Differential Rates of Inadvertent Intravascular Injection during Lumbar Transforaminal Epidural Injections Using Blunt-Tip, Pencil-Point, and Catheter-Extension Needles.

OBJECTIVE: To quantify the incidence of inadvertent vascular penetration during lumbosacral transforaminal epidural injections using blunt-tip, pencil-point, and catheter-extension needles. STUDY DESIGN/SETTING: This is a prospective, observational, consecutive cohort study. SUBJECTS: Two hundred consecutive patients undergoing lumbosacral transforaminal epidural injections at an academic outpatient spine center. METHODS: Four hundred seventy-five fluoroscopically guided lumbosacral transforaminal epidural injections were performed on consecutively consenting patients by one interventional spine physician, using three different needle types. The presence or absence of vascular uptake was determined during contrast injection under live fluoroscopy. RESULTS: Vascular uptake of contrast was observed in 58 of the total 475 injections, for an overall incidence of 12.2%. By needle type, the incidence of inadvertent vascular uptake was 16.6% (26/157) in the pencil-point group, 15.6% (24/154) in the blunt-tip group, and 4.9% (8/164) in the catheter-extension group. The difference in rates is statistically significant between the catheter-extension needle group and both the pencil-point group (P = 0.0009) and blunt-tip group (P = 0.0024). A secondary analysis was performed to quantify the incidence of functional pitfalls between needle groups, with a significantly lower incidence in the pencil-point group compared to both the catheter-extension (P = 0.0148) and blunt-tip needle (P = 0.0288) groups. CONCLUSIONS: Blunt-tip and pencil-point needles have comparable risk of inadvertent vascular injection during lumbosacral transforaminal injections. Catheter-extension needles demonstrated a reduce incidence of vascular uptake, but also result in a significantly higher rate of functional pitfalls that limits their usefulness in routine practice.

Morphologic changes in the lumbar spine after lumbar medial branch radiofrequency neurotomy: a quantitative radiological study.

BACKGROUND CONTEXT: Medial branch radiofrequency neurotomy (RFN) is a common treatment for zygapophyseal joint pain. The lumbar medial branch innervates these joints and adjacent structures. The impact of the intended neurotomy on these structures remains unclear. No studies have yet verified quantitatively the effect of medial branch RFN on intervertebral discs, facet joints, and multifidus cross-sectional area. PURPOSE: The aim of this study was to determine, using objective radiographic measures, whether there is a quantitative difference in the lumbar multifidus muscle cross-sectional area, facet joint degeneration, or intervertebral disc degeneration after segmental medial branch RFN. STUDY DESIGN/SETTING: This is a retrospective single-cohort study performed at a university spine center. PATIENT SAMPLE: The patient sample consisted of 27 patients treated with lumbar medial branch RFN, with pre- and posttreatment magnetic resonance images available for analysis. OUTCOME MEASURE: The primary study outcome measure was interval change in fat-subtracted multifidus cross-sectional area, and intervertebral disc and zygapophyseal joint degeneration grade. METHODS: In this retrospective study, segmental levels unaffected by RFN treatment were used as controls to compare against levels affected by treatment. RESULTS: Levels affected by RFN demonstrated a significantly greater amount of disc degeneration compared with unaffected levels (14.9% vs. 4.6%; p=.0489). There was no statistical difference in the multifidus cross-sectional area or rates of deterioration in the zygapophyseal joints observed. CONCLUSIONS: The full impact of RFN on multifidus function, morphology, and segmental anatomy is unknown. This retrospective study indicates that measurable changes in segmental morphology may occur after lumbar medial branch RFN. These findings require validation in a prospective, controlled study.