For any medical professional injecting hyaluronic acid (HA) dermal fillers, hyaluronidase is an indispensable enzyme that serves both corrective and critical safety functions. While often generically referred to as “Hyalase” – a specific brand name in some regions – hyaluronidase is the enzyme that breaks down hyaluronic acid. Its immediate availability and correct usage are absolute requirements in aesthetic practice, making it a cornerstone of preparedness and a tool for managing outcomes.

Mechanism of Action: How Hyaluronidase Works

Hyaluronidase is a naturally occurring enzyme found in various organisms. In aesthetic use, its mechanism is enzymatic hydrolysis – it breaks the chemical bonds within the long chains of hyaluronic acid polymers. This process rapidly reduces the viscosity of the HA gel, essentially liquefying the filler and facilitating its dispersal and reabsorption by the body’s lymphatic system. This action is specific to hyaluronic acid fillers; hyaluronidase does not break down non-HA fillers like Radiesse (CaHA) or Sculptra (PLLA).

Hyaluronidase Products Available for Aesthetic Use

Different preparations of hyaluronidase exist, varying by source and regulatory status. In the United States, several FDA-approved hyaluronidase drug products are available, including those derived from recombinant human DNA technology (e.g., Hylenex®) and purified ovine (sheep) or bovine (cattle) sources (e.g., Vitrase®). These are prescription medications obtained from licensed pharmacies.

Other branded hyaluronidase products, such as Liporase, are also utilized in aesthetic practice by practitioners seeking this enzyme, often searched for under names like “Hyalase” or other brands. Regardless of the specific brand or source, the critical factor is having a product containing active hyaluronidase enzyme that you are trained and authorized to use.

Reconstitution and Handling: Precision is Key

Proper reconstitution and handling are vital for ensuring hyaluronidase potency and safe administration:

• Diluent: Always reconstitute lyophilized hyaluronidase powder using sterile saline. Preservative-free 0.9% Sodium Chloride for Injection is typically recommended to minimize potential irritation or reactions, but always consult the specific product’s IFU.
• Dilution: The concentration after reconstitution depends on the volume of saline added per vial. Dilution varies significantly based on application:
  • Elective Dissolving: Often reconstituted at lower concentrations, e.g., 150-300 Units/mL, for precise contouring adjustments.
  • Emergency VO Management: Reconstituted at much higher concentrations, e.g., 500-1500 Units/mL, to deliver a high dose in a smaller volume rapidly. Always follow established emergency protocols learned through training for VO dosing.
• Mixing: Gently swirl the vial after adding saline; avoid vigorous shaking which can denature the enzyme.
• Shelf-Life: Once reconstituted, hyaluronidase has a limited shelf-life, typically 24 hours when refrigerated, though some preparations or dilutions may differ. Consult the IFU and discard any unused portion after the specified time.
• Storage: Store lyophilized powder and reconstituted solution according to manufacturer guidelines (often refrigeration for both, but check IFU).

Clinical Applications: Elective Correction & Emergency Safety

Hyaluronidase serves two primary roles in aesthetic practice:

Elective Dissolving

Hyaluronidase allows for precise management of suboptimal HA filler outcomes:

• Reasons: Correcting overcorrection (too much volume), asymmetry, visible lumps or irregularities, Tyndall effect (bluish hue from superficial filler), filler migration, or simply patient dissatisfaction with the result.
• Technique: Involves targeted injections into the area requiring correction. Protocols often include allergy pre-testing (see Safety section) and massaging the area after injection to facilitate dispersion. The dose and volume used depend on the area and amount of filler to be dissolved. Multiple sessions may be needed for complete dissolution.

EMERGENCY Vascular Occlusion (VO) Management

This is the single most critical use of hyaluronidase in aesthetic medicine. HA filler unintentionally injected into or compressing a blood vessel can lead to ischemia and tissue necrosis, potentially causing severe scarring, blindness (if ophthalmically involved), or stroke.

• Recognizing VO: Be vigilant for signs: immediate or delayed severe pain disproportionate to injection, sudden blanching (whitening) of skin in the area or along a vascular pathway, livedo reticularis (mottled purplish discoloration), delayed capillary refill, coolness to touch, potential visual changes (ocular emergency).
• Protocol is IMMEDIATE:
  • STOP injection immediately.
  • Remove needle/cannula.
  • Aggressive massage of the area.
  • Apply warm compress/vasodilators (e.g., nitroglycerin paste).
  • HIGH DOSE Hyaluronidase: Administer a large dose of highly concentrated hyaluronidase directly into and around the suspected area of vascular compromise without delay. Do not be conservative with dosing in an emergency. Flood the area.
  • Repeat Injections: Re-inject high-dose hyaluronidase into the area frequently (e.g., hourly) until signs of occlusion resolve or definitive treatment plan is established.
  • Supportive Measures: Aspirin (if no contraindications), hyperbaric oxygen (if available).
  • Urgent Referral: If any signs of ocular involvement (vision changes, pain) or spreading tissue compromise, urgently refer to appropriate specialists (ophthalmologist, vascular surgeon).

TIME IS CRITICAL in a VO emergency. Delaying hyaluronidase administration can lead to irreversible tissue damage. Every minute counts.

Safety, Side Effects & Contraindications

While a life-saving agent, hyaluronidase is not without potential risks:

• Allergic/Hypersensitivity Reactions: Allergic reactions can occur, ranging from local redness/swelling to rare anaphylaxis. Reactions were historically more common with animal-derived preparations. Patch testing (injecting a small amount intradermally on the forearm) is often recommended prior to elective dissolving, especially for patients with a history of allergy (e.g., bee stings) or prior exposure to animal-derived hyaluronidase. Protocols for emergency use in VO vary, but the critical nature of the emergency often outweighs the lower risk of allergy.
• Local Site Reactions: Temporary redness, swelling, bruising, or tenderness at the injection site.
• Temporary Deflation: Hyaluronidase breaks down both exogenous (filler) and endogenous (natural tissue) hyaluronic acid. Patients may experience temporary deflation or a “deflated” appearance in the treated area, which typically recovers over time as the body replenishes its own HA.
• Contraindications: Known hypersensitivity to hyaluronidase or any components; acute infection or inflammation at the proposed injection site; injection into actively infected areas.

Clinic Preparedness: Non-Negotiable

Any practice performing HA filler injections MUST be fully prepared for a vascular occlusion emergency. This is not optional.

• Emergency Kit: A readily accessible, clearly labeled emergency kit containing ample units of hyaluronidase (multiple vials), sterile saline for reconstitution, syringes, needles, alcohol wipes, gauze, marking pen, sterile gloves, as well as adjuncts like aspirin, nitroglycerin paste, phone numbers for urgent referrals, and the clinic’s written VO protocol. Check expiry dates of kit contents regularly.
• Trained Personnel: All staff involved in or present during injection procedures should be trained to recognize the signs of VO and understand the initial steps of the emergency protocol.
• Practiced Protocol: Have a clearly written, well-understood, and practiced protocol for managing VO emergencies, including steps for immediate hyaluronidase administration and seeking urgent specialist consultation.

Sourcing and Storage

Hyaluronidase is a prescription drug product. Obtaining authentic, in-date hyaluronidase is crucial. Source only from licensed pharmacies or reputable, licensed medical suppliers. Store the product (lyophilized powder and reconstituted solution) strictly according to manufacturer instructions to maintain potency.

Conclusion

Hyaluronidase is an indispensable tool in the aesthetic injector’s armamentarium, serving vital roles in both managing outcomes through elective dissolving and, critically, as the primary treatment for vascular occlusion emergencies. Understanding its mechanism, proper reconstitution, clinical applications, and potential risks is essential.

The absolute necessity of having adequate hyaluronidase readily accessible in a well-equipped emergency kit and a clearly practiced VO protocol cannot be overstated for any practice performing HA filler injections. Prioritizing training and preparedness ensures the highest standard of patient safety.

Doris Dickson

About the Author: Doris Dickson is a specialist writer for Health Supplies Plus, focusing on the aesthetic medicine industry. She diligently researches cosmetic treatments and products to provide clear, concise information relevant to licensed medical professionals. Her work supports Health Supplies Plus’s commitment to being a reliable informational resource and trusted supplier for the aesthetic community.

 

Disclaimer: The content provided in this article is intended for informational purposes only and is directed towards licensed medical professionals. It is not intended to be a substitute for professional medical advice, diagnosis, or treatment, nor does it constitute an endorsement of any specific product or technique. Practitioners must rely on their own professional judgment, clinical experience, and knowledge of patient needs, and should always consult the full product prescribing information and relevant clinical guidelines before use. Health Supplies Plus does not provide medical advice.