A lot has been published about this topic, but the better part is probably still to discover.
As Professor Pierre Lasjaunias would express as a hope more than 20 yrears ago, some day we would have a pill to treat those diseases.
Though etiology is largely unknown, several genetic associations are known, which have in common wall thinning and weakening of structures. (Wikipedia)
Disease is seldom in children and increases with progressive age. Hence we can suspect a nutritional factor.
Vessel walls are largely made up of connective and elastic tissue, in which lipids are an essential element.
Thus, I ask myself whether deficit in essential fatty acids is not main responsible factor. (Omega 3, 6 …)