Gastro-oesophageal reflux: the role of imaging in diagnosis and management

Stomach frame-count-based attenuation correction of dynamic posterior view gastric emptying scintigraphy with continuous acquisition in children

BACKGROUND

When performing dynamic gastric emptying scintigraphy with continuous acquisition in children, a single posterior view acquisition is preferred because it allows the young patient to more easily interact with a parent or technologist even though this method tends toward overestimating gastric emptying.

OBJECTIVES

The objective of our study was to develop a new attenuation correction (AC) method to improve the accuracy of the time activity curve and the measurement of residual gastric emptying from 1-h posterior images of gastric emptying scintigraphy with continuous acquisition.

MATERIALS AND METHODS

We developed a frame-count-based AC for gastric emptying scintigraphy from the posterior view (posterior AC method). We retrospectively reviewed 122 gastric emptying studies performed in children using conjugated posterior and anterior views, and evaluated the statistical differences between posterior only (without AC) and posterior AC using the geometric mean method as a reference standard.

RESULTS

The residual values obtained using posterior AC were not significantly different (P=0.813) compared to those using the geometric mean while the values using the posterior only were significantly different (P<0.001) from the geometric mean.

CONCLUSION

The proposed method can replace the geometric mean method to estimate gastric emptying residual fraction using patient-friendly posterior view without a significant difference in 1-h gastric emptying scintigraphy with continuous acquisition.

Delayed gastric emptying and typical scintigraphic gastric curves in children with gastroesophageal reflux disease: could pyloromyotomy improve this condition?

BACKGROUND/PURPOSES

Delayed gastric emptying (DGE) is a cofactor in the etiopathogenesis of gastroesophageal reflux disease (GERD). Scintigraphy is the criterion standard to evaluate gastric emptying (GE). This study aims to define typical scintigraphic activity-time curves (ATCs) related to DGE and esophageal atresia (EA) and to demonstrate the effectiveness of pyloromyotomy (P) in improving GE.

METHODS

Since 2002, 83 children underwent Nissen fundoplication. Patients were divided into 2 groups: group I, GERD-only patients; group II, patients with GERD owing to EA. Depending on preoperative scintigraphy, each group was subdivided into 2 subgroups. Before surgery and 1 year after, endoscopy and scintigraphy were performed. In the presence of DGE, P was associated with Nissen fundoplication. Gastric emptying differences at baseline and at follow-up were estimated by the Student t test. Pre- and post-ATCs were evaluated by the χ(2) test.

RESULTS

During follow-up, GE completely normalized in subgroups with DGE. Scintigraphic ATC analysis documented an association between DGE and a typical rectilinear fitting, with a higher rate in EA patients. After P, the scintigraphic pattern changed in an exponential manner related to a faster GE.

CONCLUSIONS

Delayed gastric emptying is frequent in EA, and the scintigraphic ATCs are typical. Pyloromyotomy is a safe and effective technique to fully normalize GE.

Relationship between gastric emptying and gastroesophageal reflux in infants and children

PURPOSE

The aim of our study was to evaluate the relationship between gastric emptying and gastroesophageal reflux (GER) in infants and children.

METHODS AND MATERIALS

One hundred eight patients (pts) between 3 months and 5 years of age (77 boys, 31 girls) with clinical suspicion of GER disease were included in the study. Patients were divided into 2 groups according to the age range: group A, 0-2 years (57 pts), and group B, 2-5 (51 pts) years. Each group was divided into 2 subgroups according to the scintigraphic study as GER-positive and -negative. Cow's milk with Tc-99m sulfur colloid as radiotracer was used. Gastric emptying was expressed as the half emptying time (T1/2). The detection of activity in the esophagus at any time during scintigraphy was considered an indicator of GER episodes. Reflux episodes were graded as grade 1 if activity was detected on one or 2 frames and grade 2 if activity was detected on more than 2 frames.

RESULTS

Forty of the 108 patients (37%) had GER findings on scintigraphy. The comparison of gastric emptying time between positive GER scintigraphy and negative GER scintigraphy groups was not statistically significant in any age group. No association was found between age and rate of gastric emptying time. Although the comparison of T1/2 between grade 1 patients and the GER-negative group was not statistically significant, grade 2 patients showed significant differences and had prolonged gastric emptying times. Mild statistical correlation between the number of reflux episodes and gastric emptying half time was found.

CONCLUSIONS

As a conclusion, the relation between gastroesophageal reflux and delayed gastric emptying cannot be ignored. Our results support delayed gastric emptying to be a pathogenetic factor in gastroesophageal reflux in infants and children.

The role of gastro-oesophageal reflux in the aetiology of SIDS

Gastro-oesophageal reflux (GOR) has been identified as a possible cause of SIDS. Several features of GOR unique to infants presenting with apparent life-threatening events (ALTEs) have led to its 'pathogenic' definition. One is that the life-threatening apnoea itself is initiated by GOR, another is that the ALTE relates to prolonged reflux during sleep, in a vulnerable sleep-state, and finally that the ALTE relates to excessive quantities of GOR. The presumption of GOR 'pathology' as a cause of SIDS however, is questionable in these susceptible infants for three reasons: firstly, GOR is physiological and occurs in most infants; secondly, there is no general consensus on what constitutes normal physiological reflux, and thirdly, variation in the recording technique and methods of data analysis and interpretation may account for the differences between study groups. It seems likely therefore if GOR is implicated in SIDS, additional factors are involved. Under certain circumstances, physiological GOR may trigger life-threatening apnoea in apparently healthy infants, that leads to SIDS. One mechanism that could explain such a death is reflex apnoea by stimulation of laryngeal chemoreceptors (LCR) during sleep. The conditions under which this could be fatal are the occurrence of gastric contents refluxed to the level of the pharynx during sleep, in the young infant who has depressed swallowing and arousal. That is, the occurrence of GOR to the level of the pharynx during sleep, an infrequent event that is usually innocuous, could be converted to a fatal event if swallowing is impaired and arousal depressed, by a variety of mediating factors such as prone sleeping, prematurity, sedatives, seizures or upper respiratory tract infections. The identification of LCR responses, particularly in prone sleeping and premature infants provide further evidence that this mechanism may be implicated in the aetiology of SIDS in apparently healthy infants.

Pediatric gastrointestinal motility studies

Radionuclide studies for evaluating gastrointestinal transit in adults have been adapted for use in infants and children for assessing esophageal transit, gastroesophageal reflux, and gastric emptying. However, the measurement of small- and large-bowel transit times in these patients has been limited.

Radiocontrast-induced nephropathy in a pair of xiphaomphalopagus conjoined twins during the neonatal period

One of the babies in a pair of xiphaomphalopagus conjoined twins developed oliguria, transient rise in serum creatinine and persistent nephrogram on the sixth day of life following injection of radiocontrast medium for computerised axial tomography scanning of the urinary system. The other twin was spared but developed hypertension and "dialysed" the oliguric twin. The renal profiles of both neonates subsequently remained normal until they reached adequate weight for surgical separation at a later date.