Relationship between the recurrent laryngeal nerve and the inferior thyroid artery in Japanese.

The anatomical relationship between the recurrent laryngeal nerve and the inferior thyroid artery was studied on 784 sides of the necks of 309 male and 123 female Japanese cadavers. On the right side, the nerve passed anterior to the artery in 32.4%, posterior to it in 26.7%, and between the branches of the artery in 40.9%. On the left side, the nerve was found coursing anterior to the artery in 4.9%, posterior to it in 65.8%, and between the branches in 29.3%. There was a statistically significant difference in the percentage distribution of the three types between the right and left sides, while no significant difference existed between males and females. The side difference in the relationship could be attributed to the difference in the course of the recurrent laryngeal nerve between the two sides. The collaterally symmetric cases of the relationship between the nerve and the artery were found more frequently in males (40.0%) than in females (28.6%). The present study revealed that the relationship between the nerve and the artery in Japanese was essentially similar to those in Americans and Europeans reported in other previous studies.