Of 68 patients with unclippable
aneurysms treated by proximal artery occlusion with detachable balloons, permanent occlusion was achieved in 65; of these patients, 37 had carotid artery
aneurysms below the origin of the ophthalmic artery, 21 had
aneurysms arising from the supraclinoid portion of the carotid artery, six had basilar trunk
aneurysms, and one had a distal vertebral
aneurysm. Examination for treatment selection included assessment of the circle of Willis by compression angiography and
xenon blood flow studies, with the ultimate evaluation being test occlusion under systemic heparinization with the balloon temporarily placed in the desired position. Of 67 patients who underwent a formal occlusion test, eight with carotid artery
aneurysms did not initially tolerate the occlusion test, and ischemic signs disappeared instantaneously with deflation and removal of the balloon. During test occlusion, two additional patients had ischemic events that proved to be embolic; these reversed immediately upon balloon deflation. Of the 65 patients in whom permanent occlusion was effected by detachable balloon, there were nine instances of delayed cerebral events. One of these was a seizure leading to respiratory arrest and
resuscitation 3 days following occlusion in a patient who had presented with
seizures. The other eight cases were delayed ischemic events; seven were completely reversed and one patient had residual weakness in one leg (1.5% permanent morbidity). Extracranial-intracranial bypass procedures were performed in 25 of the 65 cases. All
aneurysms of the carotid artery below the level of the ophthalmic artery presented angiographic proof of complete
thrombosis. Ten of 21
aneurysms arising from the supraclinoid portion of the carotid artery were completely thrombosed by proximal occlusion alone, without additional trapping procedures. Similarly, in three of six basilar trunk
aneurysms, proximal occlusion alone initiated complete
aneurysm thrombosis without trapping. The conclusion is that proximal balloon occlusion for unclippable
cerebral aneurysms is a convenient, safe, and effective way of producing
arterial occlusion in these cases.