Some surgeons will use the term "flank" as an atomic area while others do not.I typically avoid using the word and describe the trunk as upper and lower abdomen, waist and hips.What most people typically consider to be the flanks would be what I would call the waist.When I treat the waist, it often goes back to the spine and will cover everything up to the crease that is often seen on the lower back.Anything above the lower back crease is what we consider to be the back bra roll or simply the back.Each surgeon has different parameters of what they would consider to be the flank, but, in my opinion, it would be from the spine to the mid-axillary line. Basically, this means everything on the back of the body down to the waistline.Most patients need a full abdominal treatment to get the desired result.It can be a big mistake to liposuction the waist without doing the hips or the lower abdomen without doing the upper abdomen.Best of luck,Mats Hagstrom, M.D.