Abdominal wall defect

1. ABDOMINAL WALL
DEFECTS

2. Introduction
Abdominal wall defects are a type of congenital
defects that allows the stomach , the intestines ,
or other organs to protrude through an unusual
opening that forms on the abdomen . During the
development of the fetus , many unexpected
changes occur inside the womb .

3. Definition
Abdominal wall defects are birth defects that
allows the stomach or intestines to protrude

4. Types
The two main abdominal wall defects are;
Omphalocele
Gastroschisis

5. OMPHALOCELE
Definition
It is a defect in abdominal wall musculature
and skin with protrusion of abdominal viscera
contained within a membranous sac.

6. Incidence
Small omphalocele 1:5,000
Large omphalocele 1:10,000
Male to female ratio 1:1
Pacific Islanders have low risk for omphalocele
70% associated with congenital anomalies
such as Bowel atresia , Imperforated anus ,
Trisomes 13, 18, 21, Beckwith – Wiedman
Syndrome

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

8. Pathophysiology
o Failure of the midgut to return to abdomen by
the 10th week of gestation

9. Risk Factors
 Increased maternal age more than 40 years
 Twins
 High gravida
 Consecutive births

10. Clinical Features
Covered clinical defects of the umbilical ring
Defects may vary from 2-10cm
Sac is composed of amnion, Wharton’s jelly
& peritoneum
The umbilical cord insert directly into the sac
in an apical or lateral position
Small one contains intestinal loops only
Large one contains liver , spleen , bladder ,
testes/ovary

11. Diagnosis
o About 90% of Omphalocele & Gastroschisis
diagnosed prenatally
o Alpha – feto – protein synthesised in fetal liver &
excreted by fetal kidney & crosses placenta by 12th
weeks.
o Prenatal ultrasound after 14th week gestation is the
confirmatory test

12. Prenatal Ultrasound
Findings are
Abdominal organs herniated outside the
abdominal cavity with an abnormal insertion
of umbilical cord into the membrane rather
than into abdominal wall
The mass contents are intestinal loops , liver ,
spleen , gonads etc

13. Management
Evaluation for associated anomalies &
monitoring of fetal growth
Echocardiography: high risk for CHD
Prenatal monitoring of fetal growth : high risk
of IUGR
Other specific evaluation for associated
pulmonary hypoplasia
Prenatal counseling about the expected
hospital course & the long term prognosis

14. After Delivery
The initial evaluation & resuscitation to a babies
with an omphalocele is
Follow same protocol & sequence of all
newborns
Should be handled carefully to prevent the
omphalocele membrane from tearing
After initial stabilization for the newborn should
be inspected to confirm that it is intact & then
covered with a non adherent dressing to protect
the sac

15. Primary closure
Small defects (<4cm) excision of the sac and
closure of the fascia and skin over the
abdominal contents

16. Mesh patch
o Medium defects(6-8cm)
Consecutive
o Large defects (1o-12cm)apply topical application –
Beta-dine ointment or silver sulfadiazine to make
intact sac till the baby is bigger & more able to
tolerate major operations

17. Long Term Outcomes
Small will recovery well
The outcomes determine by the severity of
associated anomalies , so babies with giant
omphalocele have increased morality &
morbidity
GERD
Hernias
Respiratory infection
Failure to thrive

18. GASTROSCHISIS
Definition
• It is the defect in the abdominal wall was
displaced to the right of the umbilicus and
eviscerated bowel was not covered by a
membrane

19. Incidence
o 1:20,000-30,000
o Sex ratio 1:1
o 10-15% have associated anomalies
o 40% are premature /SGA

20. Etiology
Failure of migration and fusion of the lateral folds
of the embryonic disc on the 3rd – 4th week of
gestation
Disruption of the right omphalomesenteric artery
as midgut returns to abdomen by 10th week of
gestation causing ischemia of the abdominal wall
and weakness then herniation
Rupture of omphalocele
Folic acid deficiency

21. Pathophysiology
Abnormal involution of right umbilical vein
Rupture of a small omphalocele
Failure of migration and fusion of the lateral
folds of the embryonic disc on 3rd -4th week of
gestation

22. Risk Factors
Young maternal age
Low gravida
Prematurity
Low birth –weight secondary to IUGR

23. Clinical Features
o Defect to the right of intact umbilical cord
allowing extrution of abdominal content
o No covering sac
o Bowels often thickened, matted, and edematous
o Evisceration of the bowel leads to malrotation
o Constriction of the base may cause intestinal
stenosis , atresia , and volvulus
o Undecended testicles

24. Diagnosis
 About 90% of Gastroschisis & Omphalocele
diagnosed prenatally
 Polyhydramnios
 MSAFP
 Amniocentesis

25. Prenatal Ultrasound
• The diagnostic prenatal ultrasound findings of
Gastroschisis are extra abdominal loops of
bowel without covering sac

26. Management
After Delivery
• The perfusion of the herniated contents should
be carefully evaluated . If bowel ischemia or
infarction suspected immediate surgical
consultation is indicated .
• If the viscera are well perfused, it is important
to next place a clear plastic bag over the
exposed bowel as a temporary covering to
minimize evaporative heat and fluid loss .

27. Pre-operative Management
• Heat management
-sterile wrap or sterile bowel bag
-radiant warmer
• Fluid management
-IV bolus 20ml/kg LR/NS
-D10 ¼ NS 2-3 maintenance rate

28. • Nutrition
-TPN(central venous line)
• Abdominal Distention
-OG/NG tube
-urinary catheter
• Infection control
-Broad spectrum antibiotics
• Closure of the defect
• ABC

29. Surgical Management
Skin flabs
Primary closure : Use of own baby umbilical
stump as biological dressing to seal
gastrochisis defect without attempting a
primary fascial closure
Staged closure : In 1969 ,Allen and Wrenn
adapted Schuster’s technique to treat
gastroschisis

30. Long Term Outcomes
• Almost always with intestinal malformation
• Hernias at the site of repair
• Intestinal atresia
• Short bowel syndrome

31. Conclusion
Abdominal wall defects are type of congenital
defect that allows the stomach , the intestines ,or
other organs to protrude through an unusual
opening that forms on the abdomen.