Relations of the accessory nerve with the internal jugular vein: surgical implications in cervical lymph node clearances

The position of the lateral branch of the accessory nerve in relation to th e internal jugular vein is given variously by different authors. In surgery of the neck, and especially in conservative cervical lymph node clearances , the lateral branch of the accessory nerve is protected when it is situate d lateral to the vein. However, when the nerve is medial to the vein there is a risk of damage to the internal jugular vein. A prospective peroperativ e study of 123 cervical lymph node clearances, as well as a dissection stud y of 5 fresh subjects, was carried out to determine the position of the lat eral branch of the accessory nerve in relation to the internal jugular vein . The surgical study showed that the lateral branch of the nerve was anteri or and lateral to the vein in 122 of the 123 clearances, while the cadaveri c study found the nerve always anterior and lateral to the vein. Thus the r isk of injuring the internal jugular vein during cervical lymph node cleara nces is very small. The differences observed by authors may be explained by collapse of the internal jugular vein observed during cadaveric dissection s.