Comparative Effectiveness of Imaging Modalities for the Diagnosis of Intestinal Obstruction in Neonates and Infants:: A Critically Appraised Topic

High risk and low incidence diseases: Pediatric digestive volvulus

INTRODUCTION

Pediatric digestive volvulus is a serious condition that carries with it a high rate of morbidity and mortality.

OBJECTIVE

This review highlights the pearls and pitfalls of pediatric digestive volvulus, including the presentation, diagnosis, and management in the emergency department (ED) based on current evidence.

DISCUSSION

Pediatric digestive volvulus is a deadly condition most commonly associated with malrotation. It occurs when the stomach or small intestine twists on itself, resulting in ischemia and potentially strangulation with necrosis and perforation. Presentation differs based on the gastrointestinal (GI) segment affected, degree of twisting, and acuity of the volvulus. Gastric volvulus most commonly presents with retching with or without nonbilious emesis and epigastric distension with pain, while midgut volvulus typically presents with bilious emesis in infants. Patients with GI necrosis and perforation may present with hemodynamic compromise and peritonitis. If suspected, emergent consultation with the pediatric surgery specialist is necessary, and if this is not available, transfer to a center with a pediatric surgeon is recommended. Imaging includes plain radiography, ultrasound, or upper GI series, while treatment includes resuscitation, administration of antibiotics, and emergent surgical decompression and detorsion of the involved segments.

CONCLUSION

An understanding of pediatric digestive volvulus and its many potential mimics can assist emergency clinicians in diagnosing and managing this deadly disease.

Contrast-Enhanced Multispectral Optoacoustic Tomography for Functional Assessment of the Gastrointestinal Tract

Real-time imaging and functional assessment of the intestinal tract and its transit pose a significant challenge to conventional clinical diagnostic methods. Multispectral optoacoustic tomography (MSOT), a molecular-sensitive imaging technology, offers the potential to visualize endogenous and exogenous chromophores in deep tissue. Herein, a novel approach using the orally administered clinical-approved fluorescent dye indocyanine green (ICG) for bedside, non-ionizing evaluation of gastrointestinal passage is presented. The authors are able to show the detectability and stability of ICG in phantom experiments. Furthermore, ten healthy subjects underwent MSOT imaging at multiple time points over eight hours after ingestion of a standardized meal with and without ICG. ICG signals can be visualized and quantified in different intestinal segments, while its excretion is confirmed by fluorescent imaging of stool samples. These findings indicate that contrast-enhanced MSOT (CE-MSOT) provides a translatable real-time imaging approach for functional assessment of the gastrointestinal tract.

Upper Gastrointestinal Series in the Workup for Pediatric Gastrostomy Placement: Does it Delay Care?

INTRODUCTION

Upper gastrointestinal (UGI) series is often part of the workup prior to the placement of gastrostomy tubes in children. Prior studies have suggested UGI to be limited in utility and an extra financial burden. The goal of this study was to investigate the utility and cost of UGI studies.

METHODS

A retrospective, case control study of patients aged < 18 y receiving gastrostomy tubes at a free-standing children's hospital between 2012 and 2017. Total costs were obtained from the Pediatric Health Information System.

RESULTS

Six hundred eighty five patients underwent gastrostomy placement during the study period. UGI was obtained in 90.8% of patients; 23.6% of studies were abnormal. The most common abnormal findings were reflux (13.8%) and abnormal anatomy (5.8%). The median time to obtain a UGI was 0.82 d (interquartile range 0.22-1.05). Obtaining a UGI was associated with delayed care in 104 patients (15.2%). If a delay was encountered, median time was 2.47 d (interquartile range 1.86-2.99). Ladd's procedures were performed in 12 patients (1.7%) found to have malrotation on UGI. None of the 63 patients who did not undergo UGI required a Ladd's procedure. Patients that had a UGI did not experience an increase in overall length of stay (14.3 versus 15.6 d, excluding intensive care unit patients), operative time (34 versus 39 min), or a change in rate of operative complications (11.5% versus 14.3%). In addition, UGI did not have a significant impact on total adjusted costs ($49,844 versus $83,438 without UGI, P = 0.12) but did slightly increase total adjusted costs per day ($2212 versus $1999 without UGI, P = 0.01).

CONCLUSIONS

UGI prior to gastrostomy placement in children rarely identified abnormal findings that changed the operative plan, was associated with delayed care in 15% of patients, and was associated with slightly increased costs per day. Further analyses to identify subsets of children that may benefit from routine UGI are warranted.

Diagnostic value of the microcolon using ultrasonography in small bowel atresia

Background

Microcolon helps diagnose small bowel atresia (SBA) using contrast enema. However, there are no ultrasonography (US) microcolon criteria for diagnosing SBA. Therefore, this study aimed to evaluate colon accuracy and other characteristics for diagnosing SBA by US, using surgical or clinical information as the reference standard.

Methods

US was performed on 46 neonates aged ≤ 7 days old. In the study group (n = 15), neonates with SBA were confirmed following surgery. In the study group without SBA (n = 15), neonates with other gastrointestinal problems besides SBA were confirmed by surgical or clinical follow-up. Sixteen neonates without gastrointestinal problems were classified as the control group. The colonic diameter was measured, and colonic gas was sought and observed. Statistical analysis was performed to compare US parameters between the study group and other two groups. The optimal cut-off value of the colonic diameter for SBA diagnosis was obtained using receiver operating characteristic analysis.

Results

Colonic diameters (0.5 cm) in the study group (interquartile ranges [IQR], 0.5–0.6 cm) was significantly smaller than that in the group without SBA (0.9 cm; IQR, 0.8–1.2 cm) (P <  0.001) and in the control group (1.2 cm; IQR, 0.8–1.35 cm) (P < 0.001). Optimum cut-off value for diagnosing SBA was 0.65 cm (sensitivity, 90.3%; specificity, 86.7%; accuracy, 89.1%) for the colonic diameter. Combining microcolon and gas-negativity showed the best performance in SBA diagnosis using US, with increased accuracy (91.3%).

Conclusion

A colon < 0.65 cm in diameter should be called a microcolon; combining US with gas-negativity is an essential diagnostic basis for SBA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03629-z.

Chronic Diarrhea in an Infant With Malrotation: A Diagnostic Dilemma

In children, diarrhea has a global incidence of 2.7 episodes per child-year and contributes to significant disease burden and mortality in children under 5 years of age. Chronic diarrhea, defined as diarrhea lasting for more than 2 weeks, may be particularly challenging to evaluate and manage in children under 2 years of age. While most have infectious enteritis or cow milk protein intolerance, others have conditions such as malnutrition, anatomic abnormalities, or congenital enteropathies that can be challenging to diagnose and treat. We present here a complex case of chronic diarrhea in an infant and highlight such diagnostic and therapeutic challenges.

Neonatal Gastrointestinal Emergencies: A Radiological Review

BACKGROUND

Abdominal emergencies in neonates require surgical management in almost all cases and complications may include bowel perforation, sepsis, shock, and even death. Radiological imaging has become a very important aid in the clinical setting as it shortens time to diagnosis.

OBJECTIVE

The objective of this review is to discuss the more prevalent neonatal gastrointestinal emergencies, review appropriate imaging options, and illustrate common radiological presentations of these entities.

CONCLUSION

Despite advancements in imaging techniques, it is important to keep in mind that neonates have a higher susceptibility to the adverse effects of ionizing radiation, and therefore radiography and ultrasonography remain the main diagnostic modalities for ruling out the diseases with the worst prognosis. Other modalities (fluoroscopy, computed tomography, and magnetic resonance imaging) may have limited use in very specific conditions. All providers in an emergency department should be familiar with the basic radiological findings that may indicate a gastrointestinal emergency, especially in health institutions that do not have 24-h radiologist coverage.

The diagnostic accuracy of ultrasound and upper gastrointestinal contrast studies for locating atresia/stenosis and intestinal malrotation and detecting annular pancreas in pediatric patients with duodenal atresia/stenosis

PURPOSE

This study aimed to evaluate the diagnostic performance of ultrasound to locate atresia/stenosis and other abdominal anomalies in pediatric patients with duodenal atresia/stenosis, including intestinal malrotation and annular pancreas.

METHODS

We classified 36 retrospective cases of duodenal atresia/stenosis based on intestinal malrotation status, and evaluated the diagnostic performance of ultrasound/upper gastrointestinal contrast studies to locate atresia/stenosis and intestinal malrotation, as well as ultrasound for detecting additional anomalies such as annular pancreas. The incidence of annular pancreas was compared between groups using Fisher's exact test.

RESULTS

Atresia/stenosis was correctly located by ultrasound in 33 (91.7%) cases and by upper gastrointestinal contrast study in 36 (100%) cases. Of the eight cases with intestinal malrotation, five and two were correctly diagnosed by ultrasound and upper gastrointestinal contrast study, respectively. Ultrasound correctly diagnosed annular pancreas in 6/14 cases. The incidence of annular pancreas was significantly different between the groups (present/absent in groups with vs. without intestinal malrotation: 6/2 vs. 8/20, P = 0.036).

CONCLUSIONS

Ultrasound has a relatively high capability in locating atresia/stenosis. However, some cases are misdiagnosed. In clinical practice, upper gastrointestinal contrast studies should be used complementarily during diagnosis. Additional anomalies may not be detected by preoperative examinations; therefore, surgeons should carefully evaluate for additional anomalies during surgery, especially coexisting intestinal malrotation and annular pancreas.

Incidence of late severe intestinal complications after bowel atresia/stenosis

BACKGROUND

To determine the incidence and risk factors for late severe intestinal complications after surgical repair for intra-abdominal congenital intestinal atresia/stenosis.

METHODS

We included 51 patients who underwent surgical repair for congenital intestinal atresia/stenosis. Late severe intestinal complications included adhesive ileus, incisional hernia, or volvulus. Whether surgical intervention was urgent or not was recorded. The location of the atresia/stenosis was classified into two groups: atresia/stenosis located at the oral or anal side from the Treitz ligament. The type of atresia/stenosis was classified as low-risk types (type I, mucosal web/II, fibrous cord/IIIa, mesenteric gap defect) and high-risk types (IIIb, apple peel/IV, multiple atresia). We compared the incidence of late intestinal complications between the location of intestinal atresia/stenosis at the oral and anal side of Treitz ligament, and between low- and high-risk types of atresia/stenosis using Fisher's exact test.

RESULTS

Eight (15.7%) had late intestinal complications, all of which occurred in patients with intestinal atresia/stenosis located on the anal side of the ligament of Treitz. Urgent surgical intervention was needed in four cases. There was a significant difference in the location of atresia/stenosis (with vs. without late intestinal complications at oral/anal side of the Treitz ligament: 0/8 vs. 24/19; P = 0.005) and the type of intestinal atresia/stenosis (with vs. without that accompanying low-/high-risk type: 5/3 vs. 41/2; P = 0.023).

CONCLUSIONS

Physicians should consider the presence of intestinal complications that require surgical intervention in patients undergoing surgical reconstruction for jejunal and ileal atresia/stenosis with abdominal symptoms.

Neonatal and Pediatric Bowel Obstruction: Imaging Guidelines and Recommendations

Pediatric bowel obstructions are one of the most common surgical emergencies in children, and imaging plays a vital role in the evaluation and diagnosis. An evidence-based and practical imaging approach to diagnosing and localizing pediatric bowel obstructions is essential for optimal pediatric patient care. This article discusses an up-to-date practical diagnostic imaging algorithm for pediatric bowel obstructions and presents the imaging spectrum of pediatric bowel obstructions and their underlying causes.

Saline-Aided Ultrasound Versus Upper Gastrointestinal Series in Neonates and Infants With Suspected Upper Gastrointestinal Obstruction: A Prospective Multicenter Comparative Study

Background: Use of upper gastrointestinal (UGI) series to diagnose UGI obstruction has raised concern in neonates and infants given increased radiation sensitivity by developing organs. Objectives: To assess the diagnostic performance of saline-aided ultrasound for UGI obstruction in neonates and infants, in comparison with UGI series. Methods: This prospective multicenter study enrolled inpatients at three hospitals who were less than 1 year old and had suspected UGI obstruction between June 2015 and May 2018; patients with malrotation or pyloric stenosis on ultrasound were ineligible. Enrolled patients underwent both saline-aided ultrasound (saline administered by nasogastric tube) and UGI series. Surgical findings or at least one-year clinical follow-up served as reference for presence of UGI obstruction. Patients with UGI obstruction were classified in terms of level (proximal vs distal) and cause. Two radiologists independently interpreted saline-aided US examinations to assess interobserver agreement and then reached consensus. Two separate radiologists assessed upper GI series in consensus. Diagnostic performance for UGI obstruction presence and level was compared between modalities. Causes were assessed on saline-aided ultrasound. Results: A total of 209 neonates were included (median age 5 days; 116 male, 93 female); 124 (59.3%) had UGI obstruction (proximal in 108). Saline-aided ultrasound exhibited strong interobserver agreement for obstruction presence (κ=0.87) and level (κ=0.85). For presence of UGI obstruction, accuracy, sensitivity, and specificity were 94.7%, 98.4%, and 89.4% for saline-aided US, versus 89.5%, 95.2%, and 81.5% for UGI series. For obstruction level, accuracy, sensitivity, and specificity were 91.9%, 97.2%, and 56.3% for saline-aided US, versus 87.1%, 92.6%, and 50.0% for UGI series. Accuracy for presence was significantly higher for saline-aided US (p=.02); otherwise, these metrics were not different between tests (p>.05). For causes of UGI obstruction (annual pancreas, duodenal web, duodenal atresia, and duodenal stenosis), accuracy of saline-aided US ranged from 75.0% to 94.1%. Conclusion: Saline-aided US has high diagnostic performance for presence and level of UGI obstruction in neonates and infants, comparing favorably versus UGI series. Saline-aided US may have additional utility in evaluating causes of obstruction. Clinical Impact: Saline-aided US may serve as an initial screening modality for UGI obstruction in neonates and infants.

Paediatric adhesive bowel obstruction: a systematic review

Adhesions following abdominal surgery remain a common cause of bowel obstruction. The incidence is between 1 and 12.6% in children who have had previous abdominal surgery. While conservative management is usually trialled in all patients (including children) suspected of having ASBO, the majority will require surgical intervention. New materials such as Seprafilm^® have been studied in the paediatric population, with promising results of its use in index abdominal surgeries to prevent the formation of adhesions. In this article, we conducted a systematic review to present an overview of the current knowledge on the incidence, aetiology, pathophysiology, clinical presentation, and management of ASBO.

Diagnostic decision-making tool for imaging term neonatal bowel obstruction

Term neonatal bowel obstruction is common, and absence of treatment is potentially catastrophic. There is a relatively narrow differential diagnosis, with causes categorised as either low or high bowel obstruction. The commonest causes of low bowel obstruction include anorectal malformations (ARM), Hirschsprung's disease, ileal atresia, meconium ileus, meconium plug, and colonic atresia. The commonest causes of high bowel obstruction include duodenal atresia, duodenal stenosis/web, jejunal atresia, and malrotation with volvulus (and hypertrophic pyloric stenosis usually presenting in slightly older infants). Diagnosis can be decided using a step-wise binary decision tool that includes the appropriate imaging steps and evaluation of bowel calibre. This paper presents the decision-making tool from the presenting features, through plain radiographic findings and, where necessary, the additional radiological investigations to assist the general radiologist, novice paediatric radiologist and paediatric surgeon. The tool is pictorial, with the radiological findings accompanied by eight schematics, serving as a simplified visual aid for memorizing the imaging patterns of the differential diagnosis. The imaging and decision-making steps allow for a rapid, simplified diagnosis that can benefit patients by recommending when to perform surgery, when to perform further imaging, and when imaging can act in a therapeutic manner.

Diagnostic performance and role of the contrast enema for low intestinal obstruction in neonates

PURPOSE

We aim to evaluate the diagnostic performance and relationship between clinical characteristics, imaging findings, and final diagnosis for the neonatal contrast enema (CE).

METHODS

Retrospective 10-year review of all neonatal CEs including imaging findings, clinical information, indication, and final diagnosis from discharge summaries, surgical reports, and pathology (reference standard). Two blinded pediatric radiologists reinterpreted 366 CEs for obstruction, microcolon, rectosigmoid index (RSI), serrations, meconium, ileal cut-off, transition zone, diagnosis, and level of confidence. CE diagnostic performance was calculated versus reference standard.

RESULTS

Diagnoses included Hirschsprung disease (HD) (15.8%), small left colon syndrome (14.8%), small intestinal atresia/colonic atresia (SIA/CA) (12.6%), meconium ileus (MI) (4.4%), and normal (48.9%). CE had a moderate specificity (87.7%) and low sensitivity (65.5%) for HD; abnormal RSI and serrations showed high specificities (90.3%, 97.4%) but low sensitivities (46.6%, 17.2%). CE showed high specificity (97.4%) and low sensitivity (56.3%) for MI blinded to cystic fibrosis status. Microcolon was specific (96.6%) but not sensitive (68.8%) for MI. CE showed highest PPV (73.1%) (specificity 95.6%, sensitivity 82.6%) for SIA/CA. Microcolon with an abrupt cut-off was specific (99.1%) but not sensitive (41.3%) for atresias.

CONCLUSION

Neonatal CE demonstrates high specificities and low to moderate sensitivities across all diagnoses, with lowest performance in HD.

CLINICAL TRIAL REGISTRATION

None.

Diagnosis of Hirschsprung Disease

Diagnosis or exclusion of Hirschsprung disease (HSCR) is a frequent exercise in any pediatric hospital. Although HSCR may present at different ages and with varied clinical findings, the most common presentation is a neonate with severe constipation or signs of intestinal obstruction. A variety of diagnostic tests including contrast enema and anorectal manometry may be used as diagnostic screens, but diagnosis ultimately rests upon histopathological evaluation of a rectal biopsy. For the experienced pathologist, conventional hematoxylin-and-eosin-stained sections often suffice to exclude HSCR or establish the diagnosis. However, ancillary diagnostic tests such as acetylcholinesterase histochemistry or calretinin immunohistochemistry are complementary and extremely helpful in some cases. In this Perspectives article, we review the clinical and pathological features of HSCR, highlight those that are found in most patients, and discuss how to address particularly challenging aspects of the diagnostic workup.

Comparative effectiveness of imaging modalities for preoperative assessment of anorectal malformation in the pediatric population

OBJECTIVE

The aim of this study was to compare the accuracy of MRI, colostography/fistulography, and X-ray imaging modalities for preoperative diagnosis of anorectal malformations (ARMs) in pediatric patients.

METHODS

This retrospective analysis included a total of 84 pediatric patients with ARMs. Preoperative imaging findings were assessed by 2 radiologists and compared to surgical findings.

RESULTS

MRI identified anomalies of the spine in 25 of 84 patients (29.8%), anomalies of the genital system in 7 of 84 patients (8.3%), anomalies of the urinary system in 22 of 84 patients (26.2%), and underdeveloped sphincter muscle complex in 34 of 84 patients (40.5%). In the 44 subjects receiving both MRI and X-ray, MRI was more sensitive in detecting anomalies of spine (18/44 vs. 8/44; P = 0.002), and both correctly identified the distal end of the rectum in 77.3% (34/44) of the cases. In the 24 subjects receiving both MRI and colostography/fistulography, MRI was more accurate in identifying Pena's classification (22/24 vs. 15/24; P = 0.039). Distal end of the rectum was correctly identified in 75.0% (18/24) and 58.3% (14/24) of the cases (P = 0.125).

CONCLUSIONS

MRI could clearly reveal fistula anatomy and associated anomalies of ARMs and should be routinely used for preoperative evaluation of ARMs.

TYPE OF STUDY

Study of diagnostic test.

LEVEL OF EVIDENCE

Level II.

Mimics of malrotation on pediatric upper gastrointestinal series: a pictorial review

Intestinal malrotation is a continuum of congenital anomalies due to lack of rotation or incomplete rotation of the fetal intestine around the superior mesenteric artery axis. The abnormal bowel fixation (by mesenteric bands) or absence of fixation of portions of the bowel increases the risk of bowel obstruction, acute or chronic volvulus, and bowel necrosis. The clinical presentation of patients with malrotation without, with intermittent, or with chronic volvulus can be problematic, with an important minority presenting late or having atypical or chronic symptoms, such as intermittent vomiting, abdominal pain, duodenal obstruction, or failure to thrive. The diagnosis is heavily reliant on imaging. Upper GI series remain the gold standard with the normal position of the duodenojejunal junction lateral to the left-sided pedicles of the vertebral body, at the level of the duodenal bulb on frontal views and posterior (retroperitoneal) on lateral views. However, a variety of conditions might influence the position of the duodenojejunal junction, potentially leading to a misdiagnosis of malrotation. Such conditions include improper technique, gastric over distension, splenomegaly, renal or retroperitoneal tumors, liver transplant, small bowel obstruction, the presence of properly or malpositioned enteric tubes, and scoliosis. All of these may cause the duodenojejunal junction to be displaced. We present a series of cases highlighting conditions that mimic malrotation without volvulus to increase the practicing radiologist awareness and help minimize interpretation errors.

Meconium Ileus

Cystic fibrosis is one of the most common inheritable traits in Caucasians. Meconium ileus and its potential complications are the most likely reasons that these patients will need surgical care. Surgical intervention is usually needed in the neonatal period but may also be required later in life. This article discusses the various ways cystic fibrosis can affect the gastrointestinal tract. Both the operative and nonoperative management of complicated and uncomplicated meconium ileus are discussed in the neonatal period as well as long-term issues, such as distal intestinal obstructive syndrome, fibrosing colonopathy, and rectal prolapse, all of which may be seen in older children and adults.

How to write a Critically Appraised Topic: evidence to underpin routine clinical practice

Critically appraised topics (CATs) are essential tools for busy clinicians who wish to ensure that their daily clinical practice is underpinned by evidence-based medicine. CATs are short summaries of the most up-to-date, high-quality available evidence that is found using thorough structured methods. They can be used to answer specific, patient-orientated questions that arise recurrently in real-life practice. This article provides readers with a detailed guide to performing their own CATs. It is split into four main sections reflecting the four main steps involved in performing a CAT: formulation of a focused question, a search for the most relevant and highest-quality evidence, critical appraisal of the evidence and application of the results back to the patient scenario. As well as helping to improve patient care on an individual basis by answering specific clinical questions that arise, CATs can help spread and share knowledge with colleagues on an international level through publication in the evidence-based dermatology section of the British Journal of Dermatology.

Internal Hernia Masquerading As Necrotizing Enterocolitis

In extremely preterm infants, acute abdominal emergencies are fortunately less common with improving care. Spontaneous intestinal perforation and necrotizing enterocolitis are conditions where emergency surgery is most often needed. Conservative medical management and placement of temporary drain are often used in the initial management. Internal hernia (IH) is an uncommon cause of bowel obstruction in neonates, is difficult to diagnose and unfortunately are found only at autopsy. The presentation in preterm infants, distinction between these conditions, and the need for early diagnosis of IH are discussed.