Neurodevelopmental impact of hydrocortisone exposure in extremely low birth weight infants: outcomes at 1 and 2 years.

OBJECTIVE: Postnatal steroids are used in neonatal intensive care units despite known side effects. Hydrocortisone (HC) use persists as it is believed to have less deleterious effects on neurodevelopmental (ND) outcome compared to other steroids. The literature is sparse with respect to the ND impact of HC use in recent years. Hence, we sought to examine the effect of HC use on ND outcome in a contemporary cohort of extremely low birth weight (ELBW) infants. STUDY DESIGN: A total of 175 ELBW infants (86 HC exposed, 89 steroid naive) born in 2008 to 2010 were compared for mortality, morbidity and ND outcome at 8 and 20 months corrected age. Outcome measures included neurologic exam and results of the Bayley Scales of Infant and Toddler Development-III (BSITD-III). Multiple regression analyses adjusted for the effect of other risk factors on outcome. RESULT: Overall, 65 (75%) of the HC and 74 (83%) of the no-HC groups survived to discharge. HC infants were smaller (mean birth weight (BW) 719 ± 127 g vs 837 ± 99 g) and of lower gestational age (GA) (mean GA 26.0 ± 1.7 weeks vs 27.5 ± 1.8 weeks) compared to the no-HC group. Patients in the HC group were more likely to be a multiple, have a severely abnormal head ultrasound, bronchopulmonary dysplasia, retinopathy of prematurity, necrotizing enterocolitis and receive treatment for patent ductus arteriosus and hypotension than those in the no-HC group. Of the HC group, the mean age at treatment was 20 ± 19 days, mean duration of treatment 49 ± 37 days. At 8 months, the HC group had lower mean motor (87 ± 18 vs 95 ± 15, P = 0.028) and fine motor (9 ± 2.9 vs 10.5 ± 2.6, P = 0.005) and higher rate of subnormal motor (44 vs 15%, P = 0.002) and fine motor scores (24 vs 6.5%, P = 0.017). In regression analyses, HC exposure >7 days was significantly related to worse outcome on fine motor scores at 8 months while cumulative days of HC exposure was a predictor of worse outcome on language at 8 months and motor outcome at 20 months. Each additional day of HC exposure increased the odds of subnormal receptive and expressive language in the first year of life by 4 and 2%, respectively, and increased odds of subnormal motor function by 2% in the 2nd year of life. CONCLUSION: HC exposure for >7 days is associated with worse performance in fine motor skills in the first year of life, while cumulative HC exposure negatively impacts receptive and expressive language skills in the first year and motor skills in the second year of life after adjusting for neonatal and social risk factors.

Anxiety and congenital central hypoventilation syndrome.

OBJECTIVE: It has been hypothesized that individuals who cannot perceive elevations of CO2 will be less anxious than individuals with intact CO2 perception. To test this hypothesis, children with congenital central hypoventilation syndrome, who have a potentially lethal chronic illness associated with lack of CO2 perception and thus provide a natural experimental group, were studied. METHOD: Rates of anxiety symptoms and disorders in children with congenital central hypoventilation syndrome (N = 13) were compared with rates in an age-matched, nonreferred group of community subjects (N = 292) that included subgroups of children with asthma (N = 15) and other chronic medical illnesses (N = 66). Anxiety symptoms were assessed with information obtained from structured interviews of the parents, which provided both total symptom scores and DSM-III-R diagnoses. RESULTS: The children with congenital central hypoventilation syndrome exhibited significantly fewer anxiety symptoms than all other comparison subjects. Two of these children (15%) met criteria for anxiety disorders, a rate lower than that of the whole community group (24%) and of the chronically ill comparison subgroups (32%-47%). The largest difference in the prevalence of disorder emerged between the children with congenital central hypoventilation syndrome (15%) and those with asthma (47%). In the comparison of children with congenital central hypoventilation syndrome and children with other chronic illnesses, a priori analysis showed that the former had significantly lower rates of disorders that have been linked to panic in the literature. CONCLUSIONS: This study supports theories of anxiety that implicate CO2 perception in the pathophysiology of panic and related anxiety states.

Congenital central hypoventilation syndrome: mutation analysis of the receptor tyrosine kinase RET.

Congenital central hypoventilation syndrome (CCHS) usually occurs as an isolated phenotype. However, 16% of the index cases are also affected with Hirschsprung disease (HSCR). Complex segregation analysis suggests that CCHS is familial and has the same inheritance pattern with or without HSCR. We postulate that alteration of normal function of the receptor tyrosine kinase, RET, may contribute to CCHS based on RET's expression pattern and the identification of RET mutations in HSCR patients. To further explore the nature of the inheritance of CCHS, we have undertaken two main routes of investigation: cytogenetic analysis and mutation detection. Cytogenetic analysis of metaphase chromosomes showed normal karyotypes in 13 of the 14 evaluated index cases; one index case carried a familial pericentric inversion on chromosome 2. Mutation analysis showed no sequence changes unique to index cases, as compared to control individuals, and as studied by single strand conformational polymorphism (SSCP) analysis of the coding region of RET. We conclude that point mutations in the RET coding region cannot account for a substantial fraction of CCHS in this patient population, and that other candidate genes involved in neural crest cell differentiation and development must be considered.

Congenital central hypoventilation syndrome: inheritance and relation to sudden infant death syndrome.

We evaluated the families of 50 children with idiopathic congenital central hypoventilation syndrome (CCHS) to 1) test genetic hypotheses, 2) explore the relationship to Hirschsprung disease (HD), and 3) examine other clinical findings including sudden infant death syndrome (SIDS) in relatives of CCHS patients. A questionnaire was administered to parents of each proband to determine a detailed pedigree and medical history for 3 generations including 1,482 relatives. The data were analyzed under the unified mixed model method (assumes individual genotype composed of multifactorial [MF] and major locus [ML] components). Analysis was made of the Total dataset and on subdivided data sets: HIR1 = families of probands with HD (n = 8) vs. HIR2 = families of probands without HD; then under a premise that severe, chronic constipation may be a milder form of HD (i.e., ganglion cells present but dysfunctional), CON1 = families of probands with HD or constipation (n = 13) vs. CON2 = families of probands without HD or constipation. By statistical genetic analysis of the Total, HIR1, and CON1 datasets, the MF and ML hypotheses were about equally likely, with the MF model slightly more parsimonious. Although HIR2 and CON2 datasets indicated no familiality, statistical evidence of heterogeneity between the results of HIR1 and HIR2, or between CON1 and CON2 was lacking. A SIDS incidence of 11.2/1,000 was documented among the relatives of CON1 vs. 1.8/1,000 among relatives of CON2. Our results are consistent with familiality by either MF or ML models. Recurrence risk is likely < 5%. The relationship of CCHS to the high familial incidence of SIDS is intriguing and demands further investigation.

Genetic segregation analysis of autonomic nervous system dysfunction in families of probands with idiopathic congenital central hypoventilation syndrome.

Idiopathic congenital central hypoventilation syndrome (CCHS) is a very rare syndrome with major respiratory complications. Hypothesizing that CCHS is the most severe manifestation of general autonomic nervous system dysfunction (ANSD), we applied a case-control family study design to investigate the genetics of ANSD. Fifty-two probands with CCHS were identified, as well as 52 age-, race-, and gender-matched controls. ANSD phenotypic features were characterized in the cases, controls, and their family members. Our earlier studies found that most ANSD symptoms were more likely in CCHS cases and their relatives than in controls and their relatives (P < 0.05). The goal of the current study was to determine if the familiality of ANSD was consistent with a genetic pattern. We performed major locus segregation analysis of ANSD utilizing regressive models. CCHS probands were assumed to be affected; controls and relatives were designated as affected if they had two or more relevant symptoms. The hypothesis of "no transmission and no familial effects" was rejected in both case and control families. Case families were consistent with transmission of a major effect; control families were not (the difference in the pattern of results was significant, P < 0.0001). In the total data set, the best-fitting model was codominant Mendelian inheritance of a major gene for ANSD. These case-control family studies support our hypothesis that CCHS is the most severe manifestation of a general ANSD, with a family pattern consistent with Mendelian transmission, and demonstrate the potential utility of the approach to studies of other, similarly intractable disorders.

Case/control family study of autonomic nervous system dysfunction in idiopathic congenital central hypoventilation syndrome.

Children with idiopathic congenital central hypoventilation syndrome (CCHS) have a complex phenotype consistent with an imbalance of the autonomic nervous system (ANS). Since CCHS may be genetic in origin, we hypothesized that relatives of individuals with CCHS may exhibit symptoms of ANS dysfunction (ANSD), albeit in a milder form. We tested this hypothesis by assessing aspects of ANS function in relatives of CCHS cases vs. relatives of matched controls with a scripted questionnaire. Only those 35 symptoms of ANSD exhibited by > or =5% of the CCHS cases were included in the analysis as the basis for determining ANSD affection status. Two different arbitrary ANSD affection status definitions are presented in detail: any case, control, or relative with positive findings (1) in two or more symptoms, or (2) in two or more systems. The subjects included in the analysis totaled 2,353, including 56 CCHS cases, 56 age-, gender-, and race-matched controls, and their families. Under each of the two arbitrary ANSD affection statuses, CCHS cases and parents of cases were more likely to be affected than controls and parents of controls (P < 0.001 for both comparisons), 16% of the CCHS siblings had the ANSD phenotype with two or more symptoms, compared to 4% of control siblings (P = 0.03). Aunts and uncles of the CCHS cases were also significantly more likely to have two or more ANSD symptoms than were aunts and uncles of the controls (P= 0.009). These results support our hypothesis and also indicate that relatives of the CCHS cases tended to manifest a milder spectrum of ANSD, with fewer systems and/or fewer symptoms than the cases.

Congenital central hypoventilation syndrome: cardiorespiratory responses to moderate exercise, simulating daily activity.

Children with congenital central hypoventilation syndrome (CCHS) lack normal awake ventilatory responses to hypoxia and hypercarbia, yet engage in daily activities typical of similarly aged children. Our patients with CCHS are assessed annually with a walking treadmill protocol to assess physiologic responses to different levels of simulated daily activity. We hypothesized that children with CCHS (compared with age- and sex-matched healthy controls) would 1) exercise for shorter durations and reach lower peak speed and incline on the treadmill; 2) become more hypoxemic, more hypercarbic, and develop less tachycardia during activity; and 3) take longer to return to baseline oxygenation, ventilation, and heart rate than normal children. Seven children with CCHS [mean age, 6.9 +/- 3.0 (SD) years] who required 24 h/day ventilatory support (diaphragm pacers while awake and mechanical ventilation asleep) and 7 controls performed a walking protocol on a treadmill with progressive increments in speed and incline. Hemoglobin saturations (SaO2), end-tidal carbon dioxide concentrations (ETCO2), and heart rates (HR) were recorded at baseline conditions, during activity and during recovery. There were no significant differences between children with CCHS and controls in baseline values, duration of activity, peak speed, and incline achieved during walking and recovery time to baseline once the treadmill had stopped. However, children with CCHS became significantly more hypoxemic and hypercarbic during activity (P < 0.05), and they had a lower percent increase in HR during treadmill walking than controls (P < 0.05). These results offer the clinician an opportunity to adjust clinical management in children with CCHS by providing specific recommendations to parents about appropriate levels of activity for their children with CCHS.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of prenatal cocaine on respiration, heart rate, and sudden infant death syndrome.

We studied 114 neonates by pneumocardiogram recordings in order to examine the effects of cocaine with and without opiate exposure on neonatal respiration, heart rate, apparent life threatening events (ALTE), and sudden infant death syndrome (SIDS). In full-term infants exposed to cocaine without opiates we found increased longest apnea duration and more episodes of bradycardia, but decreased periodic breathing and average heart rate than in control full-term infants. Term infants prenatally exposed to cocaine with opiates also had less periodic breathing. Preterm infants exposed to cocaine with and without opiates had decreased apnea density and periodic breathing compared with preterm controls. Discriminant analysis to determine whether perinatal asphyxia or exposure to other drugs could predict cardiorespiratory abnormalities showed no consistent relationship. In 72 of 114 infants available for follow-up, no ALTE occurred but two were lost to SIDS. Our data support the hypothesis that prenatal cocaine exposure may perturb, albeit subtly, the maturation of respiratory control, resulting in disruption of postnatal respiration.

Cardiac rhythm disturbances among children with idiopathic congenital central hypoventilation syndrome.

The objective of this study was to determine whether subjects with congenital central hypoventilation syndrome (CCHS) had an increased frequency of cardiac arrhythmias and decreased heart rate variability when compared to subjects without a known deficit in control of breathing, and that these abnormalities would be exaggerated by anesthesia. Continuous ambulatory Holter recordings were obtained in patients with CCHS and compared to two otherwise healthy control groups without a deficit in control of breathing: one with an intact airway (n = 11) and a second group with a tracheostomy (n = 6). Holter recordings were obtained before, during (under general anesthesia), and after bronchoscopy. Fourteen children with CCHS (age: 9.3 +/- 4.4 years mean +/- S.D.) were studied, and 7 underwent bronchoscopy. Seventeen control children were studied (age 6.6 +/- 3.6 years): 11 without a tracheostomy, and 6 with a tracheostomy who also underwent bronchoscopy. Maximum heart rate during baseline recording was significantly lower in the CCHS subjects as compared to controls (P = 0.0001). At baseline the difference in the number of arrhythmias/24 hr/subject in all CCHS vs. all control subjects was significant (P = 0.0002); for the subjects who had bronchoscopy, CCHS vs. control, the difference was also significant (P = 0.03). In addition, there was a significant decrease in the number of events/24 hr/subject among the CCHS subjects between baseline and post-bronchoscopy (P = 0.0288). The predominant arrhythmias were sinus bradycardia and transient asystole. The longest asystole in a CCHS subject was 6.50 sec, and in a control subject, 1.42 sec (at baseline the means of the longest asystole were 2.69 +/- 1.4 vs. 1.24 +/- 0.13; P = 0.003 in the CCHS vs. control groups). Other indices of heart rate variability were significantly reduced in the CCHS subjects (P < 0.05). These results substantiate our hypothesis that subjects with CCHS have more arrhythmias than controls, an increased frequency of bradyarrhythmias, and decreased cyclical sinus arrhythmia.

Polysomnography in obese children with a history of sleep-associated breathing disorders.

We hypothesized that obese children with a history of breathing difficulty during sleep would demonstrate (1) evidence of complete and partial obstructive sleep apnea (OSA) with hypercarbia and/or hypoxemia; and (2) correlation between symptoms, degree of obesity, adenoid and tonsil size, and polysomnography (PSG) results. We evaluated 32 obese children [% ideal body weight (IBW), 196 +/- 45%] with a sleep history questionnaire, airway radiographs, electrocardiograms (ECG), and PSG. By history, we found snoring (100%), difficulty breathing (59%), sweating (44%), restlessness (53%), arousals (41%), apnea (50%), worsening with upper respiratory infection (URI) (81%), hypersomnolence (59%), and mouth breathing (59%). We found adenoid and/or tonsil enlargement on 75% of airway x-ray pictures. ECGs were abnormal in 5 patients. Among all patients, mean sleep study oxyhemoglobin saturation (SaO2) was 85 +/- 16% and mean end-tidal CO2 (PetCO2) was 51 +/- 7 torr; 84% had paradoxical inward movement of the chest on inspiration, 59% had OSA, and 66% had partial OSA. In those with > or = 200% IBW and adenotonsillar enlargement, elevated PetCO2 and the presence of hypoxemia (SaO2 < 90%) for > or = 5% of the total sleep time (TST) were correlated, unlike in patients of similar weight but without adenotonsillar enlargement. Individuals symptoms did not correlate with the severity of PSG abnormalities. By discriminant analysis, using three variables (IBW, presence of adenotonsillar tissue, and presence of > or = 5 symptoms), we could predict PSG abnormalities with up to 81% reliability. Our findings indicate that in obese children, particularly those with %IBW > or = 200 and adenotonsillar hypertrophy, with sleep-disordered breathing evaluation by polysomnography should be considered.

Hypoxia after prenatal cocaine attenuates striatal dopamine and neurotrophic activity.

We have previously shown that newborn rabbits exposed to cocaine prenatally have an altered cardiorespiratory response to hypoxia. We report the effect of postnatal hypoxia on brain DA and neurotrophic activity in New Zealand White rabbit pups (n = 41) born to cocaine-exposed does (30 mg/kg/day SC from days 7-15 of a 32-day gestation = COCaine) and control does (sterile H2O = VEHicle). Four to 6-day-old pups were exposed to 20 min of room air (0.21 fractional inspired oxygen tension, FIO2). One third of each group was then exposed to 20 min of either 0.15 (moderate hypoxia) or 0.08 (severe hypoxia) FIO2. Immediately following hypoxic challenge the pups were sacrificed. Striatal tissue extracts were subsequently assessed for DA and striatal trophic activity by monitoring the number of neuron specific enolase immunoreactive (NSEir) cells in mesencephalic culture following incubation with striatal extracts. Increasing the severity of hypoxia increased DA content (p < 0.005), but reduced DA activity (p < 0.0001) and trophic activity (p < 0.001). Cocaine exposure reduced striatal DA (p < 0.005) as well as NSEir (p < 0.001) in all conditions relative to vehicle-treated controls. These data suggest that prenatal cocaine exposure enhances the vulnerability of the DA system to the stress of hypoxia, possibly through alterations in neurotrophic activity.

Documented monitoring: an alarming turn of events.

Event recording of transthoracic impedance and electrocardiogram (documented monitoring) has recently become available to the clinician. Through its use, investigators have documented a remarkably low incidence of true alarms for apnea and bradycardia among monitored infants and children and an even lower incidence of clinically significant alarms. This technique has allowed clinicians to improve monitor management and to discontinue monitoring sooner. Coupled with recording of hemoglobin saturation and pulse waveform, this technology will serve to enhance our understanding of the pathophysiology of events that accompany apparent life-threatening events and that precede sudden infant death syndrome.

SIDS risk factor awareness: assessment among nursing students.

OBJECTIVE: To test the hypotheses that nursing students (a) have limited knowledge of risk factors for sudden infant death syndrome (SIDS) and the American Academy of Pediatrics (AAP) recommendation of placing infants on their backs or sides for sleep, and (b) after careful education about SIDS, would retain this information and teach it to parents. DESIGN: A pretest questionnaire was used to identify knowledge of 13 risk factors and personal recommendation for sleep position. Participants attended a lecture on SIDS and received written educational material. A posttest was completed after 6 weeks. SETTING: Nursing students were assessed during their family practice course. PARTICIPANTS: Fifty-one 4th-year nursing students (mean age 28.4 years, SD=7.6) enrolled in the BSN program completed the pretest; 29 completed the identical posttest. INTERVENTION: A lecture on SIDS and SIDS risk factors with written educational material after the pretest. MAIN OUTCOME MEASURES: Pretest and posttest responses. RESULTS: The Mann-Whitney test and McNemar chi-square analyses were used to determine factors on the pretest which influenced the awareness of prone position and to compare pretest and posttest data. On the pretest, 69% of students were aware of the AAP recommendation but significantly more (92%) were aware on the posttest. Posttest responses increased significantly for 12 of the 13 risk factors; 41% of the students identified all 13 risk factors on the posttest, in contrast to 0% on the pretest. On both the pretest and posttest, 93% of students stated that it was important to discuss their infant's sleep position with parents. Posttest results showed that students unanimously recommend the side or back sleep position. CONCLUSION: Nursing students were aware of the AAP recommendation, yet their knowledge of other risk factors was limited. A careful educational process resulted in retention of information about the AAP recommendation and other risk factors. In addition, students were willing to teach parents to place their infants on the back or side to sleep.

Responses of preterm infants to unimodal and multimodal sensory intervention.

PURPOSE: To examine the immediate responses of preterm infants to two forms of unimodal [auditory only (A) and tactile only (T)] and two forms of multimodal sensory stimulation [auditory, tactile and visual (ATV); auditory, tactile, visual and vestibular (ATVV)]. METHOD: A convenience sample of 54 clinically stable preterm infants (33-34 postconceptional weeks) was randomly assigned to 1 of 5 experimental groups [Control (C); (A); (T); (ATV); and (ATVV)]. Stimulation was applied for 15 minutes once daily for 4 consecutive days. RESULTS: Outcome measures included pulse (PR) and respiratory rate (RR), oxygen saturation, behavioral state (BS), and body temperature. Repeated measures ANOVA identified significant differences among the groups during intervention for PR (p < .001), RR (p = .01), and BS (p < .02). Infants receiving any intervention with a tactile component showed increasing arousal (change in BS), and increased PR and RR during stimulation. Group T infants had higher proportions of PR > 180 while Group ATVV had higher proportions of PR < 140 (p = .0001). Group ATVV showed increased alertness following stimulation (24%) in contrast to having the least alertness during stimulation (11%). CONCLUSIONS: Tactile stimulation alone may be too arousing for these infants while the addition of vestibular stimulation may modulate arousal and facilitate optimal arousal prior to feeding.

Patterns of physiologic and behavioral response of intermediate care preterm infants to intervention.

PURPOSE: To determine the safety of a developmental intervention for use with preterm infants and feasibility of a time sampling procedure. METHODOLOGY: An experimental design was used to test an intervention with clinically stable 33-34-week postconceptional age infants over a 4-day period. Repeated outcome measures included pulse rate, oxygen saturation levels, and infant behavioral state. FINDINGS: The intervention resulted in significant differences in infant behavioral state with the experimental group achieving more alertness. Physiologic parameters remained within normal limits both during and after the intervention. CONCLUSIONS: The protocol was found to be safe for implementation with clinically stable preterm infants. Behavioral state findings suggest the potential for the intervention to promote alertness. Results suggest that changes in oxygen saturation and pulse rate were dependent upon changes in behavioral state.

Cardiorespiratory events in extremely low birth weight infants: neurodevelopmental outcome at 1 and 2 years.

OBJECTIVE: To examine the association between cardiorespiratory events (CRE) and neurodevelopmental (ND) outcome at 8 and 20 months corrected age (CA) in a contemporary extremely low birth weight (ELBW )cohort. STUDY DESIGN: Retrospective chart review of 98 ELBW infants born in 2009 to 2010 who completed ND assessments at 8 and 20 months CA. Neonatal, sociodemographic, CRE and ND data were collected. ND outcome measures included neurologic examination and results from the Bayley Scales of Infant and Toddler Development-III. Multiple regression analyses adjusted for the impact of neonatal risk factors on ND outcome. RESULT: After adjusting for neonatal and social variables, greater frequency of CRE was related to worse language scores at 8 months, while CRE of greater severity were related to worse language at 20 months CA. CONCLUSION: CRE in ELBW infants have impact on language development in the first two years of life.

Reducing necrotizing enterocolitis in very low birth weight infants using quality-improvement methods.

OBJECTIVE: Owing to a rise in necrotizing enterocolitis (NEC, stage ⩾ 2) among very low birth weight (VLBW, birth weight <1500 g) infants from 4% in 2005 to 2006 to 10% in 2007 to 2008, we developed and implemented quality improvement (QI) initiatives. The objective was to evaluate the impact of QI initiatives on NEC incidence in VLBW infants. STUDY DESIGN: In September 2009, we developed an NEC QI multidisciplinary team that conducted literature reviews and reviewed practices from other institutions to develop a feeding protocol, which was implemented in December 2009. The team tracked intervention compliance and occurrence of NEC stage ⩾ 2. In May 2010, we reviewed our nasogastric tube practice and relevant literature to develop a second intervention that reduced nasogastric tube indwelling time. The infants were divided into three groups: baseline (January 2008 to Novovember 2009, n219), QI phase 1 (December 2009 to May 2010, n62) and QI phase 2 (June 2010 to November 2011, n170). RESULT: The NEC incidence did not decrease after implementation of the feeding protocol in QI phase 1 (19.4%) but did decline significantly after changing nasogastric tube management in QI phase 2 (2.9%). Multivariable logistic regression analysis demonstrated a significant relationship between QI phase and the incidence of NEC. CONCLUSION: QI initiatives were effective in decreasing NEC incidence in our high human milk-feeding NICU. Nasogastric tube bacterial contamination may have contributed to our peak in NEC incidence.

Pediatric hypoventilation syndromes.

Hypoventilation syndromes are an uncommon but important group of respiratory control disorders in infants and children. Congenital central hypoventilation syndrome (CCHS) is the principal and most important example. No specific anatomical or biochemical mechanism has yet been identified. This article summarizes current knowledge regarding CCHS in infants and children, and emphasizes the most recent and most important publications. The most recent advances in CCHS pertain to its genetics, pathophysiology, diagnosis, and treatment and provide state-of-the-art information regarding advances in diaphragm pacing, responses to exercise, and long-term outcome. CCHS is now being recognized more frequently, treatment is more successful, and long-term outcomes are encouraging with timely diagnosis, state-of-the-art treatment, and comprehensive follow-up at an experienced pediatric referral center.