Adverse outcome of congenital diaphragmatic hernia is determined by diaphragmatic agenesis, not by antenatal diagnosis

Congenital Diaphragmatic hernia - a review

Congenital Diaphragmatic hernia (CDH) is a condition characterized by a defect in the diaphragm leading to protrusion of abdominal contents into the thoracic cavity interfering with normal development of the lungs. The defect may range from a small aperture in the posterior muscle rim to complete absence of diaphragm.

The pathophysiology of CDH is a combination of lung hypoplasia and immaturity associated with persistent pulmonary hypertension of newborn (PPHN) and cardiac dysfunction. Prenatal assessment of lung to head ratio (LHR) and position of the liver by ultrasound are used to diagnose and predict outcomes. Delivery of infants with CDH is recommended close to term gestation. Immediate management at birth includes bowel decompression, avoidance of mask ventilation and endotracheal tube placement if required. The main focus of management includes gentle ventilation, hemodynamic monitoring and treatment of pulmonary hypertension followed by surgery. Although inhaled nitric oxide is not approved by FDA for the treatment of PPHN induced by CDH, it is commonly used.

Extracorporeal membrane oxygenation (ECMO) is typically considered after failure of conventional medical management for infants ≥ 34 weeks’ gestation or with weight >2 kg with CDH and no associated major lethal anomalies. Multiple factors such as prematurity, associated abnormalities, severity of PPHN, type of repair and need for ECMO can affect the survival of an infant with CDH. With advances in the management of CDH, the overall survival has improved and has been reported to be 70-90% in non-ECMO infants and up to 50% in infants who undergo ECMO.

Defect size determines survival in infants with congenital diaphragmatic hernia

OBJECTIVES

Congenital diaphragmatic hernia is a significant cause of neonatal mortality. The objective of this study was to evaluate the clinical factors associated with death in infants with congenital diaphragmatic hernia by using a large multicenter data set.

METHODS

This was a prospective cohort study of all liveborn infants with congenital diaphragmatic hernia who were cared for at tertiary referral centers belonging to the Congenital Diaphragmatic Hernia Study Group between 1995 and 2004. Factors thought to influence death included birth weight, Apgar scores, size of defect, and associated anomalies. Survival to hospital discharge, duration of mechanical ventilation, and length of hospital stay were evaluated as end points.

RESULTS

A total of 51 centers in 8 countries contributed data on 3062 liveborn infants. The overall survival rate was 69%. Five hundred thirty-eight (18%) patients did not undergo an operation and died. The defect size was the most significant factor that affected outcome; infants with a near absence of the diaphragm had a survival rate of 57% compared with infants having a primary repair with a survival rate of 95%. Infants without agenesis but who required a patch for repair had a survival rate of 79% compared with primary repair.

CONCLUSIONS

The size of the diaphragmatic defect seems to be the major factor influencing outcome in infants with congenital diaphragmatic hernia. It is likely that the defect size is a surrogate marker for the degree of pulmonary hypoplasia. Future research efforts should be directed to accurately quantitate the degree of pulmonary hypoplasia or defect size antenatally. Experimental therapies can then be targeted to prospectively identify high-risk patients who are more likely to benefit.

Treatment evolution in high-risk congenital diaphragmatic hernia: ten years' experience with diaphragmatic agenesis

OBJECTIVE

The objective of this study was to evaluate the impact of newer therapies on the highest risk patients with congenital diaphragmatic hernia (CDH), those with agenesis of the diaphragm.

SUMMARY BACKGROUND DATA

CDH remains a significant cause of neonatal mortality. Many novel therapeutic interventions have been used in these infants. Those children with large defects or agenesis of the diaphragm have the highest mortality and morbidity.

METHODS

Twenty centers from 5 countries collected data prospectively on all liveborn infants with CDH over a 10-year period. The treatment and outcomes in these patients were examined. Patients were followed until death or hospital discharge.

RESULTS

A total of 1,569 patients with CDH were seen between January 1995 and December 2004 in 20 centers. A total of 218 patients (14%) had diaphragmatic agenesis and underwent repair. The overall survival for all patients was 68%, while survival was 54% in patients with agenesis. When patients with diaphragmatic agenesis from the first 2 years were compared with similar patients from the last 2 years, there was significantly less use of ECMO (75% vs. 52%) and an increased use of inhaled nitric oxide (iNO) (30% vs. 80%). There was a trend toward improved survival in patients with agenesis from 47% in the first 2 years to 59% in the last 2 years. The survivors with diaphragmatic agenesis had prolonged hospital stays compared with patients without agenesis (median, 68 vs. 30 days). For the last 2 years of the study, 36% of the patients with agenesis were discharged on tube feedings and 22% on oxygen therapy.

CONCLUSIONS

There has been a change in the management of infants with CDH with less frequent use of ECMO and a greater use of iNO in high-risk patients with a potential improvement in survival. However, the mortality, hospital length of stay, and morbidity in agenesis patients remain significant.