Lasers in Medical Science最新文献

Purpose: Transoral robotic surgery (TORS) is an established surgical approach for oropharyngeal squamous cell carcinoma (OPSCC). Carbon dioxide (CO₂) laser offers high cutting precision and minimal collateral thermal injury, yet its use in TORS remains underreported. The purpose of this study is therefore to describe the first UK case series detailing the use of CO₂ laser via hollow waveguide in TORS.

Methods: Eight patients (six male, two female; mean age 60 years) presenting with either left tonsillar (seven cases) or right tongue base (one case) OPSCC underwent primary TORS resection with CO₂ laser at a tertiary UK head and neck centre between October 2020 and May 2024. Cases were selected based on tumour stage, anatomical suitability and patient preference. The CO₂ laser (SmartXide Trio, 3-10 W, ultra-pulse mode) was delivered via hollow waveguide mounted on one of the arms of the Da Vinci robotic system. Outcome measures included histological margin status, peri- and postoperative complications, swallowing function, and hospital length of stay.

Results: All tumours were completely excised; two of the eight had close margins on the primary specimen but were clear on additional sampling. No intraoperative complications occurred, and all procedures were completed without conversion. All patients resumed oral intake without nasogastric feeding. Mean hospital stay was 2.75 days, with no airway compromise, catastrophic bleeding, or significant swallowing dysfunction.

Conclusion: CO₂ laser dissection in TORS for OPSCC represents a viable surgical approach with acceptable postoperative functional outcomes and may possibly demonstrate reduced thermal injury compared with monopolar electrocautery.

Cutaneous aging is characterized by gradual structural and functional alterations, including collagen breakdown and reduced elasticity. In recent years, several energy-based modalities have been introduced to address these changes. The aim of this study was to assess the effectiveness of a 675 nm laser and microfocused ultrasound (MFU), applied individually or in combination, for the treatment of facial aging. This retrospective analysis included 115 patients, allocated into three groups: Group A (675 nm laser), Group B (MFU), and Group C (combined protocol). Efficacy was evaluated through the Fitzpatrick Wrinkle Scale (FWS), the Baker Gravitational Ptosis Classification (BGP), and standardized photographic assessments at 1, 3, and 6 months following treatment. At the 6-month evaluation, individuals treated with the combined protocol exhibited a more pronounced improvement in wrinkle reduction (FWS: from 1.88 to 1.13) and laxity reduction (BGP: from 2.78 to 1.55) compared with either single-treatment group. No major side effects were observed. The combined application of the 675 nm laser and MFU appears to potentiate collagen remodeling and skin tightening more effectively than monotherapy. Further prospective studies are needed to validate these results and further clarify the molecular pathways involved.

Several parameters influence the effectiveness of photobiomodulation therapy (PBMT) in improving skin flap viability, yet the role of the number of treatment sessions remains underexplored. The present study aimed to evaluate the effect of different numbers of laser PBMT sessions on skin flap viability. Thirty-two Wistar rats were randomly divided into four groups: G1 (PBMT simulation), G2 (PBMT for 2 consecutive days), G3 (PBMT for 5 days), and G4 (PBMT for 7 consecutive days). Treatment began immediately after surgery with the following parameters: GaAlAs diode laser, 660 nm wavelength, continuous mode, spot size of 0.04 cm² (probe in contact with the skin), 90 J/cm² fluence, 40 mW output power, 90 s application time, and 3.6 J of energy per point with irradiation at three points and 24-hour intervals between sessions according to each group's protocol. On the 7th postoperative day, tissue was collected from the irradiated area for analysis of necrotic area, vessel and mast cell morphometry and immunohistochemistry for angiogenesis markers. G2 showed the smallest necrotic area and a higher percentage of VEGF- and HIF-1α-positive cells compared to G1. Short PBMT protocols improved flap viability versus controls and produced outcomes comparable to extended regimens, supporting relevance for translational research.

This pilot study aimed to investigate the effects of intravascular laser irradiation of blood (ILIB) on anxiety levels and vital signs in patients undergoing third molar extraction. A randomized, placebo-controlled clinical trial was conducted with 26 patients who underwent mandibular third molar extraction. Participants were allocated to either the placebo group (n = 13) or the ILIB group (n = 13). ILIB was applied via transcutaneous over the radial artery for 30 min before the surgical procedure. Anxiety levels were assessed using the State-Trait Anxiety Inventory (STAI-Y, state subscale) at baseline and four minutes after local anesthesia. Vital signs, including heart rate (HR), systolic and diastolic blood pressure, and oxygen saturation, were also recorded at these two time points. There was no significant difference in anxiety status between the ILIB and placebo groups. However, the ILIB group demonstrated a statistically significant HR stability after local anesthesia compared to the placebo group. All parameters remained within normal limits throughout the procedure. Despite its pilot nature and small sample size, this study indicates that ILIB is feasible in routine clinical practice. Although it did not reduce anxiety compared to a placebo, ILIB helped stabilize HR after local anesthesia, suggesting a potential physiological benefit. Further research is needed to assess its clinical relevance, especially in patients with severe anxiety or systemic conditions. Brazilian Clinical Trials Registry - REBEC no. RBR-9ycg67p. Registration, March 10^th, 2023.

To explore the effect of manual linear array technology (MLAT) of ultra-pulsed CO₂ laser on keloids:a randomized self-control clinical trial 20 patients with 80 keloids in the outpatient department of dermatology at the Fourth Affiliated Hospital of Anhui Medical University were recruited for a randomized self-control study. Some skin lesions were randomly selected as observation lesions by MLAT of ultra-pulsed CO₂ laser, and the other skin lesions with similar size were selected as control lesions by manual fiction technology (MFT) in the same patient. Comparison of the effects between the two treatment methods was performed by Wilcoxon signed-rank test. Vancouver Scar Scale (VSS) score between the two methods was analyzed by two sample t-test and paired sample t-test. remarked effective rate in the observation lesions was 82.5% higher than that 57.5% in the control lesions (χ2 = 6.975),which has statistical difference (P= 0.008). The recurrence rate in the observation lesions was 2.5% lower than that 15.0% in the control lesions (χ2 = 5.563), which has statistical difference (P= 0.018). The VSS score of the observation lesions was 2.45± 1.22 lower than that 4.80± 1.68 of the control lesions (t= 7.155) after the treatment, which has statistically significant（P=0.000）. The difference of the VSS score between before and after treatment in observation lesions was 9.70± 2.15 higher than that 7.83± 2.24 in the control lesions (t= 3.818), which has statistically significant (P=0.000). There was no significant difference in the incidence of adverse reactions between the two methods (χ2 =0.157,P=0.692). MALT is effective in the treatment of keloids, which may be worthy of clinical reference or application.

To evaluate the cutting accuracy and thermal damage in oral soft tissue using different cutting techniques. Sixty specimens of sheep oral mucosa tissue, with the dimensions of 2.0 cm in length and 1.5 cm in width were prepared and divided into six groups (n = 10) representing different cutting technique. Incisions were made by sectioning each specimen using the 2000 nm continuous-wave (CW) silica based thulium-doped fibre (TDF) laser (Group A), the 1550 nm CW silica based Erbium/Ytterbium-doped fibre (EYDF) laser (Group B), electrosurgery (Group C), 980 nm diode laser (Group D), 2000 nm ultrashort-pulsed (USP) silica based TDF laser (Group E), and the scalpel (Group F or control group). Each specimen was measured for average roughness value (Ra) and thermal damage, reported as mean and standard deviation. A one-way ANOVA with post-hoc Tukey's HSD test was performed to determine significant differences among six groups, with a significance level set at p < 0.05. Among the energy-based groups, the 2000 nm USP silica based TDF laser (Group E) exhibited the lowest Ra (1.22 ± 0.71 μm) and minimal thermal damage (9.85 ± 4.01%). In contrast, the highest Ra (4.82 ± 1.36 μm) was observed in the electrosurgery (Group C), while the highest thermal damage (16.73 ± 4.57%) was recorded in the 1550 nm CW silica based EYDF laser (Group B). One-way ANOVA revealed statistically significant differences among the groups in both average roughness (F = 45.45, p < 0.001) and thermal damage (F = 11.84, p < 0.001). The findings suggest that the 2000 nm USP silica based TDF laser offers superior cutting accuracy with minimal impact of thermal damage, supporting its potential adoption into clinical protocols for oral soft tissue surgery.

This study systematically reviewed the effect of photon induced Photo-Acoustic Streaming (PIPS), compared to Conventional Syringe Irrigation (CSI), on the removal of smear layer and/or debris from root canals. Searches and screening were conducted by two independent reviewers in PubMed/MEDLINE and EMBASE up to August 2025. Eligible studies were in vitro investigations on extracted human teeth evaluating smear layer and/or debris removal using Scanning Electron Microscopy (SEM). A descriptive analysis was performed, and the quality of the studies was assessed by an adapted version of the Joanna Briggs Institute (JBI) checklist. Of 911 screened studies, 14 met the inclusion criteria. PIPS generally showed superior smear layer removal compared with CSI. One study attributed the effect to 20% EDTA rather than the activation technique. Regardless of the irrigant used (distilled water, saline, NaOCl or EDTA), PIPS enhanced smear layer reduction. Removal was more effective in the cervical and middle root thirds than in the apical third. Risk of bias assessment classified 9 articles as medium, 4 as high and 1 as low risk. PIPS appears more effective than CSI in reducing smear layer on root canal walls and can be considered an alternative irrigant activation method. However, heterogeneity among studies limits direct comparisons, highlighting the need for standardized experimental protocols to clarify the effectiveness of PIPS and other techniques. Enhancing smear layer and/or debris removal is critical for disinfection and sealing in endodontics. PIPS shows potential to improve root canal cleanliness compared with CSI.