The feasibility and efficacy of endovascular treatment for very small or tiny ruptured paraclinoid aneurysms

The aim of this study was to evaluate the feasibility of endovascular treatment (EVT) for ruptured very small (≤5 mm) or tiny (≤3 mm) paraclinoid aneurysms of the internal carotid artery (ICA).

From November 2009 to April 2012, 32 ruptured paraclinoid aneurysms (very small, 23; tiny, 9) in 31 patients received EVT. Angiographic follow-up determined occlusion rates which were classified as total/near-total (95-100 %), subtotal (80-95 %), and partial (<80 %) occlusions. Follow-up data were retrospectively analyzed and categorized using the Modified Rankin Scale (mRS).

Based on our paraclinoid aneurysm classification, 25 % (8) were classified as type I, 46.9 % (15) as type II, and 28.1 % (9) as type III. EVT was technically successful in 96.8 % (31), with coiling only in 12.5 % (4), balloon remolding coiling in 6.3 % (2), and stent-assisted coiling in 78.1 % (25). Total/near-total occlusion was immediately achieved in 34.4 % (11), subtotal occlusion in 37.5 % (12), and partial occlusion in 28.1 % (9). Follow-up angiography (mean, 9.9 ± 6.4 months) revealed total/near-total occlusion in 50 % (16) aneurysms, subtotal in 31.3 % (10), and partial occlusion in 18.8 % (6). At the end of clinical follow-up (mean, 14.8 ± 9.5 months), it revealed an mRS grade 0 in 38.7 % (12) of patients, grade 1 in 25.8 % (8), grade 2 in 22.6 % (7), grade 3 in 6.5 % (2), grade 4 in 3.2 % (1), and grade 5 in 3.2 % (1).

EVT is feasible and effective for ruptured very small or tiny paraclinoid aneurysms of the ICA.