Lipo burn or adhesion? How can I lighten vertical line of rough skin above navel? (Photos)

I encourage you to begin by visiting with your surgeon to discuss your concerns. She/He is most familiar with the details of your surgery and how you've been progressing through recovery. Depending on the nature of the line you may find improvement with lasers or microneedling.

You can try laser treatments to lighten pigment or skin bleaching creams. some of the bleaching creams do need a prescription.

Many plastic surgeons often do excessive liposuction in a straight line above the bellybutton to create a toned, athletic appearance with midline muscle definition.
Some providers do this more than others and some providers get better outcome than others.
Did you look at a lot of before and after pictures of your providers work before choosing your surgeon?
If so, you must likely saw similar outcomes since most surgeons do the same thing again and again.
In your case, you may have some reactive hyperpigmentation. if so, the darkness should settle down overtime.
I suggest you follow up with your provider and discuss your concerns with him or her.
Best,
Mats Hagstrom, MD.