Transcript ischemic colitis

Ischemic Colitis
Ri 陳宏彰
Reference books
 Harrison’s
online 15th
 Marx: Rosen's Emergency
Medicine: Concepts and Clinical
Practice, 5th ed., Copyright © 2002
Mosby, Inc
Ischemic Colitis
Ischemia of the colon most often affects
the elderly (90% of patients > 60 y/o ).
 Ischemic colitis is almost always
nonocclusive. (emboli are the most common cause

of acute mesenteric ischemia)

Shunting of blood away from the
mucosa may contribute to this condition,
but the mechanism is unknown.
Ischemic Colitis
Most patients ischemia occurs
secondary to arteriolar shunting,
spasm, or poor perfusion of mucosal
vessels.
 Most cases involve the splenic flexure,
which is supplied by end-arteries.
 The rectum is usually spared, because
its blood supply is different from the rest
of the colon and less dependent on the
inferior mesenteric artery .

Marx: Rosen's Emergency Medicine: Concepts and Clinical Practice, 5th ed
Types of Ischemic Colitis
Acute fulminant ischemic
colitis
2. Subacute ischemic colitis
1.
HARRISON’S ONLINE 15TH
Types of Ischemic Colitis
Gangrenous
ischemic
colitis
a complete loss of arterial flow causes bowel
wall infarction and gangrene, which can
progress to perforation, peritonitis, and death.
Stricturing
ischemic
colitis
Transient
ischemic
colitis
a gross impairment of the arterial supply,
leading to hemorrhagic infarction of the
mucosa, which ulcerates, heals by fibrosis,
and finally leads to stenosis.
a transient, reversible impairment of the
arterial supply, which causes a partial
mucosal slough that heals by mucosal
regeneration in a few days. the most common
Marx: Rosen's Emergency Medicine: Concepts and Clinical Practice, 5th ed
Acute fulminant ischemic colitis
manifestations
1.
2.
3.
The onset is characteristically acute,
with generalized lower abdominal
pain, usually in the left lower
quadrant, followed within 24 hours by
bloody diarrhea or rectal bleeding .
Dilation of the colon and physical signs
of peritonitis are seen in severe cases.
With the gangrenous type, both
symptoms and signs progress rapidly.
Acute fulminant ischemic colitis
Diagnostic Strategy
 No specific serum markers proven in the
diagnosis of intestinal ischemia.
 Abdominal films may reveal
thumbprinting from submucosal
hemorrhage and edema .
* (barium enema is contraindicated in cases of
gangrenous ischemic colitis because of the risk of
perforation
)
thumbprinting
Acute fulminant ischemic colitis
Diagnostic Strategy

Sigmoidoscopy or colonoscopy may
detect ulcerations, friability, and bulging
folds from submucosal hemorrhage.
(Colonoscopy is preferred over sigmoidoscopy )

The segmental distribution and rectal
sparing of the disease process are
suggestive but are not diagnostic.
Colonoscopic view showing marked
erythema and exudate in sigmoid colon
Endoscopic view of mucosal edema,
exudates, and ulcerations in sigmoid colon
Endoscopic image of descending colon showing
severe colitis with pneumatosis intestinalis.
Acute fulminant ischemic colitis
Diagnostic Strategy
 Angiography
is not helpful in the
management of patients with
presumed ischemic colitis because
a remediable occlusive lesion is
very rarely found.

CT scan is normal in early stages of
bowel infarction, although it may show
nonspecific findings such as bowel wall
thickening and pneumatosis.
CT showing left sided colonic
thickening.
Pneumatosis Intestinalis
Pneumatosis Intestinalis
Acute fulminant ischemic colitis
management
 When
ischemic colitis is
suspected, a surgeon should be
consulted.
 Gangrenous ischemic colitis or
evidence of perforation requires
immediate surgery as soon as
the patient is stabilized.
management
 Vasopressors
should be avoided, if
possible.
 Low blood-flow states
(hypotension) should be
aggressively reversed.
Types of Ischemic Colitis
Acute fulminant ischemic
colitis
2. Subacute ischemic colitis
1.
Subacute ischemic colitis
manifestations
 It
produces lesser degrees of pain
and bleeding, often occurring over
several days or weeks.
 The left colon may be involved, but
the rectum is usually spared
because of the collateral blood
supply.
Subacute ischemic colitis
management
 Subacute
Ischemic colitis without
evidence of peritonitis or perforation
is generally self-limited and
requires only conservative
management, including bowel rest,
parenteral fluids, and antibiotics.
Subacute ischemic colitis
management
 Most
cases of nonocclusive
ischemic colitis resolve in 2 to 4
weeks and do not recur.
 Surgery is not required except for
obstruction secondary to
postischemic stricture.
Differential Considerations
Ischemic colitis often mimics
infectious colitis, inflammatory bowel
disease, or even colon carcinoma.
 Many cases of colitis in the elderly once
considered to be Crohn’s disease or
ulcerative colitis in retrospect were really
colonic ischemia.

Differential Considerations

The features considered atypical in
inflammatory bowel diseases , such as
1.segmental distribution of the disease, infrequent
rectal involvement,
2.high rate of spontaneous recovery, low rate of
recurrence,
3.lack of adequate response to usual inflammatory
bowel disease therapy,
4.frequent progression to fibrotic stenosis with delayed
obstruction
 The features above are now recognized as
characteristic of colonic ischemia.
Differential Considerations
 Always
consider the diagnosis of
ischemic colitis whenever
contemplating the diagnosis of
inflammatory bowel disease in an
elderly patient.
Differential Diagnosis
Clinical
Radiologic
Ulcerative
colitis
Bloody diarrhea
Extends proximally from rectum; fine
mucosal ulceration
Crohn’s
colitis
Perianal lesions
common; frank
bleeding less
frequent than in
ulcerative colitis
Segmental disease; rectal sparing;
strictures, fissures, ulcers, fistulas;
small bowel involvement
Ischemic
colitis
Older age groups;
vascular disease;
sudden onset, often
painful
Splenic flexure; “thumb printing”;
rectal involvement rare
Conclusions
Always consider the diagnosis of
ischemic colitis whenever
contemplating the diagnosis of
inflammatory bowel disease in the elderly.
 Thumbprinting of the colon on plain
abdominal radiographs suggests
ischemic colitis.
 Surgical consultation is warranted in all
cases of suspected ischemic colitis.

Thanx for your attention