Intravascular injection in cervical medial branch block: an evaluation of 361 injections

ABSTRACT

BACKGROUND: The prevalence of persistent neck pain, secondary to involvement of cervical facet or zygapophysial joints, has been described in controlled studies as varying from 39% to 67%. Cervical medial branch block (MBB) represents a useful interventional pain management procedure indicated in patients with a chronic neck pain of facet joint origin. In the current study, we prospectively evaluated the incidence of, and the factors associated with, intravascular injection during block. In addition, we assessed the efficiencies of generally accepted safety measures, such as pre-injection aspiration and intermittent fluoroscopy to avoid intravascular injections. METHODS: We prospectively examined 361 cervical MBBs in 158 patients performed by 2 physicians. Aspiration test, spot radiography, and contrast injection under real-time fluoroscopic visualization were performed sequentially without repositioning the needle. Incidences of blood flash back and the presence of intravascular contrast spread on spot radiographic images and during real-time fluoroscopy were checked. The factors studied for intravascular injection included patient age and sex and block spinal level. RESULTS: No specific factors were found to affect the incidence of intravascular uptake during block. The overall incidence of intravascular uptake was 3.3% per nerve block (12/361), and 7 of these were predicted by pre-injection aspiration (sensitivity = 58.3%) and 8 by spot radiography (sensitivity = 66.7%). CONCLUSIONS: The aspiration test with or without spot radiography frequently missed the intravascular uptake of contrast during cervical MBBs. We strongly advocate the use of real-time fluoroscopy during contrast injection to increase diagnostic and therapeutic value and to avoid possible complications.