{"id":655,"date":"2017-12-16T16:57:32","date_gmt":"2017-12-16T16:57:32","guid":{"rendered":"http:\/\/www.drshevchuk.com.ua\/?p=655"},"modified":"2017-12-16T20:31:04","modified_gmt":"2017-12-16T20:31:04","slug":"disorders-of-the-umbilicus","status":"publish","type":"post","link":"http:\/\/www.drshevchuk.com.ua\/?p=655","title":{"rendered":"Disorders of the Umbilicus\/ \u0417\u0430\u0445\u0432\u043e\u0440\u044e\u0432\u0430\u043d\u043d\u044f \u043f\u0443\u043f\u043a\u0430"},"content":{"rendered":"
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Background<\/strong><\/p>\n

The embryology of the umbilicus and the developmental basis for surgical abnormalities has been well described for more than 100 years. Umbilical hernias, abdominal wall defects, umbilical polyps and drainage,\u00a0[1]\u00a0and omphalomesenteric remnants are well described.<\/p>\n

A stark contrast is observed between the physiologic importance of the umbilicus during development and its importance 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.<\/p>\n

Nevertheless, umbilical disorders are frequently encountered in pediatric surgery.\u00a0An understanding of the anatomy and embryology of the abdominal wall and umbilicus is important for identifying and properly treating these conditions.<\/p>\n

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 further elsewhere (see\u00a0Pediatric Omphalocele and Gastroschisis).<\/p>\n

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. The following should be noted:<\/p>\n

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
\nUmbilical 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 and from granulomas secondary to a patent urachus, both of which do not respond to silver nitrate cauterization
\nUmbilical 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, they were often, in the past, 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 and rapidly progess within hours to necrotizing fasciitis and generalized\u00a0sepsis,\u00a0and thus, prompt attention and treatment are critical
\nOmphalomesenteric 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 an umbilical cyst
\nUrachal remnants – The developing bladder remains connected to the allantois through the urachus, and remnants of this connection include a patent urachus, urachal sinus, and urachal cyst; umbilical polyps and granulomas can also be observed in association with a urachal remnant
\nUmbilical hernias – These result when persistence of a patent umbilical ring occurs; some umbilical hernias close spontaneously, but many require surgical repair\u00a0[2]\nMethods 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.<\/p>\n

Anatomy<\/h2>\n
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During development, the embryonic disk is in contact with the yolk sac anteriorly (see the image below). 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. The yolk stalk and the body stalk eventually fuse to become the umbilical cord.<\/p>\n

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\"Cartoon<\/a>Cartoon illustrating the developing umbilical cord. (A) Embryonic disk: At this stage, the ventral surface of the fetus is in contact with the yolk sac. (B) The yolk sac narrows as the fetus grows and folds. The intracoelomic yolk sac forms the intestine and communicates with the extracoelomic yolk sac through the vitelline duct. The vitelline duct is also referred to as the omphalomesenteric duct and the yolk stalk. The allantois has begun to grow into the body stalk. (C) The yolk and body stalks fuse to become the umbilical cord.<\/span><\/p>\n

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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. Residual tissue leads to remnants that require surgical intervention. During exploration for a sinus or fistula, all structures, including the round ligament, median, and medial umbilical ligaments, must be identified (see the images below). An omphalomesenteric or urachal sinus or fistula must be dissected back to its origin in the ileum or bladder, respectively.<\/p>\n

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\"Umbilical<\/a>Umbilical region viewed from the posterior surface of the abdominal wall of an infant with the umbilical cord attached. UA: Umbilical artery; UV: Umbilical vein; RL: Round ligament (obliterated umbilical vein); UR: Umbilical ring; UL: Umbilical ligament; medial (obliterated umbilical arteries); median (obliterated urachus). Note fascial covering of surface and umbilical ring.<\/span><\/p>\n

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\"Anatomic<\/a><\/div>\n

Pathophysiology<\/h2>\n
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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.<\/p>\n

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 the image below.)<\/p>\n

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\"Umbilical<\/a>Umbilical region viewed from the posterior surface of the abdominal wall of an infant with the umbilical cord attached. UA: Umbilical artery; UV: Umbilical vein; RL: Round ligament (obliterated umbilical vein); UR: Umbilical ring; UL: Umbilical ligament; medial (obliterated umbilical arteries); median (obliterated urachus). Note fascial covering of surface and umbilical ring.<\/span><\/p>\n

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Richet fascia, derived from the transversalis fascia, covers the ring. 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 the image and the video below). However, many children undergo spontaneous closure in the first few years of life. The pressure exerted on the umbilical skin, even when only a small umbilical defect is present, can result in marked stretching of the skin and a proboscis appearance.<\/p>\n

\"Variations<\/a>Variations in the umbilical ring structure. (A) Usual configuration of the round ligament and urachus. (B) Less common configuration that can result in weakness at the umbilical ring.<\/span><\/div>\n<\/div>\n<\/div>\n
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Etiology<\/h2>\n
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The development of the anterior abdominal wall depends on differential growth of embryonic tissues (see the image below). 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. This communication is lost at 5-7 weeks’ gestation. Persistence of part or all of this connection results in omphalomesenteric anomalies.<\/p>\n

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\"Cartoon<\/a>Cartoon illustrating the developing umbilical cord. (A) Embryonic disk: At this stage, the ventral surface of the fetus is in contact with the yolk sac. (B) The yolk sac narrows as the fetus grows and folds. The intracoelomic yolk sac forms the intestine and communicates with the extracoelomic yolk sac through the vitelline duct. The vitelline duct is also referred to as the omphalomesenteric duct and the yolk stalk. The allantois has begun to grow into the body stalk. (C) The yolk and body stalks fuse to become the umbilical cord.<\/span><\/p>\n

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In the third week, the yolk sac develops a diverticulum, the allantois, which grows into the body stalk. As the distal hindgut and the urogenital sinus separate, the developing bladder remains connected to the allantois through a connection called the urachus.\u00a0[3<\/a>]\u00a0<\/sup>Persistence of the urachus leads to urachal remnants. Subsequently, the yolk and body stalks fuse to become the umbilical cord. Development of the abdominal wall narrows the umbilical ring, which should close before birth. Persistence of the ring results in an umbilical hernia.<\/p>\n

Epidemiology<\/strong>
\nThe frequencies of the many different umbilical disorders vary. Umbilical infections are now identified in fewer than 1% of hospitalized newborns.<\/p>\n

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 birth weight,\u00a0Down syndrome, trisomy 13, trisomy 18, or\u00a0Beckwith-Wiedemann syndrome.<\/p>\n

Prognosis<\/h2>\n
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The outcome for infants and children with umbilical hernias and embryologic remnants is generally excellent. In most cases, no long-term problems occur. However, Rosen et al suggested that umbilical hernia repair may increase the incidence of functional gastrointestinal disorders in childhood.\u00a0[4<\/a>]<\/sup><\/p>\n

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In contrast, in most series, omphalitis leading to necrotizing fasciitis is associated with a high mortality, possibly as high as 80%. Necrotizing fasciitis can also lead to portal venous thrombosis and portal hypertension.<\/p>\n

History and Physical Examination<\/h2>\n
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Umbilical infections can occur because of an embryologic remnant or poor hygiene. Traditionally, gram-positive organisms, such as\u00a0Staphylococcus aureus<\/em>\u00a0and\u00a0Streptococcus pyogenes,<\/em>\u00a0were most commonly identified. Gram-negative and polymicrobial infections are seen today, especially in rapidly progressing cellulitis and necrotizing fasciitis.<\/p>\n

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.<\/p>\n

The presentation of omphalomesenteric remnants depends on the specific type of defect (see the first image below). 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 the second image below). 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.<\/p>\n

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\"Omphalomesenteric<\/a>Omphalomesenteric duct remnants. (A) Meckel diverticulum. Note feeding vessel. (B) Meckel diverticulum attached to posterior surface of anterior abdominal wall by a fibrous cord. (C) Fibrous cord attaching ileum to abdominal wall. (D) Intestinal-umbilical fistula. Intestinal mucosa extends to skin surface. (E) Omphalomesenteric cyst arising in a fibrous cord. The cyst may contain intestinal or gastric mucosa. (F) Umbilical sinus ending in a fibrous cord attaching to the ileum. (G, H) Omphalomesenteric cyst and sinus without intestinal attachments.<\/span><\/p>\n

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\"Photograph<\/a>Photograph of newborn with intestinal prolapse through a patent omphalomesenteric duct. Both the proximal and distal limbs of the intestine have prolapsed. The umbilicus was explored, the bowel was easily reduced, and the patent duct was excised. The child was discharged from the hospital 2 days later.<\/span><\/p>\n

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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.<\/p>\n

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. A urachal sinus manifests with drainage that can be clear or purulent and occurs through the umbilicus or midline skin below the umbilicus (see the image below).<\/p>\n

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\"Urachal<\/a>Urachal sinus with purulent drainage in midline below the umbilicus (black arrow). A laparoscope was placed in the supraumbilical crease (red arrow) for mobilization of the internal portion of the urachal remnant as depicted in the next image.<\/span><\/p>\n

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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 (see the image below). Parents often mention that the child plays with the redundant skin.<\/p>\n

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\"Preoperative<\/a>Preoperative photograph demonstrating umbilical hernia with redundant skin.<\/span><\/p>\n

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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.<\/p>\n

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.<\/p>\n

Approach Considerations<\/h2>\n
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Small umbilical granulomas usually respond to silver nitrate application. Large umbilical granulomas or those that persist after silver nitrate treatment require surgical excision.<\/p>\n

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.<\/p>\n

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.<\/p>\n

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 close spontaneously, surgery can be performed at an earlier age.<\/p>\n

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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. It is also reasonable to consider surgery in younger children who have a large protrusion of the umbilical skin that is causing distress to the parents.<\/p>\n

For necrotizing fasciitis and gangrene of the umbilical skin, emergency surgical debridement is required and can be life-saving.<\/p>\n

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.<\/p>\n

There remains some controversy regarding the optimal timing for umbilical hernia repair, and the true instance of complications related to umbilical hernias in adults is not known.<\/p>\n

Most surgeons agree that in the majority of cases, small hernias can be monitored safely. Although spontaneous closure does occur, large hernias with large fascial defects are less likely to close on their own, and continued stretching of the umbilical skin may make closure more difficult. Therefore, many surgeons advocate earlier repair in these children. Others argue that umbilical hernias should be monitored until children reach the age of 5 years.<\/p>\n

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The umbilicus is a common site for port entry for laparoscopic surgery and is being used for single-incision laparoscopic surgery.<\/p>\n

Medical Therapy<\/h2>\n
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Medical therapy is indicated only when infection is present. For\u00a0omphalitis\u00a0or\u00a0necrotizing fasciitis, broad-spectrum antibiotics are needed. Antibiotics are also administered for acute infection of omphalomesenteric and urachal remnants. Surgical drainage is often needed.<\/p>\n

Many umbilical hernias spontaneously close; currently, no medical therapy to hasten this process is recognized.<\/p>\n

Silver nitrate application to umbilical granulomas is usually successful. One or more applications may be needed. Care must be taken to avoid contact with the skin. Silver nitrate can cause painful burns. Small umbilical granulomas with a narrow base may be safely excised in the office setting. Large granulomas and those growing in response to an umbilical fistula or sinus do not resolve with silver nitrate and must be surgically excised in the operating room setting.<\/p>\n

Surgical Therapy<\/h2>\n
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Surgical therapy is the mainstay of treatment for the following umbilical conditions:<\/p>\n