Acne scars, particularly depressed or atrophic scars, are a common dermatological concern that can significantly impact a patient’s confidence and quality of life. In our clinical practice, we have developed a Four-Step Sequential CO₂ Laser Treatment Approach, combining four distinct CO₂ laser techniques to create customized treatment strategies for different scar types. This article provides a comprehensive overview of this protocol, including technical details, pain management strategies, and post-treatment care essentials.
Classification of Atrophic Acne Scars
Clinically, atrophic acne scars can be divided into three major subtypes:
- Ice Pick Scars (60–70%): <2 mm in diameter, deep, narrow, with sharply angled “V-shaped” edges.
- Boxcar Scars (20–30%): 1.5–4 mm in diameter, with vertical, well-defined “U-shaped” edges.
- Rolling Scars (15–25%): 4–5 mm in diameter, with broad, sloping edges.
CO₂ Laser Modes Used in the Four-Step Approach
- Manual Fractional Thermal Contraction Technique (MFTCT)
- Conventional CO₂ Ablative Mode – Dermabrasion Method
- Fractional CO₂ Deep Mode (Deep FX)
- Fractional CO₂ Superficial Mode (Active FX)

The Four-Step Sequential CO₂ Laser Treatment Approach
In practice, physicians select two, three, or all four modes depending on the scar type, depth, and distribution.
Step 1: Manual Fractional Thermal Contraction Technique (MFTCT)
- Settings: 1 W power
- Глубина: Deep dermis
- Техника: Non-sequential “drilling vaporization” applied selectively to the central scar area.
- Механизм: Breaks fibrotic adhesion at the scar base, induces immediate thermal contraction to lift the depressed scar, and promotes long-term collagen remodeling.

Step 2: Conventional CO₂ Ablative Mode (Dermabrasion)
- Settings: 1–2 W power
- Глубина: Epidermis to superficial dermis
- Техника: Targets sharp, rigid scar edges.
- Механизм: Precisely vaporizes sharp borders to create a smoother transition zone.

Step 3: Fractional CO₂ Deep Mode (Deep FX)
- Settings: 15–30 mJ, 5% density
- Глубина: Mid to deep dermis (up to 4 mm)
- Механизм: Stimulates deep collagen regeneration and releases scar adhesions.

Step 4: Fractional CO₂ Superficial Mode (Active FX)
- Settings: 80–170 mJ, 40–60% density
- Глубина: Epidermis to papillary dermis
- Техника: Uniform coverage over the entire face.
- Механизм: Improves skin texture, reduces pores, and evens pigmentation.

Частота лечения: Every 12 weeks; 3–6 sessions are recommended for optimal results.
Pain Management Strategy
A layered analgesic approach ensures patient comfort during treatment:
1. Pre-Treatment
- Oral analgesics (e.g., acetaminophen, tramadol) 1 hour before session.
- Thick application (1 mm) of compound lidocaine cream with occlusion (60–90 minutes).
- Optional topical brimonidine tartrate drops to reduce erythema.
2. Intra-Treatment
- Cold air cooling system (4–10°C).
- Regional nerve blocks: infraorbital and mental nerve.
3. Post-Treatment
- Topical burn ointments (e.g., MEBO® moist burn ointment or erythromycin ointment).
- Ice compresses for 15–20 minutes.
Combination Therapies for Enhanced Outcomes
- Subcision: Pre-treatment subcision to release fibrous bands in rolling and boxcar scars.
- Scar Filling: Combination with hyaluronic acid injections.
- РФ микроиглинг: Sequential treatments for synergistic collagen stimulation.
Уход после лечения
1. Wound Care
- Immediately apply a thick layer of MEBO® ointment or erythromycin ointment.
- Maintain a moist wound environment for 5–7 days.
- Apply ointment 6 times daily until complete re-epithelialization.
2. Sun Protection
- Strict physical sun protection (hat, mask, umbrella) post-procedure.
- After scab shedding, apply hydrating and repairing moisturizers daily.
Заключение
The Four-Step Sequential CO₂ Laser Approach offers a tailored, clinically proven protocol for atrophic acne scars. By integrating multiple laser modes, physicians can target different scar subtypes with precision, optimize collagen remodeling, and achieve superior cosmetic outcomes. Flexible adjustment of treatment modes and parameters according to scar type, skin characteristics, and patient tolerance is essential for maximizing safety and efficacy.







