para>Rare in patients <60 years old. 70 years is the average age at diagnosis.
Incidence
- 4.5 to 44 cases per 100,000 in the general population
- 1 of every 2,000 hospital admissions
- True incidence may be underestimated due to nonspecific clinical manifestations.
Prevalence
19 cases per 100,000 in the general population
ETIOLOGY AND PATHOPHYSIOLOGY
- Reduced blood flow to the colon, compromises the ability to meet metabolic demands
- Most commonly, an acute, self-limited process
- The colon is perfused by both the superior and inferior mesenteric arteries (SMAs and IMAs) and branches of the internal iliac arteries. Occlusion of branches of the SMA or IMA rarely leads to ischemic consequences due to extensive collateral circulation.
- Watershed areas of the colon (splenic flexure and rectosigmoid junction) are most susceptible to ischemic damage. Blood is carried by narrow branches of the SMA and IMA to these areas, putting them at increased risk for ischemia. The splenic flexure is supplied by the terminal branches of the SMA, and the rectosigmoid junction is supplied by the terminal branches of the IMA.
- Left colon is more commonly affected than the right.
- The rectum is often spared because of additional blood supply from the internal iliac arteries.
- Poor perfusion may result from systemic disease, local vascular compromise, and anatomic or functional changes in the colon itself. An occlusion of large vessels is usually not identified.
- Hypoperfusion from shock, trauma
- Embolic occlusion of mesenteric vessels
- Hypercoagulable states, vasculitis
- Sickle cell disease
- Arterial thrombosis; venous thrombosis
- Mechanical colonic obstruction (e.g., tumor, adhesions, hernia, volvulus, prolapse, diverticulitis)
- Surgical complications (e.g., related to abdominal aortic aneurysm repair)
- Medications (intestinally active vasoconstrictive substances, medications that induce hypotension and thus, hypoperfusion)
- Cocaine abuse
- Aortic dissection
- Strenuous physical activity (e.g., long-distance running)
- Acute IC is largely self-limited and often resolves without long-term complications.
- Repeated episodes of ischemia and inflammation may result in chronic colonic ischemia, possible stricture formation, recurrent bacteremia, and sepsis. These patients may have unresolving areas of colitis and require segmental colonic resection.
RISK FACTORS
- Age >60 years (90% of patients)
- Smoking (most common cause of recurrent IC) (1)
- Hypertension, diabetes mellitus
- Rheumatologic disorders/vasculitis
- Cerebrovascular disease, ischemic heart disease
- Recent abdominal surgery
- Constipation-inducing medications
- History of vascular surgery
- Hypoalbuminemia; hemodialysis
- Smoking, hypercoagulability, oral contraceptive (2)
- AAA repair (IMA ligation) (2)
- IBS-C (related to treatment with serotonin antagonist) (2)
DIAGNOSIS
- Diagnosis is based on history, risk factors, and physical examination (3)[A].
- Laboratory values and radiographic findings are usually nonspecific (3)[A].
- Colonoscopy is diagnostic (3)[A].
HISTORY
- Abdominal pain is the most common symptom (4).
- Symptoms vary depending on severity (5)[A].
- Sudden-onset, mild to moderate abdominal pain with tenderness over the affected segment of bowel (3)[A]
- Sudden urge to defecate followed by passage of either bright red or maroon stool (5)[A]
- Lower GI bleeding is rarely heavy (3)[A].
- Loose, bloody bowel movements may occur, typically within 12 to 24 hours of abdominal pain onset (5)[A].
PHYSICAL EXAM
- Individual signs and symptoms are poorly predictive of IC (6)[A].
- Vital signs: hypotension; tachycardia
- Tenderness to palpation over the involved segment of bowel (5)[A]
- Abdominal distention with vomiting due to an associated ileus (3)[A]
- In the uncommon setting of transmural ischemia, patients may develop peritoneal signs such as rebound and guarding (7)[A].
DIFFERENTIAL DIAGNOSIS
- Infectious colitis (7)[A]
- Inflammatory bowel disease (ulcerative colitis, Crohn disease) (7)[A]
- Colon cancer (7)[A]; diverticulitis (7)[A]
- Pseudomembranous colitis (6)[A]
DIAGNOSTIC TESTS & INTERPRETATION
- Depends on the clinical presentation, extent of colonic involvement, transmural involvement, and acuity (3)[A].
- CT scan is the initial diagnostic test for patients with nonspecific abdominal pain (6)[A].
- Colonoscopy is the most sensitive diagnostic test (3)[A].
- Radiographic tests and laboratory values are nonspecific (6)[A].
Initial Tests (lab, imaging)
- The following lab markers of ischemia are not specific to IC and are more common in severe ischemia (6)[A]:
- CBC (leukocytosis) (6)[A]
- BMP, ABG (signs of metabolic acidosis) (6)[A]
- Lactate (6)[A], CPK (6)[A]
- Alkaline phosphatase (6)[A]
- Lactate dehydrogenase (LDH) (6)[A], amylase (6)[A]
- Procalcitonin (8)
- Hypoxia inducible factor 1-alpha (9)
- Abdominal plain film should be obtained:
- 20% of patient show signs of IC such as thumbprinting and mural thickening (7)[A].
- Necessary to rule out bowel perforation and pneumoperitoneum (7)[A]
- No role for routine mesenteric angiography (3)[A], but it can help detect the cause of IC (10).
- Abdominal CT scan with contrast should be obtained in suspected IC (3)[A]:
- The most common CT findings are moderate continuous circumferential thickening of colonic wall and pericolonic fat stranding (10).
- Other common CT findings include hyperdense mucosa, submucosal edema, and mesenteric inflammation (3)[A].
- Pneumatosis, pneumoperitoneum, and free peritoneal fluid suggest advanced ischemia (3)[A].
Follow-Up Tests & Special Considerations
- Stool cultures, fecal leukocytes, stool ova, and parasites to rule out infection (6)[A]
- Patients undergoing aortic surgery may need postoperative colonoscopy within 2 to 3 days to look for signs of IC (5)[A].
- Cardiac workup including electrocardiogram, Holter monitoring, or transthoracic echocardiogram to exclude cardiogenic embolism as indicated (6)[A].
Diagnostic Procedures/Other
- Colonoscopy is gold standard; sigmoidoscopy also used (3)[A]
- Cyanotic hemorrhagic tissue and edematous mucosa suggests ischemia (5)[A].
- Segmental distribution (watershed), hemorrhagic nodules, and rectal sparing (5)[A]
- "Colon single-stripe sign" is a single line of erythema, with a 75% histopathologic yield (5)[A].
- Routine biopsy no longer advised, as results are typically nonspecific (3)[A].
- In cases of isolated right colon ischemia, noninvasive vascular imaging studies are recommended to evaluate acute SMA occlusion (5)[A].
Test Interpretation
- Fulminant gangrenous IC seen in 15% of cases requires surgical intervention (3)[A].
- Acute transient IC seen in 85% of cases requires clinical evaluation for further workup (3)[A].
- Biopsied specimens reveal mucosal infarction and ghost cells, which show normal cellular outlines but lack intracellular contents (3)[A].
TREATMENT
- Treatment depends on disease severity (3)[A].
- Continuous clinical monitoring, including vital signs and serial abdominal exams (7)[A]
- In the absence of colonic necrosis or perforation, most patients respond to supportive care (2)[A]:
- Bowel rest (5)[A]
- IV fluids to maintain hemodynamic stability (5)[A]
- Broad-spectrum antibiotics to cover aerobic and anaerobic bacteria to avoid bacterial translocation secondary to colonic mucosal damage (5)[A]
- Ciprofloxacin 400 mg IV BID or 500 mg PO BID
- Metronidazole 500 mg PO/IV TID
- Avoid intestinally active vasoconstrictive medications (5)[A].
- Avoid systemic corticosteroids, which may worsen ischemic damage and increase risk of perforation (3)[A].
- If ileus is present, place nasogastric tube (3)[A].
- If radiographic abnormalities are present, serial abdominal x-rays help follow improvement (5)[A].
- If signs of clinical deterioration are present despite supportive care, including increased abdominal pain, peritoneal signs, persistent diarrhea, bleeding, or sepsis, consider surgery (3)[A].
MEDICATION
- Broad-spectrum antibiotics (i.e., metronidazole, ciprofloxacin) (5)[A]
- If cardiac workup reveals CHF or cardiac arrhythmias, initiate appropriate medical treatment (5)[A].
ADDITIONAL THERAPIES
Stem cell implantation in ischemic colonic wall in a rat model enhanced tissue healing by promoting angiogenesis (11)[B].
SURGERY/OTHER PROCEDURES
- 20% of patients require surgical intervention (12)[A].
- Evidence of pneumatosis intestinalis, portal vein air, or free peritoneal air are indications for immediate surgery (3)[A].
- Surgery may be indicated for the following:
- Peritoneal signs, increased abdominal tenderness, new-onset shock, lactic acidosis, or acute renal failure (3)[A]
- Diarrhea, lower GI bleeding, or exudative colitis persisting past 14 days (3)[A]
- Most common surgical intervention is colectomy with end ileostomy (6)[A].
- Cholecystectomy may prevent resuscitation-related acute acalculous cholecystitis (3)[A].
ONGOING CARE
DIET
- Bowel rest until symptoms resolve
- Parenteral nutrition for patients needing prolonged bowel rest who have contraindications to surgery.
PROGNOSIS
- In most patients, IC symptoms IC resolve in 24 to 48 hours.
- Radiographic or endoscopic resolution within 2 weeks.
- Right-sided IC appears to be the most significant predictor of outcome. Patients with right-sided IC have a 2-fold increase in mortality and a 5-fold increase in morbidity.
- Secondary cardiovascular prevention minimizes recurrence.
- Male gender, low hemoglobin, low serum albumin, high BUN, and presence of metabolic acidosis are poor prognostic factors (2)
- Chronic kidney disease, COPD, long-term care facilities increase mortality in IC (2,13)
COMPLICATIONS
20-30% of patients develop chronic IC, with persistent diarrhea or stricture formation requiring surgical intervention.
REFERENCES
11 Sherid M, Sifuentes H, Samo S, et al. Risk factors of recurrent ischemic colitis: a multicenter retrospective study. Korean J Gastroenterol. 2014;63(5):283-291.22 Brandt LJ, Feuerstadt P, Longstreth GF, et al. ACG clinical guideline: epidemiology, risk factors, patterns of presentation, diagnosis, and management of colon ischemia (CI). Am J Gastroenterol. 2015;110(1):18-44.33 Moszkowicz D, Mariani A, Tr ©sallet C, et al. Ischemic colitis: the ABCs of diagnosis and surgical management. J Visc Surg. 2013;150(1):19-28.44 Yadav S, Dave M, Edakkanambeth Varayil J, et al. A population-based study of incidence, risk factors, clinical spectrum, and outcomes of ischemic colitis. Clin Gastroenterol Hepatol. 2015;13(4):731-738.e6.55 Feuerstadt P, Brandt LJ. Colon ischemia: recent insights and advances. Curr Gastroenterol Rep. 2010;12(5):383-390.66 Theodoropoulou A, Koutroubakis IE. Ischemic colitis: clinical practice in diagnosis and treatment. World J Gastroenterol. 2008;14(48):7302-7308.77 Sun MY, Maykel JA. Ischemic colitis. Clin Colon Rectal Surg. 2007;20(1):5-12.88 Cosse C, Sabbagh C, Browet F, et al. Serum value of procalcitonin as a marker of intestinal damages: type, extension, and prognosis. Surg Endosc. 2015;29(11):3132-3139.99 Harki J, Sana A, van Noord D, et al. Hypoxia-inducible factor 1-α in chronic gastrointestinal ischemia. Virchows Arch. 2015;466(2):125-132.1010 Sherid M, Samo S, Sulaiman S, et al. Is CT angiogram of the abdominal vessels needed following the diagnosis of ischemic colitis? A multicenter community study. ISRN Gastroenterol. 2014;2014:756926.1111 Joo HH, Jo HJ, Jung TD, et al. Adipose-derived stem cells on the healing of ischemic colitis: a therapeutic effect by angiogenesis. Int J Colorectal Dis. 2012;27(11):1437-1443.1212 Tortora A, Purchiaroni F, Scarpellini E, et al. Colitides. Eur Rev Med Pharmacol Sci. 2012;16(13):1795-1805.1313 Yoon SY, Jung SA, Na SK, et al. What's the clinical features of colitis in elderly people in long-term care facilities? Intest Res. 2015;13(2):128-134.
ADDITIONAL READING
- Iacobellis F, Berritto D, Somma F, et al. Magnetic resonance imaging: a new tool for diagnosis of acute ischemic colitis? World J Gastroenterol. 2012;18(13):1496-1501.
- O'Neill S, Yalamarthi S. Systematic review of the management of ischaemic colitis. Colorectal Dis. 2012;14(11):e751-e763. doi:10.1111/j.1463-1318.2012.03171.x.
- Paterno F, McGillicuddy EA, Schuster KM, et al. Ischemic colitis: risk factors for eventual surgery. Am J Surg. 2010;200(5):646-650.
CODES
ICD10
- K55.9 Vascular disorder of intestine, unspecified
- K55.0 Acute vascular disorders of intestine
- K55.1 Chronic vascular disorders of intestine
ICD9
- 557.9 Unspecified vascular insufficiency of intestine
- 557.0 Acute vascular insufficiency of intestine
- 557.1 Chronic vascular insufficiency of intestine
SNOMED
- 30588004 Ischemic colitis (disorder)
- 75700000 Acute ischemic colitis
- 27241008 Chronic ischemic colitis
- 235850009 Colonic gangrene (disorder)
- 235845003 Transient ischemic colitis (disorder)
CLINICAL PEARLS
- Suspect IC in patients with multiple risk factors who present with abdominal pain and loose bloody stools.
- Colonoscopy is the diagnostic gold standard.
- Most often, IC is self-limited, responding well to conservative management with IV fluids, bowel rest, and empiric broad-spectrum antibiotics.
- Peritoneal signs or lack of clinical improvement suggests more extensive ischemia and require surgical intervention.
- Right-sided IC is associated with higher morbidity and mortality.