SURGICAL JOURNAL CLUB

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SURGICAL JOURNAL CLUB

• ACUTE MESENTERIC ISCHAEMIA
• Razvan Stoita

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Case presentation

• Mr KL 66 yo male
• Background
• Liver cirrhosis secondary to ETOH
• Portal hypertension and hypersplenism with
  secondary pancytopenia
• Ascites with recent admission to ICU for SBP (E.
  coli) on prophylactic Norfloxacin
• Myelodysplasic syndrome
• Monthly blood transfusions and twice weekly G-CSF
• Atrial fibrillation/Flutter
• .

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Presentation

• 3 days history of severe RUQ pain and vomiting.
• Temp 37.6, HR 150 (A flutter), BP 93/59, RR 22.
• Oliguria.
• Abdomen tense and tender. Ascites.
• Acidotic (ph 7.23, lactate 8.5), Acute renal
  failure (creatinine 357), Pancytopenia (WCC 1.65,
  Neutrophils 1.2, PLT 26), Coagulopathy (INR 2.0)
• Non contrast abdominal CT thick walled small
  bowel. Cannot exclude ischaemia.

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Progress and management

• Fluid resuscitated, iv AB.
• Inotropic and oxygen support.
• Surgical review regarding possibility of
  ischaemic bowel.
• Following day intubated, dialysed.
• OT no evidence of bowel ischaemia.
• Rapid deterioration with subsequent death 2 days
  after presentation.

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ACUTE MESENTERIC ISCHAEMIA

• DIAGNOSIS

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SEROLOGIC MARKERS

• Leukocytosis
• CK
• Lactate and metabolic acidosis
• AST and ALP
• Diamine oxidase and hexosaminidase
• Intestinal fatty acid binding protein
• a-subunit of glutathione S-transferase
• 97-100 sensitive and 80 accurate when combined
  with lactate or WCC

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RADIOLOGIC TESTS

• Angiography
• Gold standard
• Sensitivity 90-100 Specificity 100
• Disadvantages limited availability, renal
  toxicity, expensive, time constraints
• Computed tomography angiography
• Magnetic resonance angiography
• Mainly used in the evaluation of CMI
• Lacks adequate resolution to diagnose AMI
• Other tests plain films, standard abdominal CT,
  Doppler ultrasound

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Other diagnostic tests

• Laparoscopy
• Colonoscopy routine in diagnosing colonic
  ischaemia
• Tonometry
• Peritoneal lavage

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Biphasic CT with Mesenteric CT Angiography in the
Evaluation of Acute Mesenteric Ischaemia Initial
Experience

• Radiology, 2003

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Purpose of the study

• To prospectively evaluate the sensitivity and
  specificity of biphasic abdominal CT with
  mesenteric CT angiography in the diagnosis of
  acute mesenteric ischaemia.

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Selection Criteria

• Clinical suspicion of AMI included abdominal
  pain, risk factors for ischaemia or biochemical
  evidence of ischaemia
• Exclusion criteria contraindication to the
  intravenous contrast agent (8 patients)
• 62 patients examined 21 males and 41 females
• The patients were later divided in two groups
  patients with proven AMI and a control group (no
  AMI)

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Imaging Evaluation

• Four-row multi-detector row CT scanner
• Oral contrast (water) and iv contrast
• Arterial and portal phase CT image acquisition
• Scans were prospectively evaluated by two
  radiologists
• Findings reported as consistent with, concerning
  for, or diagnostic of mesenteric ischaemia were
  considered positive for AMI

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Radiologic criteria studied

• Bowel wall thickening
• Mucosal enhancement
• Focal lack of bowel enhancement
• Bowel dilatation
• Bowel obstruction
• Mesenteric stranding
• Ascites
• Solid organ infarction
• Free intraperitoneal air

• Pneumatosis intestinalis
• Superior mesenteric or portal vein gas or
  thrombosis
• Arterial stenosis
• Occlusion in the celiac, superior mesenteric and
  inferior mesenteric arterial systems

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Statistical analysis

• The sensitivity and specificity of each
  individual CT sign were calculated using the
  patients in the control group
• Retrospective optimization of the sensitivity and
  specificity was performed using possible
  combinations of defined radiologic criteria

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Results

• 26 of 62 patients had AMI. 9 males and 17
  females. 25 patients had surgical or pathologic
  proof of AMI.
• 21 patients had an alternative diagnosis
  according to CT findings.
• 6 patients had normal CT.
• 9 patients had non specific findings on CT
• 4 patients had a false-positive diagnosis of AMI

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CT findings

• Pneumatosis intestinalis, isolated SMA occlusion,
  celiac and IMA occlusion with distal SMA disease,
  arterial embolism or venous gas were each 100
  specific and 73 sensitive for AMI
• Bowel wall thickening in addition to either focal
  lack of bowel enhancement, solid organ infarction
  or venous thrombosis was 50 sensitive and 94
  specific
• AMI diagnosis based on either of these criteria
  can theoretically achieve an optimal calculated
  sensitivity of 96 and specificity of 94.
• With these criteria one false negative and two
  false positives would have been obtained

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CT Angiographic findings

• 8 patients with proven AMI showed arterial
  abnormalities on CT angiography
• 2 of 8 patients had vascular abnormalities
  readily identifiable on the portal phase image
• 2 patients had only CT angiographic findings
• Mesenteric angiogram altered treatment in 5 (19)
  of 26 patients with ischaemia

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Patient outcomes

• 11 (42) of the 26 patients with bowel ischaemia
  died while in the hospital
• SMA or portal venous gas, pneumatosis
  intestinalis, free intraperitoneal air and solid
  organ infarction were more common in patients who
  died

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Conclusions

• Biphasic CT with mesenteric CT angiography is
  effective in diagnosing mesenteric ischaemia with
  a sensitivity of 96 and a specificity of 94.
• CT angiography provides diagnostic and management
  benefits in patients with mesenteric ischaemia.

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Pros Cons

• Prospective study
• Clear imaging protocol
• A final diagnosis was made in most cases
• Encouraging results

• Relatively small case load
• Unclear categorization criteria
• Selection bias with regards to sex and outcome