An Anatomical Variation in the Formation of the Inferior Root of Ansa Cervicalis

Abstract

During regular dissections, we observed an unusual organization of the inferior root of Ansa Cervicalis (AC). The superior root of ansa arose normally from the hypoglossal nerve. The ventral ramus of the C2 spinal nerve divided into two branches. One of its branches joined the superior root independently to form a loop at a higher level. Another branch ran along the vagus nerve, joined with the ventral ramus of C3 spinal nerve, finally connected with the superior root and formed the second loop at a lower level. No variation was found in formation of superior root. Knowledge on the possible deviations in the formation of these roots is clinically important, to prevent iatrogenic injuries in surgical procedures such as thyroplasties, arytenoids adductions, and Teflon injections.