Ischemic colitis

Description:

Diameter of the lower mesenteric artery is much less, than an upper mesenteric artery. Therefore its embolism develops less often. Ischemia of the lower mesenteric artery leads to development of ischemic colitis.

Reasons of ischemic colitis:

Narrowing of the lower mesenteric artery happens owing to atherosclerotic defeat. Usually ischemic colitis is observed at aged people of 60 — 70 years and is more senior, having heavy coronary heart disease, aneurism of a belly part of an aorta, atherosclerosis of peripheral arteries, and also Lerish's syndrome.
At system vasculites the lower mesenteric artery is involved in pathological process exclusively seldom. Extent of disturbance of vascularization can be various and depends on development of an anastomosis between upper and lower mesenteric arteries.
At chronic insufficiency of the lower mesenteric artery segmented damages of a large intestine in the field of the left bend, ileocecal and rectosigmoid departments of a large intestine are characteristic. The sigmoid colon in the field of the left bend is especially sensitive to decrease in blood supply. This part of a gut is involved in process in 80% of cases.
In usual conditions the sigmoid colon receives blood supply from a regional artery which is formed of an anastomosis between branches of verkhkny and lower mesenteric arteries. In the field of the left bend regional arteries are poorly developed and blood supply is supported from two branches of the left colonic artery. At occlusion of the lower mesenteric artery in this place ischemia develops earlier, than in other departments of a large intestine.
The rectum at ischemic colitis mostly is not involved in pathological process thanks to the effective blood supply which is carried out from other sources.
Ischemic changes of a mucous membrane of a large intestine can develop also at the acute hemorrhagic colitis caused by an escherichia if 0157 and antibiotics, and also at ulcer colitis. Ischemic changes at inflammatory diseases of a large intestine are secondary and have reversible character.
Distinguish the tranzitorny or reversible and stenosing (necrotic) forms of ischemic colitis. In development of not occlusal defeats an important role is played by the low blood stream caused by a hypovolemia and decrease in cordial emission.
In an initial stage to be surprised the mucous membrane of a large intestine. There are hypostasis, hemorrhages and erosive cankers. In hard cases all wall of a large intestine is involved in pathological process. The necrosis with a transmural heart attack of a large intestine and perforation of a gut develops in a free abdominal cavity or formation of strictures.
Weight and firmness of the subsequent pathological changes in a gut depend on the reason which caused ischemia, its duration, efficiency of collateral circulation and a condition of the general circulation.
J. Marston and соавт. (1976) offered classification of ischemic colitis which includes three forms: gangrenous, tranzitorny and strikturiruyushchy.
At a gangrenous form the gut heart attack develops. In case of tranzitorny disturbance of blood circulation in a large intestine ischemic defeat is limited only to a mucous membrane or a submucosa. Образущиеся erosive cankers can be replaced with granulyatsionny fabric with the subsequent development of fibrous strictures of various extent. Especially often fibrous strictures are localized in the left bend of a colon.

Symptoms of ischemic colitis:

Ischemic colitis in tranzitorny, or reversible, stages meets most often. The sudden beginning from pains in the left ileal area is characteristic of it. Abdominal pains are followed by swelling, diarrhea, tenesmus and proctorrhagias with fever and a leukocytosis.
The pain syndrome of a tranzitorny stage of ischemic colitis is connected with an exercise stress and digestion. At survey of a stomach tension and symptoms of irritation of a peritoneum in the left ileal area can be observed.
Bleedings at a tranzitorny form of ischemic colitis do not happen arrays. In most cases symptoms of a disease disappear in several days, and patients recover in 2 — 3 weeks. At development of an ischemic stricture symptoms of partial intestinal obstruction appear: colicy pains, bad passage of flatus and calla. At a rektoskopiya in a gleam of a gut bloody slime in the absence of damage of a mucous membrane comes to light.
At a gangrenous form of ischemic colitis the exacerbation of heart failure quite often can precede development of accident in an abdominal cavity. In a clinical picture into the forefront the strongest abdominal pain, shock and bloody diarrhea act. At a palpation of a stomach signs of irritation of a peritoneum in the left ileal area are defined. Later peritonitis and a toxaemia develop. The gangrene of intestines arising against the background of a serious cardiovascular illness serves as a cause of death at a half of patients.
At patients with ischemic recurrent colitis the ischemic stricture of a large intestine quite often develops.

Diagnosis:

A certain value for diagnosis of ischemic colitis can have communication of pains in the left ileal area with an exercise stress and meal, existence of the serious accompanying cardiovascular illness, advanced and senile age.
The main diagnostic methods of ischemic colitis are radiological and endoscopic. In a survey picture of an abdominal cavity levels of liquid and expansion of a gut are visible a large amount of air in a large intestine. The careful opaque enema gives the chance to find various extent pathological changes.
In the changed segments of a gut it is possible to see lack of haustrations, the smooth or jagged gut contours reminding "saw teeths", the defects caused by pseudopolypuses and stenoses. In the presence of submucosal hemorrhages in a gut there are pictures reminding impressions of a thumb of a hand. Also sacculate protrusions on a gut contour owing to formation of pseudo-diverticulums are characteristic.
In process of improvement of a condition of the patient the described radiological symptoms of ischemic colitis decrease or completely disappear.
At a kolonoskopiya at early stages of ischemic colitis the mucous membrane is edematous, easily bleeds, with drain hemorrhages. The cyanotic violent protrusions creating a X-ray pattern like "thumbmark" can be visible. In more expressed stage find irregular shape of an ulcer, surrounded hemorrhagic with the changed mucous membrane. In the subsequent transformation of ulcers in pseudopolypuses is possible.
Exact diagnosis of damage of the lower mesenteric artery is possible at the selection angiography or doppler sonography.
At a gangrenous form of ischemia of the lower mesenteric artery at the patient the picture of "acute abdomen" and the diagnosis, as a rule, develops establish during operation.
In recent years there were messages on increase in incidence of ischemic colitis among persons more young than 40 years. A. Kokawa and соавт. (1998) explain increase in number of patients in Japan with distribution of the European food among the population. The most characteristic early symptoms of a disease are rectal bleedings, abdominal pains and locks. The main diagnostic method — a kolonoskopiya. At all 65 patients the left part of a large intestine was surprised, at 13 of them narrowing of an affected area of a gut is revealed. At 22 patients the hyperemia of a mucous membrane, at 37 — erosion and ulcers was observed. Ulcerations met more often at patients to whom the kolonoskopiya was made in the first 3 days of a disease.

Differential diagnosis:

In most cases it is very difficult to distinguish ischemic colitis from inflammatory diseases of a large intestine — ulcer colitis and a disease Krone. Meanwhile the correct diagnosis is of great importance in the first days of a disease. Purpose of the glucocorticoids and immunodepressants shown to patients with ulcer colitis and a disease Krone at ischemic colitis not only is not shown, but also it is dangerous. On the other hand, use of kardiotropny drugs by the patient with ischemic colitis has etiotropic and pathogenetic value. However it is well known that at ulcer colitis and a disease Krone these drugs are not used.
For the correct diagnosis age criteria can have some value: ischemic colitis develops at advanced and senile age, soon after an aggravation ischemic or an idiopathic hypertensia. Ulcer colitis and a disease Krone begin at young age, can be at the age of 40 — 50 years and almost do not develop after 60 — 70 years, especially at senile age. The course of ischemic colitis in most cases softer, an acute phase quickly is replaced by remission.
The differential diagnosis with a tumor is carried out with use of a biopsy of sites of a gut, suspicious on a tumor, and does not make difficulties.
The symptoms of hypostasis of a mucous membrane creating a picture like "thumbmark" can be observed at hemorrhagic colitis — the acute infectious disease caused by an escherichia if with hemorrhagic properties. The acute beginning in the form of strong spastic abdominal pains and water diarrhea which soon becomes bloody is characteristic of hemorrhagic colitis. Fever usually is absent, can reach a noa of some 39C. In mild cases the disease proceeds 7 — 10 days. For exact bacteriological identification it is necessary to receive the corresponding biochemical characteristic of the strain of an escherichia allocated at crops if. Therefore epidemiological and clinical indicators have to serve as the main differential and diagnostic criteria.

Treatment of ischemic colitis:

Treatment in initial stages of ischemic colitis is directed to elimination of a hypovolemia, heart failure; apply an intestinal decompression by introduction to a large intestine of a colonic tube. Apply also an oxygenotherapy, plasma transfusion, albumine, a reopoliglyukina, vazodilatator, antibiotics.
In case of difficulties of differential diagnosis with ulcer colitis or a disease Krone of a large intestine treatment is usually begun with purpose of Sulfasalazinum or drugs 5-ACK (salozinat, салофальк, etc.). As a rule, these drugs render good medical effect as in a pathogeny of ischemic colitis the inflammation and dysbacteriosis of a large intestine matter. At development of a necrosis of a gut make a left-side hemicolectomy. At chronic ischemia and development of ischemic colitis the vascular operations directed to recovery of passability of the struck segment of the lower mesenteric artery are possible.

Forecast:

The forecast in many respects depends on timeliness of treatment of an ischemic bowel disease. Early detection of a disease and adequate therapeutic, and if necessary and surgical, treatment yields the encouraging results.