乙状窦后-内听道上入路的相关显微解剖研究

Microanatomic Study on the Retrosigmoid Suprameatal Approach

目的:探讨乙状窦后-内听道上入路中岩骨磨除的安全性及术中解剖学标志。方法:在头颅标本上模拟乙状窦后-内听道上入路磨除内听道上结节,然后自中颅底测量骨窗与重要结构的距离。结果:中颅底骨窗与颈内动脉C5、C6段及外展神经的最短距离依次为:(2.72±2.31)mm,(2.41±1.53)mm和(2.89±1.90)mm。6例骨窗前缘达颈内动脉C5段,无一侧骨窗外侧边达颈内动脉C6段。结论:内听道上结节向前外侧可安全磨除,向前内侧磨除可能损伤颈内动脉C5段。由于解剖学变异,术中应综合判定骨质磨除的前界,防止重要结构损伤。

Aim:This study was conducted to discuss the safety and anatomic landmarks of the ictrosigmoid suprameatal approach. Methods: Thirty suprameatal tubercles on fifteen cadaveric heads were drilled via the retrosigmoid suprameatal approach, and distances between margins of the bone window and the important structures were measured from the middle cranial fossa. Results:The shortest distance between margins of the bone window and C5,C6 segment of internal carotid artery(C5,C6) and abducent nerve was (2.72±2.31) mm, (2.41±1 .53) mm and (2.89±1 .90) mm respectively. Conclusion:The suprameatal tubercle can be safely drilled away antero-laterally without any risk of C6 injury. C5 might be injured if petrosal apex is drilled too far antero-medially. The anterior margin of bony area drilled should be determined comprehensively during operation due to anatomic variations.