Meningiomas involving the cavernous sinus: value of imaging for predicting surgical complications

The purpose of this study was to determine if it is possible to predict complications of surgery on cavernous sinus meningiomas on the basis of preoperative MR and CT findings. We retrospectively reviewed the CT, MR, and postoperative clinical findings in 65 consecutive patients with pathologically proved cavernous sinus meningiomas who had surgery during the period 1985-1991. Tumors were categorized on the basis of their relationship to the cavernous carotid artery. The presence of tumor in three anatomic sites (the sella, the sphenoid sinus, and the orbital apex) was also correlated with surgical complications. Category 1 tumors, which do not completely encircle the cavernous carotid artery, were dissected without injury, sacrifice, or grafting of the artery in 91% of cases. Category 2 lesions completely encircle the artery but do not narrow its lumen; they could be dissected from the cavernous carotid artery without arterial injury in 61% of cases, but imaging failed to discriminate differences within this group. Category 3 lesions, which completely encircle and narrow the cavernous carotid artery, are usually difficult to dissect free from the artery. The categories also correlated with recovery of extraocular motility; 84% of category 1 lesions compared with only 36% of category 2 or 3 lesions will recover to good or excellent extraocular motility after cavernous sinus surgery. Tumor involvement of the sella, orbital apex, and sphenoid sinus correlated with postoperative endocrine dysfunction, decreased visual acuity, and CSF leak, respectively. Imaging studies can frequently predict the difficulty of resecting cavernous sinus meningiomas from the cavernous carotid artery and the likelihood of permanent loss of extraocular motility after surgery on these lesions. This information is helpful in appropriate preoperative planning and in providing information to patients about to undergo such surgery.