Dr. Kenneth Hughes switched to a subdermal method of transferring fat to the buttocks and hips in 2015.   During that 9+ years of the subdermal method no fat emboli have occurred.  The subdermal method utilizes a blunt large cannula that is placed directly under the skin so that the tip is constantly visualized.  In other words, it is impossible to be more superficial with the injection or safer.   The subcutaneous method can be injected into the plane between the skin and the muscle fascia.  The problem with this method is that subcutaneous thickness varies with the individual and the various areas of the buttock.   Therefore, some surgeons may not be able to accurately gauge depth during the procedure relative to the muscle.  Some have advocated ultrasound to presumably help guide cannula position.  The problem is that any deviation from the subdermal method has the ability to deliver fat more deeply, whether or not an ultrasound probe is used.

In these fat transfer procedures, these cannula are not only used to inject in hundreds of areas but they are moved in and out of those areas.   The only way to assure that the fat is kept above the muscle is to keep injections subdermal.   An ultrasound if done correctly can potentially show the cannula and the plane of injection above the muscle.  However, the ultrasound probe would have to follow the fat injection cannula millimeter by millimeter to ensure that there is no deviation.    Not only that but the plastic surgeon would have to move in one millimeter increments and interpret the images from the ultrasound probe from each of those millimeter segments.

So the technical issue in this discussion is one of practicality.    Ultrasound and cannula mobilization so that one can be permitted to inject more deeply than the subdermal level presents a cumbersome task.  Even if performed in a very precise fashion, certain areas that are mapped by ultrasound will not be mapped fully.   That is a given.  In addition to prolonging surgical time, the technique has a problem with the fluidity phenomenon necessary in surgery.  Fat is not merely transferred to one location and then that area is finished.   Rather the surgeon must be able to inject into certain areas and be able to come back to those areas as the buttocks and hips take shape to assure symmetry and projection.  Thus, this mapping would have to be done and redone to ensure safety with a subcutaneous injection.   Finally, the usefulness of the ultrasound as the procedure continues becomes less and less reliable as hundreds or even thousands of milliliters of fat are dispersed into these areas.   Thus, the interpretation of the ultrasound to differentiate subcutaneous fat from injected fat can be an exercise in futility.  If the plastic surgeon injects precisely and only at the subdermal level, the cannula will never enter a blood vessel in the subcutaneous fat or the muscle.  In addition, the cannula tip visualization obviates any need to perform ultrasound at a deeper level, as only the most superficial level is injected.   If fat is injected just deep to the tiny vessels of the subdermal plexus (which are too small to enter with a 4 mm cannula or larger), then the surgeon does not have to worry about fat embolus either superficial or deep to the plane of injection.

While discussions of this nature can be confusing due to terminology or presentation, Dr. Kenneth Hughes presents a very logical methodology that he employs to present the best and safest results for the patients.  Visit Dr. Kenneth Hughes’s main Brazilian buttlift page.