Image Guided Bilateral Transpedicular Basivertebral Nerve Ablation in Vertebrogenic Pain: Early Experience in Expanded Indications

Theatre or CT suite based image guided bilateral transpedicular basivertebral nerve ablation. These are the same procedures performed in different settings. These are performed once, with a total procedure duration of 60-90mins. The dosage is listed below. Theatre: The procedures were performed by a spinal surgeon trained in the basivertebral nerve ablation technique with the patient prone under conscious sedation. Under fluoroscopic guidance, an 11- or 13-gauge introducer was advanced to a position near the juncture of the dorsal and medial one third of the vertebral body as viewed from lateral with fluoroscopic imaging. After insertion of the introducer and confirmation of depth on lateral, the fluoroscopy beam was then returned to the initial posterior oblique angle to visualise down the introducer. Once positioned, the introducer was removed and pediculotomy visualised. The Nimbus® (radiofrequency needle) was advanced into the pediculotomy to the vertebral body. Once both cannulas were inserted, lateral imaging was used to adjust depth of both cannulas to the juncture of the dorsal and medial one third of the vertebra. Contrast should be injected to exclude medial pedicle breach during placement. The commercially available 17-gauge Nimbus® radiofrequency (RF) needle was positioned to bracket the described nexus of the basivertebral nerve (BVN) as described by Antonacci and Bailey. While optimal interelectrode distance is less than 20 mm, larger distances are feasible for lesioning due to the high electrical and thermal conductance of intravertebral trabecular bone marrow. Thermal concordance was readily established between the two cannulas with the cathode set to 80°C as observed by temperatures at the anode which will exceed 65°C. With technically correct performance, post-procedure MRI demonstrates two discrete foci of intense intravertebral ablation with clear changes to the trabecular bone 'stippling' (T2) between the cannulas. CT suite: The procedures were performed by a musculoskeletal interventional radiologist with over 15 years of image guided radio frequency ablation experience. Patients were placed prone on the CT gantry and limited scout scan and low dose helical scan of the treatment level performed to assess gantry tilt requirements. With the patient fasted, conscious intravenous sedation was administered. Using gantry tilt of 15-30 degrees depending on the level treated, transpedicular access with 11-to-13-gauge Jamshidi needles was achieved under CT fluoroscopy guidance. To optimise lesioning, a commercially available 17-gauge Nimbus 150mm multitined expandable electrode (MEE) RF cannula was positioned aiming for the probe tips to be at the junction of the middle and posterior one third of the vertebral body in the sagittal plane. Bipolar thermal radiofrequency ablation was performed between 85 to 90°C for six to eight minutes. Reproduction of usual vertebrogenic pain during the procedure was confirmed with patient questioning.