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Case Reports  |   April 2004
Unilateral Diagnostic Infiltration of Lumbar L3 Nerve Root Resulting in an Inadvertent Discogram: The Importance of Fluoroscopic Guidance in Interventional Pain Therapy
Author Affiliations & Notes
  • Sara Haspeslagh, M.D.
    *
  • Jan Van Zundert, M.D.
    *
  • Martine Puylaert, M.D.
  • Rene Heylen, M.D.
  • Maarten van Kleef, M.D., Ph.D.
  • Kris Vissers, M.D.
  • * Multidisciplinary Pain Center, Ziekenhuis Oost-Limburg, Campus A. Dumont, and Department of Anaesthesiology and Pain Management and Research Centre, University Hospital of Maastricht. † Multidisciplinary Pain Center, Ziekenhuis Oost-Limburg, Campus A. Dumont. ‡ Professor, Department of Anaesthesiology and Pain Management and Research Centre, University Hospital of Maastricht.
  • Received from the Multidisciplinary Pain Center, Ziekenhuis Oost-Limburg, Campus A. Dumont, Genk, Belgium, and the Department of Anaesthesiology and Pain Management and Research Centre, University Hospital of Maastricht, The Netherlands.
Article Information
Case Reports
Case Reports   |   April 2004
Unilateral Diagnostic Infiltration of Lumbar L3 Nerve Root Resulting in an Inadvertent Discogram: The Importance of Fluoroscopic Guidance in Interventional Pain Therapy
Anesthesiology 4 2004, Vol.100, 1019-1021. doi:
Anesthesiology 4 2004, Vol.100, 1019-1021. doi:
SELECTIVE spinal injection procedures have become an integral part of the interdisciplinary treatment of patients with lumbar disc disease. These procedures can be powerful therapeutic tools in controlling pain and allowing early protected mobilization. Injection of the epidural space, spinal nerves, facet joints, and intervertebral discs cannot be performed safely and reliably without radiographic assistance.
Epidural steroids have been used for many years to manage low back pain and sciatica but are still controversial. 1–3 The anesthesiologist is totally dependent on the epidural anatomy and resistance to spread medication around or up to the front of the dural sac. In patients with lumbar disc herniations and radiculopathy, the target site is the interface between the posterior annulus of the intervertebral disc and the ventral dural sac or root sleeve. The commonly used transforaminal injection technique, as described in several reports, improves the delivery of a high concentration of medication to the ventral epidural space. 4–7 
Here, we describe a case of a transforaminal sleeve infiltration of the L3 nerve root. After positioning the needle, 2 ml dye was injected, and a discogram was visualized. In a MEDLINE search, we found no previous publications describing this inadvertent event. Possible implications for the interpretation of this observation in daily practice are discussed.
Case Report
A 50-yr-old man came to the pain clinic with subacute lumbar pain and radiation in the right leg by the L3 dermatome, with only a minor sensory deficit (paresthesia) and no motor deficits. A computed tomography scan of the lumbar spine showed a right lateral disc herniation of the L3–L4 intervertebral disc, with compression on the L3 nerve root and probably also on the right L4 nerve root. A lateral magnetic resonance image (fig. 1) also showed the right-sided, upward intraforaminal disc herniation at the L3–L4 level, with compression on the L3 nerve root and dehydration of the L2–L3 and L3–L4 intervertebral discs.
Fig. 1. Lateral magnetic resonance image showing the right-sided upward intraforaminal disc herniation at the L3–L4 level with compression on the L3 nerve root.
Fig. 1. Lateral magnetic resonance image showing the right-sided upward intraforaminal disc herniation at the L3–L4 level with compression on the L3 nerve root.
Fig. 1. Lateral magnetic resonance image showing the right-sided upward intraforaminal disc herniation at the L3–L4 level with compression on the L3 nerve root.
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After a neurologic examination, the neurosurgeon initiated conventional pharmacologic treatment with intramuscular nonsteroidal antiinflammatory drugs and a combination of paracetamol and a weak opioid (tramadol hydrochloride). Because of lack of efficacy, the patient was referred to the pain clinic for a transforaminal sleeve infiltration of the L3 nerve root with steroids as an initial, nonoperative treatment. After informed consent, this infiltration was performed using a conventional technique under strict sterile conditions with an image intensifier. The skin was anesthetized with 3 ml lidocaine, 2%. A 22-gauge needle (RCN-10 needle, 100 mm) was advanced obliquely toward the base of the corresponding pedicle of the L3 vertebra. The position of the needle was verified in a lateral view, where the ideal placement of the needle is with the tip in the cephaloventral corner of the neuroforamen.
Immediately after 0.5 ml dye (180 mg iodine per ml iohexol, Omnipaque®; Nycomed Ltd., Cork, Ireland) was injected, an intervertebral L3–L4 discogram was observed (fig. 2A), although the nerve root of L3 was our target. The injection was not painful and did not cause referring sensations. In the lateral view, dye was visible descending from the tip of the needle in the neuroforamen to the intervertebral disc (fig. 2B).
Fig. 2. (A  ) Anteroposterior radioscopic view of the lumbar spine with the patient in the prone position. The x-ray module is positioned in a posterior-anterior position. Needle position under the L3 pedicle is visualized; 0.5 ml dye (180 mg iodine per ml iohexol, Omnipaque®) is injected through the needle, resulting in a clear discogram of the L3–L4 intervertebral disc (the right side of the figure is the right side of the patient). (B  ) Lateral radioscopic view with the patient in the prone position, showing descending dye from the tip of the needle in the neuroforamen to the intervertebral disc, beside the discogram.
Fig. 2. (A 
	) Anteroposterior radioscopic view of the lumbar spine with the patient in the prone position. The x-ray module is positioned in a posterior-anterior position. Needle position under the L3 pedicle is visualized; 0.5 ml dye (180 mg iodine per ml iohexol, Omnipaque®) is injected through the needle, resulting in a clear discogram of the L3–L4 intervertebral disc (the right side of the figure is the right side of the patient). (B 
	) Lateral radioscopic view with the patient in the prone position, showing descending dye from the tip of the needle in the neuroforamen to the intervertebral disc, beside the discogram.
Fig. 2. (A  ) Anteroposterior radioscopic view of the lumbar spine with the patient in the prone position. The x-ray module is positioned in a posterior-anterior position. Needle position under the L3 pedicle is visualized; 0.5 ml dye (180 mg iodine per ml iohexol, Omnipaque®) is injected through the needle, resulting in a clear discogram of the L3–L4 intervertebral disc (the right side of the figure is the right side of the patient). (B  ) Lateral radioscopic view with the patient in the prone position, showing descending dye from the tip of the needle in the neuroforamen to the intervertebral disc, beside the discogram.
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The needle was withdrawn 2 mm, and another 0.5 ml dye was injected, resulting in a normal spread of the contrast medium in the neuroforamen as a sleeve nerve root infiltration. One milliliter bupivacaine, 0.5%, and 40 mg methylprednisolone acetate were injected. Thirty minutes after this injection, the patient’s radicular pain was relieved, and he was sent home. Two weeks and 2 months later, the patient’s condition was reevaluated. The radicular pain symptoms were resolved, making surgery unnecessary.
Discussion
Correct positioning of the needle for a targeted sleeve infiltration is only reliable after radiologic control in at least two planes and the use of dye on the targeted nerve root. The transforaminal technique for epidural infiltration was suggested because of the better spread of the injected fluid to the irritated nerve root and to the ventral epidural space. 4–7 Complications of this technique and of the infiltration of local anesthetics and corticosteroids are rare but must not be overlooked. Complications may be attributed to poor or incorrect patient selection, drug-related reactions, and technique. There is also the risk of lasting paraplegia by injection of the artery of Adamkiewicz, so creating vascular ischemia of the spinal cord. 8 
Recently, in disc herniations, the involvement of an important inflammatory reaction coming from the intervertebral disc and nucleus pulposus has gained attention. 9 More specifically, the importance of phospholipase A2 was shown in the generation of symptoms resembling low back pain and sciatica. 10 Because most of the inflammatory reactions in the epidural space are found nearby the intervertebral disc and thus in the anterior plane of the epidural space, a more targeted infiltration of this corticosteroid is advocated. These sleeve infiltrations are becoming more commonly practiced for the treatment of (sub)acute lumbosciatica. For correct positioning of the needle, the use of x-ray facilities is indispensable. Here, we describe a case with an inadvertent easy injection of the intervertebral disc, resulting in a discogram that could be classified as irregular. 11 The unexpected spread of the contrast dye could be due to several reasons. First, because the magnetic resonance protocol described a right-sided, upward intraforaminal disc herniation at the L3–L4 level with compression on the L3 nerve root, a direct injection in this disc herniation could be supposed. Second, the leakage of inflammatory mediators through an annulus fibrosus tear can cause severe epidural fibrosis. The placement of the needle in this fibrosis at a distance of the disc can, through fibrotic canals, give a connection with the leaking disc. Third, a true delineated anatomic connection between a nerve root and the disc are not described but could be present because both structures are of mesodermal origin.
If the above-mentioned connections are possible, even then, easy injection of contrast dye without reports of pain or other sensations from the patient is not explained. A vacuum phenomenon of the intervertebral disc is described in cadavers and in degenerated discs. 12 A patient who is placed in a prone position with a pillow under his or her pelvis has an important passive lumbar spinal extension, and this can create a decrease in intervertebral disc pressure, therefore causing negative pressure in the intervertebral disc, which probably results in a suction force toward the disc. The infiltration of only 0.5 ml contrast dye allowed visualization of a whole disc. Discography is a reliable method of evaluating the integrity of the intervertebral disc. The normal annulus fibrosus offers fair resistance to distension, and the normal disc accepts only 1– 1.5 ml contrast medium. Injection in the degenerated disc is often done without difficulty. The easy injection of 2 ml or more contrast medium into a disc is a sign of some degree of degeneration within the annulus fibrosus and the nucleus pulposus. Extravasation of contrast medium occurs through fissures and tears of the annulus and may be seen with both degeneration and herniation.
We do not support the infiltration of corticosteroids into the disc because of the lack of evidence of good outcome of this technique and because of the risk of complications.
Moreover, the target for application of corticosteroids and local anesthetics here was the nerve root adjacent to the intervertebral disc. If we had injected our local anesthetics in this case without contrast dye control, a misinterpretation of this infiltration would have been possible. We believe that this observation is important for correct clinical practice.
Conclusion
Meticulous care should be taken when a transforaminal sleeve injection of steroids, local anesthetics, or both is performed. All previous publications describe the leakage of contrast medium out of the disc by execution of a lumbar discography. There were no publications describing this event, the leakage of dye into the disc while injecting it into the neuroforamen.
This observation emphasizes the importance of the use of contrast dye and radiographic evaluation while performing a transforaminal sleeve injection to avoid inadvertent infiltrations of structures other than the target structure.
References
Koes BW, Scholten RJPM, Mens JMA, Bouter LM: Epidural steroid injections for low back pain and sciatica: An updated systematic review of randomized clinical trials. Pain Digest 1999; 9: 241–7Koes, BW Scholten, RJPM Mens, JMA Bouter, LM
Weinstein S, Herring S, Derby R: Contemporary concepts in spine care: Epidural steroid injections. Spine 1995; 20: 1842–6Weinstein, S Herring, S Derby, R
Slipman CW, Chow DW: Therapeutic spinal corticosteroid injections for the management of radiculopathies. Phys Med Rehabil Clin North Am 2002; 13: 697–711Slipman, CW Chow, DW
Barnsley L: Steroid injections: Effect on pain of spinal origin. Best Pract Res Clin Anaesthesiol 2002; 16: 579–96Barnsley, L
Karppinen J: Periradicular infiltration for sciatica: A randomized controlled trial. Spine 2001; 26: 1059–67Karppinen, J
Vad VB, Bhat AL, Lutz GE, Cammisa F: Transforaminal epidural steroid injections in lumbosacral radiculopathy: A prospective randomized study. Spine 2002; 27: 11–6Vad, VB Bhat, AL Lutz, GE Cammisa, F
Bogduk N: Epidural steroids. Spine 1995; 20: 845–8Bogduk, N
Houten JK, Errico TJ: Paraplegia after lumbosacral nerve root block: Report of three cases. Spine J 2002; 2: 70–5Houten, JK Errico, TJ
Saal JS: The role of inflammation in lumbar pain. Spine 1995; 20: 1821–7Saal, JS
Saal JS, Franson RC, Dobrow R, Saal JA, White AH, Goldthwaite N: High levels of inflammatory phospholipase A2 activity in lumbar disc herniations. Spine 1990; 15: 674–8Saal, JS Franson, RC Dobrow, R Saal, JA White, AH Goldthwaite, N
Adams MA, Dolan P, Hutton WC: The stages of disc degeneration as revealed by discograms. J Bone Joint Surg Br 1986; 68: 36–41Adams, MA Dolan, P Hutton, WC
Larde D, Mathieu D, Frija J, Gaston A, Vasile N: Spinal vacuum phenomenon: CT diagnosis and significance. J Comput Assist Tomogr 1982; 6: 671–6Larde, D Mathieu, D Frija, J Gaston, A Vasile, N
Fig. 1. Lateral magnetic resonance image showing the right-sided upward intraforaminal disc herniation at the L3–L4 level with compression on the L3 nerve root.
Fig. 1. Lateral magnetic resonance image showing the right-sided upward intraforaminal disc herniation at the L3–L4 level with compression on the L3 nerve root.
Fig. 1. Lateral magnetic resonance image showing the right-sided upward intraforaminal disc herniation at the L3–L4 level with compression on the L3 nerve root.
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Fig. 2. (A  ) Anteroposterior radioscopic view of the lumbar spine with the patient in the prone position. The x-ray module is positioned in a posterior-anterior position. Needle position under the L3 pedicle is visualized; 0.5 ml dye (180 mg iodine per ml iohexol, Omnipaque®) is injected through the needle, resulting in a clear discogram of the L3–L4 intervertebral disc (the right side of the figure is the right side of the patient). (B  ) Lateral radioscopic view with the patient in the prone position, showing descending dye from the tip of the needle in the neuroforamen to the intervertebral disc, beside the discogram.
Fig. 2. (A 
	) Anteroposterior radioscopic view of the lumbar spine with the patient in the prone position. The x-ray module is positioned in a posterior-anterior position. Needle position under the L3 pedicle is visualized; 0.5 ml dye (180 mg iodine per ml iohexol, Omnipaque®) is injected through the needle, resulting in a clear discogram of the L3–L4 intervertebral disc (the right side of the figure is the right side of the patient). (B 
	) Lateral radioscopic view with the patient in the prone position, showing descending dye from the tip of the needle in the neuroforamen to the intervertebral disc, beside the discogram.
Fig. 2. (A  ) Anteroposterior radioscopic view of the lumbar spine with the patient in the prone position. The x-ray module is positioned in a posterior-anterior position. Needle position under the L3 pedicle is visualized; 0.5 ml dye (180 mg iodine per ml iohexol, Omnipaque®) is injected through the needle, resulting in a clear discogram of the L3–L4 intervertebral disc (the right side of the figure is the right side of the patient). (B  ) Lateral radioscopic view with the patient in the prone position, showing descending dye from the tip of the needle in the neuroforamen to the intervertebral disc, beside the discogram.
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