The validity of the viscero-abdominal disproportion ratio for type of surgical closure in all fetuses with an omphalocele

Abdominal wall defects

Abdominal wall defects are common congenital anomalies with the most frequent being gastroschisis and omphalocele. Though both are the result of errors during embryologic development of the fetal abdominal wall, gastroschisis and omphalocele represent unique disorders that have different clinical sequelae. Gastroschisis is generally a solitary anomaly with postnatal outcomes related to the underlying integrity of the prolapsed bowel. In contrast, omphalocele is frequently associated with other structural anomalies or genetic syndromes that contribute more to postnatal outcomes than the omphalocele defect itself. Despite their embryological differences, both gastroschisis and omphalocele represent anomalies of fetal development that benefit from multidisciplinary and translational approaches to care, both pre- and postnatally. While definitive management of abdominal wall defects currently remains in the postnatal realm, advancements in prenatal diagnostics and therapies may one day change that. This review focuses on recent advancements, novel techniques, and current controversies related to the prenatal diagnosis and management of gastroschisis and omphalocele.

Giant Isolated Omphalocele: Role of Prenatal Diagnosis in Prognostic Asessment and Perinatal Management

Omphalocele is a congenital malformation of the abdominal wall consisting of a protrusion of the abdominal contents at the base of the umbilical cord. It has a high association with genetic and structural defects; however, if the latter is ruled out, its prognosis improves significantly. Prenatal diagnosis has a key role in this condition as omphalocele can be diagnosed by ultrasound in the first trimester scan, enabling a coordinated approach strategy to achieve the best perinatal results. We present a case report of a pregnant patient with a fetus having a giant omphalocele in which prenatal diagnosis played a decisive role, allowing the coordination of a multidisciplinary team, which was crucial in the immediate care of the newborn.

The validity of the viscero-abdominal disproportion ratio for type of surgical closure in all fetuses with an omphalocele

OBJECTIVE

To determine the predictive value of the fetal omphalocele circumference/abdominal circumference (OC/AC) ratio for type of surgical closure and survival and to describe the trajectory of OC/AC ratio throughout gestation.

METHODS

This cohort study included all live-born infants prenatally diagnosed with an omphalocele in our tertiary centre (2000-2017) with an intention to treat. The OC/AC ratio and liver position were determined using 2D ultrasound at three periods during gestation (11-16, 17-26, and/or 30-38 weeks). Primary outcome was type of closure; secondary outcome was survival. In the secondary analyses, the predictive value of the OC/AC-ratio trend for type of closure and survival was assessed.

RESULTS

Primary closure was performed in 37/63 (59%) infants, and 54/63 (86%) survived. The OC/AC ratio was predictive for type of closure and survival in all periods. Optimal cut-off values for predicting closure decreased throughout gestation from 0.69 (11-16 weeks) to 0.63 (30-38 weeks). Repeated OC/AC-ratio measurements were available in 33 (73%) fetuses. The trend of the OC/AC ratio throughout gestation was not significantly associated with type of closure. All infants without liver herniation underwent primary closure.

CONCLUSION

Type of omphalocele surgical closure and survival can be predicted prenatally on the basis of the OC/AC ratio and liver herniation independent of associated anomalies.

LEARNING OBJECTIVE

The reader will be able to use the OC/AC ratio throughout gestation in all omphalocele cases for prediction of type of closure and survival and thus patient counselling.