Hypertrophic pyloric stenosis in premature infants: evaluation of sonographic criteria and short-term outcomes

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.

Nationwide trends of laparoscopic pyloromyotomy in patients with infantile hypertrophic pyloric stenosis in Germany: A slow path forward

Since its introduction, laparoscopic pyloromyotomy (LP), has become increasingly popular in many countries. We have noticed an attenuated trend in Germany. The aim of this study was to analyse the distribution of open and LP in Germany. The national database of administrative claims data of the Institute for the Remuneration System in Hospitals (InEK) was analysed regarding numbers of patients with pyloromyotomy in the years 2019-2021. The German quality reports of the hospitals of 2019 and 2020 were analyzed regarding the number of procedures performed per hospital and pediatric surgical department. A total of 2050 patients underwent pyloromyotomy. The incidence of hypertrophic pylorus stenosis (HPS) was 699 and 657 patients in 2019 and 2021, respectively. Regarding age, 31.1% were admitted before 28 days of age. LP gradually increased from 216 patients (30.9%) in 2019 to 239 patients (36.4%) in 2021. Thirty-three laparoscopic operations (4.8%) were converted to an open approach. In 24 of all patients, there was an injury to the stomach, in 20 patients to the duodenum, needing repair with sutures. Analysis of the quality reports indicated that 44% of pediatric surgical departments performed LP. Although LP has became more prevalent in Germany recently, about two thirds of patients still undergo an open procedure.

Diagnostic accuracy of palpation and ultrasonography for diagnosing infantile hypertrophic pyloric stenosis: a systematic review and meta-analysis

Objective:

Although infantile hypertrophic pyloric stenosis (IHPS) is a well-known disease, there is no systematic review regarding the optimal diagnostic strategy. We conducted a systematic review and meta-analysis to obtain diagnostic accuracy of all methods to diagnose IHPS.

Methods:

According to the Preferred Reported Items for Systematic Reviews and Meta-Analysis guidelines, we searched MEDLINE and Embase to identify studies reporting sensitivity and specificity of all methods used to diagnose IHPS. Inclusion criteria were infants with suspicion of/or diagnosed with IHPS who underwent pyloromyotomy or had clinical follow-up. A random-effects model was used to obtain pooled estimates of sensitivity, specificity and area under the receiver operating characteristic curve.

Results:

After screening 5364 studies, we included 43 studies with in total 6085 infants (n = 4241 IHPS; n = 1844 controls). The diagnostic sensitivity of palpation ranged from 10.0 to 93.4% and decreased over time. Different parameters for ultrasonography were found. Most used parameters were pyloric muscle thickness (PMT) ≥ 3 mm (pooled sensitivity 97.6% and specificity 98.8%), PMT ≥ 4 mm (pooled sensitivity 94.0% and specificity 98.0%) or a combination of PMT ≥ 4 mm and/or pyloric canal length ≥16 mm (pooled sensitivity 94.0% and specificity 91.7%). The AUC showed high diagnostic accuracy (0.997, 0.966 and 0.981 respectively), but large heterogeneity exists. Due to the large differences in cut-off values no meta-analysis could be conducted for pyloric canal length and pyloric diameter.

Conclusion:

Palpation has limited sensitivity in diagnosing IHPS. We showed that ultrasonography has highest diagnostic accuracy to diagnose IHPS and we advise to use PMT ≥ 3 mm as cut-off.

Advances in knowledge:

This is the first systematic review and meta-analysis on diagnosing IHPS, which summarizes the available literature and may be used as a guideline.

Stratifying features for diagnosing hypertrophic stenosis on ultrasound: a diagnostic accuracy study

Background

Our aims were to determine if the diagnostic threshold for diagnosing hypertrophic pyloric stenosis (HPS) on ultrasound scan (USS) should be adjusted based on birth weight (BW), current weight (CW), gestational age (GA), chronological age (CA) or corrected gestational age (CGA).

Methods

All patients who underwent either an USS and pyloromyotomy (Group 1) or an USS for possible HPS (Group 2) at our tertiary centre between July 2013 and June 2019 were identified. Ideal threshold values are identified by measuring Youden's Index (J = sensitivity + specificity – 1; higher is better). Mean maximum Youden's Index for stratified results was compared to that for combined results.

Results

Two hundred and eighty‐four patients were included (142 patients in both Group 1 and Group 2). Combined maximum Youden's Index for all patients was 0.92 for pyloric canal thickness (PMT) and 0.87 for pyloric canal length (PCL). Mean maximum Youden's Index was higher when patients were stratified by GA, CGA, BW or CW, and equivalent for CA. For pyloric canal length (PCL), mean maximum Youden's Index was lower for all variables when stratified compared to combined. There was no visual trend observed in the diagnostic thresholds between groups.

Conclusion

Stratifying USS PMT diagnostic thresholds values based on age and weight is statistically more accurate than a single threshold in diagnosing HPS. However, the lack of visual correlation indicates a larger dataset is required to validate these results.

Current Applications of Pediatric Abdominal Point-of-Care Ultrasound

Point-of-care ultrasound (POCUS) for pediatric abdominal symptoms has expanded in both the inpatient and outpatient settings. POCUS may be used to aid in the diagnosis of appendicitis, hypertrophic pyloric stenosis, and intussusception in the pediatric population. This article reviews the benefits of POCUS for the diagnosis of these pediatric pathologies. This article also provides instruction on how to perform these important examinations. [Pediatr Ann. 2021;50(10):e419-e423.].

Differences in Outcomes Based on Sex for Pediatric Patients Undergoing Pyloromyotomy

BACKGROUND

Males and females are known to have varied responses to medical interventions. Our study aimed to determine the effect of sex on surgical outcomes after pyloromyotomy.

MATERIALS AND METHODS

Using the Kids' Inpatient Database for the years 2003-2012, we performed a serial, cross-sectional analysis of a nationally representative sample of all patients aged <1 y who underwent pyloromyotomy for hypertrophic pyloric stenosis. The primary predictor of interest was sex. Outcomes included mortality, in-hospital complications, cost, and length of stay. Regression models were adjusted by race, age group, comorbidity, complications, and whether operation was performed on the day of admission with region and year fixed effects.

RESULTS

Of 48,834 weighted operations, 81.8% were in males and 18.2% were in females. The most common reported race was white (47.3%) and most of the patients were ≥29 days old (72.5%). There was no difference in the odds of postoperative complications, but females had a significantly longer length of stay (incidence rate ratio, 1.28; 95% confidence interval [95% CI], 1.18-1.39; P ≤ 0.01), higher cost (5%, 95% CI, 1.02-1.08; P ≤ 0.01), and higher odds of mortality (odds ratio, 3.26; 95% CI, 1.52-6.98; P ≤ 0.01).

CONCLUSIONS

Our study demonstrated that females had worse outcomes after pyloromyotomy compared with males. These findings are striking and are important to consider when treating either sex to help set physician and family expectations perioperatively. Further studies are needed to determine why such differences exist and to develop targeted treatment strategies for both females and males with pyloric stenosis.

Effects of Hospital Volume on Patient Outcomes and Costs in Infants With Pyloric Stenosis

BACKGROUND

There is a well-established relationship between surgical volume and outcomes after complex pediatric operations. However, this relationship remains unclear for common pediatric procedures. The aim of our study was to investigate the effect of hospital volume on outcomes after hypertrophic pyloric stenosis (HPS).

METHODS

The Kid's Inpatient Database (2003-2012) was queried for patients with congenital HPS, who underwent pyloromyotomy. Hospitals were stratified based on case volume. Low-volume hospitals performed the lowest quartile of pyloromyotomies per year and high-volume hospitals managed the highest quartile. Outcomes included complications, mortality, length of stay (LOS), and cost.

RESULTS

Overall, 2137 hospitals performed 51,792 pyloromyotomies. The majority were low-volume hospitals (n = 1806). High-volume hospitals comprised mostly children's hospitals (68%) and teaching hospitals (96.1%). The overall mortality rate was 0.1% and median LOS was 2 d. High-volume hospitals had lower overall complications (1.8% versus 2.5%, P < 0.01) and fewer patients with prolonged LOS (17.0% versus 23.5%, P < 0.01) but had similar rates of individual complications, similar mortality, and equivalent median LOS as low-volume hospitals. High-volume hospitals also had higher costs by $1132 per patient ($5494 versus $4362, P < 0.01). Regional variations in outcomes and costs exist with higher complication rates in the West and lower costs in the South. There was no association between mortality or LOS with hospital volume or region.

CONCLUSIONS

Patients with pyloric stenosis treated at high-volume hospitals had no clinically significant difference in outcomes despite having higher costs. Although high-volume hospitals offer improved outcomes after complex pediatric surgeries, they may not provide a significant advantage over low-volume hospitals in managing common pediatric procedures, such as pyloromyotomy for congenital HPS.

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.

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.

Advances in infantile hypertrophic pyloric stenosis

Infantile hypertrophic pyloric stenosis (IHPS) is a common condition in infancy, characterized by an acquired narrowing of the pylorus, which requires surgery. These infants usually present with projectile, nonbilious vomiting, with a palpable 'olive' in the abdomen and sometimes a 'peristaltic wave' after being fed with formula or breast milk. Although IHPS is a common disorder, its etiology is largely unknown. Surgical intervention is the standard treatment, preoperative preparation, however is essential to optimal outcome. In this review, the latest advances in IHPS regarding epidemiology, etiology, diagnostics and treatment will be discussed.