Objective: Double aortic arch (DAA), right aortic arch with aberrant left subclavian artery (RAA/ALSA) and left aortic arch with aberrant right subclavian artery (LAA/ARSA) are the most common vascular rings. DAA and RAA/ALSA are usually symptomatic and form a complete vascular ring. LAA/ARSA typically is asymptomatic and does not cause a complete vascular ring. The aim of this study was to define the difference in tracheal geometry between patients with complete vascular rings, subjects with incomplete vascular rings and individuals with normal left aortic arch.
Methods: In total, 57 patients underwent multidetector computed tomography (MDCT). Patients were divided in three groups. Group A patients (n=19) had complete vascular rings; group B patients (n=19) had incomplete vascular rings; group C patients (n=19) had normal left aortic arch. Percentage of maximum area (PMA) was defined as the smallest tracheal cross-sectional luminal area divided by the largest area × 100%.
Results: In group A, significant tracheal narrowing (PMA < 50%) was observed in 8 (42.1%) of 19 patients. There were no cases of significant tracheal narrowing in groups B and C. Percentages of maximum area were 53.0±23.8%, 78.5±11.1%, 82.2±7.2% for groups A, B and C, respectively. There were significant differences between groups A and B (p<0.01) and between groups A and C (p<0.01). There was no significant difference between group B and group C.
Conclusions: Patients with complete vascular rings have significantly altered tracheal geometry compared to subjects with LAA/ARSA. Tracheal geometry in patients with incomplete vascular rings is similar to normal.