Progress in Diagnosis and Treatment of Chronic Skin Ulcers

Chronic skin ulcers are skin-defective lesions deep in the dermis and subcutaneous tissues caused by various causes, and are common skin lesions in the clinic. For patients with a disease duration of more than 1 month without significant healing tendency or frequent recurrence, it is called chronic skin ulcer(CSU). Many diseases can be complicated by CSU, such as diabetes, peripheral vascular disease, various microbial infections, trauma, radiotherapy, malignant tumors and so on.

These factors caused poor blood flow around the wound, repeated infection and ulceration of the wound surface, formation of dead space, and even nerve or bone exposure, and prolonged unhealed, eventually becoming refractory wounds. It is a long-term consumptive disease, causing great distress to doctors and patients, high disability rate, and a heavy burden on families and society. Identifying the causes and refractory factors of CSU is a prerequisite for successful treatment. This article starts with the analysis of common causes, summarizes the diagnosis and treatment ideas, and summarizes the relevant treatment progress for reference in clinical work.

1. Cause of chronic skin ulcers

1.1 Traumatic cause

Traumatic factors include mechanical, radiation damage and burns. After mechanical injury, chronic ulcers are often formed due to improper handling. Ulcers that appear on scars after burns are also difficult to heal, and their bases are pale and accompanied by contracture deformities. Radioactive damage affects cell synthesis, expression, and secretion of growth factors, weakens inflammatory cell responses, inhibits the function of extracellular matrix, and hinders tissue repair. The dysregulation and damage of these key healing factors are the main causes of such trauma.

1.2 Vascular cause

Common vascular factors include arterial ischemia, varicose veins and vasculitis, especially in the lower limbs, especially in the lower leg, accounting for more than half of all types of chronic ulcers. Arterial factors such as arterial occlusion syndrome, atherosclerotic plaque, and diabetes are common causes of ischemic ulcers. Such ulcers are more difficult to treat, and a 15-year study by the University of Pittsburgh Medical Center in the United States showed that the 10-year cumulative ischemic ulcer has an amputation rate of 30%. The lower extremity venous congestion ulcer is more common than the arterial ischemic ulcer. This is due to the special structure of the perforating venous valve in the lower extremity venous system. Once the lesion or injury, varicose veins, inflammation or embolism may occur, leading to venous return disorder. , forming a difficult wound. Vasculitis is a connective tissue disease characterized by necrotic and non-infectious inflammatory changes. Because of the small blood vessels and capillaries in the superficial dermis of patients, it is easy to form ulcers when skin lesions occur in such patients.

1.3 Infectious cause

Infectious factors include bacteria, fungi and special infections. Most chronic ulcers have bacterial infections, and the biofilm formed by bacteria can significantly inhibit the regeneration of the epithelium, which causes the wound to prolong. Tan Yang et al analyzed 172 cases of chronic skin ulcers, 136 cases received bacterial culture, and 102 cases showed positive results. The positive rate was 75.0%, 3 cases with three bacterial infections and 25 cases with two bacterial infections. A total of 29 species of bacteria were cultured, indicating that the types of infected bacteria are diverse, and Pseudomonas aeruginosa and Staphylococcus aureus are the most common. At the same time, with the improvement of the diagnostic level, the diagnosis rate of some special infection types of ulcers is also increasing, such as atypical mycobacteria, nocardia and so on.

1.4 Neoplastic cause

Skin squamous cell carcinoma, basal cell carcinoma, lymphoma, and melanoma can all manifest as skin ulcers and are difficult to heal. For such suspicious patients, a biopsy pathology should be actively diagnosed to avoid misdiagnosis and missed diagnosis.

1.5 Metabolic nutritional cause

Diabetes is the most common and typical representative. Due to the disorder of glucose metabolism, the structure and function of capillaries and arterioles are common causes of diabetic ulcers. High levels of blood glucose can inhibit immune cell activity and interfere with repair function, thus reducing the body’s ability to resist infection. Zhu Ping also found that many changes in cytokines are associated with diabetic foot ulcers. There are a series of molecular biological abnormalities in the skin tissue of diabetes, which is difficult to heal after being damaged.

1.6 Other causes

Other causes such as mental stress and ulcers caused by high altitude and sea environment. Stress (mental stress)-induced neuroendocrine immune imbalance is harmful to health, especially in terms of wound healing. Unfavorable environments such as high altitude and high altitude on the plateau are also special causes of wound healing.

2. Diagnosis and treatment ideas of chronic skin ulcers

Local wound/systemic etiological treatment and wound closure and healing are two key technical links. For chronic skin ulcers caused by common causes such as non-traumatic infection, new strategies and new concepts of sequential treatment and combination therapy should be followed. The diagnosis and treatment idea is (Fig. 1): After the initial clinical diagnosis, according to the characteristics of the wound and the secretion, the smear, culture, PCR, gene chip and other detection techniques are selected to determine whether there is an infection and pathogen type. In addition, for non-infectious ulcers, tissue biopsy or other means of examination may be employed. After the diagnosis is clear, the cause is analyzed and treated. After the cause is controlled or corrected, the healing treatment is promoted. The key steps of treatment can be summarized as: Eliminate, correct the cause, control the cause of refractory, thoroughly clean the wound and properly close the wound, and establish a favorable healing environment. Chronic skin ulcers are common in older patients, and they are characterized by deep wounds, large areas, and disease duration. These patients have low organ function and have one or more underlying diseases such as diabetes, hypoproteinemia, varicose veins, and arteriosclerosis. Because of the insufficiency of conventional debridement treatment, the rate of radical surgery failure is extremely high, and it is difficult to achieve the intended purpose by relying on a single treatment plan. Therefore, using a comprehensive approach, staged treatment can often achieve better results.

3. Treatment and progress of chronic skin ulcers

3.1 Medical treatement

Medical treatment generally includes systemic and topical treatment. Systemic treatment is often combined with drugs to achieve better anti-infection, nutritional support, immune regulation, improved circulation, etc. to eliminate or control the cause of the disease. Topical medications are based on experience and have the ability to maintain the wet and suitable temperature of the wound, and to exert its bactericidal, bacteriostatic, anti-inflammatory, local immunity, local blood circulation and local tissue regeneration in a closed, humid environment. drug.

3.2 Surgical treatment

Including debridement, surgical resection, skin grafting, flap transplantation and so on. Because the necrotic tissue on the chronic wound is the natural medium of the bacteria, it also prevents the white blood cells from phagocytizing and killing the bacteria, resulting in a longer inflammatory response. Therefore, after controlling and correcting the cause, elective surgery is an effective treatment. Some small ulcers can be directly resected and sutured. Tumor-like skin ulcers should be expanded and resected according to the guidelines and transplanted with skin grafts or skin flaps. Vascular surgery may require vascular surgery for varicose veins or arterial stent surgery. In addition to these special treatments, most ulcers require multiple debridement. The debridement method of waterjet and ultrasound can effectively treat complex wounds while reducing the pain of patients, which is a good choice.

3.3 Hyperbaric oxygen therapy

Hyperbaric oxygen therapy can improve the oxygen tension of diseased tissues in chronic wounds, improve cell proliferation and promote collagen remodeling, reduce tissue edema, improve local blood supply to wounds and ischemia and hypoxia of damaged tissues. Thereby enhancing the anti-infective ability and accelerating the healing of the unhealthy wound. Londahl was treated with randomized double-blind control in 94 patients with diabetes. The treatment group received hyperbaric oxygen plus conventional therapy. The control group received only routine treatment. The treatment rate of 12 months was found to be significantly better in the treatment group than in the control group.

3.4 Korin

Phototherapy is widely used in dermatology as a minimally invasive treatment. Laser, glare, radiofrequency and photodynamic therapy are common. Laser irradiation has many beneficial features that can induce a variety of beneficial biological reactions such as ablation, hemostasis, growth promotion, inhibition and destruction of microorganisms. Chronic wounds treated with He-Ne laser local irradiation can relax the local blood circulation and enhance immunity, thereby accelerating fibroblast proliferation, vascular and granulation tissue regeneration, and promoting ulcer healing. High-energy red light at the wavelength of 610 ~ 770nm, light and tissue biochemical effects, promote rapid cell growth, and facilitate wound healing. Photodynamic therapy is a treatment that uses photodynamic reactions between light and photosensitizers and oxygen in tissues to produce phototoxic substances that destroy target tissues. The ability to kill microorganisms without drug resistance may be one of the most promising methods for treating chronically infected wounds. It has been reported in the literature that 26 cases of chronic ulcers caused by Pseudomonas aeruginosa were treated with photodynamic therapy. Compared with the treatment of red light alone, the bacterial count and skin lesion recovery in the skin lesions were compared after treatment. After 1.5 hours of % ALA encapsulation, the red light (630nm, 80J/cm2) irradiation showed a significant decrease in bacterial counts compared with the single red light irradiation lesions, indicating that ALA-PDT had obvious bactericidal effect, while the single red light treatment had no obvious bactericidal effect.

3.5 Wound closure vacuum drainage technology

Vaccum sealing drainage(VSD) is a simple and effective treatment for clinical application. It can create a moist wound healing environment, effectively drain the wound secretion, reduce tissue edema, increase blood perfusion at the edge of the wound, thereby promoting vascular proliferation and granulation tissue formation, and shortening recovery time.

3.6 Bioengineering technology

3.6.1 Stem cell therapy

A growing body of experimental evidence indicates that stem cells have been successfully used to treat chronic and acute wounds. It regulates the inflammatory environment, promotes blood vessel and granulation, accelerates wound healing, and has been widely accepted for treating wounds using stem cells. Mesenchymal stem cells (MSCs) derived from mesoderm have strong self-replication and multi-directional differentiation potential. Jackson et al. pointed out in an analysis report of clinical studies that there is overwhelming evidence that MSCs can accelerate wounds. Closing, in addition, its nutritional effects of treatment also accelerate the healing of wounds in diabetes and prevent the recurrence of healed ulcers.

3.6.2 Tissue engineering skin

Tissue-engineered skin has been used in the treatment of refractory ulcers for many years in foreign countries, and domestic products have been rapidly developed in recent years. Common tissue-engineered skin is human dermis and epidermal cells as seed cells, inoculated on animal collagen scaffolds, and cultured in vitro to form a substitute for human skin structure. Although it contains allogeneic cells and heterologous proteins, it may not contain immune response cells and has good bio-description without causing obvious immune response in the host. In addition, it can produce growth factors and cytokines, accelerating The ulcer heals. In a meta-analysis of tissue engineering skin treatment of diabetic foot ulcers, Teng Yongjun found that after 12 weeks of comparative study, tissue engineered skin can significantly promote the healing of refractory ulcers and reduce the chance of infection. Apligraf is a tissue engineering product that has been on the market for many years in the United States. Edmonds et al. randomized a controlled group of 71 chronic ulcers. ApLgraf was used in the treatment group and polyamide and saline were applied in the control group. After 12 weeks of treatment, the cure rate was 51.5. % and 26.3%, P = 0.049, significantly better than the control group.

4. Conclusion of chronic skin ulcers

In short, chronic skin ulcers have always been a clinically difficult problem. Multiple causes and complex wound conditions have led to the ulceration of the ulcer. In order to achieve maximum efficacy, combined treatment can usually be adopted. In addition to traditional treatments such as drugs and surgery, high-pressure oxygen, phototherapy, bioengineering and other technologies are worth trying and exploring. With the development of modern medicine, the treatment methods will continue to be enriched, but the factors of ulcer refractory are complex and diverse. Therefore, flexible application of diagnosis and treatment ideas and the development of reasonable individualized treatment programs will help patients get rid of pain more quickly.