The incidence of multiple aneurysms was 10.7–34% of CA. Multiple associated factors were found; hypertension was the most significant one and others like advancing age and female sex were also documented. The estimated prevalence of UA is 5–10%. They include those aneurysms that did not rupture and discovered incidentally and those presented with symptoms rather than SAH, e.g., cranial nerve palsy or mass effect. Unruptured intracranial aneurysms are diagnosed with higher frequency nowadays as a result of imaging techniques improvement. The reported annual rate of rupture of UA is approximately 0.7–1%. The natural history of unruptured cerebral aneurysms cannot be extrapolated from the evaluation of individuals with ruptured aneurysms. Multiple cerebral aneurysms pose an even greater risk than a single aneurysm; the risk of rebleeding from the original aneurysm is larger and occurs sooner. The natural course of the disease has led to a consensus that all multiple unruptured aneurysms should be treated when technically viable. However, the prophylactic treatment of multiple unruptured is still controversial. Weighing the risk of intervention to the risk of observation is a mandatory pathway. Factors like age of patients, size and location of the aneurysms influence the decision-making and the type of therapy to be elected.

Objective : There are different types of cerebral vascular malformations. Pial arteriovenous fistulas (PAVFs) and dural arteriovenous fistulas (DAVFs) are two entities; they consist of one or more arterial connections to a single venous outlet without a true intervening nidus. The high turbulent flow of PAVFs and aggressive DAVFs with cortical venous reflux can result in venous outflow varix and aneurysmal dilatation. They pose a significant challenge to transvenous embolization (TVE), stereotactic radiosurgery, and surgical treatment. We aim to share our centers’ experience with the transarterial embolization (TAE) for arteriovenous fistulas (AVFs) with large venous pouches and to report the outcome.Methods : The authors’ two institutions’ databases were retrospectively reviewed from February 2017 to February 2021. All patients with intracranial high flow PAVFs and aggressive DAVFs with venous outlet ectasia and large venous varix and were treated by TAE were included.Results : Fifteen patients harboring 11 DAVFs and four PAVFs met our inclusion criteria. All patients underwent TAE in 17 sessions. Complete angiographic obliteration was achieved after 14 sessions in 12 patients (80%). Four patients (25%) had residual after one TAE session. Technical failure was documented in one patient (6.7%). Fourteen patients (93.3%) had favorable functional outcome (modified Rankin score 0–2).Conclusions : TAE for high flow or aggressive intracranial AVFs is a safe and considerable treatment option, especially for those associated with large venous pouches that are challenging and relatively high-risk for TVE.

Objective : Transvenous embolization (TVE) via an occluded inferior petrosal sinus (IPS) in a cavernous sinus dural arteriovenous fistula (CSDAVF) is challenging, often requiring navigation of a microcatheter through resistive obstacles between the occluded IPS and shunted pouch (SP), although the reopening technique was successfully performed. We report five cases of successful access to the cavernous sinus (CS) or SP using the rigid-tipped microguidewire such as chronic total occlusion (CTO) wire aiming to share our initial experience with this wire. Methods : In this retrospective study, four patients with CSDAVF underwent five procedures using the CTO wire puncture during transfemoral transvenous coil embolization. Puncture success, shunt occlusion, and complications including any hemorrhage and cranial nerve palsy were evaluated. Results : Despite successful access through the occluded IPS, further entry into the target area using neurointerventional devices was impossible due to a short-segment stricture before the CS (three cases) and a membranous barrier within the CS (two cases). However, puncturing these structures using the rigid-tipped microguidewire was successful in all cases. We could advance the microcatheter over the rigid-tipped microguidewire for the navigation to the SP and achieved complete occlusion of the SP without complications. Conclusion :The use of the rigid-tipped microguidewire in the TVE via the occluded IPS of the CSDAVF would be feasible and safe.