The "double bubble" sign

The role of multimodal ultrasound in diagnosis of fetal bowel dilatation and prediction of adverse neonatal outcomes: A study of 86 cases in a series of 43,562 births

Objective

To investigate the diagnostic utility of multimodal ultrasound for fetal bowel dilatation (FBD) in different parts of the bowel and to examine its prognostic potential in FBD.

Methods

This retrospective study analyzed 86 fetuses with a dilated bowel identified via ultrasound in a 10-month postnatal follow-up. Both two- and three dimensional (2D and 3D, respectively) ultrasound volume imaging were used to characterize dilation across different bowel sections. The optimal intestinal diameter cut-off values for pathological bowel dilatation were determined and a predictive model for neonatal surgery was developed.

Results

The 86 cases of dilatation were distributed as follows: duodenal (n = 36); jejunum/ileum (n = 35); and colonic (n = 15). Duodenal dilatations presented the earliest during pregnancy compared to the other 2 groups (24.4 versus [vs.] 29 vs. 33.7 weeks respectively; p < 0.05). Cases with small intestinal dilatation were delivered earlier than those with colonic dilatation (p < 0.05). Infants with duodenal dilatation had the lowest birth weight and the highest rate of multi-system abnormalities (30.6% vs. 5.7% vs. 20%; p < 0.001). More than one-half of the multi-system abnormalities had chromosomal abnormalities (multiple, 54% vs. single, 12.5%; p = 0.015). There were 2 stillbirths, 24 induced labors, 44 postnatal surgeries, and 18 normal cases after birth. In predicting adverse neonatal outcomes of jejunum/ileum dilatation using a cut-off value of 15.5 mm small intestine diameter, sensitivity was 81.5%, specificity was 62.5%, and the area under the receiver operating characteristic curve (AUC) was 0.762 (p < 0.05). For colonic dilatation, using a cut-off value of 21.5 mm colon diameter: sensitivity was 83.3%, specificity was 77.8%, and AUC was 0.861 (p < 0.05). In detecting jejunum/ileum and colonic obstruction, 3D ultrasound demonstrated significantly better diagnostic efficiency than 2D ultrasound (p < 0.05). Using the backward stepwise selection method, a predictive model for neonatal surgery in patients with jejunum/ileum and colonic dilatation was established: logit (P) = -1.58 + (2.32 × polyhydramnios) +(2.0 × ascites) +(1.14 × hyperechogenic bowel). The AUC for the prediction model was 0.874 (p < 0.05), with 76% sensitivity and 94.1% specificity.

Conclusions

Duodenal dilatation occurred earlier, with a higher incidence of chromosomal abnormalities and multi-system abnormalities than dilatation of other parts of the bowel. 3D ultrasound played an important role in the detection of jejunum/ileum and colon obstructions. Clinical signs, including polyhydramnios, ascites, and strong echoes in the intestine, can be used to predict neonatal surgery.

Novel qualitative and quantitative ultrasound markers to facilitate prenatal diagnosis of congenital duodenal obstruction

OBJECTIVE

Accurate prenatal diagnosis of congenital duodenal obstruction (CDO) is challenging. We aimed to determine new ultrasound metrics for accurate prenatal diagnosis of fetal CDO.

METHODS

Data pertaining to 46 fetuses with suspected small intestinal obstruction (26 CDO; 16 high jejunal obstructions) were retrospectively analyzed. Prenatal ultrasonographic features including dilated intestinal length, stomach length, maximum intestinal dilatation, ratio of dilated intestinal length at late gestation and dilated stomach length (I/S ratio), and location of distal end of dilated bowel segment relative to spine were compared between CDO and high jejunal obstruction groups. The diagnostic performance of ultrasound indices was evaluated using receiver operating characteristics curve analysis.

RESULTS

In 25 out of 26 CDO cases, the distal end of the dilated small intestine segment was located on the right side of spine, while that in the high jejunal obstruction group was located on the left side of spine. The dilated intestinal length and I/S ratio in CDO group were significantly smaller than those in high jejunal obstruction group (p < .05). Dilated intestinal length <51 mm or I/S ratio <1 showed high sensitivity (100, 100%) and specificity (96.1, 92.3%) for CDO (area under the curve: 0.995 and 0.988, respectively). There were no significant differences in the AUCs of dilated intestinal length and I/S ratio. Significant correlation of the site of obstruction in CDO with fetal dilated intestinal length and I/S ratio (r = 0.686; 0.660, p < .001, respectively) were noted.

CONCLUSION

Location of the distal end of the dilated small intestine segment relative to the spine, dilated intestinal length, and I/S ratio may help differentiate fetal CDO from high jejunal obstruction. The latter two metrics were associated with the site of obstruction in CDO patients.

Prenatal Sonography in Suspected Proximal Gastrointestinal Obstructions: Diagnostic Accuracy and Neonatal Outcomes

BACKGROUND

The purpose of this study was to assess diagnostic accuracy and neonatal outcomes in fetuses with a suspected proximal gastrointestinal obstruction (GIO).

METHODS

After IRB approval, a retrospective chart review was conducted on prenatally suspected and/or postnatally confirmed cases of proximal GIO at a tertiary care facility (2012-2022). Maternal-fetal records were queried for presence of a double bubble ± polyhydramnios, and neonatal outcomes were assessed to calculate the diagnostic accuracy of fetal sonography.

RESULTS

Among 56 confirmed cases, the median birthweight and gestational age at birth were 2550 g [interquartile range (IQR) 2028-3012] and 37 weeks (IQR 34-38), respectively. There was one (2%) false-positive and three (6%) false-negatives by ultrasound. Double bubble had a sensitivity, specificity, positive predictive value, and negative predictive value for proximal GIO of 85%, 98%, 98%, and 83%, respectively. Pathologies included 49 (88%) with duodenal obstruction/annular pancreas, three (5%) with malrotation, and three (5%) with jejunal atresia. The median postoperative length of stay was 27 days (IQR 19-42). Cardiac anomalies were associated with significantly higher complications (45% vs 17%, p = 0.030).

CONCLUSIONS

In this contemporary series, fetal sonography has high diagnostic accuracy for detecting proximal gastrointestinal obstruction. These data are informative for pediatric surgeons in prenatal counseling and preoperative discussions with families.

LEVEL OF EVIDENCE

Diagnostic Study, Level III.

Clinical significance of prenatal double bubble sign on perinatal outcome and literature review

OBJECTIVE

To determine the diagnostic accuracy of the double bubble sign in predicting duedonal obstruction, the prevalence of anomalies associated with congenital duedonal obstruction, and to evaluate the outcome of these pregnancies and review the literature.

METHODS

We analyzed that the cases with double bubble sign were detected in prenatal ultrasonography between January 2014 and December 2019. Ultrasound reports, karyotyping results, surgical confirmed diagnoses and long-term results were extracted from the hospital database.

RESULTS

Duodenal obstruction was detected in all operated cases with double bubble sign detected in prenatal ultrasonography. Karyotype anomaly was found in 63.9% and additional congenital anomaly was found in 69.4%. Adverse perinatal outcome was seen in 51.1% of cases. Adverse perinatal outcome was found significantly higher in abnormal karyotype and congenital anomaly groups than isolated group. 81.8% of the isolated cases lived after the operation. Only two isolated cases died.

CONCLUSION

The prenatal double bubble sign is a highly reliable predictor for duodenal obstruction and structural anomalies and/or genetic abnormalities are present in the majority of cases. Duodenal obstruction is isolated, the outcomes appear favorable.

The Double Bubble Sign: Duodenal Atresia and Associated Genetic Etiologies

BACKGROUND

The "double bubble" sign is an ultrasonographic finding that commonly represents duodenal atresia and is associated with trisomy 21.

OBJECTIVES

We sought to evaluate the positive predictive value of a prenatally identified double bubble sign for duodenal atresia and the genetic etiologies associated with it.

METHODS

We examined a retrospective cohort with prenatal double bubble sign between January 1, 2008, and June 30, 2017. Postnatal diagnoses were determined by review of operative reports and additional postnatal evaluation including cytogenetic analysis, molecular analysis, and/or clinical genetic evaluation.

RESULTS

All live births at our institution with a prenatal double bubble sign had confirmed duodenal atresia. Additional anatomic anomalies and/or genetic abnormalities were identified in 62% of cases. Out of 21 cases, 6 had trisomy 21. Of the remaining 15 cases, 8 were nonisolated duodenal atresia, 3 of which had a heterotaxy syndrome. In the 7 isolated cases, 1 likely pathogenic chromosomal microdeletion was identified.

CONCLUSIONS

Prenatal double bubble sign is a reliable predictor of duodenal atresia. In addition to trisomy 21, heterotaxy may be encountered. ZIC3 mutations as well as microdeletion of 4q22.3 may be underlying genetic etiologies to be considered in the diagnostic evaluation of a prenatal double bubble sign.