Hernias

Basics

Description

  • Protrusion of a bodily structure or organ through a defect in tissues normally containing it
  • Most commonly classified by region (ventral, groin, pelvic, flank)
  • Groin:
    • Indirect inguinal hernia:
      • Protrusion through internal ring due to persistent process vaginalis
      • Right side more common than left
    • Direct inguinal hernia:
      • Protrusion due to weakness or defect in transversalis area in Hesselbach triangle (inguinal ligament inferiorly, inferior epigastric vessels laterally, rectus abdominus medially)
    • Femoral hernia:
      • Protrusion into femoral canal beneath inguinal ligament
      • More common in females than males
      • Incarceration frequent due to protrusion through small orifice
  • Flank:
    • Lumbar hernia:
      • Protrusion through superior (more common) or inferior (less common) lumbar triangle of posterior abdominal wall
      • Usually middle-aged males
      • Left side more common than right
  • Pelvic:
    • Perineal hernia:
      • Protrusion through a congenital (rare) or acquired defect in the pelvic floor
      • Acquired perineal hernias associated with history of pelvic operations
    • Sciatic hernia:
      • Protrusion through the greater or lesser sciatic foramen
    • Obturator hernia:
      • Protrusion through the obturator canal
      • Usually thin elderly females
  • Ventral:
    • Incisional hernia:
      • Protrusion due to breakdown of previous surgical fascial closure
      • High recurrence rate (up to 30–40%)
    • Epigastric hernia:
      • Protrusion at the midline between xiphoid and umbilicus
    • Spigelian hernia:
      • Protrusion through oblique fascia lateral to rectus abdominis muscle (also known as a lateral ventral hernia)
    • Umbilical hernia:
      • Protrusion through fibromuscular umbilical ring
      • Can be congenital (in children due to failure of umbilical ring to close) or acquired (more common etiology in adults)

Epidemiology

  • Hernia repair is an extremely common general surgical procedure (>1 million performed in the US annually)
  • Prevalence: 10% of population:
    • 75% inguinal (50% direct, 25% indirect)
    • 25–30 % ventral
    • 3–5% femoral

Etiology

  • Congenital: Defect in the abdominal wall is present from birth
  • Acquired: Defect in the abdominal wall develops due to weakening or disruption of fibromuscular tissues
  • Any increased intra-abdominal pressure can lead to hernia (obesity, heavy lifting, coughing, straining, organomegaly, intra-abdominal masses, ascites, peritoneal dialysis)
  • Reducible hernia:
    • Protruding structures can be returned to abdominal cavity
  • Incarcerated hernia:
    • Contents of hernia cannot be manipulated back into abdominal cavity
  • Strangulated hernia:
    • Vascular compromise of entrapped bowel contained within hernia leading to ischemia and gangrene (skin color changes may be apparent)
    • Higher risk in hernias with small openings and large sacs
    • Signs and symptoms of bowel obstruction or ischemia may occur (nausea/vomiting, fever, leukocytosis)
  • Richter hernia: Only the antimesenteric portion of the bowel wall protrudes into the hernia defect:
    • Bowel may not be obstructed but can rapidly become strangled and gangrenous

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