The elasticity of the skin is one of the most important parameters of its health or aging,
as well as evaluating the effectiveness of procedures with intradermal injections – redermalization (RD).
There are many terms of aesthetic medicine and cosmetology that characterize exactly the mechanical properties of the skin: elasticity,
rigidity,
stiffness,
density,
tone,
flabbiness,
plasticity and others.
However,
objective instrumental methods for quantitative measurement of these fundamental parameters of the skin are rarely used in everyday practice [1-3].
Сosmetologists and clients themselves use mostly subjective data to assess the condition of the skin.
The biomechanical tests of human skin help to qualitatively and quantitatively assess the effectiveness of dermatological products and procedures,
the detection of skin diseases,
the planning of surgical and dermatological interventions and treatment.
The skin reacts to mechanical effects,
primarily to stretching,
by a series of adaptive reactions (increase in the mitotic activity of the cells of the dermis and epidermis,
the synthesis of collagen) aimed at restoring skin homeostasis [ 4,
5,
6,
7].
The mechanical properties of the skin primarily depend on the layer of the dermis,
which is saturated with connective tissue - the extracellular matrix (ECM).
It is represented by three-dimensional interlacing of protein fibers (collagen,
reticulin,
elastin) and sol,
which consists of water,
ions,
hyaluronic acid (HA) and other macromolecules.
HA has a high hydrophilicity and holding a certain amount of water and ions,
provide tissue turgor (mechanical tensions).
With age (after 25 years),
the amount of collagen and hydrophilicity (water content) of the sol changes downwards.
This causes the skin to gradually lose its mechanical properties and manifestation of sagging and wrinkles[ 8,
9].
The study of changes in the mechanical properties of living tissues in health and pathology has allowed the development Ultrasound Strain Elastography (SE) [ 1]. However,
the first attempts to use SE in dermatooncology did not lead to significant progress in the mind of the operator- and apparatus-dependence method [1,
10,
11].
New perspectives have emerged in the development of the Share Wave Elastography (SWE) for an objective and quantitative assessment of stiffness / elasticity by of Young's modulus in kPa.
The great interest are works on the use of the one-dimensional transient elastometry of the skin (1D TE) [12].
It was shown experimentally and in the clinic the possibility of studying thin layers and biomembranes (dermis,
penile tunica albuginea) by 2D-SWE [ 13,
14].
There was a possibility of accurate navigation in real time of the colorized region of interest (ROI) of elastography and sample volume (SV) of elastometry within the thickness of the dermis of 1.2-2.2 mm by B-mode [14].
It is of interest to evaluate with the influence on the mechanical properties of the skin of the combinational treatments of injectable hyaluronic and succinic acid ( HA+SA) intradermal implants by the 2D-SWE [ 9 ].
Aim was to evaluation of the skin redermalization (RD) effects by Hyalual booster injection (combination HA 22 mg/ml and SA 16 mg/ml) by Real-time 2D-SWE.