Complications of Spinal Diagnostic and Treatment Procedures

Retrograde filling of a thoracic spinal artery during transforaminal injection

INTRODUCTION

Transforaminal injection of steroids has been associated with infrequent but devastating neurological complications and death. Direct injection of particulate steroids into the vertebral artery or medullary arteries is the leading theory in the majority of these complications. Practice guidelines have been published to minimize the likelihood of directly encountering vulnerable arterial structures. However, retrograde flow into a vertebral or medullary artery has not been considered in the literature.

CASE

This case demonstrates retrograde flow into a common arterial trunk with subsequent antegrade flow of intravenous contrast into a thoracic spinal artery during thoracic transforaminal injection.

DISCUSSION

Antegrade flow of particulate steroids through direct cannulation of a vertebral or medullary artery has been advocated as one explanation for complications involving brain or spinal cord infarction. The possibility of retrograde flow into a common arterial trunk with subsequent antegrade flow into vulnerable arteries should also be considered as a possible mechanism by which embolic spinal cord or brain injury may occur.

CONCLUSION

Retrograde flow into medullary or vertebral arteries without direct cannulation can occur, and provides an alternative mechanism of potential injury to the spinal cord or brain during transforaminal injections.

Paraplegia following image-guided transforaminal lumbar spine epidural steroid injection: two case reports

OBJECTIVE

To present two case reports of a rare but devastating injury after image-guided, lumbar transforaminal injection of steroids, and to explore features in common with previously reported cases.

BACKGROUND

Image (fluoroscopic and computed tomography [CT])-guided, lumbar transforaminal injections of corticosteroids have been adopted as a treatment for radicular pain. Complications associated with these procedures are rare, but can be severe.

CASE REPORTS

An 83-year-old woman underwent a fluoroscopically guided, left L3-L4, transforaminal injection of betamethasone (Celestone Soluspan). A 79-year-old man underwent a CT-guided, right L3-L4, transforaminal injection of methylprednisolone (DepoMedrol). Both patients developed bilateral lower extremity paralysis, with neurogenic bowel and bladder, immediately after the procedures. Magnetic resonance imaging scans were consistent with spinal cord infarction. There was no evidence of intraspinal mass or hematoma.

CONCLUSION

These cases consolidate a pattern emerging in the literature. Distal cord and conus injury can occur following transforaminal injections at lumbar levels, whether injection is on the left or right. This conforms with the probability of radicular-medullary arteries forming an arteria radicularis magna at lumbar levels. All cases used particulate corticosteroids, which promotes embolization in a radicular artery as the likely mechanism of injury. The risk of this complication can be reduced, and potentially eliminated, by the utilization of particulate free steroids, testing for intra-arterial injection with digital subtraction angiography, and a preliminary injection of local anesthetic.

A narrative review of lumbar medial branch neurotomy for the treatment of back pain

BACKGROUND

Confusion persists concerning the nature and efficacy of procedures variously known as facet denervation, lumbar medial branch radiofrequency neurotomy, and radiofrequency neurotomy or denervation for the treatment of back pain. Systematic reviews have not recognized the importance of patient selection and correct surgical technique when appraising the literature. As a result, negative conclusions about procedures have been drawn because lack of efficacy of one procedure has been misattributed to other, cognate, but different procedures.

OBJECTIVES

To demonstrate how the rationale and efficacy of lumbar medial branch neurotomy depends critically on correct selection of patients and use of surgically correct technique.

METHODS

A narrative review and description of the available evidence, drawn from the personal libraries of the authors and from the bibliographies of systematic reviews.

RESULTS

Three studies, commonly accepted as evidence of lack of effectiveness, were not valid tests of lumbar medial branch neurotomy because of errors in selection of patients or errors in surgical technique, or both. Two descriptive studies and three controlled studies that used valid or acceptable techniques consistently showed that lumbar medial branch neurotomy had positive effects on pain and disability. All valid, randomized controlled trials showed medial branch neurotomy to be more effective than sham treatment.

DISCUSSION

Negative results have been reported only in studies that selected inappropriate patients or used surgically inaccurate techniques. All valid studies showed positive outcomes that cannot be attributed to placebo. Inappropriate conclusions have been drawn by systematic reviews that misrepresent invalid studies as providing evidence against the efficacy of lumbar medial branch neurotomy.