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From the Procedure Room…
The Spine Journal 6 (2006) 96–97
From the Procedure Room. When spinal injection becomes advanced imaging
A 38-year-old female experienced bilateral lumbar and radicular pain, right greater than left, after slipping and falling. After 6 months of noninvasive care, she had a markedly antalgic gait and straight leg raising intolerance at 70 degrees. Magnetic resonance imaging showed a 4-mm disc herniation in the left neural foramen at L3–L4, abutting the L3 nerve root. She was referred for a left L3–L4 transforaminal epidural steroid injection. Because of pregnancy, the procedure was delayed. After a normal delivery, the
same pains persisted and the physical findings were identical, so the procedure was rescheduled. In the procedure room, she was placed prone on a padded table and sedated. A 20-gauge, 3.5-inch spinal needle was advanced into the left third neural foramen. Advancement of the needle was guided by intermittent antero-posterior and lateral fluoroscopy. The needle was advanced into the foramen with no entry of the needle into the disc space. A total of 2 cc of Isovue M200 was injected without difficulty (Figs. 1 and 2). Transforaminal epidural injection under fluoroscopic guidance is the preferred approach to the epidural space [1], because it allows reliable introduction of injectate into that space, thereby approximating the pain generators [2]. Transforaminal injection is preferred by most pain interventionalists for treating pain from disc herniation, because it allows delivery of the injectate into the ventral
Fig. 1. Antero-posterior (A) and lateral (B) fluoroscopic images taken after injection of contrast into the epidural space at the left L3–L4 foramen. The contrast was injected to confirm epidural location before steroid injection. The needle placement, well posterior to the disc space, had been guided fluoroscopically. In addition to contrast in the epidural space, contrast is clearly seen within the disc space. 1529-9430/06/$ – see front matter Ó 2006 Elsevier Inc. All rights reserved. doi:10.1016/j.spinee.2005.08.017
Faces of Spine Care / The Spine Journal 6 (2006) 96–97
97
Fig. 2. Computerized tomographic serial axial images taken immediately after the injection confirm the presence of contrast both inside the disc space and in the epidural space. The pattern of the contrast within the disc space resembles that seen in some discograms. Because the injection had been observed fluoroscopically to enter the epidural space, we concluded that the contrast had flowed retrograde from the epidural space, through a large rent in the annulus, and into the intervertebral disc, an hypothesis that seemed compatible with these computerized tomographic images.
epidural space in front of the dural sac and behind the disc [3]. According to Bogduk and Govind [3], a preliminary test injection of contrast material via the transforaminal approach demonstrates that the injectate is in the epidural space and that it lies in the interface between the disc and dura and is not intrathecal. Without moving the needle, subsequent injection of steroid can be sure to safely reach the target site. In severely degenerated discs that have been injected for discography, there is often a diffuse spread of contrast agent through the entire disc, compatible with full thickness tear. Contrast media can spread from the center of the disc to the epidural space and remain subligamentous or it can extend through the ligament above and below the injected disc, sometimes entering the neural foramen [1]. The converse of extravasation of discogram contrast into the epidural space would be retrograde flow into the disc space of contrast injected into the epidural space. This could only occur if there were a full thickness tear in the annulus creating direct communication between the disc space and the epidural space. Additionally, the intradiscal pressure would have to be sufficiently low to allow fluid to enter passively
in preference to spreading through the epidural space. Recently, such an occurrence was described [4]. To date, there have been no reports of such an event occurring from interlaminar or caudal epidural injection.
References [1] Fenton DS, Czervionke LF. Image guided spine intervention. Philadelphia: WB Saunders; 2003. [2] Lutz GE, Vad VB, Wisneski RJ. Fluoroscopic transforaminal epidural steroids: an outcome study. Arch Phys Med Rehabil 1998;79:1362–6. [3] Bogduk N, Govind J. Medical management of acute lumbar radicular pain: an evidence based approach. Newcastle, New South Wales, Australia: Newcastle Bone and Joint Institute; 1999. [4] Renfrew DL. Atlas of spine injection. Philadelphia: WB Saunders; 2004.
Stuart D. Small, MD Richard Guyer, MD Donna D. Ohnmeiss, DrMed Plano, Texas
From the Procedure Room. When spinal injection becomes advanced imaging
A 38-year-old female experienced bilateral lumbar and radicular pain, right greater than left, after slipping and falling. After 6 months of noninvasive care, she had a markedly antalgic gait and straight leg raising intolerance at 70 degrees. Magnetic resonance imaging showed a 4-mm disc herniation in the left neural foramen at L3–L4, abutting the L3 nerve root. She was referred for a left L3–L4 transforaminal epidural steroid injection. Because of pregnancy, the procedure was delayed. After a normal delivery, the
same pains persisted and the physical findings were identical, so the procedure was rescheduled. In the procedure room, she was placed prone on a padded table and sedated. A 20-gauge, 3.5-inch spinal needle was advanced into the left third neural foramen. Advancement of the needle was guided by intermittent antero-posterior and lateral fluoroscopy. The needle was advanced into the foramen with no entry of the needle into the disc space. A total of 2 cc of Isovue M200 was injected without difficulty (Figs. 1 and 2). Transforaminal epidural injection under fluoroscopic guidance is the preferred approach to the epidural space [1], because it allows reliable introduction of injectate into that space, thereby approximating the pain generators [2]. Transforaminal injection is preferred by most pain interventionalists for treating pain from disc herniation, because it allows delivery of the injectate into the ventral
Fig. 1. Antero-posterior (A) and lateral (B) fluoroscopic images taken after injection of contrast into the epidural space at the left L3–L4 foramen. The contrast was injected to confirm epidural location before steroid injection. The needle placement, well posterior to the disc space, had been guided fluoroscopically. In addition to contrast in the epidural space, contrast is clearly seen within the disc space. 1529-9430/06/$ – see front matter Ó 2006 Elsevier Inc. All rights reserved. doi:10.1016/j.spinee.2005.08.017
Faces of Spine Care / The Spine Journal 6 (2006) 96–97
97
Fig. 2. Computerized tomographic serial axial images taken immediately after the injection confirm the presence of contrast both inside the disc space and in the epidural space. The pattern of the contrast within the disc space resembles that seen in some discograms. Because the injection had been observed fluoroscopically to enter the epidural space, we concluded that the contrast had flowed retrograde from the epidural space, through a large rent in the annulus, and into the intervertebral disc, an hypothesis that seemed compatible with these computerized tomographic images.
epidural space in front of the dural sac and behind the disc [3]. According to Bogduk and Govind [3], a preliminary test injection of contrast material via the transforaminal approach demonstrates that the injectate is in the epidural space and that it lies in the interface between the disc and dura and is not intrathecal. Without moving the needle, subsequent injection of steroid can be sure to safely reach the target site. In severely degenerated discs that have been injected for discography, there is often a diffuse spread of contrast agent through the entire disc, compatible with full thickness tear. Contrast media can spread from the center of the disc to the epidural space and remain subligamentous or it can extend through the ligament above and below the injected disc, sometimes entering the neural foramen [1]. The converse of extravasation of discogram contrast into the epidural space would be retrograde flow into the disc space of contrast injected into the epidural space. This could only occur if there were a full thickness tear in the annulus creating direct communication between the disc space and the epidural space. Additionally, the intradiscal pressure would have to be sufficiently low to allow fluid to enter passively
in preference to spreading through the epidural space. Recently, such an occurrence was described [4]. To date, there have been no reports of such an event occurring from interlaminar or caudal epidural injection.
References [1] Fenton DS, Czervionke LF. Image guided spine intervention. Philadelphia: WB Saunders; 2003. [2] Lutz GE, Vad VB, Wisneski RJ. Fluoroscopic transforaminal epidural steroids: an outcome study. Arch Phys Med Rehabil 1998;79:1362–6. [3] Bogduk N, Govind J. Medical management of acute lumbar radicular pain: an evidence based approach. Newcastle, New South Wales, Australia: Newcastle Bone and Joint Institute; 1999. [4] Renfrew DL. Atlas of spine injection. Philadelphia: WB Saunders; 2004.
Stuart D. Small, MD Richard Guyer, MD Donna D. Ohnmeiss, DrMed Plano, Texas