Association of prematurity with the development of infantile hypertrophic pyloric stenosis

Azithromycin therapy for prevention of chronic lung disease of prematurity (AZTEC): a multicentre, double-blind, randomised, placebo-controlled trial

BACKGROUND

Systematic reviews have reported conflicting evidence on whether macrolide antibiotics reduce rates of chronic lung disease of prematurity (CLD) in at-risk preterm infants born at less than 30 weeks' gestation, including in those colonised with pulmonary Ureaplasma spp. Since an adequately powered trial has been lacking, we aimed to assess if the macrolide azithromycin improved survival without the development of physiologically defined moderate or severe CLD in preterm infants.

METHODS

AZTEC was a multicentre, double-blind, randomised, placebo-controlled trial conducted in 28 tertiary neonatal intensive care units in the UK. Infants were eligible if they were born at less than 30 weeks' gestation and had received at least 2 h of either non-invasive (continuous positive airway pressure or humidified high flow nasal cannula therapy) or invasive respiratory support (via endotracheal tube) within 72 h of birth. Eligible infants were randomly allocated in a 1:1 ratio using random permuted blocks of four to receive either intravenous azithromycin at 20 mg/kg per day for 3 days followed by 10 mg/kg for 7 days, or to placebo. Allocation was stratified by centre and gestational age at birth (<28 weeks vs ≥28 weeks). Azithromycin and placebo vials were encased in tamper-evident custom cardboard cartons to ensure masking for clinicians, parents, and the research team. The primary outcome was survival without development of physiologically defined moderate or severe CLD at 36 weeks' postmenstrual age. Outcomes and safety were analysed on an intention-to-treat basis (all randomly allocated infants, regardless of any post-randomisation events). The study was registered with ISRCRN (11650227) and is closed.

FINDINGS

Infants were recruited between Oct 9, 2019, and March 22, 2022. 799 (53·1%) of 1505 eligible infants underwent random allocation; three infants were withdrawn, including consent to use their data, leaving 796 infants for analysis. Survival without moderate or severe CLD occurred in 166 (42%) of 394 infants in the intervention group and 179 (45%) of 402 in the placebo group (three-level adjusted OR [aOR] 0·84, 95% CI 0·55-1·29, p=0·43). Pulmonary Ureaplasma spp colonisation did not influence treatment effect. Overall, seven serious adverse events were reported for the azithromycin group (five graded as severe, two as moderate), and six serious adverse events were reported in the placebo group (two severe, two moderate, and two mild), as assessed by the local principal investigators.

INTERPRETATION

Since prophylactic use of azithromycin did not improve survival without development of physiologically-defined CLD, regardless of Ureaplasma spp colonisation, it cannot be recommended in clinical practice.

FUNDING

UK National Institute for Health and Care Research.

Perinatal risk factors for infantile hypertrophic pyloric stenosis: A systematic review and meta-analysis

BACKGROUND

Infantile hypertrophic pyloric stenosis (IHPS) is one of the most common diseases that require surgical intervention amongst the paediatric population. Although the treatment and the diagnosis of pyloric stenosis are well established, the perinatal risk factors associated with it still need further investigation.

METHODS

We searched the following databases: Cochrane, Google Scholar, PubMed, and Scopus. Studies were included if they were case-control or cohort in design and studied the perinatal risk factors associated with IHPS. The quality of the included studies was assessed using the Newcastle-Ottawa scale (NOS).

RESULTS

Twenty-one articles were included in this meta-analysis, including 18,104,753 participants. Our analysis showed a significant association between IHPS and male sex (RR=2.71, 95% CI:1.93-3.78), maternal smoking (RR=1.75, 95% CI: 1.54 - 2.00), bottle-feeding (RR=1.68, 95% CI: 1.42 - 1.98), being first born (RR=1.23, 95% CI:1.07-1.40), African ethnicity (RR=0.51, 95% CI: 0.35-0.75), and cesarean section (RR=1.57, 95% CI: 1.49-1.66). On the contrary, there was no significant association between IHPS and multiple gestations, preterm labour, being born in summer, and small for gestational age (SGA).

CONCLUSION

In conclusion, our analysis showed that male sex, bottle feeding, maternal smoking and African ethnicity were significantly associated with the risk of IHPS. However, most of the included articles were retrospective in design which necessitates conducting future prospective well-designed studies to further investigate the risk factors of IHPS.

Azithromycin for Eradication of Ureaplasma and Prevention of Bronchopulmonary Dysplasia in Preterm Neonates in the Neonatal Intensive Care Unit

Azithromycin has been explored as a treatment option for eradication of Ureaplasma and prevention of bronchopulmonary dysplasia (BPD) in preterm neonates. However, there is debate about the need for eradication of Ureaplasma and whether azithromycin is safe and efficacious for this indication. This literature review provides an overview of the evidence for use of azithromycin for eradication of Ureaplasma and prevention of BPD, including dosing and duration of azithromycin used in these studies. The literature search included articles published in the English language in Medline and PubMed from 1946 to January 2022. Relevant citations within identified articles were also reviewed. A total of 9 studies representing 388 neonates were included. The percentage of neonates that tested positive for Ureaplasma in these studies ranged from 18.6% to 57.1%. Azithromycin was initiated at <3 days of life in 8 studies (88.9%). Dosing was variable and ranged from 5 to 20 mg/kg/dose administered once daily, and the duration of treatment ranged from 1 to 35 days. Most studies used intravenous azithromycin. Overall, azithromycin was more efficacious than placebo at Ureaplasma eradication; however, most of these studies did not find a difference in the incidence of BPD between patients receiving azithromycin versus placebo. No adverse effects, specifically pyloric stenosis or QT interval prolongation, were noted in these studies.

Randomized trial of azithromycin to eradicate Ureaplasma respiratory colonization in preterm infants: 2-year outcomes

BACKGROUND

To assess the potential impact of azithromycin treatment in the first week following birth on 2-year outcomes in preterm infants with and without Ureaplasma respiratory colonization who participated in a double-blind, placebo-controlled randomized controlled trial.

METHODS

Respiratory morbidity was assessed at NICU discharge and at 6, 12, and 22-26 months corrected age using pulmonary questionnaires. Comprehensive neurodevelopmental assessments were completed between 22 and 26 months corrected age. The primary and secondary composite outcomes were death or severe respiratory morbidity and death or moderate-severe neurodevelopmental impairment, respectively, at 22-26 months corrected age.

RESULTS

One hundred and twenty-one randomized participants (azithromycin, N = 60; placebo, N = 61) were included in the intent-to-treat analysis. There were no significant differences in death or serious respiratory morbidity (34.8 vs 30.4%, p = 0.67) or death or moderate-severe neurodevelopmental impairment (47 vs 33%, p = 0.11) between the azithromycin and placebo groups. Among all trial participants, tracheal aspirate Ureaplasma-positive infants experienced a higher frequency of death or serious respiratory morbidity at 22-26 months corrected age (58%) than tracheal aspirate Ureaplasma-negative infants (34%) or non-intubated infants (21%) (p = 0.028).

CONCLUSIONS

We did not observe strong evidence of a difference in long-term pulmonary and neurodevelopment outcomes in preterm infants treated with azithromycin in the first week of life compared to placebo.

IMPACT

No strong evidence of a difference in long-term pulmonary and neurodevelopment outcomes was identified at 22-26 months corrected age in infants treated with azithromycin in the first week of life compared to placebo. The RCT is the first study of 2-year pulmonary and neurodevelopmental outcomes of azithromycin treatment in ELGANs. Provides evidence that ELGANs with lower respiratory tract Ureaplasma have the most frequent serious respiratory morbidity in the first 2 years of life, suggesting that a Phase III trial of azithromycin to prevent BPD targeting this population is warranted.

The Dutch Incidence of Infantile Hypertrophic Pyloric Stenosis and the Influence of Seasons

INTRODUCTION

 Studies report contradicting results on the incidence of infantile hypertrophic pyloric stenosis (IHPS) and its association with seasons. We aim to assess the IHPS incidence in the Netherlands and to determine whether seasonal variation is present in a nationwide cohort.

MATERIALS AND METHODS

 All infants with IHPS hospitalized in the Netherlands between 2007 and 2017 were included in this retrospective cohort study. Incidence rates per 1,000 livebirths (LB) were calculated using total number of LB during the matched month, season, or year, respectively. Seasonal variation based on month of birth and month of surgery was analyzed using linear mixed model and one-way ANOVA, respectively.

RESULTS

 A total of 2,479 infants were included, of which the majority was male (75.9%). Median (interquartile range) age at surgery was 34 (18) days. The average IHPS incidence rate was 1.28 per 1,000 LB (variation: 1.09-1.47 per 1,000 LB). We did not find a conclusive trend over time in IHPS incidence. Differences in incidence between season of birth and season of surgery were not significant (p = 0.677 and p = 0.206, respectively).

CONCLUSION

 We found an average IHPS incidence of 1.28 per 1,000 LB in the Netherlands. Our results showed no changing trend in incidence and no seasonal variation.

Infantile hypertrophic pyloric stenosis in Bosnia and Herzegovina: A retrospective cohort study from the largest tertiary care facility

BACKGROUND

Infantile hypertrophic pyloric stenosis (IHPS) is the most common condition requiring surgery in infancy, but the etiology of IHPS is still unclear. The study aimed to analyze the epidemiological and clinical features of the infants with IHPS in our setting and determine the yearly trends in IHPS incidence in the Sarajevo Canton between 2007 and 2016.

METHODS

We retrospectively analyzed epidemiologic, clinical, and operative data of all infants undergoing pyloromyotomy for IHPS over ten years in the largest tertiary care facility in Bosnia and Herzegovina.

RESULTS

Fifty-three IHPS patients were diagnosed, yielding an overall incidence of 1.17 per 1000 live births (1.25 and 1.09 cases in 2007-2011 and 2012-2016, respectively). IHPS was more prevalent among male infants (ratio 6.6:1, p < 0.001). The mean age at onset of symptoms was 39.6 days (range, 17-107 days). The estimated median time from symptoms onset to hospitalization was 11 days (range, 1-17 days). The mean age at diagnosis was significantly longer in premature infants compared with term infants (p = 0.003). Both first-born rank and bottle-feeding were significantly associated with IHPS (p = 0.001 and p = 0.04, respectively). No seasonal variation associated with IHPS was detected (p = 0.25). No evidence was found of differences in the incidence of IHPS related to maternal age (p = 0.24) and smoking (p = 0.59).

CONCLUSION

Our data indicate a declining trend and provide insights into the clinical characteristics of IHPS in Bosnia and Herzegovina. Most of the obtained results are in line with the published data and could improve the quality of local pediatric services.

Hypertrophic Pyloric Stenosis

Hypertrophic pyloric stenosis is a common condition seen in the first 1 to 3 months after birth. Patients typically present with nonbilious projectile emesis after feeds that may result in hypokalemic, hypochloremic metabolic alkalosis. Although inability to tolerate feeds is frequently seen with self-limited conditions such as reflux, a low threshold to obtain an ultrasonographic image is important to prevent a delay in diagnosis. Although operative intervention is the treatment, it is imperative that patients are hydrated and serum electrolyte concentrations normalized before the induction of anesthesia. Laparoscopic pyloromyotomy is safe and effective. Postoperative emesis is normal, and reassurance to parents is appropriate. There is no significant long-term physiologic impairment from pyloric stenosis after successful surgical intervention.

Randomised trial of azithromycin to eradicate Ureaplasma in preterm infants

OBJECTIVE

To test whether azithromycin eradicates Ureaplasma from the respiratory tract in preterm infants.

DESIGN

Prospective, phase IIb randomised, double-blind, placebo-controlled trial.

SETTING

Seven level III-IV US, academic, neonatal intensive care units (NICUs).

PATIENTS

Infants 24⁰-28⁶ weeks' gestation (stratified 24⁰-26⁶; 27⁰-28⁶ weeks) randomly assigned within 4 days following birth from July 2013 to August 2016.

INTERVENTIONS

Intravenous azithromycin 20 mg/kg or an equal volume of D5W (placebo) every 24 hours for 3 days.

MAIN OUTCOME MEASURES

The primary efficacy outcome was Ureaplasma-free survival. Secondary outcomes were all-cause mortality, Ureaplasma clearance, physiological bronchopulmonary dysplasia (BPD) at 36 weeks' postmenstrual age, comorbidities of prematurity and duration of respiratory support.

RESULTS

One hundred and twenty-one randomised participants (azithromycin: n=60; placebo: n=61) were included in the intent-to-treat analysis (mean gestational age 26.2±1.4 weeks). Forty-four of 121 participants (36%) were Ureaplasma positive (azithromycin: n=19; placebo: n=25). Ureaplasma-free survival was 55/60 (92% (95% CI 82% to 97%)) for azithromycin compared with 37/61 (61% (95% CI 48% to 73%)) for placebo. Mortality was similar comparing the two treatment groups (5/60 (8%) vs 6/61 (10%)). Azithromycin effectively eradicated Ureaplasma in all azithromycin-assigned colonised infants, but 21/25 (84%) Ureaplasma-colonised participants receiving placebo were culture positive at one or more follow-up timepoints. Most of the neonatal mortality and morbidity was concentrated in 21 infants with lower respiratory tract Ureaplasma colonisation. In a subgroup analysis, physiological BPD-free survival was 5/10 (50%) (95% CI 19% to 81%) among azithromycin-assigned infants with lower respiratory tract Ureaplasma colonisation versus 2/11 (18%) (95% CI 2% to 52%) in placebo-treated infants.

CONCLUSION

A 3-day azithromycin regimen effectively eradicated respiratory tract Ureaplasma colonisation in this study.

TRIAL REGISTRATION NUMBER

NCT01778634.

Differential diagnosis of perinatal Bartter, Bartter and Gitelman syndromes

The common finding of hypokalemic alkalosis in several unrelated disorders may confound the early diagnosis of salt-losing tubulopathy (SLT). Antenatal Bartter syndrome (BS) must be considered in idiopathic early-onset polyhydramnios. Fetal megabladder in BS may allow its distinction from third-trimester polyhydramnios that occurs in congenital chloride diarrhea (CCD). Fetal megacolon occurs in CCD while fecal chloride >90 mEq/L in infants is diagnostic. Failure-to-thrive, polydipsia and polyuria in early childhood are the hallmarks of classic BS. Unlike BS, there is low urinary chloride in hypokalemic alkalosis of intractable emesis and cystic fibrosis. Rarely, renal salt wasting may result from cystinosis, Dent disease, disorders of paracellular claudin-10b and Kir4.1 potassium-channel deficiency. Acquired BS may result from calcimimetic up-regulation of a calcium-sensing receptor or autoantibody inactivation of sodium chloride co-transporters in Sjögren syndrome. A relatively common event of heterozygous gene mutations for Gitelman syndrome increases the likelihood of its random occurrence in certain diseases of adult onset. Finally, diuretic abuse is the most common differential diagnosis of SLT. Unlike the persistent elevation in BS, urinary chloride concentration losses waxes and wanes on day-to-day assessment in patients with diuretic misuse.

Pyloric Stenosis: National Trends in the Incidence Rate and Resource Use in the United States From 2012 to 2016

OBJECTIVES

Infantile hypertrophic pyloric stenosis (IHPS) is the most common reason for abdominal surgery in infants; however, national-level data on incidence rate and resource use are lacking. We aimed to examine the national trends in hospitalizations for IHPS and resource use in its management in the United States from 2012 to 2016.

METHODS

We performed a retrospective serial cross-sectional study using data from the National Inpatient Sample, the largest health care database in the United States. We included infants aged ≤1 year assigned an International Classification of Diseases, Ninth Revision, or International Classification of Diseases, 10th Revision, code for IHPS who underwent pyloromyotomy or pyloroplasty. We examined the temporal trends in the incidence rate (cases per 1000 live births) according to sex, insurance status, geographic region, and race. We examined resource use using length of stay (LOS) and hospital costs. Linear regression was used for trend analysis.

RESULTS

Between 2012 and 2016, there were 32 450 cases of IHPS and 20 808 149 live births (incidence rate of 1.56 per 1000). Characteristics of the study population were 82.7% male, 53% white, and 63.3% on Medicaid, and a majority were born in large (64%), urban teaching hospitals (90%). The incidence of IHPS varied with race, sex, socioeconomic status, and geographic region. In multivariable regression analysis, the incidence rate of IHPS decreased from 1.76 to 1.57 per 1000 (adjusted odds ratio 0.93; 95% confidence interval 0.92-0.93). The median cost of care was $6078.30, whereas the median LOS was 2 days, and these remained stable during the period.

CONCLUSIONS

The incidence rate of IHPS decreased significantly between 2012 and 2016, whereas LOS and hospital costs remained stable. The reasons for the decline in the IHPS incidence rate may be multifactorial.

Prevalence and descriptive epidemiology of infantile hypertrophic pyloric stenosis in the United States: A multistate, population-based retrospective study, 1999-2010

BACKGROUND

Antecedents for infantile hypertrophic pyloric stenosis (IHPS) vary across studies; therefore, we conducted a multistate, population-based retrospective study of the prevalence and descriptive epidemiology of IHPS in the United States (US).

METHODS

Data for IHPS cases (n = 29,554) delivered from 1999-2010 and enumerated from 11 US population-based birth defect surveillance programs, along with data for live births (n = 14,707,418) delivered within the same birth period and jurisdictions, were analyzed using Poisson regression to estimate IHPS prevalence per 10,000 live births. Additional data on deliveries from 1999-2005 from seven of these programs were analyzed using multivariable logistic regression to estimate adjusted prevalence ratios (aPR)s and 95% confidence intervals (CI)s for selected infant and parental characteristics.

RESULTS

Overall, IHPS prevalence from 1999-2010 was 20.09 (95% CI = 19.87, 20.32) per 10,000 live births, with statistically significant increases from 2003-2006 and decreases from 2007-2010. Compared to their respective referents, aPRs were higher in magnitude for males, preterm births, and multiple births, but lower for birth weights <2,500 g. The aPRs for all cases increased with decreasing parental age, maternal education, and maternal parity, but decreased for parental race/ethnicity other than non-Hispanic White. Estimates restricted to isolated cases or stratified by infant sex were similar to those for all cases.

CONCLUSIONS

This study covers one of the largest samples and longest temporal period examined for IHPS in the US. Similar to findings reported in Europe, estimates suggest that IHPS prevalence has decreased recently in the US. Additional analyses supported associations with several infant and parental characteristics.

Hernia recurrence following inguinal hernia repair in children

PURPOSE

We aimed to describe the incidence, timing, and predictors of recurrence following inguinal hernia repair (IHR) in children.

METHODS

We used the TRICARE claims database, a national cohort of >3 million child dependents of members of the U.S. Armed Forces. We abstracted data on children <12y who underwent IHR (2005-2014). Our primary outcome was recurrence (ICD9-CM diagnosis codes). We calculated incidence rates for the population and stratified by age, time from repair to recurrence, and multivariable logistic regression to determine predictors.

RESULTS

Nine thousand nine hundred ninety-three children met inclusion criteria. Age at time of IHR was ≤1y in 37%, 2-3y in 23%, 4-5y in 16%, and 5-12y in 24%. Median follow-up time was 3.5y (IQR:1.6-6.1). 137 patients recurred (1.4%), with an incidence of 3.46 per 1000 person-years. Over half occurred in children 0-1y at repair (60%). The majority occurred within a year following repair (median 209 days [IQR:79-486]). Children 0-1y had 2.53 times greater odds of recurrence (compared to >5y). Children with multiple comorbidities had 5.45 times greater odds compared to those with no comorbidities.

CONCLUSIONS

The incidence of recurrence following IHR is 3.46 per 1000 person-years. The majority occurred within a year of repair. Children ≤1y and those with multiple comorbidities were at increased risk.

LEVEL OF EVIDENCE

Prognosis Study, Level II.

Laparoscopic pyloromyotomy for hypertrophic pyloric stenosis: a survey of 407 children

INTRODUCTION

Pyloromyotomy is the standard care for hypertrophic pyloric stenosis. The traditional approach for this procedure is a right upper quadrant transverse incision, although other "open" approaches, such as circumumbilical or periumbilical incision have been described. The more recent approach used is laparoscopic pyloromyotomy (LP), but experience feedback is still debated and its benefits remain unproven. The aim of this study was to make a review of all our LP procedures with an objective evaluation according to the literature.

METHODS

A retrospective analysis of all the LPs performed in one University Children's Hospital between 1 January 1996, and 30 December 2015 was realized. Information regarding the patient's status, intraoperative and postoperative data was analyzed.

RESULTS

407 patients were included in this study. The mean operative time of the overall procedure was 24 ± 13 min, which significantly increased with the length of the pyloric muscle (p = 0.004) and significantly impacted the full feeding time (p = 0.006). 3.4% required conversion to an open procedure during the LP. We observed a significant correlation between conversion for mucosal perforation and weight loss (p = 0.04) and between conversion for mucosal perforation and preoperative weight (p = 0.002). A redo procedure was indicated in 3.7%, for incomplete pyloromyotomy each time. The mean postoperative hospital length of stay for all procedures was 1.6 ± 0.8 days. There were no inflammatory scars. None had incisional hernias or wound dehiscence.

DISCUSSION

LP procedure appeared to be as quick as the open procedure. Our results were similar to others series for intraoperative complications. According to operative time, this technique does not have an impact on operative room utilization. Vomiting duration at presentation in HPS does not seem to have a significant impact on postoperative outcomes. LP procedure causes little pain during the postoperative period. No wound complications were registered.

Perinatal risk factors for infantile hypertrophic pyloric stenosis: A meta-analysis

BACKGROUND

Infantile hypertrophic pyloric stenosis (IHPS) is the most common surgical cause of nonbilious vomiting in infancy. The etiology of IHPS is not completely understood. Hence, we performed a meta-analysis to investigate the association between perinatal factors and IHPS onset.

METHODS

The MEDLINE, EMBASE, PubMed and Cochrane Library databases were searched for studies published in English before December 2016. The combined odd ratios (ORs) and 95% confidence intervals (CIs) were calculated using random-effects models.

RESULTS

Fifteen studies were included. Several perinatal factors, including first-born (OR 1.19, 95% CI: 1.07-1.33), cesarean section delivery (OR 1.63, 95% CI: 1.53-1.73), preterm birth (OR 1.37, 95% CI: 1.12-1.67), and bottle-feed (OR 2.46, 95% CI: 1.76-3.43), were significantly associated with the IHPS onset. Among these, bottle-feed was the most significantly risk factor for IHPS onset. Although few studies have evaluated the relationship between perinatal factors and IHPS, they have major limitations including retrospective collection of data on perinatal events and testing of multiple hypotheses without appropriate statistical corrections.

CONCLUSIONS

First-born, cesarean section delivery, preterm birth, and bottle-feed are associated with the development of IHPS. Well-designed future studies are needed to help understand the etiology of IHPS.

TYPE OF STUDY

Systematic reviews and meta-analyses.

LEVEL OF EVIDENCE

Level III.

Application of color Doppler ultrasound combined with Doppler imaging artifacts in the diagnosis and estimate of congenital hypertrophic pyloric stenosis

Congenital Hypertrophic Pyloric Stenosis (CHPS) is a disease condition that is caused as a result of pylorus wall hypertrophy and hyperplasia. In this study, we used color Doppler flow imaging (CDFI) and Doppler artifacts technique to observe the blood flow of hypertrophic pylorus tissue and the dynamic imaging of liquid passing through the pyloric canal in CHPS infants. 65 cases of CHPS infants and 50 infants without CHPS served as control group. We found that there were statistically significant differences between the blood flow grade of muscular layer and mucosal layer between CHPS and control infants, but no significant differences were observed in the same group. Doppler artifacts technique demonstrated the whole process of contrast agent flow through pyloric canal was directly observed in 35 of 65 subjects, and the internal diameter of the pyloric canal was 1.93 ± 0.33mm.Conclusion that CDFI combined with color Doppler artifacts technique was proved to be effective to observe the distribution feature and blood flow grade in each layer of pyloric canal in CHPS patients. This method provides the evidence for judging the degree of pyloric stenosis clinically, and furnishes the basis of therapy along with its clinical significance and good application value.

Epidemiological and clinical characteristics of 304 patients with infantile hypertrophic pyloric stenosis in Anhui Province of East China, 2012-2015

OBJECTIVE

To analyze the clinical and epidemiological features of patients with infantile hypertrophic pyloric stenosis (IHPS) so as to provide scientific evidence for diagnosis and prevention of IHPS.

METHODS

We performed a retrospective study of infants with IHPS diagnosed from 2012 to 2015 at Anhui Provincial Children's Hospital. Demographic characteristics and clinical data were collected.

RESULTS

Three hundred four patients (264 males and 40 females) were studied, of which 94.7% were full term and 75.7% were bottle fed or mixed fed; 16.8% of the patients had other congenital malformations in combination with IHPS. The proportion of IHPS cases with hyponatremia, hypokalemia, and hypochloremia was 18.4%, 12.5%, and 53.9%. A negative correlation was found between duration of disease and serum electrolytes. The mean pyloric muscle thickness, pyloric length, and diameter were 4.8 ± 0.7 mm, 19.4 ± 2.5 mm, and 13.3 ± 1.8 mm, respectively. There were significant differences in muscle thickness, pyloric length, and diameter between short (≤14 d) and long (>14 d) durations of disease. All patients underwent pyloromyotomy, and postoperative recovery was good.

CONCLUSIONS

IHPS occurs mainly in male, full-term, bottle-fed or mixed-fed infants. Patients with long duration of disease were more likely to develop electrolyte disorder and thicker muscle layer. More attention should be paid to early discovery and diagnosis, which will help to improve the curative effect and prognosis of IHPS.

Prematurity Affects Age of Presentation of Pyloric Stenosis

Term infants with hypertrophic pyloric stenosis (HPS) typically present between 4 and 6 weeks. There is limited consensus, however, regarding age of presentation of premature infants. We aim to determine if there is an association between the degree of prematurity and chronological age of presentation of HPS. A total of 2988 infants who had undergone a pyloromyotomy for HPS were identified from the 2012 and 2013 NSQIP-P Participant Use Files. Two hundred seventeen infants (7.3%) were born prematurely. A greater degree of prematurity was associated with an older chronological age of presentation ( P < .0001). Prematurity was significantly associated with an increase in overall postoperative morbidity, reintubation, readmission, and postoperative length of stay. When clinicians evaluate an infant with nonbilious emesis with a history of prematurity, they should consider pyloric stenosis if the calculated postconceptional age is between 44 and 50 weeks. When counseling families of premature infants, surgeons should discuss the increased incidence of postpyloromyotomy morbidity.