Prenatal counselling of small bowel atresia:watch the fluid!

"Keyboard sign" and "coffee bean sign" in the prenatal diagnosis of ileal atresia: A case report

BACKGROUND

Ileal atresia is a congenital abnormality where there is significant stenosis or complete absence of a portion of the ileum. The overall diagnostic accuracy of prenatal ultrasound in detecting jejunal and ileal atresia is low. We report a case of ileal atresia diagnosed prenatally by ultrasound examination with the "keyboard sign" and "coffee bean sign".

CASE SUMMARY

We report a case of ileal atresia diagnosed in utero at 31 weeks' of gestation. Prenatal ultrasound examination revealed two rows of intestines arranged in an 'S' shape in the middle abdomen. The inner diameters were 1.7 cm and 1.6 cm, respectively. A typical "keyboard sign" was observed. The intestine canal behind the "keyboard sign" showed an irregular strong echo. There was no normal intestinal wall structure, showing a typical "coffee bean sign". Termination of the pregnancy and autopsy findings confirmed the diagnosis.

CONCLUSION

The prenatal diagnosis of ileal atresia is difficult. The sonographic features of the "keyboard sign" and "coffee bean sign" are helpful in diagnosing the location of congenital jejunal and ileal atresia.

Congenital small bowel obstruction: Prenatal detection and outcome

OBJECTIVE

To evaluate and compare the outcome of fetuses and neonates with congenital small bowel obstructions (SBO), evaluate the screening performance of prenatal ultrasound for SBO and identify possible risk factors for adverse outcomes.

METHODS

All cases referred to the Amsterdam University Medical Centers between 2007 and 2021 for a prenatal suspected SBO, supplemented by cases of postnatal diagnosis of SBO, were included. The primary outcome was survival after 24 weeks of gestation until the first year of life.

RESULTS

147 cases of SBO were included with a survival rate of 86.2% (119/138) after 24 weeks of gestation until the first year of age. Additional structural or chromosomal anomalies were found to have an increased risk of adverse outcomes. Intrauterine fetal demise occurred in 10/147 (6.8%) cases and 9/147 (6.1%) cases died during postnatal follow-up. The overall positive predictive value of all prenatally diagnosed cases was 91.5%. Surgical correction was performed in 123/128 (96.0%) of the live-born cases.

CONCLUSIONS

Congenital SBO has an overall favorable prognosis, but the outcome is negatively impacted by the possible presence of additional structural or chromosomal anomalies. Fetal monitoring in the early third trimester should be considered, since all cases of Intrauterine fetal demise occurred between 30 and 35 weeks of gestation.

Accuracy of prenatal ultrasound in detecting jejunal and ileal atresia: systematic review and meta-analysis

OBJECTIVE

The accuracy of prenatal ultrasound examination in detecting jejunal and ileal atresia has been reported in the literature to be highly variable, at 25-90%. The aim of this systematic review was to evaluate the accuracy of prenatal ultrasound in detecting non-duodenal small bowel atresia (ND-SBA).

METHODS

MEDLINE, EMBASE and The Cochrane Library, including The Cochrane Database of Systematic Reviews (CDSR), Database of Abstracts of Reviews of Effects (DARE) and The Cochrane Central Register of Controlled Trials (CENTRAL), were searched electronically. The overall detection rate of jejunal or ileal atresia using ultrasound was reported. The accuracy of using polyhydramnios and dilated loops of bowel as diagnostic signs was also explored.

RESULTS

Sixteen studies involving 640 fetuses were included in this review. The detection rate of ND-SBA by prenatal ultrasound was highly variable, with values ranging from 10 to 100%, with an overall prediction of 50.6% (95% CI, 38.0-63.2%). When analyzed separately, the detection rates of jejunal and ileal atresia were 66.3%, (95% CI, 33.9-91.8%) and 25.9% (95% CI, 4.0-58.0%), respectively. Both dilated loops of bowel and polyhydramnios as diagnostic signs for ND-SBA provided a low overall detection rate.

CONCLUSIONS

The diagnostic performance of prenatal ultrasound in identifying ND-SBA is extremely variable. Large studies are needed in order to identify objective and combined criteria for the diagnosis of these anomalies.

Diagnostic Accuracy of Prenatal Ultrasound in Identifying Jejunal and Ileal Atresia

Introduction: Small bowel atresia (SBA) is one of the most common causes of congenital intestinal obstruction. However, the accuracy of prenatal ultrasound in diagnosing this condition has not been entirely ascertained. The aim of this study was to analyse the predictive accuracy of ultrasound in detecting SBA prenatally. Methodology: Retrospective study of all cases with prenatal suspicion or postnatal confirmed SBA seen in a tertiary fetal medicine and pediatric surgery units from 2007 to 2013. Cases with duodenal atresia were excluded from the study. The predictive accuracy of ultrasound and different ultrasound signs, alone and in combination, was calculated. Results: 65 fetuses with prenatal suspicion or postnatal confirmed SBA were enrolled. 58 cases had full data and were included in the analysis. Predictive accuracy of ultrasound in detecting the presence of SBA was poor, with a sensitivity of 50% (95% CI 26.0-74.0) and a specificity of 70.59% (95% CI 52.5-84.9). The presence of both bowel dilatation ≥17 mm and polyhydramnios after 32 weeks of gestation slightly increased sensitivity (66.67%, 95% CI 34.9-90.1) and specificity (80.00%, 95% CI 44.4-97.5). Conclusions: In case of suspicion of SBA before the 3rd trimester, an ultrasound after 32 weeks should be performed to confirm the presence of both polyhydramnios and bowel dilatation >17 mm.

Neonatal outcomes associated with intestinal abnormalities diagnosed by fetal ultrasound

PURPOSE

Intestinal abnormalities are sometimes seen during antenatal testing; however, the postnatal importance of these findings has not been well established. We evaluated whether abnormal intestinal appearance on fetal ultrasound (US) was ultimately related to neonatal outcome.

METHODS

Fetal US examinations from 2003 to 2006 were evaluated. Hyperechogenic bowel was defined as having the echogenicity comparable to bone, and dilated bowel was identified based on the sonographer's assessment. Persistence or resolution of US findings on subsequent US examinations and eventual outcomes were assessed. Cases were categorized as hyperechogenic or dilated and then subgrouped based on whether the US finding resolved.

RESULTS

Sixty-eight fetuses had either hyperechogenic (n = 48) or dilated bowel (n = 20) on antenatal US. In 56 cases, complete data were available for analysis. Of 44 liveborn infants, 11 (25.0%) had an abdominal abnormality, and 33 (75.0%) were normal at birth. Compared to those with dilated bowel, fetuses with hyperechogenic bowel had a higher rate of prenatal demise (20.8% vs 10%) but a lower rate of abnormality at birth (10.3% vs 53.3%). Hyperechogenic bowel resolved on subsequent US more frequently than dilated bowel (65.5% vs 20.0%). In both groups, all fetuses with sonographic resolution were normal at birth. Of 9 fetuses that had persistently hyperechogenic bowel, 3 (33.3%) were born with an abnormality, and all were found to have meconium peritonitis or meconium ileus. In the 12 cases where dilated bowel did not resolve, 8 (66.7%) were eventually born with an abnormality, most commonly intestinal atresia.

CONCLUSIONS

Hyperechogenic and dilated bowel are associated with a significant rate of fetal demise. Hyperechogenicity is more common than dilation and is more likely to be transient. Dilated bowel is more often associated with neonatal abnormality than hyperechogenic bowel. Persistence of fetal US findings predicts a higher likelihood of abnormality in the neonate.