The thoracic paravertebral space can be conceptually divided into three zones to describe the risks and benefits of performing a paravertebral block in those locations. The middle zone is the preferred location for the needle tip during the block, to minimize the risk of neuraxial block (in the medial zone), and the risk of pneumothorax (in the lateral zone). For further information refer to UpToDate content on thoracic paravertebral block.