Subcision may not be suitable in the following circumstances:

• Patients with a history of hypertrophic or keloid scars
• Current or recent (within 12 months) systemic oral retinoid (eg acitretin, isotretinoin)
• Bleeding or blood clotting disorders (coagulopathy)
• Active bacterial or viral infection

The procedure of subcision is described below:

1. The area to be treated is cleansed to remove dirt and make-up
2. The scar margins may be defined with a surgical marker, adjusting overhead lighting to delineate depressions
3. Local anaesthetic is infiltrated
4. A tri-bevelled needle (number 18 or 20 gauge) or a Nokor needle (fig.3) is inserted at an acute angle adjacent to the scar with the bevel upwards and parallel to the skin surface. Smaller gauge needles (25–27) may be used for small superficial scars and wrinkles
5. The needle is advanced through the dermis and moved back and forth in a fan-like motion. A snapping sound is heard as fibrous bands are transacted in the deep dermis and deep dermal subcutaneous plane*
6. The needle is rotated 90 degrees and moved again in a fan-like motion through the dermal scar (fanning subcision)
7. The needle is removed and squeezed circumferentially around the exit point to prevent large haematoma formation due to bleeding
8. Manual pressure is applied to the wound for several minutes.

*A common pitfall is to fan too deeply in a plane below the dermis

Immediately after subcision:

• Pressure and ice are applied to the operated site to maintain haemostasis and reduce the risk of bleeding.
• Make-up may be applied to camouflage bruised areas.
• Some authors recommend antibiotics and anti-inflammatory

The number and intensity of subcisions should be limited during the first treatment to review the patient’s response, particularly when treating areas with a predilection for a hypertrophic reaction after subcision.

Individuals vary in their ability to form collagen (scar tissue). The number of subcisions required to correct a depression will depend on the type, location, severity of depression, and intensity of treatment.

Three to six visits suffice for the majority of cases of moderate scarring. Intervals of at least one month in-between treatments are generally recommended.

The risks and complications of subcision include:

• Haematomadue to bleeding (a small haematoma is normal)
• Pain/tenderness of treated sites
• Hypertrophic scars (5–10%) or keloid scars, which are most likely in periorbital skin, glabella, labial commissure and upper lip
• Infection; this usually presents as localised acneform papule or pustule
• Temporary post-inflammatory hyperpigmentation (advise sun protection/avoidance)
• Sub-optimal response or lack of improvement in scarring
• Injury to nerve or blood vessel, which is most likely in mandibular, temporal and pre-auricular sites

Subcision as an acne scar treatment can be effectively combined with:

• Topical retinoids
• Microneedling- Dermaroller, Dermapen, which may be safely performed > 1 day after subcision
• Acid peels, eg 15% trichloracetic acid applied every 4 weeks
• TCA CROSS
• Dermal fillers
• Skin Boosters