Gastroschisis

Gastrochisis
ultrasound
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Newborn with
an anterior abdominal wall defect diagnosed on prenatal USCXR shows multiple loops of bowel without an encasing sac wrapped in gauze outside of the abdomen to the right side of the patient. The abdominal cavity is small.The diagnosis was gastroschisis.
pediatricimaging.org • CC-by-nc-sa 4.0
Premature
newborn after PICC placementAXR AP shows a left lower extremity PICC that does not follow the course of the iliac vein and whose tip projects at the level of L3 and that projects within the spinal canal on the lateral radiograph. The only gas within the abdomen is in the stomach while all of the small bowel is in a silo outside the abdomen.The diagnosis was malposition of the PICC within the spinal canal in a patient with gastroschisis.
pediatricimaging.org • CC-by-nc-sa 4.0
Newborn with
anterior abdominal wall defect. Preop AXR (left) shows no bowel gas within the abdomen and multiple bowel loops outside of and to the right of the abdomen without an encasing sac. Postop AXR AP (above right) and lateral (below right) show the bowel loops still outside the scaphoid abdomen but now encased within a silo.The diagnosis was gastroschisis.
pediatricimaging.org • CC-by-nc-sa 4.0
Newborn with
an anterior abdominal wall defect. AXR AP shows multiple loops of bowel in the midline outside of the abdomen that were not encased by and sac and thus were wrapped in a temporary gauze dressing.The diagnosis was gastroschisis.
pediatricimaging.org • CC-by-nc-sa 4.0
Radiopaedia • CC-by-nc-sa 3.0 • de

Gastroschisis refers to an extra-abdominal herniation (evisceration) of fetal or neonatal bowel loops (and occasionally portions of the stomach and or liver) into the amniotic cavity through a para-umbilical anterior abdominal wall defect.

Epidemiology

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.

Pathology

This anomaly does not have a surrounding membrane (unlike an uncomplicated omphalocele). 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.

Content

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.

Etiology

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.

Genetics

Most cases have a sporadic occurrence.

Associations

Associated anomalies are rare with gastroschisis (unlike with an omphalocoele) except for related bowel abnormalities (i.e. intestinal atresia, malrotation or stenosis from vascular compromise).

A fetus with gastroschisis may have intrauterine growth restriction (IUGR) .

Serological markers
  • maternal serum alpha-fetoprotein (MSAFP) may be elevated: the extent of AFP rise is often greater for gastroschisis than for an omphalocele

Radiographic features

Antenatal ultrasound

The herniated content is towards the right side of the umbilical cord in most cases; color 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 edema.

There can be either accompanying oligohydramnios or polyhydramnios as ancillary sonographic features.

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. Antenatal diagnosis of gastroschisis may facilitate a planned delivery in a specialized unit (tertiary care center) with parental counseling as well as surgical planning. Most infants are treated surgically on the first day of life. In general, it carries a good survival rate of post-surgery . Some state that the smaller the gastroschisis, the greater the risk of ischemia 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) is also considered a poorer outcome.

Complications

There are a number of complications which can mainly involve the bowel and include:

Differential diagnosis

General imaging differential considerations include:

History and etymology

Arises from the Greek gas-tros'ki-sis - gastro (stomach) plus schisis (fissure).

See also

Siehe auch:
und weiter:
Assoziationen und Differentialdiagnosen zu Gastroschisis: