A Multimodal Approach to Laser Treatment of Extensive Hypertrophic Burn Scar: A Case Report

Background

Hypertrophic scars are grave consequences of severe burn injuries, causing physical and psychological stresses. Adequate treatment can help alleviate these burdens. The literature contains negligible evidence supporting interventions for scar treatment. Although compression has been shown to be effective in reducing scarring [1], once the scar has developed, a more accurate evaluation of its effectiveness as a treatment option is required. There is a need to establish additional evidence-based treatment options for burn scars due to the difficulties in adhering to compression treatment regimens. To date, none of the other treatment options have undergone thorough evaluation by rigorous research studies; therefore, randomized, controlled, multicenter clinical trials are required to improve clinical care.

Surgical revision is an option for the most severely disabling scars, but the planning and choice of procedure are made on a case-by-case basis without consensus guidelines. Laser therapy, topical or intradermal pharmacotherapy (like corticosteroids), silicone gel and gel sheets, cutaneous radiation, systemic pharmacotherapy (eg, interferon), massage, and acupuncture are additional treatments that are currently being used in clinical settings, but these require more study. Massage therapy can improve scar pliability, pain, and pruritus, but with less supporting evidence [2]. The use of moisturizers and lotions can alleviate itching, but the findings are contradictory and the ideal moisturizer composition is unknown [3]. Particularly, the use of lasers as a form of treatment has grown in popularity [4].

Laser systems with CO2 sources enable skin remodeling by producing new collagen due to their dual ablative and thermal action [5–7]. Following treatment, invaginating epidermal cells completely replace the area where the fractional ablative laser caused immediate ablation at the epidermal/dermal level. The epidermal tissue is encircled by a microscopic ablative zone, and the stratum corneum contains microscopic epidermal necrotic debris (MEND). MEND begins to exfoliate on the seventh day, and 1 month after treatment, the normal stratum corneum replaces MEND [8]. As a result, these laser devices are effective in treating a wide range of imperfections and problems, including scarring and skin aging. By stimulating collagen and fibroblasts, fractional ablative CO2 lasers have proven to be a promising therapy for improving burn scar function/appearance and skin rejuvenation [9,10]. The 1540 nm wavelength is known to increase the expression of collagen-related synthesis genes while decreasing matrix protein production in cultured fibroblasts [11–14]. Recent scientific findings demonstrated that the simultaneous combination of the CO2 wavelength (10 600 nm) and the wavelength 1540 nm is a valid treatment choice for skin remodeling [15,16].

With these premises, the purpose of this study was to assess the efficacy of a new laser device (DuoGlide, Deka M.e.l.a Srl, Florence, Italy) in hypertrophic burn scar management using 2 recently developed scanning units. The first unit was the µScan DOT scanner, which combines a CO2 and 1540 nm with an estimated ablative DOT width of 120 µm @45 mJ of CO2 and 30 mJ@1540 nm [15]. The second was the Scar3 scanner, which uses a CO2 laser with an estimated ablative DOT width of 80 µm @45 mJ of CO2 [26]. In general, we combined 2 wavelengths, one with ablative activity and the other with thermal characteristics, to create a synergy that could amplify the benefits for the patient in terms of safety and efficacy. Specifically, the second wavelength of 1540 nm allows homogeneous and contiguous heating over the entire scan area, reaching significant depths in the dermis in a non-ablative way. Moreover, the sequential action of the CO2 laser with 1540 nm amplifies and improves the tissue thermal effect, as already demonstrated by previous histological studies [15]; it promotes more effective tissue remodeling, ensuring healing with the timings of a fractional emission.

Case Report

We present the case of a 34-year-old African female patient in good general health, with a body mass index (BMI) of 23.4 Kg/m2 and Fitzpatrick skin type VI, who came to our clinic for a large hypertrophic burn scar (HBS) extending from the plan-tar region to the inner arch part of the right foot. The scar formed following a burn that occurred at 9 years old and was later complicated by subsequent infection of the subcutaneous tissue. Afterwards, the scar underwent a progressive increase in size, thickness, and consistency. Over the years, the lesion resulted in a progressive functional limitation of the foot with associated pain while walking, leading to obvious claudication. In addition, the patient reported having a significant worsening of quality of life. Besides pain, it was related to embarrassment and the inability to wear open shoes comfortably. Multiple cycles of local and intralesional corticosteroids were performed before our visit, which lead to temporary relief of pain, but did not meaningfully improve the lesion’s size and consistency. With regards to the risks, benefits, and available treatment options, the patient’s informed consent was obtained. The first 2 monthly sessions were carried out using the CO2 wavelength (with a Scar3 scanner), to benefit from the greater deep ablative effect. Subsequently, we took advantage of the synergy emission of CO2 with 1540 nm to improve laxity, thanks to a greater volumetric thermal effect (with the µScan DOT scanner) causing contraction and stimulation as shown in Figure 1. After the first 2 CO2 treatments (Scar3) using a power of 25 W, spacing of 500 μm, stack 2, and pulse mode HP, the patient was treated with 3 cycles of fractional CO2 +1540 nm laser (µScan DOT) once a month, in association with topical hyaluronic acid (3 days of hyaluronic acid packs and greasy gauzes changed twice a day). One pass across the whole burn scar region was made, and both wavelengths simultaneously affected the skin. The laser settings were power of 15 W, spacing of 500 μm, Stack 2, pulse mode HP, power of 3 W, dwell time of 5 ms for the CO2 laser and 1540 laser, respectively. The treatment led to progressive scar improvement, making it softer on palpation and significantly reduced in size, in particular in the central area, with a gradual loss of consistency. Following the treatment, the patient reported noteworthy improvement in quality of life, thanks to pain alleviation and restored ability to wear any type of shoes without discomfort. Eventually, she was treated with 3 applications of a 595-nm dye laser (VasQ, Deka Mela srl) 1 month apart to avoid recurrences, with a fluence of 6.5 J/cm2 and a pulse width of 0.5 ms. The patient is currently undergoing 2 maintenance sessions with the dye laser to stop any reactivation of the scarring process.

Discussion

The management of HBS represents a significant challenge for dermatologists. The use of fractional CO2 lasers is a viable option with durable results and can be used in difficult-to-treat areas, such as the soles, where repeated skin traumas provide the stimulus for continuous fibrotic tissue deposition [17]. The CO2 laser has several benefits, including quicker recovery time, less frequent need for anaesthesia, decreased thermal damage, lessened bleeding and inflammation, and almost no adverse effects (eg, unaesthetic scarring and dyschromic effects). These advantages must be considered if considering other surgical procedures, such as diathermocoagulation and traditional surgery, which involves more frequent unaesthetic use, protracted healing, and slower scarring processes, and a higher incidence of keloids and hypertrophic scars [10]. Due to their ablative and thermal effects, CO2-based light sources induce skin remodeling and neocollagenesis [10,26,15]. The fractional ablative CO2 laser has been increasingly used to treat burn scars [18,19]. A recent case study highlighted the success of combined medical and procedural treatment with fractional lasers for extensive hypertrophic burn scars, achieving good skin color and texture results [20]. The therapeutic efficacy of fractional CO2 laser for burns scars has also been recently shown in a meta-analysis by Mahar and co-workers [21], which reported a successful case of a large HBS managed using a fractional CO2 laser in combination with 1540 nm wavelength and dye laser. In terms of collagen remodeling and stimulation, the synergy of the 2 wavelengths improves the advantages already offered by the CO2 laser systems, with both skin tone strengthening and stimulation. Specifically, while CO2 acts fractionally, the second wavelength of 1540 nm, thanks to its special spatial shape, allows for homogeneous and contiguous non-coagulative heating over the entire scan area, reaching significant depths in the dermis (not gently reachable with the ablative laser alone without increasing the CO2 energy), in a non-ablative way.

A recently published study [22] evaluated the photobiomodulation effect of 1540 nm wavelength treatment on the proliferation of cultured fibroblasts and their ability to express type I and III collagen, showing promising results. Non-ablative fractional lasers stimulate wound healing, which can result in the remodeling of surgical and post-traumatic scar texture. This means the thermal injury induced by the laser is also controlled, resulting in a natural healing process that creates healthy new tissue. Consequently, an improvement in the skin appearance occurs without the risk of inflammation [23–25]. However, in some cases, reaching significant depths is necessary for effective hypertrophic scar remodeling. This can also result in an increase in the energies administered to the skin, which can cause hyperpigmentation (PIH) in response to skin damage. Indeed, excessive stimulation of melanocytes causes higher melanin synthesis. For this reason, a scanner that can minimize the risk of hyper- and hypo-pigmentation after treatment is mandatory. Indeed, thanks to its small micro-ablation width size (DOT) it can generate deeper ablative action using less energy. This kind of scanner has been designed specifically for the remodeling of deep scars, as already demonstrated by the excellent results of Scarcella et al [26].

Continuous technological research has reduced healing times while maintaining high clinical performance in recent decades. The use of a fractional laser causes numerous areas of micro-ablation DOT on the skin, with specific depths that can be adjusted by the operator and surrounded by vital tissue, reducing re-epithelialization time. Piccolo et al [27] found the combined use of CO2 and dye lasers to be an effective keloid treatment option providing excellent results. Their study treatment protocol caused the hypertrophic burn scar to gradually soften and shrink, especially in the central area. Along with a progressive loss of consistency that made the scar more palpable, the treatment led improvement in quality of life.

Conclusions

In this case, a significant scar reduction was achieved using combined laser treatment, which effectively enhances the healing of burn scars, thereby improving the patient’s psychological well-being and health-related quality of life. This case report demonstrates the potential for successful hypertrophic burn scar treatment using 2 laser wavelengths (10 600 nm and 1540 nm) and subsequent dye laser therapy to prevent recurrence. The study provides valuable clinical insights for innovative, early applications of non-ablative, dual-wavelength 10 600/1540 nm fractional lasers.

Limitations of our study include the absence of quantitative outcome measures. Future objectives encompass extending the follow-up period, increasing the number of cases, and developing a scale with a meaningful score range for burn scar evaluation.