Lower GI Bleeding

1
Lower GI Bleeding

• 4/6/11

2
LGIB

• Distal to ligament of Treitz
• Annual incidence rate of 20.5/100,000
• Male predominance
• Incidence of significant bleeding increases with
  age
• May suggest changes associated with the small
  intestine and colon
• Reflects the prevalence of diverticulosis and
  angiodysplasia in the elderly

3
LGIB

• May present as melena or hematochezia
• Melena typically suggests bleeding from a more
  proximal source (colon or small intestine)
• Hematochezia suggests left colonic, rectal, or
  anal sources
• Upper gastrointestinal hemorrhage may present
  with rectal bleeding given bloods cathartic
  effect and rapid intestinal transit (10-15 of
  cases)

4
LGIB

• Most often the intestinal bleeding resolves
  spontaneously
• Once it resolves, investigations should begin to
  identify the potential sources
• On occasion, the intestinal hemorrhage does not
  resolve
• Creates hemodynamic compromise
• Ongoing hemorrhage demands aggressive medical and
  surgical management
• Oftentimes patients are plagued with significant
  comorbidities that complicate their individual
  resuscitation
• Comorbidities must be considered in the
  diagnostic and therapeutic phases of the care
  plan
• Current increased patient exposure to
  antiplatelet therapy associated with treatment of
  cardiovascular conditions may increase the
  comorbid challenges in patients with lower
  gastrointestinal massive hemorrhage

5
Etiology

• Diverticula
• Angiodysplasia
• Ischemic colitis
• Inflammatory bowel disease
• Intestinal tumors or malignancies
• NSAID-related nonspecific colitis
• Meckels diverticulum
• Anorectal diseases

6
Diverticular disease

• Outpouchings of the mucosa and submucosa through
  defects in the muscular layer of the bowel at
  sites of penetration of the vasa recta
• Thinning of the media in the vasa recta
  predisposes to intraluminal rupture focal injury
  may occur from trauma related to a fecalith
• incidence spans a range of 15 to 48
• relatively rare event affecting only 417 of
  patients with diverticulosis

7
Diverticular disease

• Operative management is indicated when bleeding
  continues unabated and is not amenable to
  angiographic or endoscopic therapy
• Should be considered in patients with recurrent
  bleeding localized to the same colonic segment
• In a stable healthy patient, the operation
  consists of a segmental bowel resection (usually
  a right colectomy or sigmoid colectomy) followed
  by a primary anastomosis

8
Angiodysplasia

• Thin-walled arteriovenous communications located
  within the submucosa and mucosa of the intestine
• May be congenital or acquired, isolated or
  multiple
• In the acquired form, distortions of the
  postcapillary venules may arise as a degenerative
  lesion associated with increases in intraluminal
  pressure
• Results in thickening and ectasia
• The vessels eventually entangle as tufts within
  the submucosa and erode into the mucosa proper

9
Angiodysplasia

• Colonoscopic criteria
• Mucosal surface contains a cherry red lesion that
  is typically flat
• Greater than 2 mm in size
• Have a fern-like appearance
• A central feeding vessel is not always visible

10
Occult Hemorrhage

• Occurs infrequently
• no more than 5 of all patients admitted with LGI
  massive hemorrhage
• Frequent recurrences create chronic anemic states
  in patients and require occasional admissions for
  transfusions
• May harbor angiodysplasias in the small intestine
  or right colon
• May benefit from small bowel contrast radiography
  or capsule endoscopy
• Elective angiography with cecal magnification may
  reveal small angiodysplasias

11
Occult Hemorrhage

• If the hemorrhage recurs and investigations fail
  to reveal the source, a variety of provocative
  diagnostic angiographic studies have been
  described
• Most studies prefer to incite bleeding using
  either heparin or thrombolytics
• Once the site of bleeding is identified, it may
  be difficult to control without surgery
• Prepare and hold an operating room
• Once the location is identified, a superselective
  catheter is left in the distal artery
• During surgery, the surgeon can palpate the
  catheter within the vessel and direct the
  surgical resection

12
Initial Assessment

• Establish IV access (large bore) and start IV
  fluids
• restore volume and replete red blood cell
  deficiencies
• Labs
• CBC, electrolytes, coags, type and cross
• All coagulopathies require reversal!
• NG tube placed will screen for the presence of
  upper gastric sources for bleeding
• Kovacs and Jensen noted 17.9 of LGI hemorrhage
  presentations involved an upper gastrointestinal
  source
• NG tube is effective in detecting prepyloric
  hemorrhage

13
Evaluation

• Digital anorectal examination and anoscopy
• Rigid proctosigmoidoscopy will allow the examiner
  to evacuate the rectum of blood and clots
• Excludes internal hemorrhoids, anorectal solitary
  ulcers, neoplasms, and colitis
• Colonoscopy and angiography offer therapeutic
  intervention
• Nuclear scanning is purely diagnostic

14
Evaluation

• subdivide patients into 3 general clinical
  categories
• minor and self-limited
• major and self-limited
• major and ongoing
• Major ongoing hemorrhage requires prompt
  intervention with angiography or surgery
• Minor, self-limited may undergo colonic lavage
  and colonoscopy within 24 hours
• Major, self-limited need diagnostic tests to
  determine if they require prompt therapy or
  observation

15
Radionuclide imaging

• Detects the slowest bleeding rates
• 0.10.5 mL/min
• More sensitive than angiography
• Unfortunately cannot reliably localize the site
  of hemorrhage
• The specificity of small bowel versus large
  intestine bleeding does not reliably compare with
  angiography
• Two general techniques
• technetium sulfur colloid scans
• 99mTc pertechnetate-tagged RBCs

16
Radionucleotide imaging

• Immediate positive blush (within the first 2
  minutes of scanning)
• highly predictive of a positive angiogram (60)
• predictive for surgery in 24
• If study did not demonstrate a blush
• highly predictive of a negative angiogram (93)
• the need for surgery decreased to 7

17
Colonoscopy

• If the patient appears stable with self-limited
  hemorrhage, colonoscopy is the preferred
  diagnostic study
• Major benefit depends on ability to provide a
  definitive localization of ongoing active
  bleeding and the potential for therapy
• Many landmarks for colonoscopy may be obscured
  during hemorrhage
• Once the endoscopist highlights a bleeding
  source, the region requires a tattoo to mark the
  site
• If the hemorrhage continues and fails medical
  management, the tattoo assists in localizing the
  hemorrhage
• Therapeutic armamentarium i
• thermal agents such as heater probes, bipolar
  coagulation, and laser therapy
• Injection therapy uses topical and intramucosal
  epinephrine
• Mechanical therapy includes endoscopically
  applied clips

18
Angiography

• Diagnostic and therapeutic
• Acute, major hemorrhage with ongoing bleeding
  requires emergency angiography
• Patients with an early blush during nuclear
  scintigraphy may benefit from therapeutic
  angiography
• May define a potential source for hemorrhage in
  occult and recurrent gastrointestinal hemorrhage
• Requires a hemorrhage rate of at least 1 mL/min
• Yields range from 40 to 78

19
Angiography

• Highly accurate localization provides for focused
  therapy
• Intraarterial vasopressin infusion
• 0.2 U/min up to 0.4 U/min
• Systemic effects and cardiac impact may limit
  maximizing the dosage
• Controls bleeding in 91 of patients
• Bleeding may recur in up to 50 of patients
• Arterial embolization
• Superselective mesenteric angiography with
  microcatheters in the vasa recta
• Vessels as small as 1 mm
• Risk of intestinal infarctions of larger
  selective vessels may exceed 20
• Provides immediate arrest of the bleeding
• Combination of agents to control bleeding
• Gelfoam pledgets, coils, and polyvinyl alcohol
  particles
• Arteriography also has complications
• arterial thrombosis, distant arterial emboli, and
  renal toxicity from dye

20
Operative therapy

• Few patients currently require surgical treatment
• Hemodynamically unresponsive to initial
  resuscitation
• Site of hemorrhage localized, but available
  therapeutic interventions fail to control the
  bleeding
• Patient mortality increases with their
  transfusion requirements
• Once reaches 67 units and the hemorrhage remains
  ongoing, surgical intervention becomes eminent
• First objective in surgery focuses on the
  location of the intraluminal blood with the goal
  of segmentally isolating the possible sources of
  bleeding
• if no source appears obvious, may consider
  intestinal enteroscopy

21
Operative therapy

• If the source of bleeding cannot be found, and it
  appears to arise from the colon, the surgeon
  should perform a subtotal or total colectomy
• Stable patients will tolerate a primary
  ileosigmoid or ileorectal anastomosis
• Unstable patients require an end ileostomy with
  closure of the rectal stump or a mucous fistula
• Once stable, the patient may return for ileostomy
  closure.
• The rectum and sigmoid colon require
  reexamination endoscopically to assure no
  bleeding persists.

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Algorithm
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