What is the management of mesenteric ischemia (mesenteric ischaemia) following blunt abdominal trauma?

Management of Mesenteric Ischemia Following Blunt Abdominal Trauma

Prompt surgical intervention is essential in managing mesenteric ischemia following blunt abdominal trauma, as delays in treatment significantly increase mortality, with odds of death increasing by 1% every 3 minutes in hemodynamically unstable patients. 1

Diagnosis

Initial Assessment

• High index of suspicion is critical as bowel injuries are often missed in blunt abdominal trauma 1
• CT scan with contrast is the primary diagnostic tool
• Look for specific CT findings:
  • Free air
  • Free fluid without solid organ injury
  • Intra-mesenteric fluid
  • Contrast extravasation (blush)
  • Bowel wall abnormality (thickening)
  • Mesenteric alteration (stranding) 1

CT Grading of Mesenteric Injury

McNutt's grading system 1:

Grade	CT Finding
1	Isolated mesenteric contusion
2	Mesenteric hematoma < 5 cm
3	Mesenteric hematoma > 5 cm
4	Mesenteric contusion or hematoma with bowel wall thickening and adjacent interloop fluid
5	Active vascular/oral contrast extravasation, bowel wall transection or pneumoperitoneum

Management Algorithm

Hemodynamically Unstable Patients

1. Immediate surgical exploration is mandatory when:

   • Large peritoneal effusion is present
   • Peritoneal signs are present
   • Pneumoperitoneum or intramural air is visible on CT 1

2. Damage control surgery (DCS) approach:

   • Abbreviated laparotomy with temporary abdominal closure
   • Allows reassessment of bowel viability
   • Particularly important in severe abdominal sepsis 1
   • Planned second-look procedure within 24-48 hours to avoid resection of potentially viable bowel 1

Hemodynamically Stable Patients

1. Highly specific CT findings requiring prompt surgical exploration:

   • Extraluminal air
   • Extraluminal oral contrast
   • Bowel wall defects 1

2. Endovascular interventions to consider:

   • Angiography with embolization for active mesenteric bleeding 2
   • Caution: Embolization carries risk of bowel ischemia 2

3. Non-operative management (NOM) may be appropriate when:

   • No active peritoneal bleeding
   • No bowel perforation
   • No signs of bowel infarction 1, 3

4. Laparoscopic approach may be considered in stable patients:

   • When radiologic survey suggests diaphragmatic or hollow viscus injury
   • To complete non-operative management 1
   • Reduces rate of non-therapeutic laparotomies 1

Critical Time Considerations

• Every 10-minute delay from admission to laparotomy increases 24-hour mortality by a factor of 1.5 1
• Delay of surgical treatment >24 hours after bowel perforation increases mortality fourfold 1
• Studies show increasing mortality rates with increasing time to surgical intervention:
  • 2% mortality when surgery <8 hours
  • 9% mortality when surgery 8-16 hours
  • 17% mortality when surgery 16-24 hours
  • 31% mortality when surgery >24 hours 1

Postoperative Care

• Directed toward improving intestinal perfusion
• Prevention of multiple organ failure
• ICU monitoring with focus on:
  • Fluid resuscitation
  • Optimization of cardiac output
  • Elimination of vasopressors when possible 1
  • Systemic anticoagulation may be considered

Pitfalls and Caveats

1. Delayed diagnosis is the most significant factor affecting mortality

   • Maintain high index of suspicion even with initially benign abdominal exam 3
   • Consider repeat imaging if clinical improvement is not apparent within 8 hours 1

2. Embolization risks

   • Potential for bowel ischemia as a major complication 2
   • Consider combined management (endovascular approach followed by surgical exploration) in selected cases 2

3. Vasospasm

   • Often accompanies occlusive mesenteric ischemia
   • Consider catheter-directed vasodilator infusion in selected cases 1

4. Long-term follow-up

   • Required to identify sequelae of mesenteric injuries 1
   • Clinical presentation may be delayed for weeks to months after initial trauma

Mesenteric ischemia following blunt abdominal trauma remains a challenging condition with high mortality. Early recognition, prompt intervention, and appropriate surgical or endovascular management are essential to improve outcomes.