Impact of flow and angioarchitecture on brain arteriovenous malformation outcome after gamma knife radiosurgery: the role of hemodynamics and morphology in obliteration.

BACKGROUND: Few studies have evaluated the relationship between brain arteriovenous malformations (bAVMs) angioarchitecture and the response to Gamma Knife Stereotactic Radiosurgery (GKSR). METHODS: A prospectively enrolled single-center cohort of patients with bAVMs treated by GKSR has been studied to define independent predictors of obliteration with particular attention to angioarchitectural variables. Only patients older than 18 years old (y.o.), who underwent baseline digital subtraction angiography (DSA) and clinico-radiological follow-up of at least 36 months, were included in the study. RESULTS: Data of 191 patients were evaluated. After a mean follow-up of 80 months (range 37-173), total obliteration rate after first GKSR treatment was 66%. Mean dose higher than 22 Gy (P = .019, OR = 2.39, 95% CI 1.15-4.97) and flow rate dichotomized into high vs non-high (P < .001, OR = 0.23, 95% CI 0.11-0.51) resulted to be independent predictors of obliteration. Flow-surrogate angioarchitectural features did not emerge as independent outcome predictors. CONCLUSIONS: Flow rate seems to be associated in predicting outcome after GKSR conferring high-flow AVM a lower occlusion rate. Its role should be considered when planning radiosurgical treatment of bAVM, and it could be added to other parameters used in GKRS outcome predicting scales.

Hemorrhagic burden in poor-grade aneurysmal subarachnoid hemorrhage: a volumetric analysis of different bleeding distributions.

BACKGROUND: Volumetric assessment of aneurysmal bleeding has been evaluated in few studies and emerged as a promising outcome predictor. There is a lack of studies evaluating its impact in the poor-grade population. METHODS: Retrospective review of 63 consecutive poor-grade aneurysmal subarachnoid hemorrhage (aSAH) patients, defined as grade IV and V according to the World Federation of Neurological Surgeons (WFNS) classifications. Global intracranial bleeding volume was calculated with its subarachnoid, intracerebral (ICH), and intraventricular (IVH) portions by means of analytical software. Univariate and multivariate analyses were performed in order to identify independent predictors of outcome. Good outcome was defined as modified Rankin Scale (mRS) 0-2 and mortality as mRS 6. The cutoff values of bleeding volumes were derived by receiver operating curve (ROC) analysis. RESULTS: Mean follow-up was of 12.5 (± 1.5) months. Thirty (47.7%) patients achieved good outcome, whereas 19 (30.2) patients out of 63 died. Global intracranial bleeding resulted as an independent predictor of good outcome (cutoff 24 mL). Furthermore, ICH relative percentage of global volume (10% of total) and pure SAH (64% of total) emerged respectively as independent predictors of worsened and improved outcome. Global bleeding volume (cutoff 51 mL) along with global cerebral edema showed to independently predict mortality in the examined poor-grade aSAH population. CONCLUSIONS: Volumetric assessment of aneurysmal bleeding has the potential for identifying cutoff values that independently predict outcome. Further insights into the relative importance of different bleeding volumes may be implicated in better tailoring the management of this dismal aSAH population.

Treatment Challenges of a Primary Vertebral Artery Aneurysm Causing Recurrent Ischemic Strokes.

Background. Extracranial vertebral artery aneurysms are a rare cause of embolic stroke; surgical and endovascular therapy options are debated and long-term complication may occur. Case Report. A 53-year-old man affected by neurofibromatosis type 1 (NF1) came to our attention for recurrent vertebrobasilar embolic strokes, caused by a primary giant, partially thrombosed, fusiform aneurysm of the left extracranial vertebral artery. The aneurysm was treated by endovascular approach through deposition of Guglielmi Detachable Coils in the proximal segment of the left vertebral artery. Six years later the patient presented stroke recurrence. Cerebral angiography and Color Doppler Ultrasound well characterized the unique hemodynamic condition developed over the years responsible for the new embolic event: the aneurysm had been revascularized from its distal portion by reverse blood flow coming from the patent vertebrobasilar axis. A biphasic Doppler signal in the left vertebral artery revealed a peculiar behavior of the blood flow, alternately directed to the aneurysm and backwards to the basilar artery. Surgical ligation of the distal left vertebral artery and excision of the aneurysm were thus performed. Conclusion. This is the first described case of NF1-associated extracranial vertebral artery aneurysm presenting with recurrent embolic stroke. Complete exclusion of the aneurysm from the blood circulation is advisable to achieve full resolution of the embolic source.