Filler complications and vascular occlusion

What complications can fillers cause?

As the use of fillers has grown, reports of complications have grown with it ^[5]. A 2018 expert consensus statement classified complications by when they appear and summarized how to manage each of them, including bruising, swelling, edema, infection, lumps, changes in skin color, and biofilm formation (a layer of bacteria that forms around the filler) ^[5]. This consensus statement paid particular attention to blood vessel damage and retinal artery occlusion (blockage of the artery that supplies the retina) ^[5].

Some reactions, such as bruising and swelling, are common and settle on their own, but in rare cases, serious complications can occur in which a blood vessel becomes blocked and tissue is damaged. This article focuses on vascular occlusion, one of these complications.

Why is vascular occlusion dangerous?

If the injected material gets into a blood vessel or blocks it, blood can no longer reach the tissue that the vessel supplied. A 2020 literature review considered blood vessel damage to be one of the most serious adverse reactions and explained that it can lead to tissue necrosis and, in rare cases, cause loss of vision ^[1].

A literature review of nonsurgical rhinoplasty also emphasized that although rare, there are risks of tissue loss, irreversible tissue ischemia (lack of blood supply), and irreversible blindness, so these must be fully explained before treatment ^[3].

Areas that need particular care

A 2020 literature review named the following as danger zones of the face: the temples, the area between the brows and the nose, under the eyes, the nasolabial folds and the triangular area beside the nostrils, the lips, and the chin ^[1]. It stated that although these recommendations focus on hyaluronic acid fillers, they also apply to other fillers and to fat grafting ^[1].

A 2015 literature review searched the worldwide literature and analyzed 98 cases of vision changes caused by fillers ^[2]. Among the reported cases, the area between the brows accounted for 38.8%, the nasal region for 25.5%, the nasolabial folds for 13.3%, and the forehead for 12.2% ^[2]. The most commonly used material was the patient's own fat (autologous fat), at 47.9%, followed by hyaluronic acid at 23.5% ^[2]. These percentages describe the distribution within the reported cases and do not represent the proportion of people treated who develop blindness.

• Temples
• Between the brows and the nose
• Under the eyes
• Nasolabial folds and beside the nostrils
• Lips and chin
• Forehead

What is known about vision complications

In the same 2015 literature review, the most common symptoms were immediate loss of vision and pain ^[2]. Most of the vision loss did not recover, and complications of the central nervous system also occurred in 23.5% of the cases ^[2]. No treatment was found that consistently reversed the blindness ^[2].

Although the researchers stated that the risk of blindness from fillers is rare, they concluded that it is critical for the practitioner to have a thorough knowledge of the anatomy of the blood vessels and to understand strategies for prevention and management ^[2].

Management when it occurs

For hyaluronic acid fillers, management centers on hyaluronidase, an enzyme that breaks the filler down. A 2024 literature review summarized that emergency complications such as vascular occlusion and blindness require immediate treatment with high doses of hyaluronidase ^[4]. However, it stated that for blindness, whether the enzyme should be injected behind the eyeball or above the brow is still debated, and that ultrasound guidance may improve the effectiveness of treatment ^[4].

Data from controlled studies of hyaluronidase treatment are limited, and clinical experience is still building ^[4]. A literature review of nonsurgical rhinoplasty emphasized that hyaluronidase may be partially effective when signs and symptoms are detected early, but that the best approach is still prevention ^[3]. A 2018 expert consensus statement considered that having emergency response procedures in place and keeping the necessary medications in the clinic can reduce the severity of a bad outcome ^[5].

Prevention and what to check during your consultation

A 2020 literature review considered hyaluronic acid filler treatment to be safe when the danger zones are recognized and appropriate injection techniques and fillers are used ^[1]. A 2018 literature review of nose filler treatment, which is common in Asia, described 4 layers between the skin and the bone or cartilage, and recommended injecting into the deep fat layer to prevent blood vessel damage ^[6]. It also stated that the midline of the nasal bridge should be marked and the treatment should stay along it to reduce asymmetry ^[6].

The risk is rare but the consequences can be serious, so it is a good idea to confirm in advance the explanation you will receive before treatment and how to get in touch after treatment. The risk can differ depending on your individual blood vessel anatomy and your history of previous treatments, so you should discuss it thoroughly with a specialist.

• The injection areas and the type of filler to be used
• The response procedures if a vascular complication occurs, and whether the necessary medications are kept on hand
• How to contact the clinic right away if you notice unusual symptoms after treatment
• Your history of previous filler or fat grafting