Non-recurrent laryngeal nerve related to thyroid surgery: report of three cases.

PURPOSE OF THE STUDY

We aimed to highlight a rare anatomical variation involving the recurrent laryngeal nerve, and to emphasise its implications for thyroid surgery.

MATERIALS AND METHODS

Over a period of 13 years, 993 patients underwent thyroid surgery; 1557 recurrent laryngeal nerves (887 on the right side) were exposed.

RESULTS

Three non-recurrent laryngeal nerves were found on the right side, associated with a retro-oesophageal subclavian artery. One case was suspected before surgery.

DISCUSSION

Several variations in the path and branches of the recurrent laryngeal nerve have been reported in the literature. The frequency of occurrence of a non-recurrent laryngeal nerve is about 1 per cent, for patients undergoing thyroid surgery. Other surgically relevant anatomical variations of the recurrent laryngeal nerve include associations with the inferior thyroid artery and the presence of nerve branches.

CONCLUSION

The recurrent laryngeal nerve must be carefully dissected and totally exposed during thyroid surgery in order to best preserve its function. Moreover, the thyroid surgeon must be aware of the existence of anatomical variations, which are not as rare as one may think.