Ischemic colitis — inflammatory changes of the colon caused by impaired blood supply to the intestinal wall. The share of ischemic colitis have at least one third of all diagnosed inflammatory changes of the colon in elderly age, however, the true frequency of ischemic changes were not established.
Etiology and Pathogenesis
Among the most common causes of ischemic disease of the colon include the following: atherosclerosis of mesenteric vessels, thrombosis and embolism of the inferior mesenteric artery, cardiac failure, shock, intoxication medical drugs, vasculitis, oral contraceptives, parasitic infestation, traumatic injury of the abdominal cavity, allergic reactions, surgical treatment of aneurysms of the abdominal aorta, reconstruction aortopodwzdoshnogo vascular, gynecological surgery, incompatible blood transfusion, operations on the stomach, colon and rectum.
The development of ischemic disease of the colon for thrombosis and embolism, injury to blood vessels, allergic reactions associated with the occlusion of blood vessels and, as a rule, is accompanied by the development of gangrene, although not excluded, and the transition to a chronic form with gradual formation of stricture or a long course of ulcerative colitis. The development of a particular form of the disease in this situation due to the state of collateral circulation, the diameter of the damaged vessel, the fullness and duration of occlusion, revascularization rates, etc.
In addition, there are deocclusion of defeat, the possibility of development which is associated with anatomical and functional features of the colon. In addition to the colon blood flow, compared with other organs, the lowest, there are also the most vulnerable places — the anastomoses between the branches of the main vessels of the colon. It is also necessary to consider that the functional activity of this organ and normally accompanied by a decrease in blood flow in it. In this regard, it is clear that any pathological process accompanied by hypovolemia, such as chronic heart disease with congestive heart failure, abdominal aortic aneurysm, shock, stroke, major bleeding occurring with a syndrome of hypotension, are important predisposing factors in the development of chronic ischemic disease of the colon.
Restriction of blood flow on the background of atherosclerosis of the aorta and arteries of the colon can lead to ischemia, especially in the left flexure and proximal sigmoid colon. Therefore, chronic forms of ischemic colitis more likely to exhibit segmental loss.
Described disorder of mesenteric blood circulation under the action of a vasopressor such as ephedrine, epinephrine, VA-supression, èstrogensoderžaŝimi contraceptives.
Ischemic colitis primarily affects the mucosa, as it is particularly sensitive to hypoxia. Apparently, this is due to the high activity of the metabolic processes.
In light and moderate forms of ischemic colitis, not only the serous and muscular sheath remain viable, but also changes of the mucous membrane, if they are not a necrosis, can almost completely be subjected to reverse development. Only in severe forms there are also profound damage, often leading to perforation or stricture formation.
The clinical picture of ischemic colitis is not very specific and is characterized by pain syndrome, recurrent intestinal bleeding and unstable stool with pathological impurities. The severity of certain symptoms is largely determined by the nature of the flow and form of the disease.
In the course of ischemic colitis can be acute or chronic, depending on the degree of devascularization and tissue damage there are two forms — reversible (transient ischemia) and irreversible with formation of strictures or gangrene of the bowel wall.
Reversible (transient) form. In this form of the disease pathological changes in the colon are observed only for a short time and quickly subjected to the full reverse development. The main symptom is pain in the left abdomen, occurring suddenly and just as quickly disappearing spontaneously. Attacks of pain can recur for days, and its intensity is different. Often it is not pronounced or is so insignificant that people forget about it and only with careful questioning can reveal. It is sometimes reminiscent of coronary pain, or the pain of intermittent claudication and is associated with functional activity of the intestines caused by digestion processes. The fact that pain often occurs 15-20 min after eating, abates in a few hours and is localized in the course of the colon, has important diagnostic value, pointing to a possible ischemic in nature. The pain is often accompanied by tenesmus and blood to the stool. In some cases, bleeding occurs a few days or even weeks from the onset of the disease. The blood is mixed and is both dark and bright red. Quantity of it, as a rule, is insignificant, and the massive bleeding usually testify against ischemic lesions of the intestine. Along with blood for ischemic colitis is characterized by frequent secretion of mucus from the anus, especially after the pain attack.
Fever, tachycardia, leukocytosis are the signs of progression of ischemic colitis.
Palpation of the abdomen defines moderate pain along the colon. May also show signs of peritoneal irritation. The increased peritoneal phenomena points to the coming of irreversible ischemic changes in the colon.
Sigmoidoscopy acute episode of ischemia only in rare cases, detect a typical submucosal hemorrhage; a certain diagnostic value has a rectal biopsy, which determined characteristic of ischemic changes.
Colonoscopy reveals submucosal hemorrhage and erosive process on the background of unchanged or pale (a consequence of impaired blood supply) of the mucous membrane. Changes were focal in nature and are most pronounced at the tips of gaustr.
Great value in the diagnosis of reversible ischemic disease of the colon is x-ray examination of the colon with a barium enema. Important radiological sign ishemicheskoi colitis is a symptom of the so-called “digital impressions”. It is an oval or rounded filling defects, which are projected podli-Sistemi hemorrhages in the intestinal wall. However, a reliable sign of vascular lesions is their only appearance in a tight filling of the colon barium. Hemorrhages usually resolve within a few days, and the symptom of “digital impressions” disappears. In more severe degree of ischemia, the mucous membrane over the site of hemorrhage is rejected, forming ulcerative defect.
Delaying the implementation of these research methods, particularly the barium enema may interfere with the proper diagnosis, as the lesions in reversible form often disappear without treatment.
There are two possible outcomes reversible (transient) ischemic colitis — the resolution or progression of the process with the transition into permanent form with the development of ischemic strictures.
With the further development of ischemic colitis on the site of the defects of the mucous membrane ulcers, and feces of an admixture of pus. In connection with the exudation in the lumen of the intestine stool becomes liquid. When digital examination of the rectum into the lumen may be dark blood and pus. In such cases, sigmoidoscopy may reveal ulcers of irregular shape with a sharp border, and covered with fibrinous coating. These changes can be seen on the background of unchanged or pale mucous membranes.
If the barium enema showed a significant variability in the affected areas of the colon — from short to long sections. In the modified segments are defined by the phenomena of spasm, irritability, loss of haustration, smooth or irregular, serrated contour of the colon. Spasm and swelling much more pronounced than in transient ischemia. With a sharp spasm, localized in a short segment, radiographic changes similar to the tumor process. If you have a persistent contraction, which is revealed with repeated testing, is shown colonoscopy or laparotomy to exclude diagnostic errors.
Colonoscopy detects erosive and ulcerative process, often localized in the left half of the colon, especially in the proximal part. Ulcers have different shapes, often twisted and covered with a purulent film grayish color. In more severe lesions are defined by necrosis and rejection of the mucous membrane. In this case, the inner surface of the intestine presents extensive ulcerative defects with clear boundaries.
Irreversible form of ischemic colitis. This form is more common in persons of middle and old age with heart disease or atherosclerosis diagnosed in the absence in anamnesis of indications chronic disorders of the intestine. The most typical manifestation is the formation of strictures of the colon.
The clinical picture in the formation of stricture is dominated by symptoms of increasing intestinal obstruction: colicky pain expressed by the periodic rumbling and bloating, alternating constipation and diarrhea.
Radiographic manifestations of an irreversible form along with the symptom of “digital impressions” are the irregular contours of the mucous membrane, caused by subsidence of edema and ulcerations, tubular narrowing and saccular protrusion opposite the mesentery of the bowel wall, which can be mistaken for diverticula. Ischemic stricture rarely takes on the appearance of neoplastic lesions with clearly defined borders, however, if you have persistent contraction of the colon is necessary to exclude malignant disease.
Colonoscopy reveals a narrowing of the intestine, usually of irregular shape, with ridges and Scar, the mucosa to the stricture is usually unchanged or with minor inflammatory manifestations, which distinguishes it from strictures in Crohn’s disease.
Histological changes are often confined to mucosa, but may cover the entire thickness of the intestinal wall. Along with the typical hemorrhages occur phenomena membranous and pseudomembranous colitis in which the abnormal areas are located in patches. The most characteristic microscopic sign of ischemic colitis, in addition to hemorrhage and ulceration, is the presence of many hemosiderinuria macrophages.
The greatest diagnostic significance angiography of the inferior mesenteric artery, although the testimony may conduct the study of blood flow in the right parts of the colon through cannulation of the superior mesenteric artery. Angiography vessels of the intestine produced by the conventional method.
The differential diagnosis of ischemic colitis is with ulcerative colitis, Crohn’s disease, cancer, diverticulitis and intestinal obstruction.
The vascular nature of the disease should be suspected in elderly people suffering from cardiovascular disease, with the manifestation of ulcerative colitis is atypical of the character and a short history. In cases when the patient is elderly complaining of intestinal bleeding, which appeared shortly after the collaptoid state, hypertensive crisis, etc., the diagnosis of ischemic colitis is not much difficult. Assume that ulcerative colitis almost always occurs with a lesion of the rectum and in the active stage of the process the rectal biopsy reveals characteristic changes.
From Crohn’s disease ischemic colitis is characterized by a constancy of the localization process in the splenic flexure and the lack of anal and perianal lesions. Help and histological data of detection of typical granulomas.
Proper treatment of reversible forms of ischemic disease of the colon require early diagnosis and continuous monitoring of patients with careful re-x-ray control. Therapy reversible ischemia is the purpose of the diet, easy laxatives, vasodilators and antiplatelet agents.
The importance of vitamin: ascorbic acid, askorutin, b vitamins, multivitamin preparations (undevit, undevit, ferropleks), etc.
In more severe clinic, not accompanied by shock and a picture of peritonitis, the treatment adds of transfusion therapy aimed at correction of water-electrolyte balance, blood transfusion, parenteral nutrition. It should be noted that parenteral nutrition creates a physiological rest to the colon and is therefore an important item of treatment. Analgesics should be prescribed with caution in order not to miss any possible development of peritonitis due to disease progression. In the case of accession of secondary infection should be applied antibiotics and sulfonamides, taking into account the sensitivity of flora.
When dilatation of the colon is to decompress it using the colonoscope, a flatus tube. Corticosteroids, in contrast to ulcerative colitis and Crohn’s disease in which they are effective, in ischemic disease of the colon is contraindicated.
In the complex treatment of ischemic disease of the colon occupies a special place hyperbaric oxygen therapy, because it allows dosed to increase the degree of oxygen perfusion due to physically dissolved oxygen and thereby correcting tissue hypoxia. Experience of application of hyperbaric oxygenation in the treatment of ischemic colitis shows that after 2-4 sessions, patients notice improved sleep and mood, the tide of cheerfulness. In a relatively short time eliminated the pain, accelerate the reparative processes in the colon. Hyperbaric oxygen therapy potentiate the effects of anti-inflammatory drugs.
Usually enough 1 course of treatment of 10-15 sessions conducted every day with 40-60 minutes of exposure to an optimal level of oxygen compression, individually selected titration, i.e., by gradually from session to session increase of the oxygen pressure in the range of 1.3—2 ATM. under control blood pressure, heart rate, acid-base status, clinical, ECG and Rheo-encephalographic data.
Long-term results show a positive clinical effect in 3-5 months. then the appropriate course of hyperbaric oxygenation to repeat.
It must be emphasized that the duration of ischemic damage within 7-10 days despite treatment, or when the increase in symptoms should be used surgical treatment.
After decrease in symptoms of ischaemic disease of the colon in the course of the year spend two-time x-ray examination with a barium enema, which facilitates diagnosis of the emerging strictures or shows regression of changes in the colon.
In the presence of strictures indications for surgery are signs of intestinal obstruction or suspicion of malignant degeneration in the area of narrowing. The operation is best done in a planned manner that creates the condition for resection of the colon with the simultaneous restoration of its patency.
When gangrenous form of ischemic disease of the colon the only treatment is an emergency operation, consisting in resection of the intestine nekrotizirovannah by Mikulic, or Hartmann. Simultaneous restoration of patency of the colon undesirable, as it is very difficult to determine the true prevalence of ischemic lesions. Incorrect definition of resection boundaries leads to repeated surgical interventions in connection with the ongoing necrosis and suture anastomosis. Understandable, given the older age of patients, the importance of thorough preoperative preparation and postoperative care, and prevention of hypovolemia, sepsis, renal dysfunction.
The prognosis of ischemic disease of the colon in cases of adequate therapeutic or surgical treatment is favorable.