What is an "intramural hematoma of the aorta"?

Actually, I know what the medical literature says it is. I'm wondering what to expect in the future --- something the doctors aren't willing to talk much about. My mother, almost 98 years old, suffered the hematoma a week ago. Initially, the doctors thought it was an "aortic dissection" and told the family that she might have only hours to live. After her transfer to a hospital with more services and more cardiac specialists on staff, she got the less serious diagnosis of hematoma. After about five days, the doctor said the hematoma was healing. After six days, she recovered enough to talk some, although there was still some confusion. Two days ago, she was moved to a rehab facility; her doctor proposes to call in hospice after she leaves rehab --- not because she's in imminent danger (he says) but to ensure closer medical supervision than she gets in assisted living. From what I find online, this seems to be sort of pre-dissection, and I'm assuming that we can expect another hematoma or a full dissection in the future. At her age, I'm afraid it could be quite soon. Does anyone have any experience with this? Any information about recurrence or about survival after the first episode? Thank you.