Hernias

Basics

Description

  • Protrusion of bodily structure or organ through a defect in tissues normally containing it
  • Abdominal wall hernia due to weakness or disruption of fibromuscular layer of abdominal wall
  • Classified by region (ventral, groin, pelvic, flank) or etiology such as external (hernia protrudes visibly to outside), internal (herniated contents occur within body cavity), or interparietal (hernial sac contained within abdominal wall)
  • Groin:
    • Indirect inguinal hernia:
      • Results from persistent process vaginalis
      • Peritoneal contents herniate through internal ring
      • Right side more common than left
      • 27% lifetime risk of repair for men; 3% for women
    • Direct inguinal hernia:
      • Due to weakness or defect in transversalis area in Hesselbach triangle:
      • Inguinal ligament inferiorly
      • Inferior epigastric vessels laterally
      • Lateral border of rectus abdominis medially
    • Femoral hernia:
      • Peritoneum herniates into femoral canal beneath inguinal ligament
      • Incarceration frequent due to protrusion through small orifice
      • Internal: Diaphragmatic, hernias from mesenteric/omental tears, foramen of Winslow
  • Flank:
    • Lumbar hernia:
      • Occur in superior and inferior lumbar triangle of posterior abdominal wall (incarcerate in 25% cases)
      • Usually middle-aged men, chronic low back pain with palpable mass
  • Pelvic:
    • Obturator hernia:
      • Passes through obturator membrane and exits beneath pectineal muscle
  • Ventral:
    • Incisional hernia:
      • Resultant breakdown of previous surgical fascial closure
    • Epigastric hernia:
      • Midline between xiphoid and umbilicus
    • Spigelian hernia:
      • Protrusion through oblique fascia lateral to rectus abdominis muscle
    • Umbilical hernia:
      • Congenital failure of umbilical ring to close
      • Protrusion through fibromuscular umbilical ring/umbilicus
      • Often incarcerate in adults, although rarely in infants (often spontaneously close)
      • 20–45% recurrence rate

Epidemiology

  • Hernia repair (herniorrhaphy) extremely common general surgical procedure (>750,000 performed in the U.S. annually)
  • Prevalence: 5% of population
  • Groin and femoral hernias account for 85% of hernias:
    • Umbilical and incisional hernias account for additional 10%

Etiology

  • 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)

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