The Non-Recurrent Laryngeal Nerve: Can we Predict this Pitfall in Thyroid Surgery?

The non-recurrent laryngeal nerve is a rare anatomical variation that poses a major risk for iatrogenic injury during thyroid surgery. This has been described on the right side in association with the presence of an arteria lusoria. We report two cases of non-recurrent laryngeal nerves, with emphasis on the role of pre-operative cervical ultrasound in predicting this variation. On both cases, cervical ultrasound was consistent with the presence of an arteria lusoria, which raised a strong suspicion that a non-recurrent laryngeal nerve could be found during surgery. This was confirmed during both surgical procedures, which had no intercurrences. Although it should never replace a thorough surgical dissection, we believe that this is a simple and non-invasive method which is a valuable tool to improve pre-operative diagnosis and to plan the surgical strategy and therefore to prevent the complications that may result from an unexpected anatomical variant during thyroid surgery.