Relationship between the Recurrent Laryngeal Nerve and the Inferior Thyroid Artery in the Togolese Subject: Surgical Anatomy Study from 227 Thyroidectomies

Abstract

Introduction
 Identification of the recurrent laryngeal nerve during thyroid surgeries is recommended to preserve its functionl integrity. This study aims to determine the relationship between the recurrent laryngeal nerves and the inferior thyroid arteries during thyroidectomies, as well as any particularities and intraoperative complications.
 Materials and Methods
 Observational cross-sectional study of all culturally Togolese patients who underwent thyroidectomy with nerve dissection in the ENT department of Sylvanus Olympio University Hospital from 1 January 2013 to 30 June 2017, i.e. a period of 4 years 6 months.
 Results
 The sex ratio was 0.14 i.e., 7 women for 1 man and the average age of 41.82 years. Tissue nodules and multinodular goiters were the most operated lesions in 40.97% and 33.04%, respectively, with a plunging character in 17 cases. We had 306 cases of nerve dissection but the recurrent laryngeal nerve could not be found in 1 case on the right. It was globally retro-arterial (under the trunk and under the branches of the inferior thyroid artery) in 75.08% of cases with prevalence of the truncal, pre arterial situation in 16.07% and inter-arterial in 3.28% cases. The nerve was non-recurrent (type II pathway) in 1 case on the right. There was no recurrence injury. Parathyroid devascularization (5 cases) was autotransplanted. The surgeon's experience did not have a significant impact on the occurrence of intraoperative complications (p = 0.24).
 Conclusion
 This observational cross-sectional anatomical-surgical study supports the existing data on the relationships between the recurrent laryngeal nerve and the inferior thyroid artery by confirming their variability. Nevertheless, it was marked by the predominance of the retro arterial truncal situation of the nerve unlike the literature that most often reports a situation of the nerve under the arterial branches.