Several months ago B.C. (before COVID-19), in the Park Avenue waiting room of a famous plastic surgeon (remember waiting rooms?), as I feigned interest in my phone while casually eavesdropping on a pair of millennials chatting about the injections they could.not.wait. to get, I mentally captioned the moment Ignorance is bliss. Man, I envied those two, so blithely unaware (or so it seemed) of the risks attached to the jelly-filled syringes that would soon be slicing past their vital facial arteries to sharpen their jawlines and straighten their noses.
For the record, lest you get the wrong idea, there are loads of topics—loads—I know very little about. Politics. K-Pop. The Dow Jones Industrial Average. How to fix the recurrent audio issues on my distance-learning kids’ Chromebooks. I could go on. But if you want to know about all the random things that could maybe go wrong during a routine filler appointment, I’m your girl.
“We don’t talk about this too much, because we don’t want people to be afraid of these treatments,” says Dr. Doris Day, a board-certified dermatologist in New York City. “There are millions of injections done every year, and very few lead to serious complications. But this is an important conversation to have—as is the discussion around how we minimize the risks.”
Before your next filler appointment, familiarize yourself with the little-known pitfall that is vascular occlusion—so you might caption your experience Knowledge is power.
Need-to-know #1: vascular occlusion is a rare but real filler risk.
A vascular occlusion, or compromise, occurs when a provider accidentally injects filler into an artery, clogging it and impeding the delivery of blood, oxygen, and nutrients. This injury is different from the needle’s tip nicking or cutting through a vessel and causing a bruise. “There’s some debate as to whether compression in an area can also cause vascular compromise,” notes board-certified San Diego dermatologist Dr. Arisa Ortiz. In this questionable scenario, a glob of filler smooshes a vessel closed from the outside, obstructing its flow. “The vogue has been to say that intravascular injection rather than compression is the cause [of occlusion], however, I’ve consulted on cases where compression appeared to be the most likely culprit,” adds Dr. Hema Sundaram, a board-certified dermatologist in Fairfax, Virginia.
A published case series of 14,355 filler injections administered over a 10-year stretch found the incidence of vascular compromise to be .05%. Experts generally agree that the true rate among injectors at large is likely higher, since complications commonly go unreported.
Still, Dr. Day offers this assurance: “Given the vast [number] of vessels we have in our faces, it’s amazing how hard it actually is to get into one.”
Need-to-know #2: different vessels carry different consequences.
A complex network of arteries and veins supports our facial tissues—some vessels directly nourishing the skin, others supplying the eyes and brain. You can probably see where this is going: “Blindness, stroke, even death have been reported” as the devastating consequences of injecting into a vessel, says Dr. Ortiz.
When the skin alone is robbed of blood, “there’s the potential for skin loss and scarring, if it’s not treated,” says Dr. Steven Fagien, a board-certified oculoplastic surgeon in Boca Raton, Florida. “This shouldn’t happen, particularly with [reversible] hyaluronic acid [HA] fillers, if the diagnosis is made at the appropriate time and treatment is instituted.” HA fillers can be dissolved with an injectable enzyme called hyaluronidase, restoring blood flow and heading off skin damage.
“If filler is inadvertently placed in a blood vessel that communicates with the circulation to the eye, that can lead to blindness and other ophthalmic issues,” Dr. Fagien adds. This is, however, exceedingly rare—like getting-struck-by-lightning rare, our experts say. A 2019 paper in the Aesthetic Surgery Journal estimates the risk of filler-induced blindness to be .001%.
Need-to-know #3: some injection sites are riskier than others.
The forehead, the glabella (or space between the brows), and the nose are the most notorious danger zones for filler. The temples and the nasolabial folds—particularly, the top of the folds adjacent to the outer rims of the nostrils, notes Dr. Fagien—are also considered high-risk.
Some injectors have made it their policy to avoid filling dicey areas of the anatomy. “Nonsurgical rhinoplasty is super-trendy right now, but it’s just not a procedure I personally choose to perform,” says Dr. Ortiz. “When patients come in asking for it, I tell them that the highest risk of blindness comes from injecting the nose. Once I say that, they’re like, ‘Oh, forget it.’”
For noses that have been previously operated on, that risk actually creeps up even more, since surgery can impair or rewire the normal vascular circuitry, making the anatomical landscape less predictable and more treacherous.
While there isn’t an area Dr. Day outright refuses to treat, she will often try to steer patients to safer alternatives. “If someone’s glabella is their main concern, I’ll inject a neuromodulator there first—there’s no risk of blindness with neuromodulators,” she says. “I may also use a device to lift the brows, and oftentimes that will do more for that area, in a safer way.”
Really though, there is no totally “safe” spot to inject. Vessels course through every inch of the face, traversing every plane, making the entire face a danger zone. Moreover, “we’re all unique creatures, and our individual anatomies can vary,” deviating from textbook norms, adds Dr. Sundaram. Which explains why “occlusion leading to blindness has also been reported from injection of the temples, the lips, and pretty much every other area of the face,” she says.
Need-to-know #4: there are proven ways to curtail risks.
You can judge an injector’s filler fluency by asking how they prevent and treat complications. Their answer to this question should be rather automatic.
Knowing the anatomy and its aberrations is the absolute best way to minimize risk, experts insist. “You have to know where the blood vessels are and what plane they’re in—and also that in any given person, these vessels may not be exactly where they’re supposed to be,” says Dr. Day. “There’s a range of locations for these vessels that can vary quite a bit.”
Injection technique is equally crucial. “You want to inject very slowly while moving the needle tip constantly and really try to reduce the pressure you’re putting on the plunger [of the syringe] so you’re not injecting a big bolus that theoretically could be inside a vessel,” explains Dr. Katie Beleznay, a board-certified dermatologist in Vancouver, British Columbia.
Need-to-know #5: certain safety strategies are debatable.
Injectors have been known to spar over the purported benefits of two safety measures: aspiration and cannulas.
If you’ve ever watched a doctor inject, you may have noticed that they draw back ever so slightly, right before pushing in the filler. This is what they call aspirating—they’re looking for flashback, or blood in the syringe, as evidence that the needle tip is inside a vessel.
The thing is, a lack of flashback “doesn’t guarantee that the needle isn’t in a vessel,” warns Dr. Sundaram. “Pulling back on the needle while injecting creates a vacuum that can collapse the walls of a vessel, preventing flashback even if the needle is inside. And the more viscous the filler, the greater the vacuum it may create.” It’s also difficult, doctors say, to hold the needle steady in one position for a long enough time to actually see a flashback. “It’s probably the least reliable way to know if you’re inside a vessel or not,” notes Dr. Day.
Still, there are plenty of injectors who’ve averted potential catastrophe by aspirating. “The only place I’ve ever seen a flash is in the temples—and my heart stopped,” says Dr. Ortiz. “It does take time to get a flash—you have to withdraw for at least five to seven seconds—but I find it reassuring. If you see that flash, you reposition and start again.”
Aspiration is generally thought of as a can’t-hurt-might-help tactic—assuming it doesn’t give a false sense of security. The aforementioned Aesthetic Surgery Journal article reported a false-negative rate with positive aspirations ranging from 33% to 53%.
A similar warning should come attached to cannulas. While many injectors swear by these blunt-tipped tools, finding them to be less traumatizing than needles, “complications can still occur with cannulas,” says Dr. Beleznay. “They’re not a fail-safe maneuver.”
Need-to-know #6: there are obvious warning signs of occlusion.
Sometimes injectors know the instant that filler enters a vessel, because the overlying skin turns white. “If you see blanching along the distribution of an artery, you should quickly flood the area with hyaluronidase,” says Dr. Ortiz. A single enzyme shot should go to work within minutes, but total “reestablishment of blood flow can take several treatments, given over a few hours,” adds Dr. Fagien.
Pain can be another sign of trouble. “While all injections hurt a little bit, there’s a different type of hurt associated with vascular occlusion,” says Dr. Day. At the moment of injection, you might feel an intense stinging or burning. If the blockage doesn’t make itself known right away, a throbbing, fiery, out-of-proportion pain, coupled with skin discoloration, may set in hours later. “Mottling can usually be seen within an hour or two,” Dr. Beleznay says. While it can be hard to distinguish the stain of an occlusion from a basic filler bruise, she describes the former as a patchier purple-red pattern with areas of blanching mixed in. “When in doubt, it’s always a good idea to get it looked at right away,” she adds.
When a vessel feeding the retina is impacted, there’s “unusual pain around the eye, beyond what is normally expected,” says Dr. Fagien, along with blurry or lost vision and sometimes blanching in nearby areas, like the glabella.
This tends to happen within seconds of injection and demands swift intervention—a shot of hyaluronidase behind or around the eyeball, administered, ideally, by an ophthalmologist. This treatment, called retrobulbar hyaluronidase, is a last-ditch rescue effort, and its efficacy is highly controversial.
Related: Hyaluronic Acid vs. Biostimulatory Fillers: What to Know Before You Get Injected
Need-to-know #7: blindness from filler is usually permanent.
While hyaluronidase works like magic on most occlusions affecting the skin, it’s not a reliable antidote for blindness. In fact, there is no standard treatment for filler-induced vision loss.
“Hundreds of retrobulbar injections have been performed, with varied responses that ranged from completely ineffective to complete reversal [of blindness],” says Dr. Fagien, who was among the first to publish on filler-related blindness and retrobulbar hyaluronidase as “a theoretic rescue therapy.”
Dr. Sundaram calls the treatment “anecdotal,” pointing out that case reports of successful behind-the-eye hyaluronidase injections haven’t been validated.
“We do need more research to find a cure,” says Dr. Fagien, noting that the retrobulbar technique “might prove to be effective, once researchers better understand both the mechanism of injection-related visual compromise and how the rescue therapy can work.”
Involving an ophthalmologist at the first hint of an eye emergency is vital. Beyond delivering hyaluronidase, they may perform ocular massage, give special eye drops, and have patients breathe into a paper bag to try to lower pressure inside the eye and open up blood vessels. “No one really knows if these things work, but they’re easy to do while you’re implementing other strategies,” Dr. Beleznay says.
Since stroke-like symptoms occur in up to 25% of vision-loss cases, providers should also look for signs of muscle weakness.
Need-to-know #8: hyaluronidase works only on HA fillers.
What if your injector infiltrates a vessel with an irreversible filler, like Radiesse?
“There really isn’t a great protocol for dissolving non-HA fillers,” says Dr. Ortiz. In a 2018 in vitro study, injectable sodium thiosulfate was shown to potentially dissolve Radiesse in pig skin. The drug isn’t commonly used in practice, however, and more studies are needed.
“There’s also some thought that adding heat with radiofrequency devices may dilate the vasculature, to possibly help bring blood back to the area,” notes Dr. Ortiz.
In the absence of a surefire fix, some doctors recommend flooding the area with concentrated hyaluronidase, in hopes of it “temporarily breaking down some of the hyaluronic acid naturally present within the skin, to soften the tissue surrounding the occluded vessel,” explains Dr. Sundaram. (The skin is constantly regenerating its own HA.) Additionally, hyaluronidase is believed to have antiinflammatory properties, Dr. Sundaram adds, and reducing swelling in the area may also allow the vessel to move and expand a bit, causing the blockage to dislodge (completely or partially) so that blood can flow freely again. This is pure theory at this point.
Need-to-know #9: slow, natural filler transformations are safest.
A slow-and-steady approach to injectables not only keeps you looking like yourself, but “it lowers the risk of complications, because we’re injecting less product at once,” says Dr. Day—and, ideally, over the long haul too. When people build results gradually, allowing fillers time to settle rather than rushing to add more, they often wind up not needing as much as initially thought.
“There tends to be a sense of urgency that comes with resolving whatever it is we perceive to be a problem, like getting rid of a line that’s driving us crazy,” she adds. “But if you can look at the injectables experience not as a before and after but as a journey of looking more and more beautiful, you’ll be safer and enjoy the process more.”
