Table IV. Tissue augmentation
Zyderm II (bovine)
Autologen (not available)
Isolagen (United Kingdom and Australia)
Dermalogen (not available)
Augmentation is a further alternative for management of acne scarring. This topic includes numerous variations and compositions of filler substances. Those to be addressed may or may not be available in the United States and the list is certainly not comprehensive or detailed for each product mentioned. In addition, some products, such as Autologen and Dermalogen, are mentioned for historical interest. However, there is an excellent, comprehensive, in-depth review of multiple filling agents published several years ago by Klein48; a recent review of non-Food and Drug Administration (FDA)- approved fillers by Ellis and Segall49; and a very complete, easy-to-use dermal filler product comparison chart in a separate publication.50 These alternatives may be xenografts (from a different species), autografts (obtained from the patient), homografts (same-species derived), or synthetics.
An ideal filler material would be physiologic (incorporates into the body’s tissues), simple to place (injection), permanent (no degradation), and risk free (no complications or side effects).51 Potential superficial skin products may include collagen or hyaluronic acid and deep skin products include fat, synthetics, silicone, implants, and permanents. Although close, none available meet all of these criteria completely. Most of these are applicable to depressed scars such as the atrophic rolling variant or sometimes others. Potential side effects may include pain, pigmentary changes, bruising, infection, allergic reaction, hypertrophic scarring or keloids, possible granulomas, bleeding, migration of product, ulceration, tissue death, significant distortion, or technical error on placement. If a permanent substance is chosen and is placed too deep, too shallow, or overcorrected, or if there is a persistent defect, minor surgical removal, excision, electrodessication, or steroid treatment could be required.
The first FDA-approved fillers were collagen based. The reconstituted bovine class of collagen has been available since the late 1970s to early 1980s. However, there are various other derivations. Collagen functions as a physical augmentation medium and a stimulus for scar base formation by connective tissue encapsulation. The placement should focus on mature scars rather than those that are newly created because static, noninflamed scars or those with no ongoing disease demonstrate longer efficacy.52 Its use is very technique sensitive, which also affects the quality and duration of the treatments. Placement should be superficially in the dermis and not in the subcutaneous tissue. There is fairly rapid degradation so maintenance sessions are necessary. Usually there is a benefit at 3 to greater than 6 months with some accounts of up to several years. Common to all of these products could be discomfort, inflammation, bruising, allergy, erythema, discoloration, and correction defects. Hypertrophic scars, keloids, and icepick scars are not indicated for treatment with this method. In addition, those with autoimmune disease should avoid its use because of the higher risk of sensitization or allergy. Double allergy tests over 4 to 6 weeks are even required for those with normal immune systems because of a delayed hypersensitivity in approximately 3% of the population (2% will sensitize after the first skin test exposure).53 The following paragraphs go into further depth for a few collagen products and briefly mention multiple others (Tables IV and V).
The first injectable filler approved by the FDA was Zyderm. The other similar products are Zyderm II and Zyplast. These collagen products are derived from a closed US bovine herd. Even though this helps to ensure quality, purity, and safety, its immunologic basis is not effected, therefore, skin tests are still required.44 Type I collagen represents 95% to 99% and type III collagen represents 1% to 5% of the product contained in prefilled syringes. Zyderm I was approved in 1981. It is a 25% suspension (3.5% by weight) of collagen in saline and lidocaine solution. It is usually for shallow scars, so is placed in the papillary dermis. Overcorrection is initially required because of water loss after placement. Two to 3 months of result are typically expected. Zyderm II gained approval in 1983. It is a 50% suspension (6.5% by weight) of collagen. Larger scars are more often addressed with this variant. Overcorrection is again recommended and 4 to 6 months of effect can be expected. Zyplast, approved in 1985, is a 35-mg/mL solution of collagen cross-linked with 0.0075% glutaraldehyde to slow reabsorption. Injection into the mid dermis allows for contouring and larger scar treatment. Overcorrection is not required and its duration of effect may be up to 1 year.
ArteFill or Artecoll are 20-volume percent suspensions of 30 to 50 mediameter microspheres of polymethyl-methacrylate (also known as Plexiglas or Lucite) in atelocollagen (3.5% collagen solution), saline, and lidocaine.54 ArteFill (US) is the same composition as Artecoll (Europe and Canada) but the spheres are somewhat smaller and more symmetrical. Polymethyl-methacrylate is used in bone cements for joint replacements, cataracts surgeries, dental procedures, and neurosurgical applications. The polymethyl-methacrylate is permanently deposited and encapsulated with fibrous tissue after injection while the remaining collagen is gradually resorbed.55 Both serve physical augmentation and scar stimulus functions. As noted above, skin testing is required because it is from a bovine source. There may be initial inflammation, erythema, bruising, and discomfort from the injection of these products. A 2006 article reporting 4- to 5-year outcomes with ArteFill used as a filler for wrinkle lines evaluated its safety and length of effect. Of the 128 patients who received the product (of 251 total patients in the initial study), a subgroup of 69 were reassessed. There were 6 adverse events noted within 5 patients treated with 272 injections. Four (1.5%) were mild (lumpiness) and two (0.7%) were severe (nodular, minimal to noninflammatory reactions in the nasolabial folds bilaterally). These severe events were treated with intralesional steroid injections and were resolving as the article was being published. In addition, somewhat surprisingly, it was noted in the other patients that the results actually appeared better at 5 years than at 3 months to 1 year. It was concluded that ArteFill was relatively free from side effects and was an efficacious material that demonstrated good long-term persistence and safety.56
Acne Scarring A review and current treatment modalities BACKGROUND and ACNE SCARS ACNE SCARS page 2 ACNE SCAR TREATMENT and MEDICAL MANAGEMENT SURGICAL MANAGEMENT PROCEDURAL MANAGEMENT PROCEDURAL MANAGEMENT page 2 TISSUE AUGMENTATION TISSUE AUGMENTATION page 2 TISSUE AUGMENTATION page 3 TISSUE AUGMENTATION page 4 Light, laser, and energy therapy Light, laser, and energy therapy page 2 Light, laser, and energy therapy page 3 Light, laser, and energy therapy page 4 Conclusion and REFERENCES Manufacturers of brand name drugs mentioned in this article