Gastroschisis refers to extra-abdominal herniation (evisceration) of fetal or neonatal bowel loops (and occasionally portions or the stomach and or liver) into the amniotic cavity through a para-umbilical abdominal wall defect.
The estimated incidence is at around 1-6 per 10,000 live births. There may be a male predilection and an increased incidence with younger maternal age.
This anomaly does not have a surrounding membrane (unlike an uncomplicated omphalocoele). It is the small bowel that herniates most often. The defect is invariably on the right side and usually measures between 2-4 cm. There is no covering membrane or membrane remnant.
The small intestine always herniates through the abdominal wall defect and lacks normal rotation and fixation to the posterior abdominal wall. In addition to the small intestine, the large intestine, stomach, portions of the genitourinary system and liver may herniate through the defect as well.
A compromise in vascular supply to the area in the abdominal wall adjacent to the umbilicus may be a causative factor. Some also suggest an incomplete regression of the right umbilical vein as a possible causative factor.
Most cases have a sporadic occurrence.
A fetus with a gastroschisis may have intrauterine growth restriction (IUGR) 6.
- maternal serum alpha-fetoprotein (MSAFP) may be elevated: the extent of AFP rise is often greater for a gastroschisis than for an omphalocoele
The herniated content is towards the right side of the umbilical cord in most cases; colour Doppler may be useful to locate the cord in relation to the herniation. This causes the fetal abdominal circumference to be smaller than expected for gestation age. The herniated bowel often appears free floating rather than contained. The herniated bowel wall can be thickened due to oedema.
Treatment and prognosis
There can be an intra-uterine mortality rate of 10-15%. The condition of the bowel at birth is the single most important prognostic factor. An antenatal diagnosis of gastroschisis may facilitate a planned delivery in a specialised unit (tertiary care centre) with parental counselling as well as surgical planning. Most infants are treated surgically on the first day of life. In general, it carries a good survival rate post surgery 3. Some state that the smaller the gastroschisis, the greater the risk of ischaemia to the herniated gut due to a more severe restriction of blood flow. Antenatal diagnosis of accompanying fetal bowel dilatation (especially if over 20 mm 8) is also considered a poorer outcome.
There are a number of complications which can mainly involve the bowel and include:
- in utero bowel obstruction
- in utero bowel perforation
- peritonitis: meconium peritonitis
- motility dysfunction
- necrotising enterocolitis
- short-gut syndrome
- fistula formation
- neonatal gastro-oesophageal reflux: especially following repair 4
General imaging differential considerations include:
- omphalocoele (particularly if ruptured): is accompanied by a surrounding membrane, cord insertion is central
- physiological gut herniation: can occur in early gestation (before 11 weeks)
History and etymology
Arises from the Greek gas-tros'ki-sis - gastro (stomach) plus schisis (fissure).
- 1. Daltro P, Fricke BL, Kline-fath BM et-al. Prenatal MRI of congenital abdominal and chest wall defects. AJR Am J Roentgenol. 2005;184 (3): 1010-6. AJR Am J Roentgenol (full text) - Pubmed citation
- 2. Giulian, Bertrand B.; Alvear, Domingo T. Radiology. doi:10.1148/129.2.473
- 3. Ramsden WH, Arthur RJ, Martinez D. Gastroschisis: a radiological and clinical review. Pediatr Radiol. 1997;27 (2): 166-9. Pediatr Radiol (link) - Pubmed citation
- 4. Blane CE, Wesley JR, Dipietro MA et-al. Gastrointestinal complications of gastroschisis. AJR Am J Roentgenol. 1985;144 (3): 589-91. AJR Am J Roentgenol (abstract) - Pubmed citation
- 5. Durfee SM, Downard CD, Benson CB et-al. Postnatal outcome of fetuses with the prenatal diagnosis of gastroschisis. J Ultrasound Med. 2002;21 (3): 269-74. J Ultrasound Med (full text) - Pubmed citation
- 6. Petrikovsky BM. Fetal disorders, diagnosis and management. Wiley-IEEE. (1999) ISBN:0471191523. Read it at Google Books - Find it at Amazon
- 7. Entezami M, Albig M, Knoll U et-al. Ultrasound Diagnosis of Fetal Anomalies. Thieme. (2003) ISBN:1588902129. Read it at Google Books - Find it at Amazon
- 8. Long AM, Court J, Morabito A et-al. Antenatal diagnosis of bowel dilatation in gastroschisis is predictive of poor postnatal outcome. J. Pediatr. Surg. 2011;46 (6): 1070-5. doi:10.1016/j.jpedsurg.2011.03.033 - Pubmed citation
- 9. Christison-lagay ER, Kelleher CM, Langer JC. Neonatal abdominal wall defects. Semin Fetal Neonatal Med. 2011;16 (3): 164-72. doi:10.1016/j.siny.2011.02.003 - Pubmed citation
- 9. Brugger PC, Prayer D. Development of gastroschisis as seen by magnetic resonance imaging. Ultrasound Obstet Gynecol. 2011;37 (4): 463-70. doi:10.1002/uog.8894 - Pubmed citation
- 10. Holland AJ, Walker K, Badawi N. Gastroschisis: an update. Pediatr. Surg. Int. 2010;26 (9): 871-8. doi:10.1007/s00383-010-2679-1 - Pubmed citation