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BackgroundEmbolization before stereotactic radiosurgery (SRS) for brain arteriovenous malformations (BAVMs) is controversial.ObjectiveTo compare clinical and radiographic outcomes in patients undergoing pre-SRS embolization with ethylene copolymer (Onyx) with outcomes in patients undergoing SRS alone.MethodsSeventy consecutive patients with BAVMs who underwent SRS were retrospectively reviewed. Univariate and multivariate analyses were performed to assess the factors associated with radiographic obliteration and complication.ResultsForty-one (59%) patients presented without BAVM rupture and 29 (41%) patients presented with rupture. Pre-SRS embolization was used in 20 patients (28.6%; 7 unruptured and 13 ruptured). Twenty-five of 70 (36%) patients sustained a complication from treatment, including 6 (9%) patients with a post-SRS latency period hemorrhage. Ten (14%) patients had persistent neurological deficits after treatment. Functional outcome (as modified Rankin Scale), complication rate, and radiographic obliteration at last follow-up were not significantly different between embolized and non-embolized groups in both unruptured and ruptured BAVMs. For unruptured BAVMs, 3- and 5-year rates of radiographic obliteration were 23% and 73% for non-embolized patients and 20% and 60% for embolized patients, respectively. For ruptured BAVMs, 3- and 5-year rates of radiographic obliteration were 45% and 72% for non-embolized patients and 53% and 82% for embolized patients, respectively.ConclusionPre-SRS embolization with Onyx was not associated with worse clinical or radiographic outcomes than SRS treatment without embolization. Pre-SRS embolization has a low complication rate and can safely be used to target high-risk BAVM features in carefully selected patients destined for SRS.

BACKGROUND:Cerebral bypass has been an important tool in the treatment of complex intracranial aneurysms. The recent advent of flow-diverting stents (FDS) has expanded the capacity for endovascular arterial reconstruction.OBJECTIVE:We investigated how the advent of FDS has impacted the application and outcomes of cerebral bypass in the treatment of intracranial aneurysms.METHODS:We reviewed a consecutive series of cerebral bypasses during aneurysm surgery over the course of 10 years. FDS were in active use during the last 5 years of this series. We compared the clinical characteristics, surgical technique, and outcomes of patients who required cerebral bypass for aneurysm treatment during the preflow diversion era (PreFD) with those of the postflow diversion era (PostFD).RESULTS:We treated 1061 aneurysms in the PreFD era (from July 2005 through June 2010) and 1348 in the PostFD era (from July 2010 through June 2015). Eighty-five PreFD patients (8%) and 45 PostFD patients (3%) were treated with cerebral bypass. PreFD patients had better baseline functional status compared to PostFD patients with average preoperative modified Rankin Scale score of 0.55 in PreFD and 1.18 in PostFD.CONCLUSION:After the introduction of FDS, cerebral bypass was performed in a lower proportion of patients with aneurysms. Patients selected for bypass in the flow-diverter era had worse preoperative modified Rankin Scale scores indicating a greater complexity of the patients. Cerebral bypass in well-selected patients and revascularization remains an important technique in vascular neurosurgery. It is also useful as a rescue technique after failed FDS treatment of aneurysms.

BackgroundDural arteriovenous fistulae (dAVFs) comprise 10–15% of all intracranial arteriovenous malformations. The goal of surgical or endovascular intervention is complete obliteration of the fistulous connection(s). In cases where dAVF venous drainage is separate from normal cortical drainage, transvenous embolization can provide fast and effective fistula obliteration.ObjectiveTo describe a new method of efficient transvenous embolization (the ‘dual microcatheter technique’) for the treatment of dAVFs.MethodsThree patients with dAVFs were treated using the dual microcatheter technique for transvenous embolization. Two microcatheters were placed in the distal aspect of the dAVF venous pouch, after which coil embolization reduced fistula flow, and liquid embolic agent injection with reflux into arterial feeders completed the obliteration of the fistula.ResultsLesion grade ranged from Borden–Shucart grades 2 through 3. In all cases, dAVF venous drainage was isolated from the normal cerebral venous drainage. Dual microcatheter transvenous embolization was successful in all patients, with non-target embolization and no new postoperative deficits. At the last follow-up, all three patients were symptom-free without evidence of radiographic recurrence.ConclusionsThe dual microcatheter technique of transvenous dAVF embolization is safe and feasible in cases where dAVF venous outflow is isolated from normal cerebral venous drainage.

Introduction To mitigate risks of hemorrhage, high-risk features of brain arteriovenous malformations (BAVMs) can be targeted to reduce the risk of rupture. Previous investigation has examined embolization of a pedicle supplying a high-risk feature; this study examines embolization targeted specifically at aneurysms associated with BAVMs.Materials and methods Patients with BAVMs treated at two high-volume neurointerventional services were retrospectively reviewed. Patients treated with intention to occlude only the associated aneurysm itself were analyzed. Demographic and lesion characteristics were identified, as were technical and clinical outcomes. Adverse events were defined as hemorrhage, new seizure, and death.Results Thirty-two patients met inclusion criteria out of 1103 patients treated during the study period. Twenty-seven (84.4%) BAVMs were acutely ruptured, all with the aneurysm identified as the hemorrhage source. Twenty-four (75.0%) lesions involved eloquent territory. There were equal numbers of feeding artery and nidus aneurysms. Follow-up data were available for a total of 101.3 patient-years for a mean follow-up time of 2.9 years. One patient died; the remaining 31 patients had improved functional status at last contact. Annualized rate of hemorrhage after treatment was 1.0%; rate of adverse events after treatment was 3.0%. Excluding time after confirmed occlusion following radiosurgery, annualized rates were 1.4% and 4.8%, respectively.Conclusion In inoperable BAVMs, targeted embolization of associated aneurysms can be performed safely and effectively. This should be considered in high-risk lesions prior to radiosurgery or in cases when no other treatment options are available. Such intervention warrants further investigation.

BackgroundDural venous sinus stenting has emerged as an effective and durable treatment for idiopathic intracranial hypertension (IIH). Improved visualization of the venous sinuses can improve stent placement.MethodsWe present two cases of IIH treated with venous sinus stenting in which retrograde three-dimensional rotational venography (3DRV) provided superior anatomical details of the venous sinuses for optimal sizing and positioning of stent.ResultsComparison of pre-stent 3DRV with post-stent contrast-enhanced flat panel detector CT allowed confirmation of stent placement and the result of stenosis dilation.ConclusionThis 3DRV technique provides precise visualization of venous sinus stenosis prior to stenting without the need for arterial cerebral angiography during the treatment course.

A 71-yr-old woman was discovered to have an incidental distal basilar artery (BA) fusiform aneurysm 7 × 5 mm in dimension, shaped like an "umbrella handle" with critical stenosis distal to the aneurysm. The right posterior cerebral artery (PCA) P1 segment was small; the left posterior communicating artery (PComA) was miniscule. Because the natural history of fusiform BA aneurysms is poorly defined, this was equated to a saccular aneurysm, with an estimated 10-yr rupture rate of 29%.1-8 After discussion of alternative treatments, the patient decided upon surgery. Because of inadequate collateral circulation, a bypass to the left PCA was deemed necessary.  The aneurysm was exposed by an extended trans-sylvian approach, and the left PCA P2 segment was visualized subtemporally. The left radial artery (RAG) was extracted, and pressure distended to prevent vasospasm. The RAG bypass was sutured first to the P2, and then to the cervical external carotid artery (ECA); the BA aneurysm was then clipped. The proximal anastomosis of the bypass needed revision because of poor flow; a 4-mm punch hole was made to widen the arteriotomy on the ECA. The patient was discharged home with mild memory loss and partial left cranial nerve III palsy. After discharge, she developed a severe left hemicrania, resolved with gabapentin. At 6-wk follow-up, she was asymptomatic, and computed tomography (CT) angiogram demonstrated patency of the bypass.  The patient gave informed consent for surgery and video recording. All relevant patient identifiers have been removed from the video and accompanying radiology slides.

We report successful transvenous treatment of direct carotid–cavernous fistula in a patient with Ehlers–Danlos syndrome type IV using a novel triple-overlay embolization (TAILOREd) technique without the need for arterial puncture, which is known to be highly risky in this patient group. The TAILOREd technique allowed for successful treatment using preoperative MR angiography as a three-dimensional overlay roadmap combined with cone beam CT and live fluoroscopy, precluding the need for an arterial puncture.