Hearing impairment in congenital diaphragmatic hernia: the inaudible and noiseless foot of time

Long-term follow-up of patients with congenital diaphragmatic hernia

Neonates with congenital diaphragmatic hernia encounter a number of surgical and medical morbidities that persist into adulthood. As mortality improves for this population, these survivors warrant specialized follow-up for their unique disease-specific morbidities. Multidisciplinary congenital diaphragmatic hernia clinics are best positioned to address these complex long-term morbidities, provide long-term research outcomes, and help inform standardization of best practices in this cohort of patients. This review outlines long-term morbidities experienced by congenital diaphragmatic hernia survivors that can be addressed in a comprehensive follow-up clinic.

Long-term outcomes of congenital diaphragmatic hernia: A single institution experience

BACKGROUND/PURPOSE

As survival rates for patients with congenital diaphragmatic hernia (CDH) increase, long-term sequelae become increasingly prevalent. We present the outcomes of patients who underwent CDH repair at our institution and discuss standardization of follow-up care in our long-term multidisciplinary follow-up clinic.

METHODS

A retrospective review of patients followed in multidisciplinary clinic after CDH repair at our institution from January 1, 2005 to December 1, 2020.

RESULTS

A total of 193 patients met inclusion criteria, 73 females (37.8%) and 120 males (62.2%). Left-sided defects were most common (75.7%), followed by right-sided defects (20.7%). Median age at repair was 4 days (IQR 3-6) and 59.6% of all defects required patch repair. Median length of stay was 29 days (IQR 16.8-50.0). Median length of follow up was 49 months (IQR 17.8-95.3) with 25 patients followed for more than 12 years. Long-term outcomes included gastroesophageal reflux disease (42.0%), diaphragmatic hernia recurrence (10.9%), asthma (23.6%), neurodevelopmental delay (28.6%), attention deficit hyperactivity disorder (7.3%), autism (1.6%), chest wall deformity (15.5%), scoliosis (11.4%), and inguinal hernia (6.7%).

CONCLUSION

As survival of patients with CDH improves, long-term care must be continuously studied and fine-tuned to ensure appropriate surveillance and optimization of long-term outcomes.

Unsolved problems in CDH follow-up

In patients affected by CDH, survival beyond the neonatal period continues to increase thanks to technological and pharmacological improvements. Conversely, patients, families and caregivers are more and more frequently facing "new" complex late comorbidities, including chronic pulmonary and cardiac dysfunctions, neurodevelopmental challenges, and specific nutritional requirements, that often require ongoing long-term medical or surgical care. Therefore, late morbidity is now a key focus in clinical care of CDH. The aims of this paper are to stress some of the most important "unsolved problems" for CDH patients at long-term follow-up.

The prevalence of hearing loss in children with congenital diaphragmatic hernia: A longitudinal population-based study

BACKGROUND

The true prevalence of hearing loss among children with congenital diaphragmatic hernia (CDH) is unknown, with some studies reporting rates up to 60%.

PURPOSE

The purpose of this study was to determine the prevalence of hearing loss among children with CDH and compare it to age-matched controls.

METHODS

We used population-based datasets to compare the number of hearing loss diagnoses in children younger than 10 years-of-age born between 1992 and 2009 with CDH to date-of-birth matched controls without CDH. Factors associated with CDH disease severity were analyzed to determine their effect on the prevalence of hearing loss. A sensitivity analysis was performed to determine if selection bias of improved care over the course of the study affected hearing loss in CDH patients. The prevalences of hearing loss were compared using Fisher's exact tests and statistical significance was defined as p < 0.05.

RESULTS

A total of 529 children, 38 CDH cases and their 491 date-of-birth matched controls, met the inclusion criteria. Hearing loss was found in 7 children with CDH (18.4%) compared to 26 (5.3%) controls; the risk ratio (RR) of hearing loss was 3.48 (95%CI = 1.61-7.49, p = 0.006). There was no association between CDH disease severity and hearing loss.

CONCLUSIONS

CDH is associated with hearing loss compared to the general population. Our results suggest that congenital factors may contribute to hearing loss in CDH more than perinatal exposures.

LEVEL OF EVIDENCE

3.

Analysis of drug-induced hearing loss by using a spontaneous reporting system database

Many drugs can cause hearing loss, leading to sensorineural deafness. The aim of this study was to evaluate the risk of drug-induced hearing loss (DIHL) by using the Japanese Adverse Drug Event Report (JADER) database and to obtain profiles of DIHL onset in clinical settings. We relied on the Medical Dictionary for Regulatory Activities preferred terms and standardized queries, and calculated the reporting odds ratios (RORs). Furthermore, we applied multivariate logistic regression analysis, association rule mining, and time-to-onset analysis using Weibull proportional hazard models. Of 534688 reports recorded in the JADER database from April 2004 to June 2018, adverse event signals were detected for platinum compounds, sulfonamides (plain) (loop diuretics), interferons, ribavirin, other aminoglycosides, papillomavirus vaccines, drugs used in erectile dysfunction, vancomycin, erythromycin, and pancuronium by determining RORs. The RORs of other aminoglycosides, other quaternary ammonium compounds, drugs used in erectile dysfunction, and sulfonamides (plain) were 29.4 (22.4–38.6), 18.5 (11.2–30.6), 15.4 (10.6–22.5), and 12.6 (10.0–16.0), respectively. High lift score was observed for patients with congenital diaphragmatic hernia treated with pancuronium using association rule mining. The median durations (interquartile range) for DIHL due to platinum compounds, sulfonamides (plain), interferons, antivirals for treatment of hepatitis C virus (HCV) infections, other aminoglycosides, carboxamide derivatives, macrolides, and pneumococcal vaccines were 25.5 (7.5–111.3), 80.5 (4.5–143.0), 64.0 (14.0–132.0), 53.0 (9.0–121.0), 11.0 (3.0–26.8), 1.5 (0.3–11.5), 3.5 (1.3–6.8), and 2.0 (1.0–4.5), respectively. Our results demonstrated potential risks associated with several drugs based on their RORs. We recommend to closely monitor patients treated with aminoglycosides for DIHL for at least two weeks. Moreover, individuals receiving platinum compounds, sulfonamides (plain), interferons, and antivirals for HCV infection therapy should be carefully observed for DIHL for at least several months.

Defining outcomes following congenital diaphragmatic hernia using standardised clinical assessment and management plan (SCAMP) methodology within the CDH EURO consortium

Treatment modalities for neonates born with congenital diaphragmatic hernia (CDH) have greatly improved in recent times with a concomitant increase in survival. In 2008, CDH EURO consortium, a collaboration of a large volume of CDH centers in Western Europe, was established with a goal to standardize management and facilitate multicenter research. However, limited knowledge on long-term outcomes restricts the identification of optimal care pathways for CDH survivors in adolescence and adulthood. This review aimed to evaluate the current practice of long-term follow-up within the CDH EURO consortium centers, and to review the literature on long-term outcomes published from 2000 onward. Apart from having disease-specific morbidities, children with CDH are at risk for impaired neurodevelopmental problems and failure of educational attainments which may affect participation in society and the quality of life in later years. Thus, there is every reason to offer them long-term multidisciplinary follow-up programs. We discuss a proposed collaborative project using standardized clinical assessment and management plan (SCAMP) methodology to obtain uniform and standardized follow-up of CDH patients at an international level.

Long-term morbidity of congenital diaphragmatic hernia: A plea for standardization

Congenital diaphragmatic hernia (CDH) survivors present long-term morbidities in several systems, including the neurodevelopmental, gastrointestinal, pulmonary, and musculoskeletal ones, and CDH long-term sequelae are increasingly being recognized. Due to high co-morbidity, health related quality of life in a significant proportion of CDH patients might be compromised. As a consequence of consciousness on the long-term sequelae of CDH survivors, and their consequences for life, several follow-up programs were brought to life worldwide. In this review, we will summarize the long-term sequelae of CDH survivors, the impact of new treatments, and analyze the consistency of follow-up programs.

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.

Management Practice and Mortality for Infants with Congenital Diaphragmatic Hernia

OBJECTIVE

Congenital diaphragmatic hernia (CDH) is fatal in 20 to 40% of cases, largely due to pulmonary dysmaturity, lung hypoplasia, and persistent pulmonary hypertension. Evidence for survival benefit of inhaled nitric oxide (iNO), extracorporeal membrane oxygenation (ECMO), and other medical interventions targeting pulmonary hypertension is lacking. We assessed medical interventions and mortality over time in a large multicenter cohort of infants with CDH.

STUDY DESIGN

We identified all infants ≥ 34 weeks' gestation with CDH discharged from 29 neonatal intensive care units between 1999 and 2012 with an average of ≥ 2 CDH admissions per year. We examined mortality and the proportion of infants exposed to medical interventions, comparing four periods of time: 1999-2001, 2002-2004, 2005-2007, and 2008-2012.

RESULTS

We identified 760 infants with CDH. From 1999-2001 to 2008-2012, use of iNO increased from 20% of infants to 50%, sildenafil use increased from 0 to 14%, and milrinone use increased from 0 to 22% (p < 0.001). Overall mortality (28%) did not significantly change over time compared with the earliest time period.

CONCLUSION

Despite changing use of iNO, sildenafil, and milrinone, CDH mortality has not significantly decreased in this population of infants.

Acute Neonatal Respiratory Failure

Acute respiratory failure requiring assisted ventilation is one of the most common reasons for admission to the neonatal intensive care unit. Respiratory failure is the inability to maintain either normal delivery of oxygen to the tissues or normal removal of carbon dioxide from the tissues. It occurs when there is an imbalance between the respiratory workload and ventilatory strength and endurance. Definitions are somewhat arbitrary but suggested laboratory criteria for respiratory failure include two or more of the following: PaCO₂ > 60 mmHg, PaO₂ < 50 mmHg or O₂ saturation <80 % with an FiO₂ of 1.0 and pH < 7.25 (Wen et al. 2004).

Neurodevelopmental outcome in congenital diaphragmatic hernia: Evaluation, predictors and outcome

To review the reported neurodevelopmental outcome of congenital diaphragmatic hernia (CDH) survivors, identify important predictors of developmental disabilities, and describe the pathophysiological mechanisms contributing to adverse outcome. A Medline search was performed for English-language articles cross-referencing CDH with pertinent search terms. Retrospective, prospective, and longitudinal follow-up studies were examined. The reference lists of identified articles were also searched. Neurodevelopmental dysfunction has been recognized as one of most common and potentially most disabling outcome of CDH. Intelligence appears to be in the low normal to mildly delayed range. Neuromotor dysfunction is common during early childhood. Behavioral problems, hearing impairment, and quality of life related issues are frequently encountered in older children and adolescence. Disease severity correlates with the degree of neurological dysfunction. Neurodevelopmental follow-up in CDH children should become standard of care to identify those who would benefit from early intervention services and improve neurological outcomes.

Sensorineural hearing loss in congenital diaphragmatic hernia survivors is associated with postnatal management and not defect size

BACKGROUND/PURPOSE

We determined the incidence of sensorineural hearing loss (SNHL; >20dB at any frequency) in a contemporary cohort of congenital diaphragmatic hernia (CDH) survivors at a single tertiary care center and identified potential risk factors for SNHL.

METHODS

From 2000 through 2011, clinical and audiologic data were collected on 122 surgically-repaired Bochdalek CDH patients. CDH defect size, duration of ventilation, and cumulative aminoglycoside treatment were used for multivariate logistic regression.

RESULTS

Incidence of SNHL was 7.4% (9/122). We identified one significant independent predictor of SNHL: cumulative length of aminoglycoside treatment (P<.001; OR 1.44, 95% CI: 1.13-1.83).

CONCLUSIONS

Over the last decade, the incidence of SNHL in our CDH patients is low compared to previous reports in the literature (7.4%) and is not associated with CDH defect size or the need for extracorporeal membrane oxygenation. Prolonged duration of aminoglycoside treatment increases the risk of SNHL independent of defect size and duration of ventilation.

Incidence and factors associated with sensorineural and conductive hearing loss among survivors of congenital diaphragmatic hernia

PURPOSE

The reported incidence of sensorineural hearing loss (SNHL) in long-term survivors of congenital diaphragmatic hernia varies widely in the literature. Conductive hearing loss (CHL) is also known to occur in CDH patients, but has been less widely studied. We sought to characterize the incidence and risk factors associated with SNHL and CHL in a large cohort of CDH patients who underwent standardized treatment and follow-up at a single institution.

METHODS

We retrospectively reviewed charts of all CDH patients in our pulmonary hypoplasia program from January 2004 through December 2012. Categorical variables were analyzed by Fisher's exact test and continuous variables by Mann-Whitney t-test (p≤0.05).

RESULTS

A total of 112 patients met study inclusion criteria, with 3 (2.7%) patients diagnosed with SNHL and 38 (34.0%) diagnosed with CHL. SNHL was significantly associated with requirement for ECMO (p=0.0130), prolonged course of hospitalization (p=0.0011), duration of mechanical ventilation (p=0.0046), requirement for tracheostomy (p=0.0013), and duration of loop diuretic (p=0.0005) and aminoglycoside therapy (p=0.0003).

CONCLUSIONS

We have identified hearing anomalies in over 30% of long-term CDH survivors. These findings illustrate the need for routine serial audiologic evaluations throughout childhood for all survivors of CDH and stress the importance of targeted interventions to optimize long-term developmental outcomes pertaining to speech and language.

Perinatal factors associated with poor neurocognitive outcome in early school age congenital diaphragmatic hernia survivors

OBJECTIVE

Determine predictors of neurocognitive outcome in early school age congenital diaphragmatic hernia (CDH) survivors.

STUDY DESIGN

Prospective study of infants with CDH at Duke University Medical Center. Neurocognitive delay (NCD) at school age (4 to 7years) was defined as a score<80 in any of the following areas: Verbal Scale IQ, Performance Scale IQ, Expressive Language, or Receptive Language. Logistic regression, Fisher's exact, and the Wilcoxon rank sum test were used to examine the relationship between NCD at early school age and 6 demographic and 18 medical variables.

RESULTS

Of 43 infants with CDH, twenty seven (63%) survived to hospital discharge, and 16 (59%) returned for school age testing at a median age of 4.9years. Seven (44%) of the children evaluated had NCD. Patch repair (p=0.01), extracorporeal membrane oxygenation (ECMO; p=0.02), days on ECMO (p=0.01), days of mechanical ventilation (p=0.049), and post-operative use of inhaled nitric oxide (p=0.02) were found to be associated with NCD at early school age.

CONCLUSIONS

CDH survivors are at risk for neurocognitive delay persisting into school age. Perinatal factors such as patch repair and ECMO treatment may aid in identifying CDH survivors at high risk for continued learning difficulties throughout childhood.

Sensorineural hearing loss and language development following neonatal extracorporeal membrane oxygenation

OBJECTIVES

To determine the prevalence of hearing loss in school-age children who have undergone neonatal extracorporeal membrane oxygenation treatment and to identify any effects of hearing loss on speech- and language development [corrected] .

DESIGN

Prospective longitudinal follow-up study within the framework of a structured post-extracorporeal membrane oxygenation follow-up program.

SETTING

Outpatient clinic of a level III university hospital.

RESULTS

Tone audiometry was performed by standardized protocol in 136 children aged 5-12 yrs. Hearing loss was considered clinically significant when >20 dB. Hearing was normal in 75.7% of children. Five children (3.7%) had bilateral sensorineural or combined hearing loss; three of them received special audiological care (2.2% of total sample). Of the 24 children with congenital diaphragmatic hernia, 19 (79.2%) had normal hearing and only two (8.3%) had mild sensorineural hearing loss, unilateral in one of them. Follow-up at 24 months of age had shown normal verbal and nonverbal developmental scores. Language development and intelligence median (range) scores at 5 yrs of age were also normal: receptive language development 104 (55-133), syntactical development 104 (68-132), and lexical development 101 (50-141) for 89 children; intelligence quotient 104 (68-132) for 106 children. Scores did not differ among those with normal hearing, mild hearing loss, and moderate-to-severe hearing loss (p = 0.800, p = 0.639, p = 0.876, and p = 0.886, for the respective developmental tests).

CONCLUSIONS

We found normal language development and intelligence in a cohort of neonatal extracorporeal membrane oxygenation survivors. The prevalence of bilateral sensorineural hearing loss was in accordance with that of a larger series in the United States-which exceeds the prevalence in the normal population.

Multi-institutional follow-up of patients with congenital diaphragmatic hernia reveals severe disability and variations in practice

BACKGROUND/PURPOSE

Survivors of congenital diaphragmatic hernia (CDH) have a high incidence of morbidity. Variability in follow-up practices between institutions may affect perception of disability and prevent population-based outcome analysis.

METHODS

A survey of follow-up practices at 16 centers within a population-based CDH network was performed. A descriptive analysis of outcomes (minimum 24 months postdischarge) of CDH survivors from the 2 largest centers was performed.

RESULTS

The nature of follow-up of CDH survivors was highly variable in 12 of 16 responding centers, ranging from ad hoc, community-based, and pediatrician-sponsored follow-up to a single perinatal center-based multispecialty CDH clinic. Outcomes at 24 to 36 months were reported from the 2 largest centers (n = 44). Among survivors, neurodevelopmental disability was most common (12/44; 27%) followed by gastrointestinal (9; 20.5%), pulmonary (5; 11.4%), musculoskeletal (5; 11.4%), and cardiac (2; 4.5%). Additional surgery was required in 17 patients (38.6%), including recurrent CDH repair in 7 (15.9%). Five patients (11.4%) had hearing loss. Among 41 children with available 24-month data, 32 (78%), 17 (41.5%), and 14 (34.1%) patients had weights below the 50th, 25th, and 3rd percentiles, respectively.

CONCLUSION

Congenital diaphragmatic hernia survivorship is associated with significant disability. Standardization of follow-up practices is essential to enable population-based outcomes analysis.

Congenital diaphragmatic hernia

Congenital Diaphragmatic Hernia (CDH) is defined by the presence of an orifice in the diaphragm, more often left and posterolateral that permits the herniation of abdominal contents into the thorax. The lungs are hypoplastic and have abnormal vessels that cause respiratory insufficiency and persistent pulmonary hypertension with high mortality. About one third of cases have cardiovascular malformations and lesser proportions have skeletal, neural, genitourinary, gastrointestinal or other defects. CDH can be a component of Pallister-Killian, Fryns, Ghersoni-Baruch, WAGR, Denys-Drash, Brachman-De Lange, Donnai-Barrow or Wolf-Hirschhorn syndromes. Some chromosomal anomalies involve CDH as well. The incidence is < 5 in 10,000 live-births. The etiology is unknown although clinical, genetic and experimental evidence points to disturbances in the retinoid-signaling pathway during organogenesis. Antenatal diagnosis is often made and this allows prenatal management (open correction of the hernia in the past and reversible fetoscopic tracheal obstruction nowadays) that may be indicated in cases with severe lung hypoplasia and grim prognosis. Treatment after birth requires all the refinements of critical care including extracorporeal membrane oxygenation prior to surgical correction. The best hospital series report 80% survival but it remains around 50% in population-based studies. Chronic respiratory tract disease, neurodevelopmental problems, neurosensorial hearing loss and gastroesophageal reflux are common problems in survivors. Much more research on several aspects of this severe condition is warranted.

Severe diarrhea-dehydration in infancy permanently alters auditory function

Of the myriad etiologies of sensorineural hearing impairment, metabolic stress is rarely considered. I posit that severe dehydration in conjunction with hypoxia, at least during infancy, prompts permanent changes in the cochlea. In a population-based prospective study of otitis media, children without otitis were found to have at age 4-8 years, worse auditory thresholds if as an infant had been hospitalized for diarrhea-dehydration. What is more, stapedius reflex thresholds tended to be lower in children who had been hospitalized for diarrhea-dehydration: that is, less acoustic energy for arousal or to be frightening. The hypothesis that the transient metabolic stress of dehydration with hypoxia prompts permanent sensorineural hearing impairment with reduced uncomfortable loudness thresholds, is both (1) consistent in an evolutionary sense with a subsequent survival advantage, and (2) subject to verification both by descriptive studies of children undergoing ECMO (ExtraCorporeal Membrane Oxygenation) or care for congenital diaphragmatic hernia, and by animal studies.

Developmental outcomes following major surgery: what does the literature say?

Relative to the wealth of information in the medical literature regarding developmental outcome for infants who have had cardiac surgery available, few studies specifically detail how those who have undergone major surgery grow and develop. The few published studies tend to be disease specific, making their results difficult to translate to a more general setting. As mortality for most infants who require surgery in infancy continues to decrease, the focus for researchers and clinicians should be on how these children will grow and develop. As parents realise that their infant will survive, this becomes their next major concern. The most common conditions requiring early major surgery have been reviewed in relation to data on infant developmental outcomes.

Hearing assessment in high-risk congenital diaphragmatic hernia survivors

OBJECTIVE

To report results of audiometric evaluations in high-risk congenital diaphragmatic hernia survivors and their exposure to audiological risk factors (mechanical ventilation, high frequency oscillation, aminoglycoside therapy and neuromuscular blocking agents).

DESIGN

All newborns with high-risk congenital diaphragmatic hernia born between January 2003 and June 2009 were treated consecutively at the Neonatal Intensive Care Unit, Pediatric Hospital, University of Padova. Thirty-two survived and 26 of them underwent formal audiological evaluation (tonal and speech audiometry, otoacoustic emission, and immitance measurements) and follow up.

RESULTS

Twenty-one children had normal hearing; 4 had conductive hearing loss, which was successfully treated; and 1 had severe sensorineural hearing loss and suffers from Turner syndrome.

CONCLUSIONS

Our series revealed a lower prevalence of sensorineural hearing loss in high-risk congenital diaphragmatic hernia survivors than in other studies, suggesting that the association between hearing loss and congenital diaphragmatic hernia has yet to be accurately defined and fully elucidated.

Outcomes of multigestational pregnancies affected by congenital diaphragmatic hernia

BACKGROUND/PURPOSE

The prognosis for multiple vs singleton pregnancies affected by congenital diaphragmatic hernia (CDH) is not known. To improve the counseling of families with multiple gestation pregnancies complicated by CDH, we examined outcomes of a consecutive series of CDH cases occurring in multiple gestation pregnancy referrals.

METHODS

Clinical characteristics and morbidity and mortality data were gathered for a consecutive series of infants with CDH from 16 multiple gestation pregnancies. Outcomes were compared to a cohort of 91 patients with CDH from singleton pregnancies. Multivariate regression was also used in an attempt to determine whether multiple gestation pregnancy was independently predictive of subsequent long-term adverse outcomes.

RESULTS

Four pregnancies were lost to follow-up, and 1 underwent selective reduction. Overall mortality for live-born multiple gestation fetuses affected by CDH was 30% and was 8% for unaffected siblings. No pregnancy was concordant. Clinical features were not different between the case series and control infants, except median gestational age at delivery, which was significantly lower for the multigestational infants (34 [range, 32-36] vs 38 [range, 28-41] weeks) (P = .02). Long-term morbidity was comparable between cases and controls.

CONCLUSIONS

In terms of mortality, outcomes of multigestational pregnancies affected by CDH are no worse than for CDH pregnancies in general. Long-term risk may depend more on CDH severity rather than the presence of multiple fetuses.

CONTEMPORARY NEONATAL INTENSIVE CARE MANAGEMENT IN CONGENITAL DIAPHRAGMATIC HERNIA: DOES THIS OBVIATE THE NEED FOR FETAL THERAPY?

The management of congenital diaphragmatic hernia (CDH) in the newborn infant has changed radically since the first successful outcomes were reported 60 years ago. Then it seemed a surgical problem with a surgical solution – do an operation, remove the intestines and solid viscera from the thoracic cavity, repair the defect and allow the lung to expand. CDH in that era was regarded as the quintessential neonatal surgical emergency. The expectation was that urgent surgery would result in improvement in lung function and oxygenation. That approach persisted up to the 1980s when it was realized that the problem was far more complex and involved both an abnormal pulmonary vascular bed as well as pulmonary hypoplasia. The use of systemically delivered pulmonary vasodilator therapy, principally tolazoline, became a focus of interest in the 1980s with small case reports and case series suggesting improved survival. In the 1990s, based on studies that showed worsening thoracic compliance and gas exchange following surgical repair, deferred surgery and pre-operative stabilization became the standard of care. At the same time extracorporeal membrane oxygenation (ECMO) was increasingly used either as part of pre-operative stabilization or as a rescue therapy after repair. Other centres chose to use high frequency oscillatory ventilation (HFOV). Despite all these innovations the survival in live born infants with CDH did not improve to more than 50% in large series published from high volume centres. However, in the past 10 years there has been an appreciable improvement in survival to the extent that many centres are now reporting survival rates of greater than 80%. Probably the biggest impact on this improvement has been the recognition of the role that ventilation induced lung injury plays in mortality and the need for ECMO rescue. This has ushered in an era of a lung protective or “gentle ventilation” strategy which has been widely adopted as a standard approach. While there have been these radical changes in postnatal management attempts have been made to improve outcome with prenatal interventions, starting with prenatal repair, which was abandoned because of preterm labour. More recently there has been increasing experience in the use of balloon occlusion of the trachea as a prenatal intervention strategy with patients being selected based on prenatal predictors of poor outcome. This approach can only be justified if those predictors can be validated and the outcomes (death or serious long term morbidity) can be shown to be better than those currently achievable, namely 80% survival in high volume CDH centres rather than the 50–60% survival frequently quoted in historical papers.

The long-term follow-up of patients with a congenital diaphragmatic hernia: a broad spectrum of morbidity

Congenital diaphragmatic hernia (CDH) is a life-threatening anomaly with a mortality rate of approximately 40-50%, depending on case selection. It has been suggested that new therapeutic modalities such as nitric oxide (NO), high frequency oxygenation (HFO) and extracorporal membrane oxygenation (ECMO) might decrease mortality associated with pulmonary hypertension and the sequelae of artificial ventilation. When these new therapies indeed prove to be beneficial, a larger number of children with severe forms of CDH might survive, resulting in an increase of CDH-associated complications and/or consequences. In follow-up studies of infants born with CDH, many complications including pulmonary damage, cardiovascular disease, gastro-intestinal disease, failure to thrive, neurocognitive defects and musculoskeletal abnormalities have been described. Long-term pulmonary morbidity in CDH consists of obstructive and restrictive lung function impairments due to altered lung structure and prolonged ventilatory support. CDH has also been associated with persistent pulmonary vascular abnormalities, resulting in pulmonary hypertension in the neonatal period. Long-term consequences of pulmonary hypertension are unknown. Gastro-esophageal reflux disease (GERD) is also an important contributor to overall morbidity, although the underlying mechanism has not been fully understood yet. In adult CDH survivors incidence of esophagitis is high and even Barrett's esophagus may ensue. Yet, in many CDH patients a clinical history compatible with GERD seems to be lacking, which may result in missing patients with pathologic reflux disease. Prolonged unrecognized GERD may eventually result in failure to thrive. This has been found in many young CDH patients, which may also be caused by insufficient intake due to oral aversion and increased caloric requirements due to pulmonary morbidity. Neurological outcome is determined by an increased risk of perinatal and neonatal hypoxemia in the first days of life of CDH patients. In patients treated with ECMO, the incidence of neurological deficits is even higher, probably reflecting more severe hypoxemia and the risk of ECMO associated complications. Many studies have addressed the substantial impact of the health problems described above, on the overall well-being of CDH patients, but most of them concentrate on the first years after repair and only a few studies focus on the health-related quality of life in CDH patients. Considering the scattered data indicating substantial morbidity in long-term survivors of CDH, follow-up studies that systematically assess long-term sequelae are mandatory. Based on such studies a more focused approach for routine follow-up programs may be established.

What's New in Pediatric Surgery

This is a reflection on 2 people who have had a profound influence on many lives and a review of changes in pediatric surgery.