Abstract:

Objective：With the development of modern skull base minimally invasive technology mature and neural radio surgery techniques, it is necessary to re-examine the therapeutic strategy for the treatment of petroclival meningiomas. To sum up the operative experience and methods in microsurgical resection of petroclival meningiomas by the combining trans-subtemporal and suboccipital retrosigmoid keyhole approach. To explore the minimally invasive operation approach of petroclival meningiomas, to raise the removal degree and to improve the postoperative result using this approach. Methods: The clinical data of the consecutive 21 patients with the petroclival meningiomas were reviewed retrospectively. The method, degree of tumor resection，techniques of the combining keyhole approach，Karnofsky performance score (KPS) before and after operation were also analyzed. The neuronavigation guided operation was performed in 9 cases, and 12 cases were operated in the neuroelectrophysiological monitoring. Results: Total excision of the tumor resection (Simpson, Ⅰ-Ⅱlevels) was conducted in 18 cases (85.7%, 18/21), and 3 patients underwent close resection (Simpson Ⅲ level, 14.3%, 3/21). Postoperative three-dimensional CT showed good lock bone flap restoration; Postoperative pathology confirmed meningioma. Postoperative cranial nerve dysfunction or new original nerve dysfunction were aggravated in 5 cases (23.8%) , including transient trochlear nerve (3 cases), abducent nerve (1 case), and the motor branch of trigeminal nerve paralysis (1 case). Abducent nerve paralysis (1 case) appeared， with hearing impairment. After the 3-month follow-up, 11 cases had the same KPS aspreoperation, 7 cases improved, and 3 cases not improved. The KPS score was 77.14±23.12 on average, and there was no statistically significant difference compared with that before operation (P>0.05). The postoperative follow-up for half a year showed fluent speaking and writing in 19 cases (KPS 70 or higher), and general recovery in 2 cases (KPS<70). The postoperative follow-up for 3-29 months showed no tumor recurrence or progress. Conclusion: The combining trans-subtemporal and suboccipital retrosigmoid keyhole approach is simple, safe, and minimally invasive, and an ideal operation approach of petroclival menin-gioma. To master the operation skills and the intraoperative matters needing attention in the operation, is favorable to improve the resection rate and curative effect.

Key words: Meningioma, Microsurgery, Subtemporal keyhole approach, Retrosigmoid keyhole approach