Abstract Introduction A fixed upper airway obstruction on pulmonary function testing (PFT) is a rare finding and often results from structural anomalies. A vascular sling is a rare congenital abnormality that can present as exertional dyspnea or dysphagia in adulthood. A high clinical suspicion is required for diagnosis as these findings may be dismissed as testing artifacts or owed to alternative pathology. Description A 33-year-old female with a history of mild-intermittent asthma was referred to the pulmonology office for evaluation of abnormal PFTs. There was flattening of inspiratory and expiratory limbs of the flow-volume loop, suggesting a fixed airway obstruction. The patient complained of mild symptoms including intermittent exertional dyspnea, chest tightness and occasional dysphagia with pills. Repeat testing was performed and the results were reproducible. A CT chest followed by CT angiography demonstrated a right-sided aortic arch with mirror-image branching and an aberrant left subclavian artery originating from a Kommerell’s diverticulum, with resultant compression of the trachea and esophagus. The patient was subsequently referred to vascular surgery, where operative planning of reimplantation of the left subclavian artery with repair of the diverticulum was suggested to relieve the compression. The patient elected to defer surgery in favor of close monitoring and further consultation given the mild nature of her symptoms. Discussion This case highlights the importance of careful PFT interpretation, where subtle, reproducible findings revealed a rare vascular anomaly. Aortic malformations are often diagnosed in infancy but can remain clinically silent until later in life. Aortic arch abnormalities are exceedingly rare, and a right aortic arch accounts for 0.05-0.1% of radiological examinations. This patient had a type II Kommerell’s diverticulum, which is associated with a right aortic arch and aberrant left subclavian artery. Given her symptoms and history of asthma, this finding may have been overlooked and owed to her asthma, had she not undergone repeat PFTs and subsequent imaging. This case shows the importance of vigilance when interpreting PFTs, and the necessity for multidisciplinary collaboration between pulmonology and vascular surgery for managing such patients. This abstract is funded by: None
Rizvee et al. (Fri,) studied this question.