Effectiveness of two-dimensional shear-wave sonoelastography in the diagnosis and follow-up of infantile hypertrophic pyloric stenosis.

INTRODUCTION: We sought to determine the effectiveness and utility of two-dimensional shear-wave sonoelastography (2D-SW-SE) in the diagnosis and postoperative follow-up of infantile hypertrophic pyloric stenosis (IHPS). MATERIALS AND METHODS: Twenty-three infants were included in the study, 13 in the IHPS group and 10 in the control group (CG). Preoperative B-mode ultrasonography measurements (longitudinal length and single-wall thickness of the pylorus) and 2D-SW-SE measurements (pylorus tissue stiffness and shear-wave propagation speed) were compared between the groups. The infants with IHPS then underwent Ramstedt pyloromyotomy and were invited for follow-ups on the tenth day and the first, third, and sixth months postoperatively. Measurements taken at the follow-ups were compared with the preoperative values. RESULTS: No differences were found between the groups regarding age, gender, body weight, or week of birth. The pyloric lengths in the IHPS group were longer than in the CG (p < 0.001), and the single-wall thicknesses were thicker (p < 0.001). The pylorus in the IHPS group was four times stiffer than in the CG (27.4 kPa versus 7.66 kPa), and the shear-wave propagation speed in the tissue was higher (1.34 m/s versus 2.69 m/s; p < 0.001). Both values decreased over time in the IHPS group and were normal by the third postoperative month. CONCLUSIONS: 2D-SW-SE can be used as an assistive imaging tool alongside B-mode ultrasound for diagnosing IHPS. It can also be used to identify inadequate surgery by detecting whether the pyloric tissue has softened at follow-up.

The impact of high-frequency transducers on the sonographic measurements of the pyloric muscle thickness in infants.

BACKGROUND: Ultrasound is the modality of choice for the diagnosis of hypertrophic pyloric stenosis (HPS). The evolution of high-frequency transducers in ultrasound has led to inconsistent ways of measuring the pylorus. OBJECTIVE: To standardize the measurements and evaluate the appearance of the normal and hypertrophied pylorus with high-frequency transducers. MATERIALS AND METHODS: We retrospectively analyzed abdominal ultrasounds of infants with suspected HPS from January 2019-December 2020. We classified the layers of the pylorus while assessing the stratified appearance. Two pediatric radiologists measured the muscle thickness of the pylorus independently by two methods for interrater agreement. Measurement (a) includes the muscularis propria and muscularis mucosa. Measurement (b) includes only the muscularis propria. We also evaluated the echogenicity of the muscularis propria. The interrater agreement, mean, range of the muscle thickness, and the diagnostic accuracy of the two sets of measurements were calculated. RESULTS: We included 300 infants (114 F:186 M), 59 with HPS and 241 normal cases. There was a strong agreement between the readers assessed in the first 100 cases, and ICC was 0.99 (95% CI, 0.98-0.99). Measurement (a), median thickness is 2.4 mm in normal cases and 4.8 mm in HPS. Measurement (b), median thickness is 1.4 mm in normal cases and 4.0 mm in HPS. Measurement (a) has an accuracy of 89.7% (95% CI, 85.7-92.8%) with 98.3% sensitivity and 87.6% specificity. Measurement (b) has an accuracy of 98.0% (95% CI, 95.7-99.3%) with 89.8% sensitivity and 100.0% specificity. The pylorus stratification is preserved in all normal cases and 31/59 (52.5%) cases of HPS. There was complete/partial loss of stratification in 28/59 (47.5%) cases of HPS. In all HPS cases, the muscularis propria was echogenic. CONCLUSION: Measuring the muscularis propria solely has a better diagnostic accuracy, decreasing the overlap of negative and positive cases. The loss of pyloric wall stratification and echogenic muscularis propria is only seen in HPS.

Subtotal pyloric obstruction by atypical hypertrophic pyloric muscle in a newborn.

This is a case of a neonate with suspected duodenal atresia on prenatal imaging. However, distal bowel gas was identified postnatally on regular X-rays with a possible pyloric obstructing mass visualised on ultasound. No contrast was visualised passing through the stomach on fluoroscopic studies. Operative evaluation revealed an atypical asymmetric hypertrophic pylorus with exophytic lesions of ectopic glandular tissue. Longitudinal open pyloromyotomy was performed which relieved the gastric obstruction resulting in symptomatic relief without any anatomy altering procedure required.

A systematic review of point-of-care abdominal ultrasound scans performed by general surgeons in paediatric patients.

BACKGROUND/PURPOSE: Bedside point-of-care ultrasound scans are a cheap, quick and safe diagnostic tool. There is increasing evidence for the use of point-of-care surgeon-performed ultrasound scans in adults, however there are fewer studies of its use in children. This systematic review aims to provide an up-to-date summary of the evidence behind surgeon-performed ultrasound scans in paediatric surgery. METHODS: The PubMed database was used to conduct this systematic review between the dates 1 Jan 1980 to 1 June 2020 (last search: 1 June 2020). Seven primary research studies were included in this review. RESULTS: There is good evidence for the use of ultrasound scans in appendicitis and hypertrophic pyloric stenosis. Training times are easily achievable and transferable within a surgical department. CONCLUSIONS: Although the use of surgeon-performed bedside ultrasound scans has been described in appendicitis and hypertrophic pyloric stenosis, more research is required to embed this into clinical practice, particularly in low volume centres such as district general hospitals. A robust training programme is also recommended to incorporate ultrasound scans into clinical practice.

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.

Hypertrophic pyloric stenosis masked by kidney failure in a male infant with a contiguous gene deletion syndrome at Xp22.31 involving the steroid sulfatase gene: case report.

BACKGROUND: Contiguous gene deletion syndrome at Xp22.3 resulting in nullisomy in males or Turner syndrome patients typically encompasses the steroid sulfatase gene (STS) and contiguously located other genes expanding the phenotype. In large deletions, that encompass also the Kallmann syndrome 1 gene (KAL1), occasionally infantile hypertrophic pyloric stenosis (IHPS) and congenital anomalies of the kidney and urinary tract (CAKUT) have been reported. PATIENT PRESENTATION: We report on a male newborn with family history in maternal uncle of renal abnormalities and short stature still without ichthyosiform dermatosis. The baby presented CAKUT with kidney failure and progressive vomiting. Renal bicarbonate loss masked hypochloremic and hypokalemic metabolic alkalosis classically present in IHPS and delayed its diagnosis. Antropyloric ultrasound examination and cystourethrography were diagnostic. After Fredet-Ramstedt extramucosal pyloromyotomy feeding and growing was regular and he was discharged home. Comparative whole-genome hybridization detected a maternal inherited interstitial deletion of 1.56 Mb on Xp22.31(6,552,712_8,115,153) × 0 involving the STS gene, but not the KAL1 gene. CONCLUSIONS: Aberrant cholesterol sulfate storage due to STS deletion as the underlying pathomechanism is not limited to oculocutaneous phenotypes but could also lead to co-occurrence of both IHPS and kidney abnormalities, as we report. Thus, although these two latter pathologies have a high incidence in the neonatal age, their simultaneous association in our patient is resembling not a chance but a real correlation expanding the clinical spectrum associated with Xp22.31 deletions.

Evaluating the validity of ultrasound in diagnosing hypertrophic pyloric stenosis: a cross-sectional diagnostic accuracy study.

BACKGROUND: Our aims were to evaluate the ultrasound scan (USS) criteria in diagnosing hypertrophic pyloric stenosis (HPS), determine the best diagnostic threshold values for pyloric muscle thickness (PMT) and pyloric canal length (PCL), and assess the accuracy of flow through the pylorus. METHODS: All patients who underwent pyloromyotomy at our tertiary paediatric surgery centre between July 2013 and June 2019 were identified (Group 1). All patients undergoing an USS to investigate for a possible HPS and did not undergo pyloromyotomy were also identified (Group 2). Accuracy was determined by Youden's Index (J) with the highest J determining the ideal cut-off value. RESULTS: Two hundred and eighty-four patients (142 patients in each group) were included in the analysis. Using only the last USS before surgery, PMT provided an area under the curve (AUC) of 0.987 (n = 275), and PCL an AUC of 0.977 (n = 267). Ideal threshold values were 3.0 mm for PMT (J = 0.92), and 14.5 mm for PCL (J = 0.87). Combining PMT ≥3.0 mm with a PCL ≥14.5 mm resulted in a sensitivity of 95% and specificity of 99% (J = 0.94). The absence of flow through the pylorus on dynamic USS provided a sensitivity of 99% and specificity of 91% (J = 0.91; n = 277). CONCLUSION: Combining threshold values of 3.0 mm for PMT and 14.5 mm PCL provides the highest accuracy for diagnosing pyloric stenosis on an ultrasound scan. These combined values were more accurate than observing for the absence of flow through the pylorus.

Feasibility of Point-of-Care Ultrasound for Diagnosing Hypertrophic Pyloric Stenosis in the Emergency Department.

OBJECTIVES: This study aimed to investigate the feasibility of point-of-care ultrasound (POCUS) for diagnosing hypertrophic pyloric stenosis (HPS) in the emergency department (ED). METHODS: A retrospective study was conducted in infants aged younger than 90 days who were brought to the ED due to vomiting between January 2015 and December 2019. Of these, infants who were clinically suspected of having HPS and underwent ultrasound were included and categorized into 3 groups: POCUS only, POCUS followed by radiologist-performed ultrasound (RADUS), and RADUS only. All confirmative diagnoses of HPS were made by RADUS. The diagnostic performance of POCUS was analyzed, and the ED patient flow was compared between the POCUS-performed (POCUS only or POCUS followed by RADUS) and RADUS-only groups. RESULTS: Overall, 171 patients with a median age of 34 days were included. Of these, 79 patients (46.2%) underwent POCUS only, and none had HPS; 50 patients (29.2%) underwent POCUS followed by RADUS; and 42 patients (24.5%) underwent RADUS only. Overall, 41 patients (24.0%) were diagnosed with HPS, and POCUS showed a sensitivity of 96.6% and specificity of 94.0%. In the total cohort, length of stay in the ED (EDLOS) was shorter in the POCUS-performed group than in the RADUS-only group (2.6 vs 3.8 hours, P = 0.015). Among non-HPS patients, time to disposition (1.8 vs 2.7 hours, P = 0.005) and EDLOS (2.0 vs 3.0 hours, P = 0.004) were shorter in the POCUS-performed group than in the RADUS-only group. Performing POCUS followed by RADUS did not significantly delay the treatment among HPS patients. CONCLUSIONS: Point-of-care ultrasound is accurate and useful for diagnosing HPS and improved the ED patient flow by reducing EDLOS and door-to-disposition time in non-HPS patients.

Guía de Práctica Clínica de estenosis hipertrófica del píloro / Clinical Practice Guidelines in Hypertrophic Pyloric Stenosis

La estenosis hipertrófica del píloro es una enfermedad que se presenta fundamentalmente en lactantes, ocurre por un estrechamiento del canal pilórico debido a la hipertrofia gradual de la capa muscular de su esfínter, lo que origina un síndrome pilórico. El objetivo de esta publicación es presentar una actualización sobre el tema. La etiología de la enfermedad es desconocida, la tendencia actual es que se trata de una enfermedad que no es congénita y se sugiere un origen multifactorial, donde influyen factores genéticos y ambientales. Su síntoma fundamental son los vómitos no biliosos y el diagnostico se complementa con el ultrasonido abdominal. El tratamiento de elección es quirúrgico y sus resultados generalmente satisfactorios. La aprobación de esta guía por los servicios de cirugía pediátrica del país la convierten en un útil instrumento asistencial y docente(AU)

Hypertrophic Pyloric Stenosis is a disease that occurs mainly in infants, caused by a narrowing of the pyloric channel due to the gradual hypertrophy of the muscle layer of the sphincter, which originates a pyloric syndrome. The aim of this publication is to present an update on the topic. The etiology of the disease is unknown, the current trend is that it is a disease that is not congenital and a multifactorial origin is suggested, where genetic and environmental factors influence. Its main symptom is non-bilious vomiting and diagnosis is supplemented with abdominal ultrasound. The treatment of choice is the surgical one and its results are generally satisfactory. The approval of this guidelines by the country's pediatric surgery services makes it a useful care and teaching tool(AU)

Incidence and importance of portal venous gas in children with hypertrophic pyloric stenosis.

BACKGROUND: Hypertrophic pyloric stenosis (HPS) is a common cause of gastric outlet obstruction in young infants. Infants with HPS present with projectile vomiting, sometimes have electrolyte abnormalities and typically undergo pyloromyotomy to alleviate the obstruction. Abdominal US is the gold standard imaging study for diagnosis. Case reports of incidental hepatic portal venous gas have been reported in infants with HPS; however, no large studies have been conducted to determine the incidence or possible clinical implications of this finding. OBJECTIVE: To assess the incidence of portal venous gas in infants with HPS and to determine whether the presence of this gas in infants with HPS indicates a more unstable patient, increased length of stay or worse outcome. MATERIALS AND METHODS: We conducted a retrospective review of sonographic reports containing "pyloric stenosis," excluding negative descriptor, at a tertiary-care children's hospital from November 2010 to September 2017. Data collected included pyloric thickness/length, liver evaluation, portal venous gas, any additional imaging, demographics, symptomatology days, electrolyte abnormality, and length of hospital stay. RESULTS: In a 7-year period, 545 US exams were positive for HPS. Of these, 334 exams included enough hepatic parenchyma to evaluate for portal venous gas. Infants in 6 of the 334 exams demonstrated portal venous gas (1.8%). Clinical presentation (length of symptoms and electrolyte abnormalities), demographics (male predominance and age at presentation) and imaging characteristics (pyloric thickness and length) were similar for the HPS groups with and without portal venous gas. There was no significant difference in outcome or length of hospital stay. CONCLUSION: Visualization of portal venous gas in infants with HPS is not rare and appears benign, without need for further imaging. Portal venous gas in infants with HPS does not portend a more severe patient presentation or outcome.

A man with intolerant vomiting.

Case presentationA 57-year-old man was in a healthy state until 6 hours before presenting to the emergency department, when he suffered from more than 10 episodes of vomiting after a large meal at lunchtime. On physical examination, vital signs were unremarkable. Tenderness was noted over the epigastrium on palpation. Point-of-care ultrasound (POCUS) of the abdomen is shown in figure 1 and online supplementary video 1.DC1SP110.1136/emermed-2019-208863.supp1Supplementary video emermed;37/1/41/F1F1F1Figure 1Transverse (A) and longitudinal (B) ultrasonography of the epigastrium. QUESTION: What is the most likely diagnosis?Hypertrophic pylorus stenosisAortic dissectionSuperior mesentery artery (SMA) syndromeVolvulus For answer see page 2.

Milk vomiting or regurgitation in the first 3 months of life: Something old-something new.

The age of presentation of reflux symptoms and their self-cure in babies without a sliding hernia parallel those of mild pyloric stenosis of infancy (PS). It is proposed that this is because PS and, at least some cases of reflux, share the same cause-a temporary hold-up at the pyloric sphincter owing to acid provoked hypertrophy of the pyloric sphincter. In support of this theory, the written observations of John Thomson, Pediatrician from Edinburgh, in 1921 and Isabella Forshall, Pediatric Surgeon from Alder Hey Hospital, Liverpool, in 1958 are revisited. An analysis of both papers provides supportive evidence that, in at least some cases diagnosed as simple reflux, an underlying temporary hold up is present owing to early hypertrophy of the sphincter. It is recommended that sphincter thickness measurements should be made by ultrasonic assessment whenever uncomplicated reflux is diagnosed within the first 3 months of life.

Bowel Imaging in Children: Part 1.

The bowel is a challenging abdominal organ to image. The main reason is the variable location, convoluted morphology and motility. A variety of bowel disorders such as congenital, developmental, inflammatory, infectious and neoplastic lesions can affect children and most of them are either unique to this age group or have a distinct clinico-radiological appearance compared to adults. Imaging plays a very important role in characterizing these lesions and further guiding the management. This is the first part of the series on imaging of bowel disorders in children. This article will cover the imaging modalities used for the evaluation of bowel and the imaging features of congenital /developmental disorders.

Review of bedside surgeon-performed ultrasound in pediatric patients.

PURPOSE: Pediatric surgeon performed bedside ultrasound (PSPBUS) is a targeted examination that is diagnostic or therapeutic. The aim of this paper is to review literature involving PSPBUS. METHODS: PSPBUS practices reviewed in this paper include central venous catheter placement, physiologic assessment (volume status and echocardiography), hypertrophic pyloric stenosis diagnosis, appendicitis diagnosis, the Focused Assessment with Sonography for Trauma (FAST), thoracic evaluation, and soft tissue infection evaluation. RESULTS: There are no standards for the practice of PSPBUS. CONCLUSIONS: As the role of the pediatric surgeon continues to evolve, PSPBUS will influence practice patterns, disease diagnosis, and patient management. TYPE OF STUDY: Review Article. LEVEL OF EVIDENCE: Level III.

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.

Excessive Bright Echoes Sign for Hypertrophic Pyloric Stenosis Suggest the Diagnosis: Gastric Pneumatosis and Portal Venous Gas in Infants Suggest HPS.

We describe a new finding, the "excessive bright echoes" sign, for the diagnosis of hypertrophic pyloric stenosis (HPS). Portal venous gas and gastric wall pneumatosis were noted in 4 vomiting infants proven to have HPS. Portal venous gas can be concerning for ischemic bowel. Gastric wall pneumatosis can be seen in association with necrotizing enterocolitis and has been associated with increased gastric pressure from severe, usually proximal, bowel obstruction. Our HPS cases had prominent bright punctate echoes on sonography of the liver, portal vein lumen, and gastric wall. Knowledge of this excessive bright echoes sign suggests the need for sonography of the antropyloric area. One should consider HPS as a differential diagnostic possibility when the combination of bright echoes within the liver parenchyma, consistent with portal venous gas, and bright echoes in the gastric wall, consistent with gastric pneumatosis, are seen.