What can be done about the vertical scar on my abdomen? Are these alternatives safe? (photos)

Unfortunately, we have no current technology can that can completely eliminate a scar and make the skin appear as though no surgery had been performed. However, we do have some tried and true methods for significantly improving their appearance.The photo clearly shows a depressed linear scar and a second, smaller round site that was presumably the site of a drain. Subcision, about which you can find out more in the archives of RealSelf.com, can be used to elevate the scars in order to make them more flush with the surrounding normal skin. A robust volumizing filler, such as Radiesse Plus or Voluma XC may then be injected at the time of subcision or at a subsequent visit for both its immediate filling and elevation benefits, as well as its biostimulatory ability to promote additional new, native collagen and elastic fiber production (neocollagenesis, neoelastogenesis).Finally, following the above, for the remaining surface textural and tonal irregularities, medical microneedling may be used to blend and even the surface out better with the surrounding normal skin. It would be best to seek consultation by a board certified aesthetic physician with experience and expertise in all forms of scar treatment.

Although you will always have a scar, the reason your scar is so "visible" is due to the irregular contours associated with it.  I recommend a scar revision.  A reputable surgeon will undermine at the abdominal wall level which will allow a more flush/even skin closure.  I would hesitate to use fillers or other less invasive techinques as it is not treating the problem (ie tethering to the abdominal wall) and will likely lead to less than desired results.  Consult with a board certified general or plastic surgeon.

It is possible to performa  scar revision but you may end up with a similar result.  There is no way to eliminate the scar completely.