The primary purpose is to show that administration of Haemocomplettan® P significantly reduces the amount of blood products needed during aortic surgery.

Inclusion Criteria:

• Eighteen years of age or older
• Undergoing elective thoracoabdominal aortic replacement surgery (TAAA) or thoracic aortic replacement surgery (TAA)
• Understood and willingly given written informed consent (German language) to participate following an explanation of study background, restrictions, and procedures
• Experience clinically relevant bleeding of the microvasculature following removal of CPB during surgery

Exclusion Criteria:

• Positive pregnancy test, pregnancy or lactation
• Women of child bearing age not using a medically approved method of contraception during the study
• Previous aortic replacement at the same aortic site (redo surgeries)
• Undergoing an emergency operation
• Proof or suspicion of a congenital or acquired coagulation disorder (e.g. VWD or via severe liver disease)
• Myocardial Infarction (MI) or apoplexy in the 2 months preceding study surgery
• ASA administration in the 3 days preceding study surgery, and a pathological (<74.5 U) ASPI Multiplate® test immediately preceding surgery begin
• Clopidogrel administration in the 5 days preceding study surgery, and a pathological (<31.1 U) ADP/PG Multiplate® test immediately preceding surgery begin
• Tirofiban administration in the 2 days preceding study surgery, and a pathological (<94.1 U) TRAP Multiplate® test immediately preceding surgery begin
• Phenprocoumon administration in the 5 days preceding study surgery, and an INR > 1.28 immediately preceding surgery begin
• Participation in another clinical study in the 4 weeks preceding aortic replacement
• Sensitivity to any of the components of study medication, or to MPs with a similar chemical structure to any of the components of study medication
• Any indication that the restrictions or procedures of the study may not be adhered to (e.g. an uncooperative attitude)
• Any indication that the study restrictions, procedures, or consequences therein have not been considered or understood, such that informed consent cannot be convincingly given
• Multiple morbidities, with a notably constrained remaining length of life