In situ images of the thoracic paravertebral space

In situ knowledge about the anatomic structures and the path of a needle percutaneously placed into the paravertebral space is an area that continues to be investigated. We describe an endoscopic technique that permits imaging of the contents and boundaries of the thoracic paravertebral space in cadavers.

A 43-year-old, 157-cm, 45-kg unembalmed female cadaver was placed in the prone position. Using a 2.3-mm diameter, 0 degree optical angle, fiberoptic ankle arthroscopy scope, trocar, introducer, and light source, thoracic paravertebral blocks were performed. To produce quality images, the trocar was advanced the length of the shaft, approximately 8 cm. The arthroscopy scope was then exchanged with the introducer. The trocar and arthroscopy scope were then gradually withdrawn posterior.

Representative images that show the anatomic pathway of a needle as it would be directed into the paravertebral space as well as the boundaries of the thoracic paravertebral space were obtained. These included the costotransverse ligament, the spinal nerve, and the parietal and visceral pleura.

The images help show the relationship of structures that are encountered during a paravertebral block. This new technique may be helpful in examining the spread of local anesthetic using dye or imaging the location of continuous catheters without having to dissect the insertion area.