Wound healing is a dynamic process consisting of three overlapping stages: inflammation, granulation tissue formation, and skin maturation or remodeling. The contribution of each of these stages to the healing process depends on the depth of the injury.
Shallow wounds. Shallow wounds involve the epidermis and upper layers of the dermis. Skin appendages (hair follicles, sweat and sebaceous glands) are retained. Thrombosis, inflammation and formation of granulation tissue are slightly expressed. The healing of shallow wounds is based on epithelization due to the preserved skin appendages and marginal epidermis, which ultimately leads to complete and rapid restoration of the skin with invisible scars or without them at all. Hyper- or hypopigmentation may remain at the wound site.
Deep wounds. A necessary step in the healing of deep wounds is the formation of a blood clot to stop bleeding from relatively large vessels in the deep layers of the dermis. Inflammation and granulation tissue formation are important steps in healing, along with skin tension, which brings wound edges closer together to promote epithelialization. Since the skin appendages are damaged, epithelization of deep wounds occurs only due to the marginal epidermis and the lost tissue is replaced by scar tissue.
To understand the pathogenesis of scarring, it is necessary to know how wound healing occurs normally.
Stage of inflammation
The first thing that happens when a wound heals is the formation of a hematoma. This ensures the cessation of bleeding from damaged vessels and the creation of a barrier that prevents microorganisms from entering the wound. The thrombus is a temporary matrix into which inflammatory cells migrate. When platelets are destroyed, many growth factors are released, incl. transforming growth factor (TGF-β1), epidermal growth factor, insulin-like growth factor type 1 (IGF-1) and platelet-derived growth factor, which attract inflammatory cells, promote extracellular matrix synthesis and vascular sprouting.
A number of other signaling molecules, such as fibrinolysis products, attract neutrophils and monocytes to the wound. These cells come from the bloodstream by diapedesis through the endothelium of the capillaries adjacent to the wound. The main function of neutrophils is phagocytosis and destruction of microorganisms inside cells. In addition, neutrophils produce inflammatory mediators, under the influence of which keratinocytes and macrophages can be activated already at this stage of healing.
At the end of the acute inflammatory reaction (after 1-2 days), monocytes that migrated from the bloodstream become macrophages and destroy remaining microorganisms and dead cells. These macrophages also serve as a source of growth factors and inflammatory mediators, in particular platelet-derived growth factor, which attract fibroblasts to the site of injury.
Proliferation stage
Fresh granulation tissue is very rich in blood vessels and cells. Since epithelization alone is not enough to heal deep wounds, proliferation of fibroblasts in the areas of the dermis adjacent to the wound begins already in its first stages. Fibroblasts migrate into the wound, lining an extracellular matrix consisting of fibrin, fibronectin, vitronectin and glycosaminoglycans. Fresh granulation tissue has a high ratio of type III collagen to type I collagen.
In response to the action of growth factors in the wound, proliferation of keratinocytes and fibroblasts begins. As granulations form and excess collagen matrix appears, the number of cells decreases through apoptosis. What triggers apoptosis is unknown. Under the influence of substances that stimulate angiogenesis, which serve as inducers of endothelial growth factor, TGF-β1, angiotropin and thrombospondin, vessels begin to grow into the extracellular matrix.
Myofibroblasts help bring the edges of large wounds closer together, which reduces the amount of granulation tissue required to fill the wound cavity and reduces the area of epithelialization. Due to the contractile proteins actin and desmin, fibroblasts also help bring the edges of the wound closer together. The mechanical tension that occurs after the edges of the wound are closed signals the cessation of tension.
Epithelization begins within a few hours after the wound appears. Migrating keratinocytes activate tissue plasminogen activator and urokinase and increase the number of urokinase receptors, which in turn promotes fibrinolysis, an important step necessary for keratinocyte migration. To pass through the temporary matrix formed by the thrombus, keratinocytes form additional fibronectin and collagen receptors. Migration of keratinocytes and epithelization is facilitated by the tension of the wound edges.
Stage of maturation and restructuring (complete healing)
At the restructuring stage, excess collagen and temporary matrix are removed by tissue enzymes, and inflammatory cells leave the wound. When the scar matures, a balance arises between the processes of destruction of the temporary matrix and collagen synthesis.
On the one hand, fibroblasts synthesize collagen, contractile proteins and extracellular matrix, on the other hand, fibroblasts, mast cells, endothelial cells and macrophages secrete a number of enzymes (matrix metalloproteinases) necessary for destruction and restructuring. The balance between these proteinases and their tissue inhibitors plays an important role in the repair of damaged tissues.
Interferons produced by T-lymphocytes (interferon-γ), leukocytes (interferon-α) and fibroblasts (interferon-β) prevent the development of fibrosis and suppress the synthesis of collagen and fibronectin by fibroblasts.
The restructuring process lasts from 6 to 12 months, but can last for years. The strength and elasticity of a scar is usually only 70-80% of that of intact skin, making scars more susceptible to repeated trauma.
Factors influencing wound healing and scar formation
Age. Unlike adults, wounds on fetal skin heal quickly and without scarring. The mechanism of scarless healing is unclear, but it is known that inflammation is mild, a large amount of hyaluronic acid is present in the wound contents, and collagen fibers are arranged in a certain order.
The fetal body is significantly different from the adult body. The main difference is in the characteristics of tissue oxygenation: the oxygen content in them remains relatively low throughout the entire period intrauterine development. Inflammation in fetal wounds is mild due to neutropenia. As the immune system In the fetus, the inflammatory reaction becomes more pronounced, and scars may form at the site of the wounds.
The fetal skin is constantly bathed in warm, sterile amniotic fluid, which contains many growth factors. But this alone does not explain scarless healing. In experiments on fetal lambs, isolating the wound from amniotic fluid using a silicone dressing did not prevent scarless healing; on the other hand, adult skin grafted onto the fetus healed with scar formation, despite contact with amniotic fluid.
The high content of hyaluronic acid in the extracellular matrix increases cell mobility, enhances their proliferation, and hence the restoration of the damaged area. This allows us to consider hyaluronic acid as the main factor in scar-free healing. A glycoprotein absent in adult wounds was found in fetal wounds. This glycoprotein stimulates the synthesis of hyaluronic acid. In addition, it is assumed that its long-term presence in fruit wounds promotes the orderly deposition of collagen during their healing. When treated with hyaluronic acid, the perforated tympanic membrane of rats not only recovered faster than in control animals, but there was also less scar tissue at the site of damage, and the collagen fibers were arranged in an orderly manner.
Rapid epithelization of wounds in the fetus may be due to the early accumulation of fibronectin and tenascin in the wound contents. Fetal and adult fibroblasts are different. Fetal fibroblasts at the beginning of fetal development produce more collagen types III and IV, while adult fibroblasts produce mainly type I collagen. In addition, fetal fibroblasts are capable of simultaneously proliferating and synthesizing collagen, while in the adult fibroblast proliferation precedes collagen synthesis. Thus, in adults, during wound healing, the appearance of collagen deposits is somewhat delayed, which leads to the formation of scars. Skin tension does not play a role in scarless healing, because Fetal wounds are virtually devoid of myofibroblasts.
Inflammation plays a key role in the restoration of damaged tissue and scar formation. In the fetus, in the absence of inflammation, wounds heal without scars. Wound healing is thought to decline with age. As the body ages, its inflammatory response decreases due to a weakening of the function of macrophages and T-lymphocytes, loss of reactivity and mobility of fibroblasts, a decrease in the number and other distribution of growth factors and their receptors, incl. TGF-β receptor. All this may explain the difference in the speed and quality of wound healing at different ages.
Although wounds in older people heal more slowly, their scar quality improves, which may be due to a decrease in the level of transformative growth factor(TGF-β) in damaged skin. It is also possible that fibroblasts of the fetal subtype appear in the wounds of elderly people, which leads to wound healing as in the fetus. Decreased levels of hormones, particularly estrogen, during menopause can also contribute to slower wound healing and reduced scarring.
Estrogens. In vitro studies have shown that sex hormones influence important stages of wound healing such as inflammation and proliferation. Estrogens regulate the production of TGF-β isoforms and the formation of their receptors, which plays a significant role in the development of fibrosis and scar formation. U healthy women In postmenopause, wound healing slows down, but scar quality increases, which is associated with a decrease in TGF-β1 levels in wounds.
Against the background of hormone replacement therapy, wounds begin to heal faster, which suggests direct or indirect regulation of healing by sex hormones. Studies have shown that in menopausal women, hormone replacement therapy for 3 months. accelerates epithelization and collagen deposition in wounds.
The presence of estrogen receptors on the surface of fibroblasts indicates the possibility of direct regulation of the function of these cells by estrogens. In addition, estrogens increase TFP-β1 levels in vitro.
These data suggest the involvement of estrogens in the regulation of skin fibroblast production and TGF-β1. Finally, systemic administration of estrogen antagonists has been noted to inhibit wound healing in humans. A preliminary study of scars in women who received wounds while receiving the estrogen antagonist tamoxifen showed that these scars were best quality than the scars left after healing of the same wounds in women who were not given tamoxifen.
Heredity. There is evidence of the existence hereditary factor, which affects the wound healing process by activating abnormal (pathological) scarring, which leads to the appearance of hypertrophic and keloid scars. Both autosomal dominant and autosomal recessive patterns of inheritance of keloid scars have been reported. Often, keloid scars are also observed in relatives of the patient with similar scars. In addition, the prevalence of keloid scars is significantly higher among dark-skinned populations, reaching 4.5–16% in Africans and Hispanics. The frequency of keloid scars is high in carriers of HLA-β14 and HLA-BW16, in people with blood type A (II) and those suffering from Rubinstein-Taybi syndrome.
The wound process, or healing process, is the changes occurring in the wound and the associated reactions of the whole organism.
General reactions of the body have two stages:
- the first lasts for 1-4 days after the injury. During this period, vital processes intensify - increased body temperature, weakness, decreased performance. The blood test shows leukocytosis with a shift to the left, protein appears in the urine. With significant blood loss, the number of red blood cells, hemoglobin, and hematocrit decreases;
- the second begins on the 4-5th day, when the signs of inflammation and intoxication stop, the pain subsides, the body temperature decreases, and the lab tests blood, urine.
The wound process takes place in a certain sequence and has three phases:
- Phase I - inflammation phase (days 1-5);
- Phase II - regeneration phase (6-14th day);
- Phase III - the phase of scarring and epithelization (from 15 days to 6 months).
Inflammatory phase has two periods: vascular changes and cleansing of the wound from necrotic tissue.
- The period of vascular changes - as a result of damage to blood vessels and complex biochemical processes in the damaged area, microcirculation is disrupted, exudation of plasma and lymph occurs, and formed elements (leukocytes, lymphocytes, macrophages) emerge from the vascular bed. Edema develops, leukocyte infiltration of tissues occurs, i.e., conditions are created for cleansing the wound.
- The period of cleansing the wound from necrotic tissue is necrolysis. In the tissues surrounding the wound, formed elements appear that phagocytize necrotic masses, secrete proteolytic enzymes and remove toxins, protein breakdown products and microbes from the wound with inflammatory exudate. As a result, the wound is cleared of necrotic tissue, the symptoms of inflammation are relieved, and the next phase of the wound process begins.
Regeneration phase begins on the 6th day after injury and is characterized by the development of restorative regenerative processes. In the wound there is an intensive growth of new blood vessels and lymphatic vessels, blood circulation improves, hypoxia decreases, and gradually, by the 14th day, the inflammatory reaction subsides. New vessels are formed in the wound, granulation tissue matures, which helps eliminate the tissue defect.
Scarring and epithelization phase starts on the 15th day. During this period, gradually, starting from the edges of the wound, the defect is closed by the epithelium, at the same time the connective tissue matures and a scar is formed. Its final formation ends by the 6th month or later, depending on the structure of the tissue. In tissues of a simple structure (covering epithelium, connective tissue), scarring occurs faster than in tissues of a complex structure (nervous, parenchymal, muscle).
The three-phase wound healing pattern is universal for all types of wounds. However, there are factors that influence the speed of the wound process:
- patient's age;
- fatness and body weight;
- secondary infection;
- intensity of blood supply in the damaged area;
- state of water and electrolyte balance;
- state of immunity;
- concomitant chronic diseases;
- taking anti-inflammatory drugs.
Due to the anatomical and physiological characteristics of the body in childhood wound healing processes proceed faster and more favorably than in older people.
In weakened, dehydrated patients with severe cachexia, wound healing is difficult, since normal course wound process requires plastic material and energy reserves. Regeneration processes are slowed down in obese patients with excess subcutaneous tissue, since it has poor blood supply.
If the wound suppurates, the healing period is prolonged and the healing process worsens.
In patients with weakened immunity (previous infectious diseases, HIV-infected), the phases of the wound process are significantly slowed down.
The state of the blood supply in the injury area affects the rate of healing. Thus, wounds in the face, head, and hands heal much faster than, for example, in the feet.
Chronic diseases of the cardiovascular and respiratory systems influence provision nutrients local tissues and the body as a whole. They disrupt the production of proteins, carbohydrates, and the normal supply of organs and tissues with oxygen, which leads to metabolic disorders of the entire body, and this slows down reparative processes.
In people suffering diabetes mellitus, circulatory disorders are observed, carbohydrate metabolism suffers, immunity is impaired - all this has an impact bad influence on wound healing, slows down the treatment of the wound process. Taking steroidal and non-steroidal anti-inflammatory drugs also interferes with the rate of wound healing.
V. Dmitrieva, A. Koshelev, A. Teplova
"The process of wound healing" and other articles from the section
Early healing period(the first 12 hours after the wound) is characterized mainly by the presence of a blood clot on the surface of the wound and initial reactive phenomena inflammatory in nature (leukocyte infiltrate around the vessels, in the intercellular spaces, in the fibrin clot; round cell infiltration of mononuclear cellular elements of the perivascular spaces and wound edges).
Clinically, the inflammatory reaction is not yet expressed during this period.
Degenerative-inflammatory period(approximately 5 - 8 days) is characterized by necrotic changes in damaged tissues, inflammatory swelling of the wound edges, active phagocytosis, and the formation of purulent exudate. In parallel with this, the wound is gradually cleansed of the products of degeneration and necrosis, a decrease in the polymorphonuclear leukocyte infiltrate and the proliferation of large mononuclear cells (polyblasts).
Clinically, this period is characterized by the development of a picture of inflammation with all its typical manifestations: pain, hyperemia, lymphangitis and regional lymphadenitis, local and general increase temperature, purulent discharge.
Regenerative period of wound healing(approximate duration - 30 days) is divided into 3 phases.
First phase characterized by the development of newly formed vessels, the release of the wound from necrotic tissue, and the formation of granulation tissue. Phagocytic activity in the wound and blood leukocytosis increase. The number of microorganisms in the wound decreases, their virulence decreases. Clinically, purulent discharge from the wound is reduced and also normalized general state sick.
Second phase characterized by further attenuation of the inflammatory reaction and the development of regenerative processes: granulation tissue maturing, filling the wound, fibrous connective tissue is formed. The number of bacteria in the wound progressively decreases, the number of leukocytes decreases, and differentiated cells such as fibroblasts appear. Clinically, in this phase, swelling of the wound edges is eliminated and epithelization begins.
Third phase(final) is accompanied by filling the entire wound cavity with a regenerate consisting of young connective tissue. Clinically, a slight purulent discharge is observed; a rapid decrease in the size of the wound occurs due to tightening of the edges and epithelization of the wound defect.
It should be noted that the division of wound healing processes into certain periods is largely arbitrary, since they do not strictly follow one another, but develop in parallel. However, at different stages they prevail certain processes. The speed and completeness of healing of purulent wounds is influenced by local conditions in the purulent focus and the general condition of the body, which may be favorable or unfavorable.
From local conditions that promote accelerated wound healing, we can call good blood supply, preserved innervation. Thus, wounds on the face and scalp heal faster due to good blood supply (however, the purulent process is more dangerous due to the structural features of the subcutaneous tissue and venous collaterals). On the contrary, local factors such as crushing and tissue separation, the presence of pockets, soft tissue sequestration, foreign bodies, nearby purulent foci, as well as additional infection of the wound slow down wound healing.
The general condition of the child’s body is determined by the normal function of its organs and systems, as well as age. In well-developed, physically strong children, wound healing occurs faster. Acute infectious diseases and chronic debilitating diseases (hypotrophy, rickets, diabetes, vitamin deficiency, etc.) slow down reparative processes. In infants, and especially in newborns, the healing processes become protracted, which is explained by reduced resistance to infection and a shortage of plastic material.
Treatment. In an outpatient setting, minor wounds are treated, which, as a rule, are not accompanied by general symptoms.
Principles of treatment purulent wound are in accordance with the doctrine of wound healing processes. Therapeutic measures should contribute to the rapid progress of the natural process, therefore, when constructing a treatment plan, be sure to take into account the period of the wound process and provide for local and general measures that improve the conditions of regeneration. These activities are somewhat different different periods wound healing.
IN early period treatment wound wounds, in essence, comes down to the prevention of suppuration.
In the degenerative-inflammatory period When active microbial activity and melting of dead cells and tissues predominate, it is important to suppress the activity of microorganisms and promote rapid wound cleansing.
These goals are met by:
1) antibacterial therapy and increasing the body’s defenses;
2) increased hyperemia and exudation in the wound, as well as the creation of reliable outflow of wound contents;
3) rest of the diseased organ and careful treatment of tissues.
Among antibacterial agents Antibiotics are the most widely used. Due to the emergence of penicillin-resistant forms of microbes, preference is given to broad-spectrum antibiotics, the choice of which is guided by the sensitivity of the flora isolated from the wound. Antibiotics are used in the form of irrigation or pricking the affected surface with a solution of one or another drug with novocaine. Other antibacterial methods include the Vishnevsky method, which is widely known to surgeons and is based on the use of an ointment dressing and a novocaine block. When a wound becomes infected with Pseudomonas aeruginosa, a 3% solution of boric acid is used. Along with antibacterial therapy, attention is paid to increasing the body's defenses.
An important factor accelerating wound cleansing, is an increase, intensification of the current of the wound contents. This is achieved by using bandages with hypertonic solution sodium chloride (5 - 10%), magnesium sulfate (25%), grape sugar (20 - 25%). By increasing hyperemia and exudation into the wound, hypertonic dressings, due to the osmotic effect, simultaneously promote the flow of wound discharge into the dressing. Unimpeded evacuation of exudate is achieved by drainage. For children, we usually use thin strips of rubber gloves. The use of a high frequency electric field (UHF) promotes the rejection of necrotic tissue and accelerates the resorption of infiltrate. The procedures are carried out daily until the wound is cleansed in oligothermic and low-thermal doses for 5 - 10 minutes, 7 - 8 times in total.
Rest is created for the diseased organ by immobilization. Frequent daily dressings should also not be performed, unless the interests of the method require it (for example, the presence of drainage that needs to be monitored or removed).
During the regenerative period, when the inflammatory reaction subsides, the virulence of the infection weakens, granulations develop, and the fight against the infectious agent is no longer as important as in the previous period.
Treatment measures should be aimed at creating optimal conditions for recovery processes. This goal is met by:
1) protection of the wound from damage;
2) the use of means that enhance the regeneration process.
The granulations that fill the wound serve as a protective barrier that prevents the penetration of microbes into the internal environment of the body, and the wound discharge has bactericidal properties. However, the cells and vessels of granulation tissue are easily vulnerable. A slight mechanical or chemical effect damages them and opens the entrance gates to infection. Therefore, the wound is protected with a bandage, and the damaged organ is immobilized (the latter mainly applies to the hand and foot). During the regenerative period, you cannot use hypertonic and antiseptic dressings, which also damage granulations. We attach great importance to infrequent dressing changes (once every 4-5 days).
To speed up and stimulate healing processes many remedies have been proposed. We will mention only those that find the greatest application in outpatient treatment infected wound. In the first phase of the regenerative period, very valuable means that have a beneficial effect on healing are Vishnevsky ointment, Shostakovsky balm, blood products (whole blood, plasma, serum), as well as ultraviolet irradiation, which stimulates the growth of granulations. During the treatment process, it is necessary to use stimulants wisely, because excessive growth of granulations delays the epithelization of the wound surface. Excess granulation is removed by treating the surface with a 5% solution of silver nitrate (lapis) or mechanically.
When normal granulation tissue appears in the second and third phases of the regenerative period, dressings with indifferent ointment are the best ( fish fat, Vaseline oil, etc.). When epithelization is delayed, wound healing is accelerated by bringing its edges closer together with a strip of adhesive plaster.
In addition to the methods listed above, the complex of treatment measures can also include surgical methods(bringing the edges of the wound together with sutures). In the degenerative-inflammatory period, sutures are contraindicated, but after cleansing the wound and eliminating the inflammatory process, indications for the application of secondary sutures may arise (in particular, after suppuration of the surgical wound). A suture placed on a granulating wound with movable, unfixed edges without scars (8 to 10 days after injury) is called early secondary seam, and applied to a granulating wound with the development of scar tissue after excision of its edges and bottom (after 20 or more days) - with a late secondary suture. An early secondary suture is most effective.
In children, wounds larger than 5x5 cm, localized on the head, in some cases they are not prone to self-healing. In such cases, skin grafting is used (in the hospital).
In newborns and early infants, head wounds (pincer wounds, after vacuum extraction of the fetus, incision with an infected cephalhematoma) are often complicated by contact osteomyelitis of the calvarial bones. During the treatment of such wounds, especially with prolonged healing, X-ray monitoring is necessary. The patient is promptly sent to the hospital. After osteomyelitis, large defects sometimes remain in the cranial vault, which pose a threat to the child’s life when he begins to walk and hits his head. Protective bandages are required.
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Phases of wound healing and scar formation
Scars occur due to surgical treatment, any injury, as well as after thermal, chemical and radiation damage to the skin, sometimes after infections. They make up serious problem for surgeons and patients, as they remain for life and create significant cosmetic defects and sometimes cause functional impairment in the form of limited joint mobility.
The wound process is a wound healing process that begins immediately after tissue damage and includes three main phases: inflammatory, the phase of granulation tissue formation, the phase of epithelization and scar organization.
1. Inflammatory (or exudative) phase.
It begins from the moment of injury and lasts about 5-7 days.
The body's primary response to injury is to stop bleeding. During the first hours after injury, they are biologically released from damaged tissues. active substances, which cause vasoconstriction and activation of blood clotting factors. A fresh blood clot stops bleeding and creates conditions for further wound healing. After the bleeding stops, an inflammatory reaction develops. At this stage, a cascade of complex cellular reactions occurs, aimed at implementing the mechanism of inflammation. At the same time, platelets release cytokines (factors of intercellular interactions), which attract leukocytes and fibroblasts to the wound, and also stimulate cell division and collagen synthesis. Leukocytes accumulated in the wound phagocytose foreign bodies and bacteria. After 24 hours, macrophages appear in the wound. They not only carry out phagocytosis, but also secrete chemotactic and growth factors. Growth factors stimulate the development of skin epithelium and vascular endothelium and collagen synthesis. During this phase, the wound defect is filled with new tissue, which plays an important role in wound healing. The so-called granulation tissue develops, in the construction of which fibroblasts play a decisive role. Most often, at the end of this phase, the sutures are removed from the postoperative wound (on days 5-7). If there is tension in the suture area, it may come apart, since the edges of the wound are connected by granulation tissue and not by scar. To avoid this, tension should be minimal or eliminated.
Type of wound on the first day after surgery.
2. Proliferation (phase of formation of granulation tissue)
If the course of the wound process is favorable, this phase begins on the 7th day and lasts on average up to 4 weeks. During this phase, the wound defect continues to be filled with granulation tissue, in the construction of which fibroblasts play a decisive role. They are responsible for both the production of collagen and the basic substance of the extracellular space. Subsequently, granulation tissue matures, which consists of connective tissue, new sprouting capillaries and inflammatory cells. For vascular growth and collagen maturation, it is necessary to have cytokines in the wound, a sufficient content of oxygen, zinc, iron, and vitamin C. When the granulation lining is ready, epithelial cells settle on it and close the wound. At the end of this stage, the edges of the wound are already connected by a young, fragile scar, which still remains relatively easily extensible and clearly visible due to large quantity vessels contained in it.
The scar at this time has a bright red color.
3. Formation and organization of the scar.
This phase begins around the 4th week and lasts about 1 year. Starting from the 4th week, the number of cellular elements and vessels in the scar tissue decreases significantly. There is a transformation of a brighter and more noticeable scar into a less bright and therefore less noticeable scar. The wound is finally filled with connective tissue and epithelium. Collagen growth continues: the primary delicate collagen is replaced by a rougher and stronger one. As a result, a scar is formed, the strength of which is 70–80% of the strength of the skin.
At the end of this phase, due to the contraction of smooth muscle cells, the edges of the wound are brought closer together.
A wound implies an injury in which the skin, muscles, tendons, internal organs, bones. Usually healing occurs in several stages, but not everyone knows what wound granulation is.
The wound healing process includes the stages of inflammation, granulation and epithelialization. In addition, healing can be with primary and secondary intention, as well as under the scab. How quickly the victim will recover depends on how complex the injury is and how all the phases proceed.
Stages of wound healing
When healing, any wound goes through several stages:
- Inflammation. The body's first reaction to a wound is to produce substances that clot the blood. Blood clots form, blocking the blood vessels. They prevent the development of severe bleeding. Next, cellular reactions occur, leading to an inflammatory process, new tissue begins to grow - granulation, which is impossible without the participation of fibroblasts. In cases where treatment of a wound requires sutures, they are removed after a week, but if there is tension under the suture, this can lead to divergence of the edges of the wound. This happens because a scar has formed at the edges of the wound, not granulation. The inflammatory stage lasts on average 5-7 days.
- Granulation wounds. If the healing process is favorable, a week after the wound the wound granulation stage begins. Over the course of a month, the damaged area continues to be filled with maturing granulation tissue, which includes inflammatory cells, connective tissue and newly formed vessels. Successful granulation is impossible without cytokines and sufficient oxygen. Toward the end of this phase, new epithelial cells grow on the granulation tissue, and the edges of the wound are connected by a bright red scar.
Granulation tissue has different kind depending on the stage of its development. Normal tissue initially looks like soft-grained tissue, covered with a cloudy, gray-greenish coating, is juicy, rich in thin-walled vessels, which is why it bleeds easily. In later periods, the tissue becomes paler, denser, the granularity disappears, turning into a whitish dense scar.
Granulation tissue consists of six layers that gradually transform into each other:
- superficial leukocyte-necrotic layer
- superficial layer of vascular loops
- layer of vertical vessels
- maturing layer
- layer of horizontal fibroblasts
- fibrous layer
- Epithelialization. This stage of healing begins immediately after granulation has completed. This phase lasts for almost a year. Epithelium and connective tissue completely fill the damaged space. The scar becomes lighter because there are much fewer vessels in it than initially. As a result, the healed wound becomes covered with a scar, the strength of which is approximately 85% compared to healthy skin.
All these stages of wound healing are highly individual, their duration depends on many factors, including the general condition of the patient and care of the injury.
The role of the granulation stage
Leukocytes will play an important role in wound granulation.
So, wound granulation is a complex process in which the following types of cells take part:
- leukocytes;
- mast cells;
- plasmacytes;
- histiocytes;
- fibroblasts.
A special role is played by fibroblasts, which supply collagen after granulation reaches the edges of the wound. In the presence of extensive hematomas, with a large accumulation of exudate or necrotization of tissue in the area of the wound, the process of fibroblast movement to the edges of the damage is slowed down, which increases t the time necessary for healing.
Important! The most pronounced fibroblast activity is observed on the 6th day after the formation of the damage. And the granulation process itself continues for a month.
Granulations are temporary tissue, which, after performing its function, undergoes regression and is replaced by scar tissue. The morphological basis of granulation is the globules of newly formed vessels. The growing tissue in the process of healing damage envelops these vessels, increasing in volume. Externally, granulation looks like delicate pink fabric.
Granulations formed during the healing process also perform a sanitary function, separating non-viable tissues. Such ischemic tissue areas, as the wound heals, self-regulate by lysis. When treating a wound surgically, non-viable tissue is removed mechanically.
Wound care during the early stages of healing
The optimal solution for speedy restoration of damaged tissue is the regular use of dressings. Disinfection here is carried out with solutions of potassium permanganate and hydrogen peroxide. These substances are applied warm to a gauze swab. Next, the wound is carefully soaked, avoiding touching the wound with your hands - this can lead to the development of infections.
Treatment of injured areas in the granulation phase
Granulation tissue has a delicate, loose structure. It can be easily damaged by carelessly touching it or carelessly changing the bandage. When treating a wound, you should be as careful as possible.
It is not allowed to wipe the surface of the damaged area with cotton pads or swabs.
It is only permissible to irrigate the wound with warm bactericidal solutions.
There are several types of treatment for injured tissue:
- Physiotherapeutic;
- Medication;
- Treatment at home;
When choosing a treatment method, it is necessary to take into account the nature of the wound, as well as the characteristics of its healing.
Physiotherapeutic method of treatment
Among the specific methods of accelerating regeneration, the following method should be highlighted: ultraviolet irradiation. When used, the surface of the damaged area is cleansed of pathogenic microflora, and regeneration processes are significantly accelerated. This method will be especially relevant for slowly forming, flaccid granulating tissue.
Indications for the use of irradiation:
- Wound infection;
- Copious purulent discharge;
- Weakened immunity and, as a result, disruption of repair mechanisms;
However, other treatment methods are also used to speed up the healing of the damage. Most often they resort to medicinal methods of treating the surface of the wound.
Use of drugs at the granulation stage
Correctly selected medicine promotes faster epithelization of the wound. As a rule, for hypergranulation, doctors recommend using gel forms of drugs. Whereas if the surface of the damaged area dries too quickly, ointments are used.
Basic medicines, used at the granulation stage
One of the most popular drugs prescribed at this stage is Solcoseryl. Granulation of sutures, healing of damaged areas after burns and other injuries skin accompanied by the appearance of unaesthetic scars. Solcoseryl promotes the formation of more uniform connective tissue, which looks much more natural.
Home treatment of wounds in the granulation phase
In the presence of a simple injury, in which only the superficial outer layers of the epithelium are affected, you can resort to restoration folk methods treatment. Good decision Here is the application of gauze bandages soaked in St. John's wort oil.
The presented method promotes the speedy completion of the granulation phase and active tissue renewal. To prepare the above remedy, it is enough to take approximately 300 ml of herbal refined oil and about 30-40 grams of dried St. John's wort. After mixing the ingredients, the composition should be boiled over low heat for about an hour. The cooled mass must be filtered through gauze. It can then be used to apply bandages.
Wounds at the granulation stage can also be healed using pine resin. The latter is taken in pure form, rinsed with water and, if necessary, softened with low heat. After such preparation, the substance is applied to the damaged area of tissue and fixed with a bandage.
Options for further development of the granulation stage
If the first and second stages of wound healing have passed without complications, then gradually the damaged area is completely covered with dense scar tissue and the regeneration process is successfully completed.
However, sometimes tissue repair mechanisms fail. For example, necrosis occurs in the areas adjacent to the wound.
This condition is extremely dangerous for the patient and requires immediate surgical intervention.
A necroectomy is performed - an operation to remove dead tissue. If the wound is infected with pathogenic microflora, the healing process may take a long time. Antibiotics are used to restore normal tissue regeneration .
The granulation stage of healing of a damaged area is a complex adaptation mechanism aimed at quickly separating the internal environment of the body from unfavorable external influences. It ensures the formation of new layers of tissue to replace damaged ones. Thanks to the granulation stage, the trophism of the injured area is restored and the protection of other, deeper tissues is ensured.
Surgical intervention
When granulation processes are delayed, deep wound tracts may form, in which there is an accumulation of purulent leaks. In such cases, it is difficult to clean the wound due to the use of ointments and gels. Elimination of unpleasant complications most often occurs through surgery. In this case, the specialist makes an incision, removes purulent accumulations, disinfects the wound, and then applies counter-apertures.
Finally
So we figured it out, wound granulation - what is it? As practice shows, one of the determining conditions for accelerating the healing process is differentiated treatment. The correct selection is also important medications. All this contributes to the rapid granulation of the damaged area and the formation of new, healthy tissue.
