We analyzed the efficacy of occlusion of dissection sites using detachable coils for 22 consecutive patients with ruptured dissecting vertebral aneurysms.
Over a 36-month period, 22 patients suffering from aneurysms with subarachnoid hemorrhage had dissecting vertebral aneurysms defined by angiography. Sixteen of these 22 patients were treated with platinum coil occlusion of the affected sites as early as possible after diagnosis. In 3 cases involving dominant vertebral arteries, balloon test occlusion with measurement of the stump pressure preceded the embolization. Two cases with hypoplastic vertebral arteries on the contralateral side were followed conservatively. Treatment of the aneurysms was not indicated in the other 4 cases because of intractable elevation of intracerebral pressure and severe brainstem dysfunction.
Subsequent rupture occurred in 14 (64%) of the 22 patients, all of which occurred less than 24 hours after the first attack and 3 in an ambulance. Seven (50%) had suffered cardiopulmonary arrest on arrival, but emergency measures allowed recovery in all cases. During balloon occlusion tests of dominant vertebral arteries, mean arterial stump pressure (mean arterial stump pressure ratio %: post-/pre-occlusion mean arterial pressure) was high, ranging from 79mmHg to 100mmHg (postocclusion stump pressure/preocclusion mean arterial pressure ratio of 88% to 94%). In all 16 cases, coil embolization was successfully performed without complications.
In 1 case with dissections involving bilateral vertebral arteries, minor rebleeding from a contralateral dissection occurred after embolization. In the other 15 cases, rebleeding did not occur (clinical follow-up: mean 10 months). Radiological findings showed complete occlusion of the dissection site and patency of the non-affected artery (follow-up: mean 7 months). In 6 cases without embolization, only 1 survived with a good outcome, the other 5 cases dying from repeated hemorrhage.
The high rate of rerupture during the acute phase with ruptured vertebral dissecting aneurysms requires special attention with regard to cardiopulmonary dysfunction. Retention of stump pressure at the dominant vertebral artery occlusion shows that proximal occlusion does not always achieve immediate cessation of retrograde blood flow to the dissection site. Detachable platinum coil embolization of the dissection site is a more effective treatment than proximal occlusion in ruptured vertebral dissecting aneurysms because of immediate blockage of flow to the affected site. However, in cases with bilateral dissection, hypoplastic contralateral vertebral arteries and dissection including PICA, prior bypass surgery or stent treatment to preserve the affected vertebral artery is needed.
