Caudal Epidural Steroid Injection—Steep Angle Approach: Fluoroscopic Guidance

Keywords

caudal, epidural steroid injection, fluoroscopy, radiculopathy, sacral canal, sacral hiatus

Note: Please see pages ii , iii for a list of anatomic terms/abbreviations used throughout this book.

In this technique, the AP view serves as the trajectory view, and also as a multiplanar view. The AP view is used to keep the needle midline and avoid advancing the needle too far cephalad. Appropriate needle tip depth is confirmed with the lateral view, demonstrating needle tip in the sacral canal without overpenetration. The injectate volume can be determined after observing cephalad contrast flow relative to target structures.

Trajectory View ( Fig. 7B.1 )

The Trajectory View Is Also a Multiplanar View

▪

The AP view is the trajectory view
▪

Confirm the level with the anteroposterior (AP) view.

Fig. 7B.1

A, Fluoroscopic image of the trajectory view with the needle in position within the sacral hiatus in the caudal epidural space. B, Radiopaque structures, anteroposterior/trajectory view. C, Radiolucent structures, anteroposterior/trajectory view.
▪

Adjust the C-arm tilt to square off the superior end plate of the L5 vertebral body (using cephalad and caudal tilt), and the C-arm rotation (oblique) to position the L5 spinous process equidistant from the L5 pedicles to obtain a true AP view.
▪

Place a metallic marker over the radiographic midline using the L5 spinous process and median sacral crest.
▪

Move the C-arm caudad to center the hyperlucent sacral notch in the field of view. The sacral notch is located midline, with the apex of the notch usually at about the S4 level.
▪

Advance the needle down the beam into the sacral notch.
▪

The needle will pass through the sacrococcygeal ligament and abut the anterior sacral plate, a hard bony stop.