You don't give either your husband's age,smoking
history,medical history or medication history if any. All of these would be potentially relevant to the causology. Survival after the aneurysm
actually ruptures,even if this occurred in hospital is very rare. I wonder if in fact it dissected,rather than ruptured.
Aortic aneurysms are most common in male smokers over the gae of 65 years with raised blood pressure and raised cholesterol
who are overweight
and take little exercise.