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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 was
fairly popular in the early 1900s, it seemed to have fallen into disfavor
during the mid and later part of the century, the reason for which is not
known. In 1979 Eason and Wyatt rekindled interest by describing a technique
of paravertebral catheter placement.4 Our understanding of
the safety and efficacy of TPVB has improved significantly in the last 25
years, and there has been a gradual renewal of interest in this technique.
Currently it is used not only for analgesia but also for surgical
anesthesia,5–7 and its application has been extended to
children.8–10
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The thoracic paravertebral space (TPVS) is a wedge-shaped space located
on either side of the vertebral column (Figure 43–1). The parietal
pleura forms the anterolateral boundary. The base is formed by the vertebral
body, intervertebral disc, and the intervertebral foramen with its contents.
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 (Figure 43–1, 43–2, and 43–3).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. Therefore there are two potential fascial
compartments in the TPVS: the anterior extrapleural
paravertebral compartment and the posterior
subendothoracic paravertebral compartment (see Figures
43–1 and 43–2). The TPVS contains adipose tissue within which lie the
intercostal (spinal) nerve, the dorsal ramus, intercostal vessels, rami
communicantes, and anteriorly the sympathetic chain. The spinal nerves are
segmented into small bundles and lie freely in the adipose tissue of the
TPVS, which make them accessible to local anesthetic solutions injected into
the TPVS.16
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