AUG 21, 2008
The results of this study demonstrated that the volume and location of coils in the cavernous sinus used to treat dural arteriovenous fistula (DAVF) correlate with cranial nerve palsy (CNP) development. The article highlights that coil overpacking appears to be a major cause of CNP. In order to completely obliterate a DAVF and also prevent CNP, the authors recommended occlusion of the entire cavernous sinus, including the shunt point, with as small a volume of coils as possible and avoidance of overpacking coils around cranial nerves. However, they emphasized that DAVF obliteration should take priority over concerns about the volume or location of activated coils, as the prognosis for CNP is generally favorable.
Subjects in this study were 31 patients with 33 lesions who underwent transvenous embolization for the treatment of cavernous sinus DAVF at one medical center between January 1996 and June 2006. Complete eradication of 78.8 percent of the cavernous sinus DAVFs was achieved, but CNP subsequently occurred or was aggravated in 13 cases (39.4 percent).
The volume of activated coils was significantly greater among the patients who developed CNP. Coil volume greater than 0.2 cm3 frequently resulted in the development or aggravation of CNP. Coil location was found to influence the location of CNP, with dense coil packing in the superolateral part of the anterior cavernous sinus linked to oculomotor nerve palsy development or aggravation and dense posterolateral cavernous sinus packing linked to abducent nerve palsy.
CNP occurred immediately in the cases with greater coil volume, whereas there was a lag of a few days in the CNP cases with smaller coil volume. Recovery was significantly more likely in less than three months in patients with delayed symptoms compared with those with immediate signs of CNP. The patients with immediate CNP had a longer recovery period, and two of them experienced only incomplete recovery. The authors speculated that CNP cases with smaller coil volume and delayed symptoms might be caused by thrombosis in the cavernous sinus.
Dr. Vaphiades does not have any financial interests to disclose.