Color doppler in the diagnosis of the gastroesophageal reflux in children: comparison with pH measurements and B-mode ultrasound

Gastrointestinal ultrasound in neonates, infants and children

Today US plays an important and increasing role in the assessment of many, partially age-specific conditions in the GI tract in neonates, infants and children. Knowledge of the potential capabilities of US and its restrictions together with a skillful performance of GI US examination can provide essential anatomic and functional diagnostic information in many pediatric GI disorders. The aim of this review is to highlight the potential of ultrasound (US) in the evaluation of the gastrointestinal (GI) tract in neonates, infants and children. Basic and potential applications of modern US tools in pediatric GI tract are addressed, the GI US examination technique is discussed - including some common and/or typical clinical applications of and indications for US.

US in the diagnosis of gastroesophageal reflux in children

Several techniques have been used to diagnose gastroesophageal reflux (GER) in children, but no single test is sufficiently accurate to completely investigate the problem. Gastroesophageal US has been described as a widely available, noninvasive and sensitive method. It provides morphological and functional information, but its role in the diagnosis of GER in children is still debated. In this paper we review diagnostic approaches to GER in children. We focus on current use of US in the management of children with suspected GER. Reports suggest that US allows exclusion of several non-GER causes of symptoms and that it provides morphological and functional data with high sensitivity and positive predictive value for the diagnosis of GER. Sonographic assessment of findings such as abdominal esophageal length, esophageal diameter, esophageal wall thickness and gastroesophageal angle provide important diagnostic indicators of reflux and related to the degree of GER. There is a need for standardization of the procedure and for defining diagnostic criteria.

Contrast-enhanced colour-Doppler sonography versus pH-metry in the diagnosis of gastro-oesophageal reflux in children

PURPOSE

The aim of this study was to evaluate the accuracy of contrast-enhanced colour-Doppler ultrasound (CDUS) in the diagnosis of gastro-oesophageal reflux in children.

MATERIALS AND METHODS

One hundred and twenty children (68 boys and 52 girls aged between 1 month and two years) with a clinical suspicion of gastro-oesophageal reflux (postprandial vomiting, weight loss, failure to thrive, anaemia, night-time coughing and crying, regurgitation, etc.) were studied by contrast-enhanced CDUS and subsequently by 24-hour pH-metry. Results of the two techniques were compared using the McNemar test.

RESULTS

Gastro-oesophageal reflux was detected on CDUS in 84 patients and with 24-h pH-metry in 86. In all cases of reflux, CDUS visualised the passage of contrast material from the stomach into the abdominal and middle and distal third of the thoracic oesophagus, enabling assessment of the segment of oesophagus involved by the reflux. Compared with pH-metry, CDUS had a sensitivity of 98% (p<0.0001 with McNemar's test).

CONCLUSIONS

In consideration of the results obtained and particularly of the low level of invasiveness, contrast-enhanced CDUS could be used to monitor children undergoing medical or surgical treatment for the complications of gastro-oesophageal reflux disease.

Diagnosis of gastro-oesophageal reflux in preterm infants: sonography vs. pH-monitoring

OBJECTIVES

To compare the ultrasound examination with pH-metry in order to evaluate the diagnostic accuracy of sonography for diagnosis of gastro-oesophageal reflux (GOR) in preterm infants.

METHODS

A prospective study was conducted on 31 premature infants <34 weeks with clinically diagnosed GOR. First, they underwent 24-hour pH-monitoring; successively, the sonographic assessment was performed within 12 h after pH-monitoring. The two operators who performed the pH-monitoring and sonography respectively, were unaware of each other's results.

RESULTS

Twenty-one patients (67.7%) had significant GOR with a reflux index >5 (GOR group). The median (range) reflux index in this group was 9.19% (6.04-20.1). Ten newborns (32.3%) did not have significant GOR with a reflux index <5. Sonography was positive for GOR in 8 patients (25.8%); all 8 infants with sonographic diagnosis of GOR had a reflux index >5. Therefore, sonographic diagnosis did not produce false positives. Sonography was negative in 23 newborns (74.2%); 13 of these were positive to pH-monitoring and may therefore be considered as false negatives. Respect to continuous 24-hour pH-monitoring, sonography showed a specificity of 100% but a very low sensitivity of 38% with a positive prediction value of 100% and a negative prediction value of 43%.

CONCLUSIONS

Sonography should not replace 24-hour pH monitoring for detecting GOR in preterm infants. However, sonography has a very high specificity and a positive predictive value of 100%. When clinicians suspect GOR in preterm infants, it could be useful for selection of cases to refer for pH-metry.

Modern pediatric ultrasound: potential applications and clinical significance. A review

After the introduction of ultrasound (US), the new imaging modality was first warmly welcomed, but then lost reputation and importance particularly in radiology leading to an increasing number of other -- particularly computed tomography (CT) -- investigations, which especially in pediatrics was a potentially dangerous development considering the radiation hazards. However, innovative and creative US approaches as well as new US techniques such as amplitude-coded color Doppler, harmonic and high-resolution imaging, and US contrast media or three-dimensional US have been introduced over the past decade and significantly broadened the potential of US. Thus, now, the role of US has been widened in many conditions and queries, and US today may well play a more pronounced and essential role in modern imaging algorithms at still relatively low cost, with sufficient diagnostic accuracy and conspicuity. Particularly in the pediatric setting, these new capabilities are applicable in many queries and almost all body regions and should be used to reduce the number of more invasive or radiating and relatively costly examinations that often additionally need some sedation or intravenous iodinated contrast material. To readily provide this approach for sick children, we need to promote the knowledge about modern US capabilities, to train US staff to guarantee 24-h availability of adequate pediatric US performance, and to make it known to the referring clinicians.

Poly-lactic-glycolic acid microspheres: a biodegradable marker for the diagnosis of aspiration in hamsters

Aspiration is a major cause of lung disease in infants and young children. As the symptoms and signs of aspiration are not specific, the diagnosis is delayed due to a low index of suspicion and low sensitivity and specificity of the available diagnostic tests. In the present study, we evaluated the utility of microspheres composed of a degradable polymer, polylactic glycolic acid (PLGA), as a marker to diagnose aspiration in hamsters. Thirty hamsters underwent direct tracheal instillation of 0.1 mL of a suspension of PLGA. Eighteen other animals served as controls and underwent tracheal instillation of 0.1 mL of saline. Three animals served as naive controls and had no tracheal instillation. Five animals from the PLGA group and three from the saline group underwent whole-lung lavage (WLL) on days 1, 8, 15, 29, 43, and 58. PLGA microspheres were easily identified under light microscopy inside the alveolar macrophages obtained from WLL in all PLGA-instilled animals during all studied days. The number and size of PLGA microspheres within the alveolar macrophages decreased gradually with time with a 90% rate of disappearance of about 36 d. There was a marked neutrophilic response in lung lavage and a mild peribronchial neutrophil infiltration on the first day after tracheal instillation of PLGA which subsequently disappeared. We conclude that PLGA microspheres are a sensitive and specific marker for aspiration in hamsters. The usefulness of this test in diagnosing aspiration in humans should be further evaluated in clinical studies.

Infant colic and feeding difficulties

AIMS

To examine the relation between colic and feeding difficulties and their impact on parental functioning for a primarily clinic referred sample.

METHODS

Forty three infants (and their mothers) were enrolled between 6 and 8 weeks of age. Infants were divided into two groups, colic (n = 19) and comparison (n = 24), based on a modified Wessel rule of three criteria for colic. Families were assessed at two visits; one occurred in the laboratory and one occurred in a paediatric radiology office. Outcome measures included the clinical assessment of infant oral motor skills, behavioural observation of mother-infant feeding interactions, maternal questionnaires on infant crying, sleeping and feeding behaviours, and the occurrence of gastro-oesophageal reflux (GOR) in the infants using abdominal ultrasound.

RESULTS

Infants in the colic group displayed more difficulties with feeding; including disorganised feeding behaviours, less rhythmic nutritive and non-nutritive sucking, more discomfort following feedings, and lower responsiveness during feeding interactions. Infants in the colic group also had more evidence of GOR based on the number of reflux episodes on abdominal ultrasound as well as maternal report of reflux. Mothers in the colic group reported higher levels of parenting stress.

CONCLUSIONS

Results provide the first systematic evidence of feeding problems in a subgroup of infants with colic. Data also illustrate the impact of these difficulties on parental and infant functioning. The association between feeding difficulties and colic suggests the potential for ongoing regulatory problems in infants presenting with clinically significant colic symptoms.

Sonographic measurement of the abdominal esophagus length in infancy: a diagnostic tool for gastroesophageal reflux

OBJECTIVE

Our aim was to provide exact sonographic measurements of the abdominal esophagus length in neonates and infants with and without gastroesophageal reflux (GER) and to investigate its diagnostic value. GER severity and hiatal hernia presence were also evaluated and correlated with esophageal length.

MATERIALS AND METHODS

This retrospective case-control study comprised 258 neonates and infants (150 without reflux and 108 with reflux). There were 50 children without reflux in each of three age categories: less than 1 month, 1-6 months, and 6-12 months. Of the children with reflux, 42 were less than 1 month old; 34, 1-6 months; and 32, 6-12 months. The abdominal esophagus was measured from its entrance into the diaphragm to the base of gastric folds in fed infants. The number of refluxes during a 10-min period were recorded; GER was categorized as mild, one to three refluxes; moderate, three to six refluxes; and severe, more than six refluxes. Presence of hiatal hernia was recorded.

RESULTS

Neonates and infants with reflux had a significantly shorter abdominal esophagus than subjects without reflux: the mean difference in neonates, 4.8 mm; 1-6 months, 4.5 mm; 6-12 months, 3.4 mm. Children with severe reflux had a shorter esophagus compared with those with mild and moderate reflux only in the neonate group. In contrast, children with reflux associated with hiatal hernia had a significantly shorter esophagus compared with children with mild reflux in all three age groups. Sonographic sensitivity was 94%.

CONCLUSION

Sonographic measurement of the abdominal esophagus length is highly diagnostic for GER in neonates and infants. In neonates, it can also indicate GER severity. Hiatal hernia is associated with a significantly shorter abdominal esophagus.

Correlation of color Doppler sonographic findings with pH measurements in gastroesophageal reflux in children

PURPOSE

We conducted a prospective study of color Doppler sonography in children with suspected gastroesophageal reflux (GER). The purpose of this study was to compare the accuracy of color Doppler sonography with that of continuous 24-hour pH monitoring of the esophagus in diagnosing GER and to determine how to interpret the reflux episodes detected on color Doppler sonography in children at high risk for reflux.

METHODS

Color Doppler sonography and 24-hour esophageal pH monitoring were performed in 54 children ranging in age from 2 months to 10 years (mean, 3 years). The stomach of each patient was filled for adequate gastric distention just before the color Doppler sonographic examination. We counted the number of reflux episodes over a period of 15 minutes. One day after the sonographic examination, the reflux was evaluated with esophageal pH monitoring, and the resultant reflux index (ReI) was obtained. The ReI was considered to be pathologic when it was equal to or greater than 11.99%. The number of refluxes on color Doppler sonography and the ReI were correlated for each patient.

RESULTS

The 2 tests showed an 81.5% agreement in the detection of GER. When pH monitoring was taken as the reference test, color Doppler sonography had a high sensitivity (95.5%) for diagnosing GER but a very low specificity (11.0%), with a positive predictive value of 84.3% and a negative predictive value of 33.3%. There was no statistically significant correlation between the frequencies of GER detected on color Doppler sonography and the ReIs on pH monitoring (p = 0.1103). There was no correlation between the reflux grades on sonography and the ReI grades on pH monitoring (p = 0.422).

CONCLUSIONS

Color Doppler sonography is highly sensitive and easier to use than pH monitoring. Although there are no definite criteria for evaluating the severity of GER on color Doppler imaging, this modality may be useful in screening children for GER.

Reflux in children

Gastro-oesophageal reflux (GOR) is an extremely common paediatric problem that often runs a harmless and self-limited course. Physiological GOR however can lead to marked parental anxiety, many unnecessary investigations and often unwarranted and potentially harmful therapeutic interventions. Our ability to better define GOR and gastro-oesophageal reflux disease (GORD) has improved in the past 15 years with a better understanding of the pathophysiology in infants and children due to the development and wider use of flexible endoscopy, 24-hour oesophageal pH monitoring and, more recently, the use of micromanometric methods for studying oesophageal motility. This will be further enhanced in the future with the development of non-invasive breath testing to study gastrointestinal motility and the use of electrical impedance to study fluid movement. Our therapeutic interventions have also improved particularly in the areas of acid suppression, improved surgical techniques and most recently laparoscopic fundoplication. This chapter reviews these advances in the paediatric area especially with regard to pathophysiology, diagnostic testing and therapeutic intervention.

Intraluminal impedance: an ideal technique for evaluation of pediatric gastroesophageal reflux disease

Gastroesophageal reflux (GER) in infants becomes gastroesophageal reflux disease (GERD) through association with distinct clinical symptoms. Monitoring of pH is considered the standard diagnostic tool through which episodes of acidity can be detected. Apparently, however, the major amount of GER occurs in the physiologic esophageal pH range, which is concealed to pHmetry. Intraluminal impedance is a new method for pH-independent detection of esophageal bolus movement. Long-term measurements and combination with other diagnostic methods, e.g., pHmetry or polygraphic recordings, are possible. Intraluminal impedance has proved especially useful in diagnosing GER and GERD in infants. It may develop into the ideal technique for this group of patients.