Incarcerated Hernia
A hernia felt as a lump in the abdomen is called an incarcerated hernia 1. This is a hernia where the contents (bowel, omentum, or other tissue) have become irreducible—meaning they cannot be pushed back into the abdominal cavity—due to either a narrow opening in the abdominal wall or adhesions between the contents and the hernia sac 1.
Key Clinical Distinctions
Incarcerated vs. Strangulated Hernia
While an incarcerated hernia refers to irreducible contents that are trapped, a strangulated hernia represents the more dangerous progression where blood supply to the herniated contents becomes compromised 1. This distinction is critical because:
- Incarcerated hernias present as a palpable, non-reducible lump that may or may not be tender
- Strangulated hernias require immediate emergency surgery due to risk of bowel necrosis, perforation, and death 1
Common Types of Palpable Abdominal Hernias
The specific name also depends on the anatomic location:
- Ventral hernias: Protrude through the anterior abdominal wall 1
- Incisional hernias: Occur through previous surgical incisions 1
- Spigelian hernias: Rare hernias through the semilunar line (Spigelian fascia), often presenting as lateral lower abdominal lumps that are difficult to diagnose 2, 3, 4
- Groin hernias: Include inguinal and femoral hernias that may present as lower abdominal or groin masses 1
Critical Warning Signs Requiring Emergency Surgery
Immediate surgical intervention is mandatory when strangulation is suspected 1. Red flags include:
- Systemic inflammatory response syndrome (SIRS)
- Elevated lactate levels (≥2.0 mmol/L strongly predicts non-viable bowel) 1
- Elevated serum CPK and D-dimer 1
- CT findings showing reduced bowel wall enhancement (56% sensitivity, 94% specificity for strangulation) 1
- Elevated WBC and fibrinogen levels 1
Delayed diagnosis beyond 24 hours significantly increases mortality 1, and the presence of bowel necrosis is the single most important factor affecting death rates 1.
Diagnostic Approach
For a palpable abdominal lump suspected to be a hernia:
- Ultrasound is the gold standard initial imaging, particularly for Spigelian hernias in children and adults 2, 3
- CT scanning provides detailed assessment of hernia contents, bowel viability, and can detect complications 1
- Physical examination findings of persistent point tenderness over the hernia site with a tensed abdominal wall strongly suggests incarceration 3