Autologous Plasma Gel Injection Versus Polydioxanone Cog Threads Insertion for the Treatment of Atrophic Post-acne Scars: a Split-face

The treatment area was prepared by anesthetizing the acne-scarred region with a 2% lidocaine injection mixed with 1/1000 adrenaline, administered at each entry point after sterilizing the area with povidone-iodine solution. Subcision was performed using an 18-G cannula needle inserted parallel to the skin surface. The skin was stretched while the needle was maneuvered along the scar margins on both sides of the face, creating a tunnel and releasing the scars from their bases. The procedure's endpoint was marked by a partial to complete loss of resistance in the treated area.

After subcision, patients underwent the following treatments:

Plasma Gel Therapy: One half of the face was assigned to the plasma gel therapy group. Plasma gel was prepared in two steps:

Platelet Poor Plasma (PPP) Preparation: Ten milliliters of venous blood were drawn from each patient and collected in sterile, anticoagulant-equipped vacuum tubes. The blood was centrifuged at 72 g for 15 minutes at room temperature, then the plasma layer was centrifuged again for 5 minutes at 1006 g to yield 6.5 ml of PPP and 0.5 ml of platelet-rich plasma (PRP).

Gel Formation: The PPP syringes were placed in a hot water bath (60-100°C) for 1 minute, then in a cold bath (8-0°C) for 1 minute to turn the plasma into a viscous gel. The gel was injected into the scarred areas immediately after subcision.

Thread Treatment: The other side of the face received PDO thread treatment. Cog PDO threads were inserted using a blunt-tipped cannula in a "Z pattern" within the scarred areas, filling the pockets created by subcision.

Randomization: Subcision was performed on both sides of the face, followed by either plasma gel injection or thread insertion. Patients were randomly assigned to either modality based on their patient number.

Assessment and Follow-up:

Assessments included standardized clinical photography, objective scar severity scoring, and patient-reported outcomes.

Clinical examination assessed the types and severity of acne scars using validated scales such as the Acne Scar Assessment Scale (ASAS), Goodman and Baron scale, ECCA grading scale, and Investigator Global Assessment (IGA) using a 5-point scale for improvement.

Patient satisfaction was measured using a 5-point scale from not satisfied to very satisfied. The Facial Acne Scar Quality of Life (FASQol) tool was used to assess the impact on patients' quality of life.

Photos were taken using a Samsung Galaxy S10 Plus smartphone with a 12 MP telephoto lens.

Participants were followed up at 4, 8, and 12 weeks post-treatment.

Outcome Measures:

The primary outcome measure was the change in scar severity scores from baseline to follow-up visits.

Secondary outcome measures included participant satisfaction scores, improvement in scar texture, and adverse events. Comparisons between treatment modalities were also made.