Molecular Mechanism of Pulsed-Dye Laser in Treatment of Keloids: An In Vitro Study

The Role of Physical Therapies in Wound Healing and Assisted Scarring

Wound healing (WH) is a complex multistep process in which a failure could lead to a chronic wound (CW). CW is a major health problem and includes leg venous ulcers, diabetic foot ulcers, and pressure ulcers. CW is difficult to treat and affects vulnerable and pluripathological patients. On the other hand, excessive scarring leads to keloids and hypertrophic scars causing disfiguration and sometimes itchiness and pain. Treatment of WH includes the cleaning and careful handling of injured tissue, early treatment and prevention of infection, and promotion of healing. Treatment of underlying conditions and the use of special dressings promote healing. The patient at risk and risk areas should avoid injury as much as possible. This review aims to summarize the role of physical therapies as complementary treatments in WH and scarring. The article proposes a translational view, opening the opportunity to develop these therapies in an optimal way in clinical management, as many of them are emerging. The role of laser, photobiomodulation, photodynamic therapy, electrical stimulation, ultrasound therapy, and others are highlighted in a practical and comprehensive approach.

A Review of Current Keloid Management: Mainstay Monotherapies and Emerging Approaches

Commonly affecting those with skin of color, keloids are an aberrant wound response that leads to wound tissue expanding above and beyond the original cutaneous injury. Keloids are notoriously and particularly difficult to treat because of their tendency to recur after excision. The current standard of care is intralesional steroid (triamcinolone acetonide). However, because no therapy has yet proven to be fully curative, keloid treatments have expanded to include a number of options, from injections to multimodal approaches. This review details current treatment of keloids with injections (bleomycin, verapamil, hyaluronic acid and hyaluronidase, botulinum toxin, and collagenase), cryotherapy, laser, radiofrequency ablation, radiation, extracorporeal shockwave therapy, pentoxifylline, and dupilumab.

Mitigation of Postsurgical Scars Using Lasers: A Review

Background:

Most postsurgical scars are considered esthetically and functionally acceptable. Currently, there is no definite consensus treatment for postsurgical scarring. The purpose of this review is to shed some light on the value of scar mitigation and the efficacy of different lasers employed on postsurgical wounds.

Methods:

A systematic literature review and computational analysis were conducted to identify relevant clinical articles that pertained to the use of lasers for mitigating postsurgical scars. Articles included the National Institutes of Health–National Center for Biotechnology Information–PubMed search and sources cited from relevant studies after 1995. Trials that attributed pre- and posttreatment scores of scar severity based on a verified scar evaluation scale (eg, Patient and Observer Scar Assessment Scale, Vancouver Scar Scale, Global Assessment Scale) were chosen. Clinical assessments varied for each study. To adequately assess the efficacy of the modalities, the final scaled scar appearance scores were realigned and normalized to a standard scale for unbiased comparison.

Results:

After filtering through a total of 124 studies, 14 relevant studies were isolated and thus included in the review. Studied lasers were as follows: Pulsed dye laser (PDL), carbon dioxide, diode, potassium titanyl phosphate (KTP), and erbium glass (Er-Glass) lasers.

Conclusion:

Treatment with lasers in the postsurgical wound healing phase is safe, effective, and advised in mitigation of pathologic scar formation.

Comparison of 532 nm Potassium Titanyl Phosphate Laser and 595 nm Pulsed Dye Laser in the Treatment of Erythematous Surgical Scars: A Randomized, Controlled, Open-Label Study

BACKGROUND

The pulsed dye laser (PDL) has long been used for treatment of erythematous and hypertrophic scars. Its effectiveness has been attributed in large part to its vascular-specificity. The vascular-specific potassium titanyl phosphate (KTP) laser has also been reported to be clinically effective for scars, but has not been compared to the PDL.

OBJECTIVE

To compare the safety and clinical efficacy of a 532-nm KTP laser versus a 595-nm PDL in improving the appearance of erythematous surgical scars.

METHODS

Twenty patients with matched bilateral erythematous surgical scars or a single linear erythematous scar measuring longer than 5 cm were enrolled in the study. Single scars were divided into equal halves with each half randomized to receive 3 successive treatments at 6-week intervals with either a 532-nm KTP laser (Excel V; Brisbane, CA) or a 595-nm PDL (Cynergy; Cynosure Inc., Chelmsford, MA) at equivalent laser parameters. Bilateral matched scars were similarly randomized to receive three 532-nm KTP or 595-nm PDL treatments. Clinical efficacy was evaluated 12 weeks after the third (final) laser treatment by independent, blinded photographic scar assessments. Secondary evaluations included final investigator and subject treatment/satisfaction assessments, Vancouver scar scale (VSS) scores, subject scar symptoms, intraoperative pain scores, and incidence of side effects.

RESULTS

Clinical improvement of erythematous surgical scars was observed with both 532-nm KTP and 595-nm PDL systems. No statistically significant differences between the 2 treatment arms were noted in the independent, blinded photographic scar assessments, investigator and subject treatment/satisfaction assessments, subject scar symptoms, and intraoperative pain scores. The KTP arm produced statistically significant improvement for the vascularity component of the VSS only. Side effects were limited to mild treatment discomfort and minimal transient post-treatment erythema and purpura. No vesiculation, infection, scarring or other adverse events were experienced. Subject satisfaction surveys mirrored the observed clinical effects.

CONCLUSION

The-532 nm KTP laser is comparable in efficacy and safety to the 595-nm PDL laser in the treatment of erythematous surgical scars.

Treatment of keloid scars with a 1210-nm diode laser in an animal model

BACKGROUND AND OBJECTIVE

A temperature increase can improve wound healing by activation of heat shock protein 70 and stimulation of fibroblasts. Since keloids are a dysfunction of collagen fiber synthesis and organization, this study aimed to evaluate if a 1,210 nm diode laser could have effects in a new animal model of keloid scars.

STUDY DESIGN/MATERIALS AND METHODS

A total of 39 nude mice were used for this study. Phototypes IV and V human keloids were grafted into their backs and after 1 month of healing, the mice were divided into four groups: Control, Laser, Resection, Resection/Laser. In the Laser group, the keloids were treated with a 1,210-nm diode-laser with the following parameters: 4 W; 10 seconds; fluence: 51 J/cm(2) ; spot: 18.9 × 3.7 mm(2) . In the Resection group, surgical intra-lesional excision was performed. In the Resection/Laser group, keloids were treated with the 1,210-nm laser-diode after surgical intra-lesional excision. Temperature measurements were made during the laser treatment. Clinical examination and histological study were performed on the day of treatment and 1 month, 2 months, and 3 months later.

RESULTS

Mean temperature measurement was of 44.8°C (42-48°) in the Laser groups. No healing complications or keloid proliferation was observed in any group. Keloid histologic characters were confirmed in all grafts. No histologic particularity was observed in the laser groups in comparison with the Control and Resection groups.

CONCLUSION

First, this keloid animal model appears to be adapted for laser study. Secondly, the 1,210-nm diode laser does not induce keloid thermal damage in vivo. Further studies with different 1,210-nm laser diode parameters should be performed in order to observe significant effects on keloids.

Treatment of surgical scars using a 595-nm pulsed dye laser using purpuric and nonpurpuric parameters: a comparative study

BACKGROUND

Many studies have examined laser treatment of scars, but cosmetic results have been variable. Although no studies have examined the effect of purpura on scar improvement using the pulsed dye laser (PDL), many clinicians believe inducing purpura results in better and quicker improvement.

OBJECTIVE

To determine whether PDL treatment of fresh surgical scars with purpura-inducing settings improves clinical appearance more than non-purpura-inducing settings or no treatment.

METHODS

Twenty-six subjects with surgical scars enrolled in this prospective study. Scars were divided into three equal segments; treatment was randomized: 595-nm PDL with purpuric (1.5 ms) or nonpurpuric (10 ms) settings or no treatment. Fluences were adjusted to Fitzpatrick skin type. Scars were treated three times, 1 month apart, beginning at suture removal. Outcome measures included Vancouver Scar Scale (VSS) and blind clinical ratings.

RESULTS

The nonpurpuric condition showed significant improvement on the VSS total score, vascularity, and pliability ratings. The purpuric condition demonstrated a trend for improvement on the VSS total. According to blind observer ratings, all conditions improved, without differences between groups.

CONCLUSION

Nonpurpuric settings on the PDL resulted in significant improvements in the appearance of fresh surgical scars for vascularity, pliability, and VSS total scores, although all scar segments improved over time.

Use of lasers in acute management of surgical and traumatic incisions on the face

This article is a clinically practical review structured around the specific applications of laser technologies used in acute management of soft tissue injuries in surgical incisions and trauma. Surgical and traumatic incisions and injuries provide the clinician with the unique opportunity to follow the progression and maturation of the wound healing response from a very early stage. There has been a recent interest in early cosmetic optimization of surgical and traumatic wounds on the face using optical technologies. Early clinical results for acute laser intervention starting immediately after suture removal or the first several weeks after repair have been very promising.