Thoracic & Lumbar Paravertebral Block
THORACIC PARAVERTEBRAL BLOCK
Thoracic paravertebral block (TPVB) is the technique of injecting local anesthetic alongside the thoracic vertebra close to where the spinal nerves emerge from the intervertebral foramen.1,2 This produces unilateral, segmental, somatic, and sympathetic nerve blockade,3 which is effective for anesthesia and in treating acute and chronic pain of unilateral origin from the chest and abdomen.1 Hugo Sellheim of Leipzig (1871–1936) is believed to have pioneered TPVB in 1905.1,2 Kappis, in 1919, developed the technique of paravertebral injection, which is comparable to the one in present day use.
Although paravertebral block (PVB) was fairly popular in the early 1900s, it seemed to have fallen into disfavor during the later part of the century; the reason for which is not known. In 1979, Eason and Wyatt re popularized the technique after describing paravertebral catheter placement.4 Our understanding of the safety and efficacy of TPVB has improved significantly in the last 25 years, with renewal of interest in this technique. Currently, it is used not only for analgesia but also for surgical anesthesia,5,6,7 and its application has been extended to children.8,9,10 Introduction of ultrasound to the practice of regional anesthesia led to the renewed efforts to increase safety and consistency of PVBs.
The thoracic paravertebral space (TPVS) is a wedge-shaped space located on either side of the vertebral column (Figure 81A–1). The parietal pleura forms the anterolateral boundary. The base is formed by the vertebral body, intervertebral disc, and the intervertebral foramen with its contents.
Anatomy of the thoracic paravertebral space, chest cavity and intercostal nerves.
The transverse process and the superior costotransverse ligament form the posterior boundary. Lying in between the parietal pleura anteriorly and the superior costotransverse ligament posteriorly is a fibroelastic structure, the endothoracic fascia, which is the deep fascia of the thorax (Figures 81A–1, 81A–2, 81A–3).1,11-15 Medially, the endothoracic fascia is attached to the periosteum of the vertebral body. A layer of loose areolar connective tissue, the subserous fascia, lies between the parietal pleura and the endothoracic fascia.
Crossectional anatomy of the vertebra and chest wall demonstrating relationship of paraveretbral space, sympathetic ganglia, spinal and intercostal nerves.
Sagittal section through the thoracic paravertebral space.
Therefore, there are two potential fascial compartments in the TPVS: the anterior extrapleural paravertebral compartment and the posterior subendothoracic paravertebral compartment (see Figures 81A–1 and 81A–2...