What is the next step in management for an older patient with diffuse abdominal pain and severe atherosclerosis (hardening of the arteries) on CT scan, suspected of having mesenteric ischemia?

Immediate Next Step: CT Angiography (CTA) of the Abdomen and Pelvis

Your patient with diffuse abdominal pain and severe atherosclerosis on CT requires immediate CT angiography (CTA) with triple-phase imaging (non-contrast, arterial, and portal venous phases) to evaluate for mesenteric ischemia, as this is a life-threatening emergency with mortality rates approaching 60% if diagnosis and intervention are delayed. 1, 2

Why CTA is Critical Now

• CTA is the preferred diagnostic imaging modality for suspected mesenteric ischemia, as it can identify the underlying cause (arterial occlusion, thrombosis, embolism, or venous thrombosis), evaluate for bowel complications, and guide intervention planning 1, 2

• The triple-phase protocol is essential because:

  • Arterial phase detects arterial stenosis, embolism, thrombosis, or dissection 2
  • Portal venous phase identifies mesenteric vein thrombosis 2
  • Non-contrast phase reveals intramural hyperdensity suggesting hemorrhage or ischemia 2

• Critical imaging findings to look for include:

  • Arterial occlusion or filling defects in the superior mesenteric artery (SMA) 1
  • Bowel wall thickening with abnormal enhancement (decreased or increased) 2
  • Pneumatosis intestinalis or portal/mesenteric venous gas (indicating advanced ischemia requiring immediate surgery) 1, 2
  • Mesenteric edema and ascites 2

Clinical Context Matters

Your patient's severe atherosclerosis raises two distinct possibilities:

Acute-on-Chronic Mesenteric Ischemia

• Atherosclerotic disease is the most common cause of both acute thrombotic occlusion and chronic mesenteric ischemia 1, 3
• Patients with chronic disease may have had subtle warning symptoms: postprandial pain, weight loss, or food fear (sitophobia) 1, 4
• At least two of the three main mesenteric vessels (celiac, SMA, inferior mesenteric artery) typically need to be affected before symptoms develop due to extensive collateral circulation 1, 3, 4

Acute Thrombotic Occlusion

• Occurs at sites of pre-existing atherosclerotic plaque and presents less dramatically than embolic disease 5
• Mortality approaches 50-85% when peritonitis develops, making early diagnosis paramount 5

Common Pitfall to Avoid

Do not be falsely reassured by minimal physical examination findings. The classic presentation of mesenteric ischemia is severe abdominal pain that is disproportionate to physical examination—the abdomen may appear benign despite life-threatening ischemia 1, 2. This is why your clinical suspicion based on atherosclerosis and diffuse pain is appropriate.

Immediate Management While Awaiting CTA

• Start aggressive fluid resuscitation 5
• Initiate broad-spectrum antibiotics 1, 5
• Begin systemic anticoagulation with intravenous unfractionated heparin (unless contraindicated) 5
• Check serum lactate levels—elevated lactate >2 mmol/L suggests irreversible intestinal ischemia 2
• Obtain surgical consultation immediately if any peritoneal signs are present 2, 5

Decision Algorithm Based on CTA Results

If CTA Shows Arterial Occlusion WITHOUT Peritonitis:

• Endovascular revascularization is first-line (angiography with aspiration embolectomy, thrombolysis, or angioplasty/stenting) 1, 5
• Endovascular approaches have shown decreased bowel resection, lower mortality, and reduced short bowel syndrome compared to primary surgery 1

If CTA Shows Signs of Bowel Infarction (pneumatosis, portal venous gas) OR Patient Has Peritonitis:

• Emergency laparotomy is mandatory—do not attempt endovascular therapy first 1, 5
• Surgical revascularization should be performed at the time of surgery 5

If CTA Shows Chronic Stenosis of Multiple Vessels Without Acute Occlusion:

• Endovascular therapy with angioplasty and stent placement is now favored over open surgery as first-line treatment 5, 4
• Technical success rates are 85-100% with stenting 5

If CTA Shows No Occlusion But Narrowing of Peripheral Vessels:

• Consider non-occlusive mesenteric ischemia (NOMI), which requires treatment of underlying causes (cardiac failure, shock) rather than revascularization 1, 5
• Catheter-directed vasodilator therapy may be beneficial 1, 5

High-Risk Features Requiring Immediate Action

• Age >75 years: mesenteric ischemia is more common than appendicitis as a cause of acute abdomen in this age group 2
• Leukocytosis (present in >90% of cases) and metabolic acidosis with elevated lactate (88% of cases) suggest advanced disease 2
• Any peritoneal signs mandate immediate surgical consultation before completing imaging 2, 5