I had a BBL that caused an abscess on my butt cheek. Is it safe to get another surgery to fix the scar and the flatness?

The buttocks can be reshaped with a combination of liposuction and fat grafting to that area. The revision implies that there is less fat than the first time, and scar tissue will make the surgery much more difficult on the surgeon.  The percentage of fat survival in the BBL the second time should be about the same.  You will have to find a surgeon who does mainly revisions and is capable of getting fat where others have not been able to do so. 

Dear Beautiful330016,
it is hard to tell for sure, but as long as you are free of infection, you can probably be a candidate for revision surgery. 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

Fat transfer such as the BBL is better at giving diffuse overall volume then it is to given significant volume in small areas.In addition the area of concern may have scar tissue that restricts the expansion with further fat transfer.Most of the time correcting something like this requires multiple rounds of fat transfer and may still be of limited help.You will for sure need an in person consultation to get a proper assessment.In what you describe the course of treatment proposed may work better for some than others.Follow up with your provider.Best, Mats Hagstrom MD