内耳道及面、前庭蜗神经的膜性结构显微解剖研究及其意义

目的：详细了解桥小脑角蛛网膜的分布为认识听神经瘤和其手术提供解剖学依据。方法：采用10％福尔马林固定的胎儿（28．39周）尸头标本11例22侧，利用手术显微镜和常规组织切片染色方法观察内耳道及面、前庭蜗神经的膜性结构分布情况。结果：手术显微镜下见桥小脑池蛛网膜明显向内耳道内延续占81．81％（18侧），另18．19％（4侧）的蛛网膜向内延续的同时与内耳道口及神经发生部分的粘连；72．73％（16侧）的内耳道口及其附近存在大量的蛛网膜小梁与面、前庭蜗神经相连。组织切片发现100％（22侧）的内耳道内蛛网膜贴附在内耳道骨质表面延续至内耳道底部；面、前庭蜗神经之间互相独立，只有神经外膜分隔。结论：听神经瘤为蛛网膜内的结构；熟悉内耳道及面、前庭蜗神经的膜性结构有助于提高听神经瘤手术水平。     

Microsurgical anatomy of the facial nerve

The facial nerve connections and pathways from the cortex to the brainstem are intricate and complicated. The extra‐axial part of the facial nerve leaves the lateral part of the pontomedullary sulcus and enters the temporal bone through the internal acoustic meatus. In the temporal bone, the facial nerve branches into fibers innervating the glands and tongue. After it emerges from the temporal bone it supplies various facial muscles. It contains a motor, general sensory, special sensory, and autonomic components. The physician needs comprehensive knowledge of the anatomy and courses of the facial nerve to diagnose and treat lesions and diseases of it so that surgical complications due to facial nerve injury can be avoided. This review describes the microsurgical anatomy of the facial nerve and illustrates its anatomy in relation to the surrounding bone, connective, and neurovascular structures.     

Microsurgical anatomy of the ocular motor nerves

This study was designed to provide anatomic data to help surgeons avoid damage to the ocular motor nerves during intraorbital operations. The microsurgical anatomy of the ocular motor nerves was studied in 50 adult cadaveric heads (100 orbits). Dissections were performed with a microscope. The nerves were exposed and the neural and muscular relationships of each portion of the nerve were examined and measured. The superior division of the oculomotor nerve coursed between the optic nerve and the superior rectus muscle after it left the annular tendon, and its branches entered into the superior rectus muscle and levator muscle. A mean of five fibers (range 3–7) innervated the superior rectus muscle, and a mean of one fiber (range 1–2) followed a medial direction (84%) or went straight through the superior rectus muscle (16%). The inferior division of the oculomotor nerve branched into the medial rectus, inferior rectus and inferior oblique muscles. The trochlear nerve ended on the orbital side of the posterior one-third of the superior oblique muscle in 76 specimens. The abducens nerve ended on the posterior one-third of the lateral rectus muscle in 86 specimens. If the belly of the lateral rectus muscle was divided into three superior–inferior parts, the nerve commonly entered into the middle one-third in 74 specimens. Based on the observed data, microanatomical relationships of the orbital contents were revised.     

Microsurgical anatomy of the facial nerve trunk

Dissection and manipulation of the facial nerve (FN) trunk between its exit from the cranial base through the stylomastoid foramen (SMF) and its bifurcation is a critical step in various otologic, plastic and neurosurgical procedures. This study demonstrates the anatomical relationships and variability of the FN trunk with emphasis on some important morphometric data, particularly with relevance to hypoglossal-facial nerve anastomosis (HFA). Bilateral microsurgical dissection was performed on twenty-three human cadavers fixed with formalin. The whole trunk of the FN was exposed, its diameter at the SMF and its length were measured, its branches were observed and the site of its bifurcation was determined. Anastomotic connections with other nerves and blood supply of the trunk were studied. The FN invariably emerged from the cranial base through the SMF. Its diameter upon its emergence from the foramen was 2.66 +/- 0.55 mm. Two branches consistently originated from the trunk: the posterior auricular nerve and the nerve to the digastric muscle. Less consistent were the communicating branch with the glossopharyngeal nerve and the nerve to the stylohyoid muscle. The bifurcation of the FN occurred before its penetration into the parotid gland in 15% of cases and within the gland in 85%. The length of the FN trunk was 16.44 +/- 3.2 mm. Anastomoses between the FN and other nerves were observed in one-third of the dissections. The blood supply to the FN trunk was provided by the stylomastoid artery that was identified in 91% of cases. Understanding the microsurgical anatomy of the FN trunk is essential for performing any surgical procedure in the relevant region. Surgical implications of this study are presented with emphasis on HFA surgery.     

胸神经后根的显微外科解剖

目的：为胸部选择性脊神经后根切断术(SPR术)提供可靠的后根分束的解剖学基础。方法：对成人尸体胸神经后根的自然分束和后根问神经纤维联系(CR)进行显微外科解剖学观测。结果：1条胸神经后根有4～6条根丝组成,然后形成2～4根神经亚束,最后形成上、下2股神经束。后根问神经纤维联系出现率为55．4％,根据形状可分为5型,根据位置可分为3类。结论：胸神经后根各级神经分束较易分离,神经纤维联系较为简单,有利于临床医生进行SPR术。     

面神经颞骨内段显微解剖及其临床意义

目的对面神经颞骨内段进行的显微解剖,为临床手术提供解剖学参数。方法应用10%福尔马林充分固定的成人尸头标本10例20侧;漂白干颅骨10例20侧。结合手术入路对面神经及其毗邻结构进行测量和拍照。结果面神经颞骨骨质内分支分为四段,即内耳道段、迷路段、鼓室段和乳突段,分别长为(10.11±1.41)、(3.81±0.74)、(10.51±1.44)、(15.51±1.94)mm。内耳道段与位听神经伴行,鼓室段与骨迷路和中耳关系密切,经茎乳孔出颅。结论(1)经岩前入路中可利用弓状隆起和岩大神经定位。(2)经迷路入内耳道底的Bill嵴是寻找面神经内耳道段的重要标志。(3)岩大神经起点内侧5mm的垂直线是定位耳蜗方便、可靠的标志线。(4)弓状隆起和岩大神经的夹角平分线是从颅中窝寻找内耳道的最好的解剖标志。     

面神经颅内段及管内段的应用解剖

目的:为颅底或中耳手术时防止伤及面神经管内段提供形态学依据,并积累中国人体质资料.方法:解剖测量15具正常人头颅标本的面神经颅内段、内耳道段、迷路段、鼓室段和乳突段长度和外径,并观察记录各段与周围结构的毗邻关系.具体观测包括三叉神经后外侧缘与面神经入内耳门处和岩大神经起点处的间隔;迷路动脉与前庭蜗神经和面神经的位置关系;膝神经节的形态和位置;岩大神经;鼓索的起始部位;面神经鼓室段与鼓膜内面的距离以及面神经乳突段与横窦和颈静脉孔间的距离等.结果:面神经颅内段、内耳道段、迷路段、鼓室段和乳突段长度依次为 (12.02±1.95)mm, (1 40±0.31)mm;(7.57±1.52)mm,(1.32±0 22)mm;(2.21±1.14)mm,(1.29±0.37)mm;外径依次为(7 .79±3.28)mm,(1.31±0.26)mm和(17.81±3.94)mm,(1 55±0.38)mm.结论:观测了面神经颅内段及管内段,各段的形态学特点及其与周围结构的毗邻关系,为颅底和颞骨(中耳、乳突等)手术时保护面神经提供了应用解剖学依据.     

Forces necessary for the disruption of the cisternal segments of cranial nerves II through XII

Manipulation of the cisternal segment of cranial nerves is often performed by the neurosurgeon. To date, attempts at quantifying the forces necessary to disrupt these nerves in situ, to our knowledge, has not been performed. The present study seeks to further elucidate the forces necessary to disrupt the cranial nerves while within the subarachnoid space. The cisternal segments of cranial nerves II through XII were exposed in six unfixed cadavers, all less than 6 hr postmortem. Forces to failure were then measured. Mean forces necessary to disrupt nerves for left sides in increasing order were found for cranial nerves IX, VII, IV, X, XII, III, VIII, XI, VI, V, and II, respectively. Mean forces for right-sided cranial nerves in increasing order were found for cranial nerves IX, VII, IV, X, XII, VIII, V, VI, XI, III, and II, respectively. Overall, cranial nerves requiring the least amount of force prior to failure included cranial nerves IV, VII, and IX. Those requiring the highest amount of force included cranial nerves II, V, VI, and XI. There was an approximately ten-fold difference between the least and greatest forces required to failure. Cranial nerve III was found to require significantly (P < 0.05) greater forces to failure for right versus left sides. To date, the neurosurgeon has had no experimentally derived data from humans for the in situ forces necessary to disrupt the cisternal segment of cranial nerves II through XII. We found that cranial nerve IX consistently took the least amount of force until its failure and cranial nerve II took the greatest. Other cranial nerves that took relatively small amount of force prior to failure included cranial nerves IV and VII. Although in vivo damage can occur prior to failure of a cranial nerve, our data may serve to provide a rough estimation for the maximal amount of tension that can be applied to a cranial nerve that is manipulated while within its cistern.     

面神经膝神经节手术入路的显微解剖研究

目的探讨经鼓室入路和经乳突-上鼓室入路的面神经膝神经节显微比较解剖.方法对6例(12侧)福尔马林固定的成人头颅标本采用1侧模拟经鼓室入路,1侧模拟经乳突-上鼓室入路的手术操作,对各入路涉及的解剖学标志及暴露范围进行观测.结果两种手术入路均可达到面神经膝神经节减压的目的.其中,经鼓室入路可以显示面神经的鼓室段和膝神经节;经乳突一上鼓室入路可以显示面神经的乳突段、鼓室段、膝神经节和迷路段远侧端的(0.94±0.06)mm.两种手术人路均可能需要离断听骨链,确定恒定的解剖标志.结论经鼓室入路和经乳突-上鼓室入路对面神经暴露程度不同,存在不同优缺点,临床应根据实际情况选择.     

Microsurgical anatomy of VII and VIII cranial nerves and related arteries in the cerebellopontine angle

Summary The relationships of VII and VIII cranial nerves and related arteries are reviewed in 26 preparations by microdissection techniques. These vessels may be grouped in large (AICA, PICA), medium (LA, SA, CSA, RPI) and small calibre (vasa nervorum, radicullar and medullar branches). The importance of these structures in acoustic neuroma surgery, vestibular neurectomy and cross-compression syndromes is discussed. Vascular loops and elongated arteries are normal structures present at birth.This work was supported by a grant from the AJ Roemmers Foundation     

Ⅵ～Ⅷ对脑神经生物塑化薄片断层解剖与MRI对照研究

目的 :对展神经、面神经、前庭蜗神经进行塑化切片与MRI对照研究 ,获得正常影像和断层解剖资料。方法 :采用生物塑化技术制作脑神经横断位 8例、矢状位和冠状位各 1例薄层切片 ,同时采用FLASH -3D序列完成头颅标本及 3 0例正常人脑干MR扫描 ,以MPR技术完整显示展神经、面神经、前庭蜗神经脑池段全程。结果 :塑化薄片断层、标本和活体MR扫描 ,脑神经行程、解剖形态均有良好的对应关系 ,Dorello管和展神经海绵窦段在塑化切片上显示良好 ,MRI仅能部分显示。结论 :生物塑化薄层切片能够对脑神经及相关结构进行准确显示 ,是脑神经影像学研究的重要对比方法