Coexistence of CDH and an abdominal wall defect is considered to be rare and our case 2 is the first report of gastroschisis associated with a retrosternal hernia. Borys and Taxy performed a 10-year review of autopsy records and reported that the incidence of CDH associated with omphalocele was 0.077 % [
7], while others have reported that the incidence of CDH combined with an abdominal wall defect is 1.16 % [
1], 1.87 % [
8], and 3.1 % [
9]. In 2006, Harmath
et al. reported a 9 to 11 % incidence of CDH associated with an abdominal wall defect (gastroschisis in two out of 71 cases and omphalocele in four cases) that was higher than the frequencies given in the reports just cited [
10]. Coexistence of CDH with abdominal defects has previously been reported in neonates with a septum transversum diaphragmatic defect, which leads to midline anomalies such as the pentalogy of Cantrell or CDH plus a large epigastric omphalocele without sterna or cardiac anomalies, or neonates who have omphalocele associated with a congenital intrapericardial diaphragmatic hernia [
4,
11,
12]. CDH is also associated with abdominal wall defects in Fryns syndrome: an autosomal recessive syndrome that features multiple congenital anomalies including distal digital hypoplasia, coarse facies, abnormalities of the ears, and CDH [
5,
13]. Coexistence of CDH with abdominal wall defects has also been reported in non-syndromic patients. In these patients, the diaphragmatic defect was not a typical left posterolateral Bochdalek defect, but was found on the right side [
14] or in the left anterolateral region [
2], or else the intestine was seen in the right thorax with bilateral hypoplastic lungs on fetal magnetic resonance imaging [
3]. Our two cases were considered to be non-syndromal because both did not have a typical Bochdalek defect in the diaphragm (the medial border of the defect was formed by the esophageal hiatus in case 1 and case 2 had a retrosternal defect). However, both of our patients had chromosomal abnormalities (trisomy 13 in case 1 and trisomy 21 in case 2). Harmath
et al. reported the association of CDH and omphalocele in a patient with trisomy 18 [
10], so an accumulation of more cases is needed for further analysis of the coexistence of CDH and abdominal wall defects.
Other anomalies associated with CDH may have an important influence on survival and it was recently reported that pulmonary hypoplasia is critical [
2,
3]. Accurate diagnosis of both CDH and the abdominal wall defect is required because the timing of surgical treatment for CDH is important. In patients with both anomalies, underestimation of CDH or overestimation of the abdominal cavity volume can occur. There have been reports on diagnosis of CDH after abdominal wall closure or of CDH causing symptoms such as severe respiratory distress or circulatory instability after the abdominal wall defect is treated [
11,
13,
14]. In our case 1, accurate prenatal diagnosis allowed successful treatment by establishing a silo at delivery, followed by surgical closure of the defects in the diaphragm and abdominal wall after stabilization of the patient’s general condition. In case 2, CDH was asymptomatic at delivery and emerged after approximately 6 months. Thus, the position of the defect in the diaphragm also affects the clinical course.