Had lumbar laminectomy years ago. still having severe leg pain, and lower right side back pain. what could it be?

Nerve damage: If you have never had pain relief after your surgery, the nerves involved may have been too damaged to repair themselves. If you did have relief for awhile, you may be developing bone spurs around the laminectomy. You should follow up with your surgeon to recheck the area . He or she may refer you to a pain specialist.

Need a new MRI: It could be that you are have a recurrence of the symptoms due to return in stenosis at the same level or an adjacent level. You need a new MRI to evaluate where the problem is coming from.