Applied Research Of Microvascular Depression And Percutaneous Radiofrequency Thermocoagulation For Trigeminal Neuralgia

Objectives:To evaluate the status of microvacular depression and percutaneous radiofrequency thermocoagulation in treating trigeminal neuralgia and to propose the comprehensive therapeutic strategy of trigeminal neuralgia.Methods:218 patients with primary trigeminal neuralgia were selected, 174 of them were with typical TN symptoms, 44 of them were with atypical TN symptoms. All the patients were proceed MRI with BTFE and e-thrieve sequences, the thickness of the slice was 0.5mm. The neurovascular relationship was defined into 4 types. There were 55 cases with serious compression and displacement, 125 cases with compression, 15 cases with doubtful compression, 23 cases with no compression. 94 patients with typical symptoms and determined compression were treated with MVD. 124 patients, who were with atypical symptoms or with no determined compression or had great concern with MVD, were treated with PRT. During MVD operation, the origin of the offending vessels was record and compared with MRI results. And then, recorded the compression direction of the offending vessels and found out the regular pattern of the compression direction. Finally, the cure rates, the efficiency, the relapse rate of MVD were calculated. In the PRT group, patients were divided into determined compression group and no determined compression group according to the MRI results. Compared the cure rate and the relapse rate of these two groups. At last, the invalid and relapse patients were reoperated with MVD or PRT according to the MRI results or the patients'willing. And calculated the overall efficiency of the two surgical treatment for primary TN. Results:1. The offending vessels of typical patients were mostly SCA and AICA. In atypical patients, the pretrosal vein simply or joint compression had a higher portion in offending vessels than typical patients. This compression was statistically significant.2. In MVD group, when judging the origin of offending vessels, the compliance rate of MRI was 97.9%. SCA was the most important offending vessels, accounting for 63.8%, the second was AICA, accounting for 12.8%, pretrosal vein simply compression was accounting for 9.6%, vertebrobasilar simply compression was accounting for 3.2%, the artery and vein joint compression was accounting for 4.3%, multi-artery compression was accounting for 5.3%.3. The SCA just above the root of trigeminal nerve was the most common way of SCA compression, accounting for 43.9%. The second common way was from the inside top of trigeminal nerve, accounting for 31.8%, combined 75.7%. The AICA compression was usually form the inside top and the inside bottom, accounting for 61.6%. The vertebrobasilar compression was usually from the inside of trigeminal nerve root, accounting for 66.7% in all vertebrobasilar compression. The pretrosal vein compression was usually for the outside or outside top of trigeminal nerve, accounting for 85.7% in all pretrosal vein compression.4. Using double screening according to the patients'symptoms and the MRI results, MVD can produce very good outcome in treating primary TN. 98.9% efficiency, cure rate 94.7%, 2-year follow-up recurrence rate 1.1%.5. With 3-dimension CT and stereotactic assistant, PRT can also produce good outcome. 97.4% efficiency, cure rate 71.8%, 2-year follow-up recurrence rate 12.1%. There was no significant different in cure rate between determined compression group and no determined compression group, there was significantly different in recurrence rate between determined compression group and no determined compression group.6. In the MVD group, there were 1 patient was invalid, 1 patient relapsed, both of them were treated with PRT, 1 patient was cured, 1 patient is still valid; in the PRT group, there were 2 patients were invalid, 16 patients relapsed, according to the results of the patient's MR and will, select the MVD or re-PRT. All of them have been cured.. The efficiency of combining two procedures in treating primary TN had reached 99.5%.Conclusions:The pathogeny of primary TN is complicated, typical TN symptoms and determined neurovascular compression found by MRI is strong indication for MVD surgery. PRT can also produce good outcome in treating patient with atypical TN symptoms or no determined neurovascular compression. Patients who were found determined neurovascular compression have higher recurrence rate than patients who were found no determined neurovascular compression when treated with PRT. MVD and PRT are complementary in treating primary TN, we can use both of these two procedure to increase the overall efficiency.