Technique for CT fluoroscopy-guided cervical interlaminar steroid injections

Percutaneous Treatment and Post-treatment Management of CSF Leaks and CSF-Venous Fistulas in Spontaneous Intracranial Hypotension

Spontaneous intracranial hypotension (SIH) is a treatable cause of orthostatic headaches secondary to pathologic loss of cerebrospinal fluid (CSF) from the subarachnoid space. SIH has several known pathologic causes including dural tears from disc osteophytes, leaks emanating from nerve root sleeve diverticula, and CSF-venous fistulas (CVFs). Depending on the type of leak, surgical repair or endovascular techniques may be options for definite treatment. However, epidural blood patching (EBP) remains first-line therapy for many patients due to its long track record, broad availability, and relatively lower risk profile. This review focuses on indications and techniques for the percutaneous treatment of SIH and provides an overview of post-procedural management of these patients.

CT guided cervical medial branch block and radiofrequency ablation

The purpose of this report is to describe the procedure for CT fluoroscopy- guided Cervical medial branch block and facet radiofrequency ablation. CT fluoroscopic guidance allows more-precise needle tip positioning with visualization of bony landmarks and at the same time be aware of the adjoining soft tissue anatomy with good localization of adjacent critical non-targeted areas such as the neural foramina and the dorsal root ganglia. This serves as an alternative method for performing medial branch blocks and facet radiofrequency ablation.

Cross-sectional CT Assessment of the Extent of Injectate Spread at CT Fluoroscopy-guided Cervical Epidural Interlaminar Steroid Injections

Background Previous studies analyzed contrast agent spread during cervical interlaminar epidural steroid injections (CILESIs) by using planar fluoroscopy and reported wide variance of the rate of spread to the ventral epidural space (VES). Cross-sectional CT allows for direct viewing of contrast agent in the VES, providing improved spread assessment and thereby informing needle placement decisions when targeting pain generators. Purpose To determine the extent of injectate spread at CT fluoroscopy-guided CILESI, with particular attention to the VES and bilateral neuroforamina, by using cross-sectional CT. Materials and Methods This study reviewed 83 consecutive CT fluoroscopy-guided CILESIs at which a postprocedural cervical spine CT was performed (June 2016 to December 2017). All procedures used the same injectate (2 mL corticosteroid, 3 mL contrast agent). Postprocedural CT scans were reviewed for the presence of contrast within the VES, dorsal epidural space, ipsilateral neuroforamen, and contralateral neuroforamen in every cervical interlaminar level. Descriptive data are presented as frequencies or means. McNemar tests or hierarchical logistic models were used to assess associations between covariates and contrast agent spread to particular locations. Results The study cohort included 73 individual patients (59% women; 43 of 73) (mean patient age, 57.6 years ± 11.5 [standard deviation]). Mean number of levels of cranial spread were 0.6 level for VES, 1.9 levels for contralateral neuroforamen, 2.1 levels for ipsilateral neuroforamen, and 3 levels for dorsal epidural space. No VES spread in any level was found with 35% (29 of 83) of injections. VES spread was more likely to occur in the level of needle placement (43%; 36 of 83) than in other interlaminar levels (19.5%; 97 of 498; P < .001). Spread was more likely to occur in the neuroforamen ipsilateral to the needle approach compared with contralateral (P < .001). Conclusion Cervical interlaminar epidural steroid injections have injectate spreads with a mean of less than one level cranially in the ventral epidural space (VES) and approximately two levels in the neuroforamen. VES spread occurs more frequently at the level of needle placement and within the ipsilateral neuroforamen. © RSNA, 2019.

The preliminary results of a new CT-guided periradicular cervical steroid injection technique: safety and feasibility of the lateral peri-isthmic approach in 28 patients

BACKGROUND

Computed tomography (CT)-guided cervical nerve injections are broadly being used in the treatment of cervical radiculopathy; however, catastrophic complications have been reported. Herein, we aimed to evaluate the efficacy, feasibility, and safety of a novel CT-guided cervical injection technique.

MATERIALS AND METHODS

We prospectively performed cervical injections in 28 patients with cervical radiculopathies using a novel CT-guided cervical transforaminal injection technique; lateral peri-isthmic approach in which the tip of the needle advanced to the lateral cortex of the isthmus instead of the foraminal area. Patients' pain reduction rates were evaluated using visual analog scores (VAS) at pre-treatment, immediately after treatment, at 3 weeks and 6 months after the treatment. Intra-vascular contrast medium injections and distribution of the contrast material into the foraminal, epidural or extraforaminal area during the procedure were noted.

RESULTS

Pre-treatment pain scores were reduced by 4.2 ± 1.4 (p < 0.001), 3.9 ± 1.37 (p < 0.001) and 3.25 ± 1.53 (p < 0.001) immediately after the treatment, 3 weeks and 6 months after the treatment respectively. The number of patients with >50% pain relief as measured by VAS were 21 (75%) immediately after the procedure, 19 (67.8%) at 3 weeks and 17 (60%) at 6 months after the procedure. The injected contrast material was dispersed into the neural foramen in 9 cases (32.1%), the foraminal and epidural area in 14 cases (50%) and the extraforaminal area in 5 cases (17.9%).

CONCLUSION

The CT-guided lateral peri-isthmic approach seems to be a secure and feasible method for cervical injections with satisfactory pain reduction.

Technique for CT Fluoroscopy-Guided Lumbar Medial Branch Blocks and Radiofrequency Ablation

OBJECTIVE

The purpose of this study is to describe the procedure for CT fluoroscopy-guided lumbar medial branch blocks and facet radiofrequency ablation.

CONCLUSION

CT fluoroscopic guidance allows more-precise needle tip positioning and is an alternative method for performing medial branch blocks and facet radiofrequency ablation.

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.

Incidence of Inadvertent Intravascular Injection during CT Fluoroscopy-Guided Epidural Steroid Injections

BACKGROUND AND PURPOSE

Inadvertent intravascular injection during epidural steroid injection can result in complications and has been investigated previously with conventional fluoroscopy, but not CT fluoroscopy. The purpose of this study was to determine the incidence of intravascular injections recognized during CT fluoroscopy-guided epidural steroid injection.

MATERIALS AND METHODS

We retrospectively reviewed 575 consecutive CT fluoroscopy-guided epidural steroid injections. Procedures were assessed to determine the incidence of intravascular injection. Cases positive for intravascular injection were classified on the basis of anatomic location, distance from the needle tip, washout pattern, and presence of combined epidural and vascular injection. Cases were also graded as either venous or arterial by using a 5-point scale.

RESULTS

Intravascular injection was observed in 26% of cervical transforaminal epidural steroid injections (7/27), 9% of cervical interlaminar epidural steroid injections (4/47), 8% of lumbar transforaminal epidural steroid injections (22/275), and 2% of lumbar interlaminar epidural steroid injections (4/222). Vessels were most commonly identified close to the needle, but in 30% of cases, they were visualized in the anterior paraspinal soft tissues remote from the needle. Washout was most commonly delayed (86%), though rapid washout occurred in 14% of cases. Simultaneous epidural and vascular injections occurred in 32% of cases. Most visualized vessels were venous, but 2 cases were classified as probably arterial.

CONCLUSIONS

Intravascular injections can be detected with CT fluoroscopy. The incidence in our study was similar to that in previous reports using conventional fluoroscopy. Technical factors such as the "double-tap" on CT fluoroscopy following contrast injection, assessment for discordance between injected and visualized contrast volume, and maintenance of an appropriate FOV facilitate the detection of such events.

Cervical radicular pain: the role of interlaminar and transforaminal epidural injections

Chronic neck pain and cervical radicular pain are relatively common in the adult population. Treatment for chronic radicular pain recalcitrant to conservative management includes surgical management as well as interventional techniques with epidural injections utilizing either an interlaminar approach or transforaminal approach. Although there have been multiple systematic reviews and randomized clinical trials of cervical interlaminar epidural injections, the literature is sparse in reference to cervical transforaminal epidural injections. Overall, there is good evidence for the effectiveness of cervical interlaminar epidural injections in managing cervical disc herniation and fair evidence in managing central spinal stenosis and postsurgery syndrome. The evidence is poor, however, for cervical transforaminal epidural injections. Complications with cervical interlaminar epidural injections are rare, but more commonly occur with transforaminal epidural injections and can be fatal. Emerging concepts in pain include further randomized trials; proper placebo design; focus on control design (either active control or placebo control); and appropriate methodologic quality assessment and evidence synthesis.

Optimal contrast concentration for CT-guided epidural steroid injections

BACKGROUND AND PURPOSE

Contrast is used in CT-guided epidural steroid injections to ensure proper needle placement. Once injected, undiluted contrast often obscures the needle, hindering subsequent repositioning. The purpose of this investigation was to establish the optimal contrast dilution for CT-guided epidural steroid injections.

MATERIALS AND METHODS

This investigation consisted of an initial phantom study, followed by a prospective, randomized, single-center trial assessing a range of contrast dilutions. In the phantom study, a phantom housing a chamber containing a 22-gauge needle and various dilutions of contrast was scanned, and images were evaluated for needle visibility. On the basis of these results, concentrations of 66, 100, 133, and 150 mg/mL iodine were selected for evaluation in a clinical study. Patients presenting for CT-guided epidural steroid injections were randomly assigned to a contrast dilution, and images from the procedure were evaluated by 2 readers blinded to the contrast assignment. Needle visibility was scored by use of a 5-point scale.

RESULTS

In the phantom study, the needle was not visible at contrast concentrations of ≥133 mg/mL. In the clinical study, needle visibility was strongly associated with contrast concentration (P < .0001). Significant improvements in visibility were found in 66 mg/mL and 100 mg/mL compared with higher iodine concentrations; no difference was found comparing 66 mg/mL with 100 mg/mL iodine. Neither injection location (cervical versus lumbar) nor technique (interlaminar versus transforaminal) influenced visibility scores.

CONCLUSIONS

For CT-guided epidural steroid injections, the optimal contrast concentration is 66-100 mg/mL iodine. Because these concentrations are not commercially available, proceduralists must dilute their contrast for such procedures.

CT fluoroscopy-guided cervical interlaminar steroid injections: safety, technique, and radiation dose parameters

BACKGROUND AND PURPOSE

Cervical epidural steroid injections are approached with trepidation because of concerns over safety, including direct spinal cord injury. CT fluoroscopy is an alternative to conventional fluoroscopy that could potentially help reduce the risk of injury by providing improved localization of the needle tip. We sought to determine rates of technical success and risk of complications in our initial cohort of patients treated with cervical interlaminar ESI performed under CTF guidance.

MATERIALS AND METHODS

In this retrospective case series, we reviewed procedural details and CTF images of 53 consecutive cervical interlaminar ESIs performed on 50 patients over a period of 8 months. Rates of technical success, incidence of complications, procedure times, and factors that influence radiation exposure were examined.

RESULTS

No symptomatic procedural complications were observed. A single case of intrathecal contrast injection was observed, from which the patient was asymptomatic. The remaining injections were all technically successful. Injections were performed at every cervical level, as high as C1-C2. Total procedure times averaged less than 20 minutes. Average CT fluoroscopic time was 24 seconds and median tube current was 70 mA.

CONCLUSIONS

CTF-guided cervical interlaminar ESI can be performed at all levels in the cervical spine with a low rate of procedural complications. Short total procedure times, CT-fluoroscopy times, and reduced tube current make this procedure a practical alternative to cervical ESI performed under conventional fluoroscopy.