Volume Reduction Effect of Preoperative Embolization of Only the Feeding Arteries from the External Carotid Artery on Vestibular Schwannomas

Background: Although there are many reports on the efficacy of preoperative embolization for meningioma, such as a reduction in intraoperative blood loss, its efficacy for vestibular schwannoma remains unclear. Feeding arteries of vestibular schwannomas include branches from the anterior inferior cerebellar artery and internal carotid artery, in addition to the branches from the external carotid artery (ECA). However, it has been reported that the embolization of feeding arteries from the anterior inferior cerebellar artery and the internal carotid artery has a high risk of complications. Therefore, we retrospectively analyzed the effects of preoperative embolization of only the feeding arteries from the ECA for vestibular schwannomas, particularly regarding its volume reduction effect.

Methods: Of the 805 patients with vestibular schwannoma who underwent tumor removal at our department between September 2013 and March 2022, a total of 15 patients who underwent preoperative embolization of only the feeding arteries from the ECA were analyzed. Tumor volume was measured based on contrast-enhanced T1-weighted imaging, and the effects of preoperative embolization on tumor volume reduction were analyzed.

Results: Tumor volumes before and after embolization were 16.4 ± 9.2 mL and 14.1 ± 9.6 mL, respectively, indicating a volume reduction effect of 15.3 ± 10.3% (P < 0.001). The mean time from embolization to contrast-enhanced T1-weighted imaging was 5.1 ± 3.0 days.

Conclusions: Preoperative embolization of only the feeding arteries from the ECA may be an effective adjunctive treatment for vestibular schwannomas, given the significant volume reduction effect achieved within several days after embolization, in addition to reducing intraoperative blood loss.