a non-recurrent inferior laryngeal nerve (NRLN), linked to the aberrant lusorian artery, represents a risk factor for surgical damage, thus early intraoperative detection in thyroid and parathyroid surgery is crucial. Vagus nerve stimulation early during dissection at the most distal point reached and appreciation of a short vagal latency facilitates validation and tracking of the course of the NRLN, thereby improving injury prevention in this markedly variable anatomical variant.

this is the largest single center prospective series of 70 patients with exclusively right sided NRLN undergoing neck surgery. All NRLN were identified using magnification loops, and functionally confirmed using intraoperative neuromonitoring.

Intermittent (n=23) and continuous (n=47) neuromonitoring demonstrated a significantly shorter median latency of the right vagal nerve with 2.5 ms (1.25-6.34 ms). According to Toniato's classification, 13 (19%) were type 1, 33 (47%) Type 2a and 19 were Type 2b (27%). With 132 nerves at risk (NAR), intraoperative loss of signal (LOS) with temporary right vocal cord palsy occurred in two cases (1.5%). Pre- or postoperative imaging was available in 63 (90%) patients and confirmed the aberrant A. lusoria in all, five displaying a retrotracheal und 58 retroesophageal course.

A short stimulation latency of 2.5 ms or less, combined with a failure of signal detection at the most distal point reached of the right vagus in neuromonitoring, facilitates recognition of a NRLN early in the procedure. Temporary NRLN palsy in this series was comparable to incidence rates described in the literature.