Papers by christopher cassady
The Food and Drug Administration (FDA) recently issued a request for a product warning label to m... more The Food and Drug Administration (FDA) recently issued a request for a product warning label to manufacturers of magnetic resonance imaging (MRI) contrast agents. Many pediatric practitioners choose magnetic resonance for their patients who require imaging because of its very sensitive display of
American Journal of Obstetrics and Gynecology
Dehiscence of the scar from a prior ruptured uterus in a subsequent pregnancy has significant ris... more Dehiscence of the scar from a prior ruptured uterus in a subsequent pregnancy has significant risk, usually leading to iatrogenic termination of the pregnancy. Elective repair of an enlarging uterine defect in an ongoing pregnancy has not been previously reported. A patient with an extensive uterine dehiscence with membrane exposure, diagnosed at 18 weeks' gestation, underwent a laparotomy and uterine repair using a myometrial imbrication and Gore-tex® patch buttressing technique. The baby was delivered 13 weeks later by scheduled lower segment cesarean section and did well. At delivery the uterine repair was taken down and a formal excision repair of the uterine defect was performed. This innovative approach may offer an alternative to termination of pregnancy in appropriately counseled and selected patients.
Prenatal Diagnosis
Objectives: Dandy-Walker malformation (DWM) is a common cerebellar malformation characterized by ... more Objectives: Dandy-Walker malformation (DWM) is a common cerebellar malformation characterized by vermian hypoplasia with upward rotation, cystic dilatation of the fourth ventricle and elevated torcular. DWM can be diagnosed prenatally by fetal sonogram and/or magnetic resonance imaging (MRI). However, its associated neurodevelopmental abnormalities are variable and difficult to predict in prenatal counseling. We hypothesized that DWM have abnormalities beyond cerebellum and the posterior fossa, which may potentially impact neurodevelopmental variations. Methods: We retrospectively reviewed medical record and fetal MRIs of 15 fetuses with DWM. We performed post-acquisition regional volumetric fetal MRI analysis in 11 fetuses with DWM and 12 control fetuses to measure volumes of cortical plate, subcortical parenchyma, cerebellar hemispheres, and vermis. Growth trajectories between 18 and 33 weeks' gestation in each structure were modeled for each group. A logarithmic transform of the volume data was used before fitting the linear regression model. Intergroup measures were compared using ANCOVA. Results: The median (interquartile range) gestational ages of fetal MRI studies in 11 fetuses with DWM and 12 controls were 22.6 (4.3) weeks and 25.1 (9.2) weeks, respectively (p value = 0.31). Associated abnormal MRI findings were detected in 7 of 11 fetuses with DWM: hydrocephalus (n = 3), cerebral ventriculomegaly (n = 3), complete (n = 2), and partial (n = 2) agenesis of the corpus callosum.
American Journal of Obstetrics and Gynecology
tissue repair. At present, the specific nature of astrocyte reactivity after WMI (A1s, A2s, or ot... more tissue repair. At present, the specific nature of astrocyte reactivity after WMI (A1s, A2s, or other) remains obscure. Given recent findings that A1 formation is induced by reactive microglia and that these astrocytes delay oligodendrocyte differentiation and promote neuronal death, we hypothesize that A1s play a central role in WMI and may be an exciting therapeutic target for this disease. Here we report the results of experiments aimed to investigate the formation of A1 astrocytes in WMI. STUDY DESIGN: WMI was induced in 2 day-old rat pups using a combination of hypoxic-ischemic and inflammatory insults. In situ hybridization with A1especific probes was performed on brain tissue from injured and control neonatal rats. We used immunopanning to purify astrocytes from brains of injured and control rats. mRNA isolated from these cells was used for qRT-PCR analysis. RESULTS: In situ hybridization experiments demonstrate a significant increase in the prevalence of A1 astrocytes in subcortical white matter tracts after WMI in our model. An immunopanning protocol optimized for our disease model yields acutely purified viable primary astrocytes from injured and control rat brains. qRT-PCR using mRNA from these cells reveals regulation of A1-specific transcripts over time after injury. CONCLUSION: We demonstrate the formation of A1 reactive astrocytes in a rodent model of WMI. This result is an important step towards understanding astrocyte polarization in WMI. Should ongoing experiments demonstrate that A1 formation is a pivotal step in WMI pathophysiology, this finding will open the door to new therapeutic strategies for the treatment of WMI.
Prenatal Diagnosis
The ex utero intrapartum treatment (EXIT) is utilized to transition fetuses with prenatally diagn... more The ex utero intrapartum treatment (EXIT) is utilized to transition fetuses with prenatally diagnosed airway obstruction to postnatal life. We describe the unique clinical course, diagnosis, treatment, and outcomes of patients with cervical lymphatic malformation (CLM) managed with EXIT.
Pediatric radiology, Jan 25, 2018
The original version on this paper contained an error. The names of M. John Hicks and R. Paul Gui... more The original version on this paper contained an error. The names of M. John Hicks and R. Paul Guillerman, though correctly appeared in the published version, are incorrectly displayed in indexing sites.
Pediatric radiology, Jan 27, 2018
Motion remains a major limitation of fetal magnetic resonance imaging (MRI). Some centers have re... more Motion remains a major limitation of fetal magnetic resonance imaging (MRI). Some centers have required mothers to fast before MRI in an effort to reduce motion; however, there is no current literature that describes the effect of maternal diet on fetal activity. The objective is to define associations between specific foods and beverages consumed before and the severity of fetal motion during fetal MRI. Patients were asked to recall the specific foods or drinks consumed before their scan. An experienced technologist rated the level of fetal activity on a 3-point scale, from much less motion than normal (1) to much more (3). Two hundred twenty-eight patients were included. A non-inferiority test was used to establish statistical equivalence between the MR scores of those having a particular food item and those not. For items not shown to be equivalent, an additional superiority analysis evaluated for the presence of any significant difference. Additional data on time from meal to MR...
Pediatric radiology, Sep 24, 2018
Intussusception, a common cause of bowel obstruction in young children, is primarily treated with... more Intussusception, a common cause of bowel obstruction in young children, is primarily treated with air enema reduction. There is little literature comparing the safety and efficacy of air reduction without or with a rectal balloon. To determine the safety and efficacy of a rectal balloon seal in air enema reduction. We retrospectively reviewed the records of children who underwent air reduction for ileocolic or ileo-ileocolic intussusception over an 8-year period. We sorted data from 566 children according to whether a rectal balloon was used in the reduction, and further sorted them by type and experience level of the practitioner. Using logistic regression analyses, we identified risk factors for iatrogenic bowel perforation or failed reduction. Significant associations with bowel perforation included balloon use (P=0.038), age <1 year (P<0.0001), and attending physician's level of experience <5 years (P=0.043). Younger age was associated with both perforation (P<0....
AJR. American journal of roentgenology, Jan 12, 2018
The purpose of this study is to establish normal total fetal lung volume reference ranges from 18... more The purpose of this study is to establish normal total fetal lung volume reference ranges from 18 to 38 weeks' gestation at 1-week intervals. A retrospective analysis of 665 patients who underwent fetal MRI at two tertiary fetal centers from 2001 to 2013 was performed. Total fetal lung volume was measured in at least two planes, either manually or using a 3D workstation. The mean, median, SD, minimum, maximum, and lower and upper quartiles for total fetal lung volume were determined per gestational week. A t test was used to compare our values to previously reported values. A new formula to calculate total fetal lung volume derived from our data was created using a regression model. Comparisons between total fetal lung volume obtained by different imaging planes and manual versus semiautomatic calculation were also performed. The mean normal total fetal lung volume showed a weekly increase from 18 through 35 weeks' gestation. Means were compared with the expected total fetal...
Prenatal Diagnosis
K. Aagaardt Sherif Abdel-Fattah Foad Abdullah Harald Abele Laurence Abernethy Lenore Abramsky ALf... more K. Aagaardt Sherif Abdel-Fattah Foad Abdullah Harald Abele Laurence Abernethy Lenore Abramsky ALfred Abuhamad Reem Abu-Rustum Ruben Acherman Reuven Achiron Begoña Adiego N. Scott Adzick Michael Aertsen Ranjit Akolekar Hesham AlAinany M. Alders Zarko Alfirevic Megan Allyse Sabahattin Altunyurt Carlo Alviggi David Amor Cande Ananth Michael Angastiniotis Edward Araujo Junior Flavia Araujo Bhawna Arya Wolfgang Arzt Nina Asplin Francois Audibert Neil Avent Amir Aviram Freddy Avni Roland Axt-Fliedner Nancy Ayres Mert Bahtiyar Komal Bajaj Csilla Balassy Jacob Bar John Barber Joao Arthur Barbosa Catherine Barrea Angela Barrett Antonio Barros Jose Luis Bartha Ahmed Baschat Ahmet Baschat Mark Bateman David Baud Arthur Beaudet Michael Bebbington Nicolas Behrendt Mireille Bekker Carlo Valerio Bellieni John W. Belmont Beryl Benacerraf A. Benachi Ido Ben-Ami Kurt Benirschke Peter Benn Christoph Berg Vincenzo Berghella Barbara Bernhardt Jonathan Bestwick Lean Beulen Sucheta Bhatt Diana Bianchi Barbara Biesecker Joseph Biggio Caterina Madelena Bilardo Harm-Gerd Karl Blaas Karin Blakemore Silvana Maria Blascovi-Assis Isaac Blickstein Guy Bogaert Allan Bombard Leonard Bonacquisto Carsten Bonnemann Elles Boon M. Borenstein Antoni Borrell J. Laurence Bour Tom Bourne Patricia Boyd Paul Brady Christine Brantner Andrew Breeze Amy Breman Martijn Breuning Richard Brown Irina Buhimschi The-Hung Bui Emmanuel Bujold R. Bukowski Dorothy Bulas Nicole Burger Ana Bustamante-Aragones Alison Cahill Maria Calvo Nina Canki-Klain Mingzhu Cao Pavlina Capkova Andrew Carlin Waldemar Carlo Fatima Caromano David Carr Stephen R. Carr Fran Carroll Julene Carvalho Paula Casanello Frank Casey Robert Casper Darrell Cass Christopher Cassady Ingele Casteels William Castillo Valerian Catanzarite Aaron Caughey Irene Cetin J. Challis Gihad Chalouhi Jerry Chan K. C. Chan Li-Chong Chan Lin Wai Chan Rabih Chaoui Teresa Chapman Taryn Charles Stephen Chasen Aline Chaves Benny Chayen Anjali Chellia Frank Chervenak The editors of Prenatal Diagnosis wish to gratefully acknowledge the following individuals who reviewed papers for the journal during 2015. We sincerely appreciate the time and effort they spent to provide constructive comments to our authors.
Prenatal Diagnosis
Fetuses with congenital diaphragmatic hernia (CDH) demonstrate varying degrees of left heart hypo... more Fetuses with congenital diaphragmatic hernia (CDH) demonstrate varying degrees of left heart hypoplasia. Our study assesses the relationship between fetal left-sided cardiac structural dimensions, lung size, percentage liver herniation, lung-to-head ratio, postnatal left-sided cardiac structural dimensions, and postnatal outcomes. We performed a retrospective cohort study of fetuses with left-sided CDH who had prenatal echocardiographic, ultrasound, and magnetic resonance imaging examinations at our institution between January 2007 and March 2015. Postnatal outcomes assessed include use of inhaled nitric oxide (iNO), use of extracorporeal membrane oxygenation, and death. Fifty-two fetuses with isolated left-sided CDH were included. Multivariate logistic regression models indicated that smaller fetal aortic valve z-score was associated with postnatal use of iNO (p = 0.03). Fetal mitral valve z-score correlated with lung-to-head ratio (p = 0.04), postnatal mitral valve z-score correlated with percent liver herniation (p = 0.03), and postnatal left ventricular end-diastolic dimension z-score correlated with liver herniation &amp;amp;amp;amp;lt;20% (p = 0.04). We identified associations between smaller fetal left-sided cardiac structural dimensions and classic CDH indices. Smaller aortic valve z-score was associated with iNO use; however, left heart dimensions showed no association with extracorporeal membrane oxygenation or mortality. Further study into the impact of left-sided hypoplasia on outcomes in CDH is worthy of evaluation in a larger, prospective study. © 2017 John Wiley &amp;amp;amp;amp;amp; Sons, Ltd.
Journal of pediatric surgery, 2017
The purpose of this study was to evaluate the accuracy of prenatal diagnosis for fetuses with gas... more The purpose of this study was to evaluate the accuracy of prenatal diagnosis for fetuses with gastrointestinal (GI) obstruction with correlation to postnatal outcomes. Fetuses diagnosed with GI obstruction (excluding esophageal and duodenal) were reviewed for those evaluated between 2006 and 2016. Prenatal diagnosis and imaging studies were compared to postnatal findings. Outcomes evaluated included diagnostic accuracy, rate of other anomalies, neonatal length of stay, incidence of short bowel syndrome, and discharge with TPN or gastrostomy. Forty-eight patients were diagnosed prenatally with obstruction. Six patients were excluded owing to incomplete records and follow-up. Twelve fetuses were diagnosed with ultrasound alone, and thirty-four with ultrasound and MRI. A diagnosis of obstruction was accurate in 88.1% (n=37/42) with a positive predictive value of 91.3%, while US with MRI had an accuracy of 84.4%. Associated anomalies were highest among fetuses with anorectal obstruction...
American Journal of Obstetrics and Gynecology, 2017
American Journal of Obstetrics and Gynecology, 2017
American Journal of Obstetrics and Gynecology, 2017
Obstetrics & Gynecology, 2017
To evaluate feasibility and initial outcomes of fetoscopic tracheal occlusion for severe diaphrag... more To evaluate feasibility and initial outcomes of fetoscopic tracheal occlusion for severe diaphragmatic hernia compared with a historical cohort who had not received fetal tracheal occlusion. Outcomes in a prospective observational cohort who underwent fetoscopic tracheal occlusion for severe fetal left diaphragmatic hernia without associated anomalies were compared with our historical nontreated cohort of matched fetuses of similar severity. Fetuses were classified using the same ultrasonography and magnetic resonance imaging methodology-prospectively in the fetoscopic tracheal occlusion group and retrospectively in the historical nontreated cohort. Obstetric and postnatal outcomes were evaluated and compared. Between January 2004 and June 2015, 218 fetuses with diaphragmatic hernia were evaluated. Twenty (9%) fetuses had severe left diaphragmatic hernia (lung-head ratio 1.0 or less and liver herniation), of which 9 of 20 were managed without tracheal occlusion. Eleven were offered the procedure and in 10, it was successful. Mean (±standard deviation) gestational age was 27.9±1.1 weeks at attempted balloon placement, 34.1±1.1 weeks at removal, and 35.3±2.2 weeks at delivery. One patient required an ex utero intrapartum treatment procedure at delivery to remove the balloon. There were no maternal complications or fetal deaths. All neonates underwent postnatal repair with a patch. The 6-month, 1-year, and 2-year survival rates were significantly higher in our treated cohort than in our nontreated historical cohort (80% compared with 11%, risk difference 69%, 95% confidence interval [CI] 38-100%, P=.01; 70% compared with 11%, risk difference 59%, 95% CI 24-94%, P=.02; and 67% compared with 11%, risk difference 56%, 95% CI 19-93%, P=.04, respectively) with reduced need for extracorporeal membrane oxygenation (30% compared with 70%, risk difference 40%, 95% CI 10-79%, P=.05). Fetoscopic tracheal occlusion is feasible and is associated with improved postnatal outcomes in severe left diaphragmatic hernia. ClinicalTrials.gov, https://clinicaltrials.gov, NCT00881660.
Journal of ultrasound in medicine : official journal of the American Institute of Ultrasound in Medicine, Jan 20, 2016
Liver herniation can be assessed sonographically by either a direct (liver-to-thoracic area ratio... more Liver herniation can be assessed sonographically by either a direct (liver-to-thoracic area ratio) or an indirect (stomach position) method. Our objective was to evaluate the utility of those methods to assess liver herniation for the prediction of neonatal outcomes in patients with isolated left-sided congenital diaphragmatic hernia (CDH). We conducted a retrospective cohort study of all patients with CDH who had prenatal assessment and were delivered at Texas Children's Hospital between January 2004 and April 2014. The predictive value of sonographic parameters for mortality and the need for extracorporeal membrane oxygenation was evaluated by univariate, multivariate, and factor analysis and by receiver operating characteristics curves. A total of 77 fetuses with isolated left-sided CDH were analyzed. The lung-to-head ratio, liver-to-thorax ratio, and stomach position (according to the classifications of Kitano et al [Ultrasound Obstet Gynecol 2011; 37:277-282] and Cordier et...
Journal of Pediatric Surgery, 2016
Previous reports describe lung malformations and other chest lesions in association with congenit... more Previous reports describe lung malformations and other chest lesions in association with congenital diaphragmatic hernia (CDH), yet little is known how these lesions affect outcomes. We sought to evaluate the incidence and outcomes of patients diagnosed with chest lesions in association with CDH. The charts of all infants treated for CDH in a single tertiary center from January 2004 to January 2015 were reviewed. The outcomes of those with space occupying lesions (SOLs) in association with CDH were compared to those with isolated CDH. Statistical analysis was performed using Student&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s t-test and Mann-Whitney U test for continuous variables and Fisher&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s exact for categorical variables. Of the 214 infants treated, 20 had an associated SOL (4 had&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;1 lesion). SOLs were confirmed by pathological examination and included: bronchopulmonary sequestration (n=10; 4.7%), ectopic liver (n=9; 4.2%), foregut duplication cyst (n=2; 1%), and other lesions (n=3; 1.4%). No statistical difference was noted in the long-term outcomes of patients with SOL in comparison to those with isolated CDH. SOLs are not uncommon in neonates with CDH. Despite theoretical concerns, there is no evidence that SOLs are associated with worse outcomes, a finding which is helpful during prenatal counseling of families.
Journal of Pediatric Surgery, 2016
The purpose of this study was to evaluate the impact of various types of associated anomalies on ... more The purpose of this study was to evaluate the impact of various types of associated anomalies on CDH mortality and morbidity. All CDH patients at a tertiary care center from January 2004 to January 2014 were reviewed retrospectively. Isolated CDH was defined as CDH without any associated anomalies. Cardiac anomalies were stratified into minor and major based on the Risk Adjustment for Congenital Heart Surgery-1 (RACHS-1) scoring system. Other anatomic anomalies requiring intervention in the perinatal period were classified as major anomalies. The outcomes of interest were 6-month mortality as well as pulmonary and gastrointestinal morbidity. Of 189 CDH patients, 93 (49%) had isolated CDH. Others had: cardiac anomalies alone (n=47, 25%), genetic anomalies (n=28, 15%), structural anomalies alone (n=18, 10%), and both cardiac and genetic anomalies (n=20, 11%). Fifty (26.5%) patients were dead before six months of age. Mortality rate at 6months was higher in patients with genetic and major cardiac anomalies. A major cardiac anomaly was independently associated with a 102-fold increased risk of mortality at 6months (95%CI: 3.1-3402). Pulmonary morbidity was increased in patients with genetic, major cardiac, and major structural anomalies, while gastrointestinal morbidity was higher in patients with major structural anomalies alone. Major cardiac and genetic anomalies were associated with increased 6-month mortality in CDH patients. However, the association with minor cardiac anomalies and/or structural anomalies did not affect mortality and morbidity of CDH patients. The presence of minor anomalies should not adversely impact their perinatal management or consideration for in-utero therapy.
American Journal of Obstetrics and Gynecology, 2016
Prior cesarean delivery is a known risk factor for uterine rupture with subsequent deliveries. Th... more Prior cesarean delivery is a known risk factor for uterine rupture with subsequent deliveries. There is a paucity of literature analyzing the rate of uterine rupture and risk factors for rupture among women without a prior cesarean delivery. We assessed the frequency of uterine rupture among patients without a prior cesarean delivery and analyzed possible risk factors associated with uterine rupture in this group. STUDY DESIGN: Retrospective cohort study using de-identified, vital statistics and discharge diagnosis data from the California Office of Statewide Health Planning and Development. Maternal and neonatal hospital data were linked to birth certificate files and managed by the California Maternal Quality Care Collaborative for the years 2008-2010. Study population included all deliveries of either singleton gestations or the first-born infant of multiple gestations. RESULTS: Of 1,517,827 deliveries, 1,285,434 women did not have a history of a previous cesarean section. Among this group, 195 women experienced a uterine rupture (incidence 0.02%). Women whose deliveries were complicated by uterine rupture were older (32.2 AE 6.2 vs 27.2 AE 6.3, p<0.001), more likely to be multiparous (74.4% vs 52.8%, p ¼<0.001), have had a myomectomy (1% vs 0.1%, p¼0.0335), have a uterine abnormality (3.1% vs 1.3%, p ¼ 0.0335), and have a lower birth weight (12.8% vs 6%, p<0.001) (Table). There was no association with uterine rupture and patient race (p¼0.0624), ethnicity (p¼0.1908), induction of labor (p¼0.9546), administration of oxytocin (p¼0.5088) or instrumental delivery (p¼0.5062). CONCLUSION: The rate of uterine rupture for women without prior cesarean delivery was 0.02%. The association of previous myomectomy and congenital uterine anomalies with uterine rupture illustrates the importance of underlying uterine anatomy at the time of delivery.
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Papers by christopher cassady