The Secret behind Extreme Hypoxia Tolerance: A "Slow-Growth" Thoracoabdominal Aneurysm.

A 61-year-old man presented to our institution complaining of back pain. Breathing was comfortable. An arterial blood gas showed extreme hypoxia causing chronic respiratory alkalosis. Further investigations revealed aneurysmal dilatation of the ascending aorta and the Crawford Type II thoracoabdominal aneurysm, with compression of both the left main bronchus and the right pulmonary artery. The patient was managed with a two-stage hybrid surgical approach comprising total arch replacement using the frozen elephant trunk technique followed by endovascular repair.