New soft tissue filling methods increase patient comfort

Kauai, Hawaii - Collagen and hyaluronic acid fillers have become a mainstay for dermatologists dealing with cosmetic interventions across the globe.

Sharing experiences and treatment methods among colleagues is beneficial for doctors and patients alike. Kevin C. Smith, M.D., F.R.C.P.C., F.A.C.P., runs his own cosmetic treatment center in Niagara Falls, Canada, and presented his tips and tricks on fillers at the 30^th Annual Hawaiian Dermatology Seminar, here.

Crucial factors

Choosing a filler is not always as easy as it seems, and only after careful consultation, weighing the pros and cons, can the "right" filler be chosen.

Dr. Smith explains that collagen-containing products like CosmoDerm (Inamed), CosmoPlast (Inamed), or Artefill (Artes Medical) all contain xylocaine, producing local anesthesia in the applied site directly following the injection. Xylocaine also stabilizes eosinophils and therefore may reduce the inflammatory response to the treated site. Hyaluronic acid fillers such as Restylane (Q-Med), Captique (Inamed) or Hylaform (Inamed) on the other hand, are chemically incompatible with xylocaine, so there is no local anesthetic in hyaluronic acid products.

When administering Artefill, Restylane and Radiesse (BioForm), Dr. Smith has recently begun to employ ice and vibration instead of topical or injected anesthetics, with very good results. Patents who previously received topical or injected anesthetics almost universally prefer his new method.

"I prefer ice and vibration because I can work on tissue that is not distorted by local anesthetic or by muscle relaxation secondary to local anesthetic. Also, when treating the lips, it is important to ice for a full 10 seconds on both the skin and the mucosa of the lip," Dr. Smith tells Dermatology Times.

Bleeding and bruising

Bleeding and bruising are less of a problem with collagen-containing products, because collagen stimulates the clotting cascade, which in turn causes less bleeding and bruising to the area following injection.

Hyaluronic acid does precisely the opposite, inhibiting the clotting cascade. Therefore there tends to be a bit more bleeding and bruising with hyaluronic acid products.

Dr. Smith recounts his method.

"Since January 2005, I have had an assistant apply firm, steady pressure to the injected area for five full minutes on the clock, and we have not had any severe bruises, and only a few minor transient bruises. Patient satisfaction and patient retention have never been higher," he says.

Color

Dr. Smith points out that collagen products are white and opaque so they can be injected close to the surface without worrying about any visual color abnormality.

Not so with hyaluronic acid products, as they are crystal-clear and if they are injected too close to the surface, they may appear blue due to the Tyndall effect. Therefore Dr. Smith suggests placing hyaluronic acid injections 1 mm to 2 mm below the skin surface.

Durability

Possibly the most important question about a filler is: "How long will it last?"

As soon as they are injected, collagen products start to be reabsorbed. The injected site will experience some immediate volume loss because the water in collagen-based products is absorbed in one to two days, then the collagen itself will be degraded in a linear manner over several months.

Dr. Smith says, "Hyaluronic acid products, on the other hand, retain their volume better because of three reasons. First, there is little or no free water to be absorbed. Second, because hyaluronic acid is hydrophilic, volume remains quite constant because as the hyaluronic acid matrix is degraded more of the molecules are exposed and attract water molecules, resulting in isovolemic degradation - meaning that the volume of the product remains stable until a large proportion of the cross-links have been broken down.