Impact of Type of Needle on Incidence of Intravascular Injection During Diagnostic Lumbar Medial Branch Block.

Abstract

Intravascular (IV) injection of local anesthetics is a potential cause of false-negative results after lumbar medial branch nerve blockade (L-MBB) performed to diagnose facetogenic back pain. The aim of the present study was to identify the relationship between the needle type and the incidence of IV injection in patients undergoing L-MBB using fluoroscopy with digital subtraction imaging (DSI). In this prospective randomized study, we compared the incidence of IV uptake of contrast medium using the Quincke needle and Whitacre needle under real-time DSI during L-MBB. Clinical and demographic factors associated with the occurrence of IV uptake were also investigated. In total, 126 patients were randomized into the Quincke needle group (n = 62) and Whitacre needle group (n = 64). Intravascular uptake of contrast medium was observed in 66 (9.8%) of 671 L-MBB procedures under DSI. The incidence of IV uptake was 13.9% (47/338) using the Quincke needle and 5.7% (19/333) using the Whitacre needle. In the multivariate generalized estimating equations analysis, use of a Quincke needle was related to positive IV injection at a 1.898-fold higher rate than was use of a Whitacre needle (95% confidence interval, 1.025-3.516) and a positive aspiration test predicted IV injection at a 21.735-fold higher rate (95% confidence interval, 11.996-52.258). Lumbar medial branch nerve blockade using the Quincke needle was associated with a 1.9-fold higher rate of IV injection than was L-MBB using the Whitacre needle under DSI. Although further study is needed to confirm the clinical efficacy, Whitacre needles can be considered to reduce the risk of IV injection during L-MBB.