ABDOMINAL WALL DEFECTSOMPHALOCELE VS GASTROSCHISIS

Rusila TikoitogaMBBS 42016

OBJECTIVES• Background• Epidemiology• Etiology• Pathophysiology• Clinical Features• Diagnosis• Management• Prognosis

History

• 1634 - Ambroise Paré (French barber surgeon) first described Omphalocele.

• Derived from Latin word “Omphalos” meaning prominence or navel.

• 1733 – James Calder (Scottish neonatal surgeon) first described Gastroschisis.

• Derived from the Greek word “Gaster”(Gastro) meaning belly and “schisis” meaning to tear or split from "

Epidemiology Gastroschisis Incidence - 4 per 10,000 M:F is 1:1• 10-15% association with

congenital anomalies such as CHD(VSD), cleft palate and intestinal atresia

• 40% are premature/SGA

Omphalocele Incidence - 3 per 5,000 M:F is 1.5:1 >70% association with

congenital anomalies such Bowel atresia, Imperforated anus, Trisomies 13, 18, 21, Beckwith-Wiedemann Syndrome & Pentalogy of Cantrell

Etiology• Gastroschisiso Congenital abdominal wall defect towards the

right side of the umbilicus and protruded bowel is not covered by a membrane.

o Failure of migration and fusion of the lateral folds of the embryonic disc on the 3rd-4th week of gestation.

o Disruption of the right omphalomesenteric artery as midgut returns to abdomen by the 10th week causing ischemia of the abdominal wall and weakness then herniation.

o Rupture of omphalocele

• Omphaloceleo Congenital abdominal wall defect

with protrusion of abdominal viscera contained within a parietal peritoneum and amniotic membranous sac with Wharton’s jelly.

o Due to failure of the midgut to return to abdomen by the 10th week of gestation during midgut rotation.

Risk FactorsOmphalocele

• Increased maternal age• Twins • High gravida• Consecutive children

Gastroschisis• Young maternal age • Low gravida• Prematurity• Low birth-weight

secondary to IUGR

OMPHALOCELE GASTROSCHISIS

OMPHALOCELE GASTROSCHISIS

Embryology of GIT

Clinical Features

OMPHALOCELE

• central defect of the abdominal wall beneath the

umbilical ring.

• Defect may be 2-12 cm (Small-<5cm)(Large>8cm)

• Always covered by sac

• Sac is made of amnion, Wharton’s jelly and

peritoneum

• The umbilical cord inserts directly into the sac in an

apical or lateral position.

• Small contains intestinal loops only. Large may

involve liver, spleen and bladder, testes/ovary

• >50% have associated anomalies

GASTROSCHISIS• Defect to the right of an intact umbilical cord allowing

extrusion of abdominal content

• Umbilical cord arises from normal place in abdominal

wall

• Opening <=5 cm

• No covering sac (never has a sac )

• Evisceration usually only contains intestinal loops

• Bowels often thickened, matted and edematous

• 10-15% have associated anomalies

• 40% are premature/SGA

Diagnosis• Alpha-feto-protein-synthesized in fetal liver and

excreted by fetal kidneys and crosses placenta by 12 weeks.

• Elevated maternal AFP - neural tube defects, abdominal wall defects, duodenal or esophageal atresia

• 40% false positive rate• Fetal ultrasound after 14 weeks gestation is the

confirmatory test.

Prenatal Ultrasound

• Normal umbilical cord insertion site

• Small bowel loops seen in the amniotic cavity

• No covering membrane over the loops of bowel

• Can include stomach and large bowel

• Majority occur to the right of the umbilical cord

Gastroschisis

Prenatal Ultrasound

• Umbilical cord insertion is typically midline on the mass

• Located centrally• Contents are intestinal

loops and maybe liver, spleen and gonads.

Omphalocele

ManagementPerinatal Management• Maternal Screening Fetal Ultrasound = positive findings Alpha-feto-protein elevated = 90%

Omphalocele 10% Gastroschisis• Prenatal counselling

Pre-operative Management• ABC• Heat Management

– Sterile wrap or sterile bowel bag– Radiant warmer

• Fluid Management– IV bolus 20 ml/kg LR/NS– D10¼NS 2-3 maintenance rate

• Nutrition– TPN (central venous line )

• Abdominal Distention– OG/NG tube– urinary catheter

• Infection ControlBroad-spectrum antibiotics - Ampicillin and Gentamycin

• Closure of the Defect

Omphalocele • Conservative

1. Large omphalocele (10-12cm) apply topical application - Betadine ointment or silver sulfadiazine to the intact sac.

2. Secondary eschar formation and granulation.

3. Healing lasts for 12 months then repaired as ventral hernia.

o Primary Closure Small defects (<4cm) excision of the sac and

closure of the fascia and skin over the abdominal contents

o Mesh patch Medium defects (6-8cm)

• Post operative careo NICUo Ventilationo Feeding:

– Minimal volumeo 48 hrs Antibioticso Hernia dealt with at 1

yr old

Gastroschisis• Primary closure

o If bowel easily reduced• Staged closure

o Silo fashioning:Sac excisedSilo sewn to rectus fascia/full thickness

• Post operative careo NICUo Feeding delayed for weekso Oral stimulation/sucking

reflexo Broad spectrum

antibiotics

Long Term OutcomesOmphalocele• Small - recover well• Large:

– Gastro-oesophageal reflux - 43%– Majority improve over time– 20% pulmonary insufficiency– Respiratory Infections– Asthma– Feeding difficulties;

• 60% with giant omphalocele• May need gastrostomy for feeding

– Failure to thrive

Gastroschisis• Generally excellent if no atresia• NEC:

– 18.5% of neonates more with formula– Bowel loss - short gut syndrome

• Cryptorchidism:– 15-30%– Due either being outside/prematurity– Replacement and orchidopexy by 1 yr

• 60% have psychosocial stress if umbilicus sacrificed

Summary

References:• Up to Date• Medscape• O.P Ghai E.pediatrics• Rudolph’s pediatrics