I don't think microdermabrasion is going to get rid of scars. It may diminish their appearance temporarily but it won't eliminate them entirely.  A laser treatment would eliminate them but I don't know which type works the best.
The wife of a co-worker had severe scarring from acne. She got herself into a study on the effects of lasers on skin that had been biopsied and got the treatment for free. The results were ultimately amazing but she spent weeks looking like an Arab sheik since she had to protect her skin from the sun but couldn't put sunscreen on. She says it was worth it and that she would do it again. I don't know how severe your scarring is but if you're going to do something, I'd say get out the big guns right from the start. You know it will work and you'll save yourself the time and expense involved in first trying less expensive and less effective treatments like microdermabrasion and topical creams.