Figure 9.

Tuohy needle advancement during an ultrasound guided interscalene catheter utilizing a posterior approach. In A). the needle tip is seen advancing between the C5 and C6 nerve roots. The catheter is subsequently advanced and is seen exiting the Tuohy needle between the C5 and C6 nerve roots B). Triangles refer to the needle tip in A) and the catheter exiting the needle in B). The arrows point to the roots of the brachial plexus in both (A) and (B).