Treatment of Small and Tiny Aneurysms Before and After Flow Diversion Era: A Single Center Experience of 409 Aneurysms

To explore whether we should use the Pipeline embolization device (PED) as the primary treatment modality for small and tiny aneurysms at anterior circulation. This retrospective study included 409 cases of small and tiny aneurysms, including aneurysms treated by the PED (n = 77), coiling (n = 51), and stent-assisted coiling (SAC) (n = 281). We also made a comparison regarding the safety and efficacy among these treatment modalities. A total of 55 patients with 77 small aneurysms were treated with PEDs. Technical success was achieved in 98.4% of procedures. The complete occlusion rate was 75.9% (44/58). Both the morbidity and mortality rates were 1.8%. Comparing the 3 treatment modalities, the technical event rate tended to be the highest in the PED group (4.8% vs. 2.0% and 1.1%; PED vs. Coil vs. SAC; P = 0.100), and the use of a PED neither significantly shortened the procedure duration (127.2 ± 62.8 vs. 115 ± 37.1 and 112.8 ± 40.6 minutes, P = 0.322) nor lowered the complication rate (11.1% vs. 9.8% and 6.1%; P = 0.281). SAC had the highest occlusion rate (75.9% vs. 75.8% and 94.0%; P < 0.001) and lowest morbidity rate (0.8% vs. 4.2% and 1.8%; SAC vs. Coil vs. PED; P = 0.099). Ipsilateral multiple aneurysms were more frequently seen in the PED group (33.8% vs. 3.9% and 3.2%; P < 0.001). Procedure duration tended to be lower in the PED group versus the SAC group (122.7 ± 57.4 vs. 157.5 ± 22.2 minutes; P = 0.060). For these aneurysms, the PED group had the highest occlusion rate (80.0% vs. 50.0% and 66.7%; P = 0.516). The PED is an alternative treatment for small and tiny aneurysms. However, SAC remains the safest and most efficient treatment modality. The PED should be reserved for ipsilateral multiple aneurysms.