Laser radiation has specific attributes: monochromaticity, high coherence and polarization. These properties result in the extensive use of lasers in medicine. Laser devices can be assigned into three basic groups by means of their level of energy: high, medium and low energy. All of these types of radiation are used in medicine. However, the most commonly used, in basic science and clinical studies, is low-energy radiation. Molecular effects of low energy laser irradiation on cells are generally described as "fotobiostimulation" and "fotobiomodulation". These phenomena consequently lead to attempts to exploit this kind of radiation as a treatment method (low-level laser therapy-LLLT). Areas in which LLLT is used are: regenerative medicine (for healing wounds and ulcers); aesthetic medicine (to improve appearance of scars); dentistry (to accelerate healing of implants); physiotherapy (to reduce chronic pain syndromes), orthopedics (in bone healing) and cardiology (as a prevention of restenosis after percutaneous coronary intervention). This paper discusses the medical applications of LLLT which are used in daily clinical practice as well as those used in basic science.

Low-level laser therapy (LLLT) has become an important part of the therapeutic process in various diseases. However, despite the broad use of LLLT in everyday clinical practice, the full impact of LLLT on cell life processes has not been fully understood. This paper presents the current state of knowledge concerning the mechanisms of action of LLLT on cells. A better understanding of the molecular processes occurring within the cell after laser irradiation may result in introducing numerous novel clinical applications of LLLT and potentially increases the safety profile of this therapy.

The effect of low-level laser therapy (LLLT) on the cardiovascular system is not fully established. Since the endothelium is an important endocrine element, establishing the mechanisms of LLLT action is an important issue.The aim of the study was to evaluate the effect of transdermal LLLT on endothelial function.In this study, healthy volunteers (n = 40, age = 20–40 years) were enrolled. N = 30 (14 female, 16 male, mean age 30 ± 5 years) constituted the laser-irradiated group (LG). The remaining 10 subjects (6 women, 4 men, mean age 28 ± 5 years) constituted the control group (CG). Participants were subjected to LLLT once a day for three consecutive days. Blood for biochemical assessments was drawn before the first irradiation and 24 h after the last session. In the LG, transdermal illumination of radial artery was conducted (a semiconductor laser λ = 808 nm, irradiation 50 mW, energy density 1.6 W/cm² and a dose 20 J/day, a total dose of 60 J). Biochemical parameters (reflecting angiogenesis: vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), angiostatin; antioxidative status: glutathione (GSH) and the nitric oxide metabolic pathway: symmetric dimethylarginine (SDMA), asymmetric dimethylarginine (ADMA) and l-arginine) were assessed. In the LG, a significant increase in GSH levels and considerable decrease in angiostatin concentration following the LLLT were observed. No significant differences in levels of the VEGF, FGF, SDMA, ADMA were observed.LLLT modifies vascular endothelial function by increasing its antioxidant and angiogenic potential. We found no significant differences in levels of the nitric oxide pathway metabolites within 24 h following the LLLT irradiation.

Shock Waves (SW) are acoustic disturbances that propagate through a medium carrying the energy. These specific sonic pulses are composed of two phases—high positive pressure, a rise time < 10 ns, and a tensile wave. Originally Shock Waves were introduced to clinical practice as a part of the lithotripsy therapy focused on disrupting calcific deposits in the body. Since that time, shock wave therapy (SWT) has gone far beyond the original application related to the destruction of kidney stones. In this narrative Review, we present basic clinical applications of the SWT along with the potential therapeutic application in clinical practice.

Background: The unprotected calcified Left Main disease represents a high-risk subset for percutaneous coronary intervention (PCI), and it is associated with a higher number of periprocedural complications and an increased rate of in-stent thrombosis and restenosis. Adequate lesion preparation plays a crucial role in achieving a favorable PCI outcome. Rotational Atherectomy (RA) is a well-established plaque-modifying method; nevertheless, the data regarding the effectiveness of RA in LM diseases is scarce. Recently, the novel ShockWave-Intravascular-Lithotripsy(S-IVL) device has been introduced to the PCI armamentarium in order to modify the calcified plaque. Methods: We performed a retrospective evaluation of 44 consecutive subjects who underwent the LM-PCI, and who were supported by either the RA or S-IVL. Results: The Rota group consisted of 29 patients with a mean syntax score of 28.0 ± 7.5. The S-IVL group was composed of 15 subjects with a syntax score of 23.3 ± 13.0 There were no statistical differences regarding MACE between the RA and Shockwave arms of the in-hospital group (10.3% vs. 6.7%), or in the six month (17.2% vs. 13.3%) follow-up group. Conclusions: RA and S-IVL could be safe and effective therapeutic strategies for calcified LM disease. Further studies with a higher number of participants and longer follow-up times are warranted to establish the potential benefits of RA and S-IVL for the management of LM stenosis.

Aim. The goal of the study is to develop a model allowing to investigate precisely the effect of low‐level laser therapy (LLLT) on platelet aggregation and to verify the hypothesis regarding the role of the nitric oxide (NO) bioavailability and platelet activation markers in modulating platelet aggregation. Methods. A total of 41 healthy volunteers at the age of 21–45 years were investigated. At first, platelet aggregation in response to three agonists (TRAP, ADP, and collagen) was evaluated following previous exposure to different doses of laser radiation (λ = 662 nm) to assess the dose‐response effect. Subsequently, plasma levels of platelet activation markers (PF4—platelet factor‐4 and sP‐selectin) as well as the substrate for nitric oxide synthase, L‐arginine, and its competitive inhibitors (ADMA—asymmetric dimethylarginine and SDMA—symmetric dimethylarginine) were measured. Results. All doses of laser irradiation significantly reduced the aggregation. However, the most pronounced effect was observed for 19.7 J/cm². No significant differences in the levels of platelet activation markers nor in the nitric‐oxide‐metabolic‐pathway compounds between analyzed groups were noted. Conclusions. We have demonstrated in the established in vitro experimental model that the LLLT in a reproducible manner decreases the whole blood platelet aggregation regardless of the NO bioavailability or changes in the platelet activation markers.