How can I rule out ischemia to a stoma site?

Ruling Out Ischemia in a Stoma Site

CT angiography with IV contrast is the most effective method to rule out ischemia to a stoma site, as it provides high diagnostic accuracy for detecting intestinal ischemia with sensitivity of 93% and specificity of 100%. 1

Clinical Assessment

Before imaging, perform a targeted assessment:

• Inspect the stoma for:

  • Color changes (dusky, purple, or black areas indicate ischemia)
  • Mucosal edema
  • Bleeding or drainage
  • Lack of bleeding when the mucosa is gently touched (suggests ischemia)

• Check for:

  • Abdominal pain "out of proportion to physical findings" (classic sign of mesenteric ischemia) 2
  • Abdominal distension
  • Signs of peritonitis (indicating advanced ischemia)

Diagnostic Tests

First-Line Approach: Video-Assisted Test Tube Test

• Insert a clear plastic tube into the stoma and use a video bronchoscope to visualize the mucosa 3
• This bedside technique allows assessment of mucosal color and viability beyond the surface
• Look for:
  • Pink, viable mucosa (normal)
  • Dusky or dark mucosa (concerning for ischemia)
  • Depth of any ischemic changes

Laboratory Tests

While not definitive, these can support clinical suspicion:

• Elevated lactate (>2 mmol/L suggests irreversible intestinal ischemia) 1
• Leukocytosis (present in >90% of intestinal ischemia cases) 1
• D-dimer >0.9 mg/L (specificity 82%, sensitivity 60%) 1
• Metabolic acidosis (found in 88% of cases) 1

Definitive Imaging: CT Angiography

• CT angiography with IV contrast is the gold standard for diagnosis 2

• Protocol should include:

  • No oral contrast (may delay diagnosis and increase aspiration risk) 2, 1
  • Arterial and venous phases
  • Multi-planar reconstructions 2, 1

• Look for specific CT findings of ischemia:

  • Abnormal bowel wall enhancement (decreased or increased)
  • Bowel wall thickening
  • Pneumatosis intestinalis (gas in bowel wall)
  • Mesenteric edema
  • Portal venous gas
  • Free intraperitoneal fluid 2

Important Considerations

• Do not delay CT imaging even in patients with renal dysfunction, as the consequences of missed ischemia are more detrimental than contrast exposure 2, 1

• Avoid duplex ultrasound for acute ischemia assessment as it is technically challenging and unreliable in this setting 2

• Ensure proper stoma care to prevent ischemia:

  • Make incision sufficiently large (8 mm) to prevent pressure-related ischemia 2
  • Avoid excessive tension on the external fixation plate 2
  • Allow free movement of the tube of at least 5 mm 2

When to Pursue Surgical Intervention

Immediate surgical consultation is warranted if:

• Stoma appears frankly necrotic
• CT findings show definitive ischemia
• Patient has peritoneal signs
• Video-assisted test tube test shows ischemia extending to the fascia 3

Early detection and intervention are critical, as intestinal ischemia carries a high mortality rate (30-70%) when diagnosis is delayed 1.