On the geometry of fluoroscopy views for cervical interlaminar epidural injections

Comparative analysis of contrast distribution in cervical epidural steroid injections utilizing a modified paramedian interlaminar approach with varied needle tip positions: A randomized controlled trial

BACKGROUND

Recent advancements in cervical interlaminar epidural steroid injections have given rise to the modified paramedian interlaminar (mPIL) approach. The objective of this study was to perform an analysis of the contrast spread pattern within the cervical epidural space, taking into account different needle tip positions in the mPIL approach.

METHODS

A total of 48 patients were included in the study and randomly assigned to either the medial or lateral group based on the needle tip's position in the anterior-posterior view. The primary outcome measured was the contrast flow under fluoroscopic visualization. As a secondary outcome, we analyzed the location of the needle tip position in both lateral and contralateral oblique views. Clinical effectiveness was assessed by measuring pain intensity and functional disability post-procedure.

RESULTS

Significant disparities were noted in the ventral distribution of contrast between the medial and lateral groups. In the lateral images, needle tips in the lateral group were positioned more ventrally compared to those in the medial group. Both groups exhibited statistically significant improvements in neck and radicular pain, as well as functional status, 4 weeks after treatment, with no significant differences between them.

CONCLUSIONS

Our results suggest that the ventral dispersion of contrast material during cervical interlaminar epidural steroid injections using the mPIL approach may vary depending on the needle tip location.

Contralateral oblique view can prevent dural puncture in fluoroscopy-guided cervical epidural access: a prospective observational study

INTRODUCTION

Although the contralateral oblique (CLO) view at 50°±5° is clinically useful for cervical epidural access, no previous studies have confirmed its safety. This prospective observational study was conducted to assess the safety profile, including the risk of dural puncture, in fluoroscopically guided cervical epidural access using the CLO view.

METHODS

In cervical epidural access using the CLO view, the incidence of dural puncture was investigated as the primary outcome. Other intraprocedural complications, including intravascular entry, subdural entry, spinal cord injury and vasovagal injury, and postprocedural complications were investigated as secondary outcomes. Procedural variables including first-pass success, final success, needling time, total number of needle passes and false loss of resistance (LOR) were evaluated.

RESULTS

Of the 393 patients who underwent cervical interlaminar epidural access were included for analysis, no instances of dural puncture or spinal cord injury were observed. The incidence of intravascular entry, vasovagal reaction and subdural entry were 3.1%, 0.5% and 0.3%, respectively. All procedures were successfully performed, with 85.0% of first-pass success rate. The mean needling time was 133.8 (74.9) s. The false-positive and false-negative LOR rates were 8.2% and 2.0%, respectively. All needle tips were visualized clearly during the procedure.

CONCLUSIONS

The fluoroscopy-guided CLO view at 50°±5° avoided dural puncture or spinal cord injury and decreased the incidence of false LOR during cervical epidural access with a paramedian approach.

TRIAL REGISTRATION NUMBER

NCT04774458.

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.

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.

Incidence of Unintentional Flow of Contrast into the Facet Joints During Fluoroscopy-Guided Cervical Interlaminar Epidural Injections: A Retrospective Cohort Study

OBJECTIVE

We sometimes encounter unintentional flow of contrast into the facet joints during cervical interlaminar epidural injection, which leads to false-positive epidural injection. The purposes of this study were to evaluate the rate of facet flow of contrast and to investigate various factors associated with injection into the space of Okada during fluoroscopy-guided cervical interlaminar epidural injection.

SETTING AND SUBJECTS

Images from consecutive cases of fluoroscopy-guided cervical interlaminar epidural injection performed at a single institution between July 2015 and July 2018 were obtained and reviewed.

METHODS

Cases of epidural injection were classified as either facet flow or no facet flow. Multivariate logistic regression was used to identify the predictive factors of unintended injection into the Okada space.

RESULTS

A total of 2,006 cases were included. Intra-articular flow was identified in 6.0% of cases (121/2,006). All cases of flow of contrast into the facet joints were recognized, and appropriate epidurograms were obtained during the procedures. The highest rate of unintended facet flow of the contrast (10.1%, 44/436) occurred at C5-6. Cervical interlaminar epidural injection at C5-6 and above (adjusted odds ratio [aOR] = 1.929, P = 0.001) and the paramidline approach for epidural injection (aOR = 2.427, P < 0.001) were associated with injection into the space of Okada.

CONCLUSIONS

We detected injection into the space of Okada during fluoroscopy-guided cervical interlaminar epidural injection in 6.0% of procedures. Cervical interlaminar epidural injection at C5-6 and above and the paramidline approach for epidural injection were positive predictors of unintentional facet flow of the contrast.

Interventional Radiology Suite: A Primer for Trainees

Familiarity with different instruments and understanding the basics of image guidance techniques are essential for interventional radiology trainees. However, there are no structured references in the literature, and trainees are left to “pick it up as they go”. Puncture needles, guidewires, sheath systems, and catheters represent some of the most commonly used daily instruments by interventional radiologists. There is a large variety of instruments, and understanding the properties of each tool will allow trainees to better assess which type is needed for each specific procedure. Along with understanding the tools required to perform various interventional radiology procedures, it is important for trainees to learn how to organize the room, procedural table, and various equipment that is used during the procedure. Minimizing clutter and improving organization leads to improved efficiency and decreased errors. In addition, having a fundamental knowledge of fluoroscopy, the most commonly used imaging modality, is an integral part of beginning training in interventional radiology.

Ultrasound-guided selective nerve root block versus fluoroscopy-guided interlaminar epidural block for the treatment of radicular pain in the lower cervical spine: a retrospective comparative study

PURPOSE

Recent studies have compared the therapeutic efficacy and safety of the procedure using ultrasound and fluoroscopy. However, there are no published studies comparing the therapeutic efficacy and safety of fluoroscopy (FL)-guided cervical interlaminar epidural steroid injection (CIESI) with that of ultrasound (US)-guided selective nerve root block (SNRB). This study aimed to compare the mid-term effects and advantages of US-guided SNRB with FL-guided CIESI for radicular pain in the lower cervical spine through assessment of pain relief and functional improvement.

METHODS

Patients with radicular pain in the lower cervical spine who received US-guided SNRB (n = 51) or FL-guided CIESI (n = 61) were included in this retrospective study. All procedures were performed using FL or US. The complication frequencies during the procedures, adverse events, treatment effects, and functional improvement were compared at intervals of 1, 3, and 6 months after the last injection.

RESULTS

Both the neck disability index and verbal numeric scale showed improvements at 1, 3, and 6 months after the last injection in both groups, with no significant differences between groups (p < 0.05). Furthermore, the treatment success rate at all time points was not significantly different between groups. Logistic regression analysis revealed that the injection method (US- or FL-guided), sex, analgesic use, pain duration, number of injections, and age were not independent predictors of treatment success. Blood was aspirated before injection in 8% (n = 5) and 0% of patients in the FL-guided and US-guided groups, respectively. In seven patients of the FL-guided group, intravascular contrast spread was noted during injection.

CONCLUSIONS

Our results suggest that, compared with FL-guided CIESI, US-guided SNRB requires a shorter administration duration while providing similar pain relief and functional improvements.

Cervical epidural analgesia in current anaesthesia practice: systematic review of its clinical utility and rationale, and technical considerations

Cervical epidural analgesia (CEA) is an analgesic technique, potentially useful for surgeries involving the upper body. Despite the inherent technical risks and systemic changes, it has been used for various surgeries. There have been no previously published systematic reviews aimed at assessing its clinical utility. This systematic review was performed to explore the perioperative benefits of CEA. The review was also aimed at identifying the rationale of its use, reported surgical indications and the method of use. We performed a literature search involving PubMed and Embase databases, to identify studies using CEA for surgical indications. Out of 467 potentially relevant articles, 73 articles were selected. Two independent investigators extracted data involving 5 randomized controlled trials, 17 observational comparative trials, and 51 case reports (series). The outcomes studied in most comparative studies were on effects of local anaesthetics and other agents, systemic effects, and feasibility of CEA. In one randomized controlled study, CEA was observed to decrease the resting pain scores after pharyngo-laryngeal surgeries. In a retrospective study, CEA was shown to decrease the cancer recurrence after pharyngeal-hypopharyngeal surgeries. The limited evidence, small studies, and the chosen outcomes do not allow for any specific recommendations based on the relative benefit or harm of CEA. Considering the potential for significant harm, in the face of better alternatives, its use must have a strong rationale mostly supported by unique patient and surgical demands. Future studies must aim to assess analgesic comparator effectiveness for clinically relevant outcomes.

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.

Effect of a novel fixation method for spinal cord stimulators

INTRODUCTION

Spinal cord stimulation is a well-established treatment for recalcitrant pain syndromes such as failed back surgery syndrome. Techniques minimizing surgical time and incision size and increasing lead stability are of great value to both the patient and implanting physician. We present a consecutive case series review of ten permanent percutaneous spinal cord implants utilizing a novel lead fixation device. The purpose of this case series review is to present initial findings of the minimized incision size and thoughts surrounding the new device and technique.

CASE SERIES REPORT

Ten cases were performed utilizing the new device (fiXate) and technique. Incision size was dictated by adequate visualization of the fascial stratum as well as technical working space required for lead fixation and redirection to the generator pocket. Each spinal cord stimulator lead was affixed to the thoracodorsal fascia utilizing the novel device.

DISCUSSION

In this consecutive series, the average midline incision size was 2.2 cm (range = 1.9-2.6 cm) which is greatly minimized through the use of the device. Not only may fiXate directly affect incision size, operating room and anesthesia time may also be lessened due to the semiautomated nature of the device. Of the cases performed, there were no complications or adverse events. Of note, there have been no reports of lead migrations during this case series, the average follow-up time being 18 weeks (range 11-26 weeks).

CONCLUSION

These data suggest a new method of fixation can be utilized for percutaneous spinal cord stimulation that allows a reduction in incision size. Intuitively, reduction in incision size is relevant with regard to tissue morbidity and may also have implications with regard to infection. Use of the device may also reduce operating room and anesthesia time as well as provide greater stability than standard suture.