Fluoroscopic Contralateral Oblique View in Interlaminar Interventions: A Technical Note

Real-time ultrasound guidance versus fluoroscopic guidance in thoracic epidural catheter placement: a single-center, non-inferiority, randomized, active-controlled trial

INTRODUCTION

Fluoroscopy can improve the success rate of thoracic epidural catheter placement (TECP). Real-time ultrasound (US)-guided TECP was recently introduced and showed a high first-pass success rate. We tested whether real-time US-guided TECP results in a non-inferior first-pass success rate compared with that of fluoroscopy-guided TECP.

METHODS

In this single-center, non-inferiority, randomized trial, the primary outcome was the comparison of the first-pass success rate of TECP between real-time US guidance (US group) and fluoroscopic guidance (fluoroscopy group). Secondary outcomes included time to identifying epidural space, procedure time, total number of needle passes, number of skin punctures, final success, and cross-over success.

RESULTS

We randomly assigned 132 patients to the allocated groups. The difference in the first-pass success rate between the groups did not exceed the non-inferiority margin of 15% (US group: 66.7% vs fluoroscopy group: 68.2%; difference -1.5%, 95% exact CI: -14.9% to 11.9%). The difference in the final success rate also did not differ between the groups (98.5% vs 100.0%; difference -1.5%, 95% exact CI: -4.0% to 1.0%). The time to identifying epidural space (45.6 (34-62) vs 59.0 (42-77) s, p=0.004) and procedure time (39.5 (28-78) vs 112.5 (93-166) s, p<0.001) were significantly shorter in the US group.

CONCLUSIONS

Real-time US guidance provided a non-inferior success rate and shorter time spent on preparation and procedure compared with fluoroscopic guidance in TECP.

TRIAL REGISTRATION NUMBER

KCT0006521.

Identification of cervical epidural space: A comparison study between contrast spread and loss of resistance techniques

Background and objectives

Early epidural space identification is critical to the efficacy and safety of cervical epidural steroid injections (CESI). Currently, the accepted method for epidural space recognition is the loss of resistance technique (LORT). I hypothesized that the contrast spread technique might recognize epidural space concurrently with or sooner than LORT and that smaller needles might be employed with the fluoroscopy only method but not with LORT. To test my hypotheses, I conducted a comparison study.

Methods

The study participants were patients from my practice with a clinical diagnosis of cervical radiculitis divided into two groups of 20 each, who underwent CESI with either an 18 G or a 25 G Tuohy needle. All CESIs were performed utilizing the fluoroscopy only method. Then, LOR was tested using an Epidrum device that was observed for 30 s; if the Epidrum deflated, the result was positive.

Results

LOR was positive in 12 out of 20 patients in the 18 G group and 2 out of 20 in the 25 G group. The 95% confidence interval test for proportion revealed a statistically significantly lower rate for epidural space detection by LORT in both groups: [0.385, 0.815] in the 18 G and [-0.031, 0.231] in the 25 G group. Statistical significance of the difference between groups in LOR accuracy rate (60% vs. 10%) was confirmed by z-test for independent proportions: z = 3.31 (p < 0.001), Cohen's h = 1.13.

Conclusion

Fluoroscopy only method might be a safer alternative to LORT as it employs a different concept, might recognize epidural space sooner, and favors smaller needles.

Clinical trial registration

NCT05260294.

Comparison of the contralateral oblique view with the lateral view for mid-thoracic epidural access under fluoroscopic guidance: a randomized controlled trial

BACKGROUND

The fluoroscopic-guided epidural access is occasionally challenging; therefore, the contralateral oblique (CLO) view has emerged as an alternative approach. The CLO view appears to be optimal for mid-thoracic epidural access; however, evidence on its utility is lacking. Therefore, we aimed to evaluate the clinical usefulness of the CLO view at 60°±5° compared with the lateral (LAT) view using fluoroscopic-guided mid-thoracic epidural access.

METHODS

Patients were randomly allocated to undergo mid-thoracic epidural access under the fluoroscopic LAT view (LAT group) or CLO view (CLO group). The primary outcome was the first-pass success rate of mid-thoracic epidural access. The secondary outcomes were procedural pain intensity, patient satisfaction, needling time, number of needle passes, and radiation dose.

RESULTS

Seventy-nine patients were included. The first-pass success rate was significantly higher in the CLO group than in the LAT group (68.3% vs 34.2%, difference: 34.1%; 95% CI 13.3 to 54.8; p=0.003). Procedural pain intensity was significantly lower in the CLO group than in the LAT group. Patient satisfaction was significantly greater in the CLO group than in the LAT group. The needling time and the number of needle passes were significantly lower in the CLO group than in the LAT group. Radiation dose in the CLO group was significantly reduced compared with that in the LAT group.

CONCLUSIONS

The fluoroscopic CLO view at 60°±5° increased the success rate and patient satisfaction and reduced the procedural time and patient discomfort compared with the LAT view when performing mid-thoracic epidural access. Therefore, the CLO view at 60°±5° can be considered for mid-thoracic epidural access under fluoroscopic guidance.

TRIAL REGISTRATION NUMBER

KCT0004926.

A proposed nomenclature for spinal imaging and interventional procedural reporting

Objective

To develop precise universal standard interventional spine nomenclature for reporting procedural details and anatomy.

Methods

There is no comprehensive nomenclature of spinal imaging anatomy that can be used for anatomical and procedural reporting. Given this critical lack of unifying terminology, a system of nomenclature was developed de novo by expert consensus, based upon clinical needs, and previously published reports.

Results

Nomenclature for anatomical and spine procedural reporting for interlaminar and transforaminal approaches was developed using zones in each view. Separate nomenclature for medial branch procedural reporting and discs and vertebral body location and procedural reporting is also presented.

Conclusion

There is a need for a unified anatomical location reporting system in interventional spine. The first step is the development of a precise, simple, and intuitive nomenclature, as reported here. The second is ratification followed by dissemination and adoption in clinical practice.

Comparison of contralateral oblique view with the lateral view for fluoroscopic-guided cervical epidural steroid injection: a randomized clinical trial

BACKGROUND

Cervical epidural steroid injection is associated with rare but potentially catastrophic complications. The contralateral oblique (CLO) view may be a safe and feasible alternative to the lateral (LAT) view for fluoroscopic-guided cervical epidural steroid injection. However, evidence for the clinical usefulness of the CLO view for cervical epidural steroid injection is lacking. We assessed the clinical usefulness of the CLO view for cervical epidural steroid injection in managing cervical herniated intervertebral discs.

METHODS

Patients were randomly assigned to receive fluoroscopic-guided cervical epidural steroid injection under LAT view or CLO view at 50±5° degrees groups. The primary outcome was the needling time comparison between the two groups. Secondary outcomes were comparison of first-attempt success rate, needle tip visualization and location, total number of needle passes, final success rate, crossover success rate and false-positive/negative loss of resistance. Complications and radiation dose were also compared.

RESULTS

The needling time significantly decreased in the CLO than in the LAT group. The first-attempt success rate was significantly higher in the CLO compared with the LAT group. The needle tip was clearly visualized (p<0.001) and located more often on (or just anterior to) the ventral interlaminar line (p<0.001) in the CLO than in the LAT group. There were significantly fewer needle passes (p=0.019) in the CLO than in the LAT group. There were no significant differences in the final success, crossover success, false-positive/negative loss of resistance or radiation dose between the groups. Two (5.9%) cases in the LAT group experienced complications.

CONCLUSION

The CLO view may be recommended for fluoroscopic-guided cervical epidural steroid injection, considering its better clinical usefulness over the LAT view.

Novel method for modified interlaminar approach using contralateral oblique view: A technical suggestion

A modified interlaminar (MIL) approach has been proposed for improved accessibility to the target epidural space. However, even with fluoroscopic guidance, uncertainty about the distance between the needle tip and the epidural space can remain. Using the contralateral oblique (CLO) view, determination of the epidural space can be easier with clearer identification of the interlaminar opening. We inserted the needle at the midpoint of the interlaminar opening on the fluoroscopic anteroposterior (AP) view and made the needle oriented toward the pedicle of the target side. Then, CLO view was created by rotating the intensifier approximately 45 degrees to the contralateral side of the target. Through the CLO view, the ventral interlaminar line (VILL) was confirmed and the needle was able to enter the epidural space more easily. The medical records of 29 patients who were conducted MIL approach using CLO view were retrospectively analyzed to evaluate the effectiveness and safety of this procedure. The accessibility to the ventral epidural space was 93.1%. There was no procedure-related complication. Using CLO view, uncertainty can be reduced during the MIL approach, which in turn shortens procedure time and improves safety.

Novel Technique for Insertion of Cervical Spinal Cord Stimulator Percutaneous Leads: Technical Note and Institutional Experience

OBJECTIVE

Cervical spinal cord stimulation is a safe and effective treatment for chronic axial neck pain and upper limb neuropathic pain. We report our novel institutional experience with performing cervical spinal cord stimulation trials with patients placed in an upright sitting position. This allows easy access to the cervical epidural space and has the added benefit of unobstructed access to the airway.

METHODS

We retrospectively reviewed data for patients who had undergone cervical spinal cord stimulation trial procedures in an upright, sitting position at the Vanderbilt University Medical Center. Demographic information including age, gender, preoperative diagnosis, progression to permanent implant after a successful trial, and operative time in minutes was collected.

RESULTS

A detailed description of the technique for implantation of cervical spinal cord stimulator trial leads in an upright sitting position is described. A total of 29 patients were implanted; 16 (55%) were female. Mean operative time was 78 minutes from incision to closing. The majority of patients (25/29; 86%) had successful trials and proceeded to permanent implant. No complications occurred, and the procedure was well tolerated by all patients.

CONCLUSIONS

Cervical spinal cord stimulation trials performed in an upright, sitting position allow for easy epidural access and an unobstructed airway with reasonable setup time.

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.

Method to Reduce the False-Positive Rate of Loss of Resistance in the Cervical Epidural Region

Background. The cervical epidural space can be detected by the loss of resistance (LOR) technique which is commonly performed using air. However, this technique using air has been associated with a high false-positive LOR rate during cervical interlaminar epidural steroid injections (CIESIs). Objective. We investigated whether the detection of LOR with contrast medium might reduce the false-positive LOR rate on the first attempt. Methods. We obtained data retrospectively. A total of 79 patients were divided into two groups according to the LOR technique. Groups 1 and 2 patients underwent CIESI with the LOR technique using air or contrast medium. During the procedure, the injection technique (median or paramedian approach), final depth, LOR technique (air or contrast), total number of LOR attempts, and any side effects were recorded. Results. The mean values for the total number of LOR attempts were 1.38 ± 0.65 (Group 1) and 1.07 ± 0.25 (Group 2). The false-positive rate on the first attempt was 29.4% and 6.6% in Groups 1 and 2, respectively (P = 0.012). Conclusions. The use of contrast medium for LOR technique is associated with a lower rate of false-positivity compared with the use of air.

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.

Safeguards to Prevent Neurologic Complications after Epidural Steroid Injections

Background:

Epidural corticosteroid injections are a common treatment for radicular pain caused by intervertebral disc herniations, spinal stenosis, and other disorders. Although rare, catastrophic neurologic injuries, including stroke and spinal cord injury, have occurred with these injections.

Methods:

A collaboration was undertaken between the U.S. Food and Drug Administration Safe Use Initiative, an expert multidisciplinary working group, and 13 specialty stakeholder societies. The goal of this collaboration was to review the existing evidence regarding neurologic complications associated with epidural corticosteroid injections and produce consensus procedural clinical considerations aimed at enhancing the safety of these injections. U.S. Food and Drug Administration Safe Use Initiative representatives helped convene and facilitate meetings without actively participating in the deliberations or decision-making process.

Results:

Seventeen clinical considerations aimed at improving safety were produced by the stakeholder societies. Specific clinical considerations for performing transforaminal and interlaminar injections, including the use of nonparticulate steroid, anatomic considerations, and use of radiographic guidance are given along with the existing scientific evidence for each clinical consideration.

Conclusion:

Adherence to specific recommended practices when performing epidural corticosteroid injections should lead to a reduction in the incidence of neurologic injuries.

Contralateral oblique view is superior to lateral view for interlaminar cervical and cervicothoracic epidural access

OBJECTIVE

The purpose of this study was to compare the reliability of the lateral fluoroscopic view and several contralateral oblique (CLO) views at different angles in visualizing and accurately predicting the position of the needle tip at the point of access in the posterior cervical and cervicothoracic epidural space.

DESIGN

After the epidural space was accessed but before confirmation with contrast fluoroscopy, we prospectively obtained fluoroscopic images at eight different angles. Subsequent contrast injection confirmed epidural spread. Needle tip visualization and location of needle relative to bony landmarks were analyzed.

RESULTS

The needle tip was clearly visualized in all CLO projections in all 24 subjects. CLO view at 50 degrees and at obliquity measured on magnetic resonance imaging (MRI) images provided the most consistent needle tip location. In these views, the epidural space was accessed at or just beyond the ventral laminar margin at the ventral interlaminar line or within the proximal half of the predefined CLO area in all patients. The needle tip was poorly visualized in the lateral view and the location of the needle tip was less well defined and independent of the needle location in the anteroposterior (AP) view.

CONCLUSIONS

This study provides evidence that during cervical and cervicothoracic epidural access, the CLO view at 50 degrees and at MRI-measured obliquity is superior to the lateral view for the purpose of needle tip visualization and in providing a consistent landmark for accessing the epidural space. This article also introduces the concept of zones to describe needle position in the cervical and cervicothoracic spine in AP, lateral, and oblique views.