应用改良的枕下乙状窦后入路显微外科手术切除大型岩斜区脑膜瘤

目的介绍应用改良的枕下乙状窦后入路显微外科手术切除大型岩斜区脑膜瘤的方法和经验。方法枕下乙状窦后骨窗形成后,注意将横窦、乙状窦轮廓。切开硬膜后充分向外侧和向上牵开。通过颅神经间隙完成肿瘤的内减压后,分离肿瘤与颅神经及脑干的粘连并分块切除。如果肿瘤向中颅凹延伸,可切开部分天幕后向上切除肿瘤。如果肿瘤向枕骨大孔延伸,可将乙状窦后入路与枕下远外侧入路结合起来加以切除。对于MRI显示具有侵袭性特征,侵犯海绵窦或脑干的肿瘤,不应追求肿瘤的全切除,“脑干减压”成为手术的主要目标。结果肿瘤全切除9例(60%)。手术后新增颅神经损害6例(40%)。半年随访恢复良好者13例(86.6%)。结论应用简单的枕下乙状窦后入路,结合一些新的技术改良处理大型岩斜区脑膜瘤,可获得满意的手术疗效。

Microsurgical resection of large petroclival meningiomas by modified suboccipital retrosigmoid approach

Objectives To introduce the operative experience and methods in microsurgical resection of large petroclival meningiomas by modified suboccipital retrosigmoid approach. Methods After the suboccipital retrosigmoid craniotomy completed, care must be taken to skeletonize the lateral and sigmoid sinuses, and the incised dura was fully drawn upward and sideways. We then proceeded to debulk the tumor throughout the fissure of nerves, followed by detaching the lesion in succession from cranial nerves and the brain stem, and subsequently the tumor was removed in piecemeal manner. If the tumor extended into the middle fossa, we are able to resect it upward after incising the tentorium. If the tumor involves the lower clivus and foramen magnum, it could be removed by the combined retrosigmoid and far lateral approach. For those tumors invading the cavenous sinus and brain stem with obvious infiltrative pattern on MRI,radical resection is not attempted whereas the brain stem decompression is the goal of the surgery. Results Total removal was achieved in 9 cases (60%), and the immediate postoperative new cranial nerve deficits occurred in 6 cases (40%). Good recovery was obtained in 13 cases (86.7%) with 6 months follow-up. Conclusion Even by the simple suboccipital retrosigmoid approach, which combined with some novel technical modifications, the large petroclival meningiomas could be surgically treated with good clinical results.