Inguinal hernia is the most frequent condition requiring surgery in the pediatric age group. It is more common in premature, preterm, and underweight babies. Inguinal hernias invariably present as a changing mass in the groin. Femoral hernia presents as a mass below the inguinal ligament. Umbilical hernia is fairly common and presents with an enlarged defect of the umbilical ring. A defect of varying size is normally present at birth. Inguinal and femoral herniorraphy (repair of the hernia) is usually undertaken as soon as the baby will tolerate the procedure because of concern of strangulation of hernia contents (usually bowel). Improvements in pediatric anesthesia and neonatal/pediatric intensive care units have made herniorrhaphy a low risk operation even in sick children.

Inguinal Hernia

• The abdominal wall in the groin area is made up of different structures going from deep to superficial layers (Figures 1 and 2):
  
  1. Peritoneum - the lining of the abdominal cavity (becomes the hernia sac)
     
  2. Subperitoneal fat - fat beneath the peritoneum
     
  3. Transversalis fascia - sheet of fibrous tissue that envelops the peritoneum
     
  4. Transversus abdominis muscle
     
  5. Internal oblique muscle
     
  6. External oblique muscle
     
  7. Subcutaneous fat
     
  8. Skin

Figure 1 - Layers of the abdominal wall, inguinal canal and their relations to the spermatic cord and testies. © C. Salici	Figure 2 - Anatomy of the inguinal canal and relationship to the pelvic bone. © C. Salici