Current consequences of prenatal diagnosis of congenital diaphragmatic hernia

Background

Today, the diagnosis of congenital diaphragmatic hernia (CDH) can readily be made in the prenatal period during screening ultrasound examination. Patients ought to be referred to rule out associated anomalies, and in isolated cases, prognosis is poor when the liver is intrathoracic and the lung-to-head ratio (LHR) is less than 1. In these patients, prenatal intervention aiming to reverse pulmonary hypoplasia can be considered.

Methods

We present our current algorithm for counselling patients presenting with CDH. Patients with a poor prognosis are offered percutaneous fetal endoluminal tracheal occlusion (FETO) with a balloon, inserted at 26 to 28 weeks. We report on the evolution of technique and results in a consecutive homogeneous case series and compare outcome in cases with similar severity managed in the postnatal period.

Results

Within a period of 28 months, FETO was performed between 26 and 28 weeks in 24 fetuses with severe left-sided CDH. Under general (n = 5), epidural (n = 17) or local (n = 2) anesthesia, the balloon was successfully positioned at first surgery (23/24) with a mean operation time of 20 minutes (range, 3-60 minutes). There were no serious maternal complications or direct fetal adverse effects. In the first 2 weeks after FETO, LHR increased from 0.7 to 1.7. Premature prelabour rupture of the membrane (PPROM) occurred in 16.7% and 33.3% at 28 and 32 weeks or earlier, respectively. Gestational age at delivery was 33.5 weeks. Patency of airways was restored either in the prenatal (n = 12) or perinatal period (n = 12). Early (7 days) and late (28 days) survival, and survival at discharge were 75% (18/24), 58.3% (14/24) and 50% (12/24), respectively. Half of nonsurvivors (n = 6) died of pulmonary hypoplasia and hypertension, in combination with PPROM and preterm delivery (n = 4) and balloon dislodgement (n = 2), which coincided with a short tracheal occlusion (TO) period (12 days). In the other 6, TO period was comparable to that in the 12 survivors (47 vs 42 days, respectively). In that group of 6 babies, only 2 died of pulmonary problems. Late neonatal survival (28 days) was higher with prenatal vs perinatal balloon retrieval 83.3% vs 33.3% (P = .013). In a multicentre study validating the criteria, survival till discharge in 37 comparable cases was 9% (3/32) and 13% (5/37) of parents opted for termination.

Conclusion

Fetuses with isolated left-sided CDH, liver herniation, and LHR of less than 1 have a poor prognosis. Percutaneous FETO is minimally invasive and may improve the outcome in these highly selected cases. Airways can be restored before birth, allowing vaginal delivery and return to the referring tertiary unit and may improve survival rate. The procedure carries a risk for PPROM, although that may decrease with experience.