Necrosis is an irreversible process of destruction and death of cells, human organs, which is caused by exposure to pathogenic bacteria. The cause of development may be: exposure to high temperatures (with a burn), chemical or infectious agents, mechanical damage. Necrosis can be coagulative (dry) or coagulative (wet). In the article, we will take a closer look at the causes of dry necrosis, as well as ways to treat it.
What is coagulative necrosis
Dry necrosis is more likely to affect organs that are rich in protein but low in fluid. These include:
- kidneys;
- adrenals;
- spleen;
- myocardium.
Death of organ cells occurs due to insufficient blood supply and oxygen enrichment as a result of thermal, chemical, mechanical, toxic damage. As a result, the dead cells dry up, and the process of mummification takes place. Dead cells are separated from living cells by a clear line.
Causes of dry necrosis
Dry necrosis occurs when:
- there was a process of violation of the blood supply to a specific area of a certainbody, resulting in a lack of oxygen and essential nutrients;
- disease developed gradually;
- affected areas of organs did not have enough fluid (fat, muscle tissue);
- pathogenic microbes were absent in the affected area of the cells.
The development of dry necrosis is more susceptible to people with strong immunity and malnutrition.
Coagulative necrosis: mechanism of development
Due to insufficient oxygenation of cells and impaired blood supply, the process of coagulation and compaction of protoplasm occurs, then the affected area dries up. Damaged parts have a toxic effect on neighboring living tissues.
The affected area has a characteristic appearance: dead cells are outlined by a clear line and have a pronounced yellow-gray or clay-yellow color. This area thickens over time. When cut, you can see that the tissues are absolutely dry, have a curdled consistency, while the pattern is fuzzy. As a result of the decay of the cell nucleus, they look like a mass of homogeneous cytoplasm. Further, with the development of necrosis and inflammation, one can notice the rejection of dead tissues. If the disease affects the auricle or bones of a person, a fistula is formed. However, the mechanism of development of coagulative necrosis is not yet fully understood.
Varieties of coagulative necrosis
Coagulative necrosis includes several types:
- Heart attack is the most common type. Developed due to ischemicillness. Does not develop in brain tissue. With a heart attack, complete regeneration of damaged tissues is possible.
- Waxy (Zenker) - develops as a result of severe infectious damage. The disease affects the muscle tissues, often leading the muscles of the thigh and the anterior abdominal wall. The development of necrosis is provoked by previous diseases, such as typhus or typhoid fever. Affected areas are gray.
- Caseous necrosis is a specific type of disease. Companion to tuberculosis, syphilis, leprosy, leprosy, Wegener's disease. With this type of necrosis, the stroma and parenchyma (fibers and cells) die. The peculiarity of this disease is that, in addition to dry areas, pasty or curdled granulomas are formed. Affected tissues are bright pink in color. Caseous necrosis is one of the most dangerous types due to the fact that it is able to "kill" huge areas.
- Fibrinoid - a disease in which the connective tissue is damaged. Necrosis develops in autoimmune diseases, such as lupus or rheumatism. The disease most severely affects the smooth muscles and fibers of the blood vessels. Fibrinoid necrosis is characterized by a change in the normal state of collagen fibers and the accumulation of necrotic material. On microscopic examination, the affected tissues look like fibrin. At the same time, dead ones have a bright pink color. Areas affected by fibrinoid necrosis contain large amounts of immunoglobulin, as well as fibrin and collagen breakdown products.
- Fatty - the disease is formed as a result of bruises andhemorrhages, as well as destruction in the tissues of the thyroid gland. Necrosis affects the peritoneum and mammary glands.
- Gangrenous - can be dry, wet, gasy. Bedsores in bedridden patients also belong to this type of necrosis. Most often, bacteria that enter the affected areas contribute to the onset of the disease.
Dry gangrene as a type of coagulative necrosis
Dry gangrene is a disease in which necrosis of the skin in contact with the external environment develops. As a rule, no microorganisms are involved in the development of the disease. Dry gangrene most often affects the extremities. Damaged tissues have a dark, almost black color and a well-defined outline. Color changes under the influence of hydrogen sulfide. This happens because hemoglobin pigments are converted into iron sulfide. Dry gangrene develops under the following conditions:
- With arterial thrombosis and atherosclerosis of the extremities.
- When the limbs are exposed to high or low temperatures (with burns or frostbite).
- When developing Raynaud's disease.
- When there are infections such as typhus.
Treatment is carried out only by surgical removal of dead tissue.
Wet gangrene
Wet gangrene is a disease that develops when a bacterial infection enters damaged tissues. The disease affects organs rich in moisture, can occur on the skin, but more often spreads to the internal organs. Wet gangrene affects the intestines (with obstruction of the arteries) and lungs (occurs as a consequence of pneumonia).
Often the disease occurs in children, since their immunity, when attached to an infection, is more susceptible to the formation of gangrene. The soft tissues of the cheeks and perineum are affected. This disease is called water cancer. The affected areas become very swollen and dark in color. There is no delimiting contour, so the disease is difficult to surgically treat, since it is difficult to determine where the affected tissues end. Gangrenous areas have a very unpleasant odor, and the disease is often fatal.
Gas gangrene and bedsores
Gas gangrene is very similar in its manifestations to wet gangrene, but the causes of development are different. This type of gangrene develops if bacteria of the Clostridium perfringens species enter the tissues affected by the beginning of necrosis and actively multiply. Bacteria in the course of their life activity emit a specific gas, which is found in the affected tissues. Mortality in this disease is very high.
Decubituses refer to one of the types of gangrene, in which the process of tissue death occurs. Diseases are most susceptible to bedridden patients, since certain parts of the body are under pressure due to prolonged immobilization and do not receive the necessary substances along with the blood. As a result, skin cells die. The area of the sacrum, heels, femoralbone.
Diagnosis of coagulative necrosis
To make a diagnosis of "coagulative necrosis", if the damage is superficial, it is enough for the doctor to take blood and a sample of damaged tissue for analysis.
If there is a suspicion of organ necrosis, a more extensive examination is carried out. For this you need:
- Take x-rays. This study is especially relevant if gas gangrene is suspected.
- Conduct a radioisotope study. It is prescribed if the x-ray did not reveal any changes (at the initial stage of the disease). A radioactive substance is introduced into the human body. If there is a necrotic change in the tissues of the organ, then it will be highlighted by a dark spot.
- Perform CT. Performed if bone involvement is suspected.
- Get an MRI. The most effective research method, as it shows even minor changes associated with impaired blood circulation.
Complications of necrosis
Necrosis is the "death" of damaged organs and tissues. Therefore, its various types, such as heart attack, necrosis of the brain, kidneys or liver, can lead to death of a person.
Also, extensive necrosis can lead to severe complications, for example, with multiple bedsores, a dangerous infection can join. Dead tissues release their decay products into the body, thus leading to toxic complications. Even milder forms of the disease can lead tounpleasant consequences, such as scarring in the myocardium or the formation of a cyst in the brain.
Treatment of necrosis
Treatment of necrosis begins with determining its type, assessing the damage caused by it and identifying concomitant diseases.
When diagnosing "dry skin necrosis", local treatment is prescribed:
- Treatment of affected areas with brilliant green.
- Cleansing the surface of the skin with antiseptics.
- Applying a bandage with Chlorhexidine solution.
The patient is prescribed medical and surgical treatment in order to restore normal blood circulation, including in the affected areas. To remove dead cells, a surgical operation is most often performed to resect the affected areas. Amputation of limbs is performed to protect he althy areas from the spread of the disease.
Dry necrosis of internal organs is treated with anti-inflammatory drugs, vasodilators, chondroprotectors. In case of failure of therapy, surgical treatment is carried out.
