FEASIBILITY AND SAFETY OF PULSED RADIOFREQUENCY OF THE LUMBAR DORSAL ROOT GANGLION VIA FORAMINAL APPROACH USING A MULTIFUNCTIONAL DEVICE

C. Paoletti, L.F. Nardi, F. Del Sordo | Pain Relief Surgery Unit, Casa di Cura Villa Igea, Ancona

INTRODUCTION
Chronic lumbar radicular pain is one of the most common and disabling forms of neuropathic pain, often caused by compression or irritation of the spinal nerve roots. Causes include disc herniation, foraminal stenosis, or postsurgical adhesions, with symptoms such as radiating leg pain, paresthesia, and sensory or motor deficits. Pulsed Radiofrequency (PRF) is a minimally invasive technique that modulates neuronal activity without damaging tissues. The dorsal root ganglion (DRG), a primary sensory node in pain transmission, is an ideal target in patients unresponsive to drugs, physiotherapy, or injections. Located near the intervertebral foramen, the DRG can be accessed more precisely via the foraminal route, which is preferable to interlaminar or sacral approaches in cases with anatomical alterations or epidural adhesions. We report a preliminary experience on 15 consecutive patients: 14 with radicular pain between L3 and L4, and 1 with L5 radiculopathy not accessible via the sacral route due to adhesions.
OBJECTIVE
To assess feasibility, success rate, and safety of the procedure.
METHODS
With the patient in the prone position under sedation, a 14G needle is inserted near the lumbar foramen under anteroposterior and lateral fluoroscopic guidance. Once the correct position is reached (confirmed by the injection of 2 ml of Iopamiro 300), the AlfaMed Voyager Linear® probe is introduced and slowly advanced under continuous monitoring and real-time patient feedback. Probe positioning is verified through sensory stimulation testing at 50 Hz and 2 Hz. Pulsed Radiofrequency (PRF) is then performed using standard parameters (42°C, 100 V, 2 Hz, 5 ms), for a total duration of 8 minutes delivered in two 4-minute cycles. At the end of the procedure, following the administration of 4 mg dexamethasone and 2 ml of 2% lidocaine, the probe is removed and the patient is monitored for at least 24 hours.
RESULTS
PRF is successfully completed in 13 out of 15 patients. In 2 cases, the procedure is aborted due to the inability to advance the probe because of severe foraminal stenosis and osteoarthritis. No serious adverse events are reported. Intraoperative events include transient bradycardia (1 case), a hypertensive spike (1 case), and the need for additional analgesia in 3 patients. No complications are observed immediately post-procedure or at 1- and 3-month follow-ups.
CONCLUSIONS
The use of an electrode catheter specifically designed for targeted foraminal placement allows for precise and minimally invasive PRF treatment of the lumbar dorsal root ganglion (DRG). This technique is particularly suitable for radiculopathies located above the L5 level. In our experience, it was successfully completed in 13 out of 15 patients without significant adverse events. Compared to sacral or interlaminar approaches, this method may be technically more complex and permits the treatment of only one DRG at a time.