【作者】 李海红；

【导师】 岳树源；

【作者基本信息】 天津医科大学 ， 外科学， 2011， 硕士

【摘要】 目的：通过乙状窦后锁孔入路的解剖学研究,显微观察该入路所涉及的解剖结构、显露范围和手术可利用的空间,为临床应用提供解剖学资料,并以此解剖学资料为基础,探讨乙状窦后锁孔入路的手术适应症和临床应用价值。方法：对15具成年国人尸体头颅标本血管进行乳胶灌注备用。将尸头依照手术体位固定在头架上,模拟乙状窦后锁孔入路手术方法对15具(30侧)成人头颅标本进行解剖,骨窗范围在2.0 cm×2.5cm,于4-24倍手术显微镜下解剖,打开桥小脑角,去除蛛网膜及软脑膜,调整和变换显微镜角度,探查显露范围和神经血管解剖结构,拍照并测量记录相关解剖数据,观察分析相关解剖学差异。结合临床资料,对比其他相关入路,评价乙状窦后锁孔入路的优越性。结果：乙状窦后锁孔入路可显露的解剖结构：上从天幕前侧缘,下至枕骨大孔颈静脉结节,内侧到桥脑和中脑的侧方。通过调整显微镜角度,乙状窦后锁孔入路可暴露桥小脑角区包括岩静脉、小脑上动脉及其分支、小脑前下动脉及其分支、小脑后下动脉及其分支、滑车神经、三叉神经、面听神经、后组颅神经。约37%(11侧)的小脑上动脉与三叉神经有接触或压迫。30侧标本中单干岩静脉为24侧,双干岩静脉为6侧。22.2%岩静脉在内听道内侧缘外侧注入岩上窦,63.8%的岩静脉在三叉神经入Meckel腔处的外侧缘和内听道内侧缘之间注入岩上窦,13.9%于三叉神经外侧缘以内注入岩上窦。23侧(77%)侧小脑前下动脉襻与面听神经有接触,有14侧标本中小脑前下动脉穿面前庭蜗神经之间。乙状窦后锁孔入路可良好暴露后颅窝神经血管结构,但也受骨性结构的影响。此入路对内听道口及颈静脉孔暴露良好,但在所有标本中内听道上结节的形态变异较大,其均阻挡了对Meckel憩室的暴露,颈静脉结节阻挡了对枕骨大孔前部的暴露。多数标本基底动脉暴露不佳。内镜下视野清晰,且可探查显微镜下解剖死角。结论：乙状窦后锁孔入路是一种最经典锁孔手术方法,由于骨窗位置恰当、骨窗大小适中,减少了不必要的头皮、肌肉切开,减少了不必要的颅骨切除,减少了不必要脑组织暴露,术中充分利用颅内的自然空间,所以具有脑损伤少,伤口局部反应小,组织复位好,手术时间短,术后并发症少,恢复快和不影响患者容貌等优点。通过乙状窦后锁孔入路并选取不同位置的骨窗,能适当暴露后颅窝相关区域的组织结构,可用于小脑桥脑角、上斜坡、中斜坡、下斜坡部位的髓外病变的手术,如：三叉神经痛、面肌痉挛、胆脂瘤、神经鞘瘤和脑膜瘤。乙状窦后锁孔入路是顺应现代微创理念的探索,实践证明它是一种安全、有效的手术方式,可选择性的替代传统的乙状窦后入路。更多还原

【Abstract】 Objective:A microanatomical study of the retrosigmoid keyhole approach was performed to observe the related anatomical structure, exposure and operating spaces through this approach, in order to provide anatomical reference for the clinical application of the approach. For further study, use the anatomical research to discuss the indication and clinical value of the approach.Methods:The main arteries and veins of 15 cases of the Chinese adult cadaver’s heads were perfused with lactoprene and fixed on the headstock. Simulating operation technique, a retrosigmoid keyhole craniotomy was made and the bone window was controlled within 2.5×2.0 cm. Twenty-four sides of 15 cadaver heads were dissected under 4 to 24 magnification via operating microscope. The cerebellopontine cistern was entered to expose the area and the neurovascular structures. Using microscope with varying angles of view, observe and analyze the related anatomical variation, and then measure and record related parameters. Combine with clinical operations and other approach the clinical application of the retrosigmoid keyhole approach was assessed.Results:The retrosigmoid keyhole approach exposes nearly the same anatomic region as that of conventional approach. It can expose the area superior to the anteriolateral margin of the tentorium, inferior to the foramen Magnum and the jugular tubercle, medial to the anteriolateral of pons and medulla. Using microscope with varying angles of view, retrosigmoid keyhole approach can get a clear visualization of petrosal vein, superior cerebellar artery(SCA)or its branches, the anteroinferior cerebellar artery(AICA)and its branches, the posteroinferior cerebellar artery(PICA), trochlear, trigeminal nerve, abducens, facial, and vestibuloco-chlear nerves, the glossopharyngeal, vagus, accessory, and hypoglossal nerves. SCA of 11 specimens(37%) contacted with trigeminal nerve. Of the 30 SPSs examined in 15 cadaver heads, the SPV emptied into the sinus as a single venous stem in 24 sides and as two stems in the remaining 6.22.2% of SPV emptied into the SPS above or lateral to the internal acoustic meatus (IAM),63.8% of the SPV emptied into the SPS between the lateral limit of the trigeminal nerve and the medial limit of the IAM.13.9 %the SPV emptied into the SPS at a point medial to the lateral limit of the trigeminal nerve at its site of entry into the Meckel cave. AICAs were the compressing vessel involved in 23 (77%) of 30 cases, in 14 cases, the AICAs pass between the facial and vestibulocochlear nerves. Retrosigmoid keyhole approach can provide ample exposure of the posterior fossa cranial nerves and vascular structures, but was also influenced by some bone structures. The internal auditory meatal and jugular foramen also can be clearly explored. The suprameatal tubercle was developed variably in modality, but in all specimens it obstructed exposure of Meckel’s cave under microscopic, also the jugular tubercle restricted visualization of the anterior foramen magnum. The basilar artery was not observed well in most of the specimens using the approach. With higher magnification the endoscope can achieve a clear visualization of bloodvessels and nerves, it also have the ability to look around corners and behind anatomic structures, which is not possible with a microscope.Conclusion:Retrosigmoid keyhole approach is the classical keyhole operation technique. The most accurate location and size of bone flap is much fit to the need of operation, which reduces the unnecessary cut of the scalp and muscle, reduces the unnecessary craniectomy and exploration of brain tissue, The keyhole approach through making the best of intracranial nature spaces, not only minimize the brain trauma and operation complication, but also have the advantage of less operational time, less wound response, more quick recover, better tissue and appearance restoration. Through choosing individualized bone-window location, the retrosigmoid keyhole approach can exposure the cranial nerves and vascular structures of relatived area of the posterior fossa, have wide application in the operation of the extramedullary lesions involved cerebellopontine angle, upper petroclivus, middle petroclivus, lower clivus, such as trigeminal neurinomas, hemifacial spasm, cholesteatoma, coustic neuroma, meningeoma. The retrosigmoid keyhole approach quest for minimally invading, it is in conformance with the contemporary concept of minimally invasive surgery. Clinical practice proves that it is a safe and effective technique, is a alternative replacement for the traditional retrosigmoid approach.更多还原