July 8, 2021

Can you use saline to dissolve hyaluronic acid based dermal fillers, instead of using hyaluronidase?

The ability to reverse hyaluronic acid (HA) based dermal filler is a key driver to their popularity in the last 10 to 15 years, which lead to the demise of collagen fillers and permanent products. To dissolve HA, aesthetic clinicians have a helpful tool at their disposal which is vital for both use in an emergency, in the event of a vascular occlusion, and provides an option for elective resolution of undesired results from treatment. That crucial component in your armamentarium is hyaluronidase, commonly known in the UK by the brand name Hyalase® But what if there was another option?

saline vs hyalaseRecent social media posts have seen some aesthetic practitioners advocating the use of saline to dissolve or disperse unwanted HA filler, citing reduced risks than those present with hyaluronidase, namely from allergy and anaphylaxis. But does it work, and should clinicians be adding it to their ‘kit box’?

In this blog, Dr Tim Pearce shares the results of his experiments comparing injecting saline or hyaluronidase into a hyaluronic acid-based filler product, plus a neat demonstration with blue spaghetti and a hand blender. You absolutely cannot miss that!

Dr Tim also discusses some of the common questions surrounding dermal filler reversal, how hyaluronidase works, and the effects in has on both fillers and natural tissue.

Dr Tim will be discussing more medical aesthetic training tips as part of his upcoming webinar series, so if you’re looking to increase your CPD-certified learning and want to learn more skills to make you a better practitioner, then step one is to register for the free webinars by Dr Tim.

What is Hyaluronidase?

hyaluronidaseHyaluronidase is an enzyme that is already present in our skin. We produce five different types of hyaluronidase naturally within our bodies daily. Its role is simple, to keep fluids moving within the body by essentially tidying up and clearing away hyaluronic acid, which is no longer needed or spent, so that systems such as lymph nodes do not get clogged up. It does this by breaking the bonds within the HA molecule, shattering it into its component parts, which will then easily disperse and be metabolised.

By its nature, as an enzyme, hyaluronidase is therefore a highly specific catalyst of a single reaction – hydrolysing the HA molecule so it splits apart, separates, and can be denatured.

This process is not strictly ‘dissolving’, although this term is extensively used in relation to the use of hyaluronidase to ‘dissolve filler’ when referring to the correction of hyaluronic acid-based treatments.

Types of hyaluronidase products

There are many brands of synthetic hyaluronidase products available within the UK and the U.S. marketplace. They vary in their production methods and origin, some being animal derived and others human recombinant. Brand names you may come across include Hyalase®, Vitrase®, Amphadase®, Hydase®, and Hylenex®. In the UK, aesthetic clinicians will be most familiar with Hyalase.

Will hyaluronidase also break down natural tissue?

Hyaluronidase cannot destroy other natural tissue such as collagen, however, it can break down natural hyaluronic acid at the same time as denaturing the HA filler product. Natural HA is reproduced by the body approximately every 36 hours, therefore it is important to properly educate your patients, especially the more nervous ones, that the use of hyaluronidase to correct a filler treatment is not going to destroy their skin or cause significant, long-term tissue damage.

Dr Tim Pearce has helpfully created a downloadable template for a hyaluronidase consent form which is useful to help you explain the risks from its use.

What are the advantages of using saline instead of hyaluronidase?

This may seem like a strange question when we know that hyaluronidase is the gold standard medicine for dissolving unwanted HA filler, so why would you consider using saline instead?

The biggest temptation is the fact that it is so much simpler and is low risk – no one is allergic to saline.

It could therefore be argued that it is tempting to give it a try if there is a chance that it could achieve moderate improvement to an undesired aesthetic result by simple displacement or dispersal of the HA. If a patient has a positive patch test from hyaluronidase, then there is probably no harm in trying saline as an alternative, but will it work?

The experiment – can saline dissolve hyaluronic acid?

Dr Tim dissolving filler experimentTo know and understand if it is a worthwhile option to consider using saline instead of hyaluronidase, we need to firstly see how it works in an experiment, and then how that might transfer to in vivo and work underneath the skin.

As with all experiments, the method is key. Many practical examples available on social media do not include a control. Dr Tim wanted to show an attempt to dissolve a hyaluronic acid-based filler with saline but do so alongside a control model with the same product being dissolved with hyaluronidase. The first part of the experiment consisted of placing two bolus deposits of HA filler on a mirror and then injecting saline directly into one bolus and hyaluronidase directly into the other. Both samples were repeatedly agitated with the end of the needle to simulate massage and the samples were observed over a ten-minute period.

See the results from this experiment comparing saline versus hyaluronidase to dissolve hyaluronic acid filler.

However, doing this experiment on a mirror does not mirror what is happening within the skin – excuse the pun!

To fully explain, Dr Tim morphed into a Blue Peter presenter and took two vases, two large springs, a bowl full of blue spaghetti, a hose pipe with running water and a hand blender. I think you will agree, this one is not to be missed!

Essentially, the saline (hosepipe of water) will flood the skin (the vase and spring), but the HA (the spaghetti which is now integrated within the spring inside the vase) will simply become soggy, float around more, and may possibly break into some smaller parts (smaller chains of HA molecules) but will largely remain in place as more natural fluids flow through it. Whereas the hyaluronidase (the hand blender) will break down the HA (spaghetti) into its much smaller constituent parts which can then be flushed away easily by the natural flow of fluids through the skin and the metabolic action.

See how Dr Tim Pearce explains the mode of action of applying hyaluronidase or saline to dermal filler within the skin by watching this experiment.

In conclusion, although there may be some fragmentation of the HA filler if it is injected with saline, the chances are that highly integrated HA molecules, i.e., filler that has not just been immediately injected into the skin, will remain because the saline cannot break down the molecular bonds to disperse the product in the same way as hyaluronidase. If saline is injected into a lump of HA filler, the best we can expect is local dispersal and a more even spread, but it will not completely resolve or remove it. Injecting saline is not going to replace hyaluronidase any time soon, and especially not in emergency circumstances, therefore aesthetic clinicians should always be prepared to obtain and use hyaluronidase when indicated, but having some saline available too really will not hurt.

Aesthetics Mastery Show

Can saline reverse filler?

In this Aesthetics Mastery Show, Dr Tim Pearce discusses the merits and risks of both options with an experiment that it enlightening as well as being highly entertaining!

Are you still anxious about delivering cosmetic injectables safely?

If you want to learn more about mastering medical aesthetic treatments and complications, then register for the next Dr Tim webinar.

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Dr Tim Pearce eLearning

Dr Tim Pearce MBChB BSc (Hons) MRCGP founded his eLearning concept in 2016 in order to provide readily accessible BOTOX® and dermal filler online courses for fellow Medical Aesthetics practitioners. His objective was to raise standards within the industry – a principle which remains just as relevant today.

Our exclusive video-led courses are designed to build confidence, knowledge and technique at every stage, working from foundation level to advanced treatments and management of complications.

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