Pulmonary Airway Malformation Volume Ratio Research Articles

Serial lung mass volume ratios as prognostic indicators of neonatal respiratory morbidity in fetal pulmonary malformations

Several studies have shown that the congenital pulmonary airway malformation volume ratio is a useful prognosticator of neonatal outcome in prenatally diagnosed lung lesions. However, there remains a lack of consensus on which congenital pulmonary airway malformation volume ratio values have the best predictive value because of operator dependence, inherent changes in lung lesion size throughout gestation, and the widespread use of maternal steroids. This study sought to determine the association between serial congenital pulmonary airway malformation volume ratio measurements and neonatal outcomes among fetuses with lung malformations. This was a retrospective cohort study of fetuses with a prenatally diagnosed lung malformation managed at 2 major fetal centers from January 2010 to December 2021. Prenatal variables, including prospectively measured congenital pulmonary airway malformation volume ratio measurements (initial, maximum, and final), were analyzed. The results were correlated with 3 outcome measures, namely surgical resection before 30 days of life, a need for supplemental O2 at birth, and endotracheal intubation at birth. Statistical analyses were performed using receiver operating characteristic curve analyses, Welch 2 sample t tests, and multivariable logistic regressions (P<.05). There were 123 fetuses with isolated lung lesions identified. Eight (6.5%) had hydrops. The mean initial congenital pulmonary airway malformation volume ratio was 0.67±0.61 cm2 at 22.9±3.9 weeks' gestation. The mean maximum congenital pulmonary airway malformation volume ratio was 1.08 ± 0.94 cm2 at 27.0 ± 4.0 weeks' gestation. The mean final congenital pulmonary airway malformation volume ratio was 0.58±0.60 cm2 at 33.2±4.1 weeks' gestation. At a mean gestational age at delivery of 38.3±2.6 weeks, 15 (12.2%) underwent neonatal lung resection for symptomatic disease. In a multivariable regression, all 3 congenital pulmonary airway malformation volume ratio measurements showed a significant correlation with neonatal lung resection (P<.001). Optimal congenital pulmonary airway malformation volume ratio cutoffs were established based on an initial congenital pulmonary airway malformation volume ratio of ≥0.8 cm2, maximum congenital pulmonary airway malformation volume ratio of ≥1.5 cm2, and a final congenital pulmonary airway malformation volume ratio of ≥1.3 cm2 with associated areas under the curve of 0.89, 0.97, and 0.93, respectively. The final congenital pulmonary airway malformation volume ratio had the highest specificity for predicting surgical lung resection in the early postnatal period. Measuring congenital pulmonary airway malformation volume ratios throughout pregnancy in fetuses with pulmonary malformations has clinical value for prenatal counseling and planning care transition after delivery. Fetuses with a final congenital pulmonary airway malformation volume ratio of more than 1.3 cm2 are likely to require neonatal surgery and therefore should be delivered at tertiary care centers with a neonatal intensive care unit and pediatric surgical expertise.

Prenatal ultrasound-and MRI-based imaging predictors of respiratory symptoms at birth for congenital lung malformations

BackgroundCongenital lung malformations (CLM) are rare developmental anomalies of the fetal lung with a minority of patients exhibiting symptoms around the time of birth. Although ultrasound remains the gold standard, fetal MRI has recently been incorporated as an adjunct imaging modality in the workup and prenatal counseling of patients with CLM as it is thought to more accurately delineate lesion boundaries and diagnose lesion type. We evaluate what prenatal variables correlate with postnatal respiratory symptoms. MethodsWe performed a retrospective review of patients with prenatal diagnosis of CLM treated at our institution between 2006-2020. Fetal ultrasound and magnetic resonance imaging (MRI) parameters including maximal congenital pulmonary airway malformation volume ratio (CVR), absolute cyst volume, and observed to expected normal fetal lung volume (O/E NFLV) were correlated with outcomes including postnatal respiratory symptoms, need for supplementary oxygen or mechanical ventilation, delay in tolerating full feeds, resection in the neonatal period. ResultsOur study included 111 patients, all of whom underwent fetal ultrasound with 64 patients additionally undergoing fetal MRI. Postnatal respiratory symptoms were noted in 22.5% of patients, 19.8% required supplemental oxygen, 2.7% mechanical ventilation and two patients requiring urgent resection. Ultrasound parameters including absolute cyst volume and maximal CVR correlated with need for mechanical ventilation (p=0.034 and p=0.024, respectively) and for urgent resection (p=0.018 and p=0.023, respectively) and had a marginal association with postnatal respiratory symptoms (p=0.050 and p=0.052). Absolute cyst volume became associated with postnatal respiratory symptoms (p=0.017) after multivariable analysis controlling for maternal steroid administration and gestational age. O/E NFLV did not correlate with perinatal outcomes. ConclusionWe have found that ultrasound-based measurements correlate with postnatal respiratory symptoms, while MRI derived O/E NFLV does not. Further studies are needed to elucidate the role of MRI in the prenatal workup of congenital lung malformations. Type of StudyStudy of Diagnostic Test. Level of EvidenceLevel I.

Fetal Risk Stratification and Outcomes in Children with Prenatally Diagnosed Lung Malformations: Results from a Multi-Institutional Research Collaborative.

The aim of this study was to assess current clinical outcomes in children with prenatally diagnosed congenital lung malformations (CLMs) and to identify prenatal characteristics associated with adverse outcomes. Despite a wide spectrum of clinical disease, the identification of fetal CLM subgroups at increased risk for hydrops and respiratory compromise at delivery has not been well defined. A retrospective cohort study was conducted using an operative database of prenatally diagnosed CLMs managed at 11 children's hospitals from 2009 to 2016. Statistical analyses were performed using nonparametric bivariate or multivariable logistic regression. Three hundred forty-four children were analyzed. Fifteen (5.5%) fetuses were managed with maternal steroids in the setting of hydrops, and prenatal surgical intervention was uncommon (1.7%). Seventy-five (21.8%) had respiratory symptoms at birth, and 34 (10.0%) required neonatal lung resection. Congenital pulmonary airway malformation volume ratio (CVR) measurements were recorded in 169 (49.1%) cases and were significantly associated with perinatal outcome, including hydrops, respiratory distress at birth, need for supplemental oxygen, neonatal ventilator use, and neonatal resection ( P < 0.001). An initial CVR ≤1.4 was significantly correlated with a reduced risk for hydrops [area under the curve (AUC), 0.93; 95% confidence interval (CI), 0.87-1.00]. A maximum CVR <0.9 (AUC, 0.72; 95% CI, 0.67-0.85) was associated with a low risk for respiratory symptoms at birth. In this large, multi-institutional study, an initial CVR ≤ 1.4 identifies fetuses at very low risk for hydrops, and a maximum CVR < 0.9 is associated with asymptomatic disease at birth. These findings represent an opportunity for standardization and quality improvement for prenatal counseling and delivery planning.

Comparison of the Prognostic Factors of Fetuses With Congenital Pulmonary Airway Malformations According to Type.

To compare the prognostic factors of fetuses with microcystic and macrocystic congenital pulmonary airway malformations (CPAMs). We retrospectively evaluated fetuses with CPAMs at Asan Medical Center. The CPAM size, mass effect, and maximum cyst size in macrocystic CPAMs were evaluated prenatally. The adverse postnatal outcomes, including respiratory symptoms, mechanical ventilation, and surgery, were evaluated. In 118 cases, 2 fetal deaths and 1 neonatal death occurred. All cases of fetal hydrops and complete regression after birth were in the macrocystic and microcystic CPAM groups, respectively. Twenty-four neonates (20.7%) had respiratory symptoms, and 18 (15.5%) required mechanical ventilation. Sixty-three neonates (54.3%) underwent surgery, of whom 21 (33.3%) required surgery in the neonatal period. The maximum congenital pulmonary airway malformation volume ratio was significantly associated with all postnatal outcomes (P < .05), and the optimal cutoff values were lower for respiratory symptoms, mechanical ventilation, and neonatal surgery in the macrocystic CPAMs. The maximum cyst size was also associated with all postnatal outcomes in macrocystic CPAMs (P < .05). Different cutoff values for the maximum congenital pulmonary airway malformation volume ratio should be applied according to the CPAM type for the prediction of postnatal outcomes. The maximum cyst size can also be a useful prognostic factor in macrocystic CPAMs.

In fetuses with congenital lung masses, decreased ventricular and atrioventricular valve dimensions are associated with lesion size and clinical outcome.

The clinical importance of mass effect from congenital lung masses on the fetal heart is unknown. We aimed to report cardiac measurements in fetuses with congenital lung masses and to correlate lung mass severity/size with cardiac dimensions and clinical outcomes. Cases were identified from our institutional database between 2009 and 2016. We recorded atrioventricular valve (AVVz) annulus dimensions and ventricular widths (VWz) converted into z scores, ratio of aortic to total cardiac output (AoCO), lesion side, and congenital pulmonary airway malformation volume ratio (CVR). Respiratory intervention (RI) was defined as intubation, extracorporeal membrane oxygenation (ECMO), or use of surgical intervention prior to discharge. Fifty-two fetuses comprised the study cohort. Mean AVVz and VWz were below expected for gestational age. CVR correlated with ipsilateral AVVz (RS = -.59, P < .001) and ipsilateral VWz (-0.59, P < .001). Lower AVVz and AoCO and higher CVR were associated with RI. No patient had significant structural heart disease identified postnatally. In fetuses with left-sided lung masses, ipsilateral cardiac structures tend to be smaller, but in our cohort, there were no patients with structural heart disease. However, smaller left-sided structures may contribute to the need for RI that affects a portion of these fetuses.

Development of a multi-institutional registry for children with operative congenital lung malformations

IntroductionThe purpose of this study was to develop a multi-institutional registry to characterize the demographics, management, and outcomes of a contemporary cohort of children undergoing congenital lung malformation (CLM) resection. MethodsAfter central reliance IRB approval, a web-based, secure database was created to capture retrospective cohort data on pathologically-confirmed CLMs performed between 2009 and 2015 within a multi-institutional research collaborative. ResultsEleven children's hospitals contributed 506 patients. Among 344 prenatally diagnosed lesions, the congenital pulmonary airway malformation volume ratio was measured in 49.1%, and fetal MRI was performed in 34.3%. One hundred thirty-four (26.7%) children had respiratory symptoms at birth. Fifty-eight (11.6%) underwent neonatal resection, 322 (64.1%) had surgery at 1–12 months, and 122 (24.3%) had operations after 12 months. The median age at resection was 6.7 months (interquartile range, 3.6–11.4). Among 230 elective lobectomies performed in asymptomatic patients, thoracoscopy was successfully utilized in 102 (44.3%), but there was substantial variation across centers. The most common lesions were congenital pulmonary airway malformation (n = 234, 47.3%) and intralobar bronchopulmonary sequestration (n = 106, 21.4%). ConclusionThis multicenter cohort study on operative CLMs highlights marked disease heterogeneity and substantial practice variation in preoperative evaluation and operative management. Future registry studies are planned to help establish evidence-based guidelines to optimize the care of these patients. Level of evidenceLevel II.

Predictors of early lobectomy after birth in prenatally diagnosed congenital pulmonary airway malformation

PurposeThe purpose of this study was to clarify the relationship between congenital pulmonary airway malformation volume ratio (CVR) of bronchial atresia (BA), CVR of congenital cystic adenomatoid malformations (CCAM), and time of surgery after birth. MethodWe retrospectively analyzed data of 36 BA and CCAM cases, prenatally diagnosed as CPAM from 2009 through 2014. ResultsWithin 2 h after birth, 12 neonatal patients underwent emergent (EMG) lobectomy. Five cases of lobectomy were performed urgently (UG) from 12 to 48 h after birth. Four cases of lobectomy were required within 30 days after birth (early = EAG). We performed lobectomy in 15 other patients at 11 months after birth (late = LG). Of the EMG cases, 11 were macrotype CCAM (maximal CVR >2.0), and 4 of 5 UG cases were microtype CCAM (CVR >2.0). Of the EAG cases, 3 of 4 were macrotype CCAM with CVR of <1.5. Of 15 LG, 13 were BA and showed a CVR of 0.13–3.0 (median, 0.78). The CVR of the cases operated on within 48 h after birth was significantly larger than that of the cases operated on after 2 weeks (p = 0.001). ConclusionEMG or UG lobectomy was usually required after birth in CCAM, indicating maximal CVR >2.0. By contrast, elective surgery was performed in most BA cases. Level of evidenceIV.

Thoracic Changes after Full Laser Ablation of the Feeding Artery in Fetuses with Bronchopulmonary Sequestration

Objective: To assess longitudinal intrathoracic changes after fetal laser surgery in fetuses with bronchopulmonary sequestration (BPS) with hydrops and/or hydrothorax. Study Design: The presence of intrafetal fluid effusions, the lung mass volume ratio (congenital pulmonary airway malformation volume ratio [CVR]), and the observed/expected lung-to-head circumference ratio (O/E-LHR) of both lungs were evaluated in a cohort of BPS fetuses with hydrops and/or hydrothorax treated with full laser ablation of the feeding artery (FLAFA). The longitudinal changes in intrafetal fluid effusions, lung mass volume, and pulmonary growth were analyzed by survival and multilevel analysis against days after FLAFA. Results: FLAFA was successfully performed in 15 cases at a median gestational age of 26.9 weeks. A complete disappearance of the hydrops and hydrothorax was observed a median interval of 7.5 and 21 days after the fetal intervention, respectively. A progressive decrease in the CVR and an increment in the size of both lungs were observed after FLAFA. The O/E-LHR of the lung contralateral and ipsilateral to the side of the BPS became normal on average 8 and 10 weeks after FLAFA, respectively. Conclusion: Fetal laser surgery with FLAFA promotes disappearance of all fetal fluid effusions, a lung mass regression sequence, and a normalization of pulmonary growth.

Prediction of neonatal respiratory distress in pregnancies complicated by fetal lung masses

The objective of this article is to evaluate the utility of fetal lung mass imaging for predicting neonatal respiratory distress. Pregnancies with fetal lung masses between 2009 and 2014 at a single center were analyzed. Neonatal respiratory distress was defined as intubation and mechanical ventilation at birth, surgery before discharge, or extracorporeal membrane oxygenation (ECMO). The predictive utility of the initial as well as maximal lung mass volume and congenital pulmonary airway malformation volume ratio by ultrasound (US) and magnetic resonance imaging (MRI) was analyzed. Forty-seven fetal lung mass cases were included; of those, eight (17%) had respiratory distress. The initial US was performed at similar gestational ages in pregnancies with and without respiratory distress (26.4±5.6 vs 22.3±3weeks, p=0.09); however, those with respiratory distress had higher congenital volume ratio at that time (1.0 vs 0.3, p=0.01). The strongest predictors of respiratory distress were maximal volume >24.0cm3 by MRI (100% sensitivity, 91% specificity, 60% positive predictive value, and 100% negative predictive value) and maximal volume >34.0cm3 by US (100% sensitivity, 85% specificity, 54% positive predictive value, and 100% negative predictive value). Ultrasound and MRI parameters can predict neonatal respiratory distress, even when obtained before 24weeks. Third trimester parameters demonstrated the best positive predictive value. © 2017 John Wiley & Sons, Ltd.

Surveillance of fetal lung lesions using the congenital pulmonary airway malformation volume ratio: natural history and outcomes.

The congenital pulmonary airway malformation volume ratio (CVR) is a widely used sonographic measure of relative mass size in fetuses with lung malformations. The purposes of this study were to examine serial CVR measurements to understand longitudinal growth patterns and to determine correlation with postnatal imaging. An institutional review board-approved retrospective review was performed on fetuses referred for an echogenic lung malformation between 2002 and 2014. For each fetus, the CVR was prospectively calculated using 2D ultrasound and followed with advancing gestation. Based on 40 fetuses, the mean initial CVR was 0.51 ± 0.07 at 20.5 ± 0.3 weeks of gestation. The CVR increased after 24 weeks of gestation (p = 0.0014), peaking at a CVR of 0.96 ± 0.11 at 25.5 ± 0.05 weeks, followed by a significant decrease in the CVR to 0.43 ± 0.07 prior to term (p < 0.0001). However, approximately one third showed no appreciable increase in size. The mean CVR was significantly correlated with postnatal chest computed tomography (CT) size dimensions (p = 0.0032) and likelihood for lung resection (p = 0.0055). Fetal lung malformations tend to follow one of two distinct growth patterns, characterized by either (1) a maximal CVR between 25 and 26 weeks of gestation or (2) minimal change in relative growth. The mean CVR correlates with postnatal CT size and operative management.

Vanishing fetal lung malformations: Prenatal sonographic characteristics and postnatal outcomes

Background/purposeThe purpose of this study was to examine the natural history and outcomes of prenatally diagnosed lung masses that appear to undergo complete regression before birth. MethodsAn IRB-approved retrospective review was performed on 100 consecutive fetuses with a congenital lung malformation at a single fetal center. Prenatal and postnatal imaging as well as outcomes of vanishing fetal masses was analyzed and compared to those with persistent fetal masses. ResultsSeventeen lesions (17%) became sonographically undetectable at 35.3±2.3weeks gestation. Vanishing fetal masses were associated with microcystic disease (100% vs. 69%, p=0.005) and a low initial congenital pulmonary airway malformation volume ratio (CVR; 0.31±0.35 vs. 0.70±0.66, p=0.002) when compared to those with persistent fetal lesions. Based on postnatal CT imaging and pathology data, 10.3% of all fetal masses completely regressed. The positive predictive value and negative predictive value of prenatal ultrasound for detecting lung malformations in late gestation were 96% and 43%, respectively. All infants with vanishing fetal lesions were asymptomatic at birth and were more likely to be managed nonoperatively (75% vs. 22%, p<0.0001) when compared to infants with persistent fetal masses. ConclusionsVanishing lung lesions late in gestation are relatively common and are associated with a low CVR and microcystic disease.

Fetal lung lesions: can we start to breathe easier?

The purpose of this study was to develop a simple and accurate approach for risk stratification of fetal lung lesions that are associated with respiratory compromise at birth. We conducted a retrospective review of 64 prenatal lung lesions that were managed at a single fetal care referral center (2001-2011). Sonographic data were analyzed and correlated with perinatal outcomes. Hydrops occurred in only 4 cases (6.3%). Among fetuses without hydrops, the congenital pulmonary airway malformation volume ratio (CVR) was the only variable that was associated significantly with respiratory compromise and the need for lung resection at birth (P < .01). Based on a maximum CVR >1.0, the sensitivity, specificity, positive predictive value, and negative predictive value for respiratory morbidity were 90%, 93%, 75%, and 98%, respectively. Nonhydropic fetuses with a maximum CVR >1.0 are a subgroup of patients who are at increased risk for respiratory morbidity and the need for surgical intervention. These patients should be delivered at a tertiary care center with pediatric surgery expertise to ensure optimal clinical outcomes.