I have a deBakey I dissection with a Stanford A repair. I want to go to the mountains and the passes are 9600 feet and 11, 000 feet. Would this be too risky for me; my blood pressure is well controlled, no plaque in arteries.

Prior exertion. If you have performed moderate to intense exercise after the repair without problems, subjecting yourself to similar total stress (which takes into account the elevation and low oxygen level you will be exposed to) should not cause problems in general. Co-existing health problems including cardiovascular conditions or lung conditions can impose greater stress on you. Be careful. Good luck.