West Palm Beach, Fla. - Patients report a high level of satisfaction with a cross-linked, injectable hyaluronic acid gel filler (Juvéderm, Allergan).
The gel filler is associated with a smoother and softer result than is associated with other fillers, according to Mark A. Pinsky, M.D., a board-certified plastic surgeon and the chief of the division of plastic surgery at St. Mary's Medical Center in West Palm Beach, Fla.
"I believe the new filler has advantages for several reasons," he tells Dermatology Times.
He says results from gel fillers based on hyaluronic acid differ from results of botulinum toxin (Botox, Allergan), which requires repeat treatments every four months.
The gel filler injections' results last several-fold longer than results with botulinum toxin. Therefore, the physician performing the injections needs to have a high level of skill, because the patient will live with the result for a much longer period of time, he says.
In an open-label study involving 9,000 subjects and more than 1,500 physicians performing the injections, the investigators' findings were similar to the initial study presented to the Food and Drug Administration (FDA), in which 439 patients had no systemic adverse events, and all local adverse events were categorized as minor, resolving within seven days and not requiring treatment.
The gel filler is approved for injection into the mid- to deep dermis and comes in several formulations. The strongest formulation (Juvéderm Plus) treats moderate-to-severe facial wrinkles and folds, but is also suited for adding volume to areas of the face, such as the cheeks, chin, jaw line or nose.
There are some similarities between an earlier cross-linked hyaluronic acid-based filler (Restylane, Medicis) and the newer filler on which the investigators focused. Both, for example, are cross-linked with butanediol diglycidyl ether (BDDE). Cross-linking allows the product to persist longer, so the benefits of treatment last longer.
However, the formulation of the products is different in that the earlier formulation is a gel-based particle suspension, while the newer one is manufactured through a process that makes the product a more homogeneous formulation, and also allows for a greater percentage of cross-linking of hyaluronic acid molecules. This property, in turn, also enhances the filler's persistence. Greater cross-linking also promotes a smoother, softer appearance.
"It's like the difference between sand in water and a smooth substance that is whipped," Dr. Pinsky says.
Dr. Pinsky notes that the hyaluronic acid in the newer product is more highly concentrated in that it contains a greater amount of cross-linked hyaluronic acid per cubic milliliter than does the earlier product. Therefore, the theory is that the body metabolizes the newer product more slowly than the earlier product, and that, therefore, the newer product yields longer-lasting results.
With the earlier filler, the injected hyaluronic acid has been shown to stimulate the body's own collagen formation, and some experts think that other fillers will have a similar benefit, Dr. Pinsky says.
Therefore, the hope is that repeat treatment with hyaluronic acid will encourage further collagen synthesis and extend the treatment's benefits.
According to the manufacturer, the newer product more closely mimics the body's natural contours.
Its hydrophilic nature causes the product to attract water molecules from within the body so that the treated area expands. After the injected hyaluronic acid diminishes, it tends to seek out even more water and, therefore, perpetuate its effects as a filler.
Although allergic reactions to BDDE are rare, they have occurred in fewer than 5 percent of those treated. The signs of an allergic reaction are redness, itching, pustules and discomfort.
However, the newer formulation undergoes a cleaning process after cross-linking that is designed to remove residual BDDE. Therefore, the hope is that the newer formulation will be associated with fewer allergic reactions.
Juvéderm is manufactured by Allergan. It comes in two formulations. Juvéderm Ultra is used for moderate lines and wrinkles, and Juvéderm Ultra Plus is the more highly concentrated formulation, and is used to correct deeper folds and lines.
Disclosure: Dr. Pinsky was a paid investigator for the Juvéderm trial. He is a paid consultant for Allergan and a member of the Allergan Executive Council on Breast Aesthetics.