Ischemic Colitis

Ischemic ColitisIschemic Colitis

Marcelyn ColeyMarcelyn Coley

Team IV Surgery ConferenceTeam IV Surgery Conference

Mount Sinai Hospital Mount Sinai Hospital

Intestinal ischemiaIntestinal ischemia

Mesenteric ischemiaMesenteric ischemia - reduction in - reduction in intestinal blood supplyintestinal blood supply

Acute Mesenteric IschemiaAcute Mesenteric Ischemia Most often involves SMAMost often involves SMA from emboli, arterial and venous thrombi, or from emboli, arterial and venous thrombi, or

vasoconstriction secondary to low flow vasoconstriction secondary to low flow Chronic Mesenteric IschemiaChronic Mesenteric Ischemia

postprandial abdominal pain, marked weight postprandial abdominal pain, marked weight lossloss

caused by repeated transient episodes of caused by repeated transient episodes of inadequate intestinal blood flow inadequate intestinal blood flow

AGA guideline: Intestinal Ischemia. Gastroenterology 2000; 118:951AGA guideline: Intestinal Ischemia. Gastroenterology 2000; 118:951

Colonic ischemiaColonic ischemia After aortic or cardiac bypass surgery After aortic or cardiac bypass surgery Certain systemic conditionsCertain systemic conditions

vasculitides (eg, systemic lupus erythematosis, vasculitides (eg, systemic lupus erythematosis, periarteritis nodosum)periarteritis nodosum)

infections (eg, cytomegalovirus, E. coli O157:H7) infections (eg, cytomegalovirus, E. coli O157:H7) coagulopathies (eg, protein C and S deficiencies, anti-coagulopathies (eg, protein C and S deficiencies, anti-

thrombin III deficiency, APC resistance) thrombin III deficiency, APC resistance) Medications (eg, oral contraceptives) or illicit drugs Medications (eg, oral contraceptives) or illicit drugs

(eg, cocaine) (eg, cocaine) After strenuous and prolonged physical exertion (eg, After strenuous and prolonged physical exertion (eg,

long-distance running) long-distance running) After any major cardiovascular episode accompanied by After any major cardiovascular episode accompanied by

hypotension hypotension With). With).


COLONIC ISCHEMIACOLONIC ISCHEMIA Most frequent form of mesenteric ischemia Most frequent form of mesenteric ischemia Commonly left colonCommonly left colon Mostly elderly populationMostly elderly population Etiology Etiology

Low-flow state (hypotension)Low-flow state (hypotension) Embolus (A-fib)Embolus (A-fib) Post MI (hypotension, mural thrombus)Post MI (hypotension, mural thrombus) Post AAA reconstructionPost AAA reconstruction Closed loop construction - left side with intact ileocecal Closed loop construction - left side with intact ileocecal

valvevalve VolvulusVolvulus Mesenteric Vein ThrombosisMesenteric Vein Thrombosis

Catastrophic if not recognizedCatastrophic if not recognized


IncidenceIncidence: Thought to be : Thought to be

underestimated because many mild underestimated because many mild cases may go unreported. cases may go unreported.

In contrast, the incidence in patients In contrast, the incidence in patients undergoing abdominal aortic undergoing abdominal aortic reconstructive procedures has been reconstructive procedures has been studied. studied. Hunter and Guernsey (1988) reported that Hunter and Guernsey (1988) reported that

as many as as many as 10%10% of such patients have some of such patients have some degree of ischemic colitis. degree of ischemic colitis.

Vascular Supply of the Vascular Supply of the ColonColon

Ischemic Colitis:Ischemic Colitis:Vascular Supply Vascular Supply Superior mesenteric artery (SMA)Superior mesenteric artery (SMA)

Ileocolic artery – terminal ileum, cecum, appendix, prox Ileocolic artery – terminal ileum, cecum, appendix, prox ascending colonascending colon

Right colic artery – ascending colon, hepatic flexureRight colic artery – ascending colon, hepatic flexure Middle colic artery – transverse colonMiddle colic artery – transverse colon

Inferior mesenteric artery (IMA)Inferior mesenteric artery (IMA) Left colic artery – descending, transverse colon, splenic Left colic artery – descending, transverse colon, splenic

flexureflexure Sigmoid arteries – sigmoid and descending colonSigmoid arteries – sigmoid and descending colon Superior rectal artery – proximal rectumSuperior rectal artery – proximal rectum

Collateral flowCollateral flow Marginal artery of Drummond – collateral connection Marginal artery of Drummond – collateral connection

between SMA and IMA along the mesenteric borderbetween SMA and IMA along the mesenteric border IMA and internal iliac – supply good collaterals to the IMA and internal iliac – supply good collaterals to the

rectumrectum


Watershed areasWatershed areas1.1. Splenic flexureSplenic flexure

2.2. Rectosigmoid junctionRectosigmoid junction

Most vulnerable during systemic Most vulnerable during systemic hypotensionhypotension

Ischemic Colitis: Location Ischemic Colitis: Location of ischemia by regionsof ischemia by regions

Other areas refer to combination of different regions.Other areas refer to combination of different regions.Data from: Reinus, JF, Brandt, LJ, Boley, SJ, Data from: Reinus, JF, Brandt, LJ, Boley, SJ, Gastroenterol Clin North Am 1990; 19:319Gastroenterol Clin North Am 1990; 19:319

Ischemic ColitisIschemic ColitisVenous drainageVenous drainage Veins parallel their corresponding Veins parallel their corresponding

arteriesarteries SMV – drains small intestine, cecum, SMV – drains small intestine, cecum,

ascending, and transverse colonascending, and transverse colon IMV – drains descending colon, IMV – drains descending colon,

sigmoid colonsigmoid colon Superior rectal vein – rectumSuperior rectal vein – rectum IMV fuses with splenic veinIMV fuses with splenic vein

Ischemic ColitisIschemic ColitisPathophysiologyPathophysiology Colonic ischemiaColonic ischemia usually result of a sudden usually result of a sudden

and usually temporary reduction in blood and usually temporary reduction in blood flow insufficient to meet metabolic flow insufficient to meet metabolic demands of discrete regions of the colon demands of discrete regions of the colon

OcclusionOcclusion Thrombus, embolus, atherosclerotic stenosisThrombus, embolus, atherosclerotic stenosis

Hypoperfusion (Low-flow state)Hypoperfusion (Low-flow state) GI bleeding, hypotension, Nonocclusive GI bleeding, hypotension, Nonocclusive

mesenteric ischemia (NOMI)mesenteric ischemia (NOMI) Mesenteric venous thrombosisMesenteric venous thrombosis

Distal small bowel and prox colonDistal small bowel and prox colon

Ischemic ColitisIschemic Colitis Aortoiliac surgeryAortoiliac surgery

1% to 7% develop colonic ischemia1% to 7% develop colonic ischemia Cardiopulmonary bypassCardiopulmonary bypass Post-Myocardial infarctionPost-Myocardial infarction

Hypotension, mural thrombusHypotension, mural thrombus Obstruction or potentially obstructing lesions of the colon Obstruction or potentially obstructing lesions of the colon

(carcinoma, diverticulitis, volvulus)(carcinoma, diverticulitis, volvulus) HemodialysisHemodialysis

Typically nonocclusive due to underlying atherosclerosis, diabetes, Typically nonocclusive due to underlying atherosclerosis, diabetes, and hemodialysis-induced hypotensionand hemodialysis-induced hypotension

Vasculitides (systemic lupus erythematosis, periarteritis Vasculitides (systemic lupus erythematosis, periarteritis nodosum)nodosum)

Drugs (digoxin, tegaserod, alosetron, cocaine)Drugs (digoxin, tegaserod, alosetron, cocaine) Extreme exericiseExtreme exericise Acquired and hereditary thrombotic conditionsAcquired and hereditary thrombotic conditions

Antiphospholipid antibodies, Factor V Leiden mutations, Protein C and Antiphospholipid antibodies, Factor V Leiden mutations, Protein C and S deficiency, Antithrombin III deficiencyS deficiency, Antithrombin III deficiency


Colon receives less blood supply Colon receives less blood supply compared to the rest of the gi tract compared to the rest of the gi tract thus is vulnerable to hypoperfusionthus is vulnerable to hypoperfusion

Vasospasm – a mechanism to Vasospasm – a mechanism to redirect blood to cerebral circulation redirect blood to cerebral circulation during hypotensionduring hypotension


Mechanism of InjuryMechanism of Injury Hypoxia causes detectable injury to Hypoxia causes detectable injury to

superficial mucosa within one hoursuperficial mucosa within one hour Prolonged severe ischemia – necrosis of Prolonged severe ischemia – necrosis of

villous layervillous layer Leads to transmural infarction in 8 to 16 hrsLeads to transmural infarction in 8 to 16 hrs

Reperfusion injury – mediated by release Reperfusion injury – mediated by release of oxygen free radicals and neutrophil of oxygen free radicals and neutrophil activationactivation


Clinical Manifestations Clinical Manifestations

Acute setting Acute setting Rapid mild onset abdominal pain and Rapid mild onset abdominal pain and

tenderness over affected bowel tenderness over affected bowel (lower abdominal)(lower abdominal)

Mild to moderate rectal bleeding or Mild to moderate rectal bleeding or bloody diarrheabloody diarrhea


Presenting of symptomsPresenting of symptoms 95% with abdominal pain95% with abdominal pain 44% with nausea44% with nausea 35% with vomiting35% with vomiting 35% with diarrhea35% with diarrhea 16% presented with blood per 16% presented with blood per

rectum rectum


Risk factorsRisk factors 78% - hypertension78% - hypertension 71% - tobacco use71% - tobacco use 62% - peripheral vascular disease62% - peripheral vascular disease 50% - coronary artery disease50% - coronary artery disease


Clinical ManifestationsClinical Manifestations Thrombotic/embolic mesenteric occlusion Thrombotic/embolic mesenteric occlusion

present with sudden-onset severe mid-present with sudden-onset severe mid-abdominal pain that is out of proportion to the abdominal pain that is out of proportion to the physical findingsphysical findings typically have a history of chronic postprandial typically have a history of chronic postprandial

abdominal pain and significant weight loss.abdominal pain and significant weight loss. NOMI pain usually not as sudden as that noted NOMI pain usually not as sudden as that noted

with embolic or thrombotic occlusion: it is with embolic or thrombotic occlusion: it is generally more diffuse and tends to wax and generally more diffuse and tends to wax and wane wane unlike the pain associated with occlusive disease, unlike the pain associated with occlusive disease,

which tends to get progressively worsewhich tends to get progressively worse

Ischemic Colitis

Colonic vs. small bowel ischemia

Acute Acute coloniccolonic ischemia ischemia Acute mesenteric ischemia involving Acute mesenteric ischemia involving small bowelsmall bowel

90 percent of patients over age 6090 percent of patients over age 60 Age varies with etiology of ischemiaAge varies with etiology of ischemia

Acute precipitating cause is rareAcute precipitating cause is rare Acute precipitating cause is typicalAcute precipitating cause is typical

Patients do not appear illPatients do not appear ill Patients appear very illPatients appear very ill

Mild abdominal pain, tenderness presentMild abdominal pain, tenderness present Pain is usually severe, tenderness is not prominent earlyPain is usually severe, tenderness is not prominent early

Rectal bleeding, bloody diarrhea typicalRectal bleeding, bloody diarrhea typical Bleeding uncommon until very lateBleeding uncommon until very late

Colonoscopy is procedure of choiceColonoscopy is procedure of choice Angiography indicatedAngiography indicated

Data from: Reinus, JF, Brandt, LJ, Boley, SJ, Gastroenterol Clin North Am 1990; 19:319.


Clinical stages Clinical stages Hyperactive phaseHyperactive phase

Soon after initiating event, severe pain with frequent Soon after initiating event, severe pain with frequent bloody, loose stoolsbloody, loose stools

Paralytic phaseParalytic phase Pain diminishes, more continuous, and diffusePain diminishes, more continuous, and diffuse Abdomen more distended, tender, without BSAbdomen more distended, tender, without BS

Shock phase (10 to 20%)Shock phase (10 to 20%) Massive fluid, protein, and electrolyte leakage through Massive fluid, protein, and electrolyte leakage through

gangrenous mucosagangrenous mucosa Severe, shock and metabolic acidosis, may developSevere, shock and metabolic acidosis, may develop Rapid surgical intervention required Rapid surgical intervention required


DiagnosisDiagnosis

Largely based on clinical settingLargely based on clinical setting Physical examPhysical exam LaboratoryLaboratory

Stool cultures for suspected infectious causeStool cultures for suspected infectious cause Increase serum lactate, LDH, CPK, or Increase serum lactate, LDH, CPK, or

amylaseamylase Metabolic acidosisMetabolic acidosis Elevated white count >20,000 Elevated white count >20,000

Ischemic ColitisIschemic Colitis Radiological imaging/Endoscopic Radiological imaging/Endoscopic

studiesstudies Plain abdominal x-rayPlain abdominal x-ray Contrast studiesContrast studies Computed TomographyComputed Tomography

May be normal initiallyMay be normal initially Thickening of bowel wall in segmental Thickening of bowel wall in segmental

pattern and mesenteric strandingpattern and mesenteric stranding Pneumatosis and gas in mesenteric veins in Pneumatosis and gas in mesenteric veins in

advanced stagesadvanced stages EndoscopyEndoscopy


Endoscopy of ischemic colitis may reveal continuous necrosis and mucosal friability that resembles ulcerative colitis (left panel); discrete ulcers with surrounding edema may also be seen (right panel). Courtesy of James B McGee, MD.


ColonoscopyColonoscopy no evidence of peritonitis or perforationno evidence of peritonitis or perforation Preferred to contrast enemas, more sensitive in Preferred to contrast enemas, more sensitive in

detecting mucosal lesionsdetecting mucosal lesions Segmental distribution, abrupt transition Segmental distribution, abrupt transition

between injured and non injured mucosa, between injured and non injured mucosa, rectal sparing, and rapid resolution on serial rectal sparing, and rapid resolution on serial endoscopyendoscopy

““single-stripe sign” – linear ulcer along single-stripe sign” – linear ulcer along longitudinal axislongitudinal axis

Biopsies may show non-specific changes Biopsies may show non-specific changes (mimicking Crohn’s disease)(mimicking Crohn’s disease)

Ischemic ColitisIschemic Colitis Contrast studiesContrast studies

Thumbprinting most suggestive on double Thumbprinting most suggestive on double contrast study seen early in diseasecontrast study seen early in disease

In a small series of patients with mucosal In a small series of patients with mucosal ischemia 75% +thumbprinting, 60% ischemia 75% +thumbprinting, 60% longitudinal ulcers (source)longitudinal ulcers (source)

Ischemic ColitisIschemic Colitis Invasive studies – angiography, laparoscopy (dx Invasive studies – angiography, laparoscopy (dx

unclear or means to follow patient unclear or means to follow patient postoperatively)postoperatively) Angiography (rarely helpful)Angiography (rarely helpful) LaparoscopyLaparoscopy

Particularly in elderly with comorbid disease and may not Particularly in elderly with comorbid disease and may not tolerate laparotomytolerate laparotomy

““Second-look” to assess viability of remaining bowel Second-look” to assess viability of remaining bowel Only serosal gut visualization, which may appear normal in Only serosal gut visualization, which may appear normal in

early stages; progressive phase, dark peritoneal fluid, early stages; progressive phase, dark peritoneal fluid, edematous bowel, or patchy hemorrhages, frank gangrene, or edematous bowel, or patchy hemorrhages, frank gangrene, or perforation may be presentperforation may be present

Magnetic Resonance Angiography, Duplex Magnetic Resonance Angiography, Duplex sonography – hardly ever required for colonic sonography – hardly ever required for colonic ischemiaischemia


Differential DiagnosisDifferential Diagnosis Infectious colitisInfectious colitis

C. difficile, parasiticC. difficile, parasitic Inflammatory bowel diseaseInflammatory bowel disease DiverticulitisDiverticulitis Radiation enteritisRadiation enteritis Solitary rectal ulcer syndromeSolitary rectal ulcer syndrome Colon carcinomaColon carcinoma


Management Management Nonocclusive ischemiaNonocclusive ischemia SupportiveSupportive

IVF, bowel rest, empiric antibiotics (mod to IVF, bowel rest, empiric antibiotics (mod to severe cases)severe cases)

NGT (ileus)NGT (ileus) Hold meds that can promote ischemiaHold meds that can promote ischemia Optimize cardiac and pulmonary functionOptimize cardiac and pulmonary function

Laparotomy with resectionLaparotomy with resection Clinical deterioration despite conservative Clinical deterioration despite conservative

therapytherapy

Intraoperative determination of bowel salvageability. ACS Principles and Practice

Ischemic ColitisIschemic ColitisColonic infarctionColonic infarction Requires urgent surgical interventionRequires urgent surgical intervention Bowel prep should not be given prior to surgeryBowel prep should not be given prior to surgery Right-sided ischemia/necrosisRight-sided ischemia/necrosis

Right hemicolectomy with primary anastamosisRight hemicolectomy with primary anastamosis If perforation associated with peritonitis, resection with If perforation associated with peritonitis, resection with

terminal ileostomy mucocutaneous fistulaterminal ileostomy mucocutaneous fistula Left-sided involvementLeft-sided involvement

Proximal stoma and distal mucous fistula or Hartmann’s Proximal stoma and distal mucous fistula or Hartmann’s procedureprocedure

Ostomy closure delayed 4 to 6 monthsOstomy closure delayed 4 to 6 months Fulminating type (rare)Fulminating type (rare)

Total colectomy with end-ileostomyTotal colectomy with end-ileostomy Many advocate a 2Many advocate a 2ndnd look with 12 to 24 h to document look with 12 to 24 h to document

viabilityviability Mortality following large bowel infarction as high a Mortality following large bowel infarction as high a 50 to 50 to

75%75%

PrognosisPrognosis

Most patients with non-occlusive Most patients with non-occlusive ischemia improve within 1 or 2 daysischemia improve within 1 or 2 days

A minority develop long-term A minority develop long-term complicationscomplications Segmental colitis or strictureSegmental colitis or stricture

~15% develop severe gangrene~15% develop severe gangrene 5-yr survival 70-86% those that 5-yr survival 70-86% those that

survive surgical revascularizationsurvive surgical revascularization

No randomized controlled trials No randomized controlled trials Improved Outcome bv Identification of High-

Risk Nonocclusive Mesenteric Ischemia, Aggressive Reexploration, and Delayed

Anastomosis David Ward, MD et al. St. Louis, Missouri. Am J Surg. 1995 170:577-581

34 patients with NOMI34 patients with NOMI Retrospective study over 7years Retrospective study over 7years Concluded that improved survival depended on identification of high-risk Concluded that improved survival depended on identification of high-risk

groups, aggressive re-exploration, and delayed intestinal anastamosisgroups, aggressive re-exploration, and delayed intestinal anastamosis


Summary Summary

Most frequent form of Mesenteric Most frequent form of Mesenteric IschemiaIschemia

Spectrum of conditions and Spectrum of conditions and predisposing factorspredisposing factors

Early recognition and aggressive Early recognition and aggressive treatment essential to survivaltreatment essential to survival

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Ischemic Colitis