How safe are lumbar transforaminal epidural steroid injections (ESIs)?

Updated: Aug 06, 2018
  • Author: Boqing Chen, MD, PhD; Chief Editor: Stephen Kishner, MD, MHA  more...
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The artery of Adamkiewicz, a critical radiculomedullary artery that supplies the anterior spinal artery, is known to be localized in the superior and anterior aspect of dorsal root ganglion and the exiting nerve root in the lumbar neuroforamen. Therefore, the traditional supraneural approach of transforaminal ESI runs the risk of penetration by the spinal needle and injury to this critical radiculomedullary artery, inducing vascular ischemia or injection of particulate corticosteroid, resulting distal embolism and leading to the paraplegia. Even with the DSA technique, the risk cannot be avoided. [25]

In fact, Glaser and Shah have indicated that the “safe triangle” target of the conventional lumbar transforaminal approach is an “unsafe triangle”. [26] There were more than 10 published cases of lumbar paraplegia after the transforaminal ESIs through traditional or conventional approaches. It is important to note that in each of these cases, use of particulate corticosteroid was involved. Aside from advocating using nonparticulate corticosteroids, to prevent these “black swan” events, using a different approach, Kambin triangle for lumbar transforaminal ESIs, is gaining more and more attention.

Studies have demonstrated that lumbar transforaminal ESIs through the Kambin triangle have the same efficacy as lumbar transforaminal ESIs through traditional approaches, with no report of arterial penetration or paraplegia and less risk of nerve injury post injection. [27]

In fact, surgical studies with endoscopic discectomy through the Kambin triangle also reported fewer nerve and vascular injury events. To these authors’ knowledge, there have been no case reports on the paraplegia after lumbar transforaminal ESIs using the Kambin triangle. A retrospective study on lumbar transforaminal ESIs with the Kambin triangle using live fluoroscope and DSA techniques on 200 patients revealed no arterial uptake of contrast during injections (accepted and to be presented in the 21st annual scientific meeting of International Spine Intervention Society). Thus, we agree with other interventionists. [28] Lumbar transforaminal ESIs should be performed with the Kambin-triangle approach.

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