When Things Go Wrong
Vascular occlusion, the hyaluronidase protocol, and the escalation clock
Every injector will one day stand in a treatment room with a patient whose skin is going the wrong colour. Not maybe. One day.
The difference between a story you tell at a conference and a story your defence union tells in a letter is almost never talent. It is preparation. It is whether the hyaluronidase was in the fridge, in date, and reconstituted correctly within minutes rather than hours.
This chapter is the one to read before you need it. It sets out recognition, the emergency algorithm, the hyaluronidase protocol, and the escalation clock. Read it alongside needle versus cannula and the superficial subcutaneous layer, because prevention is a depth decision long before it is an emergency decision.
This chapter is educational and does not replace formal complications training, your product licences, or local emergency protocols. Do not inject hyaluronic acid filler unless you hold hyaluronidase on site, are trained and insured to use it, and have an escalation route to ophthalmology and emergency care.
RECOGNITION — WHAT OCCLUSION ACTUALLY LOOKS LIKE
White, then grey, then a pattern that follows a vessel.
Vascular occlusion is a clinical diagnosis made at the chairside, usually within seconds to minutes of injection, occasionally hours later as the product swells or migrates against a vessel wall.
Immediate signs (0–5 minutes)
- Pain out of proportion — severe, burning, and increasing rather than settling. Note that pain may be absent if a block or lidocaine-containing filler has been used, so never rely on pain alone.
- Blanching — an immediate white or grey patch that does not refill on pressure release.
- Delayed capillary refill — over 3 seconds compared with the contralateral side.
- A pattern that follows a vessel, not your injection point — this is the single most useful discriminator. Bruising is where you injected. Occlusion is downstream of where you injected.
Early signs (5 minutes – 24 hours)
- Livedo reticularis — dusky, net-like reticulated mottling. This is the classic appearance and is often mistaken for bruising.
- Cool skin to the back of your hand compared with the other side.
- Progression from white to grey to violaceous.
Late signs (24 hours – 7 days)
- Pustules and sterile-looking papules within the reticulated area.
- Blistering, then a black eschar as full-thickness necrosis declares itself.
- Scarring that will require dermatological or plastic surgical input.
"If you are asking yourself whether it is an occlusion, treat it as an occlusion. The cost of unnecessary hyaluronidase is a lost result. The cost of waiting is a lost face."
THE DIFFERENTIAL: BRUISE, COMPRESSION, OCCLUSION
Three things look alike for about ninety seconds.
| Feature | Bruise / haematoma | External compression | Intravascular occlusion |
|---|---|---|---|
| Onset | Minutes to hours | Minutes, as swelling builds | Immediate, during injection |
| Colour | Blue-purple, uniform | Dusky, diffuse | White → grey → reticulated violet |
| Distribution | At the injection site | Around the bolus | Follows an arterial territory |
| Capillary refill | Normal | Slightly delayed | Markedly delayed or absent |
| Pain | Mild, settling | Pressure sensation | Severe, escalating (may be masked) |
| Action | Reassure, review | Hyaluronidase if not resolving | Immediate high-dose hyaluronidase |
Compression and occlusion are treated the same way in practice, because you cannot reliably distinguish them at the chairside and the treatment is identical. That is a feature of the algorithm, not a weakness in it.
THE EMERGENCY ALGORITHM
Stop. Assess. Flood. Escalate. In that order, every time.
Stop. Assess. Flood. Escalate.
- Stop injecting immediately. Do not finish the syringe. Do not finish the side.
- Confirm the diagnosis in under 60 seconds: blanching, pain, capillary refill, colour, temperature, and vision. Ask directly: "Is your vision normal in both eyes? Any pain behind the eye?"
- If there is any visual symptom, this is an ophthalmic emergency — go to the ocular section below and arrange immediate transfer while treating.
- Reconstitute and inject hyaluronidase now. Do not wait for a second opinion, a photograph, or a phone call.
- Flood the entire ischaemic territory, not just the injection point — hyaluronidase diffuses across vessel walls.
- Warm compress and massage to promote vasodilatation and disperse the enzyme.
- Aspirin 300 mg orally (if no contraindication and within your scope) as an antiplatelet measure.
- Reassess at 60 minutes. If perfusion is not restored, repeat hyaluronidase at full dose.
- Repeat hourly until reperfusion. There is no fixed ceiling in the emergency setting; under-treatment is the common error, not over-treatment.
- Document contemporaneously and photograph at every stage.
- Review at 24, 48 and 72 hours, then as clinically indicated. Give the patient your direct number.
- Report the incident to your insurer, your defence union, and via the relevant national reporting scheme (in the UK, the MHRA Yellow Card scheme).
THE HYALURONIDASE PROTOCOL
Flood the territory, not the puncture mark.
The modern standard is high-dose pulsed hyaluronidase: large doses, flooding the whole ischaemic territory, repeated hourly until perfusion returns. The historical approach of a cautious 30 units at the injection point is why early cases scarred.
Reconstitution
- A 1,500 unit vial reconstituted in 5 ml of normal saline or bacteriostatic water gives 300 units per ml — a practical working concentration for flooding a territory.
- Reconstituted in 10 ml, you get 150 units per ml — useful when you need volume to spread across a wide field such as the nasal dorsum and glabella.
- For elective dissolving of a nodule you want the opposite: small volume, high concentration, placed precisely.
| Scenario | Indicative dose per treatment round | Repeat interval |
|---|---|---|
| Small cutaneous occlusion (e.g. lip, limited area) | 500–1,500 units flooding the whole blanched territory | Hourly until reperfused |
| Large territory (nose, nasolabial, glabella, cheek) | 1,500 units or more per round, across the full territory | Hourly until reperfused |
| Any visual symptom | Maximal dosing plus immediate ophthalmology transfer | Do not delay transfer to keep treating |
| Elective dissolving of misplaced filler | 10–30 units per 0.1 ml of product, precisely placed | Reassess at 2 weeks |
Technique
- Use a needle or cannula and fan across the whole ischaemic field in multiple passes and multiple depths — dermal, subcutaneous, and down to the plane in which you originally injected.
- You are not trying to hit the vessel. Hyaluronidase crosses the vessel wall. Coverage beats accuracy.
- Massage firmly after each round; apply warmth between rounds.
- Do not stop at one round because the colour "looks a bit better". Stop when capillary refill is normal and symmetrical.
Hypersensitivity
True anaphylaxis to hyaluronidase is rare but reported. In a life-or-limb emergency you treat regardless and manage any reaction. Every clinic holding hyaluronidase must also hold in-date adrenaline 1:1000 and staff trained in anaphylaxis management. Patch testing before emergency use is not appropriate and delays treatment.
Hyaluronidase does not dissolve calcium hydroxylapatite, poly-L-lactic acid, polycaprolactone, or permanent fillers. That is one of the strongest arguments for treating vascular-risk zones with HA only — see biostimulators and treatment planning.
THE ESCALATION TIMELINE
The clock started when you injected, not when you noticed.
| Time from recognition | Action |
|---|---|
| 0 minutes | Stop injecting. Assess vision. Reconstitute hyaluronidase. |
| Within 5 minutes | First flooding dose delivered across the full territory. Warmth and massage. |
| Within 15 minutes | Aspirin 300 mg if appropriate. Photograph. Begin written record. |
| 60 minutes | Formal reassessment. Repeat full dose if refill is not normal. |
| Hourly thereafter | Repeat until reperfusion. Do not send the patient home mid-ischaemia. |
| 4 hours unresolved | Escalate to a colleague with complications experience and consider secondary care referral. |
| 24 / 48 / 72 hours | Face-to-face review. Wound care. Consider antibiotics if pustulation. Dermatology referral if eschar forms. |
| Any visual symptom, at any point | Immediate transfer to an eye casualty. Ninety minutes of retinal ischaemia is the widely quoted point of irreversibility. |
VISUAL LOSS — THE OPHTHALMIC EMERGENCY
The retina does not give you hours. It gives you minutes.
Filler-induced blindness is caused by retrograde embolisation. Injection pressure exceeding arterial pressure in a terminal branch pushes a column of filler backwards, against the direction of flow, into the ophthalmic artery. When injection pressure stops, forward flow resumes and drives the embolus into the central retinal artery or its branches.
The highest-risk territories are the glabella, nasal dorsum and tip, nasolabial fold, forehead, and temple. Every one of these communicates, directly or indirectly, with the ophthalmic circulation.
Recognition
- Sudden unilateral visual loss, a field defect, or a "curtain" — usually immediate and painful.
- Severe periorbital or retro-orbital pain, often with nausea and vomiting.
- Ptosis, ophthalmoplegia, or a fixed dilated pupil.
- Concurrent skin changes over the forehead, nose or glabella.
- Any neurological symptom — filler emboli can reach the cerebral circulation.
Immediate management
- Call the ambulance service or the nearest eye casualty before you do anything else, and state clearly: "Suspected central retinal artery occlusion following facial filler."
- Flood the injected territory and the supratrochlear and supraorbital regions with high-dose hyaluronidase while transfer is arranged.
- Retrobulbar hyaluronidase is described in the literature but is a specialist procedure — it should only be attempted by clinicians specifically trained in it, and must never delay transfer.
- Aspirin 300 mg, ocular massage, and rebreathing into a paper bag are commonly used adjuncts with limited evidence. Use them if they cost no time.
- Travel with the patient's details, the exact product, batch number, volume, and sites clearly written down.
Prevention is the only reliable treatment
- Low pressure. Small aliquots. Never more than 0.1 ml in a single deposit in a high-risk zone.
- Constant movement of the needle tip — a moving tip cannot build a sustained intravascular column.
- Cannula over needle wherever the anatomy permits.
- Aspirate before deep bolus placement, and understand what a negative aspirate does and does not prove — see needle versus cannula.
- Know the collateral anatomy of the region you are in, particularly the temple and nose.
ADJUNCTS AND WHAT THE EVIDENCE SUPPORTS
Everything else people reach for, ranked honestly.
| Adjunct | Rationale | Strength of evidence |
|---|---|---|
| High-dose pulsed hyaluronidase | Degrades the obstructing HA column | Strong — the definitive treatment |
| Warmth and massage | Vasodilatation, enzyme dispersion | Moderate, low risk |
| Aspirin 300 mg | Reduces secondary platelet thrombus | Moderate, widely adopted |
| Topical glyceryl trinitrate | Local vasodilatation | Contested — may worsen distal embolisation; not routinely recommended |
| Hyperbaric oxygen | Improves tissue oxygenation in threatened skin | Weak but reasonable as salvage where available |
| Prophylactic antibiotics | Prevents secondary infection of compromised skin | Reasonable once pustulation or blistering appears |
| Systemic steroids | Reduce inflammatory oedema | Weak; case-by-case, not routine |
DELAYED COMPLICATIONS — NODULES, BIOFILM, GRANULOMA
The slow problems that cost you patients rather than faces.
Not every complication happens on the day. The delayed group is less frightening and more common, and it is where most clinicians lose patients — not to harm, but to poor handling.
Non-inflammatory nodule (days): a lump of product in the wrong plane or the wrong quantity. Massage early; hyaluronidase 10–30 units precisely placed after two weeks if it persists.
Delayed inflammatory nodule (weeks to years): often triggered by systemic illness, dental work, or vaccination. First line is oral antibiotics — typically a tetracycline or a macrolide for two weeks — plus consideration of hyaluronidase. Steroids alone into an undiagnosed biofilm can make it worse.
Biofilm: suspect when a nodule is fluctuant, recurrent, and antibiotic-responsive but relapsing. Do not incise casually. Culture is often negative. Dissolve the substrate.
Granuloma: firm, symmetrical, often affecting all treated sites simultaneously. Requires dermatological input; intralesional steroid and 5-fluorouracil regimens are used in specialist hands.
Herpes reactivation: vesicles in a dermatomal or perioral pattern within 48 hours. Aciclovir promptly; prophylaxis for patients with a history undergoing lip or perioral work.
THE EMERGENCY KIT
A box that is useless the day you have to go looking for it.
Checked monthly. Expiry dates written on the outside of the box. Every member of staff knows where it is.
- Hyaluronidase — a minimum of 3,000–4,500 units on site, in date, in the correct storage conditions.
- Normal saline and bacteriostatic water for reconstitution, plus drawing-up needles and 1 ml, 2 ml and 5 ml syringes.
- Adrenaline 1:1000 ampoules or auto-injectors, plus an anaphylaxis algorithm on the wall.
- Aspirin 300 mg dispersible.
- Aciclovir, and an antibiotic appropriate to your prescribing scope.
- A pen torch, a timer, and a printed capillary refill comparison chart.
- A laminated one-page algorithm — the version in this chapter is designed to be printed.
- The direct number of the nearest eye casualty department, and of a colleague experienced in complications.
DOCUMENTATION, CONSENT AND ESCALATION
If the form doesn't say blindness, it isn't consent.
Consent for filler is not valid unless vascular occlusion, skin necrosis, scarring and blindness have been discussed and recorded before the needle is opened. If your consent form does not use the word "blindness", it is not a consent form.
- Record the product name, batch number, volume, plane and instrument for every site, every time.
- During an incident, write as you go or nominate a second person to scribe with timings.
- Photograph at recognition, after each round of hyaluronidase, and at every review.
- Tell the patient plainly what has happened. Concealment converts a recognised complication into a regulatory matter.
- Notify your insurer and defence organisation the same day. Report device-related harm to the relevant national scheme.
Final Word
Complication management is not a separate skill bolted onto injecting. It is part of injecting. The practitioner who understands planes, pressure and vessel anatomy causes fewer occlusions; the practitioner who has rehearsed the algorithm converts the ones they do cause into a bad afternoon rather than a permanent injury.
You are not judged on whether you ever have a complication. You are judged on the first ten minutes after it.
Questions Injectors Actually Ask
Short answers. The long ones are above.
- What are the first signs of vascular occlusion after dermal filler?
- Pain out of proportion to the injection, immediate blanching that does not refill on pressure, capillary refill over three seconds, and — the single most useful sign — a discoloured pattern that follows a vessel rather than sitting where you injected. Livedo reticularis, a dusky net-like mottling, usually appears within the first few hours.
- How much hyaluronidase is used to treat a vascular occlusion?
- High-dose pulsed hyaluronidase is the accepted approach: flood the entire ischaemic territory, not just the injection point, and repeat hourly until capillary refill, colour and pain normalise. Dosing is by territory and severity rather than by a single fixed number, and treatment continues over multiple pulses rather than stopping after one attempt.
- How quickly must filler-related vascular occlusion be treated?
- Immediately. Skin tolerates ischaemia for hours, but the retina tolerates it for minutes. Stop injecting at the first suspicion, begin hyaluronidase without waiting for certainty, and treat any visual symptom as an ophthalmic emergency requiring same-hour specialist referral.
- Can filler cause blindness, and is it reversible?
- Yes. Retrograde embolisation of filler into the ophthalmic artery can cause sudden, painful visual loss, most often reported after glabella, nose, temple and forehead injection. Recovery is rare, which is why prevention — low pressure, small aliquots, correct plane, aspiration where appropriate — matters far more than rescue.
- What should be in an aesthetic clinic emergency kit?
- In-date hyaluronidase in sufficient quantity for a full flooding protocol, sterile water or saline for reconstitution, adrenaline for anaphylaxis, aspirin, a written occlusion algorithm on the wall, documented escalation contacts for ophthalmology and emergency care, and a consent and incident record template.