Long-term outcome in patients with prenatally diagnosed cystic lung disease: special reference to ventilation and perfusion scan in the affected lung

Background/Purpose

The natural history of cystic lung disease (CLD) such as congenital cystic adenomatoid malformation (CCAM) and pulmonary sequestration has been altered by the advent of prenatal diagnosis. Although recent advances including fetal therapy have gradually improved outcome, the long-term course and the function of the residual lung have not been well clarified.

Methods

Twenty-two patients with CLD who had been prenatally diagnosed and treated between 1990 and 2004 were reviewed. The clinical outcome and growth measurements were established, and, where possible, all infants underwent ventilation and perfusion lung scan.

Results

Mediastinal shift was present in 14 fetuses. Fetal hydrops was present in 5 fetuses. Antenatal intervention was performed for hydrops in 2 fetuses (cyst-amniotic shunt and aspiration). Twenty-one infants underwent appropriate excisional surgery. Final diagnosis included CCAM (n = 12) and pulmonary sequestration (n = 7). No late death was observed. Common complications were failure to thrive (n = 5), frequent respiratory tract infection (n = 4), and asthmatic attack (n = 4). A significant decrease in lung ventilation and perfusion on the affected side was observed in patients with hydrops, lobectomy, and CCAM.

Conclusion

Long-term follow-up including respiratory care and growth assessment should be performed in prenatally diagnosed patients with CLD, especially those who present with hydrops.     

Outcome predictors for infants with cystic lung disease

Background/purpose

This study aimed at identifying characteristic features indicating congenital cystic adenomatoid malformation of the lung (CCAM) and evaluating the outcome predictors to identify prenatally subgroups of fetuses with significantly different probabilities of mortality or severe respiratory difficulty.

Methods

Twenty-eight neonates who had undergone antenatal evaluation for cystic lung disease (CLD) were reviewed retrospectively. The patients were divided into 3 groups according to the severity of their clinical course; mild (n = 7), moderate (n = 13), and severe (n = 8). Ultrasonographic findings in the fetus and their pulmonary lesion were evaluated. The normal lung to thorax transverse area ratio (L/T) was measured by ultrasonography.

Results

High echogenicity of the lesion throughout pregnancy and polyhydramnios were frequently seen in CCAM. All of the patients with other CLD showed isoechogenicity at the end of pregnancy. All patients in the severe group had both polyhydramnios and fetal hydrops. L/T was increased in mild and moderate groups, whereas no patient in the severe group had an increase in L/T at the final measurement. Each value of final L/T in the severe group was less than 0.25.

Conclusions

The subgroup of fetuses with an increased probability of mortality or severe respiratory difficulty could be predicted from the combination of polyhydramnios, fetal hydrops, and a final L/T value of less than 0.25.     

Clinicopathologic assessment of prenatally diagnosed lung diseases

Purpose

To investigate the clinical features and pathologic diagnosis of prenatally diagnosed lung diseases.

Materials and Methods

The medical records of 28 fetuses with prenatally diagnosed lung diseases were reviewed with regard to perinatal courses, ultrasonographic measurement of the lesion volume ratio, and the histopathology of lung tissue.

Results

Of the 23 fetuses with a prenatal diagnosis of congenital cystic adenomatoid malformation (CCAM), 4 required an emergency lobectomy (1 prenatally and 3 postnatally), whereas the other 14 showed uneventful courses after birth. The pathologic diagnosis of the resected lungs included CCAM (n = 4), lobar emphysema (n = 2), intralobar sequestration (n = 2), and bronchial atresia (n = 1). The peak value of the lesion volume ratio was significantly higher in the CCAM cases that required urgent surgery than in the non-CCAM cases (2.29 ± 0.46 vs 1.20 ± 0.21, P < .001). The ratio decreased after the 25th to the 30th week to less than 1.0 in the 5 non-CCAM cases, but remained higher than 2.0 in the 4 CCAM cases. Prenatally diagnosed extralobar pulmonary sequestration caused massive pleural effusion requiring a fetal intervention in 4 of the 5 fetuses.

Conclusions

The prenatally diagnosed lung lesions include various kinds of pulmonary diseases. Regardless of the diseases, sequential ultrasonographic assessment may predict perinatal risks.     

Is congenital cystic adenomatoid malformation a premalignant lesion for pleuropulmonary blastoma?

Background

The relationship between congenital cystic adenomatoid malformation (CCAM) and pleuropulmonary blastoma (PPB), whether causal, correlational, or coincidental, remains controversial. There is a lack of consensus as to the optimal treatment of patients with asymptomatic CCAM.

Method

We reviewed all cases of CCAM and PPB seen at our institution from 1999 to 2008. Institutional Research Ethics Board approval was obtained. The incidence of CCAM and PPB, respectively, was calculated based on birth numbers during the study period.

Results

Seventy-four CCAMs were resected over the study period in 129 children diagnosed with CCAM. Five PPBs were diagnosed during the study period. Three of the 5 PPB cases were initially diagnosed as CCAMs. These PPBs were not clinically or radiologically distinguishable from CCAMs. In our referral area, the incidence of CCAM was 1 in 12,000; and the incidence of PPB was 1 in 250,000 live births. The mortality rate for PPB in this cohort was 20%.

Conclusion

Asymptomatic cystic lung malformations represent a therapeutic dilemma. In this cohort, the incidence of PPB among apparently benign lung lesions was 4%. No clinical or radiological markers differentiated benign CCAMs from PPBs. Our experience provides further justification for resection of all CCAMs. This should be discussed with parents until CCAMs and PPBs can be clearly distinguished preoperatively.     

Postnatal spontaneous resolution of congenital cystic adenomatoid malformations

Purpose

Although antenatal resolution of congenital cystic adenomatoid malformations (CCAMs) is well documented, complete spontaneous postnatal resolution is rare, its existence even questioned by some.

Methods

All cases of antenatally diagnosed CCAMs over 7 years were retrospectively reviewed. Inclusion criteria were the following: (1) antenatal diagnosis of CCAM, (2) persistence on postnatal imaging, and (3) subsequent spontaneous resolution on postnatal imaging.

Results

Of 56 antenatally diagnosed CCAMs, 2 patients were identified. Both had macrocystic lesions. In case 1, the CCAM that filled the hemithorax on antenatal ultrasound was smaller on postnatal chest radiograph and disappeared by age 37 months on computed tomography. Case 2 had significant reduction of the CCAM at birth (persistence of the lesion on initial radiographs and ultrasound was documented). By 5 months, the lesion was not evident on computed tomography. Neither case was associated with symptoms, polyhydramnios, hydrops, or other abnormalities.

Conclusions

In patients with an antenatal diagnosis of CCAM, spontaneous resolution may occur postnatally in 4% of cases. Significant reduction in CCAM size may portend possible disappearance and therefore warrants an observational period before resection.     

Large fetal congenital cystic adenomatoid malformations: growth trends and patient survival

Purpose

The prognosis for fetuses with large congenital cystic adenomatoid malformations (CCAMs) remains uncertain. This study examined the natural history of large fetal CCAMs managed expectantly at a major referral center.

Methods

A 5-year retrospective review was conducted on fetuses diagnosed with a thoracic lesion (n = 59). Large CCAMs were identified on prenatal imaging and followed longitudinally. Perinatal outcomes were assessed.

Results

Twelve (20.3%) fetuses had large CCAMs in the absence of other congenital anomalies. Peak CCAM size occurred at 25.3 ± 3.6 weeks' gestation. Serial magnetic resonance volumetry demonstrated a trend toward decreasing CCAM mass volume relative to thoracic cavity volume over time. Overall, 6 patients, including 3 with signs of early hydrops, showed a marked regression of their lesions relative to estimated fetal weight. Five fetuses required an emergent intervention postnatally, including extracorporeal membrane oxygenation support (n = 1), cyst aspiration (n = 1), and lung resection (n = 5). Overall survival was 75%, with severe hydrops before 30 weeks seen in all 3 deaths.

Conclusion

Large fetal CCAMs tend to peak in size at 25 weeks' gestation and are characterized by in utero diminution relative to overall fetal growth. The prognosis for most fetuses with large CCAMs remains quite favorable under careful perinatal management.     

Antenatally suspected congenital cystic adenomatoid malformation of the lung: postnatal investigation and timing of surgery

Background

We have previously reported the outcome of a cohort of cases over a 10-year period with antenatally suspected congenital cystic adenomatoid malformation (CCAM) and have recommended elective surgery within the first year of life for persistent, asymptomatic cases because of the risk of long-term complications. The aims of this study were to document optimal postnatal investigation and timing of surgery.

Methods

Cases were identified using the Oxford Congenital Anomaly Register, theatre records, and histopathology reports. Nineteen cases from 2003 onwards were reviewed with respect to postnatal imaging with chest x-ray and computed tomography scan and timing of surgery.

Results

Chest x-ray was poor at detecting CCAM with only 61% sensitivity. Computed tomography scan was 100% sensitive with no false-positive diagnoses.Of the 19 cases since 2003, 13 cases were asymptomatic and had elective surgery. Eight had surgery at 6 months of age or older, and of these, 4 (50%) had evidence of chronic inflammation/infection on histology including 1 case with multiple abscesses found at surgery and 1 case with multiple adhesions. Five cases had surgery at less than 6 months of age and only 1 of these, aged 5.5 months, had evidence of infection present at histology.

Conclusions

All cases of antenatally suspected CCAM should be followed up postnatally and investigated with computed tomography scan. Elective surgery in asymptomatic cases, at around 3 to 6 months of age, is recommended for persistent lesions because of the risk of long-term complications.     

Prenatal steroids for microcystic congenital cystic adenomatoid malformations

Objective

The purpose of this study is to evaluate the effect of prenatal steroid treatment in fetuses with sonographically diagnosed congenital cystic adenomatoid malformations (CCAMs).

Methods

This was an institutional review board-approved retrospective review of 372 patients referred to the University of California, San Francisco (UCSF), for fetal CCAM. Inclusion criteria were (1) a predominately microcystic CCAM lesion sonographically diagnosed at our institution, (2) maternal administration of a single course of prenatal corticosteroids (betamethasone), and (3) no fetal surgery. CCAM volume-to-head ratio (CVR), presence of hydrops, mediastinal shift, and diaphragm eversion were assessed before and after administration of betamethasone. The primary end points were survival to birth and neonatal discharge.

Results

Sixteen patients with predominantly microcystic CCAMs were treated with prenatal steroids. Three were excluded because of lack of follow-up information. All remaining fetuses (13/13) survived to delivery and 11/13 (84.6%) survived to neonatal discharge. At the time of steroid administration, all patients had CVR greater than 1.6, and 9 (69.2%) also had nonimmune hydrops fetalis. After a course of steroids, CVR decreased in 8 (61.5%) of the 13 patients, and hydrops resolved in 7 (77.8%) of the 9 patients with hydrops. The 2 patients whose hydrops did not resolve with steroid treatment did not survive to discharge.

Conclusion

In high-risk fetal patients with predominantly microcystic CCAM lesions, betamethasone is an effective treatment. This series is a pilot study for a prospective randomized trial comparing treatment of CCAM with betamethasone to placebo.     

Perinatally diagnosed asymptomatic congenital cystic adenomatoid malformation: to resect or not?

Background

Management of asymptomatic congenital cystic adenomatoid malformation (CCAM) is controversial. The natural history of untreated asymptomatic CCAM is unknown, although most surgeons recommend resection of these lesions to prevent future infection. The aim of this study was to determine the relative surgical risk of resection compared with the risk of observation for these patients.

Methods

A retrospective review of hospital records between 1996 and 2002 in a tertiary care pediatric referral center was conducted. All perinatally (prenatal or neonatal) diagnosed CCAMs were included. In addition, patients presenting with late diagnosis of CCAM were also reviewed.

Results

Forty-eight children had CCAM diagnosed perinatally. Thirteen of these were symptomatic and required surgery within 6 months; these were excluded from the analysis. Of the 35 asymptomatic infants, 6 were operated on electively before 6 months of age (median age, 4.5 months). The other 29 asymptomatic infants were followed up for more than 6 months. Of these, 9 remained asymptomatic and were eventually operated on electively (median age, 13 months). Three (10%) had CCAM infections at 7, 8, and 11 months of age and required resection. The remaining 17 children have not undergone resection and are still asymptomatic (median follow-up, 3 years). An additional 12 patients presented with a late diagnosis of CCAM. All of these presented with complications (infection or pneumothorax) and underwent resection (median age, 6 years). Overall, the complication rate after resection of an asymptomatic CCAM was not significantly different from those of resected CCAM that had already developed infection or pneumothorax (P = .64).

Conclusions

Ten percent of perinatally diagnosed asymptomatic patients had 5 complications requiring surgery during follow-up. The true incidence is probably higher given the relatively short follow-up in our series. Morbidity after resection of a complicated CCAM was not statistically significantly higher than after elective resection for an asymptomatic CCAM. Although conservative management of asymptomatic CCAM may be warranted, a more extended period of follow-up is necessary before this approach can be recommended.     

Lung development is not necessary for diaphragm development in mice

Background/Purpose

Congenital diaphragmatic hernia affects approximately 1 in every 2000 live births. The etiology of these diaphragmatic defects is unknown. Using mice with a targeted deletion of fibroblast growth factor 10 (FGF10), which display a complete lack of lung tissue, we have examined the relationship between lung hypoplasia and diaphragmatic development.

Methods

The diaphragms of FGF10 null mice were examined at 2 embryonic time-points and compared with their heterozygous and wild-type littermates.

Results

FGF10 null mice had phenotypically normal diaphragms when compared with wild-type littermates at both time-points studied.

Conclusion

Normal diaphragm development appears to occur independent of lung development in mice.     

Bronchial atresia: the hidden pathology within a spectrum of prenatally diagnosed lung masses

Purpose

This study was aimed at determining whether different congenital lung masses represent diverse manifestations of a single developmental abnormality associated with fetal airway obstruction.

Methods

We conducted a 3-year retrospective review of patients who underwent surgical resection of a prenatally diagnosed lung mass. Prenatal imaging was used to define mass position and its effect on adjacent organs. Lung specimens were examined through careful full-specimen microdissections, as well as by plain and contrast roentgenograms.

Results

Twenty-five patients underwent lung resection during this study period. Based on the final pathology reports, 56% were congenital cystic adenomatoid malformations, 12% were congenital lobar emphysemas, 8% were bronchopulmonary sequestrations, and 24% had features of both cystic adenomatoid malformation and bronchopulmonary sequestrations. No bronchogenic cysts were present in this series. Overall, bronchial atresia was identified in 77% of the examined specimens (n = 22) and was associated with all types of lung malformations.

Conclusions

Bronchial atresia is a common, unrecognized component of prenatally diagnosed congenital cystic adenomatoid malformations, bronchopulmonary sequestrations, congenital lobar emphysemas, and lesions of mixed pathology. Most congenital lung masses may be part of a spectrum of anomalies linked to obstruction of the developing fetal airway as an underlying component in their pathogenesis.     

Ex utero intrapartum treatment with placement on extracorporeal membrane oxygenation for fetal thoracic masses

Purpose

We describe our experience with fetuses diagnosed with life-threatening chest masses who were delivered by ex utero intrapartum treatment with placement on extracorporeal membrane oxygenation (EXIT-to-ECMO).

Methods

The first fetus presented with a cystic mediastinal mass and enlarging echogenic lungs. Bronchoscopic evaluation during ex utero intrapartum treatment (EXIT) revealed complete airway obstruction secondary to a carinal bronchogenic cyst. The second fetus presented with a massive left congenital cystic adenomatoid malformation. The EXIT procedure was performed because of significant mediastinal shift, severe compression of the normal lung parenchyma, and signs of fetal distress.

Results

In both cases, extracorporeal membrane oxygenation (ECMO) was initiated while on placental support. The fetuses were then delivered, and a definitive resection of their thoracic lesions was successfully performed. There were no major perioperative complications. Both children made expedient recoveries without significant cardiopulmonary sequelae.

Conclusion

To our knowledge, this is the first report describing the successful use of EXIT-to-ECMO as a bridge to definitive resection of large chest masses diagnosed in utero. EXIT-to-ECMO is a novel and effective management strategy for stabilizing patients with profound respiratory compromise secondary to congenital thoracic lesions.     

Does the use of fentanyl in epidural solutions for postthoracotomy pain management in neonates affect surgical outcome?

Background/Purpose

Continuous epidural analgesia is routinely used to manage pain in infants undergoing resection of a congenital cystic adenomatoid malformation (CCAM) of the lung. Our aim was to determine if there is a difference in the length of stay (LOS), supplemental analgesic requirements, pain control, and the incidence of adverse respiratory events in infants receiving the 2 standard epidural solutions commonly used: bupivacaine 0.1% and bupivacaine 0.1% with fentanyl 2 to 5 μg/mL.

Methods

We retrospectively reviewed the charts of infants who received epidural infusions containing bupivacaine 0.1% (n = 18) and bupivacaine 0.1% with fentanyl 2 to 5 μg/mL (n = 10) after CCAM resection during a 12-month period. LOS, rescue opioid, and nonopioid analgesic use, incidence of respiratory depression, and pain scores were recorded.

Results

The LOS in patients receiving fentanyl in their epidural solution was 1 day longer than those receiving plain bupivacaine (median 4 vs 3 days, respectively). Nonopioid analgesic and rescue opioid use was greater in patients who did not have fentanyl in their epidural solutions. Pain ratings were not significantly different. The incidence of respiratory depression was greater in patients receiving epidural infusions containing fentanyl (50% vs 17%, respectively).

Conclusion

The addition of fentanyl to epidural infusions of bupivacaine in infants undergoing thoracotomy for resection of CCAM may prolong recovery and increase the incidence of adverse respiratory events without providing a significant analgesic benefit.     

Lack of consensus among Canadian pediatric surgeons regarding the management of congenital cystic adenomatoid malformation of the lung

Purpose

Review of the literature suggests that there is lack of consensus regarding the management of antenatally diagnosed congenital cystic adenomatoid malformation of the lung (CCAM) that is asymptomatic at birth. This study aims to describe the variability among Canadian pediatric surgeons in how this pathologic finding is managed.

Methods

Surveys were sent to all practicing Canadian members of Canadian Association of Pediatric Surgeons. Responders were asked to state whether they recommend resection or nonoperative management and to describe the follow-up imaging type and frequency used.

Results

A 69% response rate was obtained. There was no consistency regarding the imaging modality used to detect asymptomatic CCAM. Sixty-seven percent of responders recommend resection of persistent but asymptomatic CCAM; there was neither consensus with regard to age at which resection is performed (2-18 months) nor technical considerations at resection (61% open, 83% lobectomy). Among the responders who do not recommend resection, the frequency of follow-up was variable (every 3 months to every year), as were the imaging modality used and the length of follow-up (3 years to indefinitely); 80% of neonates in whom nonoperative management was recommended initially ultimately underwent resection.

Conclusions

Lack of consensus among Canadian pediatric surgeons, and even within institutions, regarding the management of antenatally diagnosed CCAM in the asymptomatic neonate, is demonstrated. This clearly highlights the need for prospective studies.     

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.     

Evolving experience with video-assisted thoracic surgery in congenital cystic lung lesions in a British pediatric center

Background/Purpose

Video-assisted thoracic surgery (VATS) is increasingly used for the resection of congenital cystic lung lesions (CLLs). This study aimed to evaluate the efficacy of VATS and its outcome in both antenatally and postnatally detected CLLs.

Methods

Forty-six patients managed during 2000-2005 were studied. Demographics, investigations, operative details, and outcome data were collected and evaluated. Patients were divided into 3 groups for analysis.

Results

Antenatally diagnosed (groups I and II, n = 35): group I (20) had VATS at 20 months median (range, 16-35 months). Video-assisted thoracic surgery was successful in 14 of 20 (70%), notably in all cases of extralobar sequestrations and foregut duplication cysts. Inadequate vision/lung collapse and technical difficulties were the main reasons for conversion to open thoracotomy. Group II (n = 15) was considered unsuitable for VATS because of neonatal symptoms (6 congenital cystic adenomatoid malformations of the lung [CCAMs]) and/or large size/inexperience (5 CCAMs, 4 sequestrations) and had elective thoracotomy at 8 months median (range, 6 days-20 months).Postnatally diagnosed (group III, n = 11): 3 CCAMs, 6 duplications, and 2 sequestrations were diagnosed because of recurrent chest infection (8) or stridor (2), or incidentally (1) at 8 years median (range, 1.2-14 years). Video-assisted thoracic surgery was successful in 3 foregut duplications. A duplication and an intralobar sequestration were converted; open thoracotomy was performed in others because of previous recurrent pneumonic episodes.Postoperative pain and hospital stay were significantly less (P < .001) in successful VATS resection: median of 2 days (range, 1-7 days) compared with thoracotomy median of 6 days (range, 4-20 days).

Conclusions

Video-assisted thoracic surgery is a safe and effective option for asymptomatic congenital CLLs. It is anticipated that more successful CCAM resections using VATS will occur in the future as our technical ability improves.     

Current outcome of antenally diagnosed cystic lung disease

Background/purpose

The natural history of parenchymal lung lesions such as congenital cystic adenomatoid malformation (CCAM) and pulmonary sequestration (PS) has been altered by the advent of antenatal ultrasonography. Initial reports were characterized by a high (about 30%) incidence of adverse features (eg, hydrops) and a poor outcome and did not accord with our recent experience. The authors have reviewed the outcome of fetuses that had been diagnosed in a large tertiary referral fetal medicine unit with the aim of delineating current experience. The term cystic lung disease was used throughout to avoid unjustifiable histologic precision.

Methods

The scans of all fetuses that had been diagnosed with cystic lung disease between January 1995 and July 2001 were reviewed. The outcome of each pregnancy was established, and, where possible, all infants underwent appropriate investigations, including thoracic computed tomography (CT) scans.

Results

Sixty-seven fetuses had a cystic lung abnormality diagnosed from January 1995 to July 2001. The median (range) age at diagnosis was 21 (19 to 28) weeks. The lesion was right sided in 29 (43%), left in 36 (54%), and bilateral in 2 (3%); it was characterized as dominantly macrocystic in 27 (40%), microcystic in 35 (52%), and mixed in 5 (8%). Mediastinal shift was present in 30 fetuses (45%). Severe signs of fetal distress (eg, hydrops) were present in 5 fetuses (7%). Antenatal intervention was performed in 4 fetuses (thoraco-amniotic shunts [n = 3] and percutaneous intrauterine laser therapy [n = 1]). Sixty-four (96%) of the fetuses were born alive. There was 1 termination of pregnancy and 2 intrauterine deaths (all severe microcystic lesions). Forty-two infants (63%) underwent thoracotomy and appropriate excisional surgery at a median of 7.5 months (range, 1 day to 34 months). Two infants (which included the fetus having intrauterine laser therapy) died early in the postnatal period. Both were large microcystic lesions and had antenatal features of severe fetal distress. Twelve infants were investigated in the postnatal period but did not undergo surgery. Ten infants were not appropriately investigated or were lost to follow-up. Histologic examination showed definitive diagnostic features of CCAM (n = 25) or PS (n = 6). Other lesions with hybrid features of both were also seen (n = 11). There was a degree of correlation between antenatal ultrasound features (size of cyst [P = .03], in-utero behavior [P = .06], mediastinal shift [P = 0.05]) and the need for surgery but not with the final histologic diagnosis. Surgical excision was required in 45% of lesions showing late-gestation “resolution.”

Conclusions

Antenatally diagnosed “cystic lung disease” has an excellent prognosis in the absence of signs of severe fetal distress. The need for surgery should be based on appropriate postnatal investigations (eg, CT scans), rather than on antenatal behavior.