Can I have a small amount of Hyaluronidase enzyme injected to reverse my HA filler?

Can I have a small amount of Hyaluronidase enzyme injected to reverse my HA filler?

I am often asked by patients whether I can reverse just part of their hyaluronic acid (HA) gel, particularly those who have been having HA filler injections over several years.

They have been layering the HA sequentially every six months or a year into their cheeks and under eye area and at some stage decide that they want this partly reversed. 

The reason for that can be an overcorrection or because it is making them look a little puffy underneath the eyes or when they smile the cheeks ride up quite high and do not look lateral. 

When I assess a patient for reversal of their HA filler I need to know:

• when they had the HA filler
• the name and brand of the filler
• the quantity  
• the location that it was injected
• whether it was injected by needle or cannula

I then feel the area that the patient complains about and see whether I can feel the filler and blot it between my fingers. Very often it is easy to detect and identify its margins, particularly if it has been injected somewhat as a bolus.However, what is not easy is to promise the patient that I can remove just part of it. 

I can do my best to use a very tiny amount of Hyaluronidase enzyme such as 15, 30, 45, 50 or 75 units dissolved in a small amount of saline so that it does not spread too far.

I determine the amount of enzyme to use based on where it has been injected, what was used and the quantity.However, despite that and many years of experience of injecting Hyaluronidase enzyme I cannot 100% reassure the patient that they will have the result they want.

In particular, if I am asked to reverse just a little bit of filler. In the rest of the face, there is still a lot of filler they still may not regain the appearance that they want or the appearance they remember of how their face looked. 

It is not possible to have your filler and get rid of it, so a compromise has to be sought.It may be that by using such small amounts of the enzyme that there is a minimal effect on the HA filler and you will need a second injection after a week. 

Or it may be that despite using a minute amount of enzyme, the enzyme may appear to reverse more filler than had been anticipated either by the surgeon or the patient.It is an inexact science. 

There are guidelines, there is common sense, and there is experience on how much enzyme to use. Still, no surgeon can emphatically say that they can remove just part of the filler and that the enzymes will not spread to adjoining areas with filler, or that the patient will like the appearance of their face once they desired partial reversal of filler has been carried out. 

The purpose of having a Hyaluronidase consultation assessment is not only for me to examine you and see whether there is filler there and it can be reversed, but for me to discuss with you what you can realistically expect from an injection of a hyaluronidase enzyme.How realistic it is that I can partially reverse your filler?How realistic it is that the enzyme will not spread a millimetre into the area that you do not want the filler reversed? How realistic it is that you will like the appearance when only part of your filler has been removed?

Often, the patient takes the pragmatic approach to remove all the HA filler. That makes it much easier for the oculoplastic surgeon and patient alike. Once we remove all the filler, two to three weeks later, we can place a small amount of new filler more strategically and accurately to help smooth out the under eye hollows and trans cheek lines for which filler is often employed.

Starting anew may well be a better option than several attempts to reverse small amounts of HA filler that has caused an overcorrection or be malpositioned.