Computed tomography-guided cervical selective transforaminal epidural block for a patient with bilateral anatomical variations of vertebral artery -a case report-

New Optimal Needle Entry Angle for Cervical Transforaminal Epidural Steroid Injections: A Retrospective Study

Objective: A cervical epidural steroid injection is one of the most commonly performed interventions to manage chronic neck pain and cervical radiculopathy. Despite its many severe complications, cervical transforaminal epidural steroid injection (CTFESI) is a clinically necessary modality for managing neck pain and cervical radiculopathy. We aimed in this study to find a safer optimal needle entry angle to decrease the chance of an accidental vertebral artery (VA) puncture even with a proper needle entry angle and to visualize the target of the needle tip. Methods: This retrospective study included 312 patients with neck pain or cervical radiculopathy who had undergone magnetic resonance imaging scans for diagnosis and treatment. The first line was drawn from the midpoint of the two articular pillars and passed through the exact midline of the spinous process. The second line was drawn parallel to the ventral lamina line (conventional transforaminal approach line, CTAL). The third line was drawn parallel to the ventral margin at the midpoint of the superior articular process's ventral border (new transforaminal approach line, NTAL). The angle of intersection between the midline and CTAL versus with NTAL were measured from both sides (right and left) at C5-6, C6-7, and C7-T1 levels. Also, the distance of CTAL and NTAL from VA were measured from both sides at each level. We examined whether the CTAL and NTAL would penetrate the ipsilateral VA, internal carotid artery (ICA), and internal jugular vein (IJV). Results: There were significant differences between CTAL and NTAL angles at all levels (P < 0.001). There were significant differences between the distance of CTAL and NTAL from VA at all levels (P < 0.001). There were also significant differences between the observed frequency of CTAL and NTAL that would penetrate the major ipsilateral vessel (VA, ICA, and IJV) on all levels and sides (P < 0.001~0.030). Conclusion: The angle of NTAL (approximately 70°) is safer than the angle of CTAL (approximately 50°) when considering vascular injuries to vessels, such as the VA, ICA, and IJV.

Cervical foraminal steroid injections under CT guidance: retrospective study of in situ contrast aspects in a serial of 248 cases

OBJECTIVES

To describe all the CT findings after in situ contrast injection just before steroid injection and to recognize the abnormal aspects associated with intravascular contamination.

MATERIAL AND METHODS

We retrospectively evaluated 248 cervical transforaminal steroid injections done at the university hospital in Dijon, France, in 2008-2012, to treat cervicobrachial neuralgia inadequately improved by optimal medical treatment for at least 3 weeks. Features describing the opacification patterns were recorded.

RESULTS

Five main nonvascular opacification patterns were identified: clumps of contrast agent outside the foramen (16 %), a crab claw pattern surrounding the ganglion (13 %), a "French" circumflex accent pattern (15 %), reflux along the needle (7 %), and facet joint capsule opacification (22 %). Concerning the situations requiring a change in needle position, intravenous injection occurred in 26 % of the patients, with a crab claw pattern in half the cases and a clump pattern in half the cases. Intraarteriolar injection was noted in two patients.

CONCLUSION

CT after in situ contrast injection ensures proper needle positioning outside the blood vessels before steroid injection. Penetration of the needle tip into a vein is very common, whereas arteriolar puncture is extremely rare.

Variations in Entrance of Vertebral Artery in Korean Cervical Spine: MDCT-based Analysis

Background

Knowledge of the anatomical variation of the vertebral artery has clinical importance not only for the performance of interventional or surgical procedures itself but also to ensure their safety. We conducted a study of the anatomical variation by reviewing multi-detector computed tomography (MDCT) images of the cervical spine from 460 Korean patients.

Methods

16-row MDCT data from 460 patients were used in this study. We observed 920 vertebral arteries. Examination points included level of entrance of the artery into the transverse foramen of the cervical vertebra, origin site of the vertebral artery, course of a vertebral artery with aberrant entrance.

Result

The vertebral artery in 2 (0.2%) cases in this study entered into the transverse foramen of the 7th cervical vertebra from the left. In 45 (4.9%) cases, the vertebral artery entered into the transverse foramen of the 5th cervical vertebra. Of these, the entrance was on the right in 15 (1.6%) and on the left in 30 (3.3%). We found 17 (1.8%) cases in which the artery entered into the transverse foramen of the 4th cervical vertebra, 10 (1.1%) on the right and 7 (0.7%) on the left side. As is commonly acknowledged, the 6th cervical vertebra was the most common site of entry; the vertebral artery entered the transverse foramen of the 6th cervical vertebra in the remaining 855 (93.0%) cases, on the right in 434 (47.2%) and on the left in 421 (45.8%).

Conclusions

In conclusion, the possibility of an atypical course of the vertebral artery in segments V1 and V2 should be evaluated with magnetic resonance imaging (MRI) or CT images before carrying out procedures involving the anterior cervical vertebrae.