This is a retrospective report of intracranial aneurysm treatment by flow diverter (SILK; Balt). Sixty-five patients with 77 aneurysms treated during 2008-2009 from 6 centers in France were reviewed. Acute stroke complication was observed in 7.7% without mortality. Delayed complications were observed in 10.9% including 3 ischemic complications related to clopidogrel discontinuation and 3 delayed aneurysm ruptures (all cases without additional coils). At 6-month follow-up, permanent morbidity was observed in 7.8% and mortality was 3% of patients. Complete aneurysm occlusion was achieved in 84.5% at 1-year follow-up.

The results are a bit inferior as compared to the prior results from PIPELINE flow diverting stent (eV3) groups. However, the differences in patient population and treatment strategy are taken into account. Periprocedural antiplatelet regimen and monitoring are required to prevent acute and delayed complications.

Additional concerning statistical message from this article includes the effect of additional coils integrated in flow diversion treatment session (treated in 10 out of 77 aneurysms) could prevent aneurysm shrinkage and also promote aneurysm growth on the follow-up MRI or CT scan at 1 year even with evidence of angiographic complete occlusion. Stability of the coiled aneurysms is understandable by the existing coil mass. However, high number of aneurysm with progressive growth after additional coiling (5 aneurysms) compared to aneurysm with flow diverter alone is interesting. With coil mass effect, it is quite difficult to get an accurate aneurysm size measurement especially by the CT scan. It would be good if the authors can clarify the detail in these cases including the size of aneurysms.