MICRONEEDLING – A FORM OF COLLAGEN INDUCTION THERAPY – OUR FIRST EXPERIENCES

INTRODUCTION

Innovation in the strategy of surgical therapy of severe burn trauma, together with considerable advances in intensive care, make the survival of patients with even critical body surface area burns possible. The goal of multidisciplinary care in burn centres is not only reduction of lethality of burn injuries, but also improvement of quality of life of burn patients through complex care for the resulting scars. Currently, a whole range of therapeutic approaches dedicated to improving function and appearance of the resulting scar is available (early wound closure, dermal substitutes, early rehabilitation, compression garments, splinting, silicone plates/gels, laser therapy, dermabrasion, corticotherapy, etc.).

Microneedling – a form of collagen induction therapy – is, due to its affordability, simplicity and a minimum of side effects, gradually gaining popularity in aesthetic surgery and corrective dermatology for the therapy of different skin lesions (hypertrophic scars, hypotrophic scars, scars after acne, wrinkles, stretch-marks, for rejuvenation therapy, pigmentation changes, telangiectasia, etc.).¹

The research of the effects of microtraumatization on scars – dermaneedling – was underway from the mid 1990s and proceeded in two directions: transdermal delivery of pharmaceuticals and percutaneous induction of collagen.

Many studies from the era of 2001 to 2010 involving transdermal delivery of pharmaceuticals (insulin, photodynamic therapy, photo rejuvenation) to different skin layers with the help of a Dermaroller^® confirmed an increased concentration of lipophilic and hydrophilic pharmaceuticals and of macromolecules in the layers under the stratum corneum.^2,3 An important factor was also the needle length of the Dermaroller^®. With a needle penetrating into the depth of 0.15 mm there was an accumulation of the pharmaceutical in the stratum corneum and diffusion into the deeper layers of the epidermis. With a needle length of 0.5 mm the transdermal penetration of the pharmaceutical was facilitated, and with a needle length over 1.5 mm the pharmaceuticals penetrated into the receptor compartment of the dermis. A similar penetration of the pharmaceutical was confirmed also with the use of the Dermaroller^® before the application of the drug (Dermaroller^® pre-treatment). The microtraumatization of the dermis creates micropores, which cause increased transdermal water loss for a duration of approximately two hours with subsequent occlusive dressing in place (15 minutes without occlusive dressing); it is proven that the micropores also stay open for approximately 24 to 72 hours after application in case there is an occlusive dressing in place.

The other direction of research was percutaneous collagen inducing therapy. In 1995, Orentreig demonstrated improvement of the characteristics of a hypotrophic scar through repeated puncture (“subscission”).⁴ In 1997, Camirand and Doucet described the modification of scars by perforation with an empty tattoo gun.⁵ Subsequently, in the timespan between 2000 to 2010, Schwartz and Laaff were using the Dermaroller^® with a needle length of 1.5 mm in successful therapy of acne scars, posttraumatic scars and wrinkles.⁶ In the year 2002, Fernando is publishing on the induction of neocollagenesis by the use of microneedling.⁷ In 2010, Fabbrocini et al. confirmed the use of the Dermaroller^® as a safe therapy of acne scars for all skin phototypes, with a minimum risk of inflammatory hyperpigmentation when compared to the use of dermabrasion, chemical peeling and ablative laser therapy.⁸ With the use of microneedling, Aust et al. confirms in 2009 an 80% improvement of burn scars with a normalization of the extracellular collagen – elastin matrix, significantly increased collagen deposit, thickening of epidermis – stratum granulosum by 45%, with a clinical scar improvement – Vancouver scar scale (VSS) reduction by 1 to 6 points, reduction of scar thickness by 0.3 to 3.6 mm without observation of pigmentation changes like in ablative techniques.

Pathophysiology

The principle of microneedling/dermaneedling is the creation of numerous microtraumata to the epidermal or dermal part of the skin (by piercing the skin). These cause changes in the transepithelial electrical potential, and also minimal bleeding into the micropores with a subsequent minimal inflammatory reaction, where the healing cascade is being activated under participation of serum and blood cells (thrombocytes, neutrophils), which gradually release numerous growth factors into the area. They induce proliferation of fibroblasts with an increased synthesis and deposition of collagen and elastin, and neoangiogenesis. In the remodelling phase of healing the conversion of collagen III to collagen I ensues with the participation of monocytes/macrophages. The result is an induction of collagenogenesis (neocollagenogenesis), creation of the body’s more inherent, more natural collagen type I and a gradual spatial remodelling of the parallel structure of scar collagen to the reticular (net-like) structure of the final collagen, and changes in the microvascularization of the scar.^1,9,10,11

Microneedling technique

A special, disposable hand held device (Dermaroller^®, Dermastamp^®), which pierces/ microtraumatizes the skin layers with conical needles of a diameter of 0.1 mm and a length of 0.15 to 3 mm, is being used for microneedling. The needles are placed on a cylinder, which contains up to 192 needles (Dermaroller^®) (Figure 1), or statically on a smaller area (Dermastamp^®). The goal is to reach a density of approximately 200 to 250 punctures/cm². The needle length, the size and type of device are being chosen according to skin lesion and localization of the microneedling procedure. A needle length up to 0.25 mm enables safe use even in a home environment; the use by an experienced physician in a healthcare setting is required for a needle length of 0.5 mm and up. The indications for a microneedling therapy are skin alterations like hypo- or hypertrophic scars, stretch marks, wrinkles, cellulite, pigmentation changes, teleangiectasia, alopecia and further rejuvenation and photodynamic therapy. The contraindications are all local skin infections, solar dermatitis, active herpes simplex, keloids, healing disorders, coagulation disorders, collagen disorders and malignancy at the site of application.¹

The procedure itself is being conducted approximately 45 minutes to 1 hour after application of topical anaesthesia (EMLA^® cream, occlusive dressing), under sterile precautions. To reach the needed density of perforations, the rolling needs to be performed 6 times in 4–6 directions. The goal is to reach diffuse erythema (with the use of shorter needles) or diffuse pinpoint bleeding (with the use of longer needles) (Figure 2). The application on burn scars is accompanied by a popping sound effect when the correct, deep scar layers are being pierced. Directly after the application a reddening of the area and a relatively obvious local oedema occurs, which can last for 24 to 48 hours (Figure 3), together with minimal diffuse short term bleeding. The wound should be appropriately covered with an occlusive dressing and an antiseptic/antibiotic ointment for approximately 24 to 48 hours. After the removal of dressings is sufficient routine hygiene and sun protection. The procedure is repeated in 4–10-week intervals with the use of 0.5–3 mm needles, in dermatocosmetic indications (needles up to 0.5 mm) even several times a week.

MATERIAL AND METHODS

In our pilot study, after obtaining informed consent, we used the Dermaroller^® on six patients (2 males, 4 females; age 25–73 years) with stabilized scars (1–33 years after injury) after meshed split thickness skin grafting. The extent of the treated area was between 1–4.5% TBSA (Table 1). For topical anaesthesia we used EMLA^® cream, and a customized pharmacy-made 10% lidocaine ointment in a combination with intramuscular application of analgesics. Post procedure the area was covered with a sterile occlusive dressing with Vaseline gauze and Chlorhexidine ointment. The procedure was repeated in each patient three times within an interval of 6–8 weeks. The results were documented photographically. The status of the scar was objectively evaluated with the VSS. With the subjective evaluation we focused on pain and tension within the scar.

RESULTS

In the perioperative process there were no bleeding or infectious complications noted; the postoperative pain was minimal, short, and easy to manage with common analgesics. All patients reported subjective improvement of the final quality of the scar. The subjective diminishing of tension in the scar was the most frequently appreciated feature by the patients. Objectively the scar surface and mainly the texture of the meshed graft were smoothed. Within the comparison of before and after the series of the procedures, there was an average improvement of two points (1–4 points) on the VSS scale. Change of pigmentation in terms of a more even distribution of pigment was also visible. Scar areas, which were hypertrophic and unstable, demonstrated signs of stabilization and slight flattening (Figures 4, 5).

DISCUSSION

Microneedling as a new method for modification of burn scars opens another possibility to improve the resulting scar and also to improve quality of life of the patients. In comparison with other readily available methods like laser therapy or dermabrasion, there is no extensive breach of epidermal integrity, no artificial necrotic tissue is created and there is no significant inflammatory reaction in the healing process, and the healing process is markedly shorter.^1,7,8 The limiting factor for the application of dermarolling in an ambulatory setting is the maximum dose of applicable topical anaesthesia (approximately an area of a letter-size paper). In case of a greater extent or a non-compliant patient, it is possible to use a combination of topical anaesthesia and some form of analgosedation, or even general anaesthesia with shortterm hospitalization.

Patients in our group evaluated pain as manageable. For more complicated anatomical localizations (interdigital space, perinasal area, band-like hypertrophic scars) it is necessary to use a narrower instrument (Dermaroller^® with 4 rows of needles, Dermastamp^®). The 9-row-cylinder used by us is not quite suitable in anatomically more complicated locations. The possible combination of Dermaroller^® and the application of hyaluronic acid or corticoids seems to be advantageous.

We shall be able to clinically fully analyse the effects of this method on the maturation of scars only with a time interval of at least six months after the last procedure. The publications of Liebl and Aust ^1,10,11 show unambiguously a positive influence of the method with at least six months time period after the last procedure – due to the slower maturation of burn scars. In terms of indication, it is not quite clear in what time interval it is possible to start with the method, starting from the fully healed burned tissue. In our set of patients we tried the method with patients at least one year from the application of split thickness skin graft and at the latest 33 years after the burn accident. With the next set we will focus on scars with a tendency to marked hypertrophy, especially in aesthetically and functionally important regions.

CONCLUSION

Based on our first clinical experiences with the microneedling method, it appears that this procedure is an appropriate and adjunctive miniinvasive method for possibly influencing the remodelling of collagen in burn scars.

Acknowledgment

The study was supported from the Program for the development of scientific areas at the Charles University (PRVOUK P-33).

Corresponding author:

Hubert Šuca, M.D.

Department of Burns Medicine

3^rd Medical Faculty, Charles University

and University Hospital Královské Vinohrady

Šrobárova 50

100 34 Prague 10,

Czech Republic

E-mail: hsuca@yahoo.com