Lasers in Medical Science最新文献

Simulation studies on temperature distribution in laser ablation help predict ablation rates, laser settings, and thermal damage. Despite the limited number of reported numerical studies on the temperature distribution of kidney fluid, there is no simulation study for kidney stone temperature distribution. We employ a numerical approach to study the kidney stone temperature distribution and predict ablation rates, which is an important parameter for clinical lithotripsy. The study looked at how the thulium fiber laser and the Ho:YAG laser differ in terms of temperature profile and ablation depth of kidney stones like calcium oxide monohydrate. The ablation depth increased from 152.7 µm to 489.7 µm when the TFL laser (operated at 10 Hz repetition rate and 1 ms pulse width) fluence increased from 764 J/cm² to 1146 J/cm². Correspondingly, the depth increased from 21 µm to 68 µm for the Ho: YAG laser operated at 3 Hz and 0.22 ms pulse width. We attribute this to an increase in temperature with laser energy. We further investigated the effect of pulse width on ablation depth by considering three different TFL pulse widths: 0.5 ms, 0.75 ms, and 1 ms. There was a decrease in ablation depths from 402.5 µm to 242.6 µm when the pulse width increased from 0.5 ms to 1 ms. Because of lower water absorption coefficients, the Ho:YAG laser (70 mJ/10 Hz) produced a smaller ablation depth and temperature profile than the thulium fiber laser (70 mJ/10 Hz). Experimental results from the literature validated the simulation. We found that the Ho:YAG laser worked better for ablation when it was set to 0.2 J/100 Hz for the Ho:YAG laser and 0.4 J/50 Hz for the TFL laser, which were clinical laser settings that we found in the literature. This indicates that, in addition to laser absorption by water, the laser parameters also significantly influence temperature distribution and ablation.

This research was designed to study effects of high versus low-level laser therapy (HILT and LLLT) on post-dry needling soreness (PNS) at patients with chronic neck pain. We also studied effects of HLLT or LLLT application plus dry needling (DN) on pain, range of motion (ROM), and neck disability index (NDI) at the identified patients. This is a clinical trial in 48 women with chronic neck pain aged 18-35 who were divided into three groups: HLLT, LLLT, and placebo group. All the participants received one session of DN and laser therapy. The study assessed the soreness using Visual Analog Scale for needle pain (nVAS) and Pressure Pain Threshold (PPT) before, immediately after, 24 and 48 h after laser therapy. Pain, ROM, and NDI assessed before and also different time courses after DN plus laser therapy. PPT and nVAS improved in all groups over time. In the placebo group, nVAS increased significantly (p < 0.001) after treatment. VAS, NDI, and ROM improved 48 h after treatment in all groups. The VAS scores were substantially decreased (p < 0.001) immediately after treatment for LLLT group and also 24 h after treatment for both LLLT and HLLT groups. LLLT and HLLT might prevent immediately increasing the PNS. Adding one session of LLLT or HLLT to DN could effectively eliminate the neck pain at 24 h. All groups improved NDI and ROM the same. Registration number: IRCT20190411043241N1. Registered Sep 2, 2019.

Excimer laser coronary angioplasty (ELCA) in percutaneous coronary intervention (PCI) is safe and effective. However, thrombotic complications after ELCA occasionally occur. This study aimed to evaluate the impact of lipid-rich plaque in both in-stent restenosis (ISR) and de novo lesions on thrombus formation and transient no-reflow after ELCA. We conducted a single-center, retrospective, observational study including 27 lesions in 26 patients who underwent PCI with ELCA. Optical coherence tomography (OCT) was performed on all lesions before and immediately after ELCA. We measured the lipid angle per millimeter and lipid length of plaques with signal attenuation. We also recorded ELCA-induced thrombus formation and transient no-reflow. Thrombus formation and transient no-reflow were observed in nine (33%) and four lesions (15%), respectively. The frequency of ISR was significantly higher in the no-thrombus group than in the thrombus group. ISR lesions had a significantly lower lipid index (median [interquartile range] 108° [0°-756°] vs. 2541° [1205°-4336°]; p = 0.004) than de novo lesions. Among ISR lesions, those with ELCA-induced thrombus formation had a significantly higher lipid index (1370° [756°-4992°] vs. 29° [0°-285°]; p = 0.01) and significantly longer lipid length (8 mm [7-24 mm] vs. 0.5 mm [0-2.5 mm]; p = 0.01). The findings suggest that thrombus formation was more frequently observed in de novo lesions than in ISR lesions. OCT-detected lipid-rich plaques in ISR lesions were strongly associated with thrombus formation following ELCA.

To compare the pulsed-Thulium: YAG(p-Tm: YAG) and Thulium Fiber(TFL) lasers in terms of efficiency and safety profiles during flexible ureteroscopy(fURS) and endocorporeal laser lithotripsy(ELL). A prospective single-center open-label comparative study included consecutive patients with ureteral and renal stones who underwent fURS using Thulio(p-Tm: YAG, Dornier©,Germany) or TFL Drive(TFL, Coloplast©,Danemark), with 270 μm and 150/200μm laser fibers(LF), respectively. fURS were performed by a single operator in each group. Demographics, stone size, stone density, laser-on time(LOT) and laser settings were recorded. Ablation speed(mm³/s), energy consumption(J/mm³) values for each procedure were also assessed. Stone-free rate(SFR, <3 mm fragments) and zero fragment rate(ZFR) on non-contrast computed tomography within 3 months postoperatively were also recorded. 36 and 39 patients were included in p-Tm: YAG and TFL group, respectively. Groups presented similar demographics but for high blood pressure(53vs23%,p = 0,005), anatomical abnormalities(8vs33%,p = 0,03), lower pole(8vs26%,p = 0,04) and pelvic stones(25vs13%,p = 0,04) for p-Tm: YAG and TFL, respectively. The median stone maximum diameter was higher in the p-Tm: YAG group(17.3vs13.8 mm, p = 0,001) but stone volume was similar among groups(1514vs1347mm³,p = 0,6). Laser settings were similar among groups(0,6-15 Hz,10-12 W). Shorter LOT(< 0,001) and lower UAS insertion(0,01) rates were reported for TFL compared to p-Tm: YAG. The median J/mm³ was similar(14vs17,p = 0,2) but p-Tm: YAG presented higher ablation speed(0,91vs0,73mm³/s, p = 0,04). SFR were similar among groups(75vs77%,p = 0,8) but ZFR was higher in TFL group(39vs64%,p = 0,008). No difference in complications was reported. Both p-Tm: YAG and TFL are safe and effective for ELL during fURS. SFR were similar between TFL and p-Tm: YAG but the latter presented lower ZFR, traducing its lower ability to dust. Using 200 μm laser fibers with p-Tm: YAG could nuance these findings.

To report the safety and effectiveness of selective laser trabeculoplasty (SLT) using the SLT mode of the VISULAS^® green laser in patients with primary open-angle glaucoma (POAG). Twelve months results are presented. Retrospective extension in 4 German centers of an initially prospective interventional multicenter 3-month clinical investigation using the VISULAS^® green SLT (Carl Zeiss Meditec AG, Jena, Germany) in patients with POAG who either needed treatment escalation or commenced treatment and had an IOP ≥ 17mmHg at baseline, with no previous glaucoma or other ocular surgery. Non-overlapping laser spots (100) were applied in a single session to 360° of the trabecular meshwork (TM). Glaucoma medications were not changed up to the 3-month visit. From 3 to 12 months, patients were managed according to routine standard of care. Outcome measures included IOP reduction, further glaucoma interventions, and adverse events from baseline to month 12. 25 eyes of 25 POAG patients (mean age 65.8 ± 8.5; modified intention to treat - mITT -group) were included in the extension study. Six eyes (24%) underwent additional glaucoma treatment or changed glaucoma therapy; the remaining 19 eyes (76%) had stable glaucoma therapy (SGT group) with no further glaucoma intervention or change in glaucoma medications (mean number of preoperative glaucoma medications: 2.3 ± 1.34). In the SGT group, mean baseline IOP (mmHg) was reduced from 20.0 ± 2.11 at baseline to 17.4 ± 3.25 and 16.2 ± 1.83 at 6 to 12 months, respectively (p < 0.0001): 52.6% had ≥ 20% IOP reduction at 12 months. Potential device- or procedure-related adverse events were mild to moderate and resolved without sequelae. SLT performed with the VISULAS^® green laser reduced IOP in eyes with POAG up to 12 months with no relevant safety issues. The results are comparable to other reported SLT studies.

The objective of this study was to identify, describe and synthesize the data published about the effectiveness of antimicrobial photodynamic therapy (aPDT) in the pulpectomy of primary teeth. A search was conducted in six electronic databases and the gray literature in June and July 2023, without restrictions on language or date of publication. The search strategy included indexed terms (MeSH terms) and your synonyms. Clinical trials, in vitro studies, case reports and retrospective studies that used photodynamic therapy in primary teeth pulpectomies were considered eligible. Among the 1,674 articles retrieved, 15 were included, published between 2014 and 2022, comprising six in vitro studies, five clinical trials, and four case reports. The sample consisted of children aged 2 to 8 years of both sexes, and included 1 to 62 teeth, mostly anterior. In two in vitro studies, the sample was taken from root canals. Most studies used a diode laser, methylene blue, and optical fiber. The pre-irradiation time ranged from 1 to 5 min. All protocols demonstrated microbial reduction before and after using aPDT, with no statistical difference among the groups. Furthermore, six studies demonstrated treatment success. Despite the divergence in methodology and protocols, aPDT is an effective method for reducing microorganisms, and is a promising adjunct treatment in primary teeth pulpectomies.

Neck pain is considered one of the most prevalent global public health problems. This study aimed to compare the immediate and subsequent effects of traditional acupuncture (TA) and laser acupuncture (LA) therapies in individuals with chronic non-specific neck pain. Eighty-four individuals were randomly allocated into 3 groups: TA (needle acupuncture treatment), LA (laser acupuncture treatment: 808 nm; 100 mW; 10 J per point), and S-LA (sham laser acupuncture). The participants were men and women aged between 18 and 60 years who had experienced chronic non-specific neck pain for a minimum period of 3 months. The Tianzhu, Fengchi, Jianjing, and Jianzhongshu acupuncture points were stimulated bilaterally. The primary outcomes were pain intensities at rest and during active neck movements, assessed using the Numerical Rating Scale. The secondary outcomes were Pressure Pain Threshold, Temporal Summation of pain, Conditioned Pain Modulation, and Global Perceived Effect scale. The assessments were performed immediately before and after a single treatment session. Additionally, determinations of pain intensity at rest and Global Perceived Effect were performed in a follow-up assessment one month after the interventions. The results showed that the TA and LA interventions were equally significantly superior in reducing immediate pain compared to placebo laser acupuncture (p = 0.001). Traditional acupuncture and laser acupuncture provided equally effective reductions of pain intensity in patients with chronic non-specific neck pain. Clinical Trial registration: RBR-7vbw5gd (Brazilian Registry of Clinical Trials - ReBEC).

This study aimed to assess the impact of nutritional conditions and irradiation parameters on the viability and proliferation of murine preosteoblasts. MC3T3-E1 cells were maintained under standard culture conditions (αMEM supplemented with 10% fetal bovine serum) or nutritional deficit conditions (αMEM without serum) and irradiated or not (control) with an InGaAlP diode laser at wavelengths of 660 nm (red) or 790 nm (infrared), with doses of 1, 4, or 6 J/cm², in a single dose in continuous mode. Cell viability and proliferation were assessed 24, 48, and 72 h after irradiation using the Alamar blue reduction assay. The cell cycle and events related to cell death were evaluated via propidium iodide (PI) staining and Annexin V/PI assays, respectively, through flow cytometry. The data revealed that in cells cultured with normal nutrition (10% FBS), there was no significant difference (p > 0.05) in cell viability or proliferation among the different irradiation protocols. In contrast, in the experiments conducted under nutritional deficiency, the infrared laser at a dose of 6 J/cm² significantly increased (p < 0.05) cell viability and proliferation compared with those of the control group at 72 h. The data were confirmed by cell cycle and cell death events (Annexin V/PI) assays. These results suggest that in vitro PBM yields more consistent biostimulatory effects on pre-osteoblasts subjected to nutritional deficiency, highlighting the need for attention to simulate these conditions in studies with laser therapy in in vitro bone disease models and in in vitro experiments using PBM for bone tissue engineering.

Bell's palsy, characterized by sudden facial paralysis, affects a significant proportion of the population annually, yet its exact cause remains elusive. Recently, increasing attention has been directed towards photobiomodulation therapy (PBMT) and its prospective contribution to managing various neurological and musculoskeletal conditions, including Bell's palsy. A systematic literature search of different databases was performed using a specific search strategy to find eligible studies that evaluated the potential of PBMT in managing Bell's palsy, considering its non-invasive nature and tissue healing properties. Data extraction was done based on inclusion and exclusion criteria. The systematic review included studies published from 1993 to 2022, examining the effects of photobiomodulation therapy on Bell's palsy. The studies, involving 21 to 120 participants aged 18 to 70, utilized various PBMT parameters such as wavelengths (830-850 nm and 808/905 nm), energy densities (8-20 J/cm²), and irradiation times (10-125 s). The results demonstrated significant improvements in facial muscle function, pain intensity, and muscle strength, showing that PBMT is effective in enhancing facial nerve function recovery in Bell's palsy patients. Statistical analysis showed that PBMT treatments had significant improvements compared to control groups (p < 0.05). Our systematic review indicates that photobiomodulation therapy can improve facial muscle function, pain intensity, and muscle strength in Bell's palsy patients. Notably, wavelengths of 830-850 nm and the combination of 808/905 nm yielded the most favorable results. However, due to heterogeneity in study designs, PBMT parameters, and outcome measures, further standardized and well-designed randomized controlled trials are necessary to establish optimal treatment protocols and validate these findings comprehensively.