Microvascular Decompression For Primary Trigeminal Neuralgia And The Study Of Curative Factors And Surgical Strategies

Part I Microvascular decompression for primary trigeminal neuralgia and analysis of curative factorsBackground:Primary trigeminal neuralgia (TN) is a common disease of neurosurgery department. It performs paroxysmal facial pain induced by slight movements such as speaking, chewing, washing the face, et al. The morbidity is also very high. Since the high curative rate, microvascular decompression (MVD) has become the perfectest treatment of TN. However, the postoperative effect is not always ideal or without any changes even though a complete decompression is done in the progress of surgery. The unremission rate of syndromes can reach 6%-7.6% reported by many domestic and foreign medical centers.Objective:The aim of this thesis is to explore the curative factors of TN treated by MVD, and to investigate the technique and experience associated with theses factors of microsurgery for primary TN.Methods:The clinical materials of 153 primary TN patients from the neurosurgery department of Qilu Hospital Shandong University operated by the same doctor from June 2011 to June 2015 were analyzed retrospectively. All TN patients were treated by MVD. The risk factors about clinical curative effect were evaluated by single factor analysis of chi-square test and logistic regression analysis.Results:In this series,78 patients were male and 75 were female. The age of patients varied from 24 to 77 years old,57 years old on average. The course of disease were between two month to thirty years. Clinical manifestations of pain occurred on the right side were 88 cases, another 65 cases were in the left side, without bilateral cases.7 cases (4.6%) occurred in the dominated range of VI branch,20 cases (13.1%) were in the range of V2 branch,27 cases (17.6%) were in the range of V3 branch,20 cases (13.1%) were in the range of V1V2 branches, 2 cases (1.3%) were in the range of V1V3 branches,13 cases (7.8%) were in the range of V1V2V3 branches,64 cases (42.5%) were in the range of V2V3 branches. Pain vanished in 125 cases, obviously relieved in 26 cases, not changed in 2 cases.104 cases were compressed by artery alone,40 cases had a venous-artery conflict, 8 cases had only venous conflict,1 case had no obvious conflict. The pain-free rate of venous alone conflict (62.5%) and venous-arterial conflicts (67.5%), were both obviously lower than the artery alone (89.5%), with significant differences in statistics (P=0.003<0.05). The pain-free rate of V2 was obviously lower than others (P=0.024<0.05), with significant difference in statistics; The 50% patients of V2 had their conflicts at the ventral site of the nerve, with significant difference in statistics (P=0.041<0.05). The results of logistic regression analysis showed the vein and V2 were independent risk factors about curative effect (P<0.05).Conclusions:(1) The compression of vein was one of the cause of primary trigeminal neuralgia. Compared with purely arterial conflict, the pain free rate of venous conflict TN patients was lower. Therefore, the careful preoperative imaging diagnosis and systematic surgical exploration of responsible vascular in the operation were important to improve the rate of success. (2) The pain of V2 branch treated by MVD could not eliminate completely. Furthermore, the ventral site was the crucial conflict site of the V2 patients. According to these conclusions, we could make effective surgical strategies and judge the prognosis of patients more accurately than before.Part II Comparison of effectiveness between MVD and MVD+PSR of primary trigeminal neuralgia offended by veinBackground:By the analyze of curative factors of primary trigeminal neuralgia (TN) patients treated by microvascular decompression (MVD), we summarized the conclusion that primary TN caused by venous pathogenicity was hard to cure completely. To improve the curative rate, we did MVD+partial sensory rhizotomy (PSR) instead of MVD and discussed the differences between two surgical strategies.Objective:To evaluate the effectiveness of MVD and MVD+PSR on the treatment of primary TN caused by venous factor (offended by vein alone and vein-artery).Methods:73 TN patients caused by venous factor were retrospectively analyzed in this series, there were 48 cases underwent MVD and 25 cases were operated by MVD+PSR.Results:In MVD group, pain completely vanished in 32 cases, obviously relieved in 15 cases,1 case without any changes, the pain free rate is 66.7%. In MVD+PSR group, pain completely vanished in 22 cases, obviously relieved in 3 cases,0 case not changed. The pain free rate of MVD+PSR is 88%, which is higher than MVD, with significant difference in statistics (P=0.042<0.05).*Conclusions:1 For primary trigeminal neuralgia patients who offended by venous factor, MVD+PSR was obviously superior to MVD in pain free rate.2 For primary trigeminal neuralgia patients who are old enough, offended vessel include vein, can tolerate the feeling of numbness or paresthesia after surgery, MVD+PSR is priority.