Object: Transvenous embolization (TVE) for the treatment of a cavernous sinus (CS) dural arteriovenous fistula (DAVF) occasionally causes cranial nerve palsy (CNP). Overpacking of coils is considered to result in CNP. The purpose of this study was to analyze the association of TVE-induced CNP with the volume and location of coils activated in the CS.
Methods: Thirty-one patients with CS DAVFs (33 lesions) underwent TVE.
Results: Cranial nerve palsy occurred or was aggravated in 13 cases (39.4%; CNP group). The cumulative volume of activated coils was significantly greater in the CNP group (0.241 +/- 0.172 cm3) than in the non-CNP group (0.119 +/- 0.075 cm3; p < 0.05). Of those lesions with > 0.2 cm3 of coil volume, 77.8% showed immediate aggravation or a new occurrence of CNP after TVE. Five lesions treated with a smaller volume of coils showed a delayed worsening or occurrence of CNP. In cases with induced oculomotor nerve palsy, coils had been densely packed in the superolateral part of the anterior CS. Dense packing in the lateral portion of the posterior CS frequently induced abducent nerve palsy. Although patients harboring lesions with a greater coil volume required a longer recovery time, newly developed or aggravated CNP, related to 84.6% of the lesions, resolved completely.
Conclusions: The cumulative volume and specific locations of coils in the CS correlated with TVE-induced CNP. Overpacking appeared to be the predominant cause of CNP; however, for CNP in cases involving smaller coil volumes, an alternative mechanism may be involved.