Abdominal wall defects Flashcards Preview

MFM Written Boards > Abdominal wall defects > Flashcards

Flashcards in Abdominal wall defects Deck (33)
Loading flashcards...

Anomalies associated with Pentalogy of Cantrell

Not every case will have all 5 abnl, and some cases may have assoc anomalies, usually midline defects such as cleft lip/palate, sirenomelia, exencephaly


Heart position in Pentalogy of Cantrell vs ectopia cordis

Heart in PoC is normally positioned within the chest, but with a subtle shift in axis.


Most common heart abnormality in Pentalogy of Cantrell, others?

Most common = VSD
Others = ASD, pulmonic stenosis, ToF, LV diverticulum


Other anomalies associated with Pentalogy of Cantrell

Vertebral and digital anomalies, including kyphoscoliosis and clinodactyly
Craniofacial - encephalocele, cleft lip, microphthalmia, low set ears
Absent left lung
Cloacal exstrophy
Fetal ascites


Ddx of Pentalogy of Cantrell

Ectopia cordis
Body-stalk anomaly
Simple omphalocele
Amniotic band syndrome


Management of pregnancy w/ Pentalogy of Cantrell

Estimate size and contents of omphalocele
Careful sono exam for other abnl
Surveillance for IUGR, PTL, rupture of omphalocele membrane
Reserve cesarean for obstetric indications, or if giant omphalocele


Genetics of Pentalogy of Cantrell

Primarily thought to be sporadic
Chrom abnl not usual, but abnl in 13 & 18 reported
Possible X-linked


What is an omphalocele?

Defect in ventral abdominal wall characterized by absence of abdominal muscles, fascia, skin. Defect is covered by a membrane that consists of peritoneum and amnion.


Where does the umbilical cord insert in omphalocele?

Insets into the membrane at a location distant from the abdominal wall.


Why and when does omphalocele occur?

Abnormality during process of body infolding at 3-4 weeks gestation.


Incidence of omphalocele

1/4000-7000 livebirths, 1/300-400 combined livebirths & stillbirths


Epidemiology of omphalocele

Associated with AMA


Ruptured omphalocele vs gastroschisis

Defects are usually larger with ruptured omphalocele and have at least exposed, if not extracorporeal, liver


What is Beckwith-Wiedemann syndrome?

Aka exomphalos-macroglossia-gigantism syndrome. Consists of omphalocele, visceromegaly, macroglossia, and severe neonatal hypoglycemia.
Cardiac abnl frequent.
Malignant tumors in 10% - Wilm's tumor, hepatoblastoma, adrenal tumors
Macroglossia & visceral enlargement rarely seen prior to 3rd trimester.


Frequency of visceral malformations with omphalocele

50-70% of cases


Frequency of chromosomal abnl w/ omphalocele



The absence of liver in the omphalocele increases or decreases the likelihood of chromosomal abnl & perinatal mortality?

Interestingly, it increases the likelihood. (In other words, small defects are associated with an increased risk of chromosomal abnl).


Predominant chromosomal abnl w/ omphalocele

T18 (17 of 19 cases w/ chrom abnl in one series)


Risk of chromosomal abnl in central vs epigastric omphalocele

Central - 70%
Epigastric - 12%


Risk of associated anomalies in omphalocele

65% of 349 cases detected antenatally


Risk of associated anomalies in omphalocele w/ a nl karyotype



Incidence of associated congenital heart disease w/ omphalocele



Does MSAFP have a higher sensitivity for omphalocele or gastroschisis?

Much higher for gastroschisis (for cutoff of >2.5 MoM and >3.0 MoM, detection rates were 98% and 96% for gastroschisis, and 71% and 65% for omphalocele).


Management of pregnancy w/ omphalocele

Estimate size and contents of omphalocele, location of cord insertion relative to herniation, presence of amnioperitoneal membrane
Careful sono exam for other abnl, including fetal echo
Chromosomal analysis
Consultation with pedi surgery, genetics, neonatology, pedi cards
Surveillance for IUGR (6-35%) & PTL (25-65%), and for omphalocele rupture


Risk of significant pulmonary hypoplasia and pulmonary hypertension w/ omphalocele

Up to 50%. Fetology recommends MRI for lung volume assessment at 32-34w.


Mode of delivery w/ omphalocele

Controversial. If small, Fetology recommends vaginal delivery. If giant (>5 cm) or extracorporeal liver, then CD may be necessary to avoid dystocia.


Recurrence risk of omphalocele

Depends on cause:
If T18, then 1% or age-related maternal risk, whichever is higher
IF Beckwith-Wiedemann - may be as high as 50%
If isolated - generally considered sporadic, but at least 17 cases of familial omphalocele have been described (?AD)


What is gastroschisis?

An isolated abdominal wall defect to the right of normally inserted umbilical cord, usually 2-3 cm in diameter


Why and when does gastroschisis occur?

Occurs secondary to incomplete closure of the lateral folds during the 6th week of gestation


How does the eviscerated bowel from gastroschisis look at birth? Why?

Has a thick, edematous appearance described as a "peel". The peel involves the serosa and is composed of fibrinand collagen. Thought to be caused by an inflammatory rxn due to amniotic fluid exposure, combined with constriction at the abdominal wall defect.