Just wondering if the iliac arteries dissection is improving over time, meaning from current level where no intervention is needed. ?

Depends: If it was conservatively managed, one would assume that there was no impairment of flow as a result. Most of these would be retrograde dissections such as ones that may occur during angiography procedures, i.e. Tear starting from lower part of the artery and would do well and "heal". It should however be followed closely by cardiologist, vascular surgeon, or interventional radiologist.

See vascular surgeon: Iliac artery dissection is fairly uncommon but can often be evaluated non invasively with ultrasound, pressure testing or ct scans to see if there are problems.