Carotid balloon occlusion for large and giant aneurysms: Evaluation of a new test occlusion protocol

OBJECTIVE: Validation of a new angiographic test occlusion protocol before carotid balloon occlusion in patients with carotid aneurysms. METHODS: Carotid occlusion was considered for 29 consecutive patients. From 1993 to 1995, test occlusion in four patients consisted of clinical observation for 30 minutes and during electroencephalographic registration. From 1996 onward, test occlusion in 25 patients consisted of clinical observation and angiography of collateral vessels. Permanent balloon occlusion was performed only when the cortical veins in both the occluded and the collateral vascular territories filled synchronously. RESULTS: Two of the four patients with normal clinical and electroencephalographic findings during test occlusion developed delayed hypoperfusion infarction after permanent carotid occlusion. Seventeen of 25 patients (68%) demonstrated both clinical and angiographic tolerance, and no ischemic events occurred after permanent carotid occlusion. In one patient with clinical tolerance but angiographic nontolerance, permanent carotid occlusion had to be performed, which resulted in delayed hypoperfusion infarction. In two patients with angiographic nontolerance, venous filling became synchronous after bypass surgery. Long-term clinical follow-up showed an alleviation of the symptoms of mass effect in 14 of 21 patients (67%). Magnetic resonance imaging follow-up (range, 3-70 mo) revealed a reduction in the size of the aneurysm in 19 of 21 patients (90%). CONCLUSION: Test occlusion with clinical and angiographic control is reliable, safe, and simple to perform.