Abstract ID: A34

Abstract Title: Pulsed Radiofrequency Lesioning of Dorsal Root Ganglia for Chronic Lumbosacral Radicular Pain

Authors: Vakahria, A¹, Day M², Sharma S³
UTSW medical center Dallas TX USA¹, UTSW medical center Dallas TX USA², UTSW medical center Dallas TX USA³
Poster Type: Either

ABSTRACT BODY

introduction: Pulsed radiofrequency heat treatment (PRF) has recently been introduced as a non-neurodestructive alternative to continuous radiofrequency heat lesions (CRF) (1). A study of pulsed radiofrequency treatment adjacent to the cervical dorsal root ganglion (DRG) for the treatment of chronic cervicaobrachial radicular pain reported a long lasting pain relief without neurologic complications (2). The mode of action of PRF and CRF is not known. However, a recent animal study of RF lesioning of DRG with different temperatures found that the neuronal changes in the dorsal horn was temperature independent (3). Our aim in this retrospective analysis was to determine the efficacy of PRF lesions in the treatment of chronic lumbosacral radicular pain.

Methods: Following IRB approval we analyzed data from 25 patients who received PRF lesioning of DRG for chronic lumbosacral radicular pain. These patients presented with unilateral leg pain in the distribution of the lumbosacral nerve roots for more than 1-year duration and who failed conservative management. We did diagnostic selective nerve root blocks of the suspected nerves on two occasions with local anesthetics. If the diagnostic blocks were positive then PRF lesioning of the pain –provoking nerve was performed for 120s times two with 42°C temperature at the tip of the electrode ( Radionics). Data collected were visual analog scale (VAS) at 1, 3, and 6 months, functional relief such as improvement in standing/walking/routine work ( 0-10 scale; 0 = none, 10 = 100% functional relief), patient satisfaction with the procedure, and post procedure neurological complications. Results were regarded as successful if pain reduction was more than 50% on VAS and the duration of effect was more than 3 months. Data was analyzed using paired Student-t test and P < 0.05 was considered significant.

Results: Of 25 patients, 15 were males and 10 were females; 10 had previous back surgery. Other demographics were as follows: Age (yr) - 45+13; weight (lbs) -186+55; height (inc) - 64+4. Four patients had positive diagnostic test at the L4 level, 16 had at the L5 level, and 5 had at the S1 level. There was a significant improvement in the VAS scores and functional improvement scores at 1,3, and 6 month after the PRF treatment (table). However, 7 (28%) patients did not respond favorably to PRF application ( pain reduction less than 50% and recurrence of severe pain within 3 months). Five patients had procedure repeated with no benefits. There was no report of any neurological complications.

Discussion: The results of our study showed that lumbosacral pulsed radiofrequency lesioning of dorsal root ganglia in patients with chronic lumbosacral radicular pain provides long lasting pain relief in upto 72% patients without causing any neurological deficits. However, a larger randomized trial is warranted to determine the safety and efficacy of PRF treatment compared to conventional high temperature RF lesioning in the treatment of lumbosacral radicular pain.

References:
1. Sluijter et al. pain clinic 1998:11:109-17.
2. Van Zundert et al. Neuromodulation 2003;6:6-14.
3. Jan Van Zundert et al. Anesthesiology 2005;102:125-131.

ATTACHED FILES

A34_Table.doc

Reg Anesth Pain Med 2005; 30(3):A34