Successful Postnatal Tracheobronchoplasty for Unilateral Congenital High Airway Obstruction Syndrome (CHAOS) due to Mainstem Bronchial Atresia.

INTRODUCTION: Unilateral congenital high airway obstruction syndrome (CHAOS) is caused by a complete obstruction of a mainstem bronchus with resulting hyperinflation and accelerated growth of one lung, severe mediastinal shift and hydrops. Spontaneous perforation of the atresia has been observed in CHAOS which allows hydrops to resolve but hyperinflation, mediastinal shift and a critical airway obstruction persists as the perforation is usually pinhole-sized. CASE PRESENTATION: We present a case of unilateral CHAOS presenting at 26 2/7 weeks' with observed-to-expected total lung volume (O/E TLV) of 203% with spontaneous perforation occurring at 28 weeks' with resolution of hydrops but persistence of hyperinflation and mediastinal shift with an O/E TLV of 60.5% on 34 5/7 weeks' magnetic resonance imaging (MRI), successfully managed in a 35 5/7 weeks', 1670 gm, growth restricted baby, by veno-arterial extracorporeal membrane oxygenation (VA ECMO) and resection of the tracheobronchial atresia and tracheobronchoplasty on day of life 5. The baby was separated from ECMO on post-op day 12, required tracheostomy for positive end expiratory pressure (PEEP) for tracheomalacia at 4 months. CONCLUSION: At two years of age, she has met all developmental milestones, has been weaned to room air tracheostomy collar, and is anticipating tracheal decannulation. There is persistent bronchiectasis in the hyperinflated right lung but no malacia. This is the first reported survivor of mainstem bronchial atresia suggesting the importance of preservation of the hyperplastic lung and airway reconstruction to normal long-term outcome.

Second trimester placenta percreta presenting as acute abdomen.

Diagnosing placenta percreta can be difficult. We describe a 41-year-old woman presenting at 21 weeks' gestation with intraabdominal bleeding and no signs of placental abnormality on ultrasound. The disagreement between results of the ultrasound and magnetic resonance imaging made definitive diagnosis difficult. The bleeding resolved spontaneously after a blood transfusion, and the patient was hospitalized for the remainder of the pregnancy. Delivery was by scheduled repeat cesarean at 34 weeks' gestation. Spontaneous rupture of the entire fundus occurred at the time of delivery. Placenta percreta was confirmed by histologic examination of the operatively excised uterus.

Forests, fields, and the edge of sustainability at the ancient Maya city of Tikal.

Tikal has long been viewed as one of the leading polities of the ancient Maya realm, yet how the city was able to maintain its substantial population in the midst of a tropical forest environment has been a topic of unresolved debate among researchers for decades. We present ecological, paleoethnobotanical, hydraulic, remote sensing, edaphic, and isotopic evidence that reveals how the Late Classic Maya at Tikal practiced intensive forms of agriculture (including irrigation, terrace construction, arboriculture, household gardens, and short fallow swidden) coupled with carefully controlled agroforestry and a complex system of water retention and redistribution. Empirical evidence is presented to demonstrate that this assiduously managed anthropogenic ecosystem of the Classic period Maya was a landscape optimized in a way that provided sustenance to a relatively large population in a preindustrial, low-density urban community. This landscape productivity optimization, however, came with a heavy cost of reduced environmental resiliency and a complete reliance on consistent annual rainfall. Recent speleothem data collected from regional caves showed that persistent episodes of unusually low rainfall were prevalent in the mid-9th century A.D., a time period that coincides strikingly with the abandonment of Tikal and the erection of its last dated monument in A.D. 869. The intensified resource management strategy used at Tikal-already operating at the landscape's carrying capacity-ceased to provide adequate food, fuel, and drinking water for the Late Classic populace in the face of extended periods of drought. As a result, social disorder and abandonment ensued.

Model of magnetically guided fetal cardiac intervention: potential to avoid direct cardiac puncture.

OBJECTIVE: Fetal cardiac interventions are performed via direct cardiac puncture and are associated with significant fetal morbidity. The feasibility of utilizing magnetic navigation to maneuver a guide wire and balloon across a fetal aortic valve without direct cardiac puncture is tested. METHODS: A fetal heart model was manufactured and placed in a catheterization laboratory equipped with magnetic navigation. Magnetically steerable guide wires along with commercially available coronary balloons were inserted into the model at a site mimicking a hepatic vein. RESULTS: Passage of the wire and balloon was achieved on every attempt. The model was suitable for testing although the structural characteristics of the model made wire passage from the right to the left atrium the most challenging aspect. Once the wire was positioned in the left ventricle, it was easily maneuvered 180 degrees towards the left ventricular outflow tract and then the descending aorta. Advancement of a coronary balloon over this wire was uncomplicated. CONCLUSION: In a fetal heart model, it is feasible to deliver a wire and balloon from abdominal venous access antegrade across the aortic valve. Progression to fetal lamb models is planned and may advance fetal cardiac interventions by reduction of fetal morbidity.

MRI calculation of lung volumes to predict outcome in fetuses with genitourinary abnormalities.

OBJECTIVE: The purpose of our study was to evaluate MRI total lung volumes (TLV) for predicting outcome in fetuses with genitourinary abnormalities and to compare lung volumes with the presence or absence of oligohydramnios. MATERIALS AND METHODS: Fetuses with genitourinary abnormalities underwent blinded retrospective calculation of TLV. Distribution of the TLV-gestational age ratios for survivors and nonsurvivors were compared using the Wilcoxon's rank sum test. Lung volume calculation was compared with the presence or absence of oligohydramnios. RESULTS: There were 21 survivor and 24 nonsurvivor outcomes based on neonatal discharge. TLV-gestational age ratios were significantly different between the survivor and nonsurvivor groups (p = 0.0001). No apparent difference was seen until after 26 weeks of gestation. TLV-gestational age ratios were equal to the presence or absence of oligohydramnios in predicting outcome after 26 weeks of gestation. CONCLUSION: After 26 weeks' gestation, the prediction of outcome in fetal genitourinary abnormalities using the MRI TLV-gestational age ratio is comparable to the presence or absence of oligohydramnios.

MRI of fetal genitourinary anomalies.

OBJECTIVE: The objective of our study was to show examples of fetal MRI evaluations of congenital genitourinary anomalies and to review the embryology in relation to the MRI findings. CONCLUSION: MRI was performed on 35 pregnant women with sonographic findings that suggested that their fetuses had genitourinary anomalies. Oligohydramnios or anhydramnios was identified in 22 of 35 women and did not hinder visualization of anomalies. MRI allowed the amniotic fluid and the presence, location, and morphology of kidneys and bladder to be assessed in all fetuses at any stage of gestation and depicted sufficient anatomic detail for us to evaluate the perineum in 27 of 35 pregnancies. Therefore, we found MRI to be an excellent technique for revealing the anatomy of genitourinary anomalies in the fetus.

Fetal central nervous system biometry on MR imaging.

OBJECTIVE: We sought to compare the biometry of the fetal head on MR imaging with sonographic measurements in fetuses with and without suspected central nervous system abnormalities. MATERIALS AND METHODS: Blinded retrospective measurements of biparietal diameter, head circumference, and cerebellar width obtained on MR imaging were assigned a gestational age on the basis of median sonographic measurements and compared with sonographic and clinical assignment of gestational age in fetuses with no central nervous system abnormalities. In fetuses with central nervous system abnormalities, the same MR measurements were compared with sonographic measurements obtained within 1 week. Single-shot fast spin-echo sequences were obtained. Pearson's product moment correlation coefficients and paired sample t tests were performed. RESULTS: In 22 fetuses with no suspected central nervous system abnormalities, significant correlation was seen in the assignment of gestational age by MR measurements and sonographic gestational age. In 25 fetuses with central nervous system abnormalities, significant correlation was also seen between biparietal diameter and head circumference measurements. The mean biparietal diameter on MR imaging was greater than on sonography in those fetuses with central nervous system abnormalities (p = 0.038). CONCLUSION: MR imaging measurements of biparietal diameter, head circumference, and cerebellar width are strongly correlated to gestational age in fetuses without central nervous system abnormalities. Significant correlation is found between MR imaging and sonographic measurements of biparietal diameter and head circumference in fetuses with central nervous system abnormalities. Larger biparietal diameter measurements were seen with MR imaging than with sonography in the abnormal group. Fetal central nervous system biometry can be performed as part of the MR imaging evaluation of the fetal central nervous system.

Second-opinion magnetic resonance imaging for suspected fetal central nervous system abnormalities.

OBJECTIVE: The purpose of this study was to evaluate the relationship of magnetic resonance imaging and gestational age in the setting of fetuses with suspected abnormalities of the central nervous system that were detected by ultrasound scanning. STUDY DESIGN: Multiplanar magnetic resonance studies were performed in fetuses with suspected central nervous system abnormalities on ultrasound scanning. Magnetic resonance imaging was evaluated for its ability to provide additional information, change the diagnosis, or impact obstetric treatment. Patients were grouped by gestational age at the time of magnetic resonance imaging. RESULTS: Magnetic resonance imaging provided additional information in 46 of 72 pregnancies (64%), changed the diagnosis in 20 of 72 pregnancies (28%), and potentially altered the timing or mode of delivery in 8 of 72 pregnancies (11%). Additional information increased with increasing gestational age groups (P =.03). CONCLUSION: Magnetic resonance imaging provided additional information in two thirds of the fetuses with central nervous system abnormalities, which was significantly increased with increasing gestation. Antenatal treatment was influenced by magnetic resonance imaging in 11% of the cases.

Fetal central nervous system ventricle and cisterna magna measurements by magnetic resonance imaging.

OBJECTIVE: Our purpose was to evaluate the ventricular atria and cisterna magna in fetuses with and without suspected central nervous system (CNS) anomalies by magnetic resonance (MR). STUDY DESIGN: Measurements of the right and left ventricular atria and cisterna magna were obtained by MR in two groups: those with and without CNS anomalies. Published mean ultrasound measurements of the far field atrium were compared with MR. RESULTS: MR measurements were obtained in 23 fetuses without and 37 fetuses with CNS anomalies. Atrial measurements were independent of gestational age in healthy subjects. MR atrial widths were larger in abnormal compared with normal subjects (P <.05). The atrial cutoff value derived by 2 SDs above the mean with MR is 10 mm. MR cisterna magna measurements increased with gestational age (P =.005). CONCLUSION: The cutoff value for ventriculomegaly on MR is >10 mm. MR cisterna magna measurements are dependent on gestational age. Both ventricular atria and cisterna magna are readily measured with MR.