This is part two of my megavolume fat transfer talk.
Recipient site constraints.
We have more success grafting in small amounts (like we do in the face) or into really vascular spaces (like the muscular buttock). But what about grafting a large volume into a tight space (like the breast) or a scarred, previously radiated or previously infected area? What about the skin that just won’t stretch?
Percentage Volume Change
Stating this in English, you can only increase the volume of what you are grafting into by so much. If you try to over stuff the area, the skin will be too tight, and it will exert pressure on the stuff inside. Pressure on the newly transferred fat is not good. It will cause the fat to melt, and it will cut off the blood supply to the new fat. No blood flow = no graft survival. With breast augmentation with implants, the implant is not a living thing. You don’t need to worry about pressure against the implant. Fat grafting uses living fat cells. It is totally different.
- You can measure the intersitital fluid pressure change for percentage of volume change.
- increasing the site voume by 40% causes a rise in pressure of 10mmHg
- a 100% volume increase could raise the pressure by 30mmHg- this is too much, and will cut off the blood supply to the area.the number allowed decreases with less compliant tissue like radiated tissue.
- SO, the larger the recipient and the more compliant the tissue, the more you can graft.
- DO NOT OVERGRAFT.
What is the tissue like which you are grafting into?
- Is the tisue tight and compact? or loose?
- Can you change the tissue quality?
- the theory behind BRAVA is it takes an A cup breast (surface area = about 1 1/4 palm measure = 250ml With 2ml of thickness the volume = 500ml.). If she is young and no kids, her firm breasts will not be compliant. So the max you can graft is 20% increase in volume = 100ml. If you preexpand with BRAVA, you aim for 3x the breast volume. Goal = 1500ml. You can now graft 20%= 300ml.
- He has found a linear correlation with preop expansion. “The more she invests in BRAVA wear, the better she expands, and the larger her resultant breast augmentation. The patient becomes responsible for her final result.”
I hope this helps with some understanding of why we do what we do. I know my BRAVA patients wonder why they go through all the trouble. In the future I hope we will be able to have more objective measurement of the tension and pressure.
Remember this is not all of the picture. Please see my prior blog on fat survival, but there was a good study which found fat survival rates vary by individual. They think the CD34 marker may correlate.
So, as with all things in life, the fat transfer success rate is multifactorial: your individual fat survival, the tissue you are grafting into, the pressure in the new space, among other factors.