I am interested in removal of lipoma using Kybella injections. How successful would this operation be?

The safest and most effective way to eliminate a lipoma is through surgical excision. While you might be concerned about residual scarring, let me assure you a board-certified plastic surgeon will know how to suture the incision to minimize the appearance of a scar. Your doctor will also advise you on incision care to ensure the incision heals as cleanly as possible. Make sure it is a board-certified plastic surgeon that handles your excision and you should get a good cosmetic result as well as full elimination of the lipoma. 

Dear Summerflowers517,
It is hard to tell for sure without an examination. Generally speaking, forehead lipomas can be removed using a small incision and it will leave only a small scar. If you are considering a surgery, I would suggest you to consult a board-certified plastic surgeon. Only after a thorough examination you will get more information and recommendations.
Daniel Barrett, MD
Certified, American Board of Plastic Surgery
Member, American Society of Plastic Surgery
Member, American Society of Aesthetic Plastic Surgery

In my opinion, the only method to completely remove a lipoma is by surgical excision.  This can normally be done on the forehead with a scar that will just appear as a thin line.  Kybella treatments normally involve several injection sessions and may not completely remove a lipoma, so that it could recur.  Kybella injections can also frequently cost more than surgery and treatment of lipomas with Kybella is not standard medical care.    

I would not recommend your approach. Forhead lipomas are almost always deep to the frontalis muscle. For most people and horizontal incision directly over the lipoma if done correctly by a meticulous surgeon will heal with a almost imperceptible scar. It is the most forgiving area on the body in regards to score formation. The scars are rarely anything compared to what the lipoma looks like for most people. For women to wear make up it’s a no brainer.
The contour deformity that a lipoma gives trust a shadow that can be seen from across the room. Because the scars tend to blend and fade out almost completely and leave zero deformities in regards to contour they are barely visible unless looking from very close under scrutiny.
Kybella Has he substantial chance of leaving a contour that is unpredictable and may not at all be what you had hoped for. 
Direct excision is an excellent option and would most likely give the best results in a very predictable manner.
if you talk to providers who are not board-certified plastic surgeons and use Kybella Like a nurse in a med spa and then you were most likely be told this is a good option.
I seriously doubt any board-certified plastic surgeon would say that your proposed treatment is the correct one.
Scars are very predictable from examining a patient’s skin complexion and seeing how they’ve healed from other cats, scrapes or previous surgeries. everyone has some tiny little scar someplace on their body that we can examine to predict what future scores will look like. because the four head is so forgiving what the square will look like is highly predictable. unless you have a skin complexion that’s unfavorable for healing surgery is straightforward and should be the way to go.
just my opinion.
Best,
Mats  Hagstrom MD