Prediction of Symptoms and Evaluation of Surgical Indications After Birth Based on Tracheal Morphology of Double Aortic Arch.

To establish objective criteria for predicting postnatal respiratory symptoms and determine surgical indications in fetuses with double aortic arch (DAA). This single-center, retrospective cohort study included fetuses diagnosed with DAA using fetal echocardiography and managed perinatally at Kanagawa Children's Medical Center from January 2013-December 2024. Clinical data, fetal echocardiography, postnatal contrast-enhanced computed tomography (CT) findings, surgical intervention, and outcomes were reviewed. Narrowest tracheal diameter (NTD) Z score in late gestation and narrowest-to-reference tracheal area (NTA/RTA) ratio on postnatal CT were measured. Primary and secondary outcomes included respiratory symptoms shortly after birth and elective surgery, respectively. Groups were compared using t-tests, and the optimal cutoff values were determined using receiver operating characteristic (ROC) curve analysis. Reproducibility was assessed using intraclass correlation coefficient. Twenty-two patients were included: 5 symptomatic and 17 asymptomatic (12, prophylactic surgery; 5, observation). Symptomatic patients had significantly lower NTD Z scores (median - 1.8 vs. -1.2, P = 0.012) and NTA/RTA ratios (median 0.39 vs. 0.67, P < 0.001). NTD Z score ≤ - 1.7 (area under the ROC curve [AUC] 0.87; sensitivity 80%, specificity 88%) and NTA/RTA ratio ≤ 0.5 (AUC 0.94; sensitivity 100%, specificity 82%) were optimal thresholds for predicting early symptoms. In the asymptomatic group, NTA/RTA ratio ≥ 0.56 identified candidates for observation without surgery. The ICC values for both parameters exceeded 0.85, indicating excellent reproducibility. The prenatal NTD Z score and postnatal NTA/RTA ratio accurately predict postnatal respiratory symptoms in fetuses with DAA. These quantitative parameters may guide individualized perinatal management and surgical decision-making.