Induced lumbosacral radicular symptom referral patterns: a descriptive study.

BACKGROUND CONTEXT: Lumbosacral radicular symptoms are commonly evaluated in clinical practice. Level-specific diagnosis is crucial for management. Clinical decisions are often made by correlating a patient's symptom distribution and imaging with sensory dermatomal maps. It is common for patients to describe non-dermatomal symptom patterns and for imaging to demonstrate pathology at levels not predicted by a dermatomal map. These observations suggest that the referred symptom distribution from lumbosacral nerve root provocation is different from dermatomal maps. This phenomenon has been demonstrated in the cervical spine but not in the lumbosacral spine. PURPOSE: The objective of this study was to characterize potential lumbosacral radicular symptom referral patterns induced during transforaminal epidural injections. STUDY DESIGN/SETTING: This is an observational descriptive study. PATIENT SAMPLE: The patient sample included 71 consecutive patients with lumbosacral radicular pain undergoing lumbosacral transforaminal epidural injections at an outpatient interventional spine practice. OUTCOME MEASURES: Each subject drew the location of provoked lumbosacral radicular symptoms on a pain diagram. MATERIALS AND METHODS: Seventy-one consecutive patients undergoing 125 fluoroscopically guided lumbosacral transforaminal epidural injections at an outpatient interventional spine practice were included in the study. The described location of provoked symptoms was recorded (1) after final needle positioning, (2) after injection of up to 0.5 mL of contrast solution, and (3) after injection of up to a 1 mL test dose of 1% lidocaine. Each subject drew the location of provoked symptoms on a diagram. The provoked symptom diagrams for each lumbosacral segmental level were combined to create composite nerve root, level-specific, symptom referral pattern maps. RESULTS: Of the 125 injections, 87 provoked referred symptoms and were included in the analysis. Thirty-eight injections did not provoke referred pain symptoms and were excluded from further analysis. Four nerve roots were tested at L1 and eight were tested at L2. Because of the small number of subjects, composite diagrams and statistical analysis were not completed for these levels. Eleven nerve roots were analyzed at L3, 28 at L4, 34 at L5, and 11 at S1. Composite symptom referral pattern maps were created for levels L3, L4, L5, and S1. Although the symptom distribution occasionally followed the expected dermatomal maps, most often the referral was outside of the patterns expected for each level. The most common symptom referral pattern for levels L3-S1 was the buttock, the posterior thigh, and the posterior calf. CONCLUSIONS: The level-specific provoked symptom distribution during lumbosacral transforaminal epidural injections is frequently different from that predicted by classic lumbosacral dermatomal maps. Referred pain to the buttock, the posterior thigh, or the posterior calf may come from L3, L4, L5, or S1 nerve root segmental irritation.

Image and Contrast Flow Pattern Interpretation for Attempted Epidural Steroid Injections.

Fluoroscopically guided, contrast-enhanced epidural steroid injections (ESIs) are frequently performed for radicular symptoms. Interventionalists performing these procedures should have a thorough and detailed understanding of spinal anatomy to safely and effectively deliver the desired injectate to the targeted site. Being able to differentiate epidural from nonepidural contrast flow is vital as is recognizing flow to undesired locations. This article summarizes the characteristics that distinguish between ideal epidural flow patterns and nonideal subarachnoid, intradural, and other suboptimal contrast flow patterns. Recognizing these patterns is essential for safe and successful ESIs and to prevent avoidable complications.

Lumbosacral Transitional Segments: An Interventional Spine Specialist's Practical Approach.

The presence of a lumbosacral transitional vertebrae (LSTV) should prompt a more detailed preprocedural evaluation of the vertebral column to accurately determine spinal levels. An LSTV should prompt the use of corroborating intraprocedural imaging to verify morphology. The most important factors in treating lumbosacral transitional segments are communication among treating physicians to ensure segmental enumeration consistency and associated appropriate patient treatment.

Fluoroscopic contralateral oblique view in interlaminar interventions: a technical note.

OBJECTIVE: To describe the value and utility in using a contralateral oblique (CLO) view when performing cervical, thoracic, and lumbar interlaminar procedures including epidural steroid injections and spinal cord stimulation percutaneous lead placement. METHODS AND RESULTS: Fluoroscopic images are used to illustrate the value of using CLO views. The CLO view is obtained after the level is confirmed. Then, the fluoroscope is obliqued contralateral to the needle tip to visualize the target interlaminar space and the spinolaminar line. In this fluoroscopic setup, the needle can be seen traversing between the superior and inferior lamina (elliptical appearing structures on CLO view) with the needle tip directed toward the spinolaminar line. The needle is then advanced through the ligamentum flavum into the posterior epidural space. The CLO view helps better visualize needle tip placement when patient positioning, body habitus, or other atypical anatomy makes visualization in standard lateral views challenging. The CLO provides more consistent visualization of the target structures. CONCLUSIONS: We recommend that the CLO view for thoracic and lumbar interlaminar procedures, in addition to cervical cases. Thus, when confirming proper needle placement for interlaminar procedures, the CLO view combined with anterior-posterior view yields safe multi-planar imaging and should be considered when a lateral view is unable to demonstrate target landmarks clearly.

Injectate volumes needed to reach specific landmarks in s1 transforaminal epidural injections.

OBJECTIVES: We identify the contrast volumes needed to reach specific landmarks during S1 transforaminal epidural injections (S1-TFEIs). DESIGN: Prospective, nonrandomized, observational human study. Setting. Academic/private pain management practice. Subjects. Forty-two patients undergoing S1-TFEIs were investigated. Thirty-seven patients were included in this study. Interventions. S1-TFEIs were performed using contrast-enhanced fluoroscopic visualization. MAIN OUTCOME MEASUREMENTS: After confirming appropriate spinal needle position, up to 5 mL of nonionic contrast was slowly injected. Under biplanar fluoroscopic guidance, contrast volumes were recorded as flow reached specific anatomic landmarks: the ipsilateral S1 pedicle, the superior aspect of the L5-S1 disc space, and across the midline of the spinous process. RESULTS: After injecting 2 mL of contrast, 100% of S1-TFEIs spread to the medial aspect of the ipsilateral superior pedicle of S1. After injecting 3.0 mL of contrast, 92% of S1-TFEIs spread to the superior aspect of the L5-S1 intervertebral disc. After injecting 4 mL of contrast, 27% of S1-TFEIs spread beyond the midline of the spinous process, but by only a few millimeters. CONCLUSIONS: This study demonstrates injectate volumes needed to reach specific anatomic landmarks in S1-TFEIs. A volume of 3.0 mL of contrast reaches the superior aspect of the L5-S1 intervertebral disc 92% of the time.

Discography's role in low back pain management.

SUMMARY Lumbar provocation discography is a commonly used diagnostic procedure utilized to determine the presence or absence of discogenic pain at a specific spinal segment. Although multidisciplinary societies have recognized discography as the primary criterion for identifying discogenic pain, the test remains controversial. Skeptics argue against its sensitivity and specificity, and suggest that it's risks outweigh any potential benefits. However, when properly performed and interpreted, discography is an invaluable tool. Together with a patient's history, physical examination and radiological studies, discography will safely identify both symptomatic and asymptomatic discs to provide confirmatory evidence that a particular disc is the source of the patient's pain. Since information from this study may be used to plan for percutaneous or open surgical procedures, accurate and precise interpretation of the results is vital.

Efficacy of fluoroscopically guided, contrast-enhanced lumbosacral interlaminar epidural steroid injections: a pilot study.

OBJECTIVE: To assess the efficacy of fluoroscopically guided, contrast-enhanced lumbar interlaminar epidural steroid injections (IL-ESI) for lower limb pain greater than axial low back pain using self-reported pain scores. STUDY DESIGN: Prospective, single-arm, pilot, observational human study. SETTING: An outpatient private practice interventional spine specialty referral center. DATA/RESULTS: Twenty-one patients were initially included in analysis. Thirteen patients had "complete data" and completed 3 months of data after their most recent IL-ESI. Their self-reported 3-day average Numeric Pain Rating Scale (NPRS) score (0 to 10) at inception, 2 weeks, 6 weeks, and 3 months were 6.38, 3.00, 2.88, and 3.04, respectively. The average NPRS score at 3 months was significantly lower than at inception after the IL-ESI for this group (P = 0.0001, 95% confidence interval [1.69, 5.00]). Eight patients had "incomplete data." Their self-reported 3-day average NPRS scores at inception, 2 weeks, and 6 weeks were 6.69, 4.25, and 4.00, respectively. Of the eight patients who had incomplete data, two patients had surgical intervention, five patients had lumbar transforaminal epidural steroid injections, and one patient was unable to be contacted after 6 weeks. DISCUSSION/CONCLUSION: This prospective, single-arm pilot study demonstrates that subjects who have had fluoroscopically guided, contrast-enhanced lumbar IL-ESIs for radicular > axial pain can have improved (lowered) NPRS for at least 3 months. It would be worthwhile to pursue a more rigorous study.

Injectate volumes needed to reach specific landmarks in lumbar transforaminal epidural injections.

OBJECTIVES: To identify the volumes of contrast material needed to reach specific landmarks during lumbar transforaminal epidural injections (L-TFEIs). DESIGN: Prospective, nonrandomized, observational human study. SETTING: Academic/private pain management practice. PATIENTS: Sixty-nine patients undergoing L-TFEIs were investigated. Sixty patients were included in this study. INTERVENTIONS: L-TFEIs were performed with the use of contrast-enhanced fluoroscopic visualization. MAIN OUTCOME MEASUREMENTS: After the appropriate spinal needle position was confirmed, up to 5.0 mL of nonionic contrast material was slowly injected. Under biplanar fluoroscopic guidance, contrast volumes were recorded as flow reached specific anatomic landmarks: ipsilateral neural foramen, ipsilateral disks superior and inferior to the injected level, and across the midline of the spinous process. RESULTS: After 1.1 mL of contrast was injected, 100% of L-TFEIs spread to the medial aspect of the superior pedicle (PED) of the corresponding level of injection. After 2.8 mL of contrast was injected, 95% of L-TFEIs spread to the superior aspect of the superior intervertebral disk (IVD) of the corresponding level of injection. After 3.6 mL of contrast was injected, 95% of L-TFEIs spread to the inferior aspect of the inferior IVD of the corresponding level of injection. After 3 mL of contrast was injected, 88% of L-TFEIs spread to cover both the superior and inferior IVDs of the corresponding level of injection. After 4 mL of contrast was injected, 93% of L-TFEIs spread to cover both the superior and inferior IVDs of the corresponding injection. After 4 ml of contrast was injected, 55% of L-TFEIs spread beyond the midline of the spinous process, but barely. CONCLUSION: This study demonstrates injectate volumes needed to reach specific anatomic landmarks in L-TFEIs. A volume of 4.0 mL of injectate reaches both the superior aspect of the superior IVD and the inferior aspect of the inferior IVD 93% of the time.

Contrast flow selectivity during transforaminal lumbosacral epidural steroid injections.

BACKGROUND: Lumbosacral transforaminal epidural steroid injections (LS-TFESIs) are an accepted procedure used in the comprehensive, conservative care for lumbar disc pathology and/or spinal stenosis induced low back pain with a radicular component. Historically, the terminology used to describe the transforaminal technique of instilling medications into the epidural space and/or exiting structures has varied. These procedures have also been referred to as either diagnostic or therapeutic selective nerve root blocks (SNRBs). Although this procedure is typically used to "selectively" treat isolated pathology, the "SNRB" terminology suggests that one can selectively diagnose or treat a specific nerve root as a pain generator by anesthetizing or blocking it. It has been recently demonstrated that L4 and L5 SNRBs are often non-"selective" by investigating the extent of epidural contrast flow patterns after injecting 1.0 mL of contrast. Our study attempts to identify the minimum injectate volume at which LS-TFESIs may still be considered "selective" with no injectate extending to either the adjacent (superior and/or inferior) levels or to the contralateral side. OBJECTIVE: Quantitatively evaluate contrast flow level selectivity noted during fluoroscopically guided lumbosacral transforaminal epidural steroid injections (LS-TFESIs). STUDY DESIGN: Prospective, nonrandomized, observational human study. METHODS: Thirty patients (female = 10, male = 20) undergoing LS-TFESIs were investigated. After confirming appropriate spinal needle position with biplanar imaging, 4.0 mL of nonionic contrast was slowly injected. Fluoroscopic images were recorded at 0.5 mL increments. These biplanar contrast flow images were evaluated to determine which 0.5 mL volume increment was no longer specific for the injected level. In particular, we documented when contrast extended either to a superior or inferior spinal segment or crossed the midline spine to the contralateral side. RESULTS: After injecting 0.5 mL of contrast, 30% of LS-TFESIs performed in this study were no longer "selective" for the specified root level. After injecting 1.0 mL of contrast, 67% of LS-TFESIs performed in this study were no longer "selective" for the specified root level. After injecting 1.5 mL of contrast, 87% of LS-TFESIs performed in this study were no longer "selective" for the specified root level. After injecting 2.5 mL of contrast, 90% of LS-TFESIs performed in this study were no longer "selective" for the specified root level. CONCLUSIONS: Diagnostic LS-TFESI or SNRB blocks limiting injectate to a single, ipsilateral segmental level cannot reliably be considered diagnostically selective with volumes exceeding 0.5mL. Injectate volumes greater than 0.5mL are consistently non-selective and cannot be used reliably for diagnostic block procedures in the epidural space.

Fluoroscopic axial imaging in percutaneous lumbosacral procedures: An underutilized technique.

BACKGROUND: The L4-5 and L5-S1 intervertebral disc spaces are the most frequent sites of discal spinal pathology, hence, diagnostic and therapeutic interventions are commonly performed at these levels. While performing fluoroscopically guided spinal procedures such as discography or intradiscal electrothermal anuloplasty (IDEA), antero-posterior (AP), lateral, and oblique views are utilized. However axial projection is not typically possible without three-dimensional imaging such as computerized tomography (CT). Intraprocedural CT is not commonly available. Instead, post-discography CT axial views are used to grade the degree of disruption. However, post-procedural CT is not always immediately available, and it increases costs and may increase patient discomfort, inconvenience, and radiation exposure. Intra-procedure fluoroscopic axial (F-axial) views offer the benefit of dynamic information by helping confirm needle, introducer, or intradiscal catheter position. OBJECTIVE: To describe an alternative approach to axial imaging of the L5-S1 intradiscal space. SETTING: Spine Speciality Center. TECHNIQUE: We describe a simple technique for visualizing L5-S1 axial images intra-procedurally using F-axial views. Taking advantage of the patient's lordosis, the C-arm image intensifier is rotated cadally so F-axial images are obtained. We also demonstrate other uses of intra-procedural F-axials, including confirmation of discography needle placement and IDEA introducer and catheter positioning. CONCLUSION: The L4-5 and L5-S1 intervertebral disc spaces are frequent sites of discal spinal pathology. Multiple diagnostic and therapeutic procedures are performed at these levels. This report describes an adjunctive technique for visualizing the L5-S1 axial images intra-procedurally using a fluoroscopic axial (F-axial) view.

Incidence of intravascular penetration in transforaminal cervical epidural steroid injections.

STUDY DESIGN A prospective, observational, human, study was conducted. OBJECTIVES To evaluate the incidence of vascular penetration during fluoroscopically guided, contrast-enhanced transforaminal cervical epidural steroid injections, and to determine whether the observation of blood in the needle hub can be used to predict a vascular injection. SUMMARY OF BACKGROUND DATA Incorrectly placed intravascular cervical spinal injections result in medication flow systemically and not to the desired target. A recently published study demonstrates a high incidence of intravascular injections in transforaminal lumbosacral epidural injections. No studies so far have evaluated the incidence of vascular injections in transforaminal cervical epidural steroid injections, nor have they calculated the ability of observed blood in the needle hub to predict a vascular injection in the cervical spine.METHODS The incidence of fluoroscopically confirmed intravascular uptake of contrast was prospectively observed in 337 patients treated with cervical transforaminal epidural steroid injections. The ability of observed blood in the needle hub to predict intravascular injection was also investigated. For each subject, the injection level was chosen on the basis of the clinical scenario including history, physical examination, and review of imaging studies. Some patients had multilevel injections. Using fluoroscopic guidance, the authors placed a 25-gauge needle into the epidural space using a transforaminal approach according to accepted standard technique. Needle tip location was confirmed with biplanar imaging. The presence or absence of blood in the needle hub spontaneously ("flash") and after attempted aspiration by pulling back on the syringe's plunger was documented. Contrast then was injected under real-time fluoroscopy to determine whether the location of the needle tip was intravascular. The results were recorded in a prospective manner indicating the presence or absence of blood in the needle hub and whether a vascular pattern was noted with contrast injection, and these were correlated. Relevant epidemiologic data also were recorded. RESULTS The study included 504 transforaminal epidural steroid injections. The overall rate of fluoroscopically confirmed intravascular contrast injections was 19.4%. Use of observed blood in the needle hub to predict intravascular injections was 97% specific, but only 45.9% sensitive. There was no significant difference in intravascular rates related to age or gender. CONCLUSIONS As compared with a previous study of lumbosacral epidural steroid injections, there is an overall higher incidence of intravascular injections with cervical transforaminal epidural steroid injections. Use of observed blood in the needle hub to predict an intravascular injection is not sensitive, and therefore the absence of blood in the needle hub despite aspiration is not reliable. The reported sensitivity and specificity rates are similar to lumbar data. Fluoroscopically guided procedures without contrast confirmation instill medications intravascularly, and therefore not in the desired epidural location. This study confirms that there is a need not only for fluoroscopic guidance, but also for contrast instillation in cervical transforaminal epidural steroid injections.