Congenital diaphragmatic hernia: prognostic indices in the fetal endoluminal tracheal occlusion era

Introduction

Management of congenital diaphragmatic hernia (CDH) in the UK now includes the possibility of fetal endoluminal tracheal occlusion (FETO) for poor prognosis fetuses. The objective of this study was to investigate the value of variables previously thought prognostic in the FETO era.

Methods

A retrospective single-centre study was performed of all infants with CDH born between January 1994 and December 2007. Fetal endoluminal tracheal occlusion was available and had been used with parental consent for fetuses with lung-to-head ratio (LHR) of 1.0 or less and a liver-up position from 2002. Univariate analysis was used to predict survival (to leave hospital) using both prenatal (eg, polyhydramnios) and perinatal variables [eg, best oxygenation index on day 1, or BOI (d1)] and their dependence tested in a logistic regression model. Data were quoted as medians (range). P < .05 was regarded as significant.

Results

Eighty-six infants with CDH (1994-2002, n = 35 and 2002-2007, n = 51 “FETO era”) were studied. Successful FETO intervention was performed in 31 infants.Univariate analysis showed liver position, birth weight, LHR, and BOI (d1) were significant prognostic predictors (all P < .05); however, only BOI (d1) retained significance using logistic regression analysis (odds ratio, 21; 95% confidence interval, 6-74; P < .001). Best oxygenation index on day 1 was then used as a surrogate marker for outcome to test the relationship with LHR (available since 2002) and showed a significant inverse correlation (r_s = −0.5; P < .001). There was no difference in median BOI (d1) between the FETO group and all those treated expectantly (40 [34-1046] vs 59 (23-581); P = .3].

Conclusion

Best oxygenation index on day 1 is the best early postnatal predictor of survival. The more recently evaluated prenatal index, LHR, has an observable relationship with BOI (d1) when it is used as a surrogate marker of outcome.     

Fetal lung-head ratio is not related to outcome for antenatal diagnosed congenital diaphragmatic hernia

We asked if fetal lung-to-head ratio (LHR) of 1.0 or lower or liver herniation had a statistical effect on survival or need for extracorporeal membrane oxygenation (ECMO), compared with LHR above 1.0 in patients with congenital diaphragmatic hernia (CDH).

Methods

Antenatal records of all patients diagnosed with CDH from January of 2002 to June of 2005 were examined. Inclusion criteria were isolated left-sided CDH and absence of significant cardiac or other anomalies/syndromes, treated solely at this institution. Lung-to-head ratio values were compared based on the value currently proposed for fetal intervention: LHR of 1.0 or lower vs LHR above 1.0. Outcome was assessed as survival (discharge to home) or need for ECMO.

Results

Twenty-eight patients met inclusion criteria. Overall survival was 86% (24/28). Postnatal survival in fetuses with LHR of 1.0 or lower (8/11) was not statistically different from LHR above 1.0 (16/17) (73% vs 94%, P = .114). The need for ECMO in the group with LHR of 1.0 or lower (3/11) was not significantly different from those with LHR above 1.0 (1/17) (27% vs 6%, P = .114). Herniation of the fetal liver into the chest did not affect survival or need for ECMO (P = .228).

Conclusion

Neither LHR of 1.0 or lower nor liver herniation identified a risk factor significant enough to warrant fetal intervention. Multicenter studies may be more appropriate to investigate this clinical problem.     

Chylothorax after congenital diaphragmatic hernia repair

Purpose

Chylothorax after congenital diaphragmatic hernia (CDH) repair contributes significantly to morbidity. Our aim was to identify factors contributing to chylothorax and effective treatment strategies.

Methods

We reviewed 171 patients with CDH from 1997 to 2008 and analyzed hernia characteristics, extracorporeal membrane oxygenation (ECMO) use, operative details, and treatment approaches for chylothorax.

Results

Ten (7%) patients developed chylothorax; all were left sided. Using univariate analysis, prenatal diagnosis, ECMO use, and patch repair were associated with development of chylothorax. Logistic regression analysis showed that patch repair was the only variable predictive of chylothorax (P = .028; confidence interval, 0.032-0.823). Although survival was not affected, patients with chylothorax had a significant increase in ventilator days and length of stay (t = 3.57; P = .000; t = 2.74; P = .007). All received thoracostomy and total parenteral nutrition. Six patients received octreotide, 5 of whom required pleurectomy because of failed medical management; the remaining patient died of overwhelming sepsis.

Conclusions

The incidence of chylothorax at our institution was relatively low. Patch repair was associated with the formation of chylothorax. Morbidity was substantial, but survival was not significantly affected. Total parenteral nutrition and thoracostomy were appropriate initial treatments. Octreotide was not an effective adjunct. Refractory cases were successfully treated with pleurectomy.     

Fetoscopic tracheal occlusion for the treatment of severe congenital diaphragmatic hernia: preliminary results

OBJECTIVES: To evaluate survival and lung growth in fetuses with severe congenital diaphragmatic hernia (CDH) treated with fetoscopic tracheal occlusion (FETO) compared with control fetuses and to analyze possible complications of the anesthetic techniques used. PATIENTS AND METHODS: This prospective study was performed on fetuses with CDH. FETO was undertaken before the 29th week of gestation on fetuses with a lung-to-head ratio (LHR) less than 1. FETO was not performed on fetuses with an LHR between 1.0 and 1.5 or those with an LHR less than 1 where consent was not given. Lung growth was monitored by means of LHR. FETO was performed under fetal intramuscular anesthesia and maternal epidural anesthesia and sedation with remifentanil. RESULTS: Seventeen fetuses were included in the study. FETO was performed on 11 fetuses and was effective in 9. The median percentage difference between LHR at diagnosis and prior to FETO was 1.15% (P=.183); between diagnosis and before removing the balloon, the difference was 130.5% (P=.003); and between diagnosis and before delivery, 90.18% (P=.003). In the control group (n=6), the median percentage difference between LHR at diagnosis and before delivery was 49.25% (P=.028). No significant hemodynamic or respiratory changes occurred in either mother or fetus during fetoscopy. All the fetuses in the control group died; 45.5% of those in the FETO group survived. CONCLUSIONS: The use of FETO in cases of CDH appears to increase survival and lung growth. Fetal anesthesia in association with maternal epidural anesthesia and sedation makes it possible to place and remove the endotracheal balloon via fetoscopy with acceptable maternal comfort and without notable complications.     

Dynamic tracheal occlusion improves lung morphometrics and function in the fetal lamb model of congenital diaphragmatic hernia

Background

Congenital diaphragmatic hernia (CDH) is associated with significant neonatal morbidity and mortality. Although prenatal complete tracheal occlusion (cTO) causes hypoplastic CDH lungs to enlarge, improved lung function has not been demonstrated. Furthermore, cTO interferes with the dynamic pressure change and fluid flow associated with fetal breathing.

Purpose

The purpose of the study was to assess a novel dynamic tracheal occlusion (dTO) device that preserves pressure changes and fluid flow.

Methods

In this pilot study, CDH was created in fetal lambs at 65 days of gestational age (GA). At 110 days GA, a cTO device (n = 3) or a dTO device (n = 4) was placed in the fetal trachea. At 135 days GA, lambs were delivered and resuscitated. Unoperated lamb co-twins (n = 5), sham thoracotomy lambs (n = 2), and untreated CDH lambs (n = 3) served as controls.

Results

Tracheal opening pressure, lung volume, lung fluid total protein, and phospholipid were significantly higher in the cTO group than in the dTO and unoperated control groups. Maximal oxygenation and lung compliance were significantly lower in the cTO group when compared with the unoperated control and dTO groups.

Conclusion

Preliminary results suggest that in the fetal lamb CDH model, dTO restores normal lung morphometrics and function, whereas cTO leads to enlarged but less functional lungs.     

Factors influencing survival in newborns with congenital diaphragmatic hernia: the relative role of timing of surgery

Purpose

Controversy persists regarding the factors influencing survival in patients with congenital diaphragmatic hernia (CDH), in particular, the role of timing of surgery. The authors therefore sought to determine such factors and to assess the relative role of timing of surgery on outcome.

Methods

All CDH newborns 1991 through 2002 (n = 111) were divided into those undergoing repair before (“early” n = 35), or after (“late” n = 76) 48 hours. A multivariate analysis was performed to determine the relative impact of various factors on survival rate.

Results

Overall survival rate was 64%. There was no effect on survival of heart rate, temperature, systolic blood pressure, age, extracorporeal membrane oxygenation use, mesh use, infections, or intracranial hemorrhage, and there was no difference between early (68%) or late (62%) repair (P = .2). Initial pco₂ greater than 50, po₂ less than 40, cardiac defects, or renal failure significantly decreased survival rate.

Conclusions

Significant factors influencing survival rate in patients with CDH include cardiac defects, renal failure, and the initial blood gases and not the timing of surgery. CDH repair should be based on the optimization of clinical parameters as opposed to a specific time period to improve outcome.     

Protocolized management of infants with congenital diaphragmatic hernia: effect on survival

Background/Purpose

In 2006, we introduced a new protocol for congenital diaphragmatic hernia (CDH) management featuring nitric oxide in the delivery room, gentle ventilation, lower criteria for extracorporeal membrane oxygenation (ECMO), and appropriately timed operative repair on ECMO. Our goals were to assess outcomes after institution of this protocol and to compare results with historical controls.

Methods

Charts were reviewed of all newborns admitted to a large metropolitan children's hospital from 2002 to 2009 with a diagnosis of CDH. Data were recorded regarding delivery, ECMO, operative repair, length of stay, comorbidities/anomalies, complications, and survival. Postprotocol outcomes were compared to those from the preprotocol era and to data from the international CDH Registry.

Results

Comparison of the protocolized group (n = 43) to the historical group (n = 51) revealed no significant differences in gestational age, birth weight, Apgar scores, or comorbidities. New treatment strategies substantially improved survival to discharge (67% preprotocol, 88% postprotocol; P = .015). Among ECMO patients, survival increased to 82% (20% preprotocol; P = .002).

Conclusions

Our new protocol significantly improved survival to discharge for newborns with CDH. Institution of such a protocol is valuable in improving outcomes for patients with CDH and merits consideration for widespread adoption.     

Impact of prenatal evaluation and protocol-based perinatal management on congenital diaphragmatic hernia outcomes

Background/Purpose

Although intuitive, the benefit of prenatal evaluation and multidisciplinary perinatal management for fetuses with congenital diaphragmatic hernia (CDH) is unproven. We compared the outcome of prenatally diagnosed patients with CDH whose perinatal management was by a predefined protocol with those who were diagnosed postnatally and managed by the same team. We hypothesized that patients with CDH undergoing prenatal evaluation with perinatal planning would demonstrate improved outcome.

Methods

Retrospective chart review of all patients with Bochdalek-type CDH at a single institution between 2004 and 2009 was performed. Patients were stratified by history of perinatal management, and data were analyzed by Fisher's Exact test and Student's t test.

Results

Of 116 patients, 71 fetuses presented in the prenatal period and delivered at our facility (PRE), whereas 45 infants were either outborn or postnatally diagnosed (POST). There were more high-risk patients in the PRE group compared with the POST group as indicated by higher rates of liver herniation (63% vs 36%, P = .03), need for patch repair (57% vs 27%, P = .004), and extracorporeal membrane oxygenation use (35% vs 18%, P = .05). Despite differences in risk, there was no difference in 6-month survival between groups (73% vs 73%).

Conclusions

Patients with CDH diagnosed prenatally are a higher risk group. Prenatal evaluation and multidisciplinary perinatal management allows for improved outcome in these patients.     

Prenatal risk stratification for isolated congenital diaphragmatic hernia: results of a Japanese multicenter study

Background/Purpose

The aim of this study was to establish a prenatal prognostic classification system for risk-stratified management in fetuses with isolated congenital diaphragmatic hernia (CDH).

Methods

A multi-institutional retrospective cohort study of isolated CDH, diagnosed prenatally in fetuses delivered during the 2002 to 2007 period at 5 participating institutions in Japan, was conducted. The risk stratification system was formulated based on the odds ratios of prenatal parameters for mortality at 90 days. The clinical severity in CDH infants were compared among the stratified risk groups.

Results

Patients were classified into the 3 risk groups: group A (n = 48) consisted of infants showing liver-down with contralateral lung-to-thorax transverse area ratio (L/T) ratio ≥0.08; group B of infants showing liver-down with L/T ratio <0.08 or liver-up with L/T ratio ≥0.08 (n = 35), and group C of infants showing liver-up with L/T ratio <0.08 (n = 20). The mortality at 90 days in groups A, B, and C were 0.0%, 20.0%, and 65.0%, respectively. The intact discharge rates were 95.8%, 60.0%, and 5.0%, respectively. This system also accurately reflected the clinical severity in CDH infants.

Conclusions

Our prenatal risk stratification system, which demonstrated a significant difference in postnatal status and final outcome, would allow for accurate estimation of the severity of disease in fetuses with isolated CDH, although it needs prospective validation in a different population.     

Surfactant does not improve survival rate in preterm infants with congenital diaphragmatic hernia

Background

Use of exogenous surfactant in congenital diaphragmatic hernia (CDH) patients is routine in many centers. The authors sought to determine the impact of surfactant use in the premature infant with CDH.

Methods

Data on liveborn infants with CDH from participating institutions were collected prospectively. Surfactant use and timing and outcome data were analyzed retrospectively. The authors evaluated the prenatal diagnosis patients as well. The outcome variable was survival to discharge. Odds ratios with confidence intervals were calculated.

Results

Five hundred ten infants less than 37 weeks’ gestation were entered in the CDH registry. Infants with severe anomalies (n = 80) were excluded. Information on surfactant use was available for 424 patients. Infants receiving surfactant (n = 209) had a greater odds of death than infants not receiving surfactant (n = 215, odds ratio, 2.17, 95% CI: 1.5 to 3.2; P < .01). In prenatally diagnosed infants with immediate distress, there was a trend toward worse survival rates among those receiving surfactant at 1 hour (52 patients) versus those that did not (93 patients; odds ratio, 1.93, 95% CI: 0.96 to 3.9; P < .07).

Conclusions

Surfactant, as currently used, is associated with a lower survival rate in preterm infants with CDH. The use of surfactant replacement in premature infants with CDH can be recommended only within the context of a randomized clinical trial.     

Right congenital diaphragmatic hernia: Prenatal assessment and outcome

Purpose

To understand the natural history of right congenital diaphragmatic hernia (CDH), the authors retrospectively reviewed 27 cases of right CDH that presented for prenatal evaluation or postnatal treatment.

Methods

Between 1995 and September 2002, a total of 194 cases of fetal CDH were evaluated and included 22 right-sided defects. The authors reviewed prenatal diagnostic studies (ultrasound scan, magnetic resonance imaging [MRI] echocardiography) and pre- and postnatal outcomes in these 22 cases of right CDH. Five additional cases of right CDH without a prenatal diagnosis were reviewed.

Results

The mean gestational age at evaluation was 26.1 weeks. The lung area to head circumference ratio (LHR) ranged from 0.32 to 2.5. In all cases, the fetal liver was herniated into the right chest. Associated anomalies were common. There were no karyotype abnormalities (17 of 22 tested). There were 4 terminations. Nine of the 18 (50%) continuing pregnancies had polyhydramnios, premature rupture of membranes, or preterm labor. The mean gestational age at birth was 36.8 weeks. One patient underwent tracheal occlusion at 27 weeks, and 2 patients died before postnatal repair. Overall survival rate (22 prenatal plus 5 postnatal diagnoses) was 19 of 27 (70%). Postnatal survival rate was 19 of 23 (83%). A Gore-tex (W. L. Gore and Associates, Flagstaff, AZ) patch was utilized in 14 of 21 neonates undergoing surgery. Twelve of 23 (52%) required extracorporeal membrane oxygenation (ECMO) with a 75% survival rate. Significant morbidity occurred in 10 of 19 survivors and included neurologic sequelae in 6 of 19 (32%).

Conclusions

MRI was helpful in the determination of liver position and confirmation of diagnosis. The high incidence of preterm complications, frequent need for ECMO, and high prevalence of comorbidities are indicative of the severity of this CDH population and warrant close prenatal surveillance and delivery at a tertiary care center with ECMO capability.     

The hidden mortality of congenital diaphragmatic hernia: a 20-year review

Aims

The true mortality associated with congenital diaphragmatic hernia (CDH) is hidden because survival analyses do not include fetuses with CDH. A retrospective review of all postmortems (PMs) with a diagnosis of CDH over a 20-year period was carried out to highlight this hidden mortality and also measure the nature and number of associated anomalies.

Methods

Postmortem case record details were reviewed for the period January 1986 to December 2005. Data were collected on live birth, stillbirth, therapeutic abortion, and spontaneous abortion.

Results

There was a decline in the annual number of PMs during the period of the study. The median for the four 5-year intervals being 609 (570-657), 528 (488-565), 515 (413-537), and 373 (357-388). A total of 130 PMs were identified, which included a diagnosis of CDH; 97 (75%) were left sided, 22 (17%) were right sided, and 11 (8%) were bilateral. There were 69 live births, 46 therapeutic abortions, 10 stillbirths, and 5 intrauterine deaths; 22% were right sided/bilateral in the live and therapeutic abortion groups, whereas 53% were right sided/bilateral in the latter 2 groups. Of 130, 82 (63%) had major associated anomalies, and 50% of these had at least 1 further major anomaly. The commonest categories of anomalies were cardiac (30), gastrointestinal/abdominal wall defect (28), and neural tube defects (25).

Conclusions

The true incidence of CDH is considerably higher than that seen in neonatal surgical practice. The decline in number of PMs in our region will exacerbate the underestimation of the true incidence. There is a higher incidence of right-sided/bilateral hernias and more than one major anomaly in those who die in utero.     

Morbidity in children after fetoscopic endoluminal tracheal occlusion for severe congenital diaphragmatic hernia: Results from a multidisciplinary clinic

BackgroundAlthough fetoscopic endoluminal tracheal occlusion (FETO) was recently shown to improve survival in a multicenter, randomized trial of severe congenital diaphragmatic hernia (CDH), morbidity outcomes remain essentially unknown. The purpose of this study was to assess long-term outcomes in children with severe CDH who underwent FETO.MethodsWe conducted a prospective study of severe CDH patients undergoing FETO at an experienced North American center from 2015-2021 (NCT02710968). This group was compared to a cohort of non-FETO CDH patients with severe disease as defined by liver herniation, large defect size, and/or ECMO use. Clinical data were collected through a multidisciplinary CDH clinic. Statistics were performed with t-tests and Chi-squared analyses (p≤0.05).ResultsThere were 18 FETO and 17 non-FETO patients. ECMO utilization was 56% in the FETO cohort. Despite significantly lower median observed/expected lung-to-head ratio (O/E LHR) in the FETO group, [FETO: 23% (IQR:18-25) vs. non-FETO: 36% (IQR: 28-41), p<0.001], there were comparable survival rates at discharge (FETO: 78% vs. non-FETO: 59%, p = 0.23) and at 5-years (FETO: 67% vs. non-FETO: 59%, p = 0.53) between the two cohorts. At a median follow up of 5.8 years, metrics of pulmonary hypertension, pulmonary morbidity, and gastroesophageal reflux disease improved among patients after FETO. However, most FETO patients remained on bronchodilators/inhaled corticosteroids (58%) and were feeding tube dependent (67%).ConclusionsThese North American data show that prenatal tracheal occlusion, in conjunction with a long-term multidisciplinary CDH clinic, is associated with acceptable long-term survival and morbidity in children after FETO.Level of EvidenceLevel III     

Effect of epidermal growth factor on pulmonary hypoplasia in experimental diaphragmatic hernia

Background/purpose

Currently, tracheal occlusion (TO) is a potent stimulus for fetal lung growth but also a rather invasive and high-risk procedure. The aim of this study was to investigate a new and much less invasive therapeutic strategy, namely the maternal intraperitoneal administration of epidermal growth factor (EGF) and its effect on pulmonary hypoplasia in the nitrofen-induced congenital diaphragmatic hernia (CDH) rat model, especially its effect on type II pneumocytes.

Methods

CDH was induced by maternal administration of a single oral dose (100 mg) of nitrofen on day 8.5 of pregnancy. Four groups of pregnant rats were designed on day 18.5: normal control (n = 4), CDH (n = 4), CDH plus Dex (n = 4), CDH plus EGF (n = 8). All fetuses were delivered by cesarean section on day 21. Accordingly, there were 4 groups of fetuses: normal controls (n = 33), nitrofen-induced CDH (n = 19), CDH plus Dex treatment (n = 15), and CDH plus EGF treatment (n = 24). Lung tissue weight (LW) and body weight (BW) of each fetus were recorded, lung histologic and morphometric evaluations were performed, and image analysis was combined after lung processing. Transmission electron microscopy was used for ultrastructural observation, especially type II pneumocytes.

Results

CDH was observed in 58 of the 94 rat fetuses (61.7%). Lw/Bw of CDH group was significantly lower than those of Dex and EGF (P < .05). The lungs of CDH fetuses showed marked hypoplasia, in contrast to improved mesenchymal differentiation in that of Dex and EGF fetuses. Statistical differences of these morphologic parameters (RAC, MTBD, interstitial%, and alveoli%) were found (P < .05). As to ultrastructural features, type II cells of CDH lungs had few if any lamellar bodies and cytoplasmic organelles, and showed evidence of abundant glycogen granules. The sparse type II cells also showed cytoplasmic degenerative changes. By contrast, type II cells of EGF lungs showed numerous mitochondria, abundant lamellar bodies (surfactant) and deficiency of glycogen granules, and displayed prominent microvillous projections and pitlike depressions. The density of type II pneumocyte were 65 ± 4.5, 31 ± 3.1, and 8 ± 1.5 for EGF, Dex, and CDH, respectively (EGF v Dex, P < .05; EGF v CDH, P < 0.01).

Conclusions

Compared with TO, prenatal EGF administration as a much less-invasive therapeutic strategy had shown marked improvement in pulmonary hypoplasia and promotion of type II pneumocyte differentiation in the nitrofen-induced CDH rat model. Thus, EGF could improve the prognosis of CDH by means of promoting pulmonary hypoplasia and improving the surfactant deficiency, which suggested a potential role in the clinical treatment of CDH.     

Effect of hospital case volume on outcome in congenital diaphragmatic hernia: the experience of the Canadian Pediatric Surgery Network

Purpose

Despite advances in neonatal care of congenital diaphragmatic hernia (CDH), a significant variation exists in the mortality rates reported by individual centers. Center experience (reflected by case volume) may contribute to this variation in outcome. The aim of the study was to determine whether CDH mortality is affected by hospital case volume.

Methods

The CDH cases were abstracted from a disease-specific, 16-hospital, national network. Thirteen hospitals participated in this study. Anonymized hospitals were categorized as either high (>6 cases) or low-volume (≤6 cases) centers (HVC, n = 6; LVC, n = 7) according to the median case number per center. Risk-adjusted (Score for Neonatal Acute Physiology, version II [SNAP-II] score) mortality rates were compared between HVC and LVC.

Results

One hundred twenty-one CDH cases were identified. Overall in-hospital survival was 81%. No significant difference in SNAP-II score was observed between HVC and LVC. Of 97 (15%) infants treated in 6 HVC, 15 (15%) died compared to 8 (33%) of 24 in 7 LVC (P < .05).

Conclusion

Hospital case volume may be partially responsible for mortality rate variation in CDH. This result requires careful analysis, as case volume may merely be a surrogate for other predictive variables.     

Neonatal tracheal changes following in utero fetoscopic balloon tracheal occlusion in severe congenital diaphragmatic hernia

Objective

To report postnatal tracheal changes after in utero fetoscopic balloon tracheal occlusion in severe congenital diaphragmatic hernia (CDH).

Design

Case series.

Setting

Tertiary care center, CDH National Reference Center.

Patients

Seven consecutive newborn infants with severe CDH who underwent fetoscopic balloon tracheal occlusion.

Interventions

Flexible laryngotracheoscopy and histological aspect observed at necropsy in 2 nonsurvivors.

Results

All infants displayed elongation and relaxation of the posterior tracheal wall, intermittently obstructing the lumen during tidal breathing. Whereas the cartilage displayed adequate rigidity, the pars membranacea appeared both flaccid and loose. Tracheal widening (tracheomegaly) was seen in all cases. Histology (n = 2) pointed to structural modifications throughout the pars membranacea, that is, loss of epithelial folding and of longitudinal elastic network and focal muscular disruption. The cartilage displayed no visible or histologic changes. The above tracheal changes were not symptomatic, except for a barking cough during increased respiratory efforts.

Conclusions

Tracheal widening and intermittent collapse of the posterior wall of the trachea during tidal breathing was found in 7 consecutive newborns who underwent fetoscopic balloon tracheal occlusion, causing mild clinical symptoms. Endoscopic tracheal assessment might provide useful information in children with CDH, in particular, when they underwent in utero fetoscopic balloon tracheal occlusion.     

Fetoscopic temporary tracheal occlusion for congenital diaphragmatic hernia: prelude to a randomized,controlled trial

Objective

As previously reported, high postnatal mortality seen in fetuses with congenital diaphragmatic hernia (CDH) with liver herniation and low lung-to-head ratio (LHR) appears to be improved in fetuses who undergo fetoscopic temporary tracheal occlusion (TO). To test whether further evolution of this technique produces results that justify a randomized controlled trial comparing prenatal intervention to postnatal care, the authors analyzed 11 additional cases and the cumulative experience with 19 cases.

Methods

The authors analyzed retrospectively the outcome of 11 new and 8 previously reported cases of fetoscopic temporary tracheal occlusion. Various factors were studied including maternal morbidity, antenatal outcome, physiologic lung response, and neonatal course.

Results

Temporary TO can be accomplished using 3 5-mm radially expanding uterine ports without hysterotomy. Obstetric morbidity included mild pulmonary edema in 6 cases, chorioamniotic separation and premature rupture of membranes in 12 patients, and preterm labor and delivery in all patients. Thirteen of 19 (68%) neonates survived for 90 days after delivery; one died in utero, and 5 died after birth. Late mortality included one death caused by sepsis and 2 by complications associated with tracheostomies. Morbidity from gastroesophageal reflux requiring Nissen fundoplication, tracheal injury requiring repair or tracheostomy, and recurrent hernias after diaphragmatic repair were characteristic in longterm survivors.

Conclusions

Fetoscopic temporary TO may improve outcome in poor-prognosis fetuses with CDH. However, complications related to tracheal dissection, premature delivery and late morbidity are significant. This experience has led to simpler techniques for fetoscopic tracheal occlusion and to an National Institutes of Health-sponsored randomized controlled trial comparing fetoscopic tracheal occlusion with optimal postnatal care.     

Absolute vs relative improvements in congenital diaphragmatic hernia survival: what happened to “hidden mortality”

Purpose

The aim of this study is to determine if there has been a true, absolute, or apparent relative increase in congenital diaphragmatic hernia (CDH) survival for the last 2 decades.

Method

All neonatal Bochdalek CDH patients admitted to an Ontario pediatric surgical hospital during the period when significant improvements in CDH survival was reported (from January 1, 1992, to December 31, 1999) were analyzed. Patient characteristics were assessed for CDH population homogeneity and differences between institutional and vital statistics-based population survival outcomes. SAS 9.1 (SAS Institute, Cary, NC) was used for analysis.

Result

Of 198 cohorts, demographic parameters including birth weight, gestational age, Apgar scores, sex, and associated congenital anomalies did not change significantly. Preoperative survival was 149 (75.2%) of 198, whereas postoperative survival was 133 (89.3%) of 149, and overall institutional survival was 133 (67.2%) of 198. Comparison of institution and population-based mortality (n = 65 vs 96) during the period yielded 32% of CDH deaths unaccounted for by institutions. Yearly analysis of hidden mortality consistently showed a significantly lower mortality in institution-based reporting than population.

Conclusion

A hidden mortality exists for institutionally reported CDH survival rates. Careful interpretation of research findings and more comprehensive population-based tools are needed for reliable counseling and evaluation of current and future treatments.     

Outcome of CDH infants following fetoscopic tracheal occlusion — influence of premature delivery

Purpose

To evaluate the mortality and morbidity of infants with congenital diaphragmatic hernia who had undergone fetal endoscopic tracheal occlusion (FETO) and whether this was influenced by premature birth.

Methods

The gestational age at delivery, lung–head ratio (LHR) pre and post FETO, neonatal outcomes, and respiratory, gastro-intestinal, neurological, surgical, and musculoskeletal problems at follow up of consecutive infants who had undergone FETO were determined. Elective reversal of FETO was planned at 34 weeks of gestation.

Results

The survival rate of the 61 FETO infants was 48%, with 84% delivered prematurely. Thirty-one delivered < 35 weeks of gestation. Their survival rate was 18%. Twenty-three of 24 infants who had emergency balloon removal were born < 35 weeks of gestation. Survival was related to gestational age at delivery (OR 0.55, 95% CI 0.420, 0.77, p < 0.001) and the duration of FETO (OR 0.73, 95% CI 0.59, 0.91, p < 0.005). Infants born prior to 35 weeks of gestation compared to those born at ≥ 35 weeks required a longer duration of ventilation (median 45 days versus 12 days, p < 0.001), and a greater proportion had surgery for gastro-oesophageal reflux (50% versus 9%, p = 0.011).

Conclusion

These results emphasize the need to reduce premature delivery following FETO.