Percutaneous Radiofrequency Ablation Of Vertebral Tumor Experimental And Clinical Study

Objective First, To carry out ex vivo and in vivo porcine vertebral radio frequency ablation, observe the scope of its bone coagulation and thermal field distribution. Explore the security of the spinal cord and availability of soft tissue injury around the vertebral when radiofrequency ablation. Second, after radiofrequency ablation, through the biopsy specimens of pathological section analysis, to observe the damage degree and repair process. Third, to compare ex vivo with in vivo thermal field distribution when radio frequency, analyze the effection of the flow of blood in vertebral bone and the flow of cerebrospinal fluid in vertebral canal on the process of ablation to local temperature. Fourth, to patient who suffer with vertebral metastases or vertebral hemangioma treated with radiofrequency ablation combined with vertebroplasty. Evaluation of clinical symptoms relief of pain degree and quality of life improvements and nerve function. Methods First, ex vivo experiment: 30 fresh adult porcine vertebrae were randomly divided into two groups. The depth of the needle electrodes were 10mm,20mm.After reach steady-state ablation According to the pre-designed temperature-point measure temperature. After ablation 20 minutes, along the electrode needle axial plane cut to observe the scope of coagulation area. Second, in vivo experiment:radiofrequency ablation ten vertebrae in 5 weeks.the one fetch two vertebral biopsy specimens make pathological section after ablation immediately. another ablation of ten vertebrae ablation of two vertebrae every week.,fetch all experimental vertebral biopsy specimens make pathological section on the sixth week. Every vertebrae according to the pre-designed temperature-point measure 0 times, ablation 5 minutes,10 minutes,15 minutes,20 minutes temperature. Third, clinical Cases:On three cases of vertebral metastases and one case of vertebral hemangiomas treated with radiofrequency ablation and vertebroplasty, preoperative and postoperative 24 hours,48 hours,one week,two weeks,four weeks to observe the follow-up, conduct the evaluation of VAS pain score and the classification of WHO pain treat efficacy. Results First, ex vivo experiment: the temperature in 3.5 minutes reached steady-state. Electrode on more recent the temperature rise more sooner. two groups were no around vertebral soft tissue injury. When the electrode needle depth 10mm without spinal cord injury,20mm deep needle electrode may have spinal cord injury. The temperature in two groups were different significantly (p＜0.05). Second, in vivo experiment:each temperature measuring point on "0" times was not significant difference (p> 0.05). After ablation 5 minutes,the ablation electrode tip temperature reach above 90℃,each temperature measurement point temperature difference was statistically significant (p＜0.05). Electrode tip and the vertebral bone position within 1cm deep in the melting temperature measured after 5 minutes was significantly higher than the value of the posterior vertebral body and vertebral bone cortex surface,but the temperature measurement points are increased and higher than 0 time each point of the measurement temperature.1cm deep within the vertebral bone position after 5 minutes the temperature in the melting point of the group of four record the difference was statistically significant (p＜0.05), The temperature was gradually rise process in the overall. After ablation 5 minutes, the temperature on posterior vertebral wall of the four records showed no significant difference compared in group(p> 0.05).Vertebral bone cortex surface temperature of four records also records showed no significant difference compared in group(p> 0.05). the second week after RFA vertebral fiber repair, the fifth week of repair of bone and trabecular bone throughout the callus. Third, clinical Cases:Preoperative and postoperative the evalution of VAS score for each time paired t test, the differences were statistically significant (P＜0.01). Postoperation, the patient pain symptom was significantly relieved compared with preoperation. VAS score decreased significantly especially after postoperative one week. Preoperative and postoperative the classification of WHO pain treat efficacy for each time paired t test, the differences were statistically significant (P＜0.01). Conclusion First, radiofrequency ablation the vertebrae, the cerebrospinal fluid flow in the spinal canal and the flow of blood in the vertebrae will take away some of the heat; bone cortex has some insulate function. Second, maintain the integrity of the vertebral cortical line of radiofrequency ablation will not lead to nerve, spinal cord and soft tissue injury. Third, In vivo experiments, the second week after RFA vertebral fiber repair, the fifth week of repair of bone and trabecular bone throughout the callus. Fourth, as the vertebral body after radiofrequency ablation, would lead to vertebral body necrosis, residual cavity, which will help polymtthy methacrylate full distribution. Fifth, radiofrequency ablation and vertebroplasty for the destruction of the posterior vertebral body with vertebral metastasis or vascular tumor need evaluate exactly on preoperation,be careful on operation, prevent polymtthy methacrylate leakage to compress spinal cord or nerve root. Sixth, radiofrequency ablation combined with vertebroplasty can relieve patient due to vertebral metastases or vertebral hemangiomas caused intractable pain, improve quality of life. Seventh, radiofrequency ablation combined with vertebroplasty treat the vertebral metastasis or hemangioma patient can be effective in preventing vertebral compression fractures or/and paraplegia.