A 25-year-old female patient (weight: 52 kg and height: 162 cm) with dentofacial anomalies having both anterior edge to edge bite relationship and facial asymmetry was scheduled to have Le Fort I osteotomy and bilateral sagittal split osteotomy (BSSRO) surgery under general anesthesia. The patient was also diagnosed with factor XI deficiency with an increased activated partial thromboplastin time (aPTT) of 87.5 seconds (normal: 26-35.3 seconds), and a factor XI activity of 5% (normal: 60-150%). Other laboratory values, including prothrombin time and international normalized ratio (PT INR) (1.06, normal: 0.8-1.2), and PT % (91.0%, normal: 80-120%) were within normal limits. The hemoglobin (Hb), hematocrit (Hct) and platelet counts were 12.8 g/dl (normal: 12-16 g/dl), 37.6 (normal: 36-48%), and 194,000/mm³, respectively. A chest radiograph, electrocardiogram (ECG), and other laboratory findings were unremarkable. The decision was made to operate on the patient using both the SpHb and rotation thromboelastometry for effective perioperative management.

During surgery, the patient's ECG, noninvasive blood pressure, percutaneous oxygen saturation, temperature, and arterial line were actively monitored. Intravenous thiopental 175.0 mg was used to induce anesthesia. The patient was intubated nasally after the administration of cisatracurium 12.0 mg. Anesthesia was maintained with 5-6% desflurane, 50% nitrous oxide and oxygen. The patient's vital signs were stable throughout the procedure (Fig 1). The surgery time was total 250 minutes and the anesthesia time was 300 minutes. There was a total of 560 ml blood loss, and 500 ml of urine output. The patient's Hb levels were continuously checked through the SpHb values (Fig. 2). Four units of fresh frozen plasma (FFP) and two autologous units of blood (360 ml) were used during surgery based upon the continuously monitored blood levels of Hb. At the end of surgery, the patient's Hb was 8.1 g/dl and Hct was 27%. The patient was extubated with the removal of the endotracheal tube when she resumed spontaneous breathing but before she recovered consciousness. The patient was transferred to the recovery room. The ROTEM™ analysis showed normal variables in the extrinsically activated test (EXTEM) and intrinsically activated test (INTEM) (Fig. 3).

After surgery but before the patient's discharge, her bleeding tendency was investigated using coagulation tests including aPTT. Seven days after surgery, aPTT was slightly elevated at 48.4 seconds. The patient was discharged without any complications.

Factor XI deficiency (hemophilia C) is a rare disease. As of 2005, there were only ten registered patients with factor XI deficiency in Korea, accounting for 0.5% of the population. This figure likely underestimates the true number of patients because those who with factor XI deficiencies are not diagnosed unless they experience trauma or undergo surgery. The recommended method for managing factor XI deficiency during surgery in which a large amount of bleeding is expected is with FFP transfusion [13,14]. An antifibrinolytic drug such as tranexamic acid has also been reported to be highly effective in reducing bleeding [1,3,15]. There is also literature suggesting that administering factor VII during surgery is successful, except that it also increases the risk of thrombosis [16,17,18].

The maxillofacial region is rich in vasculature. It is often difficult to control bleeding during orthognathic surgery and tends to be complicated by hemorrhage more often than do other types of surgery [19]. Prior studies have suggested that orthognathic surgery involves an average of 436.1 ml blood loss inside the oral cavity and takes an average of 196.9 minutes in operation time [20]. The amount of blood loss is directly related to the operation time and degree of intervention. The actual amount of bleeding often exceeds the expected amount; therefore, reserve blood should be prepared. Sometimes, even autologous transfusion becomes necessary.

A skilled surgical technique can significantly reduce blood loss. In addition, medications such as tranexamic acid and desmopressin can also be used [21]. In the present case, the patient lost 560.0 ml of blood during a 350-minutes operation. The patient was transfused with four units of FFP and two units of autologous blood. We also used tranexamic acid one day before surgery to prevent bleeding as much as possible.

Since orthognathic surgery is particularly associated with excess bleeding, the patient was carefully monitored throughout the procedure using both Masimo and ROTEM™. Masimo is a device capable of continuous, noninvasive hemoglobin monitoring. The device enables appropriate patient care and efficient monitoring so that clinical decisions can be made quickly, including those regarding transfusion [9]. Similarly, the ROTEM™ continuously monitors coagulation factors and provides quantitative parameters. This device provides information regarding clot stability, elasticity, formation time, and propagation. Using these data, one can predict when a transfusion may be required. The thromboelastometry curve before and after surgery is shown in Fig. 2. All figures including clotting time, and clot formation time were in the normal ranges. The curve also has a normal shape. INTEM is contact activation, and provides information similar to aPTT. EXTEM reflects tissue factor activation, providing information similar to PT [22].

ROTEM™ is especially useful during surgery of patients with bleeding disorders, because it produces results within ten minutes. In contrast, standard laboratory tests (PT, aPTT, fibrinogen concentration, platelet count) take much longer. Therefore, ROTEM™ allows providers to monitor the amount of clotting factor in hemophilia patients. In summary, this case describes orthognathic surgery conducted in a patient with Factor XI deficiency. The patient received preoperative tranexamic acids and monitored perioperatively with both the Masimo Radical 7 and ROTEM™, and later received FFP.