经枕下乙状窦后-内听道上结节入路切除岩斜区脑膜瘤

目的探讨采用枕下乙状窦后-内听道上结节入路切除岩斜区脑膜瘤的安全性、有效性,以及优缺点。方法回顾性分析自2002年1月至2004年12月采用枕下乙状窦后-内听道上结节入路切除的岩斜区脑膜瘤11例。所有肿瘤主体均位于后颅窝,侵袭海绵窦和/或Meckel's腔,其中6例伴有脑干受压移位,3例有岩尖骨性改变,5例肿瘤部分或全部包绕椎基底动脉及其主要分支。结果肿瘤全切除8例,次全切除3例。术前有听力者9例,其中1例因肿瘤巨大,术后听力丧失。出院后随访,7例、3例和1例面神经功能分别恢复至1级、2级和3级。所有患者术后恢复满意,无死亡和严重并发症发生。结论枕下乙状窦后-内听道上结节入路是一种安全有用的乙状窦后改良入路,适合于主体在后颅窝,并向中颅窝、Meckel's腔扩展的岩斜区大型肿瘤的手术切除。

Resection of petroclival meningiomas via suboccipital retrosigmoid trans-suprameatal approach

Objective To determine whether removing the suprameatal tubercle and surrounding bone via the suboccipital retrosigmoid trans-suprameatal approach would aid the exposure of petroclival meningiomas that are located predominantly in the posterior fossa extending into the middle cranial fossa, Meckel's cave, and thus avoid the need for a supratentorial craniotomy. The goal of this study is to explore the security and efficiency treated with the suboccipital retrosigmoid trans-suprameatal approach. The indication for this route in the surgical management of the petroclival meningiomas, and its advantages and disadvantages are also discussed.Methods The recent experience dealing with petroclival meningiomas was reported, which had been resected by suboccipital retrosigmoid trans-suprameatal approach. Eleven patients suffering from petroclival meningiomas, which had been treated using microsurgical technique, were retrospectively analyzed between January 2002 and December 2004. All patients possessed a large posterior fossa component of tumor, and involved the cavernous sinus, Meckel's cave. Six patients displayed central brainstem compression, three patients had bony changes at the petrous apex, and five patients displayed total or partial encasement of the vertebrobasilar artery and its major branches.Results Radical tumor resection (Simpson Grade Ⅰ or Ⅱ) was achieved in 8 of 11 patients and the rate of total removal was 72.7%. Three patients underwent subtotal resection (Simpson Grade Ⅲ) and all of three patients underwent complete resection of tumor at the posterior fossa with subtotal resection at the middle fossa. Nine of the series had serviceable hearing before the operation, 1 patient lost hearing after the operation, and this hearing loss occurred in the huge petroclival meningioma. At the last follow-up examination, facial nerve function was GradeⅠ in 7 patients, Grade II in 3 patients, and Grade Ⅲ in 1 patient. There was no mortality and severe complications or decrease in Karnofsky performance score in this series; all patients did well postoperatively and being independent at the time of their last follow-up examinations. Neurological deficits included facial paresis in 1 patient and worsening of hearing in 2 patients.Conclusion The suboccipital retrosigmoid trans-suprameatal approach is a safe and useful modification of the retrosigmoid approach, and can produce good results. Removing the suprameatal tubercle and surrounding bone can increase the 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, which allows resection of large petroclival tumors without the need for supratentorial craniotomies. Although technically meticulous, this approach is not time-consuming. So it should be considered for patients who have a large petroclival meningioma in the posterior fossa which extends into the middle fossa in the region of Meckel's cave.