eMedicine Specialties > Pediatrics: Surgery > General Surgery

Disorders of the Umbilicus

Author: Robert K Minkes, MD, PhD, Professor of Surgery, University of Texas Southwestern; Chief of Surgical Services, Children's Medical Center of Dallas-Legacy
Coauthor(s): Li Ern Chen, MD, Staff Physician, Department of Surgery, Barnes Jewish Hospital, Washington University School of Medicine; Mark V Mazziotti, MD, Assistant Professor of Pediatric Surgery, Department of Surgery, Baylor College of Medicine, Texas Children's Hospital; Eugene S Kim, MD, Consulting Staff, Pediatric Surgeon, Assistant Professor, Division of Pediatric Surgery, Michael E DeBakey Department of Surgery, Assistant Professor, Division of Pediatric Hematology-Oncology, Department of Pediatrics, Baylor College of Medicine; Attending Pediatric Surgeon, Texas Children's Hospital; Robert S Bloss, MD, Clinical Associate Professor of Surgery and Pediatrics, University of Texas Medical School; Clinical Assistant Professor, Department of Surgery, Baylor College of Medicine; Consulting Staff, Houston Pediatric Surgeons
Contributor Information and Disclosures

Updated: Oct 27, 2008

Introduction

A stark contrast is observed between the physiologic importance of the umbilicus during development and after birth. During development, the umbilicus functions as a channel that allows blood flow between the placenta and fetus. It also serves an important role in the development of the intestine and the urinary system. After birth, once the umbilical cord falls off, no evidence of these connections should be present. Nevertheless, umbilical disorders are frequently encountered in pediatric surgery. These disorders range from the very common umbilical hernia to infections such as omphalitis, which can be life threatening. Most patients with umbilical problems present with a mass or drainage from the umbilicus. An understanding of the anatomy and embryology of the abdominal wall and umbilicus is important to identify and properly treat these conditions.

History of the Procedure

The embryology of the umbilicus and the developmental basis for surgical abnormalities has been well described for more than one hundred years. Umbilical hernias, abdominal wall defects, umbilical polyps and drainage,¹ and omphalomesenteric remnants are well described. Methods of management in some disorders, such as treating umbilical granulomas with silver nitrate, have changed little over the last century. In the early 1900s, umbilical hernia repair was a challenging procedure. Spontaneous closure of these hernias and preservation of the appearance of the natural umbilicus were recognized. Today, umbilical hernia repair is one of the most common procedures performed by pediatric surgeons.

Problem

Patients with umbilical disorders present with drainage, a mass, or both. Most umbilical disorders result from failure of normal embryologic or physiologic processes. Unusual umbilical anatomy, such as a single umbilical artery or abnormal position of the umbilicus, may be associated with other congenital anomalies or syndromes. Omphalocele and gastroschisis, which are common abdominal wall defects associated with the umbilicus, are discussed in other eMedicine articles (see Omphalocele and Gastroschisis). Masses of the umbilicus may be related to lesions of the skin, embryologic remnants, or an umbilical hernia. Masses associated with the skin include dermoid cysts, hemangiomas, and inclusion cysts. Umbilical drainage is associated with granulomas and embryologic remnants.

• Delayed separation of the umbilical cord: The umbilical cord usually separates from the umbilicus 1-8 weeks postnatally. Topical antimicrobials are usually applied after delivery, followed by isopropyl alcohol until cord separation. Delayed separation may signify an underlying immune disorder.
• Umbilical granuloma: Granulation tissue may persist at the base of the umbilicus after cord separation. The tissue is composed of fibroblasts and capillaries and can grow to more than 1 cm. Umbilical granulomas must be differentiated from umbilical polyps, which do not respond to silver nitrate cauterization.
• Umbilical infections: Patients with omphalitis may present with purulent umbilical discharge or periumbilical cellulitis. Although infections may be associated with retained umbilical cord or ectopic tissue, in the past, infections were often related to poor hygiene. Current aseptic practices and the routine use of antimicrobials on the umbilical cord have reduced the incidence to less than 1%. Cellulitis may become severe within hours and progress to necrotizing fasciitis and generalized sepsis.
• Omphalomesenteric remnants: Persistence of all or portions of the omphalomesenteric duct can result in fistulas, sinus tracts, cysts, congenital bands, and mucosal remnants. Patients with mucosal remnants can present with an umbilical polyp or within an umbilical cyst.
• Urachal remnants: The developing bladder remains connected to the allantois through the urachus. Remnants of this connection include a patent urachus, urachal sinus, and urachal cyst. Umbilical polyps can also be observed in association with a urachal remnant.
• Umbilical hernia: Umbilical hernias result when persistence of a patent umbilical ring occurs. Umbilical hernias may spontaneously close, but many require surgical repair.²

Frequency

The frequency of the many different umbilical disorders varies. Umbilical infections are now identified in less than 1% of hospitalized newborns.

Umbilical hernias are commonly identified in early infancy; however, most spontaneously close. No sex predilection is noted. The incidence at age 1 year ranges from 2-15%. Incidence is increased in infants who are black and in infants with low birthweight, Down syndrome, trisomy 13, trisomy 18, or Beckwith-Wiedemann syndrome.

Etiology

The development of the anterior abdominal wall depends on differential growth of embryonic tissues (see Media file 1). As the embryo grows, the yolk sac is divided into an intracoelomic portion and an extracoelomic portion. The intracoelomic portion becomes the primitive alimentary canal and communicates with the extracoelomic portion through the vitelline duct, also known as the omphalomesenteric duct (see Media file 1). This communication is lost at 5-7 weeks' gestation. Persistence of part or all of this connection results in omphalomesenteric anomalies.

In the third week of gestation, the yolk sac develops a diverticulum, the allantois, which grows into the body stalk (see Media file 1). As the distal hindgut and the urogenital sinus separate, the developing bladder remains connected to the allantois through a connection called the urachus.³ Persistence of this communication leads to urachal remnants. Subsequently, the yolk and body stalks fuse to become the umbilical cord (see Media files 1-2). Development of the abdominal wall narrows the umbilical ring, which should close before birth. Persistence of the umbilical ring results in an umbilical hernia.

Pathophysiology

Failure of the normal obliterative processes of the vitelline duct and the urachus leads to abnormal communications or cysts. Retention of components of the umbilical cord can also produce a mass or drainage.

A patent umbilical ring at birth is responsible for most umbilical hernias. The umbilical opening is usually inferiorly reinforced by the attachments of the median umbilical ligament (the obliterated urachus) and the paired medial umbilical ligaments (the obliterated umbilical arteries) and is more weakly superiorly reinforced by the round ligament (the obliterated umbilical vein). See Media files 2-3.

Richet fascia, derived from the transversalis fascia, covers the ring (see Media file 2). The peritoneum covers the innermost portion of the ring. Variability in the attachment of the ligaments and the covering by Richet fascia may predispose some children to developing umbilical hernias (see Media file 4). However, many children undergo spontaneous closure in the first few years of life. The pressure exerted on the umbilical skin, even when a small umbilical defect is present, can result in marked stretching of the skin and a proboscis appearance (see Media file 5).

Presentation

Umbilical infections can occur because of an embryologic remnant or poor hygiene. Traditionally, gram-positive organisms, such as Staphylococcus aureus and Streptococcus pyogens, were most commonly identified. Gram-negative and polymicrobial infections are seen today, especially in rapidly progressing cellulitis and necrotizing fasciitis.

Umbilical granulomas appear as 1-mm to 1-cm, pink, friable lesions at the base of the umbilicus. They produce variable amounts of drainage that can irritate the surrounding skin. An umbilical polyp is brighter red than a granuloma and represents retained intestinal or gastric mucosa from the vitelline duct.

The presentation of omphalomesenteric remnants depends on the specific type of defect (see Media file 6). If a communication persists from the terminal ileum to the umbilicus, intestinal contents or stool can be observed leaking from the umbilicus. Prolapse of intestine through an omphalomesenteric fistula can also be observed (see Media file 7). The drainage from a fistula that does not communicate with the ileum varies; it may be clear, bloody, or purulent. Cystic remnants may become infected and manifest with pain and swelling.

The presentation of urachal remnants also varies. Clear drainage from the umbilicus is characteristic of a urachal fistula. Drainage of urine from the umbilicus may suggest bladder outlet obstruction and warrants further investigation. A urachal sinus manifests with drainage that can be clear or purulent. A urachal cyst is usually discovered as a painful mass between the umbilicus and suprapubic area when it becomes infected. Pain and retraction of the umbilicus during urination may suggest a urachal anomaly.

Patients with umbilical hernias present early in life with bulging at the umbilicus. The swelling is most prominent when the infant or child is crying or straining. Umbilical hernias are usually asymptomatic and rarely cause pain. The skin can become severely stretched, which may be alarming to parents and physicians. Parents often mention that the child plays with the redundant skin. Incarceration, strangulation, bowel obstruction, erosion of the overlying skin, and bowel perforation are rare events in infants and small children. The risk of incarceration increases significantly in adults with umbilical hernias.

Patients with umbilical infections can present with drainage from the umbilicus, swelling, and redness. Cellulitis may rapidly progress and lead to necrotizing fasciitis. Necrotizing fasciitis is characterized by abdominal distention, tachycardia, purpura, leukocytosis, and other signs of sepsis despite antibiotic therapy.

Indications

Small umbilical granulomas usually respond to silver nitrate application. Large umbilical granulomas or those that persist after silver nitrate treatment require surgical excision.

Omphalomesenteric remnants and urachal remnants require surgical excision. The precise diagnosis is often not confirmed until surgery is performed and the anatomy of the umbilicus is established.

The diameter of the umbilical ring defect is predictive of spontaneous closure. The length of the protruding skin is not prognostically significant. Umbilical hernias with ring diameters less than 1 cm are more likely to spontaneously close than those with ring diameters more than 1.5 cm. Surgery is indicated for all symptomatic umbilical hernias. Incarceration, strangulation, skin erosion, and bowel perforation are indications for immediate surgery. Similarly, patients presenting with pain should be repaired on an elective basis.

Asymptomatic umbilical hernias can be safely monitored until the child is aged 4-5 years to allow spontaneous closure, especially if the ring defect is small. Because umbilical hernias with larger defects (ie, >1.5 cm) are unlikely to spontaneously close, surgery can be performed at an earlier age. Similarly, closing umbilical hernias with large ring defects is reasonable in younger children if the child is having a general anesthetic for another procedure, such as an inguinal hernia repair. Considering surgery in younger children who have a large protrusion of the umbilical skin that is causing distress to the parents is also reasonable.

Necrotizing fasciitis and gangrene of the umbilical skin requires emergency surgical debridement and can be life saving.

Relevant Anatomy

During development, the embryonic disk is in contact with the yolk sac anteriorly (see Media file 1A). As the embryo grows and differential growth of tissues leads to the folding appearance of the embryo, the ventral attachment of the yolk sac narrows.

The intracoelomic portion of the yolk sac becomes the primitive alimentary canal and attaches to the extracoelomic portion through the vitelline duct. The allantois buds from the hindgut and grows into the body stalk (see Media file 1B). The yolk stalk and the body stalk eventually fuse to become the umbilical cord (see Media file 1C).

As the abdominal wall forms, the umbilical ring is narrowed. The vitelline and umbilical vessels, vitelline duct, and allantois should be absent in the umbilicus at term (see Media file 2). Residual tissue leads to remnants that require surgical intervention (see Media file 8).

During exploration for a sinus or fistula, all structures, including the round ligament, median, and medial umbilical ligaments, must be identified (see Media file 2, Media file 8). An omphalomesenteric or urachal sinus or fistula must be dissected back to its origin in the ileum or bladder, respectively (see Media file 8).

Contraindications

No specific contraindications to surgery for umbilical disorders are known, and timing of surgery depends on the general medical condition of the infant or child.

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