Objective  To evaluate the safety and effectiveness of a new domestic ultra-high frequency bipolar radiofrequency ablation device in minimally invasive surgery for spinal degenerative diseases.

Methods Using six fresh cadaveric lumbar spine specimens as experimental subjects, a novel domestic ultra-high frequency bipolar radiofrequency ablation device was employed for nucleus pulposus ablation and annulus fibrosus cauterization. Nucleus pulposus ablation: a total of 18 intervertebral discs from L1 to L4 were randomly divided into six groups. Radiofrequency electrodes were inserted into the intervertebral discs through the lateral aspect of the intervertebral foramen, and ablation was performed at powers of 50 W, 75 W, and 100 W for 1 min and 2 min, respectively. The ablation of the nucleus pulposus was observed, and the ablation range was recorded. Annulus fibrosus cauterization: a total of 12 intervertebral discs from L4 to S1 were divided into three groups based on cauterization time of 3 s, 10 s, or 15 s. In a constant temperature environment of a 37°C water bath, cauterization was performed at powers of 20 W, 30 W, and 40 W, respectively. After hard tissue sectioning and hematoxylin and eosin (HE) staining, the depth of cauterization and the carbonization of surrounding soft tissue were observed.

Results No obvious vaporization cavity was observed in the nucleus pulposus at 50 W for either 1 or 2 min. The 100 W-2 min group achieved the largest ablation area (7.471±0.365 mm²; P＜0.001). The temperature elevation at all four annulus fibrosus sites remained below 0.5℃ throughout the ablation process. The cauterization depth in the 20 W group was significantly lower than that in both the 30 W and 40 W groups across all time conditions (P＜0.01), whereas no statistically significant difference was observed between the latter two. No significant intra-group differences were found among varying cauterization durations within either the 30 W or 40 W group. An effective cauterization depth was already achieved at 30 W for as short as 3 s.

Conclusion The new domestic bipolar radiofrequency ablation device can meet good clinical requirements for both nucleus pulposus ablation and annulus fibrosus cauterization in spinal degenerative diseases. For nucleus pulposus ablation, it is recommended to use 100 W for 2 min, while for annulus fibrosus cauterization and shaping, it is recommended to use 30 W for 3 s.