIII concentrate containing VWF was very effective for achieving hemostasis during surgery. Notably, however, in some previously reported cases, it was evidently ineffective in patients with VWD [13, 14]. The initial dose of factor VIII concentrate containing VWF may be insufficient in some cases due to the difference of the type of VWD or the severity of VWF deficiency. Thus, if uncontrollable bleeding occurs in similar cases during surgery, further administration of factor VIII concentrate containing VWF should be considered. Moreover, further interventions should be considered such as cryoprecipitate, topically applied hemostatic agents, and the newly developed recombinant VWD product that has recently become available .
In conclusion, even slight abnormalities in preoperative laboratory tests should not be overlooked in pediatric patients even in the absence of any history of bleeding diathesis. Such pediatric patients may have coagulopathies that have not previously come to light because they have not experienced any substantial hemostatic challenges and thus have no history of abnormal bleeding. There may be a need to administer preoperative prophylactic intervention and/or prepare a sufficient amount of coagulation factor VIII concentrate containing VWF in cases involving patients suspected of having VWD or with mild deficiency of VWF undergoing minor surgeries with a substantial risk of bleeding such as adenotonsillectomy.