Ultrasound Identification of an Atypical Course of the Posterior Intercostal Artery During Paravertebral Block.

The thoracic paravertebral block (TPVB), while relatively safe, can be associated with significant complications, including inadvertent vascular injury. We describe an ultrasound-guided TPVB where a pulsatile artery was identified between the two transverse processes and in close proximity to the T7-8 paravertebral space, likely the dorsal branch of the posterior intercostal artery. A similar artery was also noted one intercostal space cephalad and caudal of this area.