STUDY DESIGN: This study examined the effect of radio-frequency thermocoagulation on cadaveric disc material. Radio-frequency lesions are induced to decompress the nerve root by coagulating the nucleus pulposus. OBJECTIVES: The purpose of this study was to assess the potential of the radio-frequency lesion technique for treating lumbar disc herniation percutaneously. The effect of radio-frequency thermocoagulation on cadaveric disc material was studied. SUMMARY OF BACKGROUND DATA: An intradiscal bipolar electrode is used for the thermocoagulation of the nucleus pulposus. METHODS: Lumbar discs of 27 adult cadavers were used for the experiments within 72 hours of donors' deaths. The physical and thermal parameters of intradiscal radio-frequency thermocoagulation were determined experimentally. Acute macroscopic and histologic changes before and after thermocoagulation were investigated. The temperature distribution of the tissue surrounding the disc was measured during the operation using thermocouples to evaluate potential heat damage. Also, computed tomography and magnetic resonance imaging of the disc were performed before and after thermocoagulation. RESULTS: Macroscopic observation showed that the lesion induced by radio-frequency thermocoagulation is homogeneous and intense without necrosis, and is limited to the nucleus pulposus. Histologically, the endplates and vertebral bodies were unaffected and an architectural disorganization of the stroma of the nucleus pulposus was seen. The temperature increase of the tissue surrounding the discs did not exceed 3-4 C. CONCLUSION: A bipolar electrode and a radio-frequency alternating current permits percutaneous intradiscal thermocoagulation for destruction of a portion of disc material in a cadaveric spine.
STUDY DESIGN: This study examined the effect of radio-frequency thermocoagulation on cadaveric disc material. Radio-frequency lesions are induced to decompress the nerve root by coagulating the nucleus pulposus. OBJECTIVES: The purpose of this study was to assess the potential of the radio-frequency lesion technique for treating lumbar disc herniation percutaneously. The effect of radio-frequency thermocoagulation on cadaveric disc material was studied. SUMMARY OF BACKGROUND DATA: An intradiscal bipolar electrode is used for the thermocoagulation of the nucleus pulposus. METHODS: Lumbar discs of 27 adult cadavers were used for the experiments within 72 hours of donors' deaths. The physical and thermal parameters of intradiscal radio-frequency thermocoagulation were determined experimentally. Acute macroscopic and histologic changes before and after thermocoagulation were investigated. The temperature distribution of the tissue surrounding the disc was measured during the operation using thermocouples to evaluate potential heat damage. Also, computed tomography and magnetic resonance imaging of the disc were performed before and after thermocoagulation. RESULTS: Macroscopic observation showed that the lesion induced by radio-frequency thermocoagulation is homogeneous and intense without necrosis, and is limited to the nucleus pulposus. Histologically, the endplates and vertebral bodies were unaffected and an architectural disorganization of the stroma of the nucleus pulposus was seen. The temperature increase of the tissue surrounding the discs did not exceed 3-4 C. CONCLUSION: A bipolar electrode and a radio-frequency alternating current permits percutaneous intradiscal thermocoagulation for destruction of a portion of disc material in a cadaveric spine.