I also had severe complications after ascending aorta aneurysm repair. I spent 10 days in the cardiac ICU and another 12 days in a step down room. I had ECMO, dialysis, pneumonia, and intubation for many days. My heart did not restart normally after the surgery. So, my chest was left open for 6 days until it could take over on it’s own and the chest could be finally closed. After 22 days I was released to go home. My husband was a superhero and it sounds like you are one, too. Let Mother Nature and Father Time do their work as your husband slowly regains his health. It takes time for the effects of much anesthesia and medicines to get out of one’s system. When he can, begin walking beside him around the house, then outside, He will transition from a walker to cane to solo as strength returns. PT helps. The initial baby steps of recovery will lengthen gradually. Keep smiling. Give each other a hug first thing each morning.