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Dermal Fillers

What Is VO In Fillers?

Vascular occlusion (VO) is a rare complication from dermal fillers caused by the blockage of blood after the cosmetic procedure. This blog discusses the causes of VO, how to detect them after fillers, and possible mitigations for its occurrence.

Everyone should carefully consider the potential risks and benefits before using dermal fillers for aesthetic reasons. After consulting with an aesthetician, patients will determine whether filler injections are a realistic way to attain their aesthetic objectives and if the associated risks are acceptable. The most significant consequence is an arterial blockage, although there is also a risk of swelling, bruising, unevenness, infection, allergy, and palpability of the filler beneath the skin. Injections with dermal fillers are non-invasive, but precautions must be taken to avoid the potential risks; even with experienced cosmetic practitioners, risks from dermal fillers may still occur. Therefore, hiring an aesthetic doctor prepared to treat adverse is crucial for excellent patient care.

What is a VO?

According to Lee et al. (2020), when an artery is punctured during injection, it causes vascular occlusion (VO). A similar effect may occur if the arteries and capillaries around the injection site are squeezed. When this happens, blood flow is restricted (thrombosis), and tissue oxygen levels drop (ischemia), leading to skin death. Vascular occlusion causes blindness, necrosis, and cerebral embolism if untreated. It is similar to what happens during a heart attack, except that the blockage is brought on by filler rather than cholesterol or a clot. 

Why Does a VO Happen?

Injecting Places with a Higher Potential for Harm

The most common places for filler to go wrong are the forehead, the glabella (the area between the brows), and the nose. The skin folds around the corners of the nose and mouth are also vulnerable. Some practitioners decline to inject the tissues in specific areas for fear of complications. Also, some aesthetic practitioners use sonar technology to locate blood veins during the injection. The danger of VO may be greatly reduced if sonar guidance is used to monitor the injection depth, the volume injected, and the location of the nasal blood arteries. However, a previously operated nose is a no-go since it would disrupt the regular placement of blood vessels and increase the likelihood of a VO incident. There is no such thing as a “safe” zone when it comes to the face because of the extensive network of blood vessels. While some regions of the face may be considered “safe,” injections into the lips, cheeks, or anywhere on the face may induce blindness.

How to Identify a VO

Rapid diagnosis is essential for halting the development of vascular occlusion, a potential danger with fillers. Among the warning signals are the following:

Extreme Discomfort

Extreme discomfort during the injection process is not typical for filler procedures. Pain that appears or worsens suddenly during or after therapy is not typical and requires immediate attention. Pain in a non-injection region is a potential indicator of vascular occlusion, which injectors should be aware of.


Skin discolors when the area’s blood supply is cut off, as after an injection. Spots of any color, from white to dark brown, do not go away with a massage or warm compress.


Bruises, which may be purple or blue-grey, are another cutaneous symptom of vascular occlusion. After the first injection, discoloration appears quickly.

Heat Loss 

When a region is injected, the blood flow to that area is reduced, and the skin starts to cool. The skin may take a few hours to calm down following treatment.


According to Vidic&Bartenjev (2018), when an eye vessel is damaged, not only does the patient experience severe pain, but their eyesight may also blur or disappear entirely. Sometimes, a white line along the blood artery supplies the eye. Rapid, quick action is essential since this often occurs within seconds after injection. In this instance, hyaluronidase injected from around or behind the eyeball by an ophthalmologist is the treatment of choice. However, this is a last-resort therapy, and its effectiveness is highly debatable.

How to MitigateDanger

A cosmetic practitioner adept at treating patients with varying facial vascular structures is crucial. The practitioner must be aware of the general location of the blood vessels and the specific planes in which they lie and understand that a patient’s blood vessels may not be in the expected position all the time. 

Slow Injection

Proper injection technique is essential; the practitioner should move the needle tip slowly when injecting. It also prevents a large bolus from being injected into a conduit by decreasing the pressure on the plunger.

Stay Away from Old Wounds

According to Courey&Naunheim (2020), arteries may become permanently immobile due to deep tissue scarring, making them more accessible to injection. Perhaps this caused changes to their anatomy or vascular system. The patient should avoid injections in scarred regions to prevent occlusion. Patients with rhinoplasty or any other surgery should also be treated cautiously.


According to King et al. (2020), doing an aspiration before administering the treatment is recommended. Injectors should not depend only on an aspiration to prevent occlusion, although it does assist. Avoid bolus injections, which deliver a large volume of medicine quickly, in sensitive locations to avoid vascular blockage. If possible, avoid giving yourself a bolus injection in a tight spot.

Anatomical Knowledge

For an anesthetic practitioner, knowing the three-dimensional anatomy of the treatment region is half the fight against occlusion. They should also be familiar with the many types of arteries and vascular structures, how occlusion may occur in each, and how age and surgery can alter the normal orientation of these systems; this is of paramount importance in potentially harmful environments.

Frequently Asked Questions About VO

What Is the Incidence Rate of Vascular Occlusion After Fillers?

Injecting dermal fillers may cause a rare but possibly life-threatening complication called vascular occlusion. Injections of dermal fillers should be done by specialists familiar with the vascular architecture of the injection site; such experts take their time, use a tiny needle, and apply little pressure.

How Uncomfortable Is Vascular Occlusion?

Although vascular occlusion often results in pain, the sole physical sign may be a temporary change in skin color. Contact your cosmetic doctor immediately if you notice anything out of the ordinary in the hours after the dermal filler injection.


Dermal fillers are relatively safe, non-invasive procedures used to enhance facial appearances. However, their safety goes as far as the expertise of the cosmetic practitioner. A cosmetic doctor’s knowledge of vascular occlusion determines the procedure’s safety. Therefore, patients should secure treatment from reputable clinics with qualified practitioners to avoid VO. Vascular occlusion is synonymous with skin discoloration shortly after the procedure; the patients should seek medical advice as soon as they notice anything outside the ordinary post the dermal filler procedure.


Courey, M. S., &Naunheim, M. R. (2020). Injection laryngoplasty for management of neurological vocal fold immobility. Advances in Neurolaryngology85, 68-84.

King, M., Walker, L., Convery, C., & Davies, E. (2020). Management of a vascular occlusion associated with cosmetic injections. The Journal of clinical and aesthetic dermatology13(1), E53.

Lee, W., Koh, I. S., Oh, W., & Yang, E. J. (2020). Ocular complications of soft tissue filler injections: a review of literature. Journal of Cosmetic Dermatology19(4), 772-781.Vidič, M., &Bartenjev, I. (2018). An adverse reaction after hyaluronic acid filler application: a case report. Acta Dermatovenerol Alp PannonicaAdriat27(3), 165-167.

Marie Salbuvik