CASE OF THE WEEK – “A rare case report of Non-recurrent laryngeal nerve in a patient who underwent total thyroidectomy” Dr Shwan Mohamad Consultant ENT Surgeon & Dr Nawal Ibrahim, Consultant Endocrinology & Internal Medicine, NMC Royal Hospital Sharjah

A rare case report of Non Recurrent Laryngeal Nerve in a patient who underwent total thyroidectomy

Introduction

The Non-Recurrent Laryngeal Nerve is a rare embryologically-derived variant of the Recurrent Laryngeal Nerve with an incidence in the literature of 0.3- 0.8 %. The presence of Non-Recurrent Laryngeal Nerve significantly increases the risk of iatrogenic injury and operative complications.

Case report

A 33 years old lady presented to Endocrinology clinic and was seen initially by Dr Nawal the consultant endocrinologist with thyrotoxicosis and pressure symptoms from enlarged thyroid gland not controlled with anti-thyroid medications. The patient was referred to ENT department for thyroid surgery. I performed Total thyroidectomy for definitive management of uncontrolled thyrotoxicosis and pressure symptoms.

During thyroidectomy , right sided recurrent laryngeal nerve could not be identified in its normal location which normally after looping around right subclavian artery on the right side and Aorta on the left side runs vertically in tracheo-oesophageal groove entering larynx through crico-thyroid membrane ( Figure A). Instead the nerve was found running horizontally coming directly from vagus nerve, hence identified as Non recurrent laryngeal nerve ( Figure B and C) . The nerve was preserved avoiding vocal cord paralysis and subsequently loss of voice. The patient had a successful surgical outcome with normal voice post operatively.

Conclusion

The Non recurrent laryngeal nerve is a rare yet clinically very relevant structure for thyroid surgeons and is associated with increased risk of iatrogenic injury, most often leading to temporary or permanent vocal cord paralysis. Thyroid surgeons should be aware of this anatomical variation to avoid surgical morbidity.

References

Coady MA, et al: Nonrecurrent laryngeal nerve during carotid artery surgery:
case report and literature review. J Vasc Surg 2000;32:192-196.