Tohoku J. Exp. Med., 2009, 218, 83-92 Ischemic Colitis 83 Review Ischemic Colitis: Surging Waves of Update Michael Stamatakos,1 Emmanuel Douzinas,2 Charikleia Stefanaki,1 Constantina Petropoulou,1 Helen Arampatzi,3 Constantinos Safioleas,1 George Giannopoulos,1 Constantinos Chatziconstantinou,4 Constantinos Xiromeritis5 and Michael Safioleas1 1Fourth Department of Surgery, Medical School, University of Athens, ATTIKON General Hospital, Athens, Greece 2Third Department of Critical Care, Medical School, Athens University, Eugenidion Hospital, Athens, Greece 3First Department of Obstetrics and Gynecology, Athens University Medical School, Alexandra Hospital, Athens, Greece 4Department of Radiology, General Hospital ‘St. Panteleimon’, Nikaia, Greece 5First Department of Surgery, University of Athens Medical School, Laikon Hospital, Athens, Greece Ischemic colitis is the most common type of intestinal ischemia, and it represents the consequences of acute or, more commonly, chronic blockage of blood flow through arteries that supply the large intestine. Ischemic colitis is manifested through a continuum of injury and considered as an illness of the elderly. The incidence of ischemic colitis has been underestimated, because many mild cases may go unreported. Patients experience abdominal pain, usually, localized to the left side of the abdomen, along with tenderness and bloody diarrhea. Severe ischemia may lead to bowel necrosis and perforation, which results in an acute abdomen and shock, frequently, being accompanied by lactic acidosis. Although computed tomography may have indicative findings, colonoscopy is the golden standard of diagnosis. Supportive care with intravenous fluids, optimization of hemodynamic status, avoidance of vasoconstrictive drugs, bowel rest, and empiric antibiotics will produce clinical improvement within 1 to 2 days in most patients. The condition resolves completely with conservative treatment, in most cases, but late diagnosis or severe ischemia can be associated with high rates of complications and death. However, when the interruption to the blood supply is more severe or more prolonged, the affected portion of the large intestine may have to be surgically removed. The present paper aims at bringing ischemic colitis up to date, by reviewing the current medical literature and extracting the contemporary data, about its presentation, diagnosis and treatment, which is of benefit to the readership, who may encounter this potentially fatal entity. ──── ischemic colitis; intestinal tract; atherosclerosis; colonic ischemia; colon. Tohoku J. Exp. Med., 2009, 218 (2), 83-92. © 2009 Tohoku University Medical Press Ischemic colitis or more appropriately, vascular disease increasing attention. Marston et al. (1966) classified this of the colon, has been known for up to 100 years. Early disease into 3 forms: transient, strictures, and gangrene. It concern equated this condition to colonic infarction second- is defined as a “reversible condition caused by obstruction ary to accidental arterial ligation during surgical procedures. of blood flow in intestinal tract mucosa without apparent Shaw and Green (1953) reported an episode of infarction blockage of the main artery” (Marston et al. 1966). In gen- after inferior mesenteric artery ligation. Although it was eral, ischemic colitis is more common, in the elderly and its known that an occasional patient manifested a relatively prevalence increases with age, but it is also seen in younger benign process after such arterial ligation, it was not until patients (Brandt and Boley 2000). Its causes include vascu- 1963, when Boley et al. (1963) reported 5 patients with a lar factors, such as ischemia and embolus, intestinal factors disease labeled “reversible vascular occlusion of the colon” such as constipation, irritable bowel syndrome and history thus providing emphasis upon the milder component of this of intestinal surgery (Pescatori et al. 2009), as well as problem. Marston et al. (1966) reported on 16 patients, who administration of drugs, such as antibiotics, appetite sup- manifested three stages of a spontaneous disease, which pressants (phentermine), chemotherapeutic agents (vinca they labeled ischemic colitis. Since that time, ischemic alkaloids and taxanes), constipation inducing medications, colitis or alternatively, colonic ischemia has drawn ever decongestants (pseudoephedrine), cardiac glucosides, Received March 5, 2009; revision accepted for publication April 2, 2009. Correspondence: Michael Stamatakos MD. Phd. Fourth Department of Surgery, Medical School, University of Athens, ATTIKON General Hospital, 153 Aigyptou, ANO GLYFADA, 16562, Athens, Greece. e-mail: [email protected] 83 84 M. Stamatakos et al. diuretics, ergot alkaloids, hormonal therapies, statins, illicit protected from ischemia to a great extent by an abundant drugs, immunosuppressive agents, laxatives, non-steroidal collateral blood supply; namely, the colon is nourished by anti-inflammatory drugs, psychotropic medications, sero- the superior mesenteric artery (SMA), the inferior mesen- tonin agonists/antagonists and vasopressors. Iatrogenic teric artery (IMA), and the branches of the internal iliac causes may result in ischemic colitis (Brandt and Boley arteries. The SMA gives rise to the middle colic, right colic, 1992; Champagne et al. 2007; Steele 2007). While surgery and ileocolic arteries, which supply the right colon and the is indicated for the gangrenous form of this disease, tran- right half of the transverse colon. The IMA branches into sient and structuring forms are often ameliorated by bowel the left colic, sigmoid, and superior rectal (hemorrhoidal) rest, fasting, and/or parenteral fluid administration. The arteries, which supply the left half of the transverse colon to duration of fasting and fluid administration varies among proximal rectum. The distal rectum is supplied by inferior individuals (Gandhi et al. 1996). Significant prolongation and middle rectal (hemorrhoidal) arteries, which are branch- of healing is sometimes observed, especially in patients es of the internal iliac artery. (Brandt and Boley 2000). with an ulcer. There is an extensive mesenteric collateral circulation that Ischemic colitis encompasses a number of clinical enti- provides substantial protection from ischemic insults. The ties, all with a final result of insufficient blood supply to a SMA and IMA communicate through the marginal artery of segment or the entire colon. This disease results in ischemic Drummond, which runs along the splenic flexure and the necrosis of a variable severity that can range from superfi- arc of Riolan. The marginal artery of Drummond is absent cial mucosal involvement to full-thickness transmural or underdeveloped in 5% of the population, placing the necrosis (Baixauli et al. 2003). Bowel ischemia is mainly a splenic flexure at particular risk of ischemia. If SMA or disease of old age, caused by atheroma of mesenteric ves- IMA is gradually occluded, the arc of Riolan or the central sels. Other causes include embolic disease, vasculitis, anastomotic artery may dilate to compensate and be termed fibromuscular hyperplasia, aortic aneurysm, blunt abdomi- the meandering artery. The IMA and the internal iliac arter- nal trauma, disseminated intravascular coagulation, irradia- ies communicate through the superior and middle/inferior tion, and hypovolemic or endotoxic shock. Occlusive mes- rectal (hemorrhoidal) arteries. The dual blood supply of the enteric infarction (embolus or thrombosis) has a 90% rectum from the mesenteric and iliac arteries makes it resis- mortality rate, whereas nonocclusive disease has a 10% tant to ischemia. However, certain areas are more vulnera- mortality rate. Venous infarction occurs in young patients, ble in some people. The marginal artery of Drummond, usually after abdominal surgery. Patients may present with which runs along the mesentery within 1 to 8 cm of the colicky abdominal pain, which becomes continuous. It may colon, is composed by the terminal portions of the branches be associated with vomiting, diarrhea, or rectal bleeding of the major vascular arcades. This artery can keep the left (Arnott et al. 1999). The colon is the most common site of colon viable when the inferior mesenteric artery is ligated gastrointestinal ischemia. Colonic ischemia is associated during rectosigmoidectomy. However, the anatomy is vastly with many precipitating factors and may be due to single- variable. For example, the marginal artery of Drummond is vessel occlusion or global hypoperfusion. The clinical occasionally tenuous at the splenic flexure, as described by manifestations are often subtle and vary, so a high level of Griffiths, and indeed is absent at this point in up to 5% of awareness is needed. Special consideration should be given patients (Griffiths 1956). It is poorly developed in the right on this disease, in the case of patients, who have recently colon in 50% of the population, explaining the occurrence undergone cardiac or aortic surgery (Parish et al. 1991). of right-sided colitis (Sonneland et al. 1958). One or more Clinical patterns vary from transient colitis to fulminant of the three branches of the superior mesenteric artery may ischemia with gangrene. Routine biochemical tests are be absent in up to 20% of people. Branches of the inferior helpful but nonspecific. It is of note that patients with isch- mesenteric artery may similarly be absent. emic colitis almost always are presented with lactic acido- On the other hand, 60%