Final answer:
The recommended sites for monitoring arterial pressures during repairs of the descending aorta with left heart bypass are the left common carotid artery, left subclavian artery, aortic arch, and the left pulmonary artery.
Step-by-step explanation:
During repairs of the descending aorta with left heart bypass, monitoring arterial pressures is crucial for the assessment of blood flow and tissue perfusion. The recommended sites for monitoring arterial pressures include the left common carotid artery, left subclavian artery, aortic arch, and the left pulmonary artery. These sites provide accurate measurements of blood pressure and help in ensuring the success of the surgical procedure.