Diagnostic value of the acute angle between the prestenotic and poststenotic duodenum in neonatal annular pancreas

Ultrasound imaging of bowel obstruction in neonates

Bowel obstruction (BO) in children has a wide differential diagnosis, ranging from non-urgent conditions to surgical emergencies. Abdominal radiographs are most often used as the first imaging modality for the evaluation of obstruction. However, for some indications, ultrasound can be the primary imaging modality. Therefore, it is incumbent on radiologists to recognize the types of bowel obstruction that can be recognized with US. Key sonographic features of BO include differential dilation of bowel loops, bowel wall thickening, and free fluid. "Do Not Miss" findings that indicate need for emergent treatment include volvulus, pneumoperitoneum, and/or signs of ischemia (bowel wall thinning and/or absent perfusion). The aim of this pictorial essay is to provide guidance on the sonographic technique and findings that enable identification of BO on US. Examples of neonatal BO on US, including common and less frequently encountered etiologies, are illustrated in this pictorial essay.

Exploring the clinical characteristics and prevalence of the annular pancreas: a meta-analysis

BACKGROUND

The annular pancreas (AP) is a rare gastrointestinal congenital malformation, in which malrotation of the pancreatic ventral bud in the seventh week of embryonic development manifests in a partial or complete ring of tissue around the second part of the duodenum.

METHODS

The main online medical databases such as PubMed, ScienceDirect, Wiley online library, Web of Science, and EBSCO discovery service were used to gather all relevant studies on the AP.

RESULTS

A total of 12,729,118 patients were analyzed in relation to the prevalence of AP. The pooled prevalence of AP was 0.0045% (95% CI: 0.0021%-0.0077%). The most frequent comorbidity in adults and children was duodenal obstruction, with a pooled prevalence of 24.04% and 52.58%, respectively (95% CI: 6.86%-46.48% and 35.56%-69.31%, respectively). The most frequent operation in adult patients with AP was duodenojejunostomy, with pooled prevalence established at 3.62% (95% CI: 0.00%-10.74%).

CONCLUSION

The diagnostic complexity of AP is accentuated by its nonspecific clinical symptoms, making accurate identification reliant on imaging studies. Therefore, having a thorough knowledge of the clinical characteristics of the AP and its associated anomalies becomes paramount when faced with this rare congenital condition.

Incidence and Clinical Implications of Anatomical Variations in the Pancreas and Its Ductal System: A Systematic Review and Meta-Analysis

OBJECTIVE

This systematic review analyzes the anatomical variants in the pancreas and its ductal system to report on their association with pancreatic pathologies.

METHODS

We conducted a search of the MEDLINE, Scopus, Web of Science, Google Scholar, CINAHL, and LILACS databases from their inception to July 2023. The methodological quality was assessed with the Anatomical Quality Assessment (AQUA) tool. Finally, the pooled prevalence was estimated using a random effects model.

RESULTS

55 studies were found that met the eligibility criteria. The overall prevalence of pancreas divisum (PD) was 18% (95% CI = 15-21%). The prevalence of PD associated with pancreatitis was 30% (95% CI = 1-61%).

CONCLUSIONS

An anatomical variant of the pancreas such as PD may be the cause of bile duct obstruction, resulting in various clinical complications, such as pancreatitis. Hence, knowing this variant is extremely important for surgeons, especially for those who treat the gastroduodenal region.

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.

The value of saline-aided ultrasound in diagnosing congenital duodenal obstruction

PURPOSE

The aim of the study is to assess the value of saline-aided ultrasound (US) in diagnosing congenital duodenal obstruction (CDO).

METHODS

The neonates with CDO were enrolled in this study, including the neonates confirmed with annular pancreas (AP) by operation, the neonates confirmed with duodenal atresia, the neonates confirmed with duodenum web, and the neonates confirmed with malrotation. Pertinent data were recorded, including the US features, intraoperative findings, and surgical procedures. The methodology of this study is a diagnostic test study which means the US feature is the test and the intraoperative finding is the gold standard.

RESULTS

A total of 95 neonates were enrolled, including 33 neonates with AP, 6 neonates with duodenal atresia, 29 neonates with duodenum web, and 27 neonates with malrotation. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of the hyperechogenic band for the detection of AP were 78.8% (26/33), 90.3% (56/62), 81.2% (26/32), 88.8% (56/63), and 86.3% (82/95), respectively. The sensitivity, specificity, NPV, and accuracy for the detection of duodenal atresia were 0% (0/6), 100% (89/89), 93.6% (89/95), and 93.6% (89/95), respectively. The sensitivity, specificity, PPV, NPV, and accuracy for the detection of duodenum web were 100% (29/29), 100% (66/66), 100% (29/29), 100% (66/66), and 100% (95/95), respectively. The sensitivity, specificity, PPV, NPV, and accuracy for the detection of malrotation were 100% (27/27), 100% (68/68), 100% (27/27), 100% (68/68), and 100% (95/95), respectively.

CONCLUSION

Saline-aided US is a feasible tool to diagnose CDO.

The application of prenatal ultrasound in the diagnosis of congenital duodenal obstruction

Background

The purpose of this research is to summarize the prenatal ultrasound characteristics of congenital duodenal obstruction (CDO), especially in the diagnosis of duodenal diaphragm and annular pancreas. At present, few researchers have summarized the specific ultrasound features of duodenal diaphragm and annular pancreas.

Methods

In this study, a retrospective analysis of 40 patients diagnosed with CDO between January 2016 and December 2019 was carried out. Data on the diagnosis, ultrasound images and outcomes of the patients were gathered, and the features of the patients were analyzed.

Results

The results showed that there were 17 patients (42.5%) of congenital duodenal diaphragm, all with a ‘rat tail’ sign on the ultrasound images. Moreover, there were 4 patients (10.0%) of CDO caused by annular pancreas, all with a ‘pliers’ sign on the ultrasound images. We summarized the imaging features of the ‘rat tail’ sign and the ‘pliers’ sign.

Conclusion

The main conclusion of this study was that the ‘rat tail’ sign could be used as an indirect ultrasound feature to diagnose duodenal diaphragm. The ‘pliers’ sign could be used as a direct ultrasound feature in the diagnosis of annular pancreas in CDO.