Hypertrophic pyloric stenosis in newborns younger than 21 days: remodeling the path of surgical intervention

An Unusual Presentation of Pyloric Stenosis: A Case Report

A full-term newborn female presented with non-bilious emesis immediately after feeding and abdominal distension on day one of life with neither palpable abdominal mass nor electrolyte derangements. The baby was initially admitted to rule out gastrointestinal obstruction versus sepsis as a cause of vomiting and abdominal distension. Initial imaging studies involving an upper gastrointestinal (GI) series showed obstruction at the level of the duodenum, but it was only during surgical exploration that the diagnosis of infantile hypertrophic pyloric stenosis was made. This case report highlights the atypical presentation of pyloric stenosis and the need to investigate cases of vomiting immediately after feeding in a newborn with ultrasonography at the least to minimize complications.

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.

Brief Overview and Updates on Infantile Hypertrophic Pyloric Stenosis: Focus on Perioperative Management

Infantile hypertrophic pyloric stenosis is the most common surgical cause of vomiting in infancy. After adequate resuscitation, surgical pyloromyotomy is the standard of care for infants with pyloric stenosis. This article provides a brief overview and updates on hypertrophic pyloric stenosis in infants, with a focus on the surgical approach as well as perioperative management of this pathology. The most controversial aspect of the management of infants with pyloric stenosis is post-pyloromyotomy feeding, as there is no clear consensus in the literature on the best regimen. More randomized controlled trials are needed to establish the optimal resuscitation protocol in the preoperative phase and the ideal feeding regimen in the postoperative phase for infants with hypertrophic pyloric stenosis. [Pediatr Ann. 2021;50:(3):e136-e141.].

A decision tree to guide long term venous access placement in children and adolescents undergoing surgery for renal tumors

BACKGROUND/PURPOSE

While many children with renal tumors require long term venous access (VA) for adjuvant chemotherapy, certainly not all do. This study develops and tests a VA decision tree (DT) to direct the placement of VA in patients with renal tumors.

METHODS

Utilizing data readily available at surgery a VADT was developed. The VADT was tested retrospectively by 2 independent reviewers on a historic cohort. The ability of the VADT to appropriately select which patients would benefit from VA placement was tested.

RESULTS

160 patients underwent renal tumor surgery between 2005 and 2018. 70 (43.8%) patients met study criteria with median age of 45.1 months (range 1.1-224); 73% required VA. Using the VADT, VA placement was "needed" in 67.1% of patients and "deferred" in 32.9%. Interrater reliability was very high (kappa = 0.97, 95% CI 0.91-1, p < 0.001). The sensitivity and specificity of the VADT to correctly decide on VA placement were 0.92 (0.8-0.98) and 1 (0.79-1). Using the VADT, no patient would have undergone unnecessary VA placement. In reality, 4.3% of patients had an unnecessary VA placed which required a subsequent removal.

CONCLUSIONS

These preliminary data support the continued study of this VADT to guide intraoperative decisions regarding VA placement in patients with renal tumors.

LEVEL OF EVIDENCE

III - Study of diagnostic test.

Predictive factors for time to full enteral feeding after pyloromyotomy for infantile hypertrophic pyloric stenosis

Background

The aim of the study was to evaluate how different parameters in the preoperative, perioperative, and postoperative period affect time to full enteral feeding (TFEF) in children undergoing pyloromyotomy.

Methods

A retrospective study of all children operated for infantile hypertrophic pyloric stenosis between 2001 and 2017 was conducted. Parameters in demographics and in the preoperative and postoperative period were evaluated against TFEF (hours) using linear regression models.

Results

In the whole cohort of 175 children, mean TFEF was 47 hours with Standard Deviation (SD) of ±35. In the multivariate model, TFEF decreased with age [beta (B): −0.62; 95% confidence interval (95% CI) −1.05 to −0.19; p=0.005) and increased with the presence of severe underlying disease (congenital heart defect or syndrome) (B: 26.5; 95% CI 3.3 to 49.7; p=0.026). Hence, for every day of age, the time to fully fed decreased by 0.6 hour, and the presence of an underlying disease increased the time to fully fed with over one day. TFEF did not seem to be affected by prematurity, weight loss, symptom duration, preoperative acid/base balance or electrolyte values, surgical method, or method of postoperative feeding.

Conclusions

TFEF decreased with higher age and increased in children with a severe underlying disease. These results may be useful in providing adequate parental information regarding what affects TFEF and the length of hospital stay.

Pediatric emergency gastrointestinal ultrasonography: pearls & pitfalls

Ultrasonography is an essential tool in pediatric imaging, particularly in the emergency setting. Although ultrasound is often the favored initial modality for abdominal imaging in children, it is highly operator-dependent and therefore prone to misinterpretation which can lead to false positive or negative exams, or even incorrect diagnoses. Conditions discussed in this series include ileocolic intussusception, hypertrophic pyloric stenosis, appendicitis, and ingested foreign bodies. We will review diagnostic criteria, highlight crucial findings, and illustrate commonly-encountered difficulties and mimics.

Infantile hypertrophic pyloric stenosis - Our experience and challenges in a developing country

BACKGROUND

This study aims to evaluate the experience and challenges in managing patients with infantile hypertrophic pyloric stenosis (IHPS).

PATIENTS AND METHODS

From January 2007 to December 2015, data from patients with IHPS were retrospectively acquired and analyzed using SPSS version 15. Pearson correlation used to assess linear relationships and Student t-test to compare means. P < 0.05 was taken as statistically significant. Results were expressed as percentages, means ± standard deviation and illustrated in tables and graphs.

RESULTS

Twenty-six cases were managed with the mean age at diagnosis of 49.16 ± 21.4 days. Mean birth weight was 3.7 kg and mean weight at presentation was 3.3 kg. Firstborn was affected in 29%; 91% were term deliveries; 9% were post-term; none was preterm; and 36% were exclusively breastfed. Mean duration of symptoms was 25.6 ± 18.9 days. Hyponatraemia was seen in 36%, hypokalaemia 37.5%, alkalosis 35% and hypochloraemia 62%. Mean pyloric tumour length was 22.85 ± 6.56 mm and pyloric wall thickness 5.51 ± 1.36 mm. There was a significant correlation between duration of symptoms and serum potassium level (R = -0.6326, P = 0.002). Mean symptom duration in patients with hypokalaemia was 39.88 ± 23.41 days and without hypokalaemia 17.15 ± 9.78 days (P = 0.006). Mean hospital stay was 9.45 ± 3.27 days. Four patients developed four complications and three patients died (11.5%). Mean age at presentation for pre-operative mortalities was 84 ± 39 days and 46 ± 17.98 days for others (P = 0.015).

CONCLUSIONS

IHPS presents late in our environment and occurs mainly in term males. There is a significant positive relationship between duration of symptoms and serum potassium level and the mean duration of symptoms was significantly longer in those with hypokalaemia. Pre-operative mortality was significantly associated with longer duration of symptoms.

Pediatric emergency medicine point-of-care ultrasound: summary of the evidence

The utility of point-of-care ultrasound is well supported by the medical literature. Consequently, pediatric emergency medicine providers have embraced this technology in everyday practice. Recently, the American Academy of Pediatrics published a policy statement endorsing the use of point-of-care ultrasound by pediatric emergency medicine providers.  To date, there is no standard guideline for the practice of point-of-care ultrasound for this specialty. This document serves as an initial step in the detailed "how to" and description of individual point-of-care ultrasound examinations.  Pediatric emergency medicine providers should refer to this paper as reference for published research, objectives for learners, and standardized reporting guidelines.

Abdominal ultrasonography of the pediatric gastrointestinal tract

Ultrasound is an invaluable imaging modality in the evaluation of pediatric gastrointestinal pathology; it can provide real-time evaluation of the bowel without the need for sedation or intravenous contrast. Recent improvements in ultrasound technique can be utilized to improve detection of bowel pathology in children: Higher resolution probes, color Doppler, harmonic and panoramic imaging are excellent tools in this setting. Graded compression and cine clips provide dynamic information and oral and intravenous contrast agents aid in detection of bowel wall pathology. Ultrasound of the bowel in children is typically a targeted exam; common indications include evaluation for appendicitis, pyloric stenosis and intussusception. Bowel abnormalities that are detected prenatally can be evaluated after birth with ultrasound. Likewise, acquired conditions such as bowel hematoma, bowel infections and hernias can be detected with ultrasound. Rare bowel neoplasms, vascular disorders and foreign bodies may first be detected with sonography, as well. At some centers, comprehensive exams of the gastrointestinal tract are performed on children with inflammatory bowel disease and celiac disease to evaluate for disease activity or to confirm the diagnosis. The goal of this article is to review up-to-date imaging techniques, normal sonographic anatomy, and characteristic sonographic features of common and uncommon disorders affecting the gastrointestinal tract in children.

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.

The ins and outs of pyloromyotomy: what we have learned in 35 years

PURPOSE/BACKGROUND

The aim of the study is to evaluate a large series of infantile hypertrophic pyloric stenosis (IHPS) patients treated by one pediatric surgeon focusing on their diagnostic difficulties and complications.

METHODS

From July 1969 to December 2003 (inclusive), the charts of 791 infants with IHPS were retrospectively reviewed.

RESULTS

There were 647 (82%) males and 144 (18%) females; mean age was 38 days, median 51 (range 7 days-10 months). When ultrasonography (US) was routinely used (1990), the age at diagnosis decreased to <40 days. The mean weight before and after routine US was 3.2 kg, median 3 (range 1.5-6). Twenty-five (3.1%) were premature at diagnosis, mean age 49 days, median 56, (range 1-3 months) and mean weight 2.5 kg, median 2.3 (range 1.5-3.2). Eighty-one (10%) had a positive family history. Forty-four (5%) were non-Caucasians. Seventy-five (9 %) had other medical conditions, anomalies and/or associated findings. Sixty (7%) patients had abnormal preoperative electrolytes. Ten (1.2%) pylorics occurred after newborn operations. Of the entire total (791) who were treated, there were 13 (1.7%) not operated on. All operations were done open initially through one of two right upper quadrant incisions, and then through an upper midline incision under general endotracheal anesthesia; 14 (1.7 %) had concomitant procedures. Prophylactic antibiotics (from 1982) decreased the wound infection rate to 3.9%. There were a total of 87 (10%) complications which included 9 (1.1%) intraoperative, (including mistaken diagnoses) 78 (9%) postoperative: 59 (2%) early (<1 month) and 19 (2.4%) late (>1 month). The 13 (1.6%) postoperative transfers (12 from non-pediatric surgeons) had 16 (18%) complications (including 1 death); five (33%) requiring reoperation (4 incomplete, 1 perforation). There were two deaths.

CONCLUSIONS

IHPS should be considered in any vomiting infant. US allows earlier diagnosis. Serious complications are uncommon and avoidable, but recognizable and easily corrected. Higher surgeon volume of pyloromyotomies (>14 per year) is associated with fewer complications.

Single-site umbilical laparoscopic pyloromyotomy in neonates less than 21-day old

PURPOSE

Single-site umbilical laparoscopic pyloromyotomy for hypertrophic pyloric stenosis in neonates <3-week old has rarely been reported in the literature. This article reports our initial experience with this procedure.

METHODS

Overall, 13 cases of hypertrophic pyloric stenosis occurred in neonates <3-week old from January 2010 to April 2013 in our hospital. All neonates were treated by a single-site laparoscopic procedure. A 5-mm trocar and endoscope were introduced through an incision in the center of the umbilicus, and two 3-mm working instruments were inserted directly into the abdomen via separate lateral fascial stab incisions in the umbilical fold, and a single-site umbilical laparoscopic pyloromyotomy was then performed.

RESULTS

The procedure was performed in 13 infants (12 male) with mean age of 17.3 days. The average length of the operation was 26 min. The mean postoperative hospital stay was 4.5 days. All patients were discharged home on full feeds. Follow-up examinations were scheduled 2 to 6 weeks after discharge, and no postoperative complications were noted in any of the patients.

CONCLUSION

These cases had shorter and thinner pylori than their older counterparts. However, the laparoscopic procedure was safe and feasible, with good postoperative results and excellent cosmesis. Surgeons should have a firm foundation of advanced minimal access surgical skills prior to attempting the procedure.

Evaluation of hypertrophic pyloric stenosis by pediatric emergency physician sonography

OBJECTIVES

The objective was to evaluate the accuracy of pediatric emergency physician (EP) sonography for infants with suspected hypertrophic pyloric stenosis (HPS).

METHODS

This was a prospective observational pilot study in an urban academic pediatric emergency department (PED). Patients were selected if the treating physician ordered an ultrasound (US) in the department of radiology for the evaluation of suspected HPS.

RESULTS

Sixty-seven patients were enrolled from August 2009 through April 2012. When identifying the pylorus, pediatric EPs correctly identified all 10 positive cases, with a sensitivity of 100% (95% confidence interval [CI] = 62% to 100%) and specificity of 100% (95% CI = 92% to 100%). There was no statistical difference between the measurements obtained by pediatric EPs and radiology staff for pyloric muscle width or length (p = 0.5 and p = 0.79, respectively).

CONCLUSIONS

Trained pediatric EPs can accurately assess the pylorus with US in the evaluation of HPS with good specificity.

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

PURPOSE

To examine the sonographic measurements of pyloric muscle and pyloric thickness in premature infants with hypertrophic pyloric stenosis (HPS) and to correlate these measurements with patients variables. We aimed also to evaluate the clinical features and short-term outcome of HPS in premature compared to term infants.

METHODS

The medical notes and the pyloric ultrasounds of all premature infants (<37 weeks) admitted to the Neonatal Surgical Unit with HPS over a 20-year period (1990-2010) were retrospectively reviewed. Sonographic measurements of the pyloric length, muscle thickness and the pyloric ratio (muscle thickness divided by pyloric diameter) were correlated to weight at presentation, duration of symptoms and corrected gestational age. Multiple regression and correlation analysis was carried out.

RESULTS

Seventy-five preterm infants were identified (51M:24F). Median gestational age was 34 weeks. Median weight at presentation was 2.74 kg. Forty-two had an ultrasound (US) before surgery, 37 measurements were analysed. Pyloric length, muscle thickness and pyloric ratio were not affected by weight at presentation (p = 0.67, p = 0.122, p = 0.849), corrected gestational age (CGA) (p = 0.921, p = 0.678, p = 0.076), or duration of symptoms (p = 0.827, p = 0.268, p = 0.281). Mean length of stay was 6 days and overall complication rate was 27 %, both higher than reported in term infants (p < 0.001).

CONCLUSIONS

Premature infants with HPS have a higher female preponderance than expected. Ultrasound measurements in premature infants with HPS are not affected by weight, corrected gestational age or duration of symptoms. In addition, they have a longer hospital stay and increased complication rate compared to term infants.

Evaluation of ultrasonographic parameters in the diagnosis of pyloric stenosis relative to patient age and size

INTRODUCTION

Pyloric thickness of 3 mm or higher and length of 15 mm or higher by ultrasonography (US) is widely accepted as diagnostic criteria for pyloric stenosis (PS). However, infants presenting at earlier ages are held to this same criteria, which may not be applicable.

METHODS

Retrospective review was conducted on patients evaluated with pyloric US to rule out PS from May 2010 through December 2010. Pearson correlation was used to detect an association between weight and age with pyloric thickness and length. Sensitivity and specificity for US parameters were determined.

RESULTS

Three hundred four patients underwent 318 ultrasounds, of which 67 had PS. Of those with PS, age and weight had a positive correlation with thickness (P < .007), and age positively correlated with length (P < .001). In patients with and without PS, there was a negative correlation for both age and weight with thickness (P < .02). Those who did not have PS held a stronger negative correlation between age and thickness (P = .002). Overall, US had a 100% sensitivity and specificity for PS. Thickness of 3 mm or higher was 100% sensitive and 99% specific, and pyloric length of 15 mm or higher was 100% sensitive and 97% specific.

CONCLUSIONS

Although significant associations between age and weight with pyloric thickness and length may exist, our data indicate that this does not have an impact on the diagnostic criteria for PS.

Infantile hypertrophic pyloric stenosis before 3 weeks of age in infants and preterm babies

BACKGROUND

Most infantile hypertrophic pyloric stenosis (IHPS) cases are diagnosed between 3 and 12 weeks after birth. Few data exist regarding Asian infants with IHPS who are younger than 3 weeks or are preterm. The goal of this study is to identify unusual clinical manifestations, clinical course, duration of hospital stay, and complications of Asian infants with IHPS who are preterm or younger than 3 weeks of age.

METHODS

From 1991 to 2004, all IHPS patients admitted to three tertiary centers in southern Taiwan were enrolled. The clinical manifestations, duration of hospital stay and complications were further compared between the IHPS patients diagnosed before and after 3 weeks; preterm and term infants.

RESULTS

A total of 214 patients were enrolled into the study; the mean age of diagnosis was 40 days of age; the average duration of hospital stay was 6.27 days. Eighteen (8.41%) patients were diagnosed before 3 weeks of age. A significantly shorter timeframe of diagnosis, a higher rate of jaundice, a lower daily body weight gain and longer duration of hospital stay were noted in the IHPS group prior to 3 weeks compared with those in IHPS group after 3 weeks. Eighteen were preterm infants. A significantly older age of symptom onset, a lower body weight at admission, more cases diagnosed by barium meal study and higher postoperative complication rates were noted in the preterm group versus full-term infants with IHPS.

CONCLUSIONS

The IHPS cases diagnosed before 3 weeks of age had longer duration of hospital stay. Preterm infants with IHPS had more postoperative complications.

Gastrointestinal tract imaging in children: current techniques

Imaging of the gastrointestinal (GI) tract in children continues to evolve, with new techniques, both radiological and non-radiological, being added to the repertoire. This article provides a summary of current imaging techniques of the GI tract (primarily the upper GI tract) and the relationship between those techniques. It covers the upper GI series and other contrast studies, US, CT and MRI. Note is also made of the contribution now made by capsule endoscopy (CE). Abdominal emergency imaging is not covered in this article.

Hypertrophic Pyloric Stenosis

Hypertrophic pyloric stenosis (HPS) is a gastric outlet obstruction related to the thickening of the pyloric muscle. It typically affects first-born males between the ages of 6 to 8 weeks. Sonography is the modality of choice for diagnosing HPS. This review discusses the etiology, signs and symptoms, sonographic findings, and treatment for hypertrophic pyloric stenosis.

Early pyloric stenosis: a case control study

OBJECTIVE

Pyloric stenosis (PS) is rare in the first 2 weeks of life, often leading to delays in diagnosis and treatment. We conducted a case control study to delineate the characteristics of patients with early PS (EPS). In addition, we tested the hypothesis that patients with EPS present with a smaller pylorus than older patients.

METHODS

A database of all patients presenting with PS to a children's hospital over a 5-year period (2002-2006) was obtained. Each patient admitted during the first 2 weeks of life (subject) was matched to a patient admitted after 4 weeks of age (control), with the same gender, electrolyte status, and treating surgeon. A single pediatric radiologist, blinded to patient age, reviewed all available ultrasounds retrospectively. Demographic, clinical, diagnostic, therapeutic, and outcome data were compared.

RESULTS

During the study period, 278 pyloromyotomies were performed for PS. Sixteen patients (5.8%) presented with EPS between 2 and 14 days of life. EPS patients had a higher prevalence of positive family history (31 vs. 0%, P = 0.043), and breast milk feeding (75 vs. 31%, P = 0.045). Sonographic measurements showed a pylorus that was of significantly less length (17.1 +/- 0.6 vs. 20.5 +/- 0.9 mm, P = 0.006) and muscle thickness (3.5 +/- 0.2 vs. 4.9 +/- 0.2 mm, P < 0.001) in patients with EPS. Hospital stay was significantly longer for EPS patients (4.3 +/- 0.9 vs. 2.0 +/- 0.1 days, P = 0.19).

CONCLUSIONS

Babies presenting with EPS are more likely to be breast fed and to have a positive family history. EPS is associated with a longer hospital stay. Use of sonographic diagnostic measurements specific to this age group may prevent delays in diagnosis and treatment, and improve outcomes.