The Last Word: Aspiration

By Dr Joanna Niciejewska / 29 Aug 2022

Dr Joanna Niciejewska debates the use of aspiration before performing dermal fillers

Preventing complications is a hot topic in aesthetic medicine, and practitioners are constantly seeking out new methods for ensuring that they keep their patients safe while obtaining optimal results. In recent years, aspiration has emerged as a technique for avoiding a vascular occlusion, but the effectiveness of the method has been greatly debated amongst practitioners.1 In this article, I will outline what I believe to be the pros and cons of aspiration and discuss whether practitioners should be implementing it as part of their clinical practice.

The Benefits

Aspiration refers to the technique where prior to an injection with dermal filler, a practitioner fixes the needle into the position on the skin where they are about to inject, pulling back on the plunger of the syringe (typically for 5-10 seconds) to ensure that no blood has pulled back into the syringe.2 If blood appears in the syringe after doing so, it implies that they might be entering into a blood vessel. This method is considered by some to be extremely useful and important when it comes to complication prevention, because it can serve as an indicator of whether the area is safe to inject or if it could cause a vascular occlusion.

Personally, I have seen a few positive aspirations throughout my career, which has stopped me from performing an injection that may have been extremely dangerous for the patient. On a separate note, I also find that my patients respond well to me aspirating because they are aware that I’m really taking their safety into consideration. Particularly for my more anxious patients, explaining what I am doing and why I’m doing it can help to put their minds at ease to see that I am doing all I can to ensure they have no negative outcomes.

The Drawbacks

While aspiration can be incredibly useful, some practitioners may be hesitant to use the technique due to the possibility of a false result, which could lead the practitioner into a false sense of security.3 Many things can impact the outcome of aspiration, including the size of the needle or any movement from the initial position.3 In addition, there may be prevention of blood flow due to the type of filler in the needle. This can be affected by product rheology, such as viscosity – those with a higher viscosity may take a few more seconds than other fillers to produce blood after aspiration. 

There is also the potential for the needle to be sitting in a collapsed blood vessel, which means blood will not be produced during aspiration and therefore the practitioner will think it’s safe to inject into.4 As such, it may be considered that the process of aspirating is unreliable. As well as false negative results, false positives can also be experienced if the needle tip is out of the vessel but continues to draw blood under the skin. However, the risk is minimal.2


The choice of aspirating is down to each individual practitioner; however, I personally aspirate every time I inject because it serves as an indicator of whether I’m about to hit a blood vessel. With that being said, I don’t rely solely on aspiration as there is a potential for a false result. As such, I implement other methods of prevention so that in the rare case of a false negative, I have done everything I can to ensure that the risk of causing a vascular occlusion is minimised. For example, I now always use an ultrasound device prior to dermal filler treatments, alongside aspiration, and ensure I have an in-depth knowledge of anatomy to make sure I am as confident as possible. Of course, ultrasound does come with its own considerations, but these are outside the scope of this article. Practitioners should also ensure that they are up to date on complication protocols should anything happen, and have the correct equipment to be able to deal with any adverse effects.5,6

It is important that all practitioners refine their technique for aspirating as I found that it can be quite difficult to begin with, and this will help to minimise the potential for false positives and negatives. To do so, I recommend that people attend relevant educational courses or training sessions run by experienced practitioners. A key point that I have learnt over the years is to keep a steady hand, which I find comes down a lot to the syringe you use, so practitioners need to find one they’re comfortable with. Practitioners should also take the time to research around their chosen filler and look at how it may react when aspirating so they can interpret the results correctly.

Overall, I believe that aspirating does have value in aesthetic medicine, but that practitioners should also experience the correct training and ensure all other preventative measures for complications are implemented so that in the event of any false results, their patient is still protected from any adverse events.

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