Treatment depends on acuteness and severity of presentation. Most cases of IC are transient and resolve spontaneously. Such patients do not require specific therapy. Very mild cases can be managed on an outpatient basis with liquid diet, close observation and antibiotics. Patients with more severe symptoms must be hospitalized. In the absence of colonic gangrene or perforation, general measures of supportive care are recommended. Patients should be placed on bowel rest and given intravenous fluids to resuscitate extracellular volume and reduce intestinal oxygen requirements. Parenteral nutrition should be considered for patients who need prolonged bowel rest and have major medical contraindications to surgery[26
]. Cardiac function and oxygenation should be optimized. Swan-Ganz catheterization may assist in guiding fluid status and cardiac function in hemodynamically unstable patients. Vasopressors or any medications which are associated with colon ischemia should be withdrawn if possible. Oral cathartics and bowel preparations should not be given because they can, in some cases, precipitate colonic perforation or toxic dilatation of the colon. Likewise, the use of systemic corticosteroids may potentiate ischemic damage and predispose to colonic perforation. Local corticosteroids may have a role in the treatment of patients with chronic IC although no published experience supports their use. A nasogastric tube should be placed if ileus is present. Decompression of a distended colon by use of a rectal tube may be useful. Empiric broad-spectrum antibiotics are given to cover aerobic and anaerobic bacteria and minimize bacterial translocation and sepsis which has been shown to occur with the loss of mucosal integrity[48
]. The use of antibiotics is based on several experimental studies which showed a reduction in severity and extent of bowel damage when antibiotics were given before or during an ischemic event[2,49
]. Antibiotics have resulted in prolonged survival after intestinal ischemia in rats[49
]. Although there is a lack of substantial evidence in humans, this practice is justified because of the difficulty in predicting who will progress to gangrenous colitis. In experimental studies[5
], substances such as papaverine, isoproterenol, bradykinin, histamine, serotonin, adenosine, vasoactive intestinal polypeptide and glucagon have been found to dilate colonic vasculature and improve local colonic blood flow and tissue oxygenation.
Frequent clinical follow up of the abdomen, careful monitoring of vital signs and serial radiographic and colonoscopic examinations are needed. Clinical suspicion of colonic infarction justifying an emergency laparotomy may arise if there are signs of clinical deterioration despite conservative therapy, such as sepsis, persistent fever and leukocytosis, peritoneal irritation, protracted pain, diarrhea or bleeding, protein-losing colopathy for more than 14 d, free intra-abdominal air, or endoscopically-proved extensive gangrene[26
About 20% of patients with acute IC will require surgery with an associated mortality rate of up to 60%[31
]. At laparotomy, the diagnosis is confirmed and all affected bowel resected. It is important to ensure normal surgical margins. The external appearance of the bowel may be normal during laparotomy since the serosa may be unaffected, despite extensive mucosal damage. The extent of resection should be guided by the distribution of disease seen on preoperative studies. Some authors have reported on intraoperative techniques such as Doppler ultrasonography, intraoperative colonoscopy, evaluation of the antimesenteric serosal surface by hand-held photoplethysmography, pulse oximetry or transcolonic oxygen saturation and intravenous fluorescein for assessment of colonic viability[49,50
]. In general, the resected segment should be examined in the operating room for mucosal injury. If needed, additional colon should be removed. Questionably viable areas of colon are generally resected. A colectomy is followed by colostomy or ileostomy. Patients with left-sided IC undergo resection with a proximal stoma and a distal mucous fistula or Hartman pouch. Primary anastomosis is unusual. Rarely, an ileocolostomy may be performed in patients with right-sided IC and viable ileum and transverse colon. In a series by Longo et al[51
], the stoma was closed in 75% of patients with IC who underwent segmental resection vs
only a third of those with total colonic involvement.
Fortunately, in the majority of patients, signs and symptoms of the disease resolve within 24 to 48 h and complete clinical, radiographic and endoscopic resolution occurs within 2 wk. In these circumstances no further therapy is indicated. In severe but reversible injury, when segmental ulcerative colitis exists, the colon may take 1 to 6 mo to heal[29
]. Asymptomatic patients should have frequent follow-up examinations to document healing or the development of strictures or persistent colitis. In such cases, the patient may have persistent diarrhea, rectal bleeding or repeated episodes of sepsis, which may lead to perforation. Chronic ischemia may respond to topical steroid preparations in addition to general conservative measures. Resection of the affected segment is curative and subsequent development of further ischemic disease is rare. Asymptomatic strictures should be observed, since some may return to normal within 12 to 24 mo with no specific therapy[31
]. When a stricture produces symptoms of obstruction, segmental resection is adequate while endoscopic dilation has been proposed as an alternative to surgery[48