Fetal intervention for congenital diaphragmatic hernia: the European experience

Prenatal diagnostic and intervention considerations in congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a life-threatening birth defect with significant morbidity and mortality. The prenatal management of a pregnancy with a fetus affected with CDH is complex and requires a multi-disciplinary team approach. An improved understanding of prenatal diagnosis and management is essential to developing strategies to optimize outcomes for these patients. In this review, we explore the current knowledge on diagnosis, severity stratification, prognostic prediction, and indications for fetal intervention in the fetus with CDH.

Congenital diaphragmatic hernia treated via fetal endoscopic tracheal occlusion improves outcome in a middle-income country

OBJECTIVES

A recent European randomized trial - Tracheal Occlusion To Accelerate Lung Growth - demonstrated that fetoscopic endoluminal tracheal occlusion (FETO) is associated with increased postnatal survival among infants with severe congenital diaphragmatic hernia (CDH). However, this differs in middle-income countries such as Brazil, where abortion is illegal and neonatal intensive care is inadequate. This study evaluated the effects of FETO on improving the survival of infants with moderate-to-severe CDH in isolated and non-isolated cases.

METHODS

This retrospective cohort study selected 49 fetuses with CDH, a normal karyotype, and a lung-to-head ratio (LHR) of <1 from a single national referral center for fetal surgery in São Paulo, Brazil, between January 2016 and November 2019. FETO was performed between 26 and 29 weeks of gestation. The primary outcomes were infant survival until discharge from the neonatal intensive care unit and survival until six months of age.

RESULTS

Forty-six women with singleton fetuses having severe CDH underwent prenatal intervention with FETO. Infant survival rates until discharge and at six months of age were both 38 %. The observed-to-expected LHR increased by 25 % after FETO in neonates who survived until discharge. Spontaneous intrauterine death occurred in four growth-restricted fetuses after FETO. Preterm birth in <37 weeks and preterm rupture of membranes in <34 weeks occurred in 56.5 % (26) and 26 % (12) cases, respectively.

CONCLUSIONS

FETO may increase neonatal survival in fetuses with severe CDH, particularly in countries with limited neonatal intensive care.

Do FETO CDH survivors need the same follow-up program as non-FETO patients?

Congenital diaphragmatic hernia (CDH) survivors are at risk of developing significant chronic health conditions and disabilities. The main purpose of this study was to compare the outcomes of CDH infants at 2 years of age (2y) according to whether the infants had undergone fetoscopic tracheal occlusion (FETO) during the prenatal period and characterize the relationship between morbidity at 2y and perinatal characteristics. Retrospective cohort single center study. Eleven years of clinical follow-up data (from 2006 to 2017) were collected. Prenatal and neonatal factors as well as growth, respiratory, and neurological evaluations at 2y were analyzed. One hundred and fourteen CDH survivors were evaluated. Failure to thrive (FTT) was present in 24.6% of patients, gastroesophageal reflux disease (GERD) in 22.8%, 28.9% developed respiratory problems, and 22% had neurodevelopment disabilities. Prematurity and birth weight < 2500 g were related to FTT and respiratory morbidity. Time to reach full enteral nutrition and prenatal severity markers seemed to influence all outcomes, but FETO therapy itself only had an effect on respiratory morbidity. Some variables related to postnatal severity (ECMO, patch closure, days on mechanic ventilation, and vasodilator treatment) were associated with almost all outcomes.  Conclusion: CDH patients have specific morbidities at 2y, most of them related to lung hypoplasia severity. Only respiratory problems were related to FETO therapy itself. The implementation of a specific multidisciplinary follow-up program for CDH patients is essential to provide them the best standard of care, but, more severe patients, regardless of whether they received prenatal therapy, need a more intensive follow-up. What is Known: • Antenatal fetoscopic endoluminal tracheal occlusion (FETO) increases survival in more severe congenital diaphragmatic hernia patients. • Congenital diaphragmatic hernia survivors are at risk of developing significant chronic health conditions and disabilities. Very limited data are available about the follow-up in patients with congenital diaphragmatic hernia and FETO therapy. What is New: • CDH patients have specific morbidities at 2 years of age, most of them related to lung hypoplasia severity. • FETO patients present more respiratory problems at 2 years of age but they don't have an increased incidence of other morbidities. More severe patients, regardless of whether they received prenatal therapy, need a more intensive follow-up.

In Utero Therapy for Congenital Diaphragmatic Hernia

Congenital diaphragmatic hernia is an anomaly that is often prenatally diagnosed and spans a wide spectrum of disease, with high morbidity and mortality associated with fetuses with severe defects. Congenital diaphragmatic hernia is thus an ideal target for fetal intervention. We review the literature on prenatal diagnosis, describe the history of fetal intervention for congenital diaphragmatic hernia, and discuss fetal endoscopic tracheal occlusion and the Tracheal Occlusion To Accelerate Lung growth trial results. Finally, we present preclinical studies for potential future directions.

The Rearing of Maternal-Fetal Surgery: The Maturation of a Field from Conception to Adulthood

Maternal-fetal surgery is fraught with inherent controversy from within the medical community and general public. Despite these challenges, the field of maternal-fetal surgery evolved into an international enterprise. Carefully nurtured by pioneers with foresight and resilience, the field navigated ethical dilemmas with rigorous scientific methodology, collaboration, transparency, and accordance. These central pillars are consistent throughout the brief but momentous history of maternal-fetal surgery, serving as the catalyst for its success. The maturation of fetal intervention is an exemplar of technological innovation propelling clinical innovation, as well as a celebration of mastering the delicate balance between caution and optimism.

Impact of fetal treatments for congenital diaphragmatic hernia on lung development

The extent of lung hypoplasia impacts the survival and severity of morbidities associated with congenital diaphragmatic hernia (CDH). The alveoli of CDH infants and in experimental models of CDH have thickened septa with fewer type II pneumocytes and capillaries. Fetal treatments of CDH-risk preterm birth. Therefore, treatments must aim to balance the need for increased gas exchange surface area with the restoration of pulmonary epithelial type II cells and the long-term respiratory and neurodevelopmental consequences of prematurity. Achievement of sufficient lung development in utero for successful postnatal transition requires adequate intra-thoracic space for lung growth, maintenance of sufficient volume and appropriate composition of fetal lung fluid, regular fetal breathing movements, appropriate gas exchange area, and ample surfactant production. The review aims to examine the rationale for current and future therapeutic strategies to improve postnatal outcomes of infants with CDH.

Impact of fetal endoscopic tracheal occlusion in fetuses with congenital diaphragmatic hernia and moderate lung hypoplasia

OBJECTIVE

To assess the effect of Fetal Endoscopic Tracheal Occlusion (FETO) on neonatal survival in fetuses with left congenital diaphragmatic hernia (CDH) and moderate lung hypoplasia.

STUDY DESIGN

CDH fetuses with moderate pulmonary hypoplasia (observed/expected lung area to head ratio between 26% and 35%, or between 36% and 45% with liver herniation) were prospectively recruited. Included patients were matched to a control group who were ineligible for FETO. Primary outcomes were survival at 28 days, at discharge, and at 6 months of age, respectively.

RESULTS

58 cases were recruited, 29 treated with FETO and 29 matched controls. Median gestational age (GA) at balloon placement and removal were 29.6 and 33.6 weeks, respectively. FETO group showed significantly lower GA at delivery (35.2 vs. 37.1 weeks, respectively, p < 0.01), higher survival at 28 days (51.7 vs. 24.1%, respectively, p = 0.03), at discharge (48.3 vs. 24.1%, respectively, p = 0.06), and at six months of age (41.4 vs. 24.1%, respectively, p = 0.16), and significantly lower length of ventilatory support (17.8 vs. 32.3 days, p = 0.01) and NICU stay (34.2 vs. 58.3 days, p = <0.01) compared to controls.

CONCLUSION

FETO was associated with a non-significant increase in survival and significantly lower neonatal respiratory morbidity among CDH fetuses with moderate lung hypoplasia.

Fetal endoscopic tracheal occlusion for congenital diaphragmatic hernia: a narrative review of the history, current practice, and future directions

Fetal intervention for fetuses with congenital diaphragmatic hernia (CDH) has been investigated for over 30 years and is summarized in this manuscript. The review begins with a discussion of the history of fetal intervention for this severe congenital anomaly beginning with open fetal surgery with repair of the anatomical defect, shifting towards tracheal occlusion via open surgery techniques, and finally fetoscopic endoluminal balloon tracheal occlusion using a percutaneous approach. The current technique of fetal endoscopic tracheal occlusion (FETO) is described in detail with steps of the procedure and complementary figures. The main outcomes of single-institutional studies and multiple systematic reviews are examined and discussed. Despite these studies, the fetal community agrees that FETO remains investigational at this time as there is insufficient evidence to recommend it as the standard of care for CDH. A randomized controlled trial, The Tracheal Occlusion to Accelerate Lung Growth (TOTAL) trial, has been designed to attempt to answer this question in an elaborate, international, multi-institutional study and is described in the text. Finally, future directions of fetal intervention for antenatally diagnosed CDH are discussed, including options for non-isolated CDH, the Smart-TO balloon for nonoperative reversal of occlusion, and transplacental sildenafil for treatment of pulmonary hypertension prior to birth.

Neurodevelopmental outcomes in children with isolated congenital diaphragmatic hernia: A systematic review and meta-analysis

BACKGROUND

Congenital diaphragmatic hernia (CDH) reportedly has neurologic consequences in childhood however little is known about the impact in isolated CDH.

AIMS

Herein we aimed to describe the risk of neurodevelopmental complications in children born with isolated CDH.

MATERIALS & METHODS

We systematically reviewed literature for reports on the neurological outcome of infants born with isolated CDH. The primary outcome was neurodevelopmental delay. Secondary outcomes included, motor skills, intelligence, vision, hearing, language and behavior abnormalities.

RESULTS

Thirteen out of 87 (15%) studies reported on isolated CDH, including 2624 out of 24,146 children. Neurodevelopmental delay was investigated in four studies and found to be present in 16% (3-34%) of children. This was mainly attributed to motor problems in 13% (2-30%), whereas cognitive dysfunction only in 5% (0-20%) and hearing in 3% (1-7%). One study assessed the effect of fetal surgery. When both isolated and non-isolated children were included, these numbers were higher.

DISCUSSION

This systematic review demonstrates that only a minority of studies focused on isolated CDH, with neurodevelopmental delay present in 16% of children born with CDH.

CONCLUSION

To accurately counsel patients, more research should focus on isolated CDH cases and examine children that underwent fetal surgery.

Survival outcome in severe left-sided congenital diaphragmatic hernia with and without fetal endoscopic tracheal occlusion in a country with suboptimal neonatal management

OBJECTIVE

To evaluate the impact of fetal endoscopic tracheal occlusion (FETO) on improving survival of fetuses with severe left-sided congenital diaphragmatic hernia (CDH), as compared with contemporaneous cases managed expectantly during pregnancy, in a country with suboptimal neonatal management.

METHODS

In this prospective cohort study, consecutive fetuses with isolated left-sided CDH, normal karyotype and severe pulmonary hypoplasia (defined as liver herniation and observed/expected lung-to-head circumference ratio below 26%) were selected for FETO at less than 32 weeks of gestation in a single tertiary referral center in Queretaro, Mexico. Postnatal outcome (survival up to 28 days after birth) was compared between fetuses treated with FETO and contemporaneous cases with similar lung size managed expectantly during pregnancy.

RESULTS

Twenty-five fetuses with isolated severe left-sided CDH treated with FETO were matched individually with 25 cases managed expectantly during pregnancy. Endotracheal placement of the balloon was performed successfully on the first attempt in all cases. The median gestational age (GA) at balloon placement was 29.1 (range, 25.6-31.8) weeks and 34.1 (range, 30.0-36.1) weeks at balloon removal. There were no technical problems with the introduction or removal of the balloon in any cases. The median GA at delivery was significantly lower in the group treated with FETO than in those managed expectantly (35.3 vs 37.7 weeks; P = 0.04). The survival rate was significantly higher in the group treated with FETO than in those without fetal intervention (32% vs 0%; P < 0.001).

CONCLUSION

In settings with suboptimal neonatal management, FETO was associated with improved neonatal survival in fetuses with isolated left-sided CDH and severe pulmonary hypoplasia. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Fetal anesthesia: intrauterine therapies and immediate postnatal anesthesia for noncardiac surgical interventions

PURPOSE OF REVIEW

This review describes maternal and fetal anesthetic management for noncardiac fetal surgical procedures, including the management of lower urinary tract obstruction, congenital diaphragmatic hernia (CDH), myelomeningocele, sacrococcygeal teratoma, prenatally anticipated difficult airway and congenital lung lesions.

RECENT FINDINGS

Fetal interventions range from minimally invasive fetoscopic procedures to mid-gestation open surgery, to ex-utero intrapartum treatment procedure. Anesthetic management depends on the fetal intervention and patient characteristics. Anesthesia for most minimally invasive procedures can consist of intravenous sedation and local anesthetic infiltration in clinically appropriate maternal patients. Open fetal and ex-utero intrapartum treatment procedures require maternal general anesthesia with volatile anesthetic and other medications to maintain uterine relaxation. Tracheal balloons are a promising therapy for CDH and can be inserted via minimally invasive techniques. Management of the prenatally anticipated difficult airway during delivery and removal of tracheal balloons from patients with CDH during delivery can be clinically dynamic and require flexibility, seamless communication and a high-functioning, multidisciplinary care team.

SUMMARY

Maternal and fetal anesthetic management is tailored to the fetal intervention and the underlying health of the fetus and mother.

The use of atosiban prolongs pregnancy in patients treated with fetoscopic endotracheal occlusion (FETO)

Objective To evaluate the impact of atosiban as a tocolytic agent in patients treated with the fetoscopic endotracheal occlusion (FETO) procedure due to congenital diaphragmatic hernia (CDH). As premature birth after fetoscopy remains a serious concern, an effort to reduce prematurity is required. Methods A total of 43 patients with severe CDH treated with FETO were enrolled in this study. The study group consisted of 22 patients who received atosiban during the FETO procedure and a control group of 21 patients who did not receive atosiban during the FETO procedure. Demographic data, gestational age (GA) at delivery, cervical length and GA at premature rupture of membranes (PROM) were evaluated. Results The GA at delivery was significantly different between the two groups studied. The median GA at delivery was 32.6 and 34.5 weeks in the no-atosiban vs. atosiban groups, respectively (P = 0.013). The median cervical length was 29.9 and 31.2 mm for the no-atosiban and atosiban groups, respectively, and was not statistically significant (P = 0.28). There were no significant correlations between groups for the occurrence of PROM, GA at the time of PROM, duration of the procedures, parity, maternal body mass index (BMI) or age. In the univariate linear regression model, the only factor independently associated with GA at delivery was the use of atosiban during FETO procedures (β = 0.375; P < 0.013). Conclusion In cases of severe CDH treated with FETO, the use of atosiban as a tocolytic agent during the procedure prolonged pregnancy by 2 weeks. Cervical length, duration of FETO or maternal characteristics were not associated with GA at delivery.

Biomaterials in fetal surgery

Fetal surgery and fetal therapy involve surgical interventions on the fetus in utero to correct or ameliorate congenital abnormalities and give a developing fetus the best chance at a healthy life. Historical use of biomaterials in fetal surgery has been limited, and most biomaterials used in fetal surgeries today were originally developed for adult or pediatric patients. However, as the field of fetal surgery moves from open surgeries to minimally invasive procedures, many opportunities exist for innovative biomaterials engineers to create materials designed specifically for the unique challenges and opportunities of maternal-fetal surgery. Here, we review biomaterials currently used in clinical fetal surgery as well as promising biomaterials in development for eventual clinical translation. We also highlight unmet challenges in fetal surgery that could particularly benefit from novel biomaterials, including fetal membrane sealing and minimally invasive myelomeningocele defect repair. Finally, we conclude with a discussion of the underdeveloped fetal immune system and opportunities for exploitation with novel immunomodulating biomaterials.

Fetal intervention for congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a condition that results from incomplete diaphragm formation during embryogenesis. The diaphragmatic defect allows for herniation of abdominal viscera into the chest, and the resulting pulmonary hypoplasia and pulmonary hypertension can lead to cardiorespiratory failure in the neonatal period. There is a wide spectrum of disease severity in CDH, and while advances in neonatal care and the introduction of extracorporeal membrane oxygenation have improved outcomes in many cases, the most severe defects are still associated with high morbidity and mortality. Improvements in prenatal diagnostic and prognostic capabilities have created an opportunity to select high risk patients for fetal intervention. Three decades of refinements in the fetal surgical therapy for CDH have led to the current technique of Fetoscopic Endoluminal Tracheal Occlusion (FETO). Herein, we review the current considerations for selecting patients for fetal intervention, and the contemporary fetal surgical operation for CDH, FETO, with a focus on early outcomes and ongoing studies.

Fetoscopy-Assisted Percutaneous Decompression of the Distal Trachea and Lungs Reverses Hydrops Fetalis and Fetal Distress in a Fetus with Laryngeal Atresia

We present a case of prenatal hydrops secondary to congenital high airway obstruction syndrome (CHAOS) that was treated with fetoscopy-assisted needle decompression. A 22-year-old G3P2 woman presented after a 21-week ultrasound demonstrated CHAOS. The fetus developed hydrops at 25 weeks, characterized by abdominal ascites, pericardial effusion, and scalp edema. Fetal MRI showed complete obstruction of the glottis and subglottic airway, suggestive of laryngeal atresia. At 27 weeks, due to the progression of the hydrops, operative fetoscopy was proposed and performed. Fetal laryngoscopy confirmed fusion of the vocal cords and laryngeal atresia. The atretic segment was a solid cartilaginous block, preventing intubation. Using the fetoscope to stabilize the fetal head and neck, we performed ultrasound-guided percutaneous needle drainage of the cervical trachea through the anterior fetal neck. We removed 17 mL of viscous fluid from the lower trachea, resulting in immediate lung decompression. Two weeks later, ultrasound confirmed hydrops resolution. The patient was delivered and tracheostomy performed at 30 weeks via an ex utero intrapartum treatment (EXIT) procedure after progression of preterm labor. At 27 days of life, the infant was stable on minimal ventilator support. To our knowledge, this is the first successful report of an ultrasound-guided percutaneous tracheal decompression through the anterior neck of a fetus with CHAOS secondary to laryngeal atresia.

A multicentre study to predict neonatal survival according to lung-to-head ratio and liver herniation in fetuses with left congenital diaphragmatic hernia (CDH): Hidden mortality from the Latin American CDH Study Group Registry

OBJECTIVE

To evaluate natural history of fetuses congenital diaphragmatic hernia (CDH) prenatally diagnosed in countries where termination of pregnancy is not legally allowed and to predict neonatal survival according to lung area and liver herniation.

METHODS

Prospective study including antenatally diagnosed CDH cases managed expectantly during pregnancy in six tertiary Latin American centres. The contribution of the observed/expected lung-to-head ratio (O/E-LHR) and liver herniation in predicting neonatal survival was assessed.

RESULTS

From the total population of 380 CDH cases, 144 isolated fetuses were selected showing an overall survival rate of 31.9% (46/144). Survivors showed significantly higher O/E-LHR (56.5% vs 34.9%; P < .001), lower proportion of liver herniation (34.8% vs 80.6%, P < .001), and higher gestational age at birth (37.8 vs 36.2 weeks, P < 0.01) than nonsurvivors. Fetuses with an O/E-LHR less than 35% showed a 3.4% of survival; those with an O/E-LHR between 35% and 45% showed 28% of survival with liver up and 50% with liver down; those with an O/E-LHR greater than 45% showed 50% of survival rate with liver up and 76.9% with liver down.

CONCLUSIONS

Neonatal mortality in CDH is higher in Latin American countries. The category of lung hypoplasia should be classified according to the survival rates in our Latin American CDH registry.

Maternal complications following open and fetoscopic fetal surgery: A systematic review and meta-analysis

OBJECTIVE

To establish maternal complication rates for fetoscopic or open fetal surgery.

METHODS

We conducted a systematic literature review for studies of fetoscopic or open fetal surgery performed since 1990, recording maternal complications during fetal surgery, the remainder of pregnancy, delivery, and after the index pregnancy.

RESULTS

One hundred sixty-six studies were included, reporting outcomes for open fetal (n = 1193 patients) and fetoscopic surgery (n = 9403 patients). No maternal deaths were reported. The risk of any maternal complication in the index pregnancy was 20.9% (95%CI, 15.22-27.13) for open fetal and 6.2% (95%CI, 4.93-7.49) for fetoscopic surgery. For severe maternal complications (grades III to V Clavien-Dindo classification of surgical complications), the risk was 4.5% (95% CI 3.24-5.98) for open fetal and 1.7% (95% CI, 1.19-2.20) for fetoscopic surgery. In subsequent pregnancies, open fetal surgery increased the risk of preterm birth but not uterine dehiscence or rupture. Nearly one quarter of reviewed studies (n = 175, 23.3%) was excluded for failing to report the presence or absence of maternal complications.

CONCLUSIONS

Maternal complications occur in 6.2% fetoscopic and 20.9% open fetal surgeries, with serious maternal complications in 1.7% fetoscopic and 4.5% open procedures. Reporting of maternal complications is variable. To properly quantify maternal risks, outcomes should be reported consistently across all fetal surgery studies.

Prenatal intervention for the management of congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is the result of incomplete formation of the diaphragm that occurs during embryogenesis. The defect in the diaphragm permits the herniation of abdominal organs into the thoracic cavity contributing to the impairment of normal growth and development of the fetal lung. In addition to the hypoplastic lung, anomalies of the pulmonary arterioles worsen the pulmonary hypertension that can have detrimental effects in severe cases. Most cases of CDH can be effectively managed postnatally. Advances in neonatal and surgical care have resulted in improved outcomes over the years. When available, extracorporeal membrane oxygenation can provide temporary cardiorespiratory support for those not effectively supported by mechanical ventilation. In spite of these advances, very severe cases of CDH still carry a very high mortality and morbidity rate. Advances in imaging and evaluation now allow for early and accurate prenatal diagnosis of CDH, thereby identifying those at greatest risk who may benefit from prenatal intervention. This review article discusses some of the surgical and non-surgical prenatal interventions in the management of isolated severe congenital diaphragmatic hernia.

Congenital Diaphragmatic Hernia: 10-Year Evaluation of Survival, Extracorporeal Membrane Oxygenation, and Foetoscopic Endotracheal Occlusion in Four High-Volume Centres

BACKGROUND

Congenital diaphragmatic hernia (CDH) is a severe congenital anomaly with significant mortality.

OBJECTIVES

The aim of this study was to determine if there were trends in survival over the last decade and to compare patient populations, treatment options, and survival rates between 4 high-volume centres, and hence determine which factors were associated with survival.

METHODS

In 4 high-volume CDH centres from the CDH EURO Consortium, data from all CDH patients born between 2004 and 2013 were analysed. The predictive value of variables known at birth and the influence of centre-specific treatments (extracorporeal membrane oxygenation, ECMO, and foetoscopic endotracheal occlusion, FETO) on survival were evaluated in multivariable logistic regression analyses.

RESULTS

Nine hundred and seventy-five patients were included in the analysis, of whom 274 (28.1%) died. ECMO was performed in 259 patients, of whom 81 (31.3%) died. One hundred and forty-five patients (14.9%) underwent FETO, and from those 76 patients (52.4%) survived. Survival differed significantly between years (p = 0.006) and between the 4 centres (p < 0.001). In the multivariable logistic regression analysis, lung-to-head ratio, gestational age at birth, ECMO, centre of birth, and year of birth were significantly associated with survival, whereas FETO was not.

CONCLUSIONS

The patient populations were different between centres, which influenced outcomes. There was a significant variability in survival over time and between centres, which should be taken into consideration in the planning of future trials.

[Fetoscopic tracheal occlusion for severe congenital diaphragmatic hernia: retrospective study]

BACKGROUND AND OBJECTIVES

The temporary fetal tracheal occlusion performed by fetoscopy accelerates lung development and reduces neonatal mortality. The aim of this paper is to present an anesthetic experience in pregnant women, whose fetuses have diaphragmatic hernia, undergoing fetoscopic tracheal occlusion (FETO).

METHOD

Retrospective, descriptive study, approved by the Institutional Ethics Committee. Data were obtained from medical and anesthetic records.

RESULTS

FETO was performed in 28 pregnant women. Demographic characteristics: age 29.8±6.5; weight 68.64±12.26; ASA I and II. Obstetric: IG 26.1±1.10 weeks (in FETO); 32.86±1.58 (reversal of occlusion); 34.96±2.78 (delivery). Delivery: cesarean section, vaginal delivery. Fetal data: Weight (g) in the occlusion and delivery times, respectively (1045.82±222.2 and 2294±553); RPC in FETO and reversal of occlusion: 0.7±0.15 and 1.32±0.34, respectively. Preoperative maternal anesthesia included ranitidine and metoclopramide, nifedipine (VO) and indomethacin (rectal). Preanesthetic medication with midazolam IV. Anesthetic techniques: combination of 0.5% hyperbaric bupivacaine (5-10mg) and sufentanil; continuous epidural predominantly with 0.5% bupivacaine associated with sufentanil, fentanyl, or morphine; general. In 8 cases, there was need to complement via catheter, with 5 submitted to PC and 3 to BC. Thirteen patients required intraoperative sedation; ephedrine was used in 15 patients. Fetal Anesthesia: fentanyl 10 to 20mg·kg^-1 and pancuronium 0,1-0,2mg·kg^-1 (IM). Neonatal survival rate was 60.7%.

CONCLUSION

FETO is a minimally invasive technique for severe congenital diaphragmatic hernia repair. Combined blockade associated with sedation and fetal anesthesia proved safe and effective for tracheal occlusion.

Congenital diaphragmatic hernia-influence of fetoscopic tracheal occlusion on outcomes and predictors of survival

The morbidity of infants with congenital diaphragmatic hernia (CDH) who had undergone foetal endoscopic tracheal occlusion (FETO) to those who had not was compared and predictors of survival regardless of antenatal intervention were identified. FETO was undertaken on the basis of the lung to head ratio or the position of the liver. A retrospective review of the records of 78 CDH infants was undertaken to determine the lung-head ratio (LHR) at referral and prior to birth, maximum oxygen saturation in the labour suite and neonatal outcomes. The 43 FETO infants were born earlier (mean 34 versus 38 weeks) (p < 0.001). They had a lower mean LHR at referral (0.65 versus 1.24) (p < 0.001) but not prior to birth and did not have a higher mortality than the 35 non-FETO infants. The FETO infants required significantly longer durations of ventilation (median: 15 versus 6 days) and supplementary oxygen (28 versus 8 days) and hospital stay (29 versus 16 days). Overall, the best predictor of survival was the OI in the first 24 h.

CONCLUSION

The FETO group had increased morbidity, but not mortality. The lowest oxygenation index in the first 24 h was the best predictor of survival regardless of antenatal intervention.

WHAT IS KNOWN

• Randomised controlled trials have demonstrated that foetal endotracheal occlusion (FETO) in high risk infants with congenital diaphragmatic hernia is associated with a higher survival rate. • Mortality is greater in foetuses who underwent FETO and delivered prior to 35 weeks of gestation. What is New: • Infants who had undergone FETO compared to those who had not had significantly longer durations of mechanical ventilation, supplementary oxygen and hospital stay. • Regardless of antenatal intervention, the lowest oxygenation index in the first 24 h was the best predictor of survival.

An evaluation of the role of concomitant anomalies on the outcomes of fetuses with congenital diaphragmatic hernia

PURPOSE

The purpose of this study was to evaluate the impact of various types of associated anomalies on CDH mortality and morbidity.

METHODS

All CDH patients at a tertiary care center from January 2004 to January 2014 were reviewed retrospectively. Isolated CDH was defined as CDH without any associated anomalies. Cardiac anomalies were stratified into minor and major based on the Risk Adjustment for Congenital Heart Surgery-1 (RACHS-1) scoring system. Other anatomic anomalies requiring intervention in the perinatal period were classified as major anomalies. The outcomes of interest were 6-month mortality as well as pulmonary and gastrointestinal morbidity.

RESULTS

Of 189 CDH patients, 93 (49%) had isolated CDH. Others had: cardiac anomalies alone (n=47, 25%), genetic anomalies (n=28, 15%), structural anomalies alone (n=18, 10%), and both cardiac and genetic anomalies (n=20, 11%). Fifty (26.5%) patients were dead before six months of age. Mortality rate at 6months was higher in patients with genetic and major cardiac anomalies. A major cardiac anomaly was independently associated with a 102-fold increased risk of mortality at 6months (95%CI: 3.1-3402). Pulmonary morbidity was increased in patients with genetic, major cardiac, and major structural anomalies, while gastrointestinal morbidity was higher in patients with major structural anomalies alone.

CONCLUSION

Major cardiac and genetic anomalies were associated with increased 6-month mortality in CDH patients. However, the association with minor cardiac anomalies and/or structural anomalies did not affect mortality and morbidity of CDH patients. The presence of minor anomalies should not adversely impact their perinatal management or consideration for in-utero therapy.

Challenges of management and outcome of neonatal surgery in Africa: a systematic review

BACKGROUND

Disparity still exists in the outcome of neonatal surgery between high-income countries and low-income and middle-income countries. This study reviews publications on neonatal surgery in Africa over 20 years with a focus on challenges of management, trends in outcome, and potential interventions to improve outcome.

METHODS

We did a literature review by searching PubMed and African Index Medicus for original articles published in any language between January 1995 and September 2014. A data extraction sheet was used to collect information, including type of study, demographics, number of cases, outcome, challenges, and suggestions to improve outcome.

RESULTS

A total of 51 studies from 11 countries met the inclusion criteria. The 16 studies in the first 10 years (1995-2004; group A) were compared with the 35 in the last 10 years (2005-2014; group B). Nigeria (n = 32; 62.7 %), South Africa (n = 7; 13.7 %), Tanzania (n = 2; 3.9 %), and Tunisia (n = 2; 3.9 %) were the predominant sources of the publications, which were retrospective in 38 (74.5 %) studies and prospective in 13 (25.5 %) studies. The mean sample size of the studies was 95.1 (range 5-640). Overall, 4849 neonates were studied, with median age of 6 days (range 1-30 days). Common neonatal conditions reported were intestinal atresia in 28 (54.9 %) studies, abdominal wall defects in 27 (52.9 %), anorectal malformations 25 in (49.0 %), and Hirschsprung's disease, necrotising enterocolitis, and volvulus neonatorum in 23 (45.1 %) each. Mortality was lowest (<3 %) in spina bifida and facial cleft procedures, and highest (>50 %) in emergency neonatal surgeries involving bowel perforation, bowel resection, congenital diaphragmatic hernia, oesophageal atresia, and ruptured omphalocele or gastroschisis. Overall average mortality rate was higher in group A than group B (36.9 vs 29.1 %; p < 0.001), and varied between the groups for some conditions. The major documented challenges were delayed presentation and inadequate facilities in 39 (76.5 %) studies, dearth of trained support personnel in 32 (62.7 %), and absence of neonatal intensive care in 29 (56.9 %). The challenges varied from country to country but did not differ in the two groups.

CONCLUSION

Improvement has been achieved in outcomes of neonatal surgery in Africa in the past two decades, although several of the studies reviewed are retrospective and poorly designed. Cost effective adaptations for neonatal intensive care, improved health-care funding, coordinated neonatal surgical care via regional centres, and collaboration with international partners are potential interventions that could help to address the challenges and further improve outcome.

Imaging findings in fetal diaphragmatic abnormalities

Imaging plays a key role in the detection of a diaphragmatic pathology in utero. US is the screening method, but MRI is increasingly performed. Congenital diaphragmatic hernia is by far the most often diagnosed diaphragmatic pathology, but unilateral or bilateral eventration or paralysis can also be identified. Extralobar pulmonary sequestration can be located in the diaphragm and, exceptionally, diaphragmatic tumors or secondary infiltration of the diaphragm from tumors originating from an adjacent organ have been observed in utero. Congenital abnormalities of the diaphragm impair normal lung development. Prenatal imaging provides a detailed anatomical evaluation of the fetus and allows volumetric lung measurements. The comparison of these data with those from normal fetuses at the same gestational age provides information about the severity of pulmonary hypoplasia and improves predictions about the fetus's outcome. This information can help doctors and families to make decisions about management during pregnancy and after birth. We describe a wide spectrum of congenital pathologies of the diaphragm and analyze their embryological basis. Moreover, we describe their prenatal imaging findings with emphasis on MR studies, discuss their differential diagnosis and evaluate the limits of imaging methods in predicting postnatal outcome.

Histologic changes of the fetal membranes after fetoscopic laser surgery for twin-twin transfusion syndrome

BACKGROUND

Preterm premature rupture of membranes remains a major complication after fetoscopic laser surgery (FLS) for twin-twin transfusion syndrome (TTTS). We studied the histologic changes of fetal membranes post-FLS and investigated a possible impact of amniotic fluid (AF) dilution.

METHODS

Fetal membranes of 31 pregnancies that underwent FLS for TTTS were investigated histologically at delivery at different sites: trocar site of recipient sac and at distance, donor sac, and inter-twin membrane.

RESULTS

The trocar insertion site on the recipient sac showed no signs of histologic hallmarks of healing. Wide-spread alteration in collagen organization and higher apoptotic index in the amnion of the recipient sac which were absent in donor's and reference membranes. To explain the mechanisms, we analyzed the AF composition of recipient sacs from TTTS pregnancies vs. GA-matched healthy singleton controls and found glucose, protein and lactate dehydrogenase activity were all significantly lower in TTTS sacs consistent with over-dilution of recipient's AF (~2-fold). In-vitro exposure of healthy amniochorion to analogous dilutional stress conditions recapitulated the histologic changes and induced apoptosis and autophagy.

CONCLUSION

Alteration in structural integrity of the recipient's amniochorion, possibly in response to dilution stress, along with ineffective repair mechanisms may explain the increased incidence of preterm birth post-FLS.

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.

The ex utero intrapartum treatment (EXIT) procedure: application of a new therapeutic paradigm

The ex utero intrapartum treatment (EXIT) procedure is a term given to a technique that can transform a potentially fatal neonatal emergency to a controlled intervention with an improved outcome. It has revolutionised the care of prenatally diagnosed congenital malformations in which severe upper airway obstruction is anticipated. An extended period of utero-placental circulation can be utilised to avoid profound cardiopulmonary compromise. Its therapeutic applications have been broadened to include fetuses with congenital diaphragmatic hernia after tracheal plugging, high-risk intrathoracic masses, severe cardiac malformations and conjoined twins. It requires the co-ordination of a highly skilled and experienced multidisciplinary team. The recent enthusiasm for the EXIT procedure needs to be balanced against maternal morbidity. Specific indications and guidelines are likely to be refined as a consequence of ongoing advances in fetal intervention and antenatal imaging.

Pulmonary alveolar and vascular morphometry after gel plug occlusion of the trachea in a fetal rabbit model of CDH

PURPOSE

Tracheal occlusion (TO) induces lung growth in congenital diaphragmatic hernia (CDH) but is also associated with drawbacks. We devised a temporary gel plug that induced lung growth when placed in the fetal trachea. This study evaluates the effects of temporary versus permanent TO on histologic radial alveolar count (RAC) and vascular morphometrics.

METHODS

Experimental CDH was created surgically in 64 New Zealand White rabbit fetuses on gestational day (GD) 24. On GD 27, these fetuses were randomized to intratracheal instillation of a fibrin gel plug (GP), tracheal suture ligation (SL), intratracheal instillation of normal saline (NS), or sham amniotomy (SH). Non-manipulated fetuses served as controls (NM). Histologic lung sections were assessed blindly for RAC and relative arterial adventitial thickness (%AT) as a variable for vascular remodelling. Results were statistically compared.

RESULTS

RAC was significantly lower in the ipsilateral lung of SH fetuses than in the contralateral lung (p = 0.011). Mean RAC was higher after SL (p < 0.001) and GP (p = 0.03) compared to SH. Furthermore, %AT was higher in GP (50 ± 28, p < 0.001) and SL (45 ±2 6, p = 0.003) fetuses than in controls (36 ± 19).

CONCLUSION

Temporary and permanent TO leads to increased RAC; this effect was more pronounced with permanent TO. Both interventions were associated with an increased %AT. These findings may explain the adverse clinical effects of TO, despite causing accelerated lung growth.

Management of prenatally diagnosed congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a congenital anomaly that presents with a broad spectrum of severity that is dependent upon components of pulmonary hypoplasia and pulmonary hypertension. While advances in neonatal care have improved the overall survival of CDH in experienced centers, mortality and morbidity remain high in a subset of CDH infants with severe CDH. Prenatal predictors have been refined for the past two decades and are the subject of another review in this issue. So far, all randomized trials comparing prenatal intervention to standard postnatal therapy have shown no benefit to prenatal intervention. Although recent non-randomized reports of success with fetoscopic endoluminal tracheal occlusion (FETO) and release are promising, prenatal therapy should not be widely adopted until a well-designed prospective randomized trial demonstrating efficacy is performed. The increased survival and subsequent morbidity of CDH survivors has resulted in the need to provide resources for the long-term follow up and support of the CDH population.

Anesthesia for fetal surgery

Fetal surgery pushes the limits of knowledge and therapy beyond conventional paradigms by treating the developing fetus as a patient. Providing anesthesia for fetal surgery is challenging for many reasons. It requires integration of both obstetric and pediatric anesthesia practice. Two patients must be anesthetized for the benefit of one, and there is little margin for error. Many disciplines are involved, and communication must be effective among all of them. Conducting anesthetic research with vulnerable populations, such as the pregnant woman carrying a fetus with a birth defect is difficult, and many questions remain to be answered. Work is needed to study possible neurotoxicity caused by exposure of the developing brain to anesthetic agents. The effects of stress on the developing fetus also must be further delineated. Anesthetic techniques vary by institution, and prospective studies to determine optimal anesthetic regimens are warranted.

Evaluation of histological changes after tracheal occlusion at different gestational ages in a fetal rat model

OBJECTIVES

To evaluate the histological changes of tracheal cartilage and epithelium caused by tracheal occlusion at different gestational ages in a fetal rat model.

METHODS

Rat fetuses were divided into two groups: a) External control, composed of non-operated rats, and b) Interventional group, composed of rats operated upon on gestational day 18.5 (term = 22 days), divided into triads: 1) Tracheal occlusion, 2) Internal control and 3) Sham (manipulated but not operated). Morphological data for body weight, total lung weight and total lung weight/body weight ratio were collected and measured on gestational days 19.5, 20.5 and 21.5. Tracheal samples were histologically processed, and epithelial, chondral and total tracheal thicknesses were measured on each gestational day.

RESULTS

The tracheal occlusion group exhibited an increase in total lung weight/body weight ratio (p<0.001). Histologically, this group had a thicker epithelial thickness (p<0.05) and thinner chondral (p<0.05) and total tracheal thicknesses (p<0.001). These differences were more prominent on gestational days 20.5 and 21.5.

CONCLUSION

Tracheal occlusion changed tracheal morphology, increased epithelial thickness and considerably decreased total tracheal thickness. These changes in the tracheal wall could explain the development of tracheomegaly, recently reported in some human fetuses subjected to tracheal occlusion.

Tracheobronchomegaly following intrauterine tracheal occlusion for congenital diaphragmatic hernia

BACKGROUND

Fetuses with severe congenital diaphragmatic hernia (CDH) and pulmonary hypoplasia may benefit from fetal endoluminal tracheal occlusion (FETO). Enlargement of the main bronchi and trachea appears to be a common complication of FETO.

OBJECTIVE

To retrospectively evaluate the trachea and main bronchi of infants who underwent FETO for CDH and compare diameters with age-matched references.

MATERIAL AND METHODS

Postnatal and follow-up chest radiographs were performed in seven children with unilateral CDH treated by FETO. Additional CT was performed in six of these (one neonate died before CT could be performed). Images were acquired from 3 days to 23 months of age. For each child, radiographs and CT images with optimal visualisation of the airways were selected for retrospective analysis. Tracheal and bronchial morphology was assessed by two experienced paediatric radiologists, and the diameters of these structures measured and compared with age-matched references.

RESULTS

Mean diameters of the trachea and main bronchi were above the age-matched normal range in all patients, regardless of the side of the hernia or the degree of lung hypoplasia.

CONCLUSION

Enlargement of the trachea and main bronchi appears following FETO and persists at least to the age of 5 years.

Developmental and genetic aspects of congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a frequent occurring cause of neonatal respiratory distress and occurs 1 in every 3,000 liveborns. Ventilatory support and pharmaceutical treatment of the co-occurring lung hypoplasia and pulmonary hypertension are insufficient in, respectively, 20% of isolated cases and 60% of complex ones leading to early perinatal death. The exact cause of CDH remains to be identified in the majority of human CDH patients and prognostic factors predicting treatment refraction are largely unknown. Their identification is hampered by the multifactorial and heterogenic nature of this congenital anomaly. However, application of high-resolution molecular cytogenetic techniques to patients' DNA now enables detection of chromosomal aberrations in 30% of the patients. Furthermore, recent insights in rodent embryogenesis pointed to a specific disruption of the early mesenchymal structures in the primordial diaphragm of CDH-induced offspring. Together, these data allowed for the introduction of new hypotheses on CDH pathogenesis, although many issues remain to be resolved. In this review, we have combined these new insights and remaining questions on diaphragm pathogenesis with a concise overview of the clinical, embryological, and genetic data available.

Intraluminal tracheal occlusion using a modified 8-mm Z-stent in a sheep model of left-sided congenital diaphragmatic hernia

OBJECTIVE

To evaluate pulmonary growth and development after fetoscopic intraluminal tracheal occlusion (FITO) using a modified 8-mm Z-stent in an ovine model of congenital left-sided diaphragmatic hernia (CDH).

METHODS

Thirty-three time-dated ewes were studied: Group I: healthy controls; Group II: CDH controls (untreated); Group III: CDH treated with FITO. CDH was created in Groups II and III at 70-80 days' gestation. FITO was performed at 100-110 days. Left lung histological, morphometric, immunohistochemical and biochemical studies were conducted after delivery and euthanasia at 138 days.

RESULTS

Fifteen (45%) animals (Group I: 3; Group II: 5; Group III: 7) were available for analysis. The left lung parenchymal volume to fetal weight ratios were similar between Groups I and III (p = 0.24), and higher than Group II (p < 0.05III (79 versus 75%, p = 0.26), compared to 41% in Group II (p < 0.05). Pulmonary hypoplasia occurred in 1/7 (16%) in the FITO group, compared to 100% in Group II and 0% in Group I (p = .003). DNA and protein were significantly increased in Group III (p < 0.001). The concentration of type II pneumocytes was similar between healthy controls and the FITO group, and was paradoxically increased in untreated hernia fetuses. There was no histological evidence of tracheal injury.

CONCLUSION

FITO with a modified 8-mm Z-stent is associated with lung growth and maturation similar to controls without obvious deleterious effects. A phase I clinical trial of FITO with the modified 8-mm Z-stent in severe CDH patients seems warranted.

Maternal-fetal surgery for structural malformations

Although most prenatally diagnosed correctable anatomic abnormalities are best addressed by surgical interventions after birth, the outcomes of a small number of severe structural malformations with predicted fetal demise or devastating sequelae postnatally may be improved by correction before birth. Consideration of maternal-fetal surgical intervention is restricted to those anatomic malformations that interfere with normal organ development and which, if alleviated, may permit normal development to proceed. Advances in prenatal diagnosis and technical innovations in the surgical approach to the fetus have resulted in an increase in the successful clinical application of fetal intervention over the past 3 decades. The purpose of this review is to describe the current status of maternal-fetal surgery, with a focus on the congenital anomalies most commonly treated by intervention before birth, and to highlight the key areas for further research in this evolving surgical specialty.

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.

Prenatal lung-head ratio: threshold to predict outcome for congenital diaphragmatic hernia

OBJECTIVE

The literature suggests that lung-head ratio (LHR) and liver position may inconsistently predict outcome for congenital diaphragmatic hernia (CDH). We reviewed our inborn neonates with isolated left-sided CDH to determine whether these variables predicted survival and to estimate the optimal LHR threshold.

METHODS

Prenatal LHR and liver position were obtained from 2002 to 2009. The primary endpoint was survival.

RESULTS

LHR was greater in survivors after adjusting for gestational age (median 1.40 versus 0.81; p < 0.001). LHR demonstrated excellent diagnostic discrimination, with area under receiver operating characteristic (ROC) curve 0.93 (95% CI 0.86-0.99). LHR threshold of 1.0 was 83% sensitive and 91% specific in predicting survival. An optimal LHR threshold of 0.85 predicted survival with 95% sensitivity and 64% specificity, reducing false negatives (survivors with low LHR). LHR > 0.85 predicted survival after adjustment for gestational age (OR = 33.6, 95% CI = 5.4-209.5). Liver position did not predict survival.

CONCLUSIONS

Prenatal LHR >0.85 predicts survival for infants with isolated left-sided CDH without compromising discrimination of survivors from non-survivors. The diagnostic utility of LHR may be confounded by gestational age at measurement. Stringent LHR threshold may minimize false-negative attribution and improve utility of this measurement as predictor of survival.

Congenital diaphragmatic hernia: lung-to-head ratio and lung volume for prediction of outcome

OBJECTIVE

The purpose of this study was to evaluate observed/expected (O/E) lung-to-head ratio (LHR) by ultrasound (US) and total fetal lung volume (TFLV) by magnetic resonance imaging as neonatal outcome predictors in isolated fetal congenital diaphragmatic hernia (CDH).

STUDY DESIGN

We conducted a retrospective study of 72 fetuses with isolated CDH, in whom O/E LHR and TFLV were evaluated as survival predictors.

RESULTS

O/E LHR on US and O/E TFLV by magnetic resonance imaging were significantly lower in newborn infants with isolated CDH who died compared with survivors (30.3 ± 8.3 vs 44.2 ± 14.2; P < .0001 for O/E LHR; 21.9 ± 6.3 vs 41.5 ± 17.6; P = .001 for O/E TFLV). Area under receiver-operator characteristics curve for survival for O/E LHR was 0.80 (95% confidence interval, 0.70-0.90). On multivariate analysis, O/E LHR predicted survival, whereas hernia side and first neonatal pH did not. For each unit increase in O/E LHR, mortality odds decreased by 11% (95% confidence interval, 4-17%).

CONCLUSION

In fetuses with isolated CDH, O/E LHR (US) independently predicts survival and may predict severity, allowing management to be optimized.

Maternal hyperoxygenation test in fetuses undergoing FETO for severe isolated congenital diaphragmatic hernia

OBJECTIVES

To predict neonatal survival and pulmonary hypertension by measurement of fetal pulmonary artery reactivity to maternal hyperoxygenation in fetuses with severe congenital diaphragmatic hernia treated by fetoscopic endoluminal tracheal occlusion (FETO).

METHODS

Thirty-eight fetuses underwent FETO at around 28 weeks' gestation and the balloon was removed at 34 weeks in most cases. We performed a hyperoxygenation test and measured the lung-to-head ratio of each fetus before and after each procedure. Outcome measures were neonatal survival, occurrence of pulmonary hypertension and its response to inhaled nitric oxide (iNO).

RESULTS

Fetuses that survived had a larger increase in lung size and decrease of resistance in the first branch of the main pulmonary artery than did those that died. Both measures were also predictive of pulmonary hypertension unresponsive to iNO. The hyperoxygenation test and lung-to-head ratio were both best predictive for neonatal survival when measured following removal of the balloon (P < 0.002). Discriminant analysis confirmed that these two parameters are independent predictors of outcome.

CONCLUSIONS

In fetuses undergoing FETO, pulmonary vascular reactivity in relation to oxygen and lung size are independent predictors of neonatal survival and pulmonary hypertension. The hyperoxygenation test merits further study in expectantly managed cases.

New and/or improved aspects of fetal surgery

Open fetal surgery through a wide hysterotomy is no longer a real option for prenatal intervention, but a minimally invasive approach has emerged as treatment for a small number of indications. Endoscopic ablation of placental vessels is the preferred treatment for severe twin-to-twin transfusion syndrome and it may be the only chance to salvage the most severe forms of congenital diaphragmatic hernia. Several other indications are currently under review and may become justified in the future, provided that diagnostic accuracy and patient selection become more accurate. Before invasive fetal intervention becomes widely accepted, however, we need to better define outcome. It is no longer acceptable to express results in terms of survival at birth. Survival at discharge and long-term morbidity must be considered as well.

Selective reduction in complicated monochorionic pregnancies: radiofrequency ablation vs. bipolar cord coagulation

OBJECTIVE

To compare radiofrequency ablation (RFA) and bipolar cord coagulation (BPC) methods for selective fetal reduction in the treatment of complicated monochorionic (MC) multifetal gestations.

METHODS

This was a retrospective review of patients who underwent selective reduction by RFA and BPC. Computer-generated random sampling was performed to match patients who had undergone BPC with patients who had undergone RFA, in a 2 : 1 ratio, controlling for gestational age and indication. The primary outcome was fetal survival.

RESULTS

Twenty patients in the RFA group were matched with 40 patients in the BPC group. Fewer additional intra-operative procedures were performed in the RFA group compared with the BPC group: amnioinfusion, 10% vs. 75%, respectively (P < 0.01); and amnioreduction, 5% vs. 40%, respectively (P = 0.004). The overall survival rates were 87.5% in the RFA group and 88% in the BPC group (P = 0.94). Median gestational age at delivery was 36 (range, 26-41) weeks in the RFA group and 39 (range, 19-40) weeks in the BPC group (P = 0.59). Preterm delivery (at < 28, < 32 or < 37 weeks), weeks gained after the procedure and birth weight at delivery were also similar. Although the preterm premature rupture of membranes (PPROM) rate was higher in the BPC group (22.5%) compared with the RFA group (5%), the difference was not statistically significant (P = 0.09).

CONCLUSIONS

Overall fetal survival rate following selective reduction in complicated MC pregnancies is similar whether reduction is performed by RFA or BPC. Fewer additional intraoperative procedures are required for RFA than for BPC. The possibility that RFA is associated with a lower rate of postoperative PPROM than is BPC will have to be confirmed in larger series.