Post-acne scarring is a very distressing problem. Atrophic acne scars are dermal depressions commonly caused by destruction of collagen after inflammatory acne. Many therapeutic measures such as chemical peeling, sub-cision, derma-brasion, fillers and punch techniques have been performed to improve acne scarring but with sub-optimal outcomes.
Ablative lasers such as Er : YAG lasers or CO2 lasers produce significant improvement at the cost of long recovery times and post-inflammatory hyper-pigmentation.
Recently, newer techniques such as micro-needling fractional radio-frequency (MFR) has been shown to be clinically efficient in managing acne scars without causing direct damage to the epidermis.
MNRF is a simple, safe, effective, and minimally invasive therapeutic technique. Needles are introduced in the skin with a preselected depth. RF is delivered through these needles to heat the dermis. RF is color blind hence can be used in any skin type safely with excellent results.
History of MNRF
RF was being used in dermatology since early 2000. Micro-needling dates back to 1995 when Orentreich and Orentreich described dermal needling in the form of subcision for scar treatment. Hantash and colleagues in 2009 proposed the concept of using needles as electrodes which allowed the RF energy to be delivered into the dermis.
How MNRF Works?
Radio-frequency is a high frequency alternating electric current. When an electric current flows through the body, the body offers resistance to its flow. This resistance of tissue is known as impedance. Joule’s law states that when electric current meets resistance, heat is generated due to the micro-oscillations of charged particles.
When the temperature of tissues rises to about 60 degrees, tissues get coagulated. RF effect is electro-thermal. Depth of penetration of RF is inversely proportional to the frequency of RF.
Mechanism of action
Zone of denatured collagen is replaced by newly formed collagen in next 3 months. New elastic fibres are also deposited in the skin. Increase in epidermal hyaluronan leads to skin rejuvenation.
Additional benefit of mechanical vertical scar disruption. Depth of the needles can be manually adjusted. It is easy to reach the reticular dermis and subcutaneous fat and non selectively destroy the eccrine sweat glands and inhibit sebaceous glands.
Types of needles
Stainless steel 34 G size coated with gold for better conductivity and then double coated with silicone insulation except the first 300 micrometer at the tip restricting the energy to be delivered only at the tip
Epidermis – physical needling damage without thermal damage leads to regeneration of epidermis
Dermis – RF energy leads to coagulation leading to restructured dermis.
Since coagulation is only at the tip, oozing and pin point bleeding is seen while performing the procedure
Multiple passes typically 3 to cover the large part of dermis.
The entire shaft of the needle is non-insulated, hence the needles act as active electrodes all the way from epidermis to the needle tips causing slight epidermal thermal damage.
No pinpoint bleeding
Minimum downtime of 48-72 hours
- Electric current follows the path of least resistance and 80% of energy is delivered at the tip of the needle.
Procedure of MNRF Treatment
- Clean the face,
- Apply topical anesthesia,
- Wipe out the cream after 30 mins to 1 hour,
- Contact the hand piece tip to epidermis,
- Power level, exposure time, depth of needle insertion is manually set on the machine depending on the indication and area to be treated.
Microneedles automatically penetrate into the skin after pressing the foot or finger switch. Microfractional holes are created in the epidermis and dermis. High RF is emitted in deep dermis inducing dermal coagulation.
Microneedles are withdrawn automatically. Single or multiple passes are given. When multiple passes are used, it is advisable to give the first pass at a deeper level than subsequent passes and reduce the exposure time and or power as one move up closer to the epidermis. After treatment face is cleaned, oozing or bleeding is controlled with minor pressure. Cooling pack or mask or cold air can be given to increase patient comfort. Antibiotic cream and sunscreen is applied. Treatment can be done once in 4-12 weeks for a total of 3-5 sessions depending on improvement.
|Acne Scars (rolling & box scars)||Seborrhea|
|Surgical Scars||Targe open pores|
& skin rejuvenation
|Skin laxity & wrinkles||Axillary hyperhidrosis|
|Transepidermal drug delivery|
- Active infection
- Herpes simplex virus infection
- Patients with pacemakers
- Patients with facial metal implants
- Patients with unrealistic expectations
- Erythema, crusting
- Post-inflammatory hyperpigmentation
- Needle track marks
- Flare-up of Acne
- Milia like eruptions
Postoperative instructions – After MNRF Treatment
- No sun exposure
- Sunscreen and moisturizers to be given
- No soaps, pricking or rubbing of skin
- Adequate skin cooling
- No fumes or steam
- No sweating and exercise
- Light makeup can be worn after 72 hours
- MNRF is a versatile technology
- It can be used safely and aggressively in patients with pigmented and tanned skin.
- Advantage of less downtime, hence better patient compliance.