For all acne scar treatment, the key principle is to induce controlled damage to the skin to allow healing to occur, forming new collagen and improvement in scar appearance.
There are different ways to induce controlled damage to the skin: surgery, subcision, using energy-based devices such as fractional lasers, fractional microneedle RF and via highly acidic chemicals such as TCA.
In terms of safety and predictability of response, I personally favour the use of energy-based devices to TCA. Treatment with energy-based devices can be precisely calibrated to the severity of scars and patient’s tolerability for downtime, and healing is generally fairly fast with minimal risk of bad complications.
As with all conditions where a variety of treatment options exist and where combination treatments may give better results compared with single modality treatment, it is important for a face to face consultation with your preferred aesthetic doctor and a thorough discussion of the various treatment options he offers and gets good results with.