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Pain Medicine 2014; 15: 1975–1988 Wiley Periodicals, Inc.
LETTERS TO THE EDITOR Transforaminal vs Interlaminar Epidural Steroid Injections: Differences in the Surgical Rates and Safety Concerns
Disclosures: None. Dear Editor, We read with great interest the study by Kennedy et al. [1] published in the most recent issue of Pain Medicine comparing the effectiveness of particulate (triamcinolone) vs nonparticulate (dexamethasone) corticosteroids in treating lumbar radicular pain due to disc herniation using a lumbar transforaminal (TFLESI) approach. While one of the touted benefits of using a TFLESI has been that it leads to a reduction in requirements for spinal surgery, we would like to focus the attention of the authors and our colleagues on the relatively high rates of surgical interventions performed on subjects in this study at 3 months—14.6% for the dexamethasone group, and 16.2% and 18.9% at 3 and 6 months, respectively, for the triamcinolone group. In our recent study wherein different interlaminar (ILESI) approaches (midline vs parasagittal) were used for lumbar epidural steroid injections (LESIs) among similarly selected patients with unilateral lumbar radicular pain, only 4% of the patients required surgery during a comprehensive 1-year follow-up (average 37 weeks after a first injection) [2]. However, neither of these two respective studies used clearly predetermined criteria for surgical interventions, and it may be argued that the patient populations were not identical. Kennedy et al. [1] indicated that different treating physicians were involved in the care of study patients, which may reflect a reality of current clinical pain practices. Involvement of physicians of different specialties for managing lumbar discogenic and radicular disorders may play a key factor in the decision-making process as to whether or not patients will ultimately undergo surgery. This factor likely results in a biased preference for proceeding to surgery when surgical specialists control the decision making, vs when chronic pain specialists do and ultimately may account for the differences in selecting lumbar epidural techniques depending on the respective levels of training and experience for particular type of intervention, such as LESI. However, the only major demographic difference between our studies was that Kennedy et al. [1] included only acutely affected patients with a duration of symptoms of less than 6 months (average duration approximately 9 weeks), whereas we included a more diverse subject population suffering from both acute and chronic pain (average pain duration 14 months), which makes it even
more difficult to determine why their patients underwent surgery at a much higher rate, regardless of choice of steroid type. Logical questions that result from analyzing studies such as these are multiple and include the following: Are patients with acute pain presentations more likely to have surgery than are patients with chronic radicular pain? Is ILESI more efficient than TFLESI in preventing the requirement for spinal surgery? Comparing these two studies [1,2] where a total of 178 patients were followed, one could suggest that the answer to both queries is “yes.” However, it is arguable that 6-month or 12-month follow-up is not a sufficient time to make decisions regarding the effectiveness of LESI, especially in terms of preventing surgery. Riew et al. in the only prospective randomized study that evaluated the ability of LESI to prevent surgery as a primary endpoint showed that 29% of patients that received nonparticulate steroids (betamethasone) required surgery during a 13- to 28-month follow-up [3]. It is possible that patients experiencing pain for less than 6 months are not good candidates for whom to evaluate the benefits of treatment modalities, particularly those that choose surgery within 3 months after injections [1]. Presence of pain for less than 6 months might not indicate a complete evolution of disc pathology as seen by MRI, which could deem these patients inappropriate for undergoing LESI. Mehling et al. [4] followed 605 patients with acute radicular low back pain for 2 years and showed that only 13% of them experienced chronic pain at 6 months and only 19% at 2 years, which further questions the prudence of sending patients with acute onset radiculartype pain for surgery at these early stages of disc pathology evolution and healing. The presence of radicular pain, absent documented motor weakness, or severe sensory loss would not be a criterion for considering surgery in our busy tertiary care center. It would be interesting to determine the ultimate failed surgery rate of those patients in the Kennedy et al.’s study [1] and to compare it with a national average. The decisions on how to approach the interface of intervertebral disc pathology and associated neural involvement are the main difference evaluated by these two studies [1,2], which further accentuates the controversial topic of assessing risk–benefit ratios when performing LESI using a TFLESI or an ILESI approach. One major factor is the safety of selecting a TFLESI or ILESI, especially following the FDA safety letter from April 23 [5] that warns of epidural corticosteroid injections resulting in “rare 1975
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Knezevic et al. but serious adverse events, including loss of vision, stroke, paralysis and death.” Nonetheless, 11 out of 17 references listed in the FDA safety letter [5] are exclusively concerned with the administration of steroids using a transforaminal approach to the spine. The other six references do not concern themselves with lumbar interlaminar injections, meaning that their entire literature support for this warning letter is aimed at transforaminal, and not interlaminar procedures. In the study by Kennedy et al. [1], all 78 patients had significant pain relief after TFLESI; however, patients receiving particulate steroids (triamcinolone acetonide) required fewer repeated injections during a 6-month follow-up than did patients receiving nonparticulate (dexamethasone phosphate) steroids. It is accepted that due to aggregation, particulate steroids have higher risks for intravascular embolization and serious complications than do nonparticulate steroids [6]. Twelve out of 15 cases with catastrophic complications cited in the FDA safety letter [5] occurred following the injection of particulate steroids. Furthermore, there are several documented cases of lumbar transforaminal injections of triamcinolone that have resulted in serious complications [7–10]. In an era of accountability where there is a high burden placed on pain physicians from the FDA, insurance companies, and the noted changes that the ACA is bringing, conclusions regarding corticosteroid utilization in chronic radicular low back pain should be drawn with great caution. Furthermore, pain physicians should decide whether to use a transforaminal approach which has been suggested in some literature as being more effective [11] or an interlaminar parasagittal approach that has been shown to be equally effective as TFLESI in prospective randomized trials [2,12,13]. The remaining question is how to justify the use of particulate steroids in TFLESI which have shown longer duration of benefit than have nonparticulate steroids [1] albeit with an increased risk of engendering serious complications. NEBOJSA NICK KNEZEVIC, MD, PhD,*† ALEXEI LISSOUNOV, MD,* and KENNETH D. CANDIDO, MD*† *Department of Anesthesiology, Advocate Illinois Masonic Medical Center; †Department of Anesthesiology, University of Illinois, Chicago, Illinois, USA References 1 Kennedy DJ, Plastaras C, Casey E, et al. Comparative effectiveness of lumbar transforaminal epidural steroid injections with particulate versus nonparticulate corticosteroids for lumbar radicular pain due to intervertebral disc herniation: A prospective, randomized, double-blind trial. Pain Med 2014;15:548–55. 2 Candido KD, Rana MV, Sauer R, et al. Concordant pressure paresthesia during interlaminar lumbar epidural steroid injections correlates with pain relief in patients with unilateral radicular pain. Pain Physician 2013;16:497–511. 1976
3 Riew KD, Yin Y, Gilula L, et al. The effect of nerve-root injections on the need for operative treatment of lumbar radicular pain. A prospective, randomized, controlled, double-blind study. J Bone Joint Surg Am 2000;82:1589–93. 4 Mehling WE, Gopisetty V, Bartmess E, et al. The prognosis of acute low back pain in primary care in the United States: A 2-year prospective cohort study. Spine (Phila Pa 1976) 2012;37:678–84. 5 FDA. FDA requires label changes to warn of rare but serious neurologic problems after epidural corticosteroid injections for pain; 2014. Available at: http:// www.fda.gov/Drugs/DrugSafety/ucm394280.htm (accessed April 2014). 6 Derby R, Lee SH, Date ES, Lee JH, Lee CH. Size and aggregation of corticosteroids used for epidural injections. Pain Med 2008;9:227–34. 7 Kennedy DJ, Dreyfuss P, Aprill CN, Bogduk N. Paraplegia following image-guided transforaminal lumbar spine epidural steroid injection: Two case reports. Pain Med 2009;10:1389–94. 8 Somayaji HS, Saifuddin A, Casey AT, Briggs TW. Spinal cord infarction following therapeutic computed tomography-guided left L2 nerve root injection. Spine 2005;30:E106–8. 9 Lyders EM, Morris PP. A case of spinal cord infarction following lumbar transforaminal epidural steroid injection: MR imaging and angiographic findings. AJNR Am J Neuroradiol 2009;30:1691–3. 10 Chang Chien GC, Candido KD, Knezevic NN. Digital subtraction angiography does not reliably prevent paraplegia associated with lumbar transforaminal epidural steroid injection. Pain Physician 2012;15:515– 23. 11 Cohen SP, Bicket MC, Jamison D, Wilkinson I, Rathmell JP. Epidural steroids: A comprehensive, evidence-based review. Reg Anesth Pain Med 2013;38:175–200. 12 Ghai B, Vadaje KS, Wig J, Dhillon MS. Lateral parasagittal versus midline interlaminar lumbar epidural steroid injection for management of low back pain with lumbosacral radicular pain: A double-blind, randomized study. Anesth Analg 2013;117:219– 27. 13 Candido KD, Raghavendra MS, Chinthagada M, Badiee S, Trepashko DW. A prospective evaluation of iodinated contrast flow patterns with fluoroscopically guided lumbar epidural steroid injections: The lateral parasagittal interlaminar epidural approach versus the transforaminal epidural approach. Anesth Analg 2008;106:638–44.
Copyright of Pain Medicine is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
Pain Medicine 2014; 15: 1975–1988 Wiley Periodicals, Inc.
LETTERS TO THE EDITOR Transforaminal vs Interlaminar Epidural Steroid Injections: Differences in the Surgical Rates and Safety Concerns
Disclosures: None. Dear Editor, We read with great interest the study by Kennedy et al. [1] published in the most recent issue of Pain Medicine comparing the effectiveness of particulate (triamcinolone) vs nonparticulate (dexamethasone) corticosteroids in treating lumbar radicular pain due to disc herniation using a lumbar transforaminal (TFLESI) approach. While one of the touted benefits of using a TFLESI has been that it leads to a reduction in requirements for spinal surgery, we would like to focus the attention of the authors and our colleagues on the relatively high rates of surgical interventions performed on subjects in this study at 3 months—14.6% for the dexamethasone group, and 16.2% and 18.9% at 3 and 6 months, respectively, for the triamcinolone group. In our recent study wherein different interlaminar (ILESI) approaches (midline vs parasagittal) were used for lumbar epidural steroid injections (LESIs) among similarly selected patients with unilateral lumbar radicular pain, only 4% of the patients required surgery during a comprehensive 1-year follow-up (average 37 weeks after a first injection) [2]. However, neither of these two respective studies used clearly predetermined criteria for surgical interventions, and it may be argued that the patient populations were not identical. Kennedy et al. [1] indicated that different treating physicians were involved in the care of study patients, which may reflect a reality of current clinical pain practices. Involvement of physicians of different specialties for managing lumbar discogenic and radicular disorders may play a key factor in the decision-making process as to whether or not patients will ultimately undergo surgery. This factor likely results in a biased preference for proceeding to surgery when surgical specialists control the decision making, vs when chronic pain specialists do and ultimately may account for the differences in selecting lumbar epidural techniques depending on the respective levels of training and experience for particular type of intervention, such as LESI. However, the only major demographic difference between our studies was that Kennedy et al. [1] included only acutely affected patients with a duration of symptoms of less than 6 months (average duration approximately 9 weeks), whereas we included a more diverse subject population suffering from both acute and chronic pain (average pain duration 14 months), which makes it even
more difficult to determine why their patients underwent surgery at a much higher rate, regardless of choice of steroid type. Logical questions that result from analyzing studies such as these are multiple and include the following: Are patients with acute pain presentations more likely to have surgery than are patients with chronic radicular pain? Is ILESI more efficient than TFLESI in preventing the requirement for spinal surgery? Comparing these two studies [1,2] where a total of 178 patients were followed, one could suggest that the answer to both queries is “yes.” However, it is arguable that 6-month or 12-month follow-up is not a sufficient time to make decisions regarding the effectiveness of LESI, especially in terms of preventing surgery. Riew et al. in the only prospective randomized study that evaluated the ability of LESI to prevent surgery as a primary endpoint showed that 29% of patients that received nonparticulate steroids (betamethasone) required surgery during a 13- to 28-month follow-up [3]. It is possible that patients experiencing pain for less than 6 months are not good candidates for whom to evaluate the benefits of treatment modalities, particularly those that choose surgery within 3 months after injections [1]. Presence of pain for less than 6 months might not indicate a complete evolution of disc pathology as seen by MRI, which could deem these patients inappropriate for undergoing LESI. Mehling et al. [4] followed 605 patients with acute radicular low back pain for 2 years and showed that only 13% of them experienced chronic pain at 6 months and only 19% at 2 years, which further questions the prudence of sending patients with acute onset radiculartype pain for surgery at these early stages of disc pathology evolution and healing. The presence of radicular pain, absent documented motor weakness, or severe sensory loss would not be a criterion for considering surgery in our busy tertiary care center. It would be interesting to determine the ultimate failed surgery rate of those patients in the Kennedy et al.’s study [1] and to compare it with a national average. The decisions on how to approach the interface of intervertebral disc pathology and associated neural involvement are the main difference evaluated by these two studies [1,2], which further accentuates the controversial topic of assessing risk–benefit ratios when performing LESI using a TFLESI or an ILESI approach. One major factor is the safety of selecting a TFLESI or ILESI, especially following the FDA safety letter from April 23 [5] that warns of epidural corticosteroid injections resulting in “rare 1975
bs_bs_banner
Knezevic et al. but serious adverse events, including loss of vision, stroke, paralysis and death.” Nonetheless, 11 out of 17 references listed in the FDA safety letter [5] are exclusively concerned with the administration of steroids using a transforaminal approach to the spine. The other six references do not concern themselves with lumbar interlaminar injections, meaning that their entire literature support for this warning letter is aimed at transforaminal, and not interlaminar procedures. In the study by Kennedy et al. [1], all 78 patients had significant pain relief after TFLESI; however, patients receiving particulate steroids (triamcinolone acetonide) required fewer repeated injections during a 6-month follow-up than did patients receiving nonparticulate (dexamethasone phosphate) steroids. It is accepted that due to aggregation, particulate steroids have higher risks for intravascular embolization and serious complications than do nonparticulate steroids [6]. Twelve out of 15 cases with catastrophic complications cited in the FDA safety letter [5] occurred following the injection of particulate steroids. Furthermore, there are several documented cases of lumbar transforaminal injections of triamcinolone that have resulted in serious complications [7–10]. In an era of accountability where there is a high burden placed on pain physicians from the FDA, insurance companies, and the noted changes that the ACA is bringing, conclusions regarding corticosteroid utilization in chronic radicular low back pain should be drawn with great caution. Furthermore, pain physicians should decide whether to use a transforaminal approach which has been suggested in some literature as being more effective [11] or an interlaminar parasagittal approach that has been shown to be equally effective as TFLESI in prospective randomized trials [2,12,13]. The remaining question is how to justify the use of particulate steroids in TFLESI which have shown longer duration of benefit than have nonparticulate steroids [1] albeit with an increased risk of engendering serious complications. NEBOJSA NICK KNEZEVIC, MD, PhD,*† ALEXEI LISSOUNOV, MD,* and KENNETH D. CANDIDO, MD*† *Department of Anesthesiology, Advocate Illinois Masonic Medical Center; †Department of Anesthesiology, University of Illinois, Chicago, Illinois, USA References 1 Kennedy DJ, Plastaras C, Casey E, et al. Comparative effectiveness of lumbar transforaminal epidural steroid injections with particulate versus nonparticulate corticosteroids for lumbar radicular pain due to intervertebral disc herniation: A prospective, randomized, double-blind trial. Pain Med 2014;15:548–55. 2 Candido KD, Rana MV, Sauer R, et al. Concordant pressure paresthesia during interlaminar lumbar epidural steroid injections correlates with pain relief in patients with unilateral radicular pain. Pain Physician 2013;16:497–511. 1976
3 Riew KD, Yin Y, Gilula L, et al. The effect of nerve-root injections on the need for operative treatment of lumbar radicular pain. A prospective, randomized, controlled, double-blind study. J Bone Joint Surg Am 2000;82:1589–93. 4 Mehling WE, Gopisetty V, Bartmess E, et al. The prognosis of acute low back pain in primary care in the United States: A 2-year prospective cohort study. Spine (Phila Pa 1976) 2012;37:678–84. 5 FDA. FDA requires label changes to warn of rare but serious neurologic problems after epidural corticosteroid injections for pain; 2014. Available at: http:// www.fda.gov/Drugs/DrugSafety/ucm394280.htm (accessed April 2014). 6 Derby R, Lee SH, Date ES, Lee JH, Lee CH. Size and aggregation of corticosteroids used for epidural injections. Pain Med 2008;9:227–34. 7 Kennedy DJ, Dreyfuss P, Aprill CN, Bogduk N. Paraplegia following image-guided transforaminal lumbar spine epidural steroid injection: Two case reports. Pain Med 2009;10:1389–94. 8 Somayaji HS, Saifuddin A, Casey AT, Briggs TW. Spinal cord infarction following therapeutic computed tomography-guided left L2 nerve root injection. Spine 2005;30:E106–8. 9 Lyders EM, Morris PP. A case of spinal cord infarction following lumbar transforaminal epidural steroid injection: MR imaging and angiographic findings. AJNR Am J Neuroradiol 2009;30:1691–3. 10 Chang Chien GC, Candido KD, Knezevic NN. Digital subtraction angiography does not reliably prevent paraplegia associated with lumbar transforaminal epidural steroid injection. Pain Physician 2012;15:515– 23. 11 Cohen SP, Bicket MC, Jamison D, Wilkinson I, Rathmell JP. Epidural steroids: A comprehensive, evidence-based review. Reg Anesth Pain Med 2013;38:175–200. 12 Ghai B, Vadaje KS, Wig J, Dhillon MS. Lateral parasagittal versus midline interlaminar lumbar epidural steroid injection for management of low back pain with lumbosacral radicular pain: A double-blind, randomized study. Anesth Analg 2013;117:219– 27. 13 Candido KD, Raghavendra MS, Chinthagada M, Badiee S, Trepashko DW. A prospective evaluation of iodinated contrast flow patterns with fluoroscopically guided lumbar epidural steroid injections: The lateral parasagittal interlaminar epidural approach versus the transforaminal epidural approach. Anesth Analg 2008;106:638–44.
Copyright of Pain Medicine is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
