Mitochondrial DNA mutations in extremely preterm infants with bronchopulmonary dysplasia.

Bronchopulmonary dysplasia (BPD) is a serious chronic lung disease affecting extremely preterm infants. While mitochondrial dysfunction has been investigated in various medical conditions, limited research has explored mitochondrial DNA (mtDNA) gene mutations, specifically in BPD. This study aimed to evaluate mitochondrial mtDNA gene mutations in extremely preterm infants with BPD. In this prospective observational study, we enrolled a cohort of extremely preterm infants diagnosed with BPD. Clinical data were collected to provide comprehensive patient profiles. Peripheral blood mononuclear cells were isolated from whole-blood samples obtained within a defined timeframe. Subsequently, mtDNA extraction and sequencing using next-generation sequencing technology were performed to identify mtDNA gene mutations. Among the cohort of ten extremely preterm infants with BPD, mtDNA sequencing revealed the presence of mutations in seven patients, resulting in a total of twenty-one point mutations. Notably, many of these mutations were identified in loci associated with critical components of the respiratory chain complexes, vital for proper mitochondrial function and cellular energy production. This pilot study provides evidence of mtDNA point mutations in a subset of extremely preterm infants with BPD. These findings suggest a potential association between mitochondrial dysfunction and the pathogenesis of BPD. Further extensive investigations are warranted to unravel the mechanisms underlying mtDNA mutations in BPD.

Survival and Morbidities in Infants with Birth Weight Less than 500 g: a Nationwide Cohort Study.

BACKGROUND: This study aimed to investigate the survival and morbidities of infants in the Korean Neonatal Network (KNN) with birth weight (BW) < 500 g. METHODS: The demographic and clinical data of 208 live-born infants with a BW < 500 g at a gestational age of ≥ 22 weeks who were treated in the neonatal intensive care units of the KNN between 2013 and 2017 were reviewed. RESULTS: The survival rate of the infants was 28%, with a median gestational age and BW of 243/7 weeks (range, 220/7-336/7) and 440 g (range, 220-499), respectively. Multivariable Cox proportional hazards analysis demonstrated that survival to discharge was associated with longer gestation, higher BW, female sex, singleton gestation, use of any antenatal corticosteroids, and higher Apgar scores at 5 minutes. The overall survival rates were significantly different between the BW categories of < 400 g and 400-499 g. However, there was no significant difference in the incidence of any morbidity between the BW groups. Half of the deaths of infants with BW < 500 g occurred within a week of life, mainly due to cardiopulmonary and neurologic causes. The major causes of death in infants after 1 week of age were infection and gastrointestinal disease. Among the surviving infants, 79% had moderate to severe bronchopulmonary dysplasia, 21% underwent surgical ligation of patent ductus arteriosus, 12% had severe intraventricular hemorrhage (grade III-IV), 38% had sepsis, 9% had necrotizing enterocolitis (stage ≥ 2), and 47% underwent laser treatment for retinopathy of prematurity. The median length of hospital stay was 132 days (range, 69-291), and 53% required assistive devices at discharge. CONCLUSION: Despite recent advances in neonatal intensive care, the survival and morbidity rates of infants with BW < 500 g need further improvement.

Functional and structural evaluation in the lungs of children with repaired congenital diaphragmatic hernia.

BACKGROUND: To evaluate the long-term functional and structural pulmonary development in children with repaired congenital diaphragmatic hernia (CDH) and to identify the associated perinatal-neonatal risk factors. METHODS: Children with repaired CDH through corrective surgery who were born at gestational age ≥ 35 weeks were included in this analysis. Those who were followed for at least 5 years were subjected to spirometry and chest computed tomography for evaluation of their functional and structural growth. Main bronchus diameters and lung volumes (total, left/right) were measured. According to total lung volume (TLV) relative to body surface area, children were grouped into TLV ≥ 50 group and TLV < 50 group and the associations with perinatal-neonatal factors were analyzed. RESULTS: Of the 28 children (mean age, 6.2 ± 0.2 years) with left-sided CDH, 7 (25%) had abnormal pulmonary function, of whom 6 (87%) showed restrictive patterns. All pulmonary functions except FEF25-75% were worse than those in matched healthy control group. Worse pulmonary function was significantly associated with small head and abdominal circumferences at birth. The mean TLV was 1339.1 ± 363.9 mL and LLV/TLV was 47.9 ± 2.5 mL. Children with abnormal pulmonary function were more likely to have smaller lung volumes. In multivariate analysis, abdominal circumference at birth was significantly associated with abnormal lung volume. CONCLUSIONS: A quarter of children with repaired CDH showed abnormal pulmonary function. Small abdominal circumference at birth was associated with abnormal pulmonary function and lower TLV. .

Extremely low birth weight infant surviving left congenital diaphragmatic hernia: a case report.

In this study, we present the case of a 900 g, male infant born at 27+5 weeks, who was placed on high frequency oscillatory ventilation (HFOV) until repair of a left congenital diaphragmatic hernia (CDH) at 39 days of life (DOL). To date, this is the smallest infant with repair of the left CDH reported in the literature. After birth, he passed the cardiopulmonary stabilization phase and successfully underwent delayed surgery; in the process, he received ventilator assistance through HFOV. He weighed 1,660 gm at the time of surgery. We performed the thoracoscopic primary closure of the diaphragmatic defect. He was extubated on post-operation day (POD) 7 and discharged from hospital on POD 36 with 0.1 L/min supplemental oxygen via nasal cannula. He is being followed for growth and development and there has been no recurrence at the surgical site at 24 months of corrected age. In this case, high mean airway pressure (MAP) was required based on the patient's weight to achieve adequate recruitment of the left lung, and the patient was diagnosed with mental developmental delay on Bayley Scales of Infant Development-II. Thus, we suggest that the postnatal course and long-term outcomes for extremely low birth weight (ELBW) and preterm infants with left CDH is different from that for full-term babies. Therefore, future research should focus on preterm infants with left CDH.

Morbidity and Mortality of Very Low Birth Weight Infants with Congenital Heart Disease.

BACKGROUND AND OBJECTIVES: This study aimed to provide morbidity and mortality information on very low birth weight (VLBW) infants with congenital heart disease (CHD-VLBWs). METHODS: The study used a 10-year cohort of VLBW infants from a single institution. CHD was classified according to International Classification of Diseases, Version 9, Clinical Modification. Mortality and neonatal outcomes were assessed by comparing the CHD-VLBWs with gestational age- and birth weight-matched controls. RESULTS: The prevalence of CHD-VLBWs was 7.5% (79/1,050), mean gestational age was 31.1±3.2 weeks, and mean birth weight was 1,126.2±268.3 g; 50.6% of the infants were small for the gestational age. The CHD-VLBWs more commonly had bronchopulmonary dysplasia (BPD), and the longer they were exposed to oxygen, the more frequently they developed BPD. Those with cyanotic heart disease developed severe BPD more frequently. Necrotizing enterocolitis (NEC) occurred frequently in the CHD-VLBWs and was not associated with their feeding patterns. CHD-VLBWs had a higher mortality rate; prematurity-related diseases were the leading cause of death before surgery, while heart-related problems were the leading cause of death after surgery. We found no significant difference in mortality from prematurity-related disease between the CHD-VLBWs and controls. In the subgroup analysis of CHD, the cyanotic CHD group had a higher incidence of BPD and higher mortality rate than the acyanotic CHD group. CONCLUSIONS: CHD-VLBWs showed higher BPD, NEC, and mortality rates than those without CHD. There was also a higher incidence of BPD and mortality in VLBW infants with cyanotic CHD than in those with acyanotic CHD.

The predictors for the non-compliance to follow-up among very low birth weight infants in the Korean neonatal network.

The critical need to emphasize preterm infant follow-up after neonatal intensive care unit (NICU) discharge assures early identification of and intervention for neurodevelopmental disability. The aims of this study were to observe the follow-up rates in high-risk follow-up clinics, and analyze factors associated with non-compliance to follow-up among very low birth weight (VLBW) infants. The data was prospectively collected for 3063 VLBW infants between January 2013 and December 2014 from 57 Korean neonatal network (KNN) centers at a corrected age of 18-24 months. Correlations among demographic data, clinical variables, and neonatal intensive care unit (NICU) volume (divided into 4 quartiles) with the occurrence of non-compliance were analyzed. The overall follow-up rate at the corrected age of 18-24 month was 65.4%. The follow-up rates were inversely related to birth weight and gestational age. Apgar score, hospital stay, maternal age, and maternal education were significantly different between the compliance and non-compliance groups. The follow-up rate was higher for mothers with chorioamnionitis, abnormal amniotic fluid, multiple pregnancy, and in vitro fertilization. Infants with respiratory distress syndrome, bronchopulmonary dysplasia, patent ductus arteriosus ligation, periventricular leukomalacia, and retinopathy of prematurity were more common in the compliance group. Follow-up rates showed significant differences according to NICU volume. Using multivariate logistic regression, high birth weight, low NICU volume, siblings, foreign maternal nationality and high 5 min APGAR scores were significant independent factors associated with the non-compliance of VLBW infants for follow-up at 18-24 months of age. This is the first nation-wide analysis of follow-up for VLBW infants in Korea. Understanding factors associated with failure of compliance could help improve the long-term follow-up rates and neurodevelopmental outcomes through early intervention.

Case of mucinous adenocarcinoma of the lung associated with congenital pulmonary airway malformation in a neonate.

Congenital pulmonary airway malformation (CPAM), previously known as congenital cystic adenomatoid malformation, is a rare developmental lung abnormality associated with rhabdomyosarcoma, pleuropulmonary blastoma, and mucinous adenocarcinoma of the lung. We report an unusual case of a 10-day-old male newborn with a left lower lobe pulmonary cyst who underwent lobectomy, which revealed type II CPAM complicated by multifocal mucinous adenocarcinoma. KRAS sequencing revealed a somatic mutation in Codon12 (GGT → GAT), suggesting the development of a mucinous adenocarcinoma in the background of mucinous metaplasia. Mucinous adenocarcinoma is the most common lung tumor associated with CPAM, but it generally occurs in older children and adults. Further, all cases in the literature are of type I CPAM. This case in a neonate indicates that malignant transformation can occur very early in type II CPAM.

Transthoracic catheter drainage for large symptomatic congenital pulmonary airway malformation.

BACKGROUND: Surgical resection of large symptomatic congenital pulmonary airway malformation (CPAM) in newborns has high risks of mortality and postoperative morbidity. This study aimed to report the clinical outcomes of newborns who underwent percutaneous transthoracic catheter drainage (PTCD) of large symptomatic CPAM before surgical resection. METHODS: This was a retrospective, descriptive study based on review of the medical records of newborn infants who required surgical resection of large symptomatic CPAM at a single tertiary hospital from 2001 to 2017. The clinical outcomes were compared between patients who underwent surgical resection following PTCD (PTCD group) and those who underwent surgical resection alone (non-PTCD group). RESULTS: A total of 17 newborns were included. PTCD was performed in seven cases; the median age at the time of the initial PTCD was 4 days (range, 0-20 days). Following PTCD in all cases, chest radiograph demonstrated a dramatic reduction in the sizes of the cysts and improvement of mediastinal shift and the Alveolar-arterial oxygen difference decreased. The median duration between initial PTCD and surgery was 4 days (range, 2-33 days). PTCD-related complications included pneumothorax (n = 2), catheter displacement (n = 1), and failure to drain (n = 1). Compared with the non-PTCD group (6 of 10), the PTCD group had a tendency toward lower rates of postoperative complications (1 of 7). CONCLUSION: PTCD can be an effective interim management for symptomatic newborn infants who require emergency surgical resection of large CPAM.

Retinopathy of Prematurity among Very-Low-Birth-Weight Infants in Korea: Incidence, Treatment, and Risk Factors.

This study was conducted to describe the incidence, risk factors, and current treatment status of retinopathy of prematurity (ROP) in very-low-birth-weight (VLBW) infants registered in the Korean Neonatal Network database. Medical records of 2,009 VLBW infants born between January 2013 and June 2014 who underwent examination by an ophthalmologist were reviewed. The total incidence of ROP was 34.1%. Of the patients, 11.6% showed ROP stage ≥ 3 and 11.5% received treatment of VLBW. Among all infants who received treatment of ROP, 63.6% underwent operation only; 16.9%, anti-vascular endothelial growth factor (anti-VEGF) treatment only; and 19.5%, both operation and anti-VEGF treatment. The mean gestational age (GA) and birth weight (BW) were significantly lower and the prevalence rates of respiratory distress syndrome, patent ductus arteriosus (PDA), invasive ventilator duration, and sepsis were significantly higher in the VLBW infants with ROP than in those without ROP. In the multivariable logistic regression analysis, PDA (odd ratio [OR], 2.1; 95% confidence interval [CI], 1.11-3.79) and invasive ventilator duration (OR, 1.0; 95% CI, 1.00-1.02) were significant risk factors of ROP and ROP stage ≥ 3. In conclusion, the high incidence of ROP is associated with low GA and BW, and attempt to reduce the aforementioned risk factors could reduce the incidence of ROP stage ≥ 3 in VLBW infants.

Delayed Dexamethasone Therapy and Neurodevelopmental Outcomes in Preterm Infants with Bronchopulmonary Dysplasia.

BACKGROUND: It remains unclear whether the benefit of postnatal corticosteroid as a respiratory rescue therapy outweighs the potential harm of neurodevelopmental impairment (NDI) in very-low-birth-weight infants at risk of bronchopulmonary dysplasia (BPD). METHODS: We reviewed the charts of very-low-birth-weight infants with oxygen dependency for 28 days or more and who survived until 18-22 months' corrected age. Patients were divided into the delayed (≥21 days after birth) dexamethasone therapy (DDT, n=71) and the control (n=60) groups. NDI was defined by the presence of cerebral palsy, Bayley Mental or Psychomotor Developmental Index less than 70, deafness, or blindness. RESULTS: The DDT group was more premature and had worse respiratory morbidities before (ventilator-dependent at 21 days, 69% vs. 17%) and after the DDT (moderate/severe BPD, 41% vs. 15%) than the control group. The risk of NDI did not differ between the DDT and the control groups in the entire cohort (odds ratio and 95% confidence interval, 1.309 [0.530-3.237]) or in the propensity-score-matched cohort (n=62; odds ratio and 95% confidence interval, 1.344 [0.455-3.976]). However, in the subgroup of infants exposed to DDT, the cumulative dexamethasone dose greater than 5.0 mg/kg was significantly associated with NDI. CONCLUSION: Among the very-low-birth-weight infants with BPD, there was no definitely harmful effect of DDT on the neurodevelopmental outcome in the short term. However, considering the potential harm of high cumulative doses of dexamethasone on the developing brain, further studies are needed to determine the optimal dosage of DDT to be administered for the prevention of BPD.

Prenatal diagnosis of atrial isomerism in the Korean population.

OBJECTIVE: To report our experiences in the prenatal diagnosis of atrial isomerism and postnatal outcomes. METHODS: A total of 80 fetuses prenatally diagnosed with atrial isomerism were retrospectively analyzed between 1999 and 2011 at a single institution. RESULTS: Of 43 fetuses with prenatally diagnosed right atrial isomerism (RAI), 40 cases were analyzed. The diagnostic accuracy was 93%. The main intracardiac anomalies in RAI were atrioventricular septal defect (AVSD), abnormal pulmonary venous connection, bilateral superior vena cava (BSVC), and pulmonary atresia. Among 28 live births, three infants were lost to follow up, and the overall survival rate was 60%. Of 37 fetuses with prenatally diagnosed left atrial isomerism (LAI), 35 were evaluated. The diagnostic accuracy was 97%. The main intracardiac anomalies in LAI were ventricular septal defect, BSVC, AVSD, double outlet right ventricle, and bradyarrhythmia. Among seven patients with bradyarrhythmia, only one showed a complete atrioventricular block. All fetuses had an interrupted inferior vena cava with azygous continuation. The overall survival rate was 90%. CONCLUSION: Our study confirms the previous findings of fetal atrial isomerism. We also demonstrates a much lower prevalence of AVSD and complete heart block in LAI and a better survival rate in RAI. Although the postnatal outcomes for RAI were worse than those for LAI, successful postnatal surgery with active management improved the survival rate.

Prenatal diagnosis of common arterial trunk: a single-center's experience.

INTRODUCTION: To report our experience in fetuses prenatally diagnosed with common arterial trunk (CAT) and to evaluate the postnatal outcomes. MATERIAL AND METHODS: This was a retrospective study conducted at Asan Medical Center, Seoul, Korea, between 2003 and 2012. Maternal medical and fetal echocardiographic records regarding fetuses were prenatally diagnosed with CAT were reviewed. Postnatal outcomes of survivors were also assessed during the mean follow-up of 36 months. RESULTS: Of the 17 fetuses that were prenatally diagnosed with CAT and had a final diagnosis by postnatal echocardiography or autopsy, 12 were confirmed to have CAT and 5 were incorrectly diagnosed with CAT. Of the latter, 3 had pulmonary atresia and 2 had aortic atresia. The diagnostic accuracy was 71%. The median gestational age at prenatal diagnosis of confirmed CAT was 24.4 weeks (range 21.1-34.3). The truncal valve was prenatally thickened in 8 fetuses. All but 1 of the 12 confirmed CAT cases had associated heart and/or extracardiac anomalies. Of the 8 liveborn cases of postnatally confirmed CAT, 2 died before or after surgery respectively. The remaining 6 remained alive after successful corrective surgery. CONCLUSION: Prenatal diagnosis of CAT can be difficult in some cases and other diseases should be excluded before diagnosing CAT. Isolated CAT can be repaired by postnatal corrective surgery with a good outcome.

A simplified formula using early blood gas analysis can predict survival outcomes and the requirements for extracorporeal membrane oxygenation in congenital diaphragmatic hernia.

The aims of this study were to investigate whether early arterial blood gas analysis (ABGA) could define the severity of disease in infants with congenital diaphragmatic hernia (CDH). We conducted a retrospective study over a 21-yr period of infants diagnosed with CDH. Outcomes were defined as death before discharge, and extracorporeal membrane oxygenation requirements (ECMO) or death. A total 114 infants were included in this study. We investigated whether simplified prediction formula [PO2-PCO2] values at 0, 4, 8, and 12 hr after birth were associated with mortality, and ECMO or death. The area under curve (AUC) of receiver operating characteristic curve was used to determine the optimum ABGA values for predicting outcomes. The value of [PO2-PCO2] at birth was the best predictor of mortality (AUC 0.803, P < 0.001) and at 4 hr after birth was the most reliable predictor of ECMO or death (AUC 0.777, P < 0.001). The value of [PO2-PCO2] from ABGA early period after birth can reliably predict outcomes in infants with CDH.

Embolization versus surgical resection of pulmonary sequestration: clinical experiences with a thoracoscopic approach.

PURPOSE: The goal of this study was to compare the safety and efficacy of treatment for pulmonary sequestration (PS) by transcatheter arterial embolization (TAE) versus surgical resection and to consider the role of a thoracoscopic approach. METHODS: A retrospective review involving 73 children (≤ 15 years of age) with PS between 2002 and 2011 was performed. RESULTS: Forty-two patients were managed with TAE, and 31 underwent surgery alone. Their presenting symptoms were pneumonia (n=11), pneumothorax (n=2), pneumomediastinum (n=1) and respiratory distress (n=6).Fifty-three (72.6%) were asymptomatic. The average age at treatment was 17.0 ± 44.4 and 31.3 ± 41.7 months for the TAE and surgery groups, respectively. In the TAE group, complete regression was observed in only 3 patients, 4 showed no regression, and 35 (83.3%) had residual lesions. Four patients developed sepsis or other blood vessel complications after TAE. The results of resection via thoracotomy versus a thoracoscopic approach were evaluated in 34 patients, including 3 who underwent the operation after TAE. Twenty-seven patients underwent thoracotomy, and 7 underwent thoracoscopic resection. There were no significant differences between the groups except time to chest tube removal, which was shorter in the thoracoscopic group (p=0.046). Complications included a wound infection in 1 patient after thoracotomy. CONCLUSIONS: We believe that even in asymptomatic patients, all PSs should be resected because of the risk of infection, the low rate of natural regression, complications after TAE, and to exclude other pathology. Our experience also shows that thoracoscopic resection of PS is feasible, efficacious, and safe in newborns and infants.

A case of campomelic dysplasia without sex reversal.

Campomelic dysplasia (CD; OMIM #114290), a rare form of congenital short-limbed dwarfism, is due to mutations in SOX9, a member of the SOX (SRY-related HMG box) gene family. Multiparous mother at 38 weeks' gestation delivered a 3,272 g baby boy with characteristic phenotypes including bowing of the lower limbs, a narrow thoracic cage, 11 pairs of ribs, hypoplastic scapulae, macrocephaly, flattened supraorbital ridges and nasal bridge, cleft palate, and micrognathia. He underwent a tracheostomy at the age of three months for severe laryngomalacia after a number of repeated hospitalizations due to respiratory problems and died at the age of four months from progressive respiratory failure. He was diagnosed as having CD based on a novel frameshift mutation (p.Gln458ArgfsX12) in the SOX9 gene, the mutation which has not yet been reported in Korea.

Collateral ventilation to congenital hyperlucent lung lesions assessed on xenon-enhanced dynamic dual-energy CT: an initial experience.

OBJECTIVE: We wanted to evaluate the resistance to collateral ventilation in congenital hyperlucent lung lesions and to correlate that with the anatomic findings on xenon-enhanced dynamic dual-energy CT. MATERIALS AND METHODS: Xenon-enhanced dynamic dual-energy CT was successfully and safely performed in eight children (median age: 5.5 years, 4 boys and 4 girls) with congenital hyperlucent lung lesions. Functional assessment of the lung lesions on the xenon map was done, including performing a time-xenon value curve analysis and assessing the amplitude of xenon enhancement (A) value, the rate of xenon enhancement (K) value and the time of arrival value. Based on the A value, the lung lesions were categorized into high or low (A value > 10 Hounsfield unit [HU]) resistance to collateral ventilation. In addition, the morphologic CT findings of the lung lesions, including cyst, mucocele and an accessory or incomplete fissure, were assessed on the weighted-average CT images. The xenon-enhanced CT radiation dose was estimated. RESULTS: Five of the eight lung lesions were categorized into the high resistance group and three lesions were categorized into the low resistance group. The A and K values in the normal lung were higher than those in the low resistance group. The time of arrival values were delayed in the low resistance group. Cysts were identified in five lesions, mucocele in four, accessory fissure in three and incomplete fissure in two. Either cyst or an accessory fissure was seen in four of the five lesions showing high resistance to collateral ventilation. The xenon-enhanced CT radiation dose was 2.3 ± 0.6 mSv. CONCLUSION: Xenon-enhanced dynamic dual-energy CT can help visualize and quantitate various degrees of collateral ventilation to congenital hyperlucent lung lesions in addition to assessing the anatomic details of the lung.

Effect of furosemide on ductal closure and renal function in indomethacin-treated preterm infants during the early neonatal period.

BACKGROUND: Furosemide is known to increase renal prostaglandin synthesis. However, its influence on ductal closure and renal toxicities of indomethacin in preterm infants has not been conclusive, especially during the early neonatal period. OBJECTIVES: To identify the effects of furosemide after indomethacin administration on the rate of patent ductus arteriosus (PDA) closure and renal function in preterm infants. METHODS: 68 infants (gestational age <34 weeks and birth weight <2,000 g) receiving indomethacin therapy (one course: 0.2-0.1-0.1 mg/kg q 12 h, mostly started <48 h after birth) were randomly assigned to the furosemide (n = 35) or control (n = 33) group. Each indomethacin dose was followed by furosemide (1.0 mg/kg) or placebo. The primary (PDA closure) and secondary (acute renal failure (ARF) and others) outcomes were assessed. Renal parameters before and 0-12 and 24-36 h after the first course of indomethacin were also investigated. RESULTS: In an intention-to-treat analysis, there were no differences in the PDA closure rate between the furosemide (29/34) and the control (27/29) group (p = 0.437). The incidence of ARF (serum creatinine >1.6 mg/dl) was greater in the furosemide group (20/34) than in the control group (3/29) (p < 0.001). Compared with the control group, serum creatinine and cystatin C levels and fractional excretion of sodium were significantly increased in the furosemide group for 24-36 h after indomethacin therapy (p < 0.01). There were no between-group differences in mortality and other neonatal morbidity rates. CONCLUSIONS: Use of furosemide in combination with indomethacin increased the incidence of ARF but did not affect the PDA closure rate in preterm infants.

Neonatal pulmonary sequestration: clinical experience with transumbilical arterial embolization.

Pulmonary sequestration (PS) is a rare congenital malformation of the lower respiratory tract. The exact natural course of PS is not well understood and there are no well-established treatment guidelines for antenatally diagnosed PS. The aim of this study was to describe clinical outcomes in neonates with PS and to evaluate the efficacy of transumbilical arterial embolization (TUE). From 1998 to 2006, total 30 neonatal cases were included. Serial antenatal ultrasound in 26 cases found 6 (23%) regressed lesions, all of which were demonstrated on postnatal chest CT. Six (20%) cases were classified as mixed-type (combined cystic) lesions. Surgery was performed early (during initial hospitalization) in two cases and lately (after the neonatal period) in four cases. TUE was performed for 17 (57%) cases of intrapulmonary PS. Follow-up images obtained a median of 19 months (range, 4-51) after TUE demonstrated complete (9, 53%), partial (5, 29%), and no (3, 18%) regression. The regression rate was significantly higher in solid-type lesions (13/13, 100%) than in mixed-type (1/4, 25%) (P = 0.006). Complications included transient hypertension (two cases, 12%), post-embolization fever (two cases, 12%) and migration of a microcoil (one case, 6%), without long-term morbidities. Natural courses could be observed in 10 cases of extralobar PS and regression was observed in 2 cases (20%) during a median follow-up of 12 months (range, 6-45). A well-designed comparative study is warranted to evaluate the long-term efficacy and safety of TUE.