Resection of petroclival meningiomas via suboccipital retrosigmoid trans-suprameatal approach

CHEN Lihua; CHEN Ling; A Samii; M Samii; LING Feng

doi:10.3969/j.issn.1671-2897.2007.01.002

Abstract：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.