Neuro-arterial relations in the region of the optic canal

Summary In this paper, we present the results of our investigations on the neuro-arterial relations in the region of the optic canal. A thorough knowledge of the microanatomic features of the ophthalmic artery, optic canal and optic nerve is very important for surgeons approaching lesions of this area. We aimed to extend our present knowledge of the origin of the ophthalmic artery and microsurgical anatomy of the optic canal with exposure of the optic nerve. The optic canal walls and width and height of the orbital and cranial apertures, and thickness of the bony roof of the optic canal were measured on the right and left sides of 57 sphenoid bones, 102 skull bases and 58 fixed adult cadaver heads. The ophthalmic artery originated from the rostromedial circumference of the internal carotid artery in 51.8%, from the medial circumference in 26.2% and the laterobasal circumference in 22% of the specimens. The outer diameter of the ophthalmic artery at its origin was 1.81±0.36 mm on the right and 1.75±0.37 mm on the left side.

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Rapports vasculo-nerveux dans la région du canal optique

Résumé Dans cet article, nous présentons les résultats de nos investigations sur les rapports vasculo-nerveux dans la région du canal optique. Une complète connaissance des caractéristiques micro-anatomiques de l'artère ophtalmique, du canal optique et du nerf optique est très importante pour les chirurgiens abordant des lésions de cette zone. Nous avons essayé d'étendre notre connaissance actuelle de l'origine de l'artère ophtalmique et de l'anatomie micro-chirurgicale du canal optique avec exposition du nerf optique. Les parois du canal optique, l'étendue et la hauteur des orifices crânien et orbitaire et l'épais seur du toit osseux du canal optique ont été mesurées sur les côtés droits et gauches de 57 os sphénoïdes, 102 bases du crâne et 58 têtes embaumées de cadavres adultes. L'artère ophtalmique naissait de la face rostro-médiale de l'artère carotide interne dans 51,8 % des cas, de la face médiale dans 26,2 % des cas, et de la face latérobasale dans 22 % des cas. Le diamètre externe de l'artère ophtalmique à son origine était de 1,81±0,36 mm du côté droit et 1,75±0,37 mm du côté gauche.

     

The ophthalmic artery and its branches,measurements and clinical importance

Summary Seventy-one Caucasian orbits (36 right, 35 left) were studied by dissection. The diameter of the ophthalmic a. (2 mm from the origin) was 1.54 ± 0.04 mm (male) and 1.31 ± 0.05 mm (female). In individual cases, there were no significant differences in vessel diameter between the right and left sides but, differences in vessel diameter between males and females were more commonly observed in the arteries which leave the orbit (extraorbital group), the individual vessels having a larger diameter in males. The incidence of the ophthalmic a. passing in the orbit medially under the optic n. was 18.6%. The lacrimal a. was observed to arise from the ophthalmic a. in only 82.5% of the cases examined, 15.9% of the cases showed the origin to be at the anastomotic branch of the middle meningealThis article is dedicated to Pr Dr Hoepke on occasion of his 100th birthday     

眼动脉的320排动态容积CT血管造影显微解剖学分析

目的探讨眼动脉的320排动态容积CT血管造影显微解剖及其临床应用价值。方法对52例患者眼动脉进行320排动态容积CT血管造影,对图像进行三维重建,观察眼动脉的显示情况及其形态学特征。结果52例患者．共104侧眼动脉均清晰显示,起始于颈内动脉有100侧,起始于脑膜中动脉有4侧。眼动脉从颈内动脉分出后5mm处直径,左侧为（1．24±0．17）mm,右侧为（1．26±0．14）mrn,男性为（1．25±0．18）mm,女性为（1．28±0．17）mm。眼动脉分为颅内、管内及眶内3段,眼动脉在颅内段和管内段以双角型最常见;眶内段依据其与视神经关系又被分为3段,其中第二段在视神经上方横过者约占90．0％。结论320排动态容积cT血管造影能够显示眼动脉起始、直径、分段、走行,为影像诊断和介入治疗以及眼科、显微外科、神经外科等手术方案的制定提供解剖学依据。     

内镜下经鼻蝶入路视神经管减压术应用解剖

目的　为内镜下行经鼻蝶入路视神经管减压术提供解剖学依据。 方法 选用12例成人尸颅标本,模拟内镜下经鼻蝶入路,观察视神经管及其周围结构。磨除视神经管,暴露并打开管内视神经鞘膜,观察鞘膜内视神经及眼动脉。 结果 视神经隆突是蝶窦内相对恒定的解剖标志,通过它可以确定视神经管眶口;眼动脉多走行于视神经的腹内侧,切开视神经鞘膜时应在外上壁进行。 结论 视神经隆突是重要的解剖标志;应在外上壁切开视神经鞘膜。     

视神经管显微解剖学研究

目的　为视神经管减压术提供解剖学依据。方法　利用解剖学方法对 10 0个颅骨和 6 7个尸头视神经管口及四壁的结构与毗邻进行了观察和测量。结果　视神经管由蝶骨小翼两根与喋骨体构成 ,管自后内向前外斜行 ,分内、外、上、下四壁和颅、眶两口。其上壁、下壁、内侧壁、外侧壁的长度分别为 10 70±0 2 3mm ,6 2 5± 0 18mm ,9 6 7± 0 18mm ,7 91± 0 17mm。内侧壁向筛窦、蝶窦内突入形成视神经管隆凸。视神经在颅口处有硬脑膜压迹 ,视神经腹侧有眼动脉形成的压迹。结论　视神经管隆凸可作为确定视神经管位置的解剖标志。视神经管下壁和内侧壁与视神经、眼动脉、颈内动脉等结构毗邻 ,切除管壁时应注意保护邻近结构。     

经鼻内镜下视神经管减压术的应用解剖

目的 通过对视神经管及其毗邻结构的研究,为临床视神经管减压术提供解剖学依据.方法 结构完整的成人头颈部标本12例,经红色乳胶灌注、10％的福尔马林固定,观察和测量如下指标:①观察视神经管的形态;②视神经管隆突的类型;③视神经管颅口、眶口及管中部的横径、纵径及横截面;④测量视神经管上、下、内、外侧壁的厚度;⑤视神经管内侧壁毗邻关系;⑥视神经管内眼动脉与视神经的位置关系.结果 视神经管由两口(颅口、眶口)和四壁(上壁、下壁、内侧壁、外侧壁)组成,其横截面积在眶口最大,管中部最窄;视神经管的内侧壁最薄,内侧壁的毗邻结构主要有3种类型:①前为同侧后筛窦、后为同侧蝶窦;②全为同侧蝶窦;③全为同侧后筛窦,眼动脉在视神经管的颅口、眶口分别以视神经的内下方和外上方多见.结论 本研究结果为经鼻内镜视神经管减压术提供了解剖学参数;当打开视神经管骨壁,鞘膜的切开选择内侧壁稍上方.     

视觉假体微电极经眶外侧壁入路植入视神经的应用解剖

目的为经眶外侧壁入路植入视神经视觉假体微电极提供解剖学依据。方法选用经4%甲醛固定及动脉灌注红色乳胶的成人头湿性标本30例,观测眶内眼动脉及相关分支的起始、数量和外径与穿入视神经鞘膜动脉的起始、外径和穿入部位、视神经外径等参数。结果泪腺动脉1～2支,经外直肌上缘上方(3.83±1.43)mm前行。外直肌-视神经间隙的深度为(8.14±0.90)mm,内有睫状短神经5～10条,颞侧睫状后动脉1～2支。穿入视神经鞘膜动脉的方位,内侧20%,上方29.3%,外侧6.7%,下方44%。视网膜中央动脉主要经下方穿入视神经,穿入处距球后(0.85±0.28)cm,该处动脉外径为(0.40±0.09)mm。眼动脉斜跨视神经处远侧端距球后(1.44±0.22)cm。在球后与总腱环中点处,视神经左右径(3.96±0.35)mm,上下径(4.18±0.33)mm。结论宜经眶外侧壁入路植入视神经视觉假体微电极,植入微电极的部位以视神经球后4～8mm处的外侧较好,植入深度应小于1.5mm。     

眼动脉显微外科解剖学观察

目的 :为视神经减压术提供眼动脉颅内段和眶内段的解剖学资料。方法 :利用显微解剖学技术及组织切片方法对 70个经甲醛固定的头颅标本眼动脉颅内段和视神经管内段的行程、毗邻、分支及眼动脉起始等进行了观察。结果 :眼动脉颅内段和视神经管内段可分为短脚、长脚和远侧部三段。有 5 5 .97%的眼动脉在视神经的腹侧形成压迹。眼动脉在视神经管内穿行于视神经的硬膜鞘壁内 ,其分支多行于视神经的腹侧。结论 :视神经管下壁切除时应注意保护眼动脉。视神经减压术管内鞘切开部位宜选择在鞘的外、上壁交界外。     

The pterion in Turkish male skulls

This study was conducted to determine the location and type of pterion in Turkish males. The importance of the pterion is its relation to the middle meningeal artery, Brocas motor speech area on the left side, and surgical interventions relating to pathologies of the sphenoid ridge and optic canal. Specific measurements were taken on both sides of 26 Turkish human male skulls, none of which showed any obvious pathology or trauma. The sphenoparietal type of pterion was the most common (96% right side, 79% left side), followed by the frontotemporal (4% right side, 17% left side), and finally the epipteric type (4% left side only). The distances on the right and left sides respectively from the center of the pterion to the frontozygomatic suture were 3.30±0.40 cm and 3.44±0.39 cm, to the zygomatic arch 4.05±0.39 cm and 3.85±0.25 cm, to the optic canal 4.39±0.40 cm and 4.36±0.40 cm, and to the sphenoid ridge 1.40±0.33 cm and 1.48±0.32 cm. The thickness of the skull at the center of the pterion was 0.41±0.14 cm and 0.39±0.12 cm on the right and left sides respectively. These findings should be of use in surgical approaches and interventions via the pterion.     

视神经管手术入路断层与应用解剖学研究

目的为开展视神经管新型手术提供精细的解剖学基础。方法在大体解剖学研究基础上,应用改进的火棉胶包埋技术对前颅底区域进行连续的三维薄切片,通过两者的有机结合,深入研究视神经管区域精细的解剖结构与复杂的毗邻关系。结果对视神经管区域解剖结构与毗邻关系显示良好精确。中鼻甲根部上缘至视神经管距离左侧为(28.0±5.0)mm,右侧为(29.0±6.0)mm。蝶窦下壁厚度左侧为(3.0±0.9)mm,右侧为(2.7±0.9)mm,视神经管与蝶窦或(和)筛窦间壁厚度左侧为(1.0±0.3)mm,右侧为(1.0±0.4)mm。结论经鼻、蝶窦或(和)筛窦入路行视神经管手术安全可行。     

眶尖区的断层解剖学研究及临床意义

目的　为眶尖区影像诊断提供断层解剖学资料。方法　应用 5 0侧成人头颅湿标本制成 0 5mm的火棉胶连续切片 ,用计算机图像分析系统对 3 6侧冠状位标本上的眶尖结构进行测量。结果　视神经管眶口处面积最小 ,管内段视神经从颅端到眶端逐渐变细 ,眼动脉进入神经经管从视神经内下方向外下方走行 ,眶上裂被Zinn腱环分为外侧区、中央区、下区 3部分。结论　冠状位是观测眶尖结构的理想层面 ,对眶尖部病变的诊断具有重要意义。     

视神经和视交叉冠状断层解剖与MRI

目的：研究视神经和视交叉在冠状断面上的解剖特征与MRI表现,为相关疾病的影像诊断和外科手术提供解剖学资料。方法：选取15例成人尸头标本,以冷冻切片法切制成连续冠状断层标本;应用3．0TMRI扫描仪,获取10例志愿者头部的sE序列T1WI和T2WI图像;在上述断层标本和MRI图像上,观察分析冠状断面上视神经的形态、位置和毗邻关系。结果：视神经眶内段居于眶中心偏内上方,断面呈圆形,其周围有视神经鞘包绕,蛛网膜下隙清晰可见,眼动脉位于其上方;视神经管内段居于眶内上方,断面呈水平卵圆形,周围可见视神经鞘,蛛网膜下隙不明显,眼动脉位于其下方;视交叉冠状断面呈“一”字型,分隔上方的视隐窝和后下方的漏斗隐窝,其上方有大脑前动脉A1段,下方为灰结节和垂体柄。结论：冠状断面町以清楚显示视神经、视交叉的形态特点与毗邻关系。     

Access of autonomic nerves through the optic canal, and their orbital distribution in man

The notion that autonomic nerves from the internal carotid plexus are transmitted to the orbit with the ophthalmic artery through the optic canal has been variously assumed, disregarded, or denied, but never demonstrated. The objective of this study was to examine the contents of the canal, identify any autonomic nerves, and follow their passage within the orbit. The soft tissues of the optic canal, and the apical tissues of the orbit were removed and examined histologically using 10 cadaver preparations. Additionally, tissues from an orbital exenteration and 10 ocular enucleation or donor specimens were prepared. Some of the latter material was examined with an electron microscope. Numerous autonomic nerves (four to 25, ranging in diameter from 23 to 130 microm) entered the orbit from the internal carotid plexus in the periosteum of the optic canal, the optic nerve dura mater, or the adventitia of the ophthalmic artery. In the orbit they advanced in the loose connective tissue covering the optic nerve dura and joined ciliary nerves close to the eye or entered the eye directly. None were observed to penetrate the dura, apart from a nerve accompanying the central retinal artery. Others were distributed with the ophthalmic artery and its branches. It is concluded that the optic canal is a regular, and often major, route for autonomic nerve distribution to the eye and orbit.     

Origin and initial course of the renal arteries a radiological study

The aim of this study was to determine the topography of the origin, implantation angle and initial course of the renal arteries in the transverse and frontal planes, from a prospective analysis of angiograms and helical CT-scans of 40 patients. In the frontal plane, the implantation angles of the right and left renal arteries were 73.8 ± 17° axsnd 65.6 ± 16° respectively 17.9% of the right renal arteries were straight compared with only 5% of the left ones. The first sinuosity was observed to be at a distance greater than the aortic diameter for 43.6% of right renal arteries and at a distance less than the aortic diameter for 62.5% for the left renal a. In the transverse plane, the right renal a. had an implantation angle of 65.6 ± 15.7° compared with 95.7 ± 16.85% for the left renal a. The artery was rectilinear in 2.6% of the cases on the right side, and in 2.5% of the cases on the left. The first sinuosity occurred before the lateral margin of the spine was reached in 60.5% of right renal arteries and after the margin of psoas major muscle for 55% of left renal arteries. A knowledge of the anatomy of the origin and initial course of the renal arteries is important when considering vessel dilatation and the implantation of stents in the renal arteries. No correlation was observed between the origin, sinuosity or angulation of the renal arteries which could aid interventional procedures.     

Paraclinoid and cavernous sinus regions: measurement of critical structures relevant for surgical procedure

Determination of the safest distance the falciform ligament can be incised from its origin to the orbital apex. Measurement of the distance between the oculomotor foramen and the IV nerve in the lateral wall of the cavernous sinus. Evaluation of the optic strut as an accurate landmark between the intradural (subarachnoid) and extradural segment of the internal carotid artery (ICA). Ten fixed human cadaver heads were examined for a total of 20 sides. A frontotemporal craniotomy, an orbito-optic osteotomy, and extradural anterior clinoidectomy were carried out followed by opening the falciform ligament, circumferentially releasing the distal dural ring and dissection of the lateral wall of the cavernous sinus under the operating microscope. We measured: 1) the distance between the entry of the III nerve and the point where the IV nerve crosses over it into the cavernous sinus; 2) the distance the falciform ligament can be incised along the optic nerve laterally until the IV nerve is encountered at the orbital apex; 3) the distance between the optic strut and the lateral part of the distal dural ring; and 4) the distance between the optic strut and the ophthalmic artery. All measurements were made in millimeters, using small calipers. The distance between the optic strut and the lateral part of the distal dural ring ranges from 3-7.5 mm (mean=5.47 mm). In all our specimens, the ophthalmic artery was found distally from the optic strut in the intradural space at a distance ranging from 0.5-7 mm (mean=3.35 mm). The distance between the entry of the third nerve and the IV nerve into the cavernous sinus ranged from 7-15 mm (mean=10.9 mm). The distance between the origin of the falciform ligament and the IV nerve at the level of the orbital apex ranged from 9-15 mm (mean=10.75 mm). The falciform ligament and the optic sheath should not be opened longer than 9 mm along the lateral optic nerve or injury to the IV nerve can occur. Starting at the oculomotor foramen, the opening of the cavernous sinus should be limited to 7 mm to avoid injuring the IV nerve. Finally, the optic strut can be a reliable bony landmark that separates the subarachnoid space and extradural compartments along the anterior and medial ICA.     

内镜经鼻入路视神经管和眼眶的解剖学

目的通过研究对视神经管和眼眶的解剖研究,为内镜经鼻入路视神经管减压和治疗眼眶内病变提供解剖基础。方法国人尸头5例,采用大体解剖和内镜下经鼻入路两种方法,观察重要的解剖标志;使用内直肌内移技术,观察视神经管和眼眶内结构的暴露情况以及重要结构的位置、毗邻、走行等。结果钩突位于中鼻甲的前下方;筛泡在钩突的后方,切开筛泡可进入筛窦;筛前后动脉是筛窦内的重要解剖标志;视神经管隆突、颈内动脉隆突和视神经管颈内动脉隆突(OCR)是蝶窦内重要的解剖标志;纸样板位于筛窦的外侧壁,切开纸样板可暴露眶内容物;在眶内,可从内直肌与下直肌之间的通路暴露视神经。在本次10侧标本中,9侧眼动脉起自于颈内动脉的床突上段;1侧眼动脉起自于颈内动脉海绵窦段。7侧眼动脉在视神经管内走行于视神经的下外侧;2侧走行于视神经的正下方;1侧走行于视神经的下内侧。结论内镜下经鼻入路可以进行视神经管和眼眶内侧部分的暴露。钩突、筛泡、筛前后动脉及后组筛窦是本入路重要解剖标志。视神经管隆突、颈内动脉隆突及视神经管颈内动脉隆突(OCR)是进行视神经管减压的重要标志。眼动脉及其眼眶内分支、筛前后动脉和颈内动脉是重要的血管结构。眼内直肌内移技术可以有助于暴露眶内解剖结构。     

视网膜中央动脉和睫状后动脉的应用解剖

目的：为视神经鞘减压术和视神经周围区手术提供视网膜中央动脉和睫状后动脉的解剖学资料。方法：采用显微解剖学技术对60例成人视网膜中央动脉和睫状后动脉进行观察。结果：（1）视网膜中央动脉多发自眼动脉角（21．7％）,内侧睫状后动脉（20．0％）,眼动脉第一段（19．3）。（2）视网膜中央动脉发起后在视神经下方弯曲前行,其起始部在眶内视神经后1／3段与眼外直肌之间者占85．0％。（3）入鞘点在视神经的正下方者68．3％,内下方者占21．7％,外下方者占10．0％。结论：视网膜中央动脉及睫状后动脉的起点、走行变化较大,视神经鞘减压术和视神经周围区手术时应保护好这些动脉,以免引起视神经等结构缺血。     

内耳道底骨性结构、前庭神经与单孔神经骨管的Micro-CT影像解剖学实验研究

目的 探讨内耳道底骨性结构及前庭神经、单孔神经骨管（神经管）的Micro-CT影像解剖学特征。方法 取10%甲醛溶液固定的成人尸头标本6具（颞骨12侧）,其中男性4具、女性2具,具体年龄不详。对12侧颞骨均行Micro-CT扫描,再应用Mimics软件对内耳道底骨性结构及其中的神经管进行三维重建,之后进行影像解剖学观察,并分别测量前庭上神经、前庭下神经、单孔神经管相关解剖学参数。结果 经Micro-CT扫描及三维重建,内耳道底骨性结构及其内穿行的前庭神经和单孔神经管显示清晰。前庭上、下神经及单孔神经的解剖形态、位置及走行存在多种解剖变异以及多交叉分布现象。左右两侧前庭上神经管长度分别为（3.68±0.79）mm和（3.54±1.04）mm,起始处前后径分别为（2.03±0.76）mm和（1.83±0.68）mm、上下径分别为（1.75±0.35）mm和（1.72±0.43）mm,中点处的前后径分别为（0.89±0.19）mm和（1.13±0.29）mm、上下径分别为（1.58±0.26）mm和（1.69±0.58）mm;左右两侧前庭下神经管前后径分别为（0.44±0.07）mm和（0.50±0.29）mm,上下径分别为（0.53±0.11）mm和（0.76±0.38）mm。左右两侧单孔神经管直线长度分别为（3.97±0.68）mm和（3.85±0.69）mm,其内侧段长度分别为（2.54±0.70）mm和（2.26±0.82）mm、外侧段长度分别为（1.82±0.57）mm和（1.99±0.39）mm,内侧段直径分别为（0.67±0.10）mm和（0.66±0.09）mm、外侧段直径分别为（0.47±0.04）mm和（0.51±0.10）mm,内外段交角分别为128.82°±17.23°和127.51°±11.70°。以上各指标测量值侧别间比较,差异均无统计学意义（P值均>0.05）。结论 Micro-CT扫描及三维重建可清晰显示内耳道底骨性结构及前庭神经、单孔神经骨管等结构及其空间位置与走行;前庭神经和单孔神经骨管解剖形态及位置、走行均存在较大变异,但左右侧别间相关解剖学测量结果无差异。     

The inter-optic course of a unique precommunicating anterior cerebral artery with aberrant origin of an ophthalmic artery: an anatomic case report

Background and importance

Some variations of the cerebral arterial circle of Willis, such as an inter-optic course of the anterior cerebral artery are exceedingly rare. Imaging of very rare anatomical features may be of interest.

Clinical presentation

In a 67-year-old male individual, the unique precommunicating part of the left anterior cerebral artery was found to course between both optic nerves. There was an agenesis of the right precommunicating cerebral artery. This variation was associated with an aberrant origin of the ophthalmic artery, arising from the anterior cerebral artery. The anatomic features, the possible high prevalence of associated aneurysms of the anterior communicating artery complex as well as implications for surgical planning or endovascular treatments are outlined and embryologic considerations are discussed.

Conclusion

To the best of our knowledge, this is a very rare illustrated case of an inter-optic course of a unique precommunicating anterior cerebral artery with aberrant origin of an ophthalmic artery.     

视交叉前间隙有关结构的解剖观察及其临床意义

目的为经额入路行蝶鞍区手术提供外科解剖学依据。方法对30个经福尔马林固定的成年人尸头标本的视交叉前间隙及有关结构在肉眼和SXQ鄄Ⅱ型手术显微镜下进行观察,对视交叉前间隙的面积进行测算。结果①视交叉前间隙之间的面积为(28.4±6.2)mm2。两侧视神经颅内段越长,夹角越小,视交叉前间隙越大;两侧视神经颅内段越短,夹角越大,视交叉前间隙越小。②视交叉前缘至鞍结节之间的距离为(4.1±0.8)mm,两侧视神经于视交叉前之间的夹角为63.2°±5.8°。③颈内动脉自前床突内侧向上穿过硬脑膜之后,先向前、内、上方行至视神经下面,再弯向后、外、上方行于视神经外侧。④分布于视交叉上后面的视交叉上动脉来源于两侧大脑前动脉水平部段和前交通动脉。分布于视交叉下前面的视交叉下动脉来源于两侧颈内动脉和后交通动脉。结论经额入路蝶鞍区手术主要是通过视交叉前间隙,在颈内动脉之间的间隙操作,手术中应注意保护好视神经和视交叉的营养动脉,以减少并发症的发生。