Injectable Fillers

GENERAL FILLER CHARACTERISTICS

Describe the ideal filler.

1. Safe/biocompatible

2. Physiologic

3. Easily obtained, stored, and used

4. Long-lasting and reversible

5. Predictable with minimal migration

6. Minimal side effects or complications

What is the molecular composition of the biodegradable fillers commercially available?

1. Bovine collagen (Zyderm/Zyplast, Resoplast)

2. Human collagen (Dermalogen)

3. Autologous fibroblasts (LAVIV, AlloDerm)

4. Hyaluronic acid (Hylaform gel, Restylane)

5. Calcium hydroxylapatite (Radiesse)

6. Poly-L-lactic acid (PLLA)

In what facial areas do fillers have greater longevity?

Relatively static areas, such as nasolabial folds, or areas rendered less dynamic by Botox allow for more sustained results. Filling dynamic areas of the face, such as the lips, reduces duration of filler effect.

What should patients avoid 5 days prior to undergoing facial rejuvenation with fillers?

1. Vitamin E

2. Gingko biloba

3. Aspirin and nonsteroidal anti-inflammatory

AUTOLOGOUS FAT TRANSFER

How should fat be harvested, prepared, and injected to ensure maximal effect?

Gentle harvest of the fat with low-pressure suction coupled with gravity sedimentation or balanced centrifugation helps to preserve fat architecture. Coleman’s technique of small aliquot injection in multiple tissue planes aids in revascularization of the transferred fat.

What percentage of fat survives after fat grafting?

60% to 80%, depending on the location of injection, method, and vascularity of surrounding tissue.

What are common techniques for processing fat after harvesting?

Fat can be processed by:

1. Balanced centrifugation

2. Cotton gauze rolling

3. Suction filtration

Which technique is effective in removing fluid and oil?

All of the above.

Which technique provides the highest in vivo graft retention?

A study looking at fat graft retention in nude mice found higher in vivo graft retention and stromal vascular fraction yield was highest with the cotton gauze rolling method.

What are the disadvantages of this method?

This method is fairly tedious and difficult to do for high-volume grafting.

COLLAGEN DERIVATIVE FILLERS

Describe Zyderm I, Zyderm II, and Zyplast.

1. Available in 1977, Zyderm I, derived from bovine collagen, is 95% type I and 5% type III collagen. Zyderm II has almost twice the concentration of bovine collagen of Zyderm I. These two formulations are injected in the more superficial dermis to treat fine-to-moderate lines, wrinkles, and scars, but they are degraded in approximately 3 months time.

2. Zyplast results from cross-linking bovine collagen with glutaraldehyde and has greater tissue longevity. It can be used in the deep dermis for deeper lines and folds but is degraded in 3 to 6 months time.

3. Allergic reaction for these products with bovine collagen has been reported as high as 5%. Therefore, antecedent skin testing with Zyderm I (about 0.1 mL) should be performed. Skin should be observed after several days and after 1 month for signs of allergic reaction. Of special note, the injection of Zyplast has resulted in retinal artery thrombosis.

How do Cosmoderm/Cosmoplast differ from Zyderm/Zyplast?

Cosmoderm 1, Cosmoderm 2, and Cosmoplast are analogous to Zyderm I, Zyderm II, and Zyplast but are human collagen dermal fillers and do not require skin testing. Cosmoderm is used for more superficial lines, whereas Cosmoplast is used for more pronounced wrinkles. Results last up to 6 months.

What is Dermalogen?

Dermalogen is derived from human dermal collagen and harvested from cadaver skin specimens. Dermalogen is sterilized and processed to inactivate virus and prions. It is purported to undergo neovascularization and collagen synthesis.

What are the contraindications of injectable collagen?

Autoimmune disease, deep pock or ice pick scars, immature or indurated scars, and positive skin reactions are the contraindications.

Why are fillers contraindicated for deep ice pick scars or fixed scars?

Deep ice pick and fixed scars cannot be mobilized because of scar tissue that extends deep to the subcutaneous tissue plane. Placing filling material would elevate the surrounding skin and produces a donut effect. The cause of the tethering should be addressed prior to consideration of fillers.

What is Evolence?

Approved in 2006, Evolence is a cross-linked porcine collagen indicated for moderate-to-deep facial wrinkles and the nasolabial fold. Evolence proved superior for the treatment of nasolabial folds to Zyplast beyond 6 months.