- Clinical science
An internal hernia is the protrusion of visceral contents through a congenital or acquired opening within the peritoneal cavity. Contained within the abdominal cavity, internal hernias have an incidence of < 1% and are significantly less common than external hernias. Patients with a history of Roux-en-Y gastric bypass or liver transplant are especially at risk of internal hernia formation. The clinical presentation of symptomatic internal hernias is often acute and nonspecific, presenting as a mechanical small bowel obstruction. CT scan is the imaging modality of choice in most cases, but surgical intervention is often required for definitive diagnosis and treatment. Incarceration or strangulation of internal hernias carries a high mortality rate and therefore rapid diagnosis and urgent surgical repair is imperative.
- Internal hernias have an overall incidence of < 1%
Epidemiological data refers to the US, unless otherwise specified.
Features of acute:
- Abdominal pain (chronic or colicky)
- Nausea and vomiting; especially postprandial
Severity of symptoms relate to the duration and reducibility of the hernia. If an internal hernia incarcerates and strangulates, the patient's clinical presentation will be similar to that of a strangulated external hernia!
- Abdominal x-ray: nonspecific signs of (e.g., distended loops of bowel, absent air in distal colon, air fluid levels proximal to obstruction)
- CT scan (best initial and gold standard imaging modality)
- Laparoscopy or laparotomy (confirmatory and therapeutic)
The diagnosis of an internal hernia is confirmed by laparoscopy in the majority of cases!
- The differential diagnosis for internal hernia is essentially that of mechanical .
- See .
The differential diagnoses listed here are not exhaustive.
Surgery: (either open or laparoscopic)
- Evidence of complicated
- Suspected internal hernia with persistent symptoms
- Procedure: reduction of the hernia with closure of the hernial pathway
If an internal hernia leads to incarceration, the mortality rate is ∼80%!