Complications and pitfalls of lumbar interlaminar and transforaminal epidural injections

Abstract

Lumbar interlaminar and transforaminal epidural injections are used in the treatment of lumbar radicular pain and other lumbar spinal pain syndromes. Complications from these procedures arise from needle placement and the administration of medication. Potential risks include infection, hematoma, intravascular injection of medication, direct nerve trauma, subdural injection of medication, air embolism, disc entry, urinary retention, radiation exposure, and hypersensitivity reactions. The objective of this article is to review the complications of lumbar interlaminar and transforaminal epidural injections and discuss the potential pitfalls related to these procedures. We performed a comprehensive literature review through a Medline search for relevant case reports, clinical trials, and review articles. Complications from lumbar epidural injections are extremely rare. Most if not all complications can be avoided by careful technique with accurate needle placement, sterile precautions, and a thorough understanding of the relevant anatomy and contrast patterns on fluoroscopic imaging.

Fig. 1

Fluoroscopic images of the target points for a left L4 TFESI. The brown circle marks the target point for the subpedicular approach, the blue circle for the retroneural approach, and the pink circle for the retrodiscal approach. a AP view. The subpedicular and retroneural approaches have the same target point on AP view. It lies at the bottom of the silhouette of the L4 pedicle (P), but is overlapped by the lateral margin of the L4 lamina [18]. The retrodiscal approach target is lateral to the L5 superior articular process (black arrow) which is not clearly seen on AP imaging. b Left oblique view. The lamina has been rotated medially to expose the target points for all three approaches. The subpedicular and retroneural approaches have the same target point on oblique view. The retrodiscal target point is more easily identified on oblique view (black arrow). c Lateral view. The subpedicular approach target area lies on the back of the L4 vertebral body. The retroneural approach target area lies more dorsal in the L4–L5 foramen underneath the L4 pedicle (P). The retrodiscal approach target area lies just dorsal to the L4–L5 disc space

Fig. 2

Model images of needle placement for a left L4 TFESI. The brown needle illustrates the subpedicular approach, the blue needle shows the retroneural approach, and the pink needle depicts the retrodiscal approach. a AP view. The subpedicular and retroneural approaches have the same target point at the “6 o’clock” position of the L4 pedicle (P). The retrodiscal approach target is lateral to the L5 superior articular process (SAP). b Left oblique view. The subpedicular and retroneural approach have the same target point at the “6 o’clock” position of the L4 pedicle (P). The retrodiscal approach target is lateral to the L5 SAP (overlapped by the brown needle). TP = transverse process. c Lateral view. The subpedicular approach target area lies on the back of the L4 vertebral body. The retroneural approach target area lies more dorsal in the L4–L5 foramen underneath the L4 pedicle (P). The retrodiscal approach target area lies just dorsal to the L4–L5 disc. TP = transverse process

Fig. 3

a AP image of needle in the right S1 foramen (white circle) of a cadaveric specimen. White arrow shows needle tip. b Lateral image depicting the needle penetrating into the pelvic cavity through the S1 ventral foramen. Green line delineating the dorsal sacral border. Red line delineating the ventral sacral border. White arrow illustrating the tip of the needle in the pelvic cavity of a cadaveric specimen

Fig. 4

Interlaminar epidural depicting epidural hematomagram (white arrows). Black arrow placed to highlight needle location

Fig. 5

a Right oblique image with attention to the L4/L5 interspace after classic subpedicular TFESIs. (Needles placed underneath the right L3, L4, L5, and S1 pedicles). Black arrow highlighting exiting right L4 spinal nerve. b Same image. White triangle illustrating “safe triangle” target area for subpedicular and retroneural approaches for TFESI. Black triangle illustrating target area for retrodiscal approach for TFESI

Fig. 6

a AP scout image of right L3 transforaminal needle placement. Right L4 and right L5 transforaminal epiduragrams are illustrated (white arrows) [43]. b Subdural injection of contrast at L3 (white arrows) [43]

Fig. 7

AP image of a left L5 transforaminal sequestered disc injection. Contrast spread along the left L5 spinal nerve (white arrow) and into the L5/S1 disc space (black arrow). Red arrow depicting needle tip placement