Lasers in Surgery and Medicine

OBJECTIVES: To examine the effects of percutaneous tetracycline delivery to the malar area using a thermomechanical device (Tixel) in patients suffering from festoons. METHODS: This retrospective study included patients who underwent combination treatment with a thermomechanical device (Tixel) followed by application of topical tetracycline 1% at two private clinics between 2019 and 2023. Demographic and medical data, treatment parameters along with before and after treatment photographs were retrieved retrospectively...

OBJECTIVES: Fluorescence spectroscopy of human urine is a method with the potential to gain importance as a diagnostic tool in the medical field, e.g., for measuring Coproporphyrin III (CPIII) as an indicator of cancer and acute types of porphyria. Food can change human urine's color, which could influence the urine fluorescence spectrum and the detection of CPIII in urine. To determine if there is a noticeable influence on the urine fluorescence spectrum or on the detection of CPIII in urine, 16 vitamin supplements, and three food items were tested...

OBJECTIVES: Knowledge of the physical effects of pulsed dye laser (PDL) treatment of psoriatic lesions is essential in unraveling the remedial mechanisms of this treatment and hence also in maximizing in its disease-modifying potential. Therefore, the main objective of this study was to provide estimates of these physical effects (for laser wavelengths of 585 and 595 nm), with the aim of identifying pathogenic processes that may be affected by these conditions. METHODS: We modeled the laser light propagation and subsequent photothermal heating by numerically solving the transient diffusion and heat equations simultaneously...

BACKGROUND AND OBJECTIVES: Femtosecond laser trabeculotomy (FLT) creates aqueous humor outflow channels through the trabecular meshwork (TM) and is an emerging noninvasive treatment for open-angle glaucoma. The purpose of this study is to investigate the effect of pulse energy on outflow channel creation during FLT. MATERIALS AND METHODS: An FLT laser (ViaLase Inc.) was used to create outflow channels through the TM (500 μm wide by 200 μm high) in human cadaver eyes using pulse energies of 10, 15, and 20 μJ...

OBJECTIVES: To develop and practically test high-precision femtosecond laser ablation models for dental hard tissue that are useful for detailed planning of automated laser dental restorative treatment. METHODS: Analytical models are proposed, derived, and demonstrated for practical calculation of ablation rates, ablation efficiency and ablated morphology of human dental enamel and dentin using femtosecond lasers. The models assume an effective optical attenuation coefficient for the irradiated material...

BACKGROUND: Port wine birthmark (PWB) is a congenital vascular malformation of the skin. Pulsed dye laser (PDL) is the "gold standard" for the treatment of PWB globally. Hematoporphyrin monomethyl ether (HMME or hemoporfin)-mediated photodynamic therapy (HMME-PDT) has emerged as the first choice for PWB treatment, particularly for young children, in many major hospitals in China during the past several decades. AIM: To evaluate whether HMME-PDT is superior to PDL by comparing the clinical efficacies of both modalities...

BACKGROUND: Limited research exists on laser treatment of giant congenital melanocytic nevus (GCMN). OBJECTIVE: We sought to elucidate the efficacy of the Erbium: YAG laser on GCMN and the histologic factors associated with a positive clinical response. METHODS AND MATERIALS: Between 2019 and 2022, we enrolled 30 medium-to-giant CMN patients who underwent Er: YAG laser treatment. All patients received biopsies before and after laser treatments...

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OBJECTIVES: Public's interest in noninvasive skin rejuvenation treatments continues to grow. The advantage of combination therapy lies in that it can target different aspects of skin rejuvenation. This study aimed to assess the efficacy and safety of microfocused ultrasound (MFU) combined with delicate pulsed light (DPL) for facial rejuvenation. METHODS: Twenty-one patients with facial relaxation were enrolled. All patients received whole-face MFU treatment, and one side of the face was randomly assigned to receive DPL...

BACKGROUND AND OBJECTIVES: A threshold fluence for melanosome disruption has the potential to provide a robust numerical indicator for establishing clinical endpoints for pigmented lesion treatment using a picosecond laser. Although the thresholds for a 755-nm picosecond laser were previously reported, the wavelength dependence has not been investigated. In this study, wavelength-dependent threshold fluences for melanosome disruption were determined. Using a mathematical model based on the thresholds, irradiation parameters for 532-, 730-, 755-, 785-, and 1064-nm picosecond laser treatments were evaluated quantitatively...

BACKGROUND AND OBJECTIVES: Laser ablation is increasingly used to treat atrial fibrillation (AF). However, atrioesophageal injury remains a potentially serious complication. While proactive esophageal cooling (PEC) reduces esophageal injury during radiofrequency ablation, the effects of PEC during laser ablation have not previously been determined. We aimed to evaluate the protective effects of PEC during laser ablation of AF by means of a theoretical study based on computer modeling...

OBJECTIVES: Subcutaneous mastectomy is a crucial component of gender affirmation therapy for transgender men (TM), but the scars that result from this procedure can frequently impair their quality of life. This study aimed to assess the efficacy and safety of 1064-nm fractional picosecond laser (FxPico) treatment for hypertrophic and atrophic postmastectomy scars in TM. METHODS: Twenty-two patients with a total of 35 pairs of bilateral symmetric mastectomy scars were enrolled...

OBJECTIVES: Café-au-lait macules (CALM) are benign birthmarks presenting as uniformly pigmented, well demarcated, brown patches that can be distressing to patients, especially when located in cosmetically sensitive areas. As with all pigmentary lesions in skin of color patients, CALMs have been particularly challenging to treat. Here we present the first case series characterizing treatment parameters and clinical outcomes utilizing the 730-nm picosecond titanium sapphire laser for the treatment of CALMs...

BACKGROUND: Facial skin tightening with wrinkle/fine line reduction is a highly demanded procedure in the aesthetic field. Although there are studies focused on the types of energy sources, the total amount of thermal energy, and the affected depth, there have been no reports examining the relationship between the shape of thermal energy and the directivity of skin tightening. We have developed a specific method to apply thermal energy to the dermis in continuous parallel lines, resembling a thread, perpendicular to the Relaxed Skin Tension Lines (RSTL) for vectorized collagen contraction using synchronous ultrasound parallel beam technology...

OBJECTIVES: Ablative fractional laser (AFL) treatment is a well-established method for reducing signs of skin photoaging. However, the biological mechanisms underlying AFL-induced healing responses and skin rejuvenation remain largely unknown. It is known that macrophages play an important role in orchestrating healing, normalization, and remodeling processes in skin. Macrophage phenotypes are characterized by inflammatory markers, including arginase-1 (Arg1), major histocompatibility class II molecules (MHC II), and CD206...

OBJECTIVES: A major challenge in non-small cell lung cancer surgery is the occurrence of positive tumor margins. This may lead to the need for additional surgeries and has been linked to poor patient prognosis. This study aims to develop an in vivo surgical tool that can differentiate cancerous from noncancerous lung tissue at the margin. METHODS: A time-resolved fluorescence and diffuse reflectance bimodal device was used to measure the lifetime, spectra, and intensities of endogenous fluorophores as well as optical properties of lung tissue...

OBJECTIVES: Ablative fractional lasers have long been considered the gold standard for facial resurfacing for advanced photoaging. These lasers offer an improved safety profile compared to traditional ablative lasers but typically require more treatment sessions given their fractional approach. In this study, we evaluate a new novel 2910 nm erbium-doped fluoride glass fiber laser (2910 nm fiber laser) (UltraClear; Acclaro Medical) for full-face and neck resurfacing for the treatment of advanced photoaging...

BACKGROUND AND OBJECTIVE: Fractional radiofrequency microneedling (FRM) is widely used as an option for skin rejuvenation, however there is a lack of histological evidence for the various energy delivery systems available. The objective was to assess thermal denaturation of tissue and the wound healing response in monopolar mode versus bipolar mode. Histological analysis was performed to demonstrate the efficacy of automatic impedance feedback system in monopolar mode. STUDY DESIGN AND METHODS: In this study, the acute thermal effects caused by monopolar FRM treatment to the dorsal skin of pigs were assessed histologically by hematoxylin & eosin (H&E) staining...

OBJECTIVES: Ultraviolet light and infrared radiation exposure to the chest and neck can result in photoaging changes, such as rhytids, skin roughness, and dyschromia, which can be treated with nonablative fractionated lasers. The low-powered fractionated 1440 and 1927-nm diode lasers have been shown to safely reduce facial photodamage. This study was conducted to investigate the safety and efficacy of a low-powered 1440 and 1927-nm nonablative fractionated diode laser in addressing photoaging symptoms, such as rhytids, skin roughness, and dyschromia, of the neck and chest...

BACKGROUND: Systemically delivered hedgehog inhibitors including vismodegib and sonidegib are widely used to treat basal cell carcinomas (BCCs). Ablative fractional laser (AFL)-assisted topical delivery of vismodegib has been demonstrated in preclinical studies. The aim of this explorative clinical study was to evaluate intratumoral vismodegib concentrations and effect on hedgehog pathway gene expression following AFL-assisted topical vismodegib delivery to BCCs. METHODS: In an open-label clinical trial, 16 nodular BCCs (in n = 9 patients) received one application of CO2 -AFL (40 mJ/microbeam, 10% density) followed by topical vismodegib emulsion...