Incidence of simultaneous epidural and vascular injection during cervical transforaminal epidural injections.

STUDY DESIGN: Prospective, observational in vivo study. OBJECTIVE: The aim of this study was to determine the incidence of simultaneous epidural and vascular contrast injection during cervical transforaminal epidural injections. SUMMARY OF BACKGROUND DATA: In the lumbar spine, vascular contrast patterns are more than twice as likely to appear simultaneous to the anticipated epidural pattern, than they are to occur alone. This is important because practitioners are more likely to miss a vascular pattern when it appears simultaneous to the expected epidural flow. The incidence of intravascular penetration in cervical transforaminal epidural injections is known to exceed than that of lumbar injections, however, no study has determined the incidence of simultaneous epidural and vascular injection in the cervical spine. METHODS: Contrast patterns were observed with live fluoroscopy during 121 injections performed on 82 patients and categorized as one of the following: epidural only, vascular only, or simultaneous epidural and vascular. RESULTS: The incidence of simultaneous epidural and vascular injection during cervical transforaminal epidural injections was 18.9%. The incidence of vascular only injection was 13.9%, for a total vascular injection incidence of 32.8%. There was no correlation between the observed contrast pattern with patients' age, sex, side of injection, needle gauge, or diagnosis. There was a significant correlation between the level of injection and the risk of vascular injection. The higher the injection level, the higher the probability of a vascular injection. Fluoroscopy time was significantly increased when a vascular injection was identified. CONCLUSION: Simultaneous epidural and vascular injection accounts for over half of all vascular injections during cervical transforaminal epidural injections. With the risk of severe complications and high incidence of vascular injections in the cervical spine, live fluoroscopy is recommended during contrast injection with specific attention to simultaneous epidural and vascular flow.

Accuracy of intermittent fluoroscopy to detect intravascular injection during transforaminal epidural injections.

STUDY DESIGN: Prospective validity study. OBJECTIVE: To determine how accurately intermittent fluoroscopy detects inadvertent intravascular injection during transforaminal epidurals. SUMMARY OF BACKGROUND DATA: Serious morbidity caused by transforaminal epidural injections is frequently related to inadvertent vascular injection of corticosteroids. Several methods have been proposed to reduce the risk of vascular injection, but none have demonstrated efficacy. Because of the fleeting appearance of vascular contrast patterns, live fluoroscopy is recommended during contrast injection. Despite this, many practitioners continue to use intermittent fluoroscopy. METHODS: During 50 epidural injections dynamic contrast flow was observed under live fluoroscopy, and the "dynamic true" image was determined. Two intermittent fluoroscopy images were saved from each injection, the first just before completing the contrast injection ("static C" image), and another 1 second after the contrast injection ceased ("static PC" image). Five physicians with experience performing these injections independently interpreted the 100 randomly ordered static images. Accuracy of intermittent fluoroscopy was determined by comparing the interpretation of the 100 static images with the dynamic true patterns observed under live fluoroscopy. RESULTS: Overall, interpretation of the static images missed 57% of the vascular injections. Timing of the static images influenced accuracy with the static C images missing 50% of vascular injections, and the static PC images missing 68% of vascular injections (P = 0.075). Accuracy was significantly worse when vascular injections occurred simultaneous to the expected epidural injection (P = 0.041), and in lumbar images (P = 0.012). CONCLUSION: Based on these findings, we recommend use of live fluoroscopy to observe dynamic contrast flow during transforaminal epidural steroid injections.

Incidence of simultaneous epidural and vascular injection during lumbosacral transforaminal epidural injections.

BACKGROUND CONTEXT: The incidence of vascular penetration during contrast confirmed fluoroscopically guided transforaminal lumbosacral epidural injections has been reported as 8.9% to 21.3% depending on the level of injection. Recently, intermittent fluoroscopy was shown to miss more than half of the vascular injections observed under live fluoroscopy. The number of misses increased when epidural and vascular contrast flow appeared simultaneously, even if the fluoroscopic image was taken during contrast injection. To date, no studies have documented the incidence of simultaneous epidural and vascular contrast injections. Also, most previous studies of vascular injections did not document use of live fluoroscopy during contrast injection, so the incidence of vascular injections may be higher than reported. PURPOSE: To determine the incidence of simultaneous epidural and vascular contrast injection during lumbosacral transforaminal epidural injections. STUDY DESIGN/SETTING: A prospective, observational, in vivo, study. PATIENT SAMPLE: Patients receiving lumbar transforaminal epidural injections at a university-based outpatient spine center. OUTCOME MEASURES: Incidence of epidural, vascular, and simultaneous epidural and vascular contrast patterns. METHODS: One interventional spine physician and three fellows under his direct supervision recorded contrast patterns observed during 191 fluoroscopically guided lumbosacral transforaminal epidural steroid injections with injection of contrast observed under live fluoroscopy. RESULTS: The incidence of simultaneous epidural and vascular injection during lumbosacral transforaminal epidural injections was 8.9%. The incidence of a vascular injection alone was 4.2%, for a total vascular injection incidence of 13.1%. Subjects with a simultaneous epidural and vascular injection who returned for repeat injection had a statistically significant chance of a repeat simultaneous epidural and vascular injection when the injection was done at the same location. Fluoroscopy time was significantly increased, an average of 8.8 seconds, when a vascular injection was identified. There was no statistically significant correlation between the incidence of simultaneous epidural and vascular injection with subjects' age, sex, level of injection, side of injection, needle gauge, or diagnosis. CONCLUSIONS: Simultaneous epidural and vascular injection is twice as likely to occur as vascular injection alone. Use of intermittent fluoroscopy can miss the transient appearance of the vascular component of these injections, giving the false impression of successful contrast placement. In light of these results, live fluoroscopy is recommended during contrast injection for confirmation of lumbosacral transforaminal epidural injections.