Omphalocele

- a covered defect of the umbilical ring into which abdominal contents herniate; sac composed of an outer layer of amnion and an inner layer of peritoneum

- >50% of infants have serious associated congenital defects (GU, cardiac, GI); always associated with malrotation

- sac may contain only intestine, but usually contains liver as well; may be associated with loss of abdominal domain, with contracted abdominal cavity

- management includes covering sac with sterile dressing; protection from hypothermia; gastric decompression; parenteral nutrition; and broad-spectrum antibiotics

- surgical treatment -- small defects can be closed primarily; moderate defects can have the skin closed with the subsequent hernia being repaired later; larger defects require staged closure using Silastico silo.

- overall survival depends on the size of the defect as well as severity of associated congenital defects; mortality averages 30-35%

mont reid p.615-616

Omphalocele: [+ THE ABSITE REVIEW, P.280]

- failure of embryonal development

- midline defect

- increased congenital anomalies (50%)

- has peritoneal sac with cord attached

- sac can contain intra-abdominal structures other than bowel (liver, spleen, etc)

Cantrell pentalogy

- cardiac defects

- pericardium defects (usually at diaphragmatic pericardium)

- sternal cleft or absence of lower sternum

- diaphragmatic septum transversum absence

- omphalocele

Treatment

- initially place saline soaked gauzes and resuscitate the patient; can lose a lot of fluid from the exposed bowel

- TPN, NPO

- repair when patient is stable

- at operation, try to place bowel back in abdomen; may need Vicryl mesh silo

- primary closure at a later date of mesh used

- worse overall prognosis compared with gastroschisis secondary to congenital anomalies

- malrotation can occur with both gastroschisis and omphalocele

the absite review, p.281

Gastroischisis vs Omphalocele

Omphalocele

- the intestines are covered by peritoneum and the umbilicus is centrally located

Gastroschiis

- the intestines are not covered by peritoneum (the defect is usually to the right of the umbilicus)

Lange neonatology, p.36

Omphalocele: Background, definition, pathophysiology

SURGICAL REVIEW, P.389

- Omphalocele and gastroschisis are developmental malformations of the anterior abdominal wall. - Omphaloceles result from devects of the umbilical ring. - They can range from 2 to 10cm in size. Larger lesions frequently result in loss of abdominal domain.

- The abdominal contents are malrotated and contained within a sac composed of both amniotic membrane and peritoneum, which prevents exposure to amniotic fluid.

Omphalocele is a herniation of bowel, and occasionally other organs including stomach and liver, into the umbilical cord and they are usually covered by a peritoneal sac, which may rupture prior to or during birth.

An omphalocele is a herniation of abdominal contents into the base of the umbilical cord.

The gross appearance of omphalocele differs from that of gastroschisis in two important respects.

a) A protective membrane encloses the malpositioned abdominal contents (unless rupture has occurred, eg. during the birth process)

b) Elements of the umbiical cord course individually over the sac and come together at its apex to form a normal-appearing umbilical cord.

Lange neonatology, p.581

ucsf NICU handbook, p.163

SR, p.389

Omphalocele: Asociated anomalies

ASSOCIATION WITH CONGENITAL DEFECTS

- Roughly 2/3 of infants with omphalocele have associated congenital anomalies, notably cardiac and chromosomal anomalies, which have a significant impact on long-term survival. [SR, p.389]

Omphalocele has a high association (>50%) with other anomalies, especially congenital heart disease, chromosomal abnormalities, Pentalogy of Cantrell and Beckwith-Wiedemann syndrome. Therefore chest x-ray, renal ultrasound, and echocardiogram should be obtained prior to operation.

Associated anomalies

- significant associated congenital anomalies occur in 25-40% of infants with omphalocele.

- problems include chromosomal abnormalities, CDH, and a variety of cardiac defects

Lange neonatology, p.581

ucsf NICU handbook, p.163

SR, p.389

Omphalocele: Clinical presentation

There are different sizes of omphaloceles.

The smaller ones typically contain only intestine

Large or giant omphaloceles contain liver and spleen as well as the GI tract.

The peritoneal cavity in infants with large or giant omphaloceles is very small because growth has proceeded without the solid organs in proper position.

Lange neonatology, p.582

Omphalocele: Diagnosis

The anomaly is usually apparent.

Ruptured omphalocele may be confused with gastroschisis; both defects are characterized by exposed intestine, but infants with omphalocele do not possess an intact umbilical cord at the level of the abdominal wall to the left of the defect.

Careful studies to identify associated congenital anomalies should be perfomed.

Often diagnosed prior to delivery by ultrasound.

Lange neonatoogy, p.582

ucsf NICU handbook, p.163

Omphalocele: Management: Ruptured sac

Reduction, even in stages over a lengthy period, may be very difficult to achieve.

RUPTURED SAC

- infants with ruptured sacs resemble those with gastroschisis.

- the unprotected intestine should be cared for as described for gastroschisis.

- the unprotected intestine should be cared for as described for gastroschisis, and the problem should be corrected surgically on an emergent basis.

Lange neonatoogy, p.582

Omphalocele: Management: Intact sac

Reduction, even in stages over a lengthy peirod, may be very difficult to achieve.

INTACT SAC

- intact omphalocele is a less urgent surgical problem.

- the protective membrane conserves heat and in most cases allows effective peristalsis.

- this sac should be carefully protected.

- some surgeons favor daily dressing changes with gauze pads impregnated with povidone-iodine until the sac toughens and desiccates.

- the timing of surgery is influenced by a number of factors, incuding the dimensions of the defect, size of the infant, and presence of other anomalies.

- nonoperative staged reduction using compressive dressings has been described.

Lange neonatology, p.582

3 y/o OEIS syndrome (omphalocele, bladder exstrophy, imperforate anus, and spinal defect), admit for reconstruction 9/20
9/19: admitted for preop bowel prep
9/20: OR for GU reconstruction, ostomy takedown, formation of ileostomy and cecostomy and ventral hernia repair
9/21: weaning vent, start TPN, place PICC
9/23: nauseous, leaving NG tube in, PICC not drawing back well
9/24: pain, dilaudid PCA and tylenol suppository in ostomy, d/c reglan
9/25: still having pain, NG clear drainage, going to clamp NG and give tylenol via G tube
9/26: pain better controlled, trial NG clamp again
9/27: pain better, clamp NG, clears

weight: 16kg
Diet: NPO, TPN 50ml/hr, FE 5ml/hr
D5W1/4NS w/20meq KCl @50cc/hr
Meds: pantoprazole
prns: tylenol, ondansetron
Abx: Zosyn

02884987

Omphalocele Management:  At delivery

Resuscitation team should be present at delivery.

Because fluid losses from the exposed bowel can be massive, the lower half of the infant's body should be placed in a sterile bowel bag (turkey bag) with some sterile 0.9% NaCl at the bottom to keep the environment moist. Close the bag above the defect.

With gastroschisis or large omphalocele, make sure that the blood supply to the bowel is not kinked by the weight of the bowel. The baby may be placed on his right side (right side down or with towels underneath the bowel bag) to help support the externalized intestine and insure adequate blood flow.

ucsf NICU p.163

Omphalocele Management: Temperature regulation

Place baby under radiant warmer to prevent hypothermia from high heat loss from the exposed bowel.

ucsf NICU handbook, p.163

Omphalocele: Management: Nasogastric decompression

Insert a Repogle tube to continuous suction to prevent bowel distension.

ucsf NICU handbook, p.163

Omphalocele: Management:  Maintenance Fluids

Start IV maintenance fluids and prophylactic antibiotics. IV fluid requirement may be as high as 300mL/kg/day, especially for gastroschisis.

ucsf NICU handbook, p.163

Omphalocele: Management: General treatment [SR, p.389]

- Small defects can be closed primarily, while larger defects may require a staged closure, utilizing compression of the sac or gradual reduction of contents and approximation of the fascial edges.

SR, p.389

As is the case of an omphalocele, large defects may result in loss of abdominal domain and may require a staged closure with the assistance of a Silastic silo.  [SR, p.389]