Mesenteric Ischemia Lin ChiuMei

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Mesenteric IschemiaLin Chiu-Mei

• Emergency Department

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Key points

• Mechanism arterial emboli, thrombotic event,
  primary vasoconstriction, or venous thrombosis
• Classically present severe abdominal pain out of
  proportion to the findings on physical exam
• Ancillary tests barium studies are
  contraindicated, the angiography is the most
  useful
• Management of mesenteric ischemia medication or
  surgical intervention

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Anatomy and Regulation of the Mesenteric
Circulation

• Mesenteric circulation 10 to 15 cardiac output
• Mesenteric circulation 70 to mucosal and
  submucosal, 30 to muscularis and serosal layers
• Primary arterial supply to splanchnic bed the
  celiac artery, the superior mesenteric artery(
  SMA), the inferior mesenteric artery

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Anatomy and Regulation of the Mesenteric
Ischemia(continuous)

• Neural input via the sympathetic nervous system
• Humoral regulation vasopressin and
  angiotensin-the most potent blood-borne
  substance, exogenous vasoactive compounds e.g..
  Epinephrine,dopamine, norepinephrine
• Intrinsic control mechanisms metabolic control,
  myogenic control

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Pathophysiology of Mesenteric Ischemia

• Embolism the most frequent causes, SMA is the
  common site
• Acute thrombosis compromised vessel lumen, such
  as atherosclerotic lesion
• Nonocclusive mesenteric ischemia multifactial,
  usually involves moderate to severe mesenteric
  atheroslerosis, marginal cardiac reserve,
  administration of vasoactive agents

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Risk Factors of Mesenteric Ischemia

• Age gt 50 y/o
• Severe valvular atherosclerotic heart disease
• Congestive heart failure
• Cardiac arrhythmias
• Recent myocardial infarction

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Clinical Presentation of Mesenteric Ischemia

• Severe abdominal pain out of proportion to the
  findings on physical examination
• Intestinal angina occur 15 to 60 min after
  eating
• Cardiac arrhythmia
• Others shock, acidosis, hemoconcentration, sepsis

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Something important

• Early diagnosis and institution of therapeutic
  measures prior to bowel infarction is essential
  to decrease mortality.
• Diagnosis lt 24 hours, 60 patient survive
• Diagnosis gt 24 hours, lt 30 patient survive

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Ancillary tests in Mesenteric Ischemia

• Hemoconcentration, leukocytosis with left shift,
  metabolic acidosis, hyperamylasemia,
  hyperphosphatemia etc
• No single laboratory test, enzyme assay, or
  combination of the two has proved a reliable
  screening test for acute mesenteric ischemia.

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Reported Markers of Acute Mesenteric Ischemia

• Serum, urine, peritoneal phosphate
• Creatine phosphokinase
• Alkaline phosphatase and LDH
• Malondialdehyde
• Oxidized glutathione
• Diamine oxidase
• Hexosaminidae and I-FABP

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Ancillary Tests of Mesenteric Ischemia(continuous)
-Abdominal Film

• Adynamic ileus
• Small bowel dilation
• Edematous, thickened bowel walls
• Gasless abdomen
• Pneumatosis intestinals
• Portal venous gas

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Ancillary Tests of Mesenteric Ischemia(continuous)

• Angiography the most useful
• Colonscopy subacute colonic ischemia
• Barium studies usually contraindicated,
  thumbprinting ( focal mucosal hemorrhage )
• CT scan and ultrasonography for complementary
  evaluation

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Benefits of Early Angiographic Evaluation with
Suspected Acute Mesenteric Ischemia

• Diagnosis may be made early enough to intervene
  effectively and prevent further damage
• Determines site and nature of occlusion
• Provides direct vascular access for the infusion
  of vasodilatory agents
• Permits evaluation of vascular bed distal to
  obstruction

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Management of Mesenteric Ischemia

• Aggressive performance of angiography, control
  arrhythmia, and congestive heart failure
• Intraaterial infusion of paraverine, rate 30-60
  mg/hr, for at least 24 to 48 hours
• Surgical management of acute mesenteric ischemia
  is both challenging and controversial.
• Fluid supply and administration of both heparine
  antibiotics
• Second-look operation, permit a more limited
  resection

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Case Presentation

• 59 y/o male patient suffered from abdominal pain
  intermittent, vomiting, and no stool passage for
  5 days
• Past Hx. DM, uremia with regular H/D, CAD s/p
  CABG twice
• Clinical manifestations septic shock with
  metabolic acidosis, fever, obscure conscious level

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Case Presentation Imaging and Operative Findings

• Images findings SMA and SMV total occlusion,
  pneumatosis of portal system
• Operative findingsalmost all intestines
  gangrenous changes