This chapter discusses the various indications to resort to cardiopulmonary bypass (CPB) in clinical circumstances outside of the routine cardiac surgical arena. Surgical procedures on the aorta can be undertaken by either disrupting flow to some organs completely or by supporting organ perfusion using CPB. The chapter summarizes commonly encountered aortic pathology, the surgical approaches used and requirements for perfusion. The most commonly encountered pathologies are dissection, aneurysmal dilatation and transection of the aorta. Deep hypothermic circulatory arrest (DHCA) is required and in addition selective antegrade cerebral perfusion or retrograde cerebral perfusion may be used to try to protect the brain from ischemia. Transection of the aorta occurs as a result of blunt thoracic injury. The commonest indication to resort to CPB is the excision of a liver or renal malignancy growing into the inferior vena cava and occasionally into the right atrium.