Screening OB Ultrasound • Xray of the Week 2016 • Week #40
This 26 year old had a routine OB ultrasound. What is the abnormality? What is the treatment?
Figure 1: Gastroschisis on ultrasound. Note the herniated small bowel to the right of the cord insertion. The bowel is freely floating in the amniotic fluid.
Gastroschisis is a sporadic congenital anomaly characterized by herniation of fetal abdominal contents, usually small bowel, and occasionally stomach, colon and/or liver into the amniotic cavity through a para-umbilical abdominal wall defect. The incidence is approximately 1 per 10,000 live births. With the defect almost always on the right side and typically 2-4 cm long, unlike omphalocele, there is no covering membrane. Associated anomalies (usually malrotation) are seen only in 10% of cases; however, omphalocele has associated anomalies in 27-91% of cases.
Figure 2: Omphalocele. The cord inserts at the apex of the abdominal wall defect and the abdominal contents are covered by a membrane. Case courtesy of Dr Ahmed Mahrous Saied, Radiopaedia.org. From the case https://radiopaedia.org/cases/34001
On prenatal ultrasound, the fetal abdominal circumference is small for gestational age due to the herniated abdominal contents. The small bowel is seen to be free floating in the amnionic fluid to the right of the umbilical cord insertion [Figure 1]. With omphalocele, the cord inserts at the apex of the abdominal wall defect and the herniated abdominal contents are covered by a membrane [Figure 2]. Most infants with gastroschisis are treated surgically on the first day of life, however, 90% of cases require multiple operations. The prognosis is good with a survival rate of greater than 90%.
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Kevin Rice, MD serves as the Medical Director of the Radiology Department of Valley Presbyterian Hospital in Los Angeles, California and is a Member of Renaissance Imaging Medical Associates. Dr. Rice has made several media appearances as part of his ongoing commitment to public education. Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. In 2015 Dr. Rice launched Global Radiology CME to provide innovative radiology education at exciting international destinations, with the world's foremost authorities in their field.
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