枕下远外侧经髁手术入路的显微解剖学研究

发布时间：2018-09-11 21:36

【摘要】： 目的:针对远外侧经髁手术入路中讨论最为集中的两个问题——椎动脉及其周围静脉丛的保护和枕髁安全有效的磨除,进行显微解剖学研究,以期为临床工作提供更多的应用解剖学知识,减少手术副损伤。方法:先对10例(20侧)成人带颈尸头湿性标本以彩色乳胶灌注动静脉血管,然后模拟远外侧经髁手术入路进行显微解剖,着重测量椎动脉水平段(V3h)内缘(穿寰枕筋膜处)与中线的距离、枕下海绵窦(The suboccipital cavernous sinus, SCS) V3h旁静脉丛内缘与中线的距离,观察椎动脉的走行及变异情况、枕下海绵窦的形态、椎动脉与枕髁等的位置关系这些与椎动脉及其周围静脉丛保护有关的项目,还有枕髁的形态(寰枕关节稳定性)、舌下神经管的走行和内容等与枕髁的安全磨除和周围结构的保护有关的项目。而枕髁的有效磨除即是枕髁的磨除范围问题,远外侧入路中枕髁对岩斜区手术视野有一定的阻挡作用,为了解枕髁对斜坡方向手术暴露范围的影响,我们以枕髁后缘向斜坡中线所引垂线与矢状面夹角为指标,将未磨除枕髁时与磨除枕髁至舌下神经管内口时两组角度进行比较,做两小样本的配对t检验,以p≤0.05为具有显著性差异,计算是否存在差异。结果:1椎动脉及其周围静脉丛的保护 1.1椎动脉的观测:椎动脉在出枢椎横突孔至进入硬脑膜这段(V3段)变异较大。主要有V3垂直段(V3v)形成的动脉环弯曲程度及方向不尽相同、V3h有时走行在骨纤维化寰枕后膜和寰椎后弓椎动脉沟形成的骨管中。椎动脉入寰枕筋膜处内缘距中线距离左侧为(14.46±2.69)mm,右侧为(16.23±2.06)mm。椎动脉与枕髁的相对位置变化较大,不移位椎动脉并不一定无法暴露枕髁,我们就遇到1例枕髁位于椎动脉前上方,不必移位椎动脉便可对枕髁进行操作的标本。 1.2枕下海绵窦的观测:枕下海绵窦形态不规则,V3h周围静脉丛中部和外侧较内侧发达,中部静脉血管向后与深层肌肉间静脉丛相交通;V3v周围静脉亦较发达并与肌肉间静脉丛相交通,但接近枢椎平面处静脉丛渐稀疏,发出分支也较少。枕下海绵窦内缘距中线距离左侧为(12.19±2.29)mm,右侧为(12.60±3.09)mm。V3h旁静脉丛存在较大的个体差异,V3h走行于骨性纤维管中者,该静脉丛多不发达,而无骨性纤维管者,相对较发达。 2枕髁的磨除 2.1枕髁的形态和寰枕关节稳定性:枕髁位于枕骨大孔前外侧1/3处,其与寰椎上关节凹形成的关节面是由倾斜的冠状面过渡为倾斜的水平面的一不规则曲面(从后外侧方向看),这种结构保证了颅颈关节的前后稳定性;枕髁关节面面积较大,有利于支撑头颅时稳定重心。 2.2舌下神经管及髁窝的观测:舌下神经管与枕髁的相对位置较固定,舌下神经从后内向前外方向穿过枕髁,远外侧经髁手术入路磨除枕髁过程中首先遇到舌下神经管内口,一般情况下磨至此处不会损伤到舌下神经。但舌下神经常常被舌下静脉丛包绕,要注意避免损伤。此外,在髁窝中有导静脉通过,一般位于舌下神经管的外上方,管径较粗大,损伤后可能引起大量出血。 2.3枕髁磨除带来的术野变化:未磨除枕髁时,枕髁后缘向斜坡中线所引垂线与矢状面夹角为71.3±5.8度;磨除枕髁至舌下神经管内口处,残余枕髁后缘向斜坡中线所引垂线与矢状面夹角为83.9±3.9度,经t检验t=18.96, p0.05,两组角度存在区别。结论: 1枕下远外侧经髁入路手术中处理V3段椎动脉需注意:①要通过周围的解剖结构仔细辨认椎动脉,对其可能出现的变异位置要加以小心,避免误损伤。②中线旁14mm内操作相对安全,一般不会损伤到椎动脉。③根据病例的具体情况决定是否分离及移位椎动脉。 2处理枕下海绵窦时需注意:①分离椎动脉尽量从中线侧(V3h段)和下方(V3v段)开始,避免一开始就处理比较棘手的静脉丛发达区域。②中线旁12mm左右可能会遇到椎动脉旁静脉丛,要加以小心。 3随着枕髁去除部分的增加寰枕关节的稳定性将越来越差,应在显露适当术野范围的基础上尽可能少量地磨除枕髁。 4在磨除枕髁过程中的注意事项:①当松质骨渐变为皮质骨时,舌下神经管即将到达。磨至舌下神经管内口处一般不会伤及舌下神经。舌下神经管由后内下走向前外上方,舌下神经周围有较发达静脉丛。了解舌下神经管走向及内容可以减少误损伤。②髁窝位于枕髁后外侧,其内有较粗大的导静脉,在磨除枕髁过程中较易受到损伤,应引起注意。③枕髁后方有椎动脉及其周围静脉丛,椎动脉入硬脑膜处紧邻枕髁内侧,在磨除枕髁过程中都极易受到损伤,手术过程中要轻柔操作,注意保护这些结构。 5磨除部分枕髁(至舌下神经管内口)能增加斜坡方向一定的手术视野,枕髁对斜坡方向术野具有阻碍作用。在临床工作中可视病变的位置大小以及切除的难易程度来决定是否磨除枕髁。
[Abstract]:Objective: To study the microsurgical anatomy of vertebral artery and its surrounding venous plexus and occipital condyle in order to provide more applied anatomy knowledge for clinical work and reduce surgical side injury.
Methods: Arteriovenous vessels were perfused with color latex in 10 adult cadavers (20 sides) with cervical head. The distances between the medial margin of vertebral artery horizontal segment (V3h) and the middle line, and the veins adjacent to the suboccipital cavernous sinus (SCS) V3h were measured. The distance between the inner edge and the middle line of the plexus, the course and variation of the vertebral artery, the morphology of the suboccipital cavernous sinus, the relationship between the vertebral artery and the occipital condyle, the items related to the protection of the vertebral artery and its surrounding venous plexus, the morphology of the occipital condyle (the stability of the atlanto-occipital joint), the course and content of the hypoglossal canal, and the safe abrasion of the occipital condyle The effective abrasion of occipital condyle is the abrasion area of occipital condyle. The occipital condyle obstructs the visual field of petroclival surgery through far lateral approach. In order to understand the influence of occipital condyle on the exposure area of clival surgery, the angle between the vertical line of occipital condyle and the sagittal plane is taken as the index. The two groups were compared when the occipital condyle was not worn off and when the occipital condyle was worn off to the hypoglossal nerve canal entrance. The paired t test of two small samples was performed. The significant difference was p < 0.05, and the difference was calculated.
Results: 1 protection of vertebral artery and its peripheral venous plexus.
1.1 Observation of vertebral artery: The vertebral artery varies greatly from the transverse foramen of the axis to the dura mater (V3 segment). There are mainly different degrees and directions of curvature of the arterial ring formed by the vertical segment of V3 (V3v). V3h sometimes travels in the bone canal formed by the posterior atlanto-occipital membrane and the vertebral artery groove of the posterior atlanto-occipital arch. The distance between the middle line and the occipital condyle was (14.46+2.69) mm on the left and (16.23+2.06) mm on the right.
1.2 Observation of the suboccipital cavernous sinus: the shape of the suboccipital cavernous sinus was irregular, the central and lateral venous plexus around V3h were more developed, and the central venous vessels communicated with the deep intermuscular venous plexus backward; the veins around V3v were also more developed and communicated with the intermuscular venous plexus, but the venous plexus near the axis plane became thinner and the branches were less. The distance from the internal margin of the inferior cavernous sinus to the median line was (12.19 [2.29] mm on the left and (12.60 [3.09] mm on the right. There were significant individual differences in the paravenous plexus. The venous plexus was more undeveloped in those who walked in the osseous fibrous duct at V3h, but more developed in those without osseous fibrous duct.
2 grinding of occipital condyle
2.1 Morphology of occipital condyle and stability of atlanto-occipital joint: occipital condyle is located at the anterolateral 1/3 of foramen magnum. The articular surface formed by occipital condyle and atlanto-supracondylar articular fovea is an irregular curved surface which transits from oblique coronal plane to oblique horizontal plane (from posterolateral direction). This structure guarantees the anterior and posterior stability of craniocervical joint. It helps to stabilize the center of gravity when supporting the head.
2.2 Observation of hypoglossal nerve canal and condylar fossa: The relative position of hypoglossal nerve canal and occipital condyle is relatively fixed. Hypoglossal nerve passes through occipital condyle from posterior medial to anterior and outward direction. In the process of removing occipital condyle by far lateral transcondylar surgical approach, hypoglossal nerve canal orifice is first encountered. Generally, the hypoglossal nerve will not be damaged here. The inferior venous plexus is surrounded by the inferior venous plexus and should be careful to avoid injury. In addition, there is a conducting vein passing through the condylar fossa, which is generally located outside and above the hypoglossal nerve canal. The diameter of the canal is larger and may cause massive bleeding after injury.
2.3 Operative field changes caused by occipital condyle abrasion: when occipital condyle was not abrased, the angle between the sagittal plane and the vertical line of the posterior margin of occipital condyle was 71.3 + 5.8 degrees; when the occipital condyle was abrased to the orifice of hypoglossal nerve canal, the angle between the vertical line of the posterior margin of occipital condyle and the sagittal plane was 83.9 + 3.9 degrees.
Conclusion: 1. Attention should be paid to the treatment of V3 vertebral artery by far lateral suboccipital transcondylar approach: (1) Vertebral artery should be identified carefully through the surrounding anatomical structure, and the possible variation of the vertebral artery should be carefully avoided. 2) The operation within 14 mm of the midline is relatively safe and generally does not damage the vertebral artery. Determine whether the vertebral artery is dislocated or displaced.
2. Attention should be paid to the treatment of suboccipital cavernous sinus: 1. The vertebral artery should be separated from the middle line (V3h segment) and the lower (V3v segment) as far as possible, so as to avoid dealing with the more difficult areas of venous plexus at the beginning.
The stability of atlanto-occipital joint will be worse and worse with the increase of occipital condyle removal. The occipital condyle should be ground as little as possible on the basis of exposure of appropriate surgical field.
4. Notes in the course of occipital condyle abrasion: 1. When cancellous bone gradually becomes cortical bone, the hypoglossal nerve canal is about to arrive. Generally, the hypoglossal nerve will not be injured at the entrance of the hypoglossal nerve canal. (2) The condylar fossa is located at the posterolateral side of the occipital condyle, and there is a large internal guide vein. It is easy to be injured during the process of grinding the occipital condyle. Attention should be paid to it. (3) There are vertebral artery and its surrounding venous plexus behind the occipital condyle. The vertebral artery is close to the medial part of the occipital condyle where it enters the dura. Pay attention to protecting these structures.
Grinding part of the occipital condyle (to the hypoglossal nerve canal) can increase the surgical field in the clivus direction. The occipital condyle can obstruct the surgical field in the clivus direction.
【学位授予单位】：河北医科大学
【学位级别】：硕士
【学位授予年份】：2008
【分类号】：R322

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