The usefulness of preoperative ultrasonographic identification of nonrecurrent inferior laryngeal nerve in neck surgery.

BACKGROUNDS AND AIMS: Nonrecurrent inferior laryngeal nerve (ILN) represents a risk factor for injury during neck surgery. It is associated to arterial abnormalities (absence of the brachiocephalic trunk and arteria lusoria) that can be identified by ultrasonography. The aim of the study was to verify the usefulness of preoperative ultrasonography in the research of nonrecurrent ILN by the means of identification of arterial abnormalities and the impact on ILN morbidity. PATIENTS AND METHODS: The study included 750 patients who underwent neck surgery with right-side ILN dissection. A preoperative ultrasonography aimed to identify arterial abnormalities associated to nonrecurrent ILN was performed in 400 patients (Group A) while no preoperative attempts were performed in the remaining patients (Group B). Patients' characteristics, time for intraoperative identification of the ILN, and morbidity were compared. RESULTS: Five and four nonrecurrent ILN were identified in groups A and B, respectively (p = NS). Preoperative ultrasonography correctly predicted nonrecurrent ILN in all cases (accuracy 100%). Nonrecurrent ILN palsy never occurred in group A, while three cases occurred in group B (p < 0.05). The mean time for intraoperative identification of both nonrecurrent and normally recurrent ILN was significantly shorter in group A (p < 0.01). CONCLUSIONS: Preoperative ultrasonography can correctly identify nonrecurrent ILN, allowing earlier nerve identification and prevention of injuries.