Immunological Responses in Bovine vs Mechanical Composite Grafts

In the first retrospective part of the study the investigators will conduct a data analysis of patients having received a bovine aortic graft. The investigators will analyze charts and CT / MRI at various time intervals and identify if there are signs of inflammation. In the second prospective part the investigators will select survivors from the first part with and without inflammation signs. If they consent to participate in the study the investigators will do a blood sampling in order to perform further immunological analysis. Additionally, the investigators will examine their quality of life by QoL SF-12 questionnaire.