The purpose of this study is to test the safety and effectiveness of Humate-P® to prevent bleeding in patients with von Willebrand Disease who are undergoing surgery.

Key Inclusion Criteria:

• Subjects of any age
• Clinical and laboratory diagnosis of vWD that can be expected to show no hemostatic response to DDAVP
• Require substitution with vWF/FVIII complex due to a surgery

Key Exclusion Criteria:

• Known significant hemostatic disorder other than vWD
• Acquired vWD
• Known antibodies to FVIII or vWF
• Known platelet type vWD
• Emergency surgery or any surgery with a degree of urgency not permitting completion of a pharmacokinetic assessment required by the study protocol
• History of allergic reaction to Humate-P®
• Treatment with any other investigational drug in the last four weeks before the entry into the study (with exception of trials concerning anti-HIV agents)
• Progressive fatal disease/life expectancy of less than 6 months
• Treatment with DDAVP, cryoprecipitate, whole blood, plasma and plasma derivatives containing substantial quantities of FVIII and/or vWF within 5 days of the pre-surgical pharmacokinetic assessment
• Pediatric patients of insufficient body weight to permit PK sampling
• Woman in the first 20 weeks of pregnancy