Subcutaneous Carboxytherapy Injection for Aesthetic Improvement of Scars

A 60-year-old woman presented with a chief complaint of scarring along the sites of a submental incision and a right preauricular incision that had been made 5 years earlier during a rhytidectomy procedure. Examination revealed tethering, hypertrophy, and erythema of the submental incision (Figure 1, A) and widening of the preauricular incision (Figure 2, A). The patient did not wish to undergo any scar revision surgeries and instead opted for noninvasive treatment with injections of carbon dioxide (CO₂) gas (carboxytherapy). She underwent 10 treatments, administered 1 to 2 weeks apart. She was satisfied with the results (Figures 1, B, and 2, B).

CO₂ is a nontoxic gas that is naturally produced by cells as they undergo the process of metabolism. CO₂ therapy for cutaneous use was introduced in France in 2000.¹ Carboxytherapy has been used to treat stretch marks, skin laxity, cellulite, dark circles under the eyes, and scars. It is believed that its mechanism of action is twofold. First, the mechanical injection of the CO causes the destruction of fat cells and the interruption of surrounding connective tissue. Second, as the CO₂ accumulates in tissues, it induces dilation of capillaries and stimulates an inflammatory response that increases collagen deposition and reorganization and eventually improves skin texture and tone.

The injection of CO₂ has been shown to be relatively safe, with little to no toxicity.^1-5 As such, carboxytherapy can be used as an adjunct to liposuction in order to remove any irregularities. Furthermore, its revascularization and collagen-remodeling effects make carboxytherapy useful for improving unsightly scars.^1-3,5

Treatment with carboxytherapy is relatively painless. The injection is carried through a 30-gauge, 5/8-inch needle with the bevel directed toward the skin. Patients typically experience a light tingling sensation at the injection site that soon dissipates. The area might feel warm for 10 to 20 minutes, and there may be some ecchymosis at the injection site. The subcutaneous crepitus that ensues is usually resolved within 1 hour, and patients are asked to avoid hot baths, hot tubs, and saunas for about 4 hours. A typical treatment protocol consists of 10 to 20 weekly treatments. Results are usually noticed after the fifth treatment, and improvement is seen with subsequent treatment.

Because of the relative absence of toxicity, ease of use, and predictable results, carboxytherapy is an excellent addition to the armamentarium of cosmetic surgeons.