Can I use my scar from a mini tummy tuck, to switch to a full tuck?

Yes, one should lower your scar at least 2-3 cm and perform full TT and liposuction. I would not consider "cutting" your umbilicus since you do not have so mush skin to be removed. Floating umbilicoplasty should be considered. Later on, you can camouflage new scar with fine tattoo. Good luck.

Dear jenwest1013,
I understand your concern. However, without a proper assessment, it would be difficult to determine what went wrong. It is best that you visit your plastic surgeon for further assessment or ask for a second opinion. Only after a thorough examination, you can get proper recommendations and advice.
Daniel Barrett, MD
Certified, American Board of Plastic Surgery
Member, American Society of Plastic Surgery
Member, American Society of Aesthetic Plastic Surgery

The length of the scar depends upon how much loose skin is removed on the sides of your abdomen. Your surgeon who is doing the surgery can give you the best idea of how long the scar will be.

Great posted photos... Unfortunately appears you do not have enough excess skin to convert the mini TT to a full TT. Might offer scar revision only. Best to virtual consult with....