Smaller deficiencies respond to serial fat grafting. Large soft tissue deficiencies may require micro vascular free tissue transfer.
Fat grafting by injection has been increasingly used for the treatment of congenital and acquired facial deformities in which there is failure of development or loss of facial soft tissue.
Depending on the size of the area to be treated and the amount of fat to be injected, regional or general anesthesia may be required.
3. Autologous fat transfer: Harvesting
The goal is to obtain maximally viable fat cells with minimum trauma to the cells. This is typically accomplished by a specially designed cannulas and syringes not larger than 10 cc (larger syringes produces too much negative suction damaging the fat cells).
Fat can be harvested from any body's site in which there is abundance (abdomen, thighs, buttocks, etc.).
Some surgeons prefer a dry technique without pre-injection of fluid. Some infiltrate the area with a diluted solution of local anesthesia with epinephrine.
4. Autologous fat transfer: Processing
Harvested fat can be refined by either centrifugation or straining through sterile gauze. The purpose of this is to remove oil, blood and local anesthetic to get a more pure product.
After this refinement, the fat is loaded into 1-3 cc syringes for injection.
The picture shows harvested fat being processed on a sterile gauze.
The picture shows refined harvested fat after processing.
The picture shows the fat as harvested (left), through processing (middle), and "pure" once blood and serum have been removed (right).
The picture shows the "pure" fat being loaded into a smaller syringe in preparation for injection.
5. Autologous fat transfer: Placement
The fat must be uniformly distributed from bone to dermis to simulate the deficient tissues. Specially designed cannulas are available for this or large bore needles can also be used.
The goal is to place very small droplets of fat (0.02-0.1 cc) in a "Swiss cheese" fashion.
Note: Care should be taken to avoid intravascular injection by the use of blunt cannulas or withdrawing of the needle as the fat is injected.
Note: Do not over graft an area. Each fat droplet should be surrounded by well vascularized tissue otherwise fat necrosis will occur.
For large defects serial fat grafting in two, three, or more times might be required.
Fat should be harvested, processed and reinjected in as short time as possible to prevent loss of viability of the transferred fat.
The fat should not be molded or manipulated after placement. Deep massage should be avoided in the first weeks after grafting.