Two arteries, an umbilical vein and a ureteric duct, are present in the umbilical cord at birth. The umbilical arteries and vein transform into fibrous cords known as the medial umbilical ligaments and the ligamentum teres hepatis, which attach to the umbilical ring. After the umbilical cord contents reduce, the umbilical ring continues to close over time and the fascia of the umbilical defect strengthens, which accounts for the spontaneous resolution of this defect in most children. The molecular basis of closure of the umbilical ring is poorly understood. Failure of these closure processes results in an umbilical hernia. The hernia sac is peritoneum and is usually very adherent to the dermis of the umbilical skin. The diameter of the actual fascial defect can range from several millimeters to 5 cm or more. Palpation is necessary to detect the actual fascial defect. Ultrasound examination may also be helpful in assessing the size of the defect but is not routinely obtained.

The incidence of umbilical hernia in the general population varies with age, race, gestational age, and coexisting disorders. In the United States, umbilical hernias are present in 15%–25% of newborns or approximately 800,000 children annually. Historical studies suggest a higher incidence of umbilical hernia in the African-American population, from birth to 1 year of age ranging from 25% to 58%, whereas Caucasian children in the same age group have an incidence of 2%–20%. Premature and low-birth-weight infants have a higher incidence than full-term infants. Infants with other conditions, such as connective tissue disorders, Beckwith–Wiedemann syndrome, Hurler syndrome, various trisomy conditions (trisomies 13, 18, and 21), and congenital hypothyroidism, also have an increased incidence, as do children requiring peritoneal dialysis.

Most umbilical hernias close gradually after birth, reducing their prevalence at 1 year to a range of 2%–10%, with the continued closure of the umbilical ring being reported until 14 years. It is believed that most of the defects (up to 90%) close before the child is 4 years old. The complication rates from pediatric umbilical hernias not surgically repaired, such as intermittent incarceration or spontaneous evisceration, are reported as 0%–7.4%. Observing the hernia until ages 4–5 years is very safe to allow for closure, since complications in the developed world are very uncommon. Until spontaneous closure, adhesive strapping is common in some areas, albeit somewhat controversial ( Fig. 48.1 ). Some reports have shown that adhesive strapping provides early spontaneous closure of umbilical hernia. Even in cases of umbilical hernia nonclosure, surgical repair was easier after adhesive strapping. We always perform adhesive strapping for neonates with umbilical hernia in our hospital. If an umbilical hernia cannot be satisfactorily treated with adhesive strapping, this procedure may contribute to decreasing sagging skin and improving the appearance of the umbilicus after definitive surgery. Because this technique can rarely cause dermatitis or ulcers, we use soft materials such as sponges or cotton balls.

The adhesive strapping technique. (A) 1-month-old girl’s umbilicus before the adhesive strapping. (B) Adhesive strapping with a cotton ball and transparent film dressing. (C) The appearance of the umbilicus at the age of 5 months. The umbilicus is concave and the fascial defect is also closed.

Surgical intervention may be considered in cases where natural closure does not occur beyond the age of 4–5 years, or when there are cosmetic issues due to excess skin. The aims of the operative closure are elimination of the hernia and formation of a slightly vertical umbilicus facing forward. Several surgical procedures for umbilical hernias have been reported. ^,

The procedure usually starts with a small transverse infraumbilical incision ( Fig. 48.2 ) around approximately one-third of the circumference, slightly medial to the inferior margin of the base of the protruding skin of the umbilicus. The incision is made inside the umbilicus, which leaves the postoperative wound less noticeable. Stay sutures to the skin provide a good surgical field. The subcutaneous tissue and hernia sac dissection is started from the caudal side and then connected for a full circumferential dissection. After the hernia has been fully dissected circumferentially with a blunt clamp, a tape may be passed around the hernia. After confirming that there is no hernia content, the hernia is dissected circumferentially using an electrocautery scalpel. Any fragile fascia or remnant of hernia sac should be trimmed. The hernia sac is sutured with transfixing ligation. The fascia is sutured with 3-0/4-0 absorbable suture. The fascia may be sutured transversely, but a longitudinal suture is preferable to create a vertical umbilicus. The tip of the hernia attached to the skin lining of the umbilical region should be trimmed to make the umbilicus deeper. We trim the skin (in those children with excessive redunant skin) into triangles to form the appropriate “normal” size and suture it with 5-0 absorbable thread to create a caudally recessed umbilical fossa with a vertical crease. The skin incision is closed with 5-0 monofilament absorbable thread. The wound is placed (hidden) inside the umbilicus. Many surgeons use a pressure dressing to help prevent the development of a hematoma and to keep the umbilical skin inverted. Another option for repair is a simple midline incision with fascial closure as is done for most laparoscopic procedures after port removal.

The technique for operative repair for an umbilical hernia. (A) An infraumbilical incision is made. (B) The umbilical hernia sac has been encircled with a blunt large clamp. (C) The umbilical hernia sac is excised and sutured with transfixing ligation. (D) Trimming large skin into triangles to form the appropriate skin size. (E) Suturing with 5-0 absorbable thread to create a caudally recessed umbilical fossa with a vertical crease. (F) The skin incision is sutured with 5-0 monofilament absorbable thread.

Complications of umbilical hernia repair are infrequent and include seroma or hematoma formation. These are usually self-limited and resolve spontaneously. Wound infections generally can be managed with local care and antibiotics. Rates of reported recurrence are low (∼2%).

The appearance of the umbilicus changes as the child grows; both vertical length and depth increase with age. Patient and parent satisfaction with the appearance of the umbilicus after surgery is rarely reported, but most are pleased with the result. In addition, the ideal appearance of the umbilicus may differ according to gender. ^, Further studies are needed to evaluate long-term outcomes after repair.