The ultrasound-assisted paraspinous approach to lumbar neuraxial blockade: a simplified technique in patients with difficult anatomy

Pre-procedural ultrasound imaging of the spine to identify the interspinous and interlaminar space has been shown to facilitate subsequent performance of lumbar neuraxial blockade. However, adequate visualization of the vertebral canal can be challenging for less-experienced operators, and particularly in subjects with difficult anatomy. In this case report, we describe a simplified technique of ultrasound-assisted neuraxial blockade that addresses these limitations and may thus be a useful fallback option. A pre-procedural scan is performed in which the main ultrasonographic landmarks to be identified are the neuraxial midline and the spinous processes, rather than the posterior and anterior complexes of the vertebral canal. Another key difference is the use of a paraspinous (or paramedian) needle approach rather than a midline approach that is advantageous where the interspinous spaces are narrowed by disease or suboptimal patient positioning. The anatomical basis and technical performance of this novel ultrasound-assisted paraspinous approach are presented in detail.