PED Case 2: Congenital diaphragmatic hernia

Rajashree Vyas, MD and Sven Laurin, MD

Imaging Sciences URMC 2008
Publication Date: 2009-06-04

History

Term gestation with poor Apgar scores, persistent hypoxia post-intubation, transferred from an outside facility. Prenatal ultrasonography demonstrated polyhydramnios.

Findings

Supine AP chest radiograph demonstrates multiple lucencies within the right hemithorax (black arrows) with near-complete opacification of the right lung field. Tip of the Replogle tube lies within the left left upper quadrant. ET tube tip projects beyond the thoracid inlet.

Discussion

Congenital diaphragmatic hernia (CDH) is caused by failure of closure of the pleuroperitoneal fold by the 9th week of gestational age. Herniated contents may include stomach, small bowel, colon and liver. CDH occurs in one in every 2000 to 4000 live births and accoutns for 8% of all major congenital anomalies. These defects are usually posterior (Bochdalek hernia) with a left-sided predominance (5:1) which may be due to the protective effect of the liver/ earlier closure of the pleuroperitoneal canal on the right.

Twenty percent demonstrate associated anomalies of the CNS (neural tube defects), GIT (malrotation, oral clefts, omphalocele), CVS and genitourinary system.

Initial radiographs of a neonate with delivery room respiratory distress may reveal dense hemithorax due to lack of gas within herniated contents. Early suspicious findings include paucity of intra-abdominal gas, abnormal position of support apparatus (such as NG tube) and an antenatal history of polyhydramnios. Over time, as gas passes through the herniated viscera, lucencies appear within the dense right hemithorax. There is associated lack of aeration of the ipsilateral lung, decreased aeration of the contralateral lung and mediastinal shift.

Age at presentation and mortality depend on the degree of pulmonary hypoplasia.

This patient was placed on extracorporeal membrane oxygenation (ECMO) for persistent desaturation episodes despite supportive therapy. He was weaned off ECMO on day 9 and underwent repair of CDH. Intra-operatively, a rim of rudimentary diaphragm was identified. Herniated contents included the right lobe of the liver, portions of the colon and small bowel loops. CDH repair with a Gore-Tex patch was performed. Subsequent radiographs demonstrated re-expansion of severely hypoplastic right lung (white arrows) with associated hydrothorax (black arrows). However, the patient subsequently succumbed to ECMO-associated coagulopathy.

DDx

Focal lucent lung lesions in a neonate include:

  1. Congenital lobar emphysema.
  2. Congenital cystic adenomatoid malformation. (CCAM).
  3. Persistent pulmonary interstitial emphysema. (PIE).
  4. CDH.

References

  1. Steinhorn RH. Congenital diaphragmatic hernia. http://www.emedicine.com/ped/topic2603.htm.
  2. Mandell G. Congenital cystic adenomatoid malformation. http://www.emedicine.com/radio/topic186.htm.
  3. Donnelly LF. Fundamentals of Pediatric Radiology. WB Saunders 2001, Chapter 3, pgs 35 – 44.

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