Safety and Efficacy of Plasma Derived Factor IX in Patients with Hemophilia B Undergoing Surgical Intervention: A Single Institution, Retrospective Analysis.

Hemophilia B patients often require orthopedic surgical intervention for the improvement of function and quality of life. In these patients, coagulation factor replacement is essential, but the safety and efficacy of plasma-derived factor IX in controlling bleeding during surgeries has been little studied. Issues of particular concern for surgical intervention include appropriate dosing of factor concentrate, pharmacokinetics, and safety considerations.

The purpose of this study was to examine outcomes in patients with hemophilia B following surgical intervention and treatment with plasma-derived factor IX.

Following IRB approval, 22 patients who underwent 31 surgical procedures at the Hemophilia Treatment Center at Orthopedic Hospital or its affiliates in Los Angeles, CA, during the period 1996 to present, were identified. Once identified, inpatient charts for these patients were reviewed and abstracted. Outcomes of interest included pre- and post operative dosing of factor IX, perioperative blood loss and use of blood products, pharmacokinetics factors, and hemostatic response.

For identified patients, 9.1% were diagnosed with mild hemophilia B (factor IX levels > 5%), 13.6% had moderate hemophilia B (factor IX levels between 1% - 5%), and 77.3% had severe hemophilia B (factor IX < 1%). The mean age at surgery was 48.0 years old. All but 3 surgical procedures were orthopedic (90.3%) and most frequently involved the knee (38.7%), elbow (16.1%), hip (12.9%), or shoulder (9.6%). All surgeries were completed under general anesthesia and average time in surgery was 3:15 hours. Dose of factor IX averaged 238 IU/kg on the day of surgery and was adjusted over the course of the hospital stay. Selection of replacement factor IX was by patient choice and AlphaNine® SD was the most common factor IX concentrate used (94% of procedures). Mean perioperative blood loss was 283ccs (range 0-1000) and blood replacement was required in only 2 surgeries (6.5%). Pharmacokinetic analysis performed pre-operatively related well to factor IX levels obtained peri- and post-operatively. Average hospital length of stay was 10.7 days and all patients were discharged to home.

The results of this study demonstrated that patients with Hemophilia B undergoing major surgery who were treated with plasma derived factor IX had little unexpected blood loss perioperatively, seldom required blood replacement, and had no bleeding related surgical complications. These results suggest that pre- and postoperative treatment with plasma derived factor IX is both safe and effective for patients with hemophilia B undergoing surgical intervention.

Logan:Grifols, S.A.: Consultancy. Quon:NovoNordisk: Speakers Bureau; Grifols, S.A.: Honoraria.