LIMB-BODY WALL COMPLEX (LBWC)

BODY STALK ANOMALY

LBWC is an abdominal wall defect in addition to a spectrum of limb and visceral anomalies. Internal anomalies are present in 95% of affected fetuses (1,2).

1:14000 – 42000 in Scottish population (14,15).

1:7500 at 10-14 wks in London and surrounding areas (6).

TYPES / PHENOTYPES

Link to Types / Phenotypes

ETIOLOGY

• Unknown but thought to be a severe form of amniotic band syndrome (3).
• Some workers believe that it can be explained by early vascular disruption affecting many structures (4,5). Many of the limb and structural defects cannot be explained by amniotic bands alone, however the predominance of disruptive defects and internal fetal defects can be explained by vascular disruption.
• Early amnion rupture before obliteration of the celomic cavity has been suggested as a possible cause (6).
• Abnormal embryonic folding has been suggested as an alternative hypothesis (faulty folding in all three axes with failure of obliteration of the celomic cavity and abnormal formation of the amniotic sac (7-9).
• Russo et.al. (11) hypothesized that:
• LBWC + craniofacial defects is caused by early vascular disruption.
• LBWC without craniofacial defects is related to defective lateral and caudal folding of the embryonic disc.
• Thoracoabdominal syndrome (including pentalogy of Cantrell) has been suggested as an X-liinked dominant disorder (12). The gene has been mapped to Xq24-q27 (13).

ULTRASOUND

• Bizarre, large, eccentric thoraco-abdominal wall defect that is not classical of gastroschisis or omphalocele (abdominoschisis / thoracoabdominoschisis with eventration of different organs).
• Defects involve the thorax, abdomen, limbs, cranial and facial clefts, abnormalities of the placental membranes and umbilical cord (2-5).
• Defect is usually eccentric and left sided (3).
• Spinal anomalies including dysraphic defects or scoliosis.

• Persistence of the extraembryonic celom with separation of the amnion & chorion is a distinguishing feature. The amnion is continuous with the skin of the body wall and cranial defects, and extends as a sheet from the margin of the umbilical cord.
• Cranial defects (anencephaly and encephalocele). Present in almost 50% of cases in one series (5).
• The upper half of the fetal body is usually in the amniotic cavity while the lower part is in the celomic cavity (6,10).
• Nuchal translucency thickness was above the 95th percentile in 71% of cases (fetal karyotype was always normal) (6).
• Very short umbilical cord.
• Single umbilical artery.
• Persistence of extra-embryonic celomic cavity.
• Maternal serum AFP levels are usually increased (6,15).
• Karyotype is usually normal (there is only one report of placental trisomy 16, maternal uniparental disomy 16 and body stalk abnormality) (16).

Abdominoschisis – liver and bowel extends outside abdominal cavity.
Thoracoabdominoschisis – liver, bowel and lung (arrow) outside thoracic and abdominal cavities
Scoliosis of thoracic spine
3D – large liver containing omphalocele
Short umbilical cord Two-vessel cord
Unfused amnion – 15 weeks of gestation

ASSOCIATED ANOMALIES

Link to Associated Anomalies

PROGNOSIS

Universally fatal, usually within minutes. The remainder dies in the perinatal period from respiratory failure.

REFERENCES

1. Emmanuel PG, Garcia GI, Angtuaco TL. Prenatal detection of abdominal wall defects in utero. Radiographics 1995;15:517-530.
2. Van Allen MI, Curry C, Gallagher L. Limb body wall complex I. Pathogenesis. Am J Med Genet 1987;28:529-548.
3. Moerman P, Fryns JP, Vandenberghe K et.al. Constrictive amniotic bands, amniotic adhesions, and limb body wall complex. Discrete disruption sequences with pathologic overlap. Am J Med Genet 1992;42:470-479.
4. Hartwig NG, Vermeij-Keers C, De Vries HE et.al. Limb body wall malformation: An embryologic etiology? Hum Pathol 1989;20:1071-1077.
5. Pattern RM, Van Allen MI, Mack LA et.al. Limb-body wall complex: in utero sonographic diagnosis of a complicated fetal malformation. AJR 1986;146:1019-1024.
6. Daskalakis G, Sebire NJ, Jurkovic RJM et.al. Body stalk anomaly at 10-14 weeks of gestation. Ultrasound Obstet Gynecol 1997;10:416-418.
7. Jauniaux E, Vyas S, Finlayson C et.al. Early sonographic diagnosis of body stalk abnormality. Prenat Diagn 1990;10:127-132.
8. Giacoia GP. Body stalk anomaly: congenital absence of the umbilical cord. Obstet Gynecol 1992;80:527-529.
9. Hiett AK, Devoe LD, Falls DG III et.al. Ultrasound diagnosis of a twin gestation with concordant body stalk anomaly. J Reprod Med 1992;37:944-946.
10. Ginsberg NE, Cadkin A, Strom C. Prenatal diagnosis of body stalk anomaly in the first trimester of pregnancy Ultrasound Obstet Gynecol 1997;10:419-421.
11. Russo R, D’Armiento M, Angrisani P et.al. Am J Med Genet 1993;47:893-900.
12. Carmi R, Barbash A, Mares AJ. The thoracoabdominal syndrome (TAS): a new X-linked dominant disorder. Am J Med Genet 1990;36:109-114.
13. Parvari R, Carmi R, Weissenbach J et.al. Refined genetic mapping of X-linked thoracoabdominal syndrome. Am J Med Gent 1996;61:401-402.
14. Mann L, Ferguson-Smith M, Desai M et.al. Prenatal assessment of anterior abdominal wall defects and their prognosis. Prenat Diagn 1984;4:427-435.
15. Morrow R, Whittle M, McNay M et.al. Prenatal diagnosis and management of anterior abdominal wall defects in the west of Scotland. Prenat Diagn 1993;13:111-115.
16. Chan Y, Silverman N, Jackson L et.al. Maternal uniparental disomy of chromosome 16 and body stalk anomaly. Am J Med Genet 2000;94:284-286.