Dermal fillers

A well-developed area of aesthetic dermatology is the use of the so-called fillers, which are injected in order to smooth the skin surface over wrinkles and sunken scars, and to enlarge lips. There are fillers of synthetic and natural origin, which, in turn, may be divided into xenogeneic (animal-derived tissue), allogeneic (human-derived tissue, mostly from the dermis and fascia, such as Alloderm®, Aymetra®, Fascian®), and autologous (own tissue).

In terms of consistency, two types of fillers may be distinguished: semi-liquid (injectable) fillers and implants, whereas in terms of the absorption rate, there are:permanent fillers - non-absorbable, semi-permanent fillers – delayed absorbable, and temporary fillers. Permanent fillers include silicone (Bioplastique®), acrylic (Artecoll®, Derma-live®, Aquamid®, Aquamid® reconstruction, Bioalcamid®), teflon (Goretex®) and calcium hydroxyapatite (Radiance®, Radiesse®). The effectiveness and usefulness of recently advocated gold thread implantation remains debatable. Among the temporary fillers the first historically significant group were collagen fillers based on bovine collagen (Zyderm®, Zyderm II®, Zyplast®, Resoplast®), porcine collagen (Fibrel®, Evolance®), allogeneic human collagen (Cosmoderm®, Cosmoplast®) and autogenoushuman collagen (Autologen®). They arebeing pushed out of the market by a large group of absorbable fillers containing hyaluronic acid (Restylane, Restylane® touch, Fine lines®, Perlane®, Restylane® Vital, SubQ Restylane®, Restylane Lipp®, Macrolane®, Rofilan®, AcHyal®, Hylaform®, Matridur®, DetHAil Coilingel®, Juvederm® 18,24,30, Juvederm® HV24, Juvederm® HV30, Juvelift®, Surgiderm®, Surgilips®, Puragen®, Viscontur®, Hyaluderm®, Natural face balance®, Natural face structure®). Tightly cross-linked hyaluronic acid-based dermal fillers, e.g. Macrolane®, are also used for improving body contours (e.g. breasts, cheeks, calves, etc.)

Formulations combining hyaluronic acid with dextran to prolong their absorption (Reviderm®, Matridex®, Dethail Lastingel®) are also available on the market.

Semi-permanent type is represented by crystalline polylactic acid (New Fill®, Sculptra®). This filler is considered useful for example in HIV-associated lipoatrophy.

There are many basic techniques of injecting liquid fillers, such as: linear threading – after the needle is inserted at the appropriate depth, the product is evenly injected as the needle is retracted; sandwich technique – the filler is deposited in the tissueat several levels; serial puncture – the needle is inserted every few millimetres along the defect line. For the last several years, a superficial technique has been advocated. It involves multiple shallow injections over the relatively large skin areas (mesotherapy). The procedure may be performed by means of a special device with a vibrating needle which facilitate an even distribution of the filler.

Various defects of the skin and subcutaneous tissue may be filled with patient's own tissue (autologous grafts). Most frequently, semi-liquid fat grafts harvested by liposuction are used, including cell suspension grafts. They can be used topically for filling depressions or all over the face under the skin surface, as in the ‘total face lipofilling’ procedure. The less commonly used technique involves the adipose tissue block grafts. Subcutaneous tissue may also be filled by means of the so-called dermal fat grafts, composed of dermis and the underlying adipose tissue, dermal grafts, and scar tissue grafts harvested during the scar correction procedure. Less frequently recommended and used in cosmetic procedures are fascia grafts. In the US there are also employed such techniques as autologous cultured fibroblasts (e.g. Isolagen®) and autologous collagen dispersion (e.g. Autologen®). An interesting approach to filing the skin folds is injecting augmentation material obtained from patient’s own blood, known as plasma gel. The material is obtained by centrifuging 20 ml of blood at 15000 rpm for 10 minutes. Subsequently, plasma is deposited in 1 ml syringes closed with 27 G needles and placed in a water bath at 70°C for 5 minutes and at 90°C for 100 seconds. After cooling, the gel formulation is ready for injection. The ready sets for obtaining and injecting platelet-rich plasma (Regeneris®) have recently been placed on the market.