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

Abstract

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.

Ultrasonographic Imaging of the Fetal Duodenal Tract

“…However, in this study, a clear distinction between the duodenum and the pancreas can be made by following the hypoechoic zone between the head of the pancreas and the descending part of the duodenum. This could provide an advantage for annular pancreas diagnosis 12 …”

“…3,11 In a retrospective study conducted by Yin et al on 40 fetuses diagnosed with congenital duodenal obstruction, it was stated that ultrasound findings such as 'rat tail sign' (the image of the dilated bowel loops above the diaphragm when scanning continues along the widening end of the duodenum) in intrinsic duodenal obstructions and 'plier sign' in annular pancreases can be seen. 12 In the aforementioned study, only the first part of the duodenum was evaluated, and no evaluation was made for the other parts. In the present study, the duodenal tract was evaluated in its first three parts, and evaluation could be made in terms of rat tail and plier sign in healthy fetuses.…”

“…This could provide an advantage for annular pancreas diagnosis. 12 In this study, an evaluation of the presence of fluid in the lumen of the fetal duodenal tract was also made. This is important for determining whether there is an obstruction in the lumen (wind suck or rat-tail sign).…”

“…The difficulties in evaluating the pyloric sphincter in a prenatal ultrasound before the 20th gestational week are known 3,11 . In a retrospective study conducted by Yin et al on 40 fetuses diagnosed with congenital duodenal obstruction, it was stated that ultrasound findings such as 'rat tail sign' (the image of the dilated bowel loops above the diaphragm when scanning continues along the widening end of the duodenum) in intrinsic duodenal obstructions and 'plier sign' in annular pancreases can be seen 12 . In the aforementioned study, only the first part of the duodenum was evaluated, and no evaluation was made for the other parts.…”

Obstrucción intestinal por páncreas anular en etapa neonatal: reporte de caso

“…La prevalencia exacta es desconocida, en la literatura se describe 1 caso por cada 20 000 recién nacidos vivos aproximadamente (1) . Se ha asociado con polihidramnios materno (2) y anomalías congénitas como atresia esofágica y duodenal, malformación anorrectal y divertículo de Meckel (3) . El páncreas anular puede clasificarse, según la distribución anatómica del parénquima pancreático alrededor del duodeno, en completo e incompleto (4) .…”