What is the workup and management for a suspected strangulated hernia?

Workup and Management of Suspected Strangulated Hernia

Patients with suspected intestinal strangulation should undergo immediate emergency hernia repair, as delayed intervention significantly increases mortality rates. 1

Clinical Evaluation for Strangulation

• Systemic Inflammatory Response Syndrome (SIRS) - fever, tachycardia, and leukocytosis are key indicators of strangulated obstruction 1, 2
• Laboratory markers with high predictive value for bowel strangulation:
  • Elevated lactate levels 1, 2
  • Increased serum creatinine phosphokinase (CPK) 1, 2
  • Elevated D-dimer levels 1, 2
• Physical examination findings suggestive of strangulation:
  • Continuous abdominal pain 2
  • Abdominal wall rigidity 2
  • Obvious peritonitis 2
• Risk factors for requiring bowel resection:
  • Symptomatic periods lasting longer than 8 hours 1, 2
  • Presence of comorbid disease and high ASA scores 1
  • Femoral hernia (OR = 8.31) 1, 2
  • Delayed treatment (>24 hours from symptom onset) 1, 3

Diagnostic Approach

• Contrast-enhanced CT is recommended when strangulation is suspected 1, 2
• Diagnostic laparoscopy may be useful for assessing bowel viability after spontaneous reduction of strangulated groin hernias 1
• Early intervention (<6 hours from symptom onset) is associated with significantly lower incidence of bowel resection (OR 0.1) 3

Surgical Management Algorithm

1. Immediate surgical intervention when strangulation is suspected 1

2. Surgical approach based on CDC wound classification:

   • Class I (Clean): Intestinal incarceration without ischemia

     • Prosthetic repair with synthetic mesh recommended 1
     • Short-term antibiotic prophylaxis 1, 2
     • Laparoscopic approach may be used 1, 4

   • Class II (Clean-contaminated): Strangulation with bowel resection without gross spillage

     • Synthetic mesh repair still recommended 1
     • 48-hour antimicrobial prophylaxis 1, 2
     • Open preperitoneal approach preferable 1

   • Class III/IV (Contaminated/Dirty): Bowel necrosis with spillage or perforation

     • For small defects (<3 cm): Primary repair recommended 1
     • For larger defects: Biological mesh if available 1
     • If biological mesh unavailable: Polyglactin mesh or open wound management with delayed repair 1
     • Full antimicrobial therapy recommended 1, 2

3. For unstable patients with sepsis/septic shock:

   • Open management to prevent abdominal compartment syndrome 1
   • Measure intra-abdominal pressure intraoperatively 1
   • After stabilization, attempt early definitive closure 1

Outcomes Based on Timing

• Mortality rates directly correlate with time to intervention:

  • 40% overall mortality for strangulated hernias 5
  • 86% mortality for patients with small bowel necrosis 5
  • 89% mortality for patients admitted after 96 hours of strangulation 5

• Bowel resection rates:

  • 80% resection rate for strangulation lasting over 72 hours 5
  • 24.1% overall bowel resection rate in emergency hernia repairs 6

Mesh Use in Contaminated Fields

• Despite traditional concerns, recent evidence supports mesh use even in contaminated fields 7
• In a prospective study of 153 patients with incarcerated/strangulated hernias:
  • Overall infection rate was only 3.3% with mesh repair 7
  • No patients required mesh removal despite infections 7
  • No recurrences were observed 7

Common Pitfalls and Caveats

• Early detection of progression from incarceration to strangulation is difficult by clinical or laboratory means alone 1, 2
• Delayed diagnosis leads to septic complications and increased mortality 1, 2
• Elapsed time from symptom onset to surgery is the most important prognostic factor 1, 2
• Component separation technique may be useful for large midline abdominal wall hernias 1