Diagnostic workup for infants and children presenting with vomiting usually starts with a thorough clinical evaluation which can lead to the definite diagnosis in many instances . Radiologic imaging is reserved for selected cases, for whom clinical practice guidelines along with ACR AC have been developed aiming for proper management [4,5,6]. Due to lack of original studies investigating the value of UGI series in children presenting with vomiting, our aim was to study the findings of UGI series and correlate them to patients’ symptoms in order to help reach standardized good quality of care for those children. In addition, we expanded the age range covered by ACR AC to involve children up to 18 years of age adopting the same clinical scenarios. Moreover, in our design, we considered associated clinical symptoms other than vomiting by calculating a novel clinical score to study the diagnostic yield of UGI series in patients with multiple symptoms associating vomiting.
Idiopathic GER was detected in only 14% of cases, and normal study was found in 47 % of cases. This relatively low diagnostic yield of UGI series especially for the diagnosis of GER is in agreement with the previously published work [12, 13] and supports the expert opinion which suggested not to use barium contrast for the diagnosis of GER in infants and children , and extended pH probe is considered the diagnostic test of choice for diagnosis of GER . UGI series is reserved for diagnosing anatomical abnormalities that should be addressed at time of surgery especially in cases with severe GERD who are planned for surgery . On the other hand, Society of Abdominal Radiology recommended to perform barium esophagography as the initial test for GERD or in conjunction with other tests such as endoscopy. This is because it is a widely available, non-invasive and inexpensive diagnostic tool; although gastroesophageal reflux could not be detected during the examination, other abnormalities that could be related to GER can be found as peptic strictures .
Three clinical scenarios had been described by ACR AC 2015: bilious vomiting, new-onset nonbilious vomiting, and intermittent nonbilious vomiting since birth. New updates of ACR AC 2020 added clinical variants involving infants in the first two days of life. In our study, applying clinical scenarios of ACR AC and the use of UGI series were found to be of value not only in patients in the first 3 months of life, but also in older patients. Older children more than 2 years of age mostly presented with new-onset non bilious vomiting. Although bilious vomiting and intermittent non bilious vomiting since birth were not frequently encountered in this age group, all patients presented with these clinical events had positive findings increasing the diagnostic yield of upper GI series when examining patients with these symptoms.
Bilious vomiting is an ominous sign that should be attributed to intestinal obstruction until proved otherwise . An initial X-ray abdomen help determine further work up strategy. If signs of upper GI obstruction are found, UGI series is considered searching for midgut malrotation and volvulus. However, normal radiograph does not exclude malrotation [17, 18]. Although malrotation was found to be the commonest cause of bilious vomiting in our series, other causes were diagnosed namely duodenal atresia in one neonate and superior mesenteric artery syndrome in another patient more than 2 years of age. Other less common causes of bilious vomiting were reported including diaphragmatic hernia involving the stomach and in unusual cases of gastric volvulus .
New-onset nonbilious vomiting can be caused by GER or gastric outlet obstruction. In our series, IHPS was found to be the offending cause in the first month of life. Beyond the neonatal period up to 2 years of age, no abnormality was detected by UGI series in most of the cases, idiopathic GER was detected in only two cases, and primary acquired gastric outlet obstruction was diagnosed in another one. Similarly, most cases above the age of 2 years had normal study with few cases with hiatus and diaphragmatic hernia and another case diagnosed finally as lymphoma. IHPS can be diagnosed clinically when the hypertrophied pyloric muscle is palpated (olive sign). If there is clinical suspicion, further imaging is requested. Ultrasound is the modality of choice for diagnosing IHPS. However, UGI series can be appropriate as first study for infants with atypical presentation . Primary acquired gastric outlet obstruction is another cause of gastric outlet obstruction. UGI series reveals dilated stomach with delayed gastric emptying, while endoscopy reveals normal stomach without intraluminal lesions, and it is not associated with pyloric muscle hypertrophy or extraluminal obstruction .
There are many causes of intermittent nonbilious vomiting since birth. In our series, idiopathic GER was found to be the most common finding followed by hiatus hernia and primary gastric volvulus. Idiopathic GER was detected in the first 2 years of life with no evidence of idiopathic GER in older patients. Less common findings included benign esophageal stricture which constitute sequel of reflux esophagitis. Similarly, GER was found to be the most common cause of intermittent nonbilious vomiting in a study of 145 infants by O’Keeffe et al [22, 23]. The frequency of GER is higher in young infants due to immaturity of the lower esophageal sphincter . Vascular ring is another cause of intermittent nonbilious vomiting; it was found in only one case in our series.
Gastric volvulus is relatively rare cause of nonbilious vomiting in children. It could occur due to absence, failure of attachment, or elongation of gastric fixation (primary volvulus) or occurs secondary to associated abnormalities to the nearby organs as in cases of diaphragmatic hernia or eventration (secondary volvulus) . In our series, gastric volvulus was detected in seven patients. It was primary in three, while secondary volvulus was seen in other four accompanying malrotation, diaphragmatic, and hiatus hernia. Primary gastric volvulus was noticed in infants below 2 years of age, while secondary volvulus was mainly found in children above the age of 2 years.
Based on expert opinion, a list of red flag signs has been developed to suggest causes other than GER for vomiting. These alarming signs necessitate further investigations . Failure to thrive, dysphagia, hematemesis, and rectal bleeding are among those symptoms. We have found that the more clinical score the more the prevalence of abnormal findings (especially with the presence of three or more symptoms).
Loss of weight or failure to thrive and to a lesser extent recurrent chest symptoms were found to be the most important indicators of positive study. Moreover, we found that presence of gastrointestinal tract bleeding was an important indicator of abnormal study regardless of the number of attacks; hiatus hernia and primary idiopathic gastric outlet obstruction were found to be the offending cause in those patients. Dysphagia was found to be associated with abnormal study results as well. Two patients with dysphagia had luminal narrowing either secondary to peptic stricture or associated with lymphomatous infiltration. The third patient had abnormally dilated esophagus which could be related to esophageal sensitivity to the refluxed acid or esophageal dysmotility that could result from reflux esophagitis .
This study was limited by relatively small number of patients per each group for each clinical scenario with lack of appropriate imaging guidance for children more than 2 years of age in different clinical situations. However, we expanded the clinical scenarios of ACR AC to investigate those patients as well. In addition, the cause of vomiting and the presence of GER could not be established in relation to a reference standard (pH monitoring) to test the diagnostic performance of UGI series in the diagnosis of GER. However, our study was among the few original research articles that express various radiological findings in different clinical scenarios for patients with vomiting in different stages of the pediatric age, taking into consideration other symptoms that could be associated with vomiting aiming for more standardization of patients’ management.