Hyaluronic Acid in Office Practice - SKINmed 2004;3(3):163-164

Marcia Ramos-e-Silva, MD, PhD, Section Editor

From the Sector of Dermatology and Post-Graduation Course, School of Medicine and Hospital Universitario Clementino Fraga, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil

Hyaluronic acid is a natural polymer with good biologic compatibility because it is a component of all connective tissues in humans and most vertebrates. This viscoelastic polysaccharide is present in the intercellular matrix of several human tissues and forms an insoluble network that has a great capacity to attract and retain water. After hydration, it forms a highly elastic gel that provides turgor to the skin. 1–3 Isolated for the first time in 1934 from the vitreous humor of bovines, it has been used in its native form as a filler for more than 20 years. It is used frequently in ophthalmologic surgeries as a substitute for the vitreous humor or in retinal detachment, and in orthopedic surgeries as a replacement for sinovial fluid. 1, 3 It is presently widely used in dermatology because it is a nearly ideal filling agent. It is easy to handle; indicated for several types of wrinkles, furrows, and scars; colorless; sterile; nonpyrogenic; nontoxic; transparent; and durable. 1, 2

Composition

Hyaluronic acid is a natural polysaccharide of high molecular weight comprising a chain of repeated disaccharides containing glucuronic acid and N-acetyl c. 1, 3 To reach the ideal properties of a filling agent, a derivative of hyaluronic acid was produced by chemically creating a great number of cross connections and bridges between its molecules. This results in a viscoelastic gel (hyaluronan) that is able to retain 99.5% water and is injectable (it is physically broken up into fragments of 100 micra) The gel is stabilized to allow isovolumetric degrading within 1 year (Restylane, Q-Med AB, Uppsala, Sweden). 1 The source materials are non-animal cells, and therefore free of the inconveniences of hyaluronic acid taken from cock crests. The hyaluronan glycosaminoglycans chain is not altered by the chemical modifications that produce the gel because it differs only 0.5%–1% from the natural hyaluronic acid. Animal tests and clinical studies indicate that the formulation does not predispose humoral or cellular immunologic reactions, does not cause local inflammatory reactions, is nontoxic, and is not recognized as a strange body in the tissue. The reason for this nonimmunogenicity is probably the similarity of the chemical structure of the hyaluronic acid molecule to that of a component of connective tissues. Thus, no skin tests are necessary before the treatment. 1

Duration

The filler lasts between 6–12 months. 2, 3 Reports state that a retouch after 2–4 weeks provides better results and can make the filler last as long as 18 months. A very thin dermis in some patients may shorten that time frame and, in our experience, patients with hyperthyroidism (mainly if uncontrolled); menopausal women who use oral hormone replacement therapy and suspend the medication; heavy smokers; and patients who, soon after the procedure, undergo a dental treatment resulting in significant local inflammation and manipulation experience a shorter duration.

Restylane/Perlane

Produced by Q-Med AB (Uppsala, Sweden), the gel can be found commercially in three formulations all containing 20 mg/mL stabilized hyaluronic acid: Restylane, Restylane Fine Lines, and Perlane 2, 3 ( Table ).

Table. Characteristics of Restylane/Perlane*

Indications

Hyaluronic acid is indicated in the correction of wrinkles and face sulci, including perioral and periorbital wrinkles, wrinkles in the genian region, lower lip elevation, and drooping of the nasogenian sulcus. 1–3 It is also appropriate for lip contour and lip augmentation 1–3 and the correction of depressed scars. 1, 3

Treatment of fine and surface facial lines should be avoided due to the possibility of forming visible papules. 1 It is important to evaluate the area and amount of substance to be applied because if great amounts are to be used the filler may not be the best choice for the patient. 2

Its use in correction of glabella wrinkles is controversial because this region is crisscrossed with relatively large blood vessels near the skin surface and can lead to the possibility of severe complications, including blindness.

Contraindications

Contraindications include pregnancy and lactation, 1, 3 disturbed coagulation and use of anticoagulants, 1–3 systemic autoimmune diseases, 1, 3 inflammation or infection at the site to be treated, 3 disturbance of behavior, 3 history of vitiligo, 2 history of keloid formation, 1 and the presence of acute or chronic cutaneous pathologies near the area to be treated. 1

Complications

Most of the adverse effects are localized and transitory and include pain, edema, and erythema at the application sites; echimoses; local hypersensitivity; hyperchromia; and transitory hypochromia. 1–3 It is important to check for history of herpes simplex lesions, mainly on the lips. In such cases, development of new lesions after application may be averted with systemic antiviral agents applied 24 hours before the procedure. 3

Overcorrection in places of fine skin should be avoided (around the mouth and eyes), where the filler can be easily detected 2, 3 and form a visible papule or even cause a temporary loss of hair, 1 besides leading to edema and pain at the application site. 2, 3

Up to 5% of patients develop acneic lesions in the injection area with spontaneous regression after 2 months, at latest. 1 There are also reports of nodules at the treated sites, some progressing to abscesses that can leave a depression and local atrophy. These are late complications arising 15–45 days after the procedure. 3

Treatment of wrinkles in the glabellar region has a potential risk of occlusion of terminal arteries that are characteristic of that region and may lead to ischemia and necrosis, an unaesthetic scar, and eventually blindness. It is a severe complication that can be detected if, at the time of application, acute pain and a whitening of the area occur. 2, 3

Conclusions

Hyaluronic acid fillers have shown great utility due to the product’s characteristics: low index of local problems, minimal inflammatory reaction, few encapsulated reactions, and lack of necessity of hypersensitivity tests. 1, 3 It is a product with very satisfying and immediate results. The satisfaction index, for both patients and doctors, is high, around 80%, despite the need for serial reapplications. 1 Of course, it is very important to evaluate the patient’s real expectations. 3

The best results are obtained in correction of face wrinkles and sulci that are not dynamic or gravitational. Is use is also extremely useful for contouring and increasing volume of the lips.

References