Irving J. Zamora

Fetal lung volume and quantification of liver herniation by magnetic resonance imaging in isolated congenital diaphragmatic hernia.

To determine associations between fetal lung and liver herniation volumes measured by magnetic resonance imaging (MRI) and mortality/need for extracorporeal membrane oxygenation (ECMO) in cases of isolated congenital diaphragmatic hernia (CDH). A secondary objective was to compare prenatal MRI parameters with two‐dimensional ultrasound lung measurements.

Prenatal MRI Fetal Lung Volumes and Percent Liver Herniation Predict Pulmonary Morbidity in Congenital Diaphragmatic Hernia (CDH)

PURPOSE The purpose of this study was to determine whether prenatal imaging parameters are predictive of postnatal CDH-associated pulmonary morbidity. METHODS The records of all neonates with CDH treated from 2004 to 2012 were reviewed. Patients requiring supplemental oxygen at 30 days of life (DOL) were classified as having chronic lung disease (CLD). Fetal MRI-measured observed/expected total fetal lung volume (O/E-TFLV) and percent liver herniation (%LH) were recorded. Receiver operating characteristic (ROC) curves and multivariate regression were applied to assess the prognostic value of O/E-TFLV and %LH for development of CLD. RESULTS Of 172 neonates with CDH, 108 had fetal MRIs, and survival was 76%. 82% (89/108) were alive at DOL 30, 46 (52%) of whom had CLD. Neonates with CLD had lower mean O/E-TFLV (30 vs.42%; p=0.001) and higher %LH (21.3±2.8 vs.7.1±1.8%; p<0.001) compared to neonates without CLD. Using ROC analysis, the best cutoffs in predicting CLD were an O/E-TFLV<35% (AUC=0.74; p<0.001) and %LH>20% (AUC=0.78; p<0.001). On logistic regression, O/E-TFLV<35% and a %LH>20% were highly associated with indicators of long-term pulmonary sequelae. On multivariate analysis, %LH was the strongest predictor of CLD in patients with CDH (OR: 10.96, 95%CI: 2.5-48.9, p=0.002). CONCLUSION Prenatal measurement of O/E-TFLV and %LH is predictive of CDH pulmonary morbidity and can aid in establishing parental expectations of postnatal outcomes.

Repair of congenital diaphragmatic hernias on Extracorporeal Membrane Oxygenation (ECMO): Does early repair improve patient survival?

INTRODUCTION The optimal timing of repair for congenital diaphragmatic hernia (CDH) patients that require ECMO is controversial. Early repair on ECMO theoretically allows for restoration of normal thoracic anatomy but entails significant bleeding risks. The purpose of this study was to examine the institutional outcomes of early CDH repair on ECMO. METHODS The records of infants with CDH placed on ECMO from 2001 to 2011 were reviewed. Since 2009, a protocol was instituted for early repair while on ECMO. For this study, three cohorts were analyzed: early repair (<72 h), late repair (>72 h), and post-decannulation. These groups were compared for outcomes regarding morbidity and survival. RESULTS Forty-six CDH patients received ECMO support with an overall survival of 53%. Twenty-nine patients (11 early/18 late) were repaired on ECMO, while 17 patients had repair post-decannulation. Survival was 73%, 50%, and 64% for those repaired early, late, or post-decannulation, respectively. Despite significantly worse prenatal factors, patients repaired early on ECMO had a similar survival. When comparing patients repaired on ECMO, the early group patients were decannulated 6 days earlier (p-value=0.009) and had significantly lower circuit complications (p=0.03). CONCLUSION In conclusion, early repair on ECMO was associated with decreased ECMO duration, decreased circuit complications, and a trend towards improved survival.

Abdominal near-infrared spectroscopy measurements are lower in preterm infants at risk for necrotizing enterocolitis.

Objective: Near-infrared spectroscopy is a noninvasive method of measuring local tissue oxygenation (StO2). Abdominal StO2 measurements in preterm piglets are directly correlated with changes in intestinal blood flow and markedly reduced by necrotizing enterocolitis. The objectives of this study were to use near-infrared spectroscopy to establish normal values for abdominal StO2 in preterm infants and test whether these values are reduced in infants who develop necrotizing enterocolitis. Design: We conducted a 2-year prospective cohort study where we prospectively measured abdominal StO2 in preterm infants, to establish reference values for preterm infants, and compared the near-infrared spectroscopy values with preterm infants in the cohort that developed necrotizing enterocolitis. Setting: Two neonatal ICUs: one at Texas Children’s Hospital and the other at Ben Taub General Hospital in Houston, TX. Patients: We enrolled 100 preterm infants (< 32 weeks’ gestation and < 1,500 g birth weight) between January 2007 and November 2008. Interventions: None. Measurements and Main Results: Eight neonates with incomplete data were excluded. Mean abdominal StO2 in normal preterm infants (n = 78) during the first week of life was significantly higher than in those who later developed necrotizing enterocolitis (n = 14) (77.3% ± 14.4% vs 70.7% ± 19.1%, respectively, p = 0.002). An StO2 less than or equal to 56% identified preterm infants progressing to necrotizing enterocolitis with 86% sensitivity, 64% specificity, 96% negative predictive value, and 30% positive predictive value. Using logistic regression, StO2 less than or equal to 56% was independently associated with a significantly increased risk of necrotizing enterocolitis (odds ratio, 14.1; p = 0.01). Furthermore, infants with necrotizing enterocolitis demonstrated significantly more variation in StO2 both during and after feeding in the first 2 weeks of life. Conclusions: This study establishes normal values for abdominal StO2 in preterm infants and demonstrates decreased values and increased variability in those with necrotizing enterocolitis. Abdominal near-infrared spectroscopy monitoring of preterm infants may be a useful tool for early diagnosis and guiding treatment of necrotizing enterocolitis.

Fetal MRI lung volumes are predictive of perinatal outcomes in fetuses with congenital lung masses.

PURPOSE The purpose of this study was to evaluate fetal magnetic resonance imaging (MRI) as a modality for predicting perinatal outcomes and lung-related morbidity in fetuses with congenital lung masses (CLM). METHODS The records of all patients treated for CLM from 2002 to 2012 were reviewed retrospectively. Fetal MRI-derived lung mass volume ratio (LMVR), observed/expected normal fetal lung volume (O/E-NFLV), and lesion-to-lung volume ratio (LLV) were calculated. Multivariate regression and receiver operating characteristic analyses were applied to determine the predictive accuracy of prenatal imaging. RESULTS Of 128 fetuses with CLM, 93% (n=118) survived. MRI data were available for 113 fetuses. In early gestation (<26weeks), MRI measurements of LMVR and LLV correlated with risk of fetal hydrops, mortality, and/or need for fetal intervention. In later gestation (>26weeks), LMVR, LLV, and O/E-NFLV correlated with neonatal respiratory distress, intubation, NICU admission and need for neonatal surgery. On multivariate regression, LMVR was the strongest predictor for development of fetal hydrops (OR: 6.97, 1.58-30.84; p=0.01) and neonatal respiratory distress (OR: 12.38, 3.52-43.61; p≤0.001). An LMVR >2.0 predicted worse perinatal outcome with 83% sensitivity and 99% specificity (AUC=0.94; p<0.001). CONCLUSION Fetal MRI volumetric measurements of lung masses and residual normal lung are predictive of perinatal outcomes in fetuses with CLM. These data may assist in perinatal risk stratification, counseling, and resource utilization.

EXIT-to-resection for fetuses with large lung masses and persistent mediastinal compression near birth

PURPOSE To identify prenatal diagnostic features that will help select fetuses with lung masses (LM) who may benefit from ex-utero intrapartum treatment (EXIT procedure) as the preferred mode of delivery. METHODS The CCAM-volume ratio (CVR), fetal treatment, and outcomes of all fetuses with LM evaluated between 2001 and 2011 were reviewed retrospectively. Fetuses with hydrops or CVR>1.6 were classified as high risk. Indications for fetal interventions included hydrops and heart failure, and indication for EXIT-to-resection was the finding of persistent mediastinal compression (PMC) near birth. RESULTS Of 110 fetuses evaluated for LM, 78 were classified as low-risk. No fetus in this group had PMC near birth and none required perinatal treatment. Of 32 high-risk fetuses, 8 developed heart failure of which 4 survived (3 following fetal surgery). Nine high-risk fetuses with no PMC near birth were asymptomatic postnatally and treated electively. Sixteen high-risk fetuses had PMC near birth. All 9 babies with PMC treated with EXIT-to-resection did well with discharge at a median of 10 days post-operatively. All 7 fetuses treated without an EXIT developed respiratory distress following birth requiring an urgent operation; 2 died. CONCLUSION The EXIT-to-resection procedure is a favorable delivery approach for those fetuses with large LM and PMC near birth.

Vitamin E in New-Generation Lipid Emulsions Protects Against Parenteral Nutrition-Associated Liver Disease in Parenteral Nutrition-Fed Preterm Pigs

INTRODUCTION Parenteral nutrition (PN) in preterm infants leads to PN-associated liver disease (PNALD). PNALD has been linked to serum accumulation of phytosterols that are abundant in plant oil but absent in fish oil emulsions. HYPOTHESIS Whether modifying the phytosterol and vitamin E composition of soy and fish oil lipid emulsions affects development of PNALD in preterm pigs. METHODS We measured markers of PNALD in preterm pigs that received 14 days of PN that included 1 of the following: (1) Intralipid (IL, 100% soybean oil), (2) Intralipid + vitamin E (ILE, d-α-tocopherol), (3) Omegaven (OV, 100% fish oil), or (4) Omegaven + phytosterols (PS, β-sitosterol, campesterol, and stigmasterol). RESULTS Serum levels of direct bilirubin, gamma glutamyl transferase, serum triglyceride, low-density lipoprotein, and hepatic triglyceride content were significantly lower (P < .05) in the ILE, OV, and PS compared to IL. Hepatic cholesterol 7-hydroxylase and organic solute transporter-α expression was lower (P < .05) and portal plasma FGF19 higher in the ILE, OV, and PS vs IL. Hepatic expression of mitochondrial carnitine palmitoyltransferase 1A and microsomal cytochrome P450 2E1 fatty acid oxidation genes was higher in ILE, OV, and PS vs IL. In vivo (13)C-CDCA clearance and expression of pregnane X receptor target genes, cytochrome P450 3A29 and multidrug resistance-associated protein 2, were higher in ILE, OV, and PS vs IL. CONCLUSIONS α-tocopherol in Omegaven and added to Intralipid prevented serum and liver increases in biliary and lipidemic markers of PNALD in preterm piglets. The addition of phytosterols to Omegaven did not produce evidence of PNALD.

Water-Absorbing Balls: A “Growing” Problem

Foreign body ingestion is a potentially serious clinical problem in children. We report a case of an 8-month-old infant who developed complete bowel obstruction requiring laparotomy due to ingestion of a superabsorbent polymer ball with advertised growth up to 400 times its original size. Most ingested foreign bodies that pass through the pylorus will make it safely through the gastrointestinal tract. This is not true for water-absorbing balls that progressively increase in size and cause intestinal obstruction. Other household products and toys on the market use a similar polymer-based water-absorbing technology, thus increasing the risk for accidental ingestion by young children. These rapidly expanding objects can cause significant morbidity, and timely diagnosis and treatment are prudent to improve patient outcomes.

Maternal morbidity and reproductive outcomes related to fetal surgery

PURPOSE The purpose of this manuscript was to examine the maternal morbidity and reproductive outcomes following maternal-fetal surgery with an emphasis on the EXIT procedure. METHODS The medical records of all women who underwent an ex-utero intrapartum treatment (EXIT) procedure or mid-gestation open maternal fetal surgery (OMFS) at our center from December 2001 to December 2011 were reviewed retrospectively. Future reproductive outcomes were obtained via telephone questionnaire. RESULTS Thirty-three women underwent maternal-fetal surgery. Twenty-six had EXIT, and seven had OMFS. The questionnaire response was 82% (27/33). Eighty-one percent (17/21) of the EXIT cohort desired future pregnancy. All who attempted (13/13) were successful. The majority (85%) conceived spontaneously and within 2.5 years on average. In the OMFS group, 40% experienced complications. One had uterine dehiscence, and another had uterine rupture requiring urgent delivery at 36 weeks. In subsequent pregnancies, 20% of OMFS cases were complicated by uterine rupture, and 8% of EXIT patients had uterine dehiscence. All had good maternal-fetal outcome. CONCLUSION Future reproductive capacity and complication rates in subsequent pregnancies following EXIT procedure are similar to those seen in the general population. In contrast, mid-gestation OMFS remains associated with relatively morbid complications. This evidence can help guide in counseling expectant mothers who are faced with the challenge of considering fetal surgery.

Initial experience with single-vessel cannulation for venovenous extracorporeal membrane oxygenation in pediatric respiratory failure.

Objectives: Venovenous extracorporeal membrane oxygenation has been used to provide cardiopulmonary support in critically ill infants and children. Recently, dual-lumen venovenous extracorporeal membrane oxygenation has gained popularity in the pediatric population. Herein, we report our institutional experience using a bicaval dual-lumen catheter for pediatric venovenous extracorporeal membrane oxygenation support, which has been our unified approach for venovenous extracorporeal membrane oxygenation since 2009. Design: This study is a retrospective review. Setting: The setting is a tertiary children’s hospital in a major metropolitan area. Patients: Between 2009 and 2011, 11 patients were cannulated using a dual-lumen bicaval venous catheter. Patient demographics, cannulation details, circuit complications, complications of catheter use, and patient outcomes were collected from a retrospective chart review. Interventions: None. Measurements and Main Results: Eleven of the patients were cannulated for venovenous extracorporeal membrane oxygenation using the dual-lumen bicaval cannula. The median age at the time of venovenous cannulation was 1.9 years (range, 0.14–17.1), and the median weight was 10.2 kg (range, 3–84). Three patients (27%) required conversion to venoarterial extracorporeal membrane oxygenation. The median duration of extracorporeal membrane oxygenation support was 10 days (2–38 days). Fifty-five percent of patients suffered from a bleeding complication (disseminated intravascular coagulation, pulmonary hemorrhage, or intraventricular hemorrhage), and 45% had a circuit complication. Adequate flow rates were achieved in all patients. The overall hospital mortality in the series was 55%. There were no cannula-related complications. Conclusions: This review presents the first single-institution experience with the dual-lumen Avalon cannula in pediatric patients. Preliminary results indicate that the catheter can be safely placed and has an acceptable complication profile; however, continued study within larger trials is necessary to fully ascertain the clinical profile of this catheter.