Umbilical (belly button) Hernia
After birth, when the end of the umbilical cord, along
with the umbilical vein, umbilical arteries, and urachal remnant, dry
up, a small opening is left in the abdominal wall. Failure of the
muscles to close around this opening causes an umbilical hernia. Because
the skin is intact and the size of the hole is relatively small this is
the mildest form of abdominal wall defect. The opening usually is
noticed within a few weeks after separation of the cord.
Incidence
Umbilical hernia is one of the most commonly encountered
abnormalities in the early months of infancy. There is a distinct racial
predilection, with African-American infants having a greatly increased
incidence of umbilical hernia. In one study, an umbilical hernia was
present in 32% of African-American infants younger than six weeks of age
and only 4% of Caucasian infants of the same age. At one year of age,
the incidence was 13% in African-American infants and 2% in Caucasian
infants. Another predisposing factor for umbilical hernia development is
low birth weight. More than 80% of infants weighing less than 1200 g at
birth have at least transient umbilical hernias compared with
approximately 21% of infants with a birth weight greater than 2500 g.
Hernias occur with equal frequency in boys and girls.
Most umbilical hernias close spontaneously so that only
a few children have a hernia that persists beyond four or five years of
age.
Diagnosis
Umbilical hernias are usually recognized in the early
weeks of life after the cord falls off and the belly button heals. They
rarely cause any symptoms and are seen as a bulge at the umbilicus. The
muscle at the umbilicus has a hole from one-eighth to one inch in
diameter.
Figure 1:
Characteristic appearance of an umbilical hernia in a
4-month-old boy. The muscle opening measures only 1.5 cm or ¾
inch. |
At times, the skin over the umbilical hernia may become
severely stretched and resemble a mushroom. When an infant strains or
cries, the umbilical hernia may become tense, but with relaxation the
contents of the hernia may be easily pushed back into the abdomen. The
skin overlying the umbilicus, although stretched out, is usually
otherwise normal.
Complications
Complications of umbilical hernias are uncommon. In
contrast to inguinal hernias, it is very rare for bowel to get stuck
(incarcerated) within an umbilical hernia, although it can happen and
children should be taken directly to a doctor if it does. Because fewer
than 1% of umbilical hernias ever incarcerate there is usually no
urgency to repair the hernia as long as the hernia can be reduced
(pushed back into the abdomen). Other complications of umbilical hernia
include erosion of the overlying skin and, very rarely, spontaneous
rupture with exposure of intestine. Umbilical hernias rarely cause
abdominal pain so children with umbilical hernias who develop pain
should be evaluated for a cause other than the hernia. Although
complications are rare for umbilical hernias in infants and children,
adults with umbilical hernias are at high risk for the hernia getting
stuck out and other problems.
Treatment
As most umbilical hernias close spontaneously, no
treatment is usually necessary in the first three to five years of life.
Umbilical strapping with a coin or other object placed over the hernia
to maintain it in a reduced position has not been shown to promote
earlier closure and is rarely recommended because of the discomfort to
the child and the likelihood of skin irritation. Surgical repair of
umbilical hernias is reserved for three groups: patients whose hernias
have become stuck out (incarcerated); patients with large, protruding
hernias; and patients with hernias that are not closing. The rare infant
who develops incarceration that requires that a doctor push the
intestines back in with difficulty should have prompt repair. Repair is
also considered appropriate for children with a large hole in the
abdominal wall of greater than 1.5 cm or ¾ inch who are older
than three years. In most children with umbilical hernias who require an
operation, the hole has simply not closed by itself by the age of four
to five. After that age closure of the hole is unlikely to occur on its
own and the hernia may remain open into adult years, when complications
are more frequent and serious. In general, it is preferable to repair
all umbilical hernias before school age, when children begin to
participate in physical activities.
Operative Technique
Repair of umbilical hernia is performed on an outpatient
basis using a general anesthetic. A curving (smile) incision is made
within the skin fold of the lower half of the umbilicus. The sac that
contains the hernia is removed and the edges of the hole in the muscle
closed with sutures. The undersurface of the dome of skin is then
sutured to the muscle near the area where it had been closed. The skin
is closed with absorbable stitches or glue. A pressure dressing may be
applied for a few days to minimize the risk of developing a wound
hematoma (blood collection), the most common and troublesome
complication after repair. Wound infection is a rare complication after
umbilical hernia repair. Recurrence of a hernia after repair is also
very unusual.
SUGGESTED READINGS
Lassaletta L, Fonkalsrud EW, Tovar J, et al: The
management of umbilical hernias in infancy and childhood. J Pediatr Surg
10:405, 1975.
This is one of the largest reported clinical studies
indicating the role of surgery for umbilical hernias in infancy and
childhood.
Luchtman M, Rahav S, Zer M, et al: Management of urachal
anomalies in children and adults. Urology 42:426, 1993.
A thorough description is provided of the various
problems associated with urachal remnants.
Scherer LR, Grosfeld JG: Inguinal hernia and umbilical
anomalies. Pediatr Clin North Am 40:1121, 1993.
This article provides a good review of the diagnosis and
management of umbilical hernias and other anomalies.
Article and graphics adapted from O'Neill: Principles of Pediatric
Surgery. © 2003, Elsevier.
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