中文摘要：

目的：为实验性高选择性腰骶神经前根小束切断术治疗圆锥上损伤的痉挛性膀胱提供可靠的神经根分束的形态学依据。方法：对6只雄性SD大鼠L1-S4节段的脊神经前根自然分束进行形态学观察和显微测量。结果：粗细不一的神经小束从脊髓发出，几个神经小束形成一个神经亚束。2～6个神经亚束构成一个神经束，或由神经小束直接形成神经束。腰骶部脊神经前根一般含有1股神经束，3～13支神经小束。L5～S2节段前根的小束数目在5支以上。每一前根内有—支神经小束较粗大，直径0．1～0．2mm左右，其余较细小，最小可至0．01mm左右，粗细程度存在较大差异。结论：实验性高选择性腰骶部前根神经小束切断术的分束可达到神经小束水平，以7～8支为宜。

英文摘要：

Objective： To provide the reliable morphologic basis of the lumbosacral ventral roots for highly selective rhizotomy in animal models with spastic bladder. Methods： 6 male SD rats were perfused and microdissected, and then the rootlets of the lumbosacral ventral root were observed and measured. Results： The lumbosacral ventral root consisted of a nerve bundle and 3-13 rootlets which was given off by the spinal cord. Several rootlets converged into a subbundle, and 2-6 subbundles converged into one. The anterior roots of L5-S2 segments comprised at least 5 rootlets. The rootlet ofeach anterior root had a greater diameter （0.1 ,-0.2 mm） compared to that of other segments, and the minimal diameter was about 0.01mm. Conclusions： In highly selective rhizotomy in animal models with spastic bladder, the anterior root shoud be divided into 7-8 rootlets.