The prenatal detection of distal tracheoesophageal fistulas in fetuses diagnosed with esophageal atresia

Background: Esophageal atresia is a major anomaly of varying severity. The complexity of surgical correction depends on the presence of a distal fistula.

Objective: This study aimed to determine the feasibility and accuracy of prenatal ultrasound detection of the distal fistula in fetuses diagnosed with esophageal atresia.

Study design: This was an observational study conducted at a single tertiary care center between 2019 and 2021. Included were pregnant patients carrying a fetus prenatally diagnosed with esophageal atresia that was confirmed postnatally during corrective surgery or at postmortem autopsy. During the scan, the performing investigator determined the presence or absence of a distal fistula by scanning the location of the lower esophagus during fetal breathing. Cases in which the lower esophagus was observed distending with amniotic fluid during breathing were deemed "fistula present," and the remaining cases "fistula absent." Test feasibility and performance indices, including sensitivity, specificity, and positive and negative predictive value were calculated. The offline clips and images were reviewed by 2 investigators for the assessment of interoperator agreement using Cohen's Kappa formula.

Results: Included were 16 fetuses with esophageal atresia scanned between 2019 and 2021. All fetuses were successfully scanned with sufficient resolution of the area of interest during at least 3 cycles of breathing. It took a median of 8.5 minutes to determine the presence or absence of a distal fistula. The feasibility of the test was 100% (16/16). The test's sensitivity, specificity, and positive and negative predictive values were 80% (95% confidence interval, 55-100), 100% (95% confidence interval, 60-100), 100% (95% confidence interval, 65-100), and 75% (95% confidence interval, 45-100), respectively. The Cohen's Kappa for interoperator agreement was calculated to be 1, P<.001, corresponding to a "perfect" level of agreement.

Conclusion: Distal fistulas in esophageal atresia can be demonstrated prenatally by targeted scanning using appropriate technique. The method provided is feasible, reproducible, and has excellent performance indices. This novel technique and observations may improve the prenatal diagnosis and counseling of esophageal atresia.