Anatomy of the Neck

The right side of the neck is usually selected for ultrasound guided CVC to avoid the theoretical risk of damage to the thoracic duct, which lies on the left side of the neck. The thoracic duct ascends through the mediastinum and enters to left internal jugular vein. While injury to the thoracic duct is unlikely, it can produce a chylothorax, which is a significant problem [7].

Traditionally, the approach was defined by finding the apex of the triangle, formed by the confluence of the sternal and clavicular parts of the sterno-cleido-mastoid muscle.

Note that excess head rotation can begin to reduce the IJV diameter, so this action is best avoided.

With ultrasound guided CVC, the exact approach can be determined by direct visualisation of the anatomy. The approach is still within the triangle, but an optimal site can readily be selected. The angle of approach within the triangle is shown by the arrow.

It is important to palpate the location of the two parts of the sterno-cleido mastoid muscle, and to recognise them by ultrasound imaging, as a needle should not be introduced through their muscle bulk.