FORT LAUDERDALE, FLA. – More children are achieving long-term survival following repair of a congenital diaphragmatic hernia, but "this new group of survivors does not appear to have much greater sequelae," Dr. Melinda Solomon said.
For example, despite early pulmonary hypertension and decreased pulmonary artery size, their cardiac function tends to be normal in adulthood. Exercise impairments tend to be mild as well, Dr. Solomon said at a seminar on pediatric pulmonology sponsored by the American College of Chest Physicians and the American Academy of Pediatrics.
"The issue used to be: Can we get these patients to survive and make it to adulthood?" Dr. Solomon said.
They are not entirely free of adverse sequelae, however; obstructive findings and the incidence of asthmalike symptoms can be significantly increased in this population, according to long-term follow-up studies. Recurrence of the hernia is also a lifelong concern, said Dr. Solomon of the division of respiratory medicine at the Hospital for Sick Children in Toronto.
In a long-term follow-up study done in the Netherlands, mean forced expiratory volume in 1 second (FEV1) was significantly lower among 53 survivors at –1.63, compared with 0.08 among controls (Eur. J. Respir. 2009;34:1140-7). "Prebronchodilatation, the FEV1 was below the lower limit of normal in 46% of patients but not in controls," Dr. Solomon said. The residual volume/total lung capacity (RV/TLC) ratio exceeded the upper limit of normal in 52% of affected children and in none of the controls, a significant difference.
The same study did not reveal a difference in exercise performance between groups. "This is good news" that children with congenital diaphragmatic hernia can have normal exercise capacity in adulthood, Dr. Solomon said.
All cardiac indexes from exercise testing were within the normal range in another follow-up study of 23 children and 23 case-matched controls at the Hospital for Sick Children (Pediatr. Pulmonol. 2006;41:522-9).
Echocardiography revealed that "they actually had very good myocardial function but, as expected, a smaller pulmonary artery on the affected side," Dr. Solomon said. Pulmonary function testing revealed abnormalities even 10-16 years after treatment, she added, but FEV1 was in the normal range. For example, mean FEV1 as percent predicted was 83% in patients versus 98% in controls; mean RV/TLC ratio was 31% in patients versus 22% in controls.
Some degree of obstructive disease is common among survivors. Airway hyperactivity with asthmalike symptoms, for example, can last well into adulthood, Dr. Solomon said. It is sometimes difficult to determine who should be prescribed bronchodilators, she added. The 2009 study in the Netherlands found that 28% of affected children responded to these agents, compared with 6% of controls.
Musculoskeletal abnormalities such as scoliosis, pectus excavatum, and chest wall asymmetry develop in almost one-third of patients, Dr. Solomon said. "This often bothers the family as the respiratory issues resolve. It’s important to warn them in advance."
Long-term neurocognitive function remains unclear, and sensorineural hearing loss and its association with congenital diaphragmatic hernia are controversial (Int. J. Pediatr. Otorhinolaryngol. 2010;74:1176-9). Because such hearing loss occurs both in those who undergo extracorporeal membrane oxygenation and in those who don’t, the underlying etiology remains unknown, she said.
Another unanswered question is whether patch repair or video-assisted thoracic surgery (VATS) yields better long-term outcomes, Dr. Solomon said. Although many studies in the literature point to a higher recurrence rate with patch repairs, at her institution, "VATS has a much higher incidence of recurrence."
Congenital diaphragmatic hernia occurs in about 1 in every 3,000 live births. About 85% are left sided, the classic posterolateral Bochdalek hernia. Comorbidities affect approximately 40%-50% of these children; congenital heart disease, in particular, is associated with an increased risk of mortality.
Dr. Solomon said she had no relevant financial disclosures.