Ultrasonic cavitation which is similar to vaser does absolutely nothing to fibrous tissue. Power assisted liposuction which is like a jack hammer on fibrous tissue is the only thing that works on buffalo humps. It does great and cost is roughly $5000 for quality work.
While this procedure isn't textbook "reversible" there are options available that can provide you with great results. Some options include a fat transfer or Sculptra injections. I suggest waiting a minimum of 3 months post op and including lymphatic massages as a part of your post op care...