2025 Poster Presentations
P132: POSTOPERATIVE EFFECTS OF THE POSTERIOR PETROSAL APPROACH FOR CEREBELLO-PONTINE ANGLE MENINGIOMAS
Takuma Kodama, MD; Osamu Akiyama, MD, PhD; Ryo Miyahara, MD; Yuzaburo Shimizu, MD, PhD; Mario Suzuki, MD, PhD; Shinichiro Teramoto, MD, PhD; Akihide Kondo, MD, PhD; Department of Neurosurgery, Juntendo University Faculty of Medicine, Tokyo, JAPAN
Background: The lateral suboccipital approach is the standard surgical approach for treating cerebello-pontine angle (CPA) meningiomas. However, this approach sometimes requires retraction of the cerebellar hemisphere depending on the origin of the tumor, direction of extension, and tumor volume, which can cause postoperative cerebellar atrophy. Therefore, we compared surgical approaches in terms of postoperative cerebellar atrophy in CPA meningiomas originating from the petrous surface.
Methods: We reviewed 82 cases of patients with posterior fossa meningiomas who underwent surgical treatment at Juntendo University Hospital. The tumors were removed using either the lateral suboccipital or posterior petrosal approach via the presigmoid dura. We analyzed the postoperative atrophic changes in the cerebellum in these two approaches using image processing software.
Results: Of the 82 patients, 21 had CPA meningiomas with a primary origin on the petrous surface. Of these, 7 had their meningiomas removed using the posterior petrosal approach via the presigmoid dura and the other 14, using the lateral suboccipital approach. Cerebellar atrophic changes tended to be less severe in the former.
Discussion: The lateral suboccipital approach is more commonly used for CPA meningiomas. Although this approach does not provide adequate access to petroclival lesions, it requires more cerebellar retraction, which may lead to atrophic changes in the cerebellum. By opening the presigmoid dura (Trautmann’s triangle), the posterior petrosal approach enables us to obtain more lateral access to CPA tumors with less retraction of the cerebellar hemisphere compared to the lateral suboccipital approach. However, mastoidectomy using this approach can be considered time-consuming and carries a higher risk of complications owing to the anatomical complexity of the region. Tumor resection via the posterior petrosal approach allows us to directly approach the petrous surface as the tumor origin, easily coagulate feeding arteries, and safely decompress the tumor with less retraction of the cerebellum, which can lead to less postoperative cerebellar atrophy.
Conclusion: The retraction of the cerebellar hemisphere can cause atrophic postoperative changes. In CPA meningiomas, the posterior petrosal approach via the presigmoid dura allows direct access to the tumor origin, which is associated with a better postoperative course. Therefore, we propose that this approach is a more appropriate surgical technique for such cases.