远外侧入路的显微解剖研究

摘要

Objective To know in detail about the related microanatomy of the far lateral approach.Methods Stepwise dissection of 10 cadaver heads was performed by bilateral simulating the far lateral approach.Its adjacent relationship and the effect of the important structures on the operative field exposure were investigated.Results The suboccipital muscle groups are mainly composed of three layers.The occipital artery (OA) runs deeply into the splenius capitis and is located in the shallow or deep layer of the trachelomastoid.Splenius capitis can be used as an anatomic landmark for searching OA.When OA is out from the digastric groove,the diameter is 2.0 ± 0.2 mm,at the level of the superior nuchal line,the diameter is 1.2 ± 0.3 mm.The vertebral artery (VA) is located in the base of the suboccipital triangle,which is wrapped by the venous plexus.VA often gave off muscular and meningeal branches,before entering the skull,they were 9.5 ± 6.1 mnm and 16.0 ± 8.0 mm respectively,and gave off the posterior spinal artery and posteior inferior cerebellar artery.Before bilateral VA convergence 5.7 ± 4.8 mm,they gave off anterior spinal artery.After removing the inner 1/3 of occipital condyle,the operative angle could increase from 43 ± 11.2 degree to 61.0 ±9.1 degree.There was significant difference (P ＜0.01).Removing the jugular tubercle,the operative angle could also increase to 68.0 ± 10.2 degree;however,compared with removing occipital condyle,there was no significant difference.Conclusions It has important significance for the relationship between familiar with the anatomical layers of suboccipital muscle groups and OA or VA anatomy for the protection of these arteries.Understanding the important anatomic structure and its adjacent relation,such as the occipital condyle,jugular tubercle,hypoglossal canal,lower cranial nerves,VA and its branches contribute to the safe exposure and resection of lesions in the anterolateral lateral medulla oblongata.Removing inner 1/3 of occipital condyle can increase the exposure of the operation area,and removing jugular tubercle can also additionally increase the exposure of operation area.%目的 详细了解远外侧入路的手术相关显微解剖.方法 通过对10具尸头双侧模拟远外侧手术入路进行逐层解剖,了解其毗邻关系及重要结构对术野显露的影响.结果 枕下肌群主要为三层肌群,枕动脉走行于头夹肌的深层,位于头最长肌的浅层或深层,头夹肌可作为寻找枕动脉的解剖标志.枕动脉在出二腹肌沟时直径为(2.0±0.2)mm,在上项线水平直径为(1.2±0.3)mm.椎动脉位于枕下三角底,由静脉丛包裹,在入颅前常发出肌支和脑膜支,其在入颅分别为(9.5±6.1)mm和(16.0 ±8.0)mm后,发出脊髓后动脉(PSA)和小脑后下动脉(PICA);在双侧椎动脉汇合前(5.7 ±4.8)mm发出脊髓前动脉(ASA).磨除后内1/3枕骨髁,可将手术视角从传统枕下入路的(43.0±11.2)°增加到(61.0±9.1)°,差异有统计学意义(P＜0.01),而磨除颈静脉结节又可使手术视角增加到(68.0±10.2)°,但与磨除枕骨髁比较,差异无统计学意义.结论 熟悉枕下肌群解剖层次及与枕动脉和椎动脉的解剖关系对于保护这些动脉具有重要意义;了解枕骨髁、颈静脉结节、舌下神经管、后组脑神经和椎动脉及其分支等重要解剖结构及其毗邻关系,有助于安全显露并切除延髓前外侧病变.磨除枕骨髁后内1/3可增加对术区的显露,磨除颈静脉结节又可额外增加术区的显露.