Minimal anterior and posterior combined transpetrosal approach for large petroclival meningiomas

OBJECTIVE Petroclival meningiomas (PCMs) remain difficult to remove, and radical tumor resection continues to pose a relatively high risk of neurological morbidity in patients with these lesions because of the proximity of the tumor to neurovascular structures. The anterior and posterior combined (APC) transpetrosal approach allows resection of a large petroclival lesion with minimal retraction of the temporal lobe. However, this approach is thought to be complex and time-consuming. The authors simplified this approach by minimizing the petrosectomy and used this method for large PCMs. This retrospective study describes the surgical technique and surgical outcomes of large PCMs. METHODS Between 2014 and 2019, 23 patients (19 women and 4 men) with benign (WHO grade I) PCMs were treated using the minimal APC (MAPC) transpetrosal approach. The mean age at surgery was 54.0 years (range 37–74 years). The mean tumor diameter was 40.3 mm (range 30–74 mm). The surgical technique consisted of a temporo-suboccipital craniotomy and minimal drilling of the petrous ridge. After opening Meckel’s cave and removing the lesion at the prepontine cistern, drilling of the petrous apex with superior mobilization of the trigeminal nerve was performed through the subdural space for further tumor resection around the petrous apex. Finally, the tumor was removed as much as possible. RESULTS The mean preoperative and postoperative tumor volumes were 26.8 and 1.3 cm 3 , respectively. The mean extent of resection was 95.4% (range 62%–100%). Postoperative impairments included facial numbness in 7 patients, trochlear nerve palsy in 3 patients, mild oculomotor nerve palsy in 2 patients, and transient abducens nerve palsy in 1 patient. Preoperative Karnofsky Performance Status was improved in 13 patients, remained stable in 9 patients, and deteriorated in 1 patient. CONCLUSIONS The MAPC transpetrosal approach provides sufficiently wide exposure of petroclival lesions. Maximal resection via the MAPC transpetrosal approach is a suitable surgical option for the treatment of large PCMs.