幕上下联合入路切除岩斜区巨大肿瘤

目的:探讨岩斜区巨大肿瘤的手术入路和早期严重并发症的处理。方法:采取幕上下联合入路(颞下经小脑幕及枕下乙状窦后联合入路)对11例岩斜区巨大肿瘤进行手术治疗。结果:10例全切除,1例大部切除,效果满意。结论:有熟悉的解剖知识,采用颞下经小脑幕和枕下乙状窦后联合入路可以切除岩斜区巨大肿瘤。     

岩斜区肿瘤手术入路选择的探讨

目的 探讨岩斜区肿瘤的手术入路选择。对53例岩斜区肿瘤患者的手术治疗进行分析。方法患者采用颞底经天幕入路11例,枕下乙状窦后入路12例;（颧弓或眶颧）翼点入路12例;乙状窦前入路2例;颞底、乙状窦后幕上下联合入路7例;颞下前岩骨硬膜外入路7例;扩大的前颅底硬膜外入路2例。结果32例（61％）患者肿瘤全切除,9例（17％）次全切除,12例（22％）大部切除。术后新发生颅神经功能障碍16例（30％）,死亡2例（4％）。结论枕下乙状窦后入路、颞底经天幕入路等岩斜区手术入路均可以在熟练的显微操作技术及神经导航、神经内镜下进行。主体生长于硬膜外的岩斜肿瘤适合于采用硬膜外入路手术切除。幕上下联合入路对巨大岩斜区肿瘤是理想的手术入路。     

一侧入路显露两侧脑动脉瘤的显微解剖研究

目的 探讨一侧入路显露两侧动脉瘤的可行性，并提供相应的解剖学基础。方法 通过20例国人成年尸头标本翼点开颅，显露对侧前循环五个动脉瘤好发部位：眼动脉(OA)段、后交通动脉(PCOA)、颈内动脉(ICA)终末段、前交通动脉(ACOA)段和大脑中动脉(MCA)膝部分叉外，并进行显微解剖测量。结果 成功显露率：OA起始部为65％，PCOA起始部为50％，ICA终末分叉为100％，ACOA起始部为100％。MCA膝部分又为60％，结论 严格选择双侧多发动脉瘤的病例，经一侧入路显露并夹闭所有动脉瘤是可行、安全和有效的。     

改良乙状窦前经部分骨迷路入路的显微解剖

目的 目的 研究改良乙状窦前经部分骨迷路入路的显微解剖暴露,探讨其对岩斜区的显露及在手术处理该区域病变中的优势. 方法 2012年4月至10月,对15具尸头标本进行手术人路的改良研究,在传统乙状窦前入路的基础上切除部分半规管和岩尖,详细记录岩斜区重要结构的显露情况. 结果 该入路能够提供至岩斜区和海绵窦后部宽大的操作空间,在乙状窦前显露范围(水平方向)为(19.41±1.58) mm,在颞叶下方的显露范围(垂直方向)为(14.18±1.88) mm,斜坡中心凹陷的最大暴露角度为(60.54±6.93)°,手术操作深度(55.87 4.34) mm.椎-基底动脉、小脑前下动脉、小脑上动脉、同侧第Ⅲ～X对和对侧第Ⅵ对脑神经、三叉神经腔、海绵窦后部等均显露良好. 结论 改良乙状窦前经部分骨迷路入路能够获得岩斜区深面和海绵窦后部良好暴露,具有暴露范围大、观察角度多、保留面听神经功能、早期阻断肿瘤的血供等方面的优势.     

改良部分迷路切除岩骨尖入路的显微解剖

目的应用锁孔理念,对部分迷路切除岩骨尖入路进行改良,并对改良后的入路进行显微解剖学研究。方法对15例30侧成人尸头采用改良部分迷路切除岩骨尖入路暴露岩斜区,测量磨除部分迷路和岩骨尖后增加的手术视野和视角,观察岩斜区解剖结构的暴露情况。结果在4cm×3cm大小的骨窗范围内可以完成所有的手术操作。磨除部分迷路和岩骨尖后,手术水平视野平均增加14·2mm,垂直视野平均增加12·5mm,手术水平视角平均增加58°,垂直视角平均增加46°,该入路可充分暴露岩斜区各解剖结构,与原入路相比无明显差别。结论改良部分迷路切除岩骨尖入路暴露充分,较原入路创伤小,脑牵拉轻,不容易损伤颈静脉球和面神经颅外段等重要结构,是一种良好的处理岩斜区病变的手术入路。     

远外侧枕骨髁上锁孔入路的显微解剖

目的在枕骨髁后锁孔入路基础上,探索磨除颈静脉结节的可行性,形成枕骨髁上锁孔入路,探讨其适应证,为临床应用提供解剖学基础。方法10%甲醛固定、颅内动静脉乳胶灌注的成人尸头8具,采用枕骨髁后锁孔入路的“S”形7cm切口,逐层游离、翻转肌肉,做枕骨髁后直径约3cm骨窗,在导航辅助下于硬膜外磨除颈静脉结节,观察显露的解剖结构并测量其长度。结果乳突中点向后2cm处至C_2水平的纵向“S”形7cm长头皮切口可充分暴露同侧颈静脉结节、寰枕关节椎动脉V3段及寰椎后弓,磨除颈静脉结节效果满意,可显露基底动脉下段、小脑前下动脉等桥延沟附近中斜坡结构；显露基底动脉的长度(15．65±1．34)mm,小脑前下动脉(20．36±4．18)mm。结论远外侧枕骨髁上锁孔入路具有可行性；磨除颈静脉结节可增加中斜坡的显露,适合椎-基系动脉瘤、小脑前下动脉瘤、累及中斜坡的延髓腹侧肿瘤以及颈静脉孔区肿瘤等手术。     

额外侧锁孔入路的显微与神经内镜解剖

目的对比研究前颅底的显微解剖与神经内镜解剖，为额外侧锁孔手术入路处理前颅底、鞍区病变提供解剖基础。方法经额外侧锁孔手术入路对15具成人尸头进行显微解剖和神经内镜下解剖，比较两种解剖所暴露的范围。结果显微解剖在嗅沟、鞍区和外侧裂存在一定范围的视野盲区；内镜有充足的照明，可将手术视野放大，无视野盲区，清楚地显示周围的解剖结构，而且看得更远。但内镜的图像为二维图像，缺乏景深。神经内镜辅助显微手术可以互补各自不足。结论额外侧锁孔入路在神经内镜的辅助下显微手术切除前颅底和鞍区的病变安全、微创。     

锁孔入路显微手术治疗颅内肿瘤

锁孔手术是神经外科微创化发展的重要组成部份。它以开颅范围小，入颅直接，手术创伤小，术后患者反应轻、恢复快等为优点，而越来越被大家所接受和重视。2003年12月至2005年10月，本院采用锁孔入路显微手术切除颅内肿瘤17例，疗效满意。现将手术方法和临床经验分析如下。     

经岩骨乙状窦前入路显微外科治疗岩斜区肿瘤

目的 探讨岩斜区肿瘤经岩骨乙状窦前入路显微外科治疗的临床疗效。方法 回顾性研究经显微手术治疗的23例岩斜区肿瘤，对肿瘤病理类型、临床和影像学特征、手术入路、手术切除技巧及术后常见并发症的处理进行系统分析。结果 在手术显微镜下肿瘤全切除16例，近全切除4例，大部分切除3例，无手术死亡。结论 经岩骨乙状窦前入路可全切除岩斜区肿瘤。该手术入路对颞叶和小脑牵拉轻，可为岩斜区肿瘤手术切除提供良好的暴露。     

Opening cranial cisterns by the anterior subtemporal keyhole approach to the superior petroclival region: anatomical study and comparative analysis

Background

Without drilling the bony structures, simple incision of the tentorium dorsal to the porus of trochlear nerve by the anterior subtemporal keyhole approach provides narrow exposure in the superior petroclival region. This study was designed to measure and compare the areas of exposure, linear distances, and angles of approach in the superior petroclival region before and after opening cranial cisterns.

Methods

The study was carried out on 20 sides of cadaver heads. With the use of a navigation system, the area of exposure in the dorsum sella and clivus, the ventrolateral area of exposure in brainstem around the BA, the linear exposure of the posterior petroclinoid fold and BA trunk, and the angles of approach to BA tip were evaluated. The length of oculomotor cistern and trochlear cistern, the distance of oculomotor porus between trochlear porus, the linear exposure of the trigeminal nerve, and the angle to the most inferior medial point in clivus were also measured.

Results

The area of exposure in the dorsum sella and clivus (157.6 ± 27.2mm²), the ventrolateral area of exposure in brainstem around BA (249.5 ± 29.7mm²), the linear exposure of the posterior petroclinoid fold (11.5 ± 0.6 mm) and BA trunk (10.3 ± 2.0 mm), and the angle of approach in the vertical axis to the BA tip (13.7° ± 1.7°) were significantly greater after opening cisterns. The angles of approach in the horizontal axis to the BA tip (24.5° ± 1.1° vs 24.7° ± 0.8°) were not statistically different. The length of oculomotor cistern and trochlear cistern, the distance of oculomotor porus and trochlear porus, the linear exposure of the trigeminal nerve, and the angle of approach to the most inferior medial point in clivus were 6.7 ± 1.3 mm, 10.7 ± 2.4 mm, 9.6 ± 2.3 mm, 15.8 ± 1.4 mm, and 13.0° ± 1.5°, respectively.

Conclusion

The areas of exposure, linear distances, and the angles of approach in the superior petroclival region can be increased after opening cranial cisterns by the anterior subtemporal keyhole approach.     

Partial labyrinthectomy petrous apicectomy approach to the petroclival region: an anatomic and technical study

OBJECTIVE: The petroclival region generally is thought to be an inaccessible area in the intracranial compartment. A number of ways of reaching this area during surgery have been described, including the presigmoid petrosal approach. The partial labyrinthectomy petrous apicectomy approach is a relatively new approach to this region and is a variant of the presigmoid petrosal approach. This study aims to demonstrate the technique and the microsurgical anatomy of the partial labyrinthectomy petrous apicectomy approach and to provide a quantitative study of its exposure to compare it with other common approaches to this region, particularly the presigmoid petrosal approach. METHODS: Bilateral stepwise dissections were performed on 15 formalin-fixed and dye-injected cadaveric heads (30 sides) under x3 to x40 magnification. A temporal craniotomy was performed after a complete mastoidectomy. A partial labyrinthectomy and petrous apicectomy were performed next. The amount of dura exposed was measured before and after the partial labyrinthectomy and the petrous apicectomy. By measuring the angles of exposure, the approach was examined to analyze how much increased access was gained. RESULTS: This approach provided wide exposure to the petroclival region, the cerebellopontine angle, Meckel's cave, the cavernous sinus, and the prepontine region. On average, there was an increase of 10.8 mm in horizontal exposure as compared with the retrolabyrinthine approach. The average angle of vision achieved with the clival pit as the target was 58.9 degrees. In most of the specimens, an area from the IIIrd to the IXth cranial nerves was easily visible without any significant brain retraction. A high jugular bulb did not reduce the exposure. CONCLUSION: The partial labyrinthectomy petrous apicectomy approach converts two narrow tunnels into a wide corridor. It increases the angle of exposure markedly, providing easy and excellent exposure of the otherwise difficult-to-access petroclival region, and it may also preserve hearing.     

Combined petrosal approach to petroclival meningiomas

OBJECTIVE: To study the use and advantages of combining the posterior petrosal approach with the anterior petrosal approach to petroclival meningiomas. METHODS: Seven cases of petroclival meningiomas operated on via the combined petrosal approach were retrospectively analyzed. The basis on which this approach was selected was assessed, as were its benefits and risks. RESULTS: Gross total resection was achieved in five of the seven patients. No mortality or decrease in Karnofsky performance score was observed at the time of the last follow-up examination. Six of the seven patients had serviceable hearing before the operation. Only one patient lost hearing after the operation, and this hearing loss occurred in only one ear. Before the operation, six patients were House-Brackmann facial nerve function Grade I, and one patient was Grade II to III. At the last follow-up examination, facial nerve function was Grade I in five patients, Grade II in one patient, and Grade V in one patient. Tumors in all patients involved the cavernous sinus, Meckel's cave, petroclival junction, and middle clivus. All patients possessed a large posterior fossa component of tumor measuring an average of 3.6 x 3.5 x 4.2 cm. In four patients, the tumor was attached for the entire width of the clivus to the contralateral petroclival junction. Four patients displayed central brainstem compression. Four patients displayed bony changes at the petrous apex. All patients displayed total or partial encasement of the vertebrobasilar artery and its major branches. CONCLUSION: The combined petrosal approach should be considered for patients who have a large petroclival meningioma and serviceable hearing. This approach enhances petroclival exposure and the degree of tumor resection, especially in the area of the petroclival junction, middle clivus, apical petrous bone, posterior cavernous sinus, and Meckel's cave. The combined petrosal approach also allows better visualization of the contralateral side and the ventral brainstem, which facilitates safe dissection of the tumor from the brainstem, the basilar artery, and the perforators. If a patient has an early draining bridging vein to the tentorial sinus (before it reaches the transverse-sigmoid junction) or a prominent sigmoid sinus and jugular bulb, the combined petrosal approach provides significant working space.     

Combined subtemporal and retrosigmoid keyhole approach for extensive petroclival meningioma surgery: report of experience with 7 cases.

OBJECTIVE: Resection of petroclival meningiomas offers great challenges to the neurosurgeons. Our experience of 7 cases using a combined subtemporal and retrosigmoid keyhole approach surgery was evaluated for the treatment of extensive petroclival meningiomas. METHODS: From July 2002 to July 2005, resections of 7 petroclival meningiomas, which involved both supra- and infratentorial regions, were performed via a combined subtemporal and retrosigmoid keyhole approach. The extent of tumor resection was evaluated by MRI 3 months after surgery, and postoperative complications were investigated. RESULTS: The maximum diameter of the tumors ranged from 3.4 to 6.0 cm (mean: 4.4 cm). Gross total resection (GTR) was achieved in 3 cases, giving a GTR rate of 43%. Subtotal resection (STR) was carried out in 4 cases. Neurological status remained intact in one case, while others presented with cranial nerve deficits (VII, VI, V, III and lower CN). No death was reported in the cases during the postoperative period. CONCLUSION: The combined keyhole approach is suitable for the treatment of extensive petroclival meningiomas. It provides easy and quick access to the supra- and infratentorial juxtaclival region without any petrous bone drilling. Complications related to the approach can be minimized.     

Combined subtemporal and retrosigmoid keyhole approach for extensive petroclival meningiomas surgery: report of experience with 7 cases.

OBJECTIVE: The resection of petroclival meningiomas offers great challenges to the neurosurgeon. Surgery via a combined subtemporal and retrosigmoid keyhole approach surgery was evaluated for the treatment of extensive petroclival meningiomas on the basis of our experience with 7 cases. METHODS: From July 2002 to July 2005, the resections of 7 petroclival meningiomas, which involved both supra- and infra-tentorial regions, were performed via a combined subtemporal and retrosigmoid keyhole approach. The extent of tumor resection was evaluated by MRI 3 months after surgery, and postoperative complications were investigated. RESULTS: The maximum diameter of tumors ranged from 3.4 to 6.0 cm (mean: 4.4 cm). Gross total resection (GTR) was achieved in 3 cases, giving a GTR rate of 43%. Subtotal resection (STR) was carried out in 4 cases. Neurological status remained intact in one case, while the others presented with cranial nerve deficits (VII, VI, V, III and lower CN). No death was reported during the postoperative period. CONCLUSION: This combined keyhole approach is suitable for the treatment of extensive petroclival meningiomas. It provides easy and quick access to the supra- and infratentorial juxta-clival regions without any petrous bone drilling. Complications related to the approach can be minimized.     

Transcrusal approach to the retrochiasmatic region with special reference to temporal lobe retraction: an anatomical study

Background  

The retrochiasmatic region is one of the most challenging areas to surgically expose. The authors evaluated the transcrusal approach, which involves removal of the superior and posterior semicircular canal from the ampulla to the common crus, to expose the retrochiasmatic region and compared it with the retrolabyrinthine approach, both of which are a variation of the posterior petrosal approach with hearing preservation, with a special emphasis on the influence of temporal lobe retraction.     

Transtemporal approach to the skull base: an anatomical study

The surgical anatomy of a transtemporal approach to the structures of the clivus was defined with the aid of dissections in 10 cadaver heads. The steps in the dissection consisted of first exposing the cervical internal carotid artery (ICA), the internal jugular vein, and the caudal cranial nerves, each at the skull base; then performing small retromastoid and temporal craniotomies; and, finally, drilling away the petrous and tympanic bone to expose the intratemporal parts of the facial nerve, the petrous ICA, the sigmoid sinus, and the jugular bulb. To expose the structures of the lower clivus, the sigmoid sinus was ligated and divided, the facial nerve was displaced anterosuperiorly, and the inner ear structures were preserved. Dural opening exposed the anterolateral and anterior surfaces of the medulla, the pontomedullary junction, and the spinomedullary junction. The ipsilateral vertebral artery and often the contralateral vertebral artery and the vertebrobasilar junction, the caudal cranial nerves, and the origin of the 6th, 7th, and 8th cranial nerves were well exposed. To expose the structures of the middle clivus, we drilled away the labyrinth, the cochlea, and a portion of the clival bone. The facial nerve was displaced posteroinferiorly. Dural opening exposed the ipsilateral anterior surface of the pons, the midbasilar artery, and the ipsilateral 5th, 6th, 7th, and 8th cranial nerves. A portion of the contralateral anterior surface of the pons was also exposed at times. The superior limit of this exposure was just above the origin of the trigeminal nerve. The exposure of the upper clival structures was limited with this approach, and required medial temporal lobe retraction. Two case reports are included to illustrate the application of the transtemporal approach to the exposure and clipping of aneurysms of the vertebrobasilar system. The advantages and disadvantages of this approach are discussed.     

Inferolateral microsurgical approach to the orbit: an anatomical study.

Using detailed cadaveric dissection this study has demonstrated the increase in exposure by using the inferolateral microsurgical approach for neurosurgical and ophthalmological access. The approach to surgical exploration of this region is divided into three steps. The neural, muscular and vascular structures of each step are discussed. We think that, with an intimate understanding of the anatomy of the orbit, many large intraorbital lesions located in the muscle cone and the inferior nasal compartment of the orbit can be safely removed through inferolateral orbitotomy.     

Endoscopic/Microscopic approach to sphenopetroclival complex: an anatomical study

A dilemma presents itself to the otoneurologist and neurosurgeon when determining the least invasive surgical approach to giant cholesterol cysts (GCC) of the petrous apex of the temporal bone. These lesions can be diagnosed with a fair degree of certainty with imaging studies. Transmastoid and subcochlear approaches may be inadequate to access these lesions, and the transcochlear approach results in the sacrifice of hearing. A minimally invasive, combined microscopic and endoscopic sublabial transsphenoid approach to drain and marsupalize these lesions has been chosen by the authors in those cases that are anatomically possible. The purpose of this article is to establish the feasibility of exenterating anterior petrous apex cells by way of this approach, and to better conceptualize the anatomy of the Spheno-Petro-Clival Complex (SPC). Ten Fresh cadaveric "whole head" specimens were dissected with, endoscopic/microscopic control, through midline, sublabial, transseptal, and transsphenoidal routes to the petrous apex. The three-dimensional relationships of the sphenoid sinus, petrous apex, and the clivus were further demonstrated by dissections of the same specimens from the posterior fossa. Sagittal cut sections were also performed. After confirming the feasibility of this approach by dissections, the technique was adopted for performing drainage of GCC of the petrous apex in clinical cases.