枕下乙状窦后-内听道上入路切除岩斜区脑膜瘤

目的介绍应用枕下乙状窦后-内听道上入路显微手术切除岩斜区脑膜瘤的显微手术技术。方法回顾性分析采用枕下乙状窦后-内听道上入路显微手术治疗的8例岩斜区脑膜瘤的临床资料,并对手术方法进行分析。结果肿瘤全切除6例,次全切除2例。术后新增脑神经损害2例,无手术死亡病例。结论枕下乙状窦后-内听道上入路是切除主体位于后颅窝、同时累及中颅窝的岩斜区脑膜瘤的安全有效的改良入路,娴熟的显微神经外科技术,熟练掌握入路的显微解剖可获得满意的手术疗效,有利于提高肿瘤切除率和疗效。     

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.     

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。     

内镜辅助显微镜下经乙状窦后入路的解剖学观察及临床应用

目的通过对经乙状窦后入路的内镜解剖与显微解剖学研究,为临床提供解剖学参考。方法 10例成人尸头,取经乙状窦后入路,在显微镜和内镜下对其内部结构进行全程观察。采用经乙状窦后入路切除桥小脑角区肿瘤57例。结果通过显微镜及不同角度内镜,能够清楚观察到桥小脑角区的重要血管、神经结构。听神经瘤全切除27例,大部分切除5例;脑膜瘤全切除15例,大部分切除3例;胆脂瘤7例均全切除。无围手术期死亡。无与神经内镜手术相关的并发症。结论内镜辅助显微镜经乙状窦后入路对桥小脑角区暴露良好,对周围组织损伤小,有效提高手术的安全性,较单纯显微手术有明显优势。     

幕上下联合锁孔入路显露岩斜区的显微解剖

目的 研究颞下和枕下乙状窦后锁孔入路对岩斜区显露的互补性.方法 尸头上模拟该锁孔入路,颞部骨窗以颧弓根部为中心前后各1.5 cm,高2.5 cm,枕下乙状窦后骨窗直径3 cm,观察显露范围并用导航标记.用带有造影剂的明胶海绵标记适于操作的有效空间,再行CT扫描和三维重建.结果 颞下入路从前外侧到达岩斜区,对颅中窝、鞍旁、幕上桥前池、脚间池下部、环池前部显露佳,切开小脑幕后环池和桥前池下部视野得到扩展,桥小脑角池方向被岩尖遮挡,是显露的死角.枕下乙状窦后入路从后外侧到达岩斜区,对同侧桥小脑角、桥前池、环池后部显露佳,但Meckel's囊开口至海绵窦后部被内听道上结节遮挡,范围小于1 cm3.结论 颞下和枕下锁孔入路的显露空间和角度有互补性,联合运用有利于切除同时累及幕上下,侵犯上斜坡和中下斜坡的岩斜脑膜瘤,尽管对海绵窦后部显露不佳,但范围小,处于放射外科的有效治疗范围之内,达到微创疗效.     

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。     

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。     

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。     

乙状窦前经迷路锁孔入路的显微解剖

目的将微创锁孔理念融入乙状窦前入路，在神经导航辅助下，设计乙状窦前经迷路锁孔入路，观察入路显微解剖，为临床应用提供依据。方法采用8具经福尔马林固定、颅内动静脉乳胶灌注的国人成人尸头，实验前建立术中导航资料。采用迷路后锁孔手术入路的7cm“C”形切口，分层向前翻开皮瓣和肌筋膜瓣，在神经导航辅助下做耳后约3．5cm×3．0cm骨窗，导航下轮廓化乙状窦、骨迷路、面神经管，依次模拟迷路后、经部分迷路及岩尖、经全迷路锁孔入路，观察各步骤显露的结构，测量重要结构长度和术野角度。结果（1）神经导航可辅助精确磨除入路相关骨质，减少盲目磨除造成的重要结构的误伤。（2）同迷路后锁孔入路比较，经部分迷路及岩尖锁孔入路和经全迷路锁孔入路的术野角度、显露的斜坡长度、面神经颅内段长度均有显著增加，但后两种入路的测量值无明显差异。（3）迷路后锁孔入路可保留听力和面神经功能，但对岩斜区的显露有限；部分迷路及岩尖磨除后可广泛显露岩斜区、桥脑小脑角、桥脑前区和海绵窦后部，多角度显露Ⅲ-Ⅺ对脑神经之间的重要结构，且面、听神经功能保有率极高；全迷路磨除后观察角度更多，但进一步增加的显露有限，且需牺牲听力。结论乙状窦前经迷路锁孔入路具有可行性，可良好显露岩斜区等。神经导航可辅助精确完成入路相关的骨质磨除。部分迷路及岩尖或全迷路磨除均可显著增加术野角度和斜坡等重要结构的显露长度，经部分迷路及岩尖锁孔入路可望保留面、听神经功能。     

颅中后窝哑铃型三叉神经鞘瘤的显微外科治疗

目的 探讨显微外科治疗颅中、后窝哑铃型三叉神经鞘瘤的手术入路与疗效。 方法 总结分析2001年6月至2009年5月显微手术治疗颅中、后窝哑铃型三叉神经鞘瘤19例的临床资料,其中采用乙状窦前入路10例,采用颞下硬脑膜外入路9例,比较两组入路显微手术的临床疗效。 结果 10例乙状窦前入路手术的全切除8例,术后出现患侧角膜溃疡2例,复视3例,术后患侧颞叶明显挫伤2例;9例颞下硬膜外入路手术的全切除8例,术后出现复视l例,没有患者出现角膜溃疡与颞叶挫裂伤。 结论 两种手术入路均可充分显露术野,能达到一期全切除肿瘤的目的,但颞下硬膜外入路手术有创伤小、术后并发症少的优点。     

Suprameatal extension of the retrosigmoid approach: microsurgical anatomy

OBJECTIVE: This study was conducted to determine whether removing the bony prominence located above the porus of the internal acoustic meatus, called the suprameatal tubercle, and surrounding bone using the retrosigmoid approach would aid in the exposure of tumors that are located predominantly in the cerebellopontine angle but that also extend into the middle cranial fossa in the region of Meckel's cave and thus avoid the need for a supratentorial craniotomy. METHODS: Thirty cerebellopontine angles from 15 cadaveric heads examined using 3 to 40x magnification provided the material for this study. A retrosigmoid craniotomy was completed and the exposure obtained before and after removing the suprameatal tubercle, and the surrounding bone was examined. In some cases, Meckel's cave and the tentorium lateral to the porus of Meckel's cave was opened to aid in the exposure. RESULTS: Removing the suprameatal tubercle and surrounding bone increased the exposure an average of 10.3 mm (range, 8.0-13.0 mm) forward of the exposure, which could be obtained without suprameatal drilling. The extent of bone removal was limited on the lateral side by the posterior and superior semicircular canals and their common crus. CONCLUSION: The suprameatal extension of the retrosigmoid approach will permit removal of some tumors that are located mainly in the posterior fossa but that extend into the middle fossa in the region of Meckel's cave. The exposure can be increased by opening the superior petrosal sinus as it crosses in the upper margin of the porus of Meckel's cave and by opening the tentorium lateral to Meckel's cave.     

Conventional posterior fossa approach for surgery on petroclival meningiomas: a report on an experience with 28 cases

BACKGROUND: This is a report of our experience with 28 cases of select petroclival meningiomas operated by a posterior fossa route encompassing the lateral supracerebellar-infratentorial and retrosigmoid avenues. METHODS: Twenty-eight cases of petroclival meningiomas treated during the period 1991 to 2002 by conventional posterior cranial fossa route are analyzed. The average length of follow-up is 48 months. RESULTS: The maximum diameter of the tumors ranged from 1.8 to 6.8 cm (mean, 4.0 cm). Five tumors extended up to or beyond the contralateral petroclival junction. Basilar artery was at least partially encased in 9 cases. Gross total tumor resection was achieved in 21 cases and a partial tumor resection was achieved in the remaining 7 cases. Two patients died in the postoperative phase. CONCLUSIONS: Conventional posterior cranial fossa surgery can be suitable for a select group of petroclival meningioma. Apart from other advantages, it provides easy and quick exposure of the tumor without any petrous bone drilling. It also provides a direct and early exposure of the tumor-cranial nerve-brainstem interface facilitating the dissection. The lateral and inferior tumor extensions in relationship to the clivus can be more easily accessed. The site of attachment of the tumor to the dura overlying the posterior face of the petrous apex can be seen directly.     

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.     

Microsurgical anatomy of the superior petrosal venous complex: new classifications and implications for subtemporal transtentorial and retrosigmoid suprameatal approaches

OBJECT: The purpose of this study was to define the patterns of drainage of the superior petrosal venous complex (SPVC) along the petrous ridge in relation to the Meckel cave and internal acoustic meatus (IAM) and to delineate its effect on the surgical exposures obtained in subtemporal transtentorial and retrosigmoid suprameatal approaches. METHODS: The patterns of drainage of the SPVC along the petrous ridge were characterized according to their relation to the Meckel cave and the IAM based on an examination of 30 hemispheres. Subtemporal transtentorial and retrosigmoid suprameatal approaches were performed in three additional cadavers to demonstrate the effect of the drainage pattern on the surgical exposures. CONCLUSIONS: The SPVC emptied into the superior petrosal sinus (SPS) within a distance of 1 cm from the midpoint of the Meckel cave. The patterns of drainage of the SPVC were classified into three groups. Type I emptied into the SPS above and lateral to the boundaries of the IAM. The most common type, Type II, emptied between the lateral limit of the trigeminal nerve at the Meckel cave and the medial limit of the facial nerve at the IAM, within an area of approximately 13 mm. Type III emptied into the SPS above or medial to the Meckel cave. The ideal SPVC for a subtemporal transtentorial approach (with or without anterior extradural petrosectomy) seems to be a Type I. In SPVC Type III and those Type II cases in which the SPVC is located near the Meckel cave, the amount of working space is significantly limited in a subtemporal transtentorial approach. In contrast, the ideal type of SPVC for a retrosigmoid suprameatal approach would be a Type III, and the SPVC must be divided in the majority of Type I and II cases for a satisfactory surgical exposure along the Meckel cave and middle fossa dura. The proposed modified classification system and its effect on the surgical exposure may aid in planning the approach directed along the petrous apex and may reduce the probability of venous complications.     

Design and microsurgical anatomy of the retrosigmoid-retrocondylar keyhole approach without occipital condyle removal.

OBJECTIVE: The goal of this study was to design a new retrosigmoid-retrocondylar keyhole approach based on the minimally invasive keyhole idea and to explore its feasibility and indications, which can be regarded as the base of this keyhole approach in clinical use. METHODS: 8 adult cadaveric heads fixed in formalin and with intracranial vessels perfused by colored latex were used in this study. To search for the most suitable length and shape of the skin incision, we examined two kinds of incision (a longitudinal "S" shape and a straight one) and two lengths (5 cm and 7 cm, respectively). Due to the complexity and thickness of the suboccipital muscles, two ways of muscle dissection were compared: 1) the muscles were incised perpendicularly in layers; 2) the muscles were detached and reflected in layers. A 3-cm diameter retrosigmoid-retrocondylar bone flap was made with a craniotome. Many anatomic structures could be observed under the microscope when the cerebellar hemisphere was retracted. After comparing and balancing the above steps in all specimens, a feasible, duplicable retrosigmoid-retrocondylar keyhole approach was devised. RESULTS: The proper incision of the retrosigmoid-retrocondylar keyhole approach was a longitudinal "S" shaped skin incision about 7 cm in length with its superior border 2 cm behind the middle point of mastoid and inferior margin at the level of C-2. The method of detachment and reflection of occipital muscles was superior to the method of cutting them perpendicularly. By means of adjusting the head position and the angle of microscope, the ipsilateral vertebral artery, posterior inferior cerebellar artery, anterior inferior cerebellar artery, VII, VIII, IX, X, XI, XII cranial nerves and the ventral lateral aspect of medulla oblongata were exposed via this keyhole approach. CONCLUSIONS: The novel retrosigmoid-retrocondylar keyhole approach has practical value for clinical applications. With the techniques of modern microsurgery, several diseases such as an aneurysm situated at the vertebral artery or the posterior inferior cerebellar artery, a small hypoglossal neurinoma and tumor located at the ventral lateral aspect of the medulla oblongata, may be operated via this retrosigmoid-retrocondylar keyhole approach without drilling the occipital condyle.     

Surgical approaches to the cavernous sinus: a microsurgical study

The surgical approaches to the cavernous sinus were examined in 50 adult cadaveric cavernous sinuses using magnification of X3 to X40. The following approaches were examined: 1) the superior intradural approach directed through a frontotemporal craniotomy and the roof of the cavernous sinus; 2) the superior intradural approach combined with an extradural approach for removing the anterior clinoid process and unroofing the optic canal and orbit; 3) the superomedial approach directed through a supraorbital craniotomy and subfrontal exposure to the wall of the sinus adjacent to the pituitary gland; 4) the lateral intradural approach directed below the temporal lobe to the lateral wall of the sinus; 5) the lateral extradural approach for exposure of the internal carotid artery in the floor of the middle cranial fossa proximal to the sinus; 6) the combined lateral and inferolateral approach, in which the infratemporal fossa was opened and the full course of the petrous carotid artery and the lateral wall of the sinus were exposed and; 7) the inferomedial approach, in which the medial wall of the sinus was exposed by the transnasal-transsphenoidal route. It was clear that a single approach was not capable of providing access to all parts of the sinus. The intracavernous structures best exposed by each route are reviewed. The osseous relationships in the region were examined in dry skulls. Anatomic variants important in exposing the cavernous sinus are reviewed.     

En bloc resection of the temporal bone by the lateral approach in carcinoma of the middle ear associated with skull base infiltration with reference to the resection of the petrous apex

En bloc resection of the temporal bone was performed by the lateral approach on two patients with carcinoma of the middle ear, which was associated with destruction in the temporal bone and tumor infiltration of the cranial base. In one of the patients, the petrous apex was resected along with the temporal bone.En bloc resection on the temporal bone with the petrous apex is believed to be difficult because the internal carotid artery (ICA), cavernous sinus, and the brainstem are adjacent to each other in the petrous apex. However, the intra- and extracranial surgical procedures by this approach allow resection of the temporal bone ranging from the anterior part including the petrous apex to the posterior part including the mastoid process, the dura of the middle and posterior cranial fossae, and the sigmoid sinus, without exposure of the tumor. Special attention should be paid to the procedural points of surgery, such as, exposure of the petrous ICA, bleeding from the petrous sinus, and dural suturing in the vicinity of the apex. With regard to surgical indication, it is important to determine whether tumor infiltration is confined to the temporal bone and the dura of the middle and posterior fossa. If tumor infiltration into the petrous ICA, the dominant side of sigmoid sinus and/or the inferior cranial nerve is observed, then indication for surgery should be determined in a more critical manner.     

Locating the Internal Auditory Canal during the Middle Fossa Approach: An Alternative Technique

Options for the surgical exposure of the internal auditory canal (IAC) include the translabyrinthine, retrosigmoid, and middle fossa approaches. Of the three, the anatomical reference points to the IAC are most subtle when it is exposed from above. The classically described methods for localizing the canal during the middle fossa approach direct the surgeon's attention initially towards the lateral extremity of the canal, a location where the margin for error is at its minimum. The cochlea, semicircular canals, and geniculate ganglion of the facial nerve are all positioned in close proximity to the fundus of the canal. An approach which is initially directed towards the porus acusticus has the advantage of locating the canal away from these vulnerable structures in an area where there is a relatively wide margin of safety. In this medially directed technique, drill excavation is commenced in the petrous apex well anterior to the anticipated location of the porus. Once the medial portion of the IAC has been well defined, dissection can proceed laterally by removal of bone directly over the known course of the canal. This strategy minimizes the risk of injury to the viscera of the petrous bone.     

En Bloc Resection of the Temporal Bone by the Lateral Approach in Carcinoma of the Middle Ear Associated with Skull Base Infiltration with Reference to the Resection of the Petrous Apex

En bloc resection of the temporal bone was performed by the lateral approach on two patients with carcinoma of the middle ear, which was associated with destruction in the temporal bone and tumor infiltration of the cranial base. In one of the patients, the petrous apex was resected along with the temporal bone.

En bloc resection on the temporal bone with the petrous apex is believed to be difficult because the internal carotid artery (ICA), cavernous sinus, and the brainstem are adjacent to each other in the petrous apex. However, the intra- and extracranial surgical procedures by this approach allow resection of the temporal bone ranging from the anterior part including the petrous apex to the posterior part including the mastoid process, the dura of the middle and posterior cranial fossae, and the sigmoid sinus, without exposure of the tumor. Special attention should be paid to the procedural points of surgery, such as, exposure of the petrous ICA, bleeding from the petrous sinus, and dural suturing in the vicinity of the apex. With regard to surgical indication, it is important to determine whether tumor infiltration is confined to the temporal bone and the dura of the middle and posterior fossa. If tumor infiltration into the petrous ICA, the dominant side of sigmoid sinus and/or the inferior cranial nerve is observed, then indication for surgery should be determined in a more critical manner.