Definition: The classical surgical definition of a hernia is the protrusion of an organ or the fascia of an organ through the wall of the cavity that normally contains it.
Risk factors for abdominal wall hernias include:
- increasing age
- surgical wounds
Clinical Features include:
- a palpable lump
- cough impulse
- obstruction: more common in femoral hernias
- strangulation: may compromise the bowel blood supply leading to infarction
Types of abdominal wall hernias:
1. Inguinal hernia:
- Inguinal hernias account for 75% of abdominal wall hernias.
- Around 95% of patients are male; men have around a 25% lifetime risk of developing an inguinal hernia.
- Above and medial to pubic tubercle Strangulation is rare
- Below and lateral to the pubic tubercle
- More common in women, particularly multiparous ones
- High risk of obstruction and strangulation
- Surgical repair is required
3. Umbilical hernia : Symmetrical bulge under the umbilicus
4. Paraumbilical hernia: Asymmetrical bulge - half the sac is covered by skin of the abdomen directly above or below the umbilicus.
5. Epigastric hernia: Lump in the midline between umbilicus and the xiphisternum. Most common in men aged 20-30 years
6. Incisional hernia: May occur in up to 10% of abdominal operations
7. Spigelian hernia:
- Also known as lateral ventral hernia.
- Rare and seen in older patients
- A hernia through the spigelian fascia (the aponeurotic layer between the rectus abdominis muscle medially and the semilunar line laterally)
8. Obturator hernia: A hernia which passes through the obturator foramen. More common in females and typical presents with bowel obstruction
9. Richter hernia: A rare type of hernia where only the antimesenteric border of the bowel herniates through the fascial defect
10. Congenital inguinal hernia:
- Indirect hernias resulting from a patent processus vaginalis
- Occur in around 1% of term babies.
- More common in premature babies and boys 60% are right sided, 10% are bilaterally
- Should be surgically repaired soon after diagnosis as at risk of incarceration
11. Infantile umbilical hernia:
- Symmetrical bulge under the umbilicus
- More common in premature and Afro-Caribbean babies
- The vast majority resolve without intervention before the age of 4-5 years
- Complications are rare