|Year : 2020 | Volume
| Issue : 3 | Page : 189-195
The outcome of fetuses diagnosed with congenital cystic adenomatous malformation of the lungs: Experience of a regional neonatal center (2004–2016)
Akuma Oti Akuma1, Ayevbekpen Grace Okoye2
1 Neonatal Intensive Care Unit, Corniche Hospital, Abu Dhabi, United Arab Emirates
2 Neonatal Intensive Care Unit, Luton and Dunstable University Hospital NHS Trust, Luton, England, UK
|Date of Submission||01-Jan-2020|
|Date of Decision||11-May-2020|
|Date of Acceptance||17-Apr-2020|
|Date of Web Publication||07-Aug-2020|
Dr. Akuma Oti Akuma
Neonatal Intensive Care Unit, Corniche Hospital, P. O. Box 378, Abu Dhabi
United Arab Emirates
Source of Support: None, Conflict of Interest: None
Objective: Although much is known about the antenatal course of congenital cystic adenomatous malformation (CCAM), the postnatal course is less well documented. The vast majority of infants remain asymptomatic at birth, with the controversy surrounding the postnatal management of such infants. We reviewed the outcome of fetuses diagnosed with CCAM in our center and evaluated their symptom burden during the 1st year of life. Methods: A retrospective review of maternal and infant medical records of all cases with antenatal diagnosis of CCAM managed in a regional perinatal center over 12 years, and infant outcome at 1 year of age is presented. Results: Forty-two eligible singleton pregnancies/infants were identified. Thirteen babies (30.9%) were symptomatic and 29/42 (69.1%) asymptomatic at birth. 7/13 (53.9%) symptomatic infants had associated antenatal complications. The fetal lesions were more likely to remain static or reduce in size during pregnancy in asymptomatic (26/29; 89.6%) than symptomatic babies (8/13; 61.6%). All babies had chest radiographs after birth, but computed tomography (CT) scan was done in only a few symptomatic babies; 7/42 (16.7%) during the neonatal period and a further 3/42 (7.1%) during infancy. The majority (8/13; 61%) of the symptomatic babies had surgical intervention compared to only 1/29 (3.4%) asymptomatic babies who had surgery. However, most babies remained symptom-free during infancy. Death within the cohort was limited to babies who were symptomatic (4/13; 31%). Conclusion: Most pregnancies diagnosed with CCAM remain uncomplicated. The behavior of the prenatal lesion could help predict the postnatal outcome. Our experience highlights that CCAM persistence cannot be excluded from chest radiographs; hence, the need for chest CT scans. Symptom surveillance should help guide the need for surgery in asymptomatic infants. However, only skilled clinicians who can offer long-term follow-up, until the transition into adulthood should oversee surveillance to ensure safety.
Keywords: Congenital cystic adenomatous malformation, fetal surgery, foetus, symptom surveillance
|How to cite this article:|
Akuma AO, Okoye AG. The outcome of fetuses diagnosed with congenital cystic adenomatous malformation of the lungs: Experience of a regional neonatal center (2004–2016). J Clin Neonatol 2020;9:189-95
|How to cite this URL:|
Akuma AO, Okoye AG. The outcome of fetuses diagnosed with congenital cystic adenomatous malformation of the lungs: Experience of a regional neonatal center (2004–2016). J Clin Neonatol [serial online] 2020 [cited 2020 Sep 25];9:189-95. Available from: http://www.jcnonweb.com/text.asp?2020/9/3/189/291637
| Introduction|| |
Congenital cystic adenomatous malformation (CCAM) is a congenital bronchopulmonary malformation characterized by a lack of normal alveoli and excess proliferation/cystic dilatation of the terminal bronchioles. It usually occurs sporadically with a reported incidence that varies from 1 in 10,000 to 1 in 35,000 live births. The widespread adoption of routine ultrasound screening during pregnancy has resulted in increased antenatal detection of affected fetuses. Similarly, a better understanding of the natural antenatal history of CCAM lesions has led to a more conservative approach to management with a resultant decrease in antenatal intervention and termination of affected pregnancies.,,,
In the postnatal period, affected infants can either be asymptomatic or symptomatic, having varying degrees of respiratory distress. It has been reported that only about 17% of infants with antenatally diagnosed CCAM are symptomatic at birth, while the vast majority remain asymptomatic. There is a consensus of opinion regarding the management of symptomatic CCAM neonates who after radiological evaluations, will need surgery. In contrast, the postnatal management of asymptomatic neonates/infants remains controversial, with some clinician advocating surgical resection between 3 and 6 months of life, and others adopt a more expectant (conservative) approach.
This controversy in postnatal management of asymptomatic infants exists mainly because of our lack of knowledge regarding the natural postnatal history of un-resected CCAM lesions. In our center, asymptomatic CCAM infants are managed conservatively. The outcome of all pregnancies with a fetal diagnosis of CCAM managed over a 12-year period is presented in this study. The symptom surveillance of affected infants during the 1st year of life was also evaluated to help ascertain the safety of conservative management approach in asymptomatic infants.
| Methods|| |
The case notes of mothers and infants with antenatal diagnosis of CCAM born between January 1, 2004 and December 31, 2015 were reviewed. Cases were identified by querying various hospital databases, including the fetal Medicine database, maternity database, the Neonatal database, histopathology database, cardiothoracic surgery database, and the regional congenital anomalies register.
Pertinent information on identified mother–infant dyad including ethnicity, gestation at diagnosis, antenatal progression/resolution of CCAM fetal lesion, antenatal management, delivery details, neonatal outcome, postnatal investigation, and management were extracted. In addition, the clinical history of all surviving children up to 1 year of age (ending December 31, 2016) was also reviewed to assess symptom burden, hospital readmission rates, and subsequent need for surgery during infancy.
Data were subjected to simple descriptive statistics and expressed as mean median, range, and percentages. Antenatal and demographic differences between symptomatic and asymptomatic infants were examined using Mann–Whitney and Fisher's exact test, and a P < 0.05 was considered statistically significant. Ethical approval was not required for this study, as this was a service evaluation exercise.
| Results|| |
A total of 51 pregnancies with antenatal diagnosis of CCAM were identified during the study period. One pregnancy with an affected fetus who also had trisomy 21 ended in stillbirth. A further three pregnancies were terminated on parental request. These four cases, coupled with another five babies who had a postnatal diagnosis of lung sequestration, were excluded, leaving a final study population of 42 pregnancies/infants. The study cohort was all singleton pregnancies that resulted in live births [Figure 1].
|Figure 1: Study Overview Flow Chart. CCAM - Congenital cystic adenomatous malformation. NICU - Neonatal Intensive Care Unit. Neo - Neonatology. CTS – Cardiothoracic Surgery. CT – Computed Tomography. *CT scan done at 9 months and Surgery at 10 months of age. **CT scan done 10 months and Surgery at 12 months of age. ***CT scan done at 2.5 months of age but Surgery not done|
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[Table 1] summarizes the demographics of the study cohort, which shows a majority of Caucasian infants with no sex predilection. The right lung was marginally more affected. Where data were available, the majority of the lesions 23/42 (54.7%) were small in size, measuring <5 cm in the widest diameter. In appearance, most of the fetal lesions, 19/42 (45.2%), were classified microcystic (Stocker type 2); 13/42 (26%) were macrocytic (Stocker type 1); 1/42 (2.4%) were of solid (Stocker type 3) and mixed variety each. This data was missing in 8/42 (19%) of cases. Fetal magnetic resonance imaging was the only other imaging used for antenatal evaluation in this cohort and was done in 6/42 (14.3%) of cases. Majority of the women delivered vaginally 31/42 (73.8%), while the remainder 11/42 (26.2%) had cesarean section.
[Table 2]: summarizes the progress of the fetal lesions during pregnancy and associated antenatal complications. The mean gestation at diagnosis of CCAM was 21 + 4 weeks (17 + 4 weeks – 31 + 3 weeks). CCAM was an isolated finding in 16/42 (38.1%) of the cohort, but in 26/42 (61.9%), there was one or more associated complications. Isolated CCAM occurred more in fetuses who were asymptomatic after birth 14/29 (48.3%) than those who were symptomatic: 2/13 (15.4%); (P = 0.084). The common complications of CCAM during pregnancy were: mediastinal shift 22/42 (52.4%), polyhydramnios 7/42 (16.9%), nonimmune hydrops 4/42 (9.5%) and pulmonary hypoplasia 3/42 (7.1%). Nonimmune hydrops and pulmonary hypoplasia were limited only to fetuses who became symptomatic after birth – A statistically significant difference. Mediastinal shift and polyhydramnios also occurred more in fetuses who became symptomatic at birth than those who were asymptomatic. The former involved: 10/13 (77%) versus 12/29 (41.4%) of cases and the latter 4/13 (30.8%) versus 3/29 (10.3%) of symptomatic and asymptomatic cases, respectively. However, neither of these differences was statistically significant.
|Table 2: Antenatal characteristics of congenital cystic adenomatous malformation lesions and postnatal outcomes - comparison between symptomatic and asymptomatic infants|
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In the majority of cases 34/42 (81%), fetal CCAM lesion remained either static in size or resolved (partial or complete) during pregnancy. This contrasts with the few cases, 3/42 (7.1%) where the CCAM lesion actually increased in size during the antenatal period. Fetal CCAM lesions were more likely to undergo partial or complete resolution during pregnancy in fetuses who became asymptomatic after birth than those who were symptomatic: 13/29 (44.8%) and 7/29 (24.1%) versus 3/13 (23.1%) and 2/13 (15.4%), respectively. In contrast, fetal CCAM lesions were more likely to either remain static or increase in size during pregnancy in fetuses who became symptomatic after birth than those who were asymptomatic: 3/13 (23.1%) and 2/13 (15.4%) versus 6/29 (20.7%) and 1/29 (3.4%), respectively. However, none of these observed differences in fetal CCAM behavior was statistically significant. Two fetuses had an antenatal intervention, and both were symptomatic after birth.
[Table 2] and [Figure 1] summarizes the differences in clinical features between the symptomatic and asymptomatic infants after birth and their progress during the neonatal period and infancy. Symptomatic infants were born at a lower mean gestation and also weighed less than their asymptomatic counterparts: 34.6 weeks and 2401.3 g versus 39.1 weeks 3293.2 g, respectively. Both differences were statistically significant. Conversely, asymptomatic infants were born in better condition than symptomatic infants with correspondingly better mean Apgar scores at 1 min and 5 min, respectively, 8.2 and 9.7 versus 7.4 and 8.8, respectively. However, only the difference in the mean Apgar scores at 5 min was statistically significant (P = 0.004).
All the symptomatic infants needed admission to the neonatal intensive care unit (NICU) in contrast to a single asymptomatic infant (1/29; 3.4%) admitted to NICU because of prematurity. The remaining asymptomatic babies were managed successfully in the postnatal ward area after birth. The mean length of hospital stay was significantly more for symptomatic infants than asymptomatic infants: 10.6 days versus 2.1 days; P = 0.001.
A chest radiograph was done in all the babies soon after birth. This initial chest X-ray was significantly more likely to be reported “abnormal” in symptomatic than asymptomatic babies: 8/13 (61.5%) versus 10/29 (34.5%); P = 0.006. In contrast, chest computed tomography (CT) scan was rarely done during the initial hospital stay after birth (neonatal period); 7/42 (16.7%). All such “early” chest CT scans were “abnormal” and done exclusively in symptomatic infants who also had abnormal initial chest X-ray report.
Three more babies 3/42 (7.1%) had CT chest scans later in infancy. One of these babies was symptomatic at birth and had a “normal” initial chest X-ray report but abnormal chest CT scan at 9 months of age. The other two babies were asymptomatic at birth. One of these two had an “abnormal” initial chest X-ray report and the other a “normal” report. The former had chest CT scan at 2.5 months of age, which was suggestive of a small area of lobar emphysema and the latter had chest CT scan at 10 months of age, which was reported “abnormal – CCAM.”
All the seven symptomatic babies who had abnormal “early” chest CT reports underwent surgery (lobectomy) in the neonatal period. Only 1/7 (14.3%) of these operated symptomatic babies died postsurgery. Two other babies in the cohort also had surgery during infancy – 10 months and 12 months, respectively. Both of these babies who had “delayed” chest CT scans at 9 months and 10 months, respectively, survived surgery. There were overall 4/42 (9.5%) deaths in the study cohort – One postsurgery and three from the complications of prematurity. All the babies who demised were symptomatic at birth.
On discharge from hospital, 6/38 (15.8%) of eligible infants did not have follow-up. The majority of the remaining eligible infants (23/38; 60.5%) had follow-up with a single disciple – Neonatology (18/23; 78.3%), cardiothoracic surgery (4/23; 17.4%), and respiratory physician (1/23; 4.3%). However, the remaining eligible infants (9/38; 23.7%) had follow-up with either two or more disciplines postdischarge from hospital. A number of infants were lost to follow-up during infancy, but the median duration of follow-up was 10 months. Majority of the babies followed up (34/38; 89.5%) remained asymptomatic during infancy. However, 4/38 (10.5%) babies became symptomatic during follow-up. The most common symptoms reported were wheezes and recurrent chest infection. Only one child needed hospital re-admission for chest infection during the follow-up period.
| Discussion|| |
Improving antenatal surveillance of congenital anomalies in recent years has led to a steady increase in the antenatal detection of CCAM., Most lesions appear during the second trimester and are detected during the routine morphology (anomaly) scan or shortly thereafter. This is congruent with our finding where the median time of detection was 21 weeks and 4 days. Once identified, it is important to undertake serial sonographic monitoring of the fetal lesion and surveillance for associated complications, which can impact postnatal outcomes. The majority of the fetal lesions will either regress to some degree or remains static in size during pregnancy. Only in a minority of cases do the CCAM lesion increases in size or disappears completely during fetal life. Mediastinal deviation, polyhydramnios, nonimmune hydrops, and pulmonary hypoplasia are some of the known complications of antenatal CCAM. All four complications were encountered in our cohort to a varying degree.
The behavior of the fetal CCAM lesion and presence of associated complications during pregnancy can be used in combination to predict the postnatal condition of the baby. Such prognostic ability could potentially assist clinicians who undertake antenatal counseling of at-risk pregnancies. Nonimmune hydrops is a recognized poor outcome predictor for antenatal CCAM.,,,,,,, In our cohort, pulmonary hypoplasia and nonimmune hydrops were limited to fetuses who became symptomatic after birth. Similarly, fetal surgical intervention is another reported marker for the poorer outcome. In our cohort, thoracentesis and thoraco-amniotic shunt were done on two fetuses who developed severe nonimmune hydrops, and both were symptomatic after birth.
Most affected fetuses, however, remained asymptomatic after birth., Our experience is in agreement with published literature, given that 69% of our cohort were asymptomatic in the neonatal period. These asymptomatic infants were born at a more mature gestation, were heavier in weight and had significantly better 5 min Apgar scores. Reassuringly, the asymptomatic infants were safely managed alongside their mothers without need for NICU admission if there were no other health concerns. These findings could also help clinicians when making a decision regarding the appropriate place for the delivery of affected pregnancies. Most of the mothers delivered vaginally, and their asymptomatic babies stayed in the hospital for a short period of time.
Chest radiograph is mandatory in affected babies and should be done irrespective of symptomatology. This initial investigation is more likely to be reported “abnormal” in symptomatic babies, a pattern observed in our study. The commonly reported “abnormal findings” included: areas of cystic lucency within a lobe with intersposed normal lungs, localized or diffuse opacification, nonspecific linear air space shadowing, mediastinal deviation and features suggestive of either localized or generalized lung hypo-/or hyper-inflation. However, despite this mandatory recommendation, the utility of chest radiograph in the evaluation of CCAM has been questioned in previous reports because of its low specificity and sensitivity.
Chest CT is a better imaging tool to delineate abnormal lung lesions, including CCAM. Chest CT (early and late) was only done on a handful of our symptomatic infants. We are therefore unable to calculate the sensitivity and specificity of chest X-ray as the initial evaluation test in our cohort because of this practice. However, chest CT scan in two babies (one symptomatic and asymptomatic) who had “normal” chest X-ray reports during infancy were “abnormal” and confirmatory of CCAM. Similarly, there were a number of both symptomatic and asymptomatic babies whose initial chest X-ray was reported “abnormal” but did not have chest CT scan. One of such baby's lung lesion was later diagnosed as lobar emphysema on a chest CT scan done in infancy. Given this observation, we would suggest that chest CT scan should be done in all affected babies after the initial chest X-ray; irrespective of the chest radiography report. This should help confirm the diagnosis of CCAM or other related lung malformations, a recommendation that is in consonance with more recent guidelines.
There is a consensus of opinion regarding the management of symptomatic neonates who have CCAM. They would usually have surgery in the immediate newborn period after the radiological evaluation of the lesion. The majority of the symptomatic babies in our cohort were managed in similar fashion and surgery, when indicated, was performed in the neonatal period. The observed postsurgery complications were generally minor and included: air leak and pleural effusion. Surgery was also performed in one of our symptomatic babies after abnormal CT scan evaluation during infancy, without associated complications. There was a single death postsurgery performed in the neonatal period in our cohort.
The postnatal management of asymptomatic neonates/infants who had fetal CCAM remains controversial, with clinicians segregating into two broad opinions. One group advocates a “conservative approach” consisting of radiological evaluation after delivery and symptom surveillance thereafter with the provision of surgery if symptoms develop or there is an increase in the size of the lesion. The second group, however, adopt a more proactive approach offering surgery during infancy after early radiological evaluation. The pros and cons of both management strategy are well documented in the literature., This controversy in postnatal management of asymptomatic infants exists mainly because of our lack of knowledge regarding the natural postnatal history of un-resected CCAM lesions. Moreover, there has been no prospective study comparing the outcomes of asymptomatic infants managed using the two management strategies.
Most clinicians in our center gravitate toward the conservative strategy in managing asymptomatic infants who had fetal CCAM. Emphasis is given to symptom surveillance during infancy. A chest CT scan is performed if the diagnosis is in doubt, and the duration of follow-up is at the discretion of the attending physician, although usually guided by future development of significant symptoms. Most of our babies remained asymptomatic during follow-up and those who became symptomatic experienced only a mild degree of symptoms. However, there was nonuniformity of personnel overseeing the follow-up with significant drop out from the follow-up program even before the end of infancy. A recent UK-based survey of 20 pediatric surgical units completed by 72 consultants in pediatric surgery (51% response rate) highlighted similar ongoing variability in the provision of care for asymptomatic infants who have CCAM as found in our study. Given this problem, it is imperative that future surveillance programs should be more robust with defined criteria and end-point. We suggest that these babies should be followed up either by a pediatric respiratory consultant or a consultant pediatrician with interest in respiratory diseases who could provide this service up until transition into adulthood. Similarly, developing an International registry to collect outcomes on these asymptomatic infants will help us gain better knowledge regarding the natural history of this condition and hopefully resolve this management debate either way.
Limitations of the study
We acknowledge that this report is based on the experiences from a single perinatal center in a region of the United Kingdom, and the duration of symptom surveillance was limited to infancy. However, this follow-up time frame was chosen to help evaluate the “safety” of the conservative approach to managing asymptomatic infants who have CCAM given that published reports suggest that most such infants become symptomatic by a median age of 6.9 months (range 2.5–10 months). Moreover, proponents of elective surgery in asymptomatic infants recommend doing lobectomy between 3 and 6 months of age. The follow-up period in our study, therefore, covered both periods and so deemed reasonable. We, however, cannot guarantee that with a longer period of surveillance, these infants would not become symptomatic, needing further radiological investigation and surgery.
Second, the issues raised in our report are relevant to many perinatal centers around the world and, therefore, valuable. We continue to lack scientific evidence to inform postnatal management of infants with antenatal diagnosis of CCAM, especially those who are asymptomatic at birth. There is, therefore, an urgent need to undertake a large multi-center, multi-national, prospective, longitudinal study of infants with antenatal diagnosis of CCAM. Such a study should help provide information on the natural history of this condition, thereby assisting in the development of best practice guidelines. Such evidence-based guidelines should help clarify who is best placed to oversee symptom surveillance and the duration of follow-up.
| Conclusion|| |
Our study has shown that when there is antenatal detection of CCAM, most of such pregnancies have only minor complications and are delivered vaginally. The behavior of the fetal lesion, coupled with the presence of complications, can help prognosticate the baby's condition postdelivery. Such knowledge can be useful during antenatal counseling and when planning the optimum place of delivery.
Chest CT scan should be performed on all affected infants to help confirm the diagnosis and to delineate the CCAM lesion postnatally. The debate regarding the management of asymptomatic infants in the postnatal period will continue for the foreseeable future since we still lack scientific evidence to inform postnatal management in this sub-group of affected infants. In the interim, conservative management strategy, employing symptom surveillance remains a tenable approach for asymptomatic infants provided this is overseen by appropriately skilled clinicians who can offer long-term follow-up till transition into adulthood.
Finally, there is an urgent need to establish an international registry to collate information regarding infants who have CCAM to help gain knowledge regarding the natural history of this condition. Such evidence should eventually facilitate the development of a robust guideline on how best to manage this rare congenital malformation.
We would like to thank Dr. Kamini Yadav, Dr. D K Vasudev, Dr. Manjiri Khare, Mr. Giles Peek, Dr. Judith Budd and Dr. Helen Porter, for their help with case identification.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2]