What often gets over looked is that nearly 50% of ascending aorta/root disect or rupture between 5 and 5.5. Mine was at 4.8 when the root ruptured during surgery for resection of aneurysm on the Right Coronary artery, ligation of complex coronary fistula and double bypass of the LAD. Fortunately the surgeon and I had a discussion of 3 different scenarios to deal with it either that day if necessary or in the future. The decision was made for us and it was over a 14 hour surgery that day and evening. Turns out the tissue was fragile and that wasn't something that showed up in CT with contrast or angiograms with catheter procedure.