Progressive volume reduction and long-term aneurysmal collapse following flow diversion treatment of giant and symptomatic cerebral aneurysms.

Background: The primary goal of conventional endovascular and microvascular approaches is the clinical and radiological resolution of the symptomatic aneurysm-induced mass effect. This study assessed the volume changes and mass effect reduction due to sac shrinkage after treatment with flow diverter stents (FD) for unruptured cerebral aneurysms. Methods: We analyzed retrospectively 36 symptomatic aneurysms that were larger or equal to 25 mm in diameter in patients treated at our center from January 2016 to April 2022. Radiological and clinical outcomes were analyzed, including aneurysmal volume changes and resolution of aneurysm-related symptoms. Results: At 6 months, 25 aneurysms decreased in size, 2 remained unchanged, and 9 aneurysms demonstrated a post-treatment dimensional increase. At 12 months, 30 aneurysms showed a progressive radiological volume reduction. Either no change or negligible shrinkage was observed in the remaining six aneurysms. At 24 months, 32 aneurysms showed aneurysmal shrinkage by a mean 47% volume loss with respect to baseline. At the last follow-up, all 13 patients who had presented with third cranial nerve palsy showed improvements. Complete reversal of the pretreatment edematous changes was confirmed in all cases. The overall post-treatment complication rate was 8.3%, as 3 patients experienced non-fatal delayed rupture of their aneurysm. There was no mortality in this study. Conclusion: Flow diversion could effectively induce progressive aneurysmal shrinkage and resolution of the mass effect associated with giant symptomatic cerebral aneurysms.

Flow Diversion for the Management of Ruptured Intracranial Arterial Infudibular Dilatation: Proof of Principle and Therapeutic Protocol.

Thought to be benign anatomical variants, cerebral infundibular dilatations (ID) are most commonly encountered at the junction of the internal carotid artery (ICA) and the posterior communicating artery (PcomA). The true nature of this entity remains controversial, as some literature reports suggest they should be considered preaneurysmal lesions and a potential source of devastating subarachnoid hemorrhage. This report describes cases of presumably ruptured IDs and their therapeutic endovascular management. We retrospectively reviewed and analyzed patients with isolated subarachnoid hemorrhage (SAH) where the only potential cause was ruptured cerebral IDs, treated or not, between January 2012 and June 2021. Morphological and radiological features, treatment and procedural considerations, clinical and angiographic outcomes were also reviewed. Natural history of the ID is poorly understood, and its relation to SAH remains controversial. Ruptured cerebral IDs can be the suspected cause of bleeding if no other vascular lesion is present during multimodal examinations. Endovascular flow diversion stenting is safe and effective for the proper treatment of ruptured IDs. Pending further validations with longitudinal data are needed to legitimate the natural course of these mysterious lesions.

Nautilus-assisted coil embolization for a complex AcomA wide-necked aneurysm in the setting of acute subarachnoid hemorrhage.

Numerous devices and sophisticated strategies have been developed to further increase the number of aneurysms amenable to endovascular treatment.1-4 Despite the superfluity of available neurovascular armamentarium, wide-necked bifurcation aneurysms can still pose a significant technical challenge to the treating clinician.5-7 Neck bridging is a conceptually new approach, which provides increased occlusion rates with lower recurrence and complications rates.8-10 The Nautilus (EndoStream Medical) is an intrasaccular bridging device intended to assist in coil embolization of wide-necked cerebral aneurysms. This CE-marked device, available in various sizes, consists of flexible-layers, and is a nitinol-based, detachable implant. The device is delivered through a standard microcatheter with a minimal 0.0165" inner diameter and is fully radiopaque and completely resheathable.Owing to its unique 'tornado' like shape the device entirely reconstructs the aneurysmal neck, which facilitates the following coil embolization. In this video 1, we demonstrate the use of Nautilus - assisted coil embolization for a complex anterior communicating artery (AcomA) wide-necked aneurysm in the setting of acute subarachnoid hemorrhage. neurintsurg;14/3/310/V1F1V1Video 1.

Nautilus-Assisted Coiling of an Unruptured Wide-Necked Aneurysm of the Posterior Communicating Artery.

A variety of recently introduced devices have allowed more complex aneurysms to be rendered for endovascular embolization. Tiny and sophisticated implants are nowadays designed to provide further either temporary or permanent remodeling of the wide-necked aneurysms and improve coil occlusion rates.1-4 Such improvements in the technical armamentarium include the Woven EndoBridge (Sequent Medical, California, USA), the Medina Embolic Device (Medtronic, Irvine, California, USA), The Contour Neurovascular System (Cerus Endovascular, Fremont, California, USA), and pCONUS 2 HPC (Phenox, GmbH, Bohum, Germany).5-7 Intrasaccular neck bridging is a conceptually new technique descending from the theoretical combination of intrasaccular flow diversion and temporary-stent assisted coiling.8 The Nautilus (EndoStream Medical, Tel Aviv, Israel) is an intrasaccular bridging device that offers complete neck reconstruction in coil embolization of wide-neck cerebral aneurysms. It has been granted a CE mark by the European Union. The detachable intrasaccular implant comprises flexible and "tornado-like"-shaped Nitinol-based layers. The device is compatible with a standard microcatheter with minimal 0.0165″ inner diameter and is fully radiopaque and fully resheathable. The device's intrasaccular nature and the fact that it does not harbor any intraluminal satellite parts suggest that the implant can be safely used in both unruptured and ruptured case scenarios without the need for dual antiplatelet therapy. This is what we consider a great advantage of the proposed technique over the alternative options of intrasaccular and intraluminal flow diversion. This technical video (Video 1) demonstrates the successful obliteration of a complex posterior communicating artery aneurysm with Nautilus-assisted endovascular coiling. To our knowledge, this is the first technical video demonstrating an in-vivo and step-by-step implementation of this novel device.

Transvenous Embolization of a Ruptured Arteriovenous Malformation.

Transvenous embolization is a not so widely used technique for treatment of arteriovenous malformations.1,2 However, in the reported cases and series in the literature, it is proven to be a safe and efficient method that can lead to total occlusion of the formation in 1 procedure.2-5 The transvenous approach is reserved for small, deeply localized formations with a single draining vein.2-4 In this video, we present a case of a successful single-session transvenous embolization of a ruptured arteriovenous malformation with Onyx. Prior to the injection of the liquid embolic agent, coils were deployed at the proximal part of the draining vein. A balloon was inflated at the arterial part to decrease the pressure inside the nidus, therefore ensuring better penetration of the embolic agent. Control angiogram at the end of the procedure showed total occlusion of the nidus of the arteriovenous malformation.