Intracranial pseudoaneurysms represent a potentially fatal complication of intracranial surgery. Our purpose is to describe their neuroradiological characteristics, prognostic features and possible treatment. Eight cases of postsurgical intracranial pseudoaneurysms have been observed at our institution since 1988. Four were observed following transsphenoidal (TS) surgery and four after pterional craniotomies. Two types of iatrogenic pseudoaneurysms were observed: "fusiform", probably due to weakening of the adventitia during surgical peeling of the tumour from the artery (three cases) and "saccular", occurring after a more focal or complete laceration of the vessel (five cases), more often after TS surgery. A thorough preoperative neuroradiological examination may identify anatomical conditions at risk for development of this severe complication. Postoperative neuroradiological follow-up is mandatory in cases in which unusual bleeding has occurred during the perioperative period, but absence of bleeding does not exclude the possible development of a pseudoaneurysm. Endovascular treatment of pseudoaneurysms represents a safe and durable procedure, specifically in those cases in which damage to the carotid siphon occurred during TS surgery.

BACKGROUND: Y-stent-assisted coiling for wide-neck intracranial aneurysms required further investigation. PURPOSE:Our aim was to analyze outcomes after Y-stent placement in wide-neck aneurysms. DATA SOURCES:We performed a systematic search of 3 data bases for studies published from 2000 to 2018. STUDY SELECTION:According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we included studies reporting Y-stent-assisted coiling of wide-neck aneurysms.DATA ANALYSIS: Random-effects meta-analysis was used to pool the following: aneurysm occlusion rate, complications, and factors influencing the studied outcomes. DATA SYNTHESIS:We included 27 studies and 750 aneurysms treated with Y-stent placement. The immediate complete/near-complete occlusion rate was 82.2% (352/468; 95% CI, 71.4%-93%; I 2 ϭ 92%), whereas the long-term complete/near-complete occlusion rate was 95.4% (564/598; 95% CI, 93.7%-97%; I 2 ϭ 0%) (mean radiologic follow-up of 14 months). The aneurysm recanalization rate was 3% (20/496; 95% CI, 1.5%-4.5%; I 2 ϭ 0%), and half of the recanalized aneurysms required retreatment. The treatment-related complication rate was 8.9% (63/614; 95% CI, 5.8%-12.1%; I 2 ϭ 44%). Morbidity and mortality after treatment were 2.4% (18/540; 95% CI, 1.2%-3.7%; I 2 ϭ 0%) and 1.1% (5/668; 95% CI, 0.3%-1.9%; I 2 ϭ 0%), respectively. Crossing Y-stent placement was associated with a slightly lower complication rate compared with the kissing configuration (56/572 ϭ 8.4%; 95% CI, 5%-11%; I 2 ϭ 46% versus 4/30 ϭ 12.7%; 95% CI, 3%-24%; I 2 ϭ 0%). Occlusion rates were quite comparable among Enterprise, Neuroform, and LVIS stents, whereas the Enterprise stent was associated with lower rates of complications (8/89 ϭ 6.5%; 95% CI, 1.6%-11%; I 2 ϭ 0%) compared with the others (20/131 ϭ 14%; 95% CI, 5%-26%; I 2 ϭ 69% and 9/64 ϭ 11%; 95% CI, 3%-20%; I 2 ϭ 18%). LIMITATIONS:This was a small, retrospective series. CONCLUSIONS: Y-stent-assisted coiling yields high rates of long-term angiographic occlusion, with a relatively low rate of treatmentrelated complications. Y-stent placement with a crossing configuration appears to be associated with better outcomes. Although Y-configuration can be obtained using many types of stents with comparable occlusion rates, the Enterprise stent is associated with lower complication rates.ABBREVIATIONS: IQR ϭ interquartile range; PRISMA ϭ Preferred Reporting Items for Systematic Reviews and Meta-Analyses; SAC ϭ stent-assisted coiling;Y-SAC ϭ Y-stent-assisted coiling W ith the improvement of angiographic imaging, operator experience, and widespread use of more complex techniques, an increased number of intracranial aneurysms can be effectively treated with endovascular techniques. However, aneurysms with wide necks, unfavorable anatomic configurations, and partial incorporation of bifurcation branches are still challenging lesions for endovascular treatment, and each technique presents specific limitations. Balloon-assisted coiling may not be suitable in case of very wide-neck aneu...

Flow diverter devices have gained wide acceptance for the treatment of unruptured intracranial aneurysms. Most studies are based on the treatment of large aneurysms harboring on the carotid syphon. However, during the last years the “off-label” use of these stents has widely grown up even if not supported by randomized studies. This review examines the relevant literature concerning “off-label” indications for flow diverter devices, such as for distal aneurysms, bifurcation aneurysms, small aneurysms, recurrent aneurysms, and direct carotid cavernous fistulas.

Y-stent assisted coiling has a high immediate occlusion rate and very good long-term stability. The procedure is relatively safe, although the complication and mortality rates are not negligible. Two Enterprise stents can be safely used for Y-stenting and, indeed, offer the advantage of easier catheterization, delivery and deployment into distal and tortuous vessels than open cell stents.