Musculoskeletal Imaging Original Research

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1 Musculoskeletal Imaging Original Research Wang et al. Fluoroscopically Guided Thoracic Foraminal Nerve Blocks Musculoskeletal Imaging Original Research Alfred Wang 1 Thomas K. Pilgram 2 Louis A. Gilula 2 Wang A, Pilgram TK, Gilula LA Keywords: complications, epidural blocks, fluoroscopy, foraminal, nerve blocks, thoracic DOI: /AJR Received February 4, 2011; accepted after revision April 28, University of Texas Southwestern Medical School, Dallas, TX. 2 Department of Orthopaedic and Plastic and Reconstructive Surgery, Washington University School of Medicine, Mallinckrodt Institute of Radiology, 510 S Kingshighway Blvd, St. Louis, MO Address correspondence to L. A. Gilula (gilulal@mir.wustl.edu). AJR 2011; 197: X/11/ American Roentgen Ray Society Immediate Complications and Pain Relief Associated With 296 Fluoroscopically Guided Thoracic Foraminal Nerve Blocks OBJECTIVE. The goal of this work is to review the thoracic foraminal nerve blocks and foraminal epidurals performed at a single institution to determine the incidence and types of immediate complications and pain relief associated with thoracic foraminal nerve blocks. MATERIALS AND METHODS. This retrospective study entailed a comprehensive review of the radiographs and reports of 296 injections performed in 225 examinations on 153 patients (60 men and 93 women). The overall mean age was years (mean age for men, years [range, years]; mean age for women, years [range, years]). The data were later analyzed with contingency tables and chi-square tests. RESULTS. The overall complication rate was 4.1% (12/296). Complication rates at the different needle tip positions measured on frontal and lateral fluoroscopic views did not approach statistical significance (p = 0.15). Complications were higher with cephalocaudal flow outside local flow (p = 0.02). No serious complications occurred except for one pneumothorax, which could have been avoided. Immediate partial or complete pain relief was obtained in 88.5% (262/296) of the injections and 88.4% (199/225) of the examinations. CONCLUSION. Fluoroscopically guided thoracic foraminal nerve blocks are safe procedures and provide immediate partial or complete pain relief in a high percentage of patients. T o help diagnose and treat spine pain, cervical and lumbar nerve root blocks are used around the world as safe and routine procedures [1 5]. However, thoracic nerve root blocks are still approached with caution, because of concern about technical complexities associated with performance of this procedure, including a narrow epidural space and close proximity to the spinal cord [6, 7]. These complexities may be associated with an increased risk of complications [8], even though imaging-guided techniques with fluoroscopy or CT have increased the efficiency of such procedures [9, 10]. Furthermore, these injections for pain management do not promise a permanent relief from pain [9], especially because there is no method with adequate specificity to identify all the potential causes of spine pain [11, 12]. This lack of certainty combined with a lack of literature regarding thoracic nerve blocks [7] emphasizes the need for more studies [13]. By critically evaluating techniques and complications associated with selective thoracic nerve blocks, a better understanding of these procedures can be gained. A prior technical note article [14] described a technical approach to perform thoracic nerve blocks and listed complications encountered up to the time of publication, without analysis of potential causes of the complications. The goal of this work is to review a larger number of thoracic foraminal nerve blocks and foraminal epidurals performed at a single institution to determine the incidence and types of immediate complications, to determine whether certain technique-related factors affected the complications and to identify the incidence of immediate pain relief associated with thoracic foraminal nerve blocks. Materials and Methods This study includes all patients who underwent fluoroscopically guided foraminal or extraforaminal thoracic nerve block with or without epidural in a single radiology section at our institution from June 27, 1997, to June 16, Institutional review board approval was obtained for this retrospective study. During this period, 296 injections were performed in 225 examinations on 153 patients (60 men and 93 women). These numbers result from the fact that some patients had more than one injection during one examination. The 1410 AJR:197, December 2011

2 Fluoroscopically Guided Thoracic Foraminal Nerve Blocks overall mean age was years (mean age for men, years [range, years]; mean age for women, years [range, years]). Patients were referred from spine surgeons, physiatrists, and internists who thought the patients had symptoms related to the thoracic level of requested block (n = 88). Most commonly, the offending agent thought to be causing radiculopathy was a herniated disk, but blocks were also requested for less common reasons to see whether pain could be relieved, as when adjacent to an old fracture or a fracture treated with vertebroplasty that had residual pain (n = 35). Twenty-five patients had radiculopathy alone; 18 had degenerative disk disease; 20 had other causes, including neuritis, metastasis, scoliosis, spondylosis, fusion, stenosis, rib fracture, and cyst; and for 39 patients, the cause of pain was not characterized, for a total of 225 indications. All the patients who underwent a fluoroscopically guided foraminal or extraforaminal thoracic nerve block, with or without epidural effect, had the procedure discussed with them to understand the risks and consequences. Both oral and written consent were obtained from patients with complications discussed, including infection, nerve or vascular injury, pneumothorax, failure to achieve pain relief, vasovagal response, increased pain, and numbness along a nerve distribution. Before the procedure, the patient completed a form describing the pain distribution patterns and the pain intensity on a visual analog scale from 0 to 10, where 0 represented no pain and 10 represented the worst pain the patient could imagine. During the procedure, the patient was placed prone on a fluoroscopy table. The correct level of needle placement was identified by careful rib counting with fluoroscopy. The entry site and technique for needle placement gradually evolved over the study period. A brief description of the current technique follows, because a detailed description of this technique has already been published [14].. The entry site was at the medial aspect of the posterior convex curve of the rib of interest below the nerve to be blocked. A 22-gauge needle inches ( cm) long with a short bent tip about 1 cm long on the pointed end (Fig. 1) was made on site by the person performing the procedure. The needle was passed from an oblique angle of about 30 from lateral to medial along the posterior superior rib margin over the superolateral edge of the transverse process. This needle bend enabled the tip to be turned anteriorly to pass to the anterior edge of the lamina, which in some cases blocked the anterior and medial advancement of the needle tip. The shortness of the bend also enabled the bent needle tip to be adjusted carefully within the diameter of the foramen. A lateral view was then obtained with a C-arm Fig. 1 Needles (22 gauge) with bent needle tips of about 50. Upper needle bend is rounded and is preferable. Lower needle bend is sharp, which makes withdrawal of inner stylette difficult, and is undesirable. Ruler marks are in centimeters. to adjust the needle tip to project along the posterior aspect of the intervertebral foramen of interest. The fluoroscope was then changed to the frontal view where the needle tip was passed medially to lie at about the 6 o clock position of the pedicle above the exiting nerve of interest. A few drops of dense myelographic contrast material were injected to ensure that the needle tip was correctly positioned. When an acceptable needle tip position was confirmed on frontal and lateral fluoroscopic views, a mixture of 1 ml of depo steroid, 1 ml of dense myelographic media, and 1 ml of anesthetic was injected. Fluoroscopic images were taken in frontal and lateral positions during and at completion of the entire injection, whereas oblique position images were taken after the injection to show distribution of the injectate (mixture of injected fluids). Early in the practice of performing these blocks, contrast agent was not given in the final injectate, and washout of the original placed contrast agent was used. The practice of adding contrast agent to the final injectate was started in 2003 and has been continued to date to more clearly show distribution of the final injectate. Ten to 20 minutes after procedure completion, the patient was asked to complete another form to indicate his or her pain on a visual analog scale from 0 to 10. Patients stayed for minutes or until they were stable for discharge from the department as assessed by residents, staff radiologists, or musculoskeletal radiology fellows. The presence of immediate complications was also recorded. Each patient was given written instructions how to contact the physician who performed the procedure if the patient had problems after leaving the department. If such a call occurred, the content of the call was recorded into a database that included all interventional procedures performed in this radiology section. Through the years, this procedure was performed by 51 residents and 22 fellows under the guidance of seven staff radiologists using this technique as it evolved over time. The technique was verified by later review of all the fluoroscopic images obtained during the procedure as part of a quality assurance check by the senior radiologist to ensure quality of the procedure. An independent observer not involved in the procedures reviewed the radiographs, reports, and complication database of the patients to identify immediate or postprocedural complications that had occurred before or shortly after the patient left the radiology department. A database was created to record complications; the presence or absence of lateral and frontal views available from each of the studies; the number, age, and sex of the patients; injectate used; nerves blocked; extent of injectate flow (medial, lateral, and cephalocaudal flow); and visual analog scale level of pain before and after the procedure. Before reviewing all the radiographs, the senior author instructed and checked the independent reviewer on anatomic features of the studies to enable independent review. The final needle tip position was ascertained on the final frontal and lateral fluoroscopic views taken at the end of the entire injection. Any doubt on position was clarified between the independent reviewer and the senior radiologist. On the frontal view (Fig. 2), final needle tip placement was rated on all the cases as zone 3 at medial to 6 o clock (inferior midpoint) on the pedicle, as zone 2 at 6 o clock on the pedicle to the lateral cortex of the pedicle (lateral one-half of the pedicle), and as zone 1 at lateral to the pedicle. On the final lateral view (Fig. 3), needle tip placement was rated as zone A when the needle tip projected over the anterior one quarter of the intervertebral foramen, as zone B when the needle tip projected over the central half of the intervertebral foramen, as zone C when the needle tip projected over the posterior one quarter of the intervertebral foramen, and as zone D when the needle was posterior to the foramen. The oblique views, as well as the frontal and lateral views, were used to determine extent AJR:197, December

3 Wang et al. Fig year-old girl. Image shows fluoroscopic frontal view of transforaminal T10 nerve block with boundaries of frontal zones. Bent needle tip (arrow) is at 6 o clock position of pedicle on left or in zone 2 (from 6 o clock position to lateral cortex of pedicle). Medial to 6 o clock position is zone 3. Lateral to pedicle is zone 1. of epidural flow of injectate when such a view was present (Fig. 4). If any of the views were absent or if the needle tip could not be identified on one of the views, the evaluation of that view was considered indeterminate. Cephalocaudal injectate flow was classified into several types. The injectate was classified as local if it localized just around the needle tip and did not move across at least one half a vertebral body above or below the needle tip. If the injectate flowed past the injected level to an adjacent vertebral body but not across the entire adjacent vertebral body, the injectate flow was classified as 0.5 above or below. If the injection passed completely across one adjacent vertebral body, flow was classified as 1 above or below; if it passed across 1.5 vertebral bodies, flow was classified as 1.5 above or below; and two or more levels were classified as 2. In some radiographs, injectate flowed outside of the image view, so these were classified with a greater than sign indication. Figure 5 presents an example of the use of this classification. In the database, the complications involved with each procedure were later matched to the final needle tip position located on the radiographs. After review of all examinations, the senior author Fig year-old girl (same patient as in Figs. 2 and 3). A and B, On frontal (A) and lateral (B) fluoroscopic spot views of T10 nerve block and T10 11 foraminal epidural, epidural flow of contrast agent mixed with injectate (arrows, A and B) is proximal and distal to needle entry site. reviewed each tenth study to establish accuracy of the independent review. In total, 22 of the total 225 examinations (9.8%) were reviewed again by the senior author. No errors were found. Data were examined for patterns by constructing contingency tables. Because there were small numbers of complications, the likelihood ratio chi-square test was used rather than Pearson chisquare test. Analyses were performed using JMP6.0 (SAS Institute). Fig year-old girl (same patient as in Fig. 2). Lateral view of transforaminal T10 nerve block with early epidural shows boundaries of lateral zones. Bent needle tip is in zone A, which includes anterior one quarter of intervertebral foramen. Zone B is central half of width of intervertebral foramen. Zone C (arrow) is posterior one quarter of intervertebral foramen width, and zone D is posterior to foramen. Results There were 296 nerve blocks or foraminal epidurals performed during 225 examinations or treatment sessions on 153 patients. Seventy-two cases involved both right and left nerve blocks performed during one treatment session (examination). Two hundred eighty-eight nerve blocks showed epidural flow, and eight did not. Eight blocks were of T1, 10 were of T2, one was of T3, 36 were of T4 6, 85 were of T7 or T8, 44 were of T9 or T10, and 41 were of the T11 or T12 nerves for a total of 225 blocks. If bilateral nerve blocks were performed, they were counted as one level. The 225 examinations relate to 225 levels, so if there were bilateral nerve blocks at one level, as right T2 and left T2, then the bilateral T2 blocks were accounted as one T2 nerve block. Of the 225 examinations studied, five had inadequate views of the intervertebral foramen on the lateral view, but these were still kept for analysis of complications. In the reports of the 296 thoracic foraminal nerve blocks, no serious complications occurred related to dural puncture, infection, vascular and neurologic injury, paraplegia, myelopathy, spinal hematoma, epidural abscess, pleural puncture, bradycardia, hypotension, or death [6]. However, there was one serious complication of pneumothorax with a 1412 AJR:197, December 2011

4 Fluoroscopically Guided Thoracic Foraminal Nerve Blocks Fig year-old girl. On lateral fluoroscopic view, injectate flow is classified as 0.5 above, because injectate flows past level under injection but not across next vertebral body. TABLE 1: Prevalence of Complications With Needle Tip Position in Lateral and Frontal Zones Zone No. of Injections No. of Complications Rate of Complications (%) Frontal a Total Lateral b A B C D Total Note The 12 complications were not included in the number of injections in any of the zones. They were listed only as complications. The total of the injections accounted for, per zone, added to the 12 complications gives a total of 296 nerve blocks. a There were two complete misses. b There were two complete misses, five indeterminate needle positions, and two incomplete views. TABLE 2: Pain Relief of Different Zones of Needle Position Presenting Pain Miss or Incomplete Zone None Partial Complete Complication Views a Frontal Total Lateral A B C D Total Note For each of the 296 injections, a presenting pain was associated with it. For example, if there was a bilateral injection with complete pain relief, then two completes were recorded. Patients with complications were not evaluated for pain relief in the table. a Two complications were associated with two of the incomplete views (see Table 1). T7 nerve block in a patient whose procedure was not performed according to the exact protocol established for the procedure in this institution [14]. In the reports, if no complications were mentioned, no complications were assumed, because it is a policy in our department that the presence of complications must be mentioned in the report. Any delayed reaction of the patient after the patient left the department was obtained from the radiology section database. Only 12 of 296 injections (4.1%) in 10 of 153 patients (6.54%) had complications. Two patients had lightheadedness, three had local numbness, two had muscle spasms, and one each had vasovagal response, headache, and pneumothorax. Only one of these 10 patients had a serious complication, which was the pneumothorax. The pneumothorax complication was avoidable because the needle was advanced above the rib without fluoroscopic control when the patient moved. The patient was treated with hospitalization and observation, did not need a chest tube, and had no subsequent problems related to the pneumothorax, which resolved. The rest of the complications were transient without sequelae. Table 1 summarizes the number of injections for each zone and the prevalence of complications related to different needle tip positions. Among the frontal zones available for review in all 12 complications, zone 1 had the highest complication rate (8.8% [6/68]), followed by zone 2 (2.7% [4/147]) and zone 3 (3.0% [2/67]), but these differences did not approach statistical significance (p = 0.15). Ten of the 12 complications had lateral views for evaluation. The complication rates among the lateral zones were nearly identical, with zone A at 3.4% (3/87), zone B at 3.8% (5/132), zone C at 3.9% (2/51), and zone D at 0% (p = 0.91). The different regions in both the frontal and lateral zones had very similar rates of complications and pain relief (Table 2). No pain relief was noted when there was no change in the patient s pain level, partial pain relief was noted when there was a decrease in pain but there was still pain, and complete pain relief was noted when the patient reported no pain after the procedure. Overall, there was partial or complete pain relief in 88.4% (199/225) of cases, including partial pain relief in 61.8% (139/225) and complete pain relief in 26.7% (60/225) of cases at the completion of the procedure, as detailed in this report (Table 3). Of the patients with partial pain relief, 21.6% had (from greater than 0) 30% pain relief; 45.9% had more than 30% but less than 60% pain relief; and 32.5% had 60% to less than 100% pain relief. For cephalocaudal flow, complications occurred in nine of 132 injections (6.8%) with AJR:197, December

5 Wang et al. TABLE 3: Presenting Pain Relief for Each Examination Presenting Pain No. of Examinations Percentage of Total Partial Complete None Complications 10 a 4.4 Total 225 b a Patients with complications were not evaluated for relief of symptoms. b There were 225 examinations in which 296 injections were performed. TABLE 4: Cephalocaudal Flow Associated With Complications Cephalocaudal Flow No. of Blocks Complication Complication Rate (%) Local > > > > > Lateral Miss injectate flow within 0.5 of a vertebral body width above or below the vertebral body injected level, in two of 10 (20%) for 1.5 or 2.0 widths above or below the body, and in one of 111 (0.9%) for local flow (Table 4). When cephalocaudal flow was local, the complication rate was markedly lower than when there was extralocal flow (0.9% [1/111] vs 5.9% [11/185]; p = 0.02). Discussion The overall complication rate was 4.1% (12/296), with one significant potentially avoidable complication of pneumothorax. The overall success rate to decrease immediate pain was 88.5% (262/296). This article reviews all the thoracic foraminal nerve blocks performed in one radiologic section in one hospital from June 27, 1997, to June 16, 2008, which, to our knowledge, is the largest reported series of such blocks. To date, other than a technical note describing how to do this procedure [14], we could find no publications reviewing immediate complications from thoracic foraminal nerve blocks that occurred in one institution in one particular time frame. Because of the lack of literature regarding thoracic foraminal nerve blocks and their complications, this article is extremely critical to determine which and how often complications can occur [8]. This study also shows that a large percentage of patients had partial or complete pain relief at the time of discharge from the radiology department. Although performing thoracic foraminal nerve blocks can be a relatively safe and effective procedure if proper care is used during administration of the block [14], there still were a few very minor complications of lightheadedness, vasovagal response, headache, local numbness or pain around the area of block, and muscle spasms. Although serious complications, including death and spinal cord injury, have been reported with spinal nerve blocks, especially cervical blocks [4], research on fluoroscopically guided extraforaminal cervical and lumbar nerve blocks shows that complications are minimal. If complications do occur, they are minor. In one study of 1036 cervical extraforaminal nerve blocks, no catastrophic complications were found and only 14 patients (1.35%) had a minor complication due to the procedure [4]. In another study of 2217 selective lumbar nerve root blocks, there were 98 minor complications encountered in a total of 1777 total patient visits, for a 5.5% complication rate [1]. The 4.1% complication rate in this series of thoracic nerve blocks, with all of them minor except for one potentially avoidable more major complication, shows that the complication rate of thoracic nerve blocks is similar to those of selective cervical and lumbar foraminal or extrafor a- minal nerve blocks. There are a few shortcomings to these gathered data. Without a control group or the capability to gather double-blind data, there are obvious gaps in research. For example, any placebo effect could not be taken into effect to ensure that the pain relief felt by patients was from the drugs themselves. Furthermore, because this study is retrospective and no long-term follow-up was performed, there is no way to be absolutely certain that no other unreported delayed minor complications occurred. Standard procedure dictated informing the patient of the potential complications that may occur in association with thoracic foraminal nerve blocks. At the end of the procedure, the patients were observed in the radiology department to identify immediate complications, which were duly recorded in the radiologic report of the procedure. After discharge, even though patients were instructed to contact the radiology department if complications occurred later, there could be a small number of patients who might have suffered a minor complication but did not deem it necessary to inform the hospital, referring physician, or radiologist who performed the procedure. However, all of these patients were referred from doctors who regularly refer patients, and it would be extremely unlikely if a patient had a complication and the doctor who performed the procedure was not contacted. Because we have reliable information only on the immediate complications and procedure effects, another downside to this study is the difficulty in identifying long-term effects of the procedures. Because other major complications besides the pneumothorax case (which was a technical problem) could not be unnoticed or ignored by the patient or his or her doctor, it is safe to say that no catastrophic event as death could have occurred without our hospital s notice. Such a major event triggers a major event investigation within our hospital. No such event occurred. Another shortcoming of this study is that the fluoroscopic images recorded only the needle position at the specific time the image was taken. Therefore, it is possible that the 1414 AJR:197, December 2011

6 Fluoroscopically Guided Thoracic Foraminal Nerve Blocks needle could have moved between the images taken. However, no needle tip movement except withdrawal of the needle took place after final fluoroscopic images were taken. It is also possible that structures could have been injured along the path of the needle placement before reaching the final needle tip placement site and that the minor complications reported could have been related to the needle tip path and not the final needle tip site. To ensure that the actual location of injection was recorded, a postinjection image was made to verify the needle tip s position and extent of injectate flow. There has been at least one report of spinal cord injury after a thoracic nerve block that was believed to be related to depo steroid blocking a collateral artery to the artery of Adamkiewicz [15]. Another article described the passage of contrast agent from epidural veins retrograde into a thoracic spinal artery [16]. The steroids used in all the cases in the present article were of the depo steroid type. The fact that depo steroids have particulates that may block a small artery is the explanation for the increased frequency of complications, such as those related to artery blockage, compared with water-soluble steroids. To decrease the rare chance of blockage of the artery of Adamkiewicz, one could do one or both of two procedures. One could stop using any depo steroids and use only nonparticulate steroids, such as dexamethasone [17]. Another technique to detect intraarterial flow would be to use digital subtraction when injecting contrast agent to observe for intraarterial flow, especially when injected liquids are washing out and one is uncertain where the washed-out fluids are passing. For this technique to work, one would need to add contrast material to the final injected liquid or injectate. The use of digital subtraction can be of additional help to watch closely where injected fluids are passing [18]. Because the complication of spinal cord infarct has been reported with lumbar foraminal epidural [19], although the incidence of such an occurrence is exceedingly infrequent, one may consider using the same practice of using water-soluble steroids, contrast agent mixed with final injectate, and digital subtraction when performing lumbar nerve blocks and foraminal epidurals to detect intraarterial flow, especially when there is a question as to where the injectate is flowing. From our results, we found a very high percentage of patients with immediate complete or partial pain relief at the end of the procedure. This pain relief supports the probability that pain was generated at the site of injectate placement. However, because the injectate commonly flowed proximal and distal to this needle tip, pain relief could have been achieved from the injectate passing to adjacent levels to the foramen injected. However, this work showed that the complications rate was higher with flow outside the local area (extralocal flow). Given the lack of short- or long-term follow-up, this article is reporting the effect of either local anesthetic or placebo with no data to support the administration of corticosteroid or role of thoracic injections as a definite therapeutic option. Because no placebo or sham procedure was performed, it is not possible to prove unequivocally that our injectate consisting of anesthetic, steroid, and contrast material was the cause of the pain relief. It has also been shown that, although steroids produced better pain relief than anesthetic alone in a blinded comparison prospective study of interlaminar lumbar epidurals, some patients receiving anesthetics alone had significant pain relief [20]. A prospective blinded study with sham procedure would be the ideal way to prove pain relief as shown in this study. However, this study, showing immediate pain relief in 88.4% (199/225) of the reports, can provide a basis on which such a study could potentially be performed. Epidural flow stayed local to the injected level in 243 of 296 foraminal nerve blocks (designated as 0.5 or local cephalocaudal flow extent) in these patients. If it is desirable to test a specific level for the source of pain, it would be desirable to keep the injectate at that level. This can be done by keeping the needle more lateral to the pedicle as in zone 1 to provide the desired selectivity. However, only by adding contrast material to the final injectate can one more accurately identify the extent of injectate passage in the epidural space. Placing contrast material and then watching contrast material washout without contrast material in the final injectate will not allow determination of the extent of injectate flow. Like any other technique-dependent procedure, the results presented here will not be universally reproducible, but, through careful attention to detail, we think that these results can be reproduced with few differences. This is emphasized by the large number of resident, fellow, and staff members who were involved in performing these blocks. In conclusion, these data indicate that, with the presented technique, thoracic foraminal nerve blocks are safe procedures to perform with few minor complications and that immediate pain relief can be obtained in a high percentage of patients. To ensure fewer complications, care must always be taken in the technical details when performing this procedure, as described in this article. Even though complications can be minimized with careful technique, it must be noted that severe complications are still possible and probably unavoidable, as in the cervical area; therefore, these interventions should not be pursued trivially. References 1. Stalcup ST, Crall TS, Gilula LA, Riew DK. Influence of needle-tip position on the incidence of immediate complications in 2,217 selective lumbar nerve root blocks. Spine J 2006; 6: Kaplan PA, Dussault RG. Image-guided selective nerve blocks in the spine. Semin Musculoskelet Radiol 1997; 1: Zennaro H, Dousset V, Viaud B, et al. Periganglionic foraminal steroid injections performed under CT control. AJNR 1998; 19: Ma DJ, Gilula LA, Riew DK. Complications of fluoroscopically guided extraforaminal cervical nerve blocks: an analysis of 1036 injections. J Bone Joint Surg Am 2005; 87: Schellhas KP, Pollei SR, Johnson BA, Golden MJ, Eklund JA, Pobiel RS. Selective cervical nerve root blockade: experience with a safe and reliable technique using an anterolateral approach for needle placement. AJNR 2007; 28: Botwin KP, Baskin M, Rao S. Adverse effects of fluoroscopically guided interlaminar thoracic epidural steroid injections. Am J Phys Med Rehabil 2006; 85: Windsor RE, Pinzon EG, Gore HC. Complications of common selective spinal injections: prevention and management. Am J Orthop 2000; 29: Sabanathan S, Richardson J, Mearns AJ. Management of pain in thoracic surgery. Br J Hosp Med 1993; 50: Silbergleit R, Bharat MA, Sanders WP, Talati SJ. Imaging-guided injection techniques with fluoroscopy and CT for spinal pain management. RadioGraphics 2001; 21: Wagner AL, Murtagh RF. Selective nerve root blocks. Tech Vasc Interv Radiol 2002; 5: Slipman CW, Isaac Z. The role of diagnostic selective nerve root blocks in the management of spinal pain. 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7 Wang et al. for continuous nerve blocks. In: Chelly JE, ed. Peripheral nerve blocks: a color atlas, 2nd ed. Philadelphia, PA: Lippincott Williams & Wilkins, 2004: Bogduk N. Thoracic transforaminal injections. In: Bogduk N, ed. Practice guidelines for spinal diagnostic and treatment procedures, 1st ed. San Francisco, CA: International Spine Intervention Society, 2004: Rosas HG, Gilula LA. Performing thoracic transforaminal injections: a new technique. Radiology 2010; 254: Glaser SE, Falco F. Paraplegia following a thoracolumbar transforaminal epidural steroid injection. Pain Physician 2005; 8: Yin W, Bogduk N. Retrograde filling of a thoracic spinal artery during transforaminal injection. Pain Med 2009; 10: Malhotra G, Abbasi A, Rhee M. Complications of transforaminal cervical epidural steroid injections. Spine 2009; 34: Gilula LA, Ma D. A cervical nerve block approach to improve safety. AJR 2007; 189: Kennedy DJ, Dreyfuss P, Aprill CH, Bogduk N. Paraplegia following image-guided transforaminal lumbar spine epidural steroid injection: two case reports. Pain Med 2009; 10: Manchikanti L, Singh V, Falco FJE, Cash KA, Pampati V. Evaluation of the effectiveness of lumbar interlaminar epidural injection in managing chronic pain of lumbar disc herniation or radiculitis: a randomized, double-blind controlled trial. Pain Physician 2010; 13: FOR YOUR INFORMATION The comprehensive book based on the ARRS 2011 annual meeting categorical course on Imaging of the Active Lifestyle: From the Weekend Warrior to the Pro Athlete is now available! For more information or to purchase a copy, see AJR:197, December 2011