Comparison of Radiation Doses of Contralateral Oblique and Lateral View for Fluoroscopy-Guided Lumbar Interlaminar Epidural Steroid Injection.

BACKGROUND: Despite newly developing technologies and techniques, the use of fluoroscopic guidance in spinal interventional treatments remains popular. Therefore, it is essential to set reference standards and techniques for reducing radiation exposure in fluoroscopy-guided procedures. OBJECTIVE: The aim of this study was is to compare the radiation doses and procedure time of the contralateral oblique (CLO) view to  lateral view imaging during fluoroscopy-guided spinal procedures. STUDY DESIGN: A retrospective study. SETTING: Pain management unit of a tertiary care center. METHODS: An evaluation of patients who received epidural steroid injections between May 2021 and May 2023 in a university hospital interventional pain management center was performed. This observational study was conducted with 248 patients aged 18 and older who underwent lumbar interlaminar epidural injections (ILESI) confirmed by CLO or lateral oblique imaging. The primary outcomes were the comparison of radiation dose and procedure time between the 2 groups. The secondary outcome was the comparison of complication rates. RESULTS: There were no significant differences between the two groups in terms of age, gender, diagnosis, body mass index, procedure level, Numeric Rating Scale, and procedure time. Although the radiation dose was lower in the CLO group, there was no significant difference between the 2 groups. However, there was a significant difference between the 2 groups in terms of complications (P < 0.001). LIMITATIONS: The study was designed in a single center and performing all the procedures with the same fluoroscopy device makes it difficult to generalize our results. CONCLUSIONS: Although there was no difference in terms of radiation dose and duration of procedure between lumbar ILESI conducting using the CLO or lateral view fluoroscopy imaging, there was a significant difference in terms of complications. Therefore, conducting lumbar ILESI using a CLO view minimizes the complication rate.

The contralateral oblique fluoroscopic view is associated with a lower incidence of postdural puncture headache in patients undergoing percutaneous spinal cord stimulation.

BACKGROUND: Spinal cord stimulation (SCS) is a minimally invasive therapy that is increasingly used to treat refractory neuropathic pain. Although this technique has a low incidence of serious long-term adverse sequelae, the risk of complications such as inadvertent dural puncture remains. OBJECTIVES: The goal of this article was to determine the impact of the contralateral oblique (CLO) fluoroscopic view incidence of postdural puncture headache (PDPH) during spinal cord stimulator implantation as compared to lateral fluoroscopic view. METHODS: This was a single academic institution retrospective analysis of electronic medical records spanning an approximate 20-year time period. Operative and postoperative notes were reviewed for details on dural puncture, including technique and spinal level of access, the development of a PDPH, and subsequent management. RESULTS: Over nearly two decades, a total of 1637 leads inserted resulted in 5 PDPH that were refractory to conservative measures but responded to epidural blood patch without long-term complications. The incidence of PDPH per lead insertion utilizing loss of resistance and lateral fluoroscopic guidance was 0.8% (4/489). However, adoption of CLO guidance was associated with a lower rate of PDPH at 0.08% (1/1148), p < 0.02. CONCLUSIONS: The incorporation of the CLO view to guide epidural needle placement can decrease the odds of a PDPH during percutaneous SCS procedures. This study further provides real-world data supporting the potential enhanced accuracy of epidural needle placement in order to avoid unintentional puncture or trauma to deeper spinal anatomic structures.

Contralateral and Lateral Views: Analysis of the Technical Aspects of Spinal Cord Stimulator Lead Insertion.

Background: Spinal cord stimulation (SCS) is an established treatment modality for neuropathic pain. The critical part of this technique is safe access to the epidural space for lead placement. There have been innovations in radiological views, improving access to the epidural space. Objectives: This study analyzes the adoption of these technical advantages in daily practice. Methods: We conducted a survey of members in the Spine Intervention Society and American Society of Regional Anesthesia in regard to the practice patterns in SCS therapy. Here we present our findings regarding the use of contralateral oblique (CLO) and lateral views as well direct upper thoracic or cervicothoracic access for SCS lead insertion. Results: A total of 195 unique responses were received between March 20, 2020 and June 26, 2020. Forty-five percent of respondents "always used" the lateral view technique while 15% "always used" CLO view for SCS lead insertion. Overall, sixty-five percent of respondents used the CLO view with varying frequency. Cervical and upper thoracic approach for cervical SCS lead placement is always or often used by 66.8% of the respondents. Conclusions: A depth view (CLO or lateral) is always used by only 45 - 60% of the respondents and CLO view has been rapidly adopted in clinical practice for SCS lead insertion. Direct cervicothoracic and upper thoracic is the preferred approach for cervical lead placement by the majority.

Evaluation of Contralateral Oblique and Lateral Views for Mid-Thoracic Epidural Access: A Prospective Observational Study.

BACKGROUND: The mid-thoracic region has been known to be the most difficult area when accessing epidural space despite using fluoroscopy. Contralateral oblique (CLO) view has been considered for use; however, it has not been evaluated in the mid-thoracic region. OBJECTIVE: To evaluate the CLO view for mid-thoracic epidural access (TEA). STUDY DESIGN: A prospective observational study. SETTING: The study took place at a single pain clinic within a tertiary medical center in Seoul, Republic of Korea. METHODS: A total of 30 patients participated in this study. After securing the mid-thoracic (T4-8) epidural space, fluoroscopic images were obtained. The needle tip location relative to the ventral interlaminar line (VILL), and the needle tip and laminar visualization were measured and analyzed on the CLO views at 40, 50, 60 degrees, and measured angle, and the lateral view. RESULTS: The needle tip was clearly visualized in all CLO views, compared with the lateral view (100% vs. 36.7%, P < 0.001). The visualization of the laminar margin and the needle tip location on (or just anterior to) VILL using the CLO measured angle were significantly clearer compared with those in the CLO view at 40 and 50 degrees and the lateral view (laminar margin: 40°, 56.7% vs. 3.3%, P < 0.001; 50°, 56.7% vs. 26.7%, P = 0.012; 90°, 56.7% vs. 26.7%, P = 0.035; needle tip location: 40°, 96.7% vs. 26.7%, P < 0.001; 50°, 96.7% vs. 63.3%, P = 0.002; 90°, 96.7% vs. 66.7%, P = 0.012). There was no difference in these values between the CLO view at 60 degrees and CLO measured angle. LIMITATIONS: Subjective and ambiguous criteria of evaluation may induce bias despite final measured values based on the consensus of an independent investigator. CONCLUSION: A CLO view at 60 degrees and CLO measured angle view can provide clearer visualization and more consistent needle tip location than the lateral and other CLO angle views for mid-TEA. A CLO view at 60 degrees and CLO measured angle views could be used to identify the needle location and achieve success in mid-TEA.

Lumbar Epidural Contrast Spread Patterns for the Interlaminar Approach: Three-Dimensional Analysis Using Antero-Posterior, Lateral, and Contralateral Oblique Views.

OBJECTIVE: To describe and analyze lumbar epidural contrast spread patterns in antero-posterior (AP), lateral, and contralateral oblique (CLO) views. METHODS: Lumbar epidural contrast spread patterns after interlaminar injection were prospectively collected in AP, lateral, and several CLO views and analyzed for multiple variables; three-dimensional mapping was also performed. RESULTS: Epidural contrast patterns were prospectively analyzed in 28 subjects. The median volume of contrast injected was 2 mL; the AP view was more sensitive than the lateral view to detect foraminal uptake (13/28, 46%, 95% confidence interval [CI] = 27-66%, vs 7/28, 25%, 95% CI = 11-45% subjects). CLO view demonstrated the most consistent location for epidural contrast spread, with contrast contacting the ventral laminar margin in 28/28 (100%, 95% CI = 87-100%) patients. The most common location of contrast spread in the lateral view was at the facet joint lucency, with only 8/28 (29%, 95% CI = 13%-49%) subjects showing contrast contacting the spinolaminar junction. Lateral view was more sensitive than the CLO view in ventral epidural contrast spread detection. The extent and distribution of the spread did not bear any relationship to the volume injected or to the needle location in AP view. CONCLUSIONS: CLO view provides the most consistent landmark for lumbar epidural contrast spread, and lateral view is most suited to confirming ventral epidural spread. The AP view may be the most optimal for determining target access when considering access to the dorsal root ganglia; in an individual patient, the volume injected and needle location in AP view do not reliably predict target access. The volume to be injected and the need to re-access or obtain multisite access must be prospectively determined, based upon observation of the spread.

Reliability and Accuracy of MRI Laminar Angle Measurements to Determine Intra-Procedural Contralateral Oblique View Angle for Cervical or Thoracic Interlaminar Epidural Steroid Injections.

BACKGROUND AND OBJECTIVE: Contralateral oblique (CLO) angle view has been a useful addition to standard views in fluoroscopically guided interlaminar epidural injections. Determination of the appropriate CLO angle is paramount in the usefulness of this technique. Using MRI laminar angle measurements as a pre-procedural guide for the intra-procedural fluoroscopic CLO angle has been proposed. The purpose of this study was to help determine if using axial MRI laminar measurements prior to a cervical or thoracic epidural steroid injection would be useful in predicting the appropriate fluoroscopic CLO angle. STUDY DESIGN: A retrospective review was performed for patients who underwent cervical or thoracic interlaminar injections. In the performance of interlaminar injections, the authors had routinely determined the true fluoroscopic contra-lateral oblique angle after epidural access was confirmed, for use during any potential future injections. The fluoroscopic CLO angle measurements were obtained from a chart review and compared blindly to each patient's MRI axial laminar angle measurements. RESULTS: 34 injections were included. Inter-rater reliability comparing the two authors' MRI angle measurements was considered fair, ICC = 0.395. Accuracy was only 57% comparing MRI laminar angle measurements to within five degrees of the true fluoroscopic CLO angle as determined during the injection procedure. Accuracy by ICC showed only fair agreement, 0.47 and 0.22, for the two authors. CONCLUSIONS: The findings of this study indicate fair inter-rater reliability in manual measurements of laminar angle on axial MRI images. MRI laminar angle measurements do not appear to be highly accurate in determining the appropriate fluoroscopic CLO angle.

Feasibility of Contralateral Oblique Fluoroscopy-guided Cervical Interlaminar Steroid Injections.

BACKGROUND: Cervical epidural steroid injection (CESI), given in conjunction with local anesthetics, is a common remedy for cervical radicular pain and is generally performed under c-arm fluoroscopic guidance, computed tomography (CT), or ultrasound. Interlaminar procedures, such as CESI, typically rely on anteroposterior and lateral (APL) views during needle placement. However, lateral views may be obscured by body habitus in certain individuals. Swimmer's view or contralateral oblique (CLO) view may be used to avoid this. OBJECTIVE: Our intent was to assess technical success and procedural risk in patients subjected to image-guided CESI procedures with CLO c-arm fluoroscopy. METHODS: A total of 186 of patients were enrolled and randomly assigned to 1 of 3 groups undergoing image-guided CESI via (1) CT, (2) c-arm fluoroscopy CLO, and (3) c-arm fluoroscopy APL. Complication rates and technical success were assessed, basing the latter on image reviews to confirm the presence of epidural contrast. RESULTS: All image-guided CESI procedures utilizing CT and CLO fluoroscopy proved technically successful. In the CT group, epidural needle tip and contrast dispersion were clearly visible at all levels of study. In the CLO subset, needle tip visibility was unclear in isolated instances at levels C6-7 and C7-T1 (1 patient each level). In APL procedures, needle tip was regularly obscured by shoulder anatomy at levels C6-7 (26 of 41 patients) and C7-T1 (15 of 16 patients), and contrast dispersion was often uncertain. CONCLUSION: CLO fluoroscopy-guided CESI is feasible and safe, comparing favorably with CT-guided CESI.