NeoQuest September 2022: Newborn with an Abdominal Wall Defect

A pregnant woman with limited prenatal care requires an emergent cesarean delivery in the setting of placental abruption. The neonatology team is present when she delivers a male infant with a six-centimeter abdominal wall defect (Figure 1). Based on the infant’s initial exam, the team estimates that his gestational age is approximately 35 weeks. 

Figure 1: Neonate with abdominal wall defect noted at delivery. From: Pimenta S, Barbosa J, Castro L, Lopes L, Mota C, Carvalho C, Pereira S. A neonatal abdominal wall defect. Neoreviews (2022);23(9):e650. 10.1542/neo.23-9-e650¹

What long-term complication is associated with this finding?

1. Chronic renal failure
2. Pulmonary hypertension
3. Recurrent herniation of abdominal viscera
4. Short bowel syndrome

Answer: B. Pulmonary hypertension

Explanation:
Figure 1 shows a neonate with an abdominal wall defect consistent with a giant omphalocele.¹ An omphalocele is a common anterior abdominal wall defect that occurs in infants. According to the Consensus of Fetal Pediatric Surgeons, a giant omphalocele is defined as a large abdominal wall defect containing most of the liver, while other definitions use an abdominal wall opening diameter of greater than five centimeters as the main diagnostic criterion (Figure 2).^2,3 This ventral defect occurs secondary to the failure of bowel loops to return from the umbilical cord to the abdominal cavity during the 12th week of gestation and results in herniation of abdominal viscera into a membrane-covered sac.⁴ The location of the liver is an important consideration; the majority of larger omphaloceles contain part of the liver and are associated with euploid fetuses, while smaller omphaloceles containing only intestines are more likely to be associated with fetal aneuploidy.⁵ Additional anomalies such as congenital heart disease may occur in more than 50% of infants with an omphalocele, while an underlying genetic syndrome or abnormal karyotype (eg, Beckwith Wiedemann syndrome; Meckel-Gruber syndrome; Trisomy 13, 18, and 21) may occur in over one-third of affected neonates.^4,5 While infants with isolated omphaloceles achieve over 90% survival rates following surgical repair, infants with giant omphaloceles are at higher risk of pulmonary hypoplasia secondary to a combination of low intra-abdominal pressure, abnormal diaphragmatic function, and thoracic deformities.⁶ For these reasons, approximately one-third of infants with a giant omphalocele develop pulmonary hypertension (Option B), which can be long-standing and result in increased morbidity and mortality.⁷

Figure 2: Fetal ultrasound at 19 weeks’ gestation demonstrating a giant omphalocele involving the liver (L), bowel (B), and a large amount of ascites (denoted by asterisk). From: Davis AS, Blumenfeld Y, Rubesova E, Abrajano C, El-Sayed YY, Dutta S, Barth RA, Hintz SR. Challenges of giant omphalocele: from fetal diagnosis to follow-up. Neoreviews. 2008;9(8):e341

The differential diagnosis of an abdominal wall defect includes omphalocele, gastroschisis, umbilical cord hernia, or other major wall defects resulting from absent or disrupted abdominal musculature (eg, Eagle-Barrett syndrome, Pentalogy of Cantrell, ectopia cordis, or amniotic band sequence).⁴ Gastroschisis typically occurs in isolation with no known genetic causes.⁸ This defect is smaller and located to the right of the umbilicus. Herniated bowel loops are not protected by an overlying sac or membrane (Figure 3).^4,8 Distinguishing features between gastroschisis, omphalocele, and umbilical cord hernias are further outlined in the Table.⁴ Young maternal age, tobacco or recreational drug use (eg, cocaine), and use of decongestants with sympathomimetic effects during pregnancy are well-established risk factors for the development of gastroschisis, suggesting a potential vascular accident hypothesis.⁴ Although survival in infants exceeds 90%, short-term morbidities include sequelae of fetal growth restriction and preterm birth. Long-term morbidities include feeding difficulties, intestinal dysmotility, or complications resulting from atretic bowel segments such as perforation or necrosis.⁴ Intestinal atresia affects 10–15% of infants with gastroschisis and most commonly affects the ileum, often requiring bowel resection with ostomy placement.^4,8 In more severe cases, a large amount of bowel may be lost secondary to vascular compromise.⁴ In both scenarios, infants are at risk for short bowel syndrome (Option D), causing intestinal malabsorption and long-term total parenteral nutrition and/or gastrostomy tube dependence.⁴ The infant in this vignette was diagnosed with a giant omphalocele, which is rarely associated with intestinal atresia or need for significant bowel resection.⁹  

Table: Characteristics of omphalocele, gastroschisis and umbilical hernia. From: Mansfield S, Jancelewicz T. Ventral abdominal wall defects. Pediatr Rev. 2019;40(12):628

Figure 3: Infant with gastroschisis with no overlying sac, which is located to the right of the umbilicus. From: Slater B, Pimpalwar A. Abdominal wall defects. Neoreviews. 2020;21(6):e385

Eagle-Barrett syndrome (EBS), also known as prune belly syndrome, is a rare condition characterized by absent or incomplete abdominal musculature (Figure 4), cryptorchidism, and anomalies of the kidney or urinary tract.¹⁰ Infants are at high risk of respiratory complications with an overall mortality rate of up to 60% due to pulmonary hypoplasia secondary to oligo/anhydramnios caused by renal dysplasia.^10-11 Approximately one-third of surviving infants develop chronic renal failure (Option A) requiring dialysis or kidney transplant.¹⁰ The infant in this vignette did not have the classic findings of abnormal abdominal wall musculature associated with EBS.

Figure 4: Male infant with Eagle-Barrett syndrome with absent abdominal musculature and palpable loops of bowel on physical exam. From: Wolfe M, Beck A, Wambach J. Respiratory distress, flaccid abdominal musculature, and cryptorchidism. Neoreviews. 2011;12(1):e56

Recurrent herniation of abdominal viscera (Option C) represents one of the most common surgical complications in survivors of congenital diaphragmatic hernia (CDH) and can occur within weeks to years after surgical repair.¹² CDH is a structural defect occurring when the pleuroperitoneal folds fail to close during the first trimester, leading to a persistent communication between peritoneal and pleural cavities across the diaphragm.¹³ Herniated abdominal contents can be detected on chest radiograph (Figure 5), with the majority occurring across the left posterolateral diaphragm.¹³ In the immediate postnatal period, respiratory failure is a result of pulmonary hypoplasia, pulmonary hypertension, and cardiac dysfunction and may require rescue therapy with extracorporeal membrane oxygenation (ECMO).¹⁴ Overall survival rates for affected infants range 70%–80%. Infants requiring ECMO therapy are at risk for decreased survival to 50% due to the severity of the lesion and increased risk of treatment comorbidities.¹⁴ Complications of CDH include pathologic reflux requiring pharmacologic treatment and feeding difficulties, resulting in growth failure and/or gastrostomy tube placement to meet caloric demands.¹⁵ Although recurrence of ventral wall herniation has been reported in infants with omphaloceles, herniation of abdominal visceral contents is rarely seen.

Figure 5: Anteroposterior chest radiograph of an infant with a left-sided congenital diaphragmatic hernia. Bowel loops are herniated into the left pleural space (black arrows). From: Kim M, Arain Y, Rhine W. Late preterm infant with respiratory distress. Neoreviews. 2019;20(9):e528

Did you know?

The abdominal wall defect associated with gastroschisis can close in utero, leading to strangulation and amputation of herniated bowel, referred to as “vanishing gastroschisis” (Figure 6).³

Figure 6: This infant with vanishing gastroschisis developed intestinal infarction caused by in utero closure of the abdominal wall defect. From: Mansfield S, Jancelewicz T. Ventral abdominal wall defects. Pediatr Rev. 2019;40(12):632

What rare syndrome consists of an omphalocele, sternal defect, anterior diaphragmatic defect and ectopia cordis? What is the “elephant trunk sign” that can be seen prenatally in an infant with OEIS syndrome?

Read the following articles for more information:

• Beam K, Wojcik M, Agrawal P, Smithers C, Estroff J. Prenatal diagnosis of a ventral abdominal wall defect. Neoreviews. 2020;21(4):e282–292
• Bernardini L, Dickie B, Estroff J. OEIS syndrome: omphalocele, exstrophy of the cloaca, imperforate anus, and spinal defects. Neoreviews. 2021;22(10):e709–718

NeoQuest September Authors
Faith Kim, MD, Columbia University Medical Center/NewYork-Presbyterian Children’s Hospital 
Anisha Bhatia, MD, Northeast Ohio Medical University

References

1. Pimenta S, Barbosa J, Castro L, Lopes L, Mota C, Carvalho C, Pereira S. A neonatal abdominal wall defect. Neoreviews. 2022;23(9):e650. 10.1542/neo.23-9-e650
2. Danzer E, Victoria T, Bebbington M, et al. Fetal MRI-calculated total lung volumes in the prediction of short-term outcome in giant omphalocele: preliminary findings. Fetal Diagn Ther. 2012;31(4):248–253
3. Davis AS, Blumenfeld Y, Rubesova E, et al. Challenges of giant omphalocele: from fetal diagnosis to follow-up. J Perinatol. 2008;9(8):e338–347
4. Mansfield S, Jancelewicz T. Ventral abdominal wall defects. Pediatr Rev. 2019;40(12):627–635
5. van Zalen-Sprock RM, Vugt JM, van Geijn HP. First-trimester sonography of physiological midgut herniation and early diagnosis of omphalocele. Prenat Diagn. 1997;17(6):511–518
6. Duggan E, Puligandla P. Respiratory disorders in patients with omphalocele. Semin Pediatr Surg. 2019;28(2):115–117
7. Partridge E, Hanna B, Panitch H, et al. Pulmonary hypertension in giant omphalocele infants. J Pediatr Surg. 2014;49(12):1767–1770
8. Slater B, Pimpalwar A. Abdominal wall defects. Neoreviews. 2020;21(6):e383–391
9. Andargie A. Ileal atresia associated with omphalocele. J Pediatr Surg Case Rep. 2022;82:102287
10. Wolfe M, Beck A, Wambach J. Respiratory distress, flaccid abdominal musculature, and cryptorchidism. Neoreviews. 2011;12(1):e55–58
11. Panitch H. Pulmonary complications of abdominal wall defects. Paediatr Respir Rev. 2015;16(1):11–17
12. Macchini F, Raffaeli G, Amodeo I, Ichino M, Encinas J, Martinez L, Wessel L, Cavallaro G. Recurrence of congenital diaphragmatic hernia: risk factors, management, and future perspectives. Front Pediatr. 2022;10:823180
13. Kim M, Arain Y, Rhine W. Late preterm infant with respiratory distress. Neoreviews. 2019;20(9):e527–529
14. Grover TR, Rintoul N, Hedrick HL. Extracorporeal membrane oxygenation in infants with congenital diaphragmatic hernia. Semin Perinatol. 2018;42(2):96–103
15. Putnam RL, Harting MT, Tsao K, Morini F, Yoder BA, Luco M, Lally PA. Congenital Diaphragmatic Hernia Study Group. Congenital diaphragmatic hernia defect size and infant morbidity at discharge. Pediatrics. 2016;138(5):e20160243