[Preoperative CT diagnosis of right nonrecurrent inferior laryngeal nerve, report of a case].

BACKGROUND The nonrecurrent inferior laryngeal nerve is an anomaly associated with the absence of the brachiocephalic artery (BCA) and the presence of arteria lusoria. METHODS The preoperative CT scans from 290 patients (9 nonrecurrent, 281 recurrent) were retrospectively reviewed. We identified the BCA or the arteria lusoria, and classified the relationship between the right subclavian artery (SCA) and the tracheoesophagus into 2 subtypes. RESULTS The arteria lusoria was identified in 6 nonrecurrent cases. The BCA was identified in 143 recurrent cases. The right SCA was detected on the ventral side of the membranous wall of the trachea in 273 recurrent cases, whereas it was detected on the dorsal side in 8 recurrent cases with enlarged thyroid, and it was detected on the dorsal side in 9 nonrecurrent cases without pressure sign. CONCLUSIONS It is possible to predict a nonrecurrent inferior laryngeal nerve by identifying the arteria lusoria or other features on the preoperative CT.