Needle type does not influence inadvertant vascular injections

SAN FRANCISCO — Altering the type of needle used during lumbar transforaminal epidural injections does not change the possibility of having an inadvertant vascular injection, according to an investigator here.

“There have been several cases of paresthesia reported, including cases that occurred with lumbar epidural injections in patients who had undiagnosed dural arteriovenous fistulas, as well as cases which occurred in patients with normal vascular anatomy,” Matthew Smuck, MD, said at the 24th Annual Meeting of the North American Spine Society. “The proposed mechanism is similar to that proposed in the cervical spine: Injection of particulate corticosteroid into a vulnerable radiculomedullary artery that causes a downstream infarction into the spinal cord.”

Smuck and Sara Cohen, MD, studied 315 injections: 157 using pencil-point (Whitacre) needles, 64 using short-beveled (Chiba) needles, and 94 using long-beveled (Quincke) needles.

“We found that 48 of the 315 injections demonstrated vascular uptake under fluoroscopy for an overall incidence of 15.2%,” Smuck said. “We were surprised to find that the pencil-point needles had the highest incidence, followed by the short-beveled needles and the long-beveled needles having the lowest incidence of vascular injections. That went against our hypothesis that the pencil-point needles would have the lowest incidence and the long-bevel would have the highest.”

However the difference between these three needle types was not statistically significant, he added.

“Changing to short-beveled needles or pencil-point needles does not improve the rates of vascular injections,” Smuck said.

Reference:
Smuck M, Cohen S. Influence of needle type on the incidence of inadvertant vascular injections: A comparison of pencil-point needles to sharp-bevel needles. Paper #75. Presented at the 24th Annual Meeting of the North American Spine Society. Nov. 10-14, 2009. San Francisco.