Introduction

Although dozens of hyaluronic acid (HA) fillers are available for soft tissue augmentation, each has its own unique characteristics. The Juvéderm^® family of fillers are well known to physicians as soft and ‘easy to inject’ gels. Juvéderm^® products are distributed in the USA by Allergan Inc., Santa Barbara, CA. They were approved by the US Food and Drug Administration (FDA) in September 2006 and began to be marketed at the beginning of 2007.

All Juvéderm^® products are composed of hyaluronic acid, or hyaluronan, a polymer found naturally in human skin, eye, muscles, and joints, as well as in the connective tissue of all mammals. It is the most abundant glycosaminoglycan in human tissue, and plays a role in dermal water retention while binding collagen and elastin fibers. Thus, HA contributes to the integral structure of the skin. HA is not species specific, regardless of its source, so bacterial-derived HA is well tolerated by humans. In its natural form, HA breaks down within hours when injected into the skin. To produce longevity, it must be cross-linked. Although there are many methods for cross-linking HA, Juvéderm^® features a proprietary cross-linking process called Hylacross^®, which results in a concentration of 24 mg/mL of HA. This unique process results in a soft, viscous, non-beaded gel and is designed to improve the durability of this filler.

Juvéderm^® was approved by the FDA after a multicenter double-blind, randomized clinical trial by Baumann and co-workers in which it was compared with bovine collagen; the 24-week study revealed superior persistence in patients injected in the nasolabial areas with Juvéderm^®. After a subsequent FDA-approved clinical trial by Pinsky et al demonstrating that, after a single treatment, the effects could last up to 12 months, the FDA granted a label extension in June 2007. More recently, Allergan released a formulation of Juvéderm^® that was pre-mixed with lidocaine (XC) to diminish the pain of injection. Levy and colleagues determined that this new mixture was more comfortable for patients in a split-face comparison. Subsequent research by Raspaldo et al confirmed that the addition of lidocaine did not reduce the long-term durability of the product.

Juvéderm formulations

Juvéderm^® is available in a variety of formulations. In the USA, it is distributed as Juvéderm^® Ultra, Juvéderm^® Ultra Plus, Juvéderm^® Ultra XC, and Juvéderm^® Ultra Plus XC (Table 4.1). Juvéderm^® Ultra Plus contains a cross-linked composition of 8% versus 6% in Juvéderm^® Ultra, making it a more robust filler. The two XC Juvéderm^® products contain 0.3% lidocaine but are otherwise identical to the Ultra formulations. In some countries Juvéderm^® Voluma^® is also available. Voluma^® is a 20 mg/mL smooth HA preparation with high cohesivity and viscosity. These features provide extra ‘lift’ when injected into tissue.

Juvéderm^® injectable gel is a sterile, biodegradable, non-pyrogenic, viscoelastic, clear, colorless, homogenized gel implant (Fig. 4.1). It consists of cross-linked HA produced by bacterial fermentation by Streptococcus equus. The gel is formulated to a concentration of 20–24 mg/mL and suspended in a physiological buffer. The package insert states that the product is approved for ‘injection into the mid- to deep dermis for correction of moderate to severe facial wrinkles and folds (such as nasolabial folds)’ but is commonly used by physicians for a variety of soft tissue augmentation indications.

Figure 4.1 Syringes of Juvéderm^® Ultra and Ultra Plus.

Contraindications and safety considerations

The package insert states that Juvéderm^® is contraindicated in patients with severe allergies and in those sensitive to bacterial proteins, since trace amounts survive the manufacturing process. The gel must not be injected intravascularly and if done so may lead to embolization and tissue necrosis. It should also not be injected into sites of obvious inflammation, such as active acne or where infection is present.

The safety of injecting more than 20 mL per 60 kg of body weight has not been established nor has injection into patients prone to keloids, hypertrophic scars or pigmentary abnormalities. However, clinical experience by Taylor et al in injecting HA fillers into patients of color has been demonstrated to be similar to Caucasians; and in the original clinical trial (described on the package insert), more than one-third of subjects were of Fitzpatrick skin phototypes IV, V, or VI. No safety studies have been done on pregnant females, on those breast feeding, or on children under 18; so, caution is prudent in considering the timing of treating these individuals. Bleeding and bruising are increased in patients on aspirin, non-steroidal inflammatory agents, fish oil, or warfarin.

Laser and/or chemical peeling procedures of many depths may or may not affect the longevity of Juvéderm^® injections, especially if performed close to the time of the injection. The package insert also warns of inflammatory reactions if these procedures are performed soon before or after the filler injection, but there are no good clinical studies to support or refute this. Theoretically, the deeper the peel or laser (or dermabrasion) penetrates the dermis, the more likely it is that there will be an effect on the performance of a filler injected soon before or after. In addition, swelling due to treatments performed immediately prior to injections may skew contour and lead to unwanted results.

Minor problems such as redness, pain, tenderness, itching, firmness, swelling, bumps/lumps, and discoloration have been reported; but all of these can be easily treated and often resolve spontaneously. Like all HA fillers, Juvéderm^® can also be dissolved using hyaluronidase. So, this provides a convenient way to remove visible bumps/lumps and also persistent allergic nodules or biofilm formation, as was described by Brody.