**6. New technologies applied in VLUs treatment**

The modern approach to the treatment of VLUs today is based on the application of various biophysical interventions such as electromagnetic therapy, phototherapy, electrical stimulation and ultrasound therapy. The modern method of treatment today includes the use of stem cell therapies, biological skin equivalents (such as bilayered living cellular construct (BLCC), or 3D-printed hydrogel dressing [42, 43].

In addition to the application of standard methods of treating VLUs, the following are also used: oxygen therapies, negative pressure wound therapy and platelet-rich plasma therapy. The use of a muscle pump activator or device with occasional pneumatic compression in a number of patients with VLUs has been shown to be very successful [44, 45].

Electromagnetic therapy (EMT) also has a significant place in VLUs therapy. EMT devices generate a pulsed electromagnetic field (PEMF). PEMF increases the number of fibroblasts and macrophages in the wound, which results in rapid wound healing. Studies have shown that PEMF increases the deposition of fibrin and collagen and reduces the inflammatory process [46].

Low-level light therapy (LLLT) as a variant of phototherapy has a prominent place in the treatment of VLUs [47, 48]. The use of LLLT devices activates cells through a photochemical effect. There is an increase in cellular activity [43] resulting in accelerated tissue healing, granulation tissue formation, increased protein synthesis, increased cell proliferation, anti-inflammatory modulation and pain reduction [43, 49]. This method is a non-contact method of treating VLUs, and LLLT devices usually direct a beam of light around the entire surface of the wound [48].

Electrical stimulation (ES) stimulates angiogenesis by activating mitogenactivated protein kinase (MAPK) and increasing vascular endothelial growth factor (VEGF). The application of ES leads to increased fibroblast proliferation by stimulating the production of fibroblast growth factors (FGF). The application of ES has been shown to be effective in reducing the inflammatory process and regulating bacterial growth [50].

Ultrasound therapy (UT) has found a significant place in the treatment of VLUs as one of the auxiliary therapeutic modalities [51, 52]. The effect of ultrasound on tissues is reflected in the increase of blood flow in the tissue and the induction of physical changes in the structure of collagen. This type of therapy promotes cell proliferation, angiogenesis and protein synthesis. UT also accelerates the formation of granulation tissue, has anti-inflammatory and anti-edematous effects [51, 52]. However, previous research on the application of UT has not given a clear answer on the in vivo healing process [51].

Clinical studies have shown that stem cell therapy (SCT) promotes wound healing in each wound repair phase. The application of SCT accelerates the healing process of VLUs, with a significant reduction in wound area and quality tissue regeneration [53, 54].

Oxygen therapy has a prominent place in the treatment of VLUs. Chronic wound tissues have a very small amount of oxygen, and due to hypoxia, the wound healing process is slowed down. This is particularly pronounced if a transcutaneous oxygen partial pressure (pO2) is lower than 40 mmHg [55]. Oxygen therapy accelerates wound healing and does not reveal relevant cell damage risk [55, 56]. Today, the following methods of oxygen therapy are used: hyperbaric oxygen therapy and topical oxygen therapy.

Negative pressure wound therapy (NPWT) accelerates the healing process of VLUs. This is achieved through several mechanisms: reduction of local edema as well as reduction of the number of bacteria, inflammatory mediators and wound exudates. NPWT promotes angiogenesis, promotes tissue perfusion, stimulates tissue granulation, causes wound shrinking, and contraction of its edges [47, 57].

*Perspective Chapter: Diagnosis and Treatment of Venous Leg Ulcer DOI: http://dx.doi.org/10.5772/intechopen.105676*

Platelet-rich plasma (PRP) or autologous platelet-rich plasma is a suspension of platelets obtained from whole blood [58]. The concentration of platelets in PRP is two to six times higher than that in the blood [59]. To form a liquid or gel that contains multiple growth factors, PRP is most commonly mixed with thrombin. PRP supplies not only a number of growth factors but also signaling cytokines that also play a key role in new tissue synthesis, angiogenesis, or inflammation regulation [58].

The role of growth factors in wound healing is very complex. Certain growth factors (e.g. TGF-beta) play different roles in different phases of healing. To date, in spite of many years of research, only one growth factor (Becaplermin, PDGF) is registered for the treatment of diabetic foot ulcers and not for venous ulcers [60].
