What are the signs and management of suspected incarcerated or strangulated inguinal hernia?

Signs and Management of Incarcerated or Strangulated Inguinal Hernia

Immediate surgical intervention is mandatory when intestinal strangulation is suspected to prevent bowel necrosis and increased morbidity and mortality. 1

Clinical Signs of Strangulation

• Systemic Inflammatory Response Syndrome (SIRS) - fever, tachycardia, and leukocytosis are common indicators of strangulated obstruction 1
• Laboratory markers - elevated lactate, serum creatinine phosphokinase (CPK), and D-dimer levels are predictive of bowel strangulation 1
• Imaging findings - contrast-enhanced CT findings suggesting strangulation 1, 2
• Physical examination - continuous abdominal pain, abdominal wall rigidity, and obvious peritonitis 1
• High white blood cell count and elevated fibrinogen levels are significantly predictive of complications 2

Risk Factors for Bowel Resection

• Symptomatic periods lasting longer than 8 hours 1
• Presence of comorbid disease and high ASA scores 1
• Femoral hernia (OR = 8.31) 1
• Obvious peritonitis (OR = 11.52) 1
• Delayed treatment (>24 hours from symptom onset) significantly increases mortality rates 1, 3

Management Algorithm

1. Initial Assessment

• Determine if hernia is reducible or incarcerated/strangulated 4
• Assess for signs of SIRS, peritonitis, or bowel ischemia 1
• Consider laboratory tests (WBC, lactate, CPK, D-dimer) 1

2. Timing of Intervention

• Early intervention (<6 hours from symptom onset) is associated with significantly lower incidence of bowel resection (OR 0.1) 3
• Immediate surgical repair is mandatory when intestinal strangulation is suspected 1

3. Surgical Approach

• For clean surgical fields (no bowel gangrene):

  • Prosthetic repair using synthetic mesh is recommended 2, 4
  • Local anesthesia can be used in the absence of bowel gangrene 2
  • Laparoscopic approach (TAPP or TEP) is associated with decreased recurrence rates (OR 0.75) and shorter hospital stays 3, 5, 6

• For clean-contaminated fields:

  • Emergent prosthetic repair with synthetic mesh is still recommended 2
  • Significantly lower risk of recurrence compared to tissue repair 2, 7

• For contaminated or dirty fields (bowel resection needed):

  • Primary tissue repair for small defects 2
  • Biological mesh or polyglactin mesh as alternatives 2
  • General anesthesia should be preferred when bowel gangrene is suspected or intestinal resection is needed 2

4. Special Techniques

• Hernioscopy (laparoscopy through hernia sac) is effective for evaluating viability of herniated bowel 2, 4
• Component separation technique may be useful for large defects 2
• For indirect hernias requiring laparoscopic approach, the deep internal ring may need to be divided anteriorly to facilitate dissection 6

5. Antimicrobial Prophylaxis

• Short-term prophylaxis for intestinal incarceration without ischemia 2
• 48-hour antimicrobial prophylaxis for intestinal strangulation and/or concurrent bowel resection 2

Common Pitfalls and Caveats

• Early detection of progression from incarceration to strangulation is difficult by clinical or laboratory means alone 1
• Delayed diagnosis can lead to septic complications and increased mortality 1
• Misdiagnosis is possible - other conditions like adductor longus tendon rupture may mimic incarcerated inguinal hernia 8
• Mesh repair is safe even in cases requiring bowel resection, with low infection rates (0.5%) reported in some studies 7
• Elapsed time from onset to surgery is the most important prognostic factor 1, 3