术中锥体束导航对手术策略的影响

Preliminary experience of 74 cases of pyramidal tract navigation and its impact on surgery strategy

目的总结74例锥体束导航辅助手术的初步经验。方法术前及术中重建椎体束，总结该技术对手术策略的影响，术前及术中锥体束变化情况、手术效果、影响锥体束保护的因素。结果36例锥体束到肿瘤的距离〈5mm，其中27例（75％）术前有肢体功能障碍；距离5～10mm之间12例，2例（16％）有功能障碍；两组差异有统计学意义（x2检验，P〈0．05）；〉10mm有26例，均无肌力异常。术后症状改善7例（9％），无变化48例（65％），轻度加重14例（19％），偏瘫5例（7％）。锥体束术中移位在（-16．2mm，＋17．2mm）间。结论锥体束导航可帮助术者制定手术人路，评估手术风险及决定切除程度，减低严重运动功能障碍的发生率。术中锥体束移位无规律，术中磁共振扫描十分必要。

Objective To summarize the experience of 74 patients with brain tumors whose pyramidal tracts were visualized by diffusion tensor imaging （DTI） based fiber tracking （FT） during perioperative period. Methods All the patients received MRI scans preoperatively and intraoperatively. Pyramidal tracts were constructed and integrated into neuronavigation system to implement fiber tracts navigation. The outcome, modification for strategy of surgery and factors influencing the protection for pyramidal tract were summarized. Results Before operation, the distance between pyramidal tract and tumor was ranged from 0 mm to 5 mm in 36 cases. 27 among the 36 cases had motor deficits. The distance in 12 cases was ranged from 5 mm to 10 mm and two had motor deficits among them. The distance was greater than 10 mm in 26 cases and none of them had motor deficits. After operation, motor deficits were improved in 7 cases, no change in 48, 14 developed new postoperative deficits and paresis was observed in 5 cases. The paresis was resolved partially in the prolonged postoperative course in 3 cases. The maximal pyramidal tract shifting was ranged from - 16. 2 mm to ＋ 17.2 mm. Conclutions Pyramidal tract navigation can help surgeon to choose right surgical approach, to lower the risk of surgery and determine the extent of resection. Thus, the rate of severe motor deficits could be decreased. The shifting of pyramidal tract during operation is irregular. Intraoperative MRI scan is necessary for detection of the shifting.