Lasers in Surgery and Medicine最新文献

Objective

Lichen sclerosus (LS) is a chronic inflammatory dermatosis that predominantly affects the genital region, but can also manifest in other areas of the body. Extragenital LS is often less responsive to standard treatments, necessitating alternative modalities. Herein, we describe the case of a young adult man with a 7-year history of an enlarging sclerotic plaque on the right thigh, refractory to high-potency topical corticosteroids and intralesional triamcinolone.

Methods

The patient underwent three sessions of fractional CO₂ laser combined with platelet-rich plasma (PRP) therapy over 6 months. Pre- and post-treatment biopsies were performed to investigate histologic changes associated with the healing response.

Results

The treatment resulted in near-complete flattening of the plaque and resolution of dermal sclerosis. A post-treatment biopsy confirmed diminished collagen hyalinization, restoration of elastic fibers, and increased fibroblasts and neovascularization. No recurrence was observed at 1-year follow-up.

Conclusion

This case highlights the potential role of fractional CO₂ laser combined with PRP as an effective therapeutic option for recalcitrant extragenital LS. Further studies are warranted to validate this combined approach.

Objective

To explore the related influencing factors of hematoporphyrin monomethyl ether photodynamic therapy (HMME-PDT) for port-wine stain(PWS) and evaluate the relationship between dermoscopic vascular patterns and treatment efficacy.

Methods

Retrospective analysis of 182 PWS patients (November 2017 to November 2023) who received HMME-PDT. Among them, 51 patients had dermoscopy before treatment. Demographic (age, gender), clinical (lesion location, colors, size, treatments), and dermoscopic data (vascular patterns) were collected. Efficacy was assessed via pre-/post-treatment photos (classified as complete regression, good improvement, slight improvement, or no improvement), and adverse reactions were recorded. SPSS 26.0 was used for statistical analysis.

Results

Among 182 PWS patients, HMME-PDT achieved an overall response rate of 77.5% (141/182), with 23.6% (43) showing complete regression, 15.9% (29) demonstrating good improvement, and 37.9% (69) experiencing slight improvement; 22.5% (41) showed no improvement. Efficacy significantly correlated with age, lesion location, color, size, and treatments (p < 0.05), but not with gender or facial partition (V1, V2, V3) (p > 0.05). Multivariate analysis identified small lesion size, facial and neck, pink and purplish red lesions as positive predictors, while fewer treatment sessions were unfavorable. Seven cases (3.85%) developed long-term adverse effects (5 scars, 2 hyperpigmentations). Dermoscopic analysis of 51 vascular patterns revealed significant efficacy differences among pattern types (p < 0.05), with type I (23.5%), type II (43.2%), and type III (29.4%) showing distinct therapeutic responses.

Conclusion

HMME-PDT efficacy correlates with age, lesion location, color, size, and treatments, but not gender and facial partition (V1, V2, V3). Dermoscopic vascular patterns can predict treatment response, with type I being the most effective.

Objectives

To theoretically evaluate the efficacy and safety of large-spot (i.e., > 4 mm) picosecond laser treatment for pigmented lesions in Asian skin using a melanosome disruption threshold fluence (MDTF) model.

Materials and Methods

The MDTF model was applied to calculate the required fluence for melanosome disruption with 532, 730, 755, 785, and 1064 nm picosecond lasers. To assess potential complication risks, energy deposition in surrounding tissues was simulated. Additionally, a clinical case series was conducted using a 1064 nm picosecond laser with a large spot size to evaluate its feasibility for treating an ectopic Mongolian spot and a nevus of Ota.

Results

At 532 nm, spot size had minimal impact on the required fluence for epidermal melanosome disruption and on collateral energy deposition. For 730–1064 nm wavelengths, the optimal spot size depended on the lesion depth. When targeting epidermal melanosomes, smaller spot sizes confined energy deposition to superficial layers, reducing collateral exposure. In contrast, for dermal melanosomes, larger spot sizes reduced the required fluence by 39%–65% and lowered collateral energy deposition, while also decreasing variation in required fluence across lesion depths. In the clinical validation, both dermal cases showed good clearance without adverse events, supporting the feasibility of this approach. However, increasing the energy output of laser devices may be necessary to achieve sufficient efficacy.

Conclusion

The theoretical analysis shows that at 532 nm, both small and large spot sizes can be effective for treating epidermal lesions. In contrast, at near-infrared wavelengths, smaller spot sizes are preferable for epidermal lesions, whereas larger spot sizes are advantageous for dermal lesions, potentially lowering the risk of complications while maintaining effective target disruption. These findings provide practical clinical guidance by clarifying wavelength- and spot-size-specific strategies according to target depth. Furthermore, the present results may help optimize treatment parameters and device specifications and inform future clinical studies using large-spot picosecond laser systems.

Objective

To evaluate the effectiveness of a structured laser safety training program and standardized competency checkoffs for physicians and physician extenders using lasers and other light-based devices in an academic plastic surgery department.

Materials and Methods

Standard operating procedure checklists were developed for two commonly used devices in our practice: an intense pulsed light (IPL) device and a 532/1064-nm neodymium:yttrium-aluminum-garnet (Nd:YAG) laser. Ten participants, including three estheticians, one aesthetic surgery fellow, and six chief plastic surgery residents, underwent an in-person training demonstration followed by two competency checkoffs. Successful completion rates were recorded and analyzed.

Results

For the IPL device, average correct completion rates improved from 89.23% to 100% (p = 0.007) across all participants. For the Nd:YAG laser, rates improved from 90% to 98.57% (p = 0.009). The residents and fellow exhibited a greater mean improvement from the initial to follow-up checkoff compared to the estheticians for both devices: 15.61% versus 8.33% for the IPL device and 13.65% versus 2.56% for the 532/1064-nm Nd:YAG laser.

Conclusion

A formalized, hands-on laser safety training session coupled with device-specific safety checklists significantly enhances both procedural competency and adherence to safety protocols, supporting such integration into departmental training. These tools not only improve technical skill but also bolsters confidence while promoting patient safety. Adoption of such checklist-based training initiatives across practices that utilize lasers and other light-based devices may help standardize care and reduce laser-related complications.

Objectives

Retinal pigment epithelium (RPE) melanin absorbs laser energy during retinal laser therapy, potentially influencing treatment efficacy and safety. This study investigated the relationship between spot visibility threshold laser power and RPE melanin content, as measured by polarization-sensitive optical coherence tomography (PS-OCT), and examined differences in RPE melanin levels between the titration and treatment areas in subthreshold microsecond pulsing retinal laser therapy (SMPL).

Methods

Twelve eyes from 11 patients who underwent SMPL for macular edema and serous retinal detachment were included. In SMPL therapy, the threshold laser power was determined through titration outside the macula, near the vascular arcade. RPE melanin levels were evaluated based on polarimetric entropy (PE) measured by PS-OCT. The relationships between the visibility threshold laser power observed in funduscopy, RPE-PE in the titration area, and RPE-PE in three distinct macular regions were analyzed.

Results

A significant inverse correlation was observed between visibility threshold laser power (1125.0 ± 154.5 mW) and RPE-PE in the titration area (0.50 ± 0.09; p = 0.028; adjusted R² = 0.34; linear regression). RPE-PE values in the central macular region (0.57 ± 0.07) were correlated with those in the titration area (p = 0.025; adjusted R² = 0.35) but were significantly higher (p < 0.01; Wilcoxon signed-rank test). The ratio of macular to titration RPE-PE values was 1.15 ± 0.17, with considerable interindividual variability.

Conclusion

The inverse correlation between individual visibility threshold laser power and RPE-PE, along with discrepancies in melanin density between the titration and macular regions, suggests that variations in RPE melanin density substantially influence the efficacy and safety of SMPL. These findings support the potential utility of PS-OCT–based RPE melanin assessment for optimizing SMPL parameters.

Background

Energy-based treatments for atrophic acne scars (AAS) in darker skin phototypes must balance efficacy with pigmentary safety. While the nonablative 675-nm laser has shown promise with minimal risk of adverse effects, prospective data in Asian populations remain limited. This study evaluated the efficacy, tolerability, and safety of a 675-nm laser for AAS in Fitzpatrick skin types (FSTs) III–IV.

Methods

Sixteen adults with AAS underwent 3 monthly sessions using sequential Moveo (low-fluence scanning) and Standard (fractional stamping) modes. Outcomes were assessed at baseline and at 1, 3, and 6 months after the final session, including Goodman and Baron quantitative scores (GBQGASGS), Antera® 3D imaging device, patient satisfaction, procedural pain, and adverse events.

Results

GBQGASGS improved by 14.5% at 6 months after the final treatment (19.81 ± 7.31 to 16.94 ± 7.18; p = 0.001), with a 9.7% reduction evident 1 month after the second session (p = 0.017). Antera® 3D analysis demonstrated improvements in skin texture (12.91 ± 4.25 to 11.38 ± 3.97; p = 0.002) and scar volume (2.54 ± 1.33 to 2.04 ± 1.26; p = 0.001). At 6 months, blinded evaluators reported ≥ 25% improvement in 50% of subjects, while 69% of patients reported ≥ 25% improvement. Adverse events were of low incidence and transient in nature, and no serious complications occurred.

Conclusions

The 675-nm laser demonstrated significant and sustained improvements in acne scar metrics in Asian patients with FST III–IV, supporting its role as a pigment-safe, nonablative option for atrophic acne scars in skin of color.

Trial Registration: Thai Clinical Trials Registry: TCTR20250218009.

Objectives

To develop an optical feedback system compatible with a commercial surgical laser for automatically distinguishing between urinary stones and soft tissues during laser lithotripsy, thereby enhancing procedural safety.

Methods

The system, based on diffuse reflectance spectroscopy (DRS), was implemented in an engineered clinical theranostic platform. In vivo experiments were conducted to collect and analyze DRS spectra of tissues during laser lithotripsy. Illumination was performed via the endoscope, and detection was performed via the treatment fiber. Classification of urinary stones and soft tissues was performed using machine learning methods, i.e., Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA).

Results

The system demonstrated high diagnostic performance, with 93% sensitivity for soft tissue identification and 93% specificity for stone detection evaluated by the LDA method. This real-time differentiation effectively minimized unintended laser exposure to non-target tissues.

Conclusions

The developed optical guidance system provides real-time feedback during laser lithotripsy, improving safety and precision by reducing the risk of accidental tissue damage. The proposed technology is expected to enhance outcomes in minimally invasive urological laser procedures.

Objectives

To assess the efficacy of antimicrobial blue light (aBL) in managing Candida albicans keratitis in rabbit corneas ex vivo and safety to retinal cells in vitro.

Methods

C. albicans (strain CEC-749) suspensions were exposed to aBL with different light irradiance to assess the susceptibility of C. albicans to aBL. An ex vivo C. albicans keratitis model using rabbit corneas infected with a bioluminescent strain CEC-749 was developed. aBL was delivered topically to the infected corneas after fungal inoculation at varying irradiances. Bioluminescent imaging was used to track corneal infection progression in real-time. To evaluate the toxicity of aBL to the retinal cells, photoreceptors (661W) and retinal pigment epithelium cells (ARPE-19) were exposed to aBL in vitro, with cell viability and apoptosis assessed. The viability change of 661W cells under intermittent irradiation of aBL is determined.

Results

At varying irradiances of 25, 50, and 100 mW/cm² and a constant 405 nm blue light exposure of 216 J/cm², 3.39-, 3.67-, and 2.83-log10 CFU of C. albicans were inactivated in suspensions, respectively. Bioluminescence imaging revealed that C. albicans keratitis was fully developed in ex vivo rabbit corneas 24 h following fungal inoculation. After exposure to 288 J/cm² aBL, the fungal burden in the 6, 18, and 24 h-infected rabbit corneas was reduced by approximately 1.57-, 2.18-, and 1.47-log10, as determined by bioluminescence imaging. The viability and apoptosis of both 661W and ARPE-19 cells were significantly affected by continuous aBL delivery at 32.43 J/cm². Intermittent irradiation with a total exposure of 37.50 J/cm², administered as 12.50 J/cm² per irradiation session with 2 h intervals for three sessions, did not affect the viability of 661W cells.

Conclusions

aBL is a potential treatment for C. albicans keratitis. The intermittent irradiation approach using aBL to treat fungal keratitis could be a safety modality for clinical application.