From Big Medical Encyclopedia

MEKKELYA DIVERTICULUM ( J. F. Meckel junior , it is mute. the anatomist, 1781 — 1833) — the congenital anomaly caused by incomplete involution of a vitelloduct and which is shown protrusion of an ileal gut. It is described by I. Mekkel Jr. in 1809.

The embryo of the person on 1 month of development receives food from the vitellicle connected with an average gut vitelline, or umbilical and intestinal, a channel (ductus omphaloentericus). Then vitelline food is gradually replaced with food from blood of mother, and the vitelloduct undergoes involution and by the end of the 3rd month completely resolves. At 2 — 3% of people the vitelloduct is not exposed to involution owing to what there are such anomalies as a granuloma of a navel, incomplete fistula of a navel, full umbilical and intestinal fistula, an enteroteratoma of a navel, an enterokistom, an umbilical and intestinal sheaf and a diverticulum of an ileal gut (Mekkel's diverticulum).

The m of proceeds from an ileal gut on average at distance of 60 cm from an ileocecal corner (this distance fluctuates from 20 cm at newborns to 1,5 m at adults). Length of a diverticulum is 4 — 6 cm. The longest diverticulum described Mack-McMurich made 104 cm.

Diameter of a diverticulum can reach width of an ileal gut.

The m of is located at antimesenteric edge of an ileal gut, in some cases — on its sidewall. In most cases the diverticulum freely hangs down in an abdominal cavity, sometimes is attached by top to an umbilical ring, a mesentery of intestines, a bladder or to other bodies that is the contributing factor to development of impassability of intestines.

Fig. 1. The diagrammatic representation of the pathological processes caused by Mekkel's diverticulum: and — full pupochnokishechny fistula (slit): 1 — an umbilical opening of fistula, 2 — umbilical and intestinal fistula, 3 — an ileal gut, 4 — a mesentery, 5 — a front abdominal wall; — a diverticulitis: 1 — the inflamed diverticulum, 2 — an ileal gut; in — the bleeding ulcer (1) of a diverticulum (a partial slit); — torsion and a necrosis of a diverticulum: 1 — the overwound edematous diverticulum; d — invagination of a diverticulum (a slit of an ileal gut): 1 — a caecum, 2 — an ileal gut, 3 — the head of an intussusceptum including the site of an ileal gut with a diverticulum; e — strangulation of a small bowel: 1 — a diverticulum in the form of a tyazh, 2 — the restrained loop of an ileal gut, 3 — the normal site of a gut.

This anomaly clinically is not shown, however at 20 — 25% of people with this anomaly acute surgical diseases of abdominal organs are observed. Patol, processes develop in M. at children's age more often though can arise also in an extreme old age. Some patol, the processes connected with M.'s presence by are given in the figure 1.

An inflammation — one of frequent diseases of M. of. The mechanism of its emergence is similar to a pathogeny of acute appendicitis (see). Distinguish catarral, phlegmonous, gangrenous and perforative forms of a diverticulitis. M.'s inflammation of usually simulates a picture of an acute appendicitis. Therefore at expressed a wedge, manifestations or detection of an exudate in an abdominal cavity against the background of minor changes of a worm-shaped shoot it is necessary to make audit of an ileal gut throughout not less than 1 m for an exception of a diverticulitis. Non-compliance with this situation can lead to emergence of complications and need of relaparotomy. It should be noted, as detection during operation of the changed worm-shaped shoot not always excludes patol, process in M.

The diverticulitis can proceed and chronically, reminding a picture hron, appendicitis.

Acute Impassability of intestines (see) in 3 — 5% of cases there is the caused M. which can be invaginated, restrained or create conditions for development of strangulyatsionny or obturatsionny impassability. The wedge, a picture of this form of Ilheus develops more slowly, than manifestations of other its forms, and patients come to later terms of a disease.

Hron, impassability of intestines can develop as a result of the commissures formed owing to hron, a diverticulitis.

In most cases the structure of a wall of M. of is similar to a structure of a wall of an ileal gut (see. Intestines, anatomy ). In 10 — 20% of cases in her mucous membrane there are inclusions of a geterotopirovanny mucous membrane of other departments went. - kish. path or exocrine part (acinus) of a pancreas. In these cases the geterotopirovainy mucous membrane of a stomach excretes salt to - that and pepsin, and exocrine pankreotsita — the proteolytic enzymes having the corroding effect on an epithelium and leading to formation of a round ulcer of a diverticulum. The ulcer arises more often at the age of 2 — 5 years. Its main symptom — sudden emergence of a bloody chair in the child who was before quite healthy. The first excrements of usually dark color, in the subsequent dark blood without clots and slime appears. Unlike gastrointestinal bleeding (see) another origins at M. does not happen a hematemesis. As a rule, bleeding happens plentiful and is followed by bystry reduction of amount of hemoglobin and number of erythrocytes (to 2 million and below). At the same time pallor of integuments, tachycardia, and sometimes and a collapse with a loss of consciousness develop. In more exceptional cases bleeding happens not plentiful, and sometimes and hidden. However, periodically repeating (in 3 — 4 months), it causes considerable anemia. Carrying out differential diagnosis of the bleeding M. of, exclude the diseases which are followed by intestinal bleeding (invagination and new growths of intestines, a disease of blood, a hemorrhagic capillary toxicosis).

Among more rare diseases of M. of it should be noted infringement it in belly hernia, M.'s presence by in a hernial bag at inguinal hernia — so-called hernia of Littre. Foreign bodys, getting to M. of, sometimes perforate it. More often fish bones, in isolated cases — metal needles and objects of plant and animal origin (needles, bristles) are the reason of perforation. New growths (a carcinoid tumor, or an adenocarcinoma) also can proceed from M. of.

Diagnosis of the diseases connected with M. is difficult as any of them has no specific symptoms. Diagnose them by process of elimination. At the same time it must be kept in mind that M. is quite often combined by with other malformations, for example an omphalocele, a delay of an obliteration uric channel (see), heart diseases, extremities and other bodies. Development of a picture of an acute abdomen against the background of these defects or existence them in the anamnesis is indirectly indicated an opportunity patol, process in M. by. The final diagnosis is established only in time laparotomies (see). Late falling away of an umbilical cord, moknuty a navel and uncertain abdominal pains, is preferential in paraumbilical area, indirectly point to M.'s presence by. At rentgenol, a research it is impossible to reveal patol, process in M. and cannot reject it since the diverticulum is seldom filled with a contrast suspension of barium. During the filling with contrast medium M. of on roentgenograms has an appearance of the blind shoot departing from an ileal gut. In M.'s diagnosis by use a tracer technique of a research of an abdominal cavity. To the child intravenously enter isotope of technetium pertekhnetat (collecting in digestive tract) at the rate of 0,1 mkkyuri/kg. In 15, 30, 60, 120, 150 min. make stsintigrafiya (see). The centers of accumulation of isotope are found in a stomach, a bladder, and in the presence of M. of — and in it.

Fig. 2. Diagrammatic representation of some stages of a wedge-shaped resection of a diverticulum of Mekkel: 1 — the diverticulum is pressed at the basis by two Kocher's forceps; 2 — the seams handles imposed on sidewalls of a gut are tense and the diverticulum is dissected away over clips, sewing up of a gut is begun; 3 — defect of a gut is taken in in transverse direction by a two-row seam.

Treatment of the diseases caused by M., surgical. At suspicion on the bleeding diverticulum, and also at repeated not clear intestinal bleedings after an exception of somatic diseases the diagnostic laparotomy is shown. At a diverticulitis access in the right ileal area is sufficient, at impassability of intestines and not clear diagnosis the median laparotomy is shown. The type of operation depends on extent of change of M. of and a condition of the patient. In all cases in the presence patol, process in M. of it is subject to removal. At accidental detection of M. of during a laparotomy concerning other disease and satisfactory condition of the patient not changed diverticulum also should be deleted to prevent possible complications. However at serious condition of the patient (perforated appendicitis, operation for new growths) or an extensive operative measure removal of an intact diverticulum is inexpedient.

The technique of operation at the narrow basis of M. of (less than 1 cm) is similar appendectomies (see). At wider basis make a diverticulectomy as wedge-shaped bowel resection (fig. 2). If the basis of a diverticulum is more than 1/2-3/4 diameters of gut, it is preferable to make circular bowel resection with formation of an anastomosis the end in the end (see. Enteroenteroanastomoz ). The lethality after operation for M. of varies within 5 — 10%. It is caused by mistakes in diagnosis and the related late operative measure against the background of serious condition of the patient.

Bibliography: Akzhigitov G. N. and Horoshkevich G. V. Mistakes and dangers at acute diseases of a diverticulum of Mekkel, Surgery, No. 8, page 101, 1975; Bairov G. A. Urgent surgery of children, page 246, L., 1973; Doletsky S. Ya. and Isakov Yu. F. Children's surgery, p. 2, page 577, M., 1970; Earth A. G. Diverticulums of digestive tract, page 154, L., 1970; D e Bartolo H. M of a. van Heerden J. A. Meckel's diverticulum, Ann. Surg., v. 183, p. 30, 1976; Meckel J. F. tiber die Divertikel am Darmkanal, Arch. Physiol. (Halle), Bd 9, S. 421, 1809; P o with h o n J.P. Das Meckelsche Diverticel und seine Komp-lication (184 Falle, mit einem Hinweis auf die Genese der Invagination), Z. Kin-derchir., Bd 12, S. 223, 1973.

Of H. Akzhigitov.