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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The blood flow within the walls of the digestive tract must be sufficient to maintain its structural and functional integrity. All episodes of vascular insufficiency cause ischemic damage to the organ and carry the threat of diffuse or focal necrosis. Certain forms of ischemic colitis or proctitis arise from episodes of reduced peripheric or splanchnic blood flow; indeed, those that do not culminate in necorsis of the colonic wall are more frequently caused by hemodynamic disorders than by vascular occlusions. The crisis is often mitigated by the development of collateral circulation, which is nevertheless of rather meager quality, such that the patients are very vulnerable to subsequent slight changes in cardiac output. Necrotic, gangrenous ischemic colitis arises from a combination of occlusive damage to the arteries and general hemodynamic disturbances. The vascular insufficiency might be slight or severe, temporary or long-lasting, localized or diffuse. In addition, the attack occurs in a septic medium in the presence of an abundant microbial flora that may be highly pathogenic. Thus infection complicates and aggravates the ischemic damage, with the result that the gangrenous aspect of the lesions tends to hide their ischemic origin. Indeed, the variability of the manifestations of the disease represents one of its primary characteristics and is a function of the different causative factors. A knowledge of the anatomy and pathophysiology of the splanchnic circulation and its hemodynamics is essential for a full appreciation of the diagnosis and treatment of the disorders and for the adoption of the aggressive approach necessary to improve the poor prognosis of ischemic diseases of the colon and rectum. The salient points have been stressed in the present chapter. The features of the different forms of the disease have been described, together with the necessary medical treatment and the indications for surgical for surgical intervention. In the relatively rare cases where operation is necessary, the tactics and techniques have been described. All treatment should be based on (a) constant, prolonged intensive care; (b) precise monitoring of any change in status; and (c) rapid excision of any necrotic (often gangrenous) tissue. Ischemic colitis is most likely to occur in elderly patients with a history of cardiovascular disease, but it is not excluded in younger individuals. It is a frequent entity and is potentially lethal. Although its clinical, radiological, and anatomical characteristics permit its classification as a separate disease, it is often confused with other disorders of the colon. Although the abdominal surgeon is most likely to be concerned with this disease, the vascular surgeon who attacks the lower aorta should always be on the lookout for possible occurrences of segmentary ischemia of the distal colon as a result of his intervention.
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PMID:Ischemic diseases of the large intestine. 38 38

Ischemic colitis or proctitis shows three evolutionary stages. a. complete recovery, b. fibrous stenosis, and c. acute ischemia leading to gangrene. The two first stages result more frequently from hemodynamic disorders than from vascular occlusions because, in the presence of the latter, collateral circulation develops. In addition, the colonic ischemia occurs in a septic medium in the presence of an abundant microbial flora which may be highly pathogenic.
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PMID:[Blood flow disorders of the colon and rectum and their therapy]. 54 43

Acute ischemic proctitis is a rare clinical entity caused by vascular insufficiency of the major or collateral circulation to the rectum. It usually occurs following aortic or aortoiliac operations. Six patients with acute ischemic proctitis are presented; four cases occurred after direct arterial interruption, one after accidental embolization of the blood supply to the rectum, and one from tumor edema. Bloody diarrhea was the most common symptom. Loss of anal sphincter tone was also an early sign in three patients. The diagnosis of ischemia was made by mucosal appearance on proctosigmoidoscopy and is differentiated from infectious proctitis by stool culture. Superficial mucosal ischemia was treated without surgery, but deeper levels of necrosis required laparotomy and Hartmann's resection. Rectal excision was not necessary. Four patients survived the ischemic event.
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PMID:Acute ischemic proctitis. Report of six cases. 158 61

Late diagnosis contributes significantly to the mortality and morbidity of mesenteric ischemia. Although flexible endoscopy permits noninvasive assessment of the colon, ischemic colitis is often difficult to differentiate from nonspecific proctitis/colitis or mucosal changes seen in inflammatory bowel diseases. Intravenously administered fluorescein sodium (FSC) has long been used intraoperatively to assess bowel viability because its uptake is inversely proportional to the degree of intestinal ischemia. The authors wished to determine if FSC could be used to augment conventional endoscopy in an attempt to identify and monitor ischemic areas of the bowel within reach of the endoscope. Segmental mesenteric ligation of canine rectum was performed, and serial transanal biopsies obtained. Endoscopy was performed after intravenous FSC administration, using a rigid proctoscope, with a long-wave ultraviolet light source inserted into the lumen of the scope. Areas of nonspecific-appearing proctitis did not take up FSC and were easily differentiated from well-perfused areas by their failure to fluoresce. Ischemic areas were monitored in this manner over a 28-day period. Complete resolution of ischemic mucosal changes occurred with late stricture formation. In humans, the sigmoid and left colon are the areas most frequently affected by ischemic colitis. Because long-wave ultraviolet light is not transmitted through glass fibers, a different light source was needed for potential clinical application. To this end, a single fiber of an argon laser was inserted through the instrument channel of a colonoscope, resulting in greater fluorescence than seen with the ultraviolet light. FSC endoscopy appears to be a sensitive and accurate method of detecting and monitoring ischemic colitis and has many potential clinical applications.
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PMID:Fluorescein endoscopy. A technique for noninvasive assessment of intestinal ischemia. 318 Sep 56

The blood flow within the walls of the digestive tract must be sufficient to maintain its structural and functional integrity. All episodes of vascular insufficiency cause ischemic damage to the organ and carry the threat of diffuse or focal necrosis. Certain forms of ischemic colitis or proctitis arise from episodes of reduced peripheric or splanchnic blood flow; indeed, those which do not culminate in necrosis of the colonic wall are more frequently caused by hemodynamic disorders than by vascular occlusions. The crisis is often mitigated by the development of collateral circulation; this is, however, of rather poor quality so patients become very vulnerable to subsequent slight changes in cardiac output. Necrotic, gangrenous ischemic colitis arises from a combination of occlusive damage to the arteries and general hemodynamic disturbances. The vascular insufficiency may be slight or severe, temporary or long-lasting, localized or diffuse. In addition, the attack occurs in a septic medium in the presence of abundant microbial flora which may be highly pathologic. Thus infection complicates and aggravates the ischemic damage, resulting in the gangrenous aspect of the lesion tending to hide its ischemic origin. Indeed, the variability of the manifestations of the disease in one of its primary characteristics, and is a function of the different causative factors. A knowledge of the anatomy and pathophysiology of the splanchnic circulation and its hemodynamics is essential for a full appreciation of the diagnosis and treatment of the disorders, and for the adoption of the aggressive approach necessary to improve the poor prognosis of ischemic diseases of the colon and rectum. All treatment should be based on 1) constant, prolonged intensive care; 2) precise monitoring of any change in status; 3) rapid excision of any necrotic (often gangrenous) tissue. Ischemic colitis is most likely to occur in elderly patients with a history of cardiovascular disease, but can also affect younger individuals. It is a frequent, potentially lethal, entity. Although it can be classified as a separate disease on the basis of its clinical, radiological and anatomical characteristics, it is often confused with other disorders of the colon. Although the abdominal surgeon is most likely to be concerned with this disease, the vascular surgeon incising the lower aorta should always be on the look-out for segmentary ischemia of the distal colon which may occur following operation.
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PMID:Ischemic diseases of the large intestine. 727 5

Fifteen patients with ischemia of the colon are presented. The majority showed a similar clinical presentation with hematochezia, abdominal pain, and diarrhea in an elderly patient population having associated disease. Colonoscopy was abnormal in all patients studied. Three endoscopic stages were recognized; (1) acute stage characterized by petechiae, pallor, and hyperemia; (2) subacute stage consisting of ulceration and exudation; and (3) chronic stage characterized by stricture, decrease in haustrations, and mucosal granularity. Conventional barium enemas were abnormal and suggested ischemic colitis in six of 15 patients. Rigid proctoscopy was normal or demonstrated nonspecific proctitis in 12 of 15 patients studied. Colonoscopic biopsies demonstrated superficial inflammatory changes in all patients. Thirteen patients had complete mucosal healing endoscopically in 2 weeks to 3 months with stricture developing in four patients. Because ischemic colitis is a distinct subtype of ischemic bowel disease most often limited to the superficial mucosa, colonoscopy is an alternative and usually safe modality in the diagnosis of this entity and proved more accurate that conventional x-ray and proctoscopy.
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PMID:Colonoscopy in ischemic colitis. 729 23

Radiation therapy of cancers in the pelvic region may lead to radiation proctitis. Radiation injury to the rectal wall eventually causes connective tissue fibrosis and obliterative endarteritis with subsequent local tissue ischemia. Patients with radiation proctitis may be minimally ill and heal spontaneously. However, symptoms of proctitis may persist, and the disease progresses to chronic bleeding and/or stricture and fistula formation. Medical therapy is often unsuccessful, and surgery is eventually required. Because of numerous postoperative complications and no guarantee of success, surgery should only be done as a last resort.
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PMID:Radiation proctitis: a review. 867 84

Recent data have confirmed that non-steroidal anti-inflammatory drugs can cause serious damage to the gastrointestinal tract involving localizations other than the well-known gastroduodenal complications. Perforation and hemorrhage of the small bowel have been reported as well as ulcerations, stenoses and diaphragm disease. The same type of lesions can occur in the large bowel in addition to ischemia and collagen colitis. Diverticular diseases of the colon can be complicated by use of non-steroidal anti-inflammatory drugs which may also trigger flare-ups of inflammatory diseases. Use in suppository form can complicate rectitis and rectal stenosis. Non-steroidal anti-inflammatory drugs apparently increase intestinal permeability by inhibiting the cyto-protective effect of prostaglandins. The exact frequency of such complications remains to be determined, but prolonged treatment in elderly subjects appears to increase risk. Current data have not shown greater or lesser toxicity for any specific drug. Non-steroidal anti-inflammatory drugs should be entertained as the cause of intestinal disorders in patients under long-term treatment.
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PMID:[Non-gastroduodenal digestive toxicity of non-steroidal anti-inflammatory agents]. 895 58

Proctitis refers to inflammation of the rectum, a diagnosis made by endoscopic evaluation. Symptoms of proctitis include rectal bleeding, urgency, tenesmus, diarrhea or constipation, and occasionally rectal pain. The causes of proctitis include infection, medication, ischemia, radiation, and ulcerative proctitis. Ulcerative proctitis is an important and increasingly common subcategory of ulcerative colitis (UC) in which inflammation is limited to the rectum. Historically, oral aminosalicylates have been the mainstay of acute and maintenance therapy. A growing body of data, however, indicates that topical aminosalicylates are effective first line agents in ulcerative proctitis and distal UC. Topical aminosalicylates act more effectively and rapidly to induce and maintain remission compared with their oral counterparts or topical steroids. Rarely ulcerative proctitis is refractory to topical therapy and in these instances systemic corticosteroids, antibiotics, immunomodulators, or surgery is required. This review highlights the pathogenesis, diagnosis, and treatment of ulcerative proctitis.
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PMID:Diagnosis and treatment of ulcerative proctitis. 1536 96

Cytomegalovirus (CMV) infection is associated with significant morbidity and mortality in immunocompromised patients. In immunocompetent individuals, the infection is usually subclinical but it can sometimes be life threatening. We describe a case of fatal CMV proctitis in a 71-year-old man following an Ivor-Lewis esophagectomy. After surgery he developed renal failure, methicillin-resistant Staphylococcus aureus pneumonia, and acute respiratory distress syndrome. He recovered but developed melena and massive fresh rectal bleeding. Sigmoidoscopy revealed severe proctitis and a biopsy was consistent with ischemia. Despite undergoing a proctectomy he continued to bleed and died despite every effort. The final histological examination of the rectum revealed a CMV infection.
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PMID:Severe proctitis, perforation, and fatal rectal bleeding secondary to cytomegalovirus in an immunocompetent patient: report of a case. 1718 50


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