Expansion
Umbilical hernias pass through the ring itself; paraumbilical hernias pass through the linea alba beside it
Expansion
- Umbilical hernia - through the umbilical ring itself. Typically congenital, from failure of the ring to close after the physiological midgut herniation returns. Common in infants, especially in Afro-Caribbean children and in those with hypothyroidism or Down syndrome. Most close spontaneously by 3 to 5 years
- Paraumbilical hernia - through the linea alba immediately above or below the umbilicus. Acquired in adults, associated with obesity, multiparity and ascites. The neck is narrow and fibrous, so the risk of incarceration and strangulation is high, and it does not resolve spontaneously
The contents are usually omentum, sometimes small bowel or transverse colon.
The narrow, rigid neck of the adult paraumbilical hernia is the key point; it means these should be repaired electively rather than watched.