Acute intestinal obstruction (more precisely – intestinal obstruction!) Is characterized by a violation of the passage of intestinal contents in the direction from the stomach to the anus. It does not represent any separate nosological form, being a complication of a variety of diseases: external abdominal hernias, intestinal tumors, cholelithiasis, etc. But, having arisen, this pathological state proceeds through a single “scenario”, causing intoxication and water-electrolyte disorders, accompanied by typical clinical manifestations. In this regard, diagnostic and therapeutic tactics are largely unified in the case of a non-intrinsic obstruction. That is why it is traditionally considered especially, like a variety of surgical diseases, both in the scientific and educational literature, and in medical statistics.
- Main part
Etiology
At the basis of the development of mechanical (especially strangulation) intestinal obstruction lie the anatomical prerequisites of an innate or acquired character. Such predisposing moments may be the congenital presence of dolichosigma, the mobile cecum, additional pockets and folds of the peritoneum. More often these factors are acquired character: adhesive process in the abdominal cavity, lengthening of the sigmoid colon at old age, external and internal abdominal hernias.
Adhesive process in the abdominal cavity develops after previously suffered inflammatory diseases, injuries and surgeries. For the emergence of acute intestinal obstruction, isolated interintestinal, intestinal-parietal, as well as parietal-glandal fusions that form coarse bands and “windows” in the abdominal cavity are of utmost importance, which can cause strangulation (internal infringement) of mobile segments of the intestine. No less dangerous in the clinical plan can be flat interintestinal, intestinal-parietal and intestinal-glandular fusion, with the formation of intestinal conglomerates, leading to obstructive obstruction with functional overload of the intestine.
Another group of factors that contribute to the development of intestinal obstruction are benign and malignant tumors of various parts of the intestine, leading to obstructive obstruction. Obturation can also occur as a result of compression of the intestinal tube by a tumor from the outside, coming from neighboring organs, as well as constriction of the intestinal lumen as a result of perifocal tumor or inflammatory infiltration. Exophytic tumors (or polyps) of the small intestine, as well as diverticulum of Meckel can cause intussusception.
In the presence of these prerequisites, the obstruction arises under the influence of producing factors. For hernias, such is the increase in intra-abdominal pressure. For other types of obstruction as a provoking factor, changes in the intestinal motility associated with changes in the food regime are frequent: the consumption of a large number of vegetables and fruits in the summer-autumn period; a plentiful food intake against a background of prolonged fasting can cause the turn of the small intestine (it is no coincidence, SI Spasokukotsky called it the disease of a hungry person); the transition from breastfeeding to artificial in children of the first year of life can be a frequent cause of ocular invagination.
The causes of dynamic intestinal obstruction are very diverse. Most often there is paralytic obstruction, which develops as a result of trauma (including operating injuries), metabolic disorders (hypokalemia), peritonitis. All acute surgical diseases of the abdominal cavity, which can potentially lead to peritonitis, occur with the phenomena of intestinal paresis. Decrease in peristaltic activity of the gastrointestinal tract is noted with the restriction of physical activity (bed rest) and as a result of long-term non-stopping biliary or renal colic. Spastic intestinal obstruction causes lesions of the brain or spinal cord (metastasis of malignant tumors, spinal dryness, etc.), poisoning with salts of heavy metals (eg, lead colic), hysteria.
Pathological anatomy
Pathological changes in both the intestine and the abdominal cavity in acute intestinal obstruction depend on its type. When the obstruction is obstructive, the circulation of the intestinal tract is primarily disturbed, and therefore the ischemic and necrobiotic changes occur much earlier and more pronounced. Obturation obstruction causes secondary blood flow disorders in the intestinal wall due to the overstretching of the leading compartment with the contents.
With acute development of the obturation, the pressure in the intestine is significantly increased proximally to the obstacle level. It swells from the overflowing gases and liquid contents. The wall of the intestine thickens due to the development of edema, as well as venous stasis and stasis, acquires a cyanotic character. In the future, it undergoes overgrowth and is considerably thinner. Increase intestinal pressure to 10 mm Hg. Art. after 24 hours causes hemorrhage and ulceration in the wall of the intestine, which reflects the ischemic damage to it. If the pressure rises to 20 mm Hg. Art. there are irreversible necrotic changes in its wall.
Destructive changes spread both along the mucous membrane, and into the depth of the intestinal wall up to the serous cover, in connection with what in its thickness there is inflammatory leukocyte infiltration. Migrating swelling in the mesentery increases venous congestion, under the influence of biologically active amines, ischemic paralysis of precapillary sphincters is attached, the stasis in the vessels of the microcirculatory bed progresses, the aggregation of the formed elements of the blood increases. Released tissue kinins and histamine disrupt the permeability of the vascular wall, which contributes to interstitial edema of the intestine and its mesentery and sweating the fluid first into the lumen of the intestine, and then into the abdominal cavity. With the preservation of circulatory disorders, the necrobiosis areas expand and deepen, merging into extensive necrosis zones of the mucosa and submucosal layers. It should be noted that necrotic changes in the serous cover of the intestinal wall appear at the very last turn and, as a rule, are smaller in length, which often complicates the precise intraoperative determination of areas of bowel inefficiency. This circumstance must be taken into account by the surgeon, who decides during the operative intervention the question of the border of resection of the intestine.
With the progression of necrosis, perforation of the intestinal wall can occur (once again we recall that disruption of the viability of the gut comes much faster with strangulation obstruction). It should be emphasized that with various forms of strangulation intestinal obstruction (retrograde infringement, curvature, nodulation), violations of the circulation of the gut are often observed in two or more places. In this case, the intestinal region, isolated from the leading and outgoing sections, as a rule, undergoes especially deep and sharply expressed pathomorphological changes. This is due to the fact that the circulation of the closed loop of the intestine, due to repeated folding of the mesentery, deep paresis, stretching with gases and liquid contents, suffers much more. With persistent obstruction pathomorphological changes in the organ progress, aggravated circulatory disorders, both in the wall of the intestine, and in its mesentery with the development of vascular thrombosis and gangrene of the intestine.
Symptoms of Acute Intestinal Obstruction:
Successful resolution of diagnostic issues, the choice of optimal surgical tactics and the scope of surgical intervention for any disease are closely related to its classification.
Classification of acute intestinal obstruction
Dynamic (functional) obstruction
- Spastic
- Paralytic
Mechanical obstruction
On the mechanism of development
- Strangulation (infringement, curvature, nodulation)
- Obturation (obturation with a tumor, foreign body, caloric or gallstone, phytobezoar, ascaris ball)
- Mixed (invaginative, adhesive)
By obstacle level
High (intestinal)
Low (large intestine)
For this pathological state, morpho-functional classification is the most acceptable, according to which, due to the occurrence, it is customary to isolate dynamic (functional) and mechanical intestinal obstruction. With dynamic obstruction, the motor function of the intestinal wall is disrupted, without a mechanical obstruction to promote intestinal contents. There are two types of dynamic obstruction: spastic and paralytic.
Mechanical obstruction is characterized by the presence of occlusion of the intestinal tube at any level, which is the reason for the violation of intestinal transit. In this type of obstruction, the allocation of strangulation and obturation of the intestine is fundamentally determined. With strangulation obstruction, the circulation of the bowel involved in the pathological process is primarily affected. This is due to the compression of the vessels of the mesentery due to infringement, curvature or knot formation, which causes a fairly rapid (within a few hours) development of the gangrene of the gut region. With obstructive intestinal obstruction, the circulatory of the above obstruction (leading) of the intestinal region is disturbed again because of its overgrowing with intestinal contents. That’s why, and with obturation, necrosis of the intestine is possible, but it takes several hours, but several days, to develop it. Obturation can be caused by malignant and benign tumors, calves and gallstones, foreign bodies, ascarids. Mixed forms of mechanical obstruction include invagination, in which the intestinal mesentery is involved in the invaginate, and the adhesion obstruction, which can occur both in a strangulation type (compression of the intestine with the mesentery) and in the type of obturation (kink in the form of a “double-barreled”), .
Diagnostic and therapeutic tactics largely depend on the localization of the obstruction in the intestines, in connection with this, the level of obstruction is distinguished: high (small intestine) and low (colonic) obstruction.
In our country, the frequency of acute intestinal obstruction is about 5 people per 100 thousand population, and in relation to urgent surgical patients – up to 5%. At the same time, for fatal outcomes in absolute figures, this pathology divides the first-second place among all acute diseases of the abdominal cavity.
Acute intestinal obstruction can occur in all age groups, but most often it occurs between the ages of 30 and 60 years. Obscurity on the basis of invagination and bowel developmental defects often develops in children, strangulation forms are predominantly observed in patients older than 40 years of age. Obturation intestinal obstruction due to the tumor process is usually observed in patients older than 50 years. With regard to the frequency of acute intestinal obstruction depending on the sex of the patient, in women it is observed in 1,5-2 times less often than in men, with the exception of adhesive obstruction, which often affects women. This type of obstruction is more than 50% of all observations of this pathological condition.
Diagnostics
Radiography of the abdominal cavity
- determination of gas and liquid levels in the bowel loops (Clauber Bowl)
- transverse striation of the intestine (symptom of the kerkring folds)
Ultrasound
- with mechanical intestinal obstruction:
- expansion of the lumen of the intestine more than 2 cm with the presence of the phenomenon of “fluid sequestration” in the lumen of the intestine;
- thickening of the wall of the small intestine more than 4 mm;
- presence of reciprocal movements of chyme in the gut;
- increase in the height of the curling folds more than 5 mm;
- the increase in the distance between the kerkring folds is more than 5 mm;
- hyperpneumatization of the intestine in the leading section
- with dynamic intestinal obstruction:
- absence of back and forth movements of chyme in the gut;
- the phenomenon of fluid sequestration in the lumen of the intestine;
- undefined relief of the curling folds;
- hyperpneumatization of the intestine in all departments
Irrigography
- contraindicated in intestinal obstruction.
III. Conclusion
In all cases when the diagnosis of acute mechanical intestinal obstruction is established or expected, the patient should be urgently hospitalized in a surgical hospital.
Emergency surgical intervention after short-term preoperative preparation (2-4 hours) is indicated only in the presence of peritonitis, in other cases the treatment starts with conservative and diagnostic (if the diagnosis is not finally confirmed) activities. The measures are aimed at combating pain, hyperperistalsis, intoxication and disturbances of homeostasis, release of the upper digestive tract from stagnant contents by setting up a gastric probe, siphon enemas.
In the absence of the effect of conservative treatment, surgical treatment is indicated. Conservative treatment is effective only in cases of disappearance of abdominal pain, abdominal distention, cessation of vomiting, nausea, adequate separation of gases and feces, disappearance or sharp decrease in splash noise and Val’s symptom, a significant reduction in the number of horizontal levels on radiographs, as well as an explicit advance of barium contrast mass on the small intestine and its appearance in the thick in 4-6 hours from the beginning of the study along with the resolution of the phenomena of coprostasis against the background of the enemas.
