Dr Zunaid Alli explores skin hydration and biorevitalisation with hyaluronic acid-based injectables
Hyaluronic acid (HA) is a widely used biocompatible component in aesthetic injectables due to its safety and efficacy. It is one of the main components of the extracellular matrix and ground substance and is therefore indispensable for the cellular framework.1
HA is capable of hydration, lubrication and returning of elasticity to the skin, maintaining the shape of tissues and strengthening tissue tone.2 The greatest amount of HA is present in the skin and comprises around half of the body’s total volume of HA.3
This article will focus on HA as the main component for skin biorevitalisation and hydration in areas of the face, neck, décolletage and dorsum of the hands using mesotherapy techniques.
Hyaluronic acid for skin hydration and biorevitalisation The majority of HA used in skin hydration and biorevitalisation is non-cross-linked. As the product is injected into the dermoepidermal junction, it aids to add HA to the layers undergoing mitotic division, hence producing better quality keratinocytes.4 As HA is water-soluble, in non-cross-linked form its effects only set in upon epidermal and/or superficial intradermal administration.4 If injected into the hypodermis, the non-crosslinked HA is transported away from the skin and metabolised, with little to no effect.4,5
Technological advances have improved the viscoelastic properties of HA skin biorevitalisers by adding cross-linked HA products such as Viscoderm Hydrobooster6 and Stylage Hydromax7 to existing dermal filler ranges to treat wrinkles and improve elasticity in dynamic areas of the skin.
In my view, practitioners should consider using non-cross-linked HA when applying a full-face protocol for skin hydration, and a cross-linked HA using a linear thread technique to treat wrinkles such as those in the periocular region or the area below the cheeks.
As the skin’s ability to protect, regenerate and restore itself declines with age, in combination with genetics and added environmental stressors such as ultraviolet light exposure, stress, pollution and diet, increasing oxidative stress results in tissue damage and the production of reactive oxygen species (free radicals).8 These are capable of protein, DNA and lipid damage.9 Volume loss and repetitive muscle movements that cause wrinkles and folds have further been described as additional factors in skin ageing.10
The intradermal benefits of HA are that it can:
The addition of antioxidants, vitamins, minerals and amino acids injected into the skin may promote fibroblast stimulation.14 As HA injected into the skin stimulates fibroblast activity, the synergistic action of the additives has been demonstrated to increase in vitro fibroblast activity significantly.15
Mesotherapy is a minimally-invasive procedure that includes various sets of techniques that delivers active substances such as HA, vitamins, minerals, amino acids and peptides into layers of either the dermis, epidermis or both. The efficacy of the treatment is based on the physical stimulation that the treatment elicits, the pharmacological effect of the components and the dose of the components delivered into the skin. Mesotherapy techniques are largely delivered by hand using specialised needles, or by pneumatic or injector devices. They include nappage (picotage), serial puncture (point-by point or multiple micro-injections), superficial linear thread, infiltration into the dermis and mixed techniques19 where the use of a blunt intradermal cannula may be used for more viscous or cross-linked HA biorevitalising products.4,20
The entire face is suitable for treatment with HA. A grid is either drawn or observed with distance between injection points being 1cm apart. A common approach for this technique follows the skin surface, which is injected in a point-to-point fashion where the needle is inserted into the skin at between 30-45o, aiming for 2-3mm in depth, which is sufficient to reach the dermal layers.4
Small aliquots of the product are injected into a papule before moving onto the next area. This ensures that the product is placed into the dermis where fibroblast activity is found. This is continued throughout the area of the face except for the nose, as direct injection on the surface of the nose may be painful.4
Here, the suggested method of injection would be the nappage technique where the bevel of the needle faces up, the syringe is held at 30-45o and the bevel is used to penetrate the skin creating microchannels where the HA is able to be massaged into them for absorption.20 This is a superficial technique and is confined to the epidermis 1-2mm depth, yet delivers HA to the skin on the nose without causing discomfort.
The treatment plan may be modified to treat areas of the face where skin hydration, rhytid improvement and skin thickening is needed, such as the periorbital region. I find that serial puncture or superficial liner thread with a 30 gauge (or higher) needle may be used to inject HA into the dermis, especially in the area adjacent to the periorbital/suprazygoma where neurotoxin may not be used. As the rhytids may extend over and below the zygomatic area, in my experience, a thicker cross-linked HA is best to inject using a superficial linear thread technique.
Mesotherapy using HA is of benefit when treating the perioral rhytids (barcode lines). I often use a combination treatment approach in this area, combining both serial puncture and superficial linear thread techniques to inject the HA to plump out the skin and smooth out individual rhytids.
Treatment of the neck in younger patients may require HA for the purpose of hydration of the skin, improvement of tonicity and to prevent ageing. A serial puncture technique of injections 1cm apart over the entire surface of the neck is commonly used.20 I find that in older patient, or patients who wish to treat horizonal neck bands, a cross-linked HA may be beneficial and can be injected using a superficial linear thread technique. If lack of hydration and tonicity is an issue, a combined approach can be successful.
Vertical rhytids that descend from the clavicle down to the centre part of the anterior chest between the breasts and crepey skin over the chest are commonly treated areas. If the rhytids are mild, serial puncture covering the entire area should be used,20 with technique as described for the face (1cm apart). For the vertical lines, superficial linear thread may be done using needle or cannula with a cross-linked product as the rhytids may be deeper.
In my experience, a combination approach to treating the dorsum and digits should be considered for successful results. While the serial puncture technique could be used, due to the superficial network of vessels on this part of the hand, I recommend a cannula technique. A single entry point just distal to the wrist is sufficient for cannula insertion with the ability to linear thread in a fanning arrangement over the dorsum with a cross-linked product so that loss of volume can be addressed. For treatment of the digits, serial puncture technique of a non-cross-linked product, 1cm apart is usually used to prevent unnecessary swelling of the digits.
Each manufacturer would provide treatment protocols for their products, which will slightly differ. The general consensus amongst all is a multiple treatment plan, usually two-to-four weeks apart for three-to-four sessions done once or twice a year depending on the severity and area being treated, which will lead the injector to choose non cross-linked HA or a cross-linked product.13
In younger patients, visible benefits can usually be seen after just one session.13 However, multiple treatments sessions have shown significantly lower transepidermal water loss and improvement in skin texture, pores and wrinkles.21
Generally, I find that mesotherapy treatments cause minimum discomfort, but I do choose to use topical or local anaesthesia to minimise patient discomfort. The most common side effects encountered are pin-point bleeding and bruising, mild oedema around the injections site and persistence of HA papules more than 24 hours after injection.4 Most side effects occur at the first treatment and are transient. Intravascular injection risk is low as these products are less viscous when compared with higher cross-linked HA fillers.
Practitioners should obtain training to ensure that the appropriate techniques are used for the specific area being treated. Inappropriate technique is linked with poor patient satisfaction, as described in a study that compared intradermal versus nappage techniques where more than 90% of patients had skin that was improved/very improved at day 60 post treatment.5
Product knowledge and training is also important in obtaining the desired results. As mesotherapy with HA requires multiple treatment sessions, patients are not likely to return if their expectations are not managed and significant improvements are not seen.
HA possesses a multitude of properties that hydrate the skin and stimulate collagen and elastin production to a desired outcome producing skin that is firmer, brighter and hydrated. There are a number of dedicated mesotherapy injectable products in use in the UK which can utilise HA alongside a wide range of additional components such as vitamins, minerals, amino acids and peptides.
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