Colon diverticula: classification
Last reviewed: 23.04.2024
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Divergent divisions are true and false. True represent the swelling of the entire intestinal wall, which contains the mucous membrane, the muscle layer and serosa. They have a wide communication with the gut and are easily emptied. Usually these are single diverticula, rarely multiple. Inflammation in them develops relatively rarely, just as not all people have appendicitis.
Pseudodiverticles are hernial-like protrusions of the mucosa between the muscle fibers of the intestinal wall. Graser (1898), and later Schreiber (1965) proposed the allocation of incomplete diverticula and complete. Incomplete diverticula, also called intramural, represent the initial stage of the formation of false diverticula. Invasion of the mucosa does not occur further than the muscle layer. At this stage, the prolapse of the mucosa can be reversible. Diverticula are small sleeves. Sometimes they have a flattened T-shaped bottom. Such diverticula are not determined radiographically. They impart a kind of saw teeth to the gut contour. However, this radiographic evidence is not specific. Emptying such diverticula is difficult. The mucous membrane in the narrow canal is easily irritated, swells, the entrance to the diverticulum is closed. Stasis of infected content in incomplete diverticula leads to chronic inflammation, often to the formation of intramural microabscesses. Inclination to inflammation is a feature of incomplete diverticula. They occur more often in groups.
Complete diverticula, or extramural, or marginal - this is a further stage in the development of diverticulum, when intussusception of the mucous membrane occurs through the entire intestinal wall. They are seen in the form of protrusions or saccate formations on the surface of the intestine and are well identified by X-ray examination. The wall of the full diverticulum consists of the mucosa, submucosa and serosa. The mucous membrane at the bottom of the diverticulum under the influence of compression of the contents gradually becomes atrophy, the muscle fibers contained in it disappear. The contractility of the diverticulum wall decreases, evacuation of the contents from it is disturbed, there is a danger of coprostasis and infection, necrosis of the diverticulum wall from pressure. The wall of the diverticulum is thin, which increases the danger of perforation and promotes the transition of inflammation to neighboring organs. These diverticula are often multiple, they can be combined with incomplete diverticula.
Localization of diverticula. The preferred localization of diverticula is the left half of the colon, primarily sigma. With generalized diverticulosis, the number of diverticula usually decreases in the oral direction. In the right divisions of the colon, including the appendix, there are often single true diverticula, which can be congenital (more often) and acquired.
More frequent lesions of the left half of the large intestine are explained by anatomical and functional peculiarities, since it is smaller in diameter, has more bends, its contents are hard and it is more often traumatized. The sigmoid colon also has a reservoir function. By regulating the progress of fecal masses, it is more often segmented than the rest of the departments, so the pressure in its cavity is higher. All this favors the appearance of diverticula.
In the rectum, which also has high motor activity, the muscular layer is more powerful than in the colon (the longitudinal muscle is not in the form of shadows, but the solid one). Diverticula in it appear rarely.
In eastern countries (Philippines, Japan, China, Hawaii), the right-sided localization of diverticulum occurs significantly more often - it accounts for 30 to 60% of cases. At the same time, the average age of patients is at least 10 years less. At the same time in the Caucasus, a left-sided bowel disease is typical for Westerners. The reason for the "Asian version" of diverticular disease is unclear.
Diverticula are single and multiple, their size varies from millet grain to cherry, less often to pigeon eggs. There are cases of giant true diverticula of the large intestine. So, Zozzi described an observation in which a diverticulum 105 cm long was found in the patient in the area of hepatic flexure.
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