## 4 Discussion  
In this work, we evaluated the possibility of using LTP for the complex treatment of pressure ulcers in patients with CCC of various etiologies. We found that the process of activation in the skin and muscle tissues of the bedsore zone proceeds most efficiently when using a current with a frequency of 6.78 MHz as compared to currents with a frequency of 2.64 and 0.11 MHz. The optimal exposure parameters for needle electrodes with a diameter of (0.30 \(\pm\) 0.05) mm and a length of 3.0-6.0 mm are power--(5.0 \(\pm\) 1.5) W and time--(2.0-3.0) s. In the main group of patients treated with LTP therapy, accelerated normalization of the microvasculature, more pronounced growth and maturation of granulation tissue with the formation of type 1 and 3 collagen fibers, both in the bottom area and in the edges of the bedsore defect, were found (Tables 1 and 2). At the same time, a more pronounced accumulation of collagens was noted in the region at the edges of the bedsores. A pronounced activation effect was formed during the period from 14 to 21 days. The effectiveness of therapy by the method of activation of WP by LTP discharges, according to the criterion of the rate of wound healing, ranged from 14 to 16%, depending on the etiology of the decubitus wound. It was established that this treatment also stimulates neo-giogenesis with VEGF expression by the vascular endothelium, which is most pronounced after 30 days, together with the accumulation of myofiblic elements (SMA) in tissues, which appear in the largest number two weeks after the start of combined local therapy for DU. In general, the changes described by immunohistochemistry correspond to the patterns of the regeneration process in the main group, obtained by histological examination. In addition, we found that combined local therapy using the LTP technology for WP activation is accompanied by a significant decrease in the bacterial contamination of decubitus wounds. At the same time, against the background of standard treatment, the bacteriological contamination of decubitus wounds is significantly slowed (Table 3). This also indicates a more favorable course for the reparative process in bedsores. Complex therapy of long-term, nonhealing DU in patients in chronic critical condition using WP activation technology provided a significant acceleration of regenerative processes over the entire area and throughout the depth of the pressure ulcer, regardless of the type of tissue structures (skin, fibrous, muscle, and adipose tissue). At the same time, the period of inpatient treatment is noticeably reduced, which, in turn, provides the possibility for an earlier start of rehabilitation measures. According to the key macroscopic parameters, the main group of subjects was ahead of the control group by about 6-7 days (Table 1). It is believed that the LTP effect is based on the synergism of strong electric fields and electromagnetic radiation [39; 40]. In this case, the action of these factors leads to the generation of reactive oxygen species (such as hydroxyl radical, superoxide, perhydroxyl, and oxide anions, together with hydrogen peroxide and ozone) or nitrogen (nitrogen oxide