Hernias are among the most frequent indications for elective surgery in children. In many institutions, patients are admitted onto the hospitalist service (with a surgical consultation). As such, the pediatric hospitalist must be aware of the relevant anatomy, presentation, and treatment options of this common condition.
Hernia refers to any opening, congenital or acquired, in the abdominal musculature or fascia that allows all or part of an abdominal viscus to protrude beyond its usual boundaries; the term is also sometimes used to refer to the protruding viscus itself. Most hernias include an extension of the peritoneum, the hernia sac, which encases the herniated viscus and must be excised as part of the surgical repair. An incarcerated hernia is one in which the herniated viscus cannot be reduced manually, usually because of edema. Strangulated hernia refers to an incarcerated hernia in which the vascular integrity of the herniated viscus is compromised. This usually involves venous and lymphatic congestion of the tissue but can progress to arterial insufficiency, ischemia, and eventually necrosis. Most incarcerated hernias constitute a surgical emergency. Sliding hernia refers to a hernia in which the serosa of an intra-abdominal organ forms part of the hernia sac, which can make for a more difficult repair.
The most common hernias in children are indirect inguinal and umbilical hernias. Essentially, all hernias in children are congenital defects and not the result of excessive straining or fascial disruption, which are often cited as causal factors in adults. Consequently, pain is rarely a symptom of an uncomplicated hernia in children. This also means that pediatric hernias rarely require fascial reconstruction or the use of prosthetic mesh, making the operation more straightforward and less painful than in adults.
Almost all hernias require operative repair, regardless of location or type. The only exception is an asymptomatic umbilical hernia in a child younger than 4 or 5 years, which will often resolve spontaneously.1 No other type of true hernia is known to resolve spontaneously and all have a small but definite risk of incarceration and subsequent ischemia of the herniated viscus.2 Reducible hernias do not require emergent repair and can usually be fixed electively, depending on the needs and preferences of the family.
Most elective hernias are repaired on an outpatient basis. Admission is indicated for young infants at risk for apnea (preterm babies less than 60 weeks corrected gestational age), some children with complex medical conditions, and those who require emergent operation for an incarcerated or otherwise complicated hernia.
The majority of inguinal hernias seen in children are indirect inguinal hernias. Indirect inguinal hernias result from persistence of the processus vaginalis, the remnant of an embryonic structure that plays a role in testicular descent and normally disappears before birth (Figure 156-1).